Adding upstream version 2.10.22.upstream/2.10.22upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

183 files changed, 67738 insertions, 0 deletions

diff --git a/app/display/Makefile.am b/app/display/Makefile.am
new file mode 100644
index 0000000..dbee710
--- /dev/null
+++ b/app/display/Makefile.am
@@ -0,0 +1,247 @@
+## Process this file with automake to produce Makefile.in
+
+if PLATFORM_OSX
+xobjective_c = "-xobjective-c"
+xobjective_cxx = "-xobjective-c++"
+xnone = "-xnone"
+endif
+
+AM_CPPFLAGS = \
+	-DG_LOG_DOMAIN=\"Gimp-Display\"	\
+	-I$(top_builddir)		\
+	-I$(top_srcdir)			\
+	-I$(top_builddir)/app		\
+	-I$(top_srcdir)/app		\
+	$(GEGL_CFLAGS)			\
+	$(GTK_CFLAGS)			\
+	-I$(includedir)
+
+AM_CFLAGS = \
+	$(xobjective_c)
+
+AM_CXXFLAGS = \
+	$(xobjective_cxx)
+
+AM_LDFLAGS = \
+	$(xnone)
+
+noinst_LIBRARIES = libappdisplay.a
+
+libappdisplay_a_sources = \
+	display-enums.h				\
+	display-types.h				\
+	gimpcanvas.c				\
+	gimpcanvas.h				\
+	gimpcanvas-style.c			\
+	gimpcanvas-style.h			\
+	gimpcanvasarc.c				\
+	gimpcanvasarc.h				\
+	gimpcanvasboundary.c			\
+	gimpcanvasboundary.h			\
+	gimpcanvasbufferpreview.c		\
+	gimpcanvasbufferpreview.h		\
+	gimpcanvascanvasboundary.c		\
+	gimpcanvascanvasboundary.h		\
+	gimpcanvascorner.c			\
+	gimpcanvascorner.h			\
+	gimpcanvascursor.c			\
+	gimpcanvascursor.h			\
+	gimpcanvasgrid.c			\
+	gimpcanvasgrid.h			\
+	gimpcanvasgroup.c			\
+	gimpcanvasgroup.h			\
+	gimpcanvasguide.c			\
+	gimpcanvasguide.h			\
+	gimpcanvashandle.c			\
+	gimpcanvashandle.h			\
+	gimpcanvasitem.c			\
+	gimpcanvasitem.h			\
+	gimpcanvasitem-utils.c			\
+	gimpcanvasitem-utils.h			\
+	gimpcanvaslayerboundary.c		\
+	gimpcanvaslayerboundary.h		\
+	gimpcanvaslimit.c			\
+	gimpcanvaslimit.h			\
+	gimpcanvasline.c			\
+	gimpcanvasline.h			\
+	gimpcanvaspassepartout.c		\
+	gimpcanvaspassepartout.h		\
+	gimpcanvaspath.c			\
+	gimpcanvaspath.h			\
+	gimpcanvaspen.c				\
+	gimpcanvaspen.h				\
+	gimpcanvaspolygon.c			\
+	gimpcanvaspolygon.h			\
+	gimpcanvasprogress.c			\
+	gimpcanvasprogress.h			\
+	gimpcanvasproxygroup.c			\
+	gimpcanvasproxygroup.h			\
+	gimpcanvasrectangle.c			\
+	gimpcanvasrectangle.h			\
+	gimpcanvasrectangleguides.c		\
+	gimpcanvasrectangleguides.h		\
+	gimpcanvassamplepoint.c			\
+	gimpcanvassamplepoint.h			\
+	gimpcanvastextcursor.c			\
+	gimpcanvastextcursor.h			\
+	gimpcanvastransformguides.c		\
+	gimpcanvastransformguides.h		\
+	gimpcanvastransformpreview.c		\
+	gimpcanvastransformpreview.h		\
+	gimpcursorview.c			\
+	gimpcursorview.h			\
+	gimpdisplay.c				\
+	gimpdisplay.h				\
+	gimpdisplay-foreach.c			\
+	gimpdisplay-foreach.h			\
+	gimpdisplay-handlers.c			\
+	gimpdisplay-handlers.h			\
+	gimpdisplayshell.c			\
+	gimpdisplayshell.h			\
+	gimpdisplayshell-actions.c		\
+	gimpdisplayshell-actions.h		\
+	gimpdisplayshell-appearance.c		\
+	gimpdisplayshell-appearance.h		\
+	gimpdisplayshell-autoscroll.c		\
+	gimpdisplayshell-autoscroll.h		\
+	gimpdisplayshell-callbacks.c		\
+	gimpdisplayshell-callbacks.h		\
+	gimpdisplayshell-close.c		\
+	gimpdisplayshell-close.h		\
+	gimpdisplayshell-cursor.c		\
+	gimpdisplayshell-cursor.h		\
+	gimpdisplayshell-dnd.c			\
+	gimpdisplayshell-dnd.h			\
+	gimpdisplayshell-draw.c			\
+	gimpdisplayshell-draw.h			\
+	gimpdisplayshell-expose.c		\
+	gimpdisplayshell-expose.h		\
+	gimpdisplayshell-grab.c			\
+	gimpdisplayshell-grab.h			\
+	gimpdisplayshell-handlers.c		\
+	gimpdisplayshell-handlers.h		\
+	gimpdisplayshell-filter.c		\
+	gimpdisplayshell-filter.h		\
+	gimpdisplayshell-filter-dialog.c	\
+	gimpdisplayshell-filter-dialog.h	\
+	gimpdisplayshell-layer-select.c		\
+	gimpdisplayshell-layer-select.h		\
+	gimpdisplayshell-icon.c			\
+	gimpdisplayshell-icon.h			\
+	gimpdisplayshell-items.c		\
+	gimpdisplayshell-items.h		\
+	gimpdisplayshell-profile.c		\
+	gimpdisplayshell-profile.h		\
+	gimpdisplayshell-progress.c		\
+	gimpdisplayshell-progress.h		\
+	gimpdisplayshell-render.c		\
+	gimpdisplayshell-render.h		\
+	gimpdisplayshell-rotate.c		\
+	gimpdisplayshell-rotate.h		\
+	gimpdisplayshell-rotate-dialog.c	\
+	gimpdisplayshell-rotate-dialog.h	\
+	gimpdisplayshell-rulers.c		\
+	gimpdisplayshell-rulers.h		\
+	gimpdisplayshell-scale.c		\
+	gimpdisplayshell-scale.h		\
+	gimpdisplayshell-scale-dialog.c		\
+	gimpdisplayshell-scale-dialog.h		\
+	gimpdisplayshell-scroll.c		\
+	gimpdisplayshell-scroll.h		\
+	gimpdisplayshell-scrollbars.c		\
+	gimpdisplayshell-scrollbars.h		\
+	gimpdisplayshell-selection.c		\
+	gimpdisplayshell-selection.h		\
+	gimpdisplayshell-title.c		\
+	gimpdisplayshell-title.h		\
+	gimpdisplayshell-tool-events.c		\
+	gimpdisplayshell-tool-events.h		\
+	gimpdisplayshell-transform.c		\
+	gimpdisplayshell-transform.h		\
+	gimpdisplayshell-utils.c		\
+	gimpdisplayshell-utils.h		\
+	gimpdisplayxfer.c			\
+	gimpdisplayxfer.h			\
+	gimpimagewindow.c			\
+	gimpimagewindow.h			\
+	gimpmotionbuffer.c			\
+	gimpmotionbuffer.h			\
+	gimpmultiwindowstrategy.c		\
+	gimpmultiwindowstrategy.h		\
+	gimpnavigationeditor.c			\
+	gimpnavigationeditor.h			\
+	gimpscalecombobox.c			\
+	gimpscalecombobox.h			\
+	gimpsinglewindowstrategy.c		\
+	gimpsinglewindowstrategy.h		\
+	gimpstatusbar.c				\
+	gimpstatusbar.h				\
+	gimptooldialog.c			\
+	gimptooldialog.h			\
+	gimptoolgui.c				\
+	gimptoolgui.h				\
+	gimptoolcompass.c			\
+	gimptoolcompass.h			\
+	gimptoolfocus.h				\
+	gimptoolfocus.c				\
+	gimptoolgyroscope.c			\
+	gimptoolgyroscope.h			\
+	gimptoolhandlegrid.c			\
+	gimptoolhandlegrid.h			\
+	gimptoolline.c				\
+	gimptoolline.h				\
+	gimptoolpath.c				\
+	gimptoolpath.h				\
+	gimptoolpolygon.c			\
+	gimptoolpolygon.h			\
+	gimptoolrectangle.c			\
+	gimptoolrectangle.h			\
+	gimptoolrotategrid.c			\
+	gimptoolrotategrid.h			\
+	gimptoolsheargrid.c			\
+	gimptoolsheargrid.h			\
+	gimptooltransform3dgrid.c		\
+	gimptooltransform3dgrid.h		\
+	gimptooltransformgrid.c			\
+	gimptooltransformgrid.h			\
+	gimptoolwidget.c			\
+	gimptoolwidget.h			\
+	gimptoolwidgetgroup.c			\
+	gimptoolwidgetgroup.h
+
+libappdisplay_a_built_sources = display-enums.c
+
+libappdisplay_a_SOURCES = \
+	$(libappdisplay_a_built_sources)	\
+	$(libappdisplay_a_sources)
+
+#
+# rules to generate built sources
+#
+# setup autogeneration dependencies
+gen_sources = xgen-dec
+CLEANFILES = $(gen_sources)
+
+xgen-dec: $(srcdir)/display-enums.h $(GIMP_MKENUMS) Makefile.am
+	$(AM_V_GEN) $(GIMP_MKENUMS) \
+		--fhead "#include \"config.h\"\n#include <gio/gio.h>\n#include \"libgimpbase/gimpbase.h\"\n#include \"display-enums.h\"\n#include\"gimp-intl.h\"" \
+		--fprod "\n/* enumerations from \"@basename@\" */" \
+		--vhead "GType\n@enum_name@_get_type (void)\n{\n  static const G@Type@Value values[] =\n  {" \
+		--vprod "    { @VALUENAME@, \"@VALUENAME@\", \"@valuenick@\" }," \
+		--vtail "    { 0, NULL, NULL }\n  };\n" \
+		--dhead "  static const Gimp@Type@Desc descs[] =\n  {" \
+		--dprod "    { @VALUENAME@, @valuedesc@, @valuehelp@ },@if ('@valueabbrev@' ne 'NULL')@\n    /* Translators: this is an abbreviated version of @valueudesc@.\n       Keep it short. */\n    { @VALUENAME@, @valueabbrev@, NULL },@endif@" \
+		--dtail "    { 0, NULL, NULL }\n  };\n\n  static GType type = 0;\n\n  if (G_UNLIKELY (! type))\n    {\n      type = g_@type@_register_static (\"@EnumName@\", values);\n      gimp_type_set_translation_context (type, \"@enumnick@\");\n      gimp_@type@_set_value_descriptions (type, descs);\n    }\n\n  return type;\n}\n" \
+		$< > $@
+
+# copy the generated enum file back to the source directory only if it's
+# changed; otherwise, only update its timestamp, so that the recipe isn't
+# executed again on the next build, however, allow this to (harmlessly) fail,
+# to support building from a read-only source tree.
+$(srcdir)/display-enums.c: xgen-dec
+	$(AM_V_GEN) if ! cmp -s $< $@; then \
+		cp $< $@; \
+	else \
+		touch $@ 2> /dev/null \
+		|| true; \
+	fi
diff --git a/app/display/Makefile.in b/app/display/Makefile.in
new file mode 100644
index 0000000..d1c91e8
--- /dev/null
+++ b/app/display/Makefile.in
@@ -0,0 +1,1545 @@
+# Makefile.in generated by automake 1.16.2 from Makefile.am.
+# @configure_input@
+
+# Copyright (C) 1994-2020 Free Software Foundation, Inc.
+
+# This Makefile.in is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+@SET_MAKE@
+
+VPATH = @srcdir@
+am__is_gnu_make = { \
+  if test -z '$(MAKELEVEL)'; then \
+    false; \
+  elif test -n '$(MAKE_HOST)'; then \
+    true; \
+  elif test -n '$(MAKE_VERSION)' && test -n '$(CURDIR)'; then \
+    true; \
+  else \
+    false; \
+  fi; \
+}
+am__make_running_with_option = \
+  case $${target_option-} in \
+      ?) ;; \
+      *) echo "am__make_running_with_option: internal error: invalid" \
+              "target option '$${target_option-}' specified" >&2; \
+         exit 1;; \
+  esac; \
+  has_opt=no; \
+  sane_makeflags=$$MAKEFLAGS; \
+  if $(am__is_gnu_make); then \
+    sane_makeflags=$$MFLAGS; \
+  else \
+    case $$MAKEFLAGS in \
+      *\\[\ \	]*) \
+        bs=\\; \
+        sane_makeflags=`printf '%s\n' "$$MAKEFLAGS" \
+          | sed "s/$$bs$$bs[$$bs $$bs	]*//g"`;; \
+    esac; \
+  fi; \
+  skip_next=no; \
+  strip_trailopt () \
+  { \
+    flg=`printf '%s\n' "$$flg" | sed "s/$$1.*$$//"`; \
+  }; \
+  for flg in $$sane_makeflags; do \
+    test $$skip_next = yes && { skip_next=no; continue; }; \
+    case $$flg in \
+      *=*|--*) continue;; \
+        -*I) strip_trailopt 'I'; skip_next=yes;; \
+      -*I?*) strip_trailopt 'I';; \
+        -*O) strip_trailopt 'O'; skip_next=yes;; \
+      -*O?*) strip_trailopt 'O';; \
+        -*l) strip_trailopt 'l'; skip_next=yes;; \
+      -*l?*) strip_trailopt 'l';; \
+      -[dEDm]) skip_next=yes;; \
+      -[JT]) skip_next=yes;; \
+    esac; \
+    case $$flg in \
+      *$$target_option*) has_opt=yes; break;; \
+    esac; \
+  done; \
+  test $$has_opt = yes
+am__make_dryrun = (target_option=n; $(am__make_running_with_option))
+am__make_keepgoing = (target_option=k; $(am__make_running_with_option))
+pkgdatadir = $(datadir)/@PACKAGE@
+pkgincludedir = $(includedir)/@PACKAGE@
+pkglibdir = $(libdir)/@PACKAGE@
+pkglibexecdir = $(libexecdir)/@PACKAGE@
+am__cd = CDPATH="$${ZSH_VERSION+.}$(PATH_SEPARATOR)" && cd
+install_sh_DATA = $(install_sh) -c -m 644
+install_sh_PROGRAM = $(install_sh) -c
+install_sh_SCRIPT = $(install_sh) -c
+INSTALL_HEADER = $(INSTALL_DATA)
+transform = $(program_transform_name)
+NORMAL_INSTALL = :
+PRE_INSTALL = :
+POST_INSTALL = :
+NORMAL_UNINSTALL = :
+PRE_UNINSTALL = :
+POST_UNINSTALL = :
+build_triplet = @build@
+host_triplet = @host@
+subdir = app/display
+ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
+am__aclocal_m4_deps = $(top_srcdir)/m4macros/gtk-doc.m4 \
+	$(top_srcdir)/m4macros/intltool.m4 \
+	$(top_srcdir)/m4macros/libtool.m4 \
+	$(top_srcdir)/m4macros/ltoptions.m4 \
+	$(top_srcdir)/m4macros/ltsugar.m4 \
+	$(top_srcdir)/m4macros/ltversion.m4 \
+	$(top_srcdir)/m4macros/lt~obsolete.m4 \
+	$(top_srcdir)/acinclude.m4 $(top_srcdir)/m4macros/alsa.m4 \
+	$(top_srcdir)/m4macros/ax_compare_version.m4 \
+	$(top_srcdir)/m4macros/ax_cxx_compile_stdcxx.m4 \
+	$(top_srcdir)/m4macros/ax_gcc_func_attribute.m4 \
+	$(top_srcdir)/m4macros/ax_prog_cc_for_build.m4 \
+	$(top_srcdir)/m4macros/ax_prog_perl_version.m4 \
+	$(top_srcdir)/m4macros/detectcflags.m4 \
+	$(top_srcdir)/m4macros/pythondev.m4 $(top_srcdir)/configure.ac
+am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
+	$(ACLOCAL_M4)
+DIST_COMMON = $(srcdir)/Makefile.am $(am__DIST_COMMON)
+mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = $(top_builddir)/config.h
+CONFIG_CLEAN_FILES =
+CONFIG_CLEAN_VPATH_FILES =
+LIBRARIES = $(noinst_LIBRARIES)
+ARFLAGS = cru
+AM_V_AR = $(am__v_AR_@AM_V@)
+am__v_AR_ = $(am__v_AR_@AM_DEFAULT_V@)
+am__v_AR_0 = @echo "  AR      " $@;
+am__v_AR_1 = 
+libappdisplay_a_AR = $(AR) $(ARFLAGS)
+libappdisplay_a_LIBADD =
+am__objects_1 = display-enums.$(OBJEXT)
+am__objects_2 = gimpcanvas.$(OBJEXT) gimpcanvas-style.$(OBJEXT) \
+	gimpcanvasarc.$(OBJEXT) gimpcanvasboundary.$(OBJEXT) \
+	gimpcanvasbufferpreview.$(OBJEXT) \
+	gimpcanvascanvasboundary.$(OBJEXT) gimpcanvascorner.$(OBJEXT) \
+	gimpcanvascursor.$(OBJEXT) gimpcanvasgrid.$(OBJEXT) \
+	gimpcanvasgroup.$(OBJEXT) gimpcanvasguide.$(OBJEXT) \
+	gimpcanvashandle.$(OBJEXT) gimpcanvasitem.$(OBJEXT) \
+	gimpcanvasitem-utils.$(OBJEXT) \
+	gimpcanvaslayerboundary.$(OBJEXT) gimpcanvaslimit.$(OBJEXT) \
+	gimpcanvasline.$(OBJEXT) gimpcanvaspassepartout.$(OBJEXT) \
+	gimpcanvaspath.$(OBJEXT) gimpcanvaspen.$(OBJEXT) \
+	gimpcanvaspolygon.$(OBJEXT) gimpcanvasprogress.$(OBJEXT) \
+	gimpcanvasproxygroup.$(OBJEXT) gimpcanvasrectangle.$(OBJEXT) \
+	gimpcanvasrectangleguides.$(OBJEXT) \
+	gimpcanvassamplepoint.$(OBJEXT) gimpcanvastextcursor.$(OBJEXT) \
+	gimpcanvastransformguides.$(OBJEXT) \
+	gimpcanvastransformpreview.$(OBJEXT) gimpcursorview.$(OBJEXT) \
+	gimpdisplay.$(OBJEXT) gimpdisplay-foreach.$(OBJEXT) \
+	gimpdisplay-handlers.$(OBJEXT) gimpdisplayshell.$(OBJEXT) \
+	gimpdisplayshell-actions.$(OBJEXT) \
+	gimpdisplayshell-appearance.$(OBJEXT) \
+	gimpdisplayshell-autoscroll.$(OBJEXT) \
+	gimpdisplayshell-callbacks.$(OBJEXT) \
+	gimpdisplayshell-close.$(OBJEXT) \
+	gimpdisplayshell-cursor.$(OBJEXT) \
+	gimpdisplayshell-dnd.$(OBJEXT) gimpdisplayshell-draw.$(OBJEXT) \
+	gimpdisplayshell-expose.$(OBJEXT) \
+	gimpdisplayshell-grab.$(OBJEXT) \
+	gimpdisplayshell-handlers.$(OBJEXT) \
+	gimpdisplayshell-filter.$(OBJEXT) \
+	gimpdisplayshell-filter-dialog.$(OBJEXT) \
+	gimpdisplayshell-layer-select.$(OBJEXT) \
+	gimpdisplayshell-icon.$(OBJEXT) \
+	gimpdisplayshell-items.$(OBJEXT) \
+	gimpdisplayshell-profile.$(OBJEXT) \
+	gimpdisplayshell-progress.$(OBJEXT) \
+	gimpdisplayshell-render.$(OBJEXT) \
+	gimpdisplayshell-rotate.$(OBJEXT) \
+	gimpdisplayshell-rotate-dialog.$(OBJEXT) \
+	gimpdisplayshell-rulers.$(OBJEXT) \
+	gimpdisplayshell-scale.$(OBJEXT) \
+	gimpdisplayshell-scale-dialog.$(OBJEXT) \
+	gimpdisplayshell-scroll.$(OBJEXT) \
+	gimpdisplayshell-scrollbars.$(OBJEXT) \
+	gimpdisplayshell-selection.$(OBJEXT) \
+	gimpdisplayshell-title.$(OBJEXT) \
+	gimpdisplayshell-tool-events.$(OBJEXT) \
+	gimpdisplayshell-transform.$(OBJEXT) \
+	gimpdisplayshell-utils.$(OBJEXT) gimpdisplayxfer.$(OBJEXT) \
+	gimpimagewindow.$(OBJEXT) gimpmotionbuffer.$(OBJEXT) \
+	gimpmultiwindowstrategy.$(OBJEXT) \
+	gimpnavigationeditor.$(OBJEXT) gimpscalecombobox.$(OBJEXT) \
+	gimpsinglewindowstrategy.$(OBJEXT) gimpstatusbar.$(OBJEXT) \
+	gimptooldialog.$(OBJEXT) gimptoolgui.$(OBJEXT) \
+	gimptoolcompass.$(OBJEXT) gimptoolfocus.$(OBJEXT) \
+	gimptoolgyroscope.$(OBJEXT) gimptoolhandlegrid.$(OBJEXT) \
+	gimptoolline.$(OBJEXT) gimptoolpath.$(OBJEXT) \
+	gimptoolpolygon.$(OBJEXT) gimptoolrectangle.$(OBJEXT) \
+	gimptoolrotategrid.$(OBJEXT) gimptoolsheargrid.$(OBJEXT) \
+	gimptooltransform3dgrid.$(OBJEXT) \
+	gimptooltransformgrid.$(OBJEXT) gimptoolwidget.$(OBJEXT) \
+	gimptoolwidgetgroup.$(OBJEXT)
+am_libappdisplay_a_OBJECTS = $(am__objects_1) $(am__objects_2)
+libappdisplay_a_OBJECTS = $(am_libappdisplay_a_OBJECTS)
+AM_V_P = $(am__v_P_@AM_V@)
+am__v_P_ = $(am__v_P_@AM_DEFAULT_V@)
+am__v_P_0 = false
+am__v_P_1 = :
+AM_V_GEN = $(am__v_GEN_@AM_V@)
+am__v_GEN_ = $(am__v_GEN_@AM_DEFAULT_V@)
+am__v_GEN_0 = @echo "  GEN     " $@;
+am__v_GEN_1 = 
+AM_V_at = $(am__v_at_@AM_V@)
+am__v_at_ = $(am__v_at_@AM_DEFAULT_V@)
+am__v_at_0 = @
+am__v_at_1 = 
+DEFAULT_INCLUDES = -I.@am__isrc@ -I$(top_builddir)
+depcomp = $(SHELL) $(top_srcdir)/depcomp
+am__maybe_remake_depfiles = depfiles
+am__depfiles_remade = ./$(DEPDIR)/display-enums.Po \
+	./$(DEPDIR)/gimpcanvas-style.Po ./$(DEPDIR)/gimpcanvas.Po \
+	./$(DEPDIR)/gimpcanvasarc.Po ./$(DEPDIR)/gimpcanvasboundary.Po \
+	./$(DEPDIR)/gimpcanvasbufferpreview.Po \
+	./$(DEPDIR)/gimpcanvascanvasboundary.Po \
+	./$(DEPDIR)/gimpcanvascorner.Po \
+	./$(DEPDIR)/gimpcanvascursor.Po ./$(DEPDIR)/gimpcanvasgrid.Po \
+	./$(DEPDIR)/gimpcanvasgroup.Po ./$(DEPDIR)/gimpcanvasguide.Po \
+	./$(DEPDIR)/gimpcanvashandle.Po \
+	./$(DEPDIR)/gimpcanvasitem-utils.Po \
+	./$(DEPDIR)/gimpcanvasitem.Po \
+	./$(DEPDIR)/gimpcanvaslayerboundary.Po \
+	./$(DEPDIR)/gimpcanvaslimit.Po ./$(DEPDIR)/gimpcanvasline.Po \
+	./$(DEPDIR)/gimpcanvaspassepartout.Po \
+	./$(DEPDIR)/gimpcanvaspath.Po ./$(DEPDIR)/gimpcanvaspen.Po \
+	./$(DEPDIR)/gimpcanvaspolygon.Po \
+	./$(DEPDIR)/gimpcanvasprogress.Po \
+	./$(DEPDIR)/gimpcanvasproxygroup.Po \
+	./$(DEPDIR)/gimpcanvasrectangle.Po \
+	./$(DEPDIR)/gimpcanvasrectangleguides.Po \
+	./$(DEPDIR)/gimpcanvassamplepoint.Po \
+	./$(DEPDIR)/gimpcanvastextcursor.Po \
+	./$(DEPDIR)/gimpcanvastransformguides.Po \
+	./$(DEPDIR)/gimpcanvastransformpreview.Po \
+	./$(DEPDIR)/gimpcursorview.Po \
+	./$(DEPDIR)/gimpdisplay-foreach.Po \
+	./$(DEPDIR)/gimpdisplay-handlers.Po ./$(DEPDIR)/gimpdisplay.Po \
+	./$(DEPDIR)/gimpdisplayshell-actions.Po \
+	./$(DEPDIR)/gimpdisplayshell-appearance.Po \
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+am__quote = @am__quote@
+am__tar = @am__tar@
+am__untar = @am__untar@
+bindir = @bindir@
+build = @build@
+build_alias = @build_alias@
+build_cpu = @build_cpu@
+build_os = @build_os@
+build_vendor = @build_vendor@
+builddir = @builddir@
+datadir = @datadir@
+datarootdir = @datarootdir@
+docdir = @docdir@
+dvidir = @dvidir@
+exec_prefix = @exec_prefix@
+gimpdatadir = @gimpdatadir@
+gimpdir = @gimpdir@
+gimplocaledir = @gimplocaledir@
+gimpplugindir = @gimpplugindir@
+gimpsysconfdir = @gimpsysconfdir@
+host = @host@
+host_alias = @host_alias@
+host_cpu = @host_cpu@
+host_os = @host_os@
+host_vendor = @host_vendor@
+htmldir = @htmldir@
+includedir = @includedir@
+infodir = @infodir@
+install_sh = @install_sh@
+intltool__v_merge_options_ = @intltool__v_merge_options_@
+intltool__v_merge_options_0 = @intltool__v_merge_options_0@
+libdir = @libdir@
+libexecdir = @libexecdir@
+localedir = @localedir@
+localstatedir = @localstatedir@
+mandir = @mandir@
+manpage_gimpdir = @manpage_gimpdir@
+mkdir_p = @mkdir_p@
+ms_librarian = @ms_librarian@
+mypaint_brushes_dir = @mypaint_brushes_dir@
+oldincludedir = @oldincludedir@
+pdfdir = @pdfdir@
+pkgpyexecdir = @pkgpyexecdir@
+pkgpythondir = @pkgpythondir@
+prefix = @prefix@
+program_transform_name = @program_transform_name@
+psdir = @psdir@
+pyexecdir = @pyexecdir@
+pythondir = @pythondir@
+runstatedir = @runstatedir@
+sbindir = @sbindir@
+sharedstatedir = @sharedstatedir@
+srcdir = @srcdir@
+sysconfdir = @sysconfdir@
+target_alias = @target_alias@
+top_build_prefix = @top_build_prefix@
+top_builddir = @top_builddir@
+top_srcdir = @top_srcdir@
+@PLATFORM_OSX_TRUE@xobjective_c = "-xobjective-c"
+@PLATFORM_OSX_TRUE@xobjective_cxx = "-xobjective-c++"
+@PLATFORM_OSX_TRUE@xnone = "-xnone"
+AM_CPPFLAGS = \
+	-DG_LOG_DOMAIN=\"Gimp-Display\"	\
+	-I$(top_builddir)		\
+	-I$(top_srcdir)			\
+	-I$(top_builddir)/app		\
+	-I$(top_srcdir)/app		\
+	$(GEGL_CFLAGS)			\
+	$(GTK_CFLAGS)			\
+	-I$(includedir)
+
+AM_CFLAGS = \
+	$(xobjective_c)
+
+AM_CXXFLAGS = \
+	$(xobjective_cxx)
+
+AM_LDFLAGS = \
+	$(xnone)
+
+noinst_LIBRARIES = libappdisplay.a
+libappdisplay_a_sources = \
+	display-enums.h				\
+	display-types.h				\
+	gimpcanvas.c				\
+	gimpcanvas.h				\
+	gimpcanvas-style.c			\
+	gimpcanvas-style.h			\
+	gimpcanvasarc.c				\
+	gimpcanvasarc.h				\
+	gimpcanvasboundary.c			\
+	gimpcanvasboundary.h			\
+	gimpcanvasbufferpreview.c		\
+	gimpcanvasbufferpreview.h		\
+	gimpcanvascanvasboundary.c		\
+	gimpcanvascanvasboundary.h		\
+	gimpcanvascorner.c			\
+	gimpcanvascorner.h			\
+	gimpcanvascursor.c			\
+	gimpcanvascursor.h			\
+	gimpcanvasgrid.c			\
+	gimpcanvasgrid.h			\
+	gimpcanvasgroup.c			\
+	gimpcanvasgroup.h			\
+	gimpcanvasguide.c			\
+	gimpcanvasguide.h			\
+	gimpcanvashandle.c			\
+	gimpcanvashandle.h			\
+	gimpcanvasitem.c			\
+	gimpcanvasitem.h			\
+	gimpcanvasitem-utils.c			\
+	gimpcanvasitem-utils.h			\
+	gimpcanvaslayerboundary.c		\
+	gimpcanvaslayerboundary.h		\
+	gimpcanvaslimit.c			\
+	gimpcanvaslimit.h			\
+	gimpcanvasline.c			\
+	gimpcanvasline.h			\
+	gimpcanvaspassepartout.c		\
+	gimpcanvaspassepartout.h		\
+	gimpcanvaspath.c			\
+	gimpcanvaspath.h			\
+	gimpcanvaspen.c				\
+	gimpcanvaspen.h				\
+	gimpcanvaspolygon.c			\
+	gimpcanvaspolygon.h			\
+	gimpcanvasprogress.c			\
+	gimpcanvasprogress.h			\
+	gimpcanvasproxygroup.c			\
+	gimpcanvasproxygroup.h			\
+	gimpcanvasrectangle.c			\
+	gimpcanvasrectangle.h			\
+	gimpcanvasrectangleguides.c		\
+	gimpcanvasrectangleguides.h		\
+	gimpcanvassamplepoint.c			\
+	gimpcanvassamplepoint.h			\
+	gimpcanvastextcursor.c			\
+	gimpcanvastextcursor.h			\
+	gimpcanvastransformguides.c		\
+	gimpcanvastransformguides.h		\
+	gimpcanvastransformpreview.c		\
+	gimpcanvastransformpreview.h		\
+	gimpcursorview.c			\
+	gimpcursorview.h			\
+	gimpdisplay.c				\
+	gimpdisplay.h				\
+	gimpdisplay-foreach.c			\
+	gimpdisplay-foreach.h			\
+	gimpdisplay-handlers.c			\
+	gimpdisplay-handlers.h			\
+	gimpdisplayshell.c			\
+	gimpdisplayshell.h			\
+	gimpdisplayshell-actions.c		\
+	gimpdisplayshell-actions.h		\
+	gimpdisplayshell-appearance.c		\
+	gimpdisplayshell-appearance.h		\
+	gimpdisplayshell-autoscroll.c		\
+	gimpdisplayshell-autoscroll.h		\
+	gimpdisplayshell-callbacks.c		\
+	gimpdisplayshell-callbacks.h		\
+	gimpdisplayshell-close.c		\
+	gimpdisplayshell-close.h		\
+	gimpdisplayshell-cursor.c		\
+	gimpdisplayshell-cursor.h		\
+	gimpdisplayshell-dnd.c			\
+	gimpdisplayshell-dnd.h			\
+	gimpdisplayshell-draw.c			\
+	gimpdisplayshell-draw.h			\
+	gimpdisplayshell-expose.c		\
+	gimpdisplayshell-expose.h		\
+	gimpdisplayshell-grab.c			\
+	gimpdisplayshell-grab.h			\
+	gimpdisplayshell-handlers.c		\
+	gimpdisplayshell-handlers.h		\
+	gimpdisplayshell-filter.c		\
+	gimpdisplayshell-filter.h		\
+	gimpdisplayshell-filter-dialog.c	\
+	gimpdisplayshell-filter-dialog.h	\
+	gimpdisplayshell-layer-select.c		\
+	gimpdisplayshell-layer-select.h		\
+	gimpdisplayshell-icon.c			\
+	gimpdisplayshell-icon.h			\
+	gimpdisplayshell-items.c		\
+	gimpdisplayshell-items.h		\
+	gimpdisplayshell-profile.c		\
+	gimpdisplayshell-profile.h		\
+	gimpdisplayshell-progress.c		\
+	gimpdisplayshell-progress.h		\
+	gimpdisplayshell-render.c		\
+	gimpdisplayshell-render.h		\
+	gimpdisplayshell-rotate.c		\
+	gimpdisplayshell-rotate.h		\
+	gimpdisplayshell-rotate-dialog.c	\
+	gimpdisplayshell-rotate-dialog.h	\
+	gimpdisplayshell-rulers.c		\
+	gimpdisplayshell-rulers.h		\
+	gimpdisplayshell-scale.c		\
+	gimpdisplayshell-scale.h		\
+	gimpdisplayshell-scale-dialog.c		\
+	gimpdisplayshell-scale-dialog.h		\
+	gimpdisplayshell-scroll.c		\
+	gimpdisplayshell-scroll.h		\
+	gimpdisplayshell-scrollbars.c		\
+	gimpdisplayshell-scrollbars.h		\
+	gimpdisplayshell-selection.c		\
+	gimpdisplayshell-selection.h		\
+	gimpdisplayshell-title.c		\
+	gimpdisplayshell-title.h		\
+	gimpdisplayshell-tool-events.c		\
+	gimpdisplayshell-tool-events.h		\
+	gimpdisplayshell-transform.c		\
+	gimpdisplayshell-transform.h		\
+	gimpdisplayshell-utils.c		\
+	gimpdisplayshell-utils.h		\
+	gimpdisplayxfer.c			\
+	gimpdisplayxfer.h			\
+	gimpimagewindow.c			\
+	gimpimagewindow.h			\
+	gimpmotionbuffer.c			\
+	gimpmotionbuffer.h			\
+	gimpmultiwindowstrategy.c		\
+	gimpmultiwindowstrategy.h		\
+	gimpnavigationeditor.c			\
+	gimpnavigationeditor.h			\
+	gimpscalecombobox.c			\
+	gimpscalecombobox.h			\
+	gimpsinglewindowstrategy.c		\
+	gimpsinglewindowstrategy.h		\
+	gimpstatusbar.c				\
+	gimpstatusbar.h				\
+	gimptooldialog.c			\
+	gimptooldialog.h			\
+	gimptoolgui.c				\
+	gimptoolgui.h				\
+	gimptoolcompass.c			\
+	gimptoolcompass.h			\
+	gimptoolfocus.h				\
+	gimptoolfocus.c				\
+	gimptoolgyroscope.c			\
+	gimptoolgyroscope.h			\
+	gimptoolhandlegrid.c			\
+	gimptoolhandlegrid.h			\
+	gimptoolline.c				\
+	gimptoolline.h				\
+	gimptoolpath.c				\
+	gimptoolpath.h				\
+	gimptoolpolygon.c			\
+	gimptoolpolygon.h			\
+	gimptoolrectangle.c			\
+	gimptoolrectangle.h			\
+	gimptoolrotategrid.c			\
+	gimptoolrotategrid.h			\
+	gimptoolsheargrid.c			\
+	gimptoolsheargrid.h			\
+	gimptooltransform3dgrid.c		\
+	gimptooltransform3dgrid.h		\
+	gimptooltransformgrid.c			\
+	gimptooltransformgrid.h			\
+	gimptoolwidget.c			\
+	gimptoolwidget.h			\
+	gimptoolwidgetgroup.c			\
+	gimptoolwidgetgroup.h
+
+libappdisplay_a_built_sources = display-enums.c
+libappdisplay_a_SOURCES = \
+	$(libappdisplay_a_built_sources)	\
+	$(libappdisplay_a_sources)
+
+
+#
+# rules to generate built sources
+#
+# setup autogeneration dependencies
+gen_sources = xgen-dec
+CLEANFILES = $(gen_sources)
+all: all-am
+
+.SUFFIXES:
+.SUFFIXES: .c .lo .o .obj
+$(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.am  $(am__configure_deps)
+	@for dep in $?; do \
+	  case '$(am__configure_deps)' in \
+	    *$$dep*) \
+	      ( cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh ) \
+	        && { if test -f $@; then exit 0; else break; fi; }; \
+	      exit 1;; \
+	  esac; \
+	done; \
+	echo ' cd $(top_srcdir) && $(AUTOMAKE) --gnu app/display/Makefile'; \
+	$(am__cd) $(top_srcdir) && \
+	  $(AUTOMAKE) --gnu app/display/Makefile
+Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
+	@case '$?' in \
+	  *config.status*) \
+	    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
+	  *) \
+	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles)'; \
+	    cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles);; \
+	esac;
+
+$(top_builddir)/config.status: $(top_srcdir)/configure $(CONFIG_STATUS_DEPENDENCIES)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+
+$(top_srcdir)/configure: @MAINTAINER_MODE_TRUE@ $(am__configure_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+$(ACLOCAL_M4): @MAINTAINER_MODE_TRUE@ $(am__aclocal_m4_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+$(am__aclocal_m4_deps):
+
+clean-noinstLIBRARIES:
+	-test -z "$(noinst_LIBRARIES)" || rm -f $(noinst_LIBRARIES)
+
+libappdisplay.a: $(libappdisplay_a_OBJECTS) $(libappdisplay_a_DEPENDENCIES) $(EXTRA_libappdisplay_a_DEPENDENCIES) 
+	$(AM_V_at)-rm -f libappdisplay.a
+	$(AM_V_AR)$(libappdisplay_a_AR) libappdisplay.a $(libappdisplay_a_OBJECTS) $(libappdisplay_a_LIBADD)
+	$(AM_V_at)$(RANLIB) libappdisplay.a
+
+mostlyclean-compile:
+	-rm -f *.$(OBJEXT)
+
+distclean-compile:
+	-rm -f *.tab.c
+
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/display-enums.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvas-style.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvas.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasarc.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasboundary.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasbufferpreview.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvascanvasboundary.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvascorner.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvascursor.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasgrid.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasgroup.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasguide.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvashandle.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasitem-utils.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasitem.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvaslayerboundary.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvaslimit.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasline.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvaspassepartout.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvaspath.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvaspen.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvaspolygon.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasprogress.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasproxygroup.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasrectangle.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvasrectangleguides.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvassamplepoint.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvastextcursor.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvastransformguides.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcanvastransformpreview.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpcursorview.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplay-foreach.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplay-handlers.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplay.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-actions.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-appearance.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-autoscroll.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-callbacks.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-close.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-cursor.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-dnd.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-draw.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-expose.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-filter-dialog.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-filter.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-grab.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-handlers.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-icon.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-items.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-layer-select.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-profile.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-progress.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-render.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-rotate-dialog.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-rotate.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-rulers.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-scale-dialog.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-scale.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-scroll.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-scrollbars.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-selection.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-title.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-tool-events.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-transform.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell-utils.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayshell.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpdisplayxfer.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpimagewindow.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpmotionbuffer.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpmultiwindowstrategy.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpnavigationeditor.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpscalecombobox.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpsinglewindowstrategy.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimpstatusbar.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimptoolcompass.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimptooldialog.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gimptoolfocus.Po@am__quote@ # am--include-marker
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+		--fprod "\n/* enumerations from \"@basename@\" */" \
+		--vhead "GType\n@enum_name@_get_type (void)\n{\n  static const G@Type@Value values[] =\n  {" \
+		--vprod "    { @VALUENAME@, \"@VALUENAME@\", \"@valuenick@\" }," \
+		--vtail "    { 0, NULL, NULL }\n  };\n" \
+		--dhead "  static const Gimp@Type@Desc descs[] =\n  {" \
+		--dprod "    { @VALUENAME@, @valuedesc@, @valuehelp@ },@if ('@valueabbrev@' ne 'NULL')@\n    /* Translators: this is an abbreviated version of @valueudesc@.\n       Keep it short. */\n    { @VALUENAME@, @valueabbrev@, NULL },@endif@" \
+		--dtail "    { 0, NULL, NULL }\n  };\n\n  static GType type = 0;\n\n  if (G_UNLIKELY (! type))\n    {\n      type = g_@type@_register_static (\"@EnumName@\", values);\n      gimp_type_set_translation_context (type, \"@enumnick@\");\n      gimp_@type@_set_value_descriptions (type, descs);\n    }\n\n  return type;\n}\n" \
+		$< > $@
+
+# copy the generated enum file back to the source directory only if it's
+# changed; otherwise, only update its timestamp, so that the recipe isn't
+# executed again on the next build, however, allow this to (harmlessly) fail,
+# to support building from a read-only source tree.
+$(srcdir)/display-enums.c: xgen-dec
+	$(AM_V_GEN) if ! cmp -s $< $@; then \
+		cp $< $@; \
+	else \
+		touch $@ 2> /dev/null \
+		|| true; \
+	fi
+
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/app/display/display-enums.c b/app/display/display-enums.c
new file mode 100644
index 0000000..438fc3e
--- /dev/null
+++ b/app/display/display-enums.c
@@ -0,0 +1,592 @@
+
+/* Generated data (by gimp-mkenums) */
+
+#include "config.h"
+#include <gio/gio.h>
+#include "libgimpbase/gimpbase.h"
+#include "display-enums.h"
+#include"gimp-intl.h"
+
+/* enumerations from "display-enums.h" */
+GType
+gimp_button_press_type_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_BUTTON_PRESS_NORMAL, "GIMP_BUTTON_PRESS_NORMAL", "normal" },
+    { GIMP_BUTTON_PRESS_DOUBLE, "GIMP_BUTTON_PRESS_DOUBLE", "double" },
+    { GIMP_BUTTON_PRESS_TRIPLE, "GIMP_BUTTON_PRESS_TRIPLE", "triple" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_BUTTON_PRESS_NORMAL, "GIMP_BUTTON_PRESS_NORMAL", NULL },
+    { GIMP_BUTTON_PRESS_DOUBLE, "GIMP_BUTTON_PRESS_DOUBLE", NULL },
+    { GIMP_BUTTON_PRESS_TRIPLE, "GIMP_BUTTON_PRESS_TRIPLE", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpButtonPressType", values);
+      gimp_type_set_translation_context (type, "button-press-type");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_button_release_type_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_BUTTON_RELEASE_NORMAL, "GIMP_BUTTON_RELEASE_NORMAL", "normal" },
+    { GIMP_BUTTON_RELEASE_CANCEL, "GIMP_BUTTON_RELEASE_CANCEL", "cancel" },
+    { GIMP_BUTTON_RELEASE_CLICK, "GIMP_BUTTON_RELEASE_CLICK", "click" },
+    { GIMP_BUTTON_RELEASE_NO_MOTION, "GIMP_BUTTON_RELEASE_NO_MOTION", "no-motion" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_BUTTON_RELEASE_NORMAL, "GIMP_BUTTON_RELEASE_NORMAL", NULL },
+    { GIMP_BUTTON_RELEASE_CANCEL, "GIMP_BUTTON_RELEASE_CANCEL", NULL },
+    { GIMP_BUTTON_RELEASE_CLICK, "GIMP_BUTTON_RELEASE_CLICK", NULL },
+    { GIMP_BUTTON_RELEASE_NO_MOTION, "GIMP_BUTTON_RELEASE_NO_MOTION", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpButtonReleaseType", values);
+      gimp_type_set_translation_context (type, "button-release-type");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_compass_orientation_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_COMPASS_ORIENTATION_AUTO, "GIMP_COMPASS_ORIENTATION_AUTO", "auto" },
+    { GIMP_COMPASS_ORIENTATION_HORIZONTAL, "GIMP_COMPASS_ORIENTATION_HORIZONTAL", "horizontal" },
+    { GIMP_COMPASS_ORIENTATION_VERTICAL, "GIMP_COMPASS_ORIENTATION_VERTICAL", "vertical" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_COMPASS_ORIENTATION_AUTO, NC_("compass-orientation", "Auto"), NULL },
+    { GIMP_COMPASS_ORIENTATION_HORIZONTAL, NC_("compass-orientation", "Horizontal"), NULL },
+    { GIMP_COMPASS_ORIENTATION_VERTICAL, NC_("compass-orientation", "Vertical"), NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpCompassOrientation", values);
+      gimp_type_set_translation_context (type, "compass-orientation");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_cursor_precision_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_CURSOR_PRECISION_PIXEL_CENTER, "GIMP_CURSOR_PRECISION_PIXEL_CENTER", "pixel-center" },
+    { GIMP_CURSOR_PRECISION_PIXEL_BORDER, "GIMP_CURSOR_PRECISION_PIXEL_BORDER", "pixel-border" },
+    { GIMP_CURSOR_PRECISION_SUBPIXEL, "GIMP_CURSOR_PRECISION_SUBPIXEL", "subpixel" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_CURSOR_PRECISION_PIXEL_CENTER, "GIMP_CURSOR_PRECISION_PIXEL_CENTER", NULL },
+    { GIMP_CURSOR_PRECISION_PIXEL_BORDER, "GIMP_CURSOR_PRECISION_PIXEL_BORDER", NULL },
+    { GIMP_CURSOR_PRECISION_SUBPIXEL, "GIMP_CURSOR_PRECISION_SUBPIXEL", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpCursorPrecision", values);
+      gimp_type_set_translation_context (type, "cursor-precision");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_guides_type_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_GUIDES_NONE, "GIMP_GUIDES_NONE", "none" },
+    { GIMP_GUIDES_CENTER_LINES, "GIMP_GUIDES_CENTER_LINES", "center-lines" },
+    { GIMP_GUIDES_THIRDS, "GIMP_GUIDES_THIRDS", "thirds" },
+    { GIMP_GUIDES_FIFTHS, "GIMP_GUIDES_FIFTHS", "fifths" },
+    { GIMP_GUIDES_GOLDEN, "GIMP_GUIDES_GOLDEN", "golden" },
+    { GIMP_GUIDES_DIAGONALS, "GIMP_GUIDES_DIAGONALS", "diagonals" },
+    { GIMP_GUIDES_N_LINES, "GIMP_GUIDES_N_LINES", "n-lines" },
+    { GIMP_GUIDES_SPACING, "GIMP_GUIDES_SPACING", "spacing" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_GUIDES_NONE, NC_("guides-type", "No guides"), NULL },
+    { GIMP_GUIDES_CENTER_LINES, NC_("guides-type", "Center lines"), NULL },
+    { GIMP_GUIDES_THIRDS, NC_("guides-type", "Rule of thirds"), NULL },
+    { GIMP_GUIDES_FIFTHS, NC_("guides-type", "Rule of fifths"), NULL },
+    { GIMP_GUIDES_GOLDEN, NC_("guides-type", "Golden sections"), NULL },
+    { GIMP_GUIDES_DIAGONALS, NC_("guides-type", "Diagonal lines"), NULL },
+    { GIMP_GUIDES_N_LINES, NC_("guides-type", "Number of lines"), NULL },
+    { GIMP_GUIDES_SPACING, NC_("guides-type", "Line spacing"), NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpGuidesType", values);
+      gimp_type_set_translation_context (type, "guides-type");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_handle_type_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_HANDLE_SQUARE, "GIMP_HANDLE_SQUARE", "square" },
+    { GIMP_HANDLE_DASHED_SQUARE, "GIMP_HANDLE_DASHED_SQUARE", "dashed-square" },
+    { GIMP_HANDLE_FILLED_SQUARE, "GIMP_HANDLE_FILLED_SQUARE", "filled-square" },
+    { GIMP_HANDLE_CIRCLE, "GIMP_HANDLE_CIRCLE", "circle" },
+    { GIMP_HANDLE_DASHED_CIRCLE, "GIMP_HANDLE_DASHED_CIRCLE", "dashed-circle" },
+    { GIMP_HANDLE_FILLED_CIRCLE, "GIMP_HANDLE_FILLED_CIRCLE", "filled-circle" },
+    { GIMP_HANDLE_DIAMOND, "GIMP_HANDLE_DIAMOND", "diamond" },
+    { GIMP_HANDLE_DASHED_DIAMOND, "GIMP_HANDLE_DASHED_DIAMOND", "dashed-diamond" },
+    { GIMP_HANDLE_FILLED_DIAMOND, "GIMP_HANDLE_FILLED_DIAMOND", "filled-diamond" },
+    { GIMP_HANDLE_CROSS, "GIMP_HANDLE_CROSS", "cross" },
+    { GIMP_HANDLE_CROSSHAIR, "GIMP_HANDLE_CROSSHAIR", "crosshair" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_HANDLE_SQUARE, "GIMP_HANDLE_SQUARE", NULL },
+    { GIMP_HANDLE_DASHED_SQUARE, "GIMP_HANDLE_DASHED_SQUARE", NULL },
+    { GIMP_HANDLE_FILLED_SQUARE, "GIMP_HANDLE_FILLED_SQUARE", NULL },
+    { GIMP_HANDLE_CIRCLE, "GIMP_HANDLE_CIRCLE", NULL },
+    { GIMP_HANDLE_DASHED_CIRCLE, "GIMP_HANDLE_DASHED_CIRCLE", NULL },
+    { GIMP_HANDLE_FILLED_CIRCLE, "GIMP_HANDLE_FILLED_CIRCLE", NULL },
+    { GIMP_HANDLE_DIAMOND, "GIMP_HANDLE_DIAMOND", NULL },
+    { GIMP_HANDLE_DASHED_DIAMOND, "GIMP_HANDLE_DASHED_DIAMOND", NULL },
+    { GIMP_HANDLE_FILLED_DIAMOND, "GIMP_HANDLE_FILLED_DIAMOND", NULL },
+    { GIMP_HANDLE_CROSS, "GIMP_HANDLE_CROSS", NULL },
+    { GIMP_HANDLE_CROSSHAIR, "GIMP_HANDLE_CROSSHAIR", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpHandleType", values);
+      gimp_type_set_translation_context (type, "handle-type");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_handle_anchor_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_HANDLE_ANCHOR_CENTER, "GIMP_HANDLE_ANCHOR_CENTER", "center" },
+    { GIMP_HANDLE_ANCHOR_NORTH, "GIMP_HANDLE_ANCHOR_NORTH", "north" },
+    { GIMP_HANDLE_ANCHOR_NORTH_WEST, "GIMP_HANDLE_ANCHOR_NORTH_WEST", "north-west" },
+    { GIMP_HANDLE_ANCHOR_NORTH_EAST, "GIMP_HANDLE_ANCHOR_NORTH_EAST", "north-east" },
+    { GIMP_HANDLE_ANCHOR_SOUTH, "GIMP_HANDLE_ANCHOR_SOUTH", "south" },
+    { GIMP_HANDLE_ANCHOR_SOUTH_WEST, "GIMP_HANDLE_ANCHOR_SOUTH_WEST", "south-west" },
+    { GIMP_HANDLE_ANCHOR_SOUTH_EAST, "GIMP_HANDLE_ANCHOR_SOUTH_EAST", "south-east" },
+    { GIMP_HANDLE_ANCHOR_WEST, "GIMP_HANDLE_ANCHOR_WEST", "west" },
+    { GIMP_HANDLE_ANCHOR_EAST, "GIMP_HANDLE_ANCHOR_EAST", "east" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_HANDLE_ANCHOR_CENTER, "GIMP_HANDLE_ANCHOR_CENTER", NULL },
+    { GIMP_HANDLE_ANCHOR_NORTH, "GIMP_HANDLE_ANCHOR_NORTH", NULL },
+    { GIMP_HANDLE_ANCHOR_NORTH_WEST, "GIMP_HANDLE_ANCHOR_NORTH_WEST", NULL },
+    { GIMP_HANDLE_ANCHOR_NORTH_EAST, "GIMP_HANDLE_ANCHOR_NORTH_EAST", NULL },
+    { GIMP_HANDLE_ANCHOR_SOUTH, "GIMP_HANDLE_ANCHOR_SOUTH", NULL },
+    { GIMP_HANDLE_ANCHOR_SOUTH_WEST, "GIMP_HANDLE_ANCHOR_SOUTH_WEST", NULL },
+    { GIMP_HANDLE_ANCHOR_SOUTH_EAST, "GIMP_HANDLE_ANCHOR_SOUTH_EAST", NULL },
+    { GIMP_HANDLE_ANCHOR_WEST, "GIMP_HANDLE_ANCHOR_WEST", NULL },
+    { GIMP_HANDLE_ANCHOR_EAST, "GIMP_HANDLE_ANCHOR_EAST", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpHandleAnchor", values);
+      gimp_type_set_translation_context (type, "handle-anchor");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_limit_type_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_LIMIT_CIRCLE, "GIMP_LIMIT_CIRCLE", "circle" },
+    { GIMP_LIMIT_SQUARE, "GIMP_LIMIT_SQUARE", "square" },
+    { GIMP_LIMIT_DIAMOND, "GIMP_LIMIT_DIAMOND", "diamond" },
+    { GIMP_LIMIT_HORIZONTAL, "GIMP_LIMIT_HORIZONTAL", "horizontal" },
+    { GIMP_LIMIT_VERTICAL, "GIMP_LIMIT_VERTICAL", "vertical" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_LIMIT_CIRCLE, "GIMP_LIMIT_CIRCLE", NULL },
+    { GIMP_LIMIT_SQUARE, "GIMP_LIMIT_SQUARE", NULL },
+    { GIMP_LIMIT_DIAMOND, "GIMP_LIMIT_DIAMOND", NULL },
+    { GIMP_LIMIT_HORIZONTAL, "GIMP_LIMIT_HORIZONTAL", NULL },
+    { GIMP_LIMIT_VERTICAL, "GIMP_LIMIT_VERTICAL", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpLimitType", values);
+      gimp_type_set_translation_context (type, "limit-type");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_path_style_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_PATH_STYLE_DEFAULT, "GIMP_PATH_STYLE_DEFAULT", "default" },
+    { GIMP_PATH_STYLE_VECTORS, "GIMP_PATH_STYLE_VECTORS", "vectors" },
+    { GIMP_PATH_STYLE_OUTLINE, "GIMP_PATH_STYLE_OUTLINE", "outline" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_PATH_STYLE_DEFAULT, "GIMP_PATH_STYLE_DEFAULT", NULL },
+    { GIMP_PATH_STYLE_VECTORS, "GIMP_PATH_STYLE_VECTORS", NULL },
+    { GIMP_PATH_STYLE_OUTLINE, "GIMP_PATH_STYLE_OUTLINE", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpPathStyle", values);
+      gimp_type_set_translation_context (type, "path-style");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_rectangle_constraint_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_RECTANGLE_CONSTRAIN_NONE, "GIMP_RECTANGLE_CONSTRAIN_NONE", "none" },
+    { GIMP_RECTANGLE_CONSTRAIN_IMAGE, "GIMP_RECTANGLE_CONSTRAIN_IMAGE", "image" },
+    { GIMP_RECTANGLE_CONSTRAIN_DRAWABLE, "GIMP_RECTANGLE_CONSTRAIN_DRAWABLE", "drawable" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_RECTANGLE_CONSTRAIN_NONE, "GIMP_RECTANGLE_CONSTRAIN_NONE", NULL },
+    { GIMP_RECTANGLE_CONSTRAIN_IMAGE, "GIMP_RECTANGLE_CONSTRAIN_IMAGE", NULL },
+    { GIMP_RECTANGLE_CONSTRAIN_DRAWABLE, "GIMP_RECTANGLE_CONSTRAIN_DRAWABLE", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpRectangleConstraint", values);
+      gimp_type_set_translation_context (type, "rectangle-constraint");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_rectangle_fixed_rule_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_RECTANGLE_FIXED_ASPECT, "GIMP_RECTANGLE_FIXED_ASPECT", "aspect" },
+    { GIMP_RECTANGLE_FIXED_WIDTH, "GIMP_RECTANGLE_FIXED_WIDTH", "width" },
+    { GIMP_RECTANGLE_FIXED_HEIGHT, "GIMP_RECTANGLE_FIXED_HEIGHT", "height" },
+    { GIMP_RECTANGLE_FIXED_SIZE, "GIMP_RECTANGLE_FIXED_SIZE", "size" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_RECTANGLE_FIXED_ASPECT, NC_("rectangle-fixed-rule", "Aspect ratio"), NULL },
+    { GIMP_RECTANGLE_FIXED_WIDTH, NC_("rectangle-fixed-rule", "Width"), NULL },
+    { GIMP_RECTANGLE_FIXED_HEIGHT, NC_("rectangle-fixed-rule", "Height"), NULL },
+    { GIMP_RECTANGLE_FIXED_SIZE, NC_("rectangle-fixed-rule", "Size"), NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpRectangleFixedRule", values);
+      gimp_type_set_translation_context (type, "rectangle-fixed-rule");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_rectangle_precision_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_RECTANGLE_PRECISION_INT, "GIMP_RECTANGLE_PRECISION_INT", "int" },
+    { GIMP_RECTANGLE_PRECISION_DOUBLE, "GIMP_RECTANGLE_PRECISION_DOUBLE", "double" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_RECTANGLE_PRECISION_INT, "GIMP_RECTANGLE_PRECISION_INT", NULL },
+    { GIMP_RECTANGLE_PRECISION_DOUBLE, "GIMP_RECTANGLE_PRECISION_DOUBLE", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpRectanglePrecision", values);
+      gimp_type_set_translation_context (type, "rectangle-precision");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_transform_3d_mode_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_TRANSFORM_3D_MODE_CAMERA, "GIMP_TRANSFORM_3D_MODE_CAMERA", "camera" },
+    { GIMP_TRANSFORM_3D_MODE_MOVE, "GIMP_TRANSFORM_3D_MODE_MOVE", "move" },
+    { GIMP_TRANSFORM_3D_MODE_ROTATE, "GIMP_TRANSFORM_3D_MODE_ROTATE", "rotate" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_TRANSFORM_3D_MODE_CAMERA, "GIMP_TRANSFORM_3D_MODE_CAMERA", NULL },
+    { GIMP_TRANSFORM_3D_MODE_MOVE, "GIMP_TRANSFORM_3D_MODE_MOVE", NULL },
+    { GIMP_TRANSFORM_3D_MODE_ROTATE, "GIMP_TRANSFORM_3D_MODE_ROTATE", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpTransform3DMode", values);
+      gimp_type_set_translation_context (type, "transform3-dmode");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_transform_function_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_TRANSFORM_FUNCTION_NONE, "GIMP_TRANSFORM_FUNCTION_NONE", "none" },
+    { GIMP_TRANSFORM_FUNCTION_MOVE, "GIMP_TRANSFORM_FUNCTION_MOVE", "move" },
+    { GIMP_TRANSFORM_FUNCTION_SCALE, "GIMP_TRANSFORM_FUNCTION_SCALE", "scale" },
+    { GIMP_TRANSFORM_FUNCTION_ROTATE, "GIMP_TRANSFORM_FUNCTION_ROTATE", "rotate" },
+    { GIMP_TRANSFORM_FUNCTION_SHEAR, "GIMP_TRANSFORM_FUNCTION_SHEAR", "shear" },
+    { GIMP_TRANSFORM_FUNCTION_PERSPECTIVE, "GIMP_TRANSFORM_FUNCTION_PERSPECTIVE", "perspective" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_TRANSFORM_FUNCTION_NONE, "GIMP_TRANSFORM_FUNCTION_NONE", NULL },
+    { GIMP_TRANSFORM_FUNCTION_MOVE, "GIMP_TRANSFORM_FUNCTION_MOVE", NULL },
+    { GIMP_TRANSFORM_FUNCTION_SCALE, "GIMP_TRANSFORM_FUNCTION_SCALE", NULL },
+    { GIMP_TRANSFORM_FUNCTION_ROTATE, "GIMP_TRANSFORM_FUNCTION_ROTATE", NULL },
+    { GIMP_TRANSFORM_FUNCTION_SHEAR, "GIMP_TRANSFORM_FUNCTION_SHEAR", NULL },
+    { GIMP_TRANSFORM_FUNCTION_PERSPECTIVE, "GIMP_TRANSFORM_FUNCTION_PERSPECTIVE", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpTransformFunction", values);
+      gimp_type_set_translation_context (type, "transform-function");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_transform_handle_mode_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_HANDLE_MODE_ADD_TRANSFORM, "GIMP_HANDLE_MODE_ADD_TRANSFORM", "add-transform" },
+    { GIMP_HANDLE_MODE_MOVE, "GIMP_HANDLE_MODE_MOVE", "move" },
+    { GIMP_HANDLE_MODE_REMOVE, "GIMP_HANDLE_MODE_REMOVE", "remove" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_HANDLE_MODE_ADD_TRANSFORM, NC_("transform-handle-mode", "Add / Transform"), NULL },
+    { GIMP_HANDLE_MODE_MOVE, NC_("transform-handle-mode", "Move"), NULL },
+    { GIMP_HANDLE_MODE_REMOVE, NC_("transform-handle-mode", "Remove"), NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpTransformHandleMode", values);
+      gimp_type_set_translation_context (type, "transform-handle-mode");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_vector_mode_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_VECTOR_MODE_DESIGN, "GIMP_VECTOR_MODE_DESIGN", "design" },
+    { GIMP_VECTOR_MODE_EDIT, "GIMP_VECTOR_MODE_EDIT", "edit" },
+    { GIMP_VECTOR_MODE_MOVE, "GIMP_VECTOR_MODE_MOVE", "move" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_VECTOR_MODE_DESIGN, NC_("vector-mode", "Design"), NULL },
+    { GIMP_VECTOR_MODE_EDIT, NC_("vector-mode", "Edit"), NULL },
+    { GIMP_VECTOR_MODE_MOVE, NC_("vector-mode", "Move"), NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpVectorMode", values);
+      gimp_type_set_translation_context (type, "vector-mode");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+GType
+gimp_zoom_focus_get_type (void)
+{
+  static const GEnumValue values[] =
+  {
+    { GIMP_ZOOM_FOCUS_BEST_GUESS, "GIMP_ZOOM_FOCUS_BEST_GUESS", "best-guess" },
+    { GIMP_ZOOM_FOCUS_POINTER, "GIMP_ZOOM_FOCUS_POINTER", "pointer" },
+    { GIMP_ZOOM_FOCUS_IMAGE_CENTER, "GIMP_ZOOM_FOCUS_IMAGE_CENTER", "image-center" },
+    { GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS, "GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS", "retain-centering-else-best-guess" },
+    { 0, NULL, NULL }
+  };
+
+  static const GimpEnumDesc descs[] =
+  {
+    { GIMP_ZOOM_FOCUS_BEST_GUESS, "GIMP_ZOOM_FOCUS_BEST_GUESS", NULL },
+    { GIMP_ZOOM_FOCUS_POINTER, "GIMP_ZOOM_FOCUS_POINTER", NULL },
+    { GIMP_ZOOM_FOCUS_IMAGE_CENTER, "GIMP_ZOOM_FOCUS_IMAGE_CENTER", NULL },
+    { GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS, "GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS", NULL },
+    { 0, NULL, NULL }
+  };
+
+  static GType type = 0;
+
+  if (G_UNLIKELY (! type))
+    {
+      type = g_enum_register_static ("GimpZoomFocus", values);
+      gimp_type_set_translation_context (type, "zoom-focus");
+      gimp_enum_set_value_descriptions (type, descs);
+    }
+
+  return type;
+}
+
+
+/* Generated data ends here */
+
diff --git a/app/display/display-enums.h b/app/display/display-enums.h
new file mode 100644
index 0000000..4cc84a8
--- /dev/null
+++ b/app/display/display-enums.h
@@ -0,0 +1,275 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __DISPLAY_ENUMS_H__
+#define __DISPLAY_ENUMS_H__
+
+
+#define GIMP_TYPE_BUTTON_PRESS_TYPE (gimp_button_press_type_get_type ())
+
+GType gimp_button_press_type_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_BUTTON_PRESS_NORMAL,
+  GIMP_BUTTON_PRESS_DOUBLE,
+  GIMP_BUTTON_PRESS_TRIPLE
+} GimpButtonPressType;
+
+
+#define GIMP_TYPE_BUTTON_RELEASE_TYPE (gimp_button_release_type_get_type ())
+
+GType gimp_button_release_type_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_BUTTON_RELEASE_NORMAL,
+  GIMP_BUTTON_RELEASE_CANCEL,
+  GIMP_BUTTON_RELEASE_CLICK,
+  GIMP_BUTTON_RELEASE_NO_MOTION
+} GimpButtonReleaseType;
+
+
+#define GIMP_TYPE_COMPASS_ORIENTATION (gimp_compass_orientation_get_type ())
+
+GType gimp_compass_orientation_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_COMPASS_ORIENTATION_AUTO,       /*< desc="Auto"       >*/
+  GIMP_COMPASS_ORIENTATION_HORIZONTAL, /*< desc="Horizontal" >*/
+  GIMP_COMPASS_ORIENTATION_VERTICAL    /*< desc="Vertical"   >*/
+} GimpCompassOrientation;
+
+
+#define GIMP_TYPE_CURSOR_PRECISION (gimp_cursor_precision_get_type ())
+
+GType gimp_cursor_precision_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_CURSOR_PRECISION_PIXEL_CENTER,
+  GIMP_CURSOR_PRECISION_PIXEL_BORDER,
+  GIMP_CURSOR_PRECISION_SUBPIXEL
+} GimpCursorPrecision;
+
+
+#define GIMP_TYPE_GUIDES_TYPE (gimp_guides_type_get_type ())
+
+GType gimp_guides_type_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_GUIDES_NONE,          /*< desc="No guides"       >*/
+  GIMP_GUIDES_CENTER_LINES,  /*< desc="Center lines"    >*/
+  GIMP_GUIDES_THIRDS,        /*< desc="Rule of thirds"  >*/
+  GIMP_GUIDES_FIFTHS,        /*< desc="Rule of fifths"  >*/
+  GIMP_GUIDES_GOLDEN,        /*< desc="Golden sections" >*/
+  GIMP_GUIDES_DIAGONALS,     /*< desc="Diagonal lines"  >*/
+  GIMP_GUIDES_N_LINES,       /*< desc="Number of lines" >*/
+  GIMP_GUIDES_SPACING        /*< desc="Line spacing"    >*/
+} GimpGuidesType;
+
+
+#define GIMP_TYPE_HANDLE_TYPE (gimp_handle_type_get_type ())
+
+GType gimp_handle_type_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_HANDLE_SQUARE,
+  GIMP_HANDLE_DASHED_SQUARE,
+  GIMP_HANDLE_FILLED_SQUARE,
+  GIMP_HANDLE_CIRCLE,
+  GIMP_HANDLE_DASHED_CIRCLE,
+  GIMP_HANDLE_FILLED_CIRCLE,
+  GIMP_HANDLE_DIAMOND,
+  GIMP_HANDLE_DASHED_DIAMOND,
+  GIMP_HANDLE_FILLED_DIAMOND,
+  GIMP_HANDLE_CROSS,
+  GIMP_HANDLE_CROSSHAIR
+} GimpHandleType;
+
+
+#define GIMP_TYPE_HANDLE_ANCHOR (gimp_handle_anchor_get_type ())
+
+GType gimp_handle_anchor_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_HANDLE_ANCHOR_CENTER,
+  GIMP_HANDLE_ANCHOR_NORTH,
+  GIMP_HANDLE_ANCHOR_NORTH_WEST,
+  GIMP_HANDLE_ANCHOR_NORTH_EAST,
+  GIMP_HANDLE_ANCHOR_SOUTH,
+  GIMP_HANDLE_ANCHOR_SOUTH_WEST,
+  GIMP_HANDLE_ANCHOR_SOUTH_EAST,
+  GIMP_HANDLE_ANCHOR_WEST,
+  GIMP_HANDLE_ANCHOR_EAST
+} GimpHandleAnchor;
+
+
+#define GIMP_TYPE_LIMIT_TYPE (gimp_limit_type_get_type ())
+
+GType gimp_limit_type_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_LIMIT_CIRCLE,
+  GIMP_LIMIT_SQUARE,
+  GIMP_LIMIT_DIAMOND,
+  GIMP_LIMIT_HORIZONTAL,
+  GIMP_LIMIT_VERTICAL
+} GimpLimitType;
+
+
+#define GIMP_TYPE_PATH_STYLE (gimp_path_style_get_type ())
+
+GType gimp_path_style_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_PATH_STYLE_DEFAULT,
+  GIMP_PATH_STYLE_VECTORS,
+  GIMP_PATH_STYLE_OUTLINE
+} GimpPathStyle;
+
+
+#define GIMP_TYPE_RECTANGLE_CONSTRAINT (gimp_rectangle_constraint_get_type ())
+
+GType gimp_rectangle_constraint_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_RECTANGLE_CONSTRAIN_NONE,
+  GIMP_RECTANGLE_CONSTRAIN_IMAGE,
+  GIMP_RECTANGLE_CONSTRAIN_DRAWABLE
+} GimpRectangleConstraint;
+
+
+#define GIMP_TYPE_RECTANGLE_FIXED_RULE (gimp_rectangle_fixed_rule_get_type ())
+
+GType gimp_rectangle_fixed_rule_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_RECTANGLE_FIXED_ASPECT, /*< desc="Aspect ratio" >*/
+  GIMP_RECTANGLE_FIXED_WIDTH,  /*< desc="Width"        >*/
+  GIMP_RECTANGLE_FIXED_HEIGHT, /*< desc="Height"       >*/
+  GIMP_RECTANGLE_FIXED_SIZE,   /*< desc="Size"         >*/
+} GimpRectangleFixedRule;
+
+
+#define GIMP_TYPE_RECTANGLE_PRECISION (gimp_rectangle_precision_get_type ())
+
+GType gimp_rectangle_precision_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_RECTANGLE_PRECISION_INT,
+  GIMP_RECTANGLE_PRECISION_DOUBLE,
+} GimpRectanglePrecision;
+
+
+#define GIMP_TYPE_TRANSFORM_3D_MODE (gimp_transform_3d_mode_get_type ())
+
+GType gimp_transform_3d_mode_get_type (void) G_GNUC_CONST;
+
+typedef enum /*< lowercase_name=gimp_transform_3d_mode >*/
+{
+  GIMP_TRANSFORM_3D_MODE_CAMERA,
+  GIMP_TRANSFORM_3D_MODE_MOVE,
+  GIMP_TRANSFORM_3D_MODE_ROTATE
+} GimpTransform3DMode;
+
+
+#define GIMP_TYPE_TRANSFORM_FUNCTION (gimp_transform_function_get_type ())
+
+GType gimp_transform_function_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_TRANSFORM_FUNCTION_NONE,
+  GIMP_TRANSFORM_FUNCTION_MOVE,
+  GIMP_TRANSFORM_FUNCTION_SCALE,
+  GIMP_TRANSFORM_FUNCTION_ROTATE,
+  GIMP_TRANSFORM_FUNCTION_SHEAR,
+  GIMP_TRANSFORM_FUNCTION_PERSPECTIVE
+} GimpTransformFunction;
+
+
+#define GIMP_TYPE_TRANSFORM_HANDLE_MODE (gimp_transform_handle_mode_get_type ())
+
+GType gimp_transform_handle_mode_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_HANDLE_MODE_ADD_TRANSFORM, /*< desc="Add / Transform" >*/
+  GIMP_HANDLE_MODE_MOVE,          /*< desc="Move"            >*/
+  GIMP_HANDLE_MODE_REMOVE         /*< desc="Remove"          >*/
+} GimpTransformHandleMode;
+
+
+#define GIMP_TYPE_VECTOR_MODE (gimp_vector_mode_get_type ())
+
+GType gimp_vector_mode_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  GIMP_VECTOR_MODE_DESIGN,      /*< desc="Design" >*/
+  GIMP_VECTOR_MODE_EDIT,        /*< desc="Edit"   >*/
+  GIMP_VECTOR_MODE_MOVE         /*< desc="Move"   >*/
+} GimpVectorMode;
+
+
+#define GIMP_TYPE_ZOOM_FOCUS (gimp_zoom_focus_get_type ())
+
+GType gimp_zoom_focus_get_type (void) G_GNUC_CONST;
+
+typedef enum
+{
+  /* Make a best guess */
+  GIMP_ZOOM_FOCUS_BEST_GUESS,
+
+  /* Use the mouse cursor (if within canvas) */
+  GIMP_ZOOM_FOCUS_POINTER,
+
+  /* Use the image center */
+  GIMP_ZOOM_FOCUS_IMAGE_CENTER,
+
+  /* If the image is centered, retain the centering. Else use
+   * _BEST_GUESS
+   */
+  GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS
+
+} GimpZoomFocus;
+
+
+/*
+ * non-registered enums; register them if needed
+ */
+
+
+typedef enum  /*< pdb-skip, skip >*/
+{
+  GIMP_HIT_NONE,
+  GIMP_HIT_INDIRECT,
+  GIMP_HIT_DIRECT
+} GimpHit;
+
+
+#endif /* __DISPLAY_ENUMS_H__ */
diff --git a/app/display/display-types.h b/app/display/display-types.h
new file mode 100644
index 0000000..6de751d
--- /dev/null
+++ b/app/display/display-types.h
@@ -0,0 +1,53 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __DISPLAY_TYPES_H__
+#define __DISPLAY_TYPES_H__
+
+
+#include "propgui/propgui-types.h"
+
+#include "display/display-enums.h"
+
+
+typedef struct _GimpCanvas               GimpCanvas;
+typedef struct _GimpCanvasGroup          GimpCanvasGroup;
+typedef struct _GimpCanvasItem           GimpCanvasItem;
+
+typedef struct _GimpDisplay              GimpDisplay;
+typedef struct _GimpDisplayShell         GimpDisplayShell;
+typedef struct _GimpMotionBuffer         GimpMotionBuffer;
+
+typedef struct _GimpImageWindow          GimpImageWindow;
+typedef struct _GimpMultiWindowStrategy  GimpMultiWindowStrategy;
+typedef struct _GimpSingleWindowStrategy GimpSingleWindowStrategy;
+
+typedef struct _GimpCursorView           GimpCursorView;
+typedef struct _GimpNavigationEditor     GimpNavigationEditor;
+typedef struct _GimpScaleComboBox        GimpScaleComboBox;
+typedef struct _GimpStatusbar            GimpStatusbar;
+
+typedef struct _GimpToolDialog           GimpToolDialog;
+typedef struct _GimpToolGui              GimpToolGui;
+typedef struct _GimpToolWidget           GimpToolWidget;
+typedef struct _GimpToolWidgetGroup      GimpToolWidgetGroup;
+
+typedef struct _GimpDisplayXfer          GimpDisplayXfer;
+typedef struct _Selection                Selection;
+
+
+#endif /* __DISPLAY_TYPES_H__ */
diff --git a/app/display/gimpcanvas-style.c b/app/display/gimpcanvas-style.c
new file mode 100644
index 0000000..8d47961
--- /dev/null
+++ b/app/display/gimpcanvas-style.c
@@ -0,0 +1,458 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvas-style.c
+ * Copyright (C) 2010  Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimp-cairo.h"
+#include "core/gimpgrid.h"
+#include "core/gimplayer.h"
+
+#include "gimpcanvas-style.h"
+
+/* Styles for common and custom guides. */
+static const GimpRGB guide_normal_fg         = { 0.0, 0.0, 0.0, 1.0 };
+static const GimpRGB guide_normal_bg         = { 0.0, 0.8, 1.0, 1.0 };
+static const GimpRGB guide_active_fg         = { 0.0, 0.0, 0.0, 1.0 };
+static const GimpRGB guide_active_bg         = { 1.0, 0.0, 0.0, 1.0 };
+
+static const GimpRGB guide_mirror_normal_fg  = { 1.0, 1.0, 1.0, 1.0 };
+static const GimpRGB guide_mirror_normal_bg  = { 0.0, 1.0, 0.0, 1.0 };
+static const GimpRGB guide_mirror_active_fg  = { 0.0, 1.0, 0.0, 1.0 };
+static const GimpRGB guide_mirror_active_bg  = { 1.0, 0.0, 0.0, 1.0 };
+
+static const GimpRGB guide_mandala_normal_fg = { 1.0, 1.0, 1.0, 1.0 };
+static const GimpRGB guide_mandala_normal_bg = { 0.0, 1.0, 1.0, 1.0 };
+static const GimpRGB guide_mandala_active_fg = { 0.0, 1.0, 1.0, 1.0 };
+static const GimpRGB guide_mandala_active_bg = { 1.0, 0.0, 0.0, 1.0 };
+
+static const GimpRGB guide_split_normal_fg   = { 1.0, 1.0, 1.0, 1.0 };
+static const GimpRGB guide_split_normal_bg   = { 1.0, 0.0, 1.0, 1.0 };
+static const GimpRGB guide_split_active_fg   = { 1.0, 0.0, 1.0, 1.0 };
+static const GimpRGB guide_split_active_bg   = { 1.0, 0.0, 0.0, 1.0 };
+
+/* Styles for other canvas items. */
+static const GimpRGB sample_point_normal = { 0.0, 0.8, 1.0, 1.0 };
+static const GimpRGB sample_point_active = { 1.0, 0.0, 0.0, 1.0 };
+
+static const GimpRGB layer_fg            = { 0.0, 0.0, 0.0, 1.0 };
+static const GimpRGB layer_bg            = { 1.0, 1.0, 0.0, 1.0 };
+
+static const GimpRGB layer_group_fg      = { 0.0, 0.0, 0.0, 1.0 };
+static const GimpRGB layer_group_bg      = { 0.0, 1.0, 1.0, 1.0 };
+
+static const GimpRGB layer_mask_fg       = { 0.0, 0.0, 0.0, 1.0 };
+static const GimpRGB layer_mask_bg       = { 0.0, 1.0, 0.0, 1.0 };
+
+static const GimpRGB canvas_fg           = { 0.0, 0.0, 0.0, 1.0 };
+static const GimpRGB canvas_bg           = { 1.0, 0.5, 0.0, 1.0 };
+
+static const GimpRGB selection_out_fg    = { 1.0, 1.0, 1.0, 1.0 };
+static const GimpRGB selection_out_bg    = { 0.5, 0.5, 0.5, 1.0 };
+
+static const GimpRGB selection_in_fg     = { 0.0, 0.0, 0.0, 1.0 };
+static const GimpRGB selection_in_bg     = { 1.0, 1.0, 1.0, 1.0 };
+
+static const GimpRGB vectors_normal_bg   = { 1.0, 1.0, 1.0, 0.6 };
+static const GimpRGB vectors_normal_fg   = { 0.0, 0.0, 1.0, 0.8 };
+
+static const GimpRGB vectors_active_bg   = { 1.0, 1.0, 1.0, 0.6 };
+static const GimpRGB vectors_active_fg   = { 1.0, 0.0, 0.0, 0.8 };
+
+static const GimpRGB outline_bg          = { 1.0, 1.0, 1.0, 0.6 };
+static const GimpRGB outline_fg          = { 0.0, 0.0, 0.0, 0.8 };
+
+static const GimpRGB passe_partout       = { 0.0, 0.0, 0.0, 1.0 };
+
+static const GimpRGB tool_bg             = { 0.0, 0.0, 0.0, 0.4 };
+static const GimpRGB tool_fg             = { 1.0, 1.0, 1.0, 0.8 };
+static const GimpRGB tool_fg_highlight   = { 1.0, 0.8, 0.2, 0.8 };
+
+
+/*  public functions  */
+
+void
+gimp_canvas_set_guide_style (GtkWidget      *canvas,
+                             cairo_t        *cr,
+                             GimpGuideStyle  style,
+                             gboolean        active,
+                             gdouble         offset_x,
+                             gdouble         offset_y)
+{
+  cairo_pattern_t *pattern;
+  GimpRGB          normal_fg;
+  GimpRGB          normal_bg;
+  GimpRGB          active_fg;
+  GimpRGB          active_bg;
+  gdouble          line_width;
+
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  switch (style)
+    {
+    case GIMP_GUIDE_STYLE_NORMAL:
+      normal_fg  = guide_normal_fg;
+      normal_bg  = guide_normal_bg;
+      active_fg  = guide_active_fg;
+      active_bg  = guide_active_bg;
+      line_width = 1.0;
+      break;
+
+    case GIMP_GUIDE_STYLE_MIRROR:
+      normal_fg  = guide_mirror_normal_fg;
+      normal_bg  = guide_mirror_normal_bg;
+      active_fg  = guide_mirror_active_fg;
+      active_bg  = guide_mirror_active_bg;
+      line_width = 1.0;
+      break;
+
+    case GIMP_GUIDE_STYLE_MANDALA:
+      normal_fg  = guide_mandala_normal_fg;
+      normal_bg  = guide_mandala_normal_bg;
+      active_fg  = guide_mandala_active_fg;
+      active_bg  = guide_mandala_active_bg;
+      line_width = 1.0;
+      break;
+
+    case GIMP_GUIDE_STYLE_SPLIT_VIEW:
+      normal_fg  = guide_split_normal_fg;
+      normal_bg  = guide_split_normal_bg;
+      active_fg  = guide_split_active_fg;
+      active_bg  = guide_split_active_bg;
+      line_width = 1.0;
+      break;
+
+    default: /* GIMP_GUIDE_STYLE_NONE */
+      /* This should not happen. */
+      g_return_if_reached ();
+    }
+
+  cairo_set_line_width (cr, line_width);
+
+  if (active)
+    pattern = gimp_cairo_pattern_create_stipple (&active_fg, &active_bg, 0,
+                                                 offset_x, offset_y);
+  else
+    pattern = gimp_cairo_pattern_create_stipple (&normal_fg, &normal_bg, 0,
+                                                 offset_x, offset_y);
+
+  cairo_set_source (cr, pattern);
+  cairo_pattern_destroy (pattern);
+}
+
+void
+gimp_canvas_set_sample_point_style (GtkWidget *canvas,
+                                    cairo_t   *cr,
+                                    gboolean   active)
+{
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+
+  if (active)
+    gimp_cairo_set_source_rgb (cr, &sample_point_active);
+  else
+    gimp_cairo_set_source_rgb (cr, &sample_point_normal);
+}
+
+void
+gimp_canvas_set_grid_style (GtkWidget *canvas,
+                            cairo_t   *cr,
+                            GimpGrid  *grid,
+                            gdouble    offset_x,
+                            gdouble    offset_y)
+{
+  GimpRGB fg;
+  GimpRGB bg;
+
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (GIMP_IS_GRID (grid));
+
+  cairo_set_line_width (cr, 1.0);
+
+  gimp_grid_get_fgcolor (grid, &fg);
+
+  switch (gimp_grid_get_style (grid))
+    {
+      cairo_pattern_t *pattern;
+
+    case GIMP_GRID_ON_OFF_DASH:
+    case GIMP_GRID_DOUBLE_DASH:
+      if (grid->style == GIMP_GRID_DOUBLE_DASH)
+        {
+          gimp_grid_get_bgcolor (grid, &bg);
+
+          pattern = gimp_cairo_pattern_create_stipple (&fg, &bg, 0,
+                                                       offset_x, offset_y);
+        }
+      else
+        {
+          gimp_rgba_set (&bg, 0.0, 0.0, 0.0, 0.0);
+
+          pattern = gimp_cairo_pattern_create_stipple (&fg, &bg, 0,
+                                                       offset_x, offset_y);
+        }
+
+      cairo_set_source (cr, pattern);
+      cairo_pattern_destroy (pattern);
+      break;
+
+    case GIMP_GRID_DOTS:
+    case GIMP_GRID_INTERSECTIONS:
+    case GIMP_GRID_SOLID:
+      gimp_cairo_set_source_rgb (cr, &fg);
+      break;
+    }
+}
+
+void
+gimp_canvas_set_pen_style (GtkWidget     *canvas,
+                           cairo_t       *cr,
+                           const GimpRGB *color,
+                           gint           width)
+{
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (color != NULL);
+
+  cairo_set_antialias (cr, CAIRO_ANTIALIAS_NONE);
+  cairo_set_line_width (cr, width);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+  cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+
+  gimp_cairo_set_source_rgb (cr, color);
+}
+
+void
+gimp_canvas_set_layer_style (GtkWidget *canvas,
+                             cairo_t   *cr,
+                             GimpLayer *layer,
+                             gdouble    offset_x,
+                             gdouble    offset_y)
+{
+  cairo_pattern_t *pattern;
+
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (GIMP_IS_LAYER (layer));
+
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
+
+  if (gimp_layer_get_mask (layer) &&
+      gimp_layer_get_edit_mask (layer))
+    {
+      pattern = gimp_cairo_pattern_create_stipple (&layer_mask_fg,
+                                                   &layer_mask_bg,
+                                                   0,
+                                                   offset_x, offset_y);
+    }
+  else if (gimp_viewable_get_children (GIMP_VIEWABLE (layer)))
+    {
+      pattern = gimp_cairo_pattern_create_stipple (&layer_group_fg,
+                                                   &layer_group_bg,
+                                                   0,
+                                                   offset_x, offset_y);
+    }
+  else
+    {
+      pattern = gimp_cairo_pattern_create_stipple (&layer_fg,
+                                                   &layer_bg,
+                                                   0,
+                                                   offset_x, offset_y);
+    }
+
+  cairo_set_source (cr, pattern);
+  cairo_pattern_destroy (pattern);
+}
+
+void
+gimp_canvas_set_canvas_style (GtkWidget *canvas,
+                              cairo_t   *cr,
+                              gdouble    offset_x,
+                              gdouble    offset_y)
+{
+  cairo_pattern_t *pattern;
+
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
+
+  pattern = gimp_cairo_pattern_create_stipple (&canvas_fg,
+                                               &canvas_bg,
+                                               0,
+                                               offset_x, offset_y);
+
+  cairo_set_source (cr, pattern);
+  cairo_pattern_destroy (pattern);
+}
+
+void
+gimp_canvas_set_selection_out_style (GtkWidget *canvas,
+                                     cairo_t   *cr,
+                                     gdouble    offset_x,
+                                     gdouble    offset_y)
+{
+  cairo_pattern_t *pattern;
+
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
+
+  pattern = gimp_cairo_pattern_create_stipple (&selection_out_fg,
+                                               &selection_out_bg,
+                                               0,
+                                               offset_x, offset_y);
+  cairo_set_source (cr, pattern);
+  cairo_pattern_destroy (pattern);
+}
+
+void
+gimp_canvas_set_selection_in_style (GtkWidget *canvas,
+                                    cairo_t   *cr,
+                                    gint       index,
+                                    gdouble    offset_x,
+                                    gdouble    offset_y)
+{
+  cairo_pattern_t *pattern;
+
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
+
+  pattern = gimp_cairo_pattern_create_stipple (&selection_in_fg,
+                                               &selection_in_bg,
+                                               index,
+                                               offset_x, offset_y);
+  cairo_set_source (cr, pattern);
+  cairo_pattern_destroy (pattern);
+}
+
+void
+gimp_canvas_set_vectors_bg_style (GtkWidget *canvas,
+                                  cairo_t   *cr,
+                                  gboolean   active)
+{
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 3.0);
+
+  if (active)
+    gimp_cairo_set_source_rgba (cr, &vectors_active_bg);
+  else
+    gimp_cairo_set_source_rgba (cr, &vectors_normal_bg);
+}
+
+void
+gimp_canvas_set_vectors_fg_style (GtkWidget *canvas,
+                                  cairo_t   *cr,
+                                  gboolean   active)
+{
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+
+  if (active)
+    gimp_cairo_set_source_rgba (cr, &vectors_active_fg);
+  else
+    gimp_cairo_set_source_rgba (cr, &vectors_normal_fg);
+}
+
+void
+gimp_canvas_set_outline_bg_style (GtkWidget *canvas,
+                                  cairo_t   *cr)
+{
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+  gimp_cairo_set_source_rgba (cr, &outline_bg);
+}
+
+void
+gimp_canvas_set_outline_fg_style (GtkWidget *canvas,
+                                  cairo_t   *cr)
+{
+  static const double dashes[] = { 4.0, 4.0 };
+
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+  gimp_cairo_set_source_rgba (cr, &outline_fg);
+  cairo_set_dash (cr, dashes, G_N_ELEMENTS (dashes), 0);
+}
+
+void
+gimp_canvas_set_passe_partout_style (GtkWidget *canvas,
+                                     cairo_t   *cr)
+{
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  gimp_cairo_set_source_rgba (cr, &passe_partout);
+}
+
+void
+gimp_canvas_set_tool_bg_style (GtkWidget *canvas,
+                               cairo_t   *cr)
+{
+  g_return_if_fail (GTK_IS_WIDGET (canvas));
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 3.0);
+  cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+
+  gimp_cairo_set_source_rgba (cr, &tool_bg);
+}
+
+void
+gimp_canvas_set_tool_fg_style (GtkWidget *canvas,
+                               cairo_t   *cr,
+                               gboolean   highlight)
+{
+  g_return_if_fail (cr != NULL);
+
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+
+  if (highlight)
+    gimp_cairo_set_source_rgba (cr, &tool_fg_highlight);
+  else
+    gimp_cairo_set_source_rgba (cr, &tool_fg);
+}
diff --git a/app/display/gimpcanvas-style.h b/app/display/gimpcanvas-style.h
new file mode 100644
index 0000000..3a37b98
--- /dev/null
+++ b/app/display/gimpcanvas-style.h
@@ -0,0 +1,81 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpdisplayshell-style.h
+ * Copyright (C) 2010  Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_STYLE_H__
+#define __GIMP_CANVAS_STYLE_H__
+
+
+void   gimp_canvas_set_guide_style         (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            GimpGuideStyle style,
+                                            gboolean       active,
+                                            gdouble        offset_x,
+                                            gdouble        offset_y);
+void   gimp_canvas_set_sample_point_style  (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            gboolean       active);
+void   gimp_canvas_set_grid_style          (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            GimpGrid      *grid,
+                                            gdouble        offset_x,
+                                            gdouble        offset_y);
+void   gimp_canvas_set_pen_style           (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            const GimpRGB *color,
+                                            gint           width);
+void   gimp_canvas_set_layer_style         (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            GimpLayer     *layer,
+                                            gdouble        offset_x,
+                                            gdouble        offset_y);
+void   gimp_canvas_set_canvas_style        (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            gdouble        offset_x,
+                                            gdouble        offset_y);
+void   gimp_canvas_set_selection_out_style (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            gdouble        offset_x,
+                                            gdouble        offset_y);
+void   gimp_canvas_set_selection_in_style  (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            gint           index,
+                                            gdouble        offset_x,
+                                            gdouble        offset_y);
+void   gimp_canvas_set_vectors_bg_style    (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            gboolean       active);
+void   gimp_canvas_set_vectors_fg_style    (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            gboolean       active);
+void   gimp_canvas_set_outline_bg_style    (GtkWidget     *canvas,
+                                            cairo_t       *cr);
+void   gimp_canvas_set_outline_fg_style    (GtkWidget     *canvas,
+                                            cairo_t       *cr);
+void   gimp_canvas_set_passe_partout_style (GtkWidget     *canvas,
+                                            cairo_t       *cr);
+
+void   gimp_canvas_set_tool_bg_style       (GtkWidget     *canvas,
+                                            cairo_t       *cr);
+void   gimp_canvas_set_tool_fg_style       (GtkWidget     *canvas,
+                                            cairo_t       *cr,
+                                            gboolean       highlight);
+
+
+#endif /* __GIMP_CANVAS_STYLE_H__ */
diff --git a/app/display/gimpcanvas.c b/app/display/gimpcanvas.c
new file mode 100644
index 0000000..46b9ff5
--- /dev/null
+++ b/app/display/gimpcanvas.c
@@ -0,0 +1,298 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvas.h"
+
+#include "gimp-intl.h"
+
+
+#define MAX_BATCH_SIZE 32000
+
+
+enum
+{
+  PROP_0,
+  PROP_CONFIG
+};
+
+
+/*  local function prototypes  */
+
+static void       gimp_canvas_set_property    (GObject         *object,
+                                               guint            property_id,
+                                               const GValue    *value,
+                                               GParamSpec      *pspec);
+static void       gimp_canvas_get_property    (GObject         *object,
+                                               guint            property_id,
+                                               GValue          *value,
+                                               GParamSpec      *pspec);
+
+static void       gimp_canvas_unrealize       (GtkWidget       *widget);
+static void       gimp_canvas_style_set       (GtkWidget       *widget,
+                                               GtkStyle        *prev_style);
+static gboolean   gimp_canvas_focus_in_event  (GtkWidget       *widget,
+                                               GdkEventFocus   *event);
+static gboolean   gimp_canvas_focus_out_event (GtkWidget       *widget,
+                                               GdkEventFocus   *event);
+static gboolean   gimp_canvas_focus           (GtkWidget       *widget,
+                                               GtkDirectionType direction);
+
+
+G_DEFINE_TYPE (GimpCanvas, gimp_canvas, GIMP_TYPE_OVERLAY_BOX)
+
+#define parent_class gimp_canvas_parent_class
+
+
+static void
+gimp_canvas_class_init (GimpCanvasClass *klass)
+{
+  GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  object_class->set_property    = gimp_canvas_set_property;
+  object_class->get_property    = gimp_canvas_get_property;
+
+  widget_class->unrealize       = gimp_canvas_unrealize;
+  widget_class->style_set       = gimp_canvas_style_set;
+  widget_class->focus_in_event  = gimp_canvas_focus_in_event;
+  widget_class->focus_out_event = gimp_canvas_focus_out_event;
+  widget_class->focus           = gimp_canvas_focus;
+
+  g_object_class_install_property (object_class, PROP_CONFIG,
+                                   g_param_spec_object ("config", NULL, NULL,
+                                                        GIMP_TYPE_DISPLAY_CONFIG,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+}
+
+static void
+gimp_canvas_init (GimpCanvas *canvas)
+{
+  GtkWidget *widget = GTK_WIDGET (canvas);
+
+  gtk_widget_set_can_focus (widget, TRUE);
+  gtk_widget_add_events (widget, GIMP_CANVAS_EVENT_MASK);
+  gtk_widget_set_extension_events (widget, GDK_EXTENSION_EVENTS_ALL);
+}
+
+static void
+gimp_canvas_set_property (GObject      *object,
+                          guint         property_id,
+                          const GValue *value,
+                          GParamSpec   *pspec)
+{
+  GimpCanvas *canvas = GIMP_CANVAS (object);
+
+  switch (property_id)
+    {
+    case PROP_CONFIG:
+      canvas->config = g_value_get_object (value); /* don't dup */
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_get_property (GObject    *object,
+                          guint       property_id,
+                          GValue     *value,
+                          GParamSpec *pspec)
+{
+  GimpCanvas *canvas = GIMP_CANVAS (object);
+
+  switch (property_id)
+    {
+    case PROP_CONFIG:
+      g_value_set_object (value, canvas->config);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_unrealize (GtkWidget *widget)
+{
+  GimpCanvas *canvas = GIMP_CANVAS (widget);
+
+  g_clear_object (&canvas->layout);
+
+  GTK_WIDGET_CLASS (parent_class)->unrealize (widget);
+}
+
+static void
+gimp_canvas_style_set (GtkWidget *widget,
+                       GtkStyle  *prev_style)
+{
+  GimpCanvas *canvas = GIMP_CANVAS (widget);
+
+  GTK_WIDGET_CLASS (parent_class)->style_set (widget, prev_style);
+
+  g_clear_object (&canvas->layout);
+}
+
+static gboolean
+gimp_canvas_focus_in_event (GtkWidget     *widget,
+                            GdkEventFocus *event)
+{
+  /*  don't allow the default impl to invalidate the whole widget,
+   *  we don't draw a focus indicator anyway.
+   */
+  return FALSE;
+}
+
+static gboolean
+gimp_canvas_focus_out_event (GtkWidget     *widget,
+                             GdkEventFocus *event)
+{
+  /*  see focus-in-event
+   */
+  return FALSE;
+}
+
+static gboolean
+gimp_canvas_focus (GtkWidget        *widget,
+                   GtkDirectionType  direction)
+{
+  GtkWidget *focus = gtk_container_get_focus_child (GTK_CONTAINER (widget));
+
+  /* override GtkContainer's focus() implementation which would always
+   * give focus to the canvas because it is focussable. Instead, try
+   * navigating in the focused overlay child first, and use
+   * GtkContainer's default implementation only if that fails (which
+   * happens when focus navigation leaves the overlay child).
+   */
+
+  if (focus && gtk_widget_child_focus (focus, direction))
+    return TRUE;
+
+  return GTK_WIDGET_CLASS (parent_class)->focus (widget, direction);
+}
+
+
+/*  public functions  */
+
+/**
+ * gimp_canvas_new:
+ *
+ * Creates a new #GimpCanvas widget.
+ *
+ * The #GimpCanvas widget is a #GtkDrawingArea abstraction. It manages
+ * a set of graphic contexts for drawing on a GIMP display. If you
+ * draw using a #GimpCanvasStyle, #GimpCanvas makes sure that the
+ * associated #GdkGC is created. All drawing on the canvas needs to
+ * happen by means of the #GimpCanvas drawing functions. Besides from
+ * not needing a #GdkGC pointer, the #GimpCanvas drawing functions
+ * look and work like their #GdkDrawable counterparts. #GimpCanvas
+ * gracefully handles attempts to draw on the unrealized widget.
+ *
+ * Return value: a new #GimpCanvas widget
+ **/
+GtkWidget *
+gimp_canvas_new (GimpDisplayConfig *config)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_CONFIG (config), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS,
+                       "name",   "gimp-canvas",
+                       "config", config,
+                       NULL);
+}
+
+/**
+ * gimp_canvas_get_layout:
+ * @canvas:  a #GimpCanvas widget
+ * @format:  a standard printf() format string.
+ * @Varargs: the parameters to insert into the format string.
+ *
+ * Returns a layout which can be used for
+ * pango_cairo_show_layout(). The layout belongs to the canvas and
+ * should not be freed, not should a pointer to it be kept around
+ * after drawing.
+ *
+ * Returns: a #PangoLayout owned by the canvas.
+ **/
+PangoLayout *
+gimp_canvas_get_layout (GimpCanvas  *canvas,
+                        const gchar *format,
+                        ...)
+{
+  va_list  args;
+  gchar   *text;
+
+  if (! canvas->layout)
+    canvas->layout = gtk_widget_create_pango_layout (GTK_WIDGET (canvas),
+                                                     NULL);
+
+  va_start (args, format);
+  text = g_strdup_vprintf (format, args);
+  va_end (args);
+
+  pango_layout_set_text (canvas->layout, text, -1);
+  g_free (text);
+
+  return canvas->layout;
+}
+
+/**
+ * gimp_canvas_set_bg_color:
+ * @canvas:   a #GimpCanvas widget
+ * @color:    a color in #GimpRGB format
+ *
+ * Sets the background color of the canvas's window.  This
+ * is the color the canvas is set to if it is cleared.
+ **/
+void
+gimp_canvas_set_bg_color (GimpCanvas *canvas,
+                          GimpRGB    *color)
+{
+  GtkWidget   *widget = GTK_WIDGET (canvas);
+  GdkColormap *colormap;
+  GdkColor     gdk_color;
+
+  if (! gtk_widget_get_realized (widget))
+    return;
+
+  gimp_rgb_get_gdk_color (color, &gdk_color);
+
+  colormap = gdk_drawable_get_colormap (gtk_widget_get_window (widget));
+  g_return_if_fail (colormap != NULL);
+  gdk_colormap_alloc_color (colormap, &gdk_color, FALSE, TRUE);
+
+  gdk_window_set_background (gtk_widget_get_window (widget), &gdk_color);
+
+  gtk_widget_queue_draw (GTK_WIDGET (canvas));
+}
diff --git a/app/display/gimpcanvas.h b/app/display/gimpcanvas.h
new file mode 100644
index 0000000..dc52be8
--- /dev/null
+++ b/app/display/gimpcanvas.h
@@ -0,0 +1,74 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_H__
+#define __GIMP_CANVAS_H__
+
+
+#include "widgets/gimpoverlaybox.h"
+
+
+#define GIMP_CANVAS_EVENT_MASK (GDK_EXPOSURE_MASK            | \
+                                GDK_POINTER_MOTION_MASK      | \
+                                GDK_BUTTON_PRESS_MASK        | \
+                                GDK_BUTTON_RELEASE_MASK      | \
+                                GDK_STRUCTURE_MASK           | \
+                                GDK_ENTER_NOTIFY_MASK        | \
+                                GDK_LEAVE_NOTIFY_MASK        | \
+                                GDK_FOCUS_CHANGE_MASK        | \
+                                GDK_KEY_PRESS_MASK           | \
+                                GDK_KEY_RELEASE_MASK         | \
+                                GDK_PROXIMITY_OUT_MASK)
+
+
+#define GIMP_TYPE_CANVAS            (gimp_canvas_get_type ())
+#define GIMP_CANVAS(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS, GimpCanvas))
+#define GIMP_CANVAS_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS, GimpCanvasClass))
+#define GIMP_IS_CANVAS(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS))
+#define GIMP_IS_CANVAS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS))
+#define GIMP_CANVAS_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS, GimpCanvasClass))
+
+
+typedef struct _GimpCanvasClass GimpCanvasClass;
+
+struct _GimpCanvas
+{
+  GimpOverlayBox     parent_instance;
+
+  GimpDisplayConfig *config;
+  PangoLayout       *layout;
+};
+
+struct _GimpCanvasClass
+{
+  GimpOverlayBoxClass  parent_class;
+};
+
+
+GType         gimp_canvas_get_type     (void) G_GNUC_CONST;
+
+GtkWidget   * gimp_canvas_new          (GimpDisplayConfig *config);
+
+PangoLayout * gimp_canvas_get_layout   (GimpCanvas        *canvas,
+                                        const gchar       *format,
+                                        ...) G_GNUC_PRINTF (2, 3);
+
+void          gimp_canvas_set_bg_color (GimpCanvas        *canvas,
+                                        GimpRGB           *color);
+
+
+#endif /*  __GIMP_CANVAS_H__  */
diff --git a/app/display/gimpcanvasarc.c b/app/display/gimpcanvasarc.c
new file mode 100644
index 0000000..a4041b2
--- /dev/null
+++ b/app/display/gimpcanvasarc.c
@@ -0,0 +1,369 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasarc.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-cairo.h"
+
+#include "gimpcanvasarc.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_CENTER_X,
+  PROP_CENTER_Y,
+  PROP_RADIUS_X,
+  PROP_RADIUS_Y,
+  PROP_START_ANGLE,
+  PROP_SLICE_ANGLE,
+  PROP_FILLED
+};
+
+
+typedef struct _GimpCanvasArcPrivate GimpCanvasArcPrivate;
+
+struct _GimpCanvasArcPrivate
+{
+  gdouble  center_x;
+  gdouble  center_y;
+  gdouble  radius_x;
+  gdouble  radius_y;
+  gdouble  start_angle;
+  gdouble  slice_angle;
+  gboolean filled;
+};
+
+#define GET_PRIVATE(arc) \
+        ((GimpCanvasArcPrivate *) gimp_canvas_arc_get_instance_private ((GimpCanvasArc *) (arc)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_arc_set_property (GObject        *object,
+                                                      guint           property_id,
+                                                      const GValue   *value,
+                                                      GParamSpec     *pspec);
+static void             gimp_canvas_arc_get_property (GObject        *object,
+                                                      guint           property_id,
+                                                      GValue         *value,
+                                                      GParamSpec     *pspec);
+static void             gimp_canvas_arc_draw         (GimpCanvasItem *item,
+                                                      cairo_t        *cr);
+static cairo_region_t * gimp_canvas_arc_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasArc, gimp_canvas_arc,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_arc_parent_class
+
+
+static void
+gimp_canvas_arc_class_init (GimpCanvasArcClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_arc_set_property;
+  object_class->get_property = gimp_canvas_arc_get_property;
+
+  item_class->draw           = gimp_canvas_arc_draw;
+  item_class->get_extents    = gimp_canvas_arc_get_extents;
+
+  g_object_class_install_property (object_class, PROP_CENTER_X,
+                                   g_param_spec_double ("center-x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_CENTER_Y,
+                                   g_param_spec_double ("center-y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_RADIUS_X,
+                                   g_param_spec_double ("radius-x", NULL, NULL,
+                                                        0, GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_RADIUS_Y,
+                                   g_param_spec_double ("radius-y", NULL, NULL,
+                                                        0, GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_START_ANGLE,
+                                   g_param_spec_double ("start-angle", NULL, NULL,
+                                                        -1000, 1000, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_SLICE_ANGLE,
+                                   g_param_spec_double ("slice-angle", NULL, NULL,
+                                                        -1000, 1000, 2 * G_PI,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_FILLED,
+                                   g_param_spec_boolean ("filled", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_arc_init (GimpCanvasArc *arc)
+{
+}
+
+static void
+gimp_canvas_arc_set_property (GObject      *object,
+                              guint         property_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
+{
+  GimpCanvasArcPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_CENTER_X:
+      private->center_x = g_value_get_double (value);
+      break;
+    case PROP_CENTER_Y:
+      private->center_y = g_value_get_double (value);
+      break;
+    case PROP_RADIUS_X:
+      private->radius_x = g_value_get_double (value);
+      break;
+    case PROP_RADIUS_Y:
+      private->radius_y = g_value_get_double (value);
+      break;
+    case PROP_START_ANGLE:
+      private->start_angle = g_value_get_double (value);
+      break;
+    case PROP_SLICE_ANGLE:
+      private->slice_angle = g_value_get_double (value);
+      break;
+    case PROP_FILLED:
+      private->filled = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_arc_get_property (GObject    *object,
+                              guint       property_id,
+                              GValue     *value,
+                              GParamSpec *pspec)
+{
+  GimpCanvasArcPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_CENTER_X:
+      g_value_set_double (value, private->center_x);
+      break;
+    case PROP_CENTER_Y:
+      g_value_set_double (value, private->center_y);
+      break;
+    case PROP_RADIUS_X:
+      g_value_set_double (value, private->radius_x);
+      break;
+    case PROP_RADIUS_Y:
+      g_value_set_double (value, private->radius_y);
+      break;
+    case PROP_START_ANGLE:
+      g_value_set_double (value, private->start_angle);
+      break;
+    case PROP_SLICE_ANGLE:
+      g_value_set_double (value, private->slice_angle);
+      break;
+    case PROP_FILLED:
+      g_value_set_boolean (value, private->filled);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_arc_transform (GimpCanvasItem *item,
+                           gdouble        *center_x,
+                           gdouble        *center_y,
+                           gdouble        *radius_x,
+                           gdouble        *radius_y)
+{
+  GimpCanvasArcPrivate *private = GET_PRIVATE (item);
+  gdouble               x1, y1;
+  gdouble               x2, y2;
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->center_x - private->radius_x,
+                                   private->center_y - private->radius_y,
+                                   &x1, &y1);
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->center_x + private->radius_x,
+                                   private->center_y + private->radius_y,
+                                   &x2, &y2);
+
+  x1 = floor (x1);
+  y1 = floor (y1);
+  x2 = ceil (x2);
+  y2 = ceil (y2);
+
+  *center_x = (x1 + x2) / 2.0;
+  *center_y = (y1 + y2) / 2.0;
+
+  *radius_x = (x2 - x1) / 2.0;
+  *radius_y = (y2 - y1) / 2.0;
+
+  if (! private->filled)
+    {
+      *radius_x = MAX (*radius_x - 0.5, 0.0);
+      *radius_y = MAX (*radius_y - 0.5, 0.0);
+    }
+
+  /* avoid cairo_scale (cr, 0.0, 0.0) */
+  if (*radius_x == 0.0) *radius_x = 0.000001;
+  if (*radius_y == 0.0) *radius_y = 0.000001;
+}
+
+static void
+gimp_canvas_arc_draw (GimpCanvasItem *item,
+                      cairo_t        *cr)
+{
+  GimpCanvasArcPrivate *private = GET_PRIVATE (item);
+  gdouble               center_x, center_y;
+  gdouble               radius_x, radius_y;
+
+  gimp_canvas_arc_transform (item,
+                             &center_x, &center_y,
+                             &radius_x, &radius_y);
+
+  cairo_save (cr);
+  cairo_translate (cr, center_x, center_y);
+  cairo_scale (cr, radius_x, radius_y);
+  gimp_cairo_arc (cr, 0.0, 0.0, 1.0,
+                  private->start_angle, private->slice_angle);
+  cairo_restore (cr);
+
+  if (private->filled)
+    _gimp_canvas_item_fill (item, cr);
+  else
+    _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_arc_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasArcPrivate  *private = GET_PRIVATE (item);
+  cairo_region_t        *region;
+  cairo_rectangle_int_t  rectangle;
+  gdouble                center_x, center_y;
+  gdouble                radius_x, radius_y;
+
+  gimp_canvas_arc_transform (item,
+                             &center_x, &center_y,
+                             &radius_x, &radius_y);
+
+  rectangle.x      = floor (center_x - radius_x - 1.5);
+  rectangle.y      = floor (center_y - radius_y - 1.5);
+  rectangle.width  = ceil (center_x + radius_x + 1.5) - rectangle.x;
+  rectangle.height = ceil (center_y + radius_y + 1.5) - rectangle.y;
+
+  region = cairo_region_create_rectangle (&rectangle);
+
+  if (! private->filled &&
+      rectangle.width > 64 * 1.43 &&
+      rectangle.height > 64 * 1.43)
+    {
+      radius_x *= 0.7;
+      radius_y *= 0.7;
+
+      rectangle.x      = ceil (center_x - radius_x + 1.5);
+      rectangle.y      = ceil (center_y - radius_y + 1.5);
+      rectangle.width  = floor (center_x + radius_x - 1.5) - rectangle.x;
+      rectangle.height = floor (center_y + radius_y - 1.5) - rectangle.y;
+
+      cairo_region_subtract_rectangle (region, &rectangle);
+    }
+
+  return region;
+}
+
+GimpCanvasItem *
+gimp_canvas_arc_new (GimpDisplayShell *shell,
+                     gdouble          center_x,
+                     gdouble          center_y,
+                     gdouble          radius_x,
+                     gdouble          radius_y,
+                     gdouble          start_angle,
+                     gdouble          slice_angle,
+                     gboolean         filled)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_ARC,
+                       "shell",       shell,
+                       "center-x",    center_x,
+                       "center-y",    center_y,
+                       "radius-x",    radius_x,
+                       "radius-y",    radius_y,
+                       "start-angle", start_angle,
+                       "slice-angle", slice_angle,
+                       "filled",      filled,
+                       NULL);
+}
+
+void
+gimp_canvas_arc_set (GimpCanvasItem *arc,
+                     gdouble         center_x,
+                     gdouble         center_y,
+                     gdouble         radius_x,
+                     gdouble         radius_y,
+                     gdouble         start_angle,
+                     gdouble         slice_angle)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ARC (arc));
+
+  gimp_canvas_item_begin_change (arc);
+  g_object_set (arc,
+                "center-x",    center_x,
+                "center-y",    center_y,
+                "radius-x",    radius_x,
+                "radius-y",    radius_y,
+                "start-angle", start_angle,
+                "slice-angle", slice_angle,
+                NULL);
+  gimp_canvas_item_end_change (arc);
+}
diff --git a/app/display/gimpcanvasarc.h b/app/display/gimpcanvasarc.h
new file mode 100644
index 0000000..1896352
--- /dev/null
+++ b/app/display/gimpcanvasarc.h
@@ -0,0 +1,69 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasarc.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_ARC_H__
+#define __GIMP_CANVAS_ARC_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_ARC            (gimp_canvas_arc_get_type ())
+#define GIMP_CANVAS_ARC(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_ARC, GimpCanvasArc))
+#define GIMP_CANVAS_ARC_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_ARC, GimpCanvasArcClass))
+#define GIMP_IS_CANVAS_ARC(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_ARC))
+#define GIMP_IS_CANVAS_ARC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_ARC))
+#define GIMP_CANVAS_ARC_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_ARC, GimpCanvasArcClass))
+
+
+typedef struct _GimpCanvasArc      GimpCanvasArc;
+typedef struct _GimpCanvasArcClass GimpCanvasArcClass;
+
+struct _GimpCanvasArc
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasArcClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_arc_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_arc_new      (GimpDisplayShell *shell,
+                                           gdouble          center_x,
+                                           gdouble          center_y,
+                                           gdouble          radius_x,
+                                           gdouble          radius_y,
+                                           gdouble          start_angle,
+                                           gdouble          slice_angle,
+                                           gboolean         filled);
+
+void             gimp_canvas_arc_set      (GimpCanvasItem  *arc,
+                                           gdouble          center_x,
+                                           gdouble          center_y,
+                                           gdouble          radius_x,
+                                           gdouble          radius_y,
+                                           gdouble          start_angle,
+                                           gdouble          slice_angle);
+
+#endif /* __GIMP_CANVAS_ARC_H__ */
diff --git a/app/display/gimpcanvasboundary.c b/app/display/gimpcanvasboundary.c
new file mode 100644
index 0000000..a6cab9d
--- /dev/null
+++ b/app/display/gimpcanvasboundary.c
@@ -0,0 +1,384 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasboundary.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-cairo.h"
+#include "core/gimp-transform-utils.h"
+#include "core/gimpboundary.h"
+#include "core/gimpparamspecs.h"
+
+#include "gimpcanvasboundary.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_SEGS,
+  PROP_TRANSFORM,
+  PROP_OFFSET_X,
+  PROP_OFFSET_Y
+};
+
+
+typedef struct _GimpCanvasBoundaryPrivate GimpCanvasBoundaryPrivate;
+
+struct _GimpCanvasBoundaryPrivate
+{
+  GimpBoundSeg *segs;
+  gint          n_segs;
+  GimpMatrix3  *transform;
+  gdouble       offset_x;
+  gdouble       offset_y;
+};
+
+#define GET_PRIVATE(boundary) \
+        ((GimpCanvasBoundaryPrivate *) gimp_canvas_boundary_get_instance_private ((GimpCanvasBoundary *) (boundary)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_boundary_finalize     (GObject        *object);
+static void             gimp_canvas_boundary_set_property (GObject        *object,
+                                                           guint           property_id,
+                                                           const GValue   *value,
+                                                           GParamSpec     *pspec);
+static void             gimp_canvas_boundary_get_property (GObject        *object,
+                                                           guint           property_id,
+                                                           GValue         *value,
+                                                           GParamSpec     *pspec);
+static void             gimp_canvas_boundary_draw         (GimpCanvasItem *item,
+                                                           cairo_t        *cr);
+static cairo_region_t * gimp_canvas_boundary_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasBoundary, gimp_canvas_boundary,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_boundary_parent_class
+
+
+static void
+gimp_canvas_boundary_class_init (GimpCanvasBoundaryClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_boundary_finalize;
+  object_class->set_property = gimp_canvas_boundary_set_property;
+  object_class->get_property = gimp_canvas_boundary_get_property;
+
+  item_class->draw           = gimp_canvas_boundary_draw;
+  item_class->get_extents    = gimp_canvas_boundary_get_extents;
+
+  g_object_class_install_property (object_class, PROP_SEGS,
+                                   gimp_param_spec_array ("segs", NULL, NULL,
+                                                          GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_TRANSFORM,
+                                   g_param_spec_pointer ("transform", NULL, NULL,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_OFFSET_X,
+                                   g_param_spec_double ("offset-x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_OFFSET_Y,
+                                   g_param_spec_double ("offset-y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_boundary_init (GimpCanvasBoundary *boundary)
+{
+  gimp_canvas_item_set_line_cap (GIMP_CANVAS_ITEM (boundary),
+                                 CAIRO_LINE_CAP_SQUARE);
+}
+
+static void
+gimp_canvas_boundary_finalize (GObject *object)
+{
+  GimpCanvasBoundaryPrivate *private = GET_PRIVATE (object);
+
+  g_clear_pointer (&private->segs, g_free);
+  private->n_segs = 0;
+
+  g_clear_pointer (&private->transform, g_free);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_boundary_set_property (GObject      *object,
+                                   guint         property_id,
+                                   const GValue *value,
+                                   GParamSpec   *pspec)
+{
+  GimpCanvasBoundaryPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_SEGS:
+      break;
+
+    case PROP_TRANSFORM:
+      {
+        GimpMatrix3 *transform = g_value_get_pointer (value);
+        if (private->transform)
+          g_free (private->transform);
+        if (transform)
+          private->transform = g_memdup (transform, sizeof (GimpMatrix3));
+        else
+          private->transform = NULL;
+      }
+      break;
+
+    case PROP_OFFSET_X:
+      private->offset_x = g_value_get_double (value);
+      break;
+    case PROP_OFFSET_Y:
+      private->offset_y = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_boundary_get_property (GObject    *object,
+                                   guint       property_id,
+                                   GValue     *value,
+                                   GParamSpec *pspec)
+{
+  GimpCanvasBoundaryPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_SEGS:
+      break;
+
+    case PROP_TRANSFORM:
+      g_value_set_pointer (value, private->transform);
+      break;
+
+    case PROP_OFFSET_X:
+      g_value_set_double (value, private->offset_x);
+      break;
+    case PROP_OFFSET_Y:
+      g_value_set_double (value, private->offset_y);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_boundary_transform (GimpCanvasItem *item,
+                                GimpSegment    *segs,
+                                gint           *n_segs)
+{
+  GimpCanvasBoundaryPrivate *private = GET_PRIVATE (item);
+  gint                       i;
+
+  if (private->transform)
+    {
+      gint n = 0;
+
+      for (i = 0; i < private->n_segs; i++)
+        {
+          GimpVector2 vertices[2];
+          GimpVector2 t_vertices[2];
+          gint        n_t_vertices;
+
+          vertices[0] = (GimpVector2) { private->segs[i].x1, private->segs[i].y1 };
+          vertices[1] = (GimpVector2) { private->segs[i].x2, private->segs[i].y2 };
+
+          gimp_transform_polygon (private->transform, vertices, 2, FALSE,
+                                  t_vertices, &n_t_vertices);
+
+          if (n_t_vertices == 2)
+            {
+              gimp_canvas_item_transform_xy (item,
+                                             t_vertices[0].x + private->offset_x,
+                                             t_vertices[0].y + private->offset_y,
+                                             &segs[n].x1, &segs[n].y1);
+              gimp_canvas_item_transform_xy (item,
+                                             t_vertices[1].x + private->offset_x,
+                                             t_vertices[1].y + private->offset_y,
+                                             &segs[n].x2, &segs[n].y2);
+
+              n++;
+            }
+        }
+
+      *n_segs = n;
+    }
+  else
+    {
+      for (i = 0; i < private->n_segs; i++)
+        {
+          gimp_canvas_item_transform_xy (item,
+                                         private->segs[i].x1 + private->offset_x,
+                                         private->segs[i].y1 + private->offset_y,
+                                         &segs[i].x1,
+                                         &segs[i].y1);
+          gimp_canvas_item_transform_xy (item,
+                                         private->segs[i].x2 + private->offset_x,
+                                         private->segs[i].y2 + private->offset_y,
+                                         &segs[i].x2,
+                                         &segs[i].y2);
+
+          /*  If this segment is a closing segment && the segments lie inside
+           *  the region, OR if this is an opening segment and the segments
+           *  lie outside the region...
+           *  we need to transform it by one display pixel
+           */
+          if (! private->segs[i].open)
+            {
+              /*  If it is vertical  */
+              if (segs[i].x1 == segs[i].x2)
+                {
+                  segs[i].x1 -= 1;
+                  segs[i].x2 -= 1;
+                }
+              else
+                {
+                  segs[i].y1 -= 1;
+                  segs[i].y2 -= 1;
+                }
+            }
+        }
+
+      *n_segs = private->n_segs;
+    }
+}
+
+static void
+gimp_canvas_boundary_draw (GimpCanvasItem *item,
+                           cairo_t        *cr)
+{
+  GimpCanvasBoundaryPrivate *private = GET_PRIVATE (item);
+  GimpSegment               *segs;
+  gint                       n_segs;
+
+  segs = g_new0 (GimpSegment, private->n_segs);
+
+  gimp_canvas_boundary_transform (item, segs, &n_segs);
+
+  gimp_cairo_segments (cr, segs, n_segs);
+
+  _gimp_canvas_item_stroke (item, cr);
+
+  g_free (segs);
+}
+
+static cairo_region_t *
+gimp_canvas_boundary_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasBoundaryPrivate *private = GET_PRIVATE (item);
+  cairo_rectangle_int_t      rectangle;
+  GimpSegment               *segs;
+  gint                       n_segs;
+  gint                       x1, y1, x2, y2;
+  gint                       i;
+
+  segs = g_new0 (GimpSegment, private->n_segs);
+
+  gimp_canvas_boundary_transform (item, segs, &n_segs);
+
+  if (n_segs == 0)
+    {
+      g_free (segs);
+
+      return cairo_region_create ();
+    }
+
+  x1 = MIN (segs[0].x1, segs[0].x2);
+  y1 = MIN (segs[0].y1, segs[0].y2);
+  x2 = MAX (segs[0].x1, segs[0].x2);
+  y2 = MAX (segs[0].y1, segs[0].y2);
+
+  for (i = 1; i < n_segs; i++)
+    {
+      gint x3 = MIN (segs[i].x1, segs[i].x2);
+      gint y3 = MIN (segs[i].y1, segs[i].y2);
+      gint x4 = MAX (segs[i].x1, segs[i].x2);
+      gint y4 = MAX (segs[i].y1, segs[i].y2);
+
+      x1 = MIN (x1, x3);
+      y1 = MIN (y1, y3);
+      x2 = MAX (x2, x4);
+      y2 = MAX (y2, y4);
+    }
+
+  g_free (segs);
+
+  rectangle.x      = x1 - 2;
+  rectangle.y      = y1 - 2;
+  rectangle.width  = x2 - x1 + 4;
+  rectangle.height = y2 - y1 + 4;
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_boundary_new (GimpDisplayShell   *shell,
+                          const GimpBoundSeg *segs,
+                          gint                n_segs,
+                          GimpMatrix3        *transform,
+                          gdouble             offset_x,
+                          gdouble             offset_y)
+{
+  GimpCanvasItem            *item;
+  GimpCanvasBoundaryPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  item = g_object_new (GIMP_TYPE_CANVAS_BOUNDARY,
+                       "shell",     shell,
+                       "transform", transform,
+                       "offset-x",  offset_x,
+                       "offset-y",  offset_y,
+                       NULL);
+  private = GET_PRIVATE (item);
+
+  /* puke */
+  private->segs   = g_memdup (segs, n_segs * sizeof (GimpBoundSeg));
+  private->n_segs = n_segs;
+
+  return item;
+}
diff --git a/app/display/gimpcanvasboundary.h b/app/display/gimpcanvasboundary.h
new file mode 100644
index 0000000..527f89e
--- /dev/null
+++ b/app/display/gimpcanvasboundary.h
@@ -0,0 +1,60 @@
+/* GIMP - The GNU Image Manipulation Program Copyright (C) 1995
+ * Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasboundary.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_BOUNDARY_H__
+#define __GIMP_CANVAS_BOUNDARY_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_BOUNDARY            (gimp_canvas_boundary_get_type ())
+#define GIMP_CANVAS_BOUNDARY(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_BOUNDARY, GimpCanvasBoundary))
+#define GIMP_CANVAS_BOUNDARY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_BOUNDARY, GimpCanvasBoundaryClass))
+#define GIMP_IS_CANVAS_BOUNDARY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_BOUNDARY))
+#define GIMP_IS_CANVAS_BOUNDARY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_BOUNDARY))
+#define GIMP_CANVAS_BOUNDARY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_BOUNDARY, GimpCanvasBoundaryClass))
+
+
+typedef struct _GimpCanvasBoundary      GimpCanvasBoundary;
+typedef struct _GimpCanvasBoundaryClass GimpCanvasBoundaryClass;
+
+struct _GimpCanvasBoundary
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasBoundaryClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_boundary_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_boundary_new      (GimpDisplayShell   *shell,
+                                                const GimpBoundSeg *segs,
+                                                gint                n_segs,
+                                                GimpMatrix3        *transform,
+                                                gdouble             offset_x,
+                                                gdouble             offset_y);
+
+
+#endif /* __GIMP_CANVAS_BOUNDARY_H__ */
diff --git a/app/display/gimpcanvasbufferpreview.c b/app/display/gimpcanvasbufferpreview.c
new file mode 100644
index 0000000..858bab6
--- /dev/null
+++ b/app/display/gimpcanvasbufferpreview.c
@@ -0,0 +1,263 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasbufferpreview.c
+ * Copyright (C) 2013 Marek Dvoroznak <dvoromar@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <cairo/cairo.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display/display-types.h"
+
+#include "core/gimpimage.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvasbufferpreview.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scroll.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_BUFFER
+};
+
+
+typedef struct _GimpCanvasBufferPreviewPrivate GimpCanvasBufferPreviewPrivate;
+
+struct _GimpCanvasBufferPreviewPrivate
+{
+  GeglBuffer *buffer;
+};
+
+
+#define GET_PRIVATE(transform_preview) \
+        ((GimpCanvasBufferPreviewPrivate *) gimp_canvas_buffer_preview_get_instance_private ((GimpCanvasBufferPreview *) (transform_preview)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_buffer_preview_dispose        (GObject               *object);
+static void             gimp_canvas_buffer_preview_set_property   (GObject               *object,
+                                                                   guint                  property_id,
+                                                                   const GValue          *value,
+                                                                   GParamSpec            *pspec);
+static void             gimp_canvas_buffer_preview_get_property   (GObject               *object,
+                                                                   guint                  property_id,
+                                                                   GValue                *value,
+                                                                   GParamSpec            *pspec);
+
+static void             gimp_canvas_buffer_preview_draw           (GimpCanvasItem        *item,
+                                                                   cairo_t               *cr);
+static cairo_region_t * gimp_canvas_buffer_preview_get_extents    (GimpCanvasItem        *item);
+static void             gimp_canvas_buffer_preview_compute_bounds (GimpCanvasItem        *item,
+                                                                   cairo_rectangle_int_t *bounds);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasBufferPreview, gimp_canvas_buffer_preview,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_buffer_preview_parent_class
+
+
+static void
+gimp_canvas_buffer_preview_class_init (GimpCanvasBufferPreviewClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->dispose      = gimp_canvas_buffer_preview_dispose;
+  object_class->set_property = gimp_canvas_buffer_preview_set_property;
+  object_class->get_property = gimp_canvas_buffer_preview_get_property;
+
+  item_class->draw           = gimp_canvas_buffer_preview_draw;
+  item_class->get_extents    = gimp_canvas_buffer_preview_get_extents;
+
+  g_object_class_install_property (object_class, PROP_BUFFER,
+                                   g_param_spec_object ("buffer",
+                                                        NULL, NULL,
+                                                        GEGL_TYPE_BUFFER,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_buffer_preview_init (GimpCanvasBufferPreview *transform_preview)
+{
+}
+
+static void
+gimp_canvas_buffer_preview_dispose (GObject *object)
+{
+  GimpCanvasBufferPreviewPrivate *private = GET_PRIVATE (object);
+
+  g_clear_object (&private->buffer);
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_canvas_buffer_preview_set_property (GObject      *object,
+                                         guint         property_id,
+                                         const GValue *value,
+                                         GParamSpec   *pspec)
+{
+  GimpCanvasBufferPreviewPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_BUFFER:
+      g_set_object (&private->buffer, g_value_get_object (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_buffer_preview_get_property (GObject    *object,
+                                         guint       property_id,
+                                         GValue     *value,
+                                         GParamSpec *pspec)
+{
+  GimpCanvasBufferPreviewPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_BUFFER:
+      g_value_set_object (value, private->buffer);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_buffer_preview_draw (GimpCanvasItem *item,
+                                 cairo_t        *cr)
+{
+  GimpDisplayShell      *shell  = gimp_canvas_item_get_shell (item);
+  GeglBuffer            *buffer = GET_PRIVATE (item)->buffer;
+  cairo_surface_t       *area;
+  guchar                *data;
+  cairo_rectangle_int_t  rectangle;
+
+  g_return_if_fail (GEGL_IS_BUFFER (buffer));
+
+  gimp_canvas_buffer_preview_compute_bounds (item, &rectangle);
+
+  area = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                     rectangle.width,
+                                     rectangle.height);
+
+  data = cairo_image_surface_get_data (area);
+  gegl_buffer_get (buffer,
+                   GEGL_RECTANGLE (rectangle.x + shell->offset_x,
+                                   rectangle.y + shell->offset_y,
+                                   rectangle.width,
+                                   rectangle.height),
+                   shell->scale_x,
+                   babl_format ("cairo-ARGB32"),
+                   data,
+                   cairo_image_surface_get_stride (area),
+                   GEGL_ABYSS_NONE);
+
+  cairo_surface_flush (area);
+  cairo_surface_mark_dirty (area);
+
+  cairo_set_source_surface (cr, area, rectangle.x, rectangle.y);
+  cairo_rectangle (cr,
+                   rectangle.x, rectangle.y,
+                   rectangle.width, rectangle.height);
+  cairo_fill (cr);
+
+  cairo_surface_destroy (area);
+}
+
+static void
+gimp_canvas_buffer_preview_compute_bounds (GimpCanvasItem        *item,
+                                           cairo_rectangle_int_t *bounds)
+{
+  GimpDisplayShell *shell  = gimp_canvas_item_get_shell (item);
+  GeglBuffer       *buffer = GET_PRIVATE (item)->buffer;
+  GeglRectangle     extent;
+  gdouble           x1, y1;
+  gdouble           x2, y2;
+
+  g_return_if_fail (GEGL_IS_BUFFER (buffer));
+
+  extent = *gegl_buffer_get_extent (buffer);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   extent.x,
+                                   extent.y,
+                                   &x1, &y1);
+  gimp_canvas_item_transform_xy_f (item,
+                                   extent.x + extent.width,
+                                   extent.y + extent.height,
+                                   &x2, &y2);
+
+  extent.x      = floor (x1);
+  extent.y      = floor (y1);
+  extent.width  = ceil  (x2) - extent.x;
+  extent.height = ceil  (y2) - extent.y;
+
+  gegl_rectangle_intersect (&extent,
+                            &extent,
+                            GEGL_RECTANGLE (0,
+                                            0,
+                                            shell->disp_width,
+                                            shell->disp_height));
+
+  bounds->x      = extent.x;
+  bounds->y      = extent.y;
+  bounds->width  = extent.width;
+  bounds->height = extent.height;
+}
+
+static cairo_region_t *
+gimp_canvas_buffer_preview_get_extents (GimpCanvasItem *item)
+{
+  cairo_rectangle_int_t rectangle;
+
+  gimp_canvas_buffer_preview_compute_bounds (item, &rectangle);
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_buffer_preview_new (GimpDisplayShell  *shell,
+                                GeglBuffer        *buffer)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (GEGL_IS_BUFFER (buffer), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_BUFFER_PREVIEW,
+                       "shell",       shell,
+                       "buffer",      buffer,
+                       NULL);
+}
diff --git a/app/display/gimpcanvasbufferpreview.h b/app/display/gimpcanvasbufferpreview.h
new file mode 100644
index 0000000..28d8806
--- /dev/null
+++ b/app/display/gimpcanvasbufferpreview.h
@@ -0,0 +1,56 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasbufferpreview.h
+ * Copyright (C) 2013 Marek Dvoroznak <dvoromar@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_BUFFER_PREVIEW_H__
+#define __GIMP_CANVAS_BUFFER_PREVIEW_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_BUFFER_PREVIEW            (gimp_canvas_buffer_preview_get_type ())
+#define GIMP_CANVAS_BUFFER_PREVIEW(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_BUFFER_PREVIEW, GimpCanvasBufferPreview))
+#define GIMP_CANVAS_BUFFER_PREVIEW_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_BUFFER_PREVIEW, GimpCanvasBufferPreviewClass))
+#define GIMP_IS_CANVAS_BUFFER_PREVIEW(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_BUFFER_PREVIEW))
+#define GIMP_IS_CANVAS_BUFFER_PREVIEW_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_BUFFER_PREVIEW))
+#define GIMP_CANVAS_BUFFER_PREVIEW_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_BUFFER_PREVIEW, GimpCanvasBufferPreviewClass))
+
+
+typedef struct _GimpCanvasBufferPreview      GimpCanvasBufferPreview;
+typedef struct _GimpCanvasBufferPreviewClass GimpCanvasBufferPreviewClass;
+
+struct _GimpCanvasBufferPreview
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasBufferPreviewClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_buffer_preview_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_buffer_preview_new      (GimpDisplayShell  *shell,
+                                                      GeglBuffer        *buffer);
+
+
+#endif /* __GIMP_CANVAS_BUFFER_PREVIEW_H__ */
diff --git a/app/display/gimpcanvascanvasboundary.c b/app/display/gimpcanvascanvasboundary.c
new file mode 100644
index 0000000..01ac5a3
--- /dev/null
+++ b/app/display/gimpcanvascanvasboundary.c
@@ -0,0 +1,270 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascanvasboundary.c
+ * Copyright (C) 2019 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpimage.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvascanvasboundary.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_IMAGE
+};
+
+
+typedef struct _GimpCanvasCanvasBoundaryPrivate GimpCanvasCanvasBoundaryPrivate;
+
+struct _GimpCanvasCanvasBoundaryPrivate
+{
+  GimpImage *image;
+};
+
+#define GET_PRIVATE(canvas_boundary) \
+        ((GimpCanvasCanvasBoundaryPrivate *) gimp_canvas_canvas_boundary_get_instance_private ((GimpCanvasCanvasBoundary *) (canvas_boundary)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_canvas_boundary_set_property (GObject        *object,
+                                                                  guint           property_id,
+                                                                  const GValue   *value,
+                                                                  GParamSpec     *pspec);
+static void             gimp_canvas_canvas_boundary_get_property (GObject        *object,
+                                                                  guint           property_id,
+                                                                  GValue         *value,
+                                                                  GParamSpec     *pspec);
+static void             gimp_canvas_canvas_boundary_finalize     (GObject        *object);
+static void             gimp_canvas_canvas_boundary_draw         (GimpCanvasItem *item,
+                                                                  cairo_t        *cr);
+static cairo_region_t * gimp_canvas_canvas_boundary_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_canvas_boundary_stroke       (GimpCanvasItem *item,
+                                                                  cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasCanvasBoundary, gimp_canvas_canvas_boundary,
+                            GIMP_TYPE_CANVAS_RECTANGLE)
+
+#define parent_class gimp_canvas_canvas_boundary_parent_class
+
+
+static void
+gimp_canvas_canvas_boundary_class_init (GimpCanvasCanvasBoundaryClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_canvas_boundary_set_property;
+  object_class->get_property = gimp_canvas_canvas_boundary_get_property;
+  object_class->finalize     = gimp_canvas_canvas_boundary_finalize;
+
+  item_class->draw           = gimp_canvas_canvas_boundary_draw;
+  item_class->get_extents    = gimp_canvas_canvas_boundary_get_extents;
+  item_class->stroke         = gimp_canvas_canvas_boundary_stroke;
+
+  g_object_class_install_property (object_class, PROP_IMAGE,
+                                   g_param_spec_object ("image", NULL, NULL,
+                                                        GIMP_TYPE_IMAGE,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_canvas_boundary_init (GimpCanvasCanvasBoundary *canvas_boundary)
+{
+}
+
+static void
+gimp_canvas_canvas_boundary_finalize (GObject *object)
+{
+  GimpCanvasCanvasBoundaryPrivate *private = GET_PRIVATE (object);
+
+  if (private->image)
+    g_object_remove_weak_pointer (G_OBJECT (private->image),
+                                  (gpointer) &private->image);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_canvas_boundary_set_property (GObject      *object,
+                                          guint         property_id,
+                                          const GValue *value,
+                                          GParamSpec   *pspec)
+{
+  GimpCanvasCanvasBoundaryPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_IMAGE:
+      if (private->image)
+        g_object_remove_weak_pointer (G_OBJECT (private->image),
+                                      (gpointer) &private->image);
+      private->image = g_value_get_object (value); /* don't ref */
+      if (private->image)
+        g_object_add_weak_pointer (G_OBJECT (private->image),
+                                   (gpointer) &private->image);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_canvas_boundary_get_property (GObject    *object,
+                                          guint       property_id,
+                                          GValue     *value,
+                                          GParamSpec *pspec)
+{
+  GimpCanvasCanvasBoundaryPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_IMAGE:
+      g_value_set_object (value, private->image);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_canvas_boundary_draw (GimpCanvasItem *item,
+                                  cairo_t        *cr)
+{
+  GimpCanvasCanvasBoundaryPrivate *private = GET_PRIVATE (item);
+
+  if (private->image)
+    GIMP_CANVAS_ITEM_CLASS (parent_class)->draw (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_canvas_boundary_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasCanvasBoundaryPrivate *private = GET_PRIVATE (item);
+
+  if (private->image)
+    return GIMP_CANVAS_ITEM_CLASS (parent_class)->get_extents (item);
+
+  return NULL;
+}
+
+static void
+gimp_canvas_canvas_boundary_stroke (GimpCanvasItem *item,
+                                    cairo_t        *cr)
+{
+  GimpDisplayShell *shell = gimp_canvas_item_get_shell (item);
+
+  gimp_canvas_set_canvas_style (gimp_canvas_item_get_canvas (item), cr,
+                                shell->offset_x, shell->offset_y);
+  cairo_stroke (cr);
+}
+
+GimpCanvasItem *
+gimp_canvas_canvas_boundary_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_CANVAS_BOUNDARY,
+                       "shell", shell,
+                       NULL);
+}
+
+void
+gimp_canvas_canvas_boundary_set_image (GimpCanvasCanvasBoundary *boundary,
+                                       GimpImage                *image)
+{
+  GimpCanvasCanvasBoundaryPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_CANVAS_BOUNDARY (boundary));
+  g_return_if_fail (image == NULL || GIMP_IS_IMAGE (image));
+
+  private = GET_PRIVATE (boundary);
+
+  if (image != private->image)
+    {
+      gimp_canvas_item_begin_change (GIMP_CANVAS_ITEM (boundary));
+
+      if (image)
+        {
+          g_object_set (boundary,
+                        "x",      (gdouble) 0,
+                        "y",      (gdouble) 0,
+                        "width",  (gdouble) gimp_image_get_width  (image),
+                        "height", (gdouble) gimp_image_get_height (image),
+                        NULL);
+        }
+
+      g_object_set (boundary,
+                    "image", image,
+                    NULL);
+
+      gimp_canvas_item_end_change (GIMP_CANVAS_ITEM (boundary));
+    }
+  else if (image && image == private->image)
+    {
+      gint    lx, ly, lw, lh;
+      gdouble x, y, w ,h;
+
+      lx = 0;
+      ly = 0;
+      lw = gimp_image_get_width  (image);
+      lh = gimp_image_get_height (image);
+
+      g_object_get (boundary,
+                    "x",      &x,
+                    "y",      &y,
+                    "width",  &w,
+                    "height", &h,
+                    NULL);
+
+      if (lx != (gint) x ||
+          ly != (gint) y ||
+          lw != (gint) w ||
+          lh != (gint) h)
+        {
+          gimp_canvas_item_begin_change (GIMP_CANVAS_ITEM (boundary));
+
+          g_object_set (boundary,
+                        "x",      (gdouble) lx,
+                        "y",      (gdouble) ly,
+                        "width",  (gdouble) lw,
+                        "height", (gdouble) lh,
+                        NULL);
+
+          gimp_canvas_item_end_change (GIMP_CANVAS_ITEM (boundary));
+        }
+    }
+}
diff --git a/app/display/gimpcanvascanvasboundary.h b/app/display/gimpcanvascanvasboundary.h
new file mode 100644
index 0000000..c8fe16f
--- /dev/null
+++ b/app/display/gimpcanvascanvasboundary.h
@@ -0,0 +1,58 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascanvasvboundary.h
+ * Copyright (C) 2019 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_CANVAS_BOUNDARY_H__
+#define __GIMP_CANVAS_CANVAS_BOUNDARY_H__
+
+
+#include "gimpcanvasrectangle.h"
+
+
+#define GIMP_TYPE_CANVAS_CANVAS_BOUNDARY            (gimp_canvas_canvas_boundary_get_type ())
+#define GIMP_CANVAS_CANVAS_BOUNDARY(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_CANVAS_BOUNDARY, GimpCanvasCanvasBoundary))
+#define GIMP_CANVAS_CANVAS_BOUNDARY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_CANVAS_BOUNDARY, GimpCanvasCanvasBoundaryClass))
+#define GIMP_IS_CANVAS_CANVAS_BOUNDARY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_CANVAS_BOUNDARY))
+#define GIMP_IS_CANVAS_CANVAS_BOUNDARY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_CANVAS_BOUNDARY))
+#define GIMP_CANVAS_CANVAS_BOUNDARY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_CANVAS_BOUNDARY, GimpCanvasCanvasBoundaryClass))
+
+
+typedef struct _GimpCanvasCanvasBoundary      GimpCanvasCanvasBoundary;
+typedef struct _GimpCanvasCanvasBoundaryClass GimpCanvasCanvasBoundaryClass;
+
+struct _GimpCanvasCanvasBoundary
+{
+  GimpCanvasRectangle  parent_instance;
+};
+
+struct _GimpCanvasCanvasBoundaryClass
+{
+  GimpCanvasRectangleClass  parent_class;
+};
+
+
+GType            gimp_canvas_canvas_boundary_get_type  (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_canvas_boundary_new       (GimpDisplayShell        *shell);
+
+void             gimp_canvas_canvas_boundary_set_image (GimpCanvasCanvasBoundary *boundary,
+                                                        GimpImage                *image);
+
+
+#endif /* __GIMP_CANVAS_CANVAS_BOUNDARY_H__ */
diff --git a/app/display/gimpcanvascorner.c b/app/display/gimpcanvascorner.c
new file mode 100644
index 0000000..50aebfb
--- /dev/null
+++ b/app/display/gimpcanvascorner.c
@@ -0,0 +1,468 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascorner.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvascorner.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_X,
+  PROP_Y,
+  PROP_WIDTH,
+  PROP_HEIGHT,
+  PROP_ANCHOR,
+  PROP_CORNER_WIDTH,
+  PROP_CORNER_HEIGHT,
+  PROP_OUTSIDE
+};
+
+
+typedef struct _GimpCanvasCornerPrivate GimpCanvasCornerPrivate;
+
+struct _GimpCanvasCornerPrivate
+{
+  gdouble          x;
+  gdouble          y;
+  gdouble          width;
+  gdouble          height;
+  GimpHandleAnchor anchor;
+  gint             corner_width;
+  gint             corner_height;
+  gboolean         outside;
+};
+
+#define GET_PRIVATE(corner) \
+        ((GimpCanvasCornerPrivate *) gimp_canvas_corner_get_instance_private ((GimpCanvasCorner *) (corner)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_corner_set_property (GObject        *object,
+                                                         guint           property_id,
+                                                         const GValue   *value,
+                                                         GParamSpec     *pspec);
+static void             gimp_canvas_corner_get_property (GObject        *object,
+                                                         guint           property_id,
+                                                         GValue         *value,
+                                                         GParamSpec     *pspec);
+static void             gimp_canvas_corner_draw         (GimpCanvasItem *item,
+                                                         cairo_t        *cr);
+static cairo_region_t * gimp_canvas_corner_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasCorner, gimp_canvas_corner,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_corner_parent_class
+
+
+static void
+gimp_canvas_corner_class_init (GimpCanvasCornerClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_corner_set_property;
+  object_class->get_property = gimp_canvas_corner_get_property;
+
+  item_class->draw           = gimp_canvas_corner_draw;
+  item_class->get_extents    = gimp_canvas_corner_get_extents;
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_WIDTH,
+                                   g_param_spec_double ("width", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_HEIGHT,
+                                   g_param_spec_double ("height", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_ANCHOR,
+                                   g_param_spec_enum ("anchor", NULL, NULL,
+                                                      GIMP_TYPE_HANDLE_ANCHOR,
+                                                      GIMP_HANDLE_ANCHOR_CENTER,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_CORNER_WIDTH,
+                                   g_param_spec_int ("corner-width", NULL, NULL,
+                                                     3, GIMP_MAX_IMAGE_SIZE, 3,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_CORNER_HEIGHT,
+                                   g_param_spec_int ("corner-height", NULL, NULL,
+                                                     3, GIMP_MAX_IMAGE_SIZE, 3,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_OUTSIDE,
+                                   g_param_spec_boolean ("outside", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_corner_init (GimpCanvasCorner *corner)
+{
+}
+
+static void
+gimp_canvas_corner_set_property (GObject      *object,
+                                 guint         property_id,
+                                 const GValue *value,
+                                 GParamSpec   *pspec)
+{
+  GimpCanvasCornerPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+    case PROP_WIDTH:
+      private->width = g_value_get_double (value);
+      break;
+    case PROP_HEIGHT:
+      private->height = g_value_get_double (value);
+      break;
+    case PROP_ANCHOR:
+      private->anchor = g_value_get_enum (value);
+      break;
+    case PROP_CORNER_WIDTH:
+      private->corner_width = g_value_get_int (value);
+      break;
+    case PROP_CORNER_HEIGHT:
+      private->corner_height = g_value_get_int (value);
+      break;
+   case PROP_OUTSIDE:
+      private->outside = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_corner_get_property (GObject    *object,
+                                 guint       property_id,
+                                 GValue     *value,
+                                 GParamSpec *pspec)
+{
+  GimpCanvasCornerPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+    case PROP_WIDTH:
+      g_value_set_double (value, private->width);
+      break;
+    case PROP_HEIGHT:
+      g_value_set_double (value, private->height);
+      break;
+    case PROP_ANCHOR:
+      g_value_set_enum (value, private->anchor);
+      break;
+    case PROP_CORNER_WIDTH:
+      g_value_set_int (value, private->corner_width);
+      break;
+    case PROP_CORNER_HEIGHT:
+      g_value_set_int (value, private->corner_height);
+      break;
+    case PROP_OUTSIDE:
+      g_value_set_boolean (value, private->outside);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_corner_transform (GimpCanvasItem *item,
+                              gdouble        *x,
+                              gdouble        *y,
+                              gdouble        *w,
+                              gdouble        *h)
+{
+  GimpCanvasCornerPrivate *private = GET_PRIVATE (item);
+  gdouble                  rx, ry;
+  gdouble                  rw, rh;
+  gint                     top_and_bottom_handle_x_offset;
+  gint                     left_and_right_handle_y_offset;
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   MIN (private->x,
+                                        private->x + private->width),
+                                   MIN (private->y,
+                                        private->y + private->height),
+                                   &rx, &ry);
+  gimp_canvas_item_transform_xy_f (item,
+                                   MAX (private->x,
+                                        private->x + private->width),
+                                   MAX (private->y,
+                                        private->y + private->height),
+                                   &rw, &rh);
+
+  rw -= rx;
+  rh -= ry;
+
+  rx = floor (rx) + 0.5;
+  ry = floor (ry) + 0.5;
+  rw = ceil (rw) - 1.0;
+  rh = ceil (rh) - 1.0;
+
+  top_and_bottom_handle_x_offset = (rw - private->corner_width)  / 2;
+  left_and_right_handle_y_offset = (rh - private->corner_height) / 2;
+
+  *w = private->corner_width;
+  *h = private->corner_height;
+
+  switch (private->anchor)
+    {
+    case GIMP_HANDLE_ANCHOR_CENTER:
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_WEST:
+      if (private->outside)
+        {
+          *x = rx - private->corner_width;
+          *y = ry - private->corner_height;
+        }
+      else
+        {
+          *x = rx;
+          *y = ry;
+        }
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_EAST:
+      if (private->outside)
+        {
+          *x = rx + rw;
+          *y = ry - private->corner_height;
+        }
+      else
+        {
+          *x = rx + rw - private->corner_width;
+          *y = ry;
+        }
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_WEST:
+      if (private->outside)
+        {
+          *x = rx - private->corner_width;
+          *y = ry + rh;
+        }
+      else
+        {
+          *x = rx;
+          *y = ry + rh - private->corner_height;
+        }
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_EAST:
+      if (private->outside)
+        {
+          *x = rx + rw;
+          *y = ry + rh;
+        }
+      else
+        {
+          *x = rx + rw - private->corner_width;
+          *y = ry + rh - private->corner_height;
+        }
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH:
+      if (private->outside)
+        {
+          *x = rx;
+          *y = ry - private->corner_height;
+          *w = rw;
+        }
+      else
+        {
+          *x = rx + top_and_bottom_handle_x_offset;
+          *y = ry;
+        }
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH:
+      if (private->outside)
+        {
+          *x = rx;
+          *y = ry + rh;
+          *w = rw;
+        }
+      else
+        {
+          *x = rx + top_and_bottom_handle_x_offset;
+          *y = ry + rh - private->corner_height;
+        }
+      break;
+
+    case GIMP_HANDLE_ANCHOR_WEST:
+      if (private->outside)
+        {
+          *x = rx - private->corner_width;
+          *y = ry;
+          *h = rh;
+        }
+      else
+        {
+          *x = rx;
+          *y = ry + left_and_right_handle_y_offset;
+        }
+      break;
+
+    case GIMP_HANDLE_ANCHOR_EAST:
+      if (private->outside)
+        {
+          *x = rx + rw;
+          *y = ry;
+          *h = rh;
+        }
+      else
+        {
+          *x = rx + rw - private->corner_width;
+          *y = ry + left_and_right_handle_y_offset;
+        }
+      break;
+    }
+}
+
+static void
+gimp_canvas_corner_draw (GimpCanvasItem *item,
+                         cairo_t        *cr)
+{
+  gdouble x, y;
+  gdouble w, h;
+
+  gimp_canvas_corner_transform (item, &x, &y, &w, &h);
+
+  cairo_rectangle (cr, x, y, w, h);
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_corner_get_extents (GimpCanvasItem *item)
+{
+  cairo_rectangle_int_t rectangle;
+  gdouble               x, y;
+  gdouble               w, h;
+
+  gimp_canvas_corner_transform (item, &x, &y, &w, &h);
+
+  rectangle.x      = floor (x - 1.5);
+  rectangle.y      = floor (y - 1.5);
+  rectangle.width  = ceil (w + 3.0);
+  rectangle.height = ceil (h + 3.0);
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_corner_new (GimpDisplayShell *shell,
+                        gdouble           x,
+                        gdouble           y,
+                        gdouble           width,
+                        gdouble           height,
+                        GimpHandleAnchor  anchor,
+                        gint              corner_width,
+                        gint              corner_height,
+                        gboolean          outside)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_CORNER,
+                       "shell",         shell,
+                       "x",             x,
+                       "y",             y,
+                       "width",         width,
+                       "height",        height,
+                       "anchor",        anchor,
+                       "corner-width",  corner_width,
+                       "corner-height", corner_height,
+                       "outside",       outside,
+                       NULL);
+}
+
+void
+gimp_canvas_corner_set (GimpCanvasItem *corner,
+                        gdouble         x,
+                        gdouble         y,
+                        gdouble         width,
+                        gdouble         height,
+                        gint            corner_width,
+                        gint            corner_height,
+                        gboolean        outside)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_CORNER (corner));
+
+  gimp_canvas_item_begin_change (corner);
+  g_object_set (corner,
+                "x",             x,
+                "y",             y,
+                "width",         width,
+                "height",        height,
+                "corner-width",  corner_width,
+                "corner-height", corner_height,
+                "outside",       outside,
+                NULL);
+  gimp_canvas_item_end_change (corner);
+}
diff --git a/app/display/gimpcanvascorner.h b/app/display/gimpcanvascorner.h
new file mode 100644
index 0000000..47cc53b
--- /dev/null
+++ b/app/display/gimpcanvascorner.h
@@ -0,0 +1,72 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascorner.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_CORNER_H__
+#define __GIMP_CANVAS_CORNER_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_CORNER            (gimp_canvas_corner_get_type ())
+#define GIMP_CANVAS_CORNER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_CORNER, GimpCanvasCorner))
+#define GIMP_CANVAS_CORNER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_CORNER, GimpCanvasCornerClass))
+#define GIMP_IS_CANVAS_CORNER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_CORNER))
+#define GIMP_IS_CANVAS_CORNER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_CORNER))
+#define GIMP_CANVAS_CORNER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_CORNER, GimpCanvasCornerClass))
+
+
+typedef struct _GimpCanvasCorner      GimpCanvasCorner;
+typedef struct _GimpCanvasCornerClass GimpCanvasCornerClass;
+
+struct _GimpCanvasCorner
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasCornerClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_corner_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_corner_new      (GimpDisplayShell *shell,
+                                              gdouble           x,
+                                              gdouble           y,
+                                              gdouble           width,
+                                              gdouble           height,
+                                              GimpHandleAnchor  anchor,
+                                              gint              corner_width,
+                                              gint              corner_height,
+                                              gboolean          outside);
+
+void             gimp_canvas_corner_set      (GimpCanvasItem   *corner,
+                                              gdouble           x,
+                                              gdouble           y,
+                                              gdouble           width,
+                                              gdouble           height,
+                                              gint              corner_width,
+                                              gint              corner_height,
+                                              gboolean          outside);
+
+
+#endif /* __GIMP_CANVAS_CORNER_H__ */
diff --git a/app/display/gimpcanvascursor.c b/app/display/gimpcanvascursor.c
new file mode 100644
index 0000000..581fa76
--- /dev/null
+++ b/app/display/gimpcanvascursor.c
@@ -0,0 +1,228 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascursor.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-cairo.h"
+
+#include "gimpcanvascursor.h"
+#include "gimpdisplayshell.h"
+
+
+#define GIMP_CURSOR_SIZE 7
+
+
+enum
+{
+  PROP_0,
+  PROP_X,
+  PROP_Y
+};
+
+
+typedef struct _GimpCanvasCursorPrivate GimpCanvasCursorPrivate;
+
+struct _GimpCanvasCursorPrivate
+{
+  gdouble x;
+  gdouble y;
+};
+
+#define GET_PRIVATE(cursor) \
+        ((GimpCanvasCursorPrivate *) gimp_canvas_cursor_get_instance_private ((GimpCanvasCursor *) (cursor)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_cursor_set_property (GObject        *object,
+                                                         guint           property_id,
+                                                         const GValue   *value,
+                                                         GParamSpec     *pspec);
+static void             gimp_canvas_cursor_get_property (GObject        *object,
+                                                         guint           property_id,
+                                                         GValue         *value,
+                                                         GParamSpec     *pspec);
+static void             gimp_canvas_cursor_draw         (GimpCanvasItem *item,
+                                                         cairo_t        *cr);
+static cairo_region_t * gimp_canvas_cursor_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasCursor, gimp_canvas_cursor,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_cursor_parent_class
+
+
+static void
+gimp_canvas_cursor_class_init (GimpCanvasCursorClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_cursor_set_property;
+  object_class->get_property = gimp_canvas_cursor_get_property;
+
+  item_class->draw           = gimp_canvas_cursor_draw;
+  item_class->get_extents    = gimp_canvas_cursor_get_extents;
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_cursor_init (GimpCanvasCursor *cursor)
+{
+  gimp_canvas_item_set_line_cap (GIMP_CANVAS_ITEM (cursor),
+                                 CAIRO_LINE_CAP_SQUARE);
+}
+
+static void
+gimp_canvas_cursor_set_property (GObject      *object,
+                                 guint         property_id,
+                                 const GValue *value,
+                                 GParamSpec   *pspec)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_cursor_get_property (GObject    *object,
+                                 guint       property_id,
+                                 GValue     *value,
+                                 GParamSpec *pspec)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_cursor_draw (GimpCanvasItem *item,
+                         cairo_t        *cr)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (item);
+  gdouble                  x, y;
+
+  x = floor (private->x) + 0.5;
+  y = floor (private->y) + 0.5;
+
+  cairo_move_to (cr, x - GIMP_CURSOR_SIZE, y);
+  cairo_line_to (cr, x + GIMP_CURSOR_SIZE, y);
+
+  cairo_move_to (cr, x, y - GIMP_CURSOR_SIZE);
+  cairo_line_to (cr, x, y + GIMP_CURSOR_SIZE);
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_cursor_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (item);
+  cairo_rectangle_int_t    rectangle;
+  gdouble                  x, y;
+
+  x = floor (private->x) + 0.5;
+  y = floor (private->y) + 0.5;
+
+  rectangle.x      = floor (x - GIMP_CURSOR_SIZE - 1.5);
+  rectangle.y      = floor (y - GIMP_CURSOR_SIZE - 1.5);
+  rectangle.width  = ceil (x + GIMP_CURSOR_SIZE + 1.5) - rectangle.x;
+  rectangle.height = ceil (y + GIMP_CURSOR_SIZE + 1.5) - rectangle.y;
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_cursor_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_CURSOR,
+                       "shell", shell,
+                       NULL);
+}
+
+void
+gimp_canvas_cursor_set (GimpCanvasItem *cursor,
+                        gdouble         x,
+                        gdouble         y)
+{
+  GimpCanvasCursorPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_CURSOR (cursor));
+
+  private = GET_PRIVATE (cursor);
+
+  if (private->x != x || private->y != y)
+    {
+      gimp_canvas_item_begin_change (cursor);
+
+      g_object_set (cursor,
+                    "x", x,
+                    "y", y,
+                    NULL);
+
+      gimp_canvas_item_end_change (cursor);
+    }
+}
diff --git a/app/display/gimpcanvascursor.h b/app/display/gimpcanvascursor.h
new file mode 100644
index 0000000..b518563
--- /dev/null
+++ b/app/display/gimpcanvascursor.h
@@ -0,0 +1,59 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascursor.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_CURSOR_H__
+#define __GIMP_CANVAS_CURSOR_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_CURSOR            (gimp_canvas_cursor_get_type ())
+#define GIMP_CANVAS_CURSOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_CURSOR, GimpCanvasCursor))
+#define GIMP_CANVAS_CURSOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_CURSOR, GimpCanvasCursorClass))
+#define GIMP_IS_CANVAS_CURSOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_CURSOR))
+#define GIMP_IS_CANVAS_CURSOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_CURSOR))
+#define GIMP_CANVAS_CURSOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_CURSOR, GimpCanvasCursorClass))
+
+
+typedef struct _GimpCanvasCursor      GimpCanvasCursor;
+typedef struct _GimpCanvasCursorClass GimpCanvasCursorClass;
+
+struct _GimpCanvasCursor
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasCursorClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_cursor_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_cursor_new      (GimpDisplayShell *shell);
+
+void             gimp_canvas_cursor_set      (GimpCanvasItem   *cursor,
+                                              gdouble           x,
+                                              gdouble           y);
+
+
+#endif /* __GIMP_CANVAS_CURSOR_H__ */
diff --git a/app/display/gimpcanvasgrid.c b/app/display/gimpcanvasgrid.c
new file mode 100644
index 0000000..23b46ee
--- /dev/null
+++ b/app/display/gimpcanvasgrid.c
@@ -0,0 +1,414 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasgrid.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpconfig/gimpconfig.h"
+
+#include "display-types.h"
+
+#include "core/gimpgrid.h"
+#include "core/gimpimage.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvasgrid.h"
+#include "gimpcanvasitem-utils.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scale.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_GRID,
+  PROP_GRID_STYLE
+};
+
+
+typedef struct _GimpCanvasGridPrivate GimpCanvasGridPrivate;
+
+struct _GimpCanvasGridPrivate
+{
+  GimpGrid *grid;
+  gboolean  grid_style;
+};
+
+#define GET_PRIVATE(grid) \
+        ((GimpCanvasGridPrivate *) gimp_canvas_grid_get_instance_private ((GimpCanvasGrid *) (grid)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_grid_finalize     (GObject        *object);
+static void             gimp_canvas_grid_set_property (GObject        *object,
+                                                       guint           property_id,
+                                                       const GValue   *value,
+                                                       GParamSpec     *pspec);
+static void             gimp_canvas_grid_get_property (GObject        *object,
+                                                       guint           property_id,
+                                                       GValue         *value,
+                                                       GParamSpec     *pspec);
+static void             gimp_canvas_grid_draw         (GimpCanvasItem *item,
+                                                       cairo_t        *cr);
+static cairo_region_t * gimp_canvas_grid_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_grid_stroke       (GimpCanvasItem *item,
+                                                       cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasGrid, gimp_canvas_grid,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_grid_parent_class
+
+
+static void
+gimp_canvas_grid_class_init (GimpCanvasGridClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_grid_finalize;
+  object_class->set_property = gimp_canvas_grid_set_property;
+  object_class->get_property = gimp_canvas_grid_get_property;
+
+  item_class->draw           = gimp_canvas_grid_draw;
+  item_class->get_extents    = gimp_canvas_grid_get_extents;
+  item_class->stroke         = gimp_canvas_grid_stroke;
+
+  g_object_class_install_property (object_class, PROP_GRID,
+                                   g_param_spec_object ("grid", NULL, NULL,
+                                                        GIMP_TYPE_GRID,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_GRID_STYLE,
+                                   g_param_spec_boolean ("grid-style",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_grid_init (GimpCanvasGrid *grid)
+{
+  GimpCanvasGridPrivate *private = GET_PRIVATE (grid);
+
+  private->grid = g_object_new (GIMP_TYPE_GRID, NULL);
+}
+
+static void
+gimp_canvas_grid_finalize (GObject *object)
+{
+  GimpCanvasGridPrivate *private = GET_PRIVATE (object);
+
+  g_clear_object (&private->grid);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_grid_set_property (GObject      *object,
+                               guint         property_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GimpCanvasGridPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_GRID:
+      {
+        GimpGrid *grid = g_value_get_object (value);
+        if (grid)
+          gimp_config_sync (G_OBJECT (grid), G_OBJECT (private->grid), 0);
+      }
+      break;
+    case PROP_GRID_STYLE:
+      private->grid_style = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_grid_get_property (GObject    *object,
+                               guint       property_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GimpCanvasGridPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_GRID:
+      g_value_set_object (value, private->grid);
+      break;
+    case PROP_GRID_STYLE:
+      g_value_set_boolean (value, private->grid_style);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_grid_draw (GimpCanvasItem *item,
+                       cairo_t        *cr)
+{
+  GimpCanvasGridPrivate *private = GET_PRIVATE (item);
+  GimpDisplayShell      *shell   = gimp_canvas_item_get_shell (item);
+  gdouble                xspacing, yspacing;
+  gdouble                xoffset, yoffset;
+  gboolean               vert, horz;
+  gdouble                dx1, dy1, dx2, dy2;
+  gint                   x1, y1, x2, y2;
+  gdouble                dx, dy;
+  gint                   x, y;
+
+#define CROSSHAIR 2
+
+  gimp_grid_get_spacing (private->grid, &xspacing, &yspacing);
+  gimp_grid_get_offset  (private->grid, &xoffset,  &yoffset);
+
+  g_return_if_fail (xspacing >= 0.0 &&
+                    yspacing >= 0.0);
+
+  xspacing *= shell->scale_x;
+  yspacing *= shell->scale_y;
+
+  xoffset  *= shell->scale_x;
+  yoffset  *= shell->scale_y;
+
+  /*  skip grid drawing when the space between grid lines starts
+   *  disappearing, see bug #599267.
+   */
+  vert = (xspacing >= 2.0);
+  horz = (yspacing >= 2.0);
+
+  if (! vert && ! horz)
+    return;
+
+  cairo_clip_extents (cr, &dx1, &dy1, &dx2, &dy2);
+
+  x1 = floor (dx1) - 1;
+  y1 = floor (dy1) - 1;
+  x2 = ceil  (dx2) + 1;
+  y2 = ceil  (dy2) + 1;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      GeglRectangle bounds;
+
+      gimp_display_shell_scale_get_image_unrotated_bounds (
+        shell,
+        &bounds.x, &bounds.y, &bounds.width, &bounds.height);
+
+      if (! gegl_rectangle_intersect (&bounds,
+                                      &bounds,
+                                      GEGL_RECTANGLE (x1,      y1,
+                                                      x2 - x1, y2 - y1)))
+        {
+          return;
+        }
+
+      x1 = bounds.x;
+      y1 = bounds.y;
+      x2 = bounds.x + bounds.width;
+      y2 = bounds.y + bounds.height;
+    }
+
+  switch (gimp_grid_get_style (private->grid))
+    {
+    case GIMP_GRID_INTERSECTIONS:
+      x1 -= CROSSHAIR;
+      y1 -= CROSSHAIR;
+      x2 += CROSSHAIR;
+      y2 += CROSSHAIR;
+      break;
+
+    case GIMP_GRID_DOTS:
+    case GIMP_GRID_ON_OFF_DASH:
+    case GIMP_GRID_DOUBLE_DASH:
+    case GIMP_GRID_SOLID:
+      break;
+    }
+
+  xoffset = fmod (xoffset - shell->offset_x - x1, xspacing);
+  yoffset = fmod (yoffset - shell->offset_y - y1, yspacing);
+
+  if (xoffset < 0.0)
+    xoffset += xspacing;
+
+  if (yoffset < 0.0)
+    yoffset += yspacing;
+
+  switch (gimp_grid_get_style (private->grid))
+    {
+    case GIMP_GRID_DOTS:
+      if (vert && horz)
+        {
+          for (dx = x1 + xoffset; dx <= x2; dx += xspacing)
+            {
+              x = RINT (dx);
+
+              for (dy = y1 + yoffset; dy <= y2; dy += yspacing)
+                {
+                  y = RINT (dy);
+
+                  cairo_move_to (cr, x,       y + 0.5);
+                  cairo_line_to (cr, x + 1.0, y + 0.5);
+                }
+            }
+        }
+      break;
+
+    case GIMP_GRID_INTERSECTIONS:
+      if (vert && horz)
+        {
+          for (dx = x1 + xoffset; dx <= x2; dx += xspacing)
+            {
+              x = RINT (dx);
+
+              for (dy = y1 + yoffset; dy <= y2; dy += yspacing)
+                {
+                  y = RINT (dy);
+
+                  cairo_move_to (cr, x + 0.5, y - CROSSHAIR);
+                  cairo_line_to (cr, x + 0.5, y + CROSSHAIR + 1.0);
+
+                  cairo_move_to (cr, x - CROSSHAIR, y + 0.5);
+                  cairo_line_to (cr, x + CROSSHAIR + 1.0, y + 0.5);
+                }
+            }
+        }
+      break;
+
+    case GIMP_GRID_ON_OFF_DASH:
+    case GIMP_GRID_DOUBLE_DASH:
+    case GIMP_GRID_SOLID:
+      if (vert)
+        {
+          for (dx = x1 + xoffset; dx < x2; dx += xspacing)
+            {
+              x = RINT (dx);
+              
+              cairo_move_to (cr, x + 0.5, y1);
+              cairo_line_to (cr, x + 0.5, y2);
+            }
+        }
+
+      if (horz)
+        {
+          for (dy = y1 + yoffset; dy < y2; dy += yspacing)
+            {
+              y = RINT (dy);
+              
+              cairo_move_to (cr, x1, y + 0.5);
+              cairo_line_to (cr, x2, y + 0.5);
+            }
+        }
+      break;
+    }
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_grid_get_extents (GimpCanvasItem *item)
+{
+  GimpDisplayShell      *shell = gimp_canvas_item_get_shell (item);
+  GimpImage             *image = gimp_canvas_item_get_image (item);
+  cairo_rectangle_int_t  rectangle;
+
+  if (! image)
+    return NULL;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      
+      gdouble x1, y1;
+      gdouble x2, y2;
+      gint    w, h;
+
+      w = gimp_image_get_width  (image);
+      h = gimp_image_get_height (image);
+
+      gimp_canvas_item_transform_xy_f (item, 0, 0, &x1, &y1);
+      gimp_canvas_item_transform_xy_f (item, w, h, &x2, &y2);
+
+      rectangle.x      = floor (x1);
+      rectangle.y      = floor (y1);
+      rectangle.width  = ceil (x2) - rectangle.x;
+      rectangle.height = ceil (y2) - rectangle.y;
+    }
+  else
+    {
+      gimp_canvas_item_untransform_viewport (item,
+                                             &rectangle.x,
+                                             &rectangle.y,
+                                             &rectangle.width,
+                                             &rectangle.height);
+    }
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+static void
+gimp_canvas_grid_stroke (GimpCanvasItem *item,
+                         cairo_t        *cr)
+{
+  GimpCanvasGridPrivate *private = GET_PRIVATE (item);
+
+  if (private->grid_style)
+    {
+      GimpDisplayShell *shell = gimp_canvas_item_get_shell (item);
+
+      gimp_canvas_set_grid_style (gimp_canvas_item_get_canvas (item), cr,
+                                  private->grid,
+                                  shell->offset_x, shell->offset_y);
+      cairo_stroke (cr);
+    }
+  else
+    {
+      GIMP_CANVAS_ITEM_CLASS (parent_class)->stroke (item, cr);
+    }
+}
+
+GimpCanvasItem *
+gimp_canvas_grid_new (GimpDisplayShell *shell,
+                      GimpGrid         *grid)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (grid == NULL || GIMP_IS_GRID (grid), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_GRID,
+                       "shell", shell,
+                       "grid",  grid,
+                       NULL);
+}
diff --git a/app/display/gimpcanvasgrid.h b/app/display/gimpcanvasgrid.h
new file mode 100644
index 0000000..391d2ea
--- /dev/null
+++ b/app/display/gimpcanvasgrid.h
@@ -0,0 +1,56 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasgrid.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_GRID_H__
+#define __GIMP_CANVAS_GRID_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_GRID            (gimp_canvas_grid_get_type ())
+#define GIMP_CANVAS_GRID(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_GRID, GimpCanvasGrid))
+#define GIMP_CANVAS_GRID_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_GRID, GimpCanvasGridClass))
+#define GIMP_IS_CANVAS_GRID(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_GRID))
+#define GIMP_IS_CANVAS_GRID_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_GRID))
+#define GIMP_CANVAS_GRID_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_GRID, GimpCanvasGridClass))
+
+
+typedef struct _GimpCanvasGrid      GimpCanvasGrid;
+typedef struct _GimpCanvasGridClass GimpCanvasGridClass;
+
+struct _GimpCanvasGrid
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasGridClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_grid_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_grid_new      (GimpDisplayShell *shell,
+                                            GimpGrid         *grid);
+
+
+#endif /* __GIMP_CANVAS_GRID_H__ */
diff --git a/app/display/gimpcanvasgroup.c b/app/display/gimpcanvasgroup.c
new file mode 100644
index 0000000..13d00ff
--- /dev/null
+++ b/app/display/gimpcanvasgroup.c
@@ -0,0 +1,387 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasgroup.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvasgroup.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_GROUP_STROKING,
+  PROP_GROUP_FILLING
+};
+
+
+struct _GimpCanvasGroupPrivate
+{
+  GQueue   *items;
+  gboolean  group_stroking;
+  gboolean  group_filling;
+};
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_group_finalize     (GObject         *object);
+static void             gimp_canvas_group_set_property (GObject         *object,
+                                                        guint            property_id,
+                                                        const GValue    *value,
+                                                        GParamSpec      *pspec);
+static void             gimp_canvas_group_get_property (GObject         *object,
+                                                        guint            property_id,
+                                                        GValue          *value,
+                                                        GParamSpec      *pspec);
+static void             gimp_canvas_group_draw         (GimpCanvasItem  *item,
+                                                        cairo_t         *cr);
+static cairo_region_t * gimp_canvas_group_get_extents  (GimpCanvasItem  *item);
+static gboolean         gimp_canvas_group_hit          (GimpCanvasItem  *item,
+                                                        gdouble          x,
+                                                        gdouble          y);
+
+static void             gimp_canvas_group_child_update (GimpCanvasItem  *item,
+                                                        cairo_region_t  *region,
+                                                        GimpCanvasGroup *group);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasGroup, gimp_canvas_group,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_group_parent_class
+
+
+static void
+gimp_canvas_group_class_init (GimpCanvasGroupClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_group_finalize;
+  object_class->set_property = gimp_canvas_group_set_property;
+  object_class->get_property = gimp_canvas_group_get_property;
+
+  item_class->draw           = gimp_canvas_group_draw;
+  item_class->get_extents    = gimp_canvas_group_get_extents;
+  item_class->hit            = gimp_canvas_group_hit;
+
+  g_object_class_install_property (object_class, PROP_GROUP_STROKING,
+                                   g_param_spec_boolean ("group-stroking",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_GROUP_FILLING,
+                                   g_param_spec_boolean ("group-filling",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_group_init (GimpCanvasGroup *group)
+{
+  group->priv = gimp_canvas_group_get_instance_private (group);
+
+  group->priv->items = g_queue_new ();
+}
+
+static void
+gimp_canvas_group_finalize (GObject *object)
+{
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (object);
+  GimpCanvasItem  *item;
+
+  while ((item = g_queue_peek_head (group->priv->items)))
+    gimp_canvas_group_remove_item (group, item);
+
+  g_queue_free (group->priv->items);
+  group->priv->items = NULL;
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_group_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (object);
+
+  switch (property_id)
+    {
+    case PROP_GROUP_STROKING:
+      group->priv->group_stroking = g_value_get_boolean (value);
+      break;
+    case PROP_GROUP_FILLING:
+      group->priv->group_filling = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_group_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (object);
+
+  switch (property_id)
+    {
+    case PROP_GROUP_STROKING:
+      g_value_set_boolean (value, group->priv->group_stroking);
+      break;
+    case PROP_GROUP_FILLING:
+      g_value_set_boolean (value, group->priv->group_filling);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_group_draw (GimpCanvasItem *item,
+                        cairo_t        *cr)
+{
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (item);
+  GList           *list;
+
+  for (list = group->priv->items->head; list; list = g_list_next (list))
+    {
+      GimpCanvasItem *sub_item = list->data;
+
+      gimp_canvas_item_draw (sub_item, cr);
+    }
+
+  if (group->priv->group_stroking)
+    _gimp_canvas_item_stroke (item, cr);
+
+  if (group->priv->group_filling)
+    _gimp_canvas_item_fill (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_group_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasGroup *group  = GIMP_CANVAS_GROUP (item);
+  cairo_region_t  *region = NULL;
+  GList           *list;
+
+  for (list = group->priv->items->head; list; list = g_list_next (list))
+    {
+      GimpCanvasItem *sub_item   = list->data;
+      cairo_region_t *sub_region = gimp_canvas_item_get_extents (sub_item);
+
+      if (! region)
+        {
+          region = sub_region;
+        }
+      else if (sub_region)
+        {
+          cairo_region_union (region, sub_region);
+          cairo_region_destroy (sub_region);
+        }
+    }
+
+  return region;
+}
+
+static gboolean
+gimp_canvas_group_hit (GimpCanvasItem *item,
+                       gdouble         x,
+                       gdouble         y)
+{
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (item);
+  GList           *list;
+
+  for (list = group->priv->items->head; list; list = g_list_next (list))
+    {
+      if (gimp_canvas_item_hit (list->data, x, y))
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_canvas_group_child_update (GimpCanvasItem  *item,
+                                cairo_region_t  *region,
+                                GimpCanvasGroup *group)
+{
+  if (_gimp_canvas_item_needs_update (GIMP_CANVAS_ITEM (group)))
+    _gimp_canvas_item_update (GIMP_CANVAS_ITEM (group), region);
+}
+
+
+/*  public functions  */
+
+GimpCanvasItem *
+gimp_canvas_group_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_GROUP,
+                       "shell", shell,
+                       NULL);
+}
+
+void
+gimp_canvas_group_add_item (GimpCanvasGroup *group,
+                            GimpCanvasItem  *item)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+  g_return_if_fail (GIMP_CANVAS_ITEM (group) != item);
+
+  if (group->priv->group_stroking)
+    gimp_canvas_item_suspend_stroking (item);
+
+  if (group->priv->group_filling)
+    gimp_canvas_item_suspend_filling (item);
+
+  g_queue_push_tail (group->priv->items, g_object_ref (item));
+
+  if (_gimp_canvas_item_needs_update (GIMP_CANVAS_ITEM (group)))
+    {
+      cairo_region_t *region = gimp_canvas_item_get_extents (item);
+
+      if (region)
+        {
+          _gimp_canvas_item_update (GIMP_CANVAS_ITEM (group), region);
+          cairo_region_destroy (region);
+        }
+    }
+
+  g_signal_connect (item, "update",
+                    G_CALLBACK (gimp_canvas_group_child_update),
+                    group);
+}
+
+void
+gimp_canvas_group_remove_item (GimpCanvasGroup *group,
+                               GimpCanvasItem  *item)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  list = g_queue_find (group->priv->items, item);
+
+  g_return_if_fail (list != NULL);
+
+  g_queue_delete_link (group->priv->items, list);
+
+  if (group->priv->group_stroking)
+    gimp_canvas_item_resume_stroking (item);
+
+  if (group->priv->group_filling)
+    gimp_canvas_item_resume_filling (item);
+
+  if (_gimp_canvas_item_needs_update (GIMP_CANVAS_ITEM (group)))
+    {
+      cairo_region_t *region = gimp_canvas_item_get_extents (item);
+
+      if (region)
+        {
+          _gimp_canvas_item_update (GIMP_CANVAS_ITEM (group), region);
+          cairo_region_destroy (region);
+        }
+    }
+
+  g_signal_handlers_disconnect_by_func (item,
+                                        gimp_canvas_group_child_update,
+                                        group);
+
+  g_object_unref (item);
+}
+
+void
+gimp_canvas_group_set_group_stroking (GimpCanvasGroup *group,
+                                      gboolean         group_stroking)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
+
+  if (group->priv->group_stroking != group_stroking)
+    {
+      GList *list;
+
+      gimp_canvas_item_begin_change (GIMP_CANVAS_ITEM (group));
+
+      g_object_set (group,
+                    "group-stroking", group_stroking ? TRUE : FALSE,
+                    NULL);
+
+      for (list = group->priv->items->head; list; list = g_list_next (list))
+        {
+          if (group->priv->group_stroking)
+            gimp_canvas_item_suspend_stroking (list->data);
+          else
+            gimp_canvas_item_resume_stroking (list->data);
+        }
+
+      gimp_canvas_item_end_change (GIMP_CANVAS_ITEM (group));
+    }
+}
+
+void
+gimp_canvas_group_set_group_filling (GimpCanvasGroup *group,
+                                     gboolean         group_filling)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
+
+  if (group->priv->group_filling != group_filling)
+    {
+      GList *list;
+
+      gimp_canvas_item_begin_change (GIMP_CANVAS_ITEM (group));
+
+      g_object_set (group,
+                    "group-filling", group_filling ? TRUE : FALSE,
+                    NULL);
+
+      for (list = group->priv->items->head; list; list = g_list_next (list))
+        {
+          if (group->priv->group_filling)
+            gimp_canvas_item_suspend_filling (list->data);
+          else
+            gimp_canvas_item_resume_filling (list->data);
+        }
+
+      gimp_canvas_item_end_change (GIMP_CANVAS_ITEM (group));
+    }
+}
diff --git a/app/display/gimpcanvasgroup.h b/app/display/gimpcanvasgroup.h
new file mode 100644
index 0000000..d2fb9cc
--- /dev/null
+++ b/app/display/gimpcanvasgroup.h
@@ -0,0 +1,68 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasgroup.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_GROUP_H__
+#define __GIMP_CANVAS_GROUP_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_GROUP            (gimp_canvas_group_get_type ())
+#define GIMP_CANVAS_GROUP(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_GROUP, GimpCanvasGroup))
+#define GIMP_CANVAS_GROUP_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_GROUP, GimpCanvasGroupClass))
+#define GIMP_IS_CANVAS_GROUP(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_GROUP))
+#define GIMP_IS_CANVAS_GROUP_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_GROUP))
+#define GIMP_CANVAS_GROUP_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_GROUP, GimpCanvasGroupClass))
+
+
+typedef struct _GimpCanvasGroupPrivate GimpCanvasGroupPrivate;
+typedef struct _GimpCanvasGroupClass   GimpCanvasGroupClass;
+
+struct _GimpCanvasGroup
+{
+  GimpCanvasItem          parent_instance;
+
+  GimpCanvasGroupPrivate *priv;
+
+};
+
+struct _GimpCanvasGroupClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_group_get_type           (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_group_new                (GimpDisplayShell *shell);
+
+void             gimp_canvas_group_add_item           (GimpCanvasGroup  *group,
+                                                       GimpCanvasItem   *item);
+void             gimp_canvas_group_remove_item        (GimpCanvasGroup  *group,
+                                                       GimpCanvasItem   *item);
+
+void             gimp_canvas_group_set_group_stroking (GimpCanvasGroup  *group,
+                                                       gboolean          group_stroking);
+void             gimp_canvas_group_set_group_filling  (GimpCanvasGroup  *group,
+                                                       gboolean          group_filling);
+
+
+#endif /* __GIMP_CANVAS_GROUP_H__ */
diff --git a/app/display/gimpcanvasguide.c b/app/display/gimpcanvasguide.c
new file mode 100644
index 0000000..5712633
--- /dev/null
+++ b/app/display/gimpcanvasguide.c
@@ -0,0 +1,295 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasguide.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvasguide.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_ORIENTATION,
+  PROP_POSITION,
+  PROP_STYLE
+};
+
+
+typedef struct _GimpCanvasGuidePrivate GimpCanvasGuidePrivate;
+
+struct _GimpCanvasGuidePrivate
+{
+  GimpOrientationType  orientation;
+  gint                 position;
+
+  GimpGuideStyle       style;
+};
+
+#define GET_PRIVATE(guide) \
+        ((GimpCanvasGuidePrivate *) gimp_canvas_guide_get_instance_private ((GimpCanvasGuide *) (guide)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_guide_set_property (GObject        *object,
+                                                        guint           property_id,
+                                                        const GValue   *value,
+                                                        GParamSpec     *pspec);
+static void             gimp_canvas_guide_get_property (GObject        *object,
+                                                        guint           property_id,
+                                                        GValue         *value,
+                                                        GParamSpec     *pspec);
+static void             gimp_canvas_guide_draw         (GimpCanvasItem *item,
+                                                        cairo_t        *cr);
+static cairo_region_t * gimp_canvas_guide_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_guide_stroke       (GimpCanvasItem *item,
+                                                        cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasGuide, gimp_canvas_guide,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_guide_parent_class
+
+
+static void
+gimp_canvas_guide_class_init (GimpCanvasGuideClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_guide_set_property;
+  object_class->get_property = gimp_canvas_guide_get_property;
+
+  item_class->draw           = gimp_canvas_guide_draw;
+  item_class->get_extents    = gimp_canvas_guide_get_extents;
+  item_class->stroke         = gimp_canvas_guide_stroke;
+
+  g_object_class_install_property (object_class, PROP_ORIENTATION,
+                                   g_param_spec_enum ("orientation", NULL, NULL,
+                                                      GIMP_TYPE_ORIENTATION_TYPE,
+                                                      GIMP_ORIENTATION_HORIZONTAL,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_POSITION,
+                                   g_param_spec_int ("position", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_STYLE,
+                                   g_param_spec_enum ("style", NULL, NULL,
+                                                      GIMP_TYPE_GUIDE_STYLE,
+                                                      GIMP_GUIDE_STYLE_NONE,
+                                                      GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_guide_init (GimpCanvasGuide *guide)
+{
+}
+
+static void
+gimp_canvas_guide_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  GimpCanvasGuidePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      private->orientation = g_value_get_enum (value);
+      break;
+    case PROP_POSITION:
+      private->position = g_value_get_int (value);
+      break;
+    case PROP_STYLE:
+      private->style = g_value_get_enum (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_guide_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  GimpCanvasGuidePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      g_value_set_enum (value, private->orientation);
+      break;
+    case PROP_POSITION:
+      g_value_set_int (value, private->position);
+      break;
+    case PROP_STYLE:
+      g_value_set_enum (value, private->style);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_guide_transform (GimpCanvasItem *item,
+                             gdouble        *x1,
+                             gdouble        *y1,
+                             gdouble        *x2,
+                             gdouble        *y2)
+{
+  GimpCanvasGuidePrivate *private = GET_PRIVATE (item);
+  GtkWidget              *canvas  = gimp_canvas_item_get_canvas (item);
+  GtkAllocation           allocation;
+  gint                    max_outside;
+  gint                    x, y;
+
+  gtk_widget_get_allocation (canvas, &allocation);
+
+  max_outside = allocation.width + allocation.height;
+
+  *x1 = -max_outside;
+  *y1 = -max_outside;
+  *x2 = allocation.width  + max_outside;
+  *y2 = allocation.height + max_outside;
+
+  switch (private->orientation)
+    {
+    case GIMP_ORIENTATION_HORIZONTAL:
+      gimp_canvas_item_transform_xy (item, 0, private->position, &x, &y);
+      *y1 = *y2 = y + 0.5;
+      break;
+
+    case GIMP_ORIENTATION_VERTICAL:
+      gimp_canvas_item_transform_xy (item, private->position, 0, &x, &y);
+      *x1 = *x2 = x + 0.5;
+      break;
+
+    case GIMP_ORIENTATION_UNKNOWN:
+      return;
+    }
+}
+
+static void
+gimp_canvas_guide_draw (GimpCanvasItem *item,
+                        cairo_t        *cr)
+{
+  gdouble x1, y1;
+  gdouble x2, y2;
+
+  gimp_canvas_guide_transform (item, &x1, &y1, &x2, &y2);
+
+  cairo_move_to (cr, x1, y1);
+  cairo_line_to (cr, x2, y2);
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_guide_get_extents (GimpCanvasItem *item)
+{
+  cairo_rectangle_int_t rectangle;
+  gdouble               x1, y1;
+  gdouble               x2, y2;
+
+  gimp_canvas_guide_transform (item, &x1, &y1, &x2, &y2);
+
+  rectangle.x      = MIN (x1, x2) - 1.5;
+  rectangle.y      = MIN (y1, y2) - 1.5;
+  rectangle.width  = ABS (x2 - x1) + 3.0;
+  rectangle.height = ABS (y2 - y1) + 3.0;
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+static void
+gimp_canvas_guide_stroke (GimpCanvasItem *item,
+                          cairo_t        *cr)
+{
+  GimpCanvasGuidePrivate *private = GET_PRIVATE (item);
+
+  if (private->style != GIMP_GUIDE_STYLE_NONE)
+    {
+      GimpDisplayShell *shell = gimp_canvas_item_get_shell (item);
+
+      gimp_canvas_set_guide_style (gimp_canvas_item_get_canvas (item), cr,
+                                   private->style,
+                                   gimp_canvas_item_get_highlight (item),
+                                   shell->offset_x, shell->offset_y);
+      cairo_stroke (cr);
+    }
+  else
+    {
+      GIMP_CANVAS_ITEM_CLASS (parent_class)->stroke (item, cr);
+    }
+}
+
+GimpCanvasItem *
+gimp_canvas_guide_new (GimpDisplayShell    *shell,
+                       GimpOrientationType  orientation,
+                       gint                 position,
+                       GimpGuideStyle       style)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_GUIDE,
+                       "shell",        shell,
+                       "orientation",  orientation,
+                       "position",     position,
+                       "style",        style,
+                       NULL);
+}
+
+void
+gimp_canvas_guide_set (GimpCanvasItem      *guide,
+                       GimpOrientationType  orientation,
+                       gint                 position)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_GUIDE (guide));
+
+  gimp_canvas_item_begin_change (guide);
+
+  g_object_set (guide,
+                "orientation", orientation,
+                "position",    position,
+                NULL);
+
+  gimp_canvas_item_end_change (guide);
+}
diff --git a/app/display/gimpcanvasguide.h b/app/display/gimpcanvasguide.h
new file mode 100644
index 0000000..54b1696
--- /dev/null
+++ b/app/display/gimpcanvasguide.h
@@ -0,0 +1,62 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasguide.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_GUIDE_H__
+#define __GIMP_CANVAS_GUIDE_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_GUIDE            (gimp_canvas_guide_get_type ())
+#define GIMP_CANVAS_GUIDE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_GUIDE, GimpCanvasGuide))
+#define GIMP_CANVAS_GUIDE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_GUIDE, GimpCanvasGuideClass))
+#define GIMP_IS_CANVAS_GUIDE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_GUIDE))
+#define GIMP_IS_CANVAS_GUIDE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_GUIDE))
+#define GIMP_CANVAS_GUIDE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_GUIDE, GimpCanvasGuideClass))
+
+
+typedef struct _GimpCanvasGuide      GimpCanvasGuide;
+typedef struct _GimpCanvasGuideClass GimpCanvasGuideClass;
+
+struct _GimpCanvasGuide
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasGuideClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_guide_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_guide_new      (GimpDisplayShell    *shell,
+                                             GimpOrientationType  orientation,
+                                             gint                 position,
+                                             GimpGuideStyle       style);
+
+void             gimp_canvas_guide_set      (GimpCanvasItem      *guide,
+                                             GimpOrientationType  orientation,
+                                             gint                 position);
+
+
+#endif /* __GIMP_CANVAS_GUIDE_H__ */
diff --git a/app/display/gimpcanvashandle.c b/app/display/gimpcanvashandle.c
new file mode 100644
index 0000000..954eead
--- /dev/null
+++ b/app/display/gimpcanvashandle.c
@@ -0,0 +1,703 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvashandle.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-cairo.h"
+
+#include "gimpcanvashandle.h"
+#include "gimpcanvasitem-utils.h"
+#include "gimpdisplayshell.h"
+
+
+#define N_DASHES       8
+#define DASH_ON_RATIO  0.3
+#define DASH_OFF_RATIO 0.7
+
+
+enum
+{
+  PROP_0,
+  PROP_TYPE,
+  PROP_ANCHOR,
+  PROP_X,
+  PROP_Y,
+  PROP_WIDTH,
+  PROP_HEIGHT,
+  PROP_START_ANGLE,
+  PROP_SLICE_ANGLE
+};
+
+
+typedef struct _GimpCanvasHandlePrivate GimpCanvasHandlePrivate;
+
+struct _GimpCanvasHandlePrivate
+{
+  GimpHandleType   type;
+  GimpHandleAnchor anchor;
+  gdouble          x;
+  gdouble          y;
+  gint             width;
+  gint             height;
+  gdouble          start_angle;
+  gdouble          slice_angle;
+};
+
+#define GET_PRIVATE(handle) \
+        ((GimpCanvasHandlePrivate *) gimp_canvas_handle_get_instance_private ((GimpCanvasHandle *) (handle)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_handle_set_property (GObject        *object,
+                                                         guint           property_id,
+                                                         const GValue   *value,
+                                                         GParamSpec     *pspec);
+static void             gimp_canvas_handle_get_property (GObject        *object,
+                                                         guint           property_id,
+                                                         GValue         *value,
+                                                         GParamSpec     *pspec);
+static void             gimp_canvas_handle_draw         (GimpCanvasItem *item,
+                                                         cairo_t        *cr);
+static cairo_region_t * gimp_canvas_handle_get_extents  (GimpCanvasItem *item);
+static gboolean         gimp_canvas_handle_hit          (GimpCanvasItem *item,
+                                                         gdouble         x,
+                                                         gdouble         y);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasHandle, gimp_canvas_handle,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_handle_parent_class
+
+
+static void
+gimp_canvas_handle_class_init (GimpCanvasHandleClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_handle_set_property;
+  object_class->get_property = gimp_canvas_handle_get_property;
+
+  item_class->draw           = gimp_canvas_handle_draw;
+  item_class->get_extents    = gimp_canvas_handle_get_extents;
+  item_class->hit            = gimp_canvas_handle_hit;
+
+  g_object_class_install_property (object_class, PROP_TYPE,
+                                   g_param_spec_enum ("type", NULL, NULL,
+                                                      GIMP_TYPE_HANDLE_TYPE,
+                                                      GIMP_HANDLE_CROSS,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_ANCHOR,
+                                   g_param_spec_enum ("anchor", NULL, NULL,
+                                                      GIMP_TYPE_HANDLE_ANCHOR,
+                                                      GIMP_HANDLE_ANCHOR_CENTER,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_WIDTH,
+                                   g_param_spec_int ("width", NULL, NULL,
+                                                     3, 1001, 7,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_HEIGHT,
+                                   g_param_spec_int ("height", NULL, NULL,
+                                                     3, 1001, 7,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_START_ANGLE,
+                                   g_param_spec_double ("start-angle", NULL, NULL,
+                                                        -1000, 1000, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_SLICE_ANGLE,
+                                   g_param_spec_double ("slice-angle", NULL, NULL,
+                                                        -1000, 1000, 2 * G_PI,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_handle_init (GimpCanvasHandle *handle)
+{
+  GimpCanvasHandlePrivate *private = GET_PRIVATE (handle);
+
+  gimp_canvas_item_set_line_cap (GIMP_CANVAS_ITEM (handle),
+                                 CAIRO_LINE_CAP_SQUARE);
+
+  private->start_angle = 0.0;
+  private->slice_angle = 2.0 * G_PI;
+}
+
+static void
+gimp_canvas_handle_set_property (GObject      *object,
+                                 guint         property_id,
+                                 const GValue *value,
+                                 GParamSpec   *pspec)
+{
+  GimpCanvasHandlePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_TYPE:
+      private->type = g_value_get_enum (value);
+      break;
+    case PROP_ANCHOR:
+      private->anchor = g_value_get_enum (value);
+      break;
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+    case PROP_WIDTH:
+      private->width = g_value_get_int (value);
+      break;
+    case PROP_HEIGHT:
+      private->height = g_value_get_int (value);
+      break;
+    case PROP_START_ANGLE:
+      private->start_angle = g_value_get_double (value);
+      break;
+    case PROP_SLICE_ANGLE:
+      private->slice_angle = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_handle_get_property (GObject    *object,
+                                 guint       property_id,
+                                 GValue     *value,
+                                 GParamSpec *pspec)
+{
+  GimpCanvasHandlePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_TYPE:
+      g_value_set_enum (value, private->type);
+      break;
+    case PROP_ANCHOR:
+      g_value_set_enum (value, private->anchor);
+      break;
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+    case PROP_WIDTH:
+      g_value_set_int (value, private->width);
+      break;
+    case PROP_HEIGHT:
+      g_value_set_int (value, private->height);
+      break;
+    case PROP_START_ANGLE:
+      g_value_set_double (value, private->start_angle);
+      break;
+    case PROP_SLICE_ANGLE:
+      g_value_set_double (value, private->slice_angle);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_handle_transform (GimpCanvasItem *item,
+                              gdouble        *x,
+                              gdouble        *y)
+{
+  GimpCanvasHandlePrivate *private = GET_PRIVATE (item);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->x, private->y,
+                                   x, y);
+
+  switch (private->type)
+    {
+    case GIMP_HANDLE_SQUARE:
+    case GIMP_HANDLE_DASHED_SQUARE:
+    case GIMP_HANDLE_FILLED_SQUARE:
+      gimp_canvas_item_shift_to_north_west (private->anchor,
+                                            *x, *y,
+                                            private->width,
+                                            private->height,
+                                            x, y);
+      break;
+
+    case GIMP_HANDLE_CIRCLE:
+    case GIMP_HANDLE_DASHED_CIRCLE:
+    case GIMP_HANDLE_FILLED_CIRCLE:
+    case GIMP_HANDLE_CROSS:
+    case GIMP_HANDLE_CROSSHAIR:
+    case GIMP_HANDLE_DIAMOND:
+    case GIMP_HANDLE_DASHED_DIAMOND:
+    case GIMP_HANDLE_FILLED_DIAMOND:
+      gimp_canvas_item_shift_to_center (private->anchor,
+                                        *x, *y,
+                                        private->width,
+                                        private->height,
+                                        x, y);
+      break;
+
+    default:
+      break;
+    }
+
+  *x = floor (*x) + 0.5;
+  *y = floor (*y) + 0.5;
+}
+
+static void
+gimp_canvas_handle_draw (GimpCanvasItem *item,
+                         cairo_t        *cr)
+{
+  GimpCanvasHandlePrivate *private = GET_PRIVATE (item);
+  gdouble                  x, y, tx, ty;
+
+  gimp_canvas_handle_transform (item, &x, &y);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->x, private->y,
+                                   &tx, &ty);
+
+  tx = floor (tx) + 0.5;
+  ty = floor (ty) + 0.5;
+
+  switch (private->type)
+    {
+    case GIMP_HANDLE_SQUARE:
+    case GIMP_HANDLE_DASHED_SQUARE:
+    case GIMP_HANDLE_FILLED_SQUARE:
+    case GIMP_HANDLE_DIAMOND:
+    case GIMP_HANDLE_DASHED_DIAMOND:
+    case GIMP_HANDLE_FILLED_DIAMOND:
+    case GIMP_HANDLE_CROSS:
+      cairo_save (cr);
+      cairo_translate (cr, tx, ty);
+      cairo_rotate (cr, private->start_angle);
+      cairo_translate (cr, -tx, -ty);
+
+      switch (private->type)
+        {
+        case GIMP_HANDLE_SQUARE:
+        case GIMP_HANDLE_DASHED_SQUARE:
+          if (private->type == GIMP_HANDLE_DASHED_SQUARE)
+            {
+              gdouble circ;
+              gdouble dashes[2];
+
+              cairo_save (cr);
+
+              circ = 2.0 * ((private->width - 1.0) + (private->height - 1.0));
+
+              dashes[0] = (circ / N_DASHES) * DASH_ON_RATIO;
+              dashes[1] = (circ / N_DASHES) * DASH_OFF_RATIO;
+
+              cairo_set_dash (cr, dashes, 2, dashes[0] / 2.0);
+            }
+
+          cairo_rectangle (cr, x, y, private->width - 1.0, private->height - 1.0);
+          _gimp_canvas_item_stroke (item, cr);
+
+          if (private->type == GIMP_HANDLE_DASHED_SQUARE)
+            cairo_restore (cr);
+          break;
+
+        case GIMP_HANDLE_FILLED_SQUARE:
+          cairo_rectangle (cr, x - 0.5, y - 0.5, private->width, private->height);
+          _gimp_canvas_item_fill (item, cr);
+          break;
+
+        case GIMP_HANDLE_DIAMOND:
+        case GIMP_HANDLE_DASHED_DIAMOND:
+        case GIMP_HANDLE_FILLED_DIAMOND:
+          if (private->type == GIMP_HANDLE_DASHED_DIAMOND)
+            {
+              gdouble circ;
+              gdouble dashes[2];
+
+              cairo_save (cr);
+
+              circ = 4.0 * hypot ((gdouble) private->width  / 2.0,
+                                  (gdouble) private->height / 2.0);
+
+              dashes[0] = (circ / N_DASHES) * DASH_ON_RATIO;
+              dashes[1] = (circ / N_DASHES) * DASH_OFF_RATIO;
+
+              cairo_set_dash (cr, dashes, 2, dashes[0] / 2.0);
+            }
+
+          cairo_move_to (cr, x, y - (gdouble) private->height / 2.0);
+          cairo_line_to (cr, x + (gdouble) private->width / 2.0, y);
+          cairo_line_to (cr, x, y + (gdouble) private->height / 2.0);
+          cairo_line_to (cr, x - (gdouble) private->width / 2.0, y);
+          cairo_line_to (cr, x, y - (gdouble) private->height / 2.0);
+          if (private->type == GIMP_HANDLE_DIAMOND ||
+              private->type == GIMP_HANDLE_DASHED_DIAMOND)
+            _gimp_canvas_item_stroke (item, cr);
+          else
+            _gimp_canvas_item_fill (item, cr);
+
+          if (private->type == GIMP_HANDLE_DASHED_SQUARE)
+            cairo_restore (cr);
+          break;
+
+        case GIMP_HANDLE_CROSS:
+          cairo_move_to (cr, x - private->width / 2.0, y);
+          cairo_line_to (cr, x + private->width / 2.0 - 0.5, y);
+          cairo_move_to (cr, x, y - private->height / 2.0);
+          cairo_line_to (cr, x, y + private->height / 2.0 - 0.5);
+          _gimp_canvas_item_stroke (item, cr);
+          break;
+
+        default:
+          gimp_assert_not_reached ();
+        }
+
+      cairo_restore (cr);
+      break;
+
+    case GIMP_HANDLE_CIRCLE:
+    case GIMP_HANDLE_DASHED_CIRCLE:
+      if (private->type == GIMP_HANDLE_DASHED_CIRCLE)
+        {
+          gdouble circ;
+          gdouble dashes[2];
+
+          cairo_save (cr);
+
+          circ = 2.0 * G_PI * (private->width / 2.0);
+
+          dashes[0] = (circ / N_DASHES) * DASH_ON_RATIO;
+          dashes[1] = (circ / N_DASHES) * DASH_OFF_RATIO;
+
+          cairo_set_dash (cr, dashes, 2, dashes[0] / 2.0);
+        }
+
+      gimp_cairo_arc (cr, x, y, private->width / 2.0,
+                      private->start_angle,
+                      private->slice_angle);
+
+      _gimp_canvas_item_stroke (item, cr);
+
+      if (private->type == GIMP_HANDLE_DASHED_CIRCLE)
+        cairo_restore (cr);
+      break;
+
+    case GIMP_HANDLE_FILLED_CIRCLE:
+      cairo_move_to (cr, x, y);
+
+      gimp_cairo_arc (cr, x, y, (gdouble) private->width / 2.0,
+                      private->start_angle,
+                      private->slice_angle);
+
+      _gimp_canvas_item_fill (item, cr);
+      break;
+
+    case GIMP_HANDLE_CROSSHAIR:
+      cairo_move_to (cr, x - private->width / 2.0, y);
+      cairo_line_to (cr, x - private->width * 0.4, y);
+
+      cairo_move_to (cr, x + private->width / 2.0 - 0.5, y);
+      cairo_line_to (cr, x + private->width * 0.4, y);
+
+      cairo_move_to (cr, x, y - private->height / 2.0);
+      cairo_line_to (cr, x, y - private->height * 0.4 - 0.5);
+
+      cairo_move_to (cr, x, y + private->height / 2.0 - 0.5);
+      cairo_line_to (cr, x, y + private->height * 0.4 - 0.5);
+
+       _gimp_canvas_item_stroke (item, cr);
+      break;
+
+    default:
+      break;
+    }
+}
+
+static cairo_region_t *
+gimp_canvas_handle_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasHandlePrivate *private = GET_PRIVATE (item);
+  cairo_rectangle_int_t    rectangle;
+  gdouble                  x, y;
+  gdouble                  w, h;
+
+  gimp_canvas_handle_transform (item, &x, &y);
+
+  switch (private->type)
+    {
+    case GIMP_HANDLE_SQUARE:
+    case GIMP_HANDLE_DASHED_SQUARE:
+    case GIMP_HANDLE_FILLED_SQUARE:
+      w = private->width * (sqrt(2) - 1) / 2;
+      h = private->height * (sqrt(2) - 1) / 2;
+      rectangle.x      = x - 1.5 - w;
+      rectangle.y      = y - 1.5 - h;
+      rectangle.width  = private->width  + 3.0 + w * 2;
+      rectangle.height = private->height + 3.0 + h * 2;
+      break;
+
+    case GIMP_HANDLE_CIRCLE:
+    case GIMP_HANDLE_DASHED_CIRCLE:
+    case GIMP_HANDLE_FILLED_CIRCLE:
+    case GIMP_HANDLE_CROSS:
+    case GIMP_HANDLE_CROSSHAIR:
+    case GIMP_HANDLE_DIAMOND:
+    case GIMP_HANDLE_DASHED_DIAMOND:
+    case GIMP_HANDLE_FILLED_DIAMOND:
+      rectangle.x      = x - private->width  / 2.0 - 2.0;
+      rectangle.y      = y - private->height / 2.0 - 2.0;
+      rectangle.width  = private->width  + 4.0;
+      rectangle.height = private->height + 4.0;
+      break;
+
+    default:
+      break;
+    }
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+static gboolean
+gimp_canvas_handle_hit (GimpCanvasItem *item,
+                        gdouble         x,
+                        gdouble         y)
+{
+  GimpCanvasHandlePrivate *private = GET_PRIVATE (item);
+  gdouble                  handle_tx, handle_ty;
+  gdouble                  mx, my, tx, ty, mmx, mmy;
+  gdouble                  diamond_offset_x = 0.0;
+  gdouble                  diamond_offset_y = 0.0;
+  gdouble                  angle            = -private->start_angle;
+
+  gimp_canvas_handle_transform (item, &handle_tx, &handle_ty);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   x, y,
+                                   &mx, &my);
+
+  switch (private->type)
+    {
+    case GIMP_HANDLE_DIAMOND:
+    case GIMP_HANDLE_DASHED_DIAMOND:
+    case GIMP_HANDLE_FILLED_DIAMOND:
+      angle -= G_PI / 4.0;
+      diamond_offset_x = private->width / 2.0;
+      diamond_offset_y = private->height / 2.0;
+    case GIMP_HANDLE_SQUARE:
+    case GIMP_HANDLE_DASHED_SQUARE:
+    case GIMP_HANDLE_FILLED_SQUARE:
+      gimp_canvas_item_transform_xy_f (item,
+                                       private->x, private->y,
+                                       &tx, &ty);
+      mmx = mx - tx; mmy = my - ty;
+      mx = cos (angle) * mmx - sin (angle) * mmy + tx + diamond_offset_x;
+      my = sin (angle) * mmx + cos (angle) * mmy + ty + diamond_offset_y;
+      return mx > handle_tx && mx < handle_tx + private->width &&
+             my > handle_ty && my < handle_ty + private->height;
+
+    case GIMP_HANDLE_CIRCLE:
+    case GIMP_HANDLE_DASHED_CIRCLE:
+    case GIMP_HANDLE_FILLED_CIRCLE:
+    case GIMP_HANDLE_CROSS:
+    case GIMP_HANDLE_CROSSHAIR:
+      {
+        gint width = private->width;
+
+        if (width != private->height)
+          width = (width + private->height) / 2;
+
+        width /= 2;
+
+        return ((SQR (handle_tx - mx) + SQR (handle_ty - my)) < SQR (width));
+      }
+
+    default:
+      break;
+    }
+
+  return FALSE;
+}
+
+GimpCanvasItem *
+gimp_canvas_handle_new (GimpDisplayShell *shell,
+                        GimpHandleType    type,
+                        GimpHandleAnchor  anchor,
+                        gdouble           x,
+                        gdouble           y,
+                        gint              width,
+                        gint              height)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_HANDLE,
+                       "shell",  shell,
+                       "type",   type,
+                       "anchor", anchor,
+                       "x",      x,
+                       "y",      y,
+                       "width",  width,
+                       "height", height,
+                       NULL);
+}
+
+void
+gimp_canvas_handle_get_position (GimpCanvasItem *handle,
+                                 gdouble        *x,
+                                 gdouble        *y)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_HANDLE (handle));
+  g_return_if_fail (x != NULL);
+  g_return_if_fail (y != NULL);
+
+  g_object_get (handle,
+                "x", x,
+                "y", y,
+                NULL);
+}
+
+void
+gimp_canvas_handle_set_position (GimpCanvasItem *handle,
+                                 gdouble         x,
+                                 gdouble         y)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_HANDLE (handle));
+
+  gimp_canvas_item_begin_change (handle);
+
+  g_object_set (handle,
+                "x", x,
+                "y", y,
+                NULL);
+
+  gimp_canvas_item_end_change (handle);
+}
+
+gint
+gimp_canvas_handle_calc_size (GimpCanvasItem *item,
+                              gdouble         mouse_x,
+                              gdouble         mouse_y,
+                              gint            normal_size,
+                              gint            hover_size)
+{
+  gdouble x, y;
+  gdouble distance;
+  gdouble size;
+  gint    full_threshold_sq    = SQR (hover_size / 2) * 9;
+  gint    partial_threshold_sq = full_threshold_sq * 5;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_HANDLE (item), normal_size);
+
+  gimp_canvas_handle_get_position (item, &x, &y);
+  distance = gimp_canvas_item_transform_distance_square (item,
+                                                         mouse_x,
+                                                         mouse_y,
+                                                         x, y);
+
+  /*  calculate the handle size based on distance from the cursor  */
+  size = (1.0 - (distance - full_threshold_sq) /
+          (partial_threshold_sq - full_threshold_sq));
+
+  size = CLAMP (size, 0.0, 1.0);
+
+  return (gint) CLAMP ((size * hover_size),
+                       normal_size,
+                       hover_size);
+}
+
+void
+gimp_canvas_handle_get_size (GimpCanvasItem *handle,
+                             gint           *width,
+                             gint           *height)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_HANDLE (handle));
+  g_return_if_fail (width != NULL);
+  g_return_if_fail (height != NULL);
+
+  g_object_get (handle,
+                "width",  width,
+                "height", height,
+                NULL);
+}
+
+void
+gimp_canvas_handle_set_size (GimpCanvasItem *handle,
+                             gint            width,
+                             gint            height)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_HANDLE (handle));
+
+  gimp_canvas_item_begin_change (handle);
+
+  g_object_set (handle,
+                "width",  width,
+                "height", height,
+                NULL);
+
+  gimp_canvas_item_end_change (handle);
+}
+
+void
+gimp_canvas_handle_set_angles (GimpCanvasItem *handle,
+                               gdouble         start_angle,
+                               gdouble         slice_angle)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_HANDLE (handle));
+
+  gimp_canvas_item_begin_change (handle);
+
+  g_object_set (handle,
+                "start-angle", start_angle,
+                "slice-angle", slice_angle,
+                NULL);
+
+  gimp_canvas_item_end_change (handle);
+}
diff --git a/app/display/gimpcanvashandle.h b/app/display/gimpcanvashandle.h
new file mode 100644
index 0000000..0dea957
--- /dev/null
+++ b/app/display/gimpcanvashandle.h
@@ -0,0 +1,92 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvashandle.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_HANDLE_H__
+#define __GIMP_CANVAS_HANDLE_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_CANVAS_HANDLE_SIZE_CIRCLE    13
+#define GIMP_CANVAS_HANDLE_SIZE_CROSS     15
+#define GIMP_CANVAS_HANDLE_SIZE_CROSSHAIR 43
+#define GIMP_CANVAS_HANDLE_SIZE_LARGE     25
+#define GIMP_CANVAS_HANDLE_SIZE_SMALL     7
+
+
+#define GIMP_TYPE_CANVAS_HANDLE            (gimp_canvas_handle_get_type ())
+#define GIMP_CANVAS_HANDLE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_HANDLE, GimpCanvasHandle))
+#define GIMP_CANVAS_HANDLE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_HANDLE, GimpCanvasHandleClass))
+#define GIMP_IS_CANVAS_HANDLE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_HANDLE))
+#define GIMP_IS_CANVAS_HANDLE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_HANDLE))
+#define GIMP_CANVAS_HANDLE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_HANDLE, GimpCanvasHandleClass))
+
+
+typedef struct _GimpCanvasHandle      GimpCanvasHandle;
+typedef struct _GimpCanvasHandleClass GimpCanvasHandleClass;
+
+struct _GimpCanvasHandle
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasHandleClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_handle_get_type     (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_handle_new          (GimpDisplayShell *shell,
+                                                  GimpHandleType    type,
+                                                  GimpHandleAnchor  anchor,
+                                                  gdouble           x,
+                                                  gdouble           y,
+                                                  gint              width,
+                                                  gint              height);
+
+void             gimp_canvas_handle_get_position (GimpCanvasItem   *handle,
+                                                  gdouble          *x,
+                                                  gdouble          *y);
+void             gimp_canvas_handle_set_position (GimpCanvasItem   *handle,
+                                                  gdouble           x,
+                                                  gdouble           y);
+
+gint             gimp_canvas_handle_calc_size    (GimpCanvasItem   *item,
+                                                  gdouble           mouse_x,
+                                                  gdouble           mouse_y,
+                                                  gint              normal_size,
+                                                  gint              hover_size);
+
+void             gimp_canvas_handle_get_size     (GimpCanvasItem   *handle,
+                                                  gint             *width,
+                                                  gint             *height);
+void             gimp_canvas_handle_set_size     (GimpCanvasItem   *handle,
+                                                  gint              width,
+                                                  gint              height);
+
+void             gimp_canvas_handle_set_angles   (GimpCanvasItem   *handle,
+                                                  gdouble           start_handle,
+                                                  gdouble           slice_handle);
+
+
+#endif /* __GIMP_CANVAS_HANDLE_H__ */
diff --git a/app/display/gimpcanvasitem-utils.c b/app/display/gimpcanvasitem-utils.c
new file mode 100644
index 0000000..4c23592
--- /dev/null
+++ b/app/display/gimpcanvasitem-utils.c
@@ -0,0 +1,474 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasitem-utils.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpimage.h"
+
+#include "vectors/gimpanchor.h"
+#include "vectors/gimpbezierstroke.h"
+#include "vectors/gimpvectors.h"
+
+#include "gimpcanvasitem.h"
+#include "gimpcanvasitem-utils.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+
+
+gboolean
+gimp_canvas_item_on_handle (GimpCanvasItem  *item,
+                            gdouble           x,
+                            gdouble           y,
+                            GimpHandleType    type,
+                            gdouble           handle_x,
+                            gdouble           handle_y,
+                            gint              width,
+                            gint              height,
+                            GimpHandleAnchor  anchor)
+{
+  GimpDisplayShell *shell;
+  gdouble           tx, ty;
+  gdouble           handle_tx, handle_ty;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), FALSE);
+
+  shell = gimp_canvas_item_get_shell (item);
+
+  gimp_display_shell_zoom_xy_f (shell,
+                                x, y,
+                                &tx, &ty);
+  gimp_display_shell_zoom_xy_f (shell,
+                                handle_x, handle_y,
+                                &handle_tx, &handle_ty);
+
+  switch (type)
+    {
+    case GIMP_HANDLE_SQUARE:
+    case GIMP_HANDLE_FILLED_SQUARE:
+    case GIMP_HANDLE_CROSS:
+    case GIMP_HANDLE_CROSSHAIR:
+      gimp_canvas_item_shift_to_north_west (anchor,
+                                            handle_tx, handle_ty,
+                                            width, height,
+                                            &handle_tx, &handle_ty);
+
+      return (tx == CLAMP (tx, handle_tx, handle_tx + width) &&
+              ty == CLAMP (ty, handle_ty, handle_ty + height));
+
+    case GIMP_HANDLE_CIRCLE:
+    case GIMP_HANDLE_FILLED_CIRCLE:
+      gimp_canvas_item_shift_to_center (anchor,
+                                        handle_tx, handle_ty,
+                                        width, height,
+                                        &handle_tx, &handle_ty);
+
+      /* FIXME */
+      if (width != height)
+        width = (width + height) / 2;
+
+      width /= 2;
+
+      return ((SQR (handle_tx - tx) + SQR (handle_ty - ty)) < SQR (width));
+
+    default:
+      g_warning ("%s: invalid handle type %d", G_STRFUNC, type);
+      break;
+    }
+
+  return FALSE;
+}
+
+gboolean
+gimp_canvas_item_on_vectors_handle (GimpCanvasItem    *item,
+                                    GimpVectors       *vectors,
+                                    const GimpCoords  *coord,
+                                    gint               width,
+                                    gint               height,
+                                    GimpAnchorType     preferred,
+                                    gboolean           exclusive,
+                                    GimpAnchor       **ret_anchor,
+                                    GimpStroke       **ret_stroke)
+{
+  GimpStroke *stroke       = NULL;
+  GimpStroke *pref_stroke  = NULL;
+  GimpAnchor *anchor       = NULL;
+  GimpAnchor *pref_anchor  = NULL;
+  gdouble     dx, dy;
+  gdouble     pref_mindist = -1;
+  gdouble     mindist      = -1;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), FALSE);
+  g_return_val_if_fail (GIMP_IS_VECTORS (vectors), FALSE);
+  g_return_val_if_fail (coord != NULL, FALSE);
+
+  if (ret_anchor) *ret_anchor = NULL;
+  if (ret_stroke) *ret_stroke = NULL;
+
+  while ((stroke = gimp_vectors_stroke_get_next (vectors, stroke)))
+    {
+      GList *anchor_list;
+      GList *list;
+
+      anchor_list = g_list_concat (gimp_stroke_get_draw_anchors (stroke),
+                                   gimp_stroke_get_draw_controls (stroke));
+
+      for (list = anchor_list; list; list = g_list_next (list))
+        {
+          dx = coord->x - GIMP_ANCHOR (list->data)->position.x;
+          dy = coord->y - GIMP_ANCHOR (list->data)->position.y;
+
+          if (mindist < 0 || mindist > dx * dx + dy * dy)
+            {
+              mindist = dx * dx + dy * dy;
+              anchor = GIMP_ANCHOR (list->data);
+
+              if (ret_stroke)
+                *ret_stroke = stroke;
+            }
+
+          if ((pref_mindist < 0 || pref_mindist > dx * dx + dy * dy) &&
+              GIMP_ANCHOR (list->data)->type == preferred)
+            {
+              pref_mindist = dx * dx + dy * dy;
+              pref_anchor = GIMP_ANCHOR (list->data);
+              pref_stroke = stroke;
+            }
+        }
+
+      g_list_free (anchor_list);
+    }
+
+  /* If the data passed into ret_anchor is a preferred anchor, return it. */
+  if (ret_anchor && *ret_anchor &&
+      gimp_canvas_item_on_handle (item,
+                                  coord->x,
+                                  coord->y,
+                                  GIMP_HANDLE_CIRCLE,
+                                  (*ret_anchor)->position.x,
+                                  (*ret_anchor)->position.y,
+                                  width, height,
+                                  GIMP_HANDLE_ANCHOR_CENTER) &&
+      (*ret_anchor)->type == preferred)
+    {
+      if (ret_stroke) *ret_stroke = pref_stroke;
+
+      return TRUE;
+    }
+
+  if (pref_anchor && gimp_canvas_item_on_handle (item,
+                                                 coord->x,
+                                                 coord->y,
+                                                 GIMP_HANDLE_CIRCLE,
+                                                 pref_anchor->position.x,
+                                                 pref_anchor->position.y,
+                                                 width, height,
+                                                 GIMP_HANDLE_ANCHOR_CENTER))
+    {
+      if (ret_anchor) *ret_anchor = pref_anchor;
+      if (ret_stroke) *ret_stroke = pref_stroke;
+
+      return TRUE;
+    }
+  else if (!exclusive && anchor &&
+           gimp_canvas_item_on_handle (item,
+                                       coord->x,
+                                       coord->y,
+                                       GIMP_HANDLE_CIRCLE,
+                                       anchor->position.x,
+                                       anchor->position.y,
+                                       width, height,
+                                       GIMP_HANDLE_ANCHOR_CENTER))
+    {
+      if (ret_anchor)
+        *ret_anchor = anchor;
+
+      /* *ret_stroke already set correctly. */
+      return TRUE;
+    }
+
+  if (ret_anchor)
+    *ret_anchor = NULL;
+  if (ret_stroke)
+    *ret_stroke = NULL;
+
+  return FALSE;
+}
+
+gboolean
+gimp_canvas_item_on_vectors_curve (GimpCanvasItem    *item,
+                                   GimpVectors       *vectors,
+                                   const GimpCoords  *coord,
+                                   gint               width,
+                                   gint               height,
+                                   GimpCoords        *ret_coords,
+                                   gdouble           *ret_pos,
+                                   GimpAnchor       **ret_segment_start,
+                                   GimpAnchor       **ret_segment_end,
+                                   GimpStroke       **ret_stroke)
+{
+  GimpStroke *stroke = NULL;
+  GimpAnchor *segment_start;
+  GimpAnchor *segment_end;
+  GimpCoords  min_coords = GIMP_COORDS_DEFAULT_VALUES;
+  GimpCoords  cur_coords;
+  gdouble     min_dist, cur_dist, cur_pos;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), FALSE);
+  g_return_val_if_fail (GIMP_IS_VECTORS (vectors), FALSE);
+  g_return_val_if_fail (coord != NULL, FALSE);
+
+  if (ret_coords)        *ret_coords        = *coord;
+  if (ret_pos)           *ret_pos           = -1.0;
+  if (ret_segment_start) *ret_segment_start = NULL;
+  if (ret_segment_end)   *ret_segment_end   = NULL;
+  if (ret_stroke)        *ret_stroke        = NULL;
+
+  min_dist = -1.0;
+
+  while ((stroke = gimp_vectors_stroke_get_next (vectors, stroke)))
+    {
+      cur_dist = gimp_stroke_nearest_point_get (stroke, coord, 1.0,
+                                                &cur_coords,
+                                                &segment_start,
+                                                &segment_end,
+                                                &cur_pos);
+
+      if (cur_dist >= 0 && (min_dist < 0 || cur_dist < min_dist))
+        {
+          min_dist   = cur_dist;
+          min_coords = cur_coords;
+
+          if (ret_coords)        *ret_coords        = cur_coords;
+          if (ret_pos)           *ret_pos           = cur_pos;
+          if (ret_segment_start) *ret_segment_start = segment_start;
+          if (ret_segment_end)   *ret_segment_end   = segment_end;
+          if (ret_stroke)        *ret_stroke        = stroke;
+        }
+    }
+
+  if (min_dist >= 0 &&
+      gimp_canvas_item_on_handle (item,
+                                  coord->x,
+                                  coord->y,
+                                  GIMP_HANDLE_CIRCLE,
+                                  min_coords.x,
+                                  min_coords.y,
+                                  width, height,
+                                  GIMP_HANDLE_ANCHOR_CENTER))
+    {
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+gboolean
+gimp_canvas_item_on_vectors (GimpCanvasItem    *item,
+                             const GimpCoords  *coords,
+                             gint               width,
+                             gint               height,
+                             GimpCoords        *ret_coords,
+                             gdouble           *ret_pos,
+                             GimpAnchor       **ret_segment_start,
+                             GimpAnchor       **ret_segment_end,
+                             GimpStroke       **ret_stroke,
+                             GimpVectors      **ret_vectors)
+{
+  GimpDisplayShell *shell;
+  GimpImage        *image;
+  GList            *all_vectors;
+  GList            *list;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), FALSE);
+  g_return_val_if_fail (coords != NULL, FALSE);
+
+  shell = gimp_canvas_item_get_shell (item);
+  image = gimp_display_get_image (shell->display);
+
+  if (ret_coords)        *ret_coords         = *coords;
+  if (ret_pos)           *ret_pos            = -1.0;
+  if (ret_segment_start) *ret_segment_start  = NULL;
+  if (ret_segment_end)   *ret_segment_end    = NULL;
+  if (ret_stroke)        *ret_stroke         = NULL;
+  if (ret_vectors)       *ret_vectors        = NULL;
+
+  all_vectors = gimp_image_get_vectors_list (image);
+
+  for (list = all_vectors; list; list = g_list_next (list))
+    {
+      GimpVectors *vectors = list->data;
+
+      if (! gimp_item_get_visible (GIMP_ITEM (vectors)))
+        continue;
+
+      if (gimp_canvas_item_on_vectors_curve (item,
+                                             vectors, coords,
+                                             width, height,
+                                             ret_coords,
+                                             ret_pos,
+                                             ret_segment_start,
+                                             ret_segment_end,
+                                             ret_stroke))
+        {
+          if (ret_vectors)
+            *ret_vectors = vectors;
+
+          g_list_free (all_vectors);
+
+          return TRUE;
+        }
+    }
+
+  g_list_free (all_vectors);
+
+  return FALSE;
+}
+
+void
+gimp_canvas_item_shift_to_north_west (GimpHandleAnchor  anchor,
+                                      gdouble           x,
+                                      gdouble           y,
+                                      gint              width,
+                                      gint              height,
+                                      gdouble          *shifted_x,
+                                      gdouble          *shifted_y)
+{
+  switch (anchor)
+    {
+    case GIMP_HANDLE_ANCHOR_CENTER:
+      x -= width  / 2;
+      y -= height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH:
+      x -= width / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_WEST:
+      /*  nothing, this is the default  */
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_EAST:
+      x -= width;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH:
+      x -= width / 2;
+      y -= height;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_WEST:
+      y -= height;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_EAST:
+      x -= width;
+      y -= height;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_WEST:
+      y -= height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_EAST:
+      x -= width;
+      y -= height / 2;
+      break;
+
+    default:
+      break;
+    }
+
+  if (shifted_x)
+    *shifted_x = x;
+
+  if (shifted_y)
+    *shifted_y = y;
+}
+
+void
+gimp_canvas_item_shift_to_center (GimpHandleAnchor  anchor,
+                                  gdouble           x,
+                                  gdouble           y,
+                                  gint              width,
+                                  gint              height,
+                                  gdouble          *shifted_x,
+                                  gdouble          *shifted_y)
+{
+  switch (anchor)
+    {
+    case GIMP_HANDLE_ANCHOR_CENTER:
+      /*  nothing, this is the default  */
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH:
+      y += height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_WEST:
+      x += width  / 2;
+      y += height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_EAST:
+      x -= width  / 2;
+      y += height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH:
+      y -= height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_WEST:
+      x += width  / 2;
+      y -= height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_EAST:
+      x -= width  / 2;
+      y -= height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_WEST:
+      x += width / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_EAST:
+      x -= width / 2;
+      break;
+
+    default:
+      break;
+    }
+
+  if (shifted_x)
+    *shifted_x = x;
+
+  if (shifted_y)
+    *shifted_y = y;
+}
diff --git a/app/display/gimpcanvasitem-utils.h b/app/display/gimpcanvasitem-utils.h
new file mode 100644
index 0000000..240385e
--- /dev/null
+++ b/app/display/gimpcanvasitem-utils.h
@@ -0,0 +1,81 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasitem-utils.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_ITEM_UTILS_H__
+#define __GIMP_CANVAS_ITEM_UTILS_H__
+
+
+gboolean   gimp_canvas_item_on_handle           (GimpCanvasItem    *item,
+                                                 gdouble            x,
+                                                 gdouble            y,
+                                                 GimpHandleType     type,
+                                                 gdouble            handle_x,
+                                                 gdouble            handle_y,
+                                                 gint               width,
+                                                 gint               height,
+                                                 GimpHandleAnchor   anchor);
+
+gboolean   gimp_canvas_item_on_vectors_handle   (GimpCanvasItem    *item,
+                                                 GimpVectors       *vectors,
+                                                 const GimpCoords  *coord,
+                                                 gint               width,
+                                                 gint               height,
+                                                 GimpAnchorType     preferred,
+                                                 gboolean           exclusive,
+                                                 GimpAnchor       **ret_anchor,
+                                                 GimpStroke       **ret_stroke);
+gboolean   gimp_canvas_item_on_vectors_curve    (GimpCanvasItem    *item,
+                                                 GimpVectors       *vectors,
+                                                 const GimpCoords  *coord,
+                                                 gint               width,
+                                                 gint               height,
+                                                 GimpCoords        *ret_coords,
+                                                 gdouble           *ret_pos,
+                                                 GimpAnchor       **ret_segment_start,
+                                                 GimpAnchor       **ret_segment_end,
+                                                 GimpStroke       **ret_stroke);
+gboolean   gimp_canvas_item_on_vectors          (GimpCanvasItem    *item,
+                                                 const GimpCoords  *coords,
+                                                 gint               width,
+                                                 gint               height,
+                                                 GimpCoords        *ret_coords,
+                                                 gdouble           *ret_pos,
+                                                 GimpAnchor       **ret_segment_start,
+                                                 GimpAnchor       **ret_segment_end,
+                                                 GimpStroke       **ret_stroke,
+                                                 GimpVectors      **ret_vectors);
+
+void       gimp_canvas_item_shift_to_north_west (GimpHandleAnchor   anchor,
+                                                 gdouble            x,
+                                                 gdouble            y,
+                                                 gint               width,
+                                                 gint               height,
+                                                 gdouble           *shifted_x,
+                                                 gdouble           *shifted_y);
+void       gimp_canvas_item_shift_to_center     (GimpHandleAnchor   anchor,
+                                                 gdouble            x,
+                                                 gdouble            y,
+                                                 gint               width,
+                                                 gint               height,
+                                                 gdouble           *shifted_x,
+                                                 gdouble           *shifted_y);
+
+
+#endif /* __GIMP_CANVAS_ITEM_UTILS_H__ */
diff --git a/app/display/gimpcanvasitem.c b/app/display/gimpcanvasitem.c
new file mode 100644
index 0000000..560210a
--- /dev/null
+++ b/app/display/gimpcanvasitem.c
@@ -0,0 +1,731 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasitem.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpmarshal.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvasitem.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_SHELL,
+  PROP_VISIBLE,
+  PROP_LINE_CAP,
+  PROP_HIGHLIGHT
+};
+
+enum
+{
+  UPDATE,
+  LAST_SIGNAL
+};
+
+
+struct _GimpCanvasItemPrivate
+{
+  GimpDisplayShell *shell;
+  gboolean          visible;
+  cairo_line_cap_t  line_cap;
+  gboolean          highlight;
+  gint              suspend_stroking;
+  gint              suspend_filling;
+  gint              change_count;
+  cairo_region_t   *change_region;
+};
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_item_dispose          (GObject         *object);
+static void             gimp_canvas_item_constructed      (GObject         *object);
+static void             gimp_canvas_item_set_property     (GObject         *object,
+                                                           guint            property_id,
+                                                           const GValue    *value,
+                                                           GParamSpec      *pspec);
+static void             gimp_canvas_item_get_property     (GObject         *object,
+                                                           guint            property_id,
+                                                           GValue          *value,
+                                                           GParamSpec      *pspec);
+static void  gimp_canvas_item_dispatch_properties_changed (GObject         *object,
+                                                           guint            n_pspecs,
+                                                           GParamSpec     **pspecs);
+
+static void             gimp_canvas_item_real_draw        (GimpCanvasItem  *item,
+                                                           cairo_t         *cr);
+static cairo_region_t * gimp_canvas_item_real_get_extents (GimpCanvasItem  *item);
+static void             gimp_canvas_item_real_stroke      (GimpCanvasItem  *item,
+                                                           cairo_t         *cr);
+static void             gimp_canvas_item_real_fill        (GimpCanvasItem  *item,
+                                                           cairo_t         *cr);
+static gboolean         gimp_canvas_item_real_hit         (GimpCanvasItem  *item,
+                                                           gdouble          x,
+                                                           gdouble          y);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasItem, gimp_canvas_item, GIMP_TYPE_OBJECT)
+
+#define parent_class gimp_canvas_item_parent_class
+
+static guint item_signals[LAST_SIGNAL] = { 0 };
+
+
+static void
+gimp_canvas_item_class_init (GimpCanvasItemClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose                     = gimp_canvas_item_dispose;
+  object_class->constructed                 = gimp_canvas_item_constructed;
+  object_class->set_property                = gimp_canvas_item_set_property;
+  object_class->get_property                = gimp_canvas_item_get_property;
+  object_class->dispatch_properties_changed = gimp_canvas_item_dispatch_properties_changed;
+
+  klass->update                             = NULL;
+  klass->draw                               = gimp_canvas_item_real_draw;
+  klass->get_extents                        = gimp_canvas_item_real_get_extents;
+  klass->stroke                             = gimp_canvas_item_real_stroke;
+  klass->fill                               = gimp_canvas_item_real_fill;
+  klass->hit                                = gimp_canvas_item_real_hit;
+
+  item_signals[UPDATE] =
+    g_signal_new ("update",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpCanvasItemClass, update),
+                  NULL, NULL,
+                  gimp_marshal_VOID__POINTER,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_POINTER);
+
+  g_object_class_install_property (object_class, PROP_SHELL,
+                                   g_param_spec_object ("shell",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_DISPLAY_SHELL,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_VISIBLE,
+                                   g_param_spec_boolean ("visible",
+                                                         NULL, NULL,
+                                                         TRUE,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_LINE_CAP,
+                                   g_param_spec_int ("line-cap",
+                                                     NULL, NULL,
+                                                     CAIRO_LINE_CAP_BUTT,
+                                                     CAIRO_LINE_CAP_SQUARE,
+                                                     CAIRO_LINE_CAP_ROUND,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_HIGHLIGHT,
+                                   g_param_spec_boolean ("highlight",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_item_init (GimpCanvasItem *item)
+{
+  GimpCanvasItemPrivate *private;
+
+  item->private = gimp_canvas_item_get_instance_private (item);
+  private = item->private;
+
+  private->shell            = NULL;
+  private->visible          = TRUE;
+  private->line_cap         = CAIRO_LINE_CAP_ROUND;
+  private->highlight        = FALSE;
+  private->suspend_stroking = 0;
+  private->suspend_filling  = 0;
+  private->change_count     = 1; /* avoid emissions during construction */
+  private->change_region    = NULL;
+}
+
+static void
+gimp_canvas_item_constructed (GObject *object)
+{
+  GimpCanvasItem *item = GIMP_CANVAS_ITEM (object);
+
+  gimp_assert (GIMP_IS_DISPLAY_SHELL (item->private->shell));
+
+  item->private->change_count = 0; /* undo hack from init() */
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+}
+
+static void
+gimp_canvas_item_dispose (GObject *object)
+{
+  GimpCanvasItem *item = GIMP_CANVAS_ITEM (object);
+
+  item->private->change_count++; /* avoid emissions during destruction */
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_canvas_item_set_property (GObject      *object,
+                               guint         property_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GimpCanvasItem        *item    = GIMP_CANVAS_ITEM (object);
+  GimpCanvasItemPrivate *private = item->private;
+
+  switch (property_id)
+    {
+    case PROP_SHELL:
+      private->shell = g_value_get_object (value); /* don't ref */
+      break;
+    case PROP_VISIBLE:
+      private->visible = g_value_get_boolean (value);
+      break;
+    case PROP_LINE_CAP:
+      private->line_cap = g_value_get_int (value);
+      break;
+    case PROP_HIGHLIGHT:
+      private->highlight = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_item_get_property (GObject    *object,
+                               guint       property_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GimpCanvasItem        *item    = GIMP_CANVAS_ITEM (object);
+  GimpCanvasItemPrivate *private = item->private;
+
+  switch (property_id)
+    {
+    case PROP_SHELL:
+      g_value_set_object (value, private->shell);
+      break;
+    case PROP_VISIBLE:
+      g_value_set_boolean (value, private->visible);
+      break;
+    case PROP_LINE_CAP:
+      g_value_set_int (value, private->line_cap);
+      break;
+    case PROP_HIGHLIGHT:
+      g_value_set_boolean (value, private->highlight);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_item_dispatch_properties_changed (GObject     *object,
+                                              guint        n_pspecs,
+                                              GParamSpec **pspecs)
+{
+  GimpCanvasItem *item = GIMP_CANVAS_ITEM (object);
+
+  G_OBJECT_CLASS (parent_class)->dispatch_properties_changed (object,
+                                                              n_pspecs,
+                                                              pspecs);
+
+  if (_gimp_canvas_item_needs_update (item))
+    {
+      cairo_region_t *region = gimp_canvas_item_get_extents (item);
+
+      if (region)
+        {
+          g_signal_emit (object, item_signals[UPDATE], 0,
+                         region);
+          cairo_region_destroy (region);
+        }
+    }
+}
+
+static void
+gimp_canvas_item_real_draw (GimpCanvasItem *item,
+                            cairo_t        *cr)
+{
+  g_warn_if_reached ();
+}
+
+static cairo_region_t *
+gimp_canvas_item_real_get_extents (GimpCanvasItem *item)
+{
+  return NULL;
+}
+
+static void
+gimp_canvas_item_real_stroke (GimpCanvasItem *item,
+                              cairo_t        *cr)
+{
+  cairo_set_line_cap (cr, item->private->line_cap);
+
+  gimp_canvas_set_tool_bg_style (gimp_canvas_item_get_canvas (item), cr);
+  cairo_stroke_preserve (cr);
+
+  gimp_canvas_set_tool_fg_style (gimp_canvas_item_get_canvas (item), cr,
+                                 item->private->highlight);
+  cairo_stroke (cr);
+}
+
+static void
+gimp_canvas_item_real_fill (GimpCanvasItem *item,
+                            cairo_t        *cr)
+{
+  gimp_canvas_set_tool_bg_style (gimp_canvas_item_get_canvas (item), cr);
+  cairo_set_line_width (cr, 2.0);
+  cairo_stroke_preserve (cr);
+
+  gimp_canvas_set_tool_fg_style (gimp_canvas_item_get_canvas (item), cr,
+                                 item->private->highlight);
+  cairo_fill (cr);
+}
+
+static gboolean
+gimp_canvas_item_real_hit (GimpCanvasItem *item,
+                           gdouble         x,
+                           gdouble         y)
+{
+  return FALSE;
+}
+
+
+/*  public functions  */
+
+GimpDisplayShell *
+gimp_canvas_item_get_shell (GimpCanvasItem *item)
+{
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), NULL);
+
+  return item->private->shell;
+}
+
+GimpImage *
+gimp_canvas_item_get_image (GimpCanvasItem *item)
+{
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), NULL);
+
+  return gimp_display_get_image (item->private->shell->display);
+}
+
+GtkWidget *
+gimp_canvas_item_get_canvas (GimpCanvasItem *item)
+{
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), NULL);
+
+  return item->private->shell->canvas;
+}
+
+void
+gimp_canvas_item_draw (GimpCanvasItem *item,
+                       cairo_t        *cr)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+  g_return_if_fail (cr != NULL);
+
+  if (item->private->visible)
+    {
+      cairo_save (cr);
+      GIMP_CANVAS_ITEM_GET_CLASS (item)->draw (item, cr);
+      cairo_restore (cr);
+    }
+}
+
+cairo_region_t *
+gimp_canvas_item_get_extents (GimpCanvasItem *item)
+{
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), NULL);
+
+  if (item->private->visible)
+    return GIMP_CANVAS_ITEM_GET_CLASS (item)->get_extents (item);
+
+  return NULL;
+}
+
+gboolean
+gimp_canvas_item_hit (GimpCanvasItem   *item,
+                      gdouble           x,
+                      gdouble           y)
+{
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), FALSE);
+
+  if (item->private->visible)
+    return GIMP_CANVAS_ITEM_GET_CLASS (item)->hit (item, x, y);
+
+  return FALSE;
+}
+
+void
+gimp_canvas_item_set_visible (GimpCanvasItem *item,
+                              gboolean        visible)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  if (item->private->visible != visible)
+    {
+      gimp_canvas_item_begin_change (item);
+      g_object_set (G_OBJECT (item),
+                    "visible", visible,
+                    NULL);
+      gimp_canvas_item_end_change (item);
+    }
+}
+
+gboolean
+gimp_canvas_item_get_visible (GimpCanvasItem *item)
+{
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), FALSE);
+
+  return item->private->visible;
+}
+
+void
+gimp_canvas_item_set_line_cap (GimpCanvasItem   *item,
+                               cairo_line_cap_t  line_cap)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  if (item->private->line_cap != line_cap)
+    {
+      gimp_canvas_item_begin_change (item);
+      g_object_set (G_OBJECT (item),
+                    "line-cap", line_cap,
+                    NULL);
+      gimp_canvas_item_end_change (item);
+    }
+}
+
+void
+gimp_canvas_item_set_highlight (GimpCanvasItem *item,
+                                gboolean        highlight)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  if (item->private->highlight != highlight)
+    {
+      g_object_set (G_OBJECT (item),
+                    "highlight", highlight,
+                    NULL);
+    }
+}
+
+gboolean
+gimp_canvas_item_get_highlight (GimpCanvasItem *item)
+{
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), FALSE);
+
+  return item->private->highlight;
+}
+
+void
+gimp_canvas_item_begin_change (GimpCanvasItem *item)
+{
+  GimpCanvasItemPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  private = item->private;
+
+  private->change_count++;
+
+  if (private->change_count == 1 &&
+      g_signal_has_handler_pending (item, item_signals[UPDATE], 0, FALSE))
+    {
+      private->change_region = gimp_canvas_item_get_extents (item);
+    }
+}
+
+void
+gimp_canvas_item_end_change (GimpCanvasItem *item)
+{
+  GimpCanvasItemPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  private = item->private;
+
+  g_return_if_fail (private->change_count > 0);
+
+  private->change_count--;
+
+  if (private->change_count == 0)
+    {
+      if (g_signal_has_handler_pending (item, item_signals[UPDATE], 0, FALSE))
+        {
+          cairo_region_t *region = gimp_canvas_item_get_extents (item);
+
+          if (! region)
+            {
+              region = private->change_region;
+            }
+          else if (private->change_region)
+            {
+              cairo_region_union (region, private->change_region);
+              cairo_region_destroy (private->change_region);
+            }
+
+          private->change_region = NULL;
+
+          if (region)
+            {
+              g_signal_emit (item, item_signals[UPDATE], 0,
+                             region);
+              cairo_region_destroy (region);
+            }
+        }
+      else
+        {
+          g_clear_pointer (&private->change_region, cairo_region_destroy);
+        }
+    }
+}
+
+void
+gimp_canvas_item_suspend_stroking (GimpCanvasItem *item)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  item->private->suspend_stroking++;
+}
+
+void
+gimp_canvas_item_resume_stroking (GimpCanvasItem *item)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  g_return_if_fail (item->private->suspend_stroking > 0);
+
+  item->private->suspend_stroking--;
+}
+
+void
+gimp_canvas_item_suspend_filling (GimpCanvasItem *item)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  item->private->suspend_filling++;
+}
+
+void
+gimp_canvas_item_resume_filling (GimpCanvasItem *item)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  g_return_if_fail (item->private->suspend_filling > 0);
+
+  item->private->suspend_filling--;
+}
+
+void
+gimp_canvas_item_transform (GimpCanvasItem *item,
+                            cairo_t        *cr)
+{
+  GimpCanvasItemPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+  g_return_if_fail (cr != NULL);
+
+  private = item->private;
+
+  cairo_translate (cr, -private->shell->offset_x, -private->shell->offset_y);
+  cairo_scale (cr, private->shell->scale_x, private->shell->scale_y);
+}
+
+void
+gimp_canvas_item_transform_xy (GimpCanvasItem *item,
+                               gdouble         x,
+                               gdouble         y,
+                               gint           *tx,
+                               gint           *ty)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_display_shell_zoom_xy (item->private->shell, x, y, tx, ty);
+}
+
+void
+gimp_canvas_item_transform_xy_f (GimpCanvasItem *item,
+                                 gdouble         x,
+                                 gdouble         y,
+                                 gdouble        *tx,
+                                 gdouble        *ty)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_display_shell_zoom_xy_f (item->private->shell, x, y, tx, ty);
+}
+
+/**
+ * gimp_canvas_item_transform_distance:
+ * @item: a #GimpCanvasItem
+ * @x1:   start point X in image coordinates
+ * @y1:   start point Y in image coordinates
+ * @x2:   end point X in image coordinates
+ * @y2:   end point Y in image coordinates
+ *
+ * If you just need to compare distances, consider to use
+ * gimp_canvas_item_transform_distance_square() instead.
+ *
+ * Returns: the distance between the given points in display coordinates
+ **/
+gdouble
+gimp_canvas_item_transform_distance (GimpCanvasItem *item,
+                                     gdouble         x1,
+                                     gdouble         y1,
+                                     gdouble         x2,
+                                     gdouble         y2)
+{
+  return sqrt (gimp_canvas_item_transform_distance_square (item,
+                                                           x1, y1, x2, y2));
+}
+
+/**
+ * gimp_canvas_item_transform_distance_square:
+ * @item: a #GimpCanvasItem
+ * @x1:   start point X in image coordinates
+ * @y1:   start point Y in image coordinates
+ * @x2:   end point X in image coordinates
+ * @y2:   end point Y in image coordinates
+ *
+ * This function is more effective than
+ * gimp_canvas_item_transform_distance() as it doesn't perform a
+ * sqrt(). Use this if you just need to compare distances.
+ *
+ * Returns: the square of the distance between the given points in
+ *          display coordinates
+ **/
+gdouble
+gimp_canvas_item_transform_distance_square (GimpCanvasItem   *item,
+                                            gdouble           x1,
+                                            gdouble           y1,
+                                            gdouble           x2,
+                                            gdouble           y2)
+{
+  gdouble tx1, ty1;
+  gdouble tx2, ty2;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_ITEM (item), 0.0);
+
+  gimp_canvas_item_transform_xy_f (item, x1, y1, &tx1, &ty1);
+  gimp_canvas_item_transform_xy_f (item, x2, y2, &tx2, &ty2);
+
+  return SQR (tx2 - tx1) + SQR (ty2 - ty1);
+}
+
+void
+gimp_canvas_item_untransform_viewport (GimpCanvasItem *item,
+                                       gint           *x,
+                                       gint           *y,
+                                       gint           *w,
+                                       gint           *h)
+{
+  GimpDisplayShell *shell;
+  gdouble           x1, y1;
+  gdouble           x2, y2;
+
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  shell = item->private->shell;
+
+  gimp_display_shell_unrotate_bounds (shell,
+                                      0.0,               0.0,
+                                      shell->disp_width, shell->disp_height,
+                                      &x1,               &y1,
+                                      &x2,               &y2);
+
+  *x = floor (x1);
+  *y = floor (y1);
+  *w = ceil  (x2) - *x;
+  *h = ceil  (y2) - *y;
+}
+
+
+/*  protected functions  */
+
+void
+_gimp_canvas_item_update (GimpCanvasItem *item,
+                          cairo_region_t *region)
+{
+  g_signal_emit (item, item_signals[UPDATE], 0,
+                 region);
+}
+
+gboolean
+_gimp_canvas_item_needs_update (GimpCanvasItem *item)
+{
+  return (item->private->change_count == 0 &&
+          g_signal_has_handler_pending (item, item_signals[UPDATE], 0, FALSE));
+}
+
+void
+_gimp_canvas_item_stroke (GimpCanvasItem *item,
+                          cairo_t        *cr)
+{
+  if (item->private->suspend_filling > 0)
+    g_warning ("_gimp_canvas_item_stroke() on an item that is in a filling group");
+
+  if (item->private->suspend_stroking == 0)
+    {
+      GIMP_CANVAS_ITEM_GET_CLASS (item)->stroke (item, cr);
+    }
+  else
+    {
+      cairo_new_sub_path (cr);
+    }
+}
+
+void
+_gimp_canvas_item_fill (GimpCanvasItem *item,
+                        cairo_t        *cr)
+{
+  if (item->private->suspend_stroking > 0)
+    g_warning ("_gimp_canvas_item_fill() on an item that is in a stroking group");
+
+  if (item->private->suspend_filling == 0)
+    {
+      GIMP_CANVAS_ITEM_GET_CLASS (item)->fill (item, cr);
+    }
+  else
+    {
+      cairo_new_sub_path (cr);
+    }
+}
diff --git a/app/display/gimpcanvasitem.h b/app/display/gimpcanvasitem.h
new file mode 100644
index 0000000..2004260
--- /dev/null
+++ b/app/display/gimpcanvasitem.h
@@ -0,0 +1,147 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasitem.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_ITEM_H__
+#define __GIMP_CANVAS_ITEM_H__
+
+
+#include "core/gimpobject.h"
+
+
+#define GIMP_TYPE_CANVAS_ITEM            (gimp_canvas_item_get_type ())
+#define GIMP_CANVAS_ITEM(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_ITEM, GimpCanvasItem))
+#define GIMP_CANVAS_ITEM_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_ITEM, GimpCanvasItemClass))
+#define GIMP_IS_CANVAS_ITEM(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_ITEM))
+#define GIMP_IS_CANVAS_ITEM_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_ITEM))
+#define GIMP_CANVAS_ITEM_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_ITEM, GimpCanvasItemClass))
+
+
+typedef struct _GimpCanvasItemPrivate GimpCanvasItemPrivate;
+typedef struct _GimpCanvasItemClass   GimpCanvasItemClass;
+
+struct _GimpCanvasItem
+{
+  GimpObject             parent_instance;
+
+  GimpCanvasItemPrivate *private;
+};
+
+struct _GimpCanvasItemClass
+{
+  GimpObjectClass  parent_class;
+
+  /*  signals  */
+  void             (* update)      (GimpCanvasItem   *item,
+                                    cairo_region_t   *region);
+
+  /*  virtual functions  */
+  void             (* draw)        (GimpCanvasItem   *item,
+                                    cairo_t          *cr);
+  cairo_region_t * (* get_extents) (GimpCanvasItem   *item);
+
+  void             (* stroke)      (GimpCanvasItem   *item,
+                                    cairo_t          *cr);
+  void             (* fill)        (GimpCanvasItem   *item,
+                                    cairo_t          *cr);
+
+  gboolean         (* hit)         (GimpCanvasItem   *item,
+                                    gdouble           x,
+                                    gdouble           y);
+};
+
+
+GType            gimp_canvas_item_get_type         (void) G_GNUC_CONST;
+
+GimpDisplayShell * gimp_canvas_item_get_shell      (GimpCanvasItem   *item);
+GimpImage      * gimp_canvas_item_get_image        (GimpCanvasItem   *item);
+GtkWidget      * gimp_canvas_item_get_canvas       (GimpCanvasItem   *item);
+
+void             gimp_canvas_item_draw             (GimpCanvasItem   *item,
+                                                    cairo_t          *cr);
+cairo_region_t * gimp_canvas_item_get_extents      (GimpCanvasItem   *item);
+
+gboolean         gimp_canvas_item_hit              (GimpCanvasItem   *item,
+                                                    gdouble           x,
+                                                    gdouble           y);
+
+void             gimp_canvas_item_set_visible      (GimpCanvasItem   *item,
+                                                    gboolean          visible);
+gboolean         gimp_canvas_item_get_visible      (GimpCanvasItem   *item);
+
+void             gimp_canvas_item_set_line_cap     (GimpCanvasItem   *item,
+                                                    cairo_line_cap_t  line_cap);
+
+void             gimp_canvas_item_set_highlight    (GimpCanvasItem   *item,
+                                                    gboolean          highlight);
+gboolean         gimp_canvas_item_get_highlight    (GimpCanvasItem   *item);
+
+void             gimp_canvas_item_begin_change     (GimpCanvasItem   *item);
+void             gimp_canvas_item_end_change       (GimpCanvasItem   *item);
+
+void             gimp_canvas_item_suspend_stroking (GimpCanvasItem   *item);
+void             gimp_canvas_item_resume_stroking  (GimpCanvasItem   *item);
+
+void             gimp_canvas_item_suspend_filling  (GimpCanvasItem   *item);
+void             gimp_canvas_item_resume_filling   (GimpCanvasItem   *item);
+
+void             gimp_canvas_item_transform        (GimpCanvasItem   *item,
+                                                    cairo_t          *cr);
+void             gimp_canvas_item_transform_xy     (GimpCanvasItem   *item,
+                                                    gdouble           x,
+                                                    gdouble           y,
+                                                    gint             *tx,
+                                                    gint             *ty);
+void             gimp_canvas_item_transform_xy_f   (GimpCanvasItem   *item,
+                                                    gdouble           x,
+                                                    gdouble           y,
+                                                    gdouble          *tx,
+                                                    gdouble          *ty);
+gdouble          gimp_canvas_item_transform_distance
+                                                   (GimpCanvasItem   *item,
+                                                    gdouble           x1,
+                                                    gdouble           y1,
+                                                    gdouble           x2,
+                                                    gdouble           y2);
+gdouble          gimp_canvas_item_transform_distance_square
+                                                   (GimpCanvasItem   *item,
+                                                    gdouble           x1,
+                                                    gdouble           y1,
+                                                    gdouble           x2,
+                                                    gdouble           y2);
+void             gimp_canvas_item_untransform_viewport
+                                                   (GimpCanvasItem   *item,
+                                                    gint             *x,
+                                                    gint             *y,
+                                                    gint             *w,
+                                                    gint             *h);
+
+
+/*  protected  */
+
+void             _gimp_canvas_item_update          (GimpCanvasItem   *item,
+                                                    cairo_region_t   *region);
+gboolean         _gimp_canvas_item_needs_update    (GimpCanvasItem   *item);
+void             _gimp_canvas_item_stroke          (GimpCanvasItem   *item,
+                                                    cairo_t          *cr);
+void             _gimp_canvas_item_fill            (GimpCanvasItem   *item,
+                                                    cairo_t          *cr);
+
+
+#endif /* __GIMP_CANVAS_ITEM_H__ */
diff --git a/app/display/gimpcanvaslayerboundary.c b/app/display/gimpcanvaslayerboundary.c
new file mode 100644
index 0000000..0e4b43b
--- /dev/null
+++ b/app/display/gimpcanvaslayerboundary.c
@@ -0,0 +1,322 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaslayerboundary.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpchannel.h"
+#include "core/gimplayer.h"
+#include "core/gimplayer-floating-selection.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvaslayerboundary.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_LAYER,
+  PROP_EDIT_MASK
+};
+
+
+typedef struct _GimpCanvasLayerBoundaryPrivate GimpCanvasLayerBoundaryPrivate;
+
+struct _GimpCanvasLayerBoundaryPrivate
+{
+  GimpLayer *layer;
+  gboolean   edit_mask;
+};
+
+#define GET_PRIVATE(layer_boundary) \
+        ((GimpCanvasLayerBoundaryPrivate *) gimp_canvas_layer_boundary_get_instance_private ((GimpCanvasLayerBoundary *) (layer_boundary)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_layer_boundary_set_property (GObject        *object,
+                                                                 guint           property_id,
+                                                                 const GValue   *value,
+                                                                 GParamSpec     *pspec);
+static void             gimp_canvas_layer_boundary_get_property (GObject        *object,
+                                                                 guint           property_id,
+                                                                 GValue         *value,
+                                                                 GParamSpec     *pspec);
+static void             gimp_canvas_layer_boundary_finalize     (GObject        *object);
+static void             gimp_canvas_layer_boundary_draw         (GimpCanvasItem *item,
+                                                                 cairo_t        *cr);
+static cairo_region_t * gimp_canvas_layer_boundary_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_layer_boundary_stroke       (GimpCanvasItem *item,
+                                                                 cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasLayerBoundary, gimp_canvas_layer_boundary,
+                            GIMP_TYPE_CANVAS_RECTANGLE)
+
+#define parent_class gimp_canvas_layer_boundary_parent_class
+
+
+static void
+gimp_canvas_layer_boundary_class_init (GimpCanvasLayerBoundaryClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_layer_boundary_set_property;
+  object_class->get_property = gimp_canvas_layer_boundary_get_property;
+  object_class->finalize     = gimp_canvas_layer_boundary_finalize;
+
+  item_class->draw           = gimp_canvas_layer_boundary_draw;
+  item_class->get_extents    = gimp_canvas_layer_boundary_get_extents;
+  item_class->stroke         = gimp_canvas_layer_boundary_stroke;
+
+  g_object_class_install_property (object_class, PROP_LAYER,
+                                   g_param_spec_object ("layer", NULL, NULL,
+                                                        GIMP_TYPE_LAYER,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_EDIT_MASK,
+                                   g_param_spec_boolean ("edit-mask", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_layer_boundary_init (GimpCanvasLayerBoundary *layer_boundary)
+{
+}
+
+static void
+gimp_canvas_layer_boundary_finalize (GObject *object)
+{
+  GimpCanvasLayerBoundaryPrivate *private = GET_PRIVATE (object);
+
+  if (private->layer)
+    g_object_remove_weak_pointer (G_OBJECT (private->layer),
+                                  (gpointer) &private->layer);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_layer_boundary_set_property (GObject      *object,
+                                         guint         property_id,
+                                         const GValue *value,
+                                         GParamSpec   *pspec)
+{
+  GimpCanvasLayerBoundaryPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_LAYER:
+      if (private->layer)
+        g_object_remove_weak_pointer (G_OBJECT (private->layer),
+                                      (gpointer) &private->layer);
+      private->layer = g_value_get_object (value); /* don't ref */
+      if (private->layer)
+        g_object_add_weak_pointer (G_OBJECT (private->layer),
+                                   (gpointer) &private->layer);
+      break;
+    case PROP_EDIT_MASK:
+      private->edit_mask = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_layer_boundary_get_property (GObject    *object,
+                                         guint       property_id,
+                                         GValue     *value,
+                                         GParamSpec *pspec)
+{
+  GimpCanvasLayerBoundaryPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_LAYER:
+      g_value_set_object (value, private->layer);
+      break;
+    case PROP_EDIT_MASK:
+      g_value_set_boolean (value, private->edit_mask);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_layer_boundary_draw (GimpCanvasItem *item,
+                                 cairo_t        *cr)
+{
+  GimpCanvasLayerBoundaryPrivate *private = GET_PRIVATE (item);
+
+  if (private->layer)
+    GIMP_CANVAS_ITEM_CLASS (parent_class)->draw (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_layer_boundary_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasLayerBoundaryPrivate *private = GET_PRIVATE (item);
+
+  if (private->layer)
+    return GIMP_CANVAS_ITEM_CLASS (parent_class)->get_extents (item);
+
+  return NULL;
+}
+
+static void
+gimp_canvas_layer_boundary_stroke (GimpCanvasItem *item,
+                                   cairo_t        *cr)
+{
+  GimpCanvasLayerBoundaryPrivate *private = GET_PRIVATE (item);
+  GimpDisplayShell               *shell   = gimp_canvas_item_get_shell (item);
+
+  gimp_canvas_set_layer_style (gimp_canvas_item_get_canvas (item), cr,
+                               private->layer,
+                               shell->offset_x, shell->offset_y);
+  cairo_stroke (cr);
+}
+
+GimpCanvasItem *
+gimp_canvas_layer_boundary_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_LAYER_BOUNDARY,
+                       "shell", shell,
+                       NULL);
+}
+
+void
+gimp_canvas_layer_boundary_set_layer (GimpCanvasLayerBoundary *boundary,
+                                      GimpLayer               *layer)
+{
+  GimpCanvasLayerBoundaryPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_LAYER_BOUNDARY (boundary));
+  g_return_if_fail (layer == NULL || GIMP_IS_LAYER (layer));
+
+  private = GET_PRIVATE (boundary);
+
+  if (layer && gimp_layer_is_floating_sel (layer))
+    {
+      GimpDrawable *drawable;
+
+      drawable = gimp_layer_get_floating_sel_drawable (layer);
+
+      if (GIMP_IS_CHANNEL (drawable))
+        {
+          /*  if the owner drawable is a channel, show no outline  */
+
+          layer = NULL;
+        }
+      else
+        {
+          /*  otherwise, set the layer to the owner drawable  */
+
+          layer = GIMP_LAYER (drawable);
+        }
+    }
+
+  if (layer != private->layer)
+    {
+      gboolean edit_mask = FALSE;
+
+      gimp_canvas_item_begin_change (GIMP_CANVAS_ITEM (boundary));
+
+      if (layer)
+        {
+          GimpItem *item = GIMP_ITEM (layer);
+
+          edit_mask = (gimp_layer_get_mask (layer) &&
+                       gimp_layer_get_edit_mask (layer));
+
+          g_object_set (boundary,
+                        "x",      (gdouble) gimp_item_get_offset_x (item),
+                        "y",      (gdouble) gimp_item_get_offset_y (item),
+                        "width",  (gdouble) gimp_item_get_width  (item),
+                        "height", (gdouble) gimp_item_get_height (item),
+                        NULL);
+        }
+
+      g_object_set (boundary,
+                    "layer",     layer,
+                    "edit-mask", edit_mask,
+                    NULL);
+
+      gimp_canvas_item_end_change (GIMP_CANVAS_ITEM (boundary));
+    }
+  else if (layer && layer == private->layer)
+    {
+      GimpItem *item = GIMP_ITEM (layer);
+      gint      lx, ly, lw, lh;
+      gdouble   x, y, w ,h;
+      gboolean  edit_mask;
+
+      lx = gimp_item_get_offset_x (item);
+      ly = gimp_item_get_offset_y (item);
+      lw = gimp_item_get_width  (item);
+      lh = gimp_item_get_height (item);
+
+      edit_mask = (gimp_layer_get_mask (layer) &&
+                   gimp_layer_get_edit_mask (layer));
+
+      g_object_get (boundary,
+                    "x",      &x,
+                    "y",      &y,
+                    "width",  &w,
+                    "height", &h,
+                    NULL);
+
+      if (lx        != (gint) x ||
+          ly        != (gint) y ||
+          lw        != (gint) w ||
+          lh        != (gint) h ||
+          edit_mask != private->edit_mask)
+        {
+          gimp_canvas_item_begin_change (GIMP_CANVAS_ITEM (boundary));
+
+          g_object_set (boundary,
+                        "x",         (gdouble) lx,
+                        "y",         (gdouble) ly,
+                        "width",     (gdouble) lw,
+                        "height",    (gdouble) lh,
+                        "edit-mask", edit_mask,
+                        NULL);
+
+          gimp_canvas_item_end_change (GIMP_CANVAS_ITEM (boundary));
+        }
+    }
+}
diff --git a/app/display/gimpcanvaslayerboundary.h b/app/display/gimpcanvaslayerboundary.h
new file mode 100644
index 0000000..5f90131
--- /dev/null
+++ b/app/display/gimpcanvaslayerboundary.h
@@ -0,0 +1,58 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaslayerboundary.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_LAYER_BOUNDARY_H__
+#define __GIMP_CANVAS_LAYER_BOUNDARY_H__
+
+
+#include "gimpcanvasrectangle.h"
+
+
+#define GIMP_TYPE_CANVAS_LAYER_BOUNDARY            (gimp_canvas_layer_boundary_get_type ())
+#define GIMP_CANVAS_LAYER_BOUNDARY(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_LAYER_BOUNDARY, GimpCanvasLayerBoundary))
+#define GIMP_CANVAS_LAYER_BOUNDARY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_LAYER_BOUNDARY, GimpCanvasLayerBoundaryClass))
+#define GIMP_IS_CANVAS_LAYER_BOUNDARY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_LAYER_BOUNDARY))
+#define GIMP_IS_CANVAS_LAYER_BOUNDARY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_LAYER_BOUNDARY))
+#define GIMP_CANVAS_LAYER_BOUNDARY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_LAYER_BOUNDARY, GimpCanvasLayerBoundaryClass))
+
+
+typedef struct _GimpCanvasLayerBoundary      GimpCanvasLayerBoundary;
+typedef struct _GimpCanvasLayerBoundaryClass GimpCanvasLayerBoundaryClass;
+
+struct _GimpCanvasLayerBoundary
+{
+  GimpCanvasRectangle  parent_instance;
+};
+
+struct _GimpCanvasLayerBoundaryClass
+{
+  GimpCanvasRectangleClass  parent_class;
+};
+
+
+GType            gimp_canvas_layer_boundary_get_type  (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_layer_boundary_new       (GimpDisplayShell        *shell);
+
+void             gimp_canvas_layer_boundary_set_layer (GimpCanvasLayerBoundary *boundary,
+                                                       GimpLayer               *layer);
+
+
+#endif /* __GIMP_CANVAS_LAYER_BOUNDARY_H__ */
diff --git a/app/display/gimpcanvaslimit.c b/app/display/gimpcanvaslimit.c
new file mode 100644
index 0000000..05dacbb
--- /dev/null
+++ b/app/display/gimpcanvaslimit.c
@@ -0,0 +1,760 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaslimit.c
+ * Copyright (C) 2020 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-cairo.h"
+
+#include "gimpcanvaslimit.h"
+#include "gimpdisplayshell.h"
+
+
+#define DASH_LENGTH   4.0
+#define HIT_DISTANCE 16.0
+
+
+enum
+{
+  PROP_0,
+  PROP_TYPE,
+  PROP_X,
+  PROP_Y,
+  PROP_RADIUS,
+  PROP_ASPECT_RATIO,
+  PROP_ANGLE,
+  PROP_DASHED
+};
+
+
+typedef struct _GimpCanvasLimitPrivate GimpCanvasLimitPrivate;
+
+struct _GimpCanvasLimitPrivate
+{
+  GimpLimitType type;
+
+  gdouble       x;
+  gdouble       y;
+  gdouble       radius;
+  gdouble       aspect_ratio;
+  gdouble       angle;
+
+  gboolean      dashed;
+};
+
+#define GET_PRIVATE(limit) \
+        ((GimpCanvasLimitPrivate *) gimp_canvas_limit_get_instance_private ((GimpCanvasLimit *) (limit)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_limit_set_property (GObject        *object,
+                                                        guint           property_id,
+                                                        const GValue   *value,
+                                                        GParamSpec     *pspec);
+static void             gimp_canvas_limit_get_property (GObject        *object,
+                                                        guint           property_id,
+                                                        GValue         *value,
+                                                        GParamSpec     *pspec);
+
+static void             gimp_canvas_limit_draw         (GimpCanvasItem *item,
+                                                        cairo_t        *cr);
+static cairo_region_t * gimp_canvas_limit_get_extents  (GimpCanvasItem *item);
+static gboolean         gimp_canvas_limit_hit          (GimpCanvasItem *item,
+                                                        gdouble         x,
+                                                        gdouble         y);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasLimit, gimp_canvas_limit,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_limit_parent_class
+
+
+/*  private functions  */
+
+static void
+gimp_canvas_limit_class_init (GimpCanvasLimitClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_limit_set_property;
+  object_class->get_property = gimp_canvas_limit_get_property;
+
+  item_class->draw           = gimp_canvas_limit_draw;
+  item_class->get_extents    = gimp_canvas_limit_get_extents;
+  item_class->hit            = gimp_canvas_limit_hit;
+
+  g_object_class_install_property (object_class, PROP_TYPE,
+                                   g_param_spec_enum ("type", NULL, NULL,
+                                                      GIMP_TYPE_LIMIT_TYPE,
+                                                      GIMP_LIMIT_CIRCLE,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_RADIUS,
+                                   g_param_spec_double ("radius", NULL, NULL,
+                                                        0.0,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_ASPECT_RATIO,
+                                   g_param_spec_double ("aspect-ratio", NULL, NULL,
+                                                        -1.0,
+                                                        +1.0,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_ANGLE,
+                                   g_param_spec_double ("angle", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_DASHED,
+                                   g_param_spec_boolean ("dashed", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_limit_init (GimpCanvasLimit *limit)
+{
+}
+
+static void
+gimp_canvas_limit_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  GimpCanvasLimitPrivate *priv = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_TYPE:
+      priv->type = g_value_get_enum (value);
+      break;
+
+    case PROP_X:
+      priv->x = g_value_get_double (value);
+      break;
+
+    case PROP_Y:
+      priv->y = g_value_get_double (value);
+      break;
+
+    case PROP_RADIUS:
+      priv->radius = g_value_get_double (value);
+      break;
+
+    case PROP_ASPECT_RATIO:
+      priv->aspect_ratio = g_value_get_double (value);
+      break;
+
+    case PROP_ANGLE:
+      priv->angle = g_value_get_double (value);
+      break;
+
+    case PROP_DASHED:
+      priv->dashed = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_limit_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  GimpCanvasLimitPrivate *priv = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_TYPE:
+      g_value_set_enum (value, priv->type);
+      break;
+
+    case PROP_X:
+      g_value_set_double (value, priv->x);
+      break;
+
+    case PROP_Y:
+      g_value_set_double (value, priv->y);
+      break;
+
+    case PROP_RADIUS:
+      g_value_set_double (value, priv->radius);
+      break;
+
+    case PROP_ASPECT_RATIO:
+      g_value_set_double (value, priv->aspect_ratio);
+      break;
+
+    case PROP_ANGLE:
+      g_value_set_double (value, priv->angle);
+      break;
+
+    case PROP_DASHED:
+      g_value_set_boolean (value, priv->dashed);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_limit_transform (GimpCanvasItem *item,
+                             gdouble        *x,
+                             gdouble        *y,
+                             gdouble        *rx,
+                             gdouble        *ry)
+{
+  GimpCanvasLimit        *limit      = GIMP_CANVAS_LIMIT (item);
+  GimpCanvasLimitPrivate *priv       = GET_PRIVATE (item);
+  gdouble                 x1, y1;
+  gdouble                 x2, y2;
+  gdouble                 min_radius = 0.0;
+
+  gimp_canvas_limit_get_radii (limit, rx, ry);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   priv->x - *rx, priv->y - *ry,
+                                   &x1,           &y1);
+  gimp_canvas_item_transform_xy_f (item,
+                                   priv->x + *rx, priv->y + *ry,
+                                   &x2,           &y2);
+
+  x1  = floor (x1) + 0.5;
+  y1  = floor (y1) + 0.5;
+
+  x2  = floor (x2) + 0.5;
+  y2  = floor (y2) + 0.5;
+
+  *x  = (x1 + x2) / 2.0;
+  *y  = (y1 + y2) / 2.0;
+
+  *rx = (x2 - x1) / 2.0;
+  *ry = (y2 - y1) / 2.0;
+
+  switch (priv->type)
+    {
+    case GIMP_LIMIT_CIRCLE:
+    case GIMP_LIMIT_SQUARE:
+      min_radius = 2.0;
+      break;
+
+    case GIMP_LIMIT_DIAMOND:
+      min_radius = 3.0;
+      break;
+
+    case GIMP_LIMIT_HORIZONTAL:
+    case GIMP_LIMIT_VERTICAL:
+      min_radius = 1.0;
+      break;
+    }
+
+  *rx = MAX (*rx, min_radius);
+  *ry = MAX (*ry, min_radius);
+}
+
+static void
+gimp_canvas_limit_paint (GimpCanvasItem *item,
+                         cairo_t        *cr)
+{
+  GimpCanvasLimitPrivate *priv  = GET_PRIVATE (item);
+  GimpDisplayShell       *shell = gimp_canvas_item_get_shell (item);
+  gdouble                 x,  y;
+  gdouble                 rx, ry;
+  gdouble                 inf;
+
+  gimp_canvas_limit_transform (item,
+                               &x,  &y,
+                               &rx, &ry);
+
+  cairo_save (cr);
+
+  cairo_translate (cr, x,  y);
+  cairo_rotate    (cr, priv->angle);
+  cairo_scale     (cr, rx, ry);
+
+  inf = MAX (x, shell->disp_width  - x) +
+        MAX (y, shell->disp_height - y);
+
+  switch (priv->type)
+    {
+    case GIMP_LIMIT_CIRCLE:
+      cairo_arc (cr, 0.0, 0.0, 1.0, 0.0, 2.0 * G_PI);
+      break;
+
+    case GIMP_LIMIT_SQUARE:
+      cairo_rectangle (cr, -1.0, -1.0, 2.0, 2.0);
+      break;
+
+    case GIMP_LIMIT_DIAMOND:
+      cairo_move_to (cr,  0.0, -1.0);
+      cairo_line_to (cr, +1.0,  0.0);
+      cairo_line_to (cr,  0.0, +1.0);
+      cairo_line_to (cr, -1.0,  0.0);
+      cairo_close_path (cr);
+      break;
+
+    case GIMP_LIMIT_HORIZONTAL:
+      cairo_move_to (cr, -inf / rx, -1.0);
+      cairo_line_to (cr, +inf / rx, -1.0);
+
+      cairo_move_to (cr, -inf / rx, +1.0);
+      cairo_line_to (cr, +inf / rx, +1.0);
+      break;
+
+    case GIMP_LIMIT_VERTICAL:
+      cairo_move_to (cr, -1.0, -inf / ry);
+      cairo_line_to (cr, -1.0, +inf / ry);
+
+      cairo_move_to (cr, +1.0, -inf / ry);
+      cairo_line_to (cr, +1.0, +inf / ry);
+      break;
+    }
+
+  cairo_restore (cr);
+}
+
+static void
+gimp_canvas_limit_draw (GimpCanvasItem *item,
+                        cairo_t        *cr)
+{
+  GimpCanvasLimitPrivate *priv = GET_PRIVATE (item);
+
+  gimp_canvas_limit_paint (item, cr);
+
+  cairo_save (cr);
+
+  if (priv->dashed)
+    cairo_set_dash (cr, (const gdouble[]) {DASH_LENGTH}, 1, 0.0);
+
+  _gimp_canvas_item_stroke (item, cr);
+
+  cairo_restore (cr);
+}
+
+static cairo_region_t *
+gimp_canvas_limit_get_extents (GimpCanvasItem *item)
+{
+  cairo_t               *cr;
+  cairo_surface_t       *surface;
+  cairo_rectangle_int_t  rectangle;
+  gdouble                x1, y1;
+  gdouble                x2, y2;
+
+  surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 1, 1);
+
+  cr = cairo_create (surface);
+
+  gimp_canvas_limit_paint (item, cr);
+
+  cairo_path_extents (cr,
+                      &x1, &y1,
+                      &x2, &y2);
+
+  cairo_destroy (cr);
+
+  cairo_surface_destroy (surface);
+
+  rectangle.x      = floor (x1 - 1.5);
+  rectangle.y      = floor (y1 - 1.5);
+  rectangle.width  = ceil  (x2 + 1.5) - rectangle.x;
+  rectangle.height = ceil  (y2 + 1.5) - rectangle.y;
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+static gboolean
+gimp_canvas_limit_hit (GimpCanvasItem *item,
+                       gdouble         x,
+                       gdouble         y)
+{
+  GimpCanvasLimit *limit = GIMP_CANVAS_LIMIT (item);
+  gdouble          bx, by;
+
+  gimp_canvas_limit_boundary_point (limit,
+                                    x,   y,
+                                    &bx, &by);
+
+  return gimp_canvas_item_transform_distance (item,
+                                              x,  y,
+                                              bx, by) <= HIT_DISTANCE;
+}
+
+
+/*  public functions  */
+
+GimpCanvasItem *
+gimp_canvas_limit_new (GimpDisplayShell *shell,
+                       GimpLimitType     type,
+                       gdouble           x,
+                       gdouble           y,
+                       gdouble           radius,
+                       gdouble           aspect_ratio,
+                       gdouble           angle,
+                       gboolean          dashed)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_LIMIT,
+                       "shell",        shell,
+                       "type",         type,
+                       "x",            x,
+                       "y",            y,
+                       "radius",       radius,
+                       "aspect-ratio", aspect_ratio,
+                       "angle",        angle,
+                       "dashed",       dashed,
+                       NULL);
+}
+
+void
+gimp_canvas_limit_get_radii (GimpCanvasLimit  *limit,
+                             gdouble          *rx,
+                             gdouble          *ry)
+{
+  GimpCanvasLimitPrivate *priv;
+
+  g_return_if_fail (GIMP_IS_CANVAS_LIMIT (limit));
+
+  priv = GET_PRIVATE (limit);
+
+  if (priv->aspect_ratio >= 0.0)
+    {
+      if (rx) *rx = priv->radius;
+      if (ry) *ry = priv->radius * (1.0 - priv->aspect_ratio);
+    }
+  else
+    {
+      if (rx) *rx = priv->radius * (1.0 + priv->aspect_ratio);
+      if (ry) *ry = priv->radius;
+    }
+}
+
+gboolean
+gimp_canvas_limit_is_inside (GimpCanvasLimit *limit,
+                             gdouble          x,
+                             gdouble          y)
+{
+  GimpCanvasLimitPrivate *priv;
+  GimpVector2             p;
+  gdouble                 rx, ry;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_LIMIT (limit), FALSE);
+
+  priv = GET_PRIVATE (limit);
+
+  gimp_canvas_limit_get_radii (limit, &rx, &ry);
+
+  if (rx == 0.0 || ry == 0.0)
+    return FALSE;
+
+  p.x = x - priv->x;
+  p.y = y - priv->y;
+
+  gimp_vector2_rotate (&p, +priv->angle);
+
+  p.x = fabs (p.x / rx);
+  p.y = fabs (p.y / ry);
+
+  switch (priv->type)
+    {
+    case GIMP_LIMIT_CIRCLE:
+      return gimp_vector2_length (&p) < 1.0;
+
+    case GIMP_LIMIT_SQUARE:
+      return p.x < 1.0 && p.y < 1.0;
+
+    case GIMP_LIMIT_DIAMOND:
+      return p.x + p.y < 1.0;
+
+    case GIMP_LIMIT_HORIZONTAL:
+      return p.y < 1.0;
+
+    case GIMP_LIMIT_VERTICAL:
+      return p.x < 1.0;
+    }
+
+  g_return_val_if_reached (FALSE);
+}
+
+void
+gimp_canvas_limit_boundary_point (GimpCanvasLimit *limit,
+                                  gdouble          x,
+                                  gdouble          y,
+                                  gdouble         *bx,
+                                  gdouble         *by)
+{
+  GimpCanvasLimitPrivate *priv;
+  GimpVector2             p;
+  gdouble                 rx, ry;
+  gboolean                flip_x = FALSE;
+  gboolean                flip_y = FALSE;
+
+  g_return_if_fail (GIMP_IS_CANVAS_LIMIT (limit));
+  g_return_if_fail (bx != NULL);
+  g_return_if_fail (by != NULL);
+
+  priv = GET_PRIVATE (limit);
+
+  gimp_canvas_limit_get_radii (limit, &rx, &ry);
+
+  p.x = x - priv->x;
+  p.y = y - priv->y;
+
+  gimp_vector2_rotate (&p, +priv->angle);
+
+  if (p.x < 0.0)
+    {
+      p.x = -p.x;
+
+      flip_x = TRUE;
+    }
+
+  if (p.y < 0.0)
+    {
+      p.y = -p.y;
+
+      flip_y = TRUE;
+    }
+
+  switch (priv->type)
+    {
+    case GIMP_LIMIT_CIRCLE:
+      if (rx == ry)
+        {
+          gimp_vector2_normalize (&p);
+
+          gimp_vector2_mul (&p, rx);
+        }
+      else
+        {
+          gdouble a0 = 0.0;
+          gdouble a1 = G_PI / 2.0;
+          gdouble a;
+          gint    i;
+
+          for (i = 0; i < 20; i++)
+            {
+              GimpVector2 r;
+              GimpVector2 n;
+
+              a = (a0 + a1) / 2.0;
+
+              r.x = p.x - rx * cos (a);
+              r.y = p.y - ry * sin (a);
+
+              n.x = 1.0;
+              n.y = tan (a) * rx / ry;
+
+              if (gimp_vector2_cross_product (&r, &n).x >= 0.0)
+                a1 = a;
+              else
+                a0 = a;
+            }
+
+          a = (a0 + a1) / 2.0;
+
+          p.x = rx * cos (a);
+          p.y = ry * sin (a);
+        }
+      break;
+
+    case GIMP_LIMIT_SQUARE:
+      if (p.x <= rx || p.y <= ry)
+        {
+          if (rx - p.x <= ry - p.y)
+            p.x = rx;
+          else
+            p.y = ry;
+        }
+      else
+        {
+          p.x = rx;
+          p.y = ry;
+        }
+      break;
+
+    case GIMP_LIMIT_DIAMOND:
+      {
+        GimpVector2 l;
+        GimpVector2 r;
+        gdouble     t;
+
+        l.x = rx;
+        l.y = -ry;
+
+        r.x = p.x;
+        r.y = p.y - ry;
+
+        t = gimp_vector2_inner_product (&r, &l) /
+            gimp_vector2_inner_product (&l, &l);
+        t = CLAMP (t, 0.0, 1.0);
+
+        p.x = rx * t;
+        p.y = ry * (1.0 - t);
+      }
+      break;
+
+    case GIMP_LIMIT_HORIZONTAL:
+      p.y = ry;
+      break;
+
+    case GIMP_LIMIT_VERTICAL:
+      p.x = rx;
+      break;
+    }
+
+  if (flip_x)
+    p.x = -p.x;
+
+  if (flip_y)
+    p.y = -p.y;
+
+  gimp_vector2_rotate (&p, -priv->angle);
+
+  *bx = priv->x + p.x;
+  *by = priv->y + p.y;
+}
+
+gdouble
+gimp_canvas_limit_boundary_radius (GimpCanvasLimit *limit,
+                                   gdouble          x,
+                                   gdouble          y)
+{
+  GimpCanvasLimitPrivate *priv;
+  GimpVector2             p;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_LIMIT (limit), 0.0);
+
+  priv = GET_PRIVATE (limit);
+
+  p.x = x - priv->x;
+  p.y = y - priv->y;
+
+  gimp_vector2_rotate (&p, +priv->angle);
+
+  p.x = fabs (p.x);
+  p.y = fabs (p.y);
+
+  if (priv->aspect_ratio >= 0.0)
+    p.y /= 1.0 - priv->aspect_ratio;
+  else
+    p.x /= 1.0 + priv->aspect_ratio;
+
+  switch (priv->type)
+    {
+    case GIMP_LIMIT_CIRCLE:
+      return gimp_vector2_length (&p);
+
+    case GIMP_LIMIT_SQUARE:
+      return MAX (p.x, p.y);
+
+    case GIMP_LIMIT_DIAMOND:
+      return p.x + p.y;
+
+    case GIMP_LIMIT_HORIZONTAL:
+      return p.y;
+
+    case GIMP_LIMIT_VERTICAL:
+      return p.x;
+    }
+
+  g_return_val_if_reached (0.0);
+}
+
+void
+gimp_canvas_limit_center_point (GimpCanvasLimit *limit,
+                                gdouble          x,
+                                gdouble          y,
+                                gdouble         *cx,
+                                gdouble         *cy)
+{
+  GimpCanvasLimitPrivate *priv;
+  GimpVector2             p;
+
+  g_return_if_fail (GIMP_IS_CANVAS_LIMIT (limit));
+  g_return_if_fail (cx != NULL);
+  g_return_if_fail (cy != NULL);
+
+  priv = GET_PRIVATE (limit);
+
+  p.x = x - priv->x;
+  p.y = y - priv->y;
+
+  gimp_vector2_rotate (&p, +priv->angle);
+
+  switch (priv->type)
+    {
+    case GIMP_LIMIT_CIRCLE:
+    case GIMP_LIMIT_SQUARE:
+    case GIMP_LIMIT_DIAMOND:
+      p.x = 0.0;
+      p.y = 0.0;
+      break;
+
+    case GIMP_LIMIT_HORIZONTAL:
+      p.y = 0.0;
+      break;
+
+    case GIMP_LIMIT_VERTICAL:
+      p.x = 0.0;
+      break;
+    }
+
+  gimp_vector2_rotate (&p, -priv->angle);
+
+  *cx = priv->x + p.x;
+  *cy = priv->y + p.y;
+}
diff --git a/app/display/gimpcanvaslimit.h b/app/display/gimpcanvaslimit.h
new file mode 100644
index 0000000..cf6ffc8
--- /dev/null
+++ b/app/display/gimpcanvaslimit.h
@@ -0,0 +1,84 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaslimit.h
+ * Copyright (C) 2020 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_LIMIT_H__
+#define __GIMP_CANVAS_LIMIT_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_LIMIT            (gimp_canvas_limit_get_type ())
+#define GIMP_CANVAS_LIMIT(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_LIMIT, GimpCanvasLimit))
+#define GIMP_CANVAS_LIMIT_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_LIMIT, GimpCanvasLimitClass))
+#define GIMP_IS_CANVAS_LIMIT(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_LIMIT))
+#define GIMP_IS_CANVAS_LIMIT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_LIMIT))
+#define GIMP_CANVAS_LIMIT_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_LIMIT, GimpCanvasLimitClass))
+
+
+typedef struct _GimpCanvasLimit      GimpCanvasLimit;
+typedef struct _GimpCanvasLimitClass GimpCanvasLimitClass;
+
+struct _GimpCanvasLimit
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasLimitClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_limit_get_type        (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_limit_new             (GimpDisplayShell *shell,
+                                                    GimpLimitType     type,
+                                                    gdouble           x,
+                                                    gdouble           y,
+                                                    gdouble           radius,
+                                                    gdouble           aspect_ratio,
+                                                    gdouble           angle,
+                                                    gboolean          dashed);
+
+void             gimp_canvas_limit_get_radii       (GimpCanvasLimit  *limit,
+                                                    gdouble          *rx,
+                                                    gdouble          *ry);
+
+gboolean         gimp_canvas_limit_is_inside       (GimpCanvasLimit  *limit,
+                                                    gdouble           x,
+                                                    gdouble           y);
+void             gimp_canvas_limit_boundary_point  (GimpCanvasLimit  *limit,
+                                                    gdouble           x,
+                                                    gdouble           y,
+                                                    gdouble          *bx,
+                                                    gdouble          *by);
+gdouble          gimp_canvas_limit_boundary_radius (GimpCanvasLimit  *limit,
+                                                    gdouble           x,
+                                                    gdouble           y);
+
+void             gimp_canvas_limit_center_point    (GimpCanvasLimit  *limit,
+                                                    gdouble           x,
+                                                    gdouble           y,
+                                                    gdouble          *cx,
+                                                    gdouble          *cy);
+
+
+#endif /* __GIMP_CANVAS_LIMIT_H__ */
diff --git a/app/display/gimpcanvasline.c b/app/display/gimpcanvasline.c
new file mode 100644
index 0000000..38a00c8
--- /dev/null
+++ b/app/display/gimpcanvasline.c
@@ -0,0 +1,281 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasline.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvasline.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_X1,
+  PROP_Y1,
+  PROP_X2,
+  PROP_Y2
+};
+
+
+typedef struct _GimpCanvasLinePrivate GimpCanvasLinePrivate;
+
+struct _GimpCanvasLinePrivate
+{
+  gdouble  x1;
+  gdouble  y1;
+  gdouble  x2;
+  gdouble  y2;
+};
+
+#define GET_PRIVATE(line) \
+        ((GimpCanvasLinePrivate *) gimp_canvas_line_get_instance_private ((GimpCanvasLine *) (line)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_line_set_property (GObject        *object,
+                                                       guint           property_id,
+                                                       const GValue   *value,
+                                                       GParamSpec     *pspec);
+static void             gimp_canvas_line_get_property (GObject        *object,
+                                                       guint           property_id,
+                                                       GValue         *value,
+                                                       GParamSpec     *pspec);
+static void             gimp_canvas_line_draw         (GimpCanvasItem *item,
+                                                       cairo_t        *cr);
+static cairo_region_t * gimp_canvas_line_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasLine, gimp_canvas_line,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_line_parent_class
+
+
+static void
+gimp_canvas_line_class_init (GimpCanvasLineClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_line_set_property;
+  object_class->get_property = gimp_canvas_line_get_property;
+
+  item_class->draw           = gimp_canvas_line_draw;
+  item_class->get_extents    = gimp_canvas_line_get_extents;
+
+  g_object_class_install_property (object_class, PROP_X1,
+                                   g_param_spec_double ("x1", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y1,
+                                   g_param_spec_double ("y1", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X2,
+                                   g_param_spec_double ("x2", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y2,
+                                   g_param_spec_double ("y2", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_line_init (GimpCanvasLine *line)
+{
+}
+
+static void
+gimp_canvas_line_set_property (GObject      *object,
+                               guint         property_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GimpCanvasLinePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X1:
+      private->x1 = g_value_get_double (value);
+      break;
+    case PROP_Y1:
+      private->y1 = g_value_get_double (value);
+      break;
+    case PROP_X2:
+      private->x2 = g_value_get_double (value);
+      break;
+    case PROP_Y2:
+      private->y2 = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_line_get_property (GObject    *object,
+                               guint       property_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GimpCanvasLinePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X1:
+      g_value_set_double (value, private->x1);
+      break;
+    case PROP_Y1:
+      g_value_set_double (value, private->y1);
+      break;
+    case PROP_X2:
+      g_value_set_double (value, private->x2);
+      break;
+    case PROP_Y2:
+      g_value_set_double (value, private->y2);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_line_transform (GimpCanvasItem *item,
+                            gdouble        *x1,
+                            gdouble        *y1,
+                            gdouble        *x2,
+                            gdouble        *y2)
+{
+  GimpCanvasLinePrivate *private = GET_PRIVATE (item);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->x1, private->y1,
+                                   x1, y1);
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->x2, private->y2,
+                                   x2, y2);
+
+  *x1 = floor (*x1) + 0.5;
+  *y1 = floor (*y1) + 0.5;
+  *x2 = floor (*x2) + 0.5;
+  *y2 = floor (*y2) + 0.5;
+}
+
+static void
+gimp_canvas_line_draw (GimpCanvasItem *item,
+                       cairo_t        *cr)
+{
+  gdouble x1, y1;
+  gdouble x2, y2;
+
+  gimp_canvas_line_transform (item, &x1, &y1, &x2, &y2);
+
+  cairo_move_to (cr, x1, y1);
+  cairo_line_to (cr, x2, y2);
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_line_get_extents (GimpCanvasItem *item)
+{
+  cairo_rectangle_int_t rectangle;
+  gdouble               x1, y1;
+  gdouble               x2, y2;
+
+  gimp_canvas_line_transform (item, &x1, &y1, &x2, &y2);
+
+  if (x1 == x2 || y1 == y2)
+    {
+      rectangle.x      = MIN (x1, x2) - 1.5;
+      rectangle.y      = MIN (y1, y2) - 1.5;
+      rectangle.width  = ABS (x2 - x1) + 3.0;
+      rectangle.height = ABS (y2 - y1) + 3.0;
+    }
+  else
+    {
+      rectangle.x      = floor (MIN (x1, x2) - 2.5);
+      rectangle.y      = floor (MIN (y1, y2) - 2.5);
+      rectangle.width  = ceil (ABS (x2 - x1) + 5.0);
+      rectangle.height = ceil (ABS (y2 - y1) + 5.0);
+    }
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_line_new (GimpDisplayShell *shell,
+                      gdouble           x1,
+                      gdouble           y1,
+                      gdouble           x2,
+                      gdouble           y2)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_LINE,
+                       "shell", shell,
+                       "x1",    x1,
+                       "y1",    y1,
+                       "x2",    x2,
+                       "y2",    y2,
+                       NULL);
+}
+
+void
+gimp_canvas_line_set (GimpCanvasItem *line,
+                      gdouble         x1,
+                      gdouble         y1,
+                      gdouble         x2,
+                      gdouble         y2)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_LINE (line));
+
+  gimp_canvas_item_begin_change (line);
+
+  g_object_set (line,
+                "x1", x1,
+                "y1", y1,
+                "x2", x2,
+                "y2", y2,
+                NULL);
+
+  gimp_canvas_item_end_change (line);
+}
diff --git a/app/display/gimpcanvasline.h b/app/display/gimpcanvasline.h
new file mode 100644
index 0000000..6f3f5f2
--- /dev/null
+++ b/app/display/gimpcanvasline.h
@@ -0,0 +1,65 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasline.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_LINE_H__
+#define __GIMP_CANVAS_LINE_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_LINE            (gimp_canvas_line_get_type ())
+#define GIMP_CANVAS_LINE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_LINE, GimpCanvasLine))
+#define GIMP_CANVAS_LINE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_LINE, GimpCanvasLineClass))
+#define GIMP_IS_CANVAS_LINE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_LINE))
+#define GIMP_IS_CANVAS_LINE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_LINE))
+#define GIMP_CANVAS_LINE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_LINE, GimpCanvasLineClass))
+
+
+typedef struct _GimpCanvasLine      GimpCanvasLine;
+typedef struct _GimpCanvasLineClass GimpCanvasLineClass;
+
+struct _GimpCanvasLine
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasLineClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_line_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_line_new      (GimpDisplayShell *shell,
+                                            gdouble           x1,
+                                            gdouble           y1,
+                                            gdouble           x2,
+                                            gdouble           y2);
+
+void             gimp_canvas_line_set      (GimpCanvasItem   *line,
+                                            gdouble           x1,
+                                            gdouble           y1,
+                                            gdouble           x2,
+                                            gdouble           y2);
+
+
+#endif /* __GIMP_CANVAS_LINE_H__ */
diff --git a/app/display/gimpcanvaspassepartout.c b/app/display/gimpcanvaspassepartout.c
new file mode 100644
index 0000000..21e7307
--- /dev/null
+++ b/app/display/gimpcanvaspassepartout.c
@@ -0,0 +1,235 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspassepartout.c
+ * Copyright (C) 2010 Sven Neumann <sven@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvasitem-utils.h"
+#include "gimpcanvaspassepartout.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scale.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_OPACITY,
+};
+
+
+typedef struct _GimpCanvasPassePartoutPrivate GimpCanvasPassePartoutPrivate;
+
+struct _GimpCanvasPassePartoutPrivate
+{
+  gdouble opacity;
+};
+
+#define GET_PRIVATE(item) \
+        ((GimpCanvasPassePartoutPrivate *) gimp_canvas_passe_partout_get_instance_private ((GimpCanvasPassePartout *) (item)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_passe_partout_set_property (GObject        *object,
+                                                                guint           property_id,
+                                                                const GValue   *value,
+                                                                GParamSpec     *pspec);
+static void             gimp_canvas_passe_partout_get_property (GObject        *object,
+                                                                guint           property_id,
+                                                                GValue         *value,
+                                                                GParamSpec     *pspec);
+static void             gimp_canvas_passe_partout_draw         (GimpCanvasItem *item,
+                                                                cairo_t        *cr);
+static cairo_region_t * gimp_canvas_passe_partout_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_passe_partout_fill         (GimpCanvasItem *item,
+                                                                cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasPassePartout, gimp_canvas_passe_partout,
+                            GIMP_TYPE_CANVAS_RECTANGLE)
+
+#define parent_class gimp_canvas_passe_partout_parent_class
+
+
+static void
+gimp_canvas_passe_partout_class_init (GimpCanvasPassePartoutClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_passe_partout_set_property;
+  object_class->get_property = gimp_canvas_passe_partout_get_property;
+
+  item_class->draw           = gimp_canvas_passe_partout_draw;
+  item_class->get_extents    = gimp_canvas_passe_partout_get_extents;
+  item_class->fill           = gimp_canvas_passe_partout_fill;
+
+  g_object_class_install_property (object_class, PROP_OPACITY,
+                                   g_param_spec_double ("opacity", NULL, NULL,
+                                                        0.0,
+                                                        1.0, 0.5,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_passe_partout_init (GimpCanvasPassePartout *passe_partout)
+{
+}
+
+static void
+gimp_canvas_passe_partout_set_property (GObject      *object,
+                                        guint         property_id,
+                                        const GValue *value,
+                                        GParamSpec   *pspec)
+{
+  GimpCanvasPassePartoutPrivate *priv = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_OPACITY:
+      priv->opacity = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_passe_partout_get_property (GObject    *object,
+                                        guint       property_id,
+                                        GValue     *value,
+                                        GParamSpec *pspec)
+{
+  GimpCanvasPassePartoutPrivate *priv = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_OPACITY:
+      g_value_set_double (value, priv->opacity);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_passe_partout_draw (GimpCanvasItem *item,
+                                cairo_t        *cr)
+{
+  GimpDisplayShell *shell = gimp_canvas_item_get_shell (item);
+  gint              x, y;
+  gint              w, h;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      x = -shell->offset_x;
+      y = -shell->offset_y;
+
+      gimp_display_shell_scale_get_image_size (shell, &w, &h);
+    }
+  else
+    {
+      gimp_canvas_item_untransform_viewport (item, &x, &y, &w, &h);
+    }
+
+  cairo_rectangle (cr, x, y, w, h);
+
+  GIMP_CANVAS_ITEM_CLASS (parent_class)->draw (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_passe_partout_get_extents (GimpCanvasItem *item)
+{
+  GimpDisplayShell      *shell = gimp_canvas_item_get_shell (item);
+  cairo_rectangle_int_t  rectangle;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      cairo_region_t *inner;
+      cairo_region_t *outer;
+
+      rectangle.x = - shell->offset_x;
+      rectangle.y = - shell->offset_y;
+      gimp_display_shell_scale_get_image_size (shell,
+                                               &rectangle.width,
+                                               &rectangle.height);
+
+      outer = cairo_region_create_rectangle (&rectangle);
+
+      inner = GIMP_CANVAS_ITEM_CLASS (parent_class)->get_extents (item);
+
+      cairo_region_xor (outer, inner);
+
+      cairo_region_destroy (inner);
+
+      return outer;
+    }
+  else
+    {
+      gimp_canvas_item_untransform_viewport (item,
+                                             &rectangle.x,
+                                             &rectangle.y,
+                                             &rectangle.width,
+                                             &rectangle.height);
+
+      return cairo_region_create_rectangle (&rectangle);
+    }
+}
+
+static void
+gimp_canvas_passe_partout_fill (GimpCanvasItem *item,
+                                cairo_t        *cr)
+{
+  GimpCanvasPassePartoutPrivate *priv = GET_PRIVATE (item);
+
+  cairo_set_fill_rule (cr, CAIRO_FILL_RULE_EVEN_ODD);
+  cairo_clip (cr);
+
+  gimp_canvas_set_passe_partout_style (gimp_canvas_item_get_canvas (item), cr);
+  cairo_paint_with_alpha (cr, priv->opacity);
+}
+
+GimpCanvasItem *
+gimp_canvas_passe_partout_new (GimpDisplayShell *shell,
+                               gdouble           x,
+                               gdouble           y,
+                               gdouble           width,
+                               gdouble           height)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_PASSE_PARTOUT,
+                       "shell", shell,
+                       "x",      x,
+                       "y",      y,
+                       "width",  width,
+                       "height", height,
+                       "filled", TRUE,
+                       NULL);
+}
diff --git a/app/display/gimpcanvaspassepartout.h b/app/display/gimpcanvaspassepartout.h
new file mode 100644
index 0000000..7356e3a
--- /dev/null
+++ b/app/display/gimpcanvaspassepartout.h
@@ -0,0 +1,59 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspassepartout.h
+ * Copyright (C) 2010 Sven Neumann <sven@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_PASSE_PARTOUT_H__
+#define __GIMP_CANVAS_PASSE_PARTOUT_H__
+
+
+#include "gimpcanvasrectangle.h"
+
+
+#define GIMP_TYPE_CANVAS_PASSE_PARTOUT            (gimp_canvas_passe_partout_get_type ())
+#define GIMP_CANVAS_PASSE_PARTOUT(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_PASSE_PARTOUT, GimpCanvasPassePartout))
+#define GIMP_CANVAS_PASSE_PARTOUT_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_PASSE_PARTOUT, GimpCanvasPassePartoutClass))
+#define GIMP_IS_CANVAS_PASSE_PARTOUT(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_PASSE_PARTOUT))
+#define GIMP_IS_CANVAS_PASSE_PARTOUT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_PASSE_PARTOUT))
+#define GIMP_CANVAS_PASSE_PARTOUT_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_PASSE_PARTOUT, GimpCanvasPassePartoutClass))
+
+
+typedef struct _GimpCanvasPassePartout      GimpCanvasPassePartout;
+typedef struct _GimpCanvasPassePartoutClass GimpCanvasPassePartoutClass;
+
+struct _GimpCanvasPassePartout
+{
+  GimpCanvasRectangle  parent_instance;
+};
+
+struct _GimpCanvasPassePartoutClass
+{
+  GimpCanvasRectangleClass  parent_class;
+};
+
+
+GType            gimp_canvas_passe_partout_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_passe_partout_new      (GimpDisplayShell *shell,
+                                                     gdouble           x,
+                                                     gdouble           y,
+                                                     gdouble           width,
+                                                     gdouble           height);
+
+
+#endif /* __GIMP_CANVAS_PASSE_PARTOUT_H__ */
diff --git a/app/display/gimpcanvaspath.c b/app/display/gimpcanvaspath.c
new file mode 100644
index 0000000..71a001f
--- /dev/null
+++ b/app/display/gimpcanvaspath.c
@@ -0,0 +1,352 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspath.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpbezierdesc.h"
+#include "core/gimpparamspecs.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvaspath.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_PATH,
+  PROP_X,
+  PROP_Y,
+  PROP_FILLED,
+  PROP_PATH_STYLE
+};
+
+
+typedef struct _GimpCanvasPathPrivate GimpCanvasPathPrivate;
+
+struct _GimpCanvasPathPrivate
+{
+  cairo_path_t *path;
+  gdouble       x;
+  gdouble       y;
+  gboolean      filled;
+  GimpPathStyle path_style;
+};
+
+#define GET_PRIVATE(path) \
+        ((GimpCanvasPathPrivate *) gimp_canvas_path_get_instance_private ((GimpCanvasPath *) (path)))
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_path_finalize     (GObject        *object);
+static void             gimp_canvas_path_set_property (GObject        *object,
+                                                       guint           property_id,
+                                                       const GValue   *value,
+                                                       GParamSpec     *pspec);
+static void             gimp_canvas_path_get_property (GObject        *object,
+                                                       guint           property_id,
+                                                       GValue         *value,
+                                                       GParamSpec     *pspec);
+static void             gimp_canvas_path_draw         (GimpCanvasItem *item,
+                                                       cairo_t        *cr);
+static cairo_region_t * gimp_canvas_path_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_path_stroke       (GimpCanvasItem *item,
+                                                       cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasPath, gimp_canvas_path,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_path_parent_class
+
+
+static void
+gimp_canvas_path_class_init (GimpCanvasPathClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_path_finalize;
+  object_class->set_property = gimp_canvas_path_set_property;
+  object_class->get_property = gimp_canvas_path_get_property;
+
+  item_class->draw           = gimp_canvas_path_draw;
+  item_class->get_extents    = gimp_canvas_path_get_extents;
+  item_class->stroke         = gimp_canvas_path_stroke;
+
+  g_object_class_install_property (object_class, PROP_PATH,
+                                   g_param_spec_boxed ("path", NULL, NULL,
+                                                       GIMP_TYPE_BEZIER_DESC,
+                                                       GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_FILLED,
+                                   g_param_spec_boolean ("filled", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+
+
+  g_object_class_install_property (object_class, PROP_PATH_STYLE,
+                                   g_param_spec_enum ("path-style", NULL, NULL,
+                                                      GIMP_TYPE_PATH_STYLE,
+                                                      GIMP_PATH_STYLE_DEFAULT,
+                                                      GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_path_init (GimpCanvasPath *path)
+{
+}
+
+static void
+gimp_canvas_path_finalize (GObject *object)
+{
+  GimpCanvasPathPrivate *private = GET_PRIVATE (object);
+
+  if (private->path)
+    {
+      gimp_bezier_desc_free (private->path);
+      private->path = NULL;
+    }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_path_set_property (GObject      *object,
+                               guint         property_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GimpCanvasPathPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_PATH:
+      if (private->path)
+        gimp_bezier_desc_free (private->path);
+      private->path = g_value_dup_boxed (value);
+      break;
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+    case PROP_FILLED:
+      private->filled = g_value_get_boolean (value);
+      break;
+    case PROP_PATH_STYLE:
+      private->path_style = g_value_get_enum (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_path_get_property (GObject    *object,
+                               guint       property_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GimpCanvasPathPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_PATH:
+      g_value_set_boxed (value, private->path);
+      break;
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+    case PROP_FILLED:
+      g_value_set_boolean (value, private->filled);
+      break;
+    case PROP_PATH_STYLE:
+      g_value_set_enum (value, private->path_style);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_path_draw (GimpCanvasItem *item,
+                       cairo_t        *cr)
+{
+  GimpCanvasPathPrivate *private = GET_PRIVATE (item);
+
+  if (private->path)
+    {
+      cairo_save (cr);
+      gimp_canvas_item_transform (item, cr);
+      cairo_translate (cr, private->x, private->y);
+
+      cairo_append_path (cr, private->path);
+      cairo_restore (cr);
+
+      if (private->filled)
+        _gimp_canvas_item_fill (item, cr);
+      else
+        _gimp_canvas_item_stroke (item, cr);
+    }
+}
+
+static cairo_region_t *
+gimp_canvas_path_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasPathPrivate *private = GET_PRIVATE (item);
+  GtkWidget             *canvas  = gimp_canvas_item_get_canvas (item);
+
+  if (private->path && gtk_widget_get_realized (canvas))
+    {
+      cairo_t               *cr;
+      cairo_rectangle_int_t  rectangle;
+      gdouble                x1, y1, x2, y2;
+
+      cr = gdk_cairo_create (gtk_widget_get_window (canvas));
+
+      cairo_save (cr);
+      gimp_canvas_item_transform (item, cr);
+      cairo_translate (cr, private->x, private->y);
+
+      cairo_append_path (cr, private->path);
+      cairo_restore (cr);
+
+      cairo_path_extents (cr, &x1, &y1, &x2, &y2);
+
+      cairo_destroy (cr);
+
+      if (private->filled)
+        {
+          rectangle.x      = floor (x1 - 1.0);
+          rectangle.y      = floor (y1 - 1.0);
+          rectangle.width  = ceil (x2 + 1.0) - rectangle.x;
+          rectangle.height = ceil (y2 + 1.0) - rectangle.y;
+        }
+      else
+        {
+          rectangle.x      = floor (x1 - 1.5);
+          rectangle.y      = floor (y1 - 1.5);
+          rectangle.width  = ceil (x2 + 1.5) - rectangle.x;
+          rectangle.height = ceil (y2 + 1.5) - rectangle.y;
+        }
+
+      return cairo_region_create_rectangle (&rectangle);
+    }
+
+  return NULL;
+}
+
+static void
+gimp_canvas_path_stroke (GimpCanvasItem *item,
+                         cairo_t        *cr)
+{
+  GimpCanvasPathPrivate *private = GET_PRIVATE (item);
+  GtkWidget             *canvas  = gimp_canvas_item_get_canvas (item);
+  gboolean               active;
+
+  switch (private->path_style)
+    {
+    case GIMP_PATH_STYLE_VECTORS:
+      active = gimp_canvas_item_get_highlight (item);
+
+      gimp_canvas_set_vectors_bg_style (canvas, cr, active);
+      cairo_stroke_preserve (cr);
+
+      gimp_canvas_set_vectors_fg_style (canvas, cr, active);
+      cairo_stroke (cr);
+      break;
+
+    case GIMP_PATH_STYLE_OUTLINE:
+      gimp_canvas_set_outline_bg_style (canvas, cr);
+      cairo_stroke_preserve (cr);
+
+      gimp_canvas_set_outline_fg_style (canvas, cr);
+      cairo_stroke (cr);
+      break;
+
+    case GIMP_PATH_STYLE_DEFAULT:
+      GIMP_CANVAS_ITEM_CLASS (parent_class)->stroke (item, cr);
+      break;
+    }
+}
+
+GimpCanvasItem *
+gimp_canvas_path_new (GimpDisplayShell     *shell,
+                      const GimpBezierDesc *bezier,
+                      gdouble               x,
+                      gdouble               y,
+                      gboolean              filled,
+                      GimpPathStyle         style)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_PATH,
+                       "shell",      shell,
+                       "path",       bezier,
+                       "x",          x,
+                       "y",          y,
+                       "filled",     filled,
+                       "path-style", style,
+                       NULL);
+}
+
+void
+gimp_canvas_path_set (GimpCanvasItem       *path,
+                      const GimpBezierDesc *bezier)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_PATH (path));
+
+  gimp_canvas_item_begin_change (path);
+
+  g_object_set (path,
+                "path", bezier,
+                NULL);
+
+  gimp_canvas_item_end_change (path);
+}
diff --git a/app/display/gimpcanvaspath.h b/app/display/gimpcanvaspath.h
new file mode 100644
index 0000000..03fbb01
--- /dev/null
+++ b/app/display/gimpcanvaspath.h
@@ -0,0 +1,63 @@
+/* GIMP - The GNU Image Manipulation Program Copyright (C) 1995
+ * Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspolygon.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_PATH_H__
+#define __GIMP_CANVAS_PATH_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_PATH            (gimp_canvas_path_get_type ())
+#define GIMP_CANVAS_PATH(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_PATH, GimpCanvasPath))
+#define GIMP_CANVAS_PATH_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_PATH, GimpCanvasPathClass))
+#define GIMP_IS_CANVAS_PATH(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_PATH))
+#define GIMP_IS_CANVAS_PATH_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_PATH))
+#define GIMP_CANVAS_PATH_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_PATH, GimpCanvasPathClass))
+
+
+typedef struct _GimpCanvasPath      GimpCanvasPath;
+typedef struct _GimpCanvasPathClass GimpCanvasPathClass;
+
+struct _GimpCanvasPath
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasPathClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_path_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_path_new      (GimpDisplayShell     *shell,
+                                            const GimpBezierDesc *bezier,
+                                            gdouble               x,
+                                            gdouble               y,
+                                            gboolean              filled,
+                                            GimpPathStyle         style);
+
+void             gimp_canvas_path_set      (GimpCanvasItem       *path,
+                                            const GimpBezierDesc *bezier);
+
+
+#endif /* __GIMP_CANVAS_PATH_H__ */
diff --git a/app/display/gimpcanvaspen.c b/app/display/gimpcanvaspen.c
new file mode 100644
index 0000000..d0d01f9
--- /dev/null
+++ b/app/display/gimpcanvaspen.c
@@ -0,0 +1,231 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspen.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpcontext.h"
+#include "core/gimpparamspecs.h"
+
+#include "gimpcanvas-style.h"
+#include "gimpcanvaspen.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_COLOR,
+  PROP_WIDTH
+};
+
+
+typedef struct _GimpCanvasPenPrivate GimpCanvasPenPrivate;
+
+struct _GimpCanvasPenPrivate
+{
+  GimpRGB color;
+  gint    width;
+};
+
+#define GET_PRIVATE(pen) \
+        ((GimpCanvasPenPrivate *) gimp_canvas_pen_get_instance_private ((GimpCanvasPen *) (pen)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_pen_set_property (GObject        *object,
+                                                      guint           property_id,
+                                                      const GValue   *value,
+                                                      GParamSpec     *pspec);
+static void             gimp_canvas_pen_get_property (GObject        *object,
+                                                      guint           property_id,
+                                                      GValue         *value,
+                                                      GParamSpec     *pspec);
+static cairo_region_t * gimp_canvas_pen_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_pen_stroke       (GimpCanvasItem *item,
+                                                      cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasPen, gimp_canvas_pen,
+                            GIMP_TYPE_CANVAS_POLYGON)
+
+#define parent_class gimp_canvas_pen_parent_class
+
+
+static void
+gimp_canvas_pen_class_init (GimpCanvasPenClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_pen_set_property;
+  object_class->get_property = gimp_canvas_pen_get_property;
+
+  item_class->get_extents    = gimp_canvas_pen_get_extents;
+  item_class->stroke         = gimp_canvas_pen_stroke;
+
+  g_object_class_install_property (object_class, PROP_COLOR,
+                                   gimp_param_spec_rgb ("color", NULL, NULL,
+                                                        FALSE, NULL,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_WIDTH,
+                                   g_param_spec_int ("width", NULL, NULL,
+                                                     1, G_MAXINT, 1,
+                                                     GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_pen_init (GimpCanvasPen *pen)
+{
+}
+
+static void
+gimp_canvas_pen_set_property (GObject      *object,
+                              guint         property_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
+{
+  GimpCanvasPenPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_COLOR:
+      gimp_value_get_rgb (value, &private->color);
+      break;
+    case PROP_WIDTH:
+      private->width = g_value_get_int (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_pen_get_property (GObject    *object,
+                              guint       property_id,
+                              GValue     *value,
+                              GParamSpec *pspec)
+{
+  GimpCanvasPenPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_COLOR:
+      gimp_value_set_rgb (value, &private->color);
+      break;
+    case PROP_WIDTH:
+      g_value_set_int (value, private->width);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static cairo_region_t *
+gimp_canvas_pen_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasPenPrivate *private = GET_PRIVATE (item);
+  cairo_region_t       *region;
+
+  region = GIMP_CANVAS_ITEM_CLASS (parent_class)->get_extents (item);
+
+  if (region)
+    {
+      cairo_rectangle_int_t rectangle;
+
+      cairo_region_get_extents (region, &rectangle);
+
+      rectangle.x      -= ceil (private->width / 2.0);
+      rectangle.y      -= ceil (private->width / 2.0);
+      rectangle.width  += private->width + 1;
+      rectangle.height += private->width + 1;
+
+      cairo_region_union_rectangle (region, &rectangle);
+    }
+
+  return region;
+}
+
+static void
+gimp_canvas_pen_stroke (GimpCanvasItem *item,
+                        cairo_t        *cr)
+{
+  GimpCanvasPenPrivate *private = GET_PRIVATE (item);
+
+  gimp_canvas_set_pen_style (gimp_canvas_item_get_canvas (item), cr,
+                             &private->color, private->width);
+  cairo_stroke (cr);
+}
+
+GimpCanvasItem *
+gimp_canvas_pen_new (GimpDisplayShell  *shell,
+                     const GimpVector2 *points,
+                     gint               n_points,
+                     GimpContext       *context,
+                     GimpActiveColor    color,
+                     gint               width)
+{
+  GimpCanvasItem *item;
+  GimpArray      *array;
+  GimpRGB         rgb;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (points != NULL && n_points > 1, NULL);
+  g_return_val_if_fail (GIMP_IS_CONTEXT (context), NULL);
+
+  array = gimp_array_new ((const guint8 *) points,
+                          n_points * sizeof (GimpVector2), TRUE);
+
+  switch (color)
+    {
+    case GIMP_ACTIVE_COLOR_FOREGROUND:
+      gimp_context_get_foreground (context, &rgb);
+      break;
+
+    case GIMP_ACTIVE_COLOR_BACKGROUND:
+      gimp_context_get_background (context, &rgb);
+      break;
+    }
+
+  item = g_object_new (GIMP_TYPE_CANVAS_PEN,
+                       "shell",  shell,
+                       "points", array,
+                       "color",  &rgb,
+                       "width",  width,
+                       NULL);
+
+  gimp_array_free (array);
+
+  return item;
+}
diff --git a/app/display/gimpcanvaspen.h b/app/display/gimpcanvaspen.h
new file mode 100644
index 0000000..3380790
--- /dev/null
+++ b/app/display/gimpcanvaspen.h
@@ -0,0 +1,60 @@
+/* GIMP - The GNU Image Manipulation Program Copyright (C) 1995
+ * Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspen.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_PEN_H__
+#define __GIMP_CANVAS_PEN_H__
+
+
+#include "gimpcanvaspolygon.h"
+
+
+#define GIMP_TYPE_CANVAS_PEN            (gimp_canvas_pen_get_type ())
+#define GIMP_CANVAS_PEN(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_PEN, GimpCanvasPen))
+#define GIMP_CANVAS_PEN_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_PEN, GimpCanvasPenClass))
+#define GIMP_IS_CANVAS_PEN(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_PEN))
+#define GIMP_IS_CANVAS_PEN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_PEN))
+#define GIMP_CANVAS_PEN_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_PEN, GimpCanvasPenClass))
+
+
+typedef struct _GimpCanvasPen      GimpCanvasPen;
+typedef struct _GimpCanvasPenClass GimpCanvasPenClass;
+
+struct _GimpCanvasPen
+{
+  GimpCanvasPolygon  parent_instance;
+};
+
+struct _GimpCanvasPenClass
+{
+  GimpCanvasPolygonClass  parent_class;
+};
+
+
+GType            gimp_canvas_pen_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_pen_new      (GimpDisplayShell  *shell,
+                                           const GimpVector2 *points,
+                                           gint               n_points,
+                                           GimpContext       *context,
+                                           GimpActiveColor    color,
+                                           gint               width);
+
+
+#endif /* __GIMP_CANVAS_PEN_H__ */
diff --git a/app/display/gimpcanvaspolygon.c b/app/display/gimpcanvaspolygon.c
new file mode 100644
index 0000000..9c670e7
--- /dev/null
+++ b/app/display/gimpcanvaspolygon.c
@@ -0,0 +1,505 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspolygon.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-transform-utils.h"
+#include "core/gimpparamspecs.h"
+
+#include "gimpcanvaspolygon.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_POINTS,
+  PROP_TRANSFORM,
+  PROP_FILLED
+};
+
+
+typedef struct _GimpCanvasPolygonPrivate GimpCanvasPolygonPrivate;
+
+struct _GimpCanvasPolygonPrivate
+{
+  GimpVector2  *points;
+  gint          n_points;
+  GimpMatrix3  *transform;
+  gboolean      filled;
+};
+
+#define GET_PRIVATE(polygon) \
+        ((GimpCanvasPolygonPrivate *) gimp_canvas_polygon_get_instance_private ((GimpCanvasPolygon *) (polygon)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_polygon_finalize     (GObject        *object);
+static void             gimp_canvas_polygon_set_property (GObject        *object,
+                                                          guint           property_id,
+                                                          const GValue   *value,
+                                                          GParamSpec     *pspec);
+static void             gimp_canvas_polygon_get_property (GObject        *object,
+                                                          guint           property_id,
+                                                          GValue         *value,
+                                                          GParamSpec     *pspec);
+static void             gimp_canvas_polygon_draw         (GimpCanvasItem *item,
+                                                          cairo_t        *cr);
+static cairo_region_t * gimp_canvas_polygon_get_extents  (GimpCanvasItem *item);
+static gboolean         gimp_canvas_polygon_hit          (GimpCanvasItem *item,
+                                                          gdouble         x,
+                                                          gdouble         y);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasPolygon, gimp_canvas_polygon,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_polygon_parent_class
+
+
+static void
+gimp_canvas_polygon_class_init (GimpCanvasPolygonClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_polygon_finalize;
+  object_class->set_property = gimp_canvas_polygon_set_property;
+  object_class->get_property = gimp_canvas_polygon_get_property;
+
+  item_class->draw           = gimp_canvas_polygon_draw;
+  item_class->get_extents    = gimp_canvas_polygon_get_extents;
+  item_class->hit            = gimp_canvas_polygon_hit;
+
+  g_object_class_install_property (object_class, PROP_POINTS,
+                                   gimp_param_spec_array ("points", NULL, NULL,
+                                                          GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_TRANSFORM,
+                                   g_param_spec_pointer ("transform", NULL, NULL,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_FILLED,
+                                   g_param_spec_boolean ("filled", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_polygon_init (GimpCanvasPolygon *polygon)
+{
+}
+
+static void
+gimp_canvas_polygon_finalize (GObject *object)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (object);
+
+  g_clear_pointer (&private->points, g_free);
+  private->n_points = 0;
+
+  g_clear_pointer (&private->transform, g_free);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_polygon_set_property (GObject      *object,
+                                  guint         property_id,
+                                  const GValue *value,
+                                  GParamSpec   *pspec)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_POINTS:
+      {
+        GimpArray *array = g_value_get_boxed (value);
+
+        g_clear_pointer (&private->points, g_free);
+        private->n_points = 0;
+
+        if (array)
+          {
+            private->points = g_memdup (array->data, array->length);
+            private->n_points = array->length / sizeof (GimpVector2);
+          }
+      }
+      break;
+
+    case PROP_TRANSFORM:
+      {
+        GimpMatrix3 *transform = g_value_get_pointer (value);
+        if (private->transform)
+          g_free (private->transform);
+        if (transform)
+          private->transform = g_memdup (transform, sizeof (GimpMatrix3));
+        else
+          private->transform = NULL;
+      }
+      break;
+
+    case PROP_FILLED:
+      private->filled = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_polygon_get_property (GObject    *object,
+                                  guint       property_id,
+                                  GValue     *value,
+                                  GParamSpec *pspec)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_POINTS:
+      if (private->points)
+        {
+          GimpArray *array;
+
+          array = gimp_array_new ((const guint8 *) private->points,
+                                  private->n_points * sizeof (GimpVector2),
+                                  FALSE);
+          g_value_take_boxed (value, array);
+        }
+      else
+        {
+          g_value_set_boxed (value, NULL);
+        }
+      break;
+
+    case PROP_TRANSFORM:
+      g_value_set_pointer (value, private->transform);
+      break;
+
+    case PROP_FILLED:
+      g_value_set_boolean (value, private->filled);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_polygon_transform (GimpCanvasItem *item,
+                               GimpVector2    *points,
+                               gint           *n_points)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (item);
+  gint                      i;
+
+  if (private->transform)
+    {
+      gimp_transform_polygon (private->transform,
+                              private->points, private->n_points, FALSE,
+                              points, n_points);
+
+      for (i = 0; i < *n_points; i++)
+        {
+          gimp_canvas_item_transform_xy_f (item,
+                                           points[i].x,
+                                           points[i].y,
+                                           &points[i].x,
+                                           &points[i].y);
+
+          points[i].x = floor (points[i].x) + 0.5;
+          points[i].y = floor (points[i].y) + 0.5;
+        }
+    }
+  else
+    {
+      for (i = 0; i < private->n_points; i++)
+        {
+          gimp_canvas_item_transform_xy_f (item,
+                                           private->points[i].x,
+                                           private->points[i].y,
+                                           &points[i].x,
+                                           &points[i].y);
+
+          points[i].x = floor (points[i].x) + 0.5;
+          points[i].y = floor (points[i].y) + 0.5;
+        }
+
+      *n_points = private->n_points;
+    }
+}
+
+static void
+gimp_canvas_polygon_draw (GimpCanvasItem *item,
+                          cairo_t        *cr)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (item);
+  GimpVector2              *points;
+  gint                      n_points;
+  gint                      i;
+
+  if (! private->points)
+    return;
+
+  n_points = private->n_points;
+
+  if (private->transform)
+    n_points = 3 * n_points / 2;
+
+  points = g_new0 (GimpVector2, n_points);
+
+  gimp_canvas_polygon_transform (item, points, &n_points);
+
+  if (n_points < 2)
+    {
+      g_free (points);
+
+      return;
+    }
+
+  cairo_move_to (cr, points[0].x, points[0].y);
+
+  for (i = 1; i < n_points; i++)
+    {
+      cairo_line_to (cr, points[i].x, points[i].y);
+    }
+
+  if (private->filled)
+    _gimp_canvas_item_fill (item, cr);
+  else
+    _gimp_canvas_item_stroke (item, cr);
+
+  g_free (points);
+}
+
+static cairo_region_t *
+gimp_canvas_polygon_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (item);
+  cairo_rectangle_int_t     rectangle;
+  GimpVector2              *points;
+  gint                      n_points;
+  gint                      x1, y1, x2, y2;
+  gint                      i;
+
+  if (! private->points)
+    return NULL;
+
+  n_points = private->n_points;
+
+  if (private->transform)
+    n_points = 3 * n_points / 2;
+
+  points = g_new0 (GimpVector2, n_points);
+
+  gimp_canvas_polygon_transform (item, points, &n_points);
+
+  if (n_points < 2)
+    {
+      g_free (points);
+
+      return NULL;
+    }
+
+  x1 = floor (points[0].x - 1.5);
+  y1 = floor (points[0].y - 1.5);
+  x2 = x1 + 3;
+  y2 = y1 + 3;
+
+  for (i = 1; i < n_points; i++)
+    {
+      gint x3 = floor (points[i].x - 1.5);
+      gint y3 = floor (points[i].y - 1.5);
+      gint x4 = x3 + 3;
+      gint y4 = y3 + 3;
+
+      x1 = MIN (x1, x3);
+      y1 = MIN (y1, y3);
+      x2 = MAX (x2, x4);
+      y2 = MAX (y2, y4);
+    }
+
+  g_free (points);
+
+  rectangle.x      = x1;
+  rectangle.y      = y1;
+  rectangle.width  = x2 - x1;
+  rectangle.height = y2 - y1;
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+static gboolean
+gimp_canvas_polygon_hit (GimpCanvasItem *item,
+                         gdouble         x,
+                         gdouble         y)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (item);
+  GimpVector2              *points;
+  gint                      n_points;
+  gdouble                   tx, ty;
+  cairo_surface_t          *surface;
+  cairo_t                  *cr;
+  gboolean                  hit;
+  gint                      i;
+
+  if (! private->points)
+    return FALSE;
+
+  gimp_canvas_item_transform_xy_f (item, x, y, &tx, &ty);
+
+  n_points = private->n_points;
+
+  if (private->transform)
+    n_points = 3 * n_points / 2;
+
+  points = g_new0 (GimpVector2, n_points);
+
+  gimp_canvas_polygon_transform (item, points, &n_points);
+
+  if (n_points < 2)
+    {
+      g_free (points);
+
+      return FALSE;
+    }
+
+  surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, 1, 1);
+  cr = cairo_create (surface);
+  cairo_surface_destroy (surface);
+
+  cairo_move_to (cr, points[0].x, points[0].y);
+
+  for (i = 1; i < private->n_points; i++)
+    {
+      cairo_line_to (cr, points[i].x, points[i].y);
+    }
+
+  g_free (points);
+
+  hit = cairo_in_fill (cr, tx, ty);
+
+  cairo_destroy (cr);
+
+  return hit;
+}
+
+GimpCanvasItem *
+gimp_canvas_polygon_new (GimpDisplayShell  *shell,
+                         const GimpVector2 *points,
+                         gint               n_points,
+                         GimpMatrix3       *transform,
+                         gboolean           filled)
+{
+  GimpCanvasItem *item;
+  GimpArray      *array;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (points == NULL || n_points > 0, NULL);
+
+  array = gimp_array_new ((const guint8 *) points,
+                          n_points * sizeof (GimpVector2), TRUE);
+
+  item = g_object_new (GIMP_TYPE_CANVAS_POLYGON,
+                       "shell",     shell,
+                       "transform", transform,
+                       "filled",    filled,
+                       "points",    array,
+                       NULL);
+
+  gimp_array_free (array);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_canvas_polygon_new_from_coords (GimpDisplayShell *shell,
+                                     const GimpCoords *coords,
+                                     gint              n_coords,
+                                     GimpMatrix3      *transform,
+                                     gboolean          filled)
+{
+  GimpCanvasItem *item;
+  GimpVector2    *points;
+  GimpArray      *array;
+  gint            i;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (coords == NULL || n_coords > 0, NULL);
+
+  points = g_new (GimpVector2, n_coords);
+
+  for (i = 0; i < n_coords; i++)
+    {
+      points[i].x = coords[i].x;
+      points[i].y = coords[i].y;
+    }
+
+  array = gimp_array_new ((const guint8 *) points,
+                          n_coords * sizeof (GimpVector2), TRUE);
+
+  item = g_object_new (GIMP_TYPE_CANVAS_POLYGON,
+                       "shell",     shell,
+                       "transform", transform,
+                       "filled",    filled,
+                       "points",    array,
+                       NULL);
+
+  gimp_array_free (array);
+  g_free (points);
+
+  return item;
+}
+
+void
+gimp_canvas_polygon_set_points (GimpCanvasItem    *polygon,
+                                const GimpVector2 *points,
+                                gint               n_points)
+{
+  GimpArray *array;
+
+  g_return_if_fail (GIMP_IS_CANVAS_POLYGON (polygon));
+  g_return_if_fail (points == NULL || n_points > 0);
+
+  array = gimp_array_new ((const guint8 *) points,
+                          n_points * sizeof (GimpVector2), TRUE);
+
+  gimp_canvas_item_begin_change (polygon);
+  g_object_set (polygon,
+                "points", array,
+                NULL);
+  gimp_canvas_item_end_change (polygon);
+
+  gimp_array_free (array);
+}
diff --git a/app/display/gimpcanvaspolygon.h b/app/display/gimpcanvaspolygon.h
new file mode 100644
index 0000000..f68e36a
--- /dev/null
+++ b/app/display/gimpcanvaspolygon.h
@@ -0,0 +1,68 @@
+/* GIMP - The GNU Image Manipulation Program Copyright (C) 1995
+ * Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspolygon.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_POLYGON_H__
+#define __GIMP_CANVAS_POLYGON_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_POLYGON            (gimp_canvas_polygon_get_type ())
+#define GIMP_CANVAS_POLYGON(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_POLYGON, GimpCanvasPolygon))
+#define GIMP_CANVAS_POLYGON_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_POLYGON, GimpCanvasPolygonClass))
+#define GIMP_IS_CANVAS_POLYGON(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_POLYGON))
+#define GIMP_IS_CANVAS_POLYGON_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_POLYGON))
+#define GIMP_CANVAS_POLYGON_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_POLYGON, GimpCanvasPolygonClass))
+
+
+typedef struct _GimpCanvasPolygon      GimpCanvasPolygon;
+typedef struct _GimpCanvasPolygonClass GimpCanvasPolygonClass;
+
+struct _GimpCanvasPolygon
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasPolygonClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_polygon_get_type        (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_polygon_new             (GimpDisplayShell  *shell,
+                                                      const GimpVector2 *points,
+                                                      gint               n_points,
+                                                      GimpMatrix3       *transform,
+                                                      gboolean           filled);
+GimpCanvasItem * gimp_canvas_polygon_new_from_coords (GimpDisplayShell  *shell,
+                                                      const GimpCoords  *coords,
+                                                      gint               n_coords,
+                                                      GimpMatrix3       *transform,
+                                                      gboolean           filled);
+
+void             gimp_canvas_polygon_set_points      (GimpCanvasItem    *polygon,
+                                                      const GimpVector2 *points,
+                                                      gint               n_points);
+
+
+#endif /* __GIMP_CANVAS_POLYGON_H__ */
diff --git a/app/display/gimpcanvasprogress.c b/app/display/gimpcanvasprogress.c
new file mode 100644
index 0000000..4def1ac
--- /dev/null
+++ b/app/display/gimpcanvasprogress.c
@@ -0,0 +1,459 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasprogress.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpprogress.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvas-style.h"
+#include "gimpcanvasitem-utils.h"
+#include "gimpcanvasprogress.h"
+#include "gimpdisplayshell.h"
+
+
+#define BORDER                5
+#define RADIUS               20
+
+#define MIN_UPDATE_INTERVAL  50000 /* microseconds */
+
+
+enum
+{
+  PROP_0,
+  PROP_ANCHOR,
+  PROP_X,
+  PROP_Y
+};
+
+
+typedef struct _GimpCanvasProgressPrivate GimpCanvasProgressPrivate;
+
+struct _GimpCanvasProgressPrivate
+{
+  GimpHandleAnchor  anchor;
+  gdouble           x;
+  gdouble           y;
+
+  gchar            *text;
+  gdouble           value;
+
+  guint64           last_update_time;
+};
+
+#define GET_PRIVATE(progress) \
+        ((GimpCanvasProgressPrivate *) gimp_canvas_progress_get_instance_private ((GimpCanvasProgress *) (progress)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_progress_iface_init   (GimpProgressInterface *iface);
+
+static void             gimp_canvas_progress_finalize     (GObject               *object);
+static void             gimp_canvas_progress_set_property (GObject               *object,
+                                                           guint                  property_id,
+                                                           const GValue          *value,
+                                                           GParamSpec            *pspec);
+static void             gimp_canvas_progress_get_property (GObject               *object,
+                                                           guint                  property_id,
+                                                           GValue                *value,
+                                                           GParamSpec            *pspec);
+static void             gimp_canvas_progress_draw         (GimpCanvasItem        *item,
+                                                           cairo_t               *cr);
+static cairo_region_t * gimp_canvas_progress_get_extents  (GimpCanvasItem        *item);
+static gboolean         gimp_canvas_progress_hit          (GimpCanvasItem        *item,
+                                                           gdouble                x,
+                                                           gdouble                y);
+
+static GimpProgress   * gimp_canvas_progress_start        (GimpProgress          *progress,
+                                                           gboolean               cancellable,
+                                                           const gchar           *message);
+static void             gimp_canvas_progress_end          (GimpProgress          *progress);
+static gboolean         gimp_canvas_progress_is_active    (GimpProgress          *progress);
+static void             gimp_canvas_progress_set_text     (GimpProgress          *progress,
+                                                           const gchar           *message);
+static void             gimp_canvas_progress_set_value    (GimpProgress          *progress,
+                                                           gdouble                percentage);
+static gdouble          gimp_canvas_progress_get_value    (GimpProgress          *progress);
+static void             gimp_canvas_progress_pulse        (GimpProgress          *progress);
+static gboolean         gimp_canvas_progress_message      (GimpProgress          *progress,
+                                                           Gimp                  *gimp,
+                                                           GimpMessageSeverity    severity,
+                                                           const gchar           *domain,
+                                                           const gchar           *message);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpCanvasProgress, gimp_canvas_progress,
+                         GIMP_TYPE_CANVAS_ITEM,
+                         G_ADD_PRIVATE (GimpCanvasProgress)
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_PROGRESS,
+                                                gimp_canvas_progress_iface_init))
+
+#define parent_class gimp_canvas_progress_parent_class
+
+
+static void
+gimp_canvas_progress_class_init (GimpCanvasProgressClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_progress_finalize;
+  object_class->set_property = gimp_canvas_progress_set_property;
+  object_class->get_property = gimp_canvas_progress_get_property;
+
+  item_class->draw           = gimp_canvas_progress_draw;
+  item_class->get_extents    = gimp_canvas_progress_get_extents;
+  item_class->hit            = gimp_canvas_progress_hit;
+
+  g_object_class_install_property (object_class, PROP_ANCHOR,
+                                   g_param_spec_enum ("anchor", NULL, NULL,
+                                                      GIMP_TYPE_HANDLE_ANCHOR,
+                                                      GIMP_HANDLE_ANCHOR_CENTER,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_progress_iface_init (GimpProgressInterface *iface)
+{
+  iface->start     = gimp_canvas_progress_start;
+  iface->end       = gimp_canvas_progress_end;
+  iface->is_active = gimp_canvas_progress_is_active;
+  iface->set_text  = gimp_canvas_progress_set_text;
+  iface->set_value = gimp_canvas_progress_set_value;
+  iface->get_value = gimp_canvas_progress_get_value;
+  iface->pulse     = gimp_canvas_progress_pulse;
+  iface->message   = gimp_canvas_progress_message;
+}
+
+static void
+gimp_canvas_progress_init (GimpCanvasProgress *progress)
+{
+}
+
+static void
+gimp_canvas_progress_finalize (GObject *object)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (object);
+
+  g_clear_pointer (&private->text, g_free);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_progress_set_property (GObject      *object,
+                                   guint         property_id,
+                                   const GValue *value,
+                                   GParamSpec   *pspec)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_ANCHOR:
+      private->anchor = g_value_get_enum (value);
+      break;
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_progress_get_property (GObject    *object,
+                                   guint       property_id,
+                                   GValue     *value,
+                                   GParamSpec *pspec)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_ANCHOR:
+      g_value_set_enum (value, private->anchor);
+      break;
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static PangoLayout *
+gimp_canvas_progress_transform (GimpCanvasItem *item,
+                                gdouble        *x,
+                                gdouble        *y,
+                                gint           *width,
+                                gint           *height)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (item);
+  GtkWidget                 *canvas  = gimp_canvas_item_get_canvas (item);
+  PangoLayout               *layout;
+
+  layout = gimp_canvas_get_layout (GIMP_CANVAS (canvas), "%s",
+                                   private->text);
+
+  pango_layout_get_pixel_size (layout, width, height);
+
+  *width = MAX (*width, 2 * RADIUS);
+
+  *width  += 2 * BORDER;
+  *height += 3 * BORDER + 2 * RADIUS;
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->x, private->y,
+                                   x, y);
+
+  gimp_canvas_item_shift_to_north_west (private->anchor,
+                                        *x, *y,
+                                        *width,
+                                        *height,
+                                        x, y);
+
+  *x = floor (*x);
+  *y = floor (*y);
+
+  return layout;
+}
+
+static void
+gimp_canvas_progress_draw (GimpCanvasItem *item,
+                           cairo_t        *cr)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (item);
+  GtkWidget                 *canvas  = gimp_canvas_item_get_canvas (item);
+  gdouble                    x, y;
+  gint                       width, height;
+
+  gimp_canvas_progress_transform (item, &x, &y, &width, &height);
+
+  cairo_move_to (cr, x, y);
+  cairo_line_to (cr, x + width, y);
+  cairo_line_to (cr, x + width, y + height - BORDER - 2 * RADIUS);
+  cairo_line_to (cr, x + 2 * BORDER + 2 * RADIUS, y + height - BORDER - 2 * RADIUS);
+  cairo_arc (cr, x + BORDER + RADIUS, y + height - BORDER - RADIUS,
+             BORDER + RADIUS, 0, G_PI);
+  cairo_close_path (cr);
+
+  _gimp_canvas_item_fill (item, cr);
+
+  cairo_move_to (cr, x + BORDER, y + BORDER);
+  cairo_set_source_rgba (cr, 0.0, 0.0, 0.0, 1.0);
+  pango_cairo_show_layout (cr,
+                           gimp_canvas_get_layout (GIMP_CANVAS (canvas),
+                                                   "%s", private->text));
+
+  gimp_canvas_set_tool_bg_style (gimp_canvas_item_get_canvas (item), cr);
+  cairo_arc (cr, x + BORDER + RADIUS, y + height - BORDER - RADIUS,
+             RADIUS, - G_PI / 2.0, 2 * G_PI - G_PI / 2.0);
+  cairo_fill (cr);
+
+  cairo_set_source_rgba (cr, 0.0, 1.0, 0.0, 1.0);
+  cairo_move_to (cr, x + BORDER + RADIUS, y + height - BORDER - RADIUS);
+  cairo_arc (cr, x + BORDER + RADIUS, y + height - BORDER - RADIUS,
+             RADIUS, - G_PI / 2.0, 2 * G_PI * private->value - G_PI / 2.0);
+  cairo_fill (cr);
+}
+
+static cairo_region_t *
+gimp_canvas_progress_get_extents (GimpCanvasItem *item)
+{
+  cairo_rectangle_int_t rectangle;
+  gdouble               x, y;
+  gint                  width, height;
+
+  gimp_canvas_progress_transform (item, &x, &y, &width, &height);
+
+  /*  add 1px on each side because fill()'s default impl does the same  */
+  rectangle.x      = (gint) x - 1;
+  rectangle.y      = (gint) y - 1;
+  rectangle.width  = width  + 2;
+  rectangle.height = height + 2;
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+static gboolean
+gimp_canvas_progress_hit (GimpCanvasItem *item,
+                          gdouble         x,
+                          gdouble         y)
+{
+  gdouble px, py;
+  gint    pwidth, pheight;
+  gdouble tx, ty;
+
+  gimp_canvas_progress_transform (item, &px, &py, &pwidth, &pheight);
+  gimp_canvas_item_transform_xy_f (item, x, y, &tx, &ty);
+
+  pheight -= BORDER + 2 * RADIUS;
+
+  return (tx >= px && tx < (px + pwidth) &&
+          ty >= py && ty < (py + pheight));
+}
+
+static GimpProgress *
+gimp_canvas_progress_start (GimpProgress *progress,
+                            gboolean      cancellable,
+                            const gchar  *message)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (progress);
+
+  gimp_canvas_progress_set_text (progress, message);
+
+  private->last_update_time = g_get_monotonic_time ();
+
+  return progress;
+}
+
+static void
+gimp_canvas_progress_end (GimpProgress *progress)
+{
+}
+
+static gboolean
+gimp_canvas_progress_is_active (GimpProgress *progress)
+{
+  return TRUE;
+}
+
+static void
+gimp_canvas_progress_set_text (GimpProgress *progress,
+                               const gchar  *message)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (progress);
+  cairo_region_t            *old_region;
+  cairo_region_t            *new_region;
+
+  old_region = gimp_canvas_item_get_extents (GIMP_CANVAS_ITEM (progress));
+
+  if (private->text)
+    g_free (private->text);
+
+  private->text = g_strdup (message);
+
+  new_region = gimp_canvas_item_get_extents (GIMP_CANVAS_ITEM (progress));
+
+  cairo_region_union (new_region, old_region);
+  cairo_region_destroy (old_region);
+
+  _gimp_canvas_item_update (GIMP_CANVAS_ITEM (progress), new_region);
+
+  cairo_region_destroy (new_region);
+}
+
+static void
+gimp_canvas_progress_set_value (GimpProgress *progress,
+                                gdouble       percentage)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (progress);
+
+  if (percentage != private->value)
+    {
+      guint64 time = g_get_monotonic_time ();
+
+      private->value = percentage;
+
+      if (time - private->last_update_time >= MIN_UPDATE_INTERVAL)
+        {
+          cairo_region_t *region;
+
+          private->last_update_time = time;
+
+          region = gimp_canvas_item_get_extents (GIMP_CANVAS_ITEM (progress));
+
+          _gimp_canvas_item_update (GIMP_CANVAS_ITEM (progress), region);
+
+          cairo_region_destroy (region);
+        }
+    }
+}
+
+static gdouble
+gimp_canvas_progress_get_value (GimpProgress *progress)
+{
+  GimpCanvasProgressPrivate *private = GET_PRIVATE (progress);
+
+  return private->value;
+}
+
+static void
+gimp_canvas_progress_pulse (GimpProgress *progress)
+{
+}
+
+static gboolean
+gimp_canvas_progress_message (GimpProgress        *progress,
+                              Gimp                *gimp,
+                              GimpMessageSeverity  severity,
+                              const gchar         *domain,
+                              const gchar         *message)
+{
+  return FALSE;
+}
+
+GimpCanvasItem *
+gimp_canvas_progress_new (GimpDisplayShell *shell,
+                          GimpHandleAnchor  anchor,
+                          gdouble           x,
+                          gdouble           y)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_PROGRESS,
+                       "shell",  shell,
+                       "anchor", anchor,
+                       "x",      x,
+                       "y",      y,
+                       NULL);
+}
diff --git a/app/display/gimpcanvasprogress.h b/app/display/gimpcanvasprogress.h
new file mode 100644
index 0000000..1f6a9c7
--- /dev/null
+++ b/app/display/gimpcanvasprogress.h
@@ -0,0 +1,58 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasprogress.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_PROGRESS_H__
+#define __GIMP_CANVAS_PROGRESS_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_PROGRESS            (gimp_canvas_progress_get_type ())
+#define GIMP_CANVAS_PROGRESS(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_PROGRESS, GimpCanvasProgress))
+#define GIMP_CANVAS_PROGRESS_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_PROGRESS, GimpCanvasProgressClass))
+#define GIMP_IS_CANVAS_PROGRESS(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_PROGRESS))
+#define GIMP_IS_CANVAS_PROGRESS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_PROGRESS))
+#define GIMP_CANVAS_PROGRESS_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_PROGRESS, GimpCanvasProgressClass))
+
+
+typedef struct _GimpCanvasProgress      GimpCanvasProgress;
+typedef struct _GimpCanvasProgressClass GimpCanvasProgressClass;
+
+struct _GimpCanvasProgress
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasProgressClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_progress_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_progress_new      (GimpDisplayShell *shell,
+                                                GimpHandleAnchor  anchor,
+                                                gdouble           x,
+                                                gdouble           y);
+
+
+#endif /* __GIMP_CANVAS_PROGRESS_H__ */
diff --git a/app/display/gimpcanvasproxygroup.c b/app/display/gimpcanvasproxygroup.c
new file mode 100644
index 0000000..a979f24
--- /dev/null
+++ b/app/display/gimpcanvasproxygroup.c
@@ -0,0 +1,197 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasproxygroup.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvasproxygroup.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0
+};
+
+
+typedef struct _GimpCanvasProxyGroupPrivate GimpCanvasProxyGroupPrivate;
+
+struct _GimpCanvasProxyGroupPrivate
+{
+  GHashTable *proxy_hash;
+};
+
+#define GET_PRIVATE(proxy_group) \
+        ((GimpCanvasProxyGroupPrivate *) gimp_canvas_proxy_group_get_instance_private ((GimpCanvasProxyGroup *) (proxy_group)))
+
+
+/*  local function prototypes  */
+
+static void        gimp_canvas_proxy_group_finalize     (GObject          *object);
+static void        gimp_canvas_proxy_group_set_property (GObject          *object,
+                                                         guint             property_id,
+                                                         const GValue     *value,
+                                                         GParamSpec       *pspec);
+static void        gimp_canvas_proxy_group_get_property (GObject          *object,
+                                                         guint             property_id,
+                                                         GValue           *value,
+                                                         GParamSpec       *pspec);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasProxyGroup, gimp_canvas_proxy_group,
+                            GIMP_TYPE_CANVAS_GROUP)
+
+#define parent_class gimp_canvas_proxy_group_parent_class
+
+
+static void
+gimp_canvas_proxy_group_class_init (GimpCanvasProxyGroupClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_proxy_group_finalize;
+  object_class->set_property = gimp_canvas_proxy_group_set_property;
+  object_class->get_property = gimp_canvas_proxy_group_get_property;
+}
+
+static void
+gimp_canvas_proxy_group_init (GimpCanvasProxyGroup *proxy_group)
+{
+  GimpCanvasProxyGroupPrivate *private = GET_PRIVATE (proxy_group);
+
+  private->proxy_hash = g_hash_table_new (g_direct_hash, g_direct_equal);
+}
+
+static void
+gimp_canvas_proxy_group_finalize (GObject *object)
+{
+  GimpCanvasProxyGroupPrivate *private = GET_PRIVATE (object);
+
+  g_clear_pointer (&private->proxy_hash, g_hash_table_unref);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_proxy_group_set_property (GObject      *object,
+                                      guint         property_id,
+                                      const GValue *value,
+                                      GParamSpec   *pspec)
+{
+  /* GimpCanvasProxyGroupPrivate *private = GET_PRIVATE (object); */
+
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_proxy_group_get_property (GObject    *object,
+                                      guint       property_id,
+                                      GValue     *value,
+                                      GParamSpec *pspec)
+{
+  /* GimpCanvasProxyGroupPrivate *private = GET_PRIVATE (object); */
+
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+GimpCanvasItem *
+gimp_canvas_proxy_group_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_PROXY_GROUP,
+                       "shell", shell,
+                       NULL);
+}
+
+void
+gimp_canvas_proxy_group_add_item (GimpCanvasProxyGroup *group,
+                                  gpointer              object,
+                                  GimpCanvasItem       *proxy_item)
+{
+  GimpCanvasProxyGroupPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
+  g_return_if_fail (object != NULL);
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (proxy_item));
+  g_return_if_fail (GIMP_CANVAS_ITEM (group) != proxy_item);
+
+  private = GET_PRIVATE (group);
+
+  g_return_if_fail (g_hash_table_lookup (private->proxy_hash, object) ==
+                    NULL);
+
+  g_hash_table_insert (private->proxy_hash, object, proxy_item);
+
+  gimp_canvas_group_add_item (GIMP_CANVAS_GROUP (group), proxy_item);
+}
+
+void
+gimp_canvas_proxy_group_remove_item (GimpCanvasProxyGroup *group,
+                                     gpointer              object)
+{
+  GimpCanvasProxyGroupPrivate *private;
+  GimpCanvasItem              *proxy_item;
+
+  g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
+  g_return_if_fail (object != NULL);
+
+  private = GET_PRIVATE (group);
+
+  proxy_item = g_hash_table_lookup (private->proxy_hash, object);
+
+  g_return_if_fail (proxy_item != NULL);
+
+  g_hash_table_remove (private->proxy_hash, object);
+
+  gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (group), proxy_item);
+}
+
+GimpCanvasItem *
+gimp_canvas_proxy_group_get_item (GimpCanvasProxyGroup *group,
+                                  gpointer              object)
+{
+  GimpCanvasProxyGroupPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_CANVAS_GROUP (group), NULL);
+  g_return_val_if_fail (object != NULL, NULL);
+
+  private = GET_PRIVATE (group);
+
+  return g_hash_table_lookup (private->proxy_hash, object);
+}
diff --git a/app/display/gimpcanvasproxygroup.h b/app/display/gimpcanvasproxygroup.h
new file mode 100644
index 0000000..be25787
--- /dev/null
+++ b/app/display/gimpcanvasproxygroup.h
@@ -0,0 +1,63 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasproxygroup.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_PROXY_GROUP_H__
+#define __GIMP_CANVAS_PROXY_GROUP_H__
+
+
+#include "gimpcanvasgroup.h"
+
+
+#define GIMP_TYPE_CANVAS_PROXY_GROUP            (gimp_canvas_proxy_group_get_type ())
+#define GIMP_CANVAS_PROXY_GROUP(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_PROXY_GROUP, GimpCanvasProxyGroup))
+#define GIMP_CANVAS_PROXY_GROUP_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_PROXY_GROUP, GimpCanvasProxyGroupClass))
+#define GIMP_IS_CANVAS_PROXY_GROUP(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_PROXY_GROUP))
+#define GIMP_IS_CANVAS_PROXY_GROUP_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_PROXY_GROUP))
+#define GIMP_CANVAS_PROXY_GROUP_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_PROXY_GROUP, GimpCanvasProxyGroupClass))
+
+
+typedef struct _GimpCanvasProxyGroup      GimpCanvasProxyGroup;
+typedef struct _GimpCanvasProxyGroupClass GimpCanvasProxyGroupClass;
+
+struct _GimpCanvasProxyGroup
+{
+  GimpCanvasGroup  parent_instance;
+};
+
+struct _GimpCanvasProxyGroupClass
+{
+  GimpCanvasGroupClass  parent_class;
+};
+
+
+GType            gimp_canvas_proxy_group_get_type    (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_proxy_group_new         (GimpDisplayShell     *shell);
+
+void             gimp_canvas_proxy_group_add_item    (GimpCanvasProxyGroup *group,
+                                                      gpointer              object,
+                                                      GimpCanvasItem       *proxy_item);
+void             gimp_canvas_proxy_group_remove_item (GimpCanvasProxyGroup *group,
+                                                      gpointer              object);
+GimpCanvasItem * gimp_canvas_proxy_group_get_item    (GimpCanvasProxyGroup *group,
+                                                      gpointer              object);
+
+
+#endif /* __GIMP_CANVAS_PROXY_GROUP_H__ */
diff --git a/app/display/gimpcanvasrectangle.c b/app/display/gimpcanvasrectangle.c
new file mode 100644
index 0000000..7ef7351
--- /dev/null
+++ b/app/display/gimpcanvasrectangle.c
@@ -0,0 +1,360 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasrectangle.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvasrectangle.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_X,
+  PROP_Y,
+  PROP_WIDTH,
+  PROP_HEIGHT,
+  PROP_FILLED
+};
+
+
+typedef struct _GimpCanvasRectanglePrivate GimpCanvasRectanglePrivate;
+
+struct _GimpCanvasRectanglePrivate
+{
+  gdouble  x;
+  gdouble  y;
+  gdouble  width;
+  gdouble  height;
+  gboolean filled;
+};
+
+#define GET_PRIVATE(rectangle) \
+        ((GimpCanvasRectanglePrivate *) gimp_canvas_rectangle_get_instance_private ((GimpCanvasRectangle *) (rectangle)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_rectangle_set_property (GObject        *object,
+                                                            guint           property_id,
+                                                            const GValue   *value,
+                                                            GParamSpec     *pspec);
+static void             gimp_canvas_rectangle_get_property (GObject        *object,
+                                                            guint           property_id,
+                                                            GValue         *value,
+                                                            GParamSpec     *pspec);
+static void             gimp_canvas_rectangle_draw         (GimpCanvasItem *item,
+                                                            cairo_t        *cr);
+static cairo_region_t * gimp_canvas_rectangle_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasRectangle, gimp_canvas_rectangle,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_rectangle_parent_class
+
+
+static void
+gimp_canvas_rectangle_class_init (GimpCanvasRectangleClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_rectangle_set_property;
+  object_class->get_property = gimp_canvas_rectangle_get_property;
+
+  item_class->draw           = gimp_canvas_rectangle_draw;
+  item_class->get_extents    = gimp_canvas_rectangle_get_extents;
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_WIDTH,
+                                   g_param_spec_double ("width", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_HEIGHT,
+                                   g_param_spec_double ("height", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_FILLED,
+                                   g_param_spec_boolean ("filled", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_rectangle_init (GimpCanvasRectangle *rectangle)
+{
+}
+
+static void
+gimp_canvas_rectangle_set_property (GObject      *object,
+                                    guint         property_id,
+                                    const GValue *value,
+                                    GParamSpec   *pspec)
+{
+  GimpCanvasRectanglePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+    case PROP_WIDTH:
+      private->width = g_value_get_double (value);
+      break;
+    case PROP_HEIGHT:
+      private->height = g_value_get_double (value);
+      break;
+    case PROP_FILLED:
+      private->filled = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_rectangle_get_property (GObject    *object,
+                                    guint       property_id,
+                                    GValue     *value,
+                                    GParamSpec *pspec)
+{
+  GimpCanvasRectanglePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+    case PROP_WIDTH:
+      g_value_set_double (value, private->width);
+      break;
+    case PROP_HEIGHT:
+      g_value_set_double (value, private->height);
+      break;
+    case PROP_FILLED:
+      g_value_set_boolean (value, private->filled);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_rectangle_transform (GimpCanvasItem *item,
+                                 gdouble        *x,
+                                 gdouble        *y,
+                                 gdouble        *w,
+                                 gdouble        *h)
+{
+  GimpCanvasRectanglePrivate *private = GET_PRIVATE (item);
+  gdouble                     x1, y1;
+  gdouble                     x2, y2;
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   MIN (private->x,
+                                        private->x + private->width),
+                                   MIN (private->y,
+                                        private->y + private->height),
+                                   &x1, &y1);
+  gimp_canvas_item_transform_xy_f (item,
+                                   MAX (private->x,
+                                        private->x + private->width),
+                                   MAX (private->y,
+                                        private->y + private->height),
+                                   &x2, &y2);
+
+  x1 = floor (x1);
+  y1 = floor (y1);
+  x2 = ceil (x2);
+  y2 = ceil (y2);
+
+  if (private->filled)
+    {
+      *x = x1;
+      *y = y1;
+      *w = x2 - x1;
+      *h = y2 - y1;
+    }
+  else
+    {
+      *x = x1 + 0.5;
+      *y = y1 + 0.5;
+      *w = x2 - 0.5 - *x;
+      *h = y2 - 0.5 - *y;
+
+      *w = MAX (0.0, *w);
+      *h = MAX (0.0, *h);
+    }
+}
+
+static void
+gimp_canvas_rectangle_draw (GimpCanvasItem *item,
+                            cairo_t        *cr)
+{
+  GimpCanvasRectanglePrivate *private = GET_PRIVATE (item);
+  gdouble                     x, y;
+  gdouble                     w, h;
+
+  gimp_canvas_rectangle_transform (item, &x, &y, &w, &h);
+
+  cairo_rectangle (cr, x, y, w, h);
+
+  if (private->filled)
+    _gimp_canvas_item_fill (item, cr);
+  else
+    _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_rectangle_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasRectanglePrivate *private = GET_PRIVATE (item);
+  cairo_rectangle_int_t       rectangle;
+  gdouble                     x, y;
+  gdouble                     w, h;
+
+  gimp_canvas_rectangle_transform (item, &x, &y, &w, &h);
+
+  if (private->filled)
+    {
+      rectangle.x      = floor (x - 1.0);
+      rectangle.y      = floor (y - 1.0);
+      rectangle.width  = ceil (w + 2.0);
+      rectangle.height = ceil (h + 2.0);
+
+      return cairo_region_create_rectangle (&rectangle);
+    }
+  else if (w > 64 && h > 64)
+    {
+      cairo_region_t *region;
+
+      /* left */
+      rectangle.x      = floor (x - 1.5);
+      rectangle.y      = floor (y - 1.5);
+      rectangle.width  = 3.0;
+      rectangle.height = ceil (h + 3.0);
+
+      region = cairo_region_create_rectangle (&rectangle);
+
+      /* right */
+      rectangle.x      = floor (x + w - 1.5);
+
+      cairo_region_union_rectangle (region, &rectangle);
+
+      /* top */
+      rectangle.x      = floor (x - 1.5);
+      rectangle.y      = floor (y - 1.5);
+      rectangle.width  = ceil (w + 3.0);
+      rectangle.height = 3.0;
+
+      cairo_region_union_rectangle (region, &rectangle);
+
+      /* bottom */
+      rectangle.y      = floor (y + h - 1.5);
+
+      cairo_region_union_rectangle (region, &rectangle);
+
+      return region;
+    }
+  else
+    {
+      rectangle.x      = floor (x - 1.5);
+      rectangle.y      = floor (y - 1.5);
+      rectangle.width  = ceil (w + 3.0);
+      rectangle.height = ceil (h + 3.0);
+
+      return cairo_region_create_rectangle (&rectangle);
+    }
+}
+
+GimpCanvasItem *
+gimp_canvas_rectangle_new (GimpDisplayShell *shell,
+                           gdouble           x,
+                           gdouble           y,
+                           gdouble           width,
+                           gdouble           height,
+                           gboolean          filled)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_RECTANGLE,
+                       "shell",  shell,
+                       "x",      x,
+                       "y",      y,
+                       "width",  width,
+                       "height", height,
+                       "filled", filled,
+                       NULL);
+}
+
+void
+gimp_canvas_rectangle_set (GimpCanvasItem *rectangle,
+                           gdouble         x,
+                           gdouble         y,
+                           gdouble         width,
+                           gdouble         height)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_RECTANGLE (rectangle));
+
+  gimp_canvas_item_begin_change (rectangle);
+
+  g_object_set (rectangle,
+                "x",      x,
+                "y",      y,
+                "width",  width,
+                "height", height,
+                NULL);
+
+  gimp_canvas_item_end_change (rectangle);
+}
diff --git a/app/display/gimpcanvasrectangle.h b/app/display/gimpcanvasrectangle.h
new file mode 100644
index 0000000..6a96c06
--- /dev/null
+++ b/app/display/gimpcanvasrectangle.h
@@ -0,0 +1,66 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasrectangle.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_RECTANGLE_H__
+#define __GIMP_CANVAS_RECTANGLE_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_RECTANGLE            (gimp_canvas_rectangle_get_type ())
+#define GIMP_CANVAS_RECTANGLE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_RECTANGLE, GimpCanvasRectangle))
+#define GIMP_CANVAS_RECTANGLE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_RECTANGLE, GimpCanvasRectangleClass))
+#define GIMP_IS_CANVAS_RECTANGLE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_RECTANGLE))
+#define GIMP_IS_CANVAS_RECTANGLE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_RECTANGLE))
+#define GIMP_CANVAS_RECTANGLE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_RECTANGLE, GimpCanvasRectangleClass))
+
+
+typedef struct _GimpCanvasRectangle      GimpCanvasRectangle;
+typedef struct _GimpCanvasRectangleClass GimpCanvasRectangleClass;
+
+struct _GimpCanvasRectangle
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasRectangleClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_rectangle_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_rectangle_new      (GimpDisplayShell *shell,
+                                                 gdouble           x,
+                                                 gdouble           y,
+                                                 gdouble           width,
+                                                 gdouble           height,
+                                                 gboolean          filled);
+
+void             gimp_canvas_rectangle_set      (GimpCanvasItem   *rectangle,
+                                                 gdouble           x,
+                                                 gdouble           y,
+                                                 gdouble           width,
+                                                 gdouble           height);
+
+
+#endif /* __GIMP_CANVAS_RECTANGLE_H__ */
diff --git a/app/display/gimpcanvasrectangleguides.c b/app/display/gimpcanvasrectangleguides.c
new file mode 100644
index 0000000..b7cc07d
--- /dev/null
+++ b/app/display/gimpcanvasrectangleguides.c
@@ -0,0 +1,422 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasrectangleguides.c
+ * Copyright (C) 2011 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvasrectangleguides.h"
+#include "gimpdisplayshell.h"
+
+
+#define SQRT5 2.236067977
+
+
+enum
+{
+  PROP_0,
+  PROP_X,
+  PROP_Y,
+  PROP_WIDTH,
+  PROP_HEIGHT,
+  PROP_TYPE,
+  PROP_N_GUIDES
+};
+
+
+typedef struct _GimpCanvasRectangleGuidesPrivate GimpCanvasRectangleGuidesPrivate;
+
+struct _GimpCanvasRectangleGuidesPrivate
+{
+  gdouble        x;
+  gdouble        y;
+  gdouble        width;
+  gdouble        height;
+  GimpGuidesType type;
+  gint           n_guides;
+};
+
+#define GET_PRIVATE(rectangle) \
+        ((GimpCanvasRectangleGuidesPrivate *) gimp_canvas_rectangle_guides_get_instance_private ((GimpCanvasRectangleGuides *) (rectangle)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_rectangle_guides_set_property (GObject        *object,
+                                                                   guint           property_id,
+                                                                   const GValue   *value,
+                                                                   GParamSpec     *pspec);
+static void             gimp_canvas_rectangle_guides_get_property (GObject        *object,
+                                                                   guint           property_id,
+                                                                   GValue         *value,
+                                                                   GParamSpec     *pspec);
+static void             gimp_canvas_rectangle_guides_draw         (GimpCanvasItem *item,
+                                                                   cairo_t        *cr);
+static cairo_region_t * gimp_canvas_rectangle_guides_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasRectangleGuides,
+                            gimp_canvas_rectangle_guides, GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_rectangle_guides_parent_class
+
+
+static void
+gimp_canvas_rectangle_guides_class_init (GimpCanvasRectangleGuidesClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_rectangle_guides_set_property;
+  object_class->get_property = gimp_canvas_rectangle_guides_get_property;
+
+  item_class->draw           = gimp_canvas_rectangle_guides_draw;
+  item_class->get_extents    = gimp_canvas_rectangle_guides_get_extents;
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_WIDTH,
+                                   g_param_spec_double ("width", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_HEIGHT,
+                                   g_param_spec_double ("height", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_TYPE,
+                                   g_param_spec_enum ("type", NULL, NULL,
+                                                      GIMP_TYPE_GUIDES_TYPE,
+                                                      GIMP_GUIDES_NONE,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_N_GUIDES,
+                                   g_param_spec_int ("n-guides", NULL, NULL,
+                                                     1, 128, 4,
+                                                     GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_rectangle_guides_init (GimpCanvasRectangleGuides *rectangle)
+{
+}
+
+static void
+gimp_canvas_rectangle_guides_set_property (GObject      *object,
+                                           guint         property_id,
+                                           const GValue *value,
+                                           GParamSpec   *pspec)
+{
+  GimpCanvasRectangleGuidesPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+    case PROP_WIDTH:
+      private->width = g_value_get_double (value);
+      break;
+    case PROP_HEIGHT:
+      private->height = g_value_get_double (value);
+      break;
+    case PROP_TYPE:
+      private->type = g_value_get_enum (value);
+      break;
+    case PROP_N_GUIDES:
+      private->n_guides = g_value_get_int (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_rectangle_guides_get_property (GObject    *object,
+                                           guint       property_id,
+                                           GValue     *value,
+                                           GParamSpec *pspec)
+{
+  GimpCanvasRectangleGuidesPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+    case PROP_WIDTH:
+      g_value_set_double (value, private->width);
+      break;
+    case PROP_HEIGHT:
+      g_value_set_double (value, private->height);
+      break;
+    case PROP_TYPE:
+      g_value_set_enum (value, private->type);
+      break;
+    case PROP_N_GUIDES:
+      g_value_set_int (value, private->n_guides);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_rectangle_guides_transform (GimpCanvasItem *item,
+                                        gdouble        *x1,
+                                        gdouble        *y1,
+                                        gdouble        *x2,
+                                        gdouble        *y2)
+{
+  GimpCanvasRectangleGuidesPrivate *private = GET_PRIVATE (item);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   MIN (private->x,
+                                        private->x + private->width),
+                                   MIN (private->y,
+                                        private->y + private->height),
+                                   x1, y1);
+  gimp_canvas_item_transform_xy_f (item,
+                                   MAX (private->x,
+                                        private->x + private->width),
+                                   MAX (private->y,
+                                        private->y + private->height),
+                                   x2, y2);
+
+  *x1 = floor (*x1) + 0.5;
+  *y1 = floor (*y1) + 0.5;
+  *x2 = ceil (*x2) - 0.5;
+  *y2 = ceil (*y2) - 0.5;
+
+  *x2 = MAX (*x1, *x2);
+  *y2 = MAX (*y1, *y2);
+}
+
+static void
+draw_hline (cairo_t *cr,
+            gdouble  x1,
+            gdouble  x2,
+            gdouble  y)
+{
+  y = floor (y) + 0.5;
+
+  cairo_move_to (cr, x1, y);
+  cairo_line_to (cr, x2, y);
+}
+
+static void
+draw_vline (cairo_t *cr,
+            gdouble  y1,
+            gdouble  y2,
+            gdouble  x)
+{
+  x = floor (x) + 0.5;
+
+  cairo_move_to (cr, x, y1);
+  cairo_line_to (cr, x, y2);
+}
+
+static void
+gimp_canvas_rectangle_guides_draw (GimpCanvasItem *item,
+                                   cairo_t        *cr)
+{
+  GimpCanvasRectangleGuidesPrivate *private = GET_PRIVATE (item);
+  gdouble                           x1, y1;
+  gdouble                           x2, y2;
+  gint                              i;
+
+  gimp_canvas_rectangle_guides_transform (item, &x1, &y1, &x2, &y2);
+
+  switch (private->type)
+    {
+    case GIMP_GUIDES_NONE:
+      break;
+
+    case GIMP_GUIDES_CENTER_LINES:
+      draw_hline (cr, x1, x2, (y1 + y2) / 2);
+      draw_vline (cr, y1, y2, (x1 + x2) / 2);
+      break;
+
+    case GIMP_GUIDES_THIRDS:
+      draw_hline (cr, x1, x2, (2 * y1 +     y2) / 3);
+      draw_hline (cr, x1, x2, (    y1 + 2 * y2) / 3);
+
+      draw_vline (cr, y1, y2, (2 * x1 +     x2) / 3);
+      draw_vline (cr, y1, y2, (    x1 + 2 * x2) / 3);
+      break;
+
+    case GIMP_GUIDES_FIFTHS:
+      for (i = 0; i < 5; i++)
+        {
+          draw_hline (cr, x1, x2, y1 + i * (y2 - y1) / 5);
+          draw_vline (cr, y1, y2, x1 + i * (x2 - x1) / 5);
+        }
+      break;
+
+    case GIMP_GUIDES_GOLDEN:
+      draw_hline (cr, x1, x2, (2 * y1 + (1 + SQRT5) * y2) / (3 + SQRT5));
+      draw_hline (cr, x1, x2, ((1 + SQRT5) * y1 + 2 * y2) / (3 + SQRT5));
+
+      draw_vline (cr, y1, y2, (2 * x1 + (1 + SQRT5) * x2) / (3 + SQRT5));
+      draw_vline (cr, y1, y2, ((1 + SQRT5) * x1 + 2 * x2) / (3 + SQRT5));
+      break;
+
+    /* This code implements the method of diagonals discovered by
+     * Edwin Westhoff - see http://www.diagonalmethod.info/
+     */
+    case GIMP_GUIDES_DIAGONALS:
+      {
+        /* the side of the largest square that can be
+         * fitted in whole into the rectangle (x1, y1), (x2, y2)
+         */
+        const gdouble square_side = MIN (x2 - x1, y2 - y1);
+
+        /* diagonal from the top-left edge */
+        cairo_move_to (cr, x1, y1);
+        cairo_line_to (cr, x1 + square_side, y1 + square_side);
+
+        /* diagonal from the top-right edge */
+        cairo_move_to (cr, x2, y1);
+        cairo_line_to (cr, x2 - square_side, y1 + square_side);
+
+        /* diagonal from the bottom-left edge */
+        cairo_move_to (cr, x1, y2);
+        cairo_line_to (cr, x1 + square_side, y2 - square_side);
+
+        /* diagonal from the bottom-right edge */
+        cairo_move_to (cr, x2, y2);
+        cairo_line_to (cr, x2 - square_side, y2 - square_side);
+      }
+      break;
+
+    case GIMP_GUIDES_N_LINES:
+      for (i = 0; i < private->n_guides; i++)
+        {
+          draw_hline (cr, x1, x2, y1 + i * (y2 - y1) / private->n_guides);
+          draw_vline (cr, y1, y2, x1 + i * (x2 - x1) / private->n_guides);
+        }
+      break;
+
+    case GIMP_GUIDES_SPACING:
+      break;
+    }
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_rectangle_guides_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasRectangleGuidesPrivate *private = GET_PRIVATE (item);
+
+  if (private->type != GIMP_GUIDES_NONE)
+    {
+      cairo_rectangle_int_t rectangle;
+      gdouble               x1, y1;
+      gdouble               x2, y2;
+
+      gimp_canvas_rectangle_guides_transform (item, &x1, &y1, &x2, &y2);
+
+      rectangle.x      = floor (x1 - 1.5);
+      rectangle.y      = floor (y1 - 1.5);
+      rectangle.width  = ceil (x2 - x1 + 3.0);
+      rectangle.height = ceil (y2 - y1 + 3.0);
+
+      return cairo_region_create_rectangle (&rectangle);
+    }
+
+  return NULL;
+}
+
+GimpCanvasItem *
+gimp_canvas_rectangle_guides_new (GimpDisplayShell *shell,
+                                  gdouble           x,
+                                  gdouble           y,
+                                  gdouble           width,
+                                  gdouble           height,
+                                  GimpGuidesType    type,
+                                  gint              n_guides)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_RECTANGLE_GUIDES,
+                       "shell",    shell,
+                       "x",        x,
+                       "y",        y,
+                       "width",    width,
+                       "height",   height,
+                       "type",     type,
+                       "n-guides", n_guides,
+                       NULL);
+}
+
+void
+gimp_canvas_rectangle_guides_set (GimpCanvasItem *rectangle,
+                                  gdouble         x,
+                                  gdouble         y,
+                                  gdouble         width,
+                                  gdouble         height,
+                                  GimpGuidesType  type,
+                                  gint            n_guides)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_RECTANGLE_GUIDES (rectangle));
+
+  gimp_canvas_item_begin_change (rectangle);
+
+  g_object_set (rectangle,
+                "x",        x,
+                "y",        y,
+                "width",    width,
+                "height",   height,
+                "type",     type,
+                "n-guides", n_guides,
+                NULL);
+
+  gimp_canvas_item_end_change (rectangle);
+}
diff --git a/app/display/gimpcanvasrectangleguides.h b/app/display/gimpcanvasrectangleguides.h
new file mode 100644
index 0000000..1d37d15
--- /dev/null
+++ b/app/display/gimpcanvasrectangleguides.h
@@ -0,0 +1,69 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasrectangleguides.h
+ * Copyright (C) 2011 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_RECTANGLE_GUIDES_H__
+#define __GIMP_CANVAS_RECTANGLE_GUIDES_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_RECTANGLE_GUIDES            (gimp_canvas_rectangle_guides_get_type ())
+#define GIMP_CANVAS_RECTANGLE_GUIDES(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_RECTANGLE_GUIDES, GimpCanvasRectangleGuides))
+#define GIMP_CANVAS_RECTANGLE_GUIDES_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_RECTANGLE_GUIDES, GimpCanvasRectangleGuidesClass))
+#define GIMP_IS_CANVAS_RECTANGLE_GUIDES(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_RECTANGLE_GUIDES))
+#define GIMP_IS_CANVAS_RECTANGLE_GUIDES_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_RECTANGLE_GUIDES))
+#define GIMP_CANVAS_RECTANGLE_GUIDES_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_RECTANGLE_GUIDES, GimpCanvasRectangleGuidesClass))
+
+
+typedef struct _GimpCanvasRectangleGuides      GimpCanvasRectangleGuides;
+typedef struct _GimpCanvasRectangleGuidesClass GimpCanvasRectangleGuidesClass;
+
+struct _GimpCanvasRectangleGuides
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasRectangleGuidesClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_rectangle_guides_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_rectangle_guides_new      (GimpDisplayShell *shell,
+                                                        gdouble           x,
+                                                        gdouble           y,
+                                                        gdouble           width,
+                                                        gdouble           height,
+                                                        GimpGuidesType    type,
+                                                        gint              n_guides);
+
+void             gimp_canvas_rectangle_guides_set      (GimpCanvasItem   *rectangle,
+                                                        gdouble           x,
+                                                        gdouble           y,
+                                                        gdouble           width,
+                                                        gdouble           height,
+                                                        GimpGuidesType    type,
+                                                        gint              n_guides);
+
+
+#endif /* __GIMP_CANVAS_RECTANGLE_GUIDES_H__ */
diff --git a/app/display/gimpcanvassamplepoint.c b/app/display/gimpcanvassamplepoint.c
new file mode 100644
index 0000000..913a5b7
--- /dev/null
+++ b/app/display/gimpcanvassamplepoint.c
@@ -0,0 +1,356 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvassamplepoint.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvas-style.h"
+#include "gimpcanvassamplepoint.h"
+#include "gimpdisplayshell.h"
+
+
+#define GIMP_SAMPLE_POINT_DRAW_SIZE 14
+
+
+enum
+{
+  PROP_0,
+  PROP_X,
+  PROP_Y,
+  PROP_INDEX,
+  PROP_SAMPLE_POINT_STYLE
+};
+
+
+typedef struct _GimpCanvasSamplePointPrivate GimpCanvasSamplePointPrivate;
+
+struct _GimpCanvasSamplePointPrivate
+{
+  gint     x;
+  gint     y;
+  gint     index;
+  gboolean sample_point_style;
+};
+
+#define GET_PRIVATE(sample_point) \
+        ((GimpCanvasSamplePointPrivate *) gimp_canvas_sample_point_get_instance_private ((GimpCanvasSamplePoint *) (sample_point)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_sample_point_set_property (GObject        *object,
+                                                               guint           property_id,
+                                                               const GValue   *value,
+                                                               GParamSpec     *pspec);
+static void             gimp_canvas_sample_point_get_property (GObject        *object,
+                                                               guint           property_id,
+                                                               GValue         *value,
+                                                               GParamSpec     *pspec);
+static void             gimp_canvas_sample_point_draw         (GimpCanvasItem *item,
+                                                               cairo_t        *cr);
+static cairo_region_t * gimp_canvas_sample_point_get_extents  (GimpCanvasItem *item);
+static void             gimp_canvas_sample_point_stroke       (GimpCanvasItem *item,
+                                                               cairo_t        *cr);
+static void             gimp_canvas_sample_point_fill         (GimpCanvasItem *item,
+                                                               cairo_t        *cr);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasSamplePoint, gimp_canvas_sample_point,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_sample_point_parent_class
+
+
+static void
+gimp_canvas_sample_point_class_init (GimpCanvasSamplePointClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_sample_point_set_property;
+  object_class->get_property = gimp_canvas_sample_point_get_property;
+
+  item_class->draw           = gimp_canvas_sample_point_draw;
+  item_class->get_extents    = gimp_canvas_sample_point_get_extents;
+  item_class->stroke         = gimp_canvas_sample_point_stroke;
+  item_class->fill           = gimp_canvas_sample_point_fill;
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_int ("x", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_int ("y", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_INDEX,
+                                   g_param_spec_int ("index", NULL, NULL,
+                                                     0, G_MAXINT, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_SAMPLE_POINT_STYLE,
+                                   g_param_spec_boolean ("sample-point-style",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_sample_point_init (GimpCanvasSamplePoint *sample_point)
+{
+}
+
+static void
+gimp_canvas_sample_point_set_property (GObject      *object,
+                                       guint         property_id,
+                                       const GValue *value,
+                                       GParamSpec   *pspec)
+{
+  GimpCanvasSamplePointPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      private->x = g_value_get_int (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_int (value);
+      break;
+    case PROP_INDEX:
+      private->index = g_value_get_int (value);
+      break;
+    case PROP_SAMPLE_POINT_STYLE:
+      private->sample_point_style = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_sample_point_get_property (GObject    *object,
+                                       guint       property_id,
+                                       GValue     *value,
+                                       GParamSpec *pspec)
+{
+  GimpCanvasSamplePointPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      g_value_set_int (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_int (value, private->x);
+      break;
+    case PROP_INDEX:
+      g_value_set_int (value, private->x);
+      break;
+    case PROP_SAMPLE_POINT_STYLE:
+      g_value_set_boolean (value, private->sample_point_style);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_sample_point_transform (GimpCanvasItem *item,
+                                    gdouble        *x,
+                                    gdouble        *y)
+{
+  GimpCanvasSamplePointPrivate *private = GET_PRIVATE (item);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   private->x + 0.5,
+                                   private->y + 0.5,
+                                   x, y);
+
+  *x = floor (*x) + 0.5;
+  *y = floor (*y) + 0.5;
+}
+
+#define HALF_SIZE (GIMP_SAMPLE_POINT_DRAW_SIZE / 2)
+
+static void
+gimp_canvas_sample_point_draw (GimpCanvasItem *item,
+                               cairo_t        *cr)
+{
+  GimpCanvasSamplePointPrivate *private = GET_PRIVATE (item);
+  GtkWidget                    *canvas  = gimp_canvas_item_get_canvas (item);
+  PangoLayout                  *layout;
+  gdouble                       x, y;
+  gint                          x1, x2, y1, y2;
+
+  gimp_canvas_sample_point_transform (item, &x, &y);
+
+  x1 = x - GIMP_SAMPLE_POINT_DRAW_SIZE;
+  x2 = x + GIMP_SAMPLE_POINT_DRAW_SIZE;
+  y1 = y - GIMP_SAMPLE_POINT_DRAW_SIZE;
+  y2 = y + GIMP_SAMPLE_POINT_DRAW_SIZE;
+
+  cairo_move_to (cr, x, y1);
+  cairo_line_to (cr, x, y1 + HALF_SIZE);
+
+  cairo_move_to (cr, x, y2);
+  cairo_line_to (cr, x, y2 - HALF_SIZE);
+
+  cairo_move_to (cr, x1,             y);
+  cairo_line_to (cr, x1 + HALF_SIZE, y);
+
+  cairo_move_to (cr, x2,             y);
+  cairo_line_to (cr, x2 - HALF_SIZE, y);
+
+  cairo_arc_negative (cr, x, y, HALF_SIZE, 0.0, 0.5 * G_PI);
+
+  _gimp_canvas_item_stroke (item, cr);
+
+  layout = gimp_canvas_get_layout (GIMP_CANVAS (canvas),
+                                   "%d", private->index);
+
+  cairo_move_to (cr, x + 3, y + 3);
+  pango_cairo_show_layout (cr, layout);
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_sample_point_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasSamplePointPrivate *private = GET_PRIVATE (item);
+  GtkWidget                    *canvas  = gimp_canvas_item_get_canvas (item);
+  cairo_rectangle_int_t         rectangle;
+  PangoLayout                  *layout;
+  PangoRectangle                ink;
+  gdouble                       x, y;
+  gint                          x1, x2, y1, y2;
+
+  gimp_canvas_sample_point_transform (item, &x, &y);
+
+  x1 = floor (x - GIMP_SAMPLE_POINT_DRAW_SIZE);
+  x2 = ceil  (x + GIMP_SAMPLE_POINT_DRAW_SIZE);
+  y1 = floor (y - GIMP_SAMPLE_POINT_DRAW_SIZE);
+  y2 = ceil  (y + GIMP_SAMPLE_POINT_DRAW_SIZE);
+
+  layout = gimp_canvas_get_layout (GIMP_CANVAS (canvas),
+                                   "%d", private->index);
+
+  pango_layout_get_extents (layout, &ink, NULL);
+
+  x2 = MAX (x2, 3 + ink.width);
+  y2 = MAX (y2, 3 + ink.height);
+
+  rectangle.x      = x1 - 1.5;
+  rectangle.y      = y1 - 1.5;
+  rectangle.width  = x2 - x1 + 3.0;
+  rectangle.height = y2 - y1 + 3.0;
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+static void
+gimp_canvas_sample_point_stroke (GimpCanvasItem *item,
+                                 cairo_t        *cr)
+{
+  GimpCanvasSamplePointPrivate *private = GET_PRIVATE (item);
+
+  if (private->sample_point_style)
+    {
+      gimp_canvas_set_tool_bg_style (gimp_canvas_item_get_canvas (item), cr);
+      cairo_stroke_preserve (cr);
+
+      gimp_canvas_set_sample_point_style (gimp_canvas_item_get_canvas (item), cr,
+                                          gimp_canvas_item_get_highlight (item));
+      cairo_stroke (cr);
+    }
+  else
+    {
+      GIMP_CANVAS_ITEM_CLASS (parent_class)->stroke (item, cr);
+    }
+}
+
+static void
+gimp_canvas_sample_point_fill (GimpCanvasItem *item,
+                               cairo_t        *cr)
+{
+  GimpCanvasSamplePointPrivate *private = GET_PRIVATE (item);
+
+  if (private->sample_point_style)
+    {
+      gimp_canvas_set_sample_point_style (gimp_canvas_item_get_canvas (item), cr,
+                                          gimp_canvas_item_get_highlight (item));
+      cairo_fill (cr);
+    }
+  else
+    {
+      GIMP_CANVAS_ITEM_CLASS (parent_class)->fill (item, cr);
+    }
+}
+
+GimpCanvasItem *
+gimp_canvas_sample_point_new (GimpDisplayShell *shell,
+                              gint              x,
+                              gint              y,
+                              gint              index,
+                              gboolean          sample_point_style)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_SAMPLE_POINT,
+                       "shell",              shell,
+                       "x",                  x,
+                       "y",                  y,
+                       "index",              index,
+                       "sample-point-style", sample_point_style,
+                       NULL);
+}
+
+void
+gimp_canvas_sample_point_set (GimpCanvasItem *sample_point,
+                              gint            x,
+                              gint            y)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_SAMPLE_POINT (sample_point));
+
+  gimp_canvas_item_begin_change (sample_point);
+
+  g_object_set (sample_point,
+                "x", x,
+                "y", y,
+                NULL);
+
+  gimp_canvas_item_end_change (sample_point);
+}
diff --git a/app/display/gimpcanvassamplepoint.h b/app/display/gimpcanvassamplepoint.h
new file mode 100644
index 0000000..00ac0d5
--- /dev/null
+++ b/app/display/gimpcanvassamplepoint.h
@@ -0,0 +1,63 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvassamplepoint.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_SAMPLE_POINT_H__
+#define __GIMP_CANVAS_SAMPLE_POINT_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_SAMPLE_POINT            (gimp_canvas_sample_point_get_type ())
+#define GIMP_CANVAS_SAMPLE_POINT(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_SAMPLE_POINT, GimpCanvasSamplePoint))
+#define GIMP_CANVAS_SAMPLE_POINT_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_SAMPLE_POINT, GimpCanvasSamplePointClass))
+#define GIMP_IS_CANVAS_SAMPLE_POINT(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_SAMPLE_POINT))
+#define GIMP_IS_CANVAS_SAMPLE_POINT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_SAMPLE_POINT))
+#define GIMP_CANVAS_SAMPLE_POINT_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_SAMPLE_POINT, GimpCanvasSamplePointClass))
+
+
+typedef struct _GimpCanvasSamplePoint      GimpCanvasSamplePoint;
+typedef struct _GimpCanvasSamplePointClass GimpCanvasSamplePointClass;
+
+struct _GimpCanvasSamplePoint
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasSamplePointClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_sample_point_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_sample_point_new      (GimpDisplayShell *shell,
+                                                    gint              x,
+                                                    gint              y,
+                                                    gint              index,
+                                                    gboolean          sample_point_style);
+
+void             gimp_canvas_sample_point_set      (GimpCanvasItem   *sample_point,
+                                                    gint              x,
+                                                    gint              y);
+
+
+#endif /* __GIMP_CANVAS_SAMPLE_POINT_H__ */
diff --git a/app/display/gimpcanvastextcursor.c b/app/display/gimpcanvastextcursor.c
new file mode 100644
index 0000000..aaa8c5f
--- /dev/null
+++ b/app/display/gimpcanvastextcursor.c
@@ -0,0 +1,386 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvastextcursor.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvastextcursor.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_X,
+  PROP_Y,
+  PROP_WIDTH,
+  PROP_HEIGHT,
+  PROP_OVERWRITE,
+  PROP_DIRECTION
+};
+
+
+typedef struct _GimpCanvasTextCursorPrivate GimpCanvasTextCursorPrivate;
+
+struct _GimpCanvasTextCursorPrivate
+{
+  gint              x;
+  gint              y;
+  gint              width;
+  gint              height;
+  gboolean          overwrite;
+  GimpTextDirection direction;
+};
+
+#define GET_PRIVATE(text_cursor) \
+        ((GimpCanvasTextCursorPrivate *) gimp_canvas_text_cursor_get_instance_private ((GimpCanvasTextCursor *) (text_cursor)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_text_cursor_set_property (GObject        *object,
+                                                              guint           property_id,
+                                                              const GValue   *value,
+                                                              GParamSpec     *pspec);
+static void             gimp_canvas_text_cursor_get_property (GObject        *object,
+                                                              guint           property_id,
+                                                              GValue         *value,
+                                                              GParamSpec     *pspec);
+static void             gimp_canvas_text_cursor_draw         (GimpCanvasItem *item,
+                                                              cairo_t        *cr);
+static cairo_region_t * gimp_canvas_text_cursor_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasTextCursor, gimp_canvas_text_cursor,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_text_cursor_parent_class
+
+
+static void
+gimp_canvas_text_cursor_class_init (GimpCanvasTextCursorClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_text_cursor_set_property;
+  object_class->get_property = gimp_canvas_text_cursor_get_property;
+
+  item_class->draw           = gimp_canvas_text_cursor_draw;
+  item_class->get_extents    = gimp_canvas_text_cursor_get_extents;
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_int ("x", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_int ("y", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_WIDTH,
+                                   g_param_spec_int ("width", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_HEIGHT,
+                                   g_param_spec_int ("height", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_OVERWRITE,
+                                   g_param_spec_boolean ("overwrite", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_DIRECTION,
+                                   g_param_spec_enum ("direction", NULL, NULL,
+                                                     gimp_text_direction_get_type(),
+                                                     GIMP_TEXT_DIRECTION_LTR,
+                                                     GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_text_cursor_init (GimpCanvasTextCursor *text_cursor)
+{
+}
+
+static void
+gimp_canvas_text_cursor_set_property (GObject      *object,
+                                      guint         property_id,
+                                      const GValue *value,
+                                      GParamSpec   *pspec)
+{
+  GimpCanvasTextCursorPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      private->x = g_value_get_int (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_int (value);
+      break;
+    case PROP_WIDTH:
+      private->width = g_value_get_int (value);
+      break;
+    case PROP_HEIGHT:
+      private->height = g_value_get_int (value);
+      break;
+    case PROP_OVERWRITE:
+      private->overwrite = g_value_get_boolean (value);
+      break;
+    case PROP_DIRECTION:
+      private->direction = g_value_get_enum (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_text_cursor_get_property (GObject    *object,
+                                      guint       property_id,
+                                      GValue     *value,
+                                      GParamSpec *pspec)
+{
+  GimpCanvasTextCursorPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      g_value_set_int (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_int (value, private->y);
+      break;
+    case PROP_WIDTH:
+      g_value_set_int (value, private->width);
+      break;
+    case PROP_HEIGHT:
+      g_value_set_int (value, private->height);
+      break;
+    case PROP_OVERWRITE:
+      g_value_set_boolean (value, private->overwrite);
+      break;
+    case PROP_DIRECTION:
+      g_value_set_enum (value, private->direction);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_text_cursor_transform (GimpCanvasItem *item,
+                                   gdouble        *x,
+                                   gdouble        *y,
+                                   gdouble        *w,
+                                   gdouble        *h)
+{
+  GimpCanvasTextCursorPrivate *private = GET_PRIVATE (item);
+
+  gimp_canvas_item_transform_xy_f (item,
+                                   MIN (private->x,
+                                        private->x + private->width),
+                                   MIN (private->y,
+                                        private->y + private->height),
+                                   x, y);
+  gimp_canvas_item_transform_xy_f (item,
+                                   MAX (private->x,
+                                        private->x + private->width),
+                                   MAX (private->y,
+                                        private->y + private->height),
+                                   w, h);
+
+  *w -= *x;
+  *h -= *y;
+
+  *x = floor (*x) + 0.5;
+  *y = floor (*y) + 0.5;
+  switch (private->direction)
+    {
+    case GIMP_TEXT_DIRECTION_LTR:
+    case GIMP_TEXT_DIRECTION_RTL:
+      break;
+    case GIMP_TEXT_DIRECTION_TTB_RTL:
+    case GIMP_TEXT_DIRECTION_TTB_RTL_UPRIGHT:
+      *x = *x - *w;
+      break;
+    case GIMP_TEXT_DIRECTION_TTB_LTR:
+    case GIMP_TEXT_DIRECTION_TTB_LTR_UPRIGHT:
+      *y = *y + *h;
+      break;
+    }
+
+  if (private->overwrite)
+    {
+      *w = ceil (*w) - 1.0;
+      *h = ceil (*h) - 1.0;
+    }
+  else
+    {
+      switch (private->direction)
+        {
+        case GIMP_TEXT_DIRECTION_LTR:
+        case GIMP_TEXT_DIRECTION_RTL:
+          *w = 0;
+          *h = ceil (*h) - 1.0;
+           break;
+        case GIMP_TEXT_DIRECTION_TTB_RTL:
+        case GIMP_TEXT_DIRECTION_TTB_RTL_UPRIGHT:
+          *w = ceil (*w) - 1.0;
+          *h = 0;
+          break;
+        case GIMP_TEXT_DIRECTION_TTB_LTR:
+        case GIMP_TEXT_DIRECTION_TTB_LTR_UPRIGHT:
+          *w = ceil (*w) - 1.0;
+          *h = 0;
+          break;
+        }
+    }
+}
+
+static void
+gimp_canvas_text_cursor_draw (GimpCanvasItem *item,
+                              cairo_t        *cr)
+{
+  GimpCanvasTextCursorPrivate *private = GET_PRIVATE (item);
+  gdouble                      x, y;
+  gdouble                      w, h;
+
+  gimp_canvas_text_cursor_transform (item, &x, &y, &w, &h);
+
+  if (private->overwrite)
+    {
+      cairo_rectangle (cr, x, y, w, h);
+    }
+  else
+    {
+      switch (private->direction)
+        {
+        case GIMP_TEXT_DIRECTION_LTR:
+        case GIMP_TEXT_DIRECTION_RTL:
+          cairo_move_to (cr, x, y);
+          cairo_line_to (cr, x, y + h);
+
+          cairo_move_to (cr, x - 3.0, y);
+          cairo_line_to (cr, x + 3.0, y);
+
+          cairo_move_to (cr, x - 3.0, y + h);
+          cairo_line_to (cr, x + 3.0, y + h);
+          break;
+        case GIMP_TEXT_DIRECTION_TTB_RTL:
+        case GIMP_TEXT_DIRECTION_TTB_RTL_UPRIGHT:
+        case GIMP_TEXT_DIRECTION_TTB_LTR:
+        case GIMP_TEXT_DIRECTION_TTB_LTR_UPRIGHT:
+          cairo_move_to (cr, x, y);
+          cairo_line_to (cr, x + w, y);
+
+          cairo_move_to (cr, x, y - 3.0);
+          cairo_line_to (cr, x, y + 3.0);
+
+          cairo_move_to (cr, x + w, y - 3.0);
+          cairo_line_to (cr, x + w, y + 3.0);
+          break;
+        }
+    }
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_text_cursor_get_extents (GimpCanvasItem *item)
+{
+  GimpCanvasTextCursorPrivate *private = GET_PRIVATE (item);
+  cairo_rectangle_int_t        rectangle;
+  gdouble                      x, y;
+  gdouble                      w, h;
+
+  gimp_canvas_text_cursor_transform (item, &x, &y, &w, &h);
+
+  if (private->overwrite)
+    {
+      rectangle.x      = floor (x - 1.5);
+      rectangle.y      = floor (y - 1.5);
+      rectangle.width  = ceil (w + 3.0);
+      rectangle.height = ceil (h + 3.0);
+    }
+  else
+    {
+      switch (private->direction)
+        {
+        case GIMP_TEXT_DIRECTION_LTR:
+        case GIMP_TEXT_DIRECTION_RTL:
+          rectangle.x      = floor (x - 4.5);
+          rectangle.y      = floor (y - 1.5);
+          rectangle.width  = ceil (9.0);
+          rectangle.height = ceil (h + 3.0);
+          break;
+        case GIMP_TEXT_DIRECTION_TTB_RTL:
+        case GIMP_TEXT_DIRECTION_TTB_RTL_UPRIGHT:
+        case GIMP_TEXT_DIRECTION_TTB_LTR:
+        case GIMP_TEXT_DIRECTION_TTB_LTR_UPRIGHT:
+          rectangle.x      = floor (x - 1.5);
+          rectangle.y      = floor (y - 4.5);
+          rectangle.width  = ceil (w + 3.0);
+          rectangle.height = ceil (9.0);
+          break;
+        }
+    }
+
+  return cairo_region_create_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_text_cursor_new (GimpDisplayShell *shell,
+                             PangoRectangle   *cursor,
+                             gboolean          overwrite,
+                             GimpTextDirection direction)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (cursor != NULL, NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_TEXT_CURSOR,
+                       "shell",     shell,
+                       "x",         cursor->x,
+                       "y",         cursor->y,
+                       "width",     cursor->width,
+                       "height",    cursor->height,
+                       "overwrite", overwrite,
+                       "direction", direction,
+                       NULL);
+}
diff --git a/app/display/gimpcanvastextcursor.h b/app/display/gimpcanvastextcursor.h
new file mode 100644
index 0000000..210b2a2
--- /dev/null
+++ b/app/display/gimpcanvastextcursor.h
@@ -0,0 +1,58 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvastextcursor.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_TEXT_CURSOR_H__
+#define __GIMP_CANVAS_TEXT_CURSOR_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_TEXT_CURSOR            (gimp_canvas_text_cursor_get_type ())
+#define GIMP_CANVAS_TEXT_CURSOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_TEXT_CURSOR, GimpCanvasTextCursor))
+#define GIMP_CANVAS_TEXT_CURSOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_TEXT_CURSOR, GimpCanvasTextCursorClass))
+#define GIMP_IS_CANVAS_TEXT_CURSOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_TEXT_CURSOR))
+#define GIMP_IS_CANVAS_TEXT_CURSOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_TEXT_CURSOR))
+#define GIMP_CANVAS_TEXT_CURSOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_TEXT_CURSOR, GimpCanvasTextCursorClass))
+
+
+typedef struct _GimpCanvasTextCursor      GimpCanvasTextCursor;
+typedef struct _GimpCanvasTextCursorClass GimpCanvasTextCursorClass;
+
+struct _GimpCanvasTextCursor
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasTextCursorClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_text_cursor_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_text_cursor_new      (GimpDisplayShell *shell,
+                                                   PangoRectangle   *cursor,
+                                                   gboolean          overwrite,
+                                                   GimpTextDirection direction);
+
+
+#endif /* __GIMP_CANVAS_RECTANGLE_H__ */
diff --git a/app/display/gimpcanvastransformguides.c b/app/display/gimpcanvastransformguides.c
new file mode 100644
index 0000000..ba6c4cb
--- /dev/null
+++ b/app/display/gimpcanvastransformguides.c
@@ -0,0 +1,683 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvastransformguides.c
+ * Copyright (C) 2011 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-transform-utils.h"
+#include "core/gimp-utils.h"
+
+#include "gimpcanvastransformguides.h"
+#include "gimpdisplayshell.h"
+
+
+#define SQRT5 2.236067977
+
+
+enum
+{
+  PROP_0,
+  PROP_TRANSFORM,
+  PROP_X1,
+  PROP_Y1,
+  PROP_X2,
+  PROP_Y2,
+  PROP_TYPE,
+  PROP_N_GUIDES,
+  PROP_CLIP
+};
+
+
+typedef struct _GimpCanvasTransformGuidesPrivate GimpCanvasTransformGuidesPrivate;
+
+struct _GimpCanvasTransformGuidesPrivate
+{
+  GimpMatrix3    transform;
+  gdouble        x1, y1;
+  gdouble        x2, y2;
+  GimpGuidesType type;
+  gint           n_guides;
+  gboolean       clip;
+};
+
+#define GET_PRIVATE(transform) \
+        ((GimpCanvasTransformGuidesPrivate *) gimp_canvas_transform_guides_get_instance_private ((GimpCanvasTransformGuides *) (transform)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_transform_guides_set_property (GObject        *object,
+                                                                   guint           property_id,
+                                                                   const GValue   *value,
+                                                                   GParamSpec     *pspec);
+static void             gimp_canvas_transform_guides_get_property (GObject        *object,
+                                                                   guint           property_id,
+                                                                   GValue         *value,
+                                                                   GParamSpec     *pspec);
+static void             gimp_canvas_transform_guides_draw         (GimpCanvasItem *item,
+                                                                   cairo_t        *cr);
+static cairo_region_t * gimp_canvas_transform_guides_get_extents  (GimpCanvasItem *item);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasTransformGuides,
+                            gimp_canvas_transform_guides, GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_transform_guides_parent_class
+
+
+static void
+gimp_canvas_transform_guides_class_init (GimpCanvasTransformGuidesClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_transform_guides_set_property;
+  object_class->get_property = gimp_canvas_transform_guides_get_property;
+
+  item_class->draw           = gimp_canvas_transform_guides_draw;
+  item_class->get_extents    = gimp_canvas_transform_guides_get_extents;
+
+  g_object_class_install_property (object_class, PROP_TRANSFORM,
+                                   gimp_param_spec_matrix3 ("transform",
+                                                            NULL, NULL,
+                                                            NULL,
+                                                            GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X1,
+                                   g_param_spec_double ("x1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y1,
+                                   g_param_spec_double ("y1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X2,
+                                   g_param_spec_double ("x2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y2,
+                                   g_param_spec_double ("y2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_TYPE,
+                                   g_param_spec_enum ("type", NULL, NULL,
+                                                      GIMP_TYPE_GUIDES_TYPE,
+                                                      GIMP_GUIDES_NONE,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_N_GUIDES,
+                                   g_param_spec_int ("n-guides", NULL, NULL,
+                                                     1, 128, 4,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_CLIP,
+                                   g_param_spec_boolean ("clip", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_transform_guides_init (GimpCanvasTransformGuides *transform)
+{
+}
+
+static void
+gimp_canvas_transform_guides_set_property (GObject      *object,
+                                           guint         property_id,
+                                           const GValue *value,
+                                           GParamSpec   *pspec)
+{
+  GimpCanvasTransformGuidesPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_TRANSFORM:
+      {
+        GimpMatrix3 *transform = g_value_get_boxed (value);
+
+        if (transform)
+          private->transform = *transform;
+        else
+          gimp_matrix3_identity (&private->transform);
+      }
+      break;
+
+    case PROP_X1:
+      private->x1 = g_value_get_double (value);
+      break;
+
+    case PROP_Y1:
+      private->y1 = g_value_get_double (value);
+      break;
+
+    case PROP_X2:
+      private->x2 = g_value_get_double (value);
+      break;
+
+    case PROP_Y2:
+      private->y2 = g_value_get_double (value);
+      break;
+
+    case PROP_TYPE:
+      private->type = g_value_get_enum (value);
+      break;
+
+    case PROP_N_GUIDES:
+      private->n_guides = g_value_get_int (value);
+      break;
+
+    case PROP_CLIP:
+      private->clip = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_transform_guides_get_property (GObject    *object,
+                                           guint       property_id,
+                                           GValue     *value,
+                                           GParamSpec *pspec)
+{
+  GimpCanvasTransformGuidesPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_TRANSFORM:
+      g_value_set_boxed (value, &private->transform);
+      break;
+
+    case PROP_X1:
+      g_value_set_double (value, private->x1);
+      break;
+
+    case PROP_Y1:
+      g_value_set_double (value, private->y1);
+      break;
+
+    case PROP_X2:
+      g_value_set_double (value, private->x2);
+      break;
+
+    case PROP_Y2:
+      g_value_set_double (value, private->y2);
+      break;
+
+    case PROP_TYPE:
+      g_value_set_enum (value, private->type);
+      break;
+
+    case PROP_N_GUIDES:
+      g_value_set_int (value, private->n_guides);
+      break;
+
+    case PROP_CLIP:
+      g_value_set_boolean (value, private->clip);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static gboolean
+gimp_canvas_transform_guides_transform (GimpCanvasItem *item,
+                                        GimpVector2    *t_vertices,
+                                        gint           *n_t_vertices)
+{
+  GimpCanvasTransformGuidesPrivate *private = GET_PRIVATE (item);
+  GimpVector2                       vertices[4];
+
+  vertices[0] = (GimpVector2) { private->x1, private->y1 };
+  vertices[1] = (GimpVector2) { private->x2, private->y1 };
+  vertices[2] = (GimpVector2) { private->x2, private->y2 };
+  vertices[3] = (GimpVector2) { private->x1, private->y2 };
+
+  if (private->clip)
+    {
+      gimp_transform_polygon (&private->transform, vertices, 4, TRUE,
+                              t_vertices, n_t_vertices);
+
+      return TRUE;
+    }
+  else
+    {
+      gint i;
+
+      for (i = 0; i < 4; i++)
+        {
+          gimp_matrix3_transform_point (&private->transform,
+                                        vertices[i].x,    vertices[i].y,
+                                        &t_vertices[i].x, &t_vertices[i].y);
+        }
+
+      *n_t_vertices = 4;
+
+      return gimp_transform_polygon_is_convex (t_vertices[0].x, t_vertices[0].y,
+                                               t_vertices[1].x, t_vertices[1].y,
+                                               t_vertices[3].x, t_vertices[3].y,
+                                               t_vertices[2].x, t_vertices[2].y);
+    }
+}
+
+static void
+draw_line (cairo_t        *cr,
+           GimpCanvasItem *item,
+           GimpMatrix3    *transform,
+           gdouble         x1,
+           gdouble         y1,
+           gdouble         x2,
+           gdouble         y2)
+{
+  GimpCanvasTransformGuidesPrivate *private = GET_PRIVATE (item);
+  GimpVector2                       vertices[2];
+  GimpVector2                       t_vertices[2];
+  gint                              n_t_vertices;
+
+  vertices[0] = (GimpVector2) { x1, y1 };
+  vertices[1] = (GimpVector2) { x2, y2 };
+
+  if (private->clip)
+    {
+      gimp_transform_polygon (transform, vertices, 2, FALSE,
+                              t_vertices, &n_t_vertices);
+    }
+  else
+    {
+      gint i;
+
+      for (i = 0; i < 2; i++)
+        {
+          gimp_matrix3_transform_point (transform,
+                                        vertices[i].x,    vertices[i].y,
+                                        &t_vertices[i].x, &t_vertices[i].y);
+        }
+
+      n_t_vertices = 2;
+    }
+
+  if (n_t_vertices == 2)
+    {
+      gint i;
+
+      for (i = 0; i < 2; i++)
+        {
+          GimpVector2 v;
+
+          gimp_canvas_item_transform_xy_f (item,
+                                           t_vertices[i].x, t_vertices[i].y,
+                                           &v.x,            &v.y);
+
+          v.x = floor (v.x) + 0.5;
+          v.y = floor (v.y) + 0.5;
+
+          if (i == 0)
+            cairo_move_to (cr, v.x, v.y);
+          else
+            cairo_line_to (cr, v.x, v.y);
+        }
+    }
+}
+
+static void
+draw_hline (cairo_t        *cr,
+            GimpCanvasItem *item,
+            GimpMatrix3    *transform,
+            gdouble         x1,
+            gdouble         x2,
+            gdouble         y)
+{
+  draw_line (cr, item, transform, x1, y, x2, y);
+}
+
+static void
+draw_vline (cairo_t        *cr,
+            GimpCanvasItem *item,
+            GimpMatrix3    *transform,
+            gdouble         y1,
+            gdouble         y2,
+            gdouble         x)
+{
+  draw_line (cr, item, transform, x, y1, x, y2);
+}
+
+static void
+gimp_canvas_transform_guides_draw (GimpCanvasItem *item,
+                                   cairo_t        *cr)
+{
+  GimpCanvasTransformGuidesPrivate *private = GET_PRIVATE (item);
+  GimpVector2                       t_vertices[5];
+  gint                              n_t_vertices;
+  gboolean                          convex;
+  gint                              i;
+
+  convex = gimp_canvas_transform_guides_transform (item,
+                                                   t_vertices, &n_t_vertices);
+
+  if (n_t_vertices < 2)
+    return;
+
+  for (i = 0; i < n_t_vertices; i++)
+    {
+      GimpVector2 v;
+
+      gimp_canvas_item_transform_xy_f (item, t_vertices[i].x, t_vertices[i].y,
+                                       &v.x, &v.y);
+
+      v.x = floor (v.x) + 0.5;
+      v.y = floor (v.y) + 0.5;
+
+      if (i == 0)
+        cairo_move_to (cr, v.x, v.y);
+      else
+        cairo_line_to (cr, v.x, v.y);
+    }
+
+  cairo_close_path (cr);
+
+  if (! convex || n_t_vertices < 3)
+    {
+      _gimp_canvas_item_stroke (item, cr);
+      return;
+    }
+
+  switch (private->type)
+    {
+    case GIMP_GUIDES_NONE:
+      break;
+
+    case GIMP_GUIDES_CENTER_LINES:
+      draw_hline (cr, item, &private->transform,
+                  private->x1, private->x2, (private->y1 + private->y2) / 2);
+      draw_vline (cr, item, &private->transform,
+                  private->y1, private->y2, (private->x1 + private->x2) / 2);
+      break;
+
+    case GIMP_GUIDES_THIRDS:
+      draw_hline (cr, item, &private->transform,
+                  private->x1, private->x2, (2 * private->y1 + private->y2) / 3);
+      draw_hline (cr, item, &private->transform,
+                  private->x1, private->x2, (private->y1 + 2 * private->y2) / 3);
+
+      draw_vline (cr, item, &private->transform,
+                  private->y1, private->y2, (2 * private->x1 + private->x2) / 3);
+      draw_vline (cr, item, &private->transform,
+                  private->y1, private->y2, (private->x1 + 2 * private->x2) / 3);
+      break;
+
+    case GIMP_GUIDES_FIFTHS:
+      for (i = 0; i < 5; i++)
+        {
+          draw_hline (cr, item, &private->transform,
+                      private->x1, private->x2,
+                      private->y1 + i * (private->y2 - private->y1) / 5);
+          draw_vline (cr, item, &private->transform,
+                      private->y1, private->y2,
+                      private->x1 + i * (private->x2 - private->x1) / 5);
+        }
+      break;
+
+    case GIMP_GUIDES_GOLDEN:
+      draw_hline (cr, item, &private->transform,
+                  private->x1, private->x2,
+                  (2 * private->y1 + (1 + SQRT5) * private->y2) / (3 + SQRT5));
+      draw_hline (cr, item, &private->transform,
+                  private->x1, private->x2,
+                  ((1 + SQRT5) * private->y1 + 2 * private->y2) / (3 + SQRT5));
+
+      draw_vline (cr, item, &private->transform,
+                  private->y1, private->y2,
+                  (2 * private->x1 + (1 + SQRT5) * private->x2) / (3 + SQRT5));
+      draw_vline (cr, item, &private->transform,
+                  private->y1, private->y2,
+                  ((1 + SQRT5) * private->x1 + 2 * private->x2) / (3 + SQRT5));
+      break;
+
+    /* This code implements the method of diagonals discovered by
+     * Edwin Westhoff - see http://www.diagonalmethod.info/
+     */
+    case GIMP_GUIDES_DIAGONALS:
+      {
+        /* the side of the largest square that can be
+         * fitted in whole into the rectangle (x1, y1), (x2, y2)
+         */
+        const gdouble square_side = MIN (private->x2 - private->x1,
+                                         private->y2 - private->y1);
+
+        /* diagonal from the top-left edge */
+        draw_line (cr, item, &private->transform,
+                   private->x1, private->y1,
+                   private->x1 + square_side,
+                   private->y1 + square_side);
+
+        /* diagonal from the top-right edge */
+        draw_line (cr, item, &private->transform,
+                   private->x2, private->y1,
+                   private->x2 - square_side,
+                   private->y1 + square_side);
+
+        /* diagonal from the bottom-left edge */
+        draw_line (cr, item, &private->transform,
+                   private->x1, private->y2,
+                   private->x1 + square_side,
+                   private->y2 - square_side);
+
+        /* diagonal from the bottom-right edge */
+        draw_line (cr, item, &private->transform,
+                   private->x2, private->y2,
+                   private->x2 - square_side,
+                   private->y2 - square_side);
+      }
+      break;
+
+    case GIMP_GUIDES_N_LINES:
+    case GIMP_GUIDES_SPACING:
+      {
+        gint width, height;
+        gint ngx, ngy;
+
+        width  = MAX (1, private->x2 - private->x1);
+        height = MAX (1, private->y2 - private->y1);
+
+        /*  the MIN() in the code below limits the grid to one line
+         *  every 5 image pixels, see bug 772667.
+         */
+
+        if (private->type == GIMP_GUIDES_N_LINES)
+          {
+            if (width <= height)
+              {
+                ngx = private->n_guides;
+                ngx = MIN (ngx, width / 5);
+
+                ngy = ngx * MAX (1, height / width);
+                ngy = MIN (ngy, height / 5);
+              }
+            else
+              {
+                ngy = private->n_guides;
+                ngy = MIN (ngy, height / 5);
+
+                ngx = ngy * MAX (1, width / height);
+                ngx = MIN (ngx, width / 5);
+              }
+          }
+        else /* GIMP_GUIDES_SPACING */
+          {
+            gint grid_size = MAX (2, private->n_guides);
+
+            ngx = width  / grid_size;
+            ngx = MIN (ngx, width / 5);
+
+            ngy = height / grid_size;
+            ngy = MIN (ngy, height / 5);
+          }
+
+        for (i = 1; i <= ngx; i++)
+          {
+            gdouble x = private->x1 + (((gdouble) i) / (ngx + 1) *
+                                       (private->x2 - private->x1));
+
+            draw_line (cr, item, &private->transform,
+                       x, private->y1,
+                       x, private->y2);
+          }
+
+        for (i = 1; i <= ngy; i++)
+          {
+            gdouble y = private->y1 + (((gdouble) i) / (ngy + 1) *
+                                       (private->y2 - private->y1));
+
+            draw_line (cr, item, &private->transform,
+                       private->x1, y,
+                       private->x2, y);
+          }
+      }
+    }
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static cairo_region_t *
+gimp_canvas_transform_guides_get_extents (GimpCanvasItem *item)
+{
+  GimpVector2           t_vertices[5];
+  gint                  n_t_vertices;
+  GimpVector2           top_left;
+  GimpVector2           bottom_right;
+  cairo_rectangle_int_t extents;
+  gint                  i;
+
+  gimp_canvas_transform_guides_transform (item, t_vertices, &n_t_vertices);
+
+  if (n_t_vertices < 2)
+    return  cairo_region_create ();
+
+  for (i = 0; i < n_t_vertices; i++)
+    {
+      GimpVector2 v;
+
+      gimp_canvas_item_transform_xy_f (item,
+                                       t_vertices[i].x, t_vertices[i].y,
+                                       &v.x,            &v.y);
+
+      if (i == 0)
+        {
+          top_left = bottom_right = v;
+        }
+      else
+        {
+          top_left.x     = MIN (top_left.x,     v.x);
+          top_left.y     = MIN (top_left.y,     v.y);
+
+          bottom_right.x = MAX (bottom_right.x, v.x);
+          bottom_right.y = MAX (bottom_right.y, v.y);
+        }
+    }
+
+  extents.x      = (gint) floor (top_left.x     - 1.5);
+  extents.y      = (gint) floor (top_left.y     - 1.5);
+  extents.width  = (gint) ceil  (bottom_right.x + 1.5) - extents.x;
+  extents.height = (gint) ceil  (bottom_right.y + 1.5) - extents.y;
+
+  return cairo_region_create_rectangle (&extents);
+}
+
+GimpCanvasItem *
+gimp_canvas_transform_guides_new (GimpDisplayShell  *shell,
+                                  const GimpMatrix3 *transform,
+                                  gdouble            x1,
+                                  gdouble            y1,
+                                  gdouble            x2,
+                                  gdouble            y2,
+                                  GimpGuidesType     type,
+                                  gint               n_guides,
+                                  gboolean           clip)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_TRANSFORM_GUIDES,
+                       "shell",     shell,
+                       "transform", transform,
+                       "x1",        x1,
+                       "y1",        y1,
+                       "x2",        x2,
+                       "y2",        y2,
+                       "type",      type,
+                       "n-guides",  n_guides,
+                       "clip",      clip,
+                       NULL);
+}
+
+void
+gimp_canvas_transform_guides_set (GimpCanvasItem    *guides,
+                                  const GimpMatrix3 *transform,
+                                  gdouble            x1,
+                                  gdouble            y1,
+                                  gdouble            x2,
+                                  gdouble            y2,
+                                  GimpGuidesType     type,
+                                  gint               n_guides,
+                                  gboolean           clip)
+{
+  g_return_if_fail (GIMP_IS_CANVAS_TRANSFORM_GUIDES (guides));
+
+  gimp_canvas_item_begin_change (guides);
+
+  g_object_set (guides,
+                "transform", transform,
+                "x1",        x1,
+                "y1",        y1,
+                "x2",        x2,
+                "y2",        y2,
+                "type",      type,
+                "n-guides",  n_guides,
+                "clip",      clip,
+                NULL);
+
+  gimp_canvas_item_end_change (guides);
+}
diff --git a/app/display/gimpcanvastransformguides.h b/app/display/gimpcanvastransformguides.h
new file mode 100644
index 0000000..4358501
--- /dev/null
+++ b/app/display/gimpcanvastransformguides.h
@@ -0,0 +1,73 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvastransformguides.h
+ * Copyright (C) 2011 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_TRANSFORM_GUIDES_H__
+#define __GIMP_CANVAS_TRANSFORM_GUIDES_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_TRANSFORM_GUIDES            (gimp_canvas_transform_guides_get_type ())
+#define GIMP_CANVAS_TRANSFORM_GUIDES(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_TRANSFORM_GUIDES, GimpCanvasTransformGuides))
+#define GIMP_CANVAS_TRANSFORM_GUIDES_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_TRANSFORM_GUIDES, GimpCanvasTransformGuidesClass))
+#define GIMP_IS_CANVAS_TRANSFORM_GUIDES(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_TRANSFORM_GUIDES))
+#define GIMP_IS_CANVAS_TRANSFORM_GUIDES_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_TRANSFORM_GUIDES))
+#define GIMP_CANVAS_TRANSFORM_GUIDES_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_TRANSFORM_GUIDES, GimpCanvasTransformGuidesClass))
+
+
+typedef struct _GimpCanvasTransformGuides      GimpCanvasTransformGuides;
+typedef struct _GimpCanvasTransformGuidesClass GimpCanvasTransformGuidesClass;
+
+struct _GimpCanvasTransformGuides
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasTransformGuidesClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_transform_guides_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_transform_guides_new      (GimpDisplayShell  *shell,
+                                                        const GimpMatrix3 *transform,
+                                                        gdouble            x1,
+                                                        gdouble            y1,
+                                                        gdouble            x2,
+                                                        gdouble            y2,
+                                                        GimpGuidesType     type,
+                                                        gint               n_guides,
+                                                        gboolean           clip);
+
+void             gimp_canvas_transform_guides_set      (GimpCanvasItem    *guides,
+                                                        const GimpMatrix3 *transform,
+                                                        gdouble            x1,
+                                                        gdouble            y1,
+                                                        gdouble            x2,
+                                                        gdouble            y2,
+                                                        GimpGuidesType     type,
+                                                        gint               n_guides,
+                                                        gboolean           clip);
+
+
+#endif /* __GIMP_CANVAS_TRANSFORM_GUIDES_H__ */
diff --git a/app/display/gimpcanvastransformpreview.c b/app/display/gimpcanvastransformpreview.c
new file mode 100644
index 0000000..8c8d950
--- /dev/null
+++ b/app/display/gimpcanvastransformpreview.c
@@ -0,0 +1,791 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvastransformpreview.c
+ * Copyright (C) 2011 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display/display-types.h"
+
+#include "gegl/gimp-gegl-nodes.h"
+#include "gegl/gimp-gegl-utils.h"
+#include "gegl/gimptilehandlervalidate.h"
+
+#include "core/gimp-transform-resize.h"
+#include "core/gimp-transform-utils.h"
+#include "core/gimp-utils.h"
+#include "core/gimpchannel.h"
+#include "core/gimpimage.h"
+#include "core/gimplayer.h"
+#include "core/gimppickable.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvastransformpreview.h"
+#include "gimpdisplayshell.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_PICKABLE,
+  PROP_TRANSFORM,
+  PROP_CLIP,
+  PROP_X1,
+  PROP_Y1,
+  PROP_X2,
+  PROP_Y2,
+  PROP_OPACITY
+};
+
+
+typedef struct _GimpCanvasTransformPreviewPrivate GimpCanvasTransformPreviewPrivate;
+
+struct _GimpCanvasTransformPreviewPrivate
+{
+  GimpPickable        *pickable;
+  GimpMatrix3          transform;
+  GimpTransformResize  clip;
+  gdouble              x1, y1;
+  gdouble              x2, y2;
+  gdouble              opacity;
+
+  GeglNode            *node;
+  GeglNode            *source_node;
+  GeglNode            *convert_format_node;
+  GeglNode            *layer_mask_source_node;
+  GeglNode            *layer_mask_opacity_node;
+  GeglNode            *mask_source_node;
+  GeglNode            *mask_translate_node;
+  GeglNode            *mask_crop_node;
+  GeglNode            *opacity_node;
+  GeglNode            *cache_node;
+  GeglNode            *transform_node;
+
+  GimpPickable        *node_pickable;
+  GimpDrawable        *node_layer_mask;
+  GimpDrawable        *node_mask;
+  GeglRectangle        node_rect;
+  gdouble              node_opacity;
+  GimpMatrix3          node_matrix;
+  GeglNode            *node_output;
+};
+
+#define GET_PRIVATE(transform_preview) \
+        ((GimpCanvasTransformPreviewPrivate *) gimp_canvas_transform_preview_get_instance_private ((GimpCanvasTransformPreview *) (transform_preview)))
+
+
+/*  local function prototypes  */
+
+static void             gimp_canvas_transform_preview_dispose       (GObject                    *object);
+static void             gimp_canvas_transform_preview_set_property  (GObject                    *object,
+                                                                     guint                       property_id,
+                                                                     const GValue               *value,
+                                                                     GParamSpec                 *pspec);
+static void             gimp_canvas_transform_preview_get_property  (GObject                    *object,
+                                                                     guint                       property_id,
+                                                                     GValue                     *value,
+                                                                     GParamSpec                 *pspec);
+
+static void             gimp_canvas_transform_preview_draw          (GimpCanvasItem             *item,
+                                                                     cairo_t                    *cr);
+static cairo_region_t * gimp_canvas_transform_preview_get_extents   (GimpCanvasItem             *item);
+
+static void             gimp_canvas_transform_preview_layer_changed (GimpLayer                  *layer,
+                                                                     GimpCanvasTransformPreview *transform_preview);
+
+static void             gimp_canvas_transform_preview_set_pickable  (GimpCanvasTransformPreview *transform_preview,
+                                                                     GimpPickable               *pickable);
+static void             gimp_canvas_transform_preview_sync_node     (GimpCanvasTransformPreview *transform_preview);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpCanvasTransformPreview,
+                            gimp_canvas_transform_preview,
+                            GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_transform_preview_parent_class
+
+
+/* private functions */
+
+
+static void
+gimp_canvas_transform_preview_class_init (GimpCanvasTransformPreviewClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->dispose      = gimp_canvas_transform_preview_dispose;
+  object_class->set_property = gimp_canvas_transform_preview_set_property;
+  object_class->get_property = gimp_canvas_transform_preview_get_property;
+
+  item_class->draw           = gimp_canvas_transform_preview_draw;
+  item_class->get_extents    = gimp_canvas_transform_preview_get_extents;
+
+  g_object_class_install_property (object_class, PROP_PICKABLE,
+                                   g_param_spec_object ("pickable",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_PICKABLE,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_TRANSFORM,
+                                   gimp_param_spec_matrix3 ("transform",
+                                                            NULL, NULL,
+                                                            NULL,
+                                                            GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_CLIP,
+                                   g_param_spec_enum ("clip",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_TRANSFORM_RESIZE,
+                                                      GIMP_TRANSFORM_RESIZE_ADJUST,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X1,
+                                   g_param_spec_double ("x1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y1,
+                                   g_param_spec_double ("y1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_X2,
+                                   g_param_spec_double ("x2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_Y2,
+                                   g_param_spec_double ("y2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_OPACITY,
+                                   g_param_spec_double ("opacity",
+                                                        NULL, NULL,
+                                                        0.0, 1.0, 1.0,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_canvas_transform_preview_init (GimpCanvasTransformPreview *transform_preview)
+{
+  GimpCanvasTransformPreviewPrivate *private = GET_PRIVATE (transform_preview);
+
+  private->clip    = GIMP_TRANSFORM_RESIZE_ADJUST;
+  private->opacity = 1.0;
+}
+
+static void
+gimp_canvas_transform_preview_dispose (GObject *object)
+{
+  GimpCanvasTransformPreview        *transform_preview = GIMP_CANVAS_TRANSFORM_PREVIEW (object);
+  GimpCanvasTransformPreviewPrivate *private           = GET_PRIVATE (object);
+
+  g_clear_object (&private->node);
+
+  gimp_canvas_transform_preview_set_pickable (transform_preview, NULL);
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_canvas_transform_preview_set_property (GObject      *object,
+                                            guint         property_id,
+                                            const GValue *value,
+                                            GParamSpec   *pspec)
+{
+  GimpCanvasTransformPreview        *transform_preview = GIMP_CANVAS_TRANSFORM_PREVIEW (object);
+  GimpCanvasTransformPreviewPrivate *private           = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_PICKABLE:
+      gimp_canvas_transform_preview_set_pickable (transform_preview,
+                                                  g_value_get_object (value));
+      break;
+
+    case PROP_TRANSFORM:
+      {
+        GimpMatrix3 *transform = g_value_get_boxed (value);
+
+        if (transform)
+          private->transform = *transform;
+        else
+          gimp_matrix3_identity (&private->transform);
+      }
+      break;
+
+    case PROP_CLIP:
+      private->clip = g_value_get_enum (value);
+      break;
+
+    case PROP_X1:
+      private->x1 = g_value_get_double (value);
+      break;
+
+    case PROP_Y1:
+      private->y1 = g_value_get_double (value);
+      break;
+
+    case PROP_X2:
+      private->x2 = g_value_get_double (value);
+      break;
+
+    case PROP_Y2:
+      private->y2 = g_value_get_double (value);
+      break;
+
+    case PROP_OPACITY:
+      private->opacity = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_transform_preview_get_property (GObject    *object,
+                                            guint       property_id,
+                                            GValue     *value,
+                                            GParamSpec *pspec)
+{
+  GimpCanvasTransformPreviewPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_PICKABLE:
+      g_value_set_object (value, private->pickable);
+      break;
+
+    case PROP_TRANSFORM:
+      g_value_set_boxed (value, &private->transform);
+      break;
+
+    case PROP_CLIP:
+      g_value_set_enum (value, private->clip);
+      break;
+
+    case PROP_X1:
+      g_value_set_double (value, private->x1);
+      break;
+
+    case PROP_Y1:
+      g_value_set_double (value, private->y1);
+      break;
+
+    case PROP_X2:
+      g_value_set_double (value, private->x2);
+      break;
+
+    case PROP_Y2:
+      g_value_set_double (value, private->y2);
+      break;
+
+    case PROP_OPACITY:
+      g_value_set_double (value, private->opacity);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static gboolean
+gimp_canvas_transform_preview_transform (GimpCanvasItem        *item,
+                                         cairo_rectangle_int_t *extents)
+{
+  GimpCanvasTransformPreviewPrivate *private = GET_PRIVATE (item);
+  gint                               x1,  y1;
+  gint                               x2,  y2;
+  gdouble                            tx1, ty1;
+  gdouble                            tx2, ty2;
+
+  if (! gimp_transform_resize_boundary (&private->transform,
+                                        private->clip,
+                                        private->x1, private->y1,
+                                        private->x2, private->y2,
+                                        &x1,         &y1,
+                                        &x2,         &y2))
+    {
+      return FALSE;
+    }
+
+  gimp_canvas_item_transform_xy_f (item, x1, y1, &tx1, &ty1);
+  gimp_canvas_item_transform_xy_f (item, x2, y2, &tx2, &ty2);
+
+  extents->x      = (gint) floor (tx1);
+  extents->y      = (gint) floor (ty1);
+  extents->width  = (gint) ceil  (tx2) - extents->x;
+  extents->height = (gint) ceil  (ty2) - extents->y;
+
+  return TRUE;
+}
+
+static void
+gimp_canvas_transform_preview_draw (GimpCanvasItem *item,
+                                    cairo_t        *cr)
+{
+  GimpCanvasTransformPreview        *transform_preview = GIMP_CANVAS_TRANSFORM_PREVIEW (item);
+  GimpCanvasTransformPreviewPrivate *private           = GET_PRIVATE (item);
+  GimpDisplayShell                  *shell             = gimp_canvas_item_get_shell (item);
+  cairo_rectangle_int_t              extents;
+  gdouble                            clip_x1, clip_y1;
+  gdouble                            clip_x2, clip_y2;
+  GeglRectangle                      bounds;
+  cairo_surface_t                   *surface;
+  guchar                            *surface_data;
+  gint                               surface_stride;
+
+  if (! gimp_canvas_transform_preview_transform (item, &extents))
+    return;
+
+  cairo_clip_extents (cr, &clip_x1, &clip_y1, &clip_x2, &clip_y2);
+
+  clip_x1 = floor (clip_x1);
+  clip_y1 = floor (clip_y1);
+  clip_x2 = ceil  (clip_x2);
+  clip_y2 = ceil  (clip_y2);
+
+  if (! gegl_rectangle_intersect (&bounds,
+                                  GEGL_RECTANGLE (extents.x,
+                                                  extents.y,
+                                                  extents.width,
+                                                  extents.height),
+                                  GEGL_RECTANGLE (clip_x1,
+                                                  clip_y1,
+                                                  clip_x2 - clip_x1,
+                                                  clip_y2 - clip_y1)))
+    {
+      return;
+    }
+
+  surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                        bounds.width, bounds.height);
+
+  g_return_if_fail (surface != NULL);
+
+  surface_data   = cairo_image_surface_get_data (surface);
+  surface_stride = cairo_image_surface_get_stride (surface);
+
+  gimp_canvas_transform_preview_sync_node (transform_preview);
+
+  gegl_node_blit (private->node_output, 1.0,
+                  GEGL_RECTANGLE (bounds.x + shell->offset_x,
+                                  bounds.y + shell->offset_y,
+                                  bounds.width,
+                                  bounds.height),
+                  babl_format ("cairo-ARGB32"), surface_data, surface_stride,
+                  GEGL_BLIT_CACHE);
+
+  cairo_surface_mark_dirty (surface);
+
+  cairo_set_source_surface (cr, surface, bounds.x, bounds.y);
+  cairo_rectangle (cr, bounds.x, bounds.y, bounds.width, bounds.height);
+  cairo_fill (cr);
+
+  cairo_surface_destroy (surface);
+}
+
+static cairo_region_t *
+gimp_canvas_transform_preview_get_extents (GimpCanvasItem *item)
+{
+  cairo_rectangle_int_t rectangle;
+
+  if (gimp_canvas_transform_preview_transform (item, &rectangle))
+    return cairo_region_create_rectangle (&rectangle);
+
+  return NULL;
+}
+
+static void
+gimp_canvas_transform_preview_layer_changed (GimpLayer                  *layer,
+                                             GimpCanvasTransformPreview *transform_preview)
+{
+  GimpCanvasItem *item = GIMP_CANVAS_ITEM (transform_preview);
+
+  gimp_canvas_item_begin_change (item);
+  gimp_canvas_item_end_change   (item);
+}
+
+static void
+gimp_canvas_transform_preview_set_pickable (GimpCanvasTransformPreview *transform_preview,
+                                            GimpPickable               *pickable)
+{
+  GimpCanvasTransformPreviewPrivate *private = GET_PRIVATE (transform_preview);
+
+  if (private->pickable && GIMP_IS_LAYER (private->pickable))
+    {
+      g_signal_handlers_disconnect_by_func (
+        private->pickable,
+        gimp_canvas_transform_preview_layer_changed,
+        transform_preview);
+    }
+
+  g_set_object (&private->pickable, pickable);
+
+  if (pickable && GIMP_IS_LAYER (pickable))
+    {
+      g_signal_connect (pickable, "opacity-changed",
+                        G_CALLBACK (gimp_canvas_transform_preview_layer_changed),
+                        transform_preview);
+      g_signal_connect (pickable, "mask-changed",
+                        G_CALLBACK (gimp_canvas_transform_preview_layer_changed),
+                        transform_preview);
+      g_signal_connect (pickable, "apply-mask-changed",
+                        G_CALLBACK (gimp_canvas_transform_preview_layer_changed),
+                        transform_preview);
+      g_signal_connect (pickable, "show-mask-changed",
+                        G_CALLBACK (gimp_canvas_transform_preview_layer_changed),
+                        transform_preview);
+    }
+}
+
+static void
+gimp_canvas_transform_preview_sync_node (GimpCanvasTransformPreview *transform_preview)
+{
+  GimpCanvasTransformPreviewPrivate *private    = GET_PRIVATE (transform_preview);
+  GimpCanvasItem                    *item       = GIMP_CANVAS_ITEM (transform_preview);
+  GimpDisplayShell                  *shell      = gimp_canvas_item_get_shell (item);
+  GimpImage                         *image      = gimp_canvas_item_get_image (item);
+  GimpPickable                      *pickable   = private->pickable;
+  GimpDrawable                      *layer_mask = NULL;
+  GimpDrawable                      *mask       = NULL;
+  gdouble                            opacity    = private->opacity;
+  gint                               offset_x   = 0;
+  gint                               offset_y   = 0;
+  GimpMatrix3                        matrix;
+
+  if (! private->node)
+    {
+      private->node = gegl_node_new ();
+
+      private->source_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gimp:buffer-source-validate",
+                             NULL);
+
+      private->convert_format_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gegl:convert-format",
+                             NULL);
+
+      private->layer_mask_source_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gimp:buffer-source-validate",
+                             NULL);
+
+      private->layer_mask_opacity_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gegl:opacity",
+                             NULL);
+
+      private->mask_source_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gimp:buffer-source-validate",
+                             NULL);
+
+      private->mask_translate_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gegl:translate",
+                             NULL);
+
+      private->mask_crop_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gegl:crop",
+                             "width",     0.0,
+                             "height",    0.0,
+                             NULL);
+
+      private->opacity_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gegl:opacity",
+                             NULL);
+
+      private->cache_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gegl:cache",
+                             NULL);
+
+      private->transform_node =
+        gegl_node_new_child (private->node,
+                             "operation", "gegl:transform",
+                             "near-z",    GIMP_TRANSFORM_NEAR_Z,
+                             "sampler",   GIMP_INTERPOLATION_NONE,
+                             NULL);
+
+      gegl_node_link_many (private->source_node,
+                           private->convert_format_node,
+                           private->transform_node,
+                           NULL);
+
+      gegl_node_connect_to (private->layer_mask_source_node,  "output",
+                            private->layer_mask_opacity_node, "aux");
+
+      gegl_node_link_many (private->mask_source_node,
+                           private->mask_translate_node,
+                           private->mask_crop_node,
+                           NULL);
+
+      private->node_pickable   = NULL;
+      private->node_layer_mask = NULL;
+      private->node_mask       = NULL;
+      private->node_rect       = *GEGL_RECTANGLE (0, 0, 0, 0);
+      private->node_opacity    = 1.0;
+      gimp_matrix3_identity (&private->node_matrix);
+      private->node_output     = private->transform_node;
+    }
+
+  if (GIMP_IS_ITEM (pickable))
+    {
+      gimp_item_get_offset (GIMP_ITEM (private->pickable),
+                            &offset_x, &offset_y);
+
+      if (gimp_item_mask_bounds (GIMP_ITEM (pickable),
+                                 NULL, NULL, NULL, NULL))
+        {
+          mask = GIMP_DRAWABLE (gimp_image_get_mask (image));
+        }
+
+      if (GIMP_IS_LAYER (pickable))
+        {
+          GimpLayer *layer = GIMP_LAYER (pickable);
+
+          opacity *= gimp_layer_get_opacity (layer);
+
+          layer_mask = GIMP_DRAWABLE (gimp_layer_get_mask (layer));
+
+          if (layer_mask)
+            {
+              if (gimp_layer_get_show_mask (layer) && ! mask)
+                {
+                  pickable   = GIMP_PICKABLE (layer_mask);
+                  layer_mask = NULL;
+                }
+              else if (! gimp_layer_get_apply_mask (layer))
+                {
+                  layer_mask = NULL;
+                }
+            }
+        }
+    }
+
+  gimp_matrix3_identity (&matrix);
+  gimp_matrix3_translate (&matrix, offset_x, offset_y);
+  gimp_matrix3_mult (&private->transform, &matrix);
+  gimp_matrix3_scale (&matrix, shell->scale_x, shell->scale_y);
+
+  if (pickable != private->node_pickable)
+    {
+      GeglBuffer *buffer;
+
+      gimp_pickable_flush (pickable);
+
+      buffer = gimp_pickable_get_buffer (pickable);
+
+      if (gimp_tile_handler_validate_get_assigned (buffer))
+        buffer = gimp_gegl_buffer_dup (buffer);
+      else
+        buffer = g_object_ref (buffer);
+
+      gegl_node_set (private->source_node,
+                     "buffer", buffer,
+                     NULL);
+      gegl_node_set (private->convert_format_node,
+                     "format", gimp_pickable_get_format_with_alpha (pickable),
+                     NULL);
+
+      g_object_unref (buffer);
+    }
+
+  if (layer_mask != private->node_layer_mask)
+    {
+      gegl_node_set (private->layer_mask_source_node,
+                     "buffer", layer_mask ?
+                                 gimp_drawable_get_buffer (layer_mask) :
+                                 NULL,
+                     NULL);
+    }
+
+  if (mask)
+    {
+      GeglRectangle  rect;
+
+      rect.x      = offset_x;
+      rect.y      = offset_y;
+      rect.width  = gimp_item_get_width  (GIMP_ITEM (private->pickable));
+      rect.height = gimp_item_get_height (GIMP_ITEM (private->pickable));
+
+      if (mask != private->node_mask)
+        {
+          gegl_node_set (private->mask_source_node,
+                         "buffer", gimp_drawable_get_buffer (mask),
+                         NULL);
+        }
+
+      if (! gegl_rectangle_equal (&rect, &private->node_rect))
+        {
+          private->node_rect = rect;
+
+          gegl_node_set (private->mask_translate_node,
+                         "x", (gdouble) -rect.x,
+                         "y", (gdouble) -rect.y,
+                         NULL);
+
+          gegl_node_set (private->mask_crop_node,
+                         "width",  (gdouble) rect.width,
+                         "height", (gdouble) rect.height,
+                         NULL);
+        }
+
+      if (! private->node_mask)
+        {
+          gegl_node_connect_to (private->mask_crop_node, "output",
+                                private->opacity_node,   "aux");
+        }
+    }
+  else if (private->node_mask)
+    {
+      gegl_node_disconnect (private->opacity_node, "aux");
+    }
+
+  if (opacity != private->node_opacity)
+    {
+      gegl_node_set (private->opacity_node,
+                     "value", opacity,
+                     NULL);
+    }
+
+  if (layer_mask       != private->node_layer_mask ||
+      mask             != private->node_mask       ||
+      (opacity != 1.0) != (private->node_opacity != 1.0))
+    {
+      GeglNode *output = private->source_node;
+
+      if (layer_mask && ! mask)
+        {
+          gegl_node_link (output, private->layer_mask_opacity_node);
+          output = private->layer_mask_opacity_node;
+        }
+      else
+        {
+          gegl_node_disconnect (private->layer_mask_opacity_node, "input");
+        }
+
+      if (mask || (opacity != 1.0))
+        {
+          gegl_node_link (output, private->opacity_node);
+          output = private->opacity_node;
+        }
+      else
+        {
+          gegl_node_disconnect (private->opacity_node, "input");
+        }
+
+      if (output == private->source_node)
+        {
+          gegl_node_disconnect (private->cache_node, "input");
+
+          gegl_node_link (output, private->convert_format_node);
+          output = private->convert_format_node;
+        }
+      else
+        {
+          gegl_node_disconnect (private->convert_format_node, "input");
+
+          gegl_node_link (output, private->cache_node);
+          output = private->cache_node;
+        }
+
+      gegl_node_link (output, private->transform_node);
+      output = private->transform_node;
+
+      if (layer_mask && mask)
+        {
+          gegl_node_link (output, private->layer_mask_opacity_node);
+          output = private->layer_mask_opacity_node;
+        }
+
+      private->node_output = output;
+    }
+
+  if (memcmp (&matrix, &private->node_matrix, sizeof (matrix)))
+    {
+      private->node_matrix = matrix;
+
+      gimp_gegl_node_set_matrix (private->transform_node, &matrix);
+    }
+
+  private->node_pickable   = pickable;
+  private->node_layer_mask = layer_mask;
+  private->node_mask       = mask;
+  private->node_opacity    = opacity;
+}
+
+
+/* public functions */
+
+
+GimpCanvasItem *
+gimp_canvas_transform_preview_new (GimpDisplayShell  *shell,
+                                   GimpPickable      *pickable,
+                                   const GimpMatrix3 *transform,
+                                   gdouble            x1,
+                                   gdouble            y1,
+                                   gdouble            x2,
+                                   gdouble            y2)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (GIMP_IS_PICKABLE (pickable), NULL);
+  g_return_val_if_fail (transform != NULL, NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_TRANSFORM_PREVIEW,
+                       "shell",     shell,
+                       "pickable",  pickable,
+                       "transform", transform,
+                       "x1",        x1,
+                       "y1",        y1,
+                       "x2",        x2,
+                       "y2",        y2,
+                       NULL);
+}
diff --git a/app/display/gimpcanvastransformpreview.h b/app/display/gimpcanvastransformpreview.h
new file mode 100644
index 0000000..a82d50c
--- /dev/null
+++ b/app/display/gimpcanvastransformpreview.h
@@ -0,0 +1,61 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvastransformpreview.h
+ * Copyright (C) 2011 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_TRANSFORM_PREVIEW_H__
+#define __GIMP_CANVAS_TRANSFORM_PREVIEW_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_TRANSFORM_PREVIEW            (gimp_canvas_transform_preview_get_type ())
+#define GIMP_CANVAS_TRANSFORM_PREVIEW(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_TRANSFORM_PREVIEW, GimpCanvasTransformPreview))
+#define GIMP_CANVAS_TRANSFORM_PREVIEW_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_TRANSFORM_PREVIEW, GimpCanvasTransformPreviewClass))
+#define GIMP_IS_CANVAS_TRANSFORM_PREVIEW(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_TRANSFORM_PREVIEW))
+#define GIMP_IS_CANVAS_TRANSFORM_PREVIEW_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_TRANSFORM_PREVIEW))
+#define GIMP_CANVAS_TRANSFORM_PREVIEW_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_TRANSFORM_PREVIEW, GimpCanvasTransformPreviewClass))
+
+
+typedef struct _GimpCanvasTransformPreview      GimpCanvasTransformPreview;
+typedef struct _GimpCanvasTransformPreviewClass GimpCanvasTransformPreviewClass;
+
+struct _GimpCanvasTransformPreview
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasTransformPreviewClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_transform_preview_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_transform_preview_new      (GimpDisplayShell  *shell,
+                                                         GimpPickable      *pickable,
+                                                         const GimpMatrix3 *transform,
+                                                         gdouble            x1,
+                                                         gdouble            y1,
+                                                         gdouble            x2,
+                                                         gdouble            y2);
+
+
+#endif /* __GIMP_CANVAS_TRANSFORM_PREVIEW_H__ */
diff --git a/app/display/gimpcursorview.c b/app/display/gimpcursorview.c
new file mode 100644
index 0000000..846df91
--- /dev/null
+++ b/app/display/gimpcursorview.c
@@ -0,0 +1,887 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcursorview.c
+ * Copyright (C) 2005-2016 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpcoreconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimpimage-pick-color.h"
+#include "core/gimpitem.h"
+
+#include "widgets/gimpcolorframe.h"
+#include "widgets/gimpdocked.h"
+#include "widgets/gimpmenufactory.h"
+#include "widgets/gimpsessioninfo-aux.h"
+
+#include "gimpcursorview.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+
+#include "gimp-intl.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_SAMPLE_MERGED
+};
+
+
+struct _GimpCursorViewPrivate
+{
+  GimpEditor        parent_instance;
+
+  GtkWidget        *coord_hbox;
+  GtkWidget        *selection_hbox;
+  GtkWidget        *color_hbox;
+
+  GtkWidget        *pixel_x_label;
+  GtkWidget        *pixel_y_label;
+  GtkWidget        *unit_x_label;
+  GtkWidget        *unit_y_label;
+  GtkWidget        *selection_x_label;
+  GtkWidget        *selection_y_label;
+  GtkWidget        *selection_width_label;
+  GtkWidget        *selection_height_label;
+  GtkWidget        *color_frame_1;
+  GtkWidget        *color_frame_2;
+
+  gboolean          sample_merged;
+
+  GimpContext      *context;
+  GimpDisplayShell *shell;
+  GimpImage        *image;
+  GimpUnit          unit;
+
+  guint             cursor_idle_id;
+  GimpImage        *cursor_image;
+  GimpUnit          cursor_unit;
+  gdouble           cursor_x;
+  gdouble           cursor_y;
+};
+
+
+static void       gimp_cursor_view_docked_iface_init     (GimpDockedInterface *iface);
+
+static void       gimp_cursor_view_dispose               (GObject             *object);
+static void       gimp_cursor_view_set_property          (GObject             *object,
+                                                          guint                property_id,
+                                                          const GValue        *value,
+                                                          GParamSpec          *pspec);
+static void       gimp_cursor_view_get_property          (GObject             *object,
+                                                          guint                property_id,
+                                                          GValue              *value,
+                                                          GParamSpec          *pspec);
+
+static void       gimp_cursor_view_style_set             (GtkWidget           *widget,
+                                                          GtkStyle            *prev_style);
+
+static void       gimp_cursor_view_set_aux_info          (GimpDocked          *docked,
+                                                          GList               *aux_info);
+static GList    * gimp_cursor_view_get_aux_info          (GimpDocked          *docked);
+
+static void       gimp_cursor_view_set_context           (GimpDocked          *docked,
+                                                          GimpContext         *context);
+static void       gimp_cursor_view_image_changed         (GimpCursorView      *view,
+                                                          GimpImage           *image,
+                                                          GimpContext         *context);
+static void       gimp_cursor_view_mask_changed          (GimpCursorView      *view,
+                                                          GimpImage           *image);
+static void       gimp_cursor_view_diplay_changed        (GimpCursorView      *view,
+                                                          GimpDisplay         *display,
+                                                          GimpContext         *context);
+static void       gimp_cursor_view_shell_unit_changed    (GimpCursorView      *view,
+                                                          GParamSpec          *pspec,
+                                                          GimpDisplayShell    *shell);
+static void       gimp_cursor_view_format_as_unit        (GimpUnit             unit,
+                                                          gchar               *output_buf,
+                                                          gint                 output_buf_size,
+                                                          gdouble              pixel_value,
+                                                          gdouble              image_res);
+static void       gimp_cursor_view_set_label_italic      (GtkWidget           *label,
+                                                          gboolean             italic);
+static void       gimp_cursor_view_update_selection_info (GimpCursorView      *view,
+                                                          GimpImage           *image,
+                                                          GimpUnit             unit);
+static gboolean   gimp_cursor_view_cursor_idle           (GimpCursorView      *view);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpCursorView, gimp_cursor_view, GIMP_TYPE_EDITOR,
+                         G_ADD_PRIVATE (GimpCursorView)
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_DOCKED,
+                                                gimp_cursor_view_docked_iface_init))
+
+#define parent_class gimp_cursor_view_parent_class
+
+static GimpDockedInterface *parent_docked_iface = NULL;
+
+
+static void
+gimp_cursor_view_class_init (GimpCursorViewClass* klass)
+{
+  GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  object_class->dispose      = gimp_cursor_view_dispose;
+  object_class->get_property = gimp_cursor_view_get_property;
+  object_class->set_property = gimp_cursor_view_set_property;
+
+  widget_class->style_set    = gimp_cursor_view_style_set;
+
+  g_object_class_install_property (object_class, PROP_SAMPLE_MERGED,
+                                   g_param_spec_boolean ("sample-merged",
+                                                         NULL, NULL,
+                                                         TRUE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_cursor_view_init (GimpCursorView *view)
+{
+  GtkWidget *frame;
+  GtkWidget *table;
+  GtkWidget *toggle;
+  gint       content_spacing;
+
+  view->priv = gimp_cursor_view_get_instance_private (view);
+
+  view->priv->sample_merged  = TRUE;
+  view->priv->context        = NULL;
+  view->priv->shell          = NULL;
+  view->priv->image          = NULL;
+  view->priv->unit           = GIMP_UNIT_PIXEL;
+  view->priv->cursor_idle_id = 0;
+
+  gtk_widget_style_get (GTK_WIDGET (view),
+                        "content-spacing", &content_spacing,
+                        NULL);
+
+
+  /* cursor information */
+
+  view->priv->coord_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL,
+                                        content_spacing);
+  gtk_box_set_homogeneous (GTK_BOX (view->priv->coord_hbox), TRUE);
+  gtk_box_pack_start (GTK_BOX (view), view->priv->coord_hbox,
+                      FALSE, FALSE, 0);
+  gtk_widget_show (view->priv->coord_hbox);
+
+  view->priv->selection_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL,
+                                            content_spacing);
+  gtk_box_set_homogeneous (GTK_BOX (view->priv->selection_hbox), TRUE);
+  gtk_box_pack_start (GTK_BOX (view), view->priv->selection_hbox,
+                      FALSE, FALSE, 0);
+  gtk_widget_show (view->priv->selection_hbox);
+
+
+  /* Pixels */
+
+  frame = gimp_frame_new (_("Pixels"));
+  gtk_box_pack_start (GTK_BOX (view->priv->coord_hbox), frame, TRUE, TRUE, 0);
+  gtk_widget_show (frame);
+
+  table = gtk_table_new (2, 2, FALSE);
+  gtk_table_set_col_spacings (GTK_TABLE (table), 6);
+  gtk_table_set_row_spacings (GTK_TABLE (table), 2);
+  gtk_container_add (GTK_CONTAINER (frame), table);
+  gtk_widget_show (table);
+
+  view->priv->pixel_x_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->pixel_x_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 0,
+                             _("X"), 0.5, 0.5,
+                             view->priv->pixel_x_label, 1, FALSE);
+
+  view->priv->pixel_y_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->pixel_y_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 1,
+                             _("Y"), 0.5, 0.5,
+                             view->priv->pixel_y_label, 1, FALSE);
+
+
+  /* Units */
+
+  frame = gimp_frame_new (_("Units"));
+  gtk_box_pack_start (GTK_BOX (view->priv->coord_hbox), frame, TRUE, TRUE, 0);
+  gtk_widget_show (frame);
+
+  table = gtk_table_new (2, 2, FALSE);
+  gtk_table_set_col_spacings (GTK_TABLE (table), 4);
+  gtk_table_set_row_spacings (GTK_TABLE (table), 2);
+  gtk_container_add (GTK_CONTAINER (frame), table);
+  gtk_widget_show (table);
+
+  view->priv->unit_x_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->unit_x_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 0,
+                             _("X"), 0.5, 0.5,
+                             view->priv->unit_x_label, 1, FALSE);
+
+  view->priv->unit_y_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->unit_y_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 1,
+                             _("Y"), 0.5, 0.5,
+                             view->priv->unit_y_label, 1, FALSE);
+
+
+  /* Selection Bounding Box */
+
+  frame = gimp_frame_new (_("Selection"));
+  gtk_box_pack_start (GTK_BOX (view->priv->selection_hbox), frame, TRUE, TRUE, 0);
+  gtk_widget_show (frame);
+
+  gimp_help_set_help_data (frame, _("The selection's bounding box"), NULL);
+
+  table = gtk_table_new (2, 2, FALSE);
+  gtk_table_set_col_spacings (GTK_TABLE (table), 6);
+  gtk_table_set_row_spacings (GTK_TABLE (table), 2);
+  gtk_container_add (GTK_CONTAINER (frame), table);
+  gtk_widget_show (table);
+
+  view->priv->selection_x_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->selection_x_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 0,
+                             _("X"), 0.5, 0.5,
+                             view->priv->selection_x_label, 1, FALSE);
+
+  view->priv->selection_y_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->selection_y_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 1,
+                             _("Y"), 0.5, 0.5,
+                             view->priv->selection_y_label, 1, FALSE);
+
+  frame = gimp_frame_new ("");
+  gtk_box_pack_start (GTK_BOX (view->priv->selection_hbox), frame, TRUE, TRUE, 0);
+  gtk_widget_show (frame);
+
+  table = gtk_table_new (2, 2, FALSE);
+  gtk_table_set_col_spacings (GTK_TABLE (table), 4);
+  gtk_table_set_row_spacings (GTK_TABLE (table), 2);
+  gtk_container_add (GTK_CONTAINER (frame), table);
+  gtk_widget_show (table);
+
+  view->priv->selection_width_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->selection_width_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 0,
+                             /* Width */
+                             _("W"), 0.5, 0.5,
+                             view->priv->selection_width_label, 1, FALSE);
+
+  view->priv->selection_height_label = gtk_label_new (_("n/a"));
+  gtk_label_set_xalign (GTK_LABEL (view->priv->selection_height_label), 1.0);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, 1,
+                             /* Height */
+                             _("H"), 0.5, 0.5,
+                             view->priv->selection_height_label, 1, FALSE);
+
+
+  /* color information */
+
+  view->priv->color_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL,
+                                        content_spacing);
+  gtk_box_set_homogeneous (GTK_BOX (view->priv->color_hbox), TRUE);
+  gtk_box_pack_start (GTK_BOX (view), view->priv->color_hbox, FALSE, FALSE, 0);
+  gtk_widget_show (view->priv->color_hbox);
+
+  view->priv->color_frame_1 = gimp_color_frame_new ();
+  gimp_color_frame_set_mode (GIMP_COLOR_FRAME (view->priv->color_frame_1),
+                             GIMP_COLOR_PICK_MODE_PIXEL);
+  gimp_color_frame_set_ellipsize (GIMP_COLOR_FRAME (view->priv->color_frame_1),
+                                  PANGO_ELLIPSIZE_END);
+  gtk_box_pack_start (GTK_BOX (view->priv->color_hbox), view->priv->color_frame_1,
+                      TRUE, TRUE, 0);
+  gtk_widget_show (view->priv->color_frame_1);
+
+  view->priv->color_frame_2 = gimp_color_frame_new ();
+  gimp_color_frame_set_mode (GIMP_COLOR_FRAME (view->priv->color_frame_2),
+                             GIMP_COLOR_PICK_MODE_RGB_PERCENT);
+  gtk_box_pack_start (GTK_BOX (view->priv->color_hbox), view->priv->color_frame_2,
+                      TRUE, TRUE, 0);
+  gtk_widget_show (view->priv->color_frame_2);
+
+  /* sample merged toggle */
+
+  toggle = gimp_prop_check_button_new (G_OBJECT (view), "sample-merged",
+                                       _("_Sample Merged"));
+  gtk_box_pack_start (GTK_BOX (view), toggle, FALSE, FALSE, 0);
+  gtk_widget_show (toggle);
+}
+
+static void
+gimp_cursor_view_docked_iface_init (GimpDockedInterface *iface)
+{
+  parent_docked_iface = g_type_interface_peek_parent (iface);
+
+  if (! parent_docked_iface)
+    parent_docked_iface = g_type_default_interface_peek (GIMP_TYPE_DOCKED);
+
+  iface->set_aux_info = gimp_cursor_view_set_aux_info;
+  iface->get_aux_info = gimp_cursor_view_get_aux_info;
+  iface->set_context  = gimp_cursor_view_set_context;
+}
+
+static void
+gimp_cursor_view_dispose (GObject *object)
+{
+  GimpCursorView *view = GIMP_CURSOR_VIEW (object);
+
+  if (view->priv->context)
+    gimp_docked_set_context (GIMP_DOCKED (view), NULL);
+
+  if (view->priv->cursor_idle_id)
+    {
+      g_source_remove (view->priv->cursor_idle_id);
+      view->priv->cursor_idle_id = 0;
+    }
+
+  g_clear_object (&view->priv->cursor_image);
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_cursor_view_set_property (GObject      *object,
+                               guint         property_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GimpCursorView *view = GIMP_CURSOR_VIEW (object);
+
+  switch (property_id)
+    {
+    case PROP_SAMPLE_MERGED:
+      view->priv->sample_merged = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_cursor_view_get_property (GObject    *object,
+                               guint       property_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GimpCursorView *view = GIMP_CURSOR_VIEW (object);
+
+  switch (property_id)
+    {
+    case PROP_SAMPLE_MERGED:
+      g_value_set_boolean (value, view->priv->sample_merged);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+#define AUX_INFO_FRAME_1_MODE "frame-1-mode"
+#define AUX_INFO_FRAME_2_MODE "frame-2-mode"
+
+static void
+gimp_cursor_view_set_aux_info (GimpDocked *docked,
+                               GList      *aux_info)
+{
+  GimpCursorView *view = GIMP_CURSOR_VIEW (docked);
+  GList          *list;
+
+  parent_docked_iface->set_aux_info (docked, aux_info);
+
+  for (list = aux_info; list; list = g_list_next (list))
+    {
+      GimpSessionInfoAux *aux   = list->data;
+      GtkWidget          *frame = NULL;
+
+      if (! strcmp (aux->name, AUX_INFO_FRAME_1_MODE))
+        frame = view->priv->color_frame_1;
+      else if (! strcmp (aux->name, AUX_INFO_FRAME_2_MODE))
+        frame = view->priv->color_frame_2;
+
+      if (frame)
+        {
+          GEnumClass *enum_class;
+          GEnumValue *enum_value;
+
+          enum_class = g_type_class_peek (GIMP_TYPE_COLOR_PICK_MODE);
+          enum_value = g_enum_get_value_by_nick (enum_class, aux->value);
+
+          if (enum_value)
+            gimp_color_frame_set_mode (GIMP_COLOR_FRAME (frame),
+                                       enum_value->value);
+        }
+    }
+}
+
+static GList *
+gimp_cursor_view_get_aux_info (GimpDocked *docked)
+{
+  GimpCursorView     *view = GIMP_CURSOR_VIEW (docked);
+  GList              *aux_info;
+  const gchar        *nick;
+  GimpSessionInfoAux *aux;
+
+  aux_info = parent_docked_iface->get_aux_info (docked);
+
+  if (gimp_enum_get_value (GIMP_TYPE_COLOR_PICK_MODE,
+                           GIMP_COLOR_FRAME (view->priv->color_frame_1)->pick_mode,
+                           NULL, &nick, NULL, NULL))
+    {
+      aux = gimp_session_info_aux_new (AUX_INFO_FRAME_1_MODE, nick);
+      aux_info = g_list_append (aux_info, aux);
+    }
+
+  if (gimp_enum_get_value (GIMP_TYPE_COLOR_PICK_MODE,
+                           GIMP_COLOR_FRAME (view->priv->color_frame_2)->pick_mode,
+                           NULL, &nick, NULL, NULL))
+    {
+      aux = gimp_session_info_aux_new (AUX_INFO_FRAME_2_MODE, nick);
+      aux_info = g_list_append (aux_info, aux);
+    }
+
+  return aux_info;
+}
+
+static void
+gimp_cursor_view_format_as_unit (GimpUnit  unit,
+                                 gchar    *output_buf,
+                                 gint      output_buf_size,
+                                 gdouble   pixel_value,
+                                 gdouble   image_res)
+{
+  gchar         format_buf[32];
+  gdouble       value;
+  gint          unit_digits = 0;
+  const gchar  *unit_str = "";
+
+  value = gimp_pixels_to_units (pixel_value, unit, image_res);
+
+  if (unit != GIMP_UNIT_PIXEL)
+    {
+      unit_digits = gimp_unit_get_scaled_digits (unit, image_res);
+      unit_str    = gimp_unit_get_abbreviation (unit);
+    }
+
+  g_snprintf (format_buf, sizeof (format_buf),
+              "%%.%df %s", unit_digits, unit_str);
+
+  g_snprintf (output_buf, output_buf_size, format_buf, value);
+}
+
+static void
+gimp_cursor_view_set_label_italic (GtkWidget *label,
+                                   gboolean   italic)
+{
+  PangoStyle attribute = italic ? PANGO_STYLE_ITALIC : PANGO_STYLE_NORMAL;
+
+  gimp_label_set_attributes (GTK_LABEL (label),
+                             PANGO_ATTR_STYLE, attribute,
+                             -1);
+}
+
+static void
+gimp_cursor_view_style_set (GtkWidget *widget,
+                            GtkStyle  *prev_style)
+{
+  GimpCursorView *view = GIMP_CURSOR_VIEW (widget);
+  gint            content_spacing;
+
+  GTK_WIDGET_CLASS (parent_class)->style_set (widget, prev_style);
+
+  gtk_widget_style_get (GTK_WIDGET (view),
+                        "content-spacing", &content_spacing,
+                        NULL);
+
+  gtk_box_set_spacing (GTK_BOX (view->priv->coord_hbox),     content_spacing);
+  gtk_box_set_spacing (GTK_BOX (view->priv->selection_hbox), content_spacing);
+  gtk_box_set_spacing (GTK_BOX (view->priv->color_hbox),     content_spacing);
+}
+
+static void
+gimp_cursor_view_set_context (GimpDocked  *docked,
+                              GimpContext *context)
+{
+  GimpCursorView  *view    = GIMP_CURSOR_VIEW (docked);
+  GimpColorConfig *config  = NULL;
+  GimpDisplay     *display = NULL;
+  GimpImage       *image   = NULL;
+
+  if (context == view->priv->context)
+    return;
+
+  if (view->priv->context)
+    {
+      g_signal_handlers_disconnect_by_func (view->priv->context,
+                                            gimp_cursor_view_diplay_changed,
+                                            view);
+      g_signal_handlers_disconnect_by_func (view->priv->context,
+                                            gimp_cursor_view_image_changed,
+                                            view);
+
+      g_object_unref (view->priv->context);
+    }
+
+  view->priv->context = context;
+
+  if (view->priv->context)
+    {
+      g_object_ref (view->priv->context);
+
+      g_signal_connect_swapped (view->priv->context, "display-changed",
+                                G_CALLBACK (gimp_cursor_view_diplay_changed),
+                                view);
+
+      g_signal_connect_swapped (view->priv->context, "image-changed",
+                                G_CALLBACK (gimp_cursor_view_image_changed),
+                                view);
+
+      config  = context->gimp->config->color_management;
+      display = gimp_context_get_display (context);
+      image   = gimp_context_get_image (context);
+    }
+
+  gimp_color_frame_set_color_config (GIMP_COLOR_FRAME (view->priv->color_frame_1),
+                                     config);
+  gimp_color_frame_set_color_config (GIMP_COLOR_FRAME (view->priv->color_frame_2),
+                                     config);
+
+  gimp_cursor_view_diplay_changed (view, display, view->priv->context);
+  gimp_cursor_view_image_changed (view, image, view->priv->context);
+}
+
+static void
+gimp_cursor_view_image_changed (GimpCursorView *view,
+                                GimpImage      *image,
+                                GimpContext    *context)
+{
+  g_return_if_fail (GIMP_IS_CURSOR_VIEW (view));
+
+  if (image == view->priv->image)
+    return;
+
+  if (view->priv->image)
+    {
+      g_signal_handlers_disconnect_by_func (view->priv->image,
+                                            gimp_cursor_view_mask_changed,
+                                            view);
+    }
+
+  view->priv->image = image;
+
+  if (view->priv->image)
+    {
+      g_signal_connect_swapped (view->priv->image, "mask-changed",
+                                G_CALLBACK (gimp_cursor_view_mask_changed),
+                                view);
+    }
+
+  gimp_cursor_view_mask_changed (view, view->priv->image);
+}
+
+static void
+gimp_cursor_view_mask_changed (GimpCursorView *view,
+                               GimpImage      *image)
+{
+  gimp_cursor_view_update_selection_info (view,
+                                          view->priv->image,
+                                          view->priv->unit);
+}
+
+static void
+gimp_cursor_view_diplay_changed (GimpCursorView *view,
+                                 GimpDisplay    *display,
+                                 GimpContext    *context)
+{
+  GimpDisplayShell *shell = NULL;
+
+  if (display)
+    shell = gimp_display_get_shell (display);
+
+  if (view->priv->shell)
+    {
+      g_signal_handlers_disconnect_by_func (view->priv->shell,
+                                            gimp_cursor_view_shell_unit_changed,
+                                            view);
+    }
+
+  view->priv->shell = shell;
+
+  if (view->priv->shell)
+    {
+      g_signal_connect_swapped (view->priv->shell, "notify::unit",
+                                G_CALLBACK (gimp_cursor_view_shell_unit_changed),
+                                view);
+    }
+
+  gimp_cursor_view_shell_unit_changed (view,
+                                       NULL,
+                                       view->priv->shell);
+}
+
+static void
+gimp_cursor_view_shell_unit_changed (GimpCursorView   *view,
+                                     GParamSpec       *pspec,
+                                     GimpDisplayShell *shell)
+{
+  GimpUnit new_unit = GIMP_UNIT_PIXEL;
+
+  if (shell)
+    {
+      new_unit = gimp_display_shell_get_unit (shell);
+    }
+
+  if (view->priv->unit != new_unit)
+    {
+      gimp_cursor_view_update_selection_info (view, view->priv->image, new_unit);
+      view->priv->unit = new_unit;
+    }
+}
+
+static void
+gimp_cursor_view_update_selection_info (GimpCursorView *view,
+                                        GimpImage      *image,
+                                        GimpUnit        unit)
+{
+  gint x, y, width, height;
+
+  if (image &&
+      gimp_item_bounds (GIMP_ITEM (gimp_image_get_mask (image)),
+                        &x, &y, &width, &height))
+    {
+      gdouble xres, yres;
+      gchar   buf[32];
+
+      gimp_image_get_resolution (image, &xres, &yres);
+
+      gimp_cursor_view_format_as_unit (unit, buf, sizeof (buf), x, xres);
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_x_label), buf);
+
+      gimp_cursor_view_format_as_unit (unit, buf, sizeof (buf), y, yres);
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_y_label), buf);
+
+      gimp_cursor_view_format_as_unit (unit, buf, sizeof (buf), width, xres);
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_width_label), buf);
+
+      gimp_cursor_view_format_as_unit (unit, buf, sizeof (buf), height, yres);
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_height_label), buf);
+    }
+  else
+    {
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_x_label),
+                          _("n/a"));
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_y_label),
+                          _("n/a"));
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_width_label),
+                          _("n/a"));
+      gtk_label_set_text (GTK_LABEL (view->priv->selection_height_label),
+                          _("n/a"));
+    }
+}
+
+static gboolean
+gimp_cursor_view_cursor_idle (GimpCursorView *view)
+{
+
+  if (view->priv->cursor_image)
+    {
+      GimpImage  *image = view->priv->cursor_image;
+      GimpUnit    unit  = view->priv->cursor_unit;
+      gdouble     x     = view->priv->cursor_x;
+      gdouble     y     = view->priv->cursor_y;
+      gboolean    in_image;
+      gchar       buf[32];
+      const Babl *sample_format;
+      gdouble     pixel[4];
+      GimpRGB     color;
+      gdouble     xres;
+      gdouble     yres;
+      gint        int_x;
+      gint        int_y;
+
+      if (unit == GIMP_UNIT_PIXEL)
+        unit = gimp_image_get_unit (image);
+
+      gimp_image_get_resolution (image, &xres, &yres);
+
+      in_image = (x >= 0.0 && x < gimp_image_get_width  (image) &&
+                  y >= 0.0 && y < gimp_image_get_height (image));
+
+      g_snprintf (buf, sizeof (buf), "%d", (gint) floor (x));
+      gtk_label_set_text (GTK_LABEL (view->priv->pixel_x_label), buf);
+      gimp_cursor_view_set_label_italic (view->priv->pixel_x_label, ! in_image);
+
+      g_snprintf (buf, sizeof (buf), "%d", (gint) floor (y));
+      gtk_label_set_text (GTK_LABEL (view->priv->pixel_y_label), buf);
+      gimp_cursor_view_set_label_italic (view->priv->pixel_y_label, ! in_image);
+
+      gimp_cursor_view_format_as_unit (unit, buf, sizeof (buf), x, xres);
+      gtk_label_set_text (GTK_LABEL (view->priv->unit_x_label), buf);
+      gimp_cursor_view_set_label_italic (view->priv->unit_x_label, ! in_image);
+
+      gimp_cursor_view_format_as_unit (unit, buf, sizeof (buf), y, yres);
+      gtk_label_set_text (GTK_LABEL (view->priv->unit_y_label), buf);
+      gimp_cursor_view_set_label_italic (view->priv->unit_y_label, ! in_image);
+
+      int_x = (gint) floor (x);
+      int_y = (gint) floor (y);
+
+      if (gimp_image_pick_color (image, NULL,
+                                 int_x, int_y,
+                                 view->priv->shell->show_all,
+                                 view->priv->sample_merged,
+                                 FALSE, 0.0,
+                                 &sample_format, pixel, &color))
+        {
+          gimp_color_frame_set_color (GIMP_COLOR_FRAME (view->priv->color_frame_1),
+                                      FALSE, sample_format, pixel, &color,
+                                      int_x, int_y);
+          gimp_color_frame_set_color (GIMP_COLOR_FRAME (view->priv->color_frame_2),
+                                      FALSE, sample_format, pixel, &color,
+                                      int_x, int_y);
+        }
+      else
+        {
+          gimp_color_frame_set_invalid (GIMP_COLOR_FRAME (view->priv->color_frame_1));
+          gimp_color_frame_set_invalid (GIMP_COLOR_FRAME (view->priv->color_frame_2));
+        }
+
+      /* Show the selection info from the image under the cursor if any */
+      gimp_cursor_view_update_selection_info (view,
+                                              image,
+                                              view->priv->cursor_unit);
+
+      g_clear_object (&view->priv->cursor_image);
+    }
+  else
+    {
+      gtk_label_set_text (GTK_LABEL (view->priv->pixel_x_label), _("n/a"));
+      gtk_label_set_text (GTK_LABEL (view->priv->pixel_y_label), _("n/a"));
+      gtk_label_set_text (GTK_LABEL (view->priv->unit_x_label),  _("n/a"));
+      gtk_label_set_text (GTK_LABEL (view->priv->unit_y_label),  _("n/a"));
+
+      gimp_color_frame_set_invalid (GIMP_COLOR_FRAME (view->priv->color_frame_1));
+      gimp_color_frame_set_invalid (GIMP_COLOR_FRAME (view->priv->color_frame_2));
+
+      /* Start showing selection info from the active image again */
+      gimp_cursor_view_update_selection_info (view,
+                                              view->priv->image,
+                                              view->priv->unit);
+    }
+
+  view->priv->cursor_idle_id = 0;
+
+  return G_SOURCE_REMOVE;
+}
+
+
+/*  public functions  */
+
+GtkWidget *
+gimp_cursor_view_new (GimpMenuFactory *menu_factory)
+{
+  g_return_val_if_fail (GIMP_IS_MENU_FACTORY (menu_factory), NULL);
+
+  return g_object_new (GIMP_TYPE_CURSOR_VIEW,
+                       "menu-factory",    menu_factory,
+                       "menu-identifier", "<CursorInfo>",
+                       "ui-path",         "/cursor-info-popup",
+                       NULL);
+}
+
+void
+gimp_cursor_view_set_sample_merged (GimpCursorView *view,
+                                    gboolean        sample_merged)
+{
+  g_return_if_fail (GIMP_IS_CURSOR_VIEW (view));
+
+  sample_merged = sample_merged ? TRUE : FALSE;
+
+  if (view->priv->sample_merged != sample_merged)
+    {
+      view->priv->sample_merged = sample_merged;
+
+      g_object_notify (G_OBJECT (view), "sample-merged");
+    }
+}
+
+gboolean
+gimp_cursor_view_get_sample_merged (GimpCursorView *view)
+{
+  g_return_val_if_fail (GIMP_IS_CURSOR_VIEW (view), FALSE);
+
+  return view->priv->sample_merged;
+}
+
+void
+gimp_cursor_view_update_cursor (GimpCursorView   *view,
+                                GimpImage        *image,
+                                GimpUnit          shell_unit,
+                                gdouble           x,
+                                gdouble           y)
+{
+  g_return_if_fail (GIMP_IS_CURSOR_VIEW (view));
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+
+  g_clear_object (&view->priv->cursor_image);
+
+  view->priv->cursor_image = g_object_ref (image);
+  view->priv->cursor_unit  = shell_unit;
+  view->priv->cursor_x     = x;
+  view->priv->cursor_y     = y;
+
+  if (view->priv->cursor_idle_id == 0)
+    {
+      view->priv->cursor_idle_id =
+        g_idle_add ((GSourceFunc) gimp_cursor_view_cursor_idle, view);
+    }
+}
+
+void
+gimp_cursor_view_clear_cursor (GimpCursorView *view)
+{
+  g_return_if_fail (GIMP_IS_CURSOR_VIEW (view));
+
+  g_clear_object (&view->priv->cursor_image);
+
+  if (view->priv->cursor_idle_id == 0)
+    {
+      view->priv->cursor_idle_id =
+        g_idle_add ((GSourceFunc) gimp_cursor_view_cursor_idle, view);
+    }
+}
diff --git a/app/display/gimpcursorview.h b/app/display/gimpcursorview.h
new file mode 100644
index 0000000..f538041
--- /dev/null
+++ b/app/display/gimpcursorview.h
@@ -0,0 +1,68 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcursorview.h
+ * Copyright (C) 2005-2016 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CURSOR_VIEW_H__
+#define __GIMP_CURSOR_VIEW_H__
+
+
+#include "widgets/gimpeditor.h"
+
+
+#define GIMP_TYPE_CURSOR_VIEW            (gimp_cursor_view_get_type ())
+#define GIMP_CURSOR_VIEW(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CURSOR_VIEW, GimpCursorView))
+#define GIMP_CURSOR_VIEW_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CURSOR_VIEW, GimpCursorViewClass))
+#define GIMP_IS_CURSOR_VIEW(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CURSOR_VIEW))
+#define GIMP_IS_CURSOR_VIEW_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CURSOR_VIEW))
+#define GIMP_CURSOR_VIEW_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CURSOR_VIEW, GimpCursorViewClass))
+
+
+typedef struct _GimpCursorViewClass   GimpCursorViewClass;
+typedef struct _GimpCursorViewPrivate GimpCursorViewPrivate;
+
+struct _GimpCursorView
+{
+  GimpEditor             parent_instance;
+
+  GimpCursorViewPrivate *priv;
+};
+
+struct _GimpCursorViewClass
+{
+  GimpEditorClass  parent_class;
+};
+
+
+GType       gimp_cursor_view_get_type          (void) G_GNUC_CONST;
+
+GtkWidget * gimp_cursor_view_new               (GimpMenuFactory *menu_factory);
+
+void        gimp_cursor_view_set_sample_merged (GimpCursorView  *view,
+                                                gboolean         sample_merged);
+gboolean    gimp_cursor_view_get_sample_merged (GimpCursorView  *view);
+
+void        gimp_cursor_view_update_cursor     (GimpCursorView  *view,
+                                                GimpImage       *image,
+                                                GimpUnit         shell_unit,
+                                                gdouble          x,
+                                                gdouble          y);
+void        gimp_cursor_view_clear_cursor      (GimpCursorView  *view);
+
+
+#endif /* __GIMP_CURSOR_VIEW_H__ */
diff --git a/app/display/gimpdisplay-foreach.c b/app/display/gimpdisplay-foreach.c
new file mode 100644
index 0000000..440113e
--- /dev/null
+++ b/app/display/gimpdisplay-foreach.c
@@ -0,0 +1,308 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontainer.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimplist.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplay-foreach.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-cursor.h"
+
+
+gboolean
+gimp_displays_dirty (Gimp *gimp)
+{
+  GList *list;
+
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), FALSE);
+
+  for (list = gimp_get_display_iter (gimp);
+       list;
+       list = g_list_next (list))
+    {
+      GimpDisplay *display = list->data;
+      GimpImage   *image   = gimp_display_get_image (display);
+
+      if (image && gimp_image_is_dirty (image))
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_displays_image_dirty_callback (GimpImage     *image,
+                                    GimpDirtyMask  dirty_mask,
+                                    GimpContainer *container)
+{
+  if (gimp_image_is_dirty (image)              &&
+      gimp_image_get_display_count (image) > 0 &&
+      ! gimp_container_have (container, GIMP_OBJECT (image)))
+    gimp_container_add (container, GIMP_OBJECT (image));
+}
+
+static void
+gimp_displays_dirty_images_disconnect (GimpContainer *dirty_container,
+                                       GimpContainer *global_container)
+{
+  GQuark handler;
+
+  handler = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (dirty_container),
+                                                "clean-handler"));
+  gimp_container_remove_handler (global_container, handler);
+
+  handler = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (dirty_container),
+                                                "dirty-handler"));
+  gimp_container_remove_handler (global_container, handler);
+}
+
+static void
+gimp_displays_image_clean_callback (GimpImage     *image,
+                                    GimpDirtyMask  dirty_mask,
+                                    GimpContainer *container)
+{
+  if (! gimp_image_is_dirty (image))
+    gimp_container_remove (container, GIMP_OBJECT (image));
+}
+
+GimpContainer *
+gimp_displays_get_dirty_images (Gimp *gimp)
+{
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), NULL);
+
+  if (gimp_displays_dirty (gimp))
+    {
+      GimpContainer *container = gimp_list_new_weak (GIMP_TYPE_IMAGE, FALSE);
+      GList         *list;
+      GQuark         handler;
+
+      handler =
+        gimp_container_add_handler (gimp->images, "clean",
+                                    G_CALLBACK (gimp_displays_image_dirty_callback),
+                                    container);
+      g_object_set_data (G_OBJECT (container), "clean-handler",
+                         GINT_TO_POINTER (handler));
+
+      handler =
+        gimp_container_add_handler (gimp->images, "dirty",
+                                    G_CALLBACK (gimp_displays_image_dirty_callback),
+                                    container);
+      g_object_set_data (G_OBJECT (container), "dirty-handler",
+                         GINT_TO_POINTER (handler));
+
+      g_signal_connect_object (container, "disconnect",
+                               G_CALLBACK (gimp_displays_dirty_images_disconnect),
+                               G_OBJECT (gimp->images), 0);
+
+      gimp_container_add_handler (container, "clean",
+                                  G_CALLBACK (gimp_displays_image_clean_callback),
+                                  container);
+      gimp_container_add_handler (container, "dirty",
+                                  G_CALLBACK (gimp_displays_image_clean_callback),
+                                  container);
+
+      for (list = gimp_get_image_iter (gimp);
+           list;
+           list = g_list_next (list))
+        {
+          GimpImage *image = list->data;
+
+          if (gimp_image_is_dirty (image) &&
+              gimp_image_get_display_count (image) > 0)
+            gimp_container_add (container, GIMP_OBJECT (image));
+        }
+
+      return container;
+    }
+
+  return NULL;
+}
+
+/**
+ * gimp_displays_delete:
+ * @gimp:
+ *
+ * Calls gimp_display_delete() an all displays in the display list.
+ * This closes all displays, including the first one which is usually
+ * kept open.
+ */
+void
+gimp_displays_delete (Gimp *gimp)
+{
+  /*  this removes the GimpDisplay from the list, so do a while loop
+   *  "around" the first element to get them all
+   */
+  while (! gimp_container_is_empty (gimp->displays))
+    {
+      GimpDisplay *display = gimp_get_display_iter (gimp)->data;
+
+      gimp_display_delete (display);
+    }
+}
+
+/**
+ * gimp_displays_close:
+ * @gimp:
+ *
+ * Calls gimp_display_close() an all displays in the display list. The
+ * first display will remain open without an image.
+ */
+void
+gimp_displays_close (Gimp *gimp)
+{
+  GList *list;
+  GList *iter;
+
+  g_return_if_fail (GIMP_IS_GIMP (gimp));
+
+  list = g_list_copy (gimp_get_display_iter (gimp));
+
+  for (iter = list; iter; iter = g_list_next (iter))
+    {
+      GimpDisplay *display = iter->data;
+
+      gimp_display_close (display);
+    }
+
+  g_list_free (list);
+}
+
+void
+gimp_displays_reconnect (Gimp      *gimp,
+                         GimpImage *old,
+                         GimpImage *new)
+{
+  GList *contexts = NULL;
+  GList *list;
+
+  g_return_if_fail (GIMP_IS_GIMP (gimp));
+  g_return_if_fail (GIMP_IS_IMAGE (old));
+  g_return_if_fail (GIMP_IS_IMAGE (new));
+
+  /*  check which contexts refer to old_image  */
+  for (list = gimp->context_list; list; list = g_list_next (list))
+    {
+      GimpContext *context = list->data;
+
+      if (gimp_context_get_image (context) == old)
+        contexts = g_list_prepend (contexts, list->data);
+    }
+
+  /*  set the new_image on the remembered contexts (in reverse order,
+   *  since older contexts are usually the parents of newer
+   *  ones). Also, update the contexts before the displays, or we
+   *  might run into menu update functions that would see an
+   *  inconsistent state (display = new, context = old), and thus
+   *  inadvertently call actions as if the user had selected a menu
+   *  item.
+   */
+  g_list_foreach (contexts, (GFunc) gimp_context_set_image, new);
+  g_list_free (contexts);
+
+  for (list = gimp_get_display_iter (gimp);
+       list;
+       list = g_list_next (list))
+    {
+      GimpDisplay *display = list->data;
+
+      if (gimp_display_get_image (display) == old)
+        gimp_display_set_image (display, new);
+    }
+}
+
+gint
+gimp_displays_get_num_visible (Gimp *gimp)
+{
+  GList *list;
+  gint   visible = 0;
+
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), 0);
+
+  for (list = gimp_get_display_iter (gimp);
+       list;
+       list = g_list_next (list))
+    {
+      GimpDisplay      *display = list->data;
+      GimpDisplayShell *shell   = gimp_display_get_shell (display);
+
+      if (gtk_widget_is_drawable (GTK_WIDGET (shell)))
+        {
+          GtkWidget *toplevel = gtk_widget_get_toplevel (GTK_WIDGET (shell));
+
+          if (GTK_IS_WINDOW (toplevel))
+            {
+              GdkWindow      *window = gtk_widget_get_window (toplevel);
+              GdkWindowState  state  = gdk_window_get_state (window);
+
+              if ((state & (GDK_WINDOW_STATE_WITHDRAWN |
+                            GDK_WINDOW_STATE_ICONIFIED)) == 0)
+                {
+                  visible++;
+                }
+            }
+        }
+    }
+
+  return visible;
+}
+
+void
+gimp_displays_set_busy (Gimp *gimp)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_IS_GIMP (gimp));
+
+  for (list = gimp_get_display_iter (gimp);
+       list;
+       list = g_list_next (list))
+    {
+      GimpDisplayShell *shell =
+        gimp_display_get_shell (GIMP_DISPLAY (list->data));
+
+      gimp_display_shell_set_override_cursor (shell, (GimpCursorType) GDK_WATCH);
+    }
+}
+
+void
+gimp_displays_unset_busy (Gimp *gimp)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_IS_GIMP (gimp));
+
+  for (list = gimp_get_display_iter (gimp);
+       list;
+       list = g_list_next (list))
+    {
+      GimpDisplayShell *shell =
+        gimp_display_get_shell (GIMP_DISPLAY (list->data));
+
+      gimp_display_shell_unset_override_cursor (shell);
+    }
+}
diff --git a/app/display/gimpdisplay-foreach.h b/app/display/gimpdisplay-foreach.h
new file mode 100644
index 0000000..09fae7c
--- /dev/null
+++ b/app/display/gimpdisplay-foreach.h
@@ -0,0 +1,36 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_FOREACH_H__
+#define __GIMP_DISPLAY_FOREACH_H__
+
+
+gboolean        gimp_displays_dirty            (Gimp      *gimp);
+GimpContainer * gimp_displays_get_dirty_images (Gimp      *gimp);
+void            gimp_displays_delete           (Gimp      *gimp);
+void            gimp_displays_close            (Gimp      *gimp);
+void            gimp_displays_reconnect        (Gimp      *gimp,
+                                                GimpImage *old,
+                                                GimpImage *new);
+
+gint            gimp_displays_get_num_visible  (Gimp      *gimp);
+
+void            gimp_displays_set_busy         (Gimp      *gimp);
+void            gimp_displays_unset_busy       (Gimp      *gimp);
+
+
+#endif /*  __GIMP_DISPLAY_FOREACH_H__  */
diff --git a/app/display/gimpdisplay-handlers.c b/app/display/gimpdisplay-handlers.c
new file mode 100644
index 0000000..94cb863
--- /dev/null
+++ b/app/display/gimpdisplay-handlers.c
@@ -0,0 +1,128 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimpimage.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplay-handlers.h"
+
+
+/*  local function prototypes  */
+
+static void   gimp_display_update_handler         (GimpProjection *projection,
+                                                   gboolean        now,
+                                                   gint            x,
+                                                   gint            y,
+                                                   gint            w,
+                                                   gint            h,
+                                                   GimpDisplay    *display);
+
+static void   gimp_display_bounds_changed_handler (GimpImage      *image,
+                                                   gint            old_x,
+                                                   gint            old_y,
+                                                   GimpDisplay    *display);
+static void   gimp_display_flush_handler          (GimpImage      *image,
+                                                   gboolean        invalidate_preview,
+                                                   GimpDisplay    *display);
+
+
+/*  public functions  */
+
+void
+gimp_display_connect (GimpDisplay *display)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  image = gimp_display_get_image (display);
+
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+
+  g_signal_connect (gimp_image_get_projection (image), "update",
+                    G_CALLBACK (gimp_display_update_handler),
+                    display);
+
+  g_signal_connect (image, "bounds-changed",
+                    G_CALLBACK (gimp_display_bounds_changed_handler),
+                    display);
+  g_signal_connect (image, "flush",
+                    G_CALLBACK (gimp_display_flush_handler),
+                    display);
+}
+
+void
+gimp_display_disconnect (GimpDisplay *display)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  image = gimp_display_get_image (display);
+
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_flush_handler,
+                                        display);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_bounds_changed_handler,
+                                        display);
+
+  g_signal_handlers_disconnect_by_func (gimp_image_get_projection (image),
+                                        gimp_display_update_handler,
+                                        display);
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_update_handler (GimpProjection *projection,
+                             gboolean        now,
+                             gint            x,
+                             gint            y,
+                             gint            w,
+                             gint            h,
+                             GimpDisplay    *display)
+{
+  gimp_display_update_area (display, now, x, y, w, h);
+}
+
+static void
+gimp_display_bounds_changed_handler (GimpImage   *image,
+                                     gint         old_x,
+                                     gint         old_y,
+                                     GimpDisplay *display)
+{
+  gimp_display_update_bounding_box (display);
+}
+
+static void
+gimp_display_flush_handler (GimpImage   *image,
+                            gboolean     invalidate_preview,
+                            GimpDisplay *display)
+{
+  gimp_display_flush (display);
+}
diff --git a/app/display/gimpdisplay-handlers.h b/app/display/gimpdisplay-handlers.h
new file mode 100644
index 0000000..34c547c
--- /dev/null
+++ b/app/display/gimpdisplay-handlers.h
@@ -0,0 +1,26 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_HANDLERS_H__
+#define __GIMP_DISPLAY_HANDLERS_H__
+
+
+void   gimp_display_connect    (GimpDisplay *display);
+void   gimp_display_disconnect (GimpDisplay *display);
+
+
+#endif /*  __GIMP_DISPLAY_HANDLERS_H__  */
diff --git a/app/display/gimpdisplay.c b/app/display/gimpdisplay.c
new file mode 100644
index 0000000..bf8a238
--- /dev/null
+++ b/app/display/gimpdisplay.c
@@ -0,0 +1,985 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+#include "tools/tools-types.h"
+
+#include "config/gimpguiconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontainer.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimpprogress.h"
+
+#include "widgets/gimpdialogfactory.h"
+
+#include "tools/gimptool.h"
+#include "tools/tool_manager.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplay-handlers.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-handlers.h"
+#include "gimpdisplayshell-icon.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-scrollbars.h"
+#include "gimpdisplayshell-title.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpimagewindow.h"
+
+#include "gimp-intl.h"
+
+
+#define FLUSH_NOW_INTERVAL      (G_TIME_SPAN_SECOND / 60)
+
+#define PAINT_AREA_CHUNK_WIDTH  32
+#define PAINT_AREA_CHUNK_HEIGHT 32
+
+
+enum
+{
+  PROP_0,
+  PROP_ID,
+  PROP_GIMP,
+  PROP_IMAGE,
+  PROP_SHELL
+};
+
+
+typedef struct _GimpDisplayPrivate GimpDisplayPrivate;
+
+struct _GimpDisplayPrivate
+{
+  gint            ID;           /*  unique identifier for this display  */
+
+  GimpImage      *image;        /*  pointer to the associated image     */
+  gint            instance;     /*  the instance # of this display as
+                                 *  taken from the image at creation    */
+
+  GeglRectangle   bounding_box;
+
+  GtkWidget      *shell;
+  cairo_region_t *update_region;
+
+  guint64         last_flush_now;
+};
+
+#define GIMP_DISPLAY_GET_PRIVATE(display) \
+        ((GimpDisplayPrivate *) gimp_display_get_instance_private ((GimpDisplay *) (display)))
+
+
+/*  local function prototypes  */
+
+static void     gimp_display_progress_iface_init  (GimpProgressInterface *iface);
+
+static void     gimp_display_set_property           (GObject             *object,
+                                                     guint                property_id,
+                                                     const GValue        *value,
+                                                     GParamSpec          *pspec);
+static void     gimp_display_get_property           (GObject             *object,
+                                                     guint                property_id,
+                                                     GValue              *value,
+                                                     GParamSpec          *pspec);
+
+static GimpProgress * gimp_display_progress_start   (GimpProgress        *progress,
+                                                     gboolean             cancellable,
+                                                     const gchar         *message);
+static void     gimp_display_progress_end           (GimpProgress        *progress);
+static gboolean gimp_display_progress_is_active     (GimpProgress        *progress);
+static void     gimp_display_progress_set_text      (GimpProgress        *progress,
+                                                     const gchar         *message);
+static void     gimp_display_progress_set_value     (GimpProgress        *progress,
+                                                     gdouble              percentage);
+static gdouble  gimp_display_progress_get_value     (GimpProgress        *progress);
+static void     gimp_display_progress_pulse         (GimpProgress        *progress);
+static guint32  gimp_display_progress_get_window_id (GimpProgress        *progress);
+static gboolean gimp_display_progress_message       (GimpProgress        *progress,
+                                                     Gimp                *gimp,
+                                                     GimpMessageSeverity  severity,
+                                                     const gchar         *domain,
+                                                     const gchar         *message);
+static void     gimp_display_progress_canceled      (GimpProgress        *progress,
+                                                     GimpDisplay         *display);
+
+static void     gimp_display_flush_whenever         (GimpDisplay         *display,
+                                                     gboolean             now);
+static void     gimp_display_paint_area             (GimpDisplay         *display,
+                                                     gint                 x,
+                                                     gint                 y,
+                                                     gint                 w,
+                                                     gint                 h);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpDisplay, gimp_display, GIMP_TYPE_OBJECT,
+                         G_ADD_PRIVATE (GimpDisplay)
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_PROGRESS,
+                                                gimp_display_progress_iface_init))
+
+#define parent_class gimp_display_parent_class
+
+
+static void
+gimp_display_class_init (GimpDisplayClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->set_property = gimp_display_set_property;
+  object_class->get_property = gimp_display_get_property;
+
+  g_object_class_install_property (object_class, PROP_ID,
+                                   g_param_spec_int ("id",
+                                                     NULL, NULL,
+                                                     0, G_MAXINT, 0,
+                                                     GIMP_PARAM_READABLE));
+
+  g_object_class_install_property (object_class, PROP_GIMP,
+                                   g_param_spec_object ("gimp",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_GIMP,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_IMAGE,
+                                   g_param_spec_object ("image",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_IMAGE,
+                                                        GIMP_PARAM_READABLE));
+
+  g_object_class_install_property (object_class, PROP_SHELL,
+                                   g_param_spec_object ("shell",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_DISPLAY_SHELL,
+                                                        GIMP_PARAM_READABLE));
+}
+
+static void
+gimp_display_init (GimpDisplay *display)
+{
+}
+
+static void
+gimp_display_progress_iface_init (GimpProgressInterface *iface)
+{
+  iface->start         = gimp_display_progress_start;
+  iface->end           = gimp_display_progress_end;
+  iface->is_active     = gimp_display_progress_is_active;
+  iface->set_text      = gimp_display_progress_set_text;
+  iface->set_value     = gimp_display_progress_set_value;
+  iface->get_value     = gimp_display_progress_get_value;
+  iface->pulse         = gimp_display_progress_pulse;
+  iface->get_window_id = gimp_display_progress_get_window_id;
+  iface->message       = gimp_display_progress_message;
+}
+
+static void
+gimp_display_set_property (GObject      *object,
+                           guint         property_id,
+                           const GValue *value,
+                           GParamSpec   *pspec)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (object);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  switch (property_id)
+    {
+    case PROP_GIMP:
+      {
+        gint ID;
+
+        display->gimp = g_value_get_object (value); /* don't ref the gimp */
+        display->config = GIMP_DISPLAY_CONFIG (display->gimp->config);
+
+        do
+          {
+            ID = display->gimp->next_display_ID++;
+
+            if (display->gimp->next_display_ID == G_MAXINT)
+              display->gimp->next_display_ID = 1;
+          }
+        while (gimp_display_get_by_ID (display->gimp, ID));
+
+        private->ID = ID;
+      }
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_display_get_property (GObject    *object,
+                           guint       property_id,
+                           GValue     *value,
+                           GParamSpec *pspec)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (object);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  switch (property_id)
+    {
+    case PROP_ID:
+      g_value_set_int (value, private->ID);
+      break;
+
+    case PROP_GIMP:
+      g_value_set_object (value, display->gimp);
+      break;
+
+    case PROP_IMAGE:
+      g_value_set_object (value, private->image);
+      break;
+
+    case PROP_SHELL:
+      g_value_set_object (value, private->shell);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static GimpProgress *
+gimp_display_progress_start (GimpProgress *progress,
+                             gboolean      cancellable,
+                             const gchar  *message)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    return gimp_progress_start (GIMP_PROGRESS (private->shell), cancellable,
+                                "%s", message);
+
+  return NULL;
+}
+
+static void
+gimp_display_progress_end (GimpProgress *progress)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    gimp_progress_end (GIMP_PROGRESS (private->shell));
+}
+
+static gboolean
+gimp_display_progress_is_active (GimpProgress *progress)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    return gimp_progress_is_active (GIMP_PROGRESS (private->shell));
+
+  return FALSE;
+}
+
+static void
+gimp_display_progress_set_text (GimpProgress *progress,
+                                const gchar  *message)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    gimp_progress_set_text_literal (GIMP_PROGRESS (private->shell), message);
+}
+
+static void
+gimp_display_progress_set_value (GimpProgress *progress,
+                                 gdouble       percentage)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    gimp_progress_set_value (GIMP_PROGRESS (private->shell), percentage);
+}
+
+static gdouble
+gimp_display_progress_get_value (GimpProgress *progress)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    return gimp_progress_get_value (GIMP_PROGRESS (private->shell));
+
+  return 0.0;
+}
+
+static void
+gimp_display_progress_pulse (GimpProgress *progress)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    gimp_progress_pulse (GIMP_PROGRESS (private->shell));
+}
+
+static guint32
+gimp_display_progress_get_window_id (GimpProgress *progress)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    return gimp_progress_get_window_id (GIMP_PROGRESS (private->shell));
+
+  return 0;
+}
+
+static gboolean
+gimp_display_progress_message (GimpProgress        *progress,
+                               Gimp                *gimp,
+                               GimpMessageSeverity  severity,
+                               const gchar         *domain,
+                               const gchar         *message)
+{
+  GimpDisplay        *display = GIMP_DISPLAY (progress);
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->shell)
+    return gimp_progress_message (GIMP_PROGRESS (private->shell), gimp,
+                                  severity, domain, message);
+
+  return FALSE;
+}
+
+static void
+gimp_display_progress_canceled (GimpProgress *progress,
+                                GimpDisplay  *display)
+{
+  gimp_progress_cancel (GIMP_PROGRESS (display));
+}
+
+
+/*  public functions  */
+
+GimpDisplay *
+gimp_display_new (Gimp              *gimp,
+                  GimpImage         *image,
+                  GimpUnit           unit,
+                  gdouble            scale,
+                  GimpUIManager     *popup_manager,
+                  GimpDialogFactory *dialog_factory,
+                  GdkScreen         *screen,
+                  gint               monitor)
+{
+  GimpDisplay        *display;
+  GimpDisplayPrivate *private;
+  GimpImageWindow    *window = NULL;
+  GimpDisplayShell   *shell;
+
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), NULL);
+  g_return_val_if_fail (image == NULL || GIMP_IS_IMAGE (image), NULL);
+  g_return_val_if_fail (GDK_IS_SCREEN (screen), NULL);
+
+  /*  If there isn't an interface, never create a display  */
+  if (gimp->no_interface)
+    return NULL;
+
+  display = g_object_new (GIMP_TYPE_DISPLAY,
+                          "gimp", gimp,
+                          NULL);
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  /*  refs the image  */
+  if (image)
+    gimp_display_set_image (display, image);
+
+  /*  get an image window  */
+  if (GIMP_GUI_CONFIG (display->config)->single_window_mode)
+    {
+      GimpDisplay *active_display;
+
+      active_display = gimp_context_get_display (gimp_get_user_context (gimp));
+
+      if (! active_display)
+        {
+          active_display =
+            GIMP_DISPLAY (gimp_container_get_first_child (gimp->displays));
+        }
+
+      if (active_display)
+        {
+          GimpDisplayShell *shell = gimp_display_get_shell (active_display);
+
+          window = gimp_display_shell_get_window (shell);
+        }
+    }
+
+  if (! window)
+    {
+      window = gimp_image_window_new (gimp,
+                                      private->image,
+                                      dialog_factory,
+                                      screen,
+                                      monitor);
+    }
+
+  /*  create the shell for the image  */
+  private->shell = gimp_display_shell_new (display, unit, scale,
+                                           popup_manager,
+                                           screen,
+                                           monitor);
+
+  shell = gimp_display_get_shell (display);
+
+  gimp_display_update_bounding_box (display);
+
+  gimp_image_window_add_shell (window, shell);
+  gimp_display_shell_present (shell);
+
+  /* make sure the docks are visible, in case all other image windows
+   * are iconified, see bug #686544.
+   */
+  gimp_dialog_factory_show_with_display (dialog_factory);
+
+  g_signal_connect (gimp_display_shell_get_statusbar (shell), "cancel",
+                    G_CALLBACK (gimp_display_progress_canceled),
+                    display);
+
+  /* add the display to the list */
+  gimp_container_add (gimp->displays, GIMP_OBJECT (display));
+
+  return display;
+}
+
+/**
+ * gimp_display_delete:
+ * @display:
+ *
+ * Closes the display and removes it from the display list. You should
+ * not call this function directly, use gimp_display_close() instead.
+ */
+void
+gimp_display_delete (GimpDisplay *display)
+{
+  GimpDisplayPrivate *private;
+  GimpTool           *active_tool;
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  /* remove the display from the list */
+  gimp_container_remove (display->gimp->displays, GIMP_OBJECT (display));
+
+  /*  unrefs the image  */
+  gimp_display_set_image (display, NULL);
+
+  active_tool = tool_manager_get_active (display->gimp);
+
+  if (active_tool && active_tool->focus_display == display)
+    tool_manager_focus_display_active (display->gimp, NULL);
+
+  if (private->shell)
+    {
+      GimpDisplayShell *shell  = gimp_display_get_shell (display);
+      GimpImageWindow  *window = gimp_display_shell_get_window (shell);
+
+      /*  set private->shell to NULL *before* destroying the shell.
+       *  all callbacks in gimpdisplayshell-callbacks.c will check
+       *  this pointer and do nothing if the shell is in destruction.
+       */
+      private->shell = NULL;
+
+      if (window)
+        {
+          if (gimp_image_window_get_n_shells (window) > 1)
+            {
+              g_object_ref (shell);
+
+              gimp_image_window_remove_shell (window, shell);
+              gtk_widget_destroy (GTK_WIDGET (shell));
+
+              g_object_unref (shell);
+            }
+          else
+            {
+              gimp_image_window_destroy (window);
+            }
+        }
+      else
+        {
+          g_object_unref (shell);
+        }
+    }
+
+  g_object_unref (display);
+}
+
+/**
+ * gimp_display_close:
+ * @display:
+ *
+ * Closes the display. If this is the last display, it will remain
+ * open, but without an image.
+ */
+void
+gimp_display_close (GimpDisplay *display)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  if (gimp_container_get_n_children (display->gimp->displays) > 1)
+    {
+      gimp_display_delete (display);
+    }
+  else
+    {
+      gimp_display_empty (display);
+    }
+}
+
+gint
+gimp_display_get_ID (GimpDisplay *display)
+{
+  GimpDisplayPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY (display), -1);
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  return private->ID;
+}
+
+GimpDisplay *
+gimp_display_get_by_ID (Gimp *gimp,
+                        gint  ID)
+{
+  GList *list;
+
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), NULL);
+
+  for (list = gimp_get_display_iter (gimp);
+       list;
+       list = g_list_next (list))
+    {
+      GimpDisplay *display = list->data;
+
+      if (gimp_display_get_ID (display) == ID)
+        return display;
+    }
+
+  return NULL;
+}
+
+/**
+ * gimp_display_get_action_name:
+ * @display:
+ *
+ * Returns: The action name for the given display. The action name
+ * depends on the display ID. The result must be freed with g_free().
+ **/
+gchar *
+gimp_display_get_action_name (GimpDisplay *display)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY (display), NULL);
+
+  return g_strdup_printf ("windows-display-%04d",
+                          gimp_display_get_ID (display));
+}
+
+Gimp *
+gimp_display_get_gimp (GimpDisplay *display)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY (display), NULL);
+
+  return display->gimp;
+}
+
+GimpImage *
+gimp_display_get_image (GimpDisplay *display)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY (display), NULL);
+
+  return GIMP_DISPLAY_GET_PRIVATE (display)->image;
+}
+
+void
+gimp_display_set_image (GimpDisplay *display,
+                        GimpImage   *image)
+{
+  GimpDisplayPrivate *private;
+  GimpImage          *old_image = NULL;
+  GimpDisplayShell   *shell;
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+  g_return_if_fail (image == NULL || GIMP_IS_IMAGE (image));
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  shell = gimp_display_get_shell (display);
+
+  if (private->image)
+    {
+      /*  stop any active tool  */
+      tool_manager_control_active (display->gimp, GIMP_TOOL_ACTION_HALT,
+                                   display);
+
+      gimp_display_shell_disconnect (shell);
+
+      gimp_display_disconnect (display);
+
+      g_clear_pointer (&private->update_region, cairo_region_destroy);
+
+      gimp_image_dec_display_count (private->image);
+
+      /*  set private->image before unrefing because there may be code
+       *  that listens for image removals and then iterates the
+       *  display list to find a valid display.
+       */
+      old_image = private->image;
+
+#if 0
+      g_print ("%s: image->ref_count before unrefing: %d\n",
+               G_STRFUNC, G_OBJECT (old_image)->ref_count);
+#endif
+    }
+
+  private->image = image;
+
+  if (image)
+    {
+#if 0
+      g_print ("%s: image->ref_count before refing: %d\n",
+               G_STRFUNC, G_OBJECT (image)->ref_count);
+#endif
+
+      g_object_ref (image);
+
+      private->instance = gimp_image_get_instance_count (image);
+      gimp_image_inc_instance_count (image);
+
+      gimp_image_inc_display_count (image);
+
+      gimp_display_connect (display);
+
+      if (shell)
+        gimp_display_shell_connect (shell);
+    }
+
+  if (old_image)
+    g_object_unref (old_image);
+
+  gimp_display_update_bounding_box (display);
+
+  if (shell)
+    {
+      if (image)
+        {
+          gimp_display_shell_reconnect (shell);
+        }
+      else
+        {
+          gimp_display_shell_title_update (shell);
+          gimp_display_shell_icon_update (shell);
+        }
+    }
+
+  if (old_image != image)
+    g_object_notify (G_OBJECT (display), "image");
+}
+
+gint
+gimp_display_get_instance (GimpDisplay *display)
+{
+  GimpDisplayPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY (display), 0);
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  return private->instance;
+}
+
+GimpDisplayShell *
+gimp_display_get_shell (GimpDisplay *display)
+{
+  GimpDisplayPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY (display), NULL);
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  return GIMP_DISPLAY_SHELL (private->shell);
+}
+
+void
+gimp_display_empty (GimpDisplay *display)
+{
+  GimpDisplayPrivate *private;
+  GList              *iter;
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  g_return_if_fail (GIMP_IS_IMAGE (private->image));
+
+  for (iter = display->gimp->context_list; iter; iter = g_list_next (iter))
+    {
+      GimpContext *context = iter->data;
+
+      if (gimp_context_get_display (context) == display)
+        gimp_context_set_image (context, NULL);
+    }
+
+  gimp_display_set_image (display, NULL);
+
+  gimp_display_shell_empty (gimp_display_get_shell (display));
+}
+
+void
+gimp_display_fill (GimpDisplay *display,
+                   GimpImage   *image,
+                   GimpUnit     unit,
+                   gdouble      scale)
+{
+  GimpDisplayPrivate *private;
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  g_return_if_fail (private->image == NULL);
+
+  gimp_display_set_image (display, image);
+
+  gimp_display_shell_fill (gimp_display_get_shell (display),
+                           image, unit, scale);
+}
+
+void
+gimp_display_update_bounding_box (GimpDisplay *display)
+{
+  GimpDisplayPrivate *private;
+  GimpDisplayShell   *shell;
+  GeglRectangle       bounding_box = {};
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+  shell   = gimp_display_get_shell (display);
+
+  if (shell)
+    {
+      bounding_box = gimp_display_shell_get_bounding_box (shell);
+
+      if (! gegl_rectangle_equal (&bounding_box, &private->bounding_box))
+        {
+          GeglRectangle diff_rects[4];
+          gint          n_diff_rects;
+          gint          i;
+
+          n_diff_rects = gegl_rectangle_subtract (diff_rects,
+                                                  &private->bounding_box,
+                                                  &bounding_box);
+
+          for (i = 0; i < n_diff_rects; i++)
+            {
+              gimp_display_paint_area (display,
+                                       diff_rects[i].x,     diff_rects[i].y,
+                                       diff_rects[i].width, diff_rects[i].height);
+            }
+
+          private->bounding_box = bounding_box;
+
+          gimp_display_shell_scroll_clamp_and_update (shell);
+          gimp_display_shell_scrollbars_update (shell);
+        }
+    }
+  else
+    {
+      private->bounding_box = bounding_box;
+    }
+}
+
+void
+gimp_display_update_area (GimpDisplay *display,
+                          gboolean     now,
+                          gint         x,
+                          gint         y,
+                          gint         w,
+                          gint         h)
+{
+  GimpDisplayPrivate *private;
+
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (now)
+    {
+      gimp_display_paint_area (display, x, y, w, h);
+    }
+  else
+    {
+      cairo_rectangle_int_t rect;
+      gint                  image_width;
+      gint                  image_height;
+
+      image_width  = gimp_image_get_width  (private->image);
+      image_height = gimp_image_get_height (private->image);
+
+      rect.x      = CLAMP (x,     0, image_width);
+      rect.y      = CLAMP (y,     0, image_height);
+      rect.width  = CLAMP (x + w, 0, image_width)  - rect.x;
+      rect.height = CLAMP (y + h, 0, image_height) - rect.y;
+
+      if (private->update_region)
+        cairo_region_union_rectangle (private->update_region, &rect);
+      else
+        private->update_region = cairo_region_create_rectangle (&rect);
+    }
+}
+
+void
+gimp_display_flush (GimpDisplay *display)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  /* FIXME: we can end up being called during shell construction if "show all"
+   * is enabled by default, in which case the shell's display pointer is still
+   * NULL
+   */
+  if (gimp_display_get_shell (display))
+    gimp_display_flush_whenever (display, FALSE);
+}
+
+void
+gimp_display_flush_now (GimpDisplay *display)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY (display));
+
+  gimp_display_flush_whenever (display, TRUE);
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_flush_whenever (GimpDisplay *display,
+                             gboolean     now)
+{
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+
+  if (private->update_region)
+    {
+      gint n_rects = cairo_region_num_rectangles (private->update_region);
+      gint i;
+
+      for (i = 0; i < n_rects; i++)
+        {
+          cairo_rectangle_int_t rect;
+
+          cairo_region_get_rectangle (private->update_region,
+                                      i, &rect);
+
+          gimp_display_paint_area (display,
+                                   rect.x,
+                                   rect.y,
+                                   rect.width,
+                                   rect.height);
+        }
+
+      g_clear_pointer (&private->update_region, cairo_region_destroy);
+    }
+
+  if (now)
+    {
+      guint64 now = g_get_monotonic_time ();
+
+      if ((now - private->last_flush_now) > FLUSH_NOW_INTERVAL)
+        {
+          gimp_display_shell_flush (gimp_display_get_shell (display), TRUE);
+
+          private->last_flush_now = now;
+        }
+    }
+  else
+    {
+      gimp_display_shell_flush (gimp_display_get_shell (display), now);
+    }
+}
+
+static void
+gimp_display_paint_area (GimpDisplay *display,
+                         gint         x,
+                         gint         y,
+                         gint         w,
+                         gint         h)
+{
+  GimpDisplayPrivate *private = GIMP_DISPLAY_GET_PRIVATE (display);
+  GimpDisplayShell   *shell   = gimp_display_get_shell (display);
+  GeglRectangle       rect;
+  gint                x1, y1, x2, y2;
+  gdouble             x1_f, y1_f, x2_f, y2_f;
+
+  if (! gegl_rectangle_intersect (&rect,
+                                  &private->bounding_box,
+                                  GEGL_RECTANGLE (x, y, w, h)))
+    {
+      return;
+    }
+
+  /*  display the area  */
+  gimp_display_shell_transform_bounds (shell,
+                                       rect.x,
+                                       rect.y,
+                                       rect.x + rect.width,
+                                       rect.y + rect.height,
+                                       &x1_f, &y1_f, &x2_f, &y2_f);
+
+  /*  make sure to expose a superset of the transformed sub-pixel expose
+   *  area, not a subset. bug #126942. --mitch
+   *
+   *  also accommodate for spill introduced by potential box filtering.
+   *  (bug #474509). --simon
+   */
+  x1 = floor (x1_f - 0.5);
+  y1 = floor (y1_f - 0.5);
+  x2 = ceil (x2_f + 0.5);
+  y2 = ceil (y2_f + 0.5);
+
+  /*  align transformed area to a coarse grid, to simplify the
+   *  invalidated area
+   */
+  x1 = floor ((gdouble) x1 / PAINT_AREA_CHUNK_WIDTH)  * PAINT_AREA_CHUNK_WIDTH;
+  y1 = floor ((gdouble) y1 / PAINT_AREA_CHUNK_HEIGHT) * PAINT_AREA_CHUNK_HEIGHT;
+  x2 = ceil  ((gdouble) x2 / PAINT_AREA_CHUNK_WIDTH)  * PAINT_AREA_CHUNK_WIDTH;
+  y2 = ceil  ((gdouble) y2 / PAINT_AREA_CHUNK_HEIGHT) * PAINT_AREA_CHUNK_HEIGHT;
+
+  gimp_display_shell_expose_area (shell, x1, y1, x2 - x1, y2 - y1);
+}
diff --git a/app/display/gimpdisplay.h b/app/display/gimpdisplay.h
new file mode 100644
index 0000000..7e676b0
--- /dev/null
+++ b/app/display/gimpdisplay.h
@@ -0,0 +1,99 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_H__
+#define __GIMP_DISPLAY_H__
+
+
+#include "core/gimpobject.h"
+
+
+#define GIMP_TYPE_DISPLAY            (gimp_display_get_type ())
+#define GIMP_DISPLAY(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_DISPLAY, GimpDisplay))
+#define GIMP_DISPLAY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_DISPLAY, GimpDisplayClass))
+#define GIMP_IS_DISPLAY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_DISPLAY))
+#define GIMP_IS_DISPLAY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_DISPLAY))
+#define GIMP_DISPLAY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_DISPLAY, GimpDisplayClass))
+
+
+typedef struct _GimpDisplayClass GimpDisplayClass;
+
+struct _GimpDisplay
+{
+  GimpObject         parent_instance;
+
+  Gimp              *gimp;
+  GimpDisplayConfig *config;
+
+};
+
+struct _GimpDisplayClass
+{
+  GimpObjectClass  parent_class;
+};
+
+
+GType              gimp_display_get_type        (void) G_GNUC_CONST;
+
+GimpDisplay      * gimp_display_new             (Gimp              *gimp,
+                                                 GimpImage         *image,
+                                                 GimpUnit           unit,
+                                                 gdouble            scale,
+                                                 GimpUIManager     *popup_manager,
+                                                 GimpDialogFactory *dialog_factory,
+                                                 GdkScreen         *screen,
+                                                 gint               monitor);
+void               gimp_display_delete          (GimpDisplay       *display);
+void               gimp_display_close           (GimpDisplay       *display);
+
+gint               gimp_display_get_ID          (GimpDisplay       *display);
+GimpDisplay      * gimp_display_get_by_ID       (Gimp              *gimp,
+                                                 gint               ID);
+
+gchar            * gimp_display_get_action_name (GimpDisplay       *display);
+
+Gimp             * gimp_display_get_gimp        (GimpDisplay       *display);
+
+GimpImage        * gimp_display_get_image       (GimpDisplay       *display);
+void               gimp_display_set_image       (GimpDisplay       *display,
+                                                 GimpImage         *image);
+
+gint               gimp_display_get_instance    (GimpDisplay       *display);
+
+GimpDisplayShell * gimp_display_get_shell       (GimpDisplay       *display);
+
+void               gimp_display_empty           (GimpDisplay       *display);
+void               gimp_display_fill            (GimpDisplay       *display,
+                                                 GimpImage         *image,
+                                                 GimpUnit           unit,
+                                                 gdouble            scale);
+
+void               gimp_display_update_bounding_box
+                                                (GimpDisplay       *display);
+
+void               gimp_display_update_area     (GimpDisplay       *display,
+                                                 gboolean           now,
+                                                 gint               x,
+                                                 gint               y,
+                                                 gint               w,
+                                                 gint               h);
+
+void               gimp_display_flush           (GimpDisplay       *display);
+void               gimp_display_flush_now       (GimpDisplay       *display);
+
+
+#endif /*  __GIMP_DISPLAY_H__  */
diff --git a/app/display/gimpdisplayshell-actions.c b/app/display/gimpdisplayshell-actions.c
new file mode 100644
index 0000000..fa0b5ef
--- /dev/null
+++ b/app/display/gimpdisplayshell-actions.c
@@ -0,0 +1,149 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontext.h"
+
+#include "widgets/gimpactiongroup.h"
+#include "widgets/gimpuimanager.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-actions.h"
+#include "gimpimagewindow.h"
+
+
+void
+gimp_display_shell_set_action_sensitive (GimpDisplayShell *shell,
+                                         const gchar      *action,
+                                         gboolean          sensitive)
+{
+  GimpImageWindow *window;
+  GimpContext     *context;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (action != NULL);
+
+  window = gimp_display_shell_get_window (shell);
+
+  if (window && gimp_image_window_get_active_shell (window) == shell)
+    {
+      GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+      GimpActionGroup *action_group;
+
+      action_group = gimp_ui_manager_get_action_group (manager, "view");
+
+      if (action_group)
+        gimp_action_group_set_action_sensitive (action_group, action, sensitive);
+    }
+
+  context = gimp_get_user_context (shell->display->gimp);
+
+  if (shell->display == gimp_context_get_display (context))
+    {
+      GimpActionGroup *action_group;
+
+      action_group = gimp_ui_manager_get_action_group (shell->popup_manager,
+                                                       "view");
+
+      if (action_group)
+        gimp_action_group_set_action_sensitive (action_group, action, sensitive);
+    }
+}
+
+void
+gimp_display_shell_set_action_active (GimpDisplayShell *shell,
+                                      const gchar      *action,
+                                      gboolean          active)
+{
+  GimpImageWindow *window;
+  GimpContext     *context;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (action != NULL);
+
+  window = gimp_display_shell_get_window (shell);
+
+  if (window && gimp_image_window_get_active_shell (window) == shell)
+    {
+      GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+      GimpActionGroup *action_group;
+
+      action_group = gimp_ui_manager_get_action_group (manager, "view");
+
+      if (action_group)
+        gimp_action_group_set_action_active (action_group, action, active);
+    }
+
+  context = gimp_get_user_context (shell->display->gimp);
+
+  if (shell->display == gimp_context_get_display (context))
+    {
+      GimpActionGroup *action_group;
+
+      action_group = gimp_ui_manager_get_action_group (shell->popup_manager,
+                                                       "view");
+
+      if (action_group)
+        gimp_action_group_set_action_active (action_group, action, active);
+    }
+}
+
+void
+gimp_display_shell_set_action_color (GimpDisplayShell *shell,
+                                     const gchar      *action,
+                                     const GimpRGB    *color)
+{
+  GimpImageWindow *window;
+  GimpContext     *context;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (action != NULL);
+
+  window = gimp_display_shell_get_window (shell);
+
+  if (window && gimp_image_window_get_active_shell (window) == shell)
+    {
+      GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+      GimpActionGroup *action_group;
+
+      action_group = gimp_ui_manager_get_action_group (manager, "view");
+
+      if (action_group)
+        gimp_action_group_set_action_color (action_group, action, color, FALSE);
+    }
+
+  context = gimp_get_user_context (shell->display->gimp);
+
+  if (shell->display == gimp_context_get_display (context))
+    {
+      GimpActionGroup *action_group;
+
+      action_group = gimp_ui_manager_get_action_group (shell->popup_manager,
+                                                       "view");
+
+      if (action_group)
+        gimp_action_group_set_action_color (action_group, action, color, FALSE);
+    }
+}
diff --git a/app/display/gimpdisplayshell-actions.h b/app/display/gimpdisplayshell-actions.h
new file mode 100644
index 0000000..5d4a4da
--- /dev/null
+++ b/app/display/gimpdisplayshell-actions.h
@@ -0,0 +1,33 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_ACTIONS_H__
+#define __GIMP_DISPLAY_SHELL_ACTIONS_H__
+
+
+void   gimp_display_shell_set_action_sensitive (GimpDisplayShell *shell,
+                                                const gchar      *action,
+                                                gboolean          sensitive);
+void   gimp_display_shell_set_action_active    (GimpDisplayShell *shell,
+                                                const gchar      *action,
+                                                gboolean          active);
+void   gimp_display_shell_set_action_color     (GimpDisplayShell *shell,
+                                                const gchar      *action,
+                                                const GimpRGB    *color);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_ACTIONS_H__ */
diff --git a/app/display/gimpdisplayshell-appearance.c b/app/display/gimpdisplayshell-appearance.c
new file mode 100644
index 0000000..1080acf
--- /dev/null
+++ b/app/display/gimpdisplayshell-appearance.c
@@ -0,0 +1,606 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "config/gimpdisplayoptions.h"
+
+#include "core/gimpimage.h"
+
+#include "widgets/gimpdockcolumns.h"
+#include "widgets/gimprender.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvasitem.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-actions.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-selection.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-scrollbars.h"
+#include "gimpimagewindow.h"
+#include "gimpstatusbar.h"
+
+
+/*  local function prototypes  */
+
+static GimpDisplayOptions * appearance_get_options (GimpDisplayShell *shell);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_appearance_update (GimpDisplayShell *shell)
+{
+  GimpDisplayOptions *options;
+  GimpImageWindow    *window;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+  window  = gimp_display_shell_get_window (shell);
+
+  if (window)
+    {
+      GimpDockColumns *left_docks;
+      GimpDockColumns *right_docks;
+      gboolean         fullscreen;
+      gboolean         has_grip;
+
+      fullscreen = gimp_image_window_get_fullscreen (window);
+
+      gimp_display_shell_set_action_active (shell, "view-fullscreen",
+                                            fullscreen);
+
+      left_docks  = gimp_image_window_get_left_docks (window);
+      right_docks = gimp_image_window_get_right_docks (window);
+
+      has_grip = (! fullscreen &&
+                  ! (left_docks  && gimp_dock_columns_get_docks (left_docks)) &&
+                  ! (right_docks && gimp_dock_columns_get_docks (right_docks)));
+
+      gtk_statusbar_set_has_resize_grip (GTK_STATUSBAR (shell->statusbar),
+                                         has_grip);
+    }
+
+  gimp_display_shell_set_show_menubar        (shell,
+                                              options->show_menubar);
+  gimp_display_shell_set_show_statusbar      (shell,
+                                              options->show_statusbar);
+
+  gimp_display_shell_set_show_rulers         (shell,
+                                              options->show_rulers);
+  gimp_display_shell_set_show_scrollbars     (shell,
+                                              options->show_scrollbars);
+  gimp_display_shell_set_show_selection      (shell,
+                                              options->show_selection);
+  gimp_display_shell_set_show_layer          (shell,
+                                              options->show_layer_boundary);
+  gimp_display_shell_set_show_canvas         (shell,
+                                              options->show_canvas_boundary);
+  gimp_display_shell_set_show_guides         (shell,
+                                              options->show_guides);
+  gimp_display_shell_set_show_grid           (shell,
+                                              options->show_grid);
+  gimp_display_shell_set_show_sample_points  (shell,
+                                              options->show_sample_points);
+  gimp_display_shell_set_padding             (shell,
+                                              options->padding_mode,
+                                              &options->padding_color);
+  gimp_display_shell_set_padding_in_show_all (shell,
+                                              options->padding_in_show_all);
+}
+
+void
+gimp_display_shell_set_show_menubar (GimpDisplayShell *shell,
+                                     gboolean          show)
+{
+  GimpDisplayOptions *options;
+  GimpImageWindow    *window;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+  window  = gimp_display_shell_get_window (shell);
+
+  g_object_set (options, "show-menubar", show, NULL);
+
+  if (window && gimp_image_window_get_active_shell (window) == shell)
+    {
+      gimp_image_window_keep_canvas_pos (gimp_display_shell_get_window (shell));
+      gimp_image_window_set_show_menubar (window, show);
+    }
+
+  gimp_display_shell_set_action_active (shell, "view-show-menubar", show);
+}
+
+gboolean
+gimp_display_shell_get_show_menubar (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_menubar;
+}
+
+void
+gimp_display_shell_set_show_statusbar (GimpDisplayShell *shell,
+                                       gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-statusbar", show, NULL);
+
+  gimp_image_window_keep_canvas_pos (gimp_display_shell_get_window (shell));
+  gimp_statusbar_set_visible (GIMP_STATUSBAR (shell->statusbar), show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-statusbar", show);
+}
+
+gboolean
+gimp_display_shell_get_show_statusbar (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_statusbar;
+}
+
+void
+gimp_display_shell_set_show_rulers (GimpDisplayShell *shell,
+                                    gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-rulers", show, NULL);
+
+  gimp_image_window_keep_canvas_pos (gimp_display_shell_get_window (shell));
+  gtk_widget_set_visible (shell->origin, show);
+  gtk_widget_set_visible (shell->hrule, show);
+  gtk_widget_set_visible (shell->vrule, show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-rulers", show);
+}
+
+gboolean
+gimp_display_shell_get_show_rulers (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_rulers;
+}
+
+void
+gimp_display_shell_set_show_scrollbars (GimpDisplayShell *shell,
+                                        gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-scrollbars", show, NULL);
+
+  gimp_image_window_keep_canvas_pos (gimp_display_shell_get_window (shell));
+  gtk_widget_set_visible (shell->nav_ebox, show);
+  gtk_widget_set_visible (shell->hsb, show);
+  gtk_widget_set_visible (shell->vsb, show);
+  gtk_widget_set_visible (shell->quick_mask_button, show);
+  gtk_widget_set_visible (shell->zoom_button, show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-scrollbars", show);
+}
+
+gboolean
+gimp_display_shell_get_show_scrollbars (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_scrollbars;
+}
+
+void
+gimp_display_shell_set_show_selection (GimpDisplayShell *shell,
+                                       gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-selection", show, NULL);
+
+  gimp_display_shell_selection_set_show (shell, show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-selection", show);
+}
+
+gboolean
+gimp_display_shell_get_show_selection (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_selection;
+}
+
+void
+gimp_display_shell_set_show_layer (GimpDisplayShell *shell,
+                                   gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-layer-boundary", show, NULL);
+
+  gimp_canvas_item_set_visible (shell->layer_boundary, show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-layer-boundary", show);
+}
+
+gboolean
+gimp_display_shell_get_show_layer (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_layer_boundary;
+}
+
+void
+gimp_display_shell_set_show_canvas (GimpDisplayShell *shell,
+                                    gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-canvas-boundary", show, NULL);
+
+  gimp_canvas_item_set_visible (shell->canvas_boundary,
+                                show && shell->show_all);
+
+  gimp_display_shell_set_action_active (shell, "view-show-canvas-boundary", show);
+}
+
+gboolean
+gimp_display_shell_get_show_canvas (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_canvas_boundary;
+}
+
+void
+gimp_display_shell_update_show_canvas (GimpDisplayShell *shell)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  gimp_canvas_item_set_visible (shell->canvas_boundary,
+                                options->show_canvas_boundary &&
+                                shell->show_all);
+}
+
+void
+gimp_display_shell_set_show_guides (GimpDisplayShell *shell,
+                                    gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-guides", show, NULL);
+
+  gimp_canvas_item_set_visible (shell->guides, show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-guides", show);
+}
+
+gboolean
+gimp_display_shell_get_show_guides (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_guides;
+}
+
+void
+gimp_display_shell_set_show_grid (GimpDisplayShell *shell,
+                                  gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-grid", show, NULL);
+
+  gimp_canvas_item_set_visible (shell->grid, show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-grid", show);
+}
+
+gboolean
+gimp_display_shell_get_show_grid (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_grid;
+}
+
+void
+gimp_display_shell_set_show_sample_points (GimpDisplayShell *shell,
+                                           gboolean          show)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "show-sample-points", show, NULL);
+
+  gimp_canvas_item_set_visible (shell->sample_points, show);
+
+  gimp_display_shell_set_action_active (shell, "view-show-sample-points", show);
+}
+
+gboolean
+gimp_display_shell_get_show_sample_points (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->show_sample_points;
+}
+
+void
+gimp_display_shell_set_snap_to_grid (GimpDisplayShell *shell,
+                                     gboolean          snap)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "snap-to-grid", snap, NULL);
+}
+
+gboolean
+gimp_display_shell_get_snap_to_grid (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->snap_to_grid;
+}
+
+void
+gimp_display_shell_set_snap_to_guides (GimpDisplayShell *shell,
+                                       gboolean          snap)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "snap-to-guides", snap, NULL);
+}
+
+gboolean
+gimp_display_shell_get_snap_to_guides (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->snap_to_guides;
+}
+
+void
+gimp_display_shell_set_snap_to_canvas (GimpDisplayShell *shell,
+                                       gboolean          snap)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "snap-to-canvas", snap, NULL);
+}
+
+gboolean
+gimp_display_shell_get_snap_to_canvas (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->snap_to_canvas;
+}
+
+void
+gimp_display_shell_set_snap_to_vectors (GimpDisplayShell *shell,
+                                        gboolean          snap)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  g_object_set (options, "snap-to-path", snap, NULL);
+}
+
+gboolean
+gimp_display_shell_get_snap_to_vectors (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->snap_to_path;
+}
+
+void
+gimp_display_shell_set_padding (GimpDisplayShell      *shell,
+                                GimpCanvasPaddingMode  padding_mode,
+                                const GimpRGB         *padding_color)
+{
+  GimpDisplayOptions *options;
+  GimpRGB             color;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (padding_color != NULL);
+
+  options = appearance_get_options (shell);
+  color   = *padding_color;
+
+  switch (padding_mode)
+    {
+    case GIMP_CANVAS_PADDING_MODE_DEFAULT:
+      if (shell->canvas)
+        {
+          GtkStyle *style;
+
+          gtk_widget_ensure_style (shell->canvas);
+
+          style = gtk_widget_get_style (shell->canvas);
+
+          gimp_rgb_set_gdk_color (&color, style->bg + GTK_STATE_NORMAL);
+        }
+      break;
+
+    case GIMP_CANVAS_PADDING_MODE_LIGHT_CHECK:
+      color = *gimp_render_light_check_color ();
+      break;
+
+    case GIMP_CANVAS_PADDING_MODE_DARK_CHECK:
+      color = *gimp_render_dark_check_color ();
+      break;
+
+    case GIMP_CANVAS_PADDING_MODE_CUSTOM:
+    case GIMP_CANVAS_PADDING_MODE_RESET:
+      break;
+    }
+
+  g_object_set (options,
+                "padding-mode",  padding_mode,
+                "padding-color", &color,
+                NULL);
+
+  gimp_canvas_set_bg_color (GIMP_CANVAS (shell->canvas), &color);
+
+  gimp_display_shell_set_action_color (shell, "view-padding-color-menu",
+                                       &options->padding_color);
+}
+
+void
+gimp_display_shell_get_padding (GimpDisplayShell       *shell,
+                                GimpCanvasPaddingMode  *padding_mode,
+                                GimpRGB                *padding_color)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  if (padding_mode)
+    *padding_mode = options->padding_mode;
+
+  if (padding_color)
+    *padding_color = options->padding_color;
+}
+
+void
+gimp_display_shell_set_padding_in_show_all (GimpDisplayShell *shell,
+                                            gboolean          keep)
+{
+  GimpDisplayOptions *options;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  options = appearance_get_options (shell);
+
+  if (options->padding_in_show_all != keep)
+    {
+      g_object_set (options, "padding-in-show-all", keep, NULL);
+
+      if (shell->display)
+        {
+          gimp_display_shell_scroll_clamp_and_update (shell);
+          gimp_display_shell_scrollbars_update (shell);
+
+          gimp_display_shell_expose_full (shell);
+        }
+
+      gimp_display_shell_set_action_active (shell,
+                                            "view-padding-color-in-show-all",
+                                            keep);
+
+      g_object_notify (G_OBJECT (shell), "infinite-canvas");
+    }
+}
+
+gboolean
+gimp_display_shell_get_padding_in_show_all (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return appearance_get_options (shell)->padding_in_show_all;
+}
+
+
+/*  private functions  */
+
+static GimpDisplayOptions *
+appearance_get_options (GimpDisplayShell *shell)
+{
+  if (gimp_display_get_image (shell->display))
+    {
+      GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+      if (window && gimp_image_window_get_fullscreen (window))
+        return shell->fullscreen_options;
+      else
+        return shell->options;
+    }
+
+  return shell->no_image_options;
+}
diff --git a/app/display/gimpdisplayshell-appearance.h b/app/display/gimpdisplayshell-appearance.h
new file mode 100644
index 0000000..0c67649
--- /dev/null
+++ b/app/display/gimpdisplayshell-appearance.h
@@ -0,0 +1,92 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_APPEARANCE_H__
+#define __GIMP_DISPLAY_SHELL_APPEARANCE_H__
+
+
+void       gimp_display_shell_appearance_update       (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_menubar        (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_menubar        (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_statusbar      (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_statusbar      (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_rulers         (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_rulers         (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_scrollbars     (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_scrollbars     (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_selection      (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_selection      (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_layer          (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_layer          (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_canvas         (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_canvas         (GimpDisplayShell       *shell);
+void       gimp_display_shell_update_show_canvas      (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_grid           (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_grid           (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_guides         (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_guides         (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_snap_to_grid        (GimpDisplayShell       *shell,
+                                                       gboolean                snap);
+gboolean   gimp_display_shell_get_snap_to_grid        (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_show_sample_points  (GimpDisplayShell       *shell,
+                                                       gboolean                show);
+gboolean   gimp_display_shell_get_show_sample_points  (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_snap_to_guides      (GimpDisplayShell       *shell,
+                                                       gboolean                snap);
+gboolean   gimp_display_shell_get_snap_to_guides      (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_snap_to_canvas      (GimpDisplayShell       *shell,
+                                                       gboolean                snap);
+gboolean   gimp_display_shell_get_snap_to_canvas      (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_snap_to_vectors     (GimpDisplayShell       *shell,
+                                                       gboolean                snap);
+gboolean   gimp_display_shell_get_snap_to_vectors     (GimpDisplayShell       *shell);
+
+void       gimp_display_shell_set_padding             (GimpDisplayShell       *shell,
+                                                       GimpCanvasPaddingMode   mode,
+                                                       const GimpRGB          *color);
+void       gimp_display_shell_get_padding             (GimpDisplayShell       *shell,
+                                                       GimpCanvasPaddingMode  *mode,
+                                                       GimpRGB                *color);
+void       gimp_display_shell_set_padding_in_show_all (GimpDisplayShell       *shell,
+                                                       gboolean                keep);
+gboolean   gimp_display_shell_get_padding_in_show_all (GimpDisplayShell       *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_APPEARANCE_H__ */
diff --git a/app/display/gimpdisplayshell-autoscroll.c b/app/display/gimpdisplayshell-autoscroll.c
new file mode 100644
index 0000000..39cf252
--- /dev/null
+++ b/app/display/gimpdisplayshell-autoscroll.c
@@ -0,0 +1,184 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "widgets/gimpdeviceinfo.h"
+#include "widgets/gimpdeviceinfo-coords.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-autoscroll.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-transform.h"
+
+#include "tools/tools-types.h"
+#include "tools/tool_manager.h"
+#include "tools/gimptool.h"
+#include "tools/gimptoolcontrol.h"
+
+
+#define AUTOSCROLL_DT  20
+#define AUTOSCROLL_DX  0.1
+
+
+typedef struct
+{
+  GdkEventMotion  *mevent;
+  GimpDeviceInfo  *device;
+  guint32          time;
+  GdkModifierType  state;
+  guint            timeout_id;
+} ScrollInfo;
+
+
+/*  local function prototypes  */
+
+static gboolean gimp_display_shell_autoscroll_timeout (gpointer data);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_autoscroll_start (GimpDisplayShell *shell,
+                                     GdkModifierType   state,
+                                     GdkEventMotion   *mevent)
+{
+  ScrollInfo *info;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->scroll_info)
+    return;
+
+  info = g_slice_new0 (ScrollInfo);
+
+  info->mevent     = mevent;
+  info->device     = gimp_device_info_get_by_device (mevent->device);
+  info->time       = gdk_event_get_time ((GdkEvent *) mevent);
+  info->state      = state;
+  info->timeout_id = g_timeout_add (AUTOSCROLL_DT,
+                                    gimp_display_shell_autoscroll_timeout,
+                                    shell);
+
+  shell->scroll_info = info;
+}
+
+void
+gimp_display_shell_autoscroll_stop (GimpDisplayShell *shell)
+{
+  ScrollInfo *info;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->scroll_info)
+    return;
+
+  info = shell->scroll_info;
+
+  if (info->timeout_id)
+    {
+      g_source_remove (info->timeout_id);
+      info->timeout_id = 0;
+    }
+
+  g_slice_free (ScrollInfo, info);
+  shell->scroll_info = NULL;
+}
+
+
+/*  private functions  */
+
+static gboolean
+gimp_display_shell_autoscroll_timeout (gpointer data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+  ScrollInfo       *info  = shell->scroll_info;
+  GimpCoords        device_coords;
+  GimpCoords        image_coords;
+  gint              dx = 0;
+  gint              dy = 0;
+
+  gimp_device_info_get_device_coords (info->device,
+                                      gtk_widget_get_window (shell->canvas),
+                                      &device_coords);
+
+  if (device_coords.x < 0)
+    dx = device_coords.x;
+  else if (device_coords.x > shell->disp_width)
+    dx = device_coords.x - shell->disp_width;
+
+  if (device_coords.y < 0)
+    dy = device_coords.y;
+  else if (device_coords.y > shell->disp_height)
+    dy = device_coords.y - shell->disp_height;
+
+  if (dx || dy)
+    {
+      GimpDisplay *display         = shell->display;
+      GimpTool    *active_tool     = tool_manager_get_active (display->gimp);
+      gint         scroll_amount_x = AUTOSCROLL_DX * dx;
+      gint         scroll_amount_y = AUTOSCROLL_DX * dy;
+
+      info->time += AUTOSCROLL_DT;
+
+      gimp_display_shell_scroll_unoverscrollify (shell,
+                                                 scroll_amount_x,
+                                                 scroll_amount_y,
+                                                 &scroll_amount_x,
+                                                 &scroll_amount_y);
+
+      gimp_display_shell_scroll (shell,
+                                 scroll_amount_x,
+                                 scroll_amount_y);
+
+      gimp_display_shell_untransform_coords (shell,
+                                             &device_coords,
+                                             &image_coords);
+
+      if (gimp_tool_control_get_snap_to (active_tool->control))
+        {
+          gint x, y, width, height;
+
+          gimp_tool_control_get_snap_offsets (active_tool->control,
+                                              &x, &y, &width, &height);
+
+          gimp_display_shell_snap_coords (shell,
+                                          &image_coords,
+                                          x, y, width, height);
+        }
+
+      tool_manager_motion_active (display->gimp,
+                                  &image_coords,
+                                  info->time, info->state,
+                                  display);
+
+      return TRUE;
+    }
+  else
+    {
+      g_slice_free (ScrollInfo, info);
+      shell->scroll_info = NULL;
+
+      return FALSE;
+    }
+}
diff --git a/app/display/gimpdisplayshell-autoscroll.h b/app/display/gimpdisplayshell-autoscroll.h
new file mode 100644
index 0000000..c030759
--- /dev/null
+++ b/app/display/gimpdisplayshell-autoscroll.h
@@ -0,0 +1,28 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_AUTOSCROLL_H__
+#define __GIMP_DISPLAY_SHELL_AUTOSCROLL_H__
+
+
+void   gimp_display_shell_autoscroll_start (GimpDisplayShell *shell,
+                                            GdkModifierType   state,
+                                            GdkEventMotion   *mevent);
+void   gimp_display_shell_autoscroll_stop  (GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_AUTOSCROLL_H__ */
diff --git a/app/display/gimpdisplayshell-callbacks.c b/app/display/gimpdisplayshell-callbacks.c
new file mode 100644
index 0000000..9b65529
--- /dev/null
+++ b/app/display/gimpdisplayshell-callbacks.c
@@ -0,0 +1,647 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpimage.h"
+#include "core/gimpimage-quick-mask.h"
+
+#include "widgets/gimpcairo-wilber.h"
+#include "widgets/gimpuimanager.h"
+
+#include "gimpcanvasitem.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-callbacks.h"
+#include "gimpdisplayshell-draw.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-scrollbars.h"
+#include "gimpdisplayshell-selection.h"
+#include "gimpdisplayshell-title.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpdisplayxfer.h"
+#include "gimpimagewindow.h"
+#include "gimpnavigationeditor.h"
+
+#include "git-version.h"
+
+#include "gimp-intl.h"
+
+
+/*  local function prototypes  */
+
+static void       gimp_display_shell_vadjustment_changed      (GtkAdjustment    *adjustment,
+                                                               GimpDisplayShell *shell);
+static void       gimp_display_shell_hadjustment_changed      (GtkAdjustment    *adjustment,
+                                                               GimpDisplayShell *shell);
+static gboolean   gimp_display_shell_vscrollbar_change_value  (GtkRange         *range,
+                                                               GtkScrollType     scroll,
+                                                               gdouble           value,
+                                                               GimpDisplayShell *shell);
+
+static gboolean   gimp_display_shell_hscrollbar_change_value  (GtkRange         *range,
+                                                               GtkScrollType     scroll,
+                                                               gdouble           value,
+                                                               GimpDisplayShell *shell);
+
+static void       gimp_display_shell_canvas_draw_image        (GimpDisplayShell *shell,
+                                                               cairo_t          *cr);
+static void       gimp_display_shell_canvas_draw_drop_zone    (GimpDisplayShell *shell,
+                                                               cairo_t          *cr);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_canvas_realize (GtkWidget        *canvas,
+                                   GimpDisplayShell *shell)
+{
+  GimpCanvasPaddingMode padding_mode;
+  GimpRGB               padding_color;
+  GtkAllocation         allocation;
+
+  gtk_widget_grab_focus (canvas);
+
+  gimp_display_shell_get_padding (shell, &padding_mode, &padding_color);
+  gimp_display_shell_set_padding (shell, padding_mode, &padding_color);
+
+  gtk_widget_get_allocation (canvas, &allocation);
+
+  gimp_display_shell_title_update (shell);
+
+  shell->disp_width  = allocation.width;
+  shell->disp_height = allocation.height;
+
+  /*  set up the scrollbar observers  */
+  g_signal_connect (shell->hsbdata, "value-changed",
+                    G_CALLBACK (gimp_display_shell_hadjustment_changed),
+                    shell);
+  g_signal_connect (shell->vsbdata, "value-changed",
+                    G_CALLBACK (gimp_display_shell_vadjustment_changed),
+                    shell);
+
+  g_signal_connect (shell->hsb, "change-value",
+                    G_CALLBACK (gimp_display_shell_hscrollbar_change_value),
+                    shell);
+
+  g_signal_connect (shell->vsb, "change-value",
+                    G_CALLBACK (gimp_display_shell_vscrollbar_change_value),
+                    shell);
+
+  /*  allow shrinking  */
+  gtk_widget_set_size_request (GTK_WIDGET (shell), 0, 0);
+
+  shell->xfer = gimp_display_xfer_realize (GTK_WIDGET(shell));
+
+  /*  HACK: remove with GTK+ 3.x: this unconditionally maps the
+   *  rulers, if configured to be hidden they are never visible to the
+   *  user because they will be hidden again right away.
+   *
+   *  For some obscure reason, having the rulers mapped once prevents
+   *  crashes with tablets and on-canvas dialogs. See bug #784480 and
+   *  all its duplicates.
+   */
+  gtk_widget_show (shell->hrule);
+  gtk_widget_show (shell->vrule);
+}
+
+void
+gimp_display_shell_canvas_realize_after (GtkWidget        *canvas,
+                                         GimpDisplayShell *shell)
+{
+  GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+  /*  HACK: see above: must go with GTK+ 3.x too. Restore the rulers'
+   *  intended visibility again.
+   */
+  gimp_image_window_suspend_keep_pos (window);
+  gimp_display_shell_appearance_update (shell);
+  gimp_image_window_resume_keep_pos (window);
+}
+
+void
+gimp_display_shell_canvas_size_allocate (GtkWidget        *widget,
+                                         GtkAllocation    *allocation,
+                                         GimpDisplayShell *shell)
+{
+  /*  are we in destruction?  */
+  if (! shell->display || ! gimp_display_get_shell (shell->display))
+    return;
+
+  if ((shell->disp_width  != allocation->width) ||
+      (shell->disp_height != allocation->height))
+    {
+      if (shell->zoom_on_resize   &&
+          shell->disp_width  > 64 &&
+          shell->disp_height > 64 &&
+          allocation->width  > 64 &&
+          allocation->height > 64)
+        {
+          gdouble scale = gimp_zoom_model_get_factor (shell->zoom);
+          gint    offset_x;
+          gint    offset_y;
+
+          /* FIXME: The code is a bit of a mess */
+
+          /*  multiply the zoom_factor with the ratio of the new and
+           *  old canvas diagonals
+           */
+          scale *= (sqrt (SQR (allocation->width) +
+                          SQR (allocation->height)) /
+                    sqrt (SQR (shell->disp_width) +
+                          SQR (shell->disp_height)));
+
+          offset_x = UNSCALEX (shell, shell->offset_x);
+          offset_y = UNSCALEX (shell, shell->offset_y);
+
+          gimp_zoom_model_zoom (shell->zoom, GIMP_ZOOM_TO, scale);
+
+          shell->offset_x = SCALEX (shell, offset_x);
+          shell->offset_y = SCALEY (shell, offset_y);
+        }
+
+      shell->disp_width  = allocation->width;
+      shell->disp_height = allocation->height;
+
+      /* When we size-allocate due to resize of the top level window,
+       * we want some additional logic. Don't apply it on
+       * zoom_on_resize though.
+       */
+      if (shell->size_allocate_from_configure_event &&
+          ! shell->zoom_on_resize)
+        {
+          gboolean center_horizontally;
+          gboolean center_vertically;
+          gint     target_offset_x;
+          gint     target_offset_y;
+          gint     sw;
+          gint     sh;
+
+          gimp_display_shell_scale_get_image_size (shell, &sw, &sh);
+
+          center_horizontally = sw <= shell->disp_width;
+          center_vertically   = sh <= shell->disp_height;
+
+          if (! gimp_display_shell_get_infinite_canvas (shell))
+            {
+              gimp_display_shell_scroll_center_image (shell,
+                                                      center_horizontally,
+                                                      center_vertically);
+            }
+          else
+            {
+              gimp_display_shell_scroll_center_content (shell,
+                                                        center_horizontally,
+                                                        center_vertically);
+            }
+
+          /* This is basically the best we can do before we get an
+           * API for storing the image offset at the start of an
+           * image window resize using the mouse
+           */
+          target_offset_x = shell->offset_x;
+          target_offset_y = shell->offset_y;
+
+          if (! center_horizontally)
+            {
+              target_offset_x = MAX (shell->offset_x, 0);
+            }
+
+          if (! center_vertically)
+            {
+              target_offset_y = MAX (shell->offset_y, 0);
+            }
+
+          gimp_display_shell_scroll_set_offset (shell,
+                                                target_offset_x,
+                                                target_offset_y);
+        }
+
+      gimp_display_shell_scroll_clamp_and_update (shell);
+      gimp_display_shell_scaled (shell);
+
+      shell->size_allocate_from_configure_event = FALSE;
+    }
+
+  if (shell->size_allocate_center_image)
+    {
+      gimp_display_shell_scroll_center_image (shell, TRUE, TRUE);
+
+      shell->size_allocate_center_image = FALSE;
+    }
+}
+
+gboolean
+gimp_display_shell_canvas_expose (GtkWidget        *widget,
+                                  GdkEventExpose   *eevent,
+                                  GimpDisplayShell *shell)
+{
+  /*  are we in destruction?  */
+  if (! shell->display || ! gimp_display_get_shell (shell->display))
+    return TRUE;
+
+  /*  we will scroll around in the next tick anyway, so we just can as
+   *  well skip the drawing of this frame and wait for the next
+   */
+  if (shell->size_allocate_center_image)
+    return TRUE;
+
+  /*  ignore events on overlays  */
+  if (eevent->window == gtk_widget_get_window (widget))
+    {
+      cairo_t *cr;
+
+      cr = gdk_cairo_create (gtk_widget_get_window (shell->canvas));
+      gdk_cairo_region (cr, eevent->region);
+      cairo_clip (cr);
+
+      if (gimp_display_get_image (shell->display))
+        {
+          gimp_display_shell_canvas_draw_image (shell, cr);
+        }
+      else
+        {
+          gimp_display_shell_canvas_draw_drop_zone (shell, cr);
+        }
+
+      cairo_destroy (cr);
+    }
+
+  return FALSE;
+}
+
+gboolean
+gimp_display_shell_origin_button_press (GtkWidget        *widget,
+                                        GdkEventButton   *event,
+                                        GimpDisplayShell *shell)
+{
+  if (! shell->display->gimp->busy)
+    {
+      if (event->type == GDK_BUTTON_PRESS && event->button == 1)
+        {
+          gboolean unused;
+
+          g_signal_emit_by_name (shell, "popup-menu", &unused);
+        }
+    }
+
+  /* Return TRUE to stop signal emission so the button doesn't grab the
+   * pointer away from us.
+   */
+  return TRUE;
+}
+
+gboolean
+gimp_display_shell_quick_mask_button_press (GtkWidget        *widget,
+                                            GdkEventButton   *bevent,
+                                            GimpDisplayShell *shell)
+{
+  if (! gimp_display_get_image (shell->display))
+    return TRUE;
+
+  if (gdk_event_triggers_context_menu ((GdkEvent *) bevent))
+    {
+      GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+      if (window)
+        {
+          GimpUIManager *manager = gimp_image_window_get_ui_manager (window);
+
+          gimp_ui_manager_ui_popup (manager,
+                                    "/quick-mask-popup",
+                                    GTK_WIDGET (shell),
+                                    NULL, NULL, NULL, NULL);
+        }
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+void
+gimp_display_shell_quick_mask_toggled (GtkWidget        *widget,
+                                       GimpDisplayShell *shell)
+{
+  GimpImage *image  = gimp_display_get_image (shell->display);
+  gboolean   active = gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (widget));
+
+  if (active != gimp_image_get_quick_mask_state (image))
+    {
+      GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+      if (window)
+        {
+          GimpUIManager *manager = gimp_image_window_get_ui_manager (window);
+
+          gimp_ui_manager_toggle_action (manager,
+                                         "quick-mask", "quick-mask-toggle",
+                                         active);
+        }
+    }
+}
+
+gboolean
+gimp_display_shell_navigation_button_press (GtkWidget        *widget,
+                                            GdkEventButton   *bevent,
+                                            GimpDisplayShell *shell)
+{
+  if (! gimp_display_get_image (shell->display))
+    return TRUE;
+
+  if (bevent->type == GDK_BUTTON_PRESS && bevent->button == 1)
+    {
+      gimp_navigation_editor_popup (shell, widget, bevent->x, bevent->y);
+    }
+
+  return TRUE;
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_shell_vadjustment_changed (GtkAdjustment    *adjustment,
+                                        GimpDisplayShell *shell)
+{
+  /*  If we are panning with mouse, scrollbars are to be ignored or
+   *  they will cause jitter in motion
+   */
+  if (! shell->scrolling)
+    gimp_display_shell_scroll (shell,
+                               0,
+                               gtk_adjustment_get_value (adjustment) -
+                               shell->offset_y);
+}
+
+static void
+gimp_display_shell_hadjustment_changed (GtkAdjustment    *adjustment,
+                                        GimpDisplayShell *shell)
+{
+  /* If we are panning with mouse, scrollbars are to be ignored or
+   * they will cause jitter in motion
+   */
+  if (! shell->scrolling)
+    gimp_display_shell_scroll (shell,
+                               gtk_adjustment_get_value (adjustment) -
+                               shell->offset_x,
+                               0);
+}
+
+static gboolean
+gimp_display_shell_hscrollbar_change_value (GtkRange         *range,
+                                            GtkScrollType     scroll,
+                                            gdouble           value,
+                                            GimpDisplayShell *shell)
+{
+  if (! shell->display)
+    return TRUE;
+
+  if ((scroll == GTK_SCROLL_JUMP)          ||
+      (scroll == GTK_SCROLL_PAGE_BACKWARD) ||
+      (scroll == GTK_SCROLL_PAGE_FORWARD))
+    return FALSE;
+
+  g_object_freeze_notify (G_OBJECT (shell->hsbdata));
+
+  gimp_display_shell_scrollbars_setup_horizontal (shell, value);
+
+  g_object_thaw_notify (G_OBJECT (shell->hsbdata)); /* emits "changed" */
+
+  return FALSE;
+}
+
+static gboolean
+gimp_display_shell_vscrollbar_change_value (GtkRange         *range,
+                                            GtkScrollType     scroll,
+                                            gdouble           value,
+                                            GimpDisplayShell *shell)
+{
+  if (! shell->display)
+    return TRUE;
+
+  if ((scroll == GTK_SCROLL_JUMP)          ||
+      (scroll == GTK_SCROLL_PAGE_BACKWARD) ||
+      (scroll == GTK_SCROLL_PAGE_FORWARD))
+    return FALSE;
+
+  g_object_freeze_notify (G_OBJECT (shell->vsbdata));
+
+  gimp_display_shell_scrollbars_setup_vertical (shell, value);
+
+  g_object_thaw_notify (G_OBJECT (shell->vsbdata)); /* emits "changed" */
+
+  return FALSE;
+}
+
+static void
+gimp_display_shell_canvas_draw_image (GimpDisplayShell *shell,
+                                      cairo_t          *cr)
+{
+  cairo_rectangle_list_t *clip_rectangles;
+  GeglRectangle           image_rect;
+  GeglRectangle           rotated_image_rect;
+  GeglRectangle           canvas_rect;
+  cairo_matrix_t          matrix;
+  gdouble                 x1, y1;
+  gdouble                 x2, y2;
+
+  gimp_display_shell_scale_get_image_unrotated_bounding_box (
+    shell,
+    &image_rect.x,
+    &image_rect.y,
+    &image_rect.width,
+    &image_rect.height);
+
+  gimp_display_shell_scale_get_image_unrotated_bounds (
+    shell,
+    &canvas_rect.x,
+    &canvas_rect.y,
+    &canvas_rect.width,
+    &canvas_rect.height);
+
+  /*  the background has already been cleared by GdkWindow
+   */
+
+
+  /*  on top, draw the exposed part of the region that is inside the
+   *  image
+   */
+
+  cairo_save (cr);
+  clip_rectangles = cairo_copy_clip_rectangle_list (cr);
+  cairo_get_matrix (cr, &matrix);
+
+  if (shell->rotate_transform)
+    cairo_transform (cr, shell->rotate_transform);
+
+  if (shell->show_all)
+    {
+      cairo_save (cr);
+
+      if (gimp_display_shell_get_padding_in_show_all (shell))
+        {
+          cairo_rectangle (cr,
+                           canvas_rect.x,
+                           canvas_rect.y,
+                           canvas_rect.width,
+                           canvas_rect.height);
+          cairo_clip (cr);
+        }
+
+      gimp_display_shell_draw_checkerboard (shell, cr);
+
+      cairo_restore (cr);
+    }
+
+  cairo_rectangle (cr,
+                   image_rect.x,
+                   image_rect.y,
+                   image_rect.width,
+                   image_rect.height);
+  cairo_clip (cr);
+
+  gimp_display_shell_rotate_bounds (shell,
+                                    image_rect.x,
+                                    image_rect.y,
+                                    image_rect.x + image_rect.width,
+                                    image_rect.y + image_rect.height,
+                                    &x1, &y1, &x2, &y2);
+
+  rotated_image_rect.x      = floor (x1);
+  rotated_image_rect.y      = floor (y1);
+  rotated_image_rect.width  = ceil  (x2) - rotated_image_rect.x;
+  rotated_image_rect.height = ceil  (y2) - rotated_image_rect.y;
+
+  if (gdk_cairo_get_clip_rectangle (cr, NULL))
+    {
+      gint i;
+
+      if (! shell->show_all)
+        {
+          cairo_save (cr);
+          gimp_display_shell_draw_checkerboard (shell, cr);
+          cairo_restore (cr);
+        }
+
+      if (shell->show_image)
+        {
+          cairo_set_matrix (cr, &matrix);
+
+          for (i = 0; i < clip_rectangles->num_rectangles; i++)
+            {
+              cairo_rectangle_t clip_rect = clip_rectangles->rectangles[i];
+              GeglRectangle     rect;
+
+              rect.x      = floor (clip_rect.x);
+              rect.y      = floor (clip_rect.y);
+              rect.width  = ceil  (clip_rect.x + clip_rect.width)  - rect.x;
+              rect.height = ceil  (clip_rect.y + clip_rect.height) - rect.y;
+
+              if (gegl_rectangle_intersect (&rect, &rect, &rotated_image_rect))
+                {
+                  gimp_display_shell_draw_image (shell, cr,
+                                                 rect.x,     rect.y,
+                                                 rect.width, rect.height);
+                }
+            }
+        }
+    }
+
+  cairo_rectangle_list_destroy (clip_rectangles);
+  cairo_restore (cr);
+
+
+  /*  finally, draw all the remaining image window stuff on top
+   */
+
+  /* draw canvas items */
+  cairo_save (cr);
+
+  if (shell->rotate_transform)
+    cairo_transform (cr, shell->rotate_transform);
+
+  gimp_canvas_item_draw (shell->canvas_item, cr);
+
+  cairo_restore (cr);
+
+  gimp_canvas_item_draw (shell->unrotated_item, cr);
+
+  /* restart (and recalculate) the selection boundaries */
+  gimp_display_shell_selection_restart (shell);
+}
+
+static void
+gimp_display_shell_canvas_draw_drop_zone (GimpDisplayShell *shell,
+                                          cairo_t          *cr)
+{
+  cairo_save (cr);
+
+  gimp_cairo_draw_drop_wilber (shell->canvas, cr, shell->blink);
+
+  cairo_restore (cr);
+
+#ifdef GIMP_UNSTABLE
+  {
+    PangoLayout   *layout;
+    gchar         *msg;
+    GtkAllocation  allocation;
+    gint           width;
+    gint           height;
+    gdouble        scale;
+
+    layout = gtk_widget_create_pango_layout (shell->canvas, NULL);
+
+    msg = g_strdup_printf (_("<big>Unstable Development Version</big>\n\n"
+                             "<small>commit <tt>%s</tt></small>\n\n"
+                             "<small>Please test bugs against "
+                             "latest git master branch\n"
+                             "before reporting them.</small>"),
+                             GIMP_GIT_VERSION_ABBREV);
+    pango_layout_set_markup (layout, msg, -1);
+    g_free (msg);
+    pango_layout_set_alignment (layout, PANGO_ALIGN_CENTER);
+
+    pango_layout_get_pixel_size (layout, &width, &height);
+    gtk_widget_get_allocation (shell->canvas, &allocation);
+
+    scale = MIN (((gdouble) allocation.width  / 2.0) / (gdouble) width,
+                 ((gdouble) allocation.height / 2.0) / (gdouble) height);
+
+    cairo_move_to (cr,
+                   (allocation.width  - (width  * scale)) / 2,
+                   (allocation.height - (height * scale)) / 2);
+
+    cairo_scale (cr, scale, scale);
+
+    pango_cairo_show_layout (cr, layout);
+
+    g_object_unref (layout);
+  }
+#endif /* GIMP_UNSTABLE */
+}
diff --git a/app/display/gimpdisplayshell-callbacks.h b/app/display/gimpdisplayshell-callbacks.h
new file mode 100644
index 0000000..de1861f
--- /dev/null
+++ b/app/display/gimpdisplayshell-callbacks.h
@@ -0,0 +1,48 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_CALLBACKS_H__
+#define __GIMP_DISPLAY_SHELL_CALLBACKS_H__
+
+
+void       gimp_display_shell_canvas_realize          (GtkWidget        *widget,
+                                                       GimpDisplayShell *shell);
+void       gimp_display_shell_canvas_realize_after    (GtkWidget        *widget,
+                                                       GimpDisplayShell *shell);
+void       gimp_display_shell_canvas_size_allocate    (GtkWidget        *widget,
+                                                       GtkAllocation    *alloc,
+                                                       GimpDisplayShell *shell);
+gboolean   gimp_display_shell_canvas_expose           (GtkWidget        *widget,
+                                                       GdkEventExpose   *eevent,
+                                                       GimpDisplayShell *shell);
+
+gboolean   gimp_display_shell_origin_button_press     (GtkWidget        *widget,
+                                                       GdkEventButton   *bevent,
+                                                       GimpDisplayShell *shell);
+
+gboolean   gimp_display_shell_quick_mask_button_press (GtkWidget        *widget,
+                                                       GdkEventButton   *bevent,
+                                                       GimpDisplayShell *shell);
+void       gimp_display_shell_quick_mask_toggled      (GtkWidget        *widget,
+                                                       GimpDisplayShell *shell);
+
+gboolean   gimp_display_shell_navigation_button_press (GtkWidget        *widget,
+                                                       GdkEventButton   *bevent,
+                                                       GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_CALLBACKS_H__ */
diff --git a/app/display/gimpdisplayshell-close.c b/app/display/gimpdisplayshell-close.c
new file mode 100644
index 0000000..b7d7c16
--- /dev/null
+++ b/app/display/gimpdisplayshell-close.c
@@ -0,0 +1,447 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <time.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontainer.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpmessagebox.h"
+#include "widgets/gimpmessagedialog.h"
+#include "widgets/gimpuimanager.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-close.h"
+#include "gimpimagewindow.h"
+
+#include "gimp-intl.h"
+
+
+/*  local function prototypes  */
+
+static void      gimp_display_shell_close_dialog       (GimpDisplayShell *shell,
+                                                        GimpImage        *image);
+static void      gimp_display_shell_close_name_changed (GimpImage        *image,
+                                                        GimpMessageBox   *box);
+static void      gimp_display_shell_close_exported     (GimpImage        *image,
+                                                        GFile            *file,
+                                                        GimpMessageBox   *box);
+static gboolean  gimp_display_shell_close_time_changed (GimpMessageBox   *box);
+static void      gimp_display_shell_close_response     (GtkWidget        *widget,
+                                                        gboolean          close,
+                                                        GimpDisplayShell *shell);
+static void      gimp_display_shell_close_accel_marshal(GClosure         *closure,
+                                                        GValue           *return_value,
+                                                        guint             n_param_values,
+                                                        const GValue     *param_values,
+                                                        gpointer          invocation_hint,
+                                                        gpointer          marshal_data);
+static void      gimp_time_since                       (gint64            then,
+                                                        gint             *hours,
+                                                        gint             *minutes);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_close (GimpDisplayShell *shell,
+                          gboolean          kill_it)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  /*  FIXME: gimp_busy HACK not really appropriate here because we only
+   *  want to prevent the busy image and display to be closed.  --Mitch
+   */
+  if (shell->display->gimp->busy)
+    return;
+
+  /*  If the image has been modified, give the user a chance to save
+   *  it before nuking it--this only applies if its the last view
+   *  to an image canvas.  (a image with disp_count = 1)
+   */
+  if (! kill_it                                 &&
+      image                                     &&
+      gimp_image_get_display_count (image) == 1 &&
+      gimp_image_is_dirty (image))
+    {
+      /*  If there's a save dialog active for this image, then raise it.
+       *  (see bug #511965)
+       */
+      GtkWidget *dialog = g_object_get_data (G_OBJECT (image),
+                                             "gimp-file-save-dialog");
+      if (dialog)
+        {
+          gtk_window_present (GTK_WINDOW (dialog));
+        }
+      else
+        {
+          gimp_display_shell_close_dialog (shell, image);
+        }
+    }
+  else if (image)
+    {
+      gimp_display_close (shell->display);
+    }
+  else
+    {
+      GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+      if (window)
+        {
+          GimpUIManager *manager = gimp_image_window_get_ui_manager (window);
+
+          /* Activate the action instead of simply calling gimp_exit(), so
+           * the quit action's sensitivity is taken into account.
+           */
+          gimp_ui_manager_activate_action (manager, "file", "file-quit");
+        }
+    }
+}
+
+
+/*  private functions  */
+
+#define RESPONSE_SAVE  1
+
+
+static void
+gimp_display_shell_close_dialog (GimpDisplayShell *shell,
+                                 GimpImage        *image)
+{
+  GtkWidget       *dialog;
+  GimpMessageBox  *box;
+  GtkWidget       *label;
+  GtkAccelGroup   *accel_group;
+  GClosure        *closure;
+  GSource         *source;
+  guint            accel_key;
+  GdkModifierType  accel_mods;
+  gchar           *title;
+  gchar           *accel_string;
+  gchar           *hint;
+  gchar           *markup;
+  GFile           *file;
+
+  if (shell->close_dialog)
+    {
+      gtk_window_present (GTK_WINDOW (shell->close_dialog));
+      return;
+    }
+
+  file = gimp_image_get_file (image);
+
+  title = g_strdup_printf (_("Close %s"), gimp_image_get_display_name (image));
+
+  shell->close_dialog =
+    dialog = gimp_message_dialog_new (title, GIMP_ICON_DOCUMENT_SAVE,
+                                      GTK_WIDGET (shell),
+                                      GTK_DIALOG_DESTROY_WITH_PARENT,
+                                      gimp_standard_help_func, NULL,
+
+                                      file ?
+                                      _("_Save") :
+                                      _("Save _As"),         RESPONSE_SAVE,
+                                      _("_Cancel"),          GTK_RESPONSE_CANCEL,
+                                      _("_Discard Changes"), GTK_RESPONSE_CLOSE,
+                                      NULL);
+
+  g_free (title);
+
+  gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_CANCEL);
+  gtk_dialog_set_alternative_button_order (GTK_DIALOG (dialog),
+                                           RESPONSE_SAVE,
+                                           GTK_RESPONSE_CLOSE,
+                                           GTK_RESPONSE_CANCEL,
+                                           -1);
+
+  g_signal_connect (dialog, "destroy",
+                    G_CALLBACK (gtk_widget_destroyed),
+                    &shell->close_dialog);
+
+  g_signal_connect (dialog, "response",
+                    G_CALLBACK (gimp_display_shell_close_response),
+                    shell);
+
+  /* connect <Primary>D to the quit/close button */
+  accel_group = gtk_accel_group_new ();
+  gtk_window_add_accel_group (GTK_WINDOW (shell->close_dialog), accel_group);
+  g_object_unref (accel_group);
+
+  closure = g_closure_new_object (sizeof (GClosure),
+                                  G_OBJECT (shell->close_dialog));
+  g_closure_set_marshal (closure, gimp_display_shell_close_accel_marshal);
+  gtk_accelerator_parse ("<Primary>D", &accel_key, &accel_mods);
+  gtk_accel_group_connect (accel_group, accel_key, accel_mods, 0, closure);
+
+  box = GIMP_MESSAGE_DIALOG (dialog)->box;
+
+  accel_string = gtk_accelerator_get_label (accel_key, accel_mods);
+  hint = g_strdup_printf (_("Press %s to discard all changes and close the image."),
+                          accel_string);
+  markup = g_strdup_printf ("<i><small>%s</small></i>", hint);
+
+  label = gtk_label_new (NULL);
+  gtk_label_set_xalign (GTK_LABEL (label), 0.0);
+  gtk_label_set_line_wrap (GTK_LABEL (label), TRUE);
+  gtk_label_set_markup (GTK_LABEL (label), markup);
+  gtk_box_pack_start (GTK_BOX (box), label, FALSE, FALSE, 0);
+  gtk_widget_show (label);
+
+  g_free (markup);
+  g_free (hint);
+  g_free (accel_string);
+
+  g_signal_connect_object (image, "name-changed",
+                           G_CALLBACK (gimp_display_shell_close_name_changed),
+                           box, 0);
+  g_signal_connect_object (image, "exported",
+                           G_CALLBACK (gimp_display_shell_close_exported),
+                           box, 0);
+
+  gimp_display_shell_close_name_changed (image, box);
+
+  closure =
+    g_cclosure_new_object (G_CALLBACK (gimp_display_shell_close_time_changed),
+                           G_OBJECT (box));
+
+  /*  update every 10 seconds  */
+  source = g_timeout_source_new_seconds (10);
+  g_source_set_closure (source, closure);
+  g_source_attach (source, NULL);
+  g_source_unref (source);
+
+  /*  The dialog is destroyed with the shell, so it should be safe
+   *  to hold an image pointer for the lifetime of the dialog.
+   */
+  g_object_set_data (G_OBJECT (box), "gimp-image", image);
+
+  gimp_display_shell_close_time_changed (box);
+
+  gtk_widget_show (dialog);
+}
+
+static void
+gimp_display_shell_close_name_changed (GimpImage      *image,
+                                       GimpMessageBox *box)
+{
+  GtkWidget *window = gtk_widget_get_toplevel (GTK_WIDGET (box));
+
+  if (GTK_IS_WINDOW (window))
+    {
+      gchar *title = g_strdup_printf (_("Close %s"),
+                                      gimp_image_get_display_name (image));
+
+      gtk_window_set_title (GTK_WINDOW (window), title);
+      g_free (title);
+    }
+
+  gimp_message_box_set_primary_text (box,
+                                     _("Save the changes to image '%s' "
+                                       "before closing?"),
+                                     gimp_image_get_display_name (image));
+}
+
+static void
+gimp_display_shell_close_exported (GimpImage      *image,
+                                   GFile          *file,
+                                   GimpMessageBox *box)
+{
+  gimp_display_shell_close_time_changed (box);
+}
+
+static gboolean
+gimp_display_shell_close_time_changed (GimpMessageBox *box)
+{
+  GimpImage   *image       = g_object_get_data (G_OBJECT (box), "gimp-image");
+  gint64       dirty_time  = gimp_image_get_dirty_time (image);
+  gchar       *time_text   = NULL;
+  gchar       *export_text = NULL;
+
+  if (dirty_time)
+    {
+      gint hours   = 0;
+      gint minutes = 0;
+
+      gimp_time_since (dirty_time, &hours, &minutes);
+
+      if (hours > 0)
+        {
+          if (hours > 1 || minutes == 0)
+            {
+              time_text =
+                g_strdup_printf (ngettext ("If you don't save the image, "
+                                           "changes from the last hour "
+                                           "will be lost.",
+                                           "If you don't save the image, "
+                                           "changes from the last %d "
+                                           "hours will be lost.",
+                                           hours), hours);
+            }
+          else
+            {
+              time_text =
+                g_strdup_printf (ngettext ("If you don't save the image, "
+                                           "changes from the last hour "
+                                           "and %d minute will be lost.",
+                                           "If you don't save the image, "
+                                           "changes from the last hour "
+                                           "and %d minutes will be lost.",
+                                           minutes), minutes);
+            }
+        }
+      else
+        {
+          time_text =
+            g_strdup_printf (ngettext ("If you don't save the image, "
+                                       "changes from the last minute "
+                                       "will be lost.",
+                                       "If you don't save the image, "
+                                       "changes from the last %d "
+                                       "minutes will be lost.",
+                                       minutes), minutes);
+        }
+    }
+
+  if (! gimp_image_is_export_dirty (image))
+    {
+      GFile *file;
+
+      file = gimp_image_get_exported_file (image);
+      if (! file)
+        file = gimp_image_get_imported_file (image);
+
+      export_text = g_strdup_printf (_("The image has been exported to '%s'."),
+                                     gimp_file_get_utf8_name (file));
+    }
+
+  if (time_text && export_text)
+    gimp_message_box_set_text (box, "%s\n\n%s", time_text, export_text);
+  else if (time_text || export_text)
+    gimp_message_box_set_text (box, "%s", time_text ? time_text : export_text);
+  else
+    gimp_message_box_set_text (box, "%s", time_text);
+
+  g_free (time_text);
+  g_free (export_text);
+
+  return TRUE;
+}
+
+static void
+gimp_display_shell_close_response (GtkWidget        *widget,
+                                   gint              response_id,
+                                   GimpDisplayShell *shell)
+{
+  gtk_widget_destroy (widget);
+
+  switch (response_id)
+    {
+    case GTK_RESPONSE_CLOSE:
+      gimp_display_close (shell->display);
+      break;
+
+    case RESPONSE_SAVE:
+      {
+        GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+        if (window)
+          {
+            GimpUIManager *manager = gimp_image_window_get_ui_manager (window);
+
+            gimp_image_window_set_active_shell (window, shell);
+
+            gimp_ui_manager_activate_action (manager,
+                                             "file", "file-save-and-close");
+          }
+      }
+      break;
+
+    default:
+      break;
+    }
+}
+
+static void
+gimp_display_shell_close_accel_marshal (GClosure     *closure,
+                                        GValue       *return_value,
+                                        guint         n_param_values,
+                                        const GValue *param_values,
+                                        gpointer      invocation_hint,
+                                        gpointer      marshal_data)
+{
+  gtk_dialog_response (GTK_DIALOG (closure->data), GTK_RESPONSE_CLOSE);
+
+  /* we handled the accelerator */
+  g_value_set_boolean (return_value, TRUE);
+}
+
+static void
+gimp_time_since (gint64 then,
+                 gint  *hours,
+                 gint  *minutes)
+{
+  gint64 now  = time (NULL);
+  gint64 diff = 1 + now - then;
+
+  g_return_if_fail (now >= then);
+
+  /*  first round up to the nearest minute  */
+  diff = (diff + 59) / 60;
+
+  /*  then optionally round minutes to multiples of 5 or 10  */
+  if (diff > 50)
+    diff = ((diff + 8) / 10) * 10;
+  else if (diff > 20)
+    diff = ((diff + 3) / 5) * 5;
+
+  /*  determine full hours  */
+  if (diff >= 60)
+    {
+      *hours = diff / 60;
+      diff = (diff % 60);
+    }
+
+  /*  round up to full hours for 2 and more  */
+  if (*hours > 1 && diff > 0)
+    {
+      *hours += 1;
+      diff = 0;
+    }
+
+  *minutes = diff;
+}
diff --git a/app/display/gimpdisplayshell-close.h b/app/display/gimpdisplayshell-close.h
new file mode 100644
index 0000000..3d55650
--- /dev/null
+++ b/app/display/gimpdisplayshell-close.h
@@ -0,0 +1,26 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_CLOSE_H__
+#define __GIMP_DISPLAY_SHELL_CLOSE_H__
+
+
+void   gimp_display_shell_close (GimpDisplayShell *shell,
+                                 gboolean          kill_it);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_CLOSE_H__ */
diff --git a/app/display/gimpdisplayshell-cursor.c b/app/display/gimpdisplayshell-cursor.c
new file mode 100644
index 0000000..5a536d5
--- /dev/null
+++ b/app/display/gimpdisplayshell-cursor.c
@@ -0,0 +1,295 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "config/gimpguiconfig.h"
+
+#include "core/gimpimage.h"
+
+#include "widgets/gimpcursor.h"
+#include "widgets/gimpdialogfactory.h"
+#include "widgets/gimpdockcontainer.h"
+#include "widgets/gimpsessioninfo.h"
+
+#include "gimpcanvascursor.h"
+#include "gimpdisplay.h"
+#include "gimpcursorview.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-cursor.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpstatusbar.h"
+
+
+static void  gimp_display_shell_real_set_cursor (GimpDisplayShell   *shell,
+                                                 GimpCursorType      cursor_type,
+                                                 GimpToolCursorType  tool_cursor,
+                                                 GimpCursorModifier  modifier,
+                                                 gboolean            always_install);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_set_cursor (GimpDisplayShell   *shell,
+                               GimpCursorType      cursor_type,
+                               GimpToolCursorType  tool_cursor,
+                               GimpCursorModifier  modifier)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->using_override_cursor)
+    {
+      gimp_display_shell_real_set_cursor (shell,
+                                          cursor_type,
+                                          tool_cursor,
+                                          modifier,
+                                          FALSE);
+    }
+}
+
+void
+gimp_display_shell_unset_cursor (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->using_override_cursor)
+    {
+      gimp_display_shell_real_set_cursor (shell,
+                                          (GimpCursorType) -1, 0, 0, FALSE);
+    }
+}
+
+void
+gimp_display_shell_set_override_cursor (GimpDisplayShell *shell,
+                                        GimpCursorType    cursor_type)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->using_override_cursor ||
+      (shell->using_override_cursor &&
+       shell->override_cursor != cursor_type))
+    {
+      shell->override_cursor       = cursor_type;
+      shell->using_override_cursor = TRUE;
+
+      gimp_cursor_set (shell->canvas,
+                       shell->cursor_handedness,
+                       cursor_type,
+                       GIMP_TOOL_CURSOR_NONE,
+                       GIMP_CURSOR_MODIFIER_NONE);
+    }
+}
+
+void
+gimp_display_shell_unset_override_cursor (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->using_override_cursor)
+    {
+      shell->using_override_cursor = FALSE;
+
+      gimp_display_shell_real_set_cursor (shell,
+                                          shell->current_cursor,
+                                          shell->tool_cursor,
+                                          shell->cursor_modifier,
+                                          TRUE);
+    }
+}
+
+void
+gimp_display_shell_update_software_cursor (GimpDisplayShell    *shell,
+                                           GimpCursorPrecision  precision,
+                                           gint                 display_x,
+                                           gint                 display_y,
+                                           gdouble              image_x,
+                                           gdouble              image_y)
+{
+  GimpImageWindow   *image_window;
+  GimpDialogFactory *factory;
+  GimpStatusbar     *statusbar;
+  GtkWidget         *widget;
+  GimpImage         *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  if (shell->draw_cursor &&
+      shell->proximity   &&
+      display_x >= 0     &&
+      display_y >= 0)
+    {
+      gimp_canvas_item_begin_change (shell->cursor);
+
+      gimp_canvas_cursor_set (shell->cursor,
+                              display_x,
+                              display_y);
+      gimp_canvas_item_set_visible (shell->cursor, TRUE);
+
+      gimp_canvas_item_end_change (shell->cursor);
+    }
+  else
+    {
+      gimp_canvas_item_set_visible (shell->cursor, FALSE);
+    }
+
+  /*  use the passed image_coords for the statusbar because they are
+   *  possibly snapped...
+   */
+  statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_statusbar_update_cursor (statusbar, precision, image_x, image_y);
+
+  image_window = gimp_display_shell_get_window (shell);
+  factory = gimp_dock_container_get_dialog_factory (GIMP_DOCK_CONTAINER (image_window));
+
+  widget = gimp_dialog_factory_find_widget (factory, "gimp-cursor-view");
+
+  if (widget)
+    {
+      GtkWidget *cursor_view = gtk_bin_get_child (GTK_BIN (widget));
+
+      if (cursor_view)
+        {
+          gint t_x = -1;
+          gint t_y = -1;
+
+          /*  ...but use the unsnapped display_coords for the info window  */
+          if (display_x >= 0 && display_y >= 0)
+            gimp_display_shell_untransform_xy (shell, display_x, display_y,
+                                               &t_x, &t_y, FALSE);
+
+          gimp_cursor_view_update_cursor (GIMP_CURSOR_VIEW (cursor_view),
+                                          image, shell->unit,
+                                          t_x, t_y);
+        }
+    }
+}
+
+void
+gimp_display_shell_clear_software_cursor (GimpDisplayShell *shell)
+{
+  GimpImageWindow   *image_window;
+  GimpDialogFactory *factory;
+  GimpStatusbar     *statusbar;
+  GtkWidget         *widget;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_canvas_item_set_visible (shell->cursor, FALSE);
+
+  statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_statusbar_clear_cursor (statusbar);
+
+  image_window = gimp_display_shell_get_window (shell);
+  factory = gimp_dock_container_get_dialog_factory (GIMP_DOCK_CONTAINER (image_window));
+
+  widget = gimp_dialog_factory_find_widget (factory, "gimp-cursor-view");
+
+  if (widget)
+    {
+      GtkWidget *cursor_view = gtk_bin_get_child (GTK_BIN (widget));
+
+      if (cursor_view)
+        gimp_cursor_view_clear_cursor (GIMP_CURSOR_VIEW (cursor_view));
+    }
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_shell_real_set_cursor (GimpDisplayShell   *shell,
+                                    GimpCursorType      cursor_type,
+                                    GimpToolCursorType  tool_cursor,
+                                    GimpCursorModifier  modifier,
+                                    gboolean            always_install)
+{
+  GimpHandedness cursor_handedness;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (cursor_type == (GimpCursorType) -1)
+    {
+      shell->current_cursor = cursor_type;
+
+      if (gtk_widget_is_drawable (shell->canvas))
+        gdk_window_set_cursor (gtk_widget_get_window (shell->canvas), NULL);
+
+      return;
+    }
+
+  if (cursor_type != GIMP_CURSOR_NONE &&
+      cursor_type != GIMP_CURSOR_BAD)
+    {
+      switch (shell->display->config->cursor_mode)
+        {
+        case GIMP_CURSOR_MODE_TOOL_ICON:
+          break;
+
+        case GIMP_CURSOR_MODE_TOOL_CROSSHAIR:
+          if (cursor_type < GIMP_CURSOR_CORNER_TOP ||
+              cursor_type > GIMP_CURSOR_SIDE_TOP_LEFT)
+            {
+              /* the corner and side cursors count as crosshair, so leave
+               * them and override everything else
+               */
+              cursor_type = GIMP_CURSOR_CROSSHAIR_SMALL;
+            }
+          break;
+
+        case GIMP_CURSOR_MODE_CROSSHAIR:
+          cursor_type = GIMP_CURSOR_CROSSHAIR;
+          tool_cursor = GIMP_TOOL_CURSOR_NONE;
+
+          if (modifier != GIMP_CURSOR_MODIFIER_BAD)
+            {
+              /* the bad modifier is always shown */
+              modifier = GIMP_CURSOR_MODIFIER_NONE;
+            }
+          break;
+        }
+    }
+
+  cursor_type = gimp_cursor_rotate (cursor_type, shell->rotate_angle);
+
+  cursor_handedness = GIMP_GUI_CONFIG (shell->display->config)->cursor_handedness;
+
+  if (shell->cursor_handedness != cursor_handedness ||
+      shell->current_cursor    != cursor_type       ||
+      shell->tool_cursor       != tool_cursor       ||
+      shell->cursor_modifier   != modifier          ||
+      always_install)
+    {
+      shell->cursor_handedness = cursor_handedness;
+      shell->current_cursor    = cursor_type;
+      shell->tool_cursor       = tool_cursor;
+      shell->cursor_modifier   = modifier;
+
+      gimp_cursor_set (shell->canvas,
+                       cursor_handedness,
+                       cursor_type, tool_cursor, modifier);
+    }
+}
diff --git a/app/display/gimpdisplayshell-cursor.h b/app/display/gimpdisplayshell-cursor.h
new file mode 100644
index 0000000..8f434c6
--- /dev/null
+++ b/app/display/gimpdisplayshell-cursor.h
@@ -0,0 +1,47 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_CURSOR_H__
+#define __GIMP_DISPLAY_SHELL_CURSOR_H__
+
+
+/*  functions dealing with the normal windowing system cursor  */
+
+void   gimp_display_shell_set_cursor             (GimpDisplayShell    *shell,
+                                                  GimpCursorType       cursor_type,
+                                                  GimpToolCursorType   tool_cursor,
+                                                  GimpCursorModifier   modifier);
+void   gimp_display_shell_unset_cursor           (GimpDisplayShell    *shell);
+void   gimp_display_shell_set_override_cursor    (GimpDisplayShell    *shell,
+                                                  GimpCursorType       cursor_type);
+void   gimp_display_shell_unset_override_cursor  (GimpDisplayShell    *shell);
+
+
+/*  functions dealing with the software cursor that is drawn to the
+ *  canvas by GIMP
+ */
+
+void   gimp_display_shell_update_software_cursor (GimpDisplayShell    *shell,
+                                                  GimpCursorPrecision  precision,
+                                                  gint                 display_x,
+                                                  gint                 display_y,
+                                                  gdouble              image_x,
+                                                  gdouble              image_y);
+void   gimp_display_shell_clear_software_cursor  (GimpDisplayShell    *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_CURSOR_H__ */
diff --git a/app/display/gimpdisplayshell-dnd.c b/app/display/gimpdisplayshell-dnd.c
new file mode 100644
index 0000000..152ca45
--- /dev/null
+++ b/app/display/gimpdisplayshell-dnd.c
@@ -0,0 +1,770 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimp-edit.h"
+#include "core/gimpbuffer.h"
+#include "core/gimpdrawable-edit.h"
+#include "core/gimpfilloptions.h"
+#include "core/gimpimage.h"
+#include "core/gimpimage-new.h"
+#include "core/gimpimage-undo.h"
+#include "core/gimplayer.h"
+#include "core/gimplayer-new.h"
+#include "core/gimplayermask.h"
+#include "core/gimppattern.h"
+#include "core/gimpprogress.h"
+
+#include "file/file-open.h"
+
+#include "text/gimptext.h"
+#include "text/gimptextlayer.h"
+
+#include "vectors/gimpvectors.h"
+#include "vectors/gimpvectors-import.h"
+
+#include "widgets/gimpdnd.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-dnd.h"
+#include "gimpdisplayshell-transform.h"
+
+#include "gimp-log.h"
+#include "gimp-intl.h"
+
+
+/*  local function prototypes  */
+
+static void   gimp_display_shell_drop_drawable  (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 GimpViewable    *viewable,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_vectors   (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 GimpViewable    *viewable,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_svg       (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 const guchar    *svg_data,
+                                                 gsize            svg_data_length,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_pattern   (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 GimpViewable    *viewable,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_color     (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 const GimpRGB   *color,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_buffer    (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 GimpViewable    *viewable,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_uri_list  (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 GList           *uri_list,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_component (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 GimpImage       *image,
+                                                 GimpChannelType  component,
+                                                 gpointer         data);
+static void   gimp_display_shell_drop_pixbuf    (GtkWidget       *widget,
+                                                 gint             x,
+                                                 gint             y,
+                                                 GdkPixbuf       *pixbuf,
+                                                 gpointer         data);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_dnd_init (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_dnd_viewable_dest_add  (shell->canvas, GIMP_TYPE_LAYER,
+                               gimp_display_shell_drop_drawable,
+                               shell);
+  gimp_dnd_viewable_dest_add  (shell->canvas, GIMP_TYPE_LAYER_MASK,
+                               gimp_display_shell_drop_drawable,
+                               shell);
+  gimp_dnd_viewable_dest_add  (shell->canvas, GIMP_TYPE_CHANNEL,
+                               gimp_display_shell_drop_drawable,
+                               shell);
+  gimp_dnd_viewable_dest_add  (shell->canvas, GIMP_TYPE_VECTORS,
+                               gimp_display_shell_drop_vectors,
+                               shell);
+  gimp_dnd_viewable_dest_add  (shell->canvas, GIMP_TYPE_PATTERN,
+                               gimp_display_shell_drop_pattern,
+                               shell);
+  gimp_dnd_viewable_dest_add  (shell->canvas, GIMP_TYPE_BUFFER,
+                               gimp_display_shell_drop_buffer,
+                               shell);
+  gimp_dnd_color_dest_add     (shell->canvas,
+                               gimp_display_shell_drop_color,
+                               shell);
+  gimp_dnd_component_dest_add (shell->canvas,
+                               gimp_display_shell_drop_component,
+                               shell);
+  gimp_dnd_uri_list_dest_add  (shell->canvas,
+                               gimp_display_shell_drop_uri_list,
+                               shell);
+  gimp_dnd_svg_dest_add       (shell->canvas,
+                               gimp_display_shell_drop_svg,
+                               shell);
+  gimp_dnd_pixbuf_dest_add    (shell->canvas,
+                               gimp_display_shell_drop_pixbuf,
+                               shell);
+}
+
+
+/*  private functions  */
+
+/*
+ * Position the dropped item in the middle of the viewport.
+ */
+static void
+gimp_display_shell_dnd_position_item (GimpDisplayShell *shell,
+                                      GimpImage        *image,
+                                      GimpItem         *item)
+{
+  gint item_width  = gimp_item_get_width  (item);
+  gint item_height = gimp_item_get_height (item);
+  gint off_x, off_y;
+
+  if (item_width  >= gimp_image_get_width  (image) &&
+      item_height >= gimp_image_get_height (image))
+    {
+      off_x = (gimp_image_get_width  (image) - item_width)  / 2;
+      off_y = (gimp_image_get_height (image) - item_height) / 2;
+    }
+  else
+    {
+      gint x, y;
+      gint width, height;
+
+      gimp_display_shell_untransform_viewport (
+        shell,
+        ! gimp_display_shell_get_infinite_canvas (shell),
+        &x, &y, &width, &height);
+
+      off_x = x + (width  - item_width)  / 2;
+      off_y = y + (height - item_height) / 2;
+    }
+
+  gimp_item_translate (item,
+                       off_x - gimp_item_get_offset_x (item),
+                       off_y - gimp_item_get_offset_y (item),
+                       FALSE);
+}
+
+static void
+gimp_display_shell_dnd_flush (GimpDisplayShell *shell,
+                              GimpImage        *image)
+{
+  gimp_display_shell_present (shell);
+
+  gimp_image_flush (image);
+
+  gimp_context_set_display (gimp_get_user_context (shell->display->gimp),
+                            shell->display);
+}
+
+static void
+gimp_display_shell_drop_drawable (GtkWidget    *widget,
+                                  gint          x,
+                                  gint          y,
+                                  GimpViewable *viewable,
+                                  gpointer      data)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *image     = gimp_display_get_image (shell->display);
+  GType             new_type;
+  GimpItem         *new_item;
+
+  GIMP_LOG (DND, NULL);
+
+  if (shell->display->gimp->busy)
+    return;
+
+  if (! image)
+    {
+      image = gimp_image_new_from_drawable (shell->display->gimp,
+                                            GIMP_DRAWABLE (viewable));
+      gimp_create_display (shell->display->gimp, image, GIMP_UNIT_PIXEL, 1.0,
+                           G_OBJECT (gtk_widget_get_screen (widget)),
+                           gimp_widget_get_monitor (widget));
+      g_object_unref (image);
+
+      return;
+    }
+
+  if (GIMP_IS_LAYER (viewable))
+    new_type = G_TYPE_FROM_INSTANCE (viewable);
+  else
+    new_type = GIMP_TYPE_LAYER;
+
+  new_item = gimp_item_convert (GIMP_ITEM (viewable), image, new_type);
+
+  if (new_item)
+    {
+      GimpLayer *new_layer = GIMP_LAYER (new_item);
+
+      gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_EDIT_PASTE,
+                                   _("Drop New Layer"));
+
+      gimp_display_shell_dnd_position_item (shell, image, new_item);
+
+      gimp_item_set_visible (new_item, TRUE, FALSE);
+      gimp_item_set_linked (new_item, FALSE, FALSE);
+
+      gimp_image_add_layer (image, new_layer,
+                            GIMP_IMAGE_ACTIVE_PARENT, -1, TRUE);
+
+      gimp_image_undo_group_end (image);
+
+      gimp_display_shell_dnd_flush (shell, image);
+    }
+}
+
+static void
+gimp_display_shell_drop_vectors (GtkWidget    *widget,
+                                 gint          x,
+                                 gint          y,
+                                 GimpViewable *viewable,
+                                 gpointer      data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *image = gimp_display_get_image (shell->display);
+  GimpItem         *new_item;
+
+  GIMP_LOG (DND, NULL);
+
+  if (shell->display->gimp->busy)
+    return;
+
+  if (! image)
+    return;
+
+  new_item = gimp_item_convert (GIMP_ITEM (viewable),
+                                image, G_TYPE_FROM_INSTANCE (viewable));
+
+  if (new_item)
+    {
+      GimpVectors *new_vectors = GIMP_VECTORS (new_item);
+
+      gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_EDIT_PASTE,
+                                   _("Drop New Path"));
+
+      gimp_image_add_vectors (image, new_vectors,
+                              GIMP_IMAGE_ACTIVE_PARENT, -1, TRUE);
+
+      gimp_image_undo_group_end (image);
+
+      gimp_display_shell_dnd_flush (shell, image);
+    }
+}
+
+static void
+gimp_display_shell_drop_svg (GtkWidget     *widget,
+                             gint           x,
+                             gint           y,
+                             const guchar  *svg_data,
+                             gsize          svg_data_len,
+                             gpointer       data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *image = gimp_display_get_image (shell->display);
+  GError           *error  = NULL;
+
+  GIMP_LOG (DND, NULL);
+
+  if (shell->display->gimp->busy)
+    return;
+
+  if (! image)
+    return;
+
+  if (! gimp_vectors_import_buffer (image,
+                                    (const gchar *) svg_data, svg_data_len,
+                                    TRUE, FALSE,
+                                    GIMP_IMAGE_ACTIVE_PARENT, -1,
+                                    NULL, &error))
+    {
+      gimp_message_literal (shell->display->gimp, G_OBJECT (shell->display),
+                            GIMP_MESSAGE_ERROR,
+                            error->message);
+      g_clear_error (&error);
+    }
+  else
+    {
+      gimp_display_shell_dnd_flush (shell, image);
+    }
+}
+
+static void
+gimp_display_shell_dnd_fill (GimpDisplayShell *shell,
+                             GimpFillOptions  *options,
+                             const gchar      *undo_desc)
+{
+  GimpImage    *image = gimp_display_get_image (shell->display);
+  GimpDrawable *drawable;
+
+  if (shell->display->gimp->busy)
+    return;
+
+  if (! image)
+    return;
+
+  drawable = gimp_image_get_active_drawable (image);
+
+  if (! drawable)
+    return;
+
+  if (gimp_viewable_get_children (GIMP_VIEWABLE (drawable)))
+    {
+      gimp_message_literal (shell->display->gimp, G_OBJECT (shell->display),
+                            GIMP_MESSAGE_ERROR,
+                            _("Cannot modify the pixels of layer groups."));
+      return;
+    }
+
+  if (gimp_item_is_content_locked (GIMP_ITEM (drawable)))
+    {
+      gimp_message_literal (shell->display->gimp, G_OBJECT (shell->display),
+                            GIMP_MESSAGE_ERROR,
+                            _("The active layer's pixels are locked."));
+      return;
+    }
+
+  /* FIXME: there should be a virtual method for this that the
+   *        GimpTextLayer can override.
+   */
+  if (gimp_fill_options_get_style (options) == GIMP_FILL_STYLE_SOLID &&
+      gimp_item_is_text_layer (GIMP_ITEM (drawable)))
+    {
+      GimpRGB color;
+
+      gimp_context_get_foreground (GIMP_CONTEXT (options), &color);
+
+      gimp_text_layer_set (GIMP_TEXT_LAYER (drawable), NULL,
+                           "color", &color,
+                           NULL);
+    }
+  else
+    {
+      gimp_drawable_edit_fill (drawable, options, undo_desc);
+    }
+
+  gimp_display_shell_dnd_flush (shell, image);
+}
+
+static void
+gimp_display_shell_drop_pattern (GtkWidget    *widget,
+                                 gint          x,
+                                 gint          y,
+                                 GimpViewable *viewable,
+                                 gpointer      data)
+{
+  GimpDisplayShell *shell   = GIMP_DISPLAY_SHELL (data);
+  GimpFillOptions  *options = gimp_fill_options_new (shell->display->gimp,
+                                                     NULL, FALSE);
+
+  GIMP_LOG (DND, NULL);
+
+  gimp_fill_options_set_style (options, GIMP_FILL_STYLE_PATTERN);
+  gimp_context_set_pattern (GIMP_CONTEXT (options), GIMP_PATTERN (viewable));
+
+  gimp_display_shell_dnd_fill (shell, options,
+                               C_("undo-type", "Drop pattern to layer"));
+
+  g_object_unref (options);
+}
+
+static void
+gimp_display_shell_drop_color (GtkWidget     *widget,
+                               gint           x,
+                               gint           y,
+                               const GimpRGB *color,
+                               gpointer       data)
+{
+  GimpDisplayShell *shell   = GIMP_DISPLAY_SHELL (data);
+  GimpFillOptions  *options = gimp_fill_options_new (shell->display->gimp,
+                                                     NULL, FALSE);
+
+  GIMP_LOG (DND, NULL);
+
+  gimp_fill_options_set_style (options, GIMP_FILL_STYLE_SOLID);
+  gimp_context_set_foreground (GIMP_CONTEXT (options), color);
+
+  gimp_display_shell_dnd_fill (shell, options,
+                               C_("undo-type", "Drop color to layer"));
+
+  g_object_unref (options);
+}
+
+static void
+gimp_display_shell_drop_buffer (GtkWidget    *widget,
+                                gint          drop_x,
+                                gint          drop_y,
+                                GimpViewable *viewable,
+                                gpointer      data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *image = gimp_display_get_image (shell->display);
+  GimpDrawable     *drawable;
+  GimpBuffer       *buffer;
+  GimpPasteType     paste_type;
+  gint              x, y, width, height;
+
+  GIMP_LOG (DND, NULL);
+
+  if (shell->display->gimp->busy)
+    return;
+
+  if (! image)
+    {
+      image = gimp_image_new_from_buffer (shell->display->gimp,
+                                          GIMP_BUFFER (viewable));
+      gimp_create_display (image->gimp, image, GIMP_UNIT_PIXEL, 1.0,
+                           G_OBJECT (gtk_widget_get_screen (widget)),
+                           gimp_widget_get_monitor (widget));
+      g_object_unref (image);
+
+      return;
+    }
+
+  paste_type = GIMP_PASTE_TYPE_FLOATING;
+
+  drawable = gimp_image_get_active_drawable (image);
+
+  if (drawable)
+    {
+      if (gimp_viewable_get_children (GIMP_VIEWABLE (drawable)))
+        {
+          gimp_message_literal (shell->display->gimp, G_OBJECT (shell->display),
+                                GIMP_MESSAGE_INFO,
+                                _("Pasted as new layer because the "
+                                  "target is a layer group."));
+
+          paste_type = GIMP_PASTE_TYPE_NEW_LAYER;
+        }
+      else if (gimp_item_is_content_locked (GIMP_ITEM (drawable)))
+        {
+          gimp_message_literal (shell->display->gimp, G_OBJECT (shell->display),
+                                GIMP_MESSAGE_ERROR,
+                                _("Pasted as new layer because the "
+                                  "target's pixels are locked."));
+
+          paste_type = GIMP_PASTE_TYPE_NEW_LAYER;
+        }
+    }
+
+  buffer = GIMP_BUFFER (viewable);
+
+  gimp_display_shell_untransform_viewport (
+    shell,
+    ! gimp_display_shell_get_infinite_canvas (shell),
+    &x, &y, &width, &height);
+
+  /* FIXME: popup a menu for selecting "Paste Into" */
+
+  gimp_edit_paste (image, drawable, GIMP_OBJECT (buffer),
+                   paste_type, x, y, width, height);
+
+  gimp_display_shell_dnd_flush (shell, image);
+}
+
+static void
+gimp_display_shell_drop_uri_list (GtkWidget *widget,
+                                  gint       x,
+                                  gint       y,
+                                  GList     *uri_list,
+                                  gpointer   data)
+{
+  GimpDisplayShell *shell   = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *image;
+  GimpContext      *context;
+  GList            *list;
+  gboolean          open_as_layers;
+
+  /* If the app is already being torn down, shell->display might be
+   * NULL here.  Play it safe.
+   */
+  if (! shell->display)
+    return;
+
+  image = gimp_display_get_image (shell->display);
+  context = gimp_get_user_context (shell->display->gimp);
+
+  GIMP_LOG (DND, NULL);
+
+  open_as_layers = (image != NULL);
+
+  if (image)
+    g_object_ref (image);
+
+  for (list = uri_list; list; list = g_list_next (list))
+    {
+      GFile             *file  = g_file_new_for_uri (list->data);
+      GimpPDBStatusType  status;
+      GError            *error = NULL;
+      gboolean           warn  = FALSE;
+
+      if (! shell->display)
+        {
+          /* It seems as if GIMP is being torn down for quitting. Bail out. */
+          g_object_unref (file);
+          g_clear_object (&image);
+          return;
+        }
+
+      if (open_as_layers)
+        {
+          GList *new_layers;
+
+          new_layers = file_open_layers (shell->display->gimp, context,
+                                         GIMP_PROGRESS (shell->display),
+                                         image, FALSE,
+                                         file, GIMP_RUN_INTERACTIVE, NULL,
+                                         &status, &error);
+
+          if (new_layers)
+            {
+              gint x      = 0;
+              gint y      = 0;
+              gint width  = gimp_image_get_width  (image);
+              gint height = gimp_image_get_height (image);
+
+              if (gimp_display_get_image (shell->display))
+                {
+                  gimp_display_shell_untransform_viewport (
+                    shell,
+                    ! gimp_display_shell_get_infinite_canvas (shell),
+                    &x, &y, &width, &height);
+                }
+
+              gimp_image_add_layers (image, new_layers,
+                                     GIMP_IMAGE_ACTIVE_PARENT, -1,
+                                     x, y, width, height,
+                                     _("Drop layers"));
+
+              g_list_free (new_layers);
+            }
+          else if (status != GIMP_PDB_CANCEL)
+            {
+              warn = TRUE;
+            }
+        }
+      else if (gimp_display_get_image (shell->display))
+        {
+          /*  open any subsequent images in a new display  */
+          GimpImage *new_image;
+
+          new_image = file_open_with_display (shell->display->gimp, context,
+                                              NULL,
+                                              file, FALSE,
+                                              G_OBJECT (gtk_widget_get_screen (widget)),
+                                              gimp_widget_get_monitor (widget),
+                                              &status, &error);
+
+          if (! new_image && status != GIMP_PDB_CANCEL)
+            warn = TRUE;
+        }
+      else
+        {
+          /*  open the first image in the empty display  */
+          image = file_open_with_display (shell->display->gimp, context,
+                                          GIMP_PROGRESS (shell->display),
+                                          file, FALSE,
+                                          G_OBJECT (gtk_widget_get_screen (widget)),
+                                          gimp_widget_get_monitor (widget),
+                                          &status, &error);
+
+          if (image)
+            {
+              g_object_ref (image);
+            }
+          else if (status != GIMP_PDB_CANCEL)
+            {
+              warn = TRUE;
+            }
+        }
+
+      /* Something above might have run a few rounds of the main loop. Check
+       * that shell->display is still there, otherwise ignore this as the app
+       * is being torn down for quitting.
+       */
+      if (warn && shell->display)
+        {
+          gimp_message (shell->display->gimp, G_OBJECT (shell->display),
+                        GIMP_MESSAGE_ERROR,
+                        _("Opening '%s' failed:\n\n%s"),
+                        gimp_file_get_utf8_name (file), error->message);
+          g_clear_error (&error);
+        }
+
+      g_object_unref (file);
+    }
+
+  if (image)
+    gimp_display_shell_dnd_flush (shell, image);
+
+  g_clear_object (&image);
+}
+
+static void
+gimp_display_shell_drop_component (GtkWidget       *widget,
+                                   gint             x,
+                                   gint             y,
+                                   GimpImage       *image,
+                                   GimpChannelType  component,
+                                   gpointer         data)
+{
+  GimpDisplayShell *shell      = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *dest_image = gimp_display_get_image (shell->display);
+  GimpChannel      *channel;
+  GimpItem         *new_item;
+  const gchar      *desc;
+
+  GIMP_LOG (DND, NULL);
+
+  if (shell->display->gimp->busy)
+    return;
+
+  if (! dest_image)
+    {
+      dest_image = gimp_image_new_from_component (image->gimp,
+                                                  image, component);
+      gimp_create_display (dest_image->gimp, dest_image, GIMP_UNIT_PIXEL, 1.0,
+                           G_OBJECT (gtk_widget_get_screen (widget)),
+                           gimp_widget_get_monitor (widget));
+      g_object_unref (dest_image);
+
+      return;
+    }
+
+  channel = gimp_channel_new_from_component (image, component, NULL, NULL);
+
+  new_item = gimp_item_convert (GIMP_ITEM (channel),
+                                dest_image, GIMP_TYPE_LAYER);
+  g_object_unref (channel);
+
+  if (new_item)
+    {
+      GimpLayer *new_layer = GIMP_LAYER (new_item);
+
+      gimp_enum_get_value (GIMP_TYPE_CHANNEL_TYPE, component,
+                           NULL, NULL, &desc, NULL);
+      gimp_object_take_name (GIMP_OBJECT (new_layer),
+                             g_strdup_printf (_("%s Channel Copy"), desc));
+
+      gimp_image_undo_group_start (dest_image, GIMP_UNDO_GROUP_EDIT_PASTE,
+                                   _("Drop New Layer"));
+
+      gimp_display_shell_dnd_position_item (shell, image, new_item);
+
+      gimp_image_add_layer (dest_image, new_layer,
+                            GIMP_IMAGE_ACTIVE_PARENT, -1, TRUE);
+
+      gimp_image_undo_group_end (dest_image);
+
+      gimp_display_shell_dnd_flush (shell, dest_image);
+    }
+}
+
+static void
+gimp_display_shell_drop_pixbuf (GtkWidget *widget,
+                                gint       x,
+                                gint       y,
+                                GdkPixbuf *pixbuf,
+                                gpointer   data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *image = gimp_display_get_image (shell->display);
+  GimpLayer        *new_layer;
+  gboolean          has_alpha = FALSE;
+
+  GIMP_LOG (DND, NULL);
+
+  if (shell->display->gimp->busy)
+    return;
+
+  if (! image)
+    {
+      image = gimp_image_new_from_pixbuf (shell->display->gimp, pixbuf,
+                                          _("Dropped Buffer"));
+      gimp_create_display (image->gimp, image, GIMP_UNIT_PIXEL, 1.0,
+                           G_OBJECT (gtk_widget_get_screen (widget)),
+                           gimp_widget_get_monitor (widget));
+      g_object_unref (image);
+
+      return;
+    }
+
+  if (gdk_pixbuf_get_n_channels (pixbuf) == 2 ||
+      gdk_pixbuf_get_n_channels (pixbuf) == 4)
+    {
+      has_alpha = TRUE;
+    }
+
+  new_layer =
+    gimp_layer_new_from_pixbuf (pixbuf, image,
+                                gimp_image_get_layer_format (image, has_alpha),
+                                _("Dropped Buffer"),
+                                GIMP_OPACITY_OPAQUE,
+                                gimp_image_get_default_new_layer_mode (image));
+
+  if (new_layer)
+    {
+      GimpItem *new_item = GIMP_ITEM (new_layer);
+
+      gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_EDIT_PASTE,
+                                   _("Drop New Layer"));
+
+      gimp_display_shell_dnd_position_item (shell, image, new_item);
+
+      gimp_image_add_layer (image, new_layer,
+                            GIMP_IMAGE_ACTIVE_PARENT, -1, TRUE);
+
+      gimp_image_undo_group_end (image);
+
+      gimp_display_shell_dnd_flush (shell, image);
+    }
+}
diff --git a/app/display/gimpdisplayshell-dnd.h b/app/display/gimpdisplayshell-dnd.h
new file mode 100644
index 0000000..d1f6e99
--- /dev/null
+++ b/app/display/gimpdisplayshell-dnd.h
@@ -0,0 +1,25 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_DND_H__
+#define __GIMP_DISPLAY_SHELL_DND_H__
+
+
+void   gimp_display_shell_dnd_init (GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_DND_H__ */
diff --git a/app/display/gimpdisplayshell-draw.c b/app/display/gimpdisplayshell-draw.c
new file mode 100644
index 0000000..d6a63d5
--- /dev/null
+++ b/app/display/gimpdisplayshell-draw.c
@@ -0,0 +1,256 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimp-cairo.h"
+#include "core/gimp-utils.h"
+#include "core/gimpimage.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvas-style.h"
+#include "gimpcanvaspath.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-draw.h"
+#include "gimpdisplayshell-render.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpdisplayxfer.h"
+
+#ifdef GDK_WINDOWING_QUARTZ
+#import <AppKit/AppKit.h>
+#endif
+
+/* #define GIMP_DISPLAY_RENDER_ENABLE_SCALING 1 */
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_draw_selection_out (GimpDisplayShell *shell,
+                                       cairo_t          *cr,
+                                       GimpSegment      *segs,
+                                       gint              n_segs)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (segs != NULL && n_segs > 0);
+
+  gimp_canvas_set_selection_out_style (shell->canvas, cr,
+                                       shell->offset_x, shell->offset_y);
+
+  gimp_cairo_segments (cr, segs, n_segs);
+  cairo_stroke (cr);
+}
+
+void
+gimp_display_shell_draw_selection_in (GimpDisplayShell   *shell,
+                                      cairo_t            *cr,
+                                      cairo_pattern_t    *mask,
+                                      gint                index)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (mask != NULL);
+
+  gimp_canvas_set_selection_in_style (shell->canvas, cr, index,
+                                      shell->offset_x, shell->offset_y);
+
+  cairo_mask (cr, mask);
+}
+
+void
+gimp_display_shell_draw_checkerboard (GimpDisplayShell *shell,
+                                      cairo_t          *cr)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (cr != NULL);
+
+  image = gimp_display_get_image (shell->display);
+
+  if (G_UNLIKELY (! shell->checkerboard))
+    {
+      GimpCheckSize  check_size;
+      GimpCheckType  check_type;
+      guchar         check_light;
+      guchar         check_dark;
+      GimpRGB        light;
+      GimpRGB        dark;
+
+      g_object_get (shell->display->config,
+                    "transparency-size", &check_size,
+                    "transparency-type", &check_type,
+                    NULL);
+
+      gimp_checks_get_shades (check_type, &check_light, &check_dark);
+      gimp_rgb_set_uchar (&light, check_light, check_light, check_light);
+      gimp_rgb_set_uchar (&dark,  check_dark,  check_dark,  check_dark);
+
+      shell->checkerboard =
+        gimp_cairo_checkerboard_create (cr,
+                                        1 << (check_size + 2), &light, &dark);
+    }
+
+  cairo_translate (cr, - shell->offset_x, - shell->offset_y);
+
+  if (gimp_image_get_component_visible (image, GIMP_CHANNEL_ALPHA))
+    cairo_set_source (cr, shell->checkerboard);
+  else
+    cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
+
+  cairo_paint (cr);
+}
+
+void
+gimp_display_shell_draw_image (GimpDisplayShell *shell,
+                               cairo_t          *cr,
+                               gint              x,
+                               gint              y,
+                               gint              w,
+                               gint              h)
+{
+  gdouble chunk_width;
+  gdouble chunk_height;
+  gdouble scale = 1.0;
+  gint    n_rows;
+  gint    n_cols;
+  gint    r, c;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (gimp_display_get_image (shell->display));
+  g_return_if_fail (cr != NULL);
+
+  /*  display the image in RENDER_BUF_WIDTH x RENDER_BUF_HEIGHT
+   *  maximally-sized image-space chunks.  adjust the screen-space
+   *  chunk size as necessary, to accommodate for the display
+   *  transform and window scale factor.
+   */
+  chunk_width  = GIMP_DISPLAY_RENDER_BUF_WIDTH;
+  chunk_height = GIMP_DISPLAY_RENDER_BUF_HEIGHT;
+
+#ifdef GIMP_DISPLAY_RENDER_ENABLE_SCALING
+  /* if we had this future API, things would look pretty on hires (retina) */
+  scale *=
+    gdk_window_get_scale_factor (
+      gtk_widget_get_window (gtk_widget_get_toplevel (GTK_WIDGET (shell))));
+#elif defined(GDK_WINDOWING_QUARTZ)
+  /* gtk2/osx retina support */
+  if ([
+      [NSScreen mainScreen]
+      respondsToSelector: @selector(backingScaleFactor)
+    ]) {
+    for (NSScreen * screen in [NSScreen screens]) {
+      float s = [screen backingScaleFactor];
+      if (s > scale) scale = s;
+    }
+  }
+#endif
+
+  scale  = MIN (scale, GIMP_DISPLAY_RENDER_MAX_SCALE);
+  scale *= MAX (shell->scale_x, shell->scale_y);
+
+  if (scale != shell->scale_x)
+    chunk_width  = (chunk_width  - 1.0) * (shell->scale_x / scale);
+  if (scale != shell->scale_y)
+    chunk_height = (chunk_height - 1.0) * (shell->scale_y / scale);
+
+  if (shell->rotate_untransform)
+    {
+      gdouble a = shell->rotate_angle * G_PI / 180.0;
+
+      chunk_width = chunk_height = (MIN (chunk_width, chunk_height) - 1.0) /
+                                   (fabs (sin (a)) + fabs (cos (a)));
+    }
+
+  /* divide the painted area to evenly-sized chunks */
+  n_rows = ceil (h / floor (chunk_height));
+  n_cols = ceil (w / floor (chunk_width));
+
+  for (r = 0; r < n_rows; r++)
+    {
+      gint y1 = y + (2 *  r      * h + n_rows) / (2 * n_rows);
+      gint y2 = y + (2 * (r + 1) * h + n_rows) / (2 * n_rows);
+
+      for (c = 0; c < n_cols; c++)
+        {
+          gint    x1 = x + (2 *  c      * w + n_cols) / (2 * n_cols);
+          gint    x2 = x + (2 * (c + 1) * w + n_cols) / (2 * n_cols);
+          gdouble ix1, iy1;
+          gdouble ix2, iy2;
+          gint    ix, iy;
+          gint    iw, ih;
+
+          /* map chunk from screen space to scaled image space */
+          gimp_display_shell_untransform_bounds_with_scale (
+            shell, scale,
+            x1,   y1,   x2,   y2,
+            &ix1, &iy1, &ix2, &iy2);
+
+          ix = floor (ix1);
+          iy = floor (iy1);
+          iw = ceil  (ix2) - ix;
+          ih = ceil  (iy2) - iy;
+
+          cairo_save (cr);
+
+          /* clip to chunk bounds, in screen space */
+          cairo_rectangle (cr, x1, y1, x2 - x1, y2 - y1);
+          cairo_clip (cr);
+
+          /* transform to scaled image space, and apply uneven scaling */
+          if (shell->rotate_transform)
+            cairo_transform (cr, shell->rotate_transform);
+          cairo_translate (cr, -shell->offset_x, -shell->offset_y);
+          cairo_scale (cr, shell->scale_x / scale, shell->scale_y / scale);
+
+          /* render image */
+          gimp_display_shell_render (shell, cr, ix, iy, iw, ih, scale);
+
+          cairo_restore (cr);
+
+          /* if the GIMP_BRICK_WALL environment variable is defined,
+           * show chunk bounds
+           */
+          {
+            static gint brick_wall = -1;
+
+            if (brick_wall < 0)
+              brick_wall = (g_getenv ("GIMP_BRICK_WALL") != NULL);
+
+            if (brick_wall)
+              {
+                cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
+                cairo_rectangle (cr, x1, y1, x2 - x1, y2 - y1);
+                cairo_stroke (cr);
+              }
+          }
+        }
+    }
+}
diff --git a/app/display/gimpdisplayshell-draw.h b/app/display/gimpdisplayshell-draw.h
new file mode 100644
index 0000000..05dd2c1
--- /dev/null
+++ b/app/display/gimpdisplayshell-draw.h
@@ -0,0 +1,41 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_DRAW_H__
+#define __GIMP_DISPLAY_SHELL_DRAW_H__
+
+
+void   gimp_display_shell_draw_selection_out (GimpDisplayShell   *shell,
+                                              cairo_t            *cr,
+                                              GimpSegment        *segs,
+                                              gint                n_segs);
+void   gimp_display_shell_draw_selection_in  (GimpDisplayShell   *shell,
+                                              cairo_t            *cr,
+                                              cairo_pattern_t    *mask,
+                                              gint                index);
+
+void   gimp_display_shell_draw_checkerboard  (GimpDisplayShell   *shell,
+                                              cairo_t            *cr);
+void   gimp_display_shell_draw_image         (GimpDisplayShell   *shell,
+                                              cairo_t            *cr,
+                                              gint                x,
+                                              gint                y,
+                                              gint                w,
+                                              gint                h);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_DRAW_H__ */
diff --git a/app/display/gimpdisplayshell-expose.c b/app/display/gimpdisplayshell-expose.c
new file mode 100644
index 0000000..2320a90
--- /dev/null
+++ b/app/display/gimpdisplayshell-expose.c
@@ -0,0 +1,76 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+
+
+void
+gimp_display_shell_expose_area (GimpDisplayShell *shell,
+                                gint              x,
+                                gint              y,
+                                gint              w,
+                                gint              h)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gtk_widget_queue_draw_area (shell->canvas, x, y, w, h);
+}
+
+void
+gimp_display_shell_expose_region (GimpDisplayShell *shell,
+                                  cairo_region_t   *region)
+{
+  GdkWindow *window;
+  gint       n_rectangles;
+  gint       i;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (region != NULL);
+
+  if (! gtk_widget_get_realized (shell->canvas))
+    return;
+
+  window = gtk_widget_get_window (shell->canvas);
+  n_rectangles = cairo_region_num_rectangles (region);
+
+  for (i = 0; i < n_rectangles; i++)
+    {
+      cairo_rectangle_int_t rectangle;
+
+      cairo_region_get_rectangle (region, i, &rectangle);
+
+      gdk_window_invalidate_rect (window,
+                                  (GdkRectangle *) &rectangle,
+                                  TRUE);
+    }
+}
+
+void
+gimp_display_shell_expose_full (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gtk_widget_queue_draw (shell->canvas);
+}
diff --git a/app/display/gimpdisplayshell-expose.h b/app/display/gimpdisplayshell-expose.h
new file mode 100644
index 0000000..36d3519
--- /dev/null
+++ b/app/display/gimpdisplayshell-expose.h
@@ -0,0 +1,32 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_EXPOSE_H__
+#define __GIMP_DISPLAY_SHELL_EXPOSE_H__
+
+
+void   gimp_display_shell_expose_area   (GimpDisplayShell   *shell,
+                                         gint                x,
+                                         gint                y,
+                                         gint                w,
+                                         gint                h);
+void   gimp_display_shell_expose_region (GimpDisplayShell   *shell,
+                                         cairo_region_t     *region);
+void   gimp_display_shell_expose_full   (GimpDisplayShell   *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_EXPOSE_H__ */
diff --git a/app/display/gimpdisplayshell-filter-dialog.c b/app/display/gimpdisplayshell-filter-dialog.c
new file mode 100644
index 0000000..720529c
--- /dev/null
+++ b/app/display/gimpdisplayshell-filter-dialog.c
@@ -0,0 +1,151 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1999 Manish Singh
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpviewable.h"
+
+#include "widgets/gimpcolordisplayeditor.h"
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpviewabledialog.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-filter.h"
+#include "gimpdisplayshell-filter-dialog.h"
+
+#include "gimp-intl.h"
+
+
+typedef struct
+{
+  GimpDisplayShell      *shell;
+  GtkWidget             *dialog;
+
+  GimpColorDisplayStack *old_stack;
+} ColorDisplayDialog;
+
+
+/*  local function prototypes  */
+
+static void gimp_display_shell_filter_dialog_response (GtkWidget          *widget,
+                                                       gint                response_id,
+                                                       ColorDisplayDialog *cdd);
+
+static void gimp_display_shell_filter_dialog_free     (ColorDisplayDialog *cdd);
+
+
+/*  public functions  */
+
+GtkWidget *
+gimp_display_shell_filter_dialog_new (GimpDisplayShell *shell)
+{
+  GimpImage          *image;
+  ColorDisplayDialog *cdd;
+  GtkWidget          *editor;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  image = gimp_display_get_image (shell->display);
+
+  cdd = g_slice_new0 (ColorDisplayDialog);
+
+  cdd->shell  = shell;
+  cdd->dialog = gimp_viewable_dialog_new (GIMP_VIEWABLE (image),
+                                          gimp_get_user_context (shell->display->gimp),
+                                          _("Color Display Filters"),
+                                          "gimp-display-filters",
+                                          GIMP_ICON_DISPLAY_FILTER,
+                                          _("Configure Color Display Filters"),
+                                          GTK_WIDGET (cdd->shell),
+                                          gimp_standard_help_func,
+                                          GIMP_HELP_DISPLAY_FILTER_DIALOG,
+
+                                          _("_Cancel"), GTK_RESPONSE_CANCEL,
+                                          _("_OK"),     GTK_RESPONSE_OK,
+
+                                          NULL);
+
+  gtk_dialog_set_alternative_button_order (GTK_DIALOG (cdd->dialog),
+                                           GTK_RESPONSE_OK,
+                                           GTK_RESPONSE_CANCEL,
+                                           -1);
+
+  gtk_window_set_destroy_with_parent (GTK_WINDOW (cdd->dialog), TRUE);
+
+  g_object_weak_ref (G_OBJECT (cdd->dialog),
+                     (GWeakNotify) gimp_display_shell_filter_dialog_free, cdd);
+
+  g_signal_connect (cdd->dialog, "response",
+                    G_CALLBACK (gimp_display_shell_filter_dialog_response),
+                    cdd);
+
+  if (shell->filter_stack)
+    {
+      cdd->old_stack = gimp_color_display_stack_clone (shell->filter_stack);
+
+      g_object_weak_ref (G_OBJECT (cdd->dialog),
+                         (GWeakNotify) g_object_unref, cdd->old_stack);
+    }
+  else
+    {
+      GimpColorDisplayStack *stack = gimp_color_display_stack_new ();
+
+      gimp_display_shell_filter_set (shell, stack);
+      g_object_unref (stack);
+    }
+
+  editor = gimp_color_display_editor_new (shell->display->gimp,
+                                          shell->filter_stack,
+                                          gimp_display_shell_get_color_config (shell),
+                                          GIMP_COLOR_MANAGED (shell));
+  gtk_container_set_border_width (GTK_CONTAINER (editor), 12);
+  gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (cdd->dialog))),
+                      editor, TRUE, TRUE, 0);
+  gtk_widget_show (editor);
+
+  return cdd->dialog;
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_shell_filter_dialog_response (GtkWidget          *widget,
+                                           gint                response_id,
+                                           ColorDisplayDialog *cdd)
+{
+  if (response_id != GTK_RESPONSE_OK)
+    gimp_display_shell_filter_set (cdd->shell, cdd->old_stack);
+
+  gtk_widget_destroy (GTK_WIDGET (cdd->dialog));
+}
+
+static void
+gimp_display_shell_filter_dialog_free (ColorDisplayDialog *cdd)
+{
+  g_slice_free (ColorDisplayDialog, cdd);
+}
diff --git a/app/display/gimpdisplayshell-filter-dialog.h b/app/display/gimpdisplayshell-filter-dialog.h
new file mode 100644
index 0000000..9f73a8b
--- /dev/null
+++ b/app/display/gimpdisplayshell-filter-dialog.h
@@ -0,0 +1,25 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1999 Manish Singh
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_FILTER_DIALOG_H__
+#define __GIMP_DISPLAY_SHELL_FILTER_DIALOG_H__
+
+
+GtkWidget * gimp_display_shell_filter_dialog_new (GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_FILTER_DIALOG_H__ */
diff --git a/app/display/gimpdisplayshell-filter.c b/app/display/gimpdisplayshell-filter.c
new file mode 100644
index 0000000..1cf60e8
--- /dev/null
+++ b/app/display/gimpdisplayshell-filter.c
@@ -0,0 +1,116 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1999 Manish Singh
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-filter.h"
+#include "gimpdisplayshell-profile.h"
+
+
+/*  local function prototypes  */
+
+static void   gimp_display_shell_filter_changed (GimpColorDisplayStack *stack,
+                                                 GimpDisplayShell      *shell);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_filter_set (GimpDisplayShell      *shell,
+                               GimpColorDisplayStack *stack)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (stack == NULL || GIMP_IS_COLOR_DISPLAY_STACK (stack));
+
+  if (stack == shell->filter_stack)
+    return;
+
+  if (shell->filter_stack)
+    {
+      g_signal_handlers_disconnect_by_func (shell->filter_stack,
+                                            gimp_display_shell_filter_changed,
+                                            shell);
+    }
+
+  g_set_object (&shell->filter_stack, stack);
+
+  if (shell->filter_stack)
+    {
+      g_signal_connect (shell->filter_stack, "changed",
+                        G_CALLBACK (gimp_display_shell_filter_changed),
+                        shell);
+    }
+
+  gimp_display_shell_filter_changed (NULL, shell);
+}
+
+gboolean
+gimp_display_shell_has_filter (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  if (shell->filter_stack)
+    {
+      GList *iter;
+
+      for (iter = shell->filter_stack->filters; iter; iter = g_list_next (iter))
+        {
+          if (gimp_color_display_get_enabled (GIMP_COLOR_DISPLAY (iter->data)))
+            return TRUE;
+        }
+    }
+
+  return FALSE;
+}
+
+
+/*  private functions  */
+
+static gboolean
+gimp_display_shell_filter_changed_idle (gpointer data)
+{
+  GimpDisplayShell *shell = data;
+
+  gimp_display_shell_profile_update (shell);
+  gimp_display_shell_expose_full (shell);
+
+  shell->filter_idle_id = 0;
+
+  return FALSE;
+}
+
+static void
+gimp_display_shell_filter_changed (GimpColorDisplayStack *stack,
+                                   GimpDisplayShell      *shell)
+{
+  if (shell->filter_idle_id)
+    g_source_remove (shell->filter_idle_id);
+
+  shell->filter_idle_id =
+    g_idle_add_full (G_PRIORITY_LOW,
+                     gimp_display_shell_filter_changed_idle,
+                     shell, NULL);
+}
diff --git a/app/display/gimpdisplayshell-filter.h b/app/display/gimpdisplayshell-filter.h
new file mode 100644
index 0000000..7543a8b
--- /dev/null
+++ b/app/display/gimpdisplayshell-filter.h
@@ -0,0 +1,28 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1999 Manish Singh
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_FILTER_H__
+#define __GIMP_DISPLAY_SHELL_FILTER_H__
+
+
+void       gimp_display_shell_filter_set (GimpDisplayShell      *shell,
+                                          GimpColorDisplayStack *stack);
+
+gboolean   gimp_display_shell_has_filter (GimpDisplayShell      *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_FILTER_H__ */
diff --git a/app/display/gimpdisplayshell-grab.c b/app/display/gimpdisplayshell-grab.c
new file mode 100644
index 0000000..d3bb550
--- /dev/null
+++ b/app/display/gimpdisplayshell-grab.c
@@ -0,0 +1,124 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpdisplayshell-grab.c
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-grab.h"
+
+
+gboolean
+gimp_display_shell_pointer_grab (GimpDisplayShell *shell,
+                                 const GdkEvent   *event,
+                                 GdkEventMask      event_mask)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+  g_return_val_if_fail (shell->pointer_grabbed == FALSE, FALSE);
+
+  if (event)
+    {
+      GdkGrabStatus status;
+
+      status = gdk_pointer_grab (gtk_widget_get_window (shell->canvas),
+                                 FALSE, event_mask, NULL, NULL,
+                                 gdk_event_get_time (event));
+
+      if (status != GDK_GRAB_SUCCESS)
+        {
+          g_printerr ("%s: gdk_pointer_grab failed with status %d\n",
+                      G_STRFUNC, status);
+          return FALSE;
+        }
+
+      shell->pointer_grab_time = gdk_event_get_time (event);
+    }
+
+  gtk_grab_add (shell->canvas);
+
+  shell->pointer_grabbed = TRUE;
+
+  return TRUE;
+}
+
+void
+gimp_display_shell_pointer_ungrab (GimpDisplayShell *shell,
+                                   const GdkEvent   *event)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->pointer_grabbed == TRUE);
+
+  gtk_grab_remove (shell->canvas);
+
+  if (event)
+    {
+      gdk_display_pointer_ungrab (gtk_widget_get_display (shell->canvas),
+                                  shell->pointer_grab_time);
+
+      shell->pointer_grab_time = 0;
+    }
+
+  shell->pointer_grabbed = FALSE;
+}
+
+gboolean
+gimp_display_shell_keyboard_grab (GimpDisplayShell *shell,
+                                  const GdkEvent   *event)
+{
+  GdkGrabStatus status;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+  g_return_val_if_fail (event != NULL, FALSE);
+  g_return_val_if_fail (shell->keyboard_grabbed == FALSE, FALSE);
+
+  status = gdk_keyboard_grab (gtk_widget_get_window (shell->canvas),
+                              FALSE,
+                              gdk_event_get_time (event));
+
+  if (status != GDK_GRAB_SUCCESS)
+    {
+      g_printerr ("%s: gdk_keyboard_grab failed with status %d\n",
+                  G_STRFUNC, status);
+      return FALSE;
+    }
+
+  shell->keyboard_grabbed   = TRUE;
+  shell->keyboard_grab_time = gdk_event_get_time (event);
+
+  return TRUE;
+}
+
+void
+gimp_display_shell_keyboard_ungrab (GimpDisplayShell *shell,
+                                    const GdkEvent   *event)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (event != NULL);
+  g_return_if_fail (shell->keyboard_grabbed == TRUE);
+
+  gdk_display_keyboard_ungrab (gtk_widget_get_display (shell->canvas),
+                               shell->keyboard_grab_time);
+
+  shell->keyboard_grabbed   = FALSE;
+  shell->keyboard_grab_time = 0;
+}
diff --git a/app/display/gimpdisplayshell-grab.h b/app/display/gimpdisplayshell-grab.h
new file mode 100644
index 0000000..915cf34
--- /dev/null
+++ b/app/display/gimpdisplayshell-grab.h
@@ -0,0 +1,36 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpdisplayshell-grab.h
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_GRAB_H__
+#define __GIMP_DISPLAY_SHELL_GRAB_H__
+
+
+gboolean   gimp_display_shell_pointer_grab    (GimpDisplayShell *shell,
+                                               const GdkEvent   *event,
+                                               GdkEventMask      event_mask);
+void       gimp_display_shell_pointer_ungrab  (GimpDisplayShell *shell,
+                                               const GdkEvent   *event);
+
+gboolean   gimp_display_shell_keyboard_grab   (GimpDisplayShell *shell,
+                                               const GdkEvent   *event);
+void       gimp_display_shell_keyboard_ungrab (GimpDisplayShell *shell,
+                                               const GdkEvent   *event);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_GRAB_H__ */
diff --git a/app/display/gimpdisplayshell-handlers.c b/app/display/gimpdisplayshell-handlers.c
new file mode 100644
index 0000000..7680467
--- /dev/null
+++ b/app/display/gimpdisplayshell-handlers.c
@@ -0,0 +1,1239 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpconfig/gimpconfig.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayoptions.h"
+#include "config/gimpguiconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimp-cairo.h"
+#include "core/gimpguide.h"
+#include "core/gimpimage.h"
+#include "core/gimpimage-grid.h"
+#include "core/gimpimage-guides.h"
+#include "core/gimpimage-quick-mask.h"
+#include "core/gimpimage-sample-points.h"
+#include "core/gimpitem.h"
+#include "core/gimpitemstack.h"
+#include "core/gimpsamplepoint.h"
+#include "core/gimptreehandler.h"
+
+#include "vectors/gimpvectors.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvascanvasboundary.h"
+#include "gimpcanvasguide.h"
+#include "gimpcanvaslayerboundary.h"
+#include "gimpcanvaspath.h"
+#include "gimpcanvasproxygroup.h"
+#include "gimpcanvassamplepoint.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-callbacks.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-handlers.h"
+#include "gimpdisplayshell-icon.h"
+#include "gimpdisplayshell-profile.h"
+#include "gimpdisplayshell-rulers.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-selection.h"
+#include "gimpdisplayshell-title.h"
+#include "gimpimagewindow.h"
+#include "gimpstatusbar.h"
+
+#include "gimp-intl.h"
+
+
+/*  local function prototypes  */
+
+static void   gimp_display_shell_clean_dirty_handler        (GimpImage        *image,
+                                                             GimpDirtyMask     dirty_mask,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_undo_event_handler         (GimpImage        *image,
+                                                             GimpUndoEvent     event,
+                                                             GimpUndo         *undo,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_grid_notify_handler        (GimpGrid         *grid,
+                                                             GParamSpec       *pspec,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_name_changed_handler       (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_selection_invalidate_handler
+                                                            (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_component_visibility_changed_handler
+                                                            (GimpImage        *image,
+                                                             GimpChannelType   channel,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_size_changed_detailed_handler
+                                                            (GimpImage        *image,
+                                                             gint              previous_origin_x,
+                                                             gint              previous_origin_y,
+                                                             gint              previous_width,
+                                                             gint              previous_height,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_resolution_changed_handler (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_quick_mask_changed_handler (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_guide_add_handler          (GimpImage        *image,
+                                                             GimpGuide        *guide,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_guide_remove_handler       (GimpImage        *image,
+                                                             GimpGuide        *guide,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_guide_move_handler         (GimpImage        *image,
+                                                             GimpGuide        *guide,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_sample_point_add_handler   (GimpImage        *image,
+                                                             GimpSamplePoint  *sample_point,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_sample_point_remove_handler(GimpImage        *image,
+                                                             GimpSamplePoint  *sample_point,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_sample_point_move_handler  (GimpImage        *image,
+                                                             GimpSamplePoint  *sample_point,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_invalidate_preview_handler (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_mode_changed_handler       (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_precision_changed_handler  (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_profile_changed_handler    (GimpColorManaged *image,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_saved_handler              (GimpImage        *image,
+                                                             GFile            *file,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_exported_handler           (GimpImage        *image,
+                                                             GFile            *file,
+                                                             GimpDisplayShell *shell);
+
+static void   gimp_display_shell_active_vectors_handler     (GimpImage        *image,
+                                                             GimpDisplayShell *shell);
+
+static void   gimp_display_shell_vectors_freeze_handler     (GimpVectors      *vectors,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_vectors_thaw_handler       (GimpVectors      *vectors,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_vectors_visible_handler    (GimpVectors      *vectors,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_vectors_add_handler        (GimpContainer    *container,
+                                                             GimpVectors      *vectors,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_vectors_remove_handler     (GimpContainer    *container,
+                                                             GimpVectors      *vectors,
+                                                             GimpDisplayShell *shell);
+
+static void   gimp_display_shell_check_notify_handler       (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_title_notify_handler       (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_nav_size_notify_handler    (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_monitor_res_notify_handler (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_padding_notify_handler     (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_ants_speed_notify_handler  (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void   gimp_display_shell_quality_notify_handler     (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void  gimp_display_shell_color_config_notify_handler (GObject          *config,
+                                                             GParamSpec       *param_spec,
+                                                             GimpDisplayShell *shell);
+static void  gimp_display_shell_display_changed_handler     (GimpContext      *context,
+                                                             GimpDisplay      *display,
+                                                             GimpDisplayShell *shell);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_connect (GimpDisplayShell *shell)
+{
+  GimpImage         *image;
+  GimpContainer     *vectors;
+  GimpDisplayConfig *config;
+  GimpColorConfig   *color_config;
+  GimpContext       *user_context;
+  GList             *list;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_DISPLAY (shell->display));
+
+  image = gimp_display_get_image (shell->display);
+
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+
+  vectors = gimp_image_get_vectors (image);
+
+  config       = shell->display->config;
+  color_config = GIMP_CORE_CONFIG (config)->color_management;
+
+  user_context = gimp_get_user_context (shell->display->gimp);
+
+  g_signal_connect (image, "clean",
+                    G_CALLBACK (gimp_display_shell_clean_dirty_handler),
+                    shell);
+  g_signal_connect (image, "dirty",
+                    G_CALLBACK (gimp_display_shell_clean_dirty_handler),
+                    shell);
+  g_signal_connect (image, "undo-event",
+                    G_CALLBACK (gimp_display_shell_undo_event_handler),
+                    shell);
+
+  g_signal_connect (gimp_image_get_grid (image), "notify",
+                    G_CALLBACK (gimp_display_shell_grid_notify_handler),
+                    shell);
+  g_object_set (shell->grid, "grid", gimp_image_get_grid (image), NULL);
+
+  g_signal_connect (image, "name-changed",
+                    G_CALLBACK (gimp_display_shell_name_changed_handler),
+                    shell);
+  g_signal_connect (image, "selection-invalidate",
+                    G_CALLBACK (gimp_display_shell_selection_invalidate_handler),
+                    shell);
+  g_signal_connect (image, "component-visibility-changed",
+                    G_CALLBACK (gimp_display_shell_component_visibility_changed_handler),
+                    shell);
+  g_signal_connect (image, "size-changed-detailed",
+                    G_CALLBACK (gimp_display_shell_size_changed_detailed_handler),
+                    shell);
+  g_signal_connect (image, "resolution-changed",
+                    G_CALLBACK (gimp_display_shell_resolution_changed_handler),
+                    shell);
+  g_signal_connect (image, "quick-mask-changed",
+                    G_CALLBACK (gimp_display_shell_quick_mask_changed_handler),
+                    shell);
+
+  g_signal_connect (image, "guide-added",
+                    G_CALLBACK (gimp_display_shell_guide_add_handler),
+                    shell);
+  g_signal_connect (image, "guide-removed",
+                    G_CALLBACK (gimp_display_shell_guide_remove_handler),
+                    shell);
+  g_signal_connect (image, "guide-moved",
+                    G_CALLBACK (gimp_display_shell_guide_move_handler),
+                    shell);
+  for (list = gimp_image_get_guides (image);
+       list;
+       list = g_list_next (list))
+    {
+      gimp_display_shell_guide_add_handler (image, list->data, shell);
+    }
+
+  g_signal_connect (image, "sample-point-added",
+                    G_CALLBACK (gimp_display_shell_sample_point_add_handler),
+                    shell);
+  g_signal_connect (image, "sample-point-removed",
+                    G_CALLBACK (gimp_display_shell_sample_point_remove_handler),
+                    shell);
+  g_signal_connect (image, "sample-point-moved",
+                    G_CALLBACK (gimp_display_shell_sample_point_move_handler),
+                    shell);
+  for (list = gimp_image_get_sample_points (image);
+       list;
+       list = g_list_next (list))
+    {
+      gimp_display_shell_sample_point_add_handler (image, list->data, shell);
+    }
+
+  g_signal_connect (image, "invalidate-preview",
+                    G_CALLBACK (gimp_display_shell_invalidate_preview_handler),
+                    shell);
+  g_signal_connect (image, "mode-changed",
+                    G_CALLBACK (gimp_display_shell_mode_changed_handler),
+                    shell);
+  g_signal_connect (image, "precision-changed",
+                    G_CALLBACK (gimp_display_shell_precision_changed_handler),
+                    shell);
+  g_signal_connect (image, "profile-changed",
+                    G_CALLBACK (gimp_display_shell_profile_changed_handler),
+                    shell);
+  g_signal_connect (image, "saved",
+                    G_CALLBACK (gimp_display_shell_saved_handler),
+                    shell);
+  g_signal_connect (image, "exported",
+                    G_CALLBACK (gimp_display_shell_exported_handler),
+                    shell);
+
+  g_signal_connect (image, "active-vectors-changed",
+                    G_CALLBACK (gimp_display_shell_active_vectors_handler),
+                    shell);
+
+  shell->vectors_freeze_handler =
+    gimp_tree_handler_connect (vectors, "freeze",
+                               G_CALLBACK (gimp_display_shell_vectors_freeze_handler),
+                               shell);
+  shell->vectors_thaw_handler =
+    gimp_tree_handler_connect (vectors, "thaw",
+                               G_CALLBACK (gimp_display_shell_vectors_thaw_handler),
+                               shell);
+  shell->vectors_visible_handler =
+    gimp_tree_handler_connect (vectors, "visibility-changed",
+                               G_CALLBACK (gimp_display_shell_vectors_visible_handler),
+                               shell);
+
+  g_signal_connect (vectors, "add",
+                    G_CALLBACK (gimp_display_shell_vectors_add_handler),
+                    shell);
+  g_signal_connect (vectors, "remove",
+                    G_CALLBACK (gimp_display_shell_vectors_remove_handler),
+                    shell);
+  for (list = gimp_item_stack_get_item_iter (GIMP_ITEM_STACK (vectors));
+       list;
+       list = g_list_next (list))
+    {
+      gimp_display_shell_vectors_add_handler (vectors, list->data, shell);
+    }
+
+  g_signal_connect (config,
+                    "notify::transparency-size",
+                    G_CALLBACK (gimp_display_shell_check_notify_handler),
+                    shell);
+  g_signal_connect (config,
+                    "notify::transparency-type",
+                    G_CALLBACK (gimp_display_shell_check_notify_handler),
+                    shell);
+
+  g_signal_connect (config,
+                    "notify::image-title-format",
+                    G_CALLBACK (gimp_display_shell_title_notify_handler),
+                    shell);
+  g_signal_connect (config,
+                    "notify::image-status-format",
+                    G_CALLBACK (gimp_display_shell_title_notify_handler),
+                    shell);
+  g_signal_connect (config,
+                    "notify::navigation-preview-size",
+                    G_CALLBACK (gimp_display_shell_nav_size_notify_handler),
+                    shell);
+  g_signal_connect (config,
+                    "notify::monitor-resolution-from-windowing-system",
+                    G_CALLBACK (gimp_display_shell_monitor_res_notify_handler),
+                    shell);
+  g_signal_connect (config,
+                    "notify::monitor-xresolution",
+                    G_CALLBACK (gimp_display_shell_monitor_res_notify_handler),
+                    shell);
+  g_signal_connect (config,
+                    "notify::monitor-yresolution",
+                    G_CALLBACK (gimp_display_shell_monitor_res_notify_handler),
+                    shell);
+
+  g_signal_connect (config->default_view,
+                    "notify::padding-mode",
+                    G_CALLBACK (gimp_display_shell_padding_notify_handler),
+                    shell);
+  g_signal_connect (config->default_view,
+                    "notify::padding-color",
+                    G_CALLBACK (gimp_display_shell_padding_notify_handler),
+                    shell);
+  g_signal_connect (config->default_fullscreen_view,
+                    "notify::padding-mode",
+                    G_CALLBACK (gimp_display_shell_padding_notify_handler),
+                    shell);
+  g_signal_connect (config->default_fullscreen_view,
+                    "notify::padding-color",
+                    G_CALLBACK (gimp_display_shell_padding_notify_handler),
+                    shell);
+
+  g_signal_connect (config,
+                    "notify::marching-ants-speed",
+                    G_CALLBACK (gimp_display_shell_ants_speed_notify_handler),
+                    shell);
+
+  g_signal_connect (config,
+                    "notify::zoom-quality",
+                    G_CALLBACK (gimp_display_shell_quality_notify_handler),
+                    shell);
+
+  g_signal_connect (color_config, "notify",
+                    G_CALLBACK (gimp_display_shell_color_config_notify_handler),
+                    shell);
+
+  g_signal_connect (user_context, "display-changed",
+                    G_CALLBACK (gimp_display_shell_display_changed_handler),
+                    shell);
+
+  gimp_display_shell_active_vectors_handler     (image, shell);
+  gimp_display_shell_invalidate_preview_handler (image, shell);
+  gimp_display_shell_quick_mask_changed_handler (image, shell);
+  gimp_display_shell_profile_changed_handler    (GIMP_COLOR_MANAGED (image),
+                                                 shell);
+  gimp_display_shell_color_config_notify_handler (G_OBJECT (color_config),
+                                                  NULL, /* sync all */
+                                                  shell);
+
+  gimp_canvas_layer_boundary_set_layer (GIMP_CANVAS_LAYER_BOUNDARY (shell->layer_boundary),
+                                        gimp_image_get_active_layer (image));
+
+  gimp_canvas_canvas_boundary_set_image (GIMP_CANVAS_CANVAS_BOUNDARY (shell->canvas_boundary),
+                                         image);
+
+  if (shell->show_all)
+    {
+      gimp_image_inc_show_all_count (image);
+
+      gimp_image_flush (image);
+    }
+}
+
+void
+gimp_display_shell_disconnect (GimpDisplayShell *shell)
+{
+  GimpImage         *image;
+  GimpContainer     *vectors;
+  GimpDisplayConfig *config;
+  GimpColorConfig   *color_config;
+  GimpContext       *user_context;
+  GList             *list;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_DISPLAY (shell->display));
+
+  image = gimp_display_get_image (shell->display);
+
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+
+  vectors = gimp_image_get_vectors (image);
+
+  config       = shell->display->config;
+  color_config = GIMP_CORE_CONFIG (config)->color_management;
+
+  user_context = gimp_get_user_context (shell->display->gimp);
+
+  gimp_display_shell_icon_update_stop (shell);
+
+  gimp_canvas_layer_boundary_set_layer (GIMP_CANVAS_LAYER_BOUNDARY (shell->layer_boundary),
+                                        NULL);
+
+  gimp_canvas_canvas_boundary_set_image (GIMP_CANVAS_CANVAS_BOUNDARY (shell->canvas_boundary),
+                                         NULL);
+
+  g_signal_handlers_disconnect_by_func (user_context,
+                                        gimp_display_shell_display_changed_handler,
+                                        shell);
+
+  g_signal_handlers_disconnect_by_func (color_config,
+                                        gimp_display_shell_color_config_notify_handler,
+                                        shell);
+  shell->color_config_set = FALSE;
+
+  g_signal_handlers_disconnect_by_func (config,
+                                        gimp_display_shell_quality_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (config,
+                                        gimp_display_shell_ants_speed_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (config->default_fullscreen_view,
+                                        gimp_display_shell_padding_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (config->default_view,
+                                        gimp_display_shell_padding_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (config,
+                                        gimp_display_shell_monitor_res_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (config,
+                                        gimp_display_shell_nav_size_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (config,
+                                        gimp_display_shell_title_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (config,
+                                        gimp_display_shell_check_notify_handler,
+                                        shell);
+
+  g_signal_handlers_disconnect_by_func (vectors,
+                                        gimp_display_shell_vectors_remove_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (vectors,
+                                        gimp_display_shell_vectors_add_handler,
+                                        shell);
+
+  gimp_tree_handler_disconnect (shell->vectors_visible_handler);
+  shell->vectors_visible_handler = NULL;
+
+  gimp_tree_handler_disconnect (shell->vectors_thaw_handler);
+  shell->vectors_thaw_handler = NULL;
+
+  gimp_tree_handler_disconnect (shell->vectors_freeze_handler);
+  shell->vectors_freeze_handler = NULL;
+
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_active_vectors_handler,
+                                        shell);
+
+  for (list = gimp_item_stack_get_item_iter (GIMP_ITEM_STACK (vectors));
+       list;
+       list = g_list_next (list))
+    {
+      gimp_canvas_proxy_group_remove_item (GIMP_CANVAS_PROXY_GROUP (shell->vectors),
+                                           list->data);
+    }
+
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_exported_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_saved_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_profile_changed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_precision_changed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_mode_changed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_invalidate_preview_handler,
+                                        shell);
+
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_guide_add_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_guide_remove_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_guide_move_handler,
+                                        shell);
+  for (list = gimp_image_get_guides (image);
+       list;
+       list = g_list_next (list))
+    {
+      gimp_canvas_proxy_group_remove_item (GIMP_CANVAS_PROXY_GROUP (shell->guides),
+                                           list->data);
+    }
+
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_sample_point_add_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_sample_point_remove_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_sample_point_move_handler,
+                                        shell);
+  for (list = gimp_image_get_sample_points (image);
+       list;
+       list = g_list_next (list))
+    {
+      gimp_canvas_proxy_group_remove_item (GIMP_CANVAS_PROXY_GROUP (shell->sample_points),
+                                           list->data);
+    }
+
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_quick_mask_changed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_resolution_changed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_component_visibility_changed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_size_changed_detailed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_selection_invalidate_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_name_changed_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (gimp_image_get_grid (image),
+                                        gimp_display_shell_grid_notify_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_undo_event_handler,
+                                        shell);
+  g_signal_handlers_disconnect_by_func (image,
+                                        gimp_display_shell_clean_dirty_handler,
+                                        shell);
+
+  if (shell->show_all)
+    {
+      gimp_image_dec_show_all_count (image);
+
+      gimp_image_flush (image);
+    }
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_shell_clean_dirty_handler (GimpImage        *image,
+                                        GimpDirtyMask     dirty_mask,
+                                        GimpDisplayShell *shell)
+{
+  gimp_display_shell_title_update (shell);
+}
+
+static void
+gimp_display_shell_undo_event_handler (GimpImage        *image,
+                                       GimpUndoEvent     event,
+                                       GimpUndo         *undo,
+                                       GimpDisplayShell *shell)
+{
+  gimp_display_shell_title_update (shell);
+}
+
+static void
+gimp_display_shell_grid_notify_handler (GimpGrid         *grid,
+                                        GParamSpec       *pspec,
+                                        GimpDisplayShell *shell)
+{
+  g_object_set (shell->grid, "grid", grid, NULL);
+}
+
+static void
+gimp_display_shell_name_changed_handler (GimpImage        *image,
+                                         GimpDisplayShell *shell)
+{
+  gimp_display_shell_title_update (shell);
+}
+
+static void
+gimp_display_shell_selection_invalidate_handler (GimpImage        *image,
+                                                 GimpDisplayShell *shell)
+{
+  gimp_display_shell_selection_undraw (shell);
+}
+
+static void
+gimp_display_shell_resolution_changed_handler (GimpImage        *image,
+                                               GimpDisplayShell *shell)
+{
+  gimp_display_shell_scale_update (shell);
+
+  if (shell->dot_for_dot)
+    {
+      if (shell->unit != GIMP_UNIT_PIXEL)
+        {
+          gimp_display_shell_rulers_update (shell);
+        }
+
+      gimp_display_shell_scaled (shell);
+    }
+  else
+    {
+      /* A resolution change has the same effect as a size change from
+       * a display shell point of view. Force a redraw of the display
+       * so that we don't get any display garbage.
+       */
+
+      GimpDisplayConfig *config = shell->display->config;
+      gboolean           resize_window;
+
+      /* Resize windows only in multi-window mode */
+      resize_window = (config->resize_windows_on_resize &&
+                       ! GIMP_GUI_CONFIG (config)->single_window_mode);
+
+      gimp_display_shell_scale_resize (shell, resize_window, FALSE);
+    }
+}
+
+static void
+gimp_display_shell_quick_mask_changed_handler (GimpImage        *image,
+                                               GimpDisplayShell *shell)
+{
+  GtkImage *gtk_image;
+  gboolean  quick_mask_state;
+
+  gtk_image = GTK_IMAGE (gtk_bin_get_child (GTK_BIN (shell->quick_mask_button)));
+
+  g_signal_handlers_block_by_func (shell->quick_mask_button,
+                                   gimp_display_shell_quick_mask_toggled,
+                                   shell);
+
+  quick_mask_state = gimp_image_get_quick_mask_state (image);
+
+  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (shell->quick_mask_button),
+                                quick_mask_state);
+
+  if (quick_mask_state)
+    gtk_image_set_from_icon_name (gtk_image, GIMP_ICON_QUICK_MASK_ON,
+                                  GTK_ICON_SIZE_MENU);
+  else
+    gtk_image_set_from_icon_name (gtk_image, GIMP_ICON_QUICK_MASK_OFF,
+                                  GTK_ICON_SIZE_MENU);
+
+  g_signal_handlers_unblock_by_func (shell->quick_mask_button,
+                                     gimp_display_shell_quick_mask_toggled,
+                                     shell);
+}
+
+static void
+gimp_display_shell_guide_add_handler (GimpImage        *image,
+                                      GimpGuide        *guide,
+                                      GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->guides);
+  GimpCanvasItem       *item;
+  GimpGuideStyle        style;
+
+  style = gimp_guide_get_style (guide);
+  item = gimp_canvas_guide_new (shell,
+                                gimp_guide_get_orientation (guide),
+                                gimp_guide_get_position (guide),
+                                style);
+
+  gimp_canvas_proxy_group_add_item (group, guide, item);
+  g_object_unref (item);
+}
+
+static void
+gimp_display_shell_guide_remove_handler (GimpImage        *image,
+                                         GimpGuide        *guide,
+                                         GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->guides);
+
+  gimp_canvas_proxy_group_remove_item (group, guide);
+}
+
+static void
+gimp_display_shell_guide_move_handler (GimpImage        *image,
+                                       GimpGuide        *guide,
+                                       GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->guides);
+  GimpCanvasItem       *item;
+
+  item = gimp_canvas_proxy_group_get_item (group, guide);
+
+  gimp_canvas_guide_set (item,
+                         gimp_guide_get_orientation (guide),
+                         gimp_guide_get_position (guide));
+}
+
+static void
+gimp_display_shell_sample_point_add_handler (GimpImage        *image,
+                                             GimpSamplePoint  *sample_point,
+                                             GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->sample_points);
+  GimpCanvasItem       *item;
+  GList                *list;
+  gint                  x;
+  gint                  y;
+  gint                  i;
+
+  gimp_sample_point_get_position (sample_point, &x, &y);
+
+  item = gimp_canvas_sample_point_new (shell, x, y, 0, TRUE);
+
+  gimp_canvas_proxy_group_add_item (group, sample_point, item);
+  g_object_unref (item);
+
+  for (list = gimp_image_get_sample_points (image), i = 1;
+       list;
+       list = g_list_next (list), i++)
+    {
+      GimpSamplePoint *sample_point = list->data;
+
+      item = gimp_canvas_proxy_group_get_item (group, sample_point);
+
+      if (item)
+        g_object_set (item,
+                      "index", i,
+                      NULL);
+    }
+}
+
+static void
+gimp_display_shell_sample_point_remove_handler (GimpImage        *image,
+                                                GimpSamplePoint  *sample_point,
+                                                GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->sample_points);
+  GList                *list;
+  gint                  i;
+
+  gimp_canvas_proxy_group_remove_item (group, sample_point);
+
+  for (list = gimp_image_get_sample_points (image), i = 1;
+       list;
+       list = g_list_next (list), i++)
+    {
+      GimpSamplePoint *sample_point = list->data;
+      GimpCanvasItem  *item;
+
+      item = gimp_canvas_proxy_group_get_item (group, sample_point);
+
+      if (item)
+        g_object_set (item,
+                      "index", i,
+                      NULL);
+    }
+}
+
+static void
+gimp_display_shell_sample_point_move_handler (GimpImage        *image,
+                                              GimpSamplePoint  *sample_point,
+                                              GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->sample_points);
+  GimpCanvasItem       *item;
+  gint                  x;
+  gint                  y;
+
+  item = gimp_canvas_proxy_group_get_item (group, sample_point);
+
+  gimp_sample_point_get_position (sample_point, &x, &y);
+
+  gimp_canvas_sample_point_set (item, x, y);
+}
+
+static void
+gimp_display_shell_component_visibility_changed_handler (GimpImage        *image,
+                                                         GimpChannelType   channel,
+                                                         GimpDisplayShell *shell)
+{
+  if (channel == GIMP_CHANNEL_ALPHA && shell->show_all)
+    gimp_display_shell_expose_full (shell);
+}
+
+static void
+gimp_display_shell_size_changed_detailed_handler (GimpImage        *image,
+                                                  gint              previous_origin_x,
+                                                  gint              previous_origin_y,
+                                                  gint              previous_width,
+                                                  gint              previous_height,
+                                                  GimpDisplayShell *shell)
+{
+  GimpDisplayConfig *config = shell->display->config;
+  gboolean           resize_window;
+
+  /* Resize windows only in multi-window mode */
+  resize_window = (config->resize_windows_on_resize &&
+                   ! GIMP_GUI_CONFIG (config)->single_window_mode);
+
+  if (resize_window)
+    {
+      GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+      if (window && gimp_image_window_get_active_shell (window) == shell)
+        {
+          /* If the window is resized just center the image in it when it
+           * has change size
+           */
+          gimp_image_window_shrink_wrap (window, FALSE);
+        }
+    }
+  else
+    {
+      GimpImage *image      = gimp_display_get_image (shell->display);
+      gint       new_width  = gimp_image_get_width  (image);
+      gint       new_height = gimp_image_get_height (image);
+      gint       scaled_previous_origin_x;
+      gint       scaled_previous_origin_y;
+      gboolean   horizontally;
+      gboolean   vertically;
+
+      scaled_previous_origin_x = SCALEX (shell, previous_origin_x);
+      scaled_previous_origin_y = SCALEY (shell, previous_origin_y);
+
+      horizontally = (SCALEX (shell, previous_width)  >  shell->disp_width  &&
+                      SCALEX (shell, new_width)       <= shell->disp_width);
+      vertically   = (SCALEY (shell, previous_height) >  shell->disp_height &&
+                      SCALEY (shell, new_height)      <= shell->disp_height);
+
+      gimp_display_shell_scroll_set_offset (shell,
+                                            shell->offset_x + scaled_previous_origin_x,
+                                            shell->offset_y + scaled_previous_origin_y);
+
+      if (! gimp_display_shell_get_infinite_canvas (shell))
+        {
+          gimp_display_shell_scroll_center_image (shell,
+                                                  horizontally, vertically);
+        }
+
+      /* The above calls might not lead to a call to
+       * gimp_display_shell_scroll_clamp_and_update() and
+       * gimp_display_shell_expose_full() in all cases because when
+       * scaling the old and new scroll offset might be the same.
+       *
+       * We need them to be called in all cases, so simply call them
+       * explicitly here at the end
+       */
+      gimp_display_shell_scroll_clamp_and_update (shell);
+
+      gimp_display_shell_expose_full (shell);
+    }
+}
+
+static void
+gimp_display_shell_invalidate_preview_handler (GimpImage        *image,
+                                               GimpDisplayShell *shell)
+{
+  gimp_display_shell_icon_update (shell);
+}
+
+static void
+gimp_display_shell_mode_changed_handler (GimpImage        *image,
+                                         GimpDisplayShell *shell)
+{
+  gimp_display_shell_profile_update (shell);
+}
+
+static void
+gimp_display_shell_precision_changed_handler (GimpImage        *image,
+                                              GimpDisplayShell *shell)
+{
+  gimp_display_shell_profile_update (shell);
+}
+
+static void
+gimp_display_shell_profile_changed_handler (GimpColorManaged *image,
+                                            GimpDisplayShell *shell)
+{
+  gimp_color_managed_profile_changed (GIMP_COLOR_MANAGED (shell));
+}
+
+static void
+gimp_display_shell_saved_handler (GimpImage        *image,
+                                  GFile            *file,
+                                  GimpDisplayShell *shell)
+{
+  GimpStatusbar *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_statusbar_push_temp (statusbar, GIMP_MESSAGE_INFO,
+                            GIMP_ICON_DOCUMENT_SAVE,
+                            _("Image saved to '%s'"),
+                            gimp_file_get_utf8_name (file));
+}
+
+static void
+gimp_display_shell_exported_handler (GimpImage        *image,
+                                     GFile            *file,
+                                     GimpDisplayShell *shell)
+{
+  GimpStatusbar *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_statusbar_push_temp (statusbar, GIMP_MESSAGE_INFO,
+                            GIMP_ICON_DOCUMENT_SAVE,
+                            _("Image exported to '%s'"),
+                            gimp_file_get_utf8_name (file));
+}
+
+static void
+gimp_display_shell_active_vectors_handler (GimpImage        *image,
+                                           GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group  = GIMP_CANVAS_PROXY_GROUP (shell->vectors);
+  GimpVectors          *active = gimp_image_get_active_vectors (image);
+  GList                *list;
+
+  for (list = gimp_image_get_vectors_iter (image);
+       list;
+       list = g_list_next (list))
+    {
+      GimpVectors    *vectors = list->data;
+      GimpCanvasItem *item;
+
+      item = gimp_canvas_proxy_group_get_item (group, vectors);
+
+      gimp_canvas_item_set_highlight (item, vectors == active);
+    }
+}
+
+static void
+gimp_display_shell_vectors_freeze_handler (GimpVectors      *vectors,
+                                           GimpDisplayShell *shell)
+{
+  /* do nothing */
+}
+
+static void
+gimp_display_shell_vectors_thaw_handler (GimpVectors      *vectors,
+                                         GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->vectors);
+  GimpCanvasItem       *item;
+
+  item = gimp_canvas_proxy_group_get_item (group, vectors);
+
+  gimp_canvas_path_set (item, gimp_vectors_get_bezier (vectors));
+}
+
+static void
+gimp_display_shell_vectors_visible_handler (GimpVectors      *vectors,
+                                            GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->vectors);
+  GimpCanvasItem       *item;
+
+  item = gimp_canvas_proxy_group_get_item (group, vectors);
+
+  gimp_canvas_item_set_visible (item,
+                                gimp_item_get_visible (GIMP_ITEM (vectors)));
+}
+
+static void
+gimp_display_shell_vectors_add_handler (GimpContainer    *container,
+                                        GimpVectors      *vectors,
+                                        GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->vectors);
+  GimpCanvasItem       *item;
+
+  item = gimp_canvas_path_new (shell,
+                               gimp_vectors_get_bezier (vectors),
+                               0, 0,
+                               FALSE,
+                               GIMP_PATH_STYLE_VECTORS);
+  gimp_canvas_item_set_visible (item,
+                                gimp_item_get_visible (GIMP_ITEM (vectors)));
+
+  gimp_canvas_proxy_group_add_item (group, vectors, item);
+  g_object_unref (item);
+}
+
+static void
+gimp_display_shell_vectors_remove_handler (GimpContainer    *container,
+                                           GimpVectors      *vectors,
+                                           GimpDisplayShell *shell)
+{
+  GimpCanvasProxyGroup *group = GIMP_CANVAS_PROXY_GROUP (shell->vectors);
+
+  gimp_canvas_proxy_group_remove_item (group, vectors);
+}
+
+static void
+gimp_display_shell_check_notify_handler (GObject          *config,
+                                         GParamSpec       *param_spec,
+                                         GimpDisplayShell *shell)
+{
+  GimpCanvasPaddingMode padding_mode;
+  GimpRGB               padding_color;
+
+  g_clear_pointer (&shell->checkerboard, cairo_pattern_destroy);
+
+  gimp_display_shell_get_padding (shell, &padding_mode, &padding_color);
+
+  switch (padding_mode)
+    {
+    case GIMP_CANVAS_PADDING_MODE_LIGHT_CHECK:
+    case GIMP_CANVAS_PADDING_MODE_DARK_CHECK:
+      gimp_display_shell_set_padding (shell, padding_mode, &padding_color);
+      break;
+
+    default:
+      break;
+    }
+
+  gimp_display_shell_expose_full (shell);
+}
+
+static void
+gimp_display_shell_title_notify_handler (GObject          *config,
+                                         GParamSpec       *param_spec,
+                                         GimpDisplayShell *shell)
+{
+  gimp_display_shell_title_update (shell);
+}
+
+static void
+gimp_display_shell_nav_size_notify_handler (GObject          *config,
+                                            GParamSpec       *param_spec,
+                                            GimpDisplayShell *shell)
+{
+  g_clear_pointer (&shell->nav_popup, gtk_widget_destroy);
+}
+
+static void
+gimp_display_shell_monitor_res_notify_handler (GObject          *config,
+                                               GParamSpec       *param_spec,
+                                               GimpDisplayShell *shell)
+{
+  if (GIMP_DISPLAY_CONFIG (config)->monitor_res_from_gdk)
+    {
+      gimp_get_monitor_resolution (gtk_widget_get_screen (GTK_WIDGET (shell)),
+                                   gimp_widget_get_monitor (GTK_WIDGET (shell)),
+                                   &shell->monitor_xres,
+                                   &shell->monitor_yres);
+    }
+  else
+    {
+      shell->monitor_xres = GIMP_DISPLAY_CONFIG (config)->monitor_xres;
+      shell->monitor_yres = GIMP_DISPLAY_CONFIG (config)->monitor_yres;
+    }
+
+  gimp_display_shell_scale_update (shell);
+
+  if (! shell->dot_for_dot)
+    {
+      gimp_display_shell_scroll_clamp_and_update (shell);
+
+      gimp_display_shell_scaled (shell);
+
+      gimp_display_shell_expose_full (shell);
+    }
+}
+
+static void
+gimp_display_shell_padding_notify_handler (GObject          *config,
+                                           GParamSpec       *param_spec,
+                                           GimpDisplayShell *shell)
+{
+  GimpDisplayConfig     *display_config;
+  GimpImageWindow       *window;
+  gboolean               fullscreen;
+  GimpCanvasPaddingMode  padding_mode;
+  GimpRGB                padding_color;
+
+  display_config = shell->display->config;
+
+  window = gimp_display_shell_get_window (shell);
+
+  if (window)
+    fullscreen = gimp_image_window_get_fullscreen (window);
+  else
+    fullscreen = FALSE;
+
+  /*  if the user did not set the padding mode for this display explicitly  */
+  if (! shell->fullscreen_options->padding_mode_set)
+    {
+      padding_mode  = display_config->default_fullscreen_view->padding_mode;
+      padding_color = display_config->default_fullscreen_view->padding_color;
+
+      if (fullscreen)
+        {
+          gimp_display_shell_set_padding (shell, padding_mode, &padding_color);
+        }
+      else
+        {
+          shell->fullscreen_options->padding_mode  = padding_mode;
+          shell->fullscreen_options->padding_color = padding_color;
+        }
+    }
+
+  /*  if the user did not set the padding mode for this display explicitly  */
+  if (! shell->options->padding_mode_set)
+    {
+      padding_mode  = display_config->default_view->padding_mode;
+      padding_color = display_config->default_view->padding_color;
+
+      if (fullscreen)
+        {
+          shell->options->padding_mode  = padding_mode;
+          shell->options->padding_color = padding_color;
+        }
+      else
+        {
+          gimp_display_shell_set_padding (shell, padding_mode, &padding_color);
+        }
+    }
+}
+
+static void
+gimp_display_shell_ants_speed_notify_handler (GObject          *config,
+                                              GParamSpec       *param_spec,
+                                              GimpDisplayShell *shell)
+{
+  gimp_display_shell_selection_pause (shell);
+  gimp_display_shell_selection_resume (shell);
+}
+
+static void
+gimp_display_shell_quality_notify_handler (GObject          *config,
+                                           GParamSpec       *param_spec,
+                                           GimpDisplayShell *shell)
+{
+  gimp_display_shell_expose_full (shell);
+}
+
+static void
+gimp_display_shell_color_config_notify_handler (GObject          *config,
+                                                GParamSpec       *param_spec,
+                                                GimpDisplayShell *shell)
+{
+  if (param_spec)
+    {
+      gboolean copy = TRUE;
+
+      if (! strcmp (param_spec->name, "mode")                                 ||
+          ! strcmp (param_spec->name, "display-rendering-intent")             ||
+          ! strcmp (param_spec->name, "display-use-black-point-compensation") ||
+          ! strcmp (param_spec->name, "printer-profile")                      ||
+          ! strcmp (param_spec->name, "simulation-rendering-intent")          ||
+          ! strcmp (param_spec->name, "simulation-use-black-point-compensation") ||
+          ! strcmp (param_spec->name, "simulation-gamut-check"))
+        {
+          if (shell->color_config_set)
+            copy = FALSE;
+        }
+
+      if (copy)
+        {
+          GValue value = G_VALUE_INIT;
+
+          g_value_init (&value, param_spec->value_type);
+
+          g_object_get_property (config,
+                                 param_spec->name, &value);
+          g_object_set_property (G_OBJECT (shell->color_config),
+                                 param_spec->name, &value);
+
+          g_value_unset (&value);
+        }
+    }
+  else
+    {
+      gimp_config_copy (GIMP_CONFIG (config),
+                        GIMP_CONFIG (shell->color_config),
+                        0);
+      shell->color_config_set = FALSE;
+    }
+}
+
+static void
+gimp_display_shell_display_changed_handler (GimpContext      *context,
+                                            GimpDisplay      *display,
+                                            GimpDisplayShell *shell)
+{
+  if (shell->display == display)
+    gimp_display_shell_update_priority_rect (shell);
+}
diff --git a/app/display/gimpdisplayshell-handlers.h b/app/display/gimpdisplayshell-handlers.h
new file mode 100644
index 0000000..49d743e
--- /dev/null
+++ b/app/display/gimpdisplayshell-handlers.h
@@ -0,0 +1,26 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_HANDLERS_H__
+#define __GIMP_DISPLAY_SHELL_HANDLERS_H__
+
+
+void   gimp_display_shell_connect    (GimpDisplayShell *shell);
+void   gimp_display_shell_disconnect (GimpDisplayShell *shell);
+
+
+#endif /*  __GIMP_DISPLAY_SHELL_HANDLERS_H__  */
diff --git a/app/display/gimpdisplayshell-icon.c b/app/display/gimpdisplayshell-icon.c
new file mode 100644
index 0000000..6168820
--- /dev/null
+++ b/app/display/gimpdisplayshell-icon.c
@@ -0,0 +1,140 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpimage.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-icon.h"
+
+
+#define GIMP_DISPLAY_UPDATE_ICON_TIMEOUT  1000
+
+static gboolean   gimp_display_shell_icon_update_idle (gpointer data);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_icon_update (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_icon_update_stop (shell);
+
+  if (gimp_display_get_image (shell->display))
+    shell->icon_idle_id = g_timeout_add_full (G_PRIORITY_LOW,
+                                              GIMP_DISPLAY_UPDATE_ICON_TIMEOUT,
+                                              gimp_display_shell_icon_update_idle,
+                                              shell,
+                                              NULL);
+  else
+    gimp_display_shell_icon_update_idle (shell);
+}
+
+void
+gimp_display_shell_icon_update_stop (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->icon_idle_id)
+    {
+      g_source_remove (shell->icon_idle_id);
+      shell->icon_idle_id = 0;
+    }
+}
+
+
+/*  private functions  */
+
+static gboolean
+gimp_display_shell_icon_update_idle (gpointer data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+  GimpImage        *image = gimp_display_get_image (shell->display);
+  GdkPixbuf        *icon  = NULL;
+
+  shell->icon_idle_id = 0;
+
+  if (image)
+    {
+      Gimp      *gimp = gimp_display_get_gimp (shell->display);
+      GdkPixbuf *pixbuf;
+      gint       width;
+      gint       height;
+      gdouble    factor = ((gdouble) gimp_image_get_height (image) /
+                           (gdouble) gimp_image_get_width  (image));
+
+      if (factor >= 1)
+        {
+          height = MAX (shell->icon_size, 1);
+          width  = MAX (((gdouble) shell->icon_size) / factor, 1);
+        }
+      else
+        {
+          height = MAX (((gdouble) shell->icon_size) * factor, 1);
+          width  = MAX (shell->icon_size, 1);
+        }
+
+      pixbuf = gimp_viewable_get_pixbuf (GIMP_VIEWABLE (image),
+                                         gimp_get_user_context (gimp),
+                                         width, height);
+
+      icon = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8,
+                             shell->icon_size, shell->icon_size);
+
+      memset (gdk_pixbuf_get_pixels (icon), 0,
+              gdk_pixbuf_get_height (icon) *
+              gdk_pixbuf_get_rowstride (icon));
+
+      gdk_pixbuf_copy_area (pixbuf, 0, 0, width, height,
+                            icon,
+                            0, shell->icon_size - height);
+
+      pixbuf = gimp_widget_load_icon (GTK_WIDGET (shell), "gimp-wilber-outline",
+                                      shell->icon_size_small);
+
+      width  = gdk_pixbuf_get_width  (pixbuf);
+      height = gdk_pixbuf_get_height (pixbuf);
+
+      gdk_pixbuf_composite (pixbuf, icon,
+                            shell->icon_size - width, 0,
+                            width, height,
+                            shell->icon_size - width, 0.0, 1.0, 1.0,
+                            GDK_INTERP_NEAREST, 255);
+      g_object_unref (pixbuf);
+    }
+
+  g_object_set (shell, "icon", icon, NULL);
+
+  if (icon)
+    g_object_unref (icon);
+
+  return FALSE;
+}
diff --git a/app/display/gimpdisplayshell-icon.h b/app/display/gimpdisplayshell-icon.h
new file mode 100644
index 0000000..6d2a673
--- /dev/null
+++ b/app/display/gimpdisplayshell-icon.h
@@ -0,0 +1,26 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_ICON_H__
+#define __GIMP_DISPLAY_SHELL_ICON_H__
+
+
+void  gimp_display_shell_icon_update      (GimpDisplayShell *shell);
+void  gimp_display_shell_icon_update_stop (GimpDisplayShell *shell);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_ICON_H__  */
diff --git a/app/display/gimpdisplayshell-items.c b/app/display/gimpdisplayshell-items.c
new file mode 100644
index 0000000..caa381a
--- /dev/null
+++ b/app/display/gimpdisplayshell-items.c
@@ -0,0 +1,284 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpdisplayshell-items.c
+ * Copyright (C) 2010  Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include <libgimpmath/gimpmath.h>
+
+#include "display-types.h"
+
+#include "gimpcanvascanvasboundary.h"
+#include "gimpcanvascursor.h"
+#include "gimpcanvasgrid.h"
+#include "gimpcanvaslayerboundary.h"
+#include "gimpcanvaspassepartout.h"
+#include "gimpcanvasproxygroup.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-items.h"
+#include "gimpdisplayshell-transform.h"
+
+
+/*  local function prototypes  */
+
+static void   gimp_display_shell_item_update           (GimpCanvasItem   *item,
+                                                        cairo_region_t   *region,
+                                                        GimpDisplayShell *shell);
+static void   gimp_display_shell_unrotated_item_update (GimpCanvasItem   *item,
+                                                        cairo_region_t   *region,
+                                                        GimpDisplayShell *shell);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_items_init (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  shell->canvas_item = gimp_canvas_group_new (shell);
+
+  shell->passe_partout = gimp_canvas_passe_partout_new (shell, 0, 0, 0, 0);
+  gimp_canvas_item_set_visible (shell->passe_partout, FALSE);
+  gimp_display_shell_add_item (shell, shell->passe_partout);
+  g_object_unref (shell->passe_partout);
+
+  shell->preview_items = gimp_canvas_group_new (shell);
+  gimp_display_shell_add_item (shell, shell->preview_items);
+  g_object_unref (shell->preview_items);
+
+  shell->vectors = gimp_canvas_proxy_group_new (shell);
+  gimp_display_shell_add_item (shell, shell->vectors);
+  g_object_unref (shell->vectors);
+
+  shell->grid = gimp_canvas_grid_new (shell, NULL);
+  gimp_canvas_item_set_visible (shell->grid, FALSE);
+  g_object_set (shell->grid, "grid-style", TRUE, NULL);
+  gimp_display_shell_add_item (shell, shell->grid);
+  g_object_unref (shell->grid);
+
+  shell->guides = gimp_canvas_proxy_group_new (shell);
+  gimp_display_shell_add_item (shell, shell->guides);
+  g_object_unref (shell->guides);
+
+  shell->sample_points = gimp_canvas_proxy_group_new (shell);
+  gimp_display_shell_add_item (shell, shell->sample_points);
+  g_object_unref (shell->sample_points);
+
+  shell->canvas_boundary = gimp_canvas_canvas_boundary_new (shell);
+  gimp_canvas_item_set_visible (shell->canvas_boundary, FALSE);
+  gimp_display_shell_add_item (shell, shell->canvas_boundary);
+  g_object_unref (shell->canvas_boundary);
+
+  shell->layer_boundary = gimp_canvas_layer_boundary_new (shell);
+  gimp_canvas_item_set_visible (shell->layer_boundary, FALSE);
+  gimp_display_shell_add_item (shell, shell->layer_boundary);
+  g_object_unref (shell->layer_boundary);
+
+  shell->tool_items = gimp_canvas_group_new (shell);
+  gimp_display_shell_add_item (shell, shell->tool_items);
+  g_object_unref (shell->tool_items);
+
+  g_signal_connect (shell->canvas_item, "update",
+                    G_CALLBACK (gimp_display_shell_item_update),
+                    shell);
+
+  shell->unrotated_item = gimp_canvas_group_new (shell);
+
+  shell->cursor = gimp_canvas_cursor_new (shell);
+  gimp_canvas_item_set_visible (shell->cursor, FALSE);
+  gimp_display_shell_add_unrotated_item (shell, shell->cursor);
+  g_object_unref (shell->cursor);
+
+  g_signal_connect (shell->unrotated_item, "update",
+                    G_CALLBACK (gimp_display_shell_unrotated_item_update),
+                    shell);
+}
+
+void
+gimp_display_shell_items_free (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->canvas_item)
+    {
+      g_signal_handlers_disconnect_by_func (shell->canvas_item,
+                                            gimp_display_shell_item_update,
+                                            shell);
+
+      g_clear_object (&shell->canvas_item);
+
+      shell->passe_partout   = NULL;
+      shell->preview_items   = NULL;
+      shell->vectors         = NULL;
+      shell->grid            = NULL;
+      shell->guides          = NULL;
+      shell->sample_points   = NULL;
+      shell->canvas_boundary = NULL;
+      shell->layer_boundary  = NULL;
+      shell->tool_items      = NULL;
+    }
+
+  if (shell->unrotated_item)
+    {
+      g_signal_handlers_disconnect_by_func (shell->unrotated_item,
+                                            gimp_display_shell_unrotated_item_update,
+                                            shell);
+
+      g_clear_object (&shell->unrotated_item);
+
+      shell->cursor = NULL;
+    }
+}
+
+void
+gimp_display_shell_add_item (GimpDisplayShell *shell,
+                             GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_add_item (GIMP_CANVAS_GROUP (shell->canvas_item), item);
+}
+
+void
+gimp_display_shell_remove_item (GimpDisplayShell *shell,
+                                GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (shell->canvas_item), item);
+}
+
+void
+gimp_display_shell_add_preview_item (GimpDisplayShell *shell,
+                                     GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_add_item (GIMP_CANVAS_GROUP (shell->preview_items), item);
+}
+
+void
+gimp_display_shell_remove_preview_item (GimpDisplayShell *shell,
+                                        GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (shell->preview_items), item);
+}
+
+void
+gimp_display_shell_add_unrotated_item (GimpDisplayShell *shell,
+                                       GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_add_item (GIMP_CANVAS_GROUP (shell->unrotated_item), item);
+}
+
+void
+gimp_display_shell_remove_unrotated_item (GimpDisplayShell *shell,
+                                          GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (shell->unrotated_item), item);
+}
+
+void
+gimp_display_shell_add_tool_item (GimpDisplayShell *shell,
+                                  GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_add_item (GIMP_CANVAS_GROUP (shell->tool_items), item);
+}
+
+void
+gimp_display_shell_remove_tool_item (GimpDisplayShell *shell,
+                                     GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (shell->tool_items), item);
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_shell_item_update (GimpCanvasItem   *item,
+                                cairo_region_t   *region,
+                                GimpDisplayShell *shell)
+{
+  if (shell->rotate_transform)
+    {
+      gint n_rects;
+      gint i;
+
+      n_rects = cairo_region_num_rectangles (region);
+
+      for (i = 0; i < n_rects; i++)
+        {
+          cairo_rectangle_int_t rect;
+          gdouble               tx1, ty1;
+          gdouble               tx2, ty2;
+          gint                  x1, y1, x2, y2;
+
+          cairo_region_get_rectangle (region, i, &rect);
+
+          gimp_display_shell_rotate_bounds (shell,
+                                            rect.x, rect.y,
+                                            rect.x + rect.width,
+                                            rect.y + rect.height,
+                                            &tx1, &ty1, &tx2, &ty2);
+
+          x1 = floor (tx1 - 0.5);
+          y1 = floor (ty1 - 0.5);
+          x2 = ceil (tx2 + 0.5);
+          y2 = ceil (ty2 + 0.5);
+
+          gimp_display_shell_expose_area (shell, x1, y1, x2 - x1, y2 - y1);
+        }
+    }
+  else
+    {
+      gimp_display_shell_expose_region (shell, region);
+    }
+}
+
+static void
+gimp_display_shell_unrotated_item_update (GimpCanvasItem   *item,
+                                          cairo_region_t   *region,
+                                          GimpDisplayShell *shell)
+{
+  gimp_display_shell_expose_region (shell, region);
+}
diff --git a/app/display/gimpdisplayshell-items.h b/app/display/gimpdisplayshell-items.h
new file mode 100644
index 0000000..84f169e
--- /dev/null
+++ b/app/display/gimpdisplayshell-items.h
@@ -0,0 +1,49 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpdisplayshell-items.h
+ * Copyright (C) 2010  Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_ITEMS_H__
+#define __GIMP_DISPLAY_SHELL_ITEMS_H__
+
+
+void   gimp_display_shell_items_init            (GimpDisplayShell *shell);
+void   gimp_display_shell_items_free            (GimpDisplayShell *shell);
+
+void   gimp_display_shell_add_item              (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+void   gimp_display_shell_remove_item           (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+
+void   gimp_display_shell_add_preview_item      (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+void   gimp_display_shell_remove_preview_item   (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+
+void   gimp_display_shell_add_unrotated_item    (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+void   gimp_display_shell_remove_unrotated_item (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+
+void   gimp_display_shell_add_tool_item         (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+void   gimp_display_shell_remove_tool_item      (GimpDisplayShell *shell,
+                                                 GimpCanvasItem   *item);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_ITEMS_H__ */
diff --git a/app/display/gimpdisplayshell-layer-select.c b/app/display/gimpdisplayshell-layer-select.c
new file mode 100644
index 0000000..0618eea
--- /dev/null
+++ b/app/display/gimpdisplayshell-layer-select.c
@@ -0,0 +1,305 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpcoreconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontainer.h"
+#include "core/gimpimage.h"
+#include "core/gimplayer.h"
+
+#include "widgets/gimpview.h"
+#include "widgets/gimpviewrenderer.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-layer-select.h"
+
+#include "gimp-intl.h"
+
+
+typedef struct
+{
+  GtkWidget *window;
+  GtkWidget *view;
+  GtkWidget *label;
+
+  GimpImage *image;
+  GimpLayer *orig_layer;
+} LayerSelect;
+
+
+/*  local function prototypes  */
+
+static LayerSelect * layer_select_new       (GimpDisplayShell *shell,
+                                             GimpImage        *image,
+                                             GimpLayer        *layer,
+                                             gint              view_size);
+static void          layer_select_destroy   (LayerSelect      *layer_select,
+                                             guint32           time);
+static void          layer_select_advance   (LayerSelect      *layer_select,
+                                             gint              move);
+static gboolean      layer_select_events    (GtkWidget        *widget,
+                                             GdkEvent         *event,
+                                             LayerSelect      *layer_select);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_layer_select_init (GimpDisplayShell *shell,
+                                      gint              move,
+                                      guint32           time)
+{
+  LayerSelect   *layer_select;
+  GimpImage     *image;
+  GimpLayer     *layer;
+  GdkGrabStatus  status;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  layer = gimp_image_get_active_layer (image);
+
+  if (! layer)
+    return;
+
+  layer_select = layer_select_new (shell, image, layer,
+                                   image->gimp->config->layer_preview_size);
+  layer_select_advance (layer_select, move);
+
+  gtk_window_set_screen (GTK_WINDOW (layer_select->window),
+                         gtk_widget_get_screen (GTK_WIDGET (shell)));
+
+  gtk_widget_show (layer_select->window);
+
+  status = gdk_keyboard_grab (gtk_widget_get_window (layer_select->window), FALSE, time);
+  if (status != GDK_GRAB_SUCCESS)
+    g_printerr ("gdk_keyboard_grab failed with status %d\n", status);
+}
+
+
+/*  private functions  */
+
+static LayerSelect *
+layer_select_new (GimpDisplayShell *shell,
+                  GimpImage        *image,
+                  GimpLayer        *layer,
+                  gint              view_size)
+{
+  LayerSelect *layer_select;
+  GtkWidget   *frame1;
+  GtkWidget   *frame2;
+  GtkWidget   *hbox;
+  GtkWidget   *alignment;
+
+  layer_select = g_slice_new0 (LayerSelect);
+
+  layer_select->image      = image;
+  layer_select->orig_layer = layer;
+
+  layer_select->window = gtk_window_new (GTK_WINDOW_POPUP);
+  gtk_window_set_role (GTK_WINDOW (layer_select->window), "gimp-layer-select");
+  gtk_window_set_title (GTK_WINDOW (layer_select->window), _("Layer Select"));
+  gtk_window_set_position (GTK_WINDOW (layer_select->window), GTK_WIN_POS_MOUSE);
+  gtk_widget_set_events (layer_select->window,
+                         GDK_KEY_PRESS_MASK   |
+                         GDK_KEY_RELEASE_MASK |
+                         GDK_BUTTON_PRESS_MASK);
+
+  g_signal_connect (layer_select->window, "event",
+                    G_CALLBACK (layer_select_events),
+                    layer_select);
+
+  frame1 = gtk_frame_new (NULL);
+  gtk_frame_set_shadow_type (GTK_FRAME (frame1), GTK_SHADOW_OUT);
+  gtk_container_add (GTK_CONTAINER (layer_select->window), frame1);
+  gtk_widget_show (frame1);
+
+  frame2 = gtk_frame_new (NULL);
+  gtk_frame_set_shadow_type (GTK_FRAME (frame2), GTK_SHADOW_IN);
+  gtk_container_add (GTK_CONTAINER (frame1), frame2);
+  gtk_widget_show (frame2);
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
+  gtk_container_set_border_width (GTK_CONTAINER (hbox), 6);
+  gtk_container_add (GTK_CONTAINER (frame2), hbox);
+  gtk_widget_show (hbox);
+
+  /*  The view  */
+  alignment = gtk_alignment_new (0.5, 0.5, 0.0, 0.0);
+  gtk_box_pack_start (GTK_BOX (hbox), alignment, FALSE, FALSE, 0);
+  gtk_widget_show (alignment);
+
+  layer_select->view =
+    gimp_view_new_by_types (gimp_get_user_context (image->gimp),
+                            GIMP_TYPE_VIEW,
+                            GIMP_TYPE_LAYER,
+                            view_size, 1, FALSE);
+  gimp_view_renderer_set_color_config (GIMP_VIEW (layer_select->view)->renderer,
+                                       gimp_display_shell_get_color_config (shell));
+  gimp_view_set_viewable (GIMP_VIEW (layer_select->view),
+                          GIMP_VIEWABLE (layer));
+  gtk_container_add (GTK_CONTAINER (alignment), layer_select->view);
+  gtk_widget_show (layer_select->view);
+  gtk_widget_show (alignment);
+
+  /*  the layer name label */
+  layer_select->label = gtk_label_new (gimp_object_get_name (layer));
+  gtk_box_pack_start (GTK_BOX (hbox), layer_select->label, FALSE, FALSE, 0);
+  gtk_widget_show (layer_select->label);
+
+  return layer_select;
+}
+
+static void
+layer_select_destroy (LayerSelect *layer_select,
+                      guint32      time)
+{
+  gdk_display_keyboard_ungrab (gtk_widget_get_display (layer_select->window),
+                                                       time);
+
+  gtk_widget_destroy (layer_select->window);
+
+  if (layer_select->orig_layer !=
+      gimp_image_get_active_layer (layer_select->image))
+    {
+      gimp_image_flush (layer_select->image);
+    }
+
+  g_slice_free (LayerSelect, layer_select);
+}
+
+static void
+layer_select_advance (LayerSelect *layer_select,
+                      gint         move)
+{
+  GimpLayer *active_layer;
+  GimpLayer *next_layer;
+  GList     *layers;
+  gint       n_layers;
+  gint       index;
+
+  if (move == 0)
+    return;
+
+  /*  If there is a floating selection, allow no advancement  */
+  if (gimp_image_get_floating_selection (layer_select->image))
+    return;
+
+  active_layer = gimp_image_get_active_layer (layer_select->image);
+
+  layers   = gimp_image_get_layer_list (layer_select->image);
+  n_layers = g_list_length (layers);
+
+  index = g_list_index (layers, active_layer);
+  index += move;
+
+  if (index < 0)
+    index = n_layers - 1;
+  else if (index >= n_layers)
+    index = 0;
+
+  next_layer = g_list_nth_data (layers, index);
+
+  g_list_free (layers);
+
+  if (next_layer && next_layer != active_layer)
+    {
+      active_layer = gimp_image_set_active_layer (layer_select->image,
+                                                  next_layer);
+
+      if (active_layer)
+        {
+          gimp_view_set_viewable (GIMP_VIEW (layer_select->view),
+                                  GIMP_VIEWABLE (active_layer));
+          gtk_label_set_text (GTK_LABEL (layer_select->label),
+                              gimp_object_get_name (active_layer));
+        }
+    }
+}
+
+static gboolean
+layer_select_events (GtkWidget   *widget,
+                     GdkEvent    *event,
+                     LayerSelect *layer_select)
+{
+  GdkEventKey    *kevent;
+  GdkEventButton *bevent;
+
+  switch (event->type)
+    {
+    case GDK_BUTTON_PRESS:
+      bevent = (GdkEventButton *) event;
+
+      layer_select_destroy (layer_select, bevent->time);
+      break;
+
+    case GDK_KEY_PRESS:
+      kevent = (GdkEventKey *) event;
+
+      switch (kevent->keyval)
+        {
+        case GDK_KEY_Tab:
+          layer_select_advance (layer_select, 1);
+          break;
+        case GDK_KEY_ISO_Left_Tab:
+          layer_select_advance (layer_select, -1);
+          break;
+        }
+      return TRUE;
+      break;
+
+    case GDK_KEY_RELEASE:
+      kevent = (GdkEventKey *) event;
+
+      switch (kevent->keyval)
+        {
+        case GDK_KEY_Alt_L: case GDK_KEY_Alt_R:
+          kevent->state &= ~GDK_MOD1_MASK;
+          break;
+        case GDK_KEY_Control_L: case GDK_KEY_Control_R:
+          kevent->state &= ~GDK_CONTROL_MASK;
+          break;
+        case GDK_KEY_Shift_L: case GDK_KEY_Shift_R:
+          kevent->state &= ~GDK_SHIFT_MASK;
+          break;
+        }
+
+      if (! (kevent->state & GDK_CONTROL_MASK))
+        layer_select_destroy (layer_select, kevent->time);
+
+      return TRUE;
+      break;
+
+    default:
+      break;
+    }
+
+  return FALSE;
+}
diff --git a/app/display/gimpdisplayshell-layer-select.h b/app/display/gimpdisplayshell-layer-select.h
new file mode 100644
index 0000000..20546c6
--- /dev/null
+++ b/app/display/gimpdisplayshell-layer-select.h
@@ -0,0 +1,27 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef  __GIMP_DISPLAY_SHELL_LAYER_SELECT_H__
+#define  __GIMP_DISPLAY_SHELL_LAYER_SELECT_H__
+
+
+void   gimp_display_shell_layer_select_init (GimpDisplayShell *shell,
+                                             gint              move,
+                                             guint32           time);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_LAYER_SELECT_H__  */
diff --git a/app/display/gimpdisplayshell-profile.c b/app/display/gimpdisplayshell-profile.c
new file mode 100644
index 0000000..71a6c94
--- /dev/null
+++ b/app/display/gimpdisplayshell-profile.c
@@ -0,0 +1,336 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995-1997 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpconfig/gimpconfig.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpcoreconfig.h"
+
+#include "gegl/gimp-babl.h"
+
+#include "core/gimpimage.h"
+#include "core/gimpprojectable.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-actions.h"
+#include "gimpdisplayshell-filter.h"
+#include "gimpdisplayshell-profile.h"
+#include "gimpdisplayxfer.h"
+
+#include "gimp-intl.h"
+
+
+/*  local function prototypes  */
+
+static void   gimp_display_shell_profile_free        (GimpDisplayShell *shell);
+
+static void   gimp_display_shell_color_config_notify (GimpColorConfig  *config,
+                                                      const GParamSpec *pspec,
+                                                      GimpDisplayShell *shell);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_profile_init (GimpDisplayShell *shell)
+{
+  GimpColorConfig *color_config;
+
+  color_config = GIMP_CORE_CONFIG (shell->display->config)->color_management;
+
+  shell->color_config = gimp_config_duplicate (GIMP_CONFIG (color_config));
+
+  /* use after so we are called after the profile cache is invalidated
+   * in gimp_widget_get_color_transform()
+   */
+  g_signal_connect_after (shell->color_config, "notify",
+                          G_CALLBACK (gimp_display_shell_color_config_notify),
+                          shell);
+}
+
+void
+gimp_display_shell_profile_finalize (GimpDisplayShell *shell)
+{
+  g_clear_object (&shell->color_config);
+
+  gimp_display_shell_profile_free (shell);
+}
+
+void
+gimp_display_shell_profile_update (GimpDisplayShell *shell)
+{
+  GimpImage        *image;
+  GimpColorProfile *src_profile;
+  const Babl       *src_format;
+  GimpColorProfile *filter_profile;
+  const Babl       *filter_format;
+  const Babl       *dest_format;
+
+  gimp_display_shell_profile_free (shell);
+
+  image = gimp_display_get_image (shell->display);
+
+  if (! image)
+    return;
+
+  src_profile = gimp_color_managed_get_color_profile (GIMP_COLOR_MANAGED (shell));
+
+  if (! src_profile)
+    return;
+
+  src_format = gimp_projectable_get_format (GIMP_PROJECTABLE (image));
+
+  if (gimp_display_shell_has_filter (shell))
+    {
+      filter_format  = shell->filter_format;
+      filter_profile = gimp_babl_format_get_color_profile (filter_format);
+    }
+  else
+    {
+      filter_format  = src_format;
+      filter_profile = src_profile;
+    }
+
+  if (! gimp_display_shell_profile_can_convert_to_u8 (shell))
+    {
+      dest_format = shell->filter_format;
+    }
+  else
+    {
+      dest_format = babl_format ("R'G'B'A u8");
+    }
+
+#if 0
+  g_printerr ("src_profile:    %s\n"
+              "src_format:     %s\n"
+              "filter_profile: %s\n"
+              "filter_format:  %s\n"
+              "dest_format:    %s\n",
+              gimp_color_profile_get_label (src_profile),
+              babl_get_name (src_format),
+              gimp_color_profile_get_label (filter_profile),
+              babl_get_name (filter_format),
+              babl_get_name (dest_format));
+#endif
+
+  if (! gimp_color_transform_can_gegl_copy (src_profile, filter_profile))
+    {
+      shell->filter_transform =
+        gimp_color_transform_new (src_profile,
+                                  src_format,
+                                  filter_profile,
+                                  filter_format,
+                                  GIMP_COLOR_RENDERING_INTENT_RELATIVE_COLORIMETRIC,
+                                  GIMP_COLOR_TRANSFORM_FLAGS_BLACK_POINT_COMPENSATION |
+                                  GIMP_COLOR_TRANSFORM_FLAGS_NOOPTIMIZE);
+    }
+
+  shell->profile_transform =
+    gimp_widget_get_color_transform (gtk_widget_get_toplevel (GTK_WIDGET (shell)),
+                                     gimp_display_shell_get_color_config (shell),
+                                     filter_profile,
+                                     filter_format,
+                                     dest_format);
+
+  if (shell->filter_transform || shell->profile_transform)
+    {
+      gint w = GIMP_DISPLAY_RENDER_BUF_WIDTH;
+      gint h = GIMP_DISPLAY_RENDER_BUF_HEIGHT;
+
+      shell->profile_data =
+        gegl_malloc (w * h * babl_format_get_bytes_per_pixel (src_format));
+
+      shell->profile_stride =
+        w * babl_format_get_bytes_per_pixel (src_format);
+
+      shell->profile_buffer =
+        gegl_buffer_linear_new_from_data (shell->profile_data,
+                                          src_format,
+                                          GEGL_RECTANGLE (0, 0, w, h),
+                                          GEGL_AUTO_ROWSTRIDE,
+                                          (GDestroyNotify) gegl_free,
+                                          shell->profile_data);
+    }
+}
+
+gboolean
+gimp_display_shell_profile_can_convert_to_u8 (GimpDisplayShell *shell)
+{
+  GimpImage *image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      GimpComponentType component_type;
+
+      if (! gimp_display_shell_has_filter (shell))
+        component_type = gimp_image_get_component_type (image);
+      else
+        component_type = gimp_babl_format_get_component_type (shell->filter_format);
+
+      switch (component_type)
+        {
+        case GIMP_COMPONENT_TYPE_U8:
+#if 0
+          /* would like to convert directly for these too, but it
+           * produces inferior results, see bug 750874
+           */
+        case GIMP_COMPONENT_TYPE_U16:
+        case GIMP_COMPONENT_TYPE_U32:
+#endif
+          return TRUE;
+
+        default:
+          break;
+        }
+    }
+
+  return FALSE;
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_shell_profile_free (GimpDisplayShell *shell)
+{
+  g_clear_object (&shell->profile_transform);
+  g_clear_object (&shell->filter_transform);
+  g_clear_object (&shell->profile_buffer);
+  shell->profile_data   = NULL;
+  shell->profile_stride = 0;
+}
+
+static void
+gimp_display_shell_color_config_notify (GimpColorConfig  *config,
+                                        const GParamSpec *pspec,
+                                        GimpDisplayShell *shell)
+{
+  if (! strcmp (pspec->name, "mode")                                    ||
+      ! strcmp (pspec->name, "display-rendering-intent")                ||
+      ! strcmp (pspec->name, "display-use-black-point-compensation")    ||
+      ! strcmp (pspec->name, "simulation-rendering-intent")             ||
+      ! strcmp (pspec->name, "simulation-use-black-point-compensation") ||
+      ! strcmp (pspec->name, "simulation-gamut-check"))
+    {
+      gboolean     managed   = FALSE;
+      gboolean     softproof = FALSE;
+      const gchar *action    = NULL;
+
+#define SET_SENSITIVE(action, sensitive) \
+      gimp_display_shell_set_action_sensitive (shell, action, sensitive);
+
+#define SET_ACTIVE(action, active) \
+      gimp_display_shell_set_action_active (shell, action, active);
+
+      switch (gimp_color_config_get_mode (config))
+        {
+        case GIMP_COLOR_MANAGEMENT_OFF:
+          break;
+
+        case GIMP_COLOR_MANAGEMENT_DISPLAY:
+          managed = TRUE;
+          break;
+
+        case GIMP_COLOR_MANAGEMENT_SOFTPROOF:
+          managed   = TRUE;
+          softproof = TRUE;
+          break;
+        }
+
+      SET_ACTIVE ("view-color-management-enable",    managed);
+      SET_ACTIVE ("view-color-management-softproof", softproof);
+
+      switch (gimp_color_config_get_display_intent (config))
+        {
+        case GIMP_COLOR_RENDERING_INTENT_PERCEPTUAL:
+          action = "view-display-intent-perceptual";
+          break;
+
+        case GIMP_COLOR_RENDERING_INTENT_RELATIVE_COLORIMETRIC:
+          action = "view-display-intent-relative-colorimetric";
+          break;
+
+        case GIMP_COLOR_RENDERING_INTENT_SATURATION:
+          action = "view-display-intent-saturation";
+          break;
+
+        case GIMP_COLOR_RENDERING_INTENT_ABSOLUTE_COLORIMETRIC:
+          action = "view-display-intent-absolute-colorimetric";
+          break;
+        }
+
+      SET_SENSITIVE ("view-display-intent-perceptual",            managed);
+      SET_SENSITIVE ("view-display-intent-relative-colorimetric", managed);
+      SET_SENSITIVE ("view-display-intent-saturation",            managed);
+      SET_SENSITIVE ("view-display-intent-absolute-colorimetric", managed);
+
+      SET_ACTIVE (action, TRUE);
+
+      SET_SENSITIVE ("view-display-black-point-compensation", managed);
+      SET_ACTIVE    ("view-display-black-point-compensation",
+                     gimp_color_config_get_display_bpc (config));
+
+      SET_SENSITIVE ("view-softproof-profile", softproof);
+
+      switch (gimp_color_config_get_simulation_intent (config))
+        {
+        case GIMP_COLOR_RENDERING_INTENT_PERCEPTUAL:
+          action = "view-softproof-intent-perceptual";
+          break;
+
+        case GIMP_COLOR_RENDERING_INTENT_RELATIVE_COLORIMETRIC:
+          action = "view-softproof-intent-relative-colorimetric";
+          break;
+
+        case GIMP_COLOR_RENDERING_INTENT_SATURATION:
+          action = "view-softproof-intent-saturation";
+          break;
+
+        case GIMP_COLOR_RENDERING_INTENT_ABSOLUTE_COLORIMETRIC:
+          action = "view-softproof-intent-absolute-colorimetric";
+          break;
+        }
+
+      SET_SENSITIVE ("view-softproof-intent-perceptual",            softproof);
+      SET_SENSITIVE ("view-softproof-intent-relative-colorimetric", softproof);
+      SET_SENSITIVE ("view-softproof-intent-saturation",            softproof);
+      SET_SENSITIVE ("view-softproof-intent-absolute-colorimetric", softproof);
+
+      SET_ACTIVE (action, TRUE);
+
+      SET_SENSITIVE ("view-softproof-black-point-compensation", softproof);
+      SET_ACTIVE    ("view-softproof-black-point-compensation",
+                     gimp_color_config_get_simulation_bpc (config));
+
+      SET_SENSITIVE ("view-softproof-gamut-check", softproof);
+      SET_ACTIVE    ("view-softproof-gamut-check",
+                     gimp_color_config_get_simulation_gamut_check (config));
+    }
+
+  gimp_color_managed_profile_changed (GIMP_COLOR_MANAGED (shell));
+}
diff --git a/app/display/gimpdisplayshell-profile.h b/app/display/gimpdisplayshell-profile.h
new file mode 100644
index 0000000..e390cac
--- /dev/null
+++ b/app/display/gimpdisplayshell-profile.h
@@ -0,0 +1,30 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_PROFILE_H__
+#define __GIMP_DISPLAY_SHELL_PROFILE_H__
+
+
+void     gimp_display_shell_profile_init              (GimpDisplayShell *shell);
+void     gimp_display_shell_profile_finalize          (GimpDisplayShell *shell);
+
+void     gimp_display_shell_profile_update            (GimpDisplayShell *shell);
+
+gboolean gimp_display_shell_profile_can_convert_to_u8 (GimpDisplayShell *shell);
+
+
+#endif /*  __GIMP_DISPLAY_SHELL_PROFILE_H__  */
diff --git a/app/display/gimpdisplayshell-progress.c b/app/display/gimpdisplayshell-progress.c
new file mode 100644
index 0000000..4314a84
--- /dev/null
+++ b/app/display/gimpdisplayshell-progress.c
@@ -0,0 +1,163 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimpprogress.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-progress.h"
+#include "gimpstatusbar.h"
+
+
+static GimpProgress *
+gimp_display_shell_progress_start (GimpProgress *progress,
+                                   gboolean      cancellable,
+                                   const gchar  *message)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  return gimp_progress_start (GIMP_PROGRESS (statusbar), cancellable,
+                              "%s", message);
+}
+
+static void
+gimp_display_shell_progress_end (GimpProgress *progress)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_progress_end (GIMP_PROGRESS (statusbar));
+}
+
+static gboolean
+gimp_display_shell_progress_is_active (GimpProgress *progress)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  return gimp_progress_is_active (GIMP_PROGRESS (statusbar));
+}
+
+static void
+gimp_display_shell_progress_set_text (GimpProgress *progress,
+                                      const gchar  *message)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_progress_set_text_literal (GIMP_PROGRESS (statusbar), message);
+}
+
+static void
+gimp_display_shell_progress_set_value (GimpProgress *progress,
+                                       gdouble       percentage)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_progress_set_value (GIMP_PROGRESS (statusbar), percentage);
+}
+
+static gdouble
+gimp_display_shell_progress_get_value (GimpProgress *progress)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  return gimp_progress_get_value (GIMP_PROGRESS (statusbar));
+}
+
+static void
+gimp_display_shell_progress_pulse (GimpProgress *progress)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_progress_pulse (GIMP_PROGRESS (statusbar));
+}
+
+static guint32
+gimp_display_shell_progress_get_window_id (GimpProgress *progress)
+{
+  GtkWidget *toplevel = gtk_widget_get_toplevel (GTK_WIDGET (progress));
+
+  if (GTK_IS_WINDOW (toplevel))
+    return gimp_window_get_native_id (GTK_WINDOW (toplevel));
+
+  return 0;
+}
+
+static gboolean
+gimp_display_shell_progress_message (GimpProgress        *progress,
+                                     Gimp                *gimp,
+                                     GimpMessageSeverity  severity,
+                                     const gchar         *domain,
+                                     const gchar         *message)
+{
+  GimpDisplayShell *shell     = GIMP_DISPLAY_SHELL (progress);
+  GimpStatusbar    *statusbar = gimp_display_shell_get_statusbar (shell);
+
+  switch (severity)
+    {
+    case GIMP_MESSAGE_ERROR:
+    case GIMP_MESSAGE_BUG_WARNING:
+    case GIMP_MESSAGE_BUG_CRITICAL:
+      /* error messages are never handled here */
+      break;
+
+    case GIMP_MESSAGE_WARNING:
+      /* warning messages go to the statusbar, if it's visible */
+      if (! gimp_statusbar_get_visible (statusbar))
+        break;
+      else
+        return gimp_progress_message (GIMP_PROGRESS (statusbar), gimp,
+                                      severity, domain, message);
+
+    case GIMP_MESSAGE_INFO:
+      /* info messages go to the statusbar;
+       * if they are not handled there, they are swallowed
+       */
+      gimp_progress_message (GIMP_PROGRESS (statusbar), gimp,
+                             severity, domain, message);
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+void
+gimp_display_shell_progress_iface_init (GimpProgressInterface *iface)
+{
+  iface->start         = gimp_display_shell_progress_start;
+  iface->end           = gimp_display_shell_progress_end;
+  iface->is_active     = gimp_display_shell_progress_is_active;
+  iface->set_text      = gimp_display_shell_progress_set_text;
+  iface->set_value     = gimp_display_shell_progress_set_value;
+  iface->get_value     = gimp_display_shell_progress_get_value;
+  iface->pulse         = gimp_display_shell_progress_pulse;
+  iface->get_window_id = gimp_display_shell_progress_get_window_id;
+  iface->message       = gimp_display_shell_progress_message;
+}
diff --git a/app/display/gimpdisplayshell-progress.h b/app/display/gimpdisplayshell-progress.h
new file mode 100644
index 0000000..d697fa1
--- /dev/null
+++ b/app/display/gimpdisplayshell-progress.h
@@ -0,0 +1,28 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_PROGRESS_H__
+#define __GIMP_DISPLAY_SHELL_PROGRESS_H__
+
+
+#include "core/gimpprogress.h"
+
+
+void   gimp_display_shell_progress_iface_init (GimpProgressInterface *iface);
+
+
+#endif /*  __GIMP_DISPLAY_SHELL_PROGRESS_H__  */
diff --git a/app/display/gimpdisplayshell-render.c b/app/display/gimpdisplayshell-render.c
new file mode 100644
index 0000000..a1525bf
--- /dev/null
+++ b/app/display/gimpdisplayshell-render.c
@@ -0,0 +1,351 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "gegl/gimp-gegl-utils.h"
+
+#include "core/gimpdrawable.h"
+#include "core/gimpimage.h"
+#include "core/gimppickable.h"
+#include "core/gimpprojectable.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpdisplayshell-filter.h"
+#include "gimpdisplayshell-profile.h"
+#include "gimpdisplayshell-render.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayxfer.h"
+
+
+void
+gimp_display_shell_render (GimpDisplayShell *shell,
+                           cairo_t          *cr,
+                           gint              x,
+                           gint              y,
+                           gint              w,
+                           gint              h,
+                           gdouble           scale)
+{
+  GimpImage       *image;
+  GeglBuffer      *buffer;
+#ifdef USE_NODE_BLIT
+  GeglNode        *node;
+#endif
+  GeglAbyssPolicy  abyss_policy;
+  cairo_surface_t *xfer;
+  gint             xfer_src_x;
+  gint             xfer_src_y;
+  gint             mask_src_x = 0;
+  gint             mask_src_y = 0;
+  gint             cairo_stride;
+  guchar          *cairo_data;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (w > 0 && w <= GIMP_DISPLAY_RENDER_BUF_WIDTH);
+  g_return_if_fail (h > 0 && h <= GIMP_DISPLAY_RENDER_BUF_HEIGHT);
+  g_return_if_fail (scale > 0.0);
+
+  image  = gimp_display_get_image (shell->display);
+  buffer = gimp_pickable_get_buffer (
+    gimp_display_shell_get_pickable (shell));
+#ifdef USE_NODE_BLIT
+  node   = gimp_projectable_get_graph (GIMP_PROJECTABLE (image));
+
+  gimp_projectable_begin_render (GIMP_PROJECTABLE (image));
+#endif
+
+  if (shell->show_all)
+    abyss_policy = GEGL_ABYSS_NONE;
+  else
+    abyss_policy = GEGL_ABYSS_CLAMP;
+
+  xfer = gimp_display_xfer_get_surface (shell->xfer, w, h,
+                                        &xfer_src_x, &xfer_src_y);
+
+  cairo_stride = cairo_image_surface_get_stride (xfer);
+  cairo_data   = cairo_image_surface_get_data (xfer) +
+                 xfer_src_y * cairo_stride + xfer_src_x * 4;
+
+  if (shell->profile_transform ||
+      gimp_display_shell_has_filter (shell))
+    {
+      gboolean can_convert_to_u8;
+
+      /*  if there is a profile transform or a display filter, we need
+       *  to use temp buffers
+       */
+
+      can_convert_to_u8 = gimp_display_shell_profile_can_convert_to_u8 (shell);
+
+      /*  create the filter buffer if we have filters, or can't convert
+       *  to u8 directly
+       */
+      if ((gimp_display_shell_has_filter (shell) || ! can_convert_to_u8) &&
+          ! shell->filter_buffer)
+        {
+          gint fw = GIMP_DISPLAY_RENDER_BUF_WIDTH;
+          gint fh = GIMP_DISPLAY_RENDER_BUF_HEIGHT;
+
+          shell->filter_data =
+            gegl_malloc (fw * fh *
+                         babl_format_get_bytes_per_pixel (shell->filter_format));
+
+          shell->filter_stride =
+            fw * babl_format_get_bytes_per_pixel (shell->filter_format);
+
+          shell->filter_buffer =
+            gegl_buffer_linear_new_from_data (shell->filter_data,
+                                              shell->filter_format,
+                                              GEGL_RECTANGLE (0, 0, fw, fh),
+                                              GEGL_AUTO_ROWSTRIDE,
+                                              (GDestroyNotify) gegl_free,
+                                              shell->filter_data);
+        }
+
+      if (! gimp_display_shell_has_filter (shell) || shell->filter_transform)
+        {
+          /*  if there are no filters, or there is a filter transform,
+           *  load the projection pixels into the profile_buffer
+           */
+#ifndef USE_NODE_BLIT
+          gegl_buffer_get (buffer,
+                           GEGL_RECTANGLE (x, y, w, h), scale,
+                           gimp_projectable_get_format (GIMP_PROJECTABLE (image)),
+                           shell->profile_data, shell->profile_stride,
+                           abyss_policy);
+#else
+          gegl_node_blit (node,
+                          scale, GEGL_RECTANGLE (x, y, w, h),
+                          gimp_projectable_get_format (GIMP_PROJECTABLE (image)),
+                          shell->profile_data, shell->profile_stride,
+                          GEGL_BLIT_CACHE);
+#endif
+        }
+      else
+        {
+          /*  otherwise, load the pixels directly into the filter_buffer
+           */
+#ifndef USE_NODE_BLIT
+          gegl_buffer_get (buffer,
+                           GEGL_RECTANGLE (x, y, w, h), scale,
+                           shell->filter_format,
+                           shell->filter_data, shell->filter_stride,
+                           abyss_policy);
+#else
+          gegl_node_blit (node,
+                          scale, GEGL_RECTANGLE (x, y, w, h),
+                          shell->filter_format,
+                          shell->filter_data, shell->filter_stride,
+                          GEGL_BLIT_CACHE);
+#endif
+        }
+
+      /*  if there is a filter transform, convert the pixels from
+       *  the profile_buffer to the filter_buffer
+       */
+      if (shell->filter_transform)
+        {
+          gimp_color_transform_process_buffer (shell->filter_transform,
+                                               shell->profile_buffer,
+                                               GEGL_RECTANGLE (0, 0, w, h),
+                                               shell->filter_buffer,
+                                               GEGL_RECTANGLE (0, 0, w, h));
+        }
+
+      /*  if there are filters, apply them
+       */
+      if (gimp_display_shell_has_filter (shell))
+        {
+          GeglBuffer *filter_buffer;
+
+          /*  shift the filter_buffer so that the area passed to
+           *  the filters is the real render area, allowing for
+           *  position-dependent filters
+           */
+          filter_buffer = g_object_new (GEGL_TYPE_BUFFER,
+                                        "source", shell->filter_buffer,
+                                        "shift-x", -x,
+                                        "shift-y", -y,
+                                        NULL);
+
+          /*  convert the filter_buffer in place
+           */
+          gimp_color_display_stack_convert_buffer (shell->filter_stack,
+                                                   filter_buffer,
+                                                   GEGL_RECTANGLE (x, y, w, h));
+
+          g_object_unref (filter_buffer);
+        }
+
+      /*  if there is a profile transform...
+       */
+      if (shell->profile_transform)
+        {
+          if (gimp_display_shell_has_filter (shell))
+            {
+              /*  if we have filters, convert the pixels in the filter_buffer
+               *  in-place
+               */
+              gimp_color_transform_process_buffer (shell->profile_transform,
+                                                   shell->filter_buffer,
+                                                   GEGL_RECTANGLE (0, 0, w, h),
+                                                   shell->filter_buffer,
+                                                   GEGL_RECTANGLE (0, 0, w, h));
+            }
+          else if (! can_convert_to_u8)
+            {
+              /*  otherwise, if we can't convert to u8 directly, convert
+               *  the pixels from the profile_buffer to the filter_buffer
+               */
+              gimp_color_transform_process_buffer (shell->profile_transform,
+                                                   shell->profile_buffer,
+                                                   GEGL_RECTANGLE (0, 0, w, h),
+                                                   shell->filter_buffer,
+                                                   GEGL_RECTANGLE (0, 0, w, h));
+            }
+          else
+            {
+              GeglBuffer *buffer =
+                gegl_buffer_linear_new_from_data (cairo_data,
+                                                  babl_format ("cairo-ARGB32"),
+                                                  GEGL_RECTANGLE (0, 0, w, h),
+                                                  cairo_stride,
+                                                  NULL, NULL);
+
+              /*  otherwise, convert the profile_buffer directly into
+               *  the cairo_buffer
+               */
+              gimp_color_transform_process_buffer (shell->profile_transform,
+                                                   shell->profile_buffer,
+                                                   GEGL_RECTANGLE (0, 0, w, h),
+                                                   buffer,
+                                                   GEGL_RECTANGLE (0, 0, w, h));
+              g_object_unref (buffer);
+            }
+        }
+
+      /*  finally, copy the filter buffer to the cairo-ARGB32 buffer,
+       *  if necessary
+       */
+      if (gimp_display_shell_has_filter (shell) || ! can_convert_to_u8)
+        {
+          gegl_buffer_get (shell->filter_buffer,
+                           GEGL_RECTANGLE (0, 0, w, h), 1.0,
+                           babl_format ("cairo-ARGB32"),
+                           cairo_data, cairo_stride,
+                           GEGL_ABYSS_NONE);
+        }
+    }
+  else
+    {
+      /*  otherwise we can copy the projection pixels straight to the
+       *  cairo-ARGB32 buffer
+       */
+#ifndef USE_NODE_BLIT
+      gegl_buffer_get (buffer,
+                       GEGL_RECTANGLE (x, y, w, h), scale,
+                       babl_format ("cairo-ARGB32"),
+                       cairo_data, cairo_stride,
+                       abyss_policy);
+#else
+      gegl_node_blit (node,
+                      scale, GEGL_RECTANGLE (x, y, w, h),
+                      babl_format ("cairo-ARGB32"),
+                      cairo_data, cairo_stride,
+                      GEGL_BLIT_CACHE);
+#endif
+    }
+
+#ifdef USE_NODE_BLIT
+  gimp_projectable_end_render (GIMP_PROJECTABLE (image));
+#endif
+
+  if (shell->mask)
+    {
+      if (! shell->mask_surface)
+        {
+          shell->mask_surface =
+            cairo_image_surface_create (CAIRO_FORMAT_A8,
+                                        GIMP_DISPLAY_RENDER_BUF_WIDTH,
+                                        GIMP_DISPLAY_RENDER_BUF_HEIGHT);
+        }
+
+      cairo_surface_mark_dirty (shell->mask_surface);
+
+      cairo_stride = cairo_image_surface_get_stride (shell->mask_surface);
+      cairo_data   = cairo_image_surface_get_data (shell->mask_surface) +
+                     mask_src_y * cairo_stride + mask_src_x;
+
+      gegl_buffer_get (shell->mask,
+                       GEGL_RECTANGLE (x - floor (shell->mask_offset_x * scale),
+                                       y - floor (shell->mask_offset_y * scale),
+                                       w, h),
+                       scale,
+                       babl_format ("Y u8"),
+                       cairo_data, cairo_stride,
+                       GEGL_ABYSS_NONE);
+
+      if (shell->mask_inverted)
+        {
+          gint mask_height = h;
+
+          while (mask_height--)
+            {
+              gint    mask_width = w;
+              guchar *d          = cairo_data;
+
+              while (mask_width--)
+                {
+                  guchar inv = 255 - *d;
+
+                  *d++ = inv;
+                }
+
+              cairo_data += cairo_stride;
+            }
+        }
+    }
+
+  /*  put it to the screen  */
+  cairo_set_source_surface (cr, xfer,
+                            x - xfer_src_x,
+                            y - xfer_src_y);
+  cairo_paint (cr);
+
+  if (shell->mask)
+    {
+      gimp_cairo_set_source_rgba (cr, &shell->mask_color);
+      cairo_mask_surface (cr, shell->mask_surface,
+                          x - mask_src_x,
+                          y - mask_src_y);
+    }
+}
diff --git a/app/display/gimpdisplayshell-render.h b/app/display/gimpdisplayshell-render.h
new file mode 100644
index 0000000..7b4a644
--- /dev/null
+++ b/app/display/gimpdisplayshell-render.h
@@ -0,0 +1,29 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_RENDER_H__
+#define __GIMP_DISPLAY_SHELL_RENDER_H__
+
+void  gimp_display_shell_render (GimpDisplayShell *shell,
+                                 cairo_t          *cr,
+                                 gint              x,
+                                 gint              y,
+                                 gint              w,
+                                 gint              h,
+                                 gdouble           scale);
+
+#endif  /*  __GIMP_DISPLAY_SHELL_RENDER_H__  */
diff --git a/app/display/gimpdisplayshell-rotate-dialog.c b/app/display/gimpdisplayshell-rotate-dialog.c
new file mode 100644
index 0000000..c899235
--- /dev/null
+++ b/app/display/gimpdisplayshell-rotate-dialog.c
@@ -0,0 +1,293 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpviewable.h"
+
+#include "widgets/gimpdial.h"
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpviewabledialog.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-rotate.h"
+#include "gimpdisplayshell-rotate-dialog.h"
+
+#include "gimp-intl.h"
+
+
+#define RESPONSE_RESET 1
+
+
+typedef struct
+{
+  GimpDisplayShell *shell;
+  GtkAdjustment    *rotate_adj;
+  gdouble           old_angle;
+} RotateDialogData;
+
+
+/*  local function prototypes  */
+
+static void  gimp_display_shell_rotate_dialog_response (GtkWidget         *widget,
+                                                        gint               response_id,
+                                                        RotateDialogData  *dialog);
+static void      gimp_display_shell_rotate_dialog_free (RotateDialogData  *dialog);
+
+static void      rotate_adjustment_changed             (GtkAdjustment     *adj,
+                                                        RotateDialogData  *dialog);
+static void      display_shell_rotated                 (GimpDisplayShell  *shell,
+                                                        RotateDialogData  *dialog);
+
+static gboolean  deg_to_rad                            (GBinding          *binding,
+                                                        const GValue      *from_value,
+                                                        GValue            *to_value,
+                                                        gpointer           user_data);
+static gboolean  rad_to_deg                            (GBinding          *binding,
+                                                        const GValue      *from_value,
+                                                        GValue            *to_value,
+                                                        gpointer           user_data);
+
+
+/*  public functions  */
+
+/**
+ * gimp_display_shell_rotate_dialog:
+ * @shell: the #GimpDisplayShell
+ *
+ * Constructs and displays a dialog allowing the user to enter a
+ * custom display rotate.
+ **/
+void
+gimp_display_shell_rotate_dialog (GimpDisplayShell *shell)
+{
+  RotateDialogData *data;
+  GimpImage        *image;
+  GtkWidget        *toplevel;
+  GtkWidget        *hbox;
+  GtkWidget        *spin;
+  GtkWidget        *dial;
+  GtkWidget        *label;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->rotate_dialog)
+    {
+      gtk_window_present (GTK_WINDOW (shell->rotate_dialog));
+      return;
+    }
+
+  image = gimp_display_get_image (shell->display);
+
+  data = g_slice_new (RotateDialogData);
+
+  data->shell     = shell;
+  data->old_angle = shell->rotate_angle;
+
+  shell->rotate_dialog =
+    gimp_viewable_dialog_new (GIMP_VIEWABLE (image),
+                              gimp_get_user_context (shell->display->gimp),
+                              _("Rotate View"), "display-rotate",
+                              GIMP_ICON_OBJECT_ROTATE_180,
+                              _("Select Rotation Angle"),
+                              GTK_WIDGET (shell),
+                              gimp_standard_help_func,
+                              GIMP_HELP_VIEW_ROTATE_OTHER,
+
+                              _("_Reset"),  RESPONSE_RESET,
+                              _("_Cancel"), GTK_RESPONSE_CANCEL,
+                              _("_OK"),     GTK_RESPONSE_OK,
+
+                              NULL);
+
+  gtk_dialog_set_alternative_button_order (GTK_DIALOG (shell->rotate_dialog),
+                                           GTK_RESPONSE_OK,
+                                           GTK_RESPONSE_CANCEL,
+                                           -1);
+
+  g_object_weak_ref (G_OBJECT (shell->rotate_dialog),
+                     (GWeakNotify) gimp_display_shell_rotate_dialog_free, data);
+
+  g_object_add_weak_pointer (G_OBJECT (shell->rotate_dialog),
+                             (gpointer) &shell->rotate_dialog);
+
+  toplevel = gtk_widget_get_toplevel (GTK_WIDGET (shell));
+
+  gtk_window_set_transient_for (GTK_WINDOW (shell->rotate_dialog),
+                                GTK_WINDOW (toplevel));
+  gtk_window_set_destroy_with_parent (GTK_WINDOW (shell->rotate_dialog), TRUE);
+
+  g_signal_connect (shell->rotate_dialog, "response",
+                    G_CALLBACK (gimp_display_shell_rotate_dialog_response),
+                    data);
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
+  gtk_container_set_border_width (GTK_CONTAINER (hbox), 12);
+  gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (shell->rotate_dialog))),
+                      hbox, TRUE, TRUE, 0);
+  gtk_widget_show (hbox);
+
+  label = gtk_label_new (_("Angle:"));
+  gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
+  gtk_widget_show (label);
+
+  data->rotate_adj = (GtkAdjustment *)
+    gtk_adjustment_new (shell->rotate_angle, 0.0, 360.0, 1, 15, 0);
+  spin = gimp_spin_button_new (data->rotate_adj, 1.0, 2);
+  gtk_spin_button_set_numeric (GTK_SPIN_BUTTON (spin), TRUE);
+  gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spin), TRUE);
+  gtk_entry_set_activates_default (GTK_ENTRY (spin), TRUE);
+  gtk_box_pack_start (GTK_BOX (hbox), spin, TRUE, TRUE, 0);
+  gtk_widget_show (spin);
+
+  label = gtk_label_new (_("degrees"));
+  gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
+  gtk_widget_show (label);
+
+  dial = gimp_dial_new ();
+  g_object_set (dial,
+                "size",       32,
+                "background", GIMP_CIRCLE_BACKGROUND_PLAIN,
+                "draw-beta",  FALSE,
+                NULL);
+  gtk_box_pack_start (GTK_BOX (hbox), dial, FALSE, FALSE, 0);
+  gtk_widget_show (dial);
+
+  g_object_bind_property_full (data->rotate_adj, "value",
+                               dial,             "alpha",
+                               G_BINDING_BIDIRECTIONAL |
+                               G_BINDING_SYNC_CREATE,
+                               deg_to_rad,
+                               rad_to_deg,
+                               NULL, NULL);
+
+  g_signal_connect (data->rotate_adj, "value-changed",
+                    G_CALLBACK (rotate_adjustment_changed),
+                    data);
+  g_signal_connect (shell, "rotated",
+                    G_CALLBACK (display_shell_rotated),
+                    data);
+
+  gtk_widget_show (shell->rotate_dialog);
+}
+
+static void
+gimp_display_shell_rotate_dialog_response (GtkWidget        *widget,
+                                           gint              response_id,
+                                           RotateDialogData *dialog)
+{
+  switch (response_id)
+    {
+    case RESPONSE_RESET:
+      gtk_adjustment_set_value (dialog->rotate_adj, 0.0);
+      break;
+
+    case GTK_RESPONSE_CANCEL:
+      gtk_adjustment_set_value (dialog->rotate_adj, dialog->old_angle);
+      /* fall thru */
+
+    default:
+      gtk_widget_destroy (dialog->shell->rotate_dialog);
+      break;
+    }
+}
+
+static void
+gimp_display_shell_rotate_dialog_free (RotateDialogData *dialog)
+{
+  g_signal_handlers_disconnect_by_func (dialog->shell,
+                                        display_shell_rotated,
+                                        dialog);
+
+  g_slice_free (RotateDialogData, dialog);
+}
+
+static void
+rotate_adjustment_changed (GtkAdjustment    *adj,
+                           RotateDialogData *dialog)
+{
+  gdouble angle = gtk_adjustment_get_value (dialog->rotate_adj);
+
+  g_signal_handlers_block_by_func (dialog->shell,
+                                   display_shell_rotated,
+                                   dialog);
+
+  gimp_display_shell_rotate_to (dialog->shell, angle);
+
+  g_signal_handlers_unblock_by_func (dialog->shell,
+                                     display_shell_rotated,
+                                     dialog);
+}
+
+static void
+display_shell_rotated (GimpDisplayShell  *shell,
+                       RotateDialogData  *dialog)
+{
+  g_signal_handlers_block_by_func (dialog->rotate_adj,
+                                   rotate_adjustment_changed,
+                                   dialog);
+
+  gtk_adjustment_set_value (dialog->rotate_adj, shell->rotate_angle);
+
+  g_signal_handlers_unblock_by_func (dialog->rotate_adj,
+                                     rotate_adjustment_changed,
+                                     dialog);
+}
+
+static gboolean
+deg_to_rad (GBinding     *binding,
+            const GValue *from_value,
+            GValue       *to_value,
+            gpointer      user_data)
+{
+  gdouble value = g_value_get_double (from_value);
+
+  value = 360.0 - value;
+
+  value *= G_PI / 180.0;
+
+  g_value_set_double (to_value, value);
+
+  return TRUE;
+}
+
+static gboolean
+rad_to_deg (GBinding     *binding,
+            const GValue *from_value,
+            GValue       *to_value,
+            gpointer      user_data)
+{
+  gdouble value = g_value_get_double (from_value);
+
+  value *= 180.0 / G_PI;
+
+  value = 360.0 - value;
+
+  g_value_set_double (to_value, value);
+
+  return TRUE;
+}
diff --git a/app/display/gimpdisplayshell-rotate-dialog.h b/app/display/gimpdisplayshell-rotate-dialog.h
new file mode 100644
index 0000000..5222d13
--- /dev/null
+++ b/app/display/gimpdisplayshell-rotate-dialog.h
@@ -0,0 +1,25 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_ROTATE_DIALOG_H__
+#define __GIMP_DISPLAY_SHELL_ROTATE_DIALOG_H__
+
+
+void  gimp_display_shell_rotate_dialog (GimpDisplayShell *shell);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_ROTATE_DIALOG_H__  */
diff --git a/app/display/gimpdisplayshell-rotate.c b/app/display/gimpdisplayshell-rotate.c
new file mode 100644
index 0000000..d14f2a5
--- /dev/null
+++ b/app/display/gimpdisplayshell-rotate.c
@@ -0,0 +1,251 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <math.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-rotate.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-transform.h"
+
+
+#define ANGLE_EPSILON 1e-3
+
+
+/*  local function prototypes  */
+
+static void   gimp_display_shell_save_viewport_center    (GimpDisplayShell *shell,
+                                                          gdouble          *x,
+                                                          gdouble          *y);
+static void   gimp_display_shell_restore_viewport_center (GimpDisplayShell *shell,
+                                                          gdouble           x,
+                                                          gdouble           y);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_flip (GimpDisplayShell *shell,
+                         gboolean          flip_horizontally,
+                         gboolean          flip_vertically)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  flip_horizontally = flip_horizontally ? TRUE : FALSE;
+  flip_vertically   = flip_vertically   ? TRUE : FALSE;
+
+  if (flip_horizontally != shell->flip_horizontally ||
+      flip_vertically   != shell->flip_vertically)
+    {
+      gdouble cx, cy;
+
+      /* Maintain the current center of the viewport. */
+      gimp_display_shell_save_viewport_center (shell, &cx, &cy);
+
+      /* freeze the active tool */
+      gimp_display_shell_pause (shell);
+
+      /* Adjust the rotation angle so that the image gets reflected across the
+       * horizontal, and/or vertical, axes in screen space, regardless of the
+       * current rotation.
+       */
+      if (flip_horizontally == shell->flip_horizontally ||
+          flip_vertically   == shell->flip_vertically)
+        {
+          if (shell->rotate_angle != 0.0)
+            shell->rotate_angle = 360.0 - shell->rotate_angle;
+        }
+
+      shell->flip_horizontally = flip_horizontally;
+      shell->flip_vertically   = flip_vertically;
+
+      gimp_display_shell_rotated (shell);
+
+      gimp_display_shell_restore_viewport_center (shell, cx, cy);
+
+      gimp_display_shell_expose_full (shell);
+
+      /* re-enable the active tool */
+      gimp_display_shell_resume (shell);
+    }
+}
+
+void
+gimp_display_shell_rotate (GimpDisplayShell *shell,
+                           gdouble           delta)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_rotate_to (shell, shell->rotate_angle + delta);
+}
+
+void
+gimp_display_shell_rotate_to (GimpDisplayShell *shell,
+                              gdouble           value)
+{
+  gdouble cx, cy;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  /* Maintain the current center of the viewport. */
+  gimp_display_shell_save_viewport_center (shell, &cx, &cy);
+
+  /* Make sure the angle is within the range [0, 360). */
+  value = fmod (value, 360.0);
+  if (value < 0.0)
+    value += 360.0;
+
+  shell->rotate_angle = value;
+
+  /* freeze the active tool */
+  gimp_display_shell_pause (shell);
+
+  gimp_display_shell_scroll_clamp_and_update (shell);
+
+  gimp_display_shell_rotated (shell);
+
+  gimp_display_shell_restore_viewport_center (shell, cx, cy);
+
+  gimp_display_shell_expose_full (shell);
+
+  /* re-enable the active tool */
+  gimp_display_shell_resume (shell);
+}
+
+void
+gimp_display_shell_rotate_drag (GimpDisplayShell *shell,
+                                gdouble           last_x,
+                                gdouble           last_y,
+                                gdouble           cur_x,
+                                gdouble           cur_y,
+                                gboolean          constrain)
+{
+  gdouble pivot_x, pivot_y;
+  gdouble src_x,   src_y,   src_angle;
+  gdouble dest_x,  dest_y,  dest_angle;
+  gdouble                   delta_angle;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  /* Rotate the image around the center of the viewport. */
+  pivot_x     = shell->disp_width  / 2.0;
+  pivot_y     = shell->disp_height / 2.0;
+
+  src_x       = last_x - pivot_x;
+  src_y       = last_y - pivot_y;
+  src_angle   = atan2 (src_y, src_x);
+
+  dest_x      = cur_x - pivot_x;
+  dest_y      = cur_y - pivot_y;
+  dest_angle  = atan2 (dest_y, dest_x);
+
+  delta_angle = dest_angle - src_angle;
+
+  shell->rotate_drag_angle += 180.0 * delta_angle / G_PI;
+
+  gimp_display_shell_rotate_to (shell,
+                                constrain ?
+                                RINT (shell->rotate_drag_angle / 15.0) * 15.0 :
+                                shell->rotate_drag_angle);
+}
+
+void
+gimp_display_shell_rotate_update_transform (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  g_clear_pointer (&shell->rotate_transform,   g_free);
+  g_clear_pointer (&shell->rotate_untransform, g_free);
+
+  if (fabs (shell->rotate_angle)         < ANGLE_EPSILON ||
+      fabs (360.0 - shell->rotate_angle) < ANGLE_EPSILON)
+    shell->rotate_angle = 0.0;
+
+  if ((shell->rotate_angle != 0.0 ||
+       shell->flip_horizontally   ||
+       shell->flip_vertically) &&
+      gimp_display_get_image (shell->display))
+    {
+      gint    image_width, image_height;
+      gdouble cx, cy;
+
+      shell->rotate_transform   = g_new (cairo_matrix_t, 1);
+      shell->rotate_untransform = g_new (cairo_matrix_t, 1);
+
+      gimp_display_shell_scale_get_image_size (shell,
+                                               &image_width, &image_height);
+
+      cx = -shell->offset_x + image_width  / 2;
+      cy = -shell->offset_y + image_height / 2;
+
+      cairo_matrix_init_translate (shell->rotate_transform, cx, cy);
+
+      if (shell->rotate_angle != 0.0)
+        cairo_matrix_rotate (shell->rotate_transform,
+                             shell->rotate_angle / 180.0 * G_PI);
+
+      if (shell->flip_horizontally)
+        cairo_matrix_scale (shell->rotate_transform, -1.0, 1.0);
+
+      if (shell->flip_vertically)
+        cairo_matrix_scale (shell->rotate_transform, 1.0, -1.0);
+
+      cairo_matrix_translate (shell->rotate_transform, -cx, -cy);
+
+      *shell->rotate_untransform = *shell->rotate_transform;
+      cairo_matrix_invert (shell->rotate_untransform);
+    }
+}
+
+
+/*  private functions  */
+
+static void
+gimp_display_shell_save_viewport_center (GimpDisplayShell *shell,
+                                         gdouble          *x,
+                                         gdouble          *y)
+{
+  gimp_display_shell_unrotate_xy_f (shell,
+                                    shell->disp_width  / 2,
+                                    shell->disp_height / 2,
+                                    x, y);
+}
+
+static void
+gimp_display_shell_restore_viewport_center (GimpDisplayShell *shell,
+                                            gdouble           x,
+                                            gdouble           y)
+{
+  gimp_display_shell_rotate_xy_f (shell, x, y, &x, &y);
+
+  x += shell->offset_x - shell->disp_width  / 2;
+  y += shell->offset_y - shell->disp_height / 2;
+
+  gimp_display_shell_scroll_set_offset (shell, RINT (x), RINT (y));
+}
diff --git a/app/display/gimpdisplayshell-rotate.h b/app/display/gimpdisplayshell-rotate.h
new file mode 100644
index 0000000..d1ffa05
--- /dev/null
+++ b/app/display/gimpdisplayshell-rotate.h
@@ -0,0 +1,40 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_ROTATE_H__
+#define __GIMP_DISPLAY_SHELL_ROTATE_H__
+
+
+void   gimp_display_shell_flip                    (GimpDisplayShell *shell,
+                                                   gboolean          flip_horizontally,
+                                                   gboolean          flip_vertically);
+
+void   gimp_display_shell_rotate                  (GimpDisplayShell *shell,
+                                                   gdouble           delta);
+void   gimp_display_shell_rotate_to               (GimpDisplayShell *shell,
+                                                   gdouble           value);
+void   gimp_display_shell_rotate_drag             (GimpDisplayShell *shell,
+                                                   gdouble           last_x,
+                                                   gdouble           last_y,
+                                                   gdouble           cur_x,
+                                                   gdouble           cur_y,
+                                                   gboolean          constrain);
+
+void   gimp_display_shell_rotate_update_transform (GimpDisplayShell *shell);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_ROTATE_H__  */
diff --git a/app/display/gimpdisplayshell-rulers.c b/app/display/gimpdisplayshell-rulers.c
new file mode 100644
index 0000000..79253c8
--- /dev/null
+++ b/app/display/gimpdisplayshell-rulers.c
@@ -0,0 +1,181 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <math.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimpimage.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-rulers.h"
+#include "gimpdisplayshell-scale.h"
+
+
+/**
+ * gimp_display_shell_rulers_update:
+ * @shell:
+ *
+ **/
+void
+gimp_display_shell_rulers_update (GimpDisplayShell *shell)
+{
+  GimpImage *image;
+  gint       image_width;
+  gint       image_height;
+  gdouble    offset_x     = 0.0;
+  gdouble    offset_y     = 0.0;
+  gdouble    scale_x      = 1.0;
+  gdouble    scale_y      = 1.0;
+  gdouble    resolution_x = 1.0;
+  gdouble    resolution_y = 1.0;
+  gdouble    horizontal_lower;
+  gdouble    horizontal_upper;
+  gdouble    horizontal_max_size;
+  gdouble    vertical_lower;
+  gdouble    vertical_upper;
+  gdouble    vertical_max_size;
+
+  if (! shell->display)
+    return;
+
+  image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      gint    image_x, image_y;
+      gdouble res_x, res_y;
+
+      gimp_display_shell_scale_get_image_bounds (shell,
+                                                 &image_x, &image_y,
+                                                 &image_width, &image_height);
+
+      gimp_display_shell_get_rotated_scale (shell, &scale_x, &scale_y);
+
+      image_width  /= scale_x;
+      image_height /= scale_y;
+
+      offset_x = shell->offset_x - image_x;
+      offset_y = shell->offset_y - image_y;
+
+      gimp_image_get_resolution (image, &res_x, &res_y);
+
+      if (shell->rotate_angle == 0.0 || res_x == res_y)
+        {
+          resolution_x = res_x;
+          resolution_y = res_y;
+        }
+      else
+        {
+          gdouble cos_a = cos (G_PI * shell->rotate_angle / 180.0);
+          gdouble sin_a = sin (G_PI * shell->rotate_angle / 180.0);
+
+          if (shell->dot_for_dot)
+            {
+              resolution_x = 1.0 / sqrt (SQR (cos_a / res_x) +
+                                         SQR (sin_a / res_y));
+              resolution_y = 1.0 / sqrt (SQR (cos_a / res_y) +
+                                         SQR (sin_a / res_x));
+            }
+          else
+            {
+              resolution_x = sqrt (SQR (res_x * cos_a) + SQR (res_y * sin_a));
+              resolution_y = sqrt (SQR (res_y * cos_a) + SQR (res_x * sin_a));
+            }
+        }
+    }
+  else
+    {
+      image_width  = shell->disp_width;
+      image_height = shell->disp_height;
+    }
+
+  /* Initialize values */
+
+  horizontal_lower = 0;
+  vertical_lower   = 0;
+
+  if (image)
+    {
+      horizontal_upper    = gimp_pixels_to_units (shell->disp_width / scale_x,
+                                                  shell->unit,
+                                                  resolution_x);
+      horizontal_max_size = gimp_pixels_to_units (MAX (image_width,
+                                                       image_height),
+                                                  shell->unit,
+                                                  resolution_x);
+
+      vertical_upper      = gimp_pixels_to_units (shell->disp_height / scale_y,
+                                                  shell->unit,
+                                                  resolution_y);
+      vertical_max_size   = gimp_pixels_to_units (MAX (image_width,
+                                                       image_height),
+                                                  shell->unit,
+                                                  resolution_y);
+    }
+  else
+    {
+      horizontal_upper    = image_width;
+      horizontal_max_size = MAX (image_width, image_height);
+
+      vertical_upper      = image_height;
+      vertical_max_size   = MAX (image_width, image_height);
+    }
+
+
+  /* Adjust due to scrolling */
+
+  if (image)
+    {
+      offset_x *= horizontal_upper / shell->disp_width;
+      offset_y *= vertical_upper   / shell->disp_height;
+
+      horizontal_lower += offset_x;
+      horizontal_upper += offset_x;
+
+      vertical_lower   += offset_y;
+      vertical_upper   += offset_y;
+    }
+
+  /* Finally setup the actual rulers */
+
+  gimp_ruler_set_range (GIMP_RULER (shell->hrule),
+                        horizontal_lower,
+                        horizontal_upper,
+                        horizontal_max_size);
+
+  gimp_ruler_set_unit  (GIMP_RULER (shell->hrule),
+                        shell->unit);
+
+  gimp_ruler_set_range (GIMP_RULER (shell->vrule),
+                        vertical_lower,
+                        vertical_upper,
+                        vertical_max_size);
+
+  gimp_ruler_set_unit  (GIMP_RULER (shell->vrule),
+                        shell->unit);
+}
diff --git a/app/display/gimpdisplayshell-rulers.h b/app/display/gimpdisplayshell-rulers.h
new file mode 100644
index 0000000..117a8f0
--- /dev/null
+++ b/app/display/gimpdisplayshell-rulers.h
@@ -0,0 +1,25 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_RULERS_H__
+#define __GIMP_DISPLAY_SHELL_RULERS_H__
+
+
+void   gimp_display_shell_rulers_update (GimpDisplayShell *shell);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_RULERS_H__  */
diff --git a/app/display/gimpdisplayshell-scale-dialog.c b/app/display/gimpdisplayshell-scale-dialog.c
new file mode 100644
index 0000000..f3d2eab
--- /dev/null
+++ b/app/display/gimpdisplayshell-scale-dialog.c
@@ -0,0 +1,293 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpviewable.h"
+
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpviewabledialog.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scale-dialog.h"
+
+#include "gimp-intl.h"
+
+
+#define SCALE_EPSILON      0.0001
+#define SCALE_EQUALS(a,b) (fabs ((a) - (b)) < SCALE_EPSILON)
+
+
+typedef struct
+{
+  GimpDisplayShell *shell;
+  GimpZoomModel    *model;
+  GtkAdjustment    *scale_adj;
+  GtkAdjustment    *num_adj;
+  GtkAdjustment    *denom_adj;
+} ScaleDialogData;
+
+
+/*  local function prototypes  */
+
+static void  gimp_display_shell_scale_dialog_response (GtkWidget        *widget,
+                                                       gint              response_id,
+                                                       ScaleDialogData  *dialog);
+static void  gimp_display_shell_scale_dialog_free     (ScaleDialogData  *dialog);
+
+static void  update_zoom_values                       (GtkAdjustment    *adj,
+                                                       ScaleDialogData  *dialog);
+
+
+
+/*  public functions  */
+
+/**
+ * gimp_display_shell_scale_dialog:
+ * @shell: the #GimpDisplayShell
+ *
+ * Constructs and displays a dialog allowing the user to enter a
+ * custom display scale.
+ **/
+void
+gimp_display_shell_scale_dialog (GimpDisplayShell *shell)
+{
+  ScaleDialogData *data;
+  GimpImage       *image;
+  GtkWidget       *toplevel;
+  GtkWidget       *hbox;
+  GtkWidget       *table;
+  GtkWidget       *spin;
+  GtkWidget       *label;
+  gint             num, denom, row;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->scale_dialog)
+    {
+      gtk_window_present (GTK_WINDOW (shell->scale_dialog));
+      return;
+    }
+
+  if (SCALE_EQUALS (shell->other_scale, 0.0))
+    {
+      /* other_scale not yet initialized */
+      shell->other_scale = gimp_zoom_model_get_factor (shell->zoom);
+    }
+
+  image = gimp_display_get_image (shell->display);
+
+  data = g_slice_new (ScaleDialogData);
+
+  data->shell = shell;
+  data->model = g_object_new (GIMP_TYPE_ZOOM_MODEL,
+                              "value", fabs (shell->other_scale),
+                              NULL);
+
+  shell->scale_dialog =
+    gimp_viewable_dialog_new (GIMP_VIEWABLE (image),
+                              gimp_get_user_context (shell->display->gimp),
+                              _("Zoom Ratio"), "display_scale",
+                              "zoom-original",
+                              _("Select Zoom Ratio"),
+                              GTK_WIDGET (shell),
+                              gimp_standard_help_func,
+                              GIMP_HELP_VIEW_ZOOM_OTHER,
+
+                              _("_Cancel"), GTK_RESPONSE_CANCEL,
+                              _("_OK"),     GTK_RESPONSE_OK,
+
+                              NULL);
+
+  gtk_dialog_set_alternative_button_order (GTK_DIALOG (shell->scale_dialog),
+                                           GTK_RESPONSE_OK,
+                                           GTK_RESPONSE_CANCEL,
+                                           -1);
+
+  g_object_weak_ref (G_OBJECT (shell->scale_dialog),
+                     (GWeakNotify) gimp_display_shell_scale_dialog_free, data);
+  g_object_weak_ref (G_OBJECT (shell->scale_dialog),
+                     (GWeakNotify) g_object_unref, data->model);
+
+  g_object_add_weak_pointer (G_OBJECT (shell->scale_dialog),
+                             (gpointer) &shell->scale_dialog);
+
+  toplevel = gtk_widget_get_toplevel (GTK_WIDGET (shell));
+
+  gtk_window_set_transient_for (GTK_WINDOW (shell->scale_dialog),
+                                GTK_WINDOW (toplevel));
+  gtk_window_set_destroy_with_parent (GTK_WINDOW (shell->scale_dialog), TRUE);
+
+  g_signal_connect (shell->scale_dialog, "response",
+                    G_CALLBACK (gimp_display_shell_scale_dialog_response),
+                    data);
+
+  table = gtk_table_new (2, 2, FALSE);
+  gtk_container_set_border_width (GTK_CONTAINER (table), 12);
+  gtk_table_set_col_spacings (GTK_TABLE (table), 6);
+  gtk_table_set_row_spacings (GTK_TABLE (table), 6);
+  gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (shell->scale_dialog))),
+                      table, TRUE, TRUE, 0);
+  gtk_widget_show (table);
+
+  row = 0;
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, row++,
+                             _("Zoom ratio:"), 0.0, 0.5,
+                             hbox, 1, FALSE);
+
+  gimp_zoom_model_get_fraction (data->model, &num, &denom);
+
+  data->num_adj = (GtkAdjustment *)
+    gtk_adjustment_new (num, 1, 256, 1, 8, 0);
+  spin = gimp_spin_button_new (data->num_adj, 1.0, 0);
+  gtk_spin_button_set_numeric (GTK_SPIN_BUTTON (spin), TRUE);
+  gtk_entry_set_activates_default (GTK_ENTRY (spin), TRUE);
+  gtk_box_pack_start (GTK_BOX (hbox), spin, TRUE, TRUE, 0);
+  gtk_widget_show (spin);
+
+  label = gtk_label_new (":");
+  gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
+  gtk_widget_show (label);
+
+  data->denom_adj = (GtkAdjustment *)
+    gtk_adjustment_new (denom, 1, 256, 1, 8, 0);
+  spin = gimp_spin_button_new (data->denom_adj, 1.0, 0);
+  gtk_spin_button_set_numeric (GTK_SPIN_BUTTON (spin), TRUE);
+  gtk_entry_set_activates_default (GTK_ENTRY (spin), TRUE);
+  gtk_box_pack_start (GTK_BOX (hbox), spin, TRUE, TRUE, 0);
+  gtk_widget_show (spin);
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
+  gimp_table_attach_aligned (GTK_TABLE (table), 0, row++,
+                             _("Zoom:"), 0.0, 0.5,
+                             hbox, 1, FALSE);
+
+  data->scale_adj = (GtkAdjustment *)
+    gtk_adjustment_new (fabs (shell->other_scale) * 100,
+                        100.0 / 256.0, 25600.0,
+                        10, 50, 0);
+  spin = gimp_spin_button_new (data->scale_adj, 1.0, 2);
+  gtk_spin_button_set_numeric (GTK_SPIN_BUTTON (spin), TRUE);
+  gtk_entry_set_activates_default (GTK_ENTRY (spin), TRUE);
+  gtk_box_pack_start (GTK_BOX (hbox), spin, TRUE, TRUE, 0);
+  gtk_widget_show (spin);
+
+  label = gtk_label_new ("%");
+  gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
+  gtk_widget_show (label);
+
+  g_signal_connect (data->scale_adj, "value-changed",
+                    G_CALLBACK (update_zoom_values), data);
+  g_signal_connect (data->num_adj, "value-changed",
+                    G_CALLBACK (update_zoom_values), data);
+  g_signal_connect (data->denom_adj, "value-changed",
+                    G_CALLBACK (update_zoom_values), data);
+
+  gtk_widget_show (shell->scale_dialog);
+}
+
+static void
+gimp_display_shell_scale_dialog_response (GtkWidget       *widget,
+                                          gint             response_id,
+                                          ScaleDialogData *dialog)
+{
+  if (response_id == GTK_RESPONSE_OK)
+    {
+      gdouble scale;
+
+      scale = gtk_adjustment_get_value (dialog->scale_adj);
+
+      gimp_display_shell_scale (dialog->shell,
+                                GIMP_ZOOM_TO,
+                                scale / 100.0,
+                                GIMP_ZOOM_FOCUS_BEST_GUESS);
+    }
+  else
+    {
+      /*  need to emit "scaled" to get the menu updated  */
+      gimp_display_shell_scaled (dialog->shell);
+    }
+
+  dialog->shell->other_scale = - fabs (dialog->shell->other_scale);
+
+  gtk_widget_destroy (dialog->shell->scale_dialog);
+}
+
+static void
+gimp_display_shell_scale_dialog_free (ScaleDialogData *dialog)
+{
+  g_slice_free (ScaleDialogData, dialog);
+}
+
+static void
+update_zoom_values (GtkAdjustment   *adj,
+                    ScaleDialogData *dialog)
+{
+  gint    num, denom;
+  gdouble scale;
+
+  g_signal_handlers_block_by_func (dialog->scale_adj,
+                                   update_zoom_values,
+                                   dialog);
+  g_signal_handlers_block_by_func (dialog->num_adj,
+                                   update_zoom_values,
+                                   dialog);
+  g_signal_handlers_block_by_func (dialog->denom_adj,
+                                   update_zoom_values,
+                                   dialog);
+
+  if (adj == dialog->scale_adj)
+    {
+      scale = gtk_adjustment_get_value (dialog->scale_adj);
+
+      gimp_zoom_model_zoom (dialog->model, GIMP_ZOOM_TO, scale / 100.0);
+      gimp_zoom_model_get_fraction (dialog->model, &num, &denom);
+
+      gtk_adjustment_set_value (dialog->num_adj, num);
+      gtk_adjustment_set_value (dialog->denom_adj, denom);
+    }
+  else /* fraction adjustments */
+    {
+      scale = (gtk_adjustment_get_value (dialog->num_adj) /
+               gtk_adjustment_get_value (dialog->denom_adj));
+
+      gtk_adjustment_set_value (dialog->scale_adj, scale * 100);
+    }
+
+  g_signal_handlers_unblock_by_func (dialog->scale_adj,
+                                     update_zoom_values,
+                                     dialog);
+  g_signal_handlers_unblock_by_func (dialog->num_adj,
+                                     update_zoom_values,
+                                     dialog);
+  g_signal_handlers_unblock_by_func (dialog->denom_adj,
+                                     update_zoom_values,
+                                     dialog);
+}
diff --git a/app/display/gimpdisplayshell-scale-dialog.h b/app/display/gimpdisplayshell-scale-dialog.h
new file mode 100644
index 0000000..eb83065
--- /dev/null
+++ b/app/display/gimpdisplayshell-scale-dialog.h
@@ -0,0 +1,25 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_SCALE_DIALOG_H__
+#define __GIMP_DISPLAY_SHELL_SCALE_DIALOG_H__
+
+
+void  gimp_display_shell_scale_dialog (GimpDisplayShell *shell);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_SCALE_DIALOG_H__  */
diff --git a/app/display/gimpdisplayshell-scale.c b/app/display/gimpdisplayshell-scale.c
new file mode 100644
index 0000000..482a9fe
--- /dev/null
+++ b/app/display/gimpdisplayshell-scale.c
@@ -0,0 +1,1449 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <math.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpguiconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpimage.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-rotate.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpimagewindow.h"
+
+
+#define SCALE_TIMEOUT             2
+#define SCALE_EPSILON             0.0001
+#define ALMOST_CENTERED_THRESHOLD 2
+
+#define SCALE_EQUALS(a,b) (fabs ((a) - (b)) < SCALE_EPSILON)
+
+
+/*  local function prototypes  */
+
+static void      gimp_display_shell_scale_get_screen_resolution
+                                                         (GimpDisplayShell *shell,
+                                                          gdouble          *xres,
+                                                          gdouble          *yres);
+static void      gimp_display_shell_scale_get_image_size_for_scale
+                                                         (GimpDisplayShell *shell,
+                                                          gdouble           scale,
+                                                          gint             *w,
+                                                          gint             *h);
+static void      gimp_display_shell_calculate_scale_x_and_y
+                                                         (GimpDisplayShell *shell,
+                                                          gdouble           scale,
+                                                          gdouble          *scale_x,
+                                                          gdouble          *scale_y);
+
+static void      gimp_display_shell_scale_to             (GimpDisplayShell *shell,
+                                                          gdouble           scale,
+                                                          gdouble           viewport_x,
+                                                          gdouble           viewport_y);
+static void      gimp_display_shell_scale_fit_or_fill    (GimpDisplayShell *shell,
+                                                          gboolean          fill);
+
+static gboolean  gimp_display_shell_scale_image_starts_to_fit
+                                                         (GimpDisplayShell *shell,
+                                                          gdouble           new_scale,
+                                                          gdouble           current_scale,
+                                                          gboolean         *vertically,
+                                                          gboolean         *horizontally);
+static gboolean  gimp_display_shell_scale_viewport_coord_almost_centered
+                                                         (GimpDisplayShell *shell,
+                                                          gint              x,
+                                                          gint              y,
+                                                          gboolean         *horizontally,
+                                                          gboolean         *vertically);
+
+static void      gimp_display_shell_scale_get_image_center_viewport
+                                                         (GimpDisplayShell *shell,
+                                                          gint             *image_center_x,
+                                                          gint             *image_center_y);
+
+
+static void      gimp_display_shell_scale_get_zoom_focus (GimpDisplayShell *shell,
+                                                          gdouble           new_scale,
+                                                          gdouble           current_scale,
+                                                          gdouble          *x,
+                                                          gdouble          *y,
+                                                          GimpZoomFocus     zoom_focus);
+
+
+/*  public functions  */
+
+/**
+ * gimp_display_shell_scale_revert:
+ * @shell:     the #GimpDisplayShell
+ *
+ * Reverts the display to the previously used scale. If no previous
+ * scale exist, then the call does nothing.
+ *
+ * Return value: %TRUE if the scale was reverted, otherwise %FALSE.
+ **/
+gboolean
+gimp_display_shell_scale_revert (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  /* don't bother if no scale has been set */
+  if (shell->last_scale < SCALE_EPSILON)
+    return FALSE;
+
+  shell->last_scale_time = 0;
+
+  gimp_display_shell_scale_by_values (shell,
+                                      shell->last_scale,
+                                      shell->last_offset_x,
+                                      shell->last_offset_y,
+                                      FALSE);   /* don't resize the window */
+
+  return TRUE;
+}
+
+/**
+ * gimp_display_shell_scale_can_revert:
+ * @shell: the #GimpDisplayShell
+ *
+ * Return value: %TRUE if a previous display scale exists, otherwise %FALSE.
+ **/
+gboolean
+gimp_display_shell_scale_can_revert (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return (shell->last_scale > SCALE_EPSILON);
+}
+
+/**
+ * gimp_display_shell_scale_save_revert_values:
+ * @shell:
+ *
+ * Handle the updating of the Revert Zoom variables.
+ **/
+void
+gimp_display_shell_scale_save_revert_values (GimpDisplayShell *shell)
+{
+  guint now;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  now = time (NULL);
+
+  if (now - shell->last_scale_time >= SCALE_TIMEOUT)
+    {
+      shell->last_scale    = gimp_zoom_model_get_factor (shell->zoom);
+      shell->last_offset_x = shell->offset_x;
+      shell->last_offset_y = shell->offset_y;
+    }
+
+  shell->last_scale_time = now;
+}
+
+/**
+ * gimp_display_shell_scale_set_dot_for_dot:
+ * @shell:        the #GimpDisplayShell
+ * @dot_for_dot:  whether "Dot for Dot" should be enabled
+ *
+ * If @dot_for_dot is set to %TRUE then the "Dot for Dot" mode (where image and
+ * screen pixels are of the same size) is activated. Dually, the mode is
+ * disabled if @dot_for_dot is %FALSE.
+ **/
+void
+gimp_display_shell_scale_set_dot_for_dot (GimpDisplayShell *shell,
+                                          gboolean          dot_for_dot)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (dot_for_dot != shell->dot_for_dot)
+    {
+      GimpDisplayConfig *config = shell->display->config;
+      gboolean           resize_window;
+
+      /* Resize windows only in multi-window mode */
+      resize_window = (config->resize_windows_on_zoom &&
+                       ! GIMP_GUI_CONFIG (config)->single_window_mode);
+
+      /* freeze the active tool */
+      gimp_display_shell_pause (shell);
+
+      shell->dot_for_dot = dot_for_dot;
+
+      gimp_display_shell_scale_update (shell);
+
+      gimp_display_shell_scale_resize (shell, resize_window, FALSE);
+
+      /* re-enable the active tool */
+      gimp_display_shell_resume (shell);
+    }
+}
+
+/**
+ * gimp_display_shell_scale_get_image_size:
+ * @shell:
+ * @w:
+ * @h:
+ *
+ * Gets the size of the rendered image after it has been scaled.
+ *
+ **/
+void
+gimp_display_shell_scale_get_image_size (GimpDisplayShell *shell,
+                                         gint             *w,
+                                         gint             *h)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_scale_get_image_size_for_scale (shell,
+                                                     gimp_zoom_model_get_factor (shell->zoom),
+                                                     w, h);
+}
+
+/**
+ * gimp_display_shell_scale_get_image_bounds:
+ * @shell:
+ * @x:
+ * @y:
+ * @w:
+ * @h:
+ *
+ * Gets the screen-space boudning box of the image, after it has
+ * been transformed (i.e., scaled, rotated, and scrolled).
+ **/
+void
+gimp_display_shell_scale_get_image_bounds (GimpDisplayShell *shell,
+                                           gint             *x,
+                                           gint             *y,
+                                           gint             *w,
+                                           gint             *h)
+{
+  GimpImage *image;
+  gdouble    x1, y1;
+  gdouble    x2, y2;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  gimp_display_shell_transform_bounds (shell,
+                                       0, 0,
+                                       gimp_image_get_width (image),
+                                       gimp_image_get_height (image),
+                                       &x1, &y1,
+                                       &x2, &y2);
+
+  x1 = ceil (x1);
+  y1 = ceil (y1);
+  x2 = floor (x2);
+  y2 = floor (y2);
+
+  if (x) *x = x1 + shell->offset_x;
+  if (y) *y = y1 + shell->offset_y;
+  if (w) *w = x2 - x1;
+  if (h) *h = y2 - y1;
+}
+
+/**
+ * gimp_display_shell_scale_get_image_unrotated_bounds:
+ * @shell:
+ * @x:
+ * @y:
+ * @w:
+ * @h:
+ *
+ * Gets the screen-space boudning box of the image, after it has
+ * been scaled and scrolled, but before it has been rotated.
+ **/
+void
+gimp_display_shell_scale_get_image_unrotated_bounds (GimpDisplayShell *shell,
+                                                     gint             *x,
+                                                     gint             *y,
+                                                     gint             *w,
+                                                     gint             *h)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  if (x) *x = -shell->offset_x;
+  if (y) *y = -shell->offset_y;
+  if (w) *w = floor (gimp_image_get_width  (image) * shell->scale_x);
+  if (h) *h = floor (gimp_image_get_height (image) * shell->scale_y);
+}
+
+/**
+ * gimp_display_shell_scale_get_image_bounding_box:
+ * @shell:
+ * @x:
+ * @y:
+ * @w:
+ * @h:
+ *
+ * Gets the screen-space boudning box of the image content, after it has
+ * been transformed (i.e., scaled, rotated, and scrolled).
+ **/
+void
+gimp_display_shell_scale_get_image_bounding_box (GimpDisplayShell *shell,
+                                                 gint             *x,
+                                                 gint             *y,
+                                                 gint             *w,
+                                                 gint             *h)
+{
+  GeglRectangle bounding_box;
+  gdouble       x1, y1;
+  gdouble       x2, y2;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  bounding_box = gimp_display_shell_get_bounding_box (shell);
+
+  gimp_display_shell_transform_bounds (shell,
+                                       bounding_box.x,
+                                       bounding_box.y,
+                                       bounding_box.x + bounding_box.width,
+                                       bounding_box.y + bounding_box.height,
+                                       &x1, &y1,
+                                       &x2, &y2);
+
+  if (! shell->show_all)
+    {
+      x1 = ceil  (x1);
+      y1 = ceil  (y1);
+      x2 = floor (x2);
+      y2 = floor (y2);
+    }
+  else
+    {
+      x1 = floor (x1);
+      y1 = floor (y1);
+      x2 = ceil  (x2);
+      y2 = ceil  (y2);
+    }
+
+  if (x) *x = x1 + shell->offset_x;
+  if (y) *y = y1 + shell->offset_y;
+  if (w) *w = x2 - x1;
+  if (h) *h = y2 - y1;
+}
+
+/**
+ * gimp_display_shell_scale_get_image_unrotated_bounding_box:
+ * @shell:
+ * @x:
+ * @y:
+ * @w:
+ * @h:
+ *
+ * Gets the screen-space boudning box of the image content, after it has
+ * been scaled and scrolled, but before it has been rotated.
+ **/
+void
+gimp_display_shell_scale_get_image_unrotated_bounding_box (GimpDisplayShell *shell,
+                                                           gint             *x,
+                                                           gint             *y,
+                                                           gint             *w,
+                                                           gint             *h)
+{
+  GeglRectangle bounding_box;
+  gdouble       x1, y1;
+  gdouble       x2, y2;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  bounding_box = gimp_display_shell_get_bounding_box (shell);
+
+  x1 = bounding_box.x * shell->scale_x -
+       shell->offset_x;
+  y1 = bounding_box.y * shell->scale_y -
+       shell->offset_y;
+
+  x2 = (bounding_box.x + bounding_box.width)  * shell->scale_x -
+       shell->offset_x;
+  y2 = (bounding_box.y + bounding_box.height) * shell->scale_y -
+       shell->offset_y;
+
+  if (! shell->show_all)
+    {
+      x1 = ceil  (x1);
+      y1 = ceil  (y1);
+      x2 = floor (x2);
+      y2 = floor (y2);
+    }
+  else
+    {
+      x1 = floor (x1);
+      y1 = floor (y1);
+      x2 = ceil  (x2);
+      y2 = ceil  (y2);
+    }
+
+  if (x) *x = x1;
+  if (y) *y = y1;
+  if (w) *w = x2 - x1;
+  if (h) *h = y2 - y1;
+}
+
+/**
+ * gimp_display_shell_scale_image_is_within_viewport:
+ * @shell:
+ *
+ * Returns: %TRUE if the (scaled) image is smaller than and within the
+ *          viewport.
+ **/
+gboolean
+gimp_display_shell_scale_image_is_within_viewport (GimpDisplayShell *shell,
+                                                   gboolean         *horizontally,
+                                                   gboolean         *vertically)
+{
+  gboolean horizontally_dummy, vertically_dummy;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  if (! horizontally) horizontally = &horizontally_dummy;
+  if (! vertically)   vertically   = &vertically_dummy;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      gint sx, sy;
+      gint sw, sh;
+
+      gimp_display_shell_scale_get_image_bounding_box (shell,
+                                                       &sx, &sy, &sw, &sh);
+
+      sx -= shell->offset_x;
+      sy -= shell->offset_y;
+
+      *horizontally = sx >= 0 && sx + sw <= shell->disp_width;
+      *vertically   = sy >= 0 && sy + sh <= shell->disp_height;
+    }
+  else
+    {
+      *horizontally = FALSE;
+      *vertically   = FALSE;
+    }
+
+  return *vertically && *horizontally;
+}
+
+/* We used to calculate the scale factor in the SCALEFACTOR_X() and
+ * SCALEFACTOR_Y() macros. But since these are rather frequently
+ * called and the values rarely change, we now store them in the
+ * shell and call this function whenever they need to be recalculated.
+ */
+void
+gimp_display_shell_scale_update (GimpDisplayShell *shell)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      gimp_display_shell_calculate_scale_x_and_y (shell,
+                                                  gimp_zoom_model_get_factor (shell->zoom),
+                                                  &shell->scale_x,
+                                                  &shell->scale_y);
+    }
+  else
+    {
+      shell->scale_x = 1.0;
+      shell->scale_y = 1.0;
+    }
+}
+
+/**
+ * gimp_display_shell_scale:
+ * @shell:     the #GimpDisplayShell
+ * @zoom_type: whether to zoom in, out or to a specific scale
+ * @scale:     ignored unless @zoom_type == %GIMP_ZOOM_TO
+ *
+ * This function figures out the context of the zoom and behaves
+ * appropriately thereafter.
+ *
+ **/
+void
+gimp_display_shell_scale (GimpDisplayShell *shell,
+                          GimpZoomType      zoom_type,
+                          gdouble           new_scale,
+                          GimpZoomFocus     zoom_focus)
+{
+  GimpDisplayConfig *config;
+  gdouble            current_scale;
+  gboolean           resize_window;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->canvas != NULL);
+
+  current_scale = gimp_zoom_model_get_factor (shell->zoom);
+
+  if (zoom_type != GIMP_ZOOM_TO)
+    new_scale = gimp_zoom_model_zoom_step (zoom_type, current_scale);
+
+  if (SCALE_EQUALS (new_scale, current_scale))
+    return;
+
+  config = shell->display->config;
+
+  /* Resize windows only in multi-window mode */
+  resize_window = (config->resize_windows_on_zoom &&
+                   ! GIMP_GUI_CONFIG (config)->single_window_mode);
+
+  if (resize_window)
+    {
+      /* If the window is resized on zoom, simply do the zoom and get
+       * things rolling
+       */
+      gimp_zoom_model_zoom (shell->zoom, GIMP_ZOOM_TO, new_scale);
+
+      gimp_display_shell_scale_resize (shell, TRUE, FALSE);
+    }
+  else
+    {
+      gdouble  x, y;
+      gint     image_center_x;
+      gint     image_center_y;
+
+      gimp_display_shell_scale_get_zoom_focus (shell,
+                                               new_scale,
+                                               current_scale,
+                                               &x,
+                                               &y,
+                                               zoom_focus);
+      gimp_display_shell_scale_get_image_center_viewport (shell,
+                                                          &image_center_x,
+                                                          &image_center_y);
+
+      gimp_display_shell_scale_to (shell, new_scale, x, y);
+
+      /* skip centering magic if pointer focus was requested */
+      if (zoom_focus != GIMP_ZOOM_FOCUS_POINTER)
+        {
+          gboolean starts_fitting_horiz;
+          gboolean starts_fitting_vert;
+          gboolean zoom_focus_almost_centered_horiz;
+          gboolean zoom_focus_almost_centered_vert;
+          gboolean image_center_almost_centered_horiz;
+          gboolean image_center_almost_centered_vert;
+
+          /* If an image axis started to fit due to zooming out or if
+           * the focus point is as good as in the center, center on
+           * that axis
+           */
+          gimp_display_shell_scale_image_starts_to_fit (shell,
+                                                        new_scale,
+                                                        current_scale,
+                                                        &starts_fitting_horiz,
+                                                        &starts_fitting_vert);
+
+          gimp_display_shell_scale_viewport_coord_almost_centered (shell,
+                                                                   x,
+                                                                   y,
+                                                                   &zoom_focus_almost_centered_horiz,
+                                                                   &zoom_focus_almost_centered_vert);
+          gimp_display_shell_scale_viewport_coord_almost_centered (shell,
+                                                                   image_center_x,
+                                                                   image_center_y,
+                                                                   &image_center_almost_centered_horiz,
+                                                                   &image_center_almost_centered_vert);
+
+          gimp_display_shell_scroll_center_image (shell,
+                                                  starts_fitting_horiz ||
+                                                  (zoom_focus_almost_centered_horiz &&
+                                                   image_center_almost_centered_horiz),
+                                                  starts_fitting_vert ||
+                                                  (zoom_focus_almost_centered_vert &&
+                                                   image_center_almost_centered_vert));
+        }
+    }
+}
+
+/**
+ * gimp_display_shell_scale_to_rectangle:
+ * @shell:         the #GimpDisplayShell
+ * @zoom_type:     whether to zoom in or out
+ * @x:             retangle's x in image coordinates
+ * @y:             retangle's y in image coordinates
+ * @width:         retangle's width in image coordinates
+ * @height:        retangle's height in image coordinates
+ * @resize_window: whether the display window should be resized
+ *
+ * Scales and scrolls to a specific image rectangle
+ **/
+void
+gimp_display_shell_scale_to_rectangle (GimpDisplayShell *shell,
+                                       GimpZoomType      zoom_type,
+                                       gdouble           x,
+                                       gdouble           y,
+                                       gdouble           width,
+                                       gdouble           height,
+                                       gboolean          resize_window)
+{
+  gdouble current_scale;
+  gdouble new_scale;
+  gdouble factor   = 1.0;
+  gint    offset_x = 0;
+  gint    offset_y = 0;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_transform_bounds (shell,
+                                       x, y,
+                                       x + width, y + height,
+                                       &x, &y,
+                                       &width, &height);
+
+  /* Convert scrolled (x1, y1, x2, y2) to unscrolled (x, y, width, height). */
+  width  -= x;
+  height -= y;
+  x      += shell->offset_x;
+  y      += shell->offset_y;
+
+  width  = MAX (1.0, width);
+  height = MAX (1.0, height);
+
+  current_scale = gimp_zoom_model_get_factor (shell->zoom);
+
+  switch (zoom_type)
+    {
+    case GIMP_ZOOM_IN:
+      factor = MIN ((shell->disp_width  / width),
+                    (shell->disp_height / height));
+      break;
+
+    case GIMP_ZOOM_OUT:
+      factor = MAX ((width  / shell->disp_width),
+                    (height / shell->disp_height));
+      break;
+
+    default:
+      g_return_if_reached ();
+      break;
+    }
+
+  new_scale = current_scale * factor;
+
+  switch (zoom_type)
+    {
+    case GIMP_ZOOM_IN:
+      /*  move the center of the rectangle to the center of the
+       *  viewport:
+       *
+       *  new_offset = center of rectangle in new scale screen coords
+       *               including offset
+       *               -
+       *               center of viewport in screen coords without
+       *               offset
+       */
+      offset_x = RINT (factor * (x + width  / 2.0) - (shell->disp_width  / 2));
+      offset_y = RINT (factor * (y + height / 2.0) - (shell->disp_height / 2));
+      break;
+
+    case GIMP_ZOOM_OUT:
+      /*  move the center of the viewport to the center of the
+       *  rectangle:
+       *
+       *  new_offset = center of viewport in new scale screen coords
+       *               including offset
+       *               -
+       *               center of rectangle in screen coords without
+       *               offset
+       */
+      offset_x = RINT (factor * (shell->offset_x + shell->disp_width  / 2) -
+                       ((x + width  / 2.0) - shell->offset_x));
+
+      offset_y = RINT (factor * (shell->offset_y + shell->disp_height / 2) -
+                       ((y + height / 2.0) - shell->offset_y));
+      break;
+
+    default:
+      break;
+    }
+
+  if (new_scale != current_scale   ||
+      offset_x  != shell->offset_x ||
+      offset_y  != shell->offset_y)
+    {
+      gimp_display_shell_scale_by_values (shell,
+                                          new_scale,
+                                          offset_x, offset_y,
+                                          resize_window);
+    }
+}
+
+/**
+ * gimp_display_shell_scale_fit_in:
+ * @shell: the #GimpDisplayShell
+ *
+ * Sets the scale such that the entire image precisely fits in the
+ * display area.
+ **/
+void
+gimp_display_shell_scale_fit_in (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_scale_fit_or_fill (shell,
+                                        /* fill = */ FALSE);
+ }
+
+/**
+ * gimp_display_shell_scale_fill:
+ * @shell: the #GimpDisplayShell
+ *
+ * Sets the scale such that the entire display area is precisely
+ * filled by the image.
+ **/
+void
+gimp_display_shell_scale_fill (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_scale_fit_or_fill (shell,
+                                        /* fill = */ TRUE);
+}
+
+/**
+ * gimp_display_shell_scale_by_values:
+ * @shell:         the #GimpDisplayShell
+ * @scale:         the new scale
+ * @offset_x:      the new X offset
+ * @offset_y:      the new Y offset
+ * @resize_window: whether the display window should be resized
+ *
+ * Directly sets the image scale and image offsets used by the display. If
+ * @resize_window is %TRUE then the display window is resized to better
+ * accommodate the image, see gimp_display_shell_shrink_wrap().
+ **/
+void
+gimp_display_shell_scale_by_values (GimpDisplayShell *shell,
+                                    gdouble           scale,
+                                    gint              offset_x,
+                                    gint              offset_y,
+                                    gboolean          resize_window)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  /*  Abort early if the values are all setup already. We don't
+   *  want to inadvertently resize the window (bug #164281).
+   */
+  if (SCALE_EQUALS (gimp_zoom_model_get_factor (shell->zoom), scale) &&
+      shell->offset_x == offset_x &&
+      shell->offset_y == offset_y)
+    return;
+
+  gimp_display_shell_scale_save_revert_values (shell);
+
+  /* freeze the active tool */
+  gimp_display_shell_pause (shell);
+
+  gimp_zoom_model_zoom (shell->zoom, GIMP_ZOOM_TO, scale);
+
+  shell->offset_x = offset_x;
+  shell->offset_y = offset_y;
+
+  gimp_display_shell_rotate_update_transform (shell);
+
+  gimp_display_shell_scale_resize (shell, resize_window, FALSE);
+
+  /* re-enable the active tool */
+  gimp_display_shell_resume (shell);
+}
+
+void
+gimp_display_shell_scale_drag (GimpDisplayShell *shell,
+                               gdouble           start_x,
+                               gdouble           start_y,
+                               gdouble           delta_x,
+                               gdouble           delta_y)
+{
+  gdouble scale;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  scale = gimp_zoom_model_get_factor (shell->zoom);
+
+  gimp_display_shell_push_zoom_focus_pointer_pos (shell, start_x, start_y);
+
+  if (delta_y > 0)
+    {
+      gimp_display_shell_scale (shell,
+                                GIMP_ZOOM_TO,
+                                scale * 1.1,
+                                GIMP_ZOOM_FOCUS_POINTER);
+    }
+  else if (delta_y < 0)
+    {
+      gimp_display_shell_scale (shell,
+                                GIMP_ZOOM_TO,
+                                scale * 0.9,
+                                GIMP_ZOOM_FOCUS_POINTER);
+    }
+}
+
+/**
+ * gimp_display_shell_scale_shrink_wrap:
+ * @shell: the #GimpDisplayShell
+ *
+ * Convenience function with the same functionality as
+ * gimp_display_shell_scale_resize(@shell, TRUE, grow_only).
+ **/
+void
+gimp_display_shell_scale_shrink_wrap (GimpDisplayShell *shell,
+                                      gboolean          grow_only)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_scale_resize (shell, TRUE, grow_only);
+}
+
+/**
+ * gimp_display_shell_scale_resize:
+ * @shell:          the #GimpDisplayShell
+ * @resize_window:  whether the display window should be resized
+ * @grow_only:      whether shrinking of the window is allowed or not
+ *
+ * Function commonly called after a change in display scale to make the changes
+ * visible to the user. If @resize_window is %TRUE then the display window is
+ * resized to accommodate the display image as per
+ * gimp_display_shell_shrink_wrap().
+ **/
+void
+gimp_display_shell_scale_resize (GimpDisplayShell *shell,
+                                 gboolean          resize_window,
+                                 gboolean          grow_only)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  /* freeze the active tool */
+  gimp_display_shell_pause (shell);
+
+  if (resize_window)
+    {
+      GimpImageWindow *window = gimp_display_shell_get_window (shell);
+
+      if (window && gimp_image_window_get_active_shell (window) == shell)
+        {
+          gimp_image_window_shrink_wrap (window, grow_only);
+        }
+    }
+
+  gimp_display_shell_scroll_clamp_and_update (shell);
+  gimp_display_shell_scaled (shell);
+
+  gimp_display_shell_expose_full (shell);
+
+  /* re-enable the active tool */
+  gimp_display_shell_resume (shell);
+}
+
+void
+gimp_display_shell_set_initial_scale (GimpDisplayShell *shell,
+                                      gdouble           scale,
+                                      gint             *display_width,
+                                      gint             *display_height)
+{
+  GimpImage *image;
+  GdkScreen *screen;
+  gint       image_width;
+  gint       image_height;
+  gint       shell_width;
+  gint       shell_height;
+  gint       screen_width;
+  gint       screen_height;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  screen = gtk_widget_get_screen (GTK_WIDGET (shell));
+
+  image_width  = gimp_image_get_width  (image);
+  image_height = gimp_image_get_height (image);
+
+  screen_width  = gdk_screen_get_width (screen)  * 0.75;
+  screen_height = gdk_screen_get_height (screen) * 0.75;
+
+  /* We need to zoom before we use SCALE[XY] */
+  gimp_zoom_model_zoom (shell->zoom, GIMP_ZOOM_TO, scale);
+
+  shell_width  = SCALEX (shell, image_width);
+  shell_height = SCALEY (shell, image_height);
+
+  if (shell->display->config->initial_zoom_to_fit)
+    {
+      /*  Limit to the size of the screen...  */
+      if (shell_width > screen_width || shell_height > screen_height)
+        {
+          gdouble new_scale;
+          gdouble current = gimp_zoom_model_get_factor (shell->zoom);
+
+          new_scale = current * MIN (((gdouble) screen_height) / shell_height,
+                                     ((gdouble) screen_width)  / shell_width);
+
+          new_scale = gimp_zoom_model_zoom_step (GIMP_ZOOM_OUT, new_scale);
+
+          /*  Since zooming out might skip a zoom step we zoom in
+           *  again and test if we are small enough.
+           */
+          gimp_zoom_model_zoom (shell->zoom, GIMP_ZOOM_TO,
+                                gimp_zoom_model_zoom_step (GIMP_ZOOM_IN,
+                                                           new_scale));
+
+          if (SCALEX (shell, image_width) > screen_width ||
+              SCALEY (shell, image_height) > screen_height)
+            gimp_zoom_model_zoom (shell->zoom, GIMP_ZOOM_TO, new_scale);
+
+          shell_width  = SCALEX (shell, image_width);
+          shell_height = SCALEY (shell, image_height);
+        }
+    }
+  else
+    {
+      /*  Set up size like above, but do not zoom to fit. Useful when
+       *  working on large images.
+       */
+      if (shell_width > screen_width)
+        shell_width = screen_width;
+
+      if (shell_height > screen_height)
+        shell_height = screen_height;
+    }
+
+  if (display_width)
+    *display_width = shell_width;
+
+  if (display_height)
+    *display_height = shell_height;
+}
+
+/**
+ * gimp_display_shell_get_rotated_scale:
+ * @shell:   the #GimpDisplayShell
+ * @scale_x: horizontal scale output
+ * @scale_y: vertical scale output
+ *
+ * Returns the screen space horizontal and vertical scaling
+ * factors, taking rotation into account.
+ **/
+void
+gimp_display_shell_get_rotated_scale (GimpDisplayShell *shell,
+                                      gdouble          *scale_x,
+                                      gdouble          *scale_y)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->rotate_angle == 0.0 || shell->scale_x == shell->scale_y)
+    {
+      if (scale_x) *scale_x = shell->scale_x;
+      if (scale_y) *scale_y = shell->scale_y;
+    }
+  else
+    {
+      gdouble a     = G_PI * shell->rotate_angle / 180.0;
+      gdouble cos_a = cos (a);
+      gdouble sin_a = sin (a);
+
+      if (scale_x) *scale_x = 1.0 / sqrt (SQR (cos_a / shell->scale_x) +
+                                          SQR (sin_a / shell->scale_y));
+
+      if (scale_y) *scale_y = 1.0 / sqrt (SQR (cos_a / shell->scale_y) +
+                                          SQR (sin_a / shell->scale_x));
+    }
+}
+
+/**
+ * gimp_display_shell_push_zoom_focus_pointer_pos:
+ * @shell:
+ * @x:
+ * @y:
+ *
+ * When the zoom focus mechanism asks for the pointer the next time,
+ * use @x and @y.
+ **/
+void
+gimp_display_shell_push_zoom_focus_pointer_pos (GimpDisplayShell *shell,
+                                                gint              x,
+                                                gint              y)
+{
+  GdkPoint *point = g_slice_new (GdkPoint);
+  point->x = x;
+  point->y = y;
+
+  g_queue_push_head (shell->zoom_focus_pointer_queue,
+                     point);
+}
+
+
+/*  private functions   */
+
+static void
+gimp_display_shell_scale_get_screen_resolution (GimpDisplayShell *shell,
+                                                gdouble          *xres,
+                                                gdouble          *yres)
+{
+  gdouble x, y;
+
+  if (shell->dot_for_dot)
+    {
+      gimp_image_get_resolution (gimp_display_get_image (shell->display),
+                                 &x, &y);
+    }
+  else
+    {
+      x = shell->monitor_xres;
+      y = shell->monitor_yres;
+    }
+
+  if (xres) *xres = x;
+  if (yres) *yres = y;
+}
+
+/**
+ * gimp_display_shell_scale_get_image_size_for_scale:
+ * @shell:
+ * @scale:
+ * @w:
+ * @h:
+ *
+ **/
+static void
+gimp_display_shell_scale_get_image_size_for_scale (GimpDisplayShell *shell,
+                                                   gdouble           scale,
+                                                   gint             *w,
+                                                   gint             *h)
+{
+  GimpImage *image = gimp_display_get_image (shell->display);
+  gdouble    scale_x;
+  gdouble    scale_y;
+
+  gimp_display_shell_calculate_scale_x_and_y (shell, scale, &scale_x, &scale_y);
+
+  if (w) *w = scale_x * gimp_image_get_width  (image);
+  if (h) *h = scale_y * gimp_image_get_height (image);
+}
+
+/**
+ * gimp_display_shell_calculate_scale_x_and_y:
+ * @shell:
+ * @scale:
+ * @scale_x:
+ * @scale_y:
+ *
+ **/
+static void
+gimp_display_shell_calculate_scale_x_and_y (GimpDisplayShell *shell,
+                                            gdouble           scale,
+                                            gdouble          *scale_x,
+                                            gdouble          *scale_y)
+{
+  GimpImage *image = gimp_display_get_image (shell->display);
+  gdouble    xres;
+  gdouble    yres;
+  gdouble    screen_xres;
+  gdouble    screen_yres;
+
+  gimp_image_get_resolution (image, &xres, &yres);
+  gimp_display_shell_scale_get_screen_resolution (shell,
+                                                  &screen_xres, &screen_yres);
+
+  if (scale_x) *scale_x = scale * screen_xres / xres;
+  if (scale_y) *scale_y = scale * screen_yres / yres;
+}
+
+/**
+ * gimp_display_shell_scale_to:
+ * @shell:
+ * @scale:
+ * @viewport_x:
+ * @viewport_y:
+ *
+ * Zooms. The display offsets are adjusted so that the point specified
+ * by @x and @y doesn't change it's position on screen.
+ **/
+static void
+gimp_display_shell_scale_to (GimpDisplayShell *shell,
+                             gdouble           scale,
+                             gdouble           viewport_x,
+                             gdouble           viewport_y)
+{
+  gdouble image_x, image_y;
+  gdouble new_viewport_x, new_viewport_y;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->display)
+    return;
+
+  /* freeze the active tool */
+  gimp_display_shell_pause (shell);
+
+  gimp_display_shell_untransform_xy_f (shell,
+                                       viewport_x,
+                                       viewport_y,
+                                       &image_x,
+                                       &image_y);
+
+  /* Note that we never come here if we need to resize_windows_on_zoom
+   */
+  gimp_display_shell_scale_by_values (shell,
+                                      scale,
+                                      shell->offset_x,
+                                      shell->offset_y,
+                                      FALSE);
+
+  gimp_display_shell_transform_xy_f (shell,
+                                     image_x,
+                                     image_y,
+                                     &new_viewport_x,
+                                     &new_viewport_y);
+
+  gimp_display_shell_scroll (shell,
+                             new_viewport_x - viewport_x,
+                             new_viewport_y - viewport_y);
+
+  /* re-enable the active tool */
+  gimp_display_shell_resume (shell);
+}
+
+/**
+ * gimp_display_shell_scale_fit_or_fill:
+ * @shell: the #GimpDisplayShell
+ * @fill:  whether to scale the image to fill the viewport,
+ *         or fit inside the viewport
+ *
+ * A common implementation for gimp_display_shell_scale_{fit_in,fill}().
+ **/
+static void
+gimp_display_shell_scale_fit_or_fill (GimpDisplayShell *shell,
+                                      gboolean          fill)
+{
+  GeglRectangle bounding_box;
+  gdouble       image_x;
+  gdouble       image_y;
+  gdouble       image_width;
+  gdouble       image_height;
+  gdouble       current_scale;
+  gdouble       zoom_factor;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      GimpImage *image = gimp_display_get_image (shell->display);
+
+      bounding_box.x      = 0;
+      bounding_box.y      = 0;
+      bounding_box.width  = gimp_image_get_width  (image);
+      bounding_box.height = gimp_image_get_height (image);
+    }
+  else
+    {
+      bounding_box = gimp_display_shell_get_bounding_box (shell);
+    }
+
+  gimp_display_shell_transform_bounds (shell,
+                                       bounding_box.x,
+                                       bounding_box.y,
+                                       bounding_box.x + bounding_box.width,
+                                       bounding_box.y + bounding_box.height,
+                                       &image_x,
+                                       &image_y,
+                                       &image_width,
+                                       &image_height);
+
+  image_width  -= image_x;
+  image_height -= image_y;
+
+  current_scale = gimp_zoom_model_get_factor (shell->zoom);
+
+  if (fill)
+    {
+      zoom_factor = MAX (shell->disp_width  / image_width,
+                         shell->disp_height / image_height);
+    }
+  else
+    {
+      zoom_factor = MIN (shell->disp_width  / image_width,
+                         shell->disp_height / image_height);
+    }
+
+  gimp_display_shell_scale (shell,
+                            GIMP_ZOOM_TO,
+                            zoom_factor * current_scale,
+                            GIMP_ZOOM_FOCUS_BEST_GUESS);
+
+  gimp_display_shell_scroll_center_content (shell, TRUE, TRUE);
+}
+
+static gboolean
+gimp_display_shell_scale_image_starts_to_fit (GimpDisplayShell *shell,
+                                              gdouble           new_scale,
+                                              gdouble           current_scale,
+                                              gboolean         *vertically,
+                                              gboolean         *horizontally)
+{
+  gboolean vertically_dummy;
+  gboolean horizontally_dummy;
+
+  if (! vertically)   vertically   = &vertically_dummy;
+  if (! horizontally) horizontally = &horizontally_dummy;
+
+  /* The image can only start to fit if we zoom out */
+  if (new_scale > current_scale ||
+      gimp_display_shell_get_infinite_canvas (shell))
+    {
+      *vertically   = FALSE;
+      *horizontally = FALSE;
+    }
+  else
+    {
+      gint current_scale_width;
+      gint current_scale_height;
+      gint new_scale_width;
+      gint new_scale_height;
+
+      gimp_display_shell_scale_get_image_size_for_scale (shell,
+                                                         current_scale,
+                                                         &current_scale_width,
+                                                         &current_scale_height);
+
+      gimp_display_shell_scale_get_image_size_for_scale (shell,
+                                                         new_scale,
+                                                         &new_scale_width,
+                                                         &new_scale_height);
+
+      *vertically   = (current_scale_width  >  shell->disp_width &&
+                       new_scale_width      <= shell->disp_width);
+      *horizontally = (current_scale_height >  shell->disp_height &&
+                       new_scale_height     <= shell->disp_height);
+    }
+
+  return *vertically && *horizontally;
+}
+
+static gboolean
+gimp_display_shell_scale_image_stops_to_fit (GimpDisplayShell *shell,
+                                             gdouble           new_scale,
+                                             gdouble           current_scale,
+                                             gboolean         *vertically,
+                                             gboolean         *horizontally)
+{
+  return gimp_display_shell_scale_image_starts_to_fit (shell,
+                                                       current_scale,
+                                                       new_scale,
+                                                       vertically,
+                                                       horizontally);
+}
+
+/**
+ * gimp_display_shell_scale_viewport_coord_almost_centered:
+ * @shell:
+ * @x:
+ * @y:
+ * @horizontally:
+ * @vertically:
+ *
+ **/
+static gboolean
+gimp_display_shell_scale_viewport_coord_almost_centered (GimpDisplayShell *shell,
+                                                         gint              x,
+                                                         gint              y,
+                                                         gboolean         *horizontally,
+                                                         gboolean         *vertically)
+{
+  gboolean local_horizontally = FALSE;
+  gboolean local_vertically   = FALSE;
+  gint     center_x           = shell->disp_width  / 2;
+  gint     center_y           = shell->disp_height / 2;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      local_horizontally = (x > center_x - ALMOST_CENTERED_THRESHOLD &&
+                            x < center_x + ALMOST_CENTERED_THRESHOLD);
+
+      local_vertically   = (y > center_y - ALMOST_CENTERED_THRESHOLD &&
+                            y < center_y + ALMOST_CENTERED_THRESHOLD);
+    }
+
+  if (horizontally) *horizontally = local_horizontally;
+  if (vertically)   *vertically   = local_vertically;
+
+  return local_horizontally && local_vertically;
+}
+
+static void
+gimp_display_shell_scale_get_image_center_viewport (GimpDisplayShell *shell,
+                                                    gint             *image_center_x,
+                                                    gint             *image_center_y)
+{
+  gint sw, sh;
+
+  gimp_display_shell_scale_get_image_size (shell, &sw, &sh);
+
+  if (image_center_x) *image_center_x = -shell->offset_x + sw / 2;
+  if (image_center_y) *image_center_y = -shell->offset_y + sh / 2;
+}
+
+/**
+ * gimp_display_shell_scale_get_zoom_focus:
+ * @shell:
+ * @new_scale:
+ * @x:
+ * @y:
+ *
+ * Calculates the viewport coordinate to focus on when zooming
+ * independently for each axis.
+ **/
+static void
+gimp_display_shell_scale_get_zoom_focus (GimpDisplayShell *shell,
+                                         gdouble           new_scale,
+                                         gdouble           current_scale,
+                                         gdouble          *x,
+                                         gdouble          *y,
+                                         GimpZoomFocus     zoom_focus)
+{
+  GtkWidget *window = GTK_WIDGET (gimp_display_shell_get_window (shell));
+  GdkEvent  *event;
+  gint       image_center_x;
+  gint       image_center_y;
+  gint       other_x;
+  gint       other_y;
+
+  /* Calculate stops-to-fit focus point */
+  gimp_display_shell_scale_get_image_center_viewport (shell,
+                                                      &image_center_x,
+                                                      &image_center_y);
+
+  /* Calculate other focus point, default is the canvas center */
+  other_x = shell->disp_width  / 2;
+  other_y = shell->disp_height / 2;
+
+  /*  Center on the mouse position instead of the display center if
+   *  one of the following conditions are fulfilled and pointer is
+   *  within the canvas:
+   *
+   *   (1) there's no current event (the action was triggered by an
+   *       input controller)
+   *   (2) the event originates from the canvas (a scroll event)
+   *   (3) the event originates from the window (a key press event)
+   *
+   *  Basically the only situation where we don't want to center on
+   *  mouse position is if the action is being called from a menu.
+   */
+  event = gtk_get_current_event ();
+
+  if (! event ||
+      gtk_get_event_widget (event) == shell->canvas ||
+      gtk_get_event_widget (event) == window)
+    {
+      GdkPoint *point = g_queue_pop_head (shell->zoom_focus_pointer_queue);
+      gint      canvas_pointer_x;
+      gint      canvas_pointer_y;
+
+      if (point)
+        {
+          canvas_pointer_x = point->x;
+          canvas_pointer_y = point->y;
+
+          g_slice_free (GdkPoint, point);
+        }
+      else
+        {
+          gtk_widget_get_pointer (shell->canvas,
+                                  &canvas_pointer_x,
+                                  &canvas_pointer_y);
+        }
+
+      if (canvas_pointer_x >= 0 &&
+          canvas_pointer_y >= 0 &&
+          canvas_pointer_x <  shell->disp_width &&
+          canvas_pointer_y <  shell->disp_height)
+        {
+          other_x = canvas_pointer_x;
+          other_y = canvas_pointer_y;
+        }
+    }
+
+  if (zoom_focus == GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS)
+    {
+      if (gimp_display_shell_scale_viewport_coord_almost_centered (shell,
+                                                                   image_center_x,
+                                                                   image_center_y,
+                                                                   NULL,
+                                                                   NULL))
+        {
+          zoom_focus = GIMP_ZOOM_FOCUS_IMAGE_CENTER;
+        }
+      else
+        {
+          zoom_focus = GIMP_ZOOM_FOCUS_BEST_GUESS;
+        }
+    }
+
+  switch (zoom_focus)
+    {
+    case GIMP_ZOOM_FOCUS_POINTER:
+      *x = other_x;
+      *y = other_y;
+      break;
+
+    case GIMP_ZOOM_FOCUS_IMAGE_CENTER:
+      *x = image_center_x;
+      *y = image_center_y;
+      break;
+
+    case GIMP_ZOOM_FOCUS_BEST_GUESS:
+    default:
+      {
+        gboolean within_horizontally, within_vertically;
+        gboolean stops_horizontally, stops_vertically;
+
+        gimp_display_shell_scale_image_is_within_viewport (shell,
+                                                           &within_horizontally,
+                                                           &within_vertically);
+
+        gimp_display_shell_scale_image_stops_to_fit (shell,
+                                                     new_scale,
+                                                     current_scale,
+                                                     &stops_horizontally,
+                                                     &stops_vertically);
+
+        *x = within_horizontally && ! stops_horizontally ? image_center_x : other_x;
+        *y = within_vertically   && ! stops_vertically   ? image_center_y : other_y;
+      }
+      break;
+    }
+}
diff --git a/app/display/gimpdisplayshell-scale.h b/app/display/gimpdisplayshell-scale.h
new file mode 100644
index 0000000..b97f9fb
--- /dev/null
+++ b/app/display/gimpdisplayshell-scale.h
@@ -0,0 +1,108 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_SCALE_H__
+#define __GIMP_DISPLAY_SHELL_SCALE_H__
+
+
+gboolean gimp_display_shell_scale_revert             (GimpDisplayShell *shell);
+gboolean gimp_display_shell_scale_can_revert         (GimpDisplayShell *shell);
+void     gimp_display_shell_scale_save_revert_values (GimpDisplayShell *shell);
+
+void     gimp_display_shell_scale_set_dot_for_dot    (GimpDisplayShell *shell,
+                                                      gboolean          dot_for_dot);
+
+void     gimp_display_shell_scale_get_image_size     (GimpDisplayShell *shell,
+                                                      gint             *w,
+                                                      gint             *h);
+void     gimp_display_shell_scale_get_image_bounds   (GimpDisplayShell *shell,
+                                                      gint             *x,
+                                                      gint             *y,
+                                                      gint             *w,
+                                                      gint             *h);
+void     gimp_display_shell_scale_get_image_unrotated_bounds
+                                                     (GimpDisplayShell *shell,
+                                                      gint             *x,
+                                                      gint             *y,
+                                                      gint             *w,
+                                                      gint             *h);
+void     gimp_display_shell_scale_get_image_bounding_box
+                                                     (GimpDisplayShell *shell,
+                                                      gint             *x,
+                                                      gint             *y,
+                                                      gint             *w,
+                                                      gint             *h);
+void     gimp_display_shell_scale_get_image_unrotated_bounding_box
+                                                     (GimpDisplayShell *shell,
+                                                      gint             *x,
+                                                      gint             *y,
+                                                      gint             *w,
+                                                      gint             *h);
+gboolean gimp_display_shell_scale_image_is_within_viewport
+                                                     (GimpDisplayShell *shell,
+                                                      gboolean         *horizontally,
+                                                      gboolean         *vertically);
+
+void     gimp_display_shell_scale_update             (GimpDisplayShell *shell);
+
+void     gimp_display_shell_scale                    (GimpDisplayShell *shell,
+                                                      GimpZoomType      zoom_type,
+                                                      gdouble           scale,
+                                                      GimpZoomFocus     zoom_focus);
+void     gimp_display_shell_scale_to_rectangle       (GimpDisplayShell *shell,
+                                                      GimpZoomType      zoom_type,
+                                                      gdouble           x,
+                                                      gdouble           y,
+                                                      gdouble           width,
+                                                      gdouble           height,
+                                                      gboolean          resize_window);
+void     gimp_display_shell_scale_fit_in             (GimpDisplayShell *shell);
+void     gimp_display_shell_scale_fill               (GimpDisplayShell *shell);
+void     gimp_display_shell_scale_by_values          (GimpDisplayShell *shell,
+                                                      gdouble           scale,
+                                                      gint              offset_x,
+                                                      gint              offset_y,
+                                                      gboolean          resize_window);
+
+void     gimp_display_shell_scale_drag               (GimpDisplayShell *shell,
+                                                      gdouble           start_x,
+                                                      gdouble           start_y,
+                                                      gdouble           delta_x,
+                                                      gdouble           delta_y);
+
+void     gimp_display_shell_scale_shrink_wrap        (GimpDisplayShell *shell,
+                                                      gboolean          grow_only);
+void     gimp_display_shell_scale_resize             (GimpDisplayShell *shell,
+                                                      gboolean          resize_window,
+                                                      gboolean          grow_only);
+void     gimp_display_shell_set_initial_scale        (GimpDisplayShell *shell,
+                                                      gdouble           scale,
+                                                      gint             *display_width,
+                                                      gint             *display_height);
+
+void     gimp_display_shell_get_rotated_scale        (GimpDisplayShell *shell,
+                                                      gdouble          *scale_x,
+                                                      gdouble          *scale_y);
+
+/*  debug API for testing  */
+
+void  gimp_display_shell_push_zoom_focus_pointer_pos (GimpDisplayShell *shell,
+                                                      gint              x,
+                                                      gint              y);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_SCALE_H__  */
diff --git a/app/display/gimpdisplayshell-scroll.c b/app/display/gimpdisplayshell-scroll.c
new file mode 100644
index 0000000..ec5084d
--- /dev/null
+++ b/app/display/gimpdisplayshell-scroll.c
@@ -0,0 +1,529 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <math.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "core/gimpimage.h"
+
+#include "gimpcanvas.h"
+#include "gimpdisplay.h"
+#include "gimpdisplay-foreach.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-rotate.h"
+#include "gimpdisplayshell-rulers.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-scrollbars.h"
+#include "gimpdisplayshell-transform.h"
+
+
+#define OVERPAN_FACTOR 0.5
+
+
+/**
+ * gimp_display_shell_scroll:
+ * @shell:
+ * @x_offset:
+ * @y_offset:
+ *
+ * This function scrolls the image in the shell's viewport. It does
+ * actual scrolling of the pixels, so only the newly scrolled-in parts
+ * are freshly redrawn.
+ *
+ * Use it for incremental actual panning.
+ **/
+void
+gimp_display_shell_scroll (GimpDisplayShell *shell,
+                           gint              x_offset,
+                           gint              y_offset)
+{
+  gint old_x;
+  gint old_y;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (x_offset == 0 && y_offset == 0)
+    return;
+
+  old_x = shell->offset_x;
+  old_y = shell->offset_y;
+
+  /* freeze the active tool */
+  gimp_display_shell_pause (shell);
+
+  shell->offset_x += x_offset;
+  shell->offset_y += y_offset;
+
+  gimp_display_shell_scroll_clamp_and_update (shell);
+
+  /*  the actual changes in offset  */
+  x_offset = (shell->offset_x - old_x);
+  y_offset = (shell->offset_y - old_y);
+
+  if (x_offset || y_offset)
+    {
+      gimp_display_shell_scrolled (shell);
+
+      gimp_overlay_box_scroll (GIMP_OVERLAY_BOX (shell->canvas),
+                               -x_offset, -y_offset);
+
+    }
+
+  /* re-enable the active tool */
+  gimp_display_shell_resume (shell);
+}
+
+/**
+ * gimp_display_shell_scroll_set_offsets:
+ * @shell:
+ * @offset_x:
+ * @offset_y:
+ *
+ * This function scrolls the image in the shell's viewport. It redraws
+ * the entire canvas.
+ *
+ * Use it for setting the scroll offset on freshly scaled images or
+ * when the window is resized. For panning, use
+ * gimp_display_shell_scroll().
+ **/
+void
+gimp_display_shell_scroll_set_offset (GimpDisplayShell *shell,
+                                      gint              offset_x,
+                                      gint              offset_y)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->offset_x == offset_x &&
+      shell->offset_y == offset_y)
+    return;
+
+  gimp_display_shell_scale_save_revert_values (shell);
+
+  /* freeze the active tool */
+  gimp_display_shell_pause (shell);
+
+  shell->offset_x = offset_x;
+  shell->offset_y = offset_y;
+
+  gimp_display_shell_scroll_clamp_and_update (shell);
+
+  gimp_display_shell_scrolled (shell);
+
+  gimp_display_shell_expose_full (shell);
+
+  /* re-enable the active tool */
+  gimp_display_shell_resume (shell);
+}
+
+/**
+ * gimp_display_shell_scroll_clamp_and_update:
+ * @shell:
+ *
+ * Helper function for calling two functions that are commonly called
+ * in pairs.
+ **/
+void
+gimp_display_shell_scroll_clamp_and_update (GimpDisplayShell *shell)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      if (! shell->show_all)
+        {
+          gint bounds_x;
+          gint bounds_y;
+          gint bounds_width;
+          gint bounds_height;
+          gint min_offset_x;
+          gint max_offset_x;
+          gint min_offset_y;
+          gint max_offset_y;
+          gint offset_x;
+          gint offset_y;
+
+          gimp_display_shell_rotate_update_transform (shell);
+
+          gimp_display_shell_scale_get_image_bounds (shell,
+                                                     &bounds_x,
+                                                     &bounds_y,
+                                                     &bounds_width,
+                                                     &bounds_height);
+
+          if (shell->disp_width < bounds_width)
+            {
+              min_offset_x = bounds_x -
+                             shell->disp_width * OVERPAN_FACTOR;
+              max_offset_x = bounds_x + bounds_width -
+                             shell->disp_width * (1.0 - OVERPAN_FACTOR);
+            }
+          else
+            {
+              gint overpan_amount;
+
+              overpan_amount = shell->disp_width -
+                               bounds_width * (1.0 - OVERPAN_FACTOR);
+
+              min_offset_x = bounds_x -
+                             overpan_amount;
+              max_offset_x = bounds_x + bounds_width - shell->disp_width +
+                             overpan_amount;
+            }
+
+          if (shell->disp_height < bounds_height)
+            {
+              min_offset_y = bounds_y -
+                             shell->disp_height * OVERPAN_FACTOR;
+              max_offset_y = bounds_y + bounds_height -
+                             shell->disp_height * (1.0 - OVERPAN_FACTOR);
+            }
+          else
+            {
+              gint overpan_amount;
+
+              overpan_amount = shell->disp_height -
+                               bounds_height * (1.0 - OVERPAN_FACTOR);
+
+              min_offset_y = bounds_y -
+                             overpan_amount;
+              max_offset_y = bounds_y + bounds_height +
+                             overpan_amount - shell->disp_height;
+            }
+
+          /* Clamp */
+
+          offset_x = CLAMP (shell->offset_x, min_offset_x, max_offset_x);
+          offset_y = CLAMP (shell->offset_y, min_offset_y, max_offset_y);
+
+          if (offset_x != shell->offset_x || offset_y != shell->offset_y)
+            {
+              shell->offset_x = offset_x;
+              shell->offset_y = offset_y;
+
+              gimp_display_shell_rotate_update_transform (shell);
+            }
+
+          /* Set scrollbar stepper sensitiity */
+
+          gimp_display_shell_scrollbars_update_steppers (shell,
+                                                         min_offset_x,
+                                                         max_offset_x,
+                                                         min_offset_y,
+                                                         max_offset_y);
+        }
+      else
+        {
+          /* Set scrollbar stepper sensitiity */
+
+          gimp_display_shell_scrollbars_update_steppers (shell,
+                                                         G_MININT,
+                                                         G_MAXINT,
+                                                         G_MININT,
+                                                         G_MAXINT);
+        }
+    }
+  else
+    {
+      shell->offset_x = 0;
+      shell->offset_y = 0;
+    }
+
+  gimp_display_shell_scrollbars_update (shell);
+  gimp_display_shell_rulers_update (shell);
+}
+
+/**
+ * gimp_display_shell_scroll_unoverscrollify:
+ * @shell:
+ * @in_offset_x:
+ * @in_offset_y:
+ * @out_offset_x:
+ * @out_offset_y:
+ *
+ * Takes a scroll offset and returns the offset that will not result
+ * in a scroll beyond the image border. If the image is already
+ * overscrolled, the return value is 0 for that given axis.
+ **/
+void
+gimp_display_shell_scroll_unoverscrollify (GimpDisplayShell *shell,
+                                           gint              in_offset_x,
+                                           gint              in_offset_y,
+                                           gint             *out_offset_x,
+                                           gint             *out_offset_y)
+{
+  gint sw, sh;
+  gint out_offset_x_dummy, out_offset_y_dummy;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! out_offset_x) out_offset_x = &out_offset_x_dummy;
+  if (! out_offset_y) out_offset_y = &out_offset_y_dummy;
+
+  *out_offset_x = in_offset_x;
+  *out_offset_y = in_offset_y;
+
+  if (! shell->show_all)
+    {
+      gimp_display_shell_scale_get_image_size (shell, &sw, &sh);
+
+      if (in_offset_x < 0)
+        {
+          *out_offset_x = MAX (in_offset_x,
+                               MIN (0, 0 - shell->offset_x));
+        }
+      else if (in_offset_x > 0)
+        {
+          gint min_offset = sw - shell->disp_width;
+
+          *out_offset_x = MIN (in_offset_x,
+                               MAX (0, min_offset - shell->offset_x));
+        }
+
+      if (in_offset_y < 0)
+        {
+          *out_offset_y = MAX (in_offset_y,
+                               MIN (0, 0 - shell->offset_y));
+        }
+      else if (in_offset_y > 0)
+        {
+          gint min_offset = sh - shell->disp_height;
+
+          *out_offset_y = MIN (in_offset_y,
+                               MAX (0, min_offset - shell->offset_y));
+        }
+    }
+}
+
+/**
+ * gimp_display_shell_scroll_center_image_xy:
+ * @shell:
+ * @image_x:
+ * @image_y:
+ *
+ * Center the viewport around the passed image coordinate
+ **/
+void
+gimp_display_shell_scroll_center_image_xy (GimpDisplayShell *shell,
+                                           gdouble           image_x,
+                                           gdouble           image_y)
+{
+  gint viewport_x;
+  gint viewport_y;
+
+  gimp_display_shell_transform_xy (shell,
+                                   image_x, image_y,
+                                   &viewport_x, &viewport_y);
+
+  gimp_display_shell_scroll (shell,
+                             viewport_x - shell->disp_width  / 2,
+                             viewport_y - shell->disp_height / 2);
+}
+
+/**
+ * gimp_display_shell_scroll_center_image:
+ * @shell:
+ * @horizontally:
+ * @vertically:
+ *
+ * Centers the image in the display shell on the desired axes.
+ **/
+void
+gimp_display_shell_scroll_center_image (GimpDisplayShell *shell,
+                                        gboolean          horizontally,
+                                        gboolean          vertically)
+{
+  gint image_x;
+  gint image_y;
+  gint image_width;
+  gint image_height;
+  gint center_x;
+  gint center_y;
+  gint offset_x = 0;
+  gint offset_y = 0;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->display                          ||
+      ! gimp_display_get_image (shell->display) ||
+      (! vertically && ! horizontally))
+    return;
+
+  gimp_display_shell_scale_get_image_bounds (shell,
+                                             &image_x, &image_y,
+                                             &image_width, &image_height);
+
+  if (shell->disp_width > image_width)
+    {
+      image_x     -= (shell->disp_width - image_width) / 2;
+      image_width  = shell->disp_width;
+    }
+
+  if (shell->disp_height > image_height)
+    {
+      image_y      -= (shell->disp_height - image_height) / 2;
+      image_height  = shell->disp_height;
+    }
+
+  center_x = image_x + image_width  / 2;
+  center_y = image_y + image_height / 2;
+
+  if (horizontally)
+    offset_x = center_x - shell->disp_width / 2 - shell->offset_x;
+
+  if (vertically)
+    offset_y = center_y - shell->disp_height / 2 - shell->offset_y;
+
+  gimp_display_shell_scroll (shell, offset_x, offset_y);
+}
+
+/**
+ * gimp_display_shell_scroll_center_image:
+ * @shell:
+ * @horizontally:
+ * @vertically:
+ *
+ * Centers the image content in the display shell on the desired axes.
+ **/
+void
+gimp_display_shell_scroll_center_content (GimpDisplayShell *shell,
+                                          gboolean          horizontally,
+                                          gboolean          vertically)
+{
+  gint content_x;
+  gint content_y;
+  gint content_width;
+  gint content_height;
+  gint center_x;
+  gint center_y;
+  gint offset_x = 0;
+  gint offset_y = 0;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->display                          ||
+      ! gimp_display_get_image (shell->display) ||
+      (! vertically && ! horizontally))
+    return;
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      gimp_display_shell_scale_get_image_bounds (shell,
+                                                 &content_x,
+                                                 &content_y,
+                                                 &content_width,
+                                                 &content_height);
+    }
+  else
+    {
+      gimp_display_shell_scale_get_image_bounding_box (shell,
+                                                       &content_x,
+                                                       &content_y,
+                                                       &content_width,
+                                                       &content_height);
+    }
+
+  if (shell->disp_width > content_width)
+    {
+      content_x     -= (shell->disp_width - content_width) / 2;
+      content_width  = shell->disp_width;
+    }
+
+  if (shell->disp_height > content_height)
+    {
+      content_y      -= (shell->disp_height - content_height) / 2;
+      content_height  = shell->disp_height;
+    }
+
+  center_x = content_x + content_width  / 2;
+  center_y = content_y + content_height / 2;
+
+  if (horizontally)
+    offset_x = center_x - shell->disp_width / 2 - shell->offset_x;
+
+  if (vertically)
+    offset_y = center_y - shell->disp_height / 2 - shell->offset_y;
+
+  gimp_display_shell_scroll (shell, offset_x, offset_y);
+}
+
+/**
+ * gimp_display_shell_scroll_get_scaled_viewport:
+ * @shell:
+ * @x:
+ * @y:
+ * @w:
+ * @h:
+ *
+ * Gets the viewport in screen coordinates, with origin at (0, 0) in
+ * the image.
+ **/
+void
+gimp_display_shell_scroll_get_scaled_viewport (GimpDisplayShell *shell,
+                                               gint             *x,
+                                               gint             *y,
+                                               gint             *w,
+                                               gint             *h)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  *x = shell->offset_x;
+  *y = shell->offset_y;
+  *w = shell->disp_width;
+  *h = shell->disp_height;
+}
+
+/**
+ * gimp_display_shell_scroll_get_viewport:
+ * @shell:
+ * @x:
+ * @y:
+ * @w:
+ * @h:
+ *
+ * Gets the viewport in image coordinates.
+ **/
+void
+gimp_display_shell_scroll_get_viewport (GimpDisplayShell *shell,
+                                        gdouble          *x,
+                                        gdouble          *y,
+                                        gdouble          *w,
+                                        gdouble          *h)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  *x = shell->offset_x    / shell->scale_x;
+  *y = shell->offset_y    / shell->scale_y;
+  *w = shell->disp_width  / shell->scale_x;
+  *h = shell->disp_height / shell->scale_y;
+}
diff --git a/app/display/gimpdisplayshell-scroll.h b/app/display/gimpdisplayshell-scroll.h
new file mode 100644
index 0000000..fba444b
--- /dev/null
+++ b/app/display/gimpdisplayshell-scroll.h
@@ -0,0 +1,59 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_SCROLL_H__
+#define __GIMP_DISPLAY_SHELL_SCROLL_H__
+
+
+void   gimp_display_shell_scroll                     (GimpDisplayShell *shell,
+                                                      gint              x_offset,
+                                                      gint              y_offset);
+void   gimp_display_shell_scroll_set_offset          (GimpDisplayShell *shell,
+                                                      gint              offset_x,
+                                                      gint              offset_y);
+
+void   gimp_display_shell_scroll_clamp_and_update    (GimpDisplayShell *shell);
+
+void   gimp_display_shell_scroll_unoverscrollify     (GimpDisplayShell *shell,
+                                                      gint              in_offset_x,
+                                                      gint              in_offset_y,
+                                                      gint             *out_offset_x,
+                                                      gint             *out_offset_y);
+
+void   gimp_display_shell_scroll_center_image_xy     (GimpDisplayShell *shell,
+                                                      gdouble           image_x,
+                                                      gdouble           image_y);
+void   gimp_display_shell_scroll_center_image        (GimpDisplayShell *shell,
+                                                      gboolean          horizontally,
+                                                      gboolean          vertically);
+void   gimp_display_shell_scroll_center_content      (GimpDisplayShell *shell,
+                                                      gboolean          horizontally,
+                                                      gboolean          vertically);
+
+void   gimp_display_shell_scroll_get_scaled_viewport (GimpDisplayShell *shell,
+                                                      gint             *x,
+                                                      gint             *y,
+                                                      gint             *w,
+                                                      gint             *h);
+void   gimp_display_shell_scroll_get_viewport        (GimpDisplayShell *shell,
+                                                      gdouble          *x,
+                                                      gdouble          *y,
+                                                      gdouble          *w,
+                                                      gdouble          *h);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_SCROLL_H__  */
diff --git a/app/display/gimpdisplayshell-scrollbars.c b/app/display/gimpdisplayshell-scrollbars.c
new file mode 100644
index 0000000..3696e01
--- /dev/null
+++ b/app/display/gimpdisplayshell-scrollbars.c
@@ -0,0 +1,244 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <math.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimpimage.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scrollbars.h"
+
+
+#define MINIMUM_STEP_AMOUNT 1.0
+
+
+/**
+ * gimp_display_shell_scrollbars_update:
+ * @shell:
+ *
+ **/
+void
+gimp_display_shell_scrollbars_update (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->display)
+    return;
+
+  /* Horizontal scrollbar */
+
+  g_object_freeze_notify (G_OBJECT (shell->hsbdata));
+
+  /* Update upper and lower value before we set the new value */
+  gimp_display_shell_scrollbars_setup_horizontal (shell, shell->offset_x);
+
+  g_object_set (shell->hsbdata,
+                "value",          (gdouble) shell->offset_x,
+                "page-size",      (gdouble) shell->disp_width,
+                "page-increment", (gdouble) shell->disp_width / 2,
+                NULL);
+
+  g_object_thaw_notify (G_OBJECT (shell->hsbdata)); /* emits "changed" */
+
+
+  /* Vertcal scrollbar */
+
+  g_object_freeze_notify (G_OBJECT (shell->vsbdata));
+
+  /* Update upper and lower value before we set the new value */
+  gimp_display_shell_scrollbars_setup_vertical (shell, shell->offset_y);
+
+  g_object_set (shell->vsbdata,
+                "value",          (gdouble) shell->offset_y,
+                "page-size",      (gdouble) shell->disp_height,
+                "page-increment", (gdouble) shell->disp_height / 2,
+                NULL);
+
+  g_object_thaw_notify (G_OBJECT (shell->vsbdata)); /* emits "changed" */
+}
+
+/**
+ * gimp_display_shell_scrollbars_setup_horizontal:
+ * @shell:
+ * @value:
+ *
+ * Setup the limits of the horizontal scrollbar
+ **/
+void
+gimp_display_shell_scrollbars_setup_horizontal (GimpDisplayShell *shell,
+                                                gdouble           value)
+{
+  gint    bounds_x;
+  gint    bounds_width;
+  gint    bounding_box_x;
+  gint    bounding_box_width;
+  gint    x1;
+  gint    x2;
+  gdouble lower;
+  gdouble upper;
+  gdouble scale_x;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->display || ! gimp_display_get_image (shell->display))
+    return;
+
+  gimp_display_shell_scale_get_image_bounds (shell,
+                                             &bounds_x,     NULL,
+                                             &bounds_width, NULL);
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      bounding_box_x     = bounds_x;
+      bounding_box_width = bounds_width;
+    }
+  else
+    {
+      gimp_display_shell_scale_get_image_bounding_box (
+        shell,
+        &bounding_box_x,     NULL,
+        &bounding_box_width, NULL);
+    }
+
+  x1 = bounding_box_x;
+  x2 = bounding_box_x + bounding_box_width;
+
+  x1 = MIN (x1, bounds_x + bounds_width / 2 - shell->disp_width       / 2);
+  x2 = MAX (x2, bounds_x + bounds_width / 2 + (shell->disp_width + 1) / 2);
+
+  lower = MIN (value,                     x1);
+  upper = MAX (value + shell->disp_width, x2);
+
+  gimp_display_shell_get_rotated_scale (shell, &scale_x, NULL);
+
+  g_object_set (shell->hsbdata,
+                "lower",          lower,
+                "upper",          upper,
+                "step-increment", (gdouble) MAX (scale_x, MINIMUM_STEP_AMOUNT),
+                NULL);
+}
+
+/**
+ * gimp_display_shell_scrollbars_setup_vertical:
+ * @shell:
+ * @value:
+ *
+ * Setup the limits of the vertical scrollbar
+ **/
+void
+gimp_display_shell_scrollbars_setup_vertical (GimpDisplayShell *shell,
+                                              gdouble           value)
+{
+  gint    bounds_y;
+  gint    bounds_height;
+  gint    bounding_box_y;
+  gint    bounding_box_height;
+  gint    y1;
+  gint    y2;
+  gdouble lower;
+  gdouble upper;
+  gdouble scale_y;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->display || ! gimp_display_get_image (shell->display))
+    return;
+
+  gimp_display_shell_scale_get_image_bounds (shell,
+                                             NULL, &bounds_y,
+                                             NULL, &bounds_height);
+
+  if (! gimp_display_shell_get_infinite_canvas (shell))
+    {
+      bounding_box_y      = bounds_y;
+      bounding_box_height = bounds_height;
+    }
+  else
+    {
+      gimp_display_shell_scale_get_image_bounding_box (
+        shell,
+        NULL, &bounding_box_y,
+        NULL, &bounding_box_height);
+    }
+
+  y1 = bounding_box_y;
+  y2 = bounding_box_y + bounding_box_height;
+
+  y1 = MIN (y1, bounds_y + bounds_height / 2 - shell->disp_height       / 2);
+  y2 = MAX (y2, bounds_y + bounds_height / 2 + (shell->disp_height + 1) / 2);
+
+  lower = MIN (value,                      y1);
+  upper = MAX (value + shell->disp_height, y2);
+
+  gimp_display_shell_get_rotated_scale (shell, NULL, &scale_y);
+
+  g_object_set (shell->vsbdata,
+                "lower",          lower,
+                "upper",          upper,
+                "step-increment", (gdouble) MAX (scale_y, MINIMUM_STEP_AMOUNT),
+                NULL);
+}
+
+/**
+ * gimp_display_shell_scrollbars_update_steppers:
+ * @shell:
+ * @min_offset_x:
+ * @max_offset_x:
+ * @min_offset_y:
+ * @max_offset_y:
+ *
+ * Sets the scrollbars' stepper sensitivity which is set differently
+ * from its adjustment limits because we support overscrolling.
+ **/
+void
+gimp_display_shell_scrollbars_update_steppers (GimpDisplayShell *shell,
+                                               gint              min_offset_x,
+                                               gint              max_offset_x,
+                                               gint              min_offset_y,
+                                               gint              max_offset_y)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->hsb),
+                                           min_offset_x < shell->offset_x ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+
+  gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->hsb),
+                                           max_offset_x > shell->offset_x ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+
+  gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->vsb),
+                                           min_offset_y < shell->offset_y ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+
+  gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->vsb),
+                                           max_offset_y > shell->offset_y ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+}
diff --git a/app/display/gimpdisplayshell-scrollbars.h b/app/display/gimpdisplayshell-scrollbars.h
new file mode 100644
index 0000000..c15f802
--- /dev/null
+++ b/app/display/gimpdisplayshell-scrollbars.h
@@ -0,0 +1,36 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_SCROLLBARS_H__
+#define __GIMP_DISPLAY_SHELL_SCROLLBARS_H__
+
+
+void   gimp_display_shell_scrollbars_update           (GimpDisplayShell *shell);
+
+void   gimp_display_shell_scrollbars_setup_horizontal (GimpDisplayShell *shell,
+                                                       gdouble           value);
+void   gimp_display_shell_scrollbars_setup_vertical   (GimpDisplayShell *shell,
+                                                       gdouble           value);
+
+void   gimp_display_shell_scrollbars_update_steppers  (GimpDisplayShell *shell,
+                                                       gint              min_offset_x,
+                                                       gint              max_offset_x,
+                                                       gint              min_offset_y,
+                                                       gint              max_offset_y);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_SCROLLBARS_H__  */
diff --git a/app/display/gimpdisplayshell-selection.c b/app/display/gimpdisplayshell-selection.c
new file mode 100644
index 0000000..3098ddc
--- /dev/null
+++ b/app/display/gimpdisplayshell-selection.c
@@ -0,0 +1,505 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimp-cairo.h"
+#include "core/gimpboundary.h"
+#include "core/gimpchannel.h"
+#include "core/gimpimage.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-draw.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-selection.h"
+#include "gimpdisplayshell-transform.h"
+
+
+struct _Selection
+{
+  GimpDisplayShell *shell;            /*  shell that owns the selection     */
+
+  GimpSegment      *segs_in;          /*  gdk segments of area boundary     */
+  gint              n_segs_in;        /*  number of segments in segs_in     */
+
+  GimpSegment      *segs_out;         /*  gdk segments of area boundary     */
+  gint              n_segs_out;       /*  number of segments in segs_out    */
+
+  guint             index;            /*  index of current stipple pattern  */
+  gint              paused;           /*  count of pause requests           */
+  gboolean          shell_visible;    /*  visility of the display shell     */
+  gboolean          show_selection;   /*  is the selection visible?         */
+  guint             timeout;          /*  timer for successive draws        */
+  cairo_pattern_t  *segs_in_mask;     /*  cache for rendered segments       */
+};
+
+
+/*  local function prototypes  */
+
+static void      selection_start          (Selection          *selection);
+static void      selection_stop           (Selection          *selection);
+
+static void      selection_draw           (Selection          *selection,
+                                           cairo_t            *cr);
+static void      selection_undraw         (Selection          *selection);
+
+static void      selection_render_mask    (Selection          *selection);
+
+static void      selection_zoom_segs      (Selection          *selection,
+                                           const GimpBoundSeg *src_segs,
+                                           GimpSegment        *dest_segs,
+                                           gint                n_segs);
+static void      selection_generate_segs  (Selection          *selection);
+static void      selection_free_segs      (Selection          *selection);
+
+static gboolean  selection_start_timeout  (Selection          *selection);
+static gboolean  selection_timeout        (Selection          *selection);
+
+static gboolean  selection_window_state_event      (GtkWidget           *shell,
+                                                    GdkEventWindowState *event,
+                                                    Selection           *selection);
+static gboolean  selection_visibility_notify_event (GtkWidget           *shell,
+                                                    GdkEventVisibility  *event,
+                                                    Selection           *selection);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_selection_init (GimpDisplayShell *shell)
+{
+  Selection *selection;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->selection == NULL);
+
+  selection = g_slice_new0 (Selection);
+
+  selection->shell          = shell;
+  selection->shell_visible  = TRUE;
+  selection->show_selection = gimp_display_shell_get_show_selection (shell);
+
+  shell->selection = selection;
+
+  g_signal_connect (shell, "window-state-event",
+                    G_CALLBACK (selection_window_state_event),
+                    selection);
+  g_signal_connect (shell, "visibility-notify-event",
+                    G_CALLBACK (selection_visibility_notify_event),
+                    selection);
+}
+
+void
+gimp_display_shell_selection_free (GimpDisplayShell *shell)
+{
+  Selection *selection;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->selection != NULL);
+
+  selection = shell->selection;
+
+  selection_stop (selection);
+
+  g_signal_handlers_disconnect_by_func (shell,
+                                        selection_window_state_event,
+                                        selection);
+  g_signal_handlers_disconnect_by_func (shell,
+                                        selection_visibility_notify_event,
+                                        selection);
+
+  selection_free_segs (selection);
+
+  g_slice_free (Selection, selection);
+
+  shell->selection = NULL;
+}
+
+void
+gimp_display_shell_selection_undraw (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->selection != NULL);
+
+  if (gimp_display_get_image (shell->display))
+    {
+      selection_undraw (shell->selection);
+    }
+  else
+    {
+      selection_stop (shell->selection);
+      selection_free_segs (shell->selection);
+    }
+}
+
+void
+gimp_display_shell_selection_restart (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->selection != NULL);
+
+  if (gimp_display_get_image (shell->display))
+    {
+      selection_start (shell->selection);
+    }
+}
+
+void
+gimp_display_shell_selection_pause (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->selection != NULL);
+
+  if (gimp_display_get_image (shell->display))
+    {
+      if (shell->selection->paused == 0)
+        selection_stop (shell->selection);
+
+      shell->selection->paused++;
+    }
+}
+
+void
+gimp_display_shell_selection_resume (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->selection != NULL);
+
+  if (gimp_display_get_image (shell->display))
+    {
+      shell->selection->paused--;
+
+      if (shell->selection->paused == 0)
+        selection_start (shell->selection);
+    }
+}
+
+void
+gimp_display_shell_selection_set_show (GimpDisplayShell *shell,
+                                       gboolean          show)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->selection != NULL);
+
+  if (gimp_display_get_image (shell->display))
+    {
+      Selection *selection = shell->selection;
+
+      if (show != selection->show_selection)
+        {
+          selection_undraw (selection);
+
+          selection->show_selection = show;
+
+          selection_start (selection);
+        }
+    }
+}
+
+
+/*  private functions  */
+
+static void
+selection_start (Selection *selection)
+{
+  selection_stop (selection);
+
+  /*  If this selection is paused, do not start it  */
+  if (selection->paused == 0)
+    {
+      selection->timeout = g_idle_add ((GSourceFunc) selection_start_timeout,
+                                       selection);
+    }
+}
+
+static void
+selection_stop (Selection *selection)
+{
+  if (selection->timeout)
+    {
+      g_source_remove (selection->timeout);
+      selection->timeout = 0;
+    }
+}
+
+static void
+selection_draw (Selection *selection,
+                cairo_t   *cr)
+{
+  if (selection->segs_in)
+    {
+      gimp_display_shell_draw_selection_in (selection->shell, cr,
+                                            selection->segs_in_mask,
+                                            selection->index % 8);
+    }
+}
+
+static void
+selection_undraw (Selection *selection)
+{
+  gint x, y, w, h;
+
+  selection_stop (selection);
+
+  if (gimp_display_shell_mask_bounds (selection->shell, &x, &y, &w, &h))
+    {
+      /* expose will restart the selection */
+      gimp_display_shell_expose_area (selection->shell, x, y, w, h);
+    }
+  else
+    {
+      selection_start (selection);
+    }
+}
+
+static void
+selection_render_mask (Selection *selection)
+{
+  GdkWindow       *window;
+  cairo_surface_t *surface;
+  cairo_t         *cr;
+
+  window = gtk_widget_get_window (selection->shell->canvas);
+  surface = gdk_window_create_similar_surface (window, CAIRO_CONTENT_ALPHA,
+                                               gdk_window_get_width  (window),
+                                               gdk_window_get_height (window));
+  cr = cairo_create (surface);
+
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
+  cairo_set_line_width (cr, 1.0);
+
+  if (selection->shell->rotate_transform)
+    cairo_transform (cr, selection->shell->rotate_transform);
+
+  gimp_cairo_segments (cr,
+                       selection->segs_in,
+                       selection->n_segs_in);
+  cairo_stroke (cr);
+
+  selection->segs_in_mask = cairo_pattern_create_for_surface (surface);
+
+  cairo_destroy (cr);
+  cairo_surface_destroy (surface);
+}
+
+static void
+selection_zoom_segs (Selection          *selection,
+                     const GimpBoundSeg *src_segs,
+                     GimpSegment        *dest_segs,
+                     gint                n_segs)
+{
+  const gint xclamp = selection->shell->disp_width + 1;
+  const gint yclamp = selection->shell->disp_height + 1;
+  gint       i;
+
+  gimp_display_shell_zoom_segments (selection->shell,
+                                    src_segs, dest_segs, n_segs,
+                                    0.0, 0.0);
+
+  for (i = 0; i < n_segs; i++)
+    {
+      if (! selection->shell->rotate_transform)
+        {
+          dest_segs[i].x1 = CLAMP (dest_segs[i].x1, -1, xclamp);
+          dest_segs[i].y1 = CLAMP (dest_segs[i].y1, -1, yclamp);
+
+          dest_segs[i].x2 = CLAMP (dest_segs[i].x2, -1, xclamp);
+          dest_segs[i].y2 = CLAMP (dest_segs[i].y2, -1, yclamp);
+        }
+
+      /*  If this segment is a closing segment && the segments lie inside
+       *  the region, OR if this is an opening segment and the segments
+       *  lie outside the region...
+       *  we need to transform it by one display pixel
+       */
+      if (! src_segs[i].open)
+        {
+          /*  If it is vertical  */
+          if (dest_segs[i].x1 == dest_segs[i].x2)
+            {
+              dest_segs[i].x1 -= 1;
+              dest_segs[i].x2 -= 1;
+            }
+          else
+            {
+              dest_segs[i].y1 -= 1;
+              dest_segs[i].y2 -= 1;
+            }
+        }
+    }
+}
+
+static void
+selection_generate_segs (Selection *selection)
+{
+  GimpImage          *image = gimp_display_get_image (selection->shell->display);
+  const GimpBoundSeg *segs_in;
+  const GimpBoundSeg *segs_out;
+
+  /*  Ask the image for the boundary of its selected region...
+   *  Then transform that information into a new buffer of GimpSegments
+   */
+  gimp_channel_boundary (gimp_image_get_mask (image),
+                         &segs_in, &segs_out,
+                         &selection->n_segs_in, &selection->n_segs_out,
+                         0, 0, 0, 0);
+
+  if (selection->n_segs_in)
+    {
+      selection->segs_in = g_new (GimpSegment, selection->n_segs_in);
+      selection_zoom_segs (selection, segs_in,
+                           selection->segs_in, selection->n_segs_in);
+
+      selection_render_mask (selection);
+    }
+  else
+    {
+      selection->segs_in = NULL;
+    }
+
+  /*  Possible secondary boundary representation  */
+  if (selection->n_segs_out)
+    {
+      selection->segs_out = g_new (GimpSegment, selection->n_segs_out);
+      selection_zoom_segs (selection, segs_out,
+                           selection->segs_out, selection->n_segs_out);
+    }
+  else
+    {
+      selection->segs_out = NULL;
+    }
+}
+
+static void
+selection_free_segs (Selection *selection)
+{
+  g_clear_pointer (&selection->segs_in, g_free);
+  selection->n_segs_in = 0;
+
+  g_clear_pointer (&selection->segs_out, g_free);
+  selection->segs_out = NULL;
+
+  g_clear_pointer (&selection->segs_in_mask, cairo_pattern_destroy);
+}
+
+static gboolean
+selection_start_timeout (Selection *selection)
+{
+  selection_free_segs (selection);
+  selection->timeout = 0;
+
+  if (! gimp_display_get_image (selection->shell->display))
+    return FALSE;
+
+  selection_generate_segs (selection);
+
+  selection->index = 0;
+
+  /*  Draw the ants  */
+  if (selection->show_selection)
+    {
+      GimpDisplayConfig *config = selection->shell->display->config;
+      cairo_t           *cr;
+
+      cr = gdk_cairo_create (gtk_widget_get_window (selection->shell->canvas));
+
+      selection_draw (selection, cr);
+
+      if (selection->segs_out)
+        {
+          if (selection->shell->rotate_transform)
+            cairo_transform (cr, selection->shell->rotate_transform);
+
+          gimp_display_shell_draw_selection_out (selection->shell, cr,
+                                                 selection->segs_out,
+                                                 selection->n_segs_out);
+        }
+
+      cairo_destroy (cr);
+
+      if (selection->segs_in && selection->shell_visible)
+        selection->timeout = g_timeout_add_full (G_PRIORITY_DEFAULT_IDLE,
+                                                 config->marching_ants_speed,
+                                                 (GSourceFunc) selection_timeout,
+                                                 selection, NULL);
+    }
+
+  return FALSE;
+}
+
+static gboolean
+selection_timeout (Selection *selection)
+{
+  cairo_t *cr;
+
+  cr = gdk_cairo_create (gtk_widget_get_window (selection->shell->canvas));
+
+  selection->index++;
+  selection_draw (selection, cr);
+
+  cairo_destroy (cr);
+
+  return TRUE;
+}
+
+static void
+selection_set_shell_visible (Selection *selection,
+                             gboolean   shell_visible)
+{
+  if (selection->shell_visible != shell_visible)
+    {
+      selection->shell_visible = shell_visible;
+
+      if (shell_visible)
+        selection_start (selection);
+      else
+        selection_stop (selection);
+    }
+}
+
+static gboolean
+selection_window_state_event (GtkWidget           *shell,
+                              GdkEventWindowState *event,
+                              Selection           *selection)
+{
+  selection_set_shell_visible (selection,
+                               (event->new_window_state & (GDK_WINDOW_STATE_WITHDRAWN |
+                                                           GDK_WINDOW_STATE_ICONIFIED)) == 0);
+
+  return FALSE;
+}
+
+static gboolean
+selection_visibility_notify_event (GtkWidget          *shell,
+                                   GdkEventVisibility *event,
+                                   Selection          *selection)
+{
+  selection_set_shell_visible (selection,
+                               event->state != GDK_VISIBILITY_FULLY_OBSCURED);
+
+  return FALSE;
+}
diff --git a/app/display/gimpdisplayshell-selection.h b/app/display/gimpdisplayshell-selection.h
new file mode 100644
index 0000000..2f63c80
--- /dev/null
+++ b/app/display/gimpdisplayshell-selection.h
@@ -0,0 +1,35 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_SELECTION_H__
+#define __GIMP_DISPLAY_SHELL_SELECTION_H__
+
+
+void   gimp_display_shell_selection_init     (GimpDisplayShell     *shell);
+void   gimp_display_shell_selection_free     (GimpDisplayShell     *shell);
+
+void   gimp_display_shell_selection_undraw   (GimpDisplayShell     *shell);
+void   gimp_display_shell_selection_restart  (GimpDisplayShell     *shell);
+
+void   gimp_display_shell_selection_pause    (GimpDisplayShell     *shell);
+void   gimp_display_shell_selection_resume   (GimpDisplayShell     *shell);
+
+void   gimp_display_shell_selection_set_show (GimpDisplayShell     *shell,
+                                              gboolean              show);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_SELECTION_H__  */
diff --git a/app/display/gimpdisplayshell-title.c b/app/display/gimpdisplayshell-title.c
new file mode 100644
index 0000000..ff356ce
--- /dev/null
+++ b/app/display/gimpdisplayshell-title.c
@@ -0,0 +1,564 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "libgimpbase/gimpbase.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "gegl/gimp-babl.h"
+
+#include "core/gimpcontainer.h"
+#include "core/gimpdrawable.h"
+#include "core/gimpimage.h"
+#include "core/gimpimage-color-profile.h"
+#include "core/gimpitem.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-title.h"
+#include "gimpstatusbar.h"
+
+#include "about.h"
+
+#include "gimp-intl.h"
+
+
+#define MAX_TITLE_BUF 512
+
+
+static gboolean gimp_display_shell_update_title_idle (gpointer          data);
+static gint     gimp_display_shell_format_title      (GimpDisplayShell *display,
+                                                      gchar            *title,
+                                                      gint              title_len,
+                                                      const gchar      *format);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_title_update (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->title_idle_id)
+    g_source_remove (shell->title_idle_id);
+
+  shell->title_idle_id = g_idle_add (gimp_display_shell_update_title_idle,
+                                     shell);
+}
+
+
+/*  private functions  */
+
+static gboolean
+gimp_display_shell_update_title_idle (gpointer data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+
+  shell->title_idle_id = 0;
+
+  if (gimp_display_get_image (shell->display))
+    {
+      GimpDisplayConfig *config = shell->display->config;
+      gchar              title[MAX_TITLE_BUF];
+      gchar              status[MAX_TITLE_BUF];
+      gint               len;
+
+      /* format the title */
+      len = gimp_display_shell_format_title (shell, title, sizeof (title),
+                                             config->image_title_format);
+
+      if (len)  /* U+2013 EN DASH */
+        len += g_strlcpy (title + len, " \342\200\223 ", sizeof (title) - len);
+
+      g_strlcpy (title + len, GIMP_ACRONYM, sizeof (title) - len);
+
+      /* format the statusbar */
+      gimp_display_shell_format_title (shell, status, sizeof (status),
+                                       config->image_status_format);
+
+      g_object_set (shell,
+                    "title",  title,
+                    "status", status,
+                    NULL);
+    }
+  else
+    {
+      g_object_set (shell,
+                    "title",  GIMP_NAME,
+                    "status", " ",
+                    NULL);
+    }
+
+  return FALSE;
+}
+
+static const gchar *
+gimp_display_shell_title_image_type (GimpImage *image)
+{
+  const gchar *name = "";
+
+  gimp_enum_get_value (GIMP_TYPE_IMAGE_BASE_TYPE,
+                       gimp_image_get_base_type (image), NULL, NULL, &name, NULL);
+
+  return name;
+}
+
+static const gchar *
+gimp_display_shell_title_image_precision (GimpImage *image)
+{
+  const gchar *name = "";
+
+  gimp_enum_get_value (GIMP_TYPE_PRECISION,
+                       gimp_image_get_precision (image), NULL, NULL, &name, NULL);
+
+  return name;
+}
+
+static gint print (gchar       *buf,
+                   gint         len,
+                   gint         start,
+                   const gchar *fmt,
+                   ...) G_GNUC_PRINTF (4, 5);
+
+static gint
+print (gchar       *buf,
+       gint         len,
+       gint         start,
+       const gchar *fmt,
+       ...)
+{
+  va_list args;
+  gint    printed;
+
+  va_start (args, fmt);
+
+  printed = g_vsnprintf (buf + start, len - start, fmt, args);
+  if (printed < 0)
+    printed = len - start;
+
+  va_end (args);
+
+  return printed;
+}
+
+static gint
+gimp_display_shell_format_title (GimpDisplayShell *shell,
+                                 gchar            *title,
+                                 gint              title_len,
+                                 const gchar      *format)
+{
+  GimpImage    *image;
+  GimpDrawable *drawable;
+  gint          num, denom;
+  gint          i = 0;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), 0);
+
+  image = gimp_display_get_image (shell->display);
+
+  if (! image)
+    {
+      title[0] = '\n';
+      return 0;
+    }
+
+  drawable = gimp_image_get_active_drawable (image);
+
+  gimp_zoom_model_get_fraction (shell->zoom, &num, &denom);
+
+  while (i < title_len && *format)
+    {
+      switch (*format)
+        {
+        case '%':
+          format++;
+          switch (*format)
+            {
+            case 0:
+              /* format string ends within %-sequence, print literal '%' */
+
+            case '%':
+              title[i++] = '%';
+              break;
+
+            case 'f': /* base filename */
+              i += print (title, title_len, i, "%s",
+                          gimp_image_get_display_name (image));
+              break;
+
+            case 'F': /* full filename */
+              i += print (title, title_len, i, "%s",
+                          gimp_image_get_display_path (image));
+              break;
+
+            case 'p': /* PDB id */
+              i += print (title, title_len, i, "%d", gimp_image_get_ID (image));
+              break;
+
+            case 'i': /* instance */
+              i += print (title, title_len, i, "%d",
+                          gimp_display_get_instance (shell->display));
+              break;
+
+            case 't': /* image type */
+              i += print (title, title_len, i, "%s %s",
+                          gimp_display_shell_title_image_type (image),
+                          gimp_display_shell_title_image_precision (image));
+              break;
+
+            case 'T': /* drawable type */
+              if (drawable)
+                {
+                  const Babl *format = gimp_drawable_get_format (drawable);
+
+                  i += print (title, title_len, i, "%s",
+                              gimp_babl_format_get_description (format));
+                }
+              break;
+
+            case 's': /* user source zoom factor */
+              i += print (title, title_len, i, "%d", denom);
+              break;
+
+            case 'd': /* user destination zoom factor */
+              i += print (title, title_len, i, "%d", num);
+              break;
+
+            case 'z': /* user zoom factor (percentage) */
+              {
+                gdouble  scale = gimp_zoom_model_get_factor (shell->zoom);
+
+                i += print (title, title_len, i,
+                            scale >= 0.15 ? "%.0f" : "%.2f", 100.0 * scale);
+              }
+              break;
+
+            case 'D': /* dirty flag */
+              if (format[1] == 0)
+                {
+                  /* format string ends within %D-sequence, print literal '%D' */
+                  i += print (title, title_len, i, "%%D");
+                  break;
+                }
+              if (gimp_image_is_dirty (image))
+                title[i++] = format[1];
+              format++;
+              break;
+
+            case 'C': /* clean flag */
+              if (format[1] == 0)
+                {
+                  /* format string ends within %C-sequence, print literal '%C' */
+                  i += print (title, title_len, i, "%%C");
+                  break;
+                }
+              if (! gimp_image_is_dirty (image))
+                title[i++] = format[1];
+              format++;
+              break;
+
+            case 'B': /* dirty flag (long) */
+              if (gimp_image_is_dirty (image))
+                i += print (title, title_len, i, "%s", _("(modified)"));
+              break;
+
+            case 'A': /* clean flag (long) */
+              if (! gimp_image_is_dirty (image))
+                i += print (title, title_len, i, "%s", _("(clean)"));
+              break;
+
+            case 'N': /* not-exported flag */
+              if (format[1] == 0)
+                {
+                  /* format string ends within %E-sequence, print literal '%E' */
+                  i += print (title, title_len, i, "%%N");
+                  break;
+                }
+              if (gimp_image_is_export_dirty (image))
+                title[i++] = format[1];
+              format++;
+              break;
+
+            case 'E': /* exported flag */
+              if (format[1] == 0)
+                {
+                  /* format string ends within %E-sequence, print literal '%E' */
+                  i += print (title, title_len, i, "%%E");
+                  break;
+                }
+              if (! gimp_image_is_export_dirty (image))
+                title[i++] = format[1];
+              format++;
+              break;
+
+            case 'm': /* memory used by image */
+              {
+                GimpObject *object = GIMP_OBJECT (image);
+                gchar      *str;
+
+                str = g_format_size (gimp_object_get_memsize (object, NULL));
+                i += print (title, title_len, i, "%s", str);
+                g_free (str);
+              }
+              break;
+
+            case 'M': /* image size in megapixels */
+              i += print (title, title_len, i, "%.1f",
+                          (gdouble) gimp_image_get_width (image) *
+                          (gdouble) gimp_image_get_height (image) / 1000000.0);
+              break;
+
+            case 'l': /* number of layers */
+              i += print (title, title_len, i, "%d",
+                          gimp_image_get_n_layers (image));
+              break;
+
+            case 'L': /* number of layers (long) */
+              {
+                gint num = gimp_image_get_n_layers (image);
+
+                i += print (title, title_len, i,
+                            ngettext ("%d layer", "%d layers", num), num);
+              }
+              break;
+
+            case 'n': /* active drawable name */
+              if (drawable)
+                {
+                  gchar *desc;
+
+                  desc = gimp_viewable_get_description (GIMP_VIEWABLE (drawable),
+                                                        NULL);
+                  i += print (title, title_len, i, "%s", desc);
+                  g_free (desc);
+                }
+              else
+                {
+                  i += print (title, title_len, i, "%s", _("(none)"));
+                }
+              break;
+
+            case 'P': /* active drawable PDB id */
+              if (drawable)
+                i += print (title, title_len, i, "%d",
+                            gimp_item_get_ID (GIMP_ITEM (drawable)));
+              else
+                i += print (title, title_len, i, "%s", _("(none)"));
+              break;
+
+            case 'W': /* width in real-world units */
+              if (shell->unit != GIMP_UNIT_PIXEL)
+                {
+                  gdouble xres;
+                  gdouble yres;
+                  gchar   unit_format[8];
+
+                  gimp_image_get_resolution (image, &xres, &yres);
+
+                  g_snprintf (unit_format, sizeof (unit_format), "%%.%df",
+                              gimp_unit_get_scaled_digits (shell->unit, xres));
+                  i += print (title, title_len, i, unit_format,
+                              gimp_pixels_to_units (gimp_image_get_width (image),
+                                                    shell->unit, xres));
+                  break;
+                }
+              /* else fallthru */
+
+            case 'w': /* width in pixels */
+              i += print (title, title_len, i, "%d",
+                          gimp_image_get_width (image));
+              break;
+
+            case 'H': /* height in real-world units */
+              if (shell->unit != GIMP_UNIT_PIXEL)
+                {
+                  gdouble xres;
+                  gdouble yres;
+                  gchar   unit_format[8];
+
+                  gimp_image_get_resolution (image, &xres, &yres);
+
+                  g_snprintf (unit_format, sizeof (unit_format), "%%.%df",
+                              gimp_unit_get_scaled_digits (shell->unit, yres));
+                  i += print (title, title_len, i, unit_format,
+                              gimp_pixels_to_units (gimp_image_get_height (image),
+                                                    shell->unit, yres));
+                  break;
+                }
+              /* else fallthru */
+
+            case 'h': /* height in pixels */
+              i += print (title, title_len, i, "%d",
+                          gimp_image_get_height (image));
+              break;
+
+            case 'u': /* unit symbol */
+              i += print (title, title_len, i, "%s",
+                          gimp_unit_get_symbol (shell->unit));
+              break;
+
+            case 'U': /* unit abbreviation */
+              i += print (title, title_len, i, "%s",
+                          gimp_unit_get_abbreviation (shell->unit));
+              break;
+
+            case 'X': /* drawable width in real world units */
+              if (drawable && shell->unit != GIMP_UNIT_PIXEL)
+                {
+                  gdouble xres;
+                  gdouble yres;
+                  gchar   unit_format[8];
+
+                  gimp_image_get_resolution (image, &xres, &yres);
+
+                  g_snprintf (unit_format, sizeof (unit_format), "%%.%df",
+                              gimp_unit_get_scaled_digits (shell->unit, xres));
+                  i += print (title, title_len, i, unit_format,
+                              gimp_pixels_to_units (gimp_item_get_width
+                                                    (GIMP_ITEM (drawable)),
+                                                    shell->unit, xres));
+                  break;
+                }
+              /* else fallthru */
+
+            case 'x': /* drawable width in pixels */
+              if (drawable)
+                i += print (title, title_len, i, "%d",
+                            gimp_item_get_width (GIMP_ITEM (drawable)));
+              break;
+
+            case 'Y': /* drawable height in real world units */
+              if (drawable && shell->unit != GIMP_UNIT_PIXEL)
+                {
+                  gdouble xres;
+                  gdouble yres;
+                  gchar   unit_format[8];
+
+                  gimp_image_get_resolution (image, &xres, &yres);
+
+                  g_snprintf (unit_format, sizeof (unit_format), "%%.%df",
+                              gimp_unit_get_scaled_digits (shell->unit, yres));
+                  i += print (title, title_len, i, unit_format,
+                              gimp_pixels_to_units (gimp_item_get_height
+                                                    (GIMP_ITEM (drawable)),
+                                                    shell->unit, yres));
+                  break;
+                }
+              /* else fallthru */
+
+            case 'y': /* drawable height in pixels */
+              if (drawable)
+                i += print (title, title_len, i, "%d",
+                            gimp_item_get_height (GIMP_ITEM (drawable)));
+              break;
+
+            case 'o': /* image's color profile name */
+              if (gimp_image_get_is_color_managed (image))
+                {
+                  GimpColorManaged *managed = GIMP_COLOR_MANAGED (image);
+                  GimpColorProfile *profile;
+
+                  profile = gimp_color_managed_get_color_profile (managed);
+
+                  i += print (title, title_len, i, "%s",
+                              gimp_color_profile_get_label (profile));
+                }
+              else
+                {
+                  i += print (title, title_len, i, "%s",
+                              _("not color managed"));
+                }
+              break;
+
+            case 'e': /* display's offsets in pixels */
+              {
+                gdouble scale    = gimp_zoom_model_get_factor (shell->zoom);
+                gdouble offset_x = shell->offset_x / scale;
+                gdouble offset_y = shell->offset_y / scale;
+
+                i += print (title, title_len, i,
+                            scale >= 0.15 ? "%.0fx%.0f" : "%.2fx%.2f",
+                            offset_x, offset_y);
+              }
+              break;
+
+            case 'r': /* view rotation angle in degrees */
+              {
+                i += print (title, title_len, i, "%.1f", shell->rotate_angle);
+              }
+              break;
+
+            case '\xc3': /* utf-8 extended char */
+              {
+                format ++;
+                switch (*format)
+                  {
+                  case '\xbe':
+                    /* line actually written at 23:55 on an Easter Sunday */
+                    i += print (title, title_len, i, "42");
+                    break;
+
+                  default:
+                    /* in the case of an unhandled utf-8 extended char format
+                     * leave the format string parsing as it was
+                    */
+                    format--;
+                    break;
+                  }
+              }
+              break;
+
+              /* Other cool things to be added:
+               * %r = xresolution
+               * %R = yresolution
+               * %ø = image's fractal dimension
+               * %þ = the answer to everything - (implemented)
+               */
+
+            default:
+              /* format string contains unknown %-sequence, print it literally */
+              i += print (title, title_len, i, "%%%c", *format);
+              break;
+            }
+          break;
+
+        default:
+          title[i++] = *format;
+          break;
+        }
+
+      format++;
+    }
+
+  title[MIN (i, title_len - 1)] = '\0';
+
+  return i;
+}
diff --git a/app/display/gimpdisplayshell-title.h b/app/display/gimpdisplayshell-title.h
new file mode 100644
index 0000000..0a3ed21
--- /dev/null
+++ b/app/display/gimpdisplayshell-title.h
@@ -0,0 +1,25 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_TITLE_H__
+#define __GIMP_DISPLAY_SHELL_TITLE_H__
+
+
+void  gimp_display_shell_title_update (GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_TITLE_H__ */
diff --git a/app/display/gimpdisplayshell-tool-events.c b/app/display/gimpdisplayshell-tool-events.c
new file mode 100644
index 0000000..714f39f
--- /dev/null
+++ b/app/display/gimpdisplayshell-tool-events.c
@@ -0,0 +1,2144 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+#include "tools/tools-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimp-filter-history.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimpimage-pick-item.h"
+#include "core/gimpitem.h"
+
+#include "widgets/gimpcontrollers.h"
+#include "widgets/gimpcontrollerkeyboard.h"
+#include "widgets/gimpcontrollermouse.h"
+#include "widgets/gimpcontrollerwheel.h"
+#include "widgets/gimpdeviceinfo.h"
+#include "widgets/gimpdeviceinfo-coords.h"
+#include "widgets/gimpdevicemanager.h"
+#include "widgets/gimpdevices.h"
+#include "widgets/gimpdialogfactory.h"
+#include "widgets/gimpuimanager.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "tools/gimpguidetool.h"
+#include "tools/gimpmovetool.h"
+#include "tools/gimpsamplepointtool.h"
+#include "tools/gimptoolcontrol.h"
+#include "tools/tool_manager.h"
+
+#include "gimpcanvas.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-autoscroll.h"
+#include "gimpdisplayshell-cursor.h"
+#include "gimpdisplayshell-grab.h"
+#include "gimpdisplayshell-layer-select.h"
+#include "gimpdisplayshell-rotate.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-tool-events.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpimagewindow.h"
+#include "gimpmotionbuffer.h"
+#include "gimpstatusbar.h"
+
+#include "gimp-intl.h"
+#include "gimp-log.h"
+
+
+/*  local function prototypes  */
+
+static gboolean   gimp_display_shell_canvas_tool_events_internal (GtkWidget          *canvas,
+                                                                  GdkEvent           *event,
+                                                                  GimpDisplayShell   *shell,
+                                                                  GdkEvent          **next_event);
+
+static GdkModifierType
+                  gimp_display_shell_key_to_state                (gint                key);
+static GdkModifierType
+                  gimp_display_shell_button_to_state             (gint                button);
+
+static void       gimp_display_shell_proximity_in                (GimpDisplayShell   *shell);
+static void       gimp_display_shell_proximity_out               (GimpDisplayShell   *shell);
+
+static void       gimp_display_shell_check_device_cursor         (GimpDisplayShell   *shell);
+
+static void       gimp_display_shell_start_scrolling             (GimpDisplayShell   *shell,
+                                                                  const GdkEvent     *event,
+                                                                  GdkModifierType     state,
+                                                                  gint                x,
+                                                                  gint                y);
+static void       gimp_display_shell_stop_scrolling              (GimpDisplayShell   *shell,
+                                                                  const GdkEvent     *event);
+static void       gimp_display_shell_handle_scrolling            (GimpDisplayShell   *shell,
+                                                                  GdkModifierType     state,
+                                                                  gint                x,
+                                                                  gint                y);
+
+static void       gimp_display_shell_space_pressed               (GimpDisplayShell   *shell,
+                                                                  const GdkEvent     *event);
+static void       gimp_display_shell_released                    (GimpDisplayShell   *shell,
+                                                                  const GdkEvent     *event,
+                                                                  const GimpCoords   *image_coords);
+
+static gboolean   gimp_display_shell_tab_pressed                 (GimpDisplayShell   *shell,
+                                                                  const GdkEventKey  *event);
+
+static void       gimp_display_shell_update_focus                (GimpDisplayShell   *shell,
+                                                                  gboolean            focus_in,
+                                                                  const GimpCoords   *image_coords,
+                                                                  GdkModifierType     state);
+static void       gimp_display_shell_update_cursor               (GimpDisplayShell   *shell,
+                                                                  const GimpCoords   *display_coords,
+                                                                  const GimpCoords   *image_coords,
+                                                                  GdkModifierType     state,
+                                                                  gboolean            update_software_cursor);
+
+static gboolean   gimp_display_shell_initialize_tool             (GimpDisplayShell   *shell,
+                                                                  const GimpCoords   *image_coords,
+                                                                  GdkModifierType     state);
+
+static void       gimp_display_shell_get_event_coords            (GimpDisplayShell   *shell,
+                                                                  const GdkEvent     *event,
+                                                                  GimpCoords         *display_coords,
+                                                                  GdkModifierType    *state,
+                                                                  guint32            *time);
+static void       gimp_display_shell_untransform_event_coords    (GimpDisplayShell   *shell,
+                                                                  const GimpCoords   *display_coords,
+                                                                  GimpCoords         *image_coords,
+                                                                  gboolean           *update_software_cursor);
+
+static GdkEvent * gimp_display_shell_compress_motion             (GdkEvent           *initial_event,
+                                                                  GdkEvent          **next_event);
+
+
+/*  public functions  */
+
+gboolean
+gimp_display_shell_events (GtkWidget        *widget,
+                           GdkEvent         *event,
+                           GimpDisplayShell *shell)
+{
+  Gimp     *gimp;
+  gboolean  set_display = FALSE;
+
+  /*  are we in destruction?  */
+  if (! shell->display || ! gimp_display_get_shell (shell->display))
+    return TRUE;
+
+  gimp = gimp_display_get_gimp (shell->display);
+
+  switch (event->type)
+    {
+    case GDK_KEY_PRESS:
+    case GDK_KEY_RELEASE:
+      {
+        GdkEventKey *kevent = (GdkEventKey *) event;
+
+        if (gimp->busy)
+          return TRUE;
+
+        /*  do not process most key events while BUTTON1 is down. We do this
+         *  so tools keep the modifier state they were in when BUTTON1 was
+         *  pressed and to prevent accelerators from being invoked.
+         */
+        if (kevent->state & GDK_BUTTON1_MASK)
+          {
+            if (kevent->keyval == GDK_KEY_Shift_L   ||
+                kevent->keyval == GDK_KEY_Shift_R   ||
+                kevent->keyval == GDK_KEY_Control_L ||
+                kevent->keyval == GDK_KEY_Control_R ||
+                kevent->keyval == GDK_KEY_Alt_L     ||
+                kevent->keyval == GDK_KEY_Alt_R     ||
+                kevent->keyval == GDK_KEY_Meta_L    ||
+                kevent->keyval == GDK_KEY_Meta_R    ||
+                kevent->keyval == GDK_KEY_space     ||
+                kevent->keyval == GDK_KEY_KP_Space)
+              {
+                break;
+              }
+
+            return TRUE;
+          }
+
+        switch (kevent->keyval)
+          {
+          case GDK_KEY_Left:      case GDK_KEY_Right:
+          case GDK_KEY_Up:        case GDK_KEY_Down:
+          case GDK_KEY_space:
+          case GDK_KEY_KP_Space:
+          case GDK_KEY_Tab:
+          case GDK_KEY_KP_Tab:
+          case GDK_KEY_ISO_Left_Tab:
+          case GDK_KEY_Alt_L:     case GDK_KEY_Alt_R:
+          case GDK_KEY_Shift_L:   case GDK_KEY_Shift_R:
+          case GDK_KEY_Control_L: case GDK_KEY_Control_R:
+          case GDK_KEY_Meta_L:    case GDK_KEY_Meta_R:
+          case GDK_KEY_Return:
+          case GDK_KEY_KP_Enter:
+          case GDK_KEY_ISO_Enter:
+          case GDK_KEY_BackSpace:
+          case GDK_KEY_Escape:
+            break;
+
+          default:
+            if (shell->space_release_pending   ||
+                shell->button1_release_pending ||
+                shell->scrolling)
+              return TRUE;
+            break;
+          }
+
+        set_display = TRUE;
+        break;
+      }
+
+    case GDK_BUTTON_PRESS:
+    case GDK_SCROLL:
+      set_display = TRUE;
+      break;
+
+    case GDK_FOCUS_CHANGE:
+      {
+        GdkEventFocus *fevent = (GdkEventFocus *) event;
+
+        if (fevent->in && shell->display->config->activate_on_focus)
+          set_display = TRUE;
+      }
+      break;
+
+    default:
+      break;
+    }
+
+  /*  Setting the context's display automatically sets the image, too  */
+  if (set_display)
+    gimp_context_set_display (gimp_get_user_context (gimp), shell->display);
+
+  return FALSE;
+}
+
+static gboolean
+gimp_display_shell_canvas_no_image_events (GtkWidget        *canvas,
+                                           GdkEvent         *event,
+                                           GimpDisplayShell *shell)
+{
+  switch (event->type)
+    {
+    case GDK_2BUTTON_PRESS:
+      {
+        GdkEventButton  *bevent = (GdkEventButton *) event;
+        if (bevent->button == 1)
+          {
+            GimpImageWindow *window  = gimp_display_shell_get_window (shell);
+            GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+
+            gimp_ui_manager_activate_action (manager, "file", "file-open");
+          }
+        return TRUE;
+      }
+      break;
+
+    case GDK_BUTTON_PRESS:
+      if (gdk_event_triggers_context_menu (event))
+        {
+          gimp_ui_manager_ui_popup (shell->popup_manager,
+                                    "/dummy-menubar/image-popup",
+                                    GTK_WIDGET (shell),
+                                    NULL, NULL, NULL, NULL);
+          return TRUE;
+        }
+      break;
+
+    case GDK_KEY_PRESS:
+      {
+        GdkEventKey *kevent = (GdkEventKey *) event;
+
+        if (kevent->keyval == GDK_KEY_Tab    ||
+            kevent->keyval == GDK_KEY_KP_Tab ||
+            kevent->keyval == GDK_KEY_ISO_Left_Tab)
+          {
+            return gimp_display_shell_tab_pressed (shell, kevent);
+          }
+      }
+      break;
+
+    default:
+      break;
+    }
+
+  return FALSE;
+}
+
+gboolean
+gimp_display_shell_canvas_tool_events (GtkWidget        *canvas,
+                                       GdkEvent         *event,
+                                       GimpDisplayShell *shell)
+{
+  GdkEvent *next_event = NULL;
+  gboolean  return_val;
+
+  g_return_val_if_fail (gtk_widget_get_realized (canvas), FALSE);
+
+  return_val = gimp_display_shell_canvas_tool_events_internal (canvas,
+                                                               event, shell,
+                                                               &next_event);
+
+  if (next_event)
+    {
+      gtk_main_do_event (next_event);
+
+      gdk_event_free (next_event);
+    }
+
+  return return_val;
+}
+
+void
+gimp_display_shell_canvas_grab_notify (GtkWidget        *canvas,
+                                       gboolean          was_grabbed,
+                                       GimpDisplayShell *shell)
+{
+  GimpDisplay *display;
+  GimpImage   *image;
+  Gimp        *gimp;
+
+  /*  are we in destruction?  */
+  if (! shell->display || ! gimp_display_get_shell (shell->display))
+    return;
+
+  display = shell->display;
+  gimp    = gimp_display_get_gimp (display);
+  image   = gimp_display_get_image (display);
+
+  if (! image)
+    return;
+
+  GIMP_LOG (TOOL_EVENTS, "grab_notify (display %p): was_grabbed = %s",
+            display, was_grabbed ? "TRUE" : "FALSE");
+
+  if (! was_grabbed)
+    {
+      if (! gimp_image_is_empty (image))
+        {
+          GimpTool *active_tool = tool_manager_get_active (gimp);
+
+          if (active_tool && active_tool->focus_display == display)
+            {
+              tool_manager_modifier_state_active (gimp, 0, display);
+            }
+        }
+    }
+}
+
+void
+gimp_display_shell_buffer_stroke (GimpMotionBuffer *buffer,
+                                  const GimpCoords *coords,
+                                  guint32           time,
+                                  GdkModifierType   state,
+                                  GimpDisplayShell *shell)
+{
+  GimpDisplay *display = shell->display;
+  Gimp        *gimp    = gimp_display_get_gimp (display);
+  GimpTool    *active_tool;
+
+  active_tool = tool_manager_get_active (gimp);
+
+  if (active_tool &&
+      gimp_tool_control_is_active (active_tool->control))
+    {
+      tool_manager_motion_active (gimp,
+                                  coords, time, state,
+                                  display);
+    }
+}
+
+void
+gimp_display_shell_buffer_hover (GimpMotionBuffer *buffer,
+                                 const GimpCoords *coords,
+                                 GdkModifierType   state,
+                                 gboolean          proximity,
+                                 GimpDisplayShell *shell)
+{
+  GimpDisplay *display = shell->display;
+  Gimp        *gimp    = gimp_display_get_gimp (display);
+  GimpTool    *active_tool;
+
+  active_tool = tool_manager_get_active (gimp);
+
+  if (active_tool &&
+      ! gimp_tool_control_is_active (active_tool->control))
+    {
+      tool_manager_oper_update_active (gimp,
+                                       coords, state, proximity,
+                                       display);
+    }
+}
+
+static gboolean
+gimp_display_shell_ruler_button_press (GtkWidget           *widget,
+                                       GdkEventButton      *event,
+                                       GimpDisplayShell    *shell,
+                                       GimpOrientationType  orientation)
+{
+  GimpDisplay *display = shell->display;
+
+  if (display->gimp->busy)
+    return TRUE;
+
+  if (! gimp_display_get_image (display))
+    return TRUE;
+
+  if (event->type == GDK_BUTTON_PRESS && event->button == 1)
+    {
+      GimpTool *active_tool = tool_manager_get_active (display->gimp);
+
+      if (active_tool)
+        {
+          gimp_display_shell_update_focus (shell, TRUE,
+                                           NULL, event->state);
+
+          if (gimp_display_shell_pointer_grab (shell, NULL, 0))
+            {
+              if (gimp_display_shell_keyboard_grab (shell,
+                                                    (GdkEvent *) event))
+                {
+                  if (event->state & gimp_get_toggle_behavior_mask ())
+                    {
+                      gimp_sample_point_tool_start_new (active_tool, display);
+                    }
+                  else
+                    {
+                      gimp_guide_tool_start_new (active_tool, display,
+                                                 orientation);
+                    }
+
+                  return TRUE;
+                }
+              else
+                {
+                  gimp_display_shell_pointer_ungrab (shell, NULL);
+                }
+            }
+        }
+    }
+
+  return FALSE;
+}
+
+gboolean
+gimp_display_shell_hruler_button_press (GtkWidget        *widget,
+                                        GdkEventButton   *event,
+                                        GimpDisplayShell *shell)
+{
+  return gimp_display_shell_ruler_button_press (widget, event, shell,
+                                                GIMP_ORIENTATION_HORIZONTAL);
+}
+
+gboolean
+gimp_display_shell_vruler_button_press (GtkWidget        *widget,
+                                        GdkEventButton   *event,
+                                        GimpDisplayShell *shell)
+{
+  return gimp_display_shell_ruler_button_press (widget, event, shell,
+                                                GIMP_ORIENTATION_VERTICAL);
+}
+
+
+/*  private functions  */
+
+static gboolean
+gimp_display_shell_canvas_tool_events_internal (GtkWidget         *canvas,
+                                                GdkEvent          *event,
+                                                GimpDisplayShell  *shell,
+                                                GdkEvent         **next_event)
+{
+  GimpDisplay     *display;
+  GimpImage       *image;
+  Gimp            *gimp;
+  GimpCoords       display_coords;
+  GimpCoords       image_coords;
+  GdkModifierType  state;
+  guint32          time;
+  gboolean         device_changed   = FALSE;
+  gboolean         return_val       = FALSE;
+  gboolean         update_sw_cursor = FALSE;
+
+  *next_event = NULL;
+
+  /*  are we in destruction?  */
+  if (! shell->display || ! gimp_display_get_shell (shell->display))
+    return TRUE;
+
+  /*  set the active display before doing any other canvas event processing  */
+  if (gimp_display_shell_events (canvas, event, shell))
+    return TRUE;
+
+  /*  events on overlays have a different window, but these windows'
+   *  user_data can still be the canvas, we need to check manually if
+   *  the event's window and the canvas' window are different.
+   */
+  if (event->any.window != gtk_widget_get_window (canvas))
+    {
+      GtkWidget *event_widget;
+
+      gdk_window_get_user_data (event->any.window, (gpointer) &event_widget);
+
+      /*  if the event came from a different window than the canvas',
+       *  check if it came from a canvas child and bail out.
+       */
+      if (gtk_widget_get_ancestor (event_widget, GIMP_TYPE_CANVAS))
+        return FALSE;
+    }
+
+  display = shell->display;
+  gimp    = gimp_display_get_gimp (display);
+  image   = gimp_display_get_image (display);
+
+  if (! image)
+    return gimp_display_shell_canvas_no_image_events (canvas, event, shell);
+
+  GIMP_LOG (TOOL_EVENTS, "event (display %p): %s",
+            display, gimp_print_event (event));
+
+  /* See bug 771444 */
+  if (shell->pointer_grabbed &&
+      event->type == GDK_MOTION_NOTIFY)
+    {
+      GimpDeviceManager *manager = gimp_devices_get_manager (gimp);
+      GimpDeviceInfo    *info;
+
+      info = gimp_device_manager_get_current_device (manager);
+
+      if (info->device != event->motion.device)
+        return FALSE;
+    }
+
+  /*  Find out what device the event occurred upon  */
+  if (! gimp->busy &&
+      ! shell->inferior_ignore_mode &&
+      gimp_devices_check_change (gimp, event))
+    {
+      gimp_display_shell_check_device_cursor (shell);
+      device_changed = TRUE;
+    }
+
+  gimp_display_shell_get_event_coords (shell, event,
+                                       &display_coords,
+                                       &state, &time);
+  gimp_display_shell_untransform_event_coords (shell,
+                                               &display_coords, &image_coords,
+                                               &update_sw_cursor);
+
+  /*  If the device (and maybe the tool) has changed, update the new
+   *  tool's state
+   */
+  if (device_changed && gtk_widget_has_focus (canvas))
+    {
+      gimp_display_shell_update_focus (shell, TRUE,
+                                       &image_coords, state);
+    }
+
+  switch (event->type)
+    {
+    case GDK_ENTER_NOTIFY:
+      {
+        GdkEventCrossing *cevent = (GdkEventCrossing *) event;
+
+        if (shell->inferior_ignore_mode &&
+            cevent->subwindow == NULL   &&
+            cevent->mode      == GDK_CROSSING_NORMAL)
+          {
+            shell->inferior_ignore_mode = FALSE;
+            gtk_widget_set_extension_events (shell->canvas,
+                                             GDK_EXTENSION_EVENTS_ALL);
+          }
+
+        if (cevent->mode != GDK_CROSSING_NORMAL)
+          return TRUE;
+
+        /*  ignore enter notify while we have a grab  */
+        if (shell->pointer_grabbed)
+          return TRUE;
+
+        gimp_display_shell_proximity_in (shell);
+        update_sw_cursor = TRUE;
+
+        tool_manager_oper_update_active (gimp,
+                                         &image_coords, state,
+                                         shell->proximity,
+                                         display);
+      }
+      break;
+
+    case GDK_LEAVE_NOTIFY:
+      {
+        GdkEventCrossing *cevent = (GdkEventCrossing *) event;
+
+        if (! shell->inferior_ignore_mode            &&
+            cevent->subwindow == NULL                &&
+            cevent->mode      == GDK_CROSSING_NORMAL &&
+            cevent->detail    == GDK_NOTIFY_INFERIOR)
+          {
+            shell->inferior_ignore_mode = TRUE;
+            gtk_widget_set_extension_events (shell->canvas,
+                                             GDK_EXTENSION_EVENTS_NONE);
+          }
+
+        if (cevent->mode != GDK_CROSSING_NORMAL)
+          return TRUE;
+
+        /*  ignore leave notify while we have a grab  */
+        if (shell->pointer_grabbed)
+          return TRUE;
+
+        gimp_display_shell_proximity_out (shell);
+
+        tool_manager_oper_update_active (gimp,
+                                         &image_coords, state,
+                                         shell->proximity,
+                                         display);
+      }
+      break;
+
+    case GDK_PROXIMITY_IN:
+      gimp_display_shell_proximity_in (shell);
+
+      tool_manager_oper_update_active (gimp,
+                                       &image_coords, state,
+                                       shell->proximity,
+                                       display);
+      break;
+
+    case GDK_PROXIMITY_OUT:
+      gimp_display_shell_proximity_out (shell);
+
+      tool_manager_oper_update_active (gimp,
+                                       &image_coords, state,
+                                       shell->proximity,
+                                       display);
+      break;
+
+    case GDK_FOCUS_CHANGE:
+      {
+        GdkEventFocus *fevent = (GdkEventFocus *) event;
+
+        if (fevent->in)
+          {
+            if (G_UNLIKELY (! gtk_widget_has_focus (canvas)))
+              g_warning ("%s: FOCUS_IN but canvas has no focus", G_STRFUNC);
+
+            /*  ignore focus changes while we have a grab  */
+            if (shell->pointer_grabbed)
+              return TRUE;
+
+            /*   press modifier keys when the canvas gets the focus  */
+            gimp_display_shell_update_focus (shell, TRUE,
+                                             &image_coords, state);
+          }
+        else
+          {
+            if (G_UNLIKELY (gtk_widget_has_focus (canvas)))
+              g_warning ("%s: FOCUS_OUT but canvas has focus", G_STRFUNC);
+
+            /*  ignore focus changes while we have a grab  */
+            if (shell->pointer_grabbed)
+              return TRUE;
+
+            /*  release modifier keys when the canvas loses the focus  */
+            gimp_display_shell_update_focus (shell, FALSE,
+                                             &image_coords, 0);
+          }
+      }
+      break;
+
+    case GDK_BUTTON_PRESS:
+      {
+        GdkEventButton  *bevent = (GdkEventButton *) event;
+        GdkModifierType  button_state;
+
+        /*  ignore new mouse events  */
+        if (gimp->busy || shell->scrolling ||
+            shell->pointer_grabbed         ||
+            shell->button1_release_pending)
+          return TRUE;
+
+        button_state = gimp_display_shell_button_to_state (bevent->button);
+
+        state |= button_state;
+
+        /* ignore new buttons while another button is down */
+        if (((state & (GDK_BUTTON1_MASK)) && (state & (GDK_BUTTON2_MASK |
+                                                       GDK_BUTTON3_MASK))) ||
+            ((state & (GDK_BUTTON2_MASK)) && (state & (GDK_BUTTON1_MASK |
+                                                       GDK_BUTTON3_MASK))) ||
+            ((state & (GDK_BUTTON3_MASK)) && (state & (GDK_BUTTON1_MASK |
+                                                       GDK_BUTTON2_MASK))))
+          return TRUE;
+
+        /*  focus the widget if it isn't; if the toplevel window
+         *  already has focus, this will generate a FOCUS_IN on the
+         *  canvas immediately, therefore we do this before logging
+         *  the BUTTON_PRESS.
+         */
+        if (! gtk_widget_has_focus (canvas))
+          gtk_widget_grab_focus (canvas);
+
+        /*  if the toplevel window didn't have focus, the above
+         *  gtk_widget_grab_focus() didn't set the canvas' HAS_FOCUS
+         *  flags, and didn't trigger a FOCUS_IN, but the tool needs
+         *  to be set up correctly regardless, so simply do the
+         *  same things here, it's safe to do them redundantly.
+         */
+        gimp_display_shell_update_focus (shell, TRUE,
+                                         &image_coords, state);
+        gimp_display_shell_update_cursor (shell, &display_coords,
+                                          &image_coords, state & ~button_state,
+                                          FALSE);
+
+        if (gdk_event_triggers_context_menu (event))
+          {
+            GimpUIManager *ui_manager;
+            const gchar   *ui_path;
+
+            ui_manager = tool_manager_get_popup_active (gimp,
+                                                        &image_coords, state,
+                                                        display,
+                                                        &ui_path);
+
+            if (ui_manager)
+              {
+                gimp_ui_manager_ui_popup (ui_manager,
+                                          ui_path,
+                                          GTK_WIDGET (shell),
+                                          NULL, NULL, NULL, NULL);
+              }
+            else
+              {
+                gimp_ui_manager_ui_popup (shell->popup_manager,
+                                          "/dummy-menubar/image-popup",
+                                          GTK_WIDGET (shell),
+                                          NULL, NULL, NULL, NULL);
+              }
+          }
+        else if (bevent->button == 1)
+          {
+            if (! gimp_display_shell_pointer_grab (shell, NULL, 0))
+              return TRUE;
+
+            if (! shell->space_release_pending)
+              if (! gimp_display_shell_keyboard_grab (shell, event))
+                {
+                  gimp_display_shell_pointer_ungrab (shell, NULL);
+                  return TRUE;
+                }
+
+            if (gimp_display_shell_initialize_tool (shell,
+                                                    &image_coords, state))
+              {
+                GimpCoords last_motion;
+
+                /* Use the last evaluated velocity&direction instead of the
+                 * button_press event's ones because the click is
+                 * usually at the same spot as the last motion event
+                 * which would give us bogus derivate dynamics.
+                 */
+                gimp_motion_buffer_begin_stroke (shell->motion_buffer, time,
+                                                 &last_motion);
+
+                image_coords.velocity = last_motion.velocity;
+                image_coords.direction = last_motion.direction;
+
+                tool_manager_button_press_active (gimp,
+                                                  &image_coords,
+                                                  time, state,
+                                                  GIMP_BUTTON_PRESS_NORMAL,
+                                                  display);
+              }
+          }
+        else if (bevent->button == 2)
+          {
+            gimp_display_shell_start_scrolling (shell, NULL, state,
+                                                bevent->x, bevent->y);
+          }
+
+        return_val = TRUE;
+      }
+      break;
+
+    case GDK_2BUTTON_PRESS:
+      {
+        GdkEventButton *bevent = (GdkEventButton *) event;
+        GimpTool       *active_tool;
+
+        if (gimp->busy)
+          return TRUE;
+
+        active_tool = tool_manager_get_active (gimp);
+
+        if (bevent->button == 1                                &&
+            active_tool                                        &&
+            gimp_tool_control_is_active (active_tool->control) &&
+            gimp_tool_control_get_wants_double_click (active_tool->control))
+          {
+            tool_manager_button_press_active (gimp,
+                                              &image_coords,
+                                              time, state,
+                                              GIMP_BUTTON_PRESS_DOUBLE,
+                                              display);
+          }
+
+        /*  don't update the cursor again on double click  */
+        return TRUE;
+      }
+      break;
+
+    case GDK_3BUTTON_PRESS:
+      {
+        GdkEventButton *bevent = (GdkEventButton *) event;
+        GimpTool       *active_tool;
+
+        if (gimp->busy)
+          return TRUE;
+
+        active_tool = tool_manager_get_active (gimp);
+
+        if (bevent->button == 1                                &&
+            active_tool                                        &&
+            gimp_tool_control_is_active (active_tool->control) &&
+            gimp_tool_control_get_wants_triple_click (active_tool->control))
+          {
+            tool_manager_button_press_active (gimp,
+                                              &image_coords,
+                                              time, state,
+                                              GIMP_BUTTON_PRESS_TRIPLE,
+                                              display);
+          }
+
+        /*  don't update the cursor again on triple click  */
+        return TRUE;
+      }
+      break;
+
+    case GDK_BUTTON_RELEASE:
+      {
+        GdkEventButton *bevent = (GdkEventButton *) event;
+        GimpTool       *active_tool;
+
+        gimp_display_shell_autoscroll_stop (shell);
+
+        if (bevent->button == 1 && shell->button1_release_pending)
+          {
+            gimp_display_shell_released (shell, event, NULL);
+            return TRUE;
+          }
+
+        if (gimp->busy)
+          return TRUE;
+
+        active_tool = tool_manager_get_active (gimp);
+
+        state &= ~gimp_display_shell_button_to_state (bevent->button);
+
+        if (bevent->button == 1)
+          {
+            if (! shell->pointer_grabbed || shell->scrolling)
+              return TRUE;
+
+            if (! shell->space_release_pending)
+              gimp_display_shell_keyboard_ungrab (shell, event);
+
+            if (active_tool &&
+                (! gimp_image_is_empty (image) ||
+                 gimp_tool_control_get_handle_empty_image (active_tool->control)))
+              {
+                gimp_motion_buffer_end_stroke (shell->motion_buffer);
+
+                if (gimp_tool_control_is_active (active_tool->control))
+                  {
+                    tool_manager_button_release_active (gimp,
+                                                        &image_coords,
+                                                        time, state,
+                                                        display);
+                  }
+              }
+
+            /*  update the tool's modifier state because it didn't get
+             *  key events while BUTTON1 was down
+             */
+            if (gtk_widget_has_focus (canvas))
+              gimp_display_shell_update_focus (shell, TRUE,
+                                               &image_coords, state);
+            else
+              gimp_display_shell_update_focus (shell, FALSE,
+                                               &image_coords, 0);
+
+            gimp_display_shell_pointer_ungrab (shell, NULL);
+          }
+        else if (bevent->button == 2)
+          {
+            if (shell->scrolling)
+              gimp_display_shell_stop_scrolling (shell, NULL);
+          }
+        else if (bevent->button == 3)
+          {
+            /* nop */
+          }
+        else
+          {
+            GdkEventButton *bevent = (GdkEventButton *) event;
+            GimpController *mouse  = gimp_controllers_get_mouse (gimp);
+
+            if (!(shell->scrolling || shell->pointer_grabbed) &&
+                mouse && gimp_controller_mouse_button (GIMP_CONTROLLER_MOUSE (mouse),
+                                                       bevent))
+              {
+                return TRUE;
+              }
+          }
+
+        return_val = TRUE;
+      }
+      break;
+
+    case GDK_SCROLL:
+      {
+        GdkEventScroll *sevent = (GdkEventScroll *) event;
+        GimpController *wheel  = gimp_controllers_get_wheel (gimp);
+
+        if (! wheel ||
+            ! gimp_controller_wheel_scroll (GIMP_CONTROLLER_WHEEL (wheel),
+                                            sevent))
+          {
+            GdkScrollDirection  direction = sevent->direction;
+
+            if (state & gimp_get_toggle_behavior_mask ())
+              {
+                switch (direction)
+                  {
+                  case GDK_SCROLL_UP:
+                    gimp_display_shell_scale (shell,
+                                              GIMP_ZOOM_IN,
+                                              0.0,
+                                              GIMP_ZOOM_FOCUS_POINTER);
+                    break;
+
+                  case GDK_SCROLL_DOWN:
+                    gimp_display_shell_scale (shell,
+                                              GIMP_ZOOM_OUT,
+                                              0.0,
+                                              GIMP_ZOOM_FOCUS_POINTER);
+                    break;
+
+                  default:
+                    break;
+                  }
+              }
+            else
+              {
+                GtkAdjustment *adj = NULL;
+                gdouble        value;
+
+                if (state & GDK_SHIFT_MASK)
+                  switch (direction)
+                    {
+                    case GDK_SCROLL_UP:    direction = GDK_SCROLL_LEFT;  break;
+                    case GDK_SCROLL_DOWN:  direction = GDK_SCROLL_RIGHT; break;
+                    case GDK_SCROLL_LEFT:  direction = GDK_SCROLL_UP;    break;
+                    case GDK_SCROLL_RIGHT: direction = GDK_SCROLL_DOWN;  break;
+                    }
+
+                switch (direction)
+                  {
+                  case GDK_SCROLL_LEFT:
+                  case GDK_SCROLL_RIGHT:
+                    adj = shell->hsbdata;
+                    break;
+
+                  case GDK_SCROLL_UP:
+                  case GDK_SCROLL_DOWN:
+                    adj = shell->vsbdata;
+                    break;
+                  }
+
+                value = (gtk_adjustment_get_value (adj) +
+                         ((direction == GDK_SCROLL_UP ||
+                           direction == GDK_SCROLL_LEFT) ?
+                          -gtk_adjustment_get_page_increment (adj) / 2 :
+                          gtk_adjustment_get_page_increment (adj) / 2));
+                value = CLAMP (value,
+                               gtk_adjustment_get_lower (adj),
+                               gtk_adjustment_get_upper (adj) -
+                               gtk_adjustment_get_page_size (adj));
+
+                gtk_adjustment_set_value (adj, value);
+              }
+          }
+
+        gimp_display_shell_untransform_event_coords (shell,
+                                                     &display_coords,
+                                                     &image_coords,
+                                                     &update_sw_cursor);
+
+        tool_manager_oper_update_active (gimp,
+                                         &image_coords, state,
+                                         shell->proximity,
+                                         display);
+
+        return_val = TRUE;
+      }
+      break;
+
+    case GDK_MOTION_NOTIFY:
+      {
+        GdkEventMotion *mevent            = (GdkEventMotion *) event;
+        GdkEvent       *compressed_motion = NULL;
+        GimpMotionMode  motion_mode       = GIMP_MOTION_MODE_EXACT;
+        GimpTool       *active_tool;
+
+        if (gimp->busy)
+          return TRUE;
+
+        active_tool = tool_manager_get_active (gimp);
+
+        if (active_tool)
+          motion_mode = gimp_tool_control_get_motion_mode (active_tool->control);
+
+        if (shell->scrolling ||
+            motion_mode == GIMP_MOTION_MODE_COMPRESS)
+          {
+            compressed_motion = gimp_display_shell_compress_motion (event,
+                                                                    next_event);
+
+            if (compressed_motion && ! shell->scrolling)
+              {
+                gimp_display_shell_get_event_coords (shell,
+                                                     compressed_motion,
+                                                     &display_coords,
+                                                     &state, &time);
+                gimp_display_shell_untransform_event_coords (shell,
+                                                             &display_coords,
+                                                             &image_coords,
+                                                             NULL);
+              }
+          }
+
+        /*  call proximity_in() here because the pointer might already
+         *  be in proximity when the canvas starts to receive events,
+         *  like when a new image has been created into an empty
+         *  display
+         */
+        gimp_display_shell_proximity_in (shell);
+        update_sw_cursor = TRUE;
+
+        if (shell->scrolling)
+          {
+            GdkEventMotion *me = (compressed_motion ?
+                                  (GdkEventMotion *) compressed_motion :
+                                  mevent);
+
+            gimp_display_shell_handle_scrolling (shell, state, me->x, me->y);
+          }
+        else if (state & GDK_BUTTON1_MASK)
+          {
+            if (active_tool                                        &&
+                gimp_tool_control_is_active (active_tool->control) &&
+                (! gimp_image_is_empty (image) ||
+                 gimp_tool_control_get_handle_empty_image (active_tool->control)))
+              {
+                GdkTimeCoord **history_events;
+                gint           n_history_events;
+                guint32        last_motion_time;
+
+                /*  if the first mouse button is down, check for automatic
+                 *  scrolling...
+                 */
+                if ((mevent->x < 0                 ||
+                     mevent->y < 0                 ||
+                     mevent->x > shell->disp_width ||
+                     mevent->y > shell->disp_height) &&
+                    ! gimp_tool_control_get_scroll_lock (active_tool->control))
+                  {
+                    gimp_display_shell_autoscroll_start (shell, state, mevent);
+                  }
+
+                /* gdk_device_get_history() has several quirks. First
+                 * is that events with borderline timestamps at both
+                 * ends are included. Because of that we need to add 1
+                 * to lower border. The second is due to poor X event
+                 * resolution. We need to do -1 to ensure that the
+                 * amount of events between timestamps is final or
+                 * risk losing some.
+                 */
+                last_motion_time =
+                  gimp_motion_buffer_get_last_motion_time (shell->motion_buffer);
+
+                if (motion_mode == GIMP_MOTION_MODE_EXACT     &&
+                    shell->display->config->use_event_history &&
+                    gdk_device_get_history (mevent->device, mevent->window,
+                                            last_motion_time + 1,
+                                            mevent->time - 1,
+                                            &history_events,
+                                            &n_history_events))
+                  {
+                    GimpDeviceInfo *device;
+                    gint            i;
+
+                    device = gimp_device_info_get_by_device (mevent->device);
+
+                    for (i = 0; i < n_history_events; i++)
+                      {
+                        gimp_device_info_get_time_coords (device,
+                                                          history_events[i],
+                                                          &display_coords);
+
+                        gimp_display_shell_untransform_event_coords (shell,
+                                                                     &display_coords,
+                                                                     &image_coords,
+                                                                     NULL);
+
+                        /* Early removal of useless events saves CPU time.
+                         */
+                        if (gimp_motion_buffer_motion_event (shell->motion_buffer,
+                                                             &image_coords,
+                                                             history_events[i]->time,
+                                                             TRUE))
+                          {
+                            gimp_motion_buffer_request_stroke (shell->motion_buffer,
+                                                               state,
+                                                               history_events[i]->time);
+                          }
+                      }
+
+                    gdk_device_free_history (history_events, n_history_events);
+                  }
+                else
+                  {
+                    gboolean event_fill = (motion_mode == GIMP_MOTION_MODE_EXACT);
+
+                    /* Early removal of useless events saves CPU time.
+                     */
+                    if (gimp_motion_buffer_motion_event (shell->motion_buffer,
+                                                         &image_coords,
+                                                         time,
+                                                         event_fill))
+                      {
+                        gimp_motion_buffer_request_stroke (shell->motion_buffer,
+                                                           state,
+                                                           time);
+                      }
+                  }
+              }
+          }
+
+        if (! (state &
+               (GDK_BUTTON1_MASK | GDK_BUTTON2_MASK | GDK_BUTTON3_MASK)))
+          {
+            /* Early removal of useless events saves CPU time.
+             * Pass event_fill = FALSE since we are only hovering.
+             */
+            if (gimp_motion_buffer_motion_event (shell->motion_buffer,
+                                                 &image_coords,
+                                                 time,
+                                                 FALSE))
+              {
+                gimp_motion_buffer_request_hover (shell->motion_buffer,
+                                                  state,
+                                                  shell->proximity);
+              }
+          }
+
+        if (compressed_motion)
+          gdk_event_free (compressed_motion);
+
+        return_val = TRUE;
+      }
+      break;
+
+    case GDK_KEY_PRESS:
+      {
+        GdkEventKey *kevent = (GdkEventKey *) event;
+        GimpTool    *active_tool;
+
+        active_tool = tool_manager_get_active (gimp);
+
+        if (state & GDK_BUTTON1_MASK)
+          {
+            if (kevent->keyval == GDK_KEY_Alt_L     ||
+                kevent->keyval == GDK_KEY_Alt_R     ||
+                kevent->keyval == GDK_KEY_Shift_L   ||
+                kevent->keyval == GDK_KEY_Shift_R   ||
+                kevent->keyval == GDK_KEY_Control_L ||
+                kevent->keyval == GDK_KEY_Control_R ||
+                kevent->keyval == GDK_KEY_Meta_L    ||
+                kevent->keyval == GDK_KEY_Meta_R)
+              {
+                GdkModifierType key;
+
+                key = gimp_display_shell_key_to_state (kevent->keyval);
+                state |= key;
+
+                if (active_tool                                        &&
+                    gimp_tool_control_is_active (active_tool->control) &&
+                    ! gimp_image_is_empty (image))
+                  {
+                    tool_manager_active_modifier_state_active (gimp, state,
+                                                               display);
+                  }
+              }
+          }
+        else
+          {
+            gboolean arrow_key = FALSE;
+
+            tool_manager_focus_display_active (gimp, display);
+
+            if (gimp_tool_control_get_wants_all_key_events (active_tool->control))
+              {
+                if (tool_manager_key_press_active (gimp, kevent, display))
+                  {
+                    /* FIXME: need to do some of the stuff below, like
+                     * calling oper_update()
+                     */
+
+                    return TRUE;
+                  }
+              }
+
+            if (! gtk_widget_has_focus (shell->canvas))
+              {
+                /*  The event was in an overlay widget and not handled
+                 *  there, make sure the overlay widgets are keyboard
+                 *  navigatable by letting the generic widget handlers
+                 *  deal with the event.
+                 */
+                return FALSE;
+              }
+
+            if (gimp_display_shell_key_to_state (kevent->keyval) == GDK_MOD1_MASK)
+              /* Make sure the picked layer is reset. */
+              shell->picked_layer = NULL;
+
+            switch (kevent->keyval)
+              {
+              case GDK_KEY_Left:
+              case GDK_KEY_Right:
+              case GDK_KEY_Up:
+              case GDK_KEY_Down:
+                arrow_key = TRUE;
+
+              case GDK_KEY_Return:
+              case GDK_KEY_KP_Enter:
+              case GDK_KEY_ISO_Enter:
+              case GDK_KEY_BackSpace:
+              case GDK_KEY_Escape:
+                if (! gimp_image_is_empty (image))
+                  return_val = tool_manager_key_press_active (gimp,
+                                                              kevent,
+                                                              display);
+
+                if (! return_val)
+                  {
+                    GimpController *keyboard = gimp_controllers_get_keyboard (gimp);
+
+                    if (keyboard)
+                      return_val =
+                        gimp_controller_keyboard_key_press (GIMP_CONTROLLER_KEYBOARD (keyboard),
+                                                            kevent);
+                  }
+
+                /* always swallow arrow keys, we don't want focus keynav */
+                if (! return_val)
+                  return_val = arrow_key;
+                break;
+
+              case GDK_KEY_space:
+              case GDK_KEY_KP_Space:
+                if (shell->button1_release_pending)
+                  shell->space_release_pending = TRUE;
+                else
+                  gimp_display_shell_space_pressed (shell, event);
+                return_val = TRUE;
+                break;
+
+              case GDK_KEY_Tab:
+              case GDK_KEY_KP_Tab:
+              case GDK_KEY_ISO_Left_Tab:
+                gimp_display_shell_tab_pressed (shell, kevent);
+                return_val = TRUE;
+                break;
+
+                /*  Update the state based on modifiers being pressed  */
+              case GDK_KEY_Alt_L:     case GDK_KEY_Alt_R:
+              case GDK_KEY_Shift_L:   case GDK_KEY_Shift_R:
+              case GDK_KEY_Control_L: case GDK_KEY_Control_R:
+              case GDK_KEY_Meta_L:    case GDK_KEY_Meta_R:
+                {
+                  GdkModifierType key;
+
+                  key = gimp_display_shell_key_to_state (kevent->keyval);
+                  state |= key;
+
+                  if (! gimp_image_is_empty (image))
+                    tool_manager_modifier_state_active (gimp, state, display);
+                }
+                break;
+              }
+
+            tool_manager_oper_update_active (gimp,
+                                             &image_coords, state,
+                                             shell->proximity,
+                                             display);
+          }
+      }
+      break;
+
+    case GDK_KEY_RELEASE:
+      {
+        GdkEventKey *kevent = (GdkEventKey *) event;
+        GimpTool    *active_tool;
+
+        active_tool = tool_manager_get_active (gimp);
+
+        if (gimp_display_shell_key_to_state (kevent->keyval) == GDK_MOD1_MASK &&
+            shell->picked_layer)
+          {
+            GimpStatusbar *statusbar;
+
+            statusbar = gimp_display_shell_get_statusbar (shell);
+            gimp_statusbar_pop_temp (statusbar);
+
+            shell->picked_layer = NULL;
+          }
+
+        if ((state & GDK_BUTTON1_MASK)      &&
+            (! shell->space_release_pending ||
+             (kevent->keyval != GDK_KEY_space &&
+              kevent->keyval != GDK_KEY_KP_Space)))
+          {
+            if (kevent->keyval == GDK_KEY_Alt_L     ||
+                kevent->keyval == GDK_KEY_Alt_R     ||
+                kevent->keyval == GDK_KEY_Shift_L   ||
+                kevent->keyval == GDK_KEY_Shift_R   ||
+                kevent->keyval == GDK_KEY_Control_L ||
+                kevent->keyval == GDK_KEY_Control_R ||
+                kevent->keyval == GDK_KEY_Meta_L    ||
+                kevent->keyval == GDK_KEY_Meta_R)
+              {
+                GdkModifierType key;
+
+                key = gimp_display_shell_key_to_state (kevent->keyval);
+                state &= ~key;
+
+                if (active_tool                                        &&
+                    gimp_tool_control_is_active (active_tool->control) &&
+                    ! gimp_image_is_empty (image))
+                  {
+                    tool_manager_active_modifier_state_active (gimp, state,
+                                                               display);
+                  }
+              }
+          }
+        else
+          {
+            tool_manager_focus_display_active (gimp, display);
+
+            if (gimp_tool_control_get_wants_all_key_events (active_tool->control))
+              {
+                if (tool_manager_key_release_active (gimp, kevent, display))
+                  {
+                    /* FIXME: need to do some of the stuff below, like
+                     * calling oper_update()
+                     */
+
+                    return TRUE;
+                  }
+              }
+
+            if (! gtk_widget_has_focus (shell->canvas))
+              {
+                /*  The event was in an overlay widget and not handled
+                 *  there, make sure the overlay widgets are keyboard
+                 *  navigatable by letting the generic widget handlers
+                 *  deal with the event.
+                 */
+                return FALSE;
+              }
+
+            switch (kevent->keyval)
+              {
+              case GDK_KEY_space:
+              case GDK_KEY_KP_Space:
+                if ((state & GDK_BUTTON1_MASK))
+                  {
+                    shell->button1_release_pending = TRUE;
+                    shell->space_release_pending   = FALSE;
+                    /* We need to ungrab the pointer in order to catch
+                     * button release events.
+                     */
+                    if (shell->pointer_grabbed)
+                      gimp_display_shell_pointer_ungrab (shell, event);
+                  }
+                else
+                  {
+                    gimp_display_shell_released (shell, event, NULL);
+                  }
+                return_val = TRUE;
+                break;
+
+                /*  Update the state based on modifiers being pressed  */
+              case GDK_KEY_Alt_L:     case GDK_KEY_Alt_R:
+              case GDK_KEY_Shift_L:   case GDK_KEY_Shift_R:
+              case GDK_KEY_Control_L: case GDK_KEY_Control_R:
+              case GDK_KEY_Meta_L:    case GDK_KEY_Meta_R:
+                {
+                  GdkModifierType key;
+
+                  key = gimp_display_shell_key_to_state (kevent->keyval);
+                  state &= ~key;
+
+                  /*  For all modifier keys: call the tools
+                   *  modifier_state *and* oper_update method so tools
+                   *  can choose if they are interested in the press
+                   *  itself or only in the resulting state
+                   */
+                  if (! gimp_image_is_empty (image))
+                    tool_manager_modifier_state_active (gimp, state, display);
+                }
+                break;
+              }
+
+            tool_manager_oper_update_active (gimp,
+                                             &image_coords, state,
+                                             shell->proximity,
+                                             display);
+          }
+      }
+      break;
+
+    default:
+      break;
+    }
+
+  /*  if we reached this point in gimp_busy mode, return now  */
+  if (gimp->busy)
+    return return_val;
+
+  /*  cursor update   */
+  gimp_display_shell_update_cursor (shell, &display_coords, &image_coords,
+                                    state, update_sw_cursor);
+
+  return return_val;
+}
+
+static GdkModifierType
+gimp_display_shell_key_to_state (gint key)
+{
+  /* FIXME: need some proper GDK API to figure this */
+
+  switch (key)
+    {
+    case GDK_KEY_Alt_L:
+    case GDK_KEY_Alt_R:
+      return GDK_MOD1_MASK;
+
+    case GDK_KEY_Shift_L:
+    case GDK_KEY_Shift_R:
+      return GDK_SHIFT_MASK;
+
+    case GDK_KEY_Control_L:
+    case GDK_KEY_Control_R:
+      return GDK_CONTROL_MASK;
+
+#ifdef GDK_WINDOWING_QUARTZ
+    case GDK_KEY_Meta_L:
+    case GDK_KEY_Meta_R:
+      return GDK_MOD2_MASK;
+#endif
+
+    default:
+      return 0;
+    }
+}
+
+static GdkModifierType
+gimp_display_shell_button_to_state (gint button)
+{
+  if (button == 1)
+    return GDK_BUTTON1_MASK;
+  else if (button == 2)
+    return GDK_BUTTON2_MASK;
+  else if (button == 3)
+    return GDK_BUTTON3_MASK;
+
+  return 0;
+}
+
+static void
+gimp_display_shell_proximity_in (GimpDisplayShell *shell)
+{
+  if (! shell->proximity)
+    {
+      shell->proximity = TRUE;
+
+      gimp_display_shell_check_device_cursor (shell);
+    }
+}
+
+static void
+gimp_display_shell_proximity_out (GimpDisplayShell *shell)
+{
+  if (shell->proximity)
+    {
+      shell->proximity = FALSE;
+
+      gimp_display_shell_clear_software_cursor (shell);
+    }
+}
+
+static void
+gimp_display_shell_check_device_cursor (GimpDisplayShell *shell)
+{
+  GimpDeviceManager *manager;
+  GimpDeviceInfo    *current_device;
+
+  manager = gimp_devices_get_manager (shell->display->gimp);
+
+  current_device = gimp_device_manager_get_current_device (manager);
+
+  shell->draw_cursor = ! gimp_device_info_has_cursor (current_device);
+}
+
+static void
+gimp_display_shell_start_scrolling (GimpDisplayShell *shell,
+                                    const GdkEvent   *event,
+                                    GdkModifierType   state,
+                                    gint              x,
+                                    gint              y)
+{
+  g_return_if_fail (! shell->scrolling);
+
+  gimp_display_shell_pointer_grab (shell, event, GDK_POINTER_MOTION_MASK);
+
+  shell->scrolling         = TRUE;
+  shell->scroll_start_x    = x;
+  shell->scroll_start_y    = y;
+  shell->scroll_last_x     = x;
+  shell->scroll_last_y     = y;
+  shell->rotating          = (state & gimp_get_extend_selection_mask ()) ? TRUE : FALSE;
+  shell->rotate_drag_angle = shell->rotate_angle;
+  shell->scaling           = (state & gimp_get_toggle_behavior_mask ()) ? TRUE : FALSE;
+  shell->layer_picking     = (state & GDK_MOD1_MASK) ? TRUE : FALSE;
+
+  if (shell->rotating)
+    {
+      gimp_display_shell_set_override_cursor (shell,
+                                              (GimpCursorType) GDK_EXCHANGE);
+    }
+  else if (shell->scaling)
+    {
+      gimp_display_shell_set_override_cursor (shell,
+                                              (GimpCursorType) GIMP_CURSOR_ZOOM);
+    }
+  else if (shell->layer_picking)
+    {
+      GimpImage  *image   = gimp_display_get_image (shell->display);
+      GimpLayer  *layer;
+      GimpCoords  image_coords;
+      GimpCoords  display_coords;
+      guint32     time;
+
+      gimp_display_shell_set_override_cursor (shell,
+                                              (GimpCursorType) GIMP_CURSOR_CROSSHAIR);
+
+      gimp_display_shell_get_event_coords (shell, event,
+                                           &display_coords,
+                                           &state, &time);
+      gimp_display_shell_untransform_event_coords (shell,
+                                                   &display_coords, &image_coords,
+                                                   NULL);
+      layer = gimp_image_pick_layer (image,
+                                     (gint) image_coords.x,
+                                     (gint) image_coords.y,
+                                     shell->picked_layer);
+
+      if (layer && ! gimp_image_get_floating_selection (image))
+        {
+          if (layer != gimp_image_get_active_layer (image))
+            {
+              GimpStatusbar *statusbar;
+
+              gimp_image_set_active_layer (image, layer);
+
+              statusbar = gimp_display_shell_get_statusbar (shell);
+              gimp_statusbar_push_temp (statusbar, GIMP_MESSAGE_INFO,
+                                        GIMP_ICON_LAYER,
+                                        _("Layer picked: '%s'"),
+                                        gimp_object_get_name (layer));
+            }
+          shell->picked_layer = layer;
+        }
+    }
+  else
+    gimp_display_shell_set_override_cursor (shell,
+                                            (GimpCursorType) GDK_FLEUR);
+}
+
+static void
+gimp_display_shell_stop_scrolling (GimpDisplayShell *shell,
+                                   const GdkEvent   *event)
+{
+  g_return_if_fail (shell->scrolling);
+
+  gimp_display_shell_unset_override_cursor (shell);
+
+  shell->scrolling         = FALSE;
+  shell->scroll_start_x    = 0;
+  shell->scroll_start_y    = 0;
+  shell->scroll_last_x     = 0;
+  shell->scroll_last_y     = 0;
+  shell->rotating          = FALSE;
+  shell->rotate_drag_angle = 0.0;
+  shell->scaling           = FALSE;
+  shell->layer_picking     = FALSE;
+
+  /* We may have ungrabbed the pointer when space was released while
+   * mouse was down, to be able to catch a GDK_BUTTON_RELEASE event.
+   */
+  if (shell->pointer_grabbed)
+    gimp_display_shell_pointer_ungrab (shell, event);
+}
+
+static void
+gimp_display_shell_handle_scrolling (GimpDisplayShell *shell,
+                                     GdkModifierType   state,
+                                     gint              x,
+                                     gint              y)
+{
+  g_return_if_fail (shell->scrolling);
+
+  if (shell->rotating)
+    {
+      gboolean constrain = (state & GDK_CONTROL_MASK) ? TRUE : FALSE;
+
+      gimp_display_shell_rotate_drag (shell,
+                                      shell->scroll_last_x,
+                                      shell->scroll_last_y,
+                                      x,
+                                      y,
+                                      constrain);
+    }
+  else if (shell->scaling)
+    {
+      gimp_display_shell_scale_drag (shell,
+                                     shell->scroll_start_x,
+                                     shell->scroll_start_y,
+                                     shell->scroll_last_x - x,
+                                     shell->scroll_last_y - y);
+    }
+  else if (shell->layer_picking)
+    {
+      /* Do nothing. We only pick the layer on click. */
+    }
+  else
+    {
+      gimp_display_shell_scroll (shell,
+                                 shell->scroll_last_x - x,
+                                 shell->scroll_last_y - y);
+    }
+
+  shell->scroll_last_x = x;
+  shell->scroll_last_y = y;
+}
+
+static void
+gimp_display_shell_space_pressed (GimpDisplayShell *shell,
+                                  const GdkEvent   *event)
+{
+  Gimp *gimp = gimp_display_get_gimp (shell->display);
+
+  if (shell->space_release_pending || shell->scrolling)
+    return;
+
+  if (! gimp_display_shell_keyboard_grab (shell, event))
+    return;
+
+  switch (shell->display->config->space_bar_action)
+    {
+    case GIMP_SPACE_BAR_ACTION_NONE:
+      break;
+
+    case GIMP_SPACE_BAR_ACTION_PAN:
+      {
+        GimpDeviceManager *manager;
+        GimpDeviceInfo    *current_device;
+        GimpCoords         coords;
+        GdkModifierType    state = 0;
+
+        manager = gimp_devices_get_manager (gimp);
+        current_device = gimp_device_manager_get_current_device (manager);
+
+        gimp_device_info_get_device_coords (current_device,
+                                            gtk_widget_get_window (shell->canvas),
+                                            &coords);
+        gdk_event_get_state (event, &state);
+
+        gimp_display_shell_start_scrolling (shell, event, state,
+                                            coords.x, coords.y);
+      }
+      break;
+
+    case GIMP_SPACE_BAR_ACTION_MOVE:
+      {
+        GimpTool *active_tool = tool_manager_get_active (gimp);
+
+        if (active_tool || ! GIMP_IS_MOVE_TOOL (active_tool))
+          {
+            GdkModifierType state;
+
+            shell->space_shaded_tool =
+              gimp_object_get_name (active_tool->tool_info);
+
+            gimp_context_set_tool (gimp_get_user_context (gimp),
+                                   gimp_get_tool_info (gimp, "gimp-move-tool"));
+
+            gdk_event_get_state (event, &state);
+
+            gimp_display_shell_update_focus (shell, TRUE,
+                                             NULL, state);
+          }
+      }
+      break;
+    }
+
+  shell->space_release_pending = TRUE;
+}
+
+static void
+gimp_display_shell_released (GimpDisplayShell *shell,
+                             const GdkEvent   *event,
+                             const GimpCoords *image_coords)
+{
+  Gimp *gimp = gimp_display_get_gimp (shell->display);
+
+  if (! shell->space_release_pending &&
+      ! shell->button1_release_pending)
+    return;
+
+  switch (shell->display->config->space_bar_action)
+    {
+    case GIMP_SPACE_BAR_ACTION_NONE:
+      break;
+
+    case GIMP_SPACE_BAR_ACTION_PAN:
+      gimp_display_shell_stop_scrolling (shell, event);
+      break;
+
+    case GIMP_SPACE_BAR_ACTION_MOVE:
+      if (shell->space_shaded_tool)
+        {
+          gimp_context_set_tool (gimp_get_user_context (gimp),
+                                 gimp_get_tool_info (gimp,
+                                                     shell->space_shaded_tool));
+          shell->space_shaded_tool = NULL;
+
+          if (gtk_widget_has_focus (shell->canvas))
+            {
+              GdkModifierType state;
+
+              gdk_event_get_state (event, &state);
+
+              gimp_display_shell_update_focus (shell, TRUE,
+                                               image_coords, state);
+            }
+          else
+            {
+              gimp_display_shell_update_focus (shell, FALSE,
+                                               image_coords, 0);
+            }
+        }
+      break;
+    }
+
+  gimp_display_shell_keyboard_ungrab (shell, event);
+
+  shell->space_release_pending   = FALSE;
+  shell->button1_release_pending = FALSE;
+}
+
+static gboolean
+gimp_display_shell_tab_pressed (GimpDisplayShell  *shell,
+                                const GdkEventKey *kevent)
+{
+  GimpImageWindow *window  = gimp_display_shell_get_window (shell);
+  GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+  GimpImage       *image   = gimp_display_get_image (shell->display);
+
+  if (kevent->state & GDK_CONTROL_MASK)
+    {
+      if (image && ! gimp_image_is_empty (image))
+        {
+          if (kevent->keyval == GDK_KEY_Tab ||
+              kevent->keyval == GDK_KEY_KP_Tab)
+            gimp_display_shell_layer_select_init (shell,
+                                                  1, kevent->time);
+          else
+            gimp_display_shell_layer_select_init (shell,
+                                                  -1, kevent->time);
+
+          return TRUE;
+        }
+    }
+  else if (kevent->state & GDK_MOD1_MASK)
+    {
+      if (image)
+        {
+          if (kevent->keyval == GDK_KEY_Tab ||
+              kevent->keyval == GDK_KEY_KP_Tab)
+            gimp_ui_manager_activate_action (manager, "windows",
+                                             "windows-show-display-next");
+          else
+            gimp_ui_manager_activate_action (manager, "windows",
+                                             "windows-show-display-previous");
+
+          return TRUE;
+        }
+    }
+  else
+    {
+      gimp_ui_manager_activate_action (manager, "windows",
+                                       "windows-hide-docks");
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_display_shell_update_focus (GimpDisplayShell *shell,
+                                 gboolean          focus_in,
+                                 const GimpCoords *image_coords,
+                                 GdkModifierType   state)
+{
+  Gimp *gimp = gimp_display_get_gimp (shell->display);
+
+  if (focus_in)
+    {
+      tool_manager_focus_display_active (gimp, shell->display);
+      tool_manager_modifier_state_active (gimp, state, shell->display);
+    }
+  else
+    {
+      tool_manager_focus_display_active (gimp, NULL);
+    }
+
+  if (image_coords)
+    tool_manager_oper_update_active (gimp,
+                                     image_coords, state,
+                                     shell->proximity,
+                                     shell->display);
+}
+
+static void
+gimp_display_shell_update_cursor (GimpDisplayShell *shell,
+                                  const GimpCoords *display_coords,
+                                  const GimpCoords *image_coords,
+                                  GdkModifierType   state,
+                                  gboolean          update_software_cursor)
+{
+  GimpDisplay *display = shell->display;
+  Gimp        *gimp    = gimp_display_get_gimp (display);
+  GimpImage   *image   = gimp_display_get_image (display);
+  GimpTool    *active_tool;
+
+  if (! shell->display->config->cursor_updating)
+    return;
+
+  active_tool = tool_manager_get_active (gimp);
+
+  if (active_tool)
+    {
+      if ((! gimp_image_is_empty (image) ||
+           gimp_tool_control_get_handle_empty_image (active_tool->control)) &&
+          ! (state & (GDK_BUTTON1_MASK |
+                      GDK_BUTTON2_MASK |
+                      GDK_BUTTON3_MASK)))
+        {
+          tool_manager_cursor_update_active (gimp,
+                                             image_coords, state,
+                                             display);
+        }
+      else if (gimp_image_is_empty (image) &&
+               ! gimp_tool_control_get_handle_empty_image (active_tool->control))
+        {
+          gimp_display_shell_set_cursor (shell,
+                                         GIMP_CURSOR_MOUSE,
+                                         gimp_tool_control_get_tool_cursor (active_tool->control),
+                                         GIMP_CURSOR_MODIFIER_BAD);
+        }
+    }
+  else
+    {
+      gimp_display_shell_set_cursor (shell,
+                                     GIMP_CURSOR_MOUSE,
+                                     GIMP_TOOL_CURSOR_NONE,
+                                     GIMP_CURSOR_MODIFIER_BAD);
+    }
+
+  if (update_software_cursor)
+    {
+      GimpCursorPrecision precision = GIMP_CURSOR_PRECISION_PIXEL_CENTER;
+
+      if (active_tool)
+        precision = gimp_tool_control_get_precision (active_tool->control);
+
+      gimp_display_shell_update_software_cursor (shell,
+                                                 precision,
+                                                 (gint) display_coords->x,
+                                                 (gint) display_coords->y,
+                                                 image_coords->x,
+                                                 image_coords->y);
+    }
+}
+
+static gboolean
+gimp_display_shell_initialize_tool (GimpDisplayShell *shell,
+                                    const GimpCoords *image_coords,
+                                    GdkModifierType   state)
+{
+  GimpDisplay *display     = shell->display;
+  GimpImage   *image       = gimp_display_get_image (display);
+  Gimp        *gimp        = gimp_display_get_gimp (display);
+  gboolean     initialized = FALSE;
+  GimpTool    *active_tool;
+
+  active_tool = tool_manager_get_active (gimp);
+
+  if (active_tool &&
+      (! gimp_image_is_empty (image) ||
+       gimp_tool_control_get_handle_empty_image (active_tool->control)))
+    {
+      /*  initialize the current tool if it has no drawable  */
+      if (! active_tool->drawable)
+        {
+          initialized = tool_manager_initialize_active (gimp, display);
+        }
+      else if ((active_tool->drawable !=
+                gimp_image_get_active_drawable (image)) &&
+               (! gimp_tool_control_get_preserve (active_tool->control) &&
+                (gimp_tool_control_get_dirty_mask (active_tool->control) &
+                 GIMP_DIRTY_ACTIVE_DRAWABLE)))
+        {
+          GimpProcedure *procedure = g_object_get_data (G_OBJECT (active_tool),
+                                                        "gimp-gegl-procedure");
+
+          if (image == gimp_item_get_image (GIMP_ITEM (active_tool->drawable)))
+            {
+              /*  When changing between drawables if the *same* image,
+               *  stop the tool using its dirty action, so it doesn't
+               *  get committed on tool change, in case its dirty action
+               *  is HALT. This is a pure "probably better this way"
+               *  decision because the user is likely changing their
+               *  mind or was simply on the wrong layer. See bug #776370.
+               *
+               *  See also issues #1180 and #1202 for cases where we
+               *  actually *don't* want to halt the tool here, but rather
+               *  commit it, hence the use of the tool's dirty action.
+               */
+              tool_manager_control_active (
+                gimp,
+                gimp_tool_control_get_dirty_action (active_tool->control),
+                active_tool->display);
+            }
+
+          if (procedure)
+            {
+              /*  We can't just recreate an operation tool, we must
+               *  make sure the right stuff gets set on it, so
+               *  re-activate the procedure that created it instead of
+               *  just calling gimp_context_tool_changed(). See
+               *  GimpGeglProcedure and bug #776370.
+               */
+              GimpImageWindow *window;
+              GimpUIManager   *manager;
+
+              window  = gimp_display_shell_get_window (shell);
+              manager = gimp_image_window_get_ui_manager (window);
+
+              gimp_filter_history_add (gimp, procedure);
+              gimp_ui_manager_activate_action (manager, "filters",
+                                               "filters-reshow");
+
+              /*  the procedure already initialized the tool; don't
+               *  reinitialize it below, since this can lead to errors.
+               */
+              initialized = TRUE;
+            }
+          else
+            {
+              /*  create a new one, deleting the current  */
+              gimp_context_tool_changed (gimp_get_user_context (gimp));
+            }
+
+          /*  make sure the newly created tool has the right state  */
+          gimp_display_shell_update_focus (shell, TRUE, image_coords, state);
+
+          if (! initialized)
+            initialized = tool_manager_initialize_active (gimp, display);
+        }
+      else
+        {
+          initialized = TRUE;
+        }
+    }
+
+  return initialized;
+}
+
+static void
+gimp_display_shell_get_event_coords (GimpDisplayShell *shell,
+                                     const GdkEvent   *event,
+                                     GimpCoords       *display_coords,
+                                     GdkModifierType  *state,
+                                     guint32          *time)
+{
+  Gimp              *gimp = gimp_display_get_gimp (shell->display);
+  GimpDeviceManager *manager;
+  GimpDeviceInfo    *current_device;
+
+  manager = gimp_devices_get_manager (gimp);
+  current_device = gimp_device_manager_get_current_device (manager);
+
+  gimp_device_info_get_event_coords (current_device,
+                                     gtk_widget_get_window (shell->canvas),
+                                     event,
+                                     display_coords);
+
+  gimp_device_info_get_event_state (current_device,
+                                    gtk_widget_get_window (shell->canvas),
+                                    event,
+                                    state);
+
+  *time = gdk_event_get_time (event);
+}
+
+static void
+gimp_display_shell_untransform_event_coords (GimpDisplayShell *shell,
+                                             const GimpCoords *display_coords,
+                                             GimpCoords       *image_coords,
+                                             gboolean         *update_software_cursor)
+{
+  Gimp     *gimp = gimp_display_get_gimp (shell->display);
+  GimpTool *active_tool;
+
+  /*  GimpCoords passed to tools are ALWAYS in image coordinates  */
+  gimp_display_shell_untransform_coords (shell,
+                                         display_coords,
+                                         image_coords);
+
+  active_tool = tool_manager_get_active (gimp);
+
+  if (active_tool && gimp_tool_control_get_snap_to (active_tool->control))
+    {
+      gint x, y, width, height;
+
+      gimp_tool_control_get_snap_offsets (active_tool->control,
+                                          &x, &y, &width, &height);
+
+      if (gimp_display_shell_snap_coords (shell,
+                                          image_coords,
+                                          x, y, width, height))
+        {
+          if (update_software_cursor)
+            *update_software_cursor = TRUE;
+        }
+    }
+}
+
+/* gimp_display_shell_compress_motion:
+ *
+ * This function walks the GDK event queue, seeking motion events at the
+ * front of the queue corresponding to the same widget as, and having
+ * similar characteristics to, `initial_event`.   If it finds any it will
+ * remove them from the queue, and return the most recent motion event.
+ * Otherwise it will return NULL.
+ *
+ * If `*next_event` is non-NULL upon return, the caller must dispatch and
+ * free this event after handling the motion event.
+ *
+ * The gimp_display_shell_compress_motion function source may be re-used under
+ * the XFree86-style license. <adam@gimp.org>
+ */
+static GdkEvent *
+gimp_display_shell_compress_motion (GdkEvent  *initial_event,
+                                    GdkEvent **next_event)
+{
+  GdkEvent  *last_motion = NULL;
+  GtkWidget *widget;
+
+  *next_event = NULL;
+
+  if (initial_event->any.type != GDK_MOTION_NOTIFY)
+    return NULL;
+
+  widget = gtk_get_event_widget (initial_event);
+
+  while (gdk_events_pending ())
+    {
+      GdkEvent *event = gdk_event_get ();
+
+      if (!event)
+        {
+          /* Do nothing */
+        }
+      else if ((gtk_get_event_widget (event) == widget)               &&
+               (event->any.type      == GDK_MOTION_NOTIFY)            &&
+               (event->any.window    == initial_event->any.window)    &&
+               (event->motion.state  == initial_event->motion.state)  &&
+               (event->motion.device == initial_event->motion.device))
+        {
+          /* Discard previous motion event */
+          if (last_motion)
+            gdk_event_free (last_motion);
+
+          last_motion = event;
+        }
+      else
+        {
+          /* Let the caller dispatch the event */
+          *next_event = event;
+
+          break;
+        }
+    }
+
+  return last_motion;
+}
diff --git a/app/display/gimpdisplayshell-tool-events.h b/app/display/gimpdisplayshell-tool-events.h
new file mode 100644
index 0000000..4458a92
--- /dev/null
+++ b/app/display/gimpdisplayshell-tool-events.h
@@ -0,0 +1,52 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_TOOL_EVENTS_H__
+#define __GIMP_DISPLAY_SHELL_TOOL_EVENTS_H__
+
+
+gboolean   gimp_display_shell_events                  (GtkWidget        *widget,
+                                                       GdkEvent         *event,
+                                                       GimpDisplayShell *shell);
+
+gboolean   gimp_display_shell_canvas_tool_events      (GtkWidget        *widget,
+                                                       GdkEvent         *event,
+                                                       GimpDisplayShell *shell);
+void       gimp_display_shell_canvas_grab_notify      (GtkWidget        *widget,
+                                                       gboolean          was_grabbed,
+                                                       GimpDisplayShell *shell);
+
+void       gimp_display_shell_buffer_stroke           (GimpMotionBuffer *buffer,
+                                                       const GimpCoords *coords,
+                                                       guint32           time,
+                                                       GdkModifierType   state,
+                                                       GimpDisplayShell *shell);
+void       gimp_display_shell_buffer_hover            (GimpMotionBuffer *buffer,
+                                                       const GimpCoords *coords,
+                                                       GdkModifierType   state,
+                                                       gboolean          proximity,
+                                                       GimpDisplayShell *shell);
+
+gboolean   gimp_display_shell_hruler_button_press     (GtkWidget        *widget,
+                                                       GdkEventButton   *bevent,
+                                                       GimpDisplayShell *shell);
+gboolean   gimp_display_shell_vruler_button_press     (GtkWidget        *widget,
+                                                       GdkEventButton   *bevent,
+                                                       GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_TOOL_EVENT_H__ */
diff --git a/app/display/gimpdisplayshell-transform.c b/app/display/gimpdisplayshell-transform.c
new file mode 100644
index 0000000..f9cd2e5
--- /dev/null
+++ b/app/display/gimpdisplayshell-transform.c
@@ -0,0 +1,1025 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <math.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpboundary.h"
+#include "core/gimpdrawable.h"
+#include "core/gimpimage.h"
+#include "core/gimp-utils.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-transform.h"
+
+
+/*  local function prototypes  */
+
+static void gimp_display_shell_transform_xy_f_noround (GimpDisplayShell *shell,
+                                                       gdouble           x,
+                                                       gdouble           y,
+                                                       gdouble          *nx,
+                                                       gdouble          *ny);
+
+/*  public functions  */
+
+/**
+ * gimp_display_shell_zoom_coords:
+ * @shell:          a #GimpDisplayShell
+ * @image_coords:   image coordinates
+ * @display_coords: returns the corresponding display coordinates
+ *
+ * Zooms from image coordinates to display coordinates, so that
+ * objects can be rendered at the correct points on the display.
+ **/
+void
+gimp_display_shell_zoom_coords (GimpDisplayShell *shell,
+                                const GimpCoords *image_coords,
+                                GimpCoords       *display_coords)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (image_coords != NULL);
+  g_return_if_fail (display_coords != NULL);
+
+  *display_coords = *image_coords;
+
+  display_coords->x = SCALEX (shell, image_coords->x);
+  display_coords->y = SCALEY (shell, image_coords->y);
+
+  display_coords->x -= shell->offset_x;
+  display_coords->y -= shell->offset_y;
+}
+
+/**
+ * gimp_display_shell_unzoom_coords:
+ * @shell:          a #GimpDisplayShell
+ * @display_coords: display coordinates
+ * @image_coords:   returns the corresponding image coordinates
+ *
+ * Zooms from display coordinates to image coordinates, so that
+ * points on the display can be mapped to points in the image.
+ **/
+void
+gimp_display_shell_unzoom_coords (GimpDisplayShell *shell,
+                                  const GimpCoords *display_coords,
+                                  GimpCoords       *image_coords)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (display_coords != NULL);
+  g_return_if_fail (image_coords != NULL);
+
+  *image_coords = *display_coords;
+
+  image_coords->x += shell->offset_x;
+  image_coords->y += shell->offset_y;
+
+  image_coords->x /= shell->scale_x;
+  image_coords->y /= shell->scale_y;
+}
+
+/**
+ * gimp_display_shell_zoom_xy:
+ * @shell:
+ * @x:
+ * @y:
+ * @nx:
+ * @ny:
+ *
+ * Zooms an image coordinate to a shell coordinate.
+ **/
+void
+gimp_display_shell_zoom_xy (GimpDisplayShell *shell,
+                            gdouble           x,
+                            gdouble           y,
+                            gint             *nx,
+                            gint             *ny)
+{
+  gint64 tx;
+  gint64 ty;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  tx = x * shell->scale_x;
+  ty = y * shell->scale_y;
+
+  tx -= shell->offset_x;
+  ty -= shell->offset_y;
+
+  /*  The projected coordinates might overflow a gint in the case of
+   *  big images at high zoom levels, so we clamp them here to avoid
+   *  problems.
+   */
+  *nx = CLAMP (tx, G_MININT, G_MAXINT);
+  *ny = CLAMP (ty, G_MININT, G_MAXINT);
+}
+
+/**
+ * gimp_display_shell_unzoom_xy:
+ * @shell:       a #GimpDisplayShell
+ * @x:           x coordinate in display coordinates
+ * @y:           y coordinate in display coordinates
+ * @nx:          returns x oordinate in image coordinates
+ * @ny:          returns y coordinate in image coordinates
+ * @round:       if %TRUE, round the results to the nearest integer;
+ *               if %FALSE, simply cast them to @gint.
+ *
+ * Zoom from display coordinates to image coordinates, so that
+ * points on the display can be mapped to the corresponding points
+ * in the image.
+ **/
+void
+gimp_display_shell_unzoom_xy (GimpDisplayShell *shell,
+                              gint              x,
+                              gint              y,
+                              gint             *nx,
+                              gint             *ny,
+                              gboolean          round)
+{
+  gint64 tx;
+  gint64 ty;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  if (round)
+    {
+      tx = SIGNED_ROUND (((gdouble) x + shell->offset_x) / shell->scale_x);
+      ty = SIGNED_ROUND (((gdouble) y + shell->offset_y) / shell->scale_y);
+    }
+  else
+    {
+      tx = ((gint64) x + shell->offset_x) / shell->scale_x;
+      ty = ((gint64) y + shell->offset_y) / shell->scale_y;
+    }
+
+  *nx = CLAMP (tx, G_MININT, G_MAXINT);
+  *ny = CLAMP (ty, G_MININT, G_MAXINT);
+}
+
+/**
+ * gimp_display_shell_zoom_xy_f:
+ * @shell: a #GimpDisplayShell
+ * @x:     image x coordinate of point
+ * @y:     image y coordinate of point
+ * @nx:    returned shell canvas x coordinate
+ * @ny:    returned shell canvas y coordinate
+ *
+ * Zooms from image coordinates to display shell canvas
+ * coordinates.
+ **/
+void
+gimp_display_shell_zoom_xy_f (GimpDisplayShell *shell,
+                              gdouble           x,
+                              gdouble           y,
+                              gdouble          *nx,
+                              gdouble          *ny)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  *nx = SCALEX (shell, x) - shell->offset_x;
+  *ny = SCALEY (shell, y) - shell->offset_y;
+}
+
+/**
+ * gimp_display_shell_unzoom_xy_f:
+ * @shell:       a #GimpDisplayShell
+ * @x:           x coordinate in display coordinates
+ * @y:           y coordinate in display coordinates
+ * @nx:          place to return x coordinate in image coordinates
+ * @ny:          place to return y coordinate in image coordinates
+ *
+ * This function is identical to gimp_display_shell_unzoom_xy(),
+ * except that the input and output coordinates are doubles rather than
+ * ints, and consequently there is no option related to rounding.
+ **/
+void
+gimp_display_shell_unzoom_xy_f (GimpDisplayShell *shell,
+                                gdouble           x,
+                                gdouble           y,
+                                gdouble          *nx,
+                                gdouble          *ny)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  *nx = (x + shell->offset_x) / shell->scale_x;
+  *ny = (y + shell->offset_y) / shell->scale_y;
+}
+
+/**
+ * gimp_display_shell_zoom_segments:
+ * @shell:       a #GimpDisplayShell
+ * @src_segs:    array of segments in image coordinates
+ * @dest_segs:   returns the corresponding segments in display coordinates
+ * @n_segs:      number of segments
+ *
+ * Zooms from image coordinates to display coordinates, so that
+ * objects can be rendered at the correct points on the display.
+ **/
+void
+gimp_display_shell_zoom_segments (GimpDisplayShell   *shell,
+                                  const GimpBoundSeg *src_segs,
+                                  GimpSegment        *dest_segs,
+                                  gint                n_segs,
+                                  gdouble             offset_x,
+                                  gdouble             offset_y)
+{
+  gint i;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  for (i = 0; i < n_segs ; i++)
+    {
+      gdouble x1, x2;
+      gdouble y1, y2;
+
+      x1 = src_segs[i].x1 + offset_x;
+      x2 = src_segs[i].x2 + offset_x;
+      y1 = src_segs[i].y1 + offset_y;
+      y2 = src_segs[i].y2 + offset_y;
+
+      dest_segs[i].x1 = SCALEX (shell, x1) - shell->offset_x;
+      dest_segs[i].x2 = SCALEX (shell, x2) - shell->offset_x;
+      dest_segs[i].y1 = SCALEY (shell, y1) - shell->offset_y;
+      dest_segs[i].y2 = SCALEY (shell, y2) - shell->offset_y;
+    }
+}
+
+/**
+ * gimp_display_shell_rotate_coords:
+ * @shell:          a #GimpDisplayShell
+ * @image_coords:   unrotated display coordinates
+ * @display_coords: returns the corresponding rotated display coordinates
+ *
+ * Rotates from unrotated display coordinates to rotated display
+ * coordinates, so that objects can be rendered at the correct points
+ * on the display.
+ **/
+void
+gimp_display_shell_rotate_coords (GimpDisplayShell *shell,
+                                  const GimpCoords *unrotated_coords,
+                                  GimpCoords       *rotated_coords)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (unrotated_coords != NULL);
+  g_return_if_fail (rotated_coords != NULL);
+
+  *rotated_coords = *unrotated_coords;
+
+  if (shell->rotate_transform)
+    cairo_matrix_transform_point (shell->rotate_transform,
+                                  &rotated_coords->x,
+                                  &rotated_coords->y);
+}
+
+/**
+ * gimp_display_shell_unrotate_coords:
+ * @shell:          a #GimpDisplayShell
+ * @display_coords: rotated display coordinates
+ * @image_coords:   returns the corresponding unrotated display coordinates
+ *
+ * Rotates from rotated display coordinates to unrotated display coordinates.
+ **/
+void
+gimp_display_shell_unrotate_coords (GimpDisplayShell *shell,
+                                    const GimpCoords *rotated_coords,
+                                    GimpCoords       *unrotated_coords)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (rotated_coords != NULL);
+  g_return_if_fail (unrotated_coords != NULL);
+
+  *unrotated_coords = *rotated_coords;
+
+  if (shell->rotate_untransform)
+    cairo_matrix_transform_point (shell->rotate_untransform,
+                                  &unrotated_coords->x,
+                                  &unrotated_coords->y);
+}
+
+/**
+ * gimp_display_shell_rotate_xy:
+ * @shell:
+ * @x:
+ * @y:
+ * @nx:
+ * @ny:
+ *
+ * Rotates an unrotated display coordinate to a rotated shell coordinate.
+ **/
+void
+gimp_display_shell_rotate_xy (GimpDisplayShell *shell,
+                              gdouble           x,
+                              gdouble           y,
+                              gint             *nx,
+                              gint             *ny)
+{
+  gint64 tx;
+  gint64 ty;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  if (shell->rotate_transform)
+    cairo_matrix_transform_point (shell->rotate_transform, &x, &y);
+
+  tx = x;
+  ty = y;
+
+  /*  The projected coordinates might overflow a gint in the case of
+   *  big images at high zoom levels, so we clamp them here to avoid
+   *  problems.
+   */
+  *nx = CLAMP (tx, G_MININT, G_MAXINT);
+  *ny = CLAMP (ty, G_MININT, G_MAXINT);
+}
+
+/**
+ * gimp_display_shell_unrotate_xy:
+ * @shell:       a #GimpDisplayShell
+ * @x:           x coordinate in rotated display coordinates
+ * @y:           y coordinate in rotated display coordinates
+ * @nx:          returns x oordinate in unrotated display coordinates
+ * @ny:          returns y coordinate in unrotated display coordinates
+ *
+ * Rotate from rotated display coordinates to unrotated display
+ * coordinates.
+ **/
+void
+gimp_display_shell_unrotate_xy (GimpDisplayShell *shell,
+                                gint              x,
+                                gint              y,
+                                gint             *nx,
+                                gint             *ny)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  if (shell->rotate_untransform)
+    {
+      gdouble fx = x;
+      gdouble fy = y;
+
+      cairo_matrix_transform_point (shell->rotate_untransform, &fx, &fy);
+
+      *nx = CLAMP (fx, G_MININT, G_MAXINT);
+      *ny = CLAMP (fy, G_MININT, G_MAXINT);
+    }
+  else
+    {
+      *nx = x;
+      *ny = y;
+    }
+}
+
+/**
+ * gimp_display_shell_rotate_xy_f:
+ * @shell: a #GimpDisplayShell
+ * @x:     image x coordinate of point
+ * @y:     image y coordinate of point
+ * @nx:    returned shell canvas x coordinate
+ * @ny:    returned shell canvas y coordinate
+ *
+ * Rotates from untransformed display coordinates to rotated display
+ * coordinates.
+ **/
+void
+gimp_display_shell_rotate_xy_f (GimpDisplayShell *shell,
+                                gdouble           x,
+                                gdouble           y,
+                                gdouble          *nx,
+                                gdouble          *ny)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  *nx = x;
+  *ny = y;
+
+  if (shell->rotate_transform)
+    cairo_matrix_transform_point (shell->rotate_transform, nx, ny);
+}
+
+/**
+ * gimp_display_shell_unrotate_xy_f:
+ * @shell:       a #GimpDisplayShell
+ * @x:           x coordinate in rotated display coordinates
+ * @y:           y coordinate in rotated display coordinates
+ * @nx:          place to return x coordinate in unrotated display coordinates
+ * @ny:          place to return y coordinate in unrotated display  coordinates
+ *
+ * This function is identical to gimp_display_shell_unrotate_xy(),
+ * except that the input and output coordinates are doubles rather
+ * than ints.
+ **/
+void
+gimp_display_shell_unrotate_xy_f (GimpDisplayShell *shell,
+                                  gdouble           x,
+                                  gdouble           y,
+                                  gdouble          *nx,
+                                  gdouble          *ny)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  *nx = x;
+  *ny = y;
+
+  if (shell->rotate_untransform)
+    cairo_matrix_transform_point (shell->rotate_untransform, nx, ny);
+}
+
+void
+gimp_display_shell_rotate_bounds (GimpDisplayShell *shell,
+                                  gdouble           x1,
+                                  gdouble           y1,
+                                  gdouble           x2,
+                                  gdouble           y2,
+                                  gdouble          *nx1,
+                                  gdouble          *ny1,
+                                  gdouble          *nx2,
+                                  gdouble          *ny2)
+{
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->rotate_transform)
+    {
+      gdouble tx1 = x1;
+      gdouble ty1 = y1;
+      gdouble tx2 = x1;
+      gdouble ty2 = y2;
+      gdouble tx3 = x2;
+      gdouble ty3 = y1;
+      gdouble tx4 = x2;
+      gdouble ty4 = y2;
+
+      cairo_matrix_transform_point (shell->rotate_transform, &tx1, &ty1);
+      cairo_matrix_transform_point (shell->rotate_transform, &tx2, &ty2);
+      cairo_matrix_transform_point (shell->rotate_transform, &tx3, &ty3);
+      cairo_matrix_transform_point (shell->rotate_transform, &tx4, &ty4);
+
+      *nx1 = MIN4 (tx1, tx2, tx3, tx4);
+      *ny1 = MIN4 (ty1, ty2, ty3, ty4);
+      *nx2 = MAX4 (tx1, tx2, tx3, tx4);
+      *ny2 = MAX4 (ty1, ty2, ty3, ty4);
+    }
+  else
+    {
+      *nx1 = x1;
+      *ny1 = y1;
+      *nx2 = x2;
+      *ny2 = y2;
+    }
+}
+
+void
+gimp_display_shell_unrotate_bounds (GimpDisplayShell *shell,
+                                    gdouble           x1,
+                                    gdouble           y1,
+                                    gdouble           x2,
+                                    gdouble           y2,
+                                    gdouble          *nx1,
+                                    gdouble          *ny1,
+                                    gdouble          *nx2,
+                                    gdouble          *ny2)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->rotate_untransform)
+    {
+      gdouble tx1 = x1;
+      gdouble ty1 = y1;
+      gdouble tx2 = x1;
+      gdouble ty2 = y2;
+      gdouble tx3 = x2;
+      gdouble ty3 = y1;
+      gdouble tx4 = x2;
+      gdouble ty4 = y2;
+
+      cairo_matrix_transform_point (shell->rotate_untransform, &tx1, &ty1);
+      cairo_matrix_transform_point (shell->rotate_untransform, &tx2, &ty2);
+      cairo_matrix_transform_point (shell->rotate_untransform, &tx3, &ty3);
+      cairo_matrix_transform_point (shell->rotate_untransform, &tx4, &ty4);
+
+      *nx1 = MIN4 (tx1, tx2, tx3, tx4);
+      *ny1 = MIN4 (ty1, ty2, ty3, ty4);
+      *nx2 = MAX4 (tx1, tx2, tx3, tx4);
+      *ny2 = MAX4 (ty1, ty2, ty3, ty4);
+    }
+  else
+    {
+      *nx1 = x1;
+      *ny1 = y1;
+      *nx2 = x2;
+      *ny2 = y2;
+    }
+}
+
+/**
+ * gimp_display_shell_transform_coords:
+ * @shell:          a #GimpDisplayShell
+ * @image_coords:   image coordinates
+ * @display_coords: returns the corresponding display coordinates
+ *
+ * Transforms from image coordinates to display coordinates, so that
+ * objects can be rendered at the correct points on the display.
+ **/
+void
+gimp_display_shell_transform_coords (GimpDisplayShell *shell,
+                                     const GimpCoords *image_coords,
+                                     GimpCoords       *display_coords)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (image_coords != NULL);
+  g_return_if_fail (display_coords != NULL);
+
+  *display_coords = *image_coords;
+
+  display_coords->x = SCALEX (shell, image_coords->x);
+  display_coords->y = SCALEY (shell, image_coords->y);
+
+  display_coords->x -= shell->offset_x;
+  display_coords->y -= shell->offset_y;
+
+  if (shell->rotate_transform)
+    cairo_matrix_transform_point (shell->rotate_transform,
+                                  &display_coords->x,
+                                  &display_coords->y);
+}
+
+/**
+ * gimp_display_shell_untransform_coords:
+ * @shell:          a #GimpDisplayShell
+ * @display_coords: display coordinates
+ * @image_coords:   returns the corresponding image coordinates
+ *
+ * Transforms from display coordinates to image coordinates, so that
+ * points on the display can be mapped to points in the image.
+ **/
+void
+gimp_display_shell_untransform_coords (GimpDisplayShell *shell,
+                                       const GimpCoords *display_coords,
+                                       GimpCoords       *image_coords)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (display_coords != NULL);
+  g_return_if_fail (image_coords != NULL);
+
+  *image_coords = *display_coords;
+
+  if (shell->rotate_untransform)
+    cairo_matrix_transform_point (shell->rotate_untransform,
+                                  &image_coords->x,
+                                  &image_coords->y);
+
+  image_coords->x += shell->offset_x;
+  image_coords->y += shell->offset_y;
+
+  image_coords->x /= shell->scale_x;
+  image_coords->y /= shell->scale_y;
+
+  image_coords->xscale  = shell->scale_x;
+  image_coords->yscale  = shell->scale_y;
+  image_coords->angle   = shell->rotate_angle / 360.0;
+  image_coords->reflect = shell->flip_horizontally ^ shell->flip_vertically;
+
+  if (shell->flip_vertically)
+    image_coords->angle += 0.5;
+}
+
+/**
+ * gimp_display_shell_transform_xy:
+ * @shell:
+ * @x:
+ * @y:
+ * @nx:
+ * @ny:
+ *
+ * Transforms an image coordinate to a shell coordinate.
+ **/
+void
+gimp_display_shell_transform_xy (GimpDisplayShell *shell,
+                                 gdouble           x,
+                                 gdouble           y,
+                                 gint             *nx,
+                                 gint             *ny)
+{
+  gint64 tx;
+  gint64 ty;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  tx = x * shell->scale_x;
+  ty = y * shell->scale_y;
+
+  tx -= shell->offset_x;
+  ty -= shell->offset_y;
+
+  if (shell->rotate_transform)
+    {
+      gdouble fx = tx;
+      gdouble fy = ty;
+
+      cairo_matrix_transform_point (shell->rotate_transform, &fx, &fy);
+
+      tx = fx;
+      ty = fy;
+    }
+
+  /*  The projected coordinates might overflow a gint in the case of
+   *  big images at high zoom levels, so we clamp them here to avoid
+   *  problems.
+   */
+  *nx = CLAMP (tx, G_MININT, G_MAXINT);
+  *ny = CLAMP (ty, G_MININT, G_MAXINT);
+}
+
+/**
+ * gimp_display_shell_untransform_xy:
+ * @shell:       a #GimpDisplayShell
+ * @x:           x coordinate in display coordinates
+ * @y:           y coordinate in display coordinates
+ * @nx:          returns x oordinate in image coordinates
+ * @ny:          returns y coordinate in image coordinates
+ * @round:       if %TRUE, round the results to the nearest integer;
+ *               if %FALSE, simply cast them to @gint.
+ *
+ * Transform from display coordinates to image coordinates, so that
+ * points on the display can be mapped to the corresponding points
+ * in the image.
+ **/
+void
+gimp_display_shell_untransform_xy (GimpDisplayShell *shell,
+                                   gint              x,
+                                   gint              y,
+                                   gint             *nx,
+                                   gint             *ny,
+                                   gboolean          round)
+{
+  gint64 tx;
+  gint64 ty;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  if (shell->rotate_untransform)
+    {
+      gdouble fx = x;
+      gdouble fy = y;
+
+      cairo_matrix_transform_point (shell->rotate_untransform, &fx, &fy);
+
+      x = fx;
+      y = fy;
+    }
+
+  if (round)
+    {
+      tx = SIGNED_ROUND (((gdouble) x + shell->offset_x) / shell->scale_x);
+      ty = SIGNED_ROUND (((gdouble) y + shell->offset_y) / shell->scale_y);
+    }
+  else
+    {
+      tx = ((gint64) x + shell->offset_x) / shell->scale_x;
+      ty = ((gint64) y + shell->offset_y) / shell->scale_y;
+    }
+
+  *nx = CLAMP (tx, G_MININT, G_MAXINT);
+  *ny = CLAMP (ty, G_MININT, G_MAXINT);
+}
+
+/**
+ * gimp_display_shell_transform_xy_f:
+ * @shell: a #GimpDisplayShell
+ * @x:     image x coordinate of point
+ * @y:     image y coordinate of point
+ * @nx:    returned shell canvas x coordinate
+ * @ny:    returned shell canvas y coordinate
+ *
+ * Transforms from image coordinates to display shell canvas
+ * coordinates.
+ **/
+void
+gimp_display_shell_transform_xy_f (GimpDisplayShell *shell,
+                                   gdouble           x,
+                                   gdouble           y,
+                                   gdouble          *nx,
+                                   gdouble          *ny)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  *nx = SCALEX (shell, x) - shell->offset_x;
+  *ny = SCALEY (shell, y) - shell->offset_y;
+
+  if (shell->rotate_transform)
+    cairo_matrix_transform_point (shell->rotate_transform, nx, ny);
+}
+
+/**
+ * gimp_display_shell_untransform_xy_f:
+ * @shell:       a #GimpDisplayShell
+ * @x:           x coordinate in display coordinates
+ * @y:           y coordinate in display coordinates
+ * @nx:          place to return x coordinate in image coordinates
+ * @ny:          place to return y coordinate in image coordinates
+ *
+ * This function is identical to gimp_display_shell_untransform_xy(),
+ * except that the input and output coordinates are doubles rather than
+ * ints, and consequently there is no option related to rounding.
+ **/
+void
+gimp_display_shell_untransform_xy_f (GimpDisplayShell *shell,
+                                     gdouble           x,
+                                     gdouble           y,
+                                     gdouble          *nx,
+                                     gdouble          *ny)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx != NULL);
+  g_return_if_fail (ny != NULL);
+
+  if (shell->rotate_untransform)
+    cairo_matrix_transform_point (shell->rotate_untransform, &x, &y);
+
+  *nx = (x + shell->offset_x) / shell->scale_x;
+  *ny = (y + shell->offset_y) / shell->scale_y;
+}
+
+void
+gimp_display_shell_transform_bounds (GimpDisplayShell *shell,
+                                     gdouble           x1,
+                                     gdouble           y1,
+                                     gdouble           x2,
+                                     gdouble           y2,
+                                     gdouble          *nx1,
+                                     gdouble          *ny1,
+                                     gdouble          *nx2,
+                                     gdouble          *ny2)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx1 != NULL);
+  g_return_if_fail (ny1 != NULL);
+  g_return_if_fail (nx2 != NULL);
+  g_return_if_fail (ny2 != NULL);
+
+  if (shell->rotate_transform)
+    {
+      gdouble tx1, ty1;
+      gdouble tx2, ty2;
+      gdouble tx3, ty3;
+      gdouble tx4, ty4;
+
+      gimp_display_shell_transform_xy_f_noround (shell, x1, y1, &tx1, &ty1);
+      gimp_display_shell_transform_xy_f_noround (shell, x1, y2, &tx2, &ty2);
+      gimp_display_shell_transform_xy_f_noround (shell, x2, y1, &tx3, &ty3);
+      gimp_display_shell_transform_xy_f_noround (shell, x2, y2, &tx4, &ty4);
+
+      *nx1 = MIN4 (tx1, tx2, tx3, tx4);
+      *ny1 = MIN4 (ty1, ty2, ty3, ty4);
+      *nx2 = MAX4 (tx1, tx2, tx3, tx4);
+      *ny2 = MAX4 (ty1, ty2, ty3, ty4);
+    }
+  else
+    {
+      gimp_display_shell_transform_xy_f_noround (shell, x1, y1, nx1, ny1);
+      gimp_display_shell_transform_xy_f_noround (shell, x2, y2, nx2, ny2);
+    }
+}
+
+void
+gimp_display_shell_untransform_bounds (GimpDisplayShell *shell,
+                                       gdouble           x1,
+                                       gdouble           y1,
+                                       gdouble           x2,
+                                       gdouble           y2,
+                                       gdouble          *nx1,
+                                       gdouble          *ny1,
+                                       gdouble          *nx2,
+                                       gdouble          *ny2)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (nx1 != NULL);
+  g_return_if_fail (ny1 != NULL);
+  g_return_if_fail (nx2 != NULL);
+  g_return_if_fail (ny2 != NULL);
+
+  if (shell->rotate_untransform)
+    {
+      gdouble tx1, ty1;
+      gdouble tx2, ty2;
+      gdouble tx3, ty3;
+      gdouble tx4, ty4;
+
+      gimp_display_shell_untransform_xy_f (shell, x1, y1, &tx1, &ty1);
+      gimp_display_shell_untransform_xy_f (shell, x1, y2, &tx2, &ty2);
+      gimp_display_shell_untransform_xy_f (shell, x2, y1, &tx3, &ty3);
+      gimp_display_shell_untransform_xy_f (shell, x2, y2, &tx4, &ty4);
+
+      *nx1 = MIN4 (tx1, tx2, tx3, tx4);
+      *ny1 = MIN4 (ty1, ty2, ty3, ty4);
+      *nx2 = MAX4 (tx1, tx2, tx3, tx4);
+      *ny2 = MAX4 (ty1, ty2, ty3, ty4);
+    }
+  else
+    {
+      gimp_display_shell_untransform_xy_f (shell, x1, y1, nx1, ny1);
+      gimp_display_shell_untransform_xy_f (shell, x2, y2, nx2, ny2);
+    }
+}
+
+/* transforms a bounding box from image-space, uniformly scaled by a factor of
+ * 'scale', to display-space.  this is equivalent to, but more accurate than,
+ * dividing the input by 'scale', and using
+ * gimp_display_shell_transform_bounds(), in particular, in that if 'scale'
+ * equals 'shell->scale_x' or 'shell->scale_y', there is no loss in accuracy
+ * in the corresponding dimension due to scaling (although there might be loss
+ * of accuracy due to rotation or translation.)
+ */
+void
+gimp_display_shell_transform_bounds_with_scale (GimpDisplayShell *shell,
+                                                gdouble           scale,
+                                                gdouble           x1,
+                                                gdouble           y1,
+                                                gdouble           x2,
+                                                gdouble           y2,
+                                                gdouble          *nx1,
+                                                gdouble          *ny1,
+                                                gdouble          *nx2,
+                                                gdouble          *ny2)
+{
+  gdouble factor_x;
+  gdouble factor_y;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (scale > 0.0);
+  g_return_if_fail (nx1 != NULL);
+  g_return_if_fail (ny1 != NULL);
+  g_return_if_fail (nx2 != NULL);
+  g_return_if_fail (ny2 != NULL);
+
+  factor_x = shell->scale_x / scale;
+  factor_y = shell->scale_y / scale;
+
+  x1 = x1 * factor_x - shell->offset_x;
+  y1 = y1 * factor_y - shell->offset_y;
+  x2 = x2 * factor_x - shell->offset_x;
+  y2 = y2 * factor_y - shell->offset_y;
+
+  gimp_display_shell_rotate_bounds (shell,
+                                    x1,  y1,  x2,  y2,
+                                    nx1, ny1, nx2, ny2);
+}
+
+/* transforms a bounding box from display-space to image-space, uniformly
+ * scaled by a factor of 'scale'.  this is equivalent to, but more accurate
+ * than, using gimp_display_shell_untransform_bounds(), and multiplying the
+ * output by 'scale', in particular, in that if 'scale' equals 'shell->scale_x'
+ * or 'shell->scale_y', there is no loss in accuracy in the corresponding
+ * dimension due to scaling (although there might be loss of accuracy due to
+ * rotation or translation.)
+ */
+void
+gimp_display_shell_untransform_bounds_with_scale (GimpDisplayShell *shell,
+                                                  gdouble           scale,
+                                                  gdouble           x1,
+                                                  gdouble           y1,
+                                                  gdouble           x2,
+                                                  gdouble           y2,
+                                                  gdouble          *nx1,
+                                                  gdouble          *ny1,
+                                                  gdouble          *nx2,
+                                                  gdouble          *ny2)
+{
+  gdouble factor_x;
+  gdouble factor_y;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (scale > 0.0);
+  g_return_if_fail (nx1 != NULL);
+  g_return_if_fail (ny1 != NULL);
+  g_return_if_fail (nx2 != NULL);
+  g_return_if_fail (ny2 != NULL);
+
+  factor_x = scale / shell->scale_x;
+  factor_y = scale / shell->scale_y;
+
+  gimp_display_shell_unrotate_bounds (shell,
+                                      x1,  y1,  x2,  y2,
+                                      nx1, ny1, nx2, ny2);
+
+  *nx1 = (*nx1 + shell->offset_x) * factor_x;
+  *ny1 = (*ny1 + shell->offset_y) * factor_y;
+  *nx2 = (*nx2 + shell->offset_x) * factor_x;
+  *ny2 = (*ny2 + shell->offset_y) * factor_y;
+}
+
+/**
+ * gimp_display_shell_untransform_viewport:
+ * @shell:  a #GimpDisplayShell
+ * @clip:   whether to clip the result to the image bounds
+ * @x:      returns image x coordinate of display upper left corner
+ * @y:      returns image y coordinate of display upper left corner
+ * @width:  returns width of display measured in image coordinates
+ * @height: returns height of display measured in image coordinates
+ *
+ * This function calculates the part of the image, in image coordinates,
+ * that corresponds to the display viewport.
+ **/
+void
+gimp_display_shell_untransform_viewport (GimpDisplayShell *shell,
+                                         gboolean          clip,
+                                         gint             *x,
+                                         gint             *y,
+                                         gint             *width,
+                                         gint             *height)
+{
+  gdouble x1, y1, x2, y2;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_untransform_bounds (shell,
+                                         0, 0,
+                                         shell->disp_width, shell->disp_height,
+                                         &x1, &y1,
+                                         &x2, &y2);
+
+  x1 = floor (x1);
+  y1 = floor (y1);
+  x2 = ceil (x2);
+  y2 = ceil (y2);
+
+  if (clip)
+    {
+      GimpImage *image = gimp_display_get_image (shell->display);
+
+      x1 = MAX (x1, 0);
+      y1 = MAX (y1, 0);
+      x2 = MIN (x2, gimp_image_get_width  (image));
+      y2 = MIN (y2, gimp_image_get_height (image));
+    }
+
+  if (x)      *x      = x1;
+  if (y)      *y      = y1;
+  if (width)  *width  = x2 - x1;
+  if (height) *height = y2 - y1;
+}
+
+
+/*  private functions  */
+
+/* Same as gimp_display_shell_transform_xy_f(), but doesn't do any rounding
+ * for the transformed coordinates.
+ */
+static void
+gimp_display_shell_transform_xy_f_noround (GimpDisplayShell *shell,
+                                           gdouble           x,
+                                           gdouble           y,
+                                           gdouble          *nx,
+                                           gdouble          *ny)
+{
+  *nx = shell->scale_x * x - shell->offset_x;
+  *ny = shell->scale_y * y - shell->offset_y;
+
+  if (shell->rotate_transform)
+    cairo_matrix_transform_point (shell->rotate_transform, nx, ny);
+}
diff --git a/app/display/gimpdisplayshell-transform.h b/app/display/gimpdisplayshell-transform.h
new file mode 100644
index 0000000..1877b13
--- /dev/null
+++ b/app/display/gimpdisplayshell-transform.h
@@ -0,0 +1,200 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_TRANSFORM_H__
+#define __GIMP_DISPLAY_SHELL_TRANSFORM_H__
+
+
+/*  zoom: functions to transform from image space to unrotated display
+ *  space and back, taking into account scroll offset and scale
+ */
+
+void  gimp_display_shell_zoom_coords                   (GimpDisplayShell   *shell,
+                                                        const GimpCoords   *image_coords,
+                                                        GimpCoords         *display_coords);
+void  gimp_display_shell_unzoom_coords                 (GimpDisplayShell   *shell,
+                                                        const GimpCoords   *display_coords,
+                                                        GimpCoords         *image_coords);
+
+void  gimp_display_shell_zoom_xy                       (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gint               *nx,
+                                                        gint               *ny);
+void  gimp_display_shell_unzoom_xy                     (GimpDisplayShell   *shell,
+                                                        gint                x,
+                                                        gint                y,
+                                                        gint               *nx,
+                                                        gint               *ny,
+                                                        gboolean            round);
+
+void  gimp_display_shell_zoom_xy_f                     (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gdouble            *nx,
+                                                        gdouble            *ny);
+void  gimp_display_shell_unzoom_xy_f                   (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gdouble            *nx,
+                                                        gdouble            *ny);
+
+void  gimp_display_shell_zoom_segments                 (GimpDisplayShell   *shell,
+                                                        const GimpBoundSeg *src_segs,
+                                                        GimpSegment        *dest_segs,
+                                                        gint                n_segs,
+                                                        gdouble             offset_x,
+                                                        gdouble             offset_y);
+
+
+/*  rotate: functions to transform from unrotated and unflipped but
+ *  zoomed display space to rotated and filpped display space and back
+ */
+
+void  gimp_display_shell_rotate_coords                 (GimpDisplayShell   *shell,
+                                                        const GimpCoords   *image_coords,
+                                                        GimpCoords         *display_coords);
+void  gimp_display_shell_unrotate_coords               (GimpDisplayShell   *shell,
+                                                        const GimpCoords   *display_coords,
+                                                        GimpCoords         *image_coords);
+
+void  gimp_display_shell_rotate_xy                     (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gint               *nx,
+                                                        gint               *ny);
+void  gimp_display_shell_unrotate_xy                   (GimpDisplayShell   *shell,
+                                                        gint                x,
+                                                        gint                y,
+                                                        gint               *nx,
+                                                        gint               *ny);
+
+void  gimp_display_shell_rotate_xy_f                   (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gdouble            *nx,
+                                                        gdouble            *ny);
+void  gimp_display_shell_unrotate_xy_f                 (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gdouble            *nx,
+                                                        gdouble            *ny);
+
+void  gimp_display_shell_rotate_bounds                 (GimpDisplayShell   *shell,
+                                                        gdouble             x1,
+                                                        gdouble             y1,
+                                                        gdouble             x2,
+                                                        gdouble             y2,
+                                                        gdouble            *nx1,
+                                                        gdouble            *ny1,
+                                                        gdouble            *nx2,
+                                                        gdouble            *ny2);
+void  gimp_display_shell_unrotate_bounds               (GimpDisplayShell   *shell,
+                                                        gdouble             x1,
+                                                        gdouble             y1,
+                                                        gdouble             x2,
+                                                        gdouble             y2,
+                                                        gdouble            *nx1,
+                                                        gdouble            *ny1,
+                                                        gdouble            *nx2,
+                                                        gdouble            *ny2);
+
+
+/*  transform: functions to transform from image space to rotated
+ *  display space and back, taking into account scroll offset, scale,
+ *  rotation and flipping
+ */
+
+void  gimp_display_shell_transform_coords              (GimpDisplayShell   *shell,
+                                                        const GimpCoords   *image_coords,
+                                                        GimpCoords         *display_coords);
+void  gimp_display_shell_untransform_coords            (GimpDisplayShell   *shell,
+                                                        const GimpCoords   *display_coords,
+                                                        GimpCoords         *image_coords);
+
+void  gimp_display_shell_transform_xy                  (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gint               *nx,
+                                                        gint               *ny);
+void  gimp_display_shell_untransform_xy                (GimpDisplayShell   *shell,
+                                                        gint                x,
+                                                        gint                y,
+                                                        gint               *nx,
+                                                        gint               *ny,
+                                                        gboolean            round);
+
+void  gimp_display_shell_transform_xy_f                (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gdouble            *nx,
+                                                        gdouble            *ny);
+void  gimp_display_shell_untransform_xy_f              (GimpDisplayShell   *shell,
+                                                        gdouble             x,
+                                                        gdouble             y,
+                                                        gdouble            *nx,
+                                                        gdouble            *ny);
+
+void  gimp_display_shell_transform_bounds              (GimpDisplayShell   *shell,
+                                                        gdouble             x1,
+                                                        gdouble             y1,
+                                                        gdouble             x2,
+                                                        gdouble             y2,
+                                                        gdouble            *nx1,
+                                                        gdouble            *ny1,
+                                                        gdouble            *nx2,
+                                                        gdouble            *ny2);
+void  gimp_display_shell_untransform_bounds            (GimpDisplayShell   *shell,
+                                                        gdouble             x1,
+                                                        gdouble             y1,
+                                                        gdouble             x2,
+                                                        gdouble             y2,
+                                                        gdouble            *nx1,
+                                                        gdouble            *ny1,
+                                                        gdouble            *nx2,
+                                                        gdouble            *ny2);
+
+void  gimp_display_shell_transform_bounds_with_scale   (GimpDisplayShell   *shell,
+                                                        gdouble             scale,
+                                                        gdouble             x1,
+                                                        gdouble             y1,
+                                                        gdouble             x2,
+                                                        gdouble             y2,
+                                                        gdouble            *nx1,
+                                                        gdouble            *ny1,
+                                                        gdouble            *nx2,
+                                                        gdouble            *ny2);
+void  gimp_display_shell_untransform_bounds_with_scale (GimpDisplayShell   *shell,
+                                                        gdouble             scale,
+                                                        gdouble             x1,
+                                                        gdouble             y1,
+                                                        gdouble             x2,
+                                                        gdouble             y2,
+                                                        gdouble            *nx1,
+                                                        gdouble            *ny1,
+                                                        gdouble            *nx2,
+                                                        gdouble            *ny2);
+
+void  gimp_display_shell_untransform_viewport          (GimpDisplayShell   *shell,
+                                                        gboolean            clip,
+                                                        gint               *x,
+                                                        gint               *y,
+                                                        gint               *width,
+                                                        gint               *height);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_TRANSFORM_H__ */
diff --git a/app/display/gimpdisplayshell-utils.c b/app/display/gimpdisplayshell-utils.c
new file mode 100644
index 0000000..8e85e71
--- /dev/null
+++ b/app/display/gimpdisplayshell-utils.c
@@ -0,0 +1,220 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-utils.h"
+#include "core/gimpimage.h"
+#include "core/gimpunit.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-utils.h"
+
+#include "gimp-intl.h"
+
+void
+gimp_display_shell_get_constrained_line_params (GimpDisplayShell *shell,
+                                                gdouble          *offset_angle,
+                                                gdouble          *xres,
+                                                gdouble          *yres)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (offset_angle != NULL);
+  g_return_if_fail (xres != NULL);
+  g_return_if_fail (yres != NULL);
+
+  if (shell->flip_horizontally ^ shell->flip_vertically)
+    *offset_angle = +shell->rotate_angle;
+  else
+    *offset_angle = -shell->rotate_angle;
+
+  *xres = 1.0;
+  *yres = 1.0;
+
+  if (! shell->dot_for_dot)
+    {
+      GimpImage *image = gimp_display_get_image (shell->display);
+
+      if (image)
+        gimp_image_get_resolution (image, xres, yres);
+    }
+}
+
+void
+gimp_display_shell_constrain_line (GimpDisplayShell *shell,
+                                   gdouble           start_x,
+                                   gdouble           start_y,
+                                   gdouble          *end_x,
+                                   gdouble          *end_y,
+                                   gint              n_snap_lines)
+{
+  gdouble offset_angle;
+  gdouble xres, yres;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (end_x != NULL);
+  g_return_if_fail (end_y != NULL);
+
+  gimp_display_shell_get_constrained_line_params (shell,
+                                                  &offset_angle,
+                                                  &xres, &yres);
+
+  gimp_constrain_line (start_x, start_y,
+                       end_x,   end_y,
+                       n_snap_lines,
+                       offset_angle,
+                       xres, yres);
+}
+
+gdouble
+gimp_display_shell_constrain_angle (GimpDisplayShell *shell,
+                                    gdouble           angle,
+                                    gint              n_snap_lines)
+{
+  gdouble x, y;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), 0.0);
+
+  x = cos (angle);
+  y = sin (angle);
+
+  gimp_display_shell_constrain_line (shell,
+                                     0.0, 0.0,
+                                     &x,  &y,
+                                     n_snap_lines);
+
+  return atan2 (y, x);
+}
+
+/**
+ * gimp_display_shell_get_line_status:
+ * @status:    initial status text.
+ * @separator: separator text between the line information and @status.
+ * @shell:     #GimpDisplayShell this status text will be displayed for.
+ * @x1:        abscissa of first point.
+ * @y1:        ordinate of first point.
+ * @x2:        abscissa of second point.
+ * @y2:        ordinate of second point.
+ *
+ * Utility function to prepend the status message with a distance and
+ * angle value. Obviously this is only to be used for tools when it
+ * makes sense, and in particular when there is a concept of line. For
+ * instance when shift-clicking a painting tool or in the blend tool,
+ * etc.
+ * This utility prevents code duplication but also ensures a common
+ * display for every tool where such a status is needed. It will take
+ * into account the shell unit settings and will use the ideal digit
+ * precision according to current image resolution.
+ *
+ * Return value: a newly allocated string containing the enhanced status.
+ **/
+gchar *
+gimp_display_shell_get_line_status (GimpDisplayShell *shell,
+                                    const gchar      *status,
+                                    const gchar      *separator,
+                                    gdouble           x1,
+                                    gdouble           y1,
+                                    gdouble           x2,
+                                    gdouble           y2)
+{
+  GimpImage *image;
+  gchar     *enhanced_status;
+  gdouble    xres;
+  gdouble    yres;
+  gdouble    dx, dy, pixel_dist;
+  gdouble    angle;
+
+  image = gimp_display_get_image (shell->display);
+  if (! image)
+    {
+      /* This makes no sense to add line information when no image is
+       * attached to the display. */
+      return g_strdup (status);
+    }
+
+  if (shell->unit == GIMP_UNIT_PIXEL)
+    xres = yres = 1.0;
+  else
+    gimp_image_get_resolution (image, &xres, &yres);
+
+  dx = x2 - x1;
+  dy = y2 - y1;
+  pixel_dist = sqrt (SQR (dx) + SQR (dy));
+
+  if (dx)
+    {
+      angle = gimp_rad_to_deg (atan ((dy/yres) / (dx/xres)));
+      if (dx > 0)
+        {
+          if (dy > 0)
+            angle = 360.0 - angle;
+          else if (dy < 0)
+            angle = -angle;
+        }
+      else
+        {
+          angle = 180.0 - angle;
+        }
+    }
+  else if (dy)
+    {
+      angle = dy > 0 ? 270.0 : 90.0;
+    }
+  else
+    {
+      angle = 0.0;
+    }
+
+  if (shell->unit == GIMP_UNIT_PIXEL)
+    {
+      enhanced_status = g_strdup_printf ("%.1f %s, %.2f\302\260%s%s",
+                                         pixel_dist, _("pixels"), angle,
+                                         separator, status);
+    }
+  else
+    {
+      gdouble inch_dist;
+      gdouble unit_dist;
+      gint    digits = 0;
+
+      /* The distance in unit. */
+      inch_dist = sqrt (SQR (dx / xres) + SQR (dy / yres));
+      unit_dist = gimp_unit_get_factor (shell->unit) * inch_dist;
+
+      /* The ideal digit precision for unit in current resolution. */
+      if (inch_dist)
+        digits = gimp_unit_get_scaled_digits (shell->unit,
+                                              pixel_dist / inch_dist);
+
+      enhanced_status = g_strdup_printf ("%.*f %s, %.2f\302\260%s%s",
+                                         digits, unit_dist,
+                                         gimp_unit_get_symbol (shell->unit),
+                                         angle, separator, status);
+
+    }
+
+  return enhanced_status;
+}
diff --git a/app/display/gimpdisplayshell-utils.h b/app/display/gimpdisplayshell-utils.h
new file mode 100644
index 0000000..3eb52e3
--- /dev/null
+++ b/app/display/gimpdisplayshell-utils.h
@@ -0,0 +1,45 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_UTILS_H__
+#define __GIMP_DISPLAY_SHELL_UTILS_H__
+
+
+void      gimp_display_shell_get_constrained_line_params (GimpDisplayShell *shell,
+                                                          gdouble          *offset_angle,
+                                                          gdouble          *xres,
+                                                          gdouble          *yres);
+void      gimp_display_shell_constrain_line              (GimpDisplayShell *shell,
+                                                          gdouble           start_x,
+                                                          gdouble           start_y,
+                                                          gdouble          *end_x,
+                                                          gdouble          *end_y,
+                                                          gint              n_snap_lines);
+gdouble   gimp_display_shell_constrain_angle             (GimpDisplayShell *shell,
+                                                          gdouble           angle,
+                                                          gint              n_snap_lines);
+
+gchar   * gimp_display_shell_get_line_status             (GimpDisplayShell *shell,
+                                                          const gchar      *status,
+                                                          const gchar      *separator,
+                                                          gdouble           x1,
+                                                          gdouble           y1,
+                                                          gdouble           x2,
+                                                          gdouble           y2);
+
+
+#endif  /*  __GIMP_DISPLAY_SHELL_UTILS_H__  */
diff --git a/app/display/gimpdisplayshell.c b/app/display/gimpdisplayshell.c
new file mode 100644
index 0000000..6db94e4
--- /dev/null
+++ b/app/display/gimpdisplayshell.c
@@ -0,0 +1,2140 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+#include <stdlib.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpconfig/gimpconfig.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+#include "tools/tools-types.h"
+
+#include "config/gimpcoreconfig.h"
+#include "config/gimpdisplayconfig.h"
+#include "config/gimpdisplayoptions.h"
+
+#include "core/gimp.h"
+#include "core/gimp-utils.h"
+#include "core/gimpchannel.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimpimage-grid.h"
+#include "core/gimpimage-guides.h"
+#include "core/gimpimage-snap.h"
+#include "core/gimppickable.h"
+#include "core/gimpprojectable.h"
+#include "core/gimpprojection.h"
+#include "core/gimpmarshal.h"
+#include "core/gimptemplate.h"
+
+#include "widgets/gimpdevices.h"
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpuimanager.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "tools/tool_manager.h"
+
+#include "gimpcanvas.h"
+#include "gimpcanvascanvasboundary.h"
+#include "gimpcanvaslayerboundary.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-callbacks.h"
+#include "gimpdisplayshell-cursor.h"
+#include "gimpdisplayshell-dnd.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-filter.h"
+#include "gimpdisplayshell-handlers.h"
+#include "gimpdisplayshell-items.h"
+#include "gimpdisplayshell-profile.h"
+#include "gimpdisplayshell-progress.h"
+#include "gimpdisplayshell-render.h"
+#include "gimpdisplayshell-rotate.h"
+#include "gimpdisplayshell-rulers.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-scrollbars.h"
+#include "gimpdisplayshell-selection.h"
+#include "gimpdisplayshell-title.h"
+#include "gimpdisplayshell-tool-events.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpimagewindow.h"
+#include "gimpmotionbuffer.h"
+#include "gimpstatusbar.h"
+
+#include "about.h"
+#include "gimp-log.h"
+#include "gimp-priorities.h"
+
+#include "gimp-intl.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_POPUP_MANAGER,
+  PROP_INITIAL_SCREEN,
+  PROP_INITIAL_MONITOR,
+  PROP_DISPLAY,
+  PROP_UNIT,
+  PROP_TITLE,
+  PROP_STATUS,
+  PROP_ICON,
+  PROP_SHOW_ALL,
+  PROP_INFINITE_CANVAS
+};
+
+enum
+{
+  SCALED,
+  SCROLLED,
+  ROTATED,
+  RECONNECT,
+  LAST_SIGNAL
+};
+
+
+typedef struct _GimpDisplayShellOverlay GimpDisplayShellOverlay;
+
+struct _GimpDisplayShellOverlay
+{
+  gdouble          image_x;
+  gdouble          image_y;
+  GimpHandleAnchor anchor;
+  gint             spacing_x;
+  gint             spacing_y;
+};
+
+
+/*  local function prototypes  */
+
+static void      gimp_color_managed_iface_init     (GimpColorManagedInterface *iface);
+
+static void      gimp_display_shell_constructed    (GObject          *object);
+static void      gimp_display_shell_dispose        (GObject          *object);
+static void      gimp_display_shell_finalize       (GObject          *object);
+static void      gimp_display_shell_set_property   (GObject          *object,
+                                                    guint             property_id,
+                                                    const GValue     *value,
+                                                    GParamSpec       *pspec);
+static void      gimp_display_shell_get_property   (GObject          *object,
+                                                    guint             property_id,
+                                                    GValue           *value,
+                                                    GParamSpec       *pspec);
+
+static void      gimp_display_shell_unrealize      (GtkWidget        *widget);
+static void      gimp_display_shell_unmap          (GtkWidget        *widget);
+static void      gimp_display_shell_screen_changed (GtkWidget        *widget,
+                                                    GdkScreen        *previous);
+static gboolean  gimp_display_shell_popup_menu     (GtkWidget        *widget);
+
+static void      gimp_display_shell_real_scaled    (GimpDisplayShell *shell);
+static void      gimp_display_shell_real_scrolled  (GimpDisplayShell *shell);
+static void      gimp_display_shell_real_rotated   (GimpDisplayShell *shell);
+
+static const guint8 *
+                 gimp_display_shell_get_icc_profile(GimpColorManaged *managed,
+                                                    gsize            *len);
+static GimpColorProfile *
+               gimp_display_shell_get_color_profile(GimpColorManaged *managed);
+static void      gimp_display_shell_profile_changed(GimpColorManaged *managed);
+
+static void      gimp_display_shell_menu_position  (GtkMenu          *menu,
+                                                    gint             *x,
+                                                    gint             *y,
+                                                    gpointer          data);
+static void      gimp_display_shell_zoom_button_callback
+                                                   (GimpDisplayShell *shell,
+                                                    GtkWidget        *zoom_button);
+static void      gimp_display_shell_sync_config    (GimpDisplayShell  *shell,
+                                                    GimpDisplayConfig *config);
+
+static void      gimp_display_shell_remove_overlay (GtkWidget        *canvas,
+                                                    GtkWidget        *child,
+                                                    GimpDisplayShell *shell);
+static void   gimp_display_shell_transform_overlay (GimpDisplayShell *shell,
+                                                    GtkWidget        *child,
+                                                    gdouble          *x,
+                                                    gdouble          *y);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpDisplayShell, gimp_display_shell,
+                         GTK_TYPE_EVENT_BOX,
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_PROGRESS,
+                                                gimp_display_shell_progress_iface_init)
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_COLOR_MANAGED,
+                                                gimp_color_managed_iface_init))
+
+
+#define parent_class gimp_display_shell_parent_class
+
+static guint display_shell_signals[LAST_SIGNAL] = { 0 };
+
+
+static const gchar display_rc_style[] =
+  "style \"check-button-style\"\n"
+  "{\n"
+  "  GtkToggleButton::child-displacement-x = 0\n"
+  "  GtkToggleButton::child-displacement-y = 0\n"
+  "}\n"
+  "widget \"*\" style \"check-button-style\"";
+
+static void
+gimp_display_shell_class_init (GimpDisplayShellClass *klass)
+{
+  GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  display_shell_signals[SCALED] =
+    g_signal_new ("scaled",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpDisplayShellClass, scaled),
+                  NULL, NULL,
+                  gimp_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  display_shell_signals[SCROLLED] =
+    g_signal_new ("scrolled",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpDisplayShellClass, scrolled),
+                  NULL, NULL,
+                  gimp_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  display_shell_signals[ROTATED] =
+    g_signal_new ("rotated",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpDisplayShellClass, rotated),
+                  NULL, NULL,
+                  gimp_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  display_shell_signals[RECONNECT] =
+    g_signal_new ("reconnect",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpDisplayShellClass, reconnect),
+                  NULL, NULL,
+                  gimp_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  object_class->constructed        = gimp_display_shell_constructed;
+  object_class->dispose            = gimp_display_shell_dispose;
+  object_class->finalize           = gimp_display_shell_finalize;
+  object_class->set_property       = gimp_display_shell_set_property;
+  object_class->get_property       = gimp_display_shell_get_property;
+
+  widget_class->unrealize          = gimp_display_shell_unrealize;
+  widget_class->unmap              = gimp_display_shell_unmap;
+  widget_class->screen_changed     = gimp_display_shell_screen_changed;
+  widget_class->popup_menu         = gimp_display_shell_popup_menu;
+
+  klass->scaled                    = gimp_display_shell_real_scaled;
+  klass->scrolled                  = gimp_display_shell_real_scrolled;
+  klass->rotated                   = gimp_display_shell_real_rotated;
+  klass->reconnect                 = NULL;
+
+  g_object_class_install_property (object_class, PROP_POPUP_MANAGER,
+                                   g_param_spec_object ("popup-manager",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_UI_MANAGER,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_INITIAL_SCREEN,
+                                   g_param_spec_object ("initial-screen",
+                                                        NULL, NULL,
+                                                        GDK_TYPE_SCREEN,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_INITIAL_MONITOR,
+                                   g_param_spec_int ("initial-monitor",
+                                                     NULL, NULL,
+                                                     0, 16, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_DISPLAY,
+                                   g_param_spec_object ("display", NULL, NULL,
+                                                        GIMP_TYPE_DISPLAY,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_UNIT,
+                                   gimp_param_spec_unit ("unit", NULL, NULL,
+                                                         TRUE, FALSE,
+                                                         GIMP_UNIT_PIXEL,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_TITLE,
+                                   g_param_spec_string ("title", NULL, NULL,
+                                                        GIMP_NAME,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_STATUS,
+                                   g_param_spec_string ("status", NULL, NULL,
+                                                        NULL,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_ICON,
+                                   g_param_spec_object ("icon", NULL, NULL,
+                                                        GDK_TYPE_PIXBUF,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_SHOW_ALL,
+                                   g_param_spec_boolean ("show-all",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_INFINITE_CANVAS,
+                                   g_param_spec_boolean ("infinite-canvas",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READABLE));
+
+  gtk_rc_parse_string (display_rc_style);
+}
+
+static void
+gimp_color_managed_iface_init (GimpColorManagedInterface *iface)
+{
+  iface->get_icc_profile   = gimp_display_shell_get_icc_profile;
+  iface->get_color_profile = gimp_display_shell_get_color_profile;
+  iface->profile_changed   = gimp_display_shell_profile_changed;
+}
+
+static void
+gimp_display_shell_init (GimpDisplayShell *shell)
+{
+  shell->options            = g_object_new (GIMP_TYPE_DISPLAY_OPTIONS, NULL);
+  shell->fullscreen_options = g_object_new (GIMP_TYPE_DISPLAY_OPTIONS_FULLSCREEN, NULL);
+  shell->no_image_options   = g_object_new (GIMP_TYPE_DISPLAY_OPTIONS_NO_IMAGE, NULL);
+
+  shell->zoom        = gimp_zoom_model_new ();
+  shell->dot_for_dot = TRUE;
+  shell->scale_x     = 1.0;
+  shell->scale_y     = 1.0;
+
+  shell->show_image  = TRUE;
+
+  shell->show_all    = FALSE;
+
+  gimp_display_shell_items_init (shell);
+
+  shell->icon_size       = 128;
+  shell->icon_size_small = 96;
+
+  shell->cursor_handedness = GIMP_HANDEDNESS_RIGHT;
+  shell->current_cursor    = (GimpCursorType) -1;
+  shell->tool_cursor       = GIMP_TOOL_CURSOR_NONE;
+  shell->cursor_modifier   = GIMP_CURSOR_MODIFIER_NONE;
+  shell->override_cursor   = (GimpCursorType) -1;
+
+  shell->filter_format     = babl_format ("R'G'B'A float");
+
+  shell->motion_buffer   = gimp_motion_buffer_new ();
+
+  g_signal_connect (shell->motion_buffer, "stroke",
+                    G_CALLBACK (gimp_display_shell_buffer_stroke),
+                    shell);
+  g_signal_connect (shell->motion_buffer, "hover",
+                    G_CALLBACK (gimp_display_shell_buffer_hover),
+                    shell);
+
+  shell->zoom_focus_pointer_queue = g_queue_new ();
+
+  gtk_widget_set_events (GTK_WIDGET (shell), (GDK_POINTER_MOTION_MASK    |
+                                              GDK_BUTTON_PRESS_MASK      |
+                                              GDK_KEY_PRESS_MASK         |
+                                              GDK_KEY_RELEASE_MASK       |
+                                              GDK_FOCUS_CHANGE_MASK      |
+                                              GDK_VISIBILITY_NOTIFY_MASK |
+                                              GDK_SCROLL_MASK));
+
+  /*  zoom model callback  */
+  g_signal_connect_swapped (shell->zoom, "zoomed",
+                            G_CALLBACK (gimp_display_shell_scale_update),
+                            shell);
+
+  /*  active display callback  */
+  g_signal_connect (shell, "button-press-event",
+                    G_CALLBACK (gimp_display_shell_events),
+                    shell);
+  g_signal_connect (shell, "button-release-event",
+                    G_CALLBACK (gimp_display_shell_events),
+                    shell);
+  g_signal_connect (shell, "key-press-event",
+                    G_CALLBACK (gimp_display_shell_events),
+                    shell);
+
+  gimp_help_connect (GTK_WIDGET (shell), gimp_standard_help_func,
+                     GIMP_HELP_IMAGE_WINDOW, NULL);
+}
+
+static void
+gimp_display_shell_constructed (GObject *object)
+{
+  GimpDisplayShell  *shell = GIMP_DISPLAY_SHELL (object);
+  GimpDisplayConfig *config;
+  GimpImage         *image;
+  GtkWidget         *main_vbox;
+  GtkWidget         *upper_hbox;
+  GtkWidget         *right_vbox;
+  GtkWidget         *lower_hbox;
+  GtkWidget         *inner_table;
+  GtkWidget         *gtk_image;
+  GimpAction        *action;
+  gint               image_width;
+  gint               image_height;
+  gint               shell_width;
+  gint               shell_height;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  gimp_assert (GIMP_IS_UI_MANAGER (shell->popup_manager));
+  gimp_assert (GIMP_IS_DISPLAY (shell->display));
+
+  config = shell->display->config;
+  image  = gimp_display_get_image (shell->display);
+
+  gimp_display_shell_profile_init (shell);
+
+  if (image)
+    {
+      image_width  = gimp_image_get_width  (image);
+      image_height = gimp_image_get_height (image);
+    }
+  else
+    {
+      /* These values are arbitrary. The width is determined by the
+       * menubar and the height is chosen to give a window aspect
+       * ratio of roughly 3:1 (as requested by the UI team).
+       */
+      image_width  = GIMP_DEFAULT_IMAGE_WIDTH;
+      image_height = GIMP_DEFAULT_IMAGE_HEIGHT / 3;
+    }
+
+  shell->dot_for_dot = config->default_dot_for_dot;
+
+  if (config->monitor_res_from_gdk)
+    {
+      gimp_get_monitor_resolution (shell->initial_screen,
+                                   shell->initial_monitor,
+                                   &shell->monitor_xres, &shell->monitor_yres);
+    }
+  else
+    {
+      shell->monitor_xres = config->monitor_xres;
+      shell->monitor_yres = config->monitor_yres;
+    }
+
+  /* adjust the initial scale -- so that window fits on screen. */
+  if (image)
+    {
+      gimp_display_shell_set_initial_scale (shell, 1.0, //scale,
+                                            &shell_width, &shell_height);
+    }
+  else
+    {
+      shell_width  = -1;
+      shell_height = image_height;
+    }
+
+  gimp_display_shell_sync_config (shell, config);
+
+  /*  GtkTable widgets are not able to shrink a row/column correctly if
+   *  widgets are attached with GTK_EXPAND even if those widgets have
+   *  other rows/columns in their rowspan/colspan where they could
+   *  nicely expand without disturbing the row/column which is supposed
+   *  to shrink. --Mitch
+   *
+   *  Changed the packing to use hboxes and vboxes which behave nicer:
+   *
+   *  shell
+   *     |
+   *     +-- main_vbox
+   *            |
+   *            +-- upper_hbox
+   *            |      |
+   *            |      +-- inner_table
+   *            |      |      |
+   *            |      |      +-- origin
+   *            |      |      +-- hruler
+   *            |      |      +-- vruler
+   *            |      |      +-- canvas
+   *            |      |
+   *            |      +-- right_vbox
+   *            |             |
+   *            |             +-- zoom_on_resize_button
+   *            |             +-- vscrollbar
+   *            |
+   *            +-- lower_hbox
+   *            |      |
+   *            |      +-- quick_mask
+   *            |      +-- hscrollbar
+   *            |      +-- navbutton
+   *            |
+   *            +-- statusbar
+   *
+   *  Note that we separate "shell" and "main_vbox", so that we can make
+   *  "shell" a GtkEventBox, giving it its own window.  This isolates our
+   *  events from those of our ancestors, avoiding some potential slowdowns,
+   *  and making things generally smoother.  See bug #778966.
+   */
+
+  /*  first, set up the container hierarchy  *********************************/
+
+  /*  the root vbox  */
+
+  main_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
+  gtk_container_add (GTK_CONTAINER (shell), main_vbox);
+  gtk_widget_show (main_vbox);
+
+  /*  a hbox for the inner_table and the vertical scrollbar  */
+  upper_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+  gtk_box_pack_start (GTK_BOX (main_vbox), upper_hbox, TRUE, TRUE, 0);
+  gtk_widget_show (upper_hbox);
+
+  /*  the table containing origin, rulers and the canvas  */
+  inner_table = gtk_table_new (2, 2, FALSE);
+  gtk_table_set_col_spacing (GTK_TABLE (inner_table), 0, 0);
+  gtk_table_set_row_spacing (GTK_TABLE (inner_table), 0, 0);
+  gtk_box_pack_start (GTK_BOX (upper_hbox), inner_table, TRUE, TRUE, 0);
+  gtk_widget_show (inner_table);
+
+  /*  the vbox containing the color button and the vertical scrollbar  */
+  right_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 1);
+  gtk_box_pack_start (GTK_BOX (upper_hbox), right_vbox, FALSE, FALSE, 0);
+  gtk_widget_show (right_vbox);
+
+  /*  the hbox containing the quickmask button, vertical scrollbar and
+   *  the navigation button
+   */
+  lower_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 1);
+  gtk_box_pack_start (GTK_BOX (main_vbox), lower_hbox, FALSE, FALSE, 0);
+  gtk_widget_show (lower_hbox);
+
+  /*  create the scrollbars  *************************************************/
+
+  /*  the horizontal scrollbar  */
+  shell->hsbdata = GTK_ADJUSTMENT (gtk_adjustment_new (0, 0, image_width,
+                                                       1, 1, image_width));
+  shell->hsb = gtk_scrollbar_new (GTK_ORIENTATION_HORIZONTAL, shell->hsbdata);
+  gtk_widget_set_can_focus (shell->hsb, FALSE);
+
+  /*  the vertical scrollbar  */
+  shell->vsbdata = GTK_ADJUSTMENT (gtk_adjustment_new (0, 0, image_height,
+                                                       1, 1, image_height));
+  shell->vsb = gtk_scrollbar_new (GTK_ORIENTATION_VERTICAL, shell->vsbdata);
+  gtk_widget_set_can_focus (shell->vsb, FALSE);
+
+  /*  create the contents of the inner_table  ********************************/
+
+  /*  the menu popup button  */
+  shell->origin = gtk_event_box_new ();
+
+  gtk_image = gtk_image_new_from_icon_name (GIMP_ICON_MENU_RIGHT,
+                                            GTK_ICON_SIZE_MENU);
+  gtk_container_add (GTK_CONTAINER (shell->origin), gtk_image);
+  gtk_widget_show (gtk_image);
+
+  g_signal_connect (shell->origin, "button-press-event",
+                    G_CALLBACK (gimp_display_shell_origin_button_press),
+                    shell);
+
+  gimp_help_set_help_data (shell->origin,
+                           _("Access the image menu"),
+                           GIMP_HELP_IMAGE_WINDOW_ORIGIN);
+
+  shell->canvas = gimp_canvas_new (config);
+  gtk_widget_set_size_request (shell->canvas, shell_width, shell_height);
+  gtk_container_set_border_width (GTK_CONTAINER (shell->canvas), 10);
+
+  g_signal_connect (shell->canvas, "remove",
+                    G_CALLBACK (gimp_display_shell_remove_overlay),
+                    shell);
+
+  gimp_display_shell_dnd_init (shell);
+  gimp_display_shell_selection_init (shell);
+
+  /*  the horizontal ruler  */
+  shell->hrule = gimp_ruler_new (GTK_ORIENTATION_HORIZONTAL);
+  gtk_widget_set_events (GTK_WIDGET (shell->hrule),
+                         GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
+
+  gimp_ruler_add_track_widget (GIMP_RULER (shell->hrule), shell->canvas);
+  g_signal_connect (shell->hrule, "button-press-event",
+                    G_CALLBACK (gimp_display_shell_hruler_button_press),
+                    shell);
+
+  gimp_help_set_help_data (shell->hrule, NULL, GIMP_HELP_IMAGE_WINDOW_RULER);
+
+  /*  the vertical ruler  */
+  shell->vrule = gimp_ruler_new (GTK_ORIENTATION_VERTICAL);
+  gtk_widget_set_events (GTK_WIDGET (shell->vrule),
+                         GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
+
+  gimp_ruler_add_track_widget (GIMP_RULER (shell->vrule), shell->canvas);
+  g_signal_connect (shell->vrule, "button-press-event",
+                    G_CALLBACK (gimp_display_shell_vruler_button_press),
+                    shell);
+
+  gimp_help_set_help_data (shell->vrule, NULL, GIMP_HELP_IMAGE_WINDOW_RULER);
+
+  /*  set the rulers as track widgets for each other, so we don't end up
+   *  with one ruler wrongly being stuck a few pixels off while we are
+   *  hovering the other
+   */
+  gimp_ruler_add_track_widget (GIMP_RULER (shell->hrule), shell->vrule);
+  gimp_ruler_add_track_widget (GIMP_RULER (shell->vrule), shell->hrule);
+
+  gimp_devices_add_widget (shell->display->gimp, shell->hrule);
+  gimp_devices_add_widget (shell->display->gimp, shell->vrule);
+
+  g_signal_connect (shell->canvas, "grab-notify",
+                    G_CALLBACK (gimp_display_shell_canvas_grab_notify),
+                    shell);
+
+  g_signal_connect (shell->canvas, "realize",
+                    G_CALLBACK (gimp_display_shell_canvas_realize),
+                    shell);
+  g_signal_connect (shell->canvas, "realize",
+                    G_CALLBACK (gimp_display_shell_canvas_realize_after),
+                    shell);
+  g_signal_connect (shell->canvas, "size-allocate",
+                    G_CALLBACK (gimp_display_shell_canvas_size_allocate),
+                    shell);
+  g_signal_connect (shell->canvas, "expose-event",
+                    G_CALLBACK (gimp_display_shell_canvas_expose),
+                    shell);
+
+  g_signal_connect (shell->canvas, "enter-notify-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "leave-notify-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "proximity-in-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "proximity-out-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "focus-in-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "focus-out-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "button-press-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "button-release-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "scroll-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "motion-notify-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "key-press-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+  g_signal_connect (shell->canvas, "key-release-event",
+                    G_CALLBACK (gimp_display_shell_canvas_tool_events),
+                    shell);
+
+  /*  create the contents of the right_vbox  *********************************/
+
+  shell->zoom_button = g_object_new (GTK_TYPE_CHECK_BUTTON,
+                                     "draw-indicator", FALSE,
+                                     "relief",         GTK_RELIEF_NONE,
+                                     "width-request",  18,
+                                     "height-request", 18,
+                                     NULL);
+  gtk_widget_set_can_focus (shell->zoom_button, FALSE);
+
+  gtk_image = gtk_image_new_from_icon_name (GIMP_ICON_ZOOM_FOLLOW_WINDOW,
+                                            GTK_ICON_SIZE_MENU);
+  gtk_container_add (GTK_CONTAINER (shell->zoom_button), gtk_image);
+  gtk_widget_show (gtk_image);
+
+  gimp_help_set_help_data (shell->zoom_button,
+                           _("Zoom image when window size changes"),
+                           GIMP_HELP_IMAGE_WINDOW_ZOOM_FOLLOW_BUTTON);
+
+  g_signal_connect_swapped (shell->zoom_button, "toggled",
+                            G_CALLBACK (gimp_display_shell_zoom_button_callback),
+                            shell);
+
+  /*  create the contents of the lower_hbox  *********************************/
+
+  /*  the quick mask button  */
+  shell->quick_mask_button = g_object_new (GTK_TYPE_CHECK_BUTTON,
+                                           "draw-indicator", FALSE,
+                                           "relief",         GTK_RELIEF_NONE,
+                                           "width-request",  18,
+                                           "height-request", 18,
+                                           NULL);
+  gtk_widget_set_can_focus (shell->quick_mask_button, FALSE);
+
+  gtk_image = gtk_image_new_from_icon_name (GIMP_ICON_QUICK_MASK_OFF,
+                                            GTK_ICON_SIZE_MENU);
+  gtk_container_add (GTK_CONTAINER (shell->quick_mask_button), gtk_image);
+  gtk_widget_show (gtk_image);
+
+  action = gimp_ui_manager_find_action (shell->popup_manager,
+                                        "quick-mask", "quick-mask-toggle");
+  if (action)
+    gimp_widget_set_accel_help (shell->quick_mask_button, action);
+  else
+    gimp_help_set_help_data (shell->quick_mask_button,
+                             _("Toggle Quick Mask"),
+                             GIMP_HELP_IMAGE_WINDOW_QUICK_MASK_BUTTON);
+
+  g_signal_connect (shell->quick_mask_button, "toggled",
+                    G_CALLBACK (gimp_display_shell_quick_mask_toggled),
+                    shell);
+  g_signal_connect (shell->quick_mask_button, "button-press-event",
+                    G_CALLBACK (gimp_display_shell_quick_mask_button_press),
+                    shell);
+
+  /*  the navigation window button  */
+  shell->nav_ebox = gtk_event_box_new ();
+
+  gtk_image = gtk_image_new_from_icon_name (GIMP_ICON_DIALOG_NAVIGATION,
+                                            GTK_ICON_SIZE_MENU);
+  gtk_container_add (GTK_CONTAINER (shell->nav_ebox), gtk_image);
+  gtk_widget_show (gtk_image);
+
+  g_signal_connect (shell->nav_ebox, "button-press-event",
+                    G_CALLBACK (gimp_display_shell_navigation_button_press),
+                    shell);
+
+  gimp_help_set_help_data (shell->nav_ebox,
+                           _("Navigate the image display"),
+                           GIMP_HELP_IMAGE_WINDOW_NAV_BUTTON);
+
+  /*  the statusbar  ********************************************************/
+
+  shell->statusbar = gimp_statusbar_new ();
+  gimp_statusbar_set_shell (GIMP_STATUSBAR (shell->statusbar), shell);
+  gimp_help_set_help_data (shell->statusbar, NULL,
+                           GIMP_HELP_IMAGE_WINDOW_STATUS_BAR);
+  gtk_box_pack_end (GTK_BOX (main_vbox), shell->statusbar, FALSE, FALSE, 0);
+
+  /*  pack all the widgets  **************************************************/
+
+  /*  fill the inner_table  */
+  gtk_table_attach (GTK_TABLE (inner_table), shell->origin, 0, 1, 0, 1,
+                    GTK_FILL, GTK_FILL, 0, 0);
+  gtk_table_attach (GTK_TABLE (inner_table), shell->hrule, 1, 2, 0, 1,
+                    GTK_EXPAND | GTK_SHRINK | GTK_FILL, GTK_FILL, 0, 0);
+  gtk_table_attach (GTK_TABLE (inner_table), shell->vrule, 0, 1, 1, 2,
+                    GTK_FILL, GTK_EXPAND | GTK_SHRINK | GTK_FILL, 0, 0);
+  gtk_table_attach (GTK_TABLE (inner_table), shell->canvas, 1, 2, 1, 2,
+                    GTK_EXPAND | GTK_SHRINK | GTK_FILL,
+                    GTK_EXPAND | GTK_SHRINK | GTK_FILL, 0, 0);
+
+  /*  fill the right_vbox  */
+  gtk_box_pack_start (GTK_BOX (right_vbox),
+                      shell->zoom_button, FALSE, FALSE, 0);
+  gtk_box_pack_start (GTK_BOX (right_vbox),
+                      shell->vsb, TRUE, TRUE, 0);
+
+  /*  fill the lower_hbox  */
+  gtk_box_pack_start (GTK_BOX (lower_hbox),
+                      shell->quick_mask_button, FALSE, FALSE, 0);
+  gtk_box_pack_start (GTK_BOX (lower_hbox),
+                      shell->hsb, TRUE, TRUE, 0);
+  gtk_box_pack_start (GTK_BOX (lower_hbox),
+                      shell->nav_ebox, FALSE, FALSE, 0);
+
+  /*  show everything that is always shown ***********************************/
+
+  gtk_widget_show (GTK_WIDGET (shell->canvas));
+
+  if (image)
+    {
+      gimp_display_shell_connect (shell);
+
+      /* After connecting to the image we want to center it. Since we
+       * not even finished creating the display shell, we can safely
+       * assume we will get a size-allocate later.
+       */
+      shell->size_allocate_center_image = TRUE;
+    }
+  else
+    {
+#if 0
+      /* Disabled because it sets GDK_POINTER_MOTION_HINT on
+       * shell->canvas. For info see Bug 677375
+       */
+      gimp_help_set_help_data (shell->canvas,
+                               _("Drop image files here to open them"),
+                               NULL);
+#endif
+
+      gimp_statusbar_empty (GIMP_STATUSBAR (shell->statusbar));
+    }
+
+  /* make sure the information is up-to-date */
+  gimp_display_shell_scale_update (shell);
+
+  gimp_display_shell_set_show_all (shell, config->default_show_all);
+}
+
+static void
+gimp_display_shell_dispose (GObject *object)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (object);
+
+  if (shell->display && gimp_display_get_shell (shell->display))
+    gimp_display_shell_disconnect (shell);
+
+  shell->popup_manager = NULL;
+
+  if (shell->selection)
+    gimp_display_shell_selection_free (shell);
+
+  gimp_display_shell_filter_set (shell, NULL);
+
+  if (shell->filter_idle_id)
+    {
+      g_source_remove (shell->filter_idle_id);
+      shell->filter_idle_id = 0;
+    }
+
+  g_clear_pointer (&shell->mask_surface, cairo_surface_destroy);
+  g_clear_pointer (&shell->checkerboard, cairo_pattern_destroy);
+
+  gimp_display_shell_profile_finalize (shell);
+
+  g_clear_object (&shell->filter_buffer);
+  shell->filter_data   = NULL;
+  shell->filter_stride = 0;
+
+  g_clear_object (&shell->mask);
+
+  gimp_display_shell_items_free (shell);
+
+  g_clear_object (&shell->motion_buffer);
+
+  g_clear_pointer (&shell->zoom_focus_pointer_queue, g_queue_free);
+
+  if (shell->title_idle_id)
+    {
+      g_source_remove (shell->title_idle_id);
+      shell->title_idle_id = 0;
+    }
+
+  if (shell->fill_idle_id)
+    {
+      g_source_remove (shell->fill_idle_id);
+      shell->fill_idle_id = 0;
+    }
+
+  g_clear_pointer (&shell->nav_popup, gtk_widget_destroy);
+
+  if (shell->blink_timeout_id)
+    {
+      g_source_remove (shell->blink_timeout_id);
+      shell->blink_timeout_id = 0;
+    }
+
+  shell->display = NULL;
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_display_shell_finalize (GObject *object)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (object);
+
+  g_clear_object (&shell->zoom);
+  g_clear_pointer (&shell->rotate_transform,   g_free);
+  g_clear_pointer (&shell->rotate_untransform, g_free);
+  g_clear_object (&shell->options);
+  g_clear_object (&shell->fullscreen_options);
+  g_clear_object (&shell->no_image_options);
+  g_clear_pointer (&shell->title,  g_free);
+  g_clear_pointer (&shell->status, g_free);
+  g_clear_object (&shell->icon);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_display_shell_set_property (GObject      *object,
+                                 guint         property_id,
+                                 const GValue *value,
+                                 GParamSpec   *pspec)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (object);
+
+  switch (property_id)
+    {
+    case PROP_POPUP_MANAGER:
+      shell->popup_manager = g_value_get_object (value);
+      break;
+    case PROP_INITIAL_SCREEN:
+      shell->initial_screen = g_value_get_object (value);
+      break;
+    case PROP_INITIAL_MONITOR:
+      shell->initial_monitor = g_value_get_int (value);
+      break;
+    case PROP_DISPLAY:
+      shell->display = g_value_get_object (value);
+      break;
+    case PROP_UNIT:
+      gimp_display_shell_set_unit (shell, g_value_get_int (value));
+      break;
+    case PROP_TITLE:
+      g_free (shell->title);
+      shell->title = g_value_dup_string (value);
+      break;
+    case PROP_STATUS:
+      g_free (shell->status);
+      shell->status = g_value_dup_string (value);
+      break;
+    case PROP_ICON:
+      if (shell->icon)
+        g_object_unref (shell->icon);
+      shell->icon = g_value_dup_object (value);
+      break;
+    case PROP_SHOW_ALL:
+      gimp_display_shell_set_show_all (shell, g_value_get_boolean (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_display_shell_get_property (GObject    *object,
+                                 guint       property_id,
+                                 GValue     *value,
+                                 GParamSpec *pspec)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (object);
+
+  switch (property_id)
+    {
+    case PROP_POPUP_MANAGER:
+      g_value_set_object (value, shell->popup_manager);
+      break;
+    case PROP_INITIAL_SCREEN:
+      g_value_set_object (value, shell->initial_screen);
+      break;
+    case PROP_INITIAL_MONITOR:
+      g_value_set_int (value, shell->initial_monitor);
+      break;
+    case PROP_DISPLAY:
+      g_value_set_object (value, shell->display);
+      break;
+    case PROP_UNIT:
+      g_value_set_int (value, shell->unit);
+      break;
+    case PROP_TITLE:
+      g_value_set_string (value, shell->title);
+      break;
+    case PROP_STATUS:
+      g_value_set_string (value, shell->status);
+      break;
+    case PROP_ICON:
+      g_value_set_object (value, shell->icon);
+      break;
+    case PROP_SHOW_ALL:
+      g_value_set_boolean (value, shell->show_all);
+      break;
+    case PROP_INFINITE_CANVAS:
+      g_value_set_boolean (value,
+                           gimp_display_shell_get_infinite_canvas (shell));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_display_shell_unrealize (GtkWidget *widget)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (widget);
+
+  if (shell->nav_popup)
+    gtk_widget_unrealize (shell->nav_popup);
+
+  GTK_WIDGET_CLASS (parent_class)->unrealize (widget);
+}
+
+static void
+gimp_display_shell_unmap (GtkWidget *widget)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (widget);
+
+  gimp_display_shell_selection_undraw (shell);
+
+  GTK_WIDGET_CLASS (parent_class)->unmap (widget);
+}
+
+static void
+gimp_display_shell_screen_changed (GtkWidget *widget,
+                                   GdkScreen *previous)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (widget);
+
+  if (GTK_WIDGET_CLASS (parent_class)->screen_changed)
+    GTK_WIDGET_CLASS (parent_class)->screen_changed (widget, previous);
+
+  if (shell->display->config->monitor_res_from_gdk)
+    {
+      gimp_get_monitor_resolution (gtk_widget_get_screen (widget),
+                                   gimp_widget_get_monitor (widget),
+                                   &shell->monitor_xres,
+                                   &shell->monitor_yres);
+    }
+  else
+    {
+      shell->monitor_xres = shell->display->config->monitor_xres;
+      shell->monitor_yres = shell->display->config->monitor_yres;
+    }
+}
+
+static gboolean
+gimp_display_shell_popup_menu (GtkWidget *widget)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (widget);
+
+  gimp_context_set_display (gimp_get_user_context (shell->display->gimp),
+                            shell->display);
+
+  gimp_ui_manager_ui_popup (shell->popup_manager, "/dummy-menubar/image-popup",
+                            GTK_WIDGET (shell),
+                            gimp_display_shell_menu_position,
+                            shell->origin,
+                            NULL, NULL);
+
+  return TRUE;
+}
+
+static void
+gimp_display_shell_real_scaled (GimpDisplayShell *shell)
+{
+  GimpContext *user_context;
+
+  if (! shell->display)
+    return;
+
+  gimp_display_shell_title_update (shell);
+
+  user_context = gimp_get_user_context (shell->display->gimp);
+
+  if (shell->display == gimp_context_get_display (user_context))
+    {
+      gimp_display_shell_update_priority_rect (shell);
+
+      gimp_ui_manager_update (shell->popup_manager, shell->display);
+    }
+}
+
+static void
+gimp_display_shell_real_scrolled (GimpDisplayShell *shell)
+{
+  GimpContext *user_context;
+
+  if (! shell->display)
+    return;
+
+  gimp_display_shell_title_update (shell);
+
+  user_context = gimp_get_user_context (shell->display->gimp);
+
+  if (shell->display == gimp_context_get_display (user_context))
+    {
+      gimp_display_shell_update_priority_rect (shell);
+
+    }
+}
+
+static void
+gimp_display_shell_real_rotated (GimpDisplayShell *shell)
+{
+  GimpContext *user_context;
+
+  if (! shell->display)
+    return;
+
+  gimp_display_shell_title_update (shell);
+
+  user_context = gimp_get_user_context (shell->display->gimp);
+
+  if (shell->display == gimp_context_get_display (user_context))
+    {
+      gimp_display_shell_update_priority_rect (shell);
+
+      gimp_ui_manager_update (shell->popup_manager, shell->display);
+    }
+}
+
+static const guint8 *
+gimp_display_shell_get_icc_profile (GimpColorManaged *managed,
+                                    gsize            *len)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (managed);
+  GimpImage        *image = gimp_display_get_image (shell->display);
+
+  if (image)
+    return gimp_color_managed_get_icc_profile (GIMP_COLOR_MANAGED (image), len);
+
+  return NULL;
+}
+
+static GimpColorProfile *
+gimp_display_shell_get_color_profile (GimpColorManaged *managed)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (managed);
+  GimpImage        *image = gimp_display_get_image (shell->display);
+
+  if (image)
+    return gimp_color_managed_get_color_profile (GIMP_COLOR_MANAGED (image));
+
+  return NULL;
+}
+
+static void
+gimp_display_shell_profile_changed (GimpColorManaged *managed)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (managed);
+
+  gimp_display_shell_profile_update (shell);
+  gimp_display_shell_expose_full (shell);
+}
+
+static void
+gimp_display_shell_menu_position (GtkMenu  *menu,
+                                  gint     *x,
+                                  gint     *y,
+                                  gpointer  data)
+{
+  gimp_button_menu_position (GTK_WIDGET (data), menu, GTK_POS_RIGHT, x, y);
+}
+
+static void
+gimp_display_shell_zoom_button_callback (GimpDisplayShell *shell,
+                                         GtkWidget        *zoom_button)
+{
+  shell->zoom_on_resize =
+    gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (zoom_button));
+
+  if (shell->zoom_on_resize &&
+      gimp_display_shell_scale_image_is_within_viewport (shell, NULL, NULL))
+    {
+      /* Implicitly make a View -> Fit Image in Window */
+      gimp_display_shell_scale_fit_in (shell);
+    }
+}
+
+static void
+gimp_display_shell_sync_config (GimpDisplayShell  *shell,
+                                GimpDisplayConfig *config)
+{
+  gimp_config_sync (G_OBJECT (config->default_view),
+                    G_OBJECT (shell->options), 0);
+  gimp_config_sync (G_OBJECT (config->default_fullscreen_view),
+                    G_OBJECT (shell->fullscreen_options), 0);
+}
+
+static void
+gimp_display_shell_remove_overlay (GtkWidget        *canvas,
+                                   GtkWidget        *child,
+                                   GimpDisplayShell *shell)
+{
+  shell->children = g_list_remove (shell->children, child);
+}
+
+static void
+gimp_display_shell_transform_overlay (GimpDisplayShell *shell,
+                                      GtkWidget        *child,
+                                      gdouble          *x,
+                                      gdouble          *y)
+{
+  GimpDisplayShellOverlay *overlay;
+  GtkRequisition           requisition;
+
+  overlay = g_object_get_data (G_OBJECT (child), "image-coords-overlay");
+
+  gimp_display_shell_transform_xy_f (shell,
+                                     overlay->image_x,
+                                     overlay->image_y,
+                                     x, y);
+
+  gtk_widget_size_request (child, &requisition);
+
+  switch (overlay->anchor)
+    {
+    case GIMP_HANDLE_ANCHOR_CENTER:
+      *x -= requisition.width  / 2;
+      *y -= requisition.height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH:
+      *x -= requisition.width / 2;
+      *y += overlay->spacing_y;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_WEST:
+      *x += overlay->spacing_x;
+      *y += overlay->spacing_y;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_EAST:
+      *x -= requisition.width + overlay->spacing_x;
+      *y += overlay->spacing_y;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH:
+      *x -= requisition.width / 2;
+      *y -= requisition.height + overlay->spacing_y;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_WEST:
+      *x += overlay->spacing_x;
+      *y -= requisition.height + overlay->spacing_y;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_EAST:
+      *x -= requisition.width + overlay->spacing_x;
+      *y -= requisition.height + overlay->spacing_y;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_WEST:
+      *x += overlay->spacing_x;
+      *y -= requisition.height / 2;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_EAST:
+      *x -= requisition.width + overlay->spacing_x;
+      *y -= requisition.height / 2;
+      break;
+    }
+}
+
+
+/*  public functions  */
+
+GtkWidget *
+gimp_display_shell_new (GimpDisplay   *display,
+                        GimpUnit       unit,
+                        gdouble        scale,
+                        GimpUIManager *popup_manager,
+                        GdkScreen     *screen,
+                        gint           monitor)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY (display), NULL);
+  g_return_val_if_fail (GIMP_IS_UI_MANAGER (popup_manager), NULL);
+  g_return_val_if_fail (GDK_IS_SCREEN (screen), NULL);
+
+  return g_object_new (GIMP_TYPE_DISPLAY_SHELL,
+                       "popup-manager",   popup_manager,
+                       "initial-screen",  screen,
+                       "initial-monitor", monitor,
+                       "display",         display,
+                       "unit",            unit,
+                       NULL);
+}
+
+void
+gimp_display_shell_add_overlay (GimpDisplayShell *shell,
+                                GtkWidget        *child,
+                                gdouble           image_x,
+                                gdouble           image_y,
+                                GimpHandleAnchor  anchor,
+                                gint              spacing_x,
+                                gint              spacing_y)
+{
+  GimpDisplayShellOverlay *overlay;
+  gdouble                  x, y;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GTK_IS_WIDGET (shell));
+
+  overlay = g_new0 (GimpDisplayShellOverlay, 1);
+
+  overlay->image_x   = image_x;
+  overlay->image_y   = image_y;
+  overlay->anchor    = anchor;
+  overlay->spacing_x = spacing_x;
+  overlay->spacing_y = spacing_y;
+
+  g_object_set_data_full (G_OBJECT (child), "image-coords-overlay", overlay,
+                          (GDestroyNotify) g_free);
+
+  shell->children = g_list_prepend (shell->children, child);
+
+  gimp_display_shell_transform_overlay (shell, child, &x, &y);
+
+  gimp_overlay_box_add_child (GIMP_OVERLAY_BOX (shell->canvas), child, 0.0, 0.0);
+  gimp_overlay_box_set_child_position (GIMP_OVERLAY_BOX (shell->canvas),
+                                       child, x, y);
+}
+
+void
+gimp_display_shell_move_overlay (GimpDisplayShell *shell,
+                                 GtkWidget        *child,
+                                 gdouble           image_x,
+                                 gdouble           image_y,
+                                 GimpHandleAnchor  anchor,
+                                 gint              spacing_x,
+                                 gint              spacing_y)
+{
+  GimpDisplayShellOverlay *overlay;
+  gdouble                  x, y;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GTK_IS_WIDGET (shell));
+
+  overlay = g_object_get_data (G_OBJECT (child), "image-coords-overlay");
+
+  g_return_if_fail (overlay != NULL);
+
+  overlay->image_x   = image_x;
+  overlay->image_y   = image_y;
+  overlay->anchor    = anchor;
+  overlay->spacing_x = spacing_x;
+  overlay->spacing_y = spacing_y;
+
+  gimp_display_shell_transform_overlay (shell, child, &x, &y);
+
+  gimp_overlay_box_set_child_position (GIMP_OVERLAY_BOX (shell->canvas),
+                                       child, x, y);
+}
+
+GimpImageWindow *
+gimp_display_shell_get_window (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return GIMP_IMAGE_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (shell),
+                                                     GIMP_TYPE_IMAGE_WINDOW));
+}
+
+GimpStatusbar *
+gimp_display_shell_get_statusbar (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return GIMP_STATUSBAR (shell->statusbar);
+}
+
+GimpColorConfig *
+gimp_display_shell_get_color_config (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return shell->color_config;
+}
+
+void
+gimp_display_shell_present (GimpDisplayShell *shell)
+{
+  GimpImageWindow *window;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  window = gimp_display_shell_get_window (shell);
+
+  if (window)
+    {
+      gimp_image_window_set_active_shell (window, shell);
+
+      gtk_window_present (GTK_WINDOW (window));
+    }
+}
+
+void
+gimp_display_shell_reconnect (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_DISPLAY (shell->display));
+  g_return_if_fail (gimp_display_get_image (shell->display) != NULL);
+
+  if (shell->fill_idle_id)
+    {
+      g_source_remove (shell->fill_idle_id);
+      shell->fill_idle_id = 0;
+    }
+
+  g_signal_emit (shell, display_shell_signals[RECONNECT], 0);
+
+  gimp_color_managed_profile_changed (GIMP_COLOR_MANAGED (shell));
+
+  gimp_display_shell_scroll_clamp_and_update (shell);
+
+  gimp_display_shell_scaled (shell);
+
+  gimp_display_shell_expose_full (shell);
+}
+
+static gboolean
+gimp_display_shell_blink (GimpDisplayShell *shell)
+{
+  shell->blink_timeout_id = 0;
+
+  if (shell->blink)
+    {
+      shell->blink = FALSE;
+    }
+  else
+    {
+      shell->blink = TRUE;
+
+      shell->blink_timeout_id =
+        g_timeout_add (100, (GSourceFunc) gimp_display_shell_blink, shell);
+    }
+
+  gimp_display_shell_expose_full (shell);
+
+  return FALSE;
+}
+
+void
+gimp_display_shell_empty (GimpDisplayShell *shell)
+{
+  GimpContext     *user_context;
+  GimpImageWindow *window;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_DISPLAY (shell->display));
+  g_return_if_fail (gimp_display_get_image (shell->display) == NULL);
+
+  window = gimp_display_shell_get_window (shell);
+
+  if (shell->fill_idle_id)
+    {
+      g_source_remove (shell->fill_idle_id);
+      shell->fill_idle_id = 0;
+    }
+
+  gimp_display_shell_selection_undraw (shell);
+
+  gimp_display_shell_unset_cursor (shell);
+
+  gimp_display_shell_filter_set (shell, NULL);
+
+  gimp_display_shell_sync_config (shell, shell->display->config);
+
+  gimp_display_shell_appearance_update (shell);
+  gimp_image_window_update_tabs (window);
+#if 0
+  gimp_help_set_help_data (shell->canvas,
+                           _("Drop image files here to open them"), NULL);
+#endif
+
+  gimp_statusbar_empty (GIMP_STATUSBAR (shell->statusbar));
+
+  shell->flip_horizontally = FALSE;
+  shell->flip_vertically   = FALSE;
+  shell->rotate_angle      = 0.0;
+  gimp_display_shell_rotate_update_transform (shell);
+
+  gimp_display_shell_expose_full (shell);
+
+  user_context = gimp_get_user_context (shell->display->gimp);
+
+  if (shell->display == gimp_context_get_display (user_context))
+    gimp_ui_manager_update (shell->popup_manager, shell->display);
+
+  shell->blink_timeout_id =
+    g_timeout_add (1403230, (GSourceFunc) gimp_display_shell_blink, shell);
+}
+
+static gboolean
+gimp_display_shell_fill_idle (GimpDisplayShell *shell)
+{
+  GtkWidget *toplevel = gtk_widget_get_toplevel (GTK_WIDGET (shell));
+
+  shell->fill_idle_id = 0;
+
+  if (GTK_IS_WINDOW (toplevel))
+    {
+      gimp_display_shell_scale_shrink_wrap (shell, TRUE);
+
+      gtk_window_present (GTK_WINDOW (toplevel));
+    }
+
+  return FALSE;
+}
+
+void
+gimp_display_shell_fill (GimpDisplayShell *shell,
+                         GimpImage        *image,
+                         GimpUnit          unit,
+                         gdouble           scale)
+{
+  GimpDisplayConfig *config;
+  GimpImageWindow   *window;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_DISPLAY (shell->display));
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+
+  config = shell->display->config;
+  window = gimp_display_shell_get_window (shell);
+
+  shell->show_image  = TRUE;
+
+  shell->dot_for_dot = config->default_dot_for_dot;
+
+  gimp_display_shell_set_unit (shell, unit);
+  gimp_display_shell_set_initial_scale (shell, scale, NULL, NULL);
+  gimp_display_shell_scale_update (shell);
+
+  gimp_display_shell_sync_config (shell, config);
+
+  gimp_image_window_suspend_keep_pos (window);
+  gimp_display_shell_appearance_update (shell);
+  gimp_image_window_resume_keep_pos (window);
+
+  gimp_image_window_update_tabs (window);
+#if 0
+  gimp_help_set_help_data (shell->canvas, NULL, NULL);
+#endif
+
+  gimp_statusbar_fill (GIMP_STATUSBAR (shell->statusbar));
+
+  /* make sure a size-allocate always occurs, even when the rulers and
+   * scrollbars are hidden.  see issue #4968.
+   */
+  shell->size_allocate_center_image = TRUE;
+  gtk_widget_queue_resize (GTK_WIDGET (shell->canvas));
+
+  if (shell->blink_timeout_id)
+    {
+      g_source_remove (shell->blink_timeout_id);
+      shell->blink_timeout_id = 0;
+    }
+
+  shell->fill_idle_id =
+    g_idle_add_full (GIMP_PRIORITY_DISPLAY_SHELL_FILL_IDLE,
+                     (GSourceFunc) gimp_display_shell_fill_idle, shell,
+                     NULL);
+
+  gimp_display_shell_set_show_all (shell, config->default_show_all);
+}
+
+void
+gimp_display_shell_scaled (GimpDisplayShell *shell)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_rotate_update_transform (shell);
+
+  for (list = shell->children; list; list = g_list_next (list))
+    {
+      GtkWidget *child = list->data;
+      gdouble    x, y;
+
+      gimp_display_shell_transform_overlay (shell, child, &x, &y);
+
+      gimp_overlay_box_set_child_position (GIMP_OVERLAY_BOX (shell->canvas),
+                                           child, x, y);
+    }
+
+  g_signal_emit (shell, display_shell_signals[SCALED], 0);
+}
+
+void
+gimp_display_shell_scrolled (GimpDisplayShell *shell)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_rotate_update_transform (shell);
+
+  for (list = shell->children; list; list = g_list_next (list))
+    {
+      GtkWidget *child = list->data;
+      gdouble    x, y;
+
+      gimp_display_shell_transform_overlay (shell, child, &x, &y);
+
+      gimp_overlay_box_set_child_position (GIMP_OVERLAY_BOX (shell->canvas),
+                                           child, x, y);
+    }
+
+  g_signal_emit (shell, display_shell_signals[SCROLLED], 0);
+}
+
+void
+gimp_display_shell_rotated (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gimp_display_shell_rotate_update_transform (shell);
+
+  g_signal_emit (shell, display_shell_signals[ROTATED], 0);
+}
+
+void
+gimp_display_shell_set_unit (GimpDisplayShell *shell,
+                             GimpUnit          unit)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->unit != unit)
+    {
+      shell->unit = unit;
+
+      gimp_display_shell_rulers_update (shell);
+
+      gimp_display_shell_scaled (shell);
+
+      g_object_notify (G_OBJECT (shell), "unit");
+    }
+}
+
+GimpUnit
+gimp_display_shell_get_unit (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), GIMP_UNIT_PIXEL);
+
+  return shell->unit;
+}
+
+gboolean
+gimp_display_shell_snap_coords (GimpDisplayShell *shell,
+                                GimpCoords       *coords,
+                                gint              snap_offset_x,
+                                gint              snap_offset_y,
+                                gint              snap_width,
+                                gint              snap_height)
+{
+  GimpImage *image;
+  gboolean   snap_to_guides  = FALSE;
+  gboolean   snap_to_grid    = FALSE;
+  gboolean   snap_to_canvas  = FALSE;
+  gboolean   snap_to_vectors = FALSE;
+  gboolean   snapped         = FALSE;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+  g_return_val_if_fail (coords != NULL, FALSE);
+
+  image = gimp_display_get_image (shell->display);
+
+  if (gimp_display_shell_get_snap_to_guides (shell) &&
+      gimp_image_get_guides (image))
+    {
+      snap_to_guides = TRUE;
+    }
+
+  if (gimp_display_shell_get_snap_to_grid (shell) &&
+      gimp_image_get_grid (image))
+    {
+      snap_to_grid = TRUE;
+    }
+
+  snap_to_canvas = gimp_display_shell_get_snap_to_canvas (shell);
+
+  if (gimp_display_shell_get_snap_to_vectors (shell) &&
+      gimp_image_get_active_vectors (image))
+    {
+      snap_to_vectors = TRUE;
+    }
+
+  if (snap_to_guides || snap_to_grid || snap_to_canvas || snap_to_vectors)
+    {
+      gint    snap_distance;
+      gdouble tx, ty;
+
+      snap_distance = shell->display->config->snap_distance;
+
+      if (snap_width > 0 && snap_height > 0)
+        {
+          snapped = gimp_image_snap_rectangle (image,
+                                               coords->x + snap_offset_x,
+                                               coords->y + snap_offset_y,
+                                               coords->x + snap_offset_x +
+                                               snap_width,
+                                               coords->y + snap_offset_y +
+                                               snap_height,
+                                               &tx,
+                                               &ty,
+                                               FUNSCALEX (shell, snap_distance),
+                                               FUNSCALEY (shell, snap_distance),
+                                               snap_to_guides,
+                                               snap_to_grid,
+                                               snap_to_canvas,
+                                               snap_to_vectors);
+        }
+      else
+        {
+          snapped = gimp_image_snap_point (image,
+                                           coords->x + snap_offset_x,
+                                           coords->y + snap_offset_y,
+                                           &tx,
+                                           &ty,
+                                           FUNSCALEX (shell, snap_distance),
+                                           FUNSCALEY (shell, snap_distance),
+                                           snap_to_guides,
+                                           snap_to_grid,
+                                           snap_to_canvas,
+                                           snap_to_vectors);
+        }
+
+      if (snapped)
+        {
+          coords->x = tx - snap_offset_x;
+          coords->y = ty - snap_offset_y;
+        }
+    }
+
+  return snapped;
+}
+
+gboolean
+gimp_display_shell_mask_bounds (GimpDisplayShell *shell,
+                                gint             *x,
+                                gint             *y,
+                                gint             *width,
+                                gint             *height)
+{
+  GimpImage *image;
+  GimpLayer *layer;
+  gint       x1, y1;
+  gint       x2, y2;
+  gdouble    x1_f, y1_f;
+  gdouble    x2_f, y2_f;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+  g_return_val_if_fail (x != NULL, FALSE);
+  g_return_val_if_fail (y != NULL, FALSE);
+  g_return_val_if_fail (width != NULL, FALSE);
+  g_return_val_if_fail (height != NULL, FALSE);
+
+  image = gimp_display_get_image (shell->display);
+
+  /*  If there is a floating selection, handle things differently  */
+  if ((layer = gimp_image_get_floating_selection (image)))
+    {
+      gint fs_x;
+      gint fs_y;
+      gint fs_width;
+      gint fs_height;
+
+      gimp_item_get_offset (GIMP_ITEM (layer), &fs_x, &fs_y);
+      fs_width  = gimp_item_get_width  (GIMP_ITEM (layer));
+      fs_height = gimp_item_get_height (GIMP_ITEM (layer));
+
+      if (! gimp_item_bounds (GIMP_ITEM (gimp_image_get_mask (image)),
+                              x, y, width, height))
+        {
+          *x      = fs_x;
+          *y      = fs_y;
+          *width  = fs_width;
+          *height = fs_height;
+        }
+      else
+        {
+          gimp_rectangle_union (*x, *y, *width, *height,
+                                fs_x, fs_y, fs_width, fs_height,
+                                x, y, width, height);
+        }
+    }
+  else if (! gimp_item_bounds (GIMP_ITEM (gimp_image_get_mask (image)),
+                               x, y, width, height))
+    {
+      return FALSE;
+    }
+
+  x1 = *x;
+  y1 = *y;
+  x2 = *x + *width;
+  y2 = *y + *height;
+
+  gimp_display_shell_transform_bounds (shell,
+                                       x1, y1, x2, y2,
+                                       &x1_f, &y1_f, &x2_f, &y2_f);
+
+  /*  Make sure the extents are within bounds  */
+  x1 = CLAMP (floor (x1_f), 0, shell->disp_width);
+  y1 = CLAMP (floor (y1_f), 0, shell->disp_height);
+  x2 = CLAMP (ceil (x2_f),  0, shell->disp_width);
+  y2 = CLAMP (ceil (y2_f),  0, shell->disp_height);
+
+  *x      = x1;
+  *y      = y1;
+  *width  = x2 - x1;
+  *height = y2 - y1;
+
+  return (*width > 0) && (*height > 0);
+}
+
+void
+gimp_display_shell_set_show_image (GimpDisplayShell *shell,
+                                   gboolean          show_image)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (show_image != shell->show_image)
+    {
+      shell->show_image = show_image;
+
+      gimp_display_shell_expose_full (shell);
+    }
+}
+
+void
+gimp_display_shell_set_show_all (GimpDisplayShell *shell,
+                                 gboolean          show_all)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (show_all != shell->show_all)
+    {
+      shell->show_all = show_all;
+
+      if (shell->display && gimp_display_get_image (shell->display))
+        {
+          GimpImage   *image = gimp_display_get_image (shell->display);
+          GimpContext *user_context;
+
+          if (show_all)
+            gimp_image_inc_show_all_count (image);
+          else
+            gimp_image_dec_show_all_count (image);
+
+          gimp_image_flush (image);
+
+          gimp_display_update_bounding_box (shell->display);
+
+          gimp_display_shell_update_show_canvas (shell);
+
+          gimp_display_shell_scroll_clamp_and_update (shell);
+          gimp_display_shell_scrollbars_update (shell);
+
+          gimp_display_shell_expose_full (shell);
+
+          user_context = gimp_get_user_context (shell->display->gimp);
+
+          if (shell->display == gimp_context_get_display (user_context))
+            {
+              gimp_display_shell_update_priority_rect (shell);
+
+              gimp_ui_manager_update (shell->popup_manager, shell->display);
+            }
+        }
+
+      g_object_notify (G_OBJECT (shell), "show-all");
+      g_object_notify (G_OBJECT (shell), "infinite-canvas");
+    }
+}
+
+
+GimpPickable *
+gimp_display_shell_get_pickable (GimpDisplayShell *shell)
+{
+  GimpImage *image;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      if (! shell->show_all)
+        return GIMP_PICKABLE (image);
+      else
+        return GIMP_PICKABLE (gimp_image_get_projection (image));
+    }
+
+  return NULL;
+}
+
+GimpPickable *
+gimp_display_shell_get_canvas_pickable (GimpDisplayShell *shell)
+{
+  GimpImage *image;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      if (! gimp_display_shell_get_infinite_canvas (shell))
+        return GIMP_PICKABLE (image);
+      else
+        return GIMP_PICKABLE (gimp_image_get_projection (image));
+    }
+
+  return NULL;
+}
+
+GeglRectangle
+gimp_display_shell_get_bounding_box (GimpDisplayShell *shell)
+{
+  GeglRectangle  bounding_box = {};
+  GimpImage     *image;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), bounding_box);
+
+  image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      if (! shell->show_all)
+        {
+          bounding_box.width  = gimp_image_get_width  (image);
+          bounding_box.height = gimp_image_get_height (image);
+        }
+      else
+        {
+          bounding_box = gimp_projectable_get_bounding_box (
+            GIMP_PROJECTABLE (image));
+        }
+    }
+
+  return bounding_box;
+}
+
+gboolean
+gimp_display_shell_get_infinite_canvas (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), FALSE);
+
+  return shell->show_all &&
+         ! gimp_display_shell_get_padding_in_show_all (shell);
+}
+
+void
+gimp_display_shell_update_priority_rect (GimpDisplayShell *shell)
+{
+  GimpImage *image;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  image = gimp_display_get_image (shell->display);
+
+  if (image)
+    {
+      GimpProjection *projection = gimp_image_get_projection (image);
+      gint            x, y;
+      gint            width, height;
+
+      gimp_display_shell_untransform_viewport (shell, ! shell->show_all,
+                                               &x, &y, &width, &height);
+      gimp_projection_set_priority_rect (projection, x, y, width, height);
+    }
+}
+
+void
+gimp_display_shell_flush (GimpDisplayShell *shell,
+                          gboolean          now)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (now)
+    {
+      gdk_window_process_updates (gtk_widget_get_window (shell->canvas),
+                                  FALSE);
+    }
+  else
+    {
+      GimpImageWindow *window = gimp_display_shell_get_window (shell);
+      GimpContext     *context;
+
+      gimp_display_shell_title_update (shell);
+
+      gimp_canvas_layer_boundary_set_layer (GIMP_CANVAS_LAYER_BOUNDARY (shell->layer_boundary),
+                                            gimp_image_get_active_layer (gimp_display_get_image (shell->display)));
+
+      gimp_canvas_canvas_boundary_set_image (GIMP_CANVAS_CANVAS_BOUNDARY (shell->canvas_boundary),
+                                             gimp_display_get_image (shell->display));
+
+      if (window && gimp_image_window_get_active_shell (window) == shell)
+        {
+          GimpUIManager *manager = gimp_image_window_get_ui_manager (window);
+
+          gimp_ui_manager_update (manager, shell->display);
+        }
+
+      context = gimp_get_user_context (shell->display->gimp);
+
+      if (shell->display == gimp_context_get_display (context))
+        {
+          gimp_ui_manager_update (shell->popup_manager, shell->display);
+        }
+    }
+}
+
+/**
+ * gimp_display_shell_pause:
+ * @shell: a display shell
+ *
+ * This function increments the pause count or the display shell.
+ * If it was zero coming in, then the function pauses the active tool,
+ * so that operations on the display can take place without corrupting
+ * anything that the tool has drawn.  It "undraws" the current tool
+ * drawing, and must be followed by gimp_display_shell_resume() after
+ * the operation in question is completed.
+ **/
+void
+gimp_display_shell_pause (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  shell->paused_count++;
+
+  if (shell->paused_count == 1)
+    {
+      /*  pause the currently active tool  */
+      tool_manager_control_active (shell->display->gimp,
+                                   GIMP_TOOL_ACTION_PAUSE,
+                                   shell->display);
+    }
+}
+
+/**
+ * gimp_display_shell_resume:
+ * @shell: a display shell
+ *
+ * This function decrements the pause count for the display shell.
+ * If this brings it to zero, then the current tool is resumed.
+ * It is an error to call this function without having previously
+ * called gimp_display_shell_pause().
+ **/
+void
+gimp_display_shell_resume (GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (shell->paused_count > 0);
+
+  shell->paused_count--;
+
+  if (shell->paused_count == 0)
+    {
+      /* start the currently active tool */
+      tool_manager_control_active (shell->display->gimp,
+                                   GIMP_TOOL_ACTION_RESUME,
+                                   shell->display);
+    }
+}
+
+/**
+ * gimp_display_shell_set_highlight:
+ * @shell:     a #GimpDisplayShell
+ * @highlight: a rectangle in image coordinates that should be brought out
+ * @opacity:   how much to hide the unselected area
+ *
+ * This function sets an area of the image that should be
+ * accentuated. The actual implementation is to dim all pixels outside
+ * this rectangle. Passing %NULL for @highlight unsets the rectangle.
+ **/
+void
+gimp_display_shell_set_highlight (GimpDisplayShell   *shell,
+                                  const GdkRectangle *highlight,
+                                  gdouble             opacity)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (highlight)
+    {
+      gimp_canvas_item_begin_change (shell->passe_partout);
+
+      gimp_canvas_rectangle_set (shell->passe_partout,
+                                 highlight->x,
+                                 highlight->y,
+                                 highlight->width,
+                                 highlight->height);
+      g_object_set (shell->passe_partout, "opacity", opacity, NULL);
+
+      gimp_canvas_item_set_visible (shell->passe_partout, TRUE);
+
+      gimp_canvas_item_end_change (shell->passe_partout);
+    }
+  else
+    {
+      gimp_canvas_item_set_visible (shell->passe_partout, FALSE);
+    }
+}
+
+/**
+ * gimp_display_shell_set_mask:
+ * @shell: a #GimpDisplayShell
+ * @mask:  a #GimpDrawable (1 byte per pixel)
+ * @color: the color to use for drawing the mask
+ * @inverted: #TRUE if the mask should be drawn inverted
+ *
+ * Previews a mask originating at offset_x, offset_x. Depending on
+ * @inverted, pixels that are selected or not selected are tinted with
+ * the given color.
+ **/
+void
+gimp_display_shell_set_mask (GimpDisplayShell *shell,
+                             GeglBuffer       *mask,
+                             gint              offset_x,
+                             gint              offset_y,
+                             const GimpRGB    *color,
+                             gboolean          inverted)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (mask == NULL || GEGL_IS_BUFFER (mask));
+  g_return_if_fail (mask == NULL || color != NULL);
+
+  if (mask)
+    g_object_ref (mask);
+
+  if (shell->mask)
+    g_object_unref (shell->mask);
+
+  shell->mask = mask;
+
+  shell->mask_offset_x = offset_x;
+  shell->mask_offset_y = offset_y;
+
+  if (mask)
+    shell->mask_color = *color;
+
+  shell->mask_inverted = inverted;
+
+  gimp_display_shell_expose_full (shell);
+}
diff --git a/app/display/gimpdisplayshell.h b/app/display/gimpdisplayshell.h
new file mode 100644
index 0000000..1da9d8f
--- /dev/null
+++ b/app/display/gimpdisplayshell.h
@@ -0,0 +1,340 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_SHELL_H__
+#define __GIMP_DISPLAY_SHELL_H__
+
+
+/* Apply to a float the same rounding mode used in the renderer */
+#define  PROJ_ROUND(coord)   ((gint) RINT (coord))
+#define  PROJ_ROUND64(coord) ((gint64) RINT (coord))
+
+/* scale values */
+#define  SCALEX(s,x)      PROJ_ROUND ((x) * (s)->scale_x)
+#define  SCALEY(s,y)      PROJ_ROUND ((y) * (s)->scale_y)
+
+/* unscale values */
+#define  UNSCALEX(s,x)    ((gint) ((x) / (s)->scale_x))
+#define  UNSCALEY(s,y)    ((gint) ((y) / (s)->scale_y))
+/* (and float-returning versions) */
+#define  FUNSCALEX(s,x)   ((x) / (s)->scale_x)
+#define  FUNSCALEY(s,y)   ((y) / (s)->scale_y)
+
+
+#define GIMP_TYPE_DISPLAY_SHELL            (gimp_display_shell_get_type ())
+#define GIMP_DISPLAY_SHELL(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_DISPLAY_SHELL, GimpDisplayShell))
+#define GIMP_DISPLAY_SHELL_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_DISPLAY_SHELL, GimpDisplayShellClass))
+#define GIMP_IS_DISPLAY_SHELL(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_DISPLAY_SHELL))
+#define GIMP_IS_DISPLAY_SHELL_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_DISPLAY_SHELL))
+#define GIMP_DISPLAY_SHELL_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_DISPLAY_SHELL, GimpDisplayShellClass))
+
+
+typedef struct _GimpDisplayShellClass  GimpDisplayShellClass;
+
+struct _GimpDisplayShell
+{
+  GtkEventBox        parent_instance;
+
+  GimpDisplay       *display;
+
+  GimpUIManager     *popup_manager;
+  GdkScreen         *initial_screen;
+  gint               initial_monitor;
+
+  GimpDisplayOptions *options;
+  GimpDisplayOptions *fullscreen_options;
+  GimpDisplayOptions *no_image_options;
+
+  GimpUnit           unit;
+
+  gint               offset_x;         /*  offset of display image            */
+  gint               offset_y;
+
+  gdouble            scale_x;          /*  horizontal scale factor            */
+  gdouble            scale_y;          /*  vertical scale factor              */
+
+  gboolean           flip_horizontally;
+  gboolean           flip_vertically;
+  gdouble            rotate_angle;
+  cairo_matrix_t    *rotate_transform;
+  cairo_matrix_t    *rotate_untransform;
+
+  gdouble            monitor_xres;
+  gdouble            monitor_yres;
+  gboolean           dot_for_dot;      /*  ignore monitor resolution          */
+
+  GimpZoomModel     *zoom;
+
+  gdouble            last_scale;       /*  scale used when reverting zoom     */
+  guint              last_scale_time;  /*  time when last_scale was set       */
+  gint               last_offset_x;    /*  offsets used when reverting zoom   */
+  gint               last_offset_y;
+
+  gdouble            other_scale;      /*  scale factor entered in Zoom->Other*/
+
+  gint               disp_width;       /*  width of drawing area              */
+  gint               disp_height;      /*  height of drawing area             */
+
+  gboolean           proximity;        /*  is a device in proximity           */
+
+  gboolean           show_image;       /*  whether to show the image          */
+
+  gboolean           show_all;         /*  show the entire image              */
+
+  Selection         *selection;        /*  Selection (marching ants)          */
+
+  GList             *children;
+
+  GtkWidget         *canvas;           /*  GimpCanvas widget                  */
+
+  GtkAdjustment     *hsbdata;          /*  adjustments                        */
+  GtkAdjustment     *vsbdata;
+  GtkWidget         *hsb;              /*  scroll bars                        */
+  GtkWidget         *vsb;
+
+  GtkWidget         *hrule;            /*  rulers                             */
+  GtkWidget         *vrule;
+
+  GtkWidget         *origin;           /*  NW: origin                         */
+  GtkWidget         *quick_mask_button;/*  SW: quick mask button              */
+  GtkWidget         *zoom_button;      /*  NE: zoom toggle button             */
+  GtkWidget         *nav_ebox;         /*  SE: navigation event box           */
+
+  GtkWidget         *statusbar;        /*  statusbar                          */
+
+  GimpCanvasItem    *canvas_item;      /*  items drawn on the canvas          */
+  GimpCanvasItem    *unrotated_item;   /*  unrotated items for e.g. cursor    */
+  GimpCanvasItem    *passe_partout;    /*  item for the highlight             */
+  GimpCanvasItem    *preview_items;    /*  item for previews                  */
+  GimpCanvasItem    *vectors;          /*  item proxy of vectors              */
+  GimpCanvasItem    *grid;             /*  item proxy of the grid             */
+  GimpCanvasItem    *guides;           /*  item proxies of guides             */
+  GimpCanvasItem    *sample_points;    /*  item proxies of sample points      */
+  GimpCanvasItem    *canvas_boundary;  /*  item for the cabvas boundary       */
+  GimpCanvasItem    *layer_boundary;   /*  item for the layer boundary        */
+  GimpCanvasItem    *tool_items;       /*  tools items, below the cursor      */
+  GimpCanvasItem    *cursor;           /*  item for the software cursor       */
+
+  guint              title_idle_id;    /*  title update idle ID               */
+  gchar             *title;            /*  current title                      */
+  gchar             *status;           /*  current default statusbar content  */
+
+  gint               icon_size;        /*  size of the icon pixbuf            */
+  gint               icon_size_small;  /*  size of the icon's wilber pixbuf   */
+  guint              icon_idle_id;     /*  ID of the idle-function            */
+  GdkPixbuf         *icon;             /*  icon                               */
+
+  guint              fill_idle_id;     /*  display_shell_fill() idle ID       */
+
+  GimpHandedness     cursor_handedness;/*  Handedness for cursor display      */
+  GimpCursorType     current_cursor;   /*  Currently installed main cursor    */
+  GimpToolCursorType tool_cursor;      /*  Current Tool cursor                */
+  GimpCursorModifier cursor_modifier;  /*  Cursor modifier (plus, minus, ...) */
+
+  GimpCursorType     override_cursor;  /*  Overriding cursor                  */
+  gboolean           using_override_cursor;
+  gboolean           draw_cursor;      /* should we draw software cursor ?    */
+
+  GtkWidget         *close_dialog;     /*  close dialog                       */
+  GtkWidget         *scale_dialog;     /*  scale (zoom) dialog                */
+  GtkWidget         *rotate_dialog;    /*  rotate dialog                      */
+  GtkWidget         *nav_popup;        /*  navigation popup                   */
+
+  GimpColorConfig   *color_config;     /*  color management settings          */
+  gboolean           color_config_set; /*  settings changed from defaults     */
+
+  GimpColorTransform *profile_transform;
+  GeglBuffer         *profile_buffer;  /*  buffer for profile transform       */
+  guchar             *profile_data;    /*  profile_buffer's pixels            */
+  gint                profile_stride;  /*  profile_buffer's stride            */
+
+  GimpColorDisplayStack *filter_stack; /*  color display conversion stuff     */
+  guint                  filter_idle_id;
+
+  GimpColorTransform *filter_transform;
+  const Babl         *filter_format;   /*  filter_buffer's format             */
+  GeglBuffer         *filter_buffer;   /*  buffer for display filters         */
+  guchar             *filter_data;     /*  filter_buffer's pixels             */
+  gint                filter_stride;   /*  filter_buffer's stride             */
+
+  GimpDisplayXfer   *xfer;             /*  manages image buffer transfers     */
+  cairo_surface_t   *mask_surface;     /*  buffer for rendering the mask      */
+  cairo_pattern_t   *checkerboard;     /*  checkerboard pattern               */
+
+  gint               paused_count;
+
+  GimpTreeHandler   *vectors_freeze_handler;
+  GimpTreeHandler   *vectors_thaw_handler;
+  GimpTreeHandler   *vectors_visible_handler;
+
+  gboolean           zoom_on_resize;
+
+  gboolean           size_allocate_from_configure_event;
+  gboolean           size_allocate_center_image;
+
+  /*  the state of gimp_display_shell_tool_events()  */
+  gboolean           pointer_grabbed;
+  guint32            pointer_grab_time;
+
+  gboolean           keyboard_grabbed;
+  guint32            keyboard_grab_time;
+
+  gboolean           inferior_ignore_mode;
+
+  /* Two states are possible when the shell is grabbed: it can be
+   * grabbed with space (or space+button1 which is the same state),
+   * then if space is released but button1 was still pressed, we wait
+   * for button1 to be released as well.
+   */
+  gboolean           space_release_pending;
+  gboolean           button1_release_pending;
+  const gchar       *space_shaded_tool;
+
+  gboolean           scrolling;
+  gint               scroll_start_x;
+  gint               scroll_start_y;
+  gint               scroll_last_x;
+  gint               scroll_last_y;
+  gboolean           rotating;
+  gdouble            rotate_drag_angle;
+  gboolean           scaling;
+  gpointer           scroll_info;
+  gboolean           layer_picking;
+  GimpLayer         *picked_layer;
+
+  GeglBuffer        *mask;
+  gint               mask_offset_x;
+  gint               mask_offset_y;
+  GimpRGB            mask_color;
+  gboolean           mask_inverted;
+
+  GimpMotionBuffer  *motion_buffer;
+
+  GQueue            *zoom_focus_pointer_queue;
+
+  gboolean           blink;
+  guint              blink_timeout_id;
+};
+
+struct _GimpDisplayShellClass
+{
+  GtkEventBoxClass  parent_class;
+
+  void (* scaled)    (GimpDisplayShell *shell);
+  void (* scrolled)  (GimpDisplayShell *shell);
+  void (* rotated)   (GimpDisplayShell *shell);
+  void (* reconnect) (GimpDisplayShell *shell);
+};
+
+
+GType             gimp_display_shell_get_type      (void) G_GNUC_CONST;
+
+GtkWidget       * gimp_display_shell_new           (GimpDisplay        *display,
+                                                    GimpUnit            unit,
+                                                    gdouble             scale,
+                                                    GimpUIManager      *popup_manager,
+                                                    GdkScreen          *screen,
+                                                    gint                monitor);
+
+void              gimp_display_shell_add_overlay   (GimpDisplayShell   *shell,
+                                                    GtkWidget          *child,
+                                                    gdouble             image_x,
+                                                    gdouble             image_y,
+                                                    GimpHandleAnchor    anchor,
+                                                    gint                spacing_x,
+                                                    gint                spacing_y);
+void              gimp_display_shell_move_overlay  (GimpDisplayShell   *shell,
+                                                    GtkWidget          *child,
+                                                    gdouble             image_x,
+                                                    gdouble             image_y,
+                                                    GimpHandleAnchor    anchor,
+                                                    gint                spacing_x,
+                                                    gint                spacing_y);
+
+GimpImageWindow * gimp_display_shell_get_window    (GimpDisplayShell   *shell);
+GimpStatusbar   * gimp_display_shell_get_statusbar (GimpDisplayShell   *shell);
+
+GimpColorConfig * gimp_display_shell_get_color_config
+                                                   (GimpDisplayShell   *shell);
+
+void              gimp_display_shell_present       (GimpDisplayShell   *shell);
+
+void              gimp_display_shell_reconnect     (GimpDisplayShell   *shell);
+
+void              gimp_display_shell_empty         (GimpDisplayShell   *shell);
+void              gimp_display_shell_fill          (GimpDisplayShell   *shell,
+                                                    GimpImage          *image,
+                                                    GimpUnit            unit,
+                                                    gdouble             scale);
+
+void              gimp_display_shell_scaled        (GimpDisplayShell   *shell);
+void              gimp_display_shell_scrolled      (GimpDisplayShell   *shell);
+void              gimp_display_shell_rotated       (GimpDisplayShell   *shell);
+
+void              gimp_display_shell_set_unit      (GimpDisplayShell   *shell,
+                                                    GimpUnit            unit);
+GimpUnit          gimp_display_shell_get_unit      (GimpDisplayShell   *shell);
+
+gboolean          gimp_display_shell_snap_coords   (GimpDisplayShell   *shell,
+                                                    GimpCoords         *coords,
+                                                    gint                snap_offset_x,
+                                                    gint                snap_offset_y,
+                                                    gint                snap_width,
+                                                    gint                snap_height);
+
+gboolean          gimp_display_shell_mask_bounds   (GimpDisplayShell   *shell,
+                                                    gint               *x,
+                                                    gint               *y,
+                                                    gint               *width,
+                                                    gint               *height);
+
+void              gimp_display_shell_set_show_image
+                                                   (GimpDisplayShell   *shell,
+                                                    gboolean            show_image);
+
+void              gimp_display_shell_set_show_all  (GimpDisplayShell   *shell,
+                                                    gboolean            show_all);
+
+GimpPickable    * gimp_display_shell_get_pickable  (GimpDisplayShell   *shell);
+GimpPickable    * gimp_display_shell_get_canvas_pickable
+                                                   (GimpDisplayShell   *shell);
+GeglRectangle     gimp_display_shell_get_bounding_box
+                                                   (GimpDisplayShell   *shell);
+gboolean          gimp_display_shell_get_infinite_canvas
+                                                   (GimpDisplayShell   *shell);
+
+void              gimp_display_shell_update_priority_rect
+                                                   (GimpDisplayShell *shell);
+
+void              gimp_display_shell_flush         (GimpDisplayShell   *shell,
+                                                    gboolean            now);
+
+void              gimp_display_shell_pause         (GimpDisplayShell   *shell);
+void              gimp_display_shell_resume        (GimpDisplayShell   *shell);
+
+void              gimp_display_shell_set_highlight (GimpDisplayShell   *shell,
+                                                    const GdkRectangle *highlight,
+                                                    double              opacity);
+void              gimp_display_shell_set_mask      (GimpDisplayShell   *shell,
+                                                    GeglBuffer         *mask,
+                                                    gint                offset_x,
+                                                    gint                offset_y,
+                                                    const GimpRGB      *color,
+                                                    gboolean            inverted);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_H__ */
diff --git a/app/display/gimpdisplayxfer.c b/app/display/gimpdisplayxfer.c
new file mode 100644
index 0000000..1dcd13c
--- /dev/null
+++ b/app/display/gimpdisplayxfer.c
@@ -0,0 +1,289 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "gimpdisplayxfer.h"
+
+
+#define NUM_PAGES 2
+
+typedef struct _RTree     RTree;
+typedef struct _RTreeNode RTreeNode;
+
+struct _RTreeNode
+{
+  RTreeNode *children[2];
+  RTreeNode *next;
+  gint       x, y, w, h;
+};
+
+struct _RTree
+{
+  RTreeNode  root;
+  RTreeNode *available;
+};
+
+struct _GimpDisplayXfer
+{
+  /* track subregions of render_surface for efficient uploads */
+  RTree            rtree;
+  cairo_surface_t *render_surface[NUM_PAGES];
+  gint             page;
+};
+
+
+gint GIMP_DISPLAY_RENDER_BUF_WIDTH  = 256;
+gint GIMP_DISPLAY_RENDER_BUF_HEIGHT = 256;
+
+
+static RTreeNode *
+rtree_node_create (RTree      *rtree,
+                   RTreeNode **prev,
+                   gint        x,
+                   gint        y,
+                   gint        w,
+                   gint        h)
+{
+  RTreeNode *node;
+
+  gimp_assert (x >= 0 && x+w <= rtree->root.w);
+  gimp_assert (y >= 0 && y+h <= rtree->root.h);
+
+  if (w <= 0 || h <= 0)
+    return NULL;
+
+  node = g_slice_alloc (sizeof (*node));
+
+  node->children[0] = NULL;
+  node->children[1] = NULL;
+  node->x = x;
+  node->y = y;
+  node->w = w;
+  node->h = h;
+
+  node->next = *prev;
+  *prev = node;
+
+  return node;
+}
+
+static void
+rtree_node_destroy (RTree     *rtree,
+                    RTreeNode *node)
+{
+  gint i;
+
+  for (i = 0; i < 2; i++)
+    {
+      if (node->children[i])
+        rtree_node_destroy (rtree, node->children[i]);
+    }
+
+  g_slice_free (RTreeNode, node);
+}
+
+static RTreeNode *
+rtree_node_insert (RTree      *rtree,
+                   RTreeNode **prev,
+                   RTreeNode  *node,
+                   gint        w,
+                   gint        h)
+{
+  *prev = node->next;
+
+  if (((node->w - w) | (node->h - h)) > 1)
+    {
+      gint ww = node->w - w;
+      gint hh = node->h - h;
+
+      if (ww >= hh)
+        {
+          node->children[0] = rtree_node_create (rtree, prev,
+                                                 node->x + w, node->y,
+                                                 ww, node->h);
+          node->children[1] = rtree_node_create (rtree, prev,
+                                                 node->x, node->y + h,
+                                                 w, hh);
+        }
+      else
+        {
+          node->children[0] = rtree_node_create (rtree, prev,
+                                                 node->x, node->y + h,
+                                                 node->w, hh);
+          node->children[1] = rtree_node_create (rtree, prev,
+                                                 node->x + w, node->y,
+                                                 ww, h);
+        }
+    }
+
+  return node;
+}
+
+static RTreeNode *
+rtree_insert (RTree *rtree,
+              gint   w,
+              gint   h)
+{
+  RTreeNode *node, **prev;
+
+  for (prev = &rtree->available; (node = *prev); prev = &node->next)
+    if (node->w >= w && node->h >= h)
+      return rtree_node_insert (rtree, prev, node, w, h);
+
+  return NULL;
+}
+
+static void
+rtree_init (RTree *rtree,
+            gint   w,
+            gint   h)
+{
+  rtree->root.x = 0;
+  rtree->root.y = 0;
+  rtree->root.w = w;
+  rtree->root.h = h;
+  rtree->root.children[0] = NULL;
+  rtree->root.children[1] = NULL;
+  rtree->root.next = NULL;
+  rtree->available = &rtree->root;
+}
+
+static void
+rtree_reset (RTree *rtree)
+{
+  gint i;
+
+  for (i = 0; i < 2; i++)
+    {
+      if (rtree->root.children[i] == NULL)
+        continue;
+
+      rtree_node_destroy (rtree, rtree->root.children[i]);
+      rtree->root.children[i] = NULL;
+    }
+
+  rtree->root.next = NULL;
+  rtree->available = &rtree->root;
+}
+
+static void
+xfer_destroy (void *data)
+{
+  GimpDisplayXfer *xfer = data;
+  gint             i;
+
+  for (i = 0; i < NUM_PAGES; i++)
+    cairo_surface_destroy (xfer->render_surface[i]);
+
+  rtree_reset (&xfer->rtree);
+  g_free (xfer);
+}
+
+GimpDisplayXfer *
+gimp_display_xfer_realize (GtkWidget *widget)
+{
+  GdkScreen       *screen;
+  GimpDisplayXfer *xfer;
+  const gchar     *env;
+
+  env = g_getenv ("GIMP_DISPLAY_RENDER_BUF_SIZE");
+  if (env)
+    {
+      gint width  = atoi (env);
+      gint height = width;
+
+      env = strchr (env, 'x');
+      if (env)
+        height = atoi (env + 1);
+
+      if (width  > 0 && width  <= 8192 &&
+          height > 0 && height <= 8192)
+        {
+          GIMP_DISPLAY_RENDER_BUF_WIDTH  = width;
+          GIMP_DISPLAY_RENDER_BUF_HEIGHT = height;
+        }
+    }
+
+  screen = gtk_widget_get_screen (widget);
+  xfer = g_object_get_data (G_OBJECT (screen), "gimp-display-xfer");
+
+  if (xfer == NULL)
+    {
+      cairo_t *cr;
+      gint     w = GIMP_DISPLAY_RENDER_BUF_WIDTH;
+      gint     h = GIMP_DISPLAY_RENDER_BUF_HEIGHT;
+      int      n;
+
+      xfer = g_new (GimpDisplayXfer, 1);
+      rtree_init (&xfer->rtree, w, h);
+
+      cr = gdk_cairo_create (gtk_widget_get_window (widget));
+      for (n = 0; n < NUM_PAGES; n++)
+        {
+          xfer->render_surface[n] =
+            cairo_surface_create_similar_image (cairo_get_target (cr),
+                                                CAIRO_FORMAT_ARGB32, w, h);
+          cairo_surface_mark_dirty (xfer->render_surface[n]);
+        }
+      cairo_destroy (cr);
+      xfer->page = 0;
+
+      g_object_set_data_full (G_OBJECT (screen),
+                              "gimp-display-xfer",
+                              xfer, xfer_destroy);
+    }
+
+  return xfer;
+}
+
+cairo_surface_t *
+gimp_display_xfer_get_surface (GimpDisplayXfer *xfer,
+                               gint             w,
+                               gint             h,
+                               gint            *src_x,
+                               gint            *src_y)
+{
+  RTreeNode *node;
+
+  gimp_assert (w <= GIMP_DISPLAY_RENDER_BUF_WIDTH &&
+               h <= GIMP_DISPLAY_RENDER_BUF_HEIGHT);
+
+  node = rtree_insert (&xfer->rtree, w, h);
+  if (node == NULL)
+    {
+      xfer->page = (xfer->page + 1) % NUM_PAGES;
+      cairo_surface_flush (xfer->render_surface[xfer->page]);
+      rtree_reset (&xfer->rtree);
+      cairo_surface_mark_dirty (xfer->render_surface[xfer->page]); /* XXX */
+      node = rtree_insert (&xfer->rtree, w, h);
+      gimp_assert (node != NULL);
+    }
+
+  *src_x = node->x;
+  *src_y = node->y;
+
+  return xfer->render_surface[xfer->page];
+}
diff --git a/app/display/gimpdisplayxfer.h b/app/display/gimpdisplayxfer.h
new file mode 100644
index 0000000..20656b9
--- /dev/null
+++ b/app/display/gimpdisplayxfer.h
@@ -0,0 +1,37 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_DISPLAY_XFER_H__
+#define __GIMP_DISPLAY_XFER_H__
+
+
+extern gint GIMP_DISPLAY_RENDER_BUF_WIDTH;
+extern gint GIMP_DISPLAY_RENDER_BUF_HEIGHT;
+
+#define GIMP_DISPLAY_RENDER_MAX_SCALE  4.0
+
+
+GimpDisplayXfer * gimp_display_xfer_realize     (GtkWidget       *widget);
+
+cairo_surface_t * gimp_display_xfer_get_surface (GimpDisplayXfer *xfer,
+                                                 gint             w,
+                                                 gint             h,
+                                                 gint            *src_x,
+                                                 gint            *src_y);
+
+
+#endif  /*  __GIMP_DISPLAY_XFER_H__  */
diff --git a/app/display/gimpimagewindow.c b/app/display/gimpimagewindow.c
new file mode 100644
index 0000000..fd5c501
--- /dev/null
+++ b/app/display/gimpimagewindow.c
@@ -0,0 +1,2428 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <math.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#ifdef G_OS_WIN32
+#include <windef.h>
+#include <winbase.h>
+#include <windows.h>
+#endif
+
+#ifdef GDK_WINDOWING_QUARTZ
+#import <AppKit/AppKit.h>
+#include <gdk/gdkquartz.h>
+#endif /* !GDK_WINDOWING_QUARTZ */
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpguiconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimpprogress.h"
+#include "core/gimpcontainer.h"
+
+#include "widgets/gimpactiongroup.h"
+#include "widgets/gimpdialogfactory.h"
+#include "widgets/gimpdock.h"
+#include "widgets/gimpdockbook.h"
+#include "widgets/gimpdockcolumns.h"
+#include "widgets/gimpdockcontainer.h"
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpmenufactory.h"
+#include "widgets/gimpsessioninfo.h"
+#include "widgets/gimpsessioninfo-aux.h"
+#include "widgets/gimpsessionmanaged.h"
+#include "widgets/gimpsessioninfo-dock.h"
+#include "widgets/gimptoolbox.h"
+#include "widgets/gimpuimanager.h"
+#include "widgets/gimpview.h"
+#include "widgets/gimpviewrenderer.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplay-foreach.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-close.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-tool-events.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpimagewindow.h"
+#include "gimpstatusbar.h"
+
+#include "gimp-log.h"
+#include "gimp-priorities.h"
+
+#include "gimp-intl.h"
+
+
+#define GIMP_EMPTY_IMAGE_WINDOW_ENTRY_ID   "gimp-empty-image-window"
+#define GIMP_SINGLE_IMAGE_WINDOW_ENTRY_ID  "gimp-single-image-window"
+
+/* The width of the left and right dock areas */
+#define GIMP_IMAGE_WINDOW_LEFT_DOCKS_WIDTH  "left-docks-width"
+#define GIMP_IMAGE_WINDOW_RIGHT_DOCKS_WIDTH "right-docks-width"
+
+/* deprecated property: GtkPaned position of the right docks area */
+#define GIMP_IMAGE_WINDOW_RIGHT_DOCKS_POS  "right-docks-position"
+
+/* Whether the window's maximized or not */
+#define GIMP_IMAGE_WINDOW_MAXIMIZED        "maximized"
+
+#if MAC_OS_X_VERSION_MAX_ALLOWED < 1070
+#define NSWindowCollectionBehaviorFullScreenAuxiliary (1 << 8)
+#endif
+
+
+enum
+{
+  PROP_0,
+  PROP_GIMP,
+  PROP_DIALOG_FACTORY,
+  PROP_INITIAL_SCREEN,
+  PROP_INITIAL_MONITOR
+};
+
+
+typedef struct _GimpImageWindowPrivate GimpImageWindowPrivate;
+
+struct _GimpImageWindowPrivate
+{
+  Gimp              *gimp;
+  GimpUIManager     *menubar_manager;
+  GimpDialogFactory *dialog_factory;
+
+  GList             *shells;
+  GimpDisplayShell  *active_shell;
+
+  GtkWidget         *main_vbox;
+  GtkWidget         *menubar;
+  GtkWidget         *hbox;
+  GtkWidget         *left_hpane;
+  GtkWidget         *left_docks;
+  GtkWidget         *right_hpane;
+  GtkWidget         *notebook;
+  GtkWidget         *right_docks;
+
+  GdkWindowState     window_state;
+
+  const gchar       *entry_id;
+
+  GdkScreen         *initial_screen;
+  gint               initial_monitor;
+
+  gint               suspend_keep_pos;
+
+  gint               update_ui_manager_idle_id;
+};
+
+typedef struct
+{
+  gint canvas_x;
+  gint canvas_y;
+  gint window_x;
+  gint window_y;
+} PosCorrectionData;
+
+
+#define GIMP_IMAGE_WINDOW_GET_PRIVATE(window) \
+        ((GimpImageWindowPrivate *) gimp_image_window_get_instance_private ((GimpImageWindow *) (window)))
+
+
+/*  local function prototypes  */
+
+static void      gimp_image_window_dock_container_iface_init
+                                                       (GimpDockContainerInterface
+                                                                            *iface);
+static void      gimp_image_window_session_managed_iface_init
+                                                       (GimpSessionManagedInterface
+                                                                            *iface);
+static void      gimp_image_window_constructed         (GObject             *object);
+static void      gimp_image_window_dispose             (GObject             *object);
+static void      gimp_image_window_finalize            (GObject             *object);
+static void      gimp_image_window_set_property        (GObject             *object,
+                                                        guint                property_id,
+                                                        const GValue        *value,
+                                                        GParamSpec          *pspec);
+static void      gimp_image_window_get_property        (GObject             *object,
+                                                        guint                property_id,
+                                                        GValue              *value,
+                                                        GParamSpec          *pspec);
+
+static void      gimp_image_window_map                 (GtkWidget           *widget);
+static gboolean  gimp_image_window_delete_event        (GtkWidget           *widget,
+                                                        GdkEventAny         *event);
+static gboolean  gimp_image_window_configure_event     (GtkWidget           *widget,
+                                                        GdkEventConfigure   *event);
+static gboolean  gimp_image_window_window_state_event  (GtkWidget           *widget,
+                                                        GdkEventWindowState *event);
+static void      gimp_image_window_style_set           (GtkWidget           *widget,
+                                                        GtkStyle            *prev_style);
+
+static void      gimp_image_window_monitor_changed     (GimpWindow          *window,
+                                                        GdkScreen           *screen,
+                                                        gint                 monitor);
+
+static GList *   gimp_image_window_get_docks           (GimpDockContainer   *dock_container);
+static GimpDialogFactory *
+                 gimp_image_window_dock_container_get_dialog_factory
+                                                       (GimpDockContainer   *dock_container);
+static GimpUIManager *
+                 gimp_image_window_dock_container_get_ui_manager
+                                                       (GimpDockContainer   *dock_container);
+static void      gimp_image_window_add_dock            (GimpDockContainer   *dock_container,
+                                                        GimpDock            *dock,
+                                                        GimpSessionInfoDock *dock_info);
+static GimpAlignmentType
+                 gimp_image_window_get_dock_side       (GimpDockContainer   *dock_container,
+                                                        GimpDock            *dock);
+static GList   * gimp_image_window_get_aux_info        (GimpSessionManaged  *session_managed);
+static void      gimp_image_window_set_aux_info        (GimpSessionManaged  *session_managed,
+                                                        GList               *aux_info);
+
+static void      gimp_image_window_config_notify       (GimpImageWindow     *window,
+                                                        GParamSpec          *pspec,
+                                                        GimpGuiConfig       *config);
+static void      gimp_image_window_session_clear       (GimpImageWindow     *window);
+static void      gimp_image_window_session_apply       (GimpImageWindow     *window,
+                                                        const gchar         *entry_id,
+                                                        GdkScreen           *screen,
+                                                        gint                 monitor);
+static void      gimp_image_window_session_update      (GimpImageWindow     *window,
+                                                        GimpDisplay         *new_display,
+                                                        const gchar         *new_entry_id,
+                                                        GdkScreen           *screen,
+                                                        gint                 monitor);
+static const gchar *
+                 gimp_image_window_config_to_entry_id  (GimpGuiConfig       *config);
+static void      gimp_image_window_show_tooltip        (GimpUIManager       *manager,
+                                                        const gchar         *tooltip,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_hide_tooltip        (GimpUIManager       *manager,
+                                                        GimpImageWindow     *window);
+static gboolean  gimp_image_window_update_ui_manager_idle
+                                                       (GimpImageWindow     *window);
+static void      gimp_image_window_update_ui_manager   (GimpImageWindow     *window);
+
+static void      gimp_image_window_shell_size_allocate (GimpDisplayShell    *shell,
+                                                        GtkAllocation       *allocation,
+                                                        PosCorrectionData   *data);
+static gboolean  gimp_image_window_shell_events        (GtkWidget           *widget,
+                                                        GdkEvent            *event,
+                                                        GimpImageWindow     *window);
+
+static void      gimp_image_window_switch_page         (GtkNotebook         *notebook,
+                                                        gpointer             page,
+                                                        gint                 page_num,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_page_removed        (GtkNotebook         *notebook,
+                                                        GtkWidget           *widget,
+                                                        gint                 page_num,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_page_reordered      (GtkNotebook         *notebook,
+                                                        GtkWidget           *widget,
+                                                        gint                 page_num,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_disconnect_from_active_shell
+                                                       (GimpImageWindow *window);
+
+static void      gimp_image_window_image_notify        (GimpDisplay         *display,
+                                                        const GParamSpec    *pspec,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_shell_scaled        (GimpDisplayShell    *shell,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_shell_rotated       (GimpDisplayShell    *shell,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_shell_title_notify  (GimpDisplayShell    *shell,
+                                                        const GParamSpec    *pspec,
+                                                        GimpImageWindow     *window);
+static void      gimp_image_window_shell_icon_notify   (GimpDisplayShell    *shell,
+                                                        const GParamSpec    *pspec,
+                                                        GimpImageWindow     *window);
+static GtkWidget *
+                 gimp_image_window_create_tab_label    (GimpImageWindow     *window,
+                                                        GimpDisplayShell    *shell);
+static void      gimp_image_window_update_tab_labels   (GimpImageWindow     *window);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpImageWindow, gimp_image_window, GIMP_TYPE_WINDOW,
+                         G_ADD_PRIVATE (GimpImageWindow)
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_DOCK_CONTAINER,
+                                                gimp_image_window_dock_container_iface_init)
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_SESSION_MANAGED,
+                                                gimp_image_window_session_managed_iface_init))
+
+#define parent_class gimp_image_window_parent_class
+
+
+static const gchar image_window_rc_style[] =
+  "style \"fullscreen-menubar-style\"\n"
+  "{\n"
+  "  GtkMenuBar::shadow-type      = none\n"
+  "  GtkMenuBar::internal-padding = 0\n"
+  "}\n"
+  "widget \"*.gimp-menubar-fullscreen\" style \"fullscreen-menubar-style\"\n";
+
+static void
+gimp_image_window_class_init (GimpImageWindowClass *klass)
+{
+  GObjectClass    *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass  *widget_class = GTK_WIDGET_CLASS (klass);
+  GimpWindowClass *window_class = GIMP_WINDOW_CLASS (klass);
+
+  object_class->constructed        = gimp_image_window_constructed;
+  object_class->dispose            = gimp_image_window_dispose;
+  object_class->finalize           = gimp_image_window_finalize;
+  object_class->set_property       = gimp_image_window_set_property;
+  object_class->get_property       = gimp_image_window_get_property;
+
+  widget_class->map                = gimp_image_window_map;
+  widget_class->delete_event       = gimp_image_window_delete_event;
+  widget_class->configure_event    = gimp_image_window_configure_event;
+  widget_class->window_state_event = gimp_image_window_window_state_event;
+  widget_class->style_set          = gimp_image_window_style_set;
+
+  window_class->monitor_changed    = gimp_image_window_monitor_changed;
+
+  g_object_class_install_property (object_class, PROP_GIMP,
+                                   g_param_spec_object ("gimp",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_GIMP,
+                                                        GIMP_PARAM_WRITABLE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_DIALOG_FACTORY,
+                                   g_param_spec_object ("dialog-factory",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_DIALOG_FACTORY,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_INITIAL_SCREEN,
+                                   g_param_spec_object ("initial-screen",
+                                                        NULL, NULL,
+                                                        GDK_TYPE_SCREEN,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+  g_object_class_install_property (object_class, PROP_INITIAL_MONITOR,
+                                   g_param_spec_int ("initial-monitor",
+                                                     NULL, NULL,
+                                                     0, 16, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT_ONLY));
+
+  gtk_rc_parse_string (image_window_rc_style);
+}
+
+static void
+gimp_image_window_init (GimpImageWindow *window)
+{
+  static gint  role_serial = 1;
+  gchar       *role;
+
+  role = g_strdup_printf ("gimp-image-window-%d", role_serial++);
+  gtk_window_set_role (GTK_WINDOW (window), role);
+  g_free (role);
+
+  gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
+}
+
+static void
+gimp_image_window_dock_container_iface_init (GimpDockContainerInterface *iface)
+{
+  iface->get_docks          = gimp_image_window_get_docks;
+  iface->get_dialog_factory = gimp_image_window_dock_container_get_dialog_factory;
+  iface->get_ui_manager     = gimp_image_window_dock_container_get_ui_manager;
+  iface->add_dock           = gimp_image_window_add_dock;
+  iface->get_dock_side      = gimp_image_window_get_dock_side;
+}
+
+static void
+gimp_image_window_session_managed_iface_init (GimpSessionManagedInterface *iface)
+{
+  iface->get_aux_info = gimp_image_window_get_aux_info;
+  iface->set_aux_info = gimp_image_window_set_aux_info;
+}
+
+static void
+gimp_image_window_constructed (GObject *object)
+{
+  GimpImageWindow        *window  = GIMP_IMAGE_WINDOW (object);
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpMenuFactory        *menu_factory;
+  GimpGuiConfig          *config;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  gimp_assert (GIMP_IS_GIMP (private->gimp));
+  gimp_assert (GIMP_IS_DIALOG_FACTORY (private->dialog_factory));
+
+  menu_factory = gimp_dialog_factory_get_menu_factory (private->dialog_factory);
+
+  private->menubar_manager = gimp_menu_factory_manager_new (menu_factory,
+                                                            "<Image>",
+                                                            window,
+                                                            FALSE);
+
+  g_signal_connect_object (private->dialog_factory, "dock-window-added",
+                           G_CALLBACK (gimp_image_window_update_ui_manager),
+                           window, G_CONNECT_SWAPPED);
+  g_signal_connect_object (private->dialog_factory, "dock-window-removed",
+                           G_CALLBACK (gimp_image_window_update_ui_manager),
+                           window, G_CONNECT_SWAPPED);
+
+  gtk_window_add_accel_group (GTK_WINDOW (window),
+                              gimp_ui_manager_get_accel_group (private->menubar_manager));
+
+  g_signal_connect (private->menubar_manager, "show-tooltip",
+                    G_CALLBACK (gimp_image_window_show_tooltip),
+                    window);
+  g_signal_connect (private->menubar_manager, "hide-tooltip",
+                    G_CALLBACK (gimp_image_window_hide_tooltip),
+                    window);
+
+  config = GIMP_GUI_CONFIG (private->gimp->config);
+
+  /* Create the window toplevel container */
+  private->main_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
+  gtk_container_add (GTK_CONTAINER (window), private->main_vbox);
+  gtk_widget_show (private->main_vbox);
+
+  /* Create the menubar */
+#ifndef GDK_WINDOWING_QUARTZ
+  private->menubar = gimp_ui_manager_get_widget (private->menubar_manager,
+                                                 "/image-menubar");
+#endif /* !GDK_WINDOWING_QUARTZ */
+  if (private->menubar)
+    {
+      gtk_box_pack_start (GTK_BOX (private->main_vbox),
+                          private->menubar, FALSE, FALSE, 0);
+
+      /*  make sure we can activate accels even if the menubar is invisible
+       *  (see https://bugzilla.gnome.org/show_bug.cgi?id=137151)
+       */
+      g_signal_connect (private->menubar, "can-activate-accel",
+                        G_CALLBACK (gtk_true),
+                        NULL);
+
+      /*  active display callback  */
+      g_signal_connect (private->menubar, "button-press-event",
+                        G_CALLBACK (gimp_image_window_shell_events),
+                        window);
+      g_signal_connect (private->menubar, "button-release-event",
+                        G_CALLBACK (gimp_image_window_shell_events),
+                        window);
+      g_signal_connect (private->menubar, "key-press-event",
+                        G_CALLBACK (gimp_image_window_shell_events),
+                        window);
+    }
+
+  /* Create the hbox that contains docks and images */
+  private->hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+  gtk_box_pack_start (GTK_BOX (private->main_vbox), private->hbox,
+                      TRUE, TRUE, 0);
+  gtk_widget_show (private->hbox);
+
+  /* Create the left pane */
+  private->left_hpane = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
+  gtk_box_pack_start (GTK_BOX (private->hbox), private->left_hpane,
+                      TRUE, TRUE, 0);
+  gtk_widget_show (private->left_hpane);
+
+  /* Create the left dock columns widget */
+  private->left_docks =
+    gimp_dock_columns_new (gimp_get_user_context (private->gimp),
+                           private->dialog_factory,
+                           private->menubar_manager);
+  gtk_paned_pack1 (GTK_PANED (private->left_hpane), private->left_docks,
+                   FALSE, FALSE);
+  gtk_widget_set_visible (private->left_docks, config->single_window_mode);
+
+  /* Create the right pane */
+  private->right_hpane = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
+  gtk_paned_pack2 (GTK_PANED (private->left_hpane), private->right_hpane,
+                   TRUE, FALSE);
+  gtk_widget_show (private->right_hpane);
+
+  /* Create notebook that contains images */
+  private->notebook = gtk_notebook_new ();
+  gtk_notebook_set_scrollable (GTK_NOTEBOOK (private->notebook), TRUE);
+  gtk_notebook_set_show_border (GTK_NOTEBOOK (private->notebook), FALSE);
+  gtk_notebook_set_show_tabs (GTK_NOTEBOOK (private->notebook), FALSE);
+  gtk_notebook_set_tab_pos (GTK_NOTEBOOK (private->notebook), GTK_POS_TOP);
+
+  gtk_paned_pack1 (GTK_PANED (private->right_hpane), private->notebook,
+                   TRUE, TRUE);
+
+  g_signal_connect (private->notebook, "switch-page",
+                    G_CALLBACK (gimp_image_window_switch_page),
+                    window);
+  g_signal_connect (private->notebook, "page-removed",
+                    G_CALLBACK (gimp_image_window_page_removed),
+                    window);
+  g_signal_connect (private->notebook, "page-reordered",
+                    G_CALLBACK (gimp_image_window_page_reordered),
+                    window);
+  gtk_widget_show (private->notebook);
+
+  /* Create the right dock columns widget */
+  private->right_docks =
+    gimp_dock_columns_new (gimp_get_user_context (private->gimp),
+                           private->dialog_factory,
+                           private->menubar_manager);
+  gtk_paned_pack2 (GTK_PANED (private->right_hpane), private->right_docks,
+                   FALSE, FALSE);
+  gtk_widget_set_visible (private->right_docks, config->single_window_mode);
+
+  g_signal_connect_object (config, "notify::single-window-mode",
+                           G_CALLBACK (gimp_image_window_config_notify),
+                           window, G_CONNECT_SWAPPED);
+  g_signal_connect_object (config, "notify::show-tabs",
+                           G_CALLBACK (gimp_image_window_config_notify),
+                           window, G_CONNECT_SWAPPED);
+  g_signal_connect_object (config, "notify::hide-docks",
+                           G_CALLBACK (gimp_image_window_config_notify),
+                           window, G_CONNECT_SWAPPED);
+  g_signal_connect_object (config, "notify::tabs-position",
+                           G_CALLBACK (gimp_image_window_config_notify),
+                           window, G_CONNECT_SWAPPED);
+
+  gimp_image_window_session_update (window,
+                                    NULL /*new_display*/,
+                                    gimp_image_window_config_to_entry_id (config),
+                                    private->initial_screen,
+                                    private->initial_monitor);
+}
+
+static void
+gimp_image_window_dispose (GObject *object)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (object);
+
+  if (private->dialog_factory)
+    {
+      g_signal_handlers_disconnect_by_func (private->dialog_factory,
+                                            gimp_image_window_update_ui_manager,
+                                            object);
+      private->dialog_factory = NULL;
+    }
+
+  g_clear_object (&private->menubar_manager);
+
+  if (private->update_ui_manager_idle_id)
+    {
+      g_source_remove (private->update_ui_manager_idle_id);
+      private->update_ui_manager_idle_id = 0;
+    }
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_image_window_finalize (GObject *object)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (object);
+
+  if (private->shells)
+    {
+      g_list_free (private->shells);
+      private->shells = NULL;
+    }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_image_window_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  GimpImageWindow        *window  = GIMP_IMAGE_WINDOW (object);
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  switch (property_id)
+    {
+    case PROP_GIMP:
+      private->gimp = g_value_get_object (value);
+      break;
+    case PROP_DIALOG_FACTORY:
+      private->dialog_factory = g_value_get_object (value);
+      break;
+    case PROP_INITIAL_SCREEN:
+      private->initial_screen = g_value_get_object (value);
+      break;
+    case PROP_INITIAL_MONITOR:
+      private->initial_monitor = g_value_get_int (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_image_window_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  GimpImageWindow        *window  = GIMP_IMAGE_WINDOW (object);
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  switch (property_id)
+    {
+    case PROP_GIMP:
+      g_value_set_object (value, private->gimp);
+      break;
+    case PROP_DIALOG_FACTORY:
+      g_value_set_object (value, private->dialog_factory);
+      break;
+    case PROP_INITIAL_SCREEN:
+      g_value_set_object (value, private->initial_screen);
+      break;
+    case PROP_INITIAL_MONITOR:
+      g_value_set_int (value, private->initial_monitor);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_image_window_map (GtkWidget *widget)
+{
+#ifdef GDK_WINDOWING_QUARTZ
+  GdkWindow *gdk_window;
+  NSWindow  *ns_window;
+#endif /* !GDK_WINDOWING_QUARTZ */
+
+  GTK_WIDGET_CLASS (parent_class)->map (widget);
+
+#ifdef GDK_WINDOWING_QUARTZ
+  gdk_window = gtk_widget_get_window (GTK_WIDGET (widget));
+  ns_window = gdk_quartz_window_get_nswindow (gdk_window);
+
+  /* Disable the new-style full screen mode. For now only the "old-style"
+   * full screen mode, via the "View" menu, is supported. In the future, and
+   * as soon as GTK+ has proper support for this, we will migrate to the
+   * new-style full screen mode.
+   */
+  ns_window.collectionBehavior |= NSWindowCollectionBehaviorFullScreenAuxiliary;
+#endif /* !GDK_WINDOWING_QUARTZ */
+}
+
+static gboolean
+gimp_image_window_delete_event (GtkWidget   *widget,
+                                GdkEventAny *event)
+{
+  GimpImageWindow        *window  = GIMP_IMAGE_WINDOW (widget);
+  GimpDisplayShell       *shell   = gimp_image_window_get_active_shell (window);
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpGuiConfig          *config  = GIMP_GUI_CONFIG (private->gimp->config);
+
+  if (config->single_window_mode)
+    gimp_ui_manager_activate_action (gimp_image_window_get_ui_manager (window),
+                                     "file", "file-quit");
+  else if (shell)
+    gimp_display_shell_close (shell, FALSE);
+
+  return TRUE;
+}
+
+static gboolean
+gimp_image_window_configure_event (GtkWidget         *widget,
+                                   GdkEventConfigure *event)
+{
+  GimpImageWindow *window = GIMP_IMAGE_WINDOW (widget);
+  GtkAllocation    allocation;
+  gint             current_width;
+  gint             current_height;
+
+  gtk_widget_get_allocation (widget, &allocation);
+
+  /* Grab the size before we run the parent implementation */
+  current_width  = allocation.width;
+  current_height = allocation.height;
+
+  /* Run the parent implementation */
+  if (GTK_WIDGET_CLASS (parent_class)->configure_event)
+    GTK_WIDGET_CLASS (parent_class)->configure_event (widget, event);
+
+  /* If the window size has changed, make sure additoinal logic is run
+   * in the display shell's size-allocate
+   */
+  if (event->width  != current_width ||
+      event->height != current_height)
+    {
+      /* FIXME multiple shells */
+      GimpDisplayShell *shell = gimp_image_window_get_active_shell (window);
+
+      if (shell && gimp_display_get_image (shell->display))
+        shell->size_allocate_from_configure_event = TRUE;
+    }
+
+  return TRUE;
+}
+
+static gboolean
+gimp_image_window_window_state_event (GtkWidget           *widget,
+                                      GdkEventWindowState *event)
+{
+  GimpImageWindow        *window  = GIMP_IMAGE_WINDOW (widget);
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpDisplayShell       *shell   = gimp_image_window_get_active_shell (window);
+
+  if (! shell)
+    return FALSE;
+
+  private->window_state = event->new_window_state;
+
+  if (event->changed_mask & GDK_WINDOW_STATE_FULLSCREEN)
+    {
+      gboolean fullscreen = gimp_image_window_get_fullscreen (window);
+
+      GIMP_LOG (WM, "Image window '%s' [%p] set fullscreen %s",
+                gtk_window_get_title (GTK_WINDOW (widget)),
+                widget,
+                fullscreen ? "TRUE" : "FALSE");
+
+      if (private->menubar)
+        gtk_widget_set_name (private->menubar,
+                             fullscreen ? "gimp-menubar-fullscreen" : NULL);
+
+      gimp_image_window_suspend_keep_pos (window);
+      gimp_display_shell_appearance_update (shell);
+      gimp_image_window_resume_keep_pos (window);
+    }
+
+  if (event->changed_mask & GDK_WINDOW_STATE_ICONIFIED)
+    {
+      GimpStatusbar *statusbar = gimp_display_shell_get_statusbar (shell);
+      gboolean       iconified = gimp_image_window_is_iconified (window);
+
+      GIMP_LOG (WM, "Image window '%s' [%p] set %s",
+                gtk_window_get_title (GTK_WINDOW (widget)),
+                widget,
+                iconified ? "iconified" : "uniconified");
+
+      if (iconified)
+        {
+          if (gimp_displays_get_num_visible (private->gimp) == 0)
+            {
+              GIMP_LOG (WM, "No displays visible any longer");
+
+              gimp_dialog_factory_hide_with_display (private->dialog_factory);
+            }
+        }
+      else
+        {
+          gimp_dialog_factory_show_with_display (private->dialog_factory);
+        }
+
+      if (gimp_progress_is_active (GIMP_PROGRESS (statusbar)))
+        {
+          if (iconified)
+            gimp_statusbar_override_window_title (statusbar);
+          else
+            gtk_window_set_title (GTK_WINDOW (window), shell->title);
+        }
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_image_window_style_set (GtkWidget *widget,
+                             GtkStyle  *prev_style)
+{
+  GimpImageWindow        *window        = GIMP_IMAGE_WINDOW (widget);
+  GimpImageWindowPrivate *private       = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpDisplayShell       *shell         = gimp_image_window_get_active_shell (window);
+  GimpStatusbar          *statusbar     = NULL;
+  GtkRequisition          requisition   = { 0, };
+  GdkGeometry             geometry      = { 0, };
+  GdkWindowHints          geometry_mask = 0;
+
+  GTK_WIDGET_CLASS (parent_class)->style_set (widget, prev_style);
+
+  if (! shell)
+    return;
+
+  statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gtk_widget_size_request (GTK_WIDGET (statusbar), &requisition);
+
+  geometry.min_height = 23;
+
+  geometry.min_width   = requisition.width;
+  geometry.min_height += requisition.height;
+
+  if (private->menubar)
+    {
+      gtk_widget_size_request (private->menubar, &requisition);
+
+      geometry.min_height += requisition.height;
+    }
+
+  geometry_mask = GDK_HINT_MIN_SIZE;
+
+  /*  Only set user pos on the empty display because it gets a pos
+   *  set by gimp. All other displays should be placed by the window
+   *  manager. See https://bugzilla.gnome.org/show_bug.cgi?id=559580
+   */
+  if (! gimp_display_get_image (shell->display))
+    geometry_mask |= GDK_HINT_USER_POS;
+
+  gtk_window_set_geometry_hints (GTK_WINDOW (widget), NULL,
+                                 &geometry, geometry_mask);
+
+  gimp_dialog_factory_set_has_min_size (GTK_WINDOW (widget), TRUE);
+}
+
+static void
+gimp_image_window_monitor_changed (GimpWindow *window,
+                                   GdkScreen  *screen,
+                                   gint        monitor)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GList                  *list;
+
+  for (list = private->shells; list; list = g_list_next (list))
+    {
+      /*  hack, this should live here, and screen_changed call
+       *  monitor_changed
+       */
+      g_signal_emit_by_name (list->data, "screen-changed",
+                             gtk_widget_get_screen (list->data));
+
+      /*  make it fetch the new monitor's resolution  */
+      gimp_display_shell_scale_update (GIMP_DISPLAY_SHELL (list->data));
+
+      /*  make it fetch the right monitor profile  */
+      gimp_color_managed_profile_changed (GIMP_COLOR_MANAGED (list->data));
+    }
+}
+
+static GList *
+gimp_image_window_get_docks (GimpDockContainer *dock_container)
+{
+  GimpImageWindowPrivate *private;
+  GList                  *iter;
+  GList                  *all_docks = NULL;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (dock_container), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (dock_container);
+
+  for (iter = gimp_dock_columns_get_docks (GIMP_DOCK_COLUMNS (private->left_docks));
+       iter;
+       iter = g_list_next (iter))
+    {
+      all_docks = g_list_append (all_docks, GIMP_DOCK (iter->data));
+    }
+
+  for (iter = gimp_dock_columns_get_docks (GIMP_DOCK_COLUMNS (private->right_docks));
+       iter;
+       iter = g_list_next (iter))
+    {
+      all_docks = g_list_append (all_docks, GIMP_DOCK (iter->data));
+    }
+
+  return all_docks;
+}
+
+static GimpDialogFactory *
+gimp_image_window_dock_container_get_dialog_factory (GimpDockContainer *dock_container)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (dock_container);
+
+  return private->dialog_factory;
+}
+
+static GimpUIManager *
+gimp_image_window_dock_container_get_ui_manager (GimpDockContainer *dock_container)
+{
+  GimpImageWindow *window = GIMP_IMAGE_WINDOW (dock_container);
+
+  return gimp_image_window_get_ui_manager (window);
+}
+
+void
+gimp_image_window_add_dock (GimpDockContainer   *dock_container,
+                            GimpDock            *dock,
+                            GimpSessionInfoDock *dock_info)
+{
+  GimpImageWindow        *window;
+  GimpDisplayShell       *active_shell;
+  GimpImageWindowPrivate *private;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (dock_container));
+
+  window  = GIMP_IMAGE_WINDOW (dock_container);
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  if (dock_info->side == GIMP_ALIGN_LEFT)
+    {
+      gimp_dock_columns_add_dock (GIMP_DOCK_COLUMNS (private->left_docks),
+                                  dock,
+                                  -1 /*index*/);
+    }
+  else
+    {
+      gimp_dock_columns_add_dock (GIMP_DOCK_COLUMNS (private->right_docks),
+                                  dock,
+                                  -1 /*index*/);
+    }
+
+  active_shell = gimp_image_window_get_active_shell (window);
+  if (active_shell)
+    gimp_display_shell_appearance_update (active_shell);
+}
+
+static GimpAlignmentType
+gimp_image_window_get_dock_side (GimpDockContainer *dock_container,
+                                 GimpDock          *dock)
+{
+  GimpAlignmentType       side = -1;
+  GimpImageWindowPrivate *private;
+  GList                  *iter;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (dock_container), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (dock_container);
+
+  for (iter = gimp_dock_columns_get_docks (GIMP_DOCK_COLUMNS (private->left_docks));
+       iter && side == -1;
+       iter = g_list_next (iter))
+    {
+      GimpDock *dock_iter = GIMP_DOCK (iter->data);
+
+      if (dock_iter == dock)
+        side = GIMP_ALIGN_LEFT;
+    }
+
+  for (iter = gimp_dock_columns_get_docks (GIMP_DOCK_COLUMNS (private->right_docks));
+       iter && side == -1;
+       iter = g_list_next (iter))
+    {
+      GimpDock *dock_iter = GIMP_DOCK (iter->data);
+
+      if (dock_iter == dock)
+        side = GIMP_ALIGN_RIGHT;
+    }
+
+  return side;
+}
+
+static GList *
+gimp_image_window_get_aux_info (GimpSessionManaged *session_managed)
+{
+  GList                  *aux_info = NULL;
+  GimpImageWindowPrivate *private;
+  GimpGuiConfig          *config;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (session_managed), NULL);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (session_managed);
+  config  = GIMP_GUI_CONFIG (private->gimp->config);
+
+  if (config->single_window_mode)
+    {
+      GimpSessionInfoAux *aux;
+      GtkAllocation       allocation;
+      gchar               widthbuf[128];
+
+      g_snprintf (widthbuf, sizeof (widthbuf), "%d",
+                  gtk_paned_get_position (GTK_PANED (private->left_hpane)));
+      aux = gimp_session_info_aux_new (GIMP_IMAGE_WINDOW_LEFT_DOCKS_WIDTH,
+                                       widthbuf);
+      aux_info = g_list_append (aux_info, aux);
+
+      gtk_widget_get_allocation (private->right_hpane, &allocation);
+
+      g_snprintf (widthbuf, sizeof (widthbuf), "%d",
+                  allocation.width -
+                  gtk_paned_get_position (GTK_PANED (private->right_hpane)));
+      aux = gimp_session_info_aux_new (GIMP_IMAGE_WINDOW_RIGHT_DOCKS_WIDTH,
+                                       widthbuf);
+      aux_info = g_list_append (aux_info, aux);
+
+      aux = gimp_session_info_aux_new (GIMP_IMAGE_WINDOW_MAXIMIZED,
+                                       gimp_image_window_is_maximized (GIMP_IMAGE_WINDOW (session_managed)) ?
+                                       "yes" : "no");
+      aux_info = g_list_append (aux_info, aux);
+    }
+
+  return aux_info;
+}
+
+static void
+gimp_image_window_set_right_docks_width (GtkPaned      *paned,
+                                         GtkAllocation *allocation,
+                                         void          *data)
+{
+  gint width = GPOINTER_TO_INT (data);
+
+  g_return_if_fail (GTK_IS_PANED (paned));
+
+  if (width > 0)
+    gtk_paned_set_position (paned, allocation->width - width);
+  else
+    gtk_paned_set_position (paned, - width);
+
+  g_signal_handlers_disconnect_by_func (paned,
+                                        gimp_image_window_set_right_docks_width,
+                                        data);
+}
+
+static void
+gimp_image_window_set_aux_info (GimpSessionManaged *session_managed,
+                                GList              *aux_info)
+{
+  GimpImageWindowPrivate *private;
+  GList                  *iter;
+  gint                    left_docks_width      = G_MININT;
+  gint                    right_docks_width     = G_MININT;
+  gboolean                wait_with_right_docks = FALSE;
+  gboolean                maximized             = FALSE;
+#ifdef G_OS_WIN32
+  STARTUPINFO             StartupInfo;
+
+  GetStartupInfo (&StartupInfo);
+#endif
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (session_managed));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (session_managed);
+
+  for (iter = aux_info; iter; iter = g_list_next (iter))
+    {
+      GimpSessionInfoAux *aux   = iter->data;
+      gint               *width = NULL;
+
+      if (! strcmp (aux->name, GIMP_IMAGE_WINDOW_LEFT_DOCKS_WIDTH))
+        width = &left_docks_width;
+      else if (! strcmp (aux->name, GIMP_IMAGE_WINDOW_RIGHT_DOCKS_WIDTH))
+        width = &right_docks_width;
+      else if (! strcmp (aux->name, GIMP_IMAGE_WINDOW_RIGHT_DOCKS_POS))
+        width = &right_docks_width;
+      else if (! strcmp (aux->name, GIMP_IMAGE_WINDOW_MAXIMIZED))
+        if (! g_ascii_strcasecmp (aux->value, "yes"))
+          maximized = TRUE;
+
+      if (width)
+        sscanf (aux->value, "%d", width);
+
+      /* compat handling for right docks */
+      if (! strcmp (aux->name, GIMP_IMAGE_WINDOW_RIGHT_DOCKS_POS))
+        {
+          /* negate the value because negative docks pos means docks width,
+           * also use the negativenes of a real docks pos as condition below.
+           */
+          *width = - *width;
+        }
+    }
+
+  if (left_docks_width != G_MININT &&
+      gtk_paned_get_position (GTK_PANED (private->left_hpane)) !=
+      left_docks_width)
+    {
+      gtk_paned_set_position (GTK_PANED (private->left_hpane), left_docks_width);
+
+      /* We can't set the position of the right docks, because it will
+       * be undesirably adjusted when its get a new size
+       * allocation. We must wait until after the size allocation.
+       */
+      wait_with_right_docks = TRUE;
+    }
+
+  if (right_docks_width != G_MININT &&
+      gtk_paned_get_position (GTK_PANED (private->right_hpane)) !=
+      right_docks_width)
+    {
+      if (wait_with_right_docks || right_docks_width > 0)
+        {
+          /* We must wait for a size allocation before we can set the
+           * position
+           */
+          g_signal_connect_data (private->right_hpane, "size-allocate",
+                                 G_CALLBACK (gimp_image_window_set_right_docks_width),
+                                 GINT_TO_POINTER (right_docks_width), NULL,
+                                 G_CONNECT_AFTER);
+        }
+      else
+        {
+          /* We can set the position directly, because we didn't
+           * change the left hpane position, and we got the old compat
+           * dock pos property.
+           */
+          gtk_paned_set_position (GTK_PANED (private->right_hpane),
+                                  - right_docks_width);
+        }
+    }
+
+#ifdef G_OS_WIN32
+  /* On Windows, user can provide startup hints to have a program
+   * maximized/minimized on startup. This can be done through command
+   * line: `start /max gimp-2.9.exe` or with the shortcut's "run"
+   * property.
+   * When such a hint is given, we should follow it and bypass the
+   * session's information.
+   */
+  if (StartupInfo.wShowWindow == SW_SHOWMAXIMIZED)
+    gtk_window_maximize (GTK_WINDOW (session_managed));
+  else if (StartupInfo.wShowWindow == SW_SHOWMINIMIZED   ||
+           StartupInfo.wShowWindow == SW_SHOWMINNOACTIVE ||
+           StartupInfo.wShowWindow == SW_MINIMIZE)
+    /* XXX Iconification does not seem to work. I see the
+     * window being iconified and immediately re-raised.
+     * I leave this piece of code for later improvement. */
+    gtk_window_iconify (GTK_WINDOW (session_managed));
+  else
+    /* Another show property not relevant to min/max.
+     * Defaults is: SW_SHOWNORMAL
+     */
+#endif
+    if (maximized)
+      gtk_window_maximize (GTK_WINDOW (session_managed));
+    else
+      gtk_window_unmaximize (GTK_WINDOW (session_managed));
+}
+
+
+/*  public functions  */
+
+GimpImageWindow *
+gimp_image_window_new (Gimp              *gimp,
+                       GimpImage         *image,
+                       GimpDialogFactory *dialog_factory,
+                       GdkScreen         *screen,
+                       gint               monitor)
+{
+  GimpImageWindow        *window;
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), NULL);
+  g_return_val_if_fail (image == NULL || GIMP_IS_IMAGE (image), NULL);
+  g_return_val_if_fail (GIMP_IS_DIALOG_FACTORY (dialog_factory), NULL);
+  g_return_val_if_fail (GDK_IS_SCREEN (screen), NULL);
+
+  window = g_object_new (GIMP_TYPE_IMAGE_WINDOW,
+                         "gimp",            gimp,
+                         "dialog-factory",  dialog_factory,
+                         "initial-screen",  screen,
+                         "initial-monitor", monitor,
+                         /* The window position will be overridden by the
+                          * dialog factory, it is only really used on first
+                          * startup.
+                          */
+                         image ? NULL : "window-position",
+                         GTK_WIN_POS_CENTER,
+                         NULL);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  gimp->image_windows = g_list_append (gimp->image_windows, window);
+
+  if (! GIMP_GUI_CONFIG (private->gimp->config)->single_window_mode)
+    {
+      GdkScreen *pointer_screen;
+      gint       pointer_monitor;
+
+      pointer_monitor = gimp_get_monitor_at_pointer (&pointer_screen);
+
+      /*  If we are supposed to go to a monitor other than where the
+       *  pointer is, place the window on that monitor manually,
+       *  otherwise simply let the window manager place the window on
+       *  the poiner's monitor.
+       */
+      if (pointer_screen  != screen ||
+          pointer_monitor != monitor)
+        {
+          GdkRectangle rect;
+          gchar        geom[32];
+
+          gdk_screen_get_monitor_workarea (screen, monitor, &rect);
+
+          /*  FIXME: image window placement
+           *
+           *  This is ugly beyond description but better than showing
+           *  the window on the wrong monitor
+           */
+          g_snprintf (geom, sizeof (geom), "%+d%+d",
+                      rect.x + 300, rect.y + 30);
+          gtk_window_parse_geometry (GTK_WINDOW (window), geom);
+        }
+    }
+
+  return window;
+}
+
+void
+gimp_image_window_destroy (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  private->gimp->image_windows = g_list_remove (private->gimp->image_windows,
+                                                window);
+
+  gtk_widget_destroy (GTK_WIDGET (window));
+}
+
+GimpUIManager *
+gimp_image_window_get_ui_manager (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return private->menubar_manager;
+}
+
+GimpDockColumns  *
+gimp_image_window_get_left_docks (GimpImageWindow  *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return GIMP_DOCK_COLUMNS (private->left_docks);
+}
+
+GimpDockColumns  *
+gimp_image_window_get_right_docks (GimpImageWindow  *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return GIMP_DOCK_COLUMNS (private->right_docks);
+}
+
+void
+gimp_image_window_add_shell (GimpImageWindow  *window,
+                             GimpDisplayShell *shell)
+{
+  GimpImageWindowPrivate *private;
+  GtkWidget              *tab_label;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  g_return_if_fail (g_list_find (private->shells, shell) == NULL);
+
+  private->shells = g_list_append (private->shells, shell);
+
+  tab_label = gimp_image_window_create_tab_label (window, shell);
+
+  gtk_notebook_append_page (GTK_NOTEBOOK (private->notebook),
+                            GTK_WIDGET (shell), tab_label);
+  gtk_notebook_set_tab_reorderable (GTK_NOTEBOOK (private->notebook),
+                                    GTK_WIDGET (shell), TRUE);
+
+  gtk_widget_show (GTK_WIDGET (shell));
+
+  /*  make it fetch the right monitor profile  */
+  gimp_color_managed_profile_changed (GIMP_COLOR_MANAGED (shell));
+}
+
+GimpDisplayShell *
+gimp_image_window_get_shell (GimpImageWindow *window,
+                             gint             index)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), NULL);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return g_list_nth_data (private->shells, index);
+}
+
+void
+gimp_image_window_remove_shell (GimpImageWindow  *window,
+                                GimpDisplayShell *shell)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  g_return_if_fail (g_list_find (private->shells, shell) != NULL);
+
+  private->shells = g_list_remove (private->shells, shell);
+
+  gtk_container_remove (GTK_CONTAINER (private->notebook),
+                        GTK_WIDGET (shell));
+}
+
+gint
+gimp_image_window_get_n_shells (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), 0);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return g_list_length (private->shells);
+}
+
+void
+gimp_image_window_set_active_shell (GimpImageWindow  *window,
+                                    GimpDisplayShell *shell)
+{
+  GimpImageWindowPrivate *private;
+  gint                    page_num;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  g_return_if_fail (g_list_find (private->shells, shell));
+
+  page_num = gtk_notebook_page_num (GTK_NOTEBOOK (private->notebook),
+                                    GTK_WIDGET (shell));
+
+  gtk_notebook_set_current_page (GTK_NOTEBOOK (private->notebook), page_num);
+}
+
+GimpDisplayShell *
+gimp_image_window_get_active_shell (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), NULL);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return private->active_shell;
+}
+
+void
+gimp_image_window_set_fullscreen (GimpImageWindow *window,
+                                  gboolean         fullscreen)
+{
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  if (fullscreen != gimp_image_window_get_fullscreen (window))
+    {
+      if (fullscreen)
+        gtk_window_fullscreen (GTK_WINDOW (window));
+      else
+        gtk_window_unfullscreen (GTK_WINDOW (window));
+    }
+}
+
+gboolean
+gimp_image_window_get_fullscreen (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return (private->window_state & GDK_WINDOW_STATE_FULLSCREEN) != 0;
+}
+
+void
+gimp_image_window_set_show_menubar (GimpImageWindow *window,
+                                    gboolean         show)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  if (private->menubar)
+    gtk_widget_set_visible (private->menubar, show);
+}
+
+gboolean
+gimp_image_window_get_show_menubar (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  if (private->menubar)
+    return gtk_widget_get_visible (private->menubar);
+
+  return FALSE;
+}
+
+gboolean
+gimp_image_window_is_iconified (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return (private->window_state & GDK_WINDOW_STATE_ICONIFIED) != 0;
+}
+
+gboolean
+gimp_image_window_is_maximized (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  return (private->window_state & GDK_WINDOW_STATE_MAXIMIZED) != 0;
+}
+
+/**
+ * gimp_image_window_has_toolbox:
+ * @window:
+ *
+ * Returns: %TRUE if the image window contains a GimpToolbox.
+ **/
+gboolean
+gimp_image_window_has_toolbox (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+  GList                  *iter = NULL;
+
+  g_return_val_if_fail (GIMP_IS_IMAGE_WINDOW (window), FALSE);
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  for (iter = gimp_dock_columns_get_docks (GIMP_DOCK_COLUMNS (private->left_docks));
+       iter;
+       iter = g_list_next (iter))
+    {
+      if (GIMP_IS_TOOLBOX (iter->data))
+        return TRUE;
+    }
+
+  for (iter = gimp_dock_columns_get_docks (GIMP_DOCK_COLUMNS (private->right_docks));
+       iter;
+       iter = g_list_next (iter))
+    {
+      if (GIMP_IS_TOOLBOX (iter->data))
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+void
+gimp_image_window_shrink_wrap (GimpImageWindow *window,
+                               gboolean         grow_only)
+{
+  GimpDisplayShell *active_shell;
+  GtkWidget        *widget;
+  GtkAllocation     allocation;
+  GdkScreen        *screen;
+  GdkRectangle      rect;
+  gint              monitor;
+  gint              disp_width, disp_height;
+  gint              width, height;
+  gint              max_auto_width, max_auto_height;
+  gint              border_width, border_height;
+  gboolean          resize = FALSE;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  if (! gtk_widget_get_realized (GTK_WIDGET (window)))
+    return;
+
+  /* FIXME this so needs cleanup and shell/window separation */
+
+  active_shell = gimp_image_window_get_active_shell (window);
+
+  if (!active_shell)
+    return;
+
+  widget = GTK_WIDGET (window);
+  screen = gtk_widget_get_screen (widget);
+
+  gtk_widget_get_allocation (widget, &allocation);
+
+  monitor = gdk_screen_get_monitor_at_window (screen,
+                                              gtk_widget_get_window (widget));
+  gdk_screen_get_monitor_workarea (screen, monitor, &rect);
+
+  if (! gimp_display_shell_get_infinite_canvas (active_shell))
+    {
+      gimp_display_shell_scale_get_image_size (active_shell,
+                                               &width, &height);
+    }
+  else
+    {
+      gimp_display_shell_scale_get_image_bounding_box (active_shell,
+                                                       NULL,   NULL,
+                                                       &width, &height);
+    }
+
+  disp_width  = active_shell->disp_width;
+  disp_height = active_shell->disp_height;
+
+
+  /* As long as the disp_width/disp_height is larger than 1 we
+   * can reliably depend on it to calculate the
+   * border_width/border_height because that means there is enough
+   * room in the top-level for the canvas as well as the rulers and
+   * scrollbars. If it is 1 or smaller it is likely that the rulers
+   * and scrollbars are overlapping each other and thus we cannot use
+   * the normal approach to border size, so special case that.
+   */
+  if (disp_width > 1 || !active_shell->vsb)
+    {
+      border_width = allocation.width - disp_width;
+    }
+  else
+    {
+      GtkAllocation vsb_allocation;
+
+      gtk_widget_get_allocation (active_shell->vsb, &vsb_allocation);
+
+      border_width = allocation.width - disp_width + vsb_allocation.width;
+    }
+
+  if (disp_height > 1 || !active_shell->hsb)
+    {
+      border_height = allocation.height - disp_height;
+    }
+  else
+    {
+      GtkAllocation hsb_allocation;
+
+      gtk_widget_get_allocation (active_shell->hsb, &hsb_allocation);
+
+      border_height = allocation.height - disp_height + hsb_allocation.height;
+    }
+
+
+  max_auto_width  = (rect.width  - border_width)  * 0.75;
+  max_auto_height = (rect.height - border_height) * 0.75;
+
+  /* If one of the display dimensions has changed and one of the
+   * dimensions fits inside the screen
+   */
+  if (((width  + border_width)  < rect.width ||
+       (height + border_height) < rect.height) &&
+      (width  != disp_width ||
+       height != disp_height))
+    {
+      width  = ((width  + border_width)  < rect.width)  ? width  : max_auto_width;
+      height = ((height + border_height) < rect.height) ? height : max_auto_height;
+
+      resize = TRUE;
+    }
+
+  /*  If the projected dimension is greater than current, but less than
+   *  3/4 of the screen size, expand automagically
+   */
+  else if ((width  > disp_width ||
+            height > disp_height) &&
+           (disp_width  < max_auto_width ||
+            disp_height < max_auto_height))
+    {
+      width  = MIN (max_auto_width,  width);
+      height = MIN (max_auto_height, height);
+
+      resize = TRUE;
+    }
+
+  if (resize)
+    {
+      GimpStatusbar *statusbar = gimp_display_shell_get_statusbar (active_shell);
+      gint           statusbar_width;
+
+      gtk_widget_get_size_request (GTK_WIDGET (statusbar),
+                                   &statusbar_width, NULL);
+
+      if (width < statusbar_width)
+        width = statusbar_width;
+
+      width  = width  + border_width;
+      height = height + border_height;
+
+      if (grow_only)
+        {
+          if (width < allocation.width)
+            width = allocation.width;
+
+          if (height < allocation.height)
+            height = allocation.height;
+        }
+
+      gtk_window_resize (GTK_WINDOW (window), width, height);
+    }
+
+  /* A wrap always means that we should center the image too. If the
+   * window changes size another center will be done in
+   * GimpDisplayShell::configure_event().
+   */
+  /* FIXME multiple shells */
+  gimp_display_shell_scroll_center_content (active_shell, TRUE, TRUE);
+}
+
+static GtkWidget *
+gimp_image_window_get_first_dockbook (GimpDockColumns *columns)
+{
+  GList *dock_iter;
+
+  for (dock_iter = gimp_dock_columns_get_docks (columns);
+       dock_iter;
+       dock_iter = g_list_next (dock_iter))
+    {
+      GimpDock *dock      = GIMP_DOCK (dock_iter->data);
+      GList    *dockbooks = gimp_dock_get_dockbooks (dock);
+
+      if (dockbooks)
+        return GTK_WIDGET (dockbooks->data);
+    }
+
+  return NULL;
+}
+
+/**
+ * gimp_image_window_get_default_dockbook:
+ * @window:
+ *
+ * Gets the default dockbook, which is the dockbook in which new
+ * dockables should be put in single-window mode.
+ *
+ * Returns: The default dockbook for new dockables, or NULL if no
+ *          dockbook were available.
+ **/
+GtkWidget *
+gimp_image_window_get_default_dockbook (GimpImageWindow  *window)
+{
+  GimpImageWindowPrivate *private;
+  GimpDockColumns        *dock_columns;
+  GtkWidget              *dockbook = NULL;
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  /* First try the first dockbook in the right docks */
+  dock_columns = GIMP_DOCK_COLUMNS (private->right_docks);
+  dockbook     = gimp_image_window_get_first_dockbook (dock_columns);
+
+  /* Then the left docks */
+  if (! dockbook)
+    {
+      dock_columns = GIMP_DOCK_COLUMNS (private->left_docks);
+      dockbook     = gimp_image_window_get_first_dockbook (dock_columns);
+    }
+
+  return dockbook;
+}
+
+/**
+ * gimp_image_window_keep_canvas_pos:
+ * @window:
+ *
+ * Stores the coordinates of the current image canvas origin relatively
+ * its GtkWindow; and on the first size-allocate sets the offsets in
+ * the shell so that the image origin remains the same (even on another
+ * GtkWindow).
+ *
+ * Example use case: The user hides docks attached to the side of image
+ * windows. You want the image to remain fixed on the screen though,
+ * so you use this function to keep the image fixed after the docks
+ * have been hidden.
+ **/
+void
+gimp_image_window_keep_canvas_pos (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+  GimpDisplayShell       *shell;
+  gint                    canvas_x;
+  gint                    canvas_y;
+  gint                    window_x;
+  gint                    window_y;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  if (private->suspend_keep_pos > 0)
+    return;
+
+  shell = gimp_image_window_get_active_shell (window);
+
+  gimp_display_shell_transform_xy (shell, 0.0, 0.0, &canvas_x, &canvas_y);
+
+  if (gtk_widget_translate_coordinates (GTK_WIDGET (shell->canvas),
+                                        GTK_WIDGET (window),
+                                        canvas_x, canvas_y,
+                                        &window_x, &window_y))
+    {
+      PosCorrectionData *data = g_new0 (PosCorrectionData, 1);
+
+      data->canvas_x = canvas_x;
+      data->canvas_y = canvas_y;
+      data->window_x = window_x;
+      data->window_y = window_y;
+
+      g_signal_connect_data (shell, "size-allocate",
+                             G_CALLBACK (gimp_image_window_shell_size_allocate),
+                             data, (GClosureNotify) g_free,
+                             G_CONNECT_AFTER);
+    }
+}
+
+void
+gimp_image_window_suspend_keep_pos (GimpImageWindow  *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  private->suspend_keep_pos++;
+}
+
+void
+gimp_image_window_resume_keep_pos (GimpImageWindow  *window)
+{
+  GimpImageWindowPrivate *private;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  g_return_if_fail (private->suspend_keep_pos > 0);
+
+  private->suspend_keep_pos--;
+}
+
+/**
+ * gimp_image_window_update_tabs:
+ * @window: the Image Window to update.
+ *
+ * Holds the logics of whether shell tabs are to be shown or not in the
+ * Image Window @window. This function should be called after every
+ * change to @window where one might expect tab visibility to change.
+ *
+ * No direct call to gtk_notebook_set_show_tabs() should ever be made.
+ * If we change the logics of tab hiding, we should only change this
+ * procedure instead.
+ **/
+void
+gimp_image_window_update_tabs (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private;
+  GimpGuiConfig          *config;
+  GtkPositionType         position;
+
+  g_return_if_fail (GIMP_IS_IMAGE_WINDOW (window));
+
+  private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  config = GIMP_GUI_CONFIG (private->gimp->config);
+
+  /* Tab visibility. */
+  gtk_notebook_set_show_tabs (GTK_NOTEBOOK (private->notebook),
+                              config->single_window_mode &&
+                              config->show_tabs          &&
+                              ! config->hide_docks       &&
+                              ((private->active_shell          &&
+                                private->active_shell->display &&
+                                gimp_display_get_image (private->active_shell->display)) ||
+                               g_list_length (private->shells) > 1));
+
+  /* Tab position. */
+  switch (config->tabs_position)
+    {
+    case GIMP_POSITION_TOP:
+      position = GTK_POS_TOP;
+      break;
+    case GIMP_POSITION_BOTTOM:
+      position = GTK_POS_BOTTOM;
+      break;
+    case GIMP_POSITION_LEFT:
+      position = GTK_POS_LEFT;
+      break;
+    case GIMP_POSITION_RIGHT:
+      position = GTK_POS_RIGHT;
+      break;
+    default:
+      /* If we have any strange value, just reset to default. */
+      position = GTK_POS_TOP;
+      break;
+    }
+
+  gtk_notebook_set_tab_pos (GTK_NOTEBOOK (private->notebook), position);
+}
+
+
+/*  private functions  */
+
+static void
+gimp_image_window_show_tooltip (GimpUIManager   *manager,
+                                const gchar     *tooltip,
+                                GimpImageWindow *window)
+{
+  GimpDisplayShell *shell     = gimp_image_window_get_active_shell (window);
+  GimpStatusbar    *statusbar = NULL;
+
+  if (! shell)
+    return;
+
+  statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_statusbar_push (statusbar, "menu-tooltip",
+                       NULL, "%s", tooltip);
+}
+
+static void
+gimp_image_window_config_notify (GimpImageWindow *window,
+                                 GParamSpec      *pspec,
+                                 GimpGuiConfig   *config)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  /* Dock column visibility */
+  if (strcmp (pspec->name, "single-window-mode") == 0 ||
+      strcmp (pspec->name, "hide-docks")         == 0 ||
+      strcmp (pspec->name, "show-tabs")          == 0 ||
+      strcmp (pspec->name, "tabs-position")      == 0)
+    {
+      if (strcmp (pspec->name, "single-window-mode") == 0 ||
+          strcmp (pspec->name, "hide-docks")         == 0)
+        {
+          gboolean show_docks = (config->single_window_mode &&
+                                 ! config->hide_docks);
+
+          gimp_image_window_keep_canvas_pos (window);
+          gtk_widget_set_visible (private->left_docks, show_docks);
+          gtk_widget_set_visible (private->right_docks, show_docks);
+
+          /* If docks are being shown, and we are in multi-window-mode,
+           * and this is the window of the active display, try to set
+           * the keyboard focus to this window because it might have
+           * been stolen by a dock. See bug #567333.
+           */
+          if (strcmp (pspec->name, "hide-docks") == 0 &&
+              ! config->single_window_mode            &&
+              ! config->hide_docks)
+            {
+              GimpDisplayShell *shell;
+              GimpContext      *user_context;
+
+              shell        = gimp_image_window_get_active_shell (window);
+              user_context = gimp_get_user_context (private->gimp);
+
+              if (gimp_context_get_display (user_context) == shell->display)
+                {
+                  GdkWindow *w = gtk_widget_get_window (GTK_WIDGET (window));
+
+                  if (w)
+                    gdk_window_focus (w, gtk_get_current_event_time ());
+                }
+            }
+        }
+
+      gimp_image_window_update_tabs (window);
+    }
+
+  /* Session management */
+  if (strcmp (pspec->name, "single-window-mode") == 0)
+    {
+      gimp_image_window_session_update (window,
+                                        NULL /*new_display*/,
+                                        gimp_image_window_config_to_entry_id (config),
+                                        gtk_widget_get_screen (GTK_WIDGET (window)),
+                                        gimp_widget_get_monitor (GTK_WIDGET (window)));
+    }
+}
+
+static void
+gimp_image_window_hide_tooltip (GimpUIManager   *manager,
+                                GimpImageWindow *window)
+{
+  GimpDisplayShell *shell     = gimp_image_window_get_active_shell (window);
+  GimpStatusbar    *statusbar = NULL;
+
+  if (! shell)
+    return;
+
+  statusbar = gimp_display_shell_get_statusbar (shell);
+
+  gimp_statusbar_pop (statusbar, "menu-tooltip");
+}
+
+static gboolean
+gimp_image_window_update_ui_manager_idle (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  gimp_assert (private->active_shell != NULL);
+
+  gimp_ui_manager_update (private->menubar_manager,
+                          private->active_shell->display);
+
+  private->update_ui_manager_idle_id = 0;
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+gimp_image_window_update_ui_manager (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  if (! private->update_ui_manager_idle_id)
+    {
+      private->update_ui_manager_idle_id =
+        g_idle_add_full (GIMP_PRIORITY_IMAGE_WINDOW_UPDATE_UI_MANAGER_IDLE,
+                         (GSourceFunc) gimp_image_window_update_ui_manager_idle,
+                         window,
+                         NULL);
+    }
+}
+
+static void
+gimp_image_window_shell_size_allocate (GimpDisplayShell  *shell,
+                                       GtkAllocation     *allocation,
+                                       PosCorrectionData *data)
+{
+  GimpImageWindow *window = gimp_display_shell_get_window (shell);
+  gint             new_window_x;
+  gint             new_window_y;
+
+  if (gtk_widget_translate_coordinates (GTK_WIDGET (shell->canvas),
+                                        GTK_WIDGET (window),
+                                        data->canvas_x, data->canvas_y,
+                                        &new_window_x, &new_window_y))
+    {
+      gint off_x = new_window_x - data->window_x;
+      gint off_y = new_window_y - data->window_y;
+
+      if (off_x || off_y)
+        gimp_display_shell_scroll (shell, off_x, off_y);
+    }
+
+  g_signal_handlers_disconnect_by_func (shell,
+                                        gimp_image_window_shell_size_allocate,
+                                        data);
+}
+
+static gboolean
+gimp_image_window_shell_events (GtkWidget       *widget,
+                                GdkEvent        *event,
+                                GimpImageWindow *window)
+{
+  GimpDisplayShell *shell = gimp_image_window_get_active_shell (window);
+
+  if (! shell)
+    return FALSE;
+
+  return gimp_display_shell_events (widget, event, shell);
+}
+
+static void
+gimp_image_window_switch_page (GtkNotebook     *notebook,
+                               gpointer         page,
+                               gint             page_num,
+                               GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpDisplayShell       *shell;
+  GimpDisplay            *active_display;
+
+  shell = GIMP_DISPLAY_SHELL (gtk_notebook_get_nth_page (notebook, page_num));
+
+  if (shell == private->active_shell)
+    return;
+
+  gimp_image_window_disconnect_from_active_shell (window);
+
+  GIMP_LOG (WM, "GimpImageWindow %p, private->active_shell = %p; \n",
+            window, shell);
+  private->active_shell = shell;
+
+  gimp_window_set_primary_focus_widget (GIMP_WINDOW (window),
+                                        shell->canvas);
+
+  active_display = private->active_shell->display;
+
+  g_signal_connect (active_display, "notify::image",
+                    G_CALLBACK (gimp_image_window_image_notify),
+                    window);
+
+  g_signal_connect (private->active_shell, "scaled",
+                    G_CALLBACK (gimp_image_window_shell_scaled),
+                    window);
+  g_signal_connect (private->active_shell, "rotated",
+                    G_CALLBACK (gimp_image_window_shell_rotated),
+                    window);
+  g_signal_connect (private->active_shell, "notify::title",
+                    G_CALLBACK (gimp_image_window_shell_title_notify),
+                    window);
+  g_signal_connect (private->active_shell, "notify::icon",
+                    G_CALLBACK (gimp_image_window_shell_icon_notify),
+                    window);
+
+  gtk_window_set_title (GTK_WINDOW (window), shell->title);
+  gtk_window_set_icon (GTK_WINDOW (window), shell->icon);
+
+  gimp_display_shell_appearance_update (private->active_shell);
+
+  if (gtk_widget_get_window (GTK_WIDGET (window)))
+    {
+      /*  we are fully initialized, use the window's current monitor
+       */
+      gimp_image_window_session_update (window,
+                                        active_display,
+                                        NULL /*new_entry_id*/,
+                                        gtk_widget_get_screen (GTK_WIDGET (window)),
+                                        gimp_widget_get_monitor (GTK_WIDGET (window)));
+    }
+  else
+    {
+      /*  we are in construction, use the initial monitor; calling
+       *  gimp_widget_get_monitor() would get us the monitor where the
+       *  pointer is
+       */
+      gimp_image_window_session_update (window,
+                                        active_display,
+                                        NULL /*new_entry_id*/,
+                                        private->initial_screen,
+                                        private->initial_monitor);
+    }
+
+  gimp_context_set_display (gimp_get_user_context (private->gimp),
+                            active_display);
+
+  gimp_image_window_update_ui_manager (window);
+
+  gimp_image_window_update_tab_labels (window);
+}
+
+static void
+gimp_image_window_page_removed (GtkNotebook     *notebook,
+                                GtkWidget       *widget,
+                                gint             page_num,
+                                GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  if (GTK_WIDGET (private->active_shell) == widget)
+    {
+      GIMP_LOG (WM, "GimpImageWindow %p, private->active_shell = %p; \n",
+                window, NULL);
+      gimp_image_window_disconnect_from_active_shell (window);
+      private->active_shell = NULL;
+    }
+}
+
+static void
+gimp_image_window_page_reordered (GtkNotebook     *notebook,
+                                  GtkWidget       *widget,
+                                  gint             page_num,
+                                  GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private  = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpContainer          *displays = private->gimp->displays;
+  gint                    index    = g_list_index (private->shells, widget);
+
+  if (index != page_num)
+    {
+      private->shells = g_list_remove (private->shells, widget);
+      private->shells = g_list_insert (private->shells, widget, page_num);
+    }
+
+  /* We need to reorder the displays as well in order to update the
+   * numbered accelerators (alt-1, alt-2, etc.).
+   */
+  gimp_container_reorder (displays,
+                          GIMP_OBJECT (GIMP_DISPLAY_SHELL (widget)->display),
+                          page_num);
+
+  gtk_notebook_reorder_child (notebook, widget, page_num);
+}
+
+static void
+gimp_image_window_disconnect_from_active_shell (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private        = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpDisplay            *active_display = NULL;
+
+  if (! private->active_shell)
+    return;
+
+  active_display = private->active_shell->display;
+
+  if (active_display)
+    g_signal_handlers_disconnect_by_func (active_display,
+                                          gimp_image_window_image_notify,
+                                          window);
+
+  g_signal_handlers_disconnect_by_func (private->active_shell,
+                                        gimp_image_window_shell_scaled,
+                                        window);
+  g_signal_handlers_disconnect_by_func (private->active_shell,
+                                        gimp_image_window_shell_rotated,
+                                        window);
+  g_signal_handlers_disconnect_by_func (private->active_shell,
+                                        gimp_image_window_shell_title_notify,
+                                        window);
+  g_signal_handlers_disconnect_by_func (private->active_shell,
+                                        gimp_image_window_shell_icon_notify,
+                                        window);
+
+  if (private->menubar_manager)
+    gimp_image_window_hide_tooltip (private->menubar_manager, window);
+
+  if (private->update_ui_manager_idle_id)
+    {
+      g_source_remove (private->update_ui_manager_idle_id);
+      private->update_ui_manager_idle_id = 0;
+    }
+}
+
+static void
+gimp_image_window_image_notify (GimpDisplay      *display,
+                                const GParamSpec *pspec,
+                                GimpImageWindow  *window)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GtkWidget              *tab_label;
+  GList                  *children;
+  GtkWidget              *view;
+
+  gimp_image_window_session_update (window,
+                                    display,
+                                    NULL /*new_entry_id*/,
+                                    gtk_widget_get_screen (GTK_WIDGET (window)),
+                                    gimp_widget_get_monitor (GTK_WIDGET (window)));
+
+  tab_label = gtk_notebook_get_tab_label (GTK_NOTEBOOK (private->notebook),
+                                          GTK_WIDGET (gimp_display_get_shell (display)));
+  children  = gtk_container_get_children (GTK_CONTAINER (tab_label));
+  view      = GTK_WIDGET (children->data);
+  g_list_free (children);
+
+  gimp_view_set_viewable (GIMP_VIEW (view),
+                          GIMP_VIEWABLE (gimp_display_get_image (display)));
+
+  gimp_image_window_update_ui_manager (window);
+}
+
+static void
+gimp_image_window_session_clear (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GtkWidget              *widget  = GTK_WIDGET (window);
+
+  if (gimp_dialog_factory_from_widget (widget, NULL))
+    gimp_dialog_factory_remove_dialog (private->dialog_factory,
+                                       widget);
+}
+
+static void
+gimp_image_window_session_apply (GimpImageWindow *window,
+                                 const gchar     *entry_id,
+                                 GdkScreen       *screen,
+                                 gint             monitor)
+{
+  GimpImageWindowPrivate *private      = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GimpSessionInfo        *session_info = NULL;
+  gint                    width        = -1;
+  gint                    height       = -1;
+
+  gtk_window_unfullscreen (GTK_WINDOW (window));
+
+  /*  get the NIW size before adding the display to the dialog
+   *  factory so the window's current size doesn't affect the
+   *  stored session info entry.
+   */
+  session_info =
+    gimp_dialog_factory_find_session_info (private->dialog_factory, entry_id);
+
+  if (session_info)
+    {
+      width  = gimp_session_info_get_width  (session_info);
+      height = gimp_session_info_get_height (session_info);
+    }
+  else
+    {
+      GtkAllocation allocation;
+
+      gtk_widget_get_allocation (GTK_WIDGET (window), &allocation);
+
+      width  = allocation.width;
+      height = allocation.height;
+    }
+
+  gimp_dialog_factory_add_foreign (private->dialog_factory,
+                                   entry_id,
+                                   GTK_WIDGET (window),
+                                   screen,
+                                   monitor);
+
+  gtk_window_unmaximize (GTK_WINDOW (window));
+  gtk_window_resize (GTK_WINDOW (window), width, height);
+}
+
+static void
+gimp_image_window_session_update (GimpImageWindow *window,
+                                  GimpDisplay     *new_display,
+                                  const gchar     *new_entry_id,
+                                  GdkScreen       *screen,
+                                  gint             monitor)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+
+  /* Handle changes to the entry id */
+  if (new_entry_id)
+    {
+      if (! private->entry_id)
+        {
+          /* We're initializing. If we're in single-window mode, this
+           * will be the only window, so start to session manage
+           * it. If we're in multi-window mode, we will find out if we
+           * should session manage ourselves when we get a display
+           */
+          if (strcmp (new_entry_id, GIMP_SINGLE_IMAGE_WINDOW_ENTRY_ID) == 0)
+            {
+              gimp_image_window_session_apply (window, new_entry_id,
+                                               screen, monitor);
+            }
+        }
+      else if (strcmp (private->entry_id, new_entry_id) != 0)
+        {
+          /* The entry id changed, immediately and always stop session
+           * managing the old entry
+           */
+          gimp_image_window_session_clear (window);
+
+          if (strcmp (new_entry_id, GIMP_EMPTY_IMAGE_WINDOW_ENTRY_ID) == 0)
+            {
+              /* If there is only one imageless display, we shall
+               * become the empty image window
+               */
+              if (private->active_shell &&
+                  private->active_shell->display &&
+                  ! gimp_display_get_image (private->active_shell->display) &&
+                  g_list_length (private->shells) <= 1)
+                {
+                  gimp_image_window_session_apply (window, new_entry_id,
+                                                   screen, monitor);
+                }
+            }
+          else if (strcmp (new_entry_id, GIMP_SINGLE_IMAGE_WINDOW_ENTRY_ID) == 0)
+            {
+              /* As soon as we become the single image window, we
+               * shall session manage ourself until single-window mode
+               * is exited
+               */
+              gimp_image_window_session_apply (window, new_entry_id,
+                                               screen, monitor);
+            }
+        }
+
+      private->entry_id = new_entry_id;
+    }
+
+  /* Handle changes to the displays. When in single-window mode, we
+   * just keep session managing the single image window. We only need
+   * to care about the multi-window mode case here
+   */
+  if (new_display &&
+      strcmp (private->entry_id, GIMP_EMPTY_IMAGE_WINDOW_ENTRY_ID) == 0)
+    {
+      if (gimp_display_get_image (new_display))
+        {
+          /* As soon as we have an image we should not affect the size of the
+           * empty image window
+           */
+          gimp_image_window_session_clear (window);
+        }
+      else if (! gimp_display_get_image (new_display) &&
+               g_list_length (private->shells) <= 1)
+        {
+          /* As soon as we have no image (and no other shells that may
+           * contain images) we should become the empty image window
+           */
+          gimp_image_window_session_apply (window, private->entry_id,
+                                           screen, monitor);
+        }
+    }
+}
+
+static const gchar *
+gimp_image_window_config_to_entry_id (GimpGuiConfig *config)
+{
+  return (config->single_window_mode ?
+          GIMP_SINGLE_IMAGE_WINDOW_ENTRY_ID :
+          GIMP_EMPTY_IMAGE_WINDOW_ENTRY_ID);
+}
+
+static void
+gimp_image_window_shell_scaled (GimpDisplayShell *shell,
+                                GimpImageWindow  *window)
+{
+  /* update the <Image>/View/Zoom menu */
+  gimp_image_window_update_ui_manager (window);
+}
+
+static void
+gimp_image_window_shell_rotated (GimpDisplayShell *shell,
+                                 GimpImageWindow  *window)
+{
+  /* update the <Image>/View/Rotate menu */
+  gimp_image_window_update_ui_manager (window);
+}
+
+static void
+gimp_image_window_shell_title_notify (GimpDisplayShell *shell,
+                                      const GParamSpec *pspec,
+                                      GimpImageWindow  *window)
+{
+  gtk_window_set_title (GTK_WINDOW (window), shell->title);
+}
+
+static void
+gimp_image_window_shell_icon_notify (GimpDisplayShell *shell,
+                                     const GParamSpec *pspec,
+                                     GimpImageWindow  *window)
+{
+  gtk_window_set_icon (GTK_WINDOW (window), shell->icon);
+}
+
+static void
+gimp_image_window_shell_close_button_callback (GimpDisplayShell *shell)
+{
+  if (shell)
+    gimp_display_shell_close (shell, FALSE);
+}
+
+static GtkWidget *
+gimp_image_window_create_tab_label (GimpImageWindow  *window,
+                                    GimpDisplayShell *shell)
+{
+  GtkWidget *hbox;
+  GtkWidget *view;
+  GimpImage *image;
+  GtkWidget *button;
+  GtkWidget *gtk_image;
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 2);
+  gtk_widget_show (hbox);
+
+  view = gimp_view_new_by_types (gimp_get_user_context (shell->display->gimp),
+                                 GIMP_TYPE_VIEW, GIMP_TYPE_IMAGE,
+                                 GIMP_VIEW_SIZE_LARGE, 0, FALSE);
+  gtk_widget_set_size_request (view, GIMP_VIEW_SIZE_LARGE, -1);
+  gimp_view_renderer_set_color_config (GIMP_VIEW (view)->renderer,
+                                       gimp_display_shell_get_color_config (shell));
+  gtk_box_pack_start (GTK_BOX (hbox), view, FALSE, FALSE, 0);
+  gtk_widget_show (view);
+
+  image = gimp_display_get_image (shell->display);
+  if (image)
+    gimp_view_set_viewable (GIMP_VIEW (view), GIMP_VIEWABLE (image));
+
+  button = gtk_button_new ();
+  gtk_widget_set_can_focus (button, FALSE);
+  gtk_button_set_relief (GTK_BUTTON (button), GTK_RELIEF_NONE);
+  gtk_box_pack_start (GTK_BOX (hbox), button, FALSE, FALSE, 0);
+  gtk_widget_show (button);
+
+  gtk_image = gtk_image_new_from_icon_name (GIMP_ICON_CLOSE,
+                                            GTK_ICON_SIZE_MENU);
+  gtk_container_add (GTK_CONTAINER (button), gtk_image);
+  gtk_widget_show (gtk_image);
+
+  g_signal_connect_swapped (button, "clicked",
+                            G_CALLBACK (gimp_image_window_shell_close_button_callback),
+                            shell);
+
+  g_object_set_data (G_OBJECT (hbox), "close-button", button);
+
+  return hbox;
+}
+
+static void
+gimp_image_window_update_tab_labels (GimpImageWindow *window)
+{
+  GimpImageWindowPrivate *private = GIMP_IMAGE_WINDOW_GET_PRIVATE (window);
+  GList                  *children;
+  GList                  *list;
+
+  children = gtk_container_get_children (GTK_CONTAINER (private->notebook));
+
+  for (list = children; list; list = g_list_next (list))
+    {
+      GtkWidget *shell = list->data;
+      GtkWidget *tab_widget;
+      GtkWidget *close_button;
+
+      tab_widget = gtk_notebook_get_tab_label (GTK_NOTEBOOK (private->notebook),
+                                               shell);
+
+      close_button = g_object_get_data (G_OBJECT (tab_widget), "close-button");
+
+      if (gimp_context_get_display (gimp_get_user_context (private->gimp)) ==
+          GIMP_DISPLAY_SHELL (shell)->display)
+        {
+          gtk_widget_show (close_button);
+        }
+      else
+        {
+          gtk_widget_hide (close_button);
+        }
+    }
+
+  g_list_free (children);
+}
diff --git a/app/display/gimpimagewindow.h b/app/display/gimpimagewindow.h
new file mode 100644
index 0000000..121dc71
--- /dev/null
+++ b/app/display/gimpimagewindow.h
@@ -0,0 +1,100 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_IMAGE_WINDOW_H__
+#define __GIMP_IMAGE_WINDOW_H__
+
+
+#include "widgets/gimpwindow.h"
+
+
+#define GIMP_TYPE_IMAGE_WINDOW            (gimp_image_window_get_type ())
+#define GIMP_IMAGE_WINDOW(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_IMAGE_WINDOW, GimpImageWindow))
+#define GIMP_IMAGE_WINDOW_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_IMAGE_WINDOW, GimpImageWindowClass))
+#define GIMP_IS_IMAGE_WINDOW(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_IMAGE_WINDOW))
+#define GIMP_IS_IMAGE_WINDOW_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_IMAGE_WINDOW))
+#define GIMP_IMAGE_WINDOW_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_IMAGE_WINDOW, GimpImageWindowClass))
+
+
+typedef struct _GimpImageWindowClass  GimpImageWindowClass;
+
+struct _GimpImageWindow
+{
+  GimpWindow  parent_instance;
+};
+
+struct _GimpImageWindowClass
+{
+  GimpWindowClass  parent_class;
+};
+
+
+GType              gimp_image_window_get_type             (void) G_GNUC_CONST;
+
+GimpImageWindow  * gimp_image_window_new                  (Gimp              *gimp,
+                                                           GimpImage         *image,
+                                                           GimpDialogFactory *dialog_factory,
+                                                           GdkScreen         *screen,
+                                                           gint               monitor);
+void               gimp_image_window_destroy              (GimpImageWindow   *window);
+
+GimpUIManager    * gimp_image_window_get_ui_manager       (GimpImageWindow  *window);
+GimpDockColumns  * gimp_image_window_get_left_docks       (GimpImageWindow  *window);
+GimpDockColumns  * gimp_image_window_get_right_docks      (GimpImageWindow  *window);
+
+void               gimp_image_window_add_shell            (GimpImageWindow  *window,
+                                                           GimpDisplayShell *shell);
+GimpDisplayShell * gimp_image_window_get_shell            (GimpImageWindow  *window,
+                                                           gint              index);
+void               gimp_image_window_remove_shell         (GimpImageWindow  *window,
+                                                           GimpDisplayShell *shell);
+
+gint               gimp_image_window_get_n_shells         (GimpImageWindow  *window);
+
+void               gimp_image_window_set_active_shell     (GimpImageWindow  *window,
+                                                           GimpDisplayShell *shell);
+GimpDisplayShell * gimp_image_window_get_active_shell     (GimpImageWindow  *window);
+
+void               gimp_image_window_set_fullscreen       (GimpImageWindow  *window,
+                                                           gboolean          fullscreen);
+gboolean           gimp_image_window_get_fullscreen       (GimpImageWindow  *window);
+
+void               gimp_image_window_set_show_menubar     (GimpImageWindow  *window,
+                                                           gboolean          show);
+gboolean           gimp_image_window_get_show_menubar     (GimpImageWindow  *window);
+
+void               gimp_image_window_set_show_statusbar   (GimpImageWindow  *window,
+                                                           gboolean          show);
+gboolean           gimp_image_window_get_show_statusbar   (GimpImageWindow  *window);
+
+gboolean           gimp_image_window_is_iconified         (GimpImageWindow  *window);
+gboolean           gimp_image_window_is_maximized         (GimpImageWindow  *window);
+
+gboolean           gimp_image_window_has_toolbox          (GimpImageWindow  *window);
+
+void               gimp_image_window_shrink_wrap          (GimpImageWindow  *window,
+                                                           gboolean          grow_only);
+
+GtkWidget        * gimp_image_window_get_default_dockbook (GimpImageWindow  *window);
+
+void               gimp_image_window_keep_canvas_pos      (GimpImageWindow  *window);
+void               gimp_image_window_suspend_keep_pos     (GimpImageWindow  *window);
+void               gimp_image_window_resume_keep_pos      (GimpImageWindow  *window);
+
+void               gimp_image_window_update_tabs          (GimpImageWindow  *window);
+
+#endif /* __GIMP_IMAGE_WINDOW_H__ */
diff --git a/app/display/gimpmotionbuffer.c b/app/display/gimpmotionbuffer.c
new file mode 100644
index 0000000..549f6f0
--- /dev/null
+++ b/app/display/gimpmotionbuffer.c
@@ -0,0 +1,594 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpcoords.h"
+#include "core/gimpcoords-interpolate.h"
+#include "core/gimpmarshal.h"
+
+#include "gimpmotionbuffer.h"
+
+
+/* Velocity unit is screen pixels per millisecond we pass to tools as 1. */
+#define VELOCITY_UNIT        3.0
+#define EVENT_FILL_PRECISION 6.0
+#define DIRECTION_RADIUS     (1.0 / MAX (scale_x, scale_y))
+#define SMOOTH_FACTOR        0.3
+
+
+enum
+{
+  PROP_0
+};
+
+enum
+{
+  STROKE,
+  HOVER,
+  LAST_SIGNAL
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_motion_buffer_dispose             (GObject          *object);
+static void     gimp_motion_buffer_finalize            (GObject          *object);
+static void     gimp_motion_buffer_set_property        (GObject          *object,
+                                                        guint             property_id,
+                                                        const GValue     *value,
+                                                        GParamSpec       *pspec);
+static void     gimp_motion_buffer_get_property        (GObject          *object,
+                                                        guint             property_id,
+                                                        GValue           *value,
+                                                        GParamSpec       *pspec);
+
+static void     gimp_motion_buffer_push_event_history  (GimpMotionBuffer *buffer,
+                                                        const GimpCoords *coords);
+static void     gimp_motion_buffer_pop_event_queue     (GimpMotionBuffer *buffer,
+                                                        GimpCoords       *coords);
+
+static void     gimp_motion_buffer_interpolate_stroke  (GimpMotionBuffer *buffer,
+                                                        GimpCoords       *coords);
+static gboolean gimp_motion_buffer_event_queue_timeout (GimpMotionBuffer *buffer);
+
+
+G_DEFINE_TYPE (GimpMotionBuffer, gimp_motion_buffer, GIMP_TYPE_OBJECT)
+
+#define parent_class gimp_motion_buffer_parent_class
+
+static guint motion_buffer_signals[LAST_SIGNAL] = { 0 };
+
+
+static void
+gimp_motion_buffer_class_init (GimpMotionBufferClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  motion_buffer_signals[STROKE] =
+    g_signal_new ("stroke",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpMotionBufferClass, stroke),
+                  NULL, NULL,
+                  gimp_marshal_VOID__POINTER_UINT_FLAGS,
+                  G_TYPE_NONE, 3,
+                  G_TYPE_POINTER,
+                  G_TYPE_UINT,
+                  GDK_TYPE_MODIFIER_TYPE);
+
+  motion_buffer_signals[HOVER] =
+    g_signal_new ("hover",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpMotionBufferClass, hover),
+                  NULL, NULL,
+                  gimp_marshal_VOID__POINTER_FLAGS_BOOLEAN,
+                  G_TYPE_NONE, 3,
+                  G_TYPE_POINTER,
+                  GDK_TYPE_MODIFIER_TYPE,
+                  G_TYPE_BOOLEAN);
+
+  object_class->dispose      = gimp_motion_buffer_dispose;
+  object_class->finalize     = gimp_motion_buffer_finalize;
+  object_class->set_property = gimp_motion_buffer_set_property;
+  object_class->get_property = gimp_motion_buffer_get_property;
+}
+
+static void
+gimp_motion_buffer_init (GimpMotionBuffer *buffer)
+{
+  buffer->event_history = g_array_new (FALSE, FALSE, sizeof (GimpCoords));
+  buffer->event_queue   = g_array_new (FALSE, FALSE, sizeof (GimpCoords));
+}
+
+static void
+gimp_motion_buffer_dispose (GObject *object)
+{
+  GimpMotionBuffer *buffer = GIMP_MOTION_BUFFER (object);
+
+  if (buffer->event_delay_timeout)
+    {
+      g_source_remove (buffer->event_delay_timeout);
+      buffer->event_delay_timeout = 0;
+    }
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_motion_buffer_finalize (GObject *object)
+{
+  GimpMotionBuffer *buffer = GIMP_MOTION_BUFFER (object);
+
+  if (buffer->event_history)
+    {
+      g_array_free (buffer->event_history, TRUE);
+      buffer->event_history = NULL;
+    }
+
+  if (buffer->event_queue)
+    {
+      g_array_free (buffer->event_queue, TRUE);
+      buffer->event_queue = NULL;
+    }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_motion_buffer_set_property (GObject      *object,
+                                 guint         property_id,
+                                 const GValue *value,
+                                 GParamSpec   *pspec)
+{
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_motion_buffer_get_property (GObject    *object,
+                                 guint       property_id,
+                                 GValue     *value,
+                                 GParamSpec *pspec)
+{
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+
+/*  public functions  */
+
+GimpMotionBuffer *
+gimp_motion_buffer_new (void)
+{
+  return g_object_new (GIMP_TYPE_MOTION_BUFFER,
+                       NULL);
+}
+
+void
+gimp_motion_buffer_begin_stroke (GimpMotionBuffer *buffer,
+                                 guint32           time,
+                                 GimpCoords       *last_motion)
+{
+  g_return_if_fail (GIMP_IS_MOTION_BUFFER (buffer));
+  g_return_if_fail (last_motion != NULL);
+
+  buffer->last_read_motion_time = time;
+
+  *last_motion = buffer->last_coords;
+}
+
+void
+gimp_motion_buffer_end_stroke (GimpMotionBuffer *buffer)
+{
+  g_return_if_fail (GIMP_IS_MOTION_BUFFER (buffer));
+
+  if (buffer->event_delay_timeout)
+    {
+      g_source_remove (buffer->event_delay_timeout);
+      buffer->event_delay_timeout = 0;
+    }
+
+  gimp_motion_buffer_event_queue_timeout (buffer);
+}
+
+/**
+ * gimp_motion_buffer_motion_event:
+ * @buffer:
+ * @coords:
+ * @time:
+ * @event_fill:
+ *
+ * This function evaluates the event to decide if the change is big
+ * enough to need handling and returns FALSE, if change is less than
+ * set filter level taking a whole lot of load off any draw tools that
+ * have no use for these events anyway. If the event is seen fit at
+ * first look, it is evaluated for speed and smoothed.  Due to lousy
+ * time resolution of events pretty strong smoothing is applied to
+ * timestamps for sensible speed result. This function is also ideal
+ * for other event adjustment like pressure curve or calculating other
+ * derived dynamics factors like angular velocity calculation from
+ * tilt values, to allow for even more dynamic brushes. Calculated
+ * distance to last event is stored in GimpCoords because its a
+ * sideproduct of velocity calculation and is currently calculated in
+ * each tool. If they were to use this distance, more resources on
+ * recalculating the same value would be saved.
+ *
+ * Return value: %TRUE if the motion was significant enough to be
+ *               processed, %FALSE otherwise.
+ **/
+gboolean
+gimp_motion_buffer_motion_event (GimpMotionBuffer *buffer,
+                                 GimpCoords       *coords,
+                                 guint32           time,
+                                 gboolean          event_fill)
+{
+  gdouble  delta_time  = 0.001;
+  gdouble  delta_x     = 0.0;
+  gdouble  delta_y     = 0.0;
+  gdouble  distance    = 1.0;
+  gdouble  scale_x     = coords->xscale;
+  gdouble  scale_y     = coords->yscale;
+
+  g_return_val_if_fail (GIMP_IS_MOTION_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (coords != NULL, FALSE);
+
+  /*  the last_read_motion_time most be set unconditionally, so set
+   *  it early
+   */
+  buffer->last_read_motion_time = time;
+
+  delta_time = (buffer->last_motion_delta_time * (1 - SMOOTH_FACTOR) +
+                (time - buffer->last_motion_time) * SMOOTH_FACTOR);
+
+  if (buffer->last_motion_time == 0)
+    {
+      /*  First pair is invalid to do any velocity calculation, so we
+       *  apply a constant value.
+       */
+      coords->velocity = 1.0;
+    }
+  else
+    {
+      GimpCoords last_dir_event = buffer->last_coords;
+      gdouble    filter;
+      gdouble    dist;
+      gdouble    delta_dir;
+      gdouble    dir_delta_x = 0.0;
+      gdouble    dir_delta_y = 0.0;
+
+      delta_x = last_dir_event.x - coords->x;
+      delta_y = last_dir_event.y - coords->y;
+
+      /*  Events with distances less than the screen resolution are
+       *  not worth handling.
+       */
+      filter = MIN (1.0 / scale_x, 1.0 / scale_y) / 2.0;
+
+      if (fabs (delta_x) < filter &&
+          fabs (delta_y) < filter)
+        {
+          return FALSE;
+        }
+
+      distance = dist = sqrt (SQR (delta_x) + SQR (delta_y));
+
+      /*  If even smoothed time resolution does not allow to guess for
+       *  speed, use last velocity.
+       */
+      if (delta_time == 0)
+        {
+          coords->velocity = buffer->last_coords.velocity;
+        }
+      else
+        {
+          /*  We need to calculate the velocity in screen coordinates
+           *  for human interaction
+           */
+          gdouble screen_distance = (distance * MIN (scale_x, scale_y));
+
+          /* Calculate raw valocity */
+          coords->velocity = ((screen_distance / delta_time) / VELOCITY_UNIT);
+
+          /* Adding velocity dependent smoothing, feels better in tools. */
+          coords->velocity = (buffer->last_coords.velocity *
+                              (1 - MIN (SMOOTH_FACTOR, coords->velocity)) +
+                              coords->velocity *
+                              MIN (SMOOTH_FACTOR, coords->velocity));
+
+          /* Speed needs upper limit */
+          coords->velocity = MIN (coords->velocity, 1.0);
+        }
+
+      if (((fabs (delta_x) > DIRECTION_RADIUS) &&
+           (fabs (delta_y) > DIRECTION_RADIUS)) ||
+          (buffer->event_history->len < 4))
+        {
+          dir_delta_x = delta_x;
+          dir_delta_y = delta_y;
+        }
+      else
+        {
+          gint x = CLAMP ((buffer->event_history->len - 1), 3, 15);
+
+          while (((fabs (dir_delta_x) < DIRECTION_RADIUS) ||
+                  (fabs (dir_delta_y) < DIRECTION_RADIUS)) &&
+                 (x >= 0))
+            {
+              last_dir_event = g_array_index (buffer->event_history,
+                                              GimpCoords, x);
+
+              dir_delta_x = last_dir_event.x - coords->x;
+              dir_delta_y = last_dir_event.y - coords->y;
+
+              x--;
+            }
+        }
+
+      if ((fabs (dir_delta_x) < DIRECTION_RADIUS) ||
+          (fabs (dir_delta_y) < DIRECTION_RADIUS))
+        {
+          coords->direction = buffer->last_coords.direction;
+        }
+      else
+        {
+          coords->direction = gimp_coords_direction (&last_dir_event, coords);
+        }
+
+      coords->direction = coords->direction - floor (coords->direction);
+
+      delta_dir = coords->direction - buffer->last_coords.direction;
+
+      if (delta_dir < -0.5)
+        {
+          coords->direction = (0.5 * coords->direction +
+                               0.5 * (buffer->last_coords.direction - 1.0));
+        }
+      else if (delta_dir > 0.5)
+        {
+          coords->direction = (0.5 * coords->direction +
+                               0.5 * (buffer->last_coords.direction + 1.0));
+        }
+      else
+        {
+          coords->direction = (0.5 * coords->direction +
+                               0.5 * buffer->last_coords.direction);
+        }
+
+      coords->direction = coords->direction - floor (coords->direction);
+
+      /* do event fill for devices that do not provide enough events */
+      if (distance >= EVENT_FILL_PRECISION &&
+          event_fill                       &&
+          buffer->event_history->len >= 2)
+        {
+          if (buffer->event_delay)
+            {
+              gimp_motion_buffer_interpolate_stroke (buffer, coords);
+            }
+          else
+            {
+              buffer->event_delay = TRUE;
+              gimp_motion_buffer_push_event_history (buffer, coords);
+            }
+        }
+      else
+        {
+          if (buffer->event_delay)
+            buffer->event_delay = FALSE;
+
+          gimp_motion_buffer_push_event_history (buffer, coords);
+        }
+
+#ifdef EVENT_VERBOSE
+      g_printerr ("DIST: %f, DT:%f, Vel:%f, Press:%f,smooth_dd:%f, POS: (%f, %f)\n",
+                  distance,
+                  delta_time,
+                  buffer->last_coords.velocity,
+                  coords->pressure,
+                  distance - dist,
+                  coords->x,
+                  coords->y);
+#endif
+    }
+
+  g_array_append_val (buffer->event_queue, *coords);
+
+  buffer->last_coords            = *coords;
+  buffer->last_motion_time       = time;
+  buffer->last_motion_delta_time = delta_time;
+  buffer->last_motion_delta_x    = delta_x;
+  buffer->last_motion_delta_y    = delta_y;
+  buffer->last_motion_distance   = distance;
+
+  return TRUE;
+}
+
+guint32
+gimp_motion_buffer_get_last_motion_time (GimpMotionBuffer *buffer)
+{
+  g_return_val_if_fail (GIMP_IS_MOTION_BUFFER (buffer), 0);
+
+  return buffer->last_read_motion_time;
+}
+
+void
+gimp_motion_buffer_request_stroke (GimpMotionBuffer *buffer,
+                                   GdkModifierType   state,
+                                   guint32           time)
+{
+  GdkModifierType  event_state;
+  gint             keep = 0;
+
+  g_return_if_fail (GIMP_IS_MOTION_BUFFER (buffer));
+
+  if (buffer->event_delay)
+    {
+      /* If we are in delay we use LAST state, not current */
+      event_state = buffer->last_active_state;
+
+      keep = 1; /* Holding one event in buf */
+    }
+  else
+    {
+      /* Save the state */
+      event_state = state;
+    }
+
+  if (buffer->event_delay_timeout)
+    {
+      g_source_remove (buffer->event_delay_timeout);
+      buffer->event_delay_timeout = 0;
+    }
+
+  buffer->last_active_state = state;
+
+  while (buffer->event_queue->len > keep)
+    {
+      GimpCoords buf_coords;
+
+      gimp_motion_buffer_pop_event_queue (buffer, &buf_coords);
+
+      g_signal_emit (buffer, motion_buffer_signals[STROKE], 0,
+                     &buf_coords, time, event_state);
+    }
+
+  if (buffer->event_delay)
+    {
+      buffer->event_delay_timeout =
+        g_timeout_add (50,
+                       (GSourceFunc) gimp_motion_buffer_event_queue_timeout,
+                       buffer);
+    }
+}
+
+void
+gimp_motion_buffer_request_hover (GimpMotionBuffer *buffer,
+                                  GdkModifierType   state,
+                                  gboolean          proximity)
+{
+  g_return_if_fail (GIMP_IS_MOTION_BUFFER (buffer));
+
+  if (buffer->event_queue->len > 0)
+    {
+      GimpCoords buf_coords = g_array_index (buffer->event_queue,
+                                             GimpCoords,
+                                             buffer->event_queue->len - 1);
+
+      g_signal_emit (buffer, motion_buffer_signals[HOVER], 0,
+                     &buf_coords, state, proximity);
+
+      g_array_set_size (buffer->event_queue, 0);
+    }
+}
+
+
+/*  private functions  */
+
+static void
+gimp_motion_buffer_push_event_history (GimpMotionBuffer *buffer,
+                                       const GimpCoords *coords)
+{
+  if (buffer->event_history->len == 4)
+    g_array_remove_index (buffer->event_history, 0);
+
+  g_array_append_val (buffer->event_history, *coords);
+}
+
+static void
+gimp_motion_buffer_pop_event_queue (GimpMotionBuffer *buffer,
+                                    GimpCoords       *coords)
+{
+  *coords = g_array_index (buffer->event_queue, GimpCoords, 0);
+
+  g_array_remove_index (buffer->event_queue, 0);
+}
+
+static void
+gimp_motion_buffer_interpolate_stroke (GimpMotionBuffer *buffer,
+                                       GimpCoords       *coords)
+{
+  GimpCoords  catmull[4];
+  GArray     *ret_coords;
+  gint        i = buffer->event_history->len - 1;
+
+  /* Note that there must be exactly one event in buffer or bad things
+   * can happen. This must never get called under other circumstances.
+   */
+  ret_coords = g_array_new (FALSE, FALSE, sizeof (GimpCoords));
+
+  catmull[0] = g_array_index (buffer->event_history, GimpCoords, i - 1);
+  catmull[1] = g_array_index (buffer->event_history, GimpCoords, i);
+  catmull[2] = g_array_index (buffer->event_queue,   GimpCoords, 0);
+  catmull[3] = *coords;
+
+  gimp_coords_interpolate_catmull (catmull, EVENT_FILL_PRECISION / 2,
+                                   ret_coords, NULL);
+
+  /* Push the last actual event in history */
+  gimp_motion_buffer_push_event_history (buffer,
+                                         &g_array_index (buffer->event_queue,
+                                                         GimpCoords, 0));
+
+  g_array_set_size (buffer->event_queue, 0);
+
+  g_array_append_vals (buffer->event_queue,
+                       &g_array_index (ret_coords, GimpCoords, 0),
+                       ret_coords->len);
+
+  g_array_free (ret_coords, TRUE);
+}
+
+static gboolean
+gimp_motion_buffer_event_queue_timeout (GimpMotionBuffer *buffer)
+{
+  buffer->event_delay         = FALSE;
+  buffer->event_delay_timeout = 0;
+
+  if (buffer->event_queue->len > 0)
+    {
+      GimpCoords last_coords = g_array_index (buffer->event_queue,
+                                              GimpCoords,
+                                              buffer->event_queue->len - 1);
+
+      gimp_motion_buffer_push_event_history (buffer, &last_coords);
+
+      gimp_motion_buffer_request_stroke (buffer,
+                                         buffer->last_active_state,
+                                         buffer->last_read_motion_time);
+    }
+
+  return FALSE;
+}
diff --git a/app/display/gimpmotionbuffer.h b/app/display/gimpmotionbuffer.h
new file mode 100644
index 0000000..c7aee64
--- /dev/null
+++ b/app/display/gimpmotionbuffer.h
@@ -0,0 +1,99 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpmotionbuffer.h
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_MOTION_BUFFER_H__
+#define __GIMP_MOTION_BUFFER_H__
+
+
+#include "core/gimpobject.h"
+
+
+#define GIMP_TYPE_MOTION_BUFFER            (gimp_motion_buffer_get_type ())
+#define GIMP_MOTION_BUFFER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_MOTION_BUFFER, GimpMotionBuffer))
+#define GIMP_MOTION_BUFFER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_MOTION_BUFFER, GimpMotionBufferClass))
+#define GIMP_IS_MOTION_BUFFER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_MOTION_BUFFER))
+#define GIMP_IS_MOTION_BUFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_MOTION_BUFFER))
+#define GIMP_MOTION_BUFFER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_MOTION_BUFFER, GimpMotionBufferClass))
+
+
+typedef struct _GimpMotionBufferClass GimpMotionBufferClass;
+
+struct _GimpMotionBuffer
+{
+  GimpObject  parent_instance;
+
+  guint32     last_read_motion_time;
+
+  guint32     last_motion_time; /*  previous time of a forwarded motion event  */
+  gdouble     last_motion_delta_time;
+  gdouble     last_motion_delta_x;
+  gdouble     last_motion_delta_y;
+  gdouble     last_motion_distance;
+
+  GimpCoords  last_coords;      /* last motion event                   */
+
+  GArray     *event_history;
+  GArray     *event_queue;
+  gboolean    event_delay;      /* TRUE if there's an unsent event in
+                                 *  the history buffer
+                                 */
+
+  gint               event_delay_timeout;
+  GdkModifierType    last_active_state;
+};
+
+struct _GimpMotionBufferClass
+{
+  GimpObjectClass  parent_class;
+
+  void (* stroke) (GimpMotionBuffer *buffer,
+                   const GimpCoords *coords,
+                   guint32           time,
+                   GdkModifierType   state);
+  void (* hover)  (GimpMotionBuffer *buffer,
+                   const GimpCoords *coords,
+                   GdkModifierType   state,
+                   gboolean          proximity);
+};
+
+
+GType              gimp_motion_buffer_get_type     (void) G_GNUC_CONST;
+
+GimpMotionBuffer * gimp_motion_buffer_new          (void);
+
+void       gimp_motion_buffer_begin_stroke         (GimpMotionBuffer *buffer,
+                                                    guint32           time,
+                                                    GimpCoords       *last_motion);
+void       gimp_motion_buffer_end_stroke           (GimpMotionBuffer *buffer);
+
+gboolean   gimp_motion_buffer_motion_event         (GimpMotionBuffer *buffer,
+                                                    GimpCoords       *coords,
+                                                    guint32           time,
+                                                    gboolean          event_fill);
+guint32    gimp_motion_buffer_get_last_motion_time (GimpMotionBuffer *buffer);
+
+void       gimp_motion_buffer_request_stroke       (GimpMotionBuffer *buffer,
+                                                    GdkModifierType   state,
+                                                    guint32           time);
+void       gimp_motion_buffer_request_hover        (GimpMotionBuffer *buffer,
+                                                    GdkModifierType   state,
+                                                    gboolean          proximity);
+
+
+#endif /* __GIMP_MOTION_BUFFER_H__ */
diff --git a/app/display/gimpmultiwindowstrategy.c b/app/display/gimpmultiwindowstrategy.c
new file mode 100644
index 0000000..ca5cb22
--- /dev/null
+++ b/app/display/gimpmultiwindowstrategy.c
@@ -0,0 +1,89 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpmultiwindowstrategy.c
+ * Copyright (C) 2011 Martin Nordholts <martinn@src.gnome.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+
+#include "widgets/gimpdialogfactory.h"
+#include "widgets/gimpwindowstrategy.h"
+
+#include "gimpmultiwindowstrategy.h"
+
+
+static void        gimp_multi_window_strategy_window_strategy_iface_init (GimpWindowStrategyInterface *iface);
+static GtkWidget * gimp_multi_window_strategy_show_dockable_dialog       (GimpWindowStrategy          *strategy,
+                                                                          Gimp                        *gimp,
+                                                                          GimpDialogFactory           *factory,
+                                                                          GdkScreen                   *screen,
+                                                                          gint                         monitor,
+                                                                          const gchar                 *identifiers);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpMultiWindowStrategy, gimp_multi_window_strategy, GIMP_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_WINDOW_STRATEGY,
+                                                gimp_multi_window_strategy_window_strategy_iface_init))
+
+#define parent_class gimp_multi_window_strategy_parent_class
+
+
+static void
+gimp_multi_window_strategy_class_init (GimpMultiWindowStrategyClass *klass)
+{
+}
+
+static void
+gimp_multi_window_strategy_init (GimpMultiWindowStrategy *strategy)
+{
+}
+
+static void
+gimp_multi_window_strategy_window_strategy_iface_init (GimpWindowStrategyInterface *iface)
+{
+  iface->show_dockable_dialog = gimp_multi_window_strategy_show_dockable_dialog;
+}
+
+static GtkWidget *
+gimp_multi_window_strategy_show_dockable_dialog (GimpWindowStrategy *strategy,
+                                                 Gimp               *gimp,
+                                                 GimpDialogFactory  *factory,
+                                                 GdkScreen          *screen,
+                                                 gint                monitor,
+                                                 const gchar        *identifiers)
+{
+  return gimp_dialog_factory_dialog_raise (factory, screen, monitor,
+                                           identifiers, -1);
+}
+
+GimpObject *
+gimp_multi_window_strategy_get_singleton (void)
+{
+  static GimpObject *singleton = NULL;
+
+  if (! singleton)
+    singleton = g_object_new (GIMP_TYPE_MULTI_WINDOW_STRATEGY, NULL);
+
+  return singleton;
+}
diff --git a/app/display/gimpmultiwindowstrategy.h b/app/display/gimpmultiwindowstrategy.h
new file mode 100644
index 0000000..4df8873
--- /dev/null
+++ b/app/display/gimpmultiwindowstrategy.h
@@ -0,0 +1,54 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpmultiwindowstrategy.h
+ * Copyright (C) 2011 Martin Nordholts <martinn@src.gnome.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_MULTI_WINDOW_STRATEGY_H__
+#define __GIMP_MULTI_WINDOW_STRATEGY_H__
+
+
+#include "core/gimpobject.h"
+
+
+#define GIMP_TYPE_MULTI_WINDOW_STRATEGY            (gimp_multi_window_strategy_get_type ())
+#define GIMP_MULTI_WINDOW_STRATEGY(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_MULTI_WINDOW_STRATEGY, GimpMultiWindowStrategy))
+#define GIMP_MULTI_WINDOW_STRATEGY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_MULTI_WINDOW_STRATEGY, GimpMultiWindowStrategyClass))
+#define GIMP_IS_MULTI_WINDOW_STRATEGY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_MULTI_WINDOW_STRATEGY))
+#define GIMP_IS_MULTI_WINDOW_STRATEGY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_MULTI_WINDOW_STRATEGY))
+#define GIMP_MULTI_WINDOW_STRATEGY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_MULTI_WINDOW_STRATEGY, GimpMultiWindowStrategyClass))
+
+
+typedef struct _GimpMultiWindowStrategyClass GimpMultiWindowStrategyClass;
+
+struct _GimpMultiWindowStrategy
+{
+  GimpObject  parent_instance;
+};
+
+struct _GimpMultiWindowStrategyClass
+{
+  GimpObjectClass  parent_class;
+};
+
+
+GType        gimp_multi_window_strategy_get_type          (void) G_GNUC_CONST;
+
+GimpObject * gimp_multi_window_strategy_get_singleton     (void);
+
+
+#endif /* __GIMP_MULTI_WINDOW_STRATEGY_H__ */
diff --git a/app/display/gimpnavigationeditor.c b/app/display/gimpnavigationeditor.c
new file mode 100644
index 0000000..a518882
--- /dev/null
+++ b/app/display/gimpnavigationeditor.c
@@ -0,0 +1,890 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpnavigationeditor.c
+ * Copyright (C) 2001 Michael Natterer <mitch@gimp.org>
+ *
+ * partly based on app/nav_window
+ * Copyright (C) 1999 Andy Thomas <alt@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimpimageproxy.h"
+
+#include "widgets/gimpdocked.h"
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpmenufactory.h"
+#include "widgets/gimpnavigationview.h"
+#include "widgets/gimpuimanager.h"
+#include "widgets/gimpviewrenderer.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpnavigationeditor.h"
+
+#include "gimp-intl.h"
+
+
+#define UPDATE_DELAY 300 /* From GtkRange in GTK+ 2.22 */
+
+
+static void        gimp_navigation_editor_docked_iface_init            (GimpDockedInterface  *iface);
+
+static void        gimp_navigation_editor_dispose                      (GObject              *object);
+
+static void        gimp_navigation_editor_set_context                  (GimpDocked           *docked,
+                                                                        GimpContext          *context);
+
+static GtkWidget * gimp_navigation_editor_new_private                  (GimpMenuFactory      *menu_factory,
+                                                                        GimpDisplayShell     *shell);
+
+static void        gimp_navigation_editor_set_shell                    (GimpNavigationEditor *editor,
+                                                                        GimpDisplayShell     *shell);
+static gboolean    gimp_navigation_editor_button_release               (GtkWidget            *widget,
+                                                                        GdkEventButton       *bevent,
+                                                                        GimpDisplayShell     *shell);
+static void        gimp_navigation_editor_marker_changed               (GimpNavigationView   *view,
+                                                                        gdouble               center_x,
+                                                                        gdouble               center_y,
+                                                                        gdouble               width,
+                                                                        gdouble               height,
+                                                                        GimpNavigationEditor *editor);
+static void        gimp_navigation_editor_zoom                         (GimpNavigationView   *view,
+                                                                        GimpZoomType          direction,
+                                                                        GimpNavigationEditor *editor);
+static void        gimp_navigation_editor_scroll                       (GimpNavigationView   *view,
+                                                                        GdkScrollDirection    direction,
+                                                                        GimpNavigationEditor *editor);
+
+static void        gimp_navigation_editor_zoom_adj_changed             (GtkAdjustment        *adj,
+                                                                        GimpNavigationEditor *editor);
+
+static void        gimp_navigation_editor_shell_infinite_canvas_notify (GimpDisplayShell     *shell,
+                                                                        const GParamSpec     *pspec,
+                                                                        GimpNavigationEditor *editor);
+static void        gimp_navigation_editor_shell_scaled                 (GimpDisplayShell     *shell,
+                                                                        GimpNavigationEditor *editor);
+static void        gimp_navigation_editor_shell_scrolled               (GimpDisplayShell     *shell,
+                                                                        GimpNavigationEditor *editor);
+static void        gimp_navigation_editor_shell_rotated                (GimpDisplayShell     *shell,
+                                                                        GimpNavigationEditor *editor);
+static void        gimp_navigation_editor_shell_reconnect              (GimpDisplayShell     *shell,
+                                                                        GimpNavigationEditor *editor);
+
+static void        gimp_navigation_editor_viewable_size_changed        (GimpViewable         *viewable,
+                                                                        GimpNavigationEditor *editor);
+
+static void        gimp_navigation_editor_options_show_canvas_notify   (GimpDisplayOptions   *options,
+                                                                        const GParamSpec     *pspec,
+                                                                        GimpNavigationEditor *editor);
+
+static void        gimp_navigation_editor_update_marker                (GimpNavigationEditor *editor);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpNavigationEditor, gimp_navigation_editor,
+                         GIMP_TYPE_EDITOR,
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_DOCKED,
+                                                gimp_navigation_editor_docked_iface_init))
+
+#define parent_class gimp_navigation_editor_parent_class
+
+
+static void
+gimp_navigation_editor_class_init (GimpNavigationEditorClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gimp_navigation_editor_dispose;
+}
+
+static void
+gimp_navigation_editor_docked_iface_init (GimpDockedInterface *iface)
+{
+  iface->set_context = gimp_navigation_editor_set_context;
+}
+
+static void
+gimp_navigation_editor_init (GimpNavigationEditor *editor)
+{
+  GtkWidget *frame;
+
+  editor->context       = NULL;
+  editor->shell         = NULL;
+  editor->scale_timeout = 0;
+
+  frame = gtk_frame_new (NULL);
+  gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_IN);
+  gtk_box_pack_start (GTK_BOX (editor), frame, TRUE, TRUE, 0);
+  gtk_widget_show (frame);
+
+  editor->view = gimp_view_new_by_types (NULL,
+                                         GIMP_TYPE_NAVIGATION_VIEW,
+                                         GIMP_TYPE_IMAGE_PROXY,
+                                         GIMP_VIEW_SIZE_MEDIUM, 0, TRUE);
+  gtk_container_add (GTK_CONTAINER (frame), editor->view);
+  gtk_widget_show (editor->view);
+
+  g_signal_connect (editor->view, "marker-changed",
+                    G_CALLBACK (gimp_navigation_editor_marker_changed),
+                    editor);
+  g_signal_connect (editor->view, "zoom",
+                    G_CALLBACK (gimp_navigation_editor_zoom),
+                    editor);
+  g_signal_connect (editor->view, "scroll",
+                    G_CALLBACK (gimp_navigation_editor_scroll),
+                    editor);
+
+  gtk_widget_set_sensitive (GTK_WIDGET (editor), FALSE);
+}
+
+static void
+gimp_navigation_editor_dispose (GObject *object)
+{
+  GimpNavigationEditor *editor = GIMP_NAVIGATION_EDITOR (object);
+
+  if (editor->shell)
+    gimp_navigation_editor_set_shell (editor, NULL);
+
+  if (editor->scale_timeout)
+    {
+      g_source_remove (editor->scale_timeout);
+      editor->scale_timeout = 0;
+    }
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_navigation_editor_display_changed (GimpContext          *context,
+                                        GimpDisplay          *display,
+                                        GimpNavigationEditor *editor)
+{
+  GimpDisplayShell *shell = NULL;
+
+  if (display && gimp_display_get_image (display))
+    shell = gimp_display_get_shell (display);
+
+  gimp_navigation_editor_set_shell (editor, shell);
+}
+
+static void
+gimp_navigation_editor_image_chaged (GimpContext          *context,
+                                     GimpImage            *image,
+                                     GimpNavigationEditor *editor)
+{
+  GimpDisplay      *display = gimp_context_get_display (context);
+  GimpDisplayShell *shell   = NULL;
+
+  if (display && image)
+    shell = gimp_display_get_shell (display);
+
+  gimp_navigation_editor_set_shell (editor, shell);
+}
+
+static void
+gimp_navigation_editor_set_context (GimpDocked  *docked,
+                                    GimpContext *context)
+{
+  GimpNavigationEditor *editor  = GIMP_NAVIGATION_EDITOR (docked);
+  GimpDisplay          *display = NULL;
+
+  if (editor->context)
+    {
+      g_signal_handlers_disconnect_by_func (editor->context,
+                                            gimp_navigation_editor_display_changed,
+                                            editor);
+      g_signal_handlers_disconnect_by_func (editor->context,
+                                            gimp_navigation_editor_image_chaged,
+                                            editor);
+    }
+
+  editor->context = context;
+
+  if (editor->context)
+    {
+      g_signal_connect (context, "display-changed",
+                        G_CALLBACK (gimp_navigation_editor_display_changed),
+                        editor);
+      /* make sure to also call gimp_navigation_editor_set_shell() when the
+       * last image is closed, even though the display isn't changed, so that
+       * the editor is properly cleared.
+       */
+      g_signal_connect (context, "image-changed",
+                        G_CALLBACK (gimp_navigation_editor_image_chaged),
+                        editor);
+
+      display = gimp_context_get_display (context);
+    }
+
+  gimp_view_renderer_set_context (GIMP_VIEW (editor->view)->renderer,
+                                  context);
+
+  gimp_navigation_editor_display_changed (editor->context,
+                                          display,
+                                          editor);
+}
+
+
+/*  public functions  */
+
+GtkWidget *
+gimp_navigation_editor_new (GimpMenuFactory *menu_factory)
+{
+  return gimp_navigation_editor_new_private (menu_factory, NULL);
+}
+
+void
+gimp_navigation_editor_popup (GimpDisplayShell *shell,
+                              GtkWidget        *widget,
+                              gint              click_x,
+                              gint              click_y)
+{
+  GtkStyle             *style = gtk_widget_get_style (widget);
+  GimpNavigationEditor *editor;
+  GimpNavigationView   *view;
+  GdkScreen            *screen;
+  gint                  x, y;
+  gint                  view_marker_center_x, view_marker_center_y;
+  gint                  view_marker_width, view_marker_height;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  if (! shell->nav_popup)
+    {
+      GtkWidget *frame;
+
+      shell->nav_popup = gtk_window_new (GTK_WINDOW_POPUP);
+
+      frame = gtk_frame_new (NULL);
+      gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_OUT);
+      gtk_container_add (GTK_CONTAINER (shell->nav_popup), frame);
+      gtk_widget_show (frame);
+
+      editor =
+        GIMP_NAVIGATION_EDITOR (gimp_navigation_editor_new_private (NULL,
+                                                                    shell));
+      gtk_container_add (GTK_CONTAINER (frame), GTK_WIDGET (editor));
+      gtk_widget_show (GTK_WIDGET (editor));
+
+      g_signal_connect (editor->view, "button-release-event",
+                        G_CALLBACK (gimp_navigation_editor_button_release),
+                        shell);
+    }
+  else
+    {
+      GtkWidget *bin = gtk_bin_get_child (GTK_BIN (shell->nav_popup));
+
+      editor = GIMP_NAVIGATION_EDITOR (gtk_bin_get_child (GTK_BIN (bin)));
+    }
+
+  view = GIMP_NAVIGATION_VIEW (editor->view);
+
+  /* Set poup screen */
+  screen = gtk_widget_get_screen (widget);
+  gtk_window_set_screen (GTK_WINDOW (shell->nav_popup), screen);
+
+  gimp_navigation_view_get_local_marker (view,
+                                         &view_marker_center_x,
+                                         &view_marker_center_y,
+                                         &view_marker_width,
+                                         &view_marker_height);
+  /* Position the popup */
+  {
+    gint x_origin, y_origin;
+    gint popup_width, popup_height;
+    gint border_width, border_height;
+    gint screen_click_x, screen_click_y;
+
+    gdk_window_get_origin (gtk_widget_get_window (widget),
+                           &x_origin, &y_origin);
+
+    screen_click_x = x_origin + click_x;
+    screen_click_y = y_origin + click_y;
+    border_width   = 2 * style->xthickness;
+    border_height  = 2 * style->ythickness;
+    popup_width    = GIMP_VIEW (view)->renderer->width  - 2 * border_width;
+    popup_height   = GIMP_VIEW (view)->renderer->height - 2 * border_height;
+
+    x = screen_click_x -
+        border_width -
+        view_marker_center_x;
+
+    y = screen_click_y -
+        border_height -
+        view_marker_center_y;
+
+    /* When the image is zoomed out and overscrolled, the above
+     * calculation risks positioning the popup far far away from the
+     * click coordinate. We don't want that, so perform some clamping.
+     */
+    x = CLAMP (x, screen_click_x - popup_width,  screen_click_x);
+    y = CLAMP (y, screen_click_y - popup_height, screen_click_y);
+
+    /* If the popup doesn't fit into the screen, we have a problem.
+     * We move the popup onscreen and risk that the pointer is not
+     * in the square representing the viewable area anymore. Moving
+     * the pointer will make the image scroll by a large amount,
+     * but then it works as usual. Probably better than a popup that
+     * is completely unusable in the lower right of the screen.
+     *
+     * Warping the pointer would be another solution ...
+     */
+    x = CLAMP (x, 0, gdk_screen_get_width (screen)  - popup_width);
+    y = CLAMP (y, 0, gdk_screen_get_height (screen) - popup_height);
+
+    gtk_window_move (GTK_WINDOW (shell->nav_popup), x, y);
+  }
+
+  gtk_widget_show (shell->nav_popup);
+  gdk_flush ();
+
+  /* fill in then grab pointer */
+  gimp_navigation_view_set_motion_offset (view, 0, 0);
+  gimp_navigation_view_grab_pointer (view);
+}
+
+
+/*  private functions  */
+
+static GtkWidget *
+gimp_navigation_editor_new_private (GimpMenuFactory  *menu_factory,
+                                    GimpDisplayShell *shell)
+{
+  GimpNavigationEditor *editor;
+
+  g_return_val_if_fail (menu_factory == NULL ||
+                        GIMP_IS_MENU_FACTORY (menu_factory), NULL);
+  g_return_val_if_fail (shell == NULL || GIMP_IS_DISPLAY_SHELL (shell), NULL);
+  g_return_val_if_fail (menu_factory || shell, NULL);
+
+  if (shell)
+    {
+      Gimp              *gimp   = shell->display->gimp;
+      GimpDisplayConfig *config = shell->display->config;
+      GimpView          *view;
+
+      editor = g_object_new (GIMP_TYPE_NAVIGATION_EDITOR, NULL);
+
+      view = GIMP_VIEW (editor->view);
+
+      gimp_view_renderer_set_size (view->renderer,
+                                   config->nav_preview_size * 3,
+                                   view->renderer->border_width);
+      gimp_view_renderer_set_context (view->renderer,
+                                      gimp_get_user_context (gimp));
+      gimp_view_renderer_set_color_config (view->renderer,
+                                           gimp_display_shell_get_color_config (shell));
+
+      gimp_navigation_editor_set_shell (editor, shell);
+
+    }
+  else
+    {
+      GtkWidget *hscale;
+      GtkWidget *hbox;
+
+      editor = g_object_new (GIMP_TYPE_NAVIGATION_EDITOR,
+                             "menu-factory",    menu_factory,
+                             "menu-identifier", "<NavigationEditor>",
+                             NULL);
+
+      gtk_widget_set_size_request (editor->view,
+                                   GIMP_VIEW_SIZE_HUGE,
+                                   GIMP_VIEW_SIZE_HUGE);
+      gimp_view_set_expand (GIMP_VIEW (editor->view), TRUE);
+
+      /* the editor buttons */
+
+      editor->zoom_out_button =
+        gimp_editor_add_action_button (GIMP_EDITOR (editor), "view",
+                                       "view-zoom-out", NULL);
+
+      editor->zoom_in_button =
+        gimp_editor_add_action_button (GIMP_EDITOR (editor), "view",
+                                       "view-zoom-in", NULL);
+
+      editor->zoom_100_button =
+        gimp_editor_add_action_button (GIMP_EDITOR (editor), "view",
+                                       "view-zoom-1-1", NULL);
+
+      editor->zoom_fit_in_button =
+        gimp_editor_add_action_button (GIMP_EDITOR (editor), "view",
+                                       "view-zoom-fit-in", NULL);
+
+      editor->zoom_fill_button =
+        gimp_editor_add_action_button (GIMP_EDITOR (editor), "view",
+                                       "view-zoom-fill", NULL);
+
+      editor->shrink_wrap_button =
+        gimp_editor_add_action_button (GIMP_EDITOR (editor), "view",
+                                       "view-shrink-wrap", NULL);
+
+      /* the zoom scale */
+
+      hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
+      gtk_box_pack_end (GTK_BOX (editor), hbox, FALSE, FALSE, 0);
+      gtk_widget_show (hbox);
+
+      editor->zoom_adjustment =
+        GTK_ADJUSTMENT (gtk_adjustment_new (0.0, -8.0, 8.0, 0.5, 1.0, 0.0));
+
+      g_signal_connect (editor->zoom_adjustment, "value-changed",
+                        G_CALLBACK (gimp_navigation_editor_zoom_adj_changed),
+                        editor);
+
+      hscale = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL,
+                              editor->zoom_adjustment);
+      gtk_scale_set_draw_value (GTK_SCALE (hscale), FALSE);
+      gtk_box_pack_start (GTK_BOX (hbox), hscale, TRUE, TRUE, 0);
+      gtk_widget_show (hscale);
+
+      /* the zoom label */
+
+      editor->zoom_label = gtk_label_new ("100%");
+      gtk_label_set_width_chars (GTK_LABEL (editor->zoom_label), 7);
+      gtk_box_pack_start (GTK_BOX (hbox), editor->zoom_label, FALSE, FALSE, 0);
+      gtk_widget_show (editor->zoom_label);
+    }
+
+  gimp_view_renderer_set_background (GIMP_VIEW (editor->view)->renderer,
+                                     GIMP_ICON_TEXTURE);
+
+  return GTK_WIDGET (editor);
+}
+
+static void
+gimp_navigation_editor_set_shell (GimpNavigationEditor *editor,
+                                  GimpDisplayShell     *shell)
+{
+  g_return_if_fail (GIMP_IS_NAVIGATION_EDITOR (editor));
+  g_return_if_fail (! shell || GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell == editor->shell)
+    return;
+
+  if (editor->shell)
+    {
+      g_signal_handlers_disconnect_by_func (editor->shell,
+                                            gimp_navigation_editor_shell_infinite_canvas_notify,
+                                            editor);
+      g_signal_handlers_disconnect_by_func (editor->shell,
+                                            gimp_navigation_editor_shell_scaled,
+                                            editor);
+      g_signal_handlers_disconnect_by_func (editor->shell,
+                                            gimp_navigation_editor_shell_scrolled,
+                                            editor);
+      g_signal_handlers_disconnect_by_func (editor->shell,
+                                            gimp_navigation_editor_shell_rotated,
+                                            editor);
+      g_signal_handlers_disconnect_by_func (editor->shell,
+                                            gimp_navigation_editor_shell_reconnect,
+                                            editor);
+
+      g_signal_handlers_disconnect_by_func (editor->shell->options,
+                                            gimp_navigation_editor_options_show_canvas_notify,
+                                            editor);
+      g_signal_handlers_disconnect_by_func (editor->shell->fullscreen_options,
+                                            gimp_navigation_editor_options_show_canvas_notify,
+                                            editor);
+    }
+  else if (shell)
+    {
+      gtk_widget_set_sensitive (GTK_WIDGET (editor), TRUE);
+    }
+
+  editor->shell = shell;
+
+  if (editor->shell)
+    {
+      GimpImage *image = gimp_display_get_image (shell->display);
+
+      g_clear_object (&editor->image_proxy);
+
+      if (image)
+        {
+          editor->image_proxy = gimp_image_proxy_new (image);
+
+          g_signal_connect (
+            editor->image_proxy, "size-changed",
+            G_CALLBACK (gimp_navigation_editor_viewable_size_changed),
+            editor);
+        }
+
+      gimp_view_set_viewable (GIMP_VIEW (editor->view),
+                              GIMP_VIEWABLE (editor->image_proxy));
+
+      g_signal_connect (editor->shell, "notify::infinite-canvas",
+                        G_CALLBACK (gimp_navigation_editor_shell_infinite_canvas_notify),
+                        editor);
+      g_signal_connect (editor->shell, "scaled",
+                        G_CALLBACK (gimp_navigation_editor_shell_scaled),
+                        editor);
+      g_signal_connect (editor->shell, "scrolled",
+                        G_CALLBACK (gimp_navigation_editor_shell_scrolled),
+                        editor);
+      g_signal_connect (editor->shell, "rotated",
+                        G_CALLBACK (gimp_navigation_editor_shell_rotated),
+                        editor);
+      g_signal_connect (editor->shell, "reconnect",
+                        G_CALLBACK (gimp_navigation_editor_shell_reconnect),
+                        editor);
+
+      g_signal_connect (editor->shell->options, "notify::show-canvas-boundary",
+                        G_CALLBACK (gimp_navigation_editor_options_show_canvas_notify),
+                        editor);
+      g_signal_connect (editor->shell->fullscreen_options, "notify::show-canvas-boundary",
+                        G_CALLBACK (gimp_navigation_editor_options_show_canvas_notify),
+                        editor);
+
+      gimp_navigation_editor_shell_scaled (editor->shell, editor);
+    }
+  else
+    {
+      gimp_view_set_viewable (GIMP_VIEW (editor->view), NULL);
+      gtk_widget_set_sensitive (GTK_WIDGET (editor), FALSE);
+
+      g_clear_object (&editor->image_proxy);
+    }
+
+  if (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)))
+    gimp_ui_manager_update (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)),
+                            gimp_editor_get_popup_data (GIMP_EDITOR (editor)));
+}
+
+static gboolean
+gimp_navigation_editor_button_release (GtkWidget        *widget,
+                                       GdkEventButton   *bevent,
+                                       GimpDisplayShell *shell)
+{
+  if (bevent->button == 1)
+    {
+      gtk_widget_hide (shell->nav_popup);
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_navigation_editor_marker_changed (GimpNavigationView   *view,
+                                       gdouble               center_x,
+                                       gdouble               center_y,
+                                       gdouble               width,
+                                       gdouble               height,
+                                       GimpNavigationEditor *editor)
+{
+  GimpViewRenderer *renderer = GIMP_VIEW (editor->view)->renderer;
+
+  if (editor->shell)
+    {
+      if (gimp_display_get_image (editor->shell->display))
+        {
+          GeglRectangle bounding_box;
+
+          bounding_box = gimp_image_proxy_get_bounding_box (
+            GIMP_IMAGE_PROXY (renderer->viewable));
+
+          center_x += bounding_box.x;
+          center_y += bounding_box.y;
+
+          gimp_display_shell_scroll_center_image_xy (editor->shell,
+                                                     center_x, center_y);
+        }
+    }
+}
+
+static void
+gimp_navigation_editor_zoom (GimpNavigationView   *view,
+                             GimpZoomType          direction,
+                             GimpNavigationEditor *editor)
+{
+  g_return_if_fail (direction != GIMP_ZOOM_TO);
+
+  if (editor->shell)
+    {
+      if (gimp_display_get_image (editor->shell->display))
+        gimp_display_shell_scale (editor->shell,
+                                  direction,
+                                  0.0,
+                                  GIMP_ZOOM_FOCUS_BEST_GUESS);
+    }
+}
+
+static void
+gimp_navigation_editor_scroll (GimpNavigationView   *view,
+                               GdkScrollDirection    direction,
+                               GimpNavigationEditor *editor)
+{
+  if (editor->shell)
+    {
+      GtkAdjustment *adj = NULL;
+      gdouble        value;
+
+      switch (direction)
+        {
+        case GDK_SCROLL_LEFT:
+        case GDK_SCROLL_RIGHT:
+          adj = editor->shell->hsbdata;
+          break;
+
+        case GDK_SCROLL_UP:
+        case GDK_SCROLL_DOWN:
+          adj = editor->shell->vsbdata;
+          break;
+        }
+
+      gimp_assert (adj != NULL);
+
+      value = gtk_adjustment_get_value (adj);
+
+      switch (direction)
+        {
+        case GDK_SCROLL_LEFT:
+        case GDK_SCROLL_UP:
+          value -= gtk_adjustment_get_page_increment (adj) / 2;
+          break;
+
+        case GDK_SCROLL_RIGHT:
+        case GDK_SCROLL_DOWN:
+          value += gtk_adjustment_get_page_increment (adj) / 2;
+          break;
+        }
+
+      value = CLAMP (value,
+                     gtk_adjustment_get_lower (adj),
+                     gtk_adjustment_get_upper (adj) -
+                     gtk_adjustment_get_page_size (adj));
+
+      gtk_adjustment_set_value (adj, value);
+    }
+}
+
+static gboolean
+gimp_navigation_editor_zoom_adj_changed_timeout (gpointer data)
+{
+  GimpNavigationEditor *editor = GIMP_NAVIGATION_EDITOR (data);
+  GtkAdjustment        *adj    = editor->zoom_adjustment;
+
+  if (gimp_display_get_image (editor->shell->display))
+    gimp_display_shell_scale (editor->shell,
+                              GIMP_ZOOM_TO,
+                              pow (2.0, gtk_adjustment_get_value (adj)),
+                              GIMP_ZOOM_FOCUS_BEST_GUESS);
+
+  editor->scale_timeout = 0;
+
+  return FALSE;
+}
+
+static void
+gimp_navigation_editor_zoom_adj_changed (GtkAdjustment        *adj,
+                                         GimpNavigationEditor *editor)
+{
+  if (editor->scale_timeout)
+    g_source_remove (editor->scale_timeout);
+
+  editor->scale_timeout =
+    g_timeout_add (UPDATE_DELAY,
+                   gimp_navigation_editor_zoom_adj_changed_timeout,
+                   editor);
+}
+
+static void
+gimp_navigation_editor_shell_infinite_canvas_notify (GimpDisplayShell     *shell,
+                                                     const GParamSpec     *pspec,
+                                                     GimpNavigationEditor *editor)
+{
+  gimp_navigation_editor_update_marker (editor);
+
+  if (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)))
+    gimp_ui_manager_update (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)),
+                            gimp_editor_get_popup_data (GIMP_EDITOR (editor)));
+}
+
+static void
+gimp_navigation_editor_shell_scaled (GimpDisplayShell     *shell,
+                                     GimpNavigationEditor *editor)
+{
+  if (editor->zoom_label)
+    {
+      gchar *str;
+
+      g_object_get (shell->zoom,
+                    "percentage", &str,
+                    NULL);
+      gtk_label_set_text (GTK_LABEL (editor->zoom_label), str);
+      g_free (str);
+    }
+
+  if (editor->zoom_adjustment)
+    {
+      gdouble val;
+
+      val = log (gimp_zoom_model_get_factor (shell->zoom)) / G_LN2;
+
+      g_signal_handlers_block_by_func (editor->zoom_adjustment,
+                                       gimp_navigation_editor_zoom_adj_changed,
+                                       editor);
+
+      gtk_adjustment_set_value (editor->zoom_adjustment, val);
+
+      g_signal_handlers_unblock_by_func (editor->zoom_adjustment,
+                                         gimp_navigation_editor_zoom_adj_changed,
+                                         editor);
+    }
+
+  gimp_navigation_editor_update_marker (editor);
+
+  if (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)))
+    gimp_ui_manager_update (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)),
+                            gimp_editor_get_popup_data (GIMP_EDITOR (editor)));
+}
+
+static void
+gimp_navigation_editor_shell_scrolled (GimpDisplayShell     *shell,
+                                       GimpNavigationEditor *editor)
+{
+  gimp_navigation_editor_update_marker (editor);
+
+  if (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)))
+    gimp_ui_manager_update (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)),
+                            gimp_editor_get_popup_data (GIMP_EDITOR (editor)));
+}
+
+static void
+gimp_navigation_editor_shell_rotated (GimpDisplayShell     *shell,
+                                      GimpNavigationEditor *editor)
+{
+  gimp_navigation_editor_update_marker (editor);
+
+  if (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)))
+    gimp_ui_manager_update (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)),
+                            gimp_editor_get_popup_data (GIMP_EDITOR (editor)));
+}
+
+static void
+gimp_navigation_editor_viewable_size_changed (GimpViewable         *viewable,
+                                              GimpNavigationEditor *editor)
+{
+  gimp_navigation_editor_update_marker (editor);
+
+  if (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)))
+    gimp_ui_manager_update (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)),
+                            gimp_editor_get_popup_data (GIMP_EDITOR (editor)));
+}
+
+static void
+gimp_navigation_editor_options_show_canvas_notify (GimpDisplayOptions   *options,
+                                                   const GParamSpec     *pspec,
+                                                   GimpNavigationEditor *editor)
+{
+  gimp_navigation_editor_update_marker (editor);
+}
+
+static void
+gimp_navigation_editor_shell_reconnect (GimpDisplayShell     *shell,
+                                        GimpNavigationEditor *editor)
+{
+  GimpImage *image = gimp_display_get_image (shell->display);
+
+  g_clear_object (&editor->image_proxy);
+
+  if (image)
+    {
+      editor->image_proxy = gimp_image_proxy_new (image);
+
+      g_signal_connect (
+        editor->image_proxy, "size-changed",
+        G_CALLBACK (gimp_navigation_editor_viewable_size_changed),
+        editor);
+    }
+
+  gimp_view_set_viewable (GIMP_VIEW (editor->view),
+                          GIMP_VIEWABLE (editor->image_proxy));
+
+  if (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)))
+    gimp_ui_manager_update (gimp_editor_get_ui_manager (GIMP_EDITOR (editor)),
+                            gimp_editor_get_popup_data (GIMP_EDITOR (editor)));
+}
+
+static void
+gimp_navigation_editor_update_marker (GimpNavigationEditor *editor)
+{
+  GimpViewRenderer *renderer = GIMP_VIEW (editor->view)->renderer;
+  GimpDisplayShell *shell    = editor->shell;
+
+  if (renderer->dot_for_dot != shell->dot_for_dot)
+    gimp_view_renderer_set_dot_for_dot (renderer, shell->dot_for_dot);
+
+  if (renderer->viewable)
+    {
+      GimpNavigationView *view = GIMP_NAVIGATION_VIEW (editor->view);
+      GimpImage          *image;
+      GeglRectangle       bounding_box;
+      gdouble             x, y;
+      gdouble             w, h;
+
+      image = gimp_image_proxy_get_image (
+        GIMP_IMAGE_PROXY (renderer->viewable));
+
+      gimp_image_proxy_set_show_all (
+        GIMP_IMAGE_PROXY (renderer->viewable),
+        gimp_display_shell_get_infinite_canvas (shell));
+
+      bounding_box = gimp_image_proxy_get_bounding_box (
+        GIMP_IMAGE_PROXY (renderer->viewable));
+
+      gimp_display_shell_scroll_get_viewport (shell, &x, &y, &w, &h);
+      gimp_display_shell_untransform_xy_f (shell,
+                                           shell->disp_width  / 2,
+                                           shell->disp_height / 2,
+                                           &x, &y);
+
+      x -= bounding_box.x;
+      y -= bounding_box.y;
+
+      gimp_navigation_view_set_marker (view,
+                                       x, y, w, h,
+                                       shell->flip_horizontally,
+                                       shell->flip_vertically,
+                                       shell->rotate_angle);
+
+      gimp_navigation_view_set_canvas (
+        view,
+        gimp_display_shell_get_infinite_canvas (shell) &&
+        gimp_display_shell_get_show_canvas (shell),
+        -bounding_box.x,              -bounding_box.y,
+        gimp_image_get_width (image), gimp_image_get_height (image));
+    }
+}
diff --git a/app/display/gimpnavigationeditor.h b/app/display/gimpnavigationeditor.h
new file mode 100644
index 0000000..8e876c2
--- /dev/null
+++ b/app/display/gimpnavigationeditor.h
@@ -0,0 +1,79 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpnavigationeditor.h
+ * Copyright (C) 2002 Michael Natterer <mitch@gimp.org>
+ *
+ * partly based on app/nav_window
+ * Copyright (C) 1999 Andy Thomas <alt@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_NAVIGATION_EDITOR_H__
+#define __GIMP_NAVIGATION_EDITOR_H__
+
+
+#include "widgets/gimpeditor.h"
+
+
+#define GIMP_TYPE_NAVIGATION_EDITOR            (gimp_navigation_editor_get_type ())
+#define GIMP_NAVIGATION_EDITOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_NAVIGATION_EDITOR, GimpNavigationEditor))
+#define GIMP_NAVIGATION_EDITOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_NAVIGATION_EDITOR, GimpNavigationEditorClass))
+#define GIMP_IS_NAVIGATION_EDITOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_NAVIGATION_EDITOR))
+#define GIMP_IS_NAVIGATION_EDITOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_NAVIGATION_EDITOR))
+#define GIMP_NAVIGATION_EDITOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_NAVIGATION_EDITOR, GimpNavigationEditorClass))
+
+
+typedef struct _GimpNavigationEditorClass  GimpNavigationEditorClass;
+
+struct _GimpNavigationEditor
+{
+  GimpEditor        parent_instance;
+
+  GimpContext      *context;
+  GimpDisplayShell *shell;
+
+  GimpImageProxy   *image_proxy;
+
+  GtkWidget        *view;
+  GtkWidget        *zoom_label;
+  GtkAdjustment    *zoom_adjustment;
+
+  GtkWidget        *zoom_out_button;
+  GtkWidget        *zoom_in_button;
+  GtkWidget        *zoom_100_button;
+  GtkWidget        *zoom_fit_in_button;
+  GtkWidget        *zoom_fill_button;
+  GtkWidget        *shrink_wrap_button;
+
+  guint             scale_timeout;
+};
+
+struct _GimpNavigationEditorClass
+{
+  GimpEditorClass  parent_class;
+};
+
+
+GType       gimp_navigation_editor_get_type  (void) G_GNUC_CONST;
+
+GtkWidget * gimp_navigation_editor_new       (GimpMenuFactory  *menu_factory);
+void        gimp_navigation_editor_popup     (GimpDisplayShell *shell,
+                                              GtkWidget        *widget,
+                                              gint              click_x,
+                                              gint              click_y);
+
+
+#endif  /*  __GIMP_NAVIGATION_EDITOR_H__  */
diff --git a/app/display/gimpscalecombobox.c b/app/display/gimpscalecombobox.c
new file mode 100644
index 0000000..3a5bba0
--- /dev/null
+++ b/app/display/gimpscalecombobox.c
@@ -0,0 +1,562 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpscalecombobox.c
+ * Copyright (C) 2004, 2008  Sven Neumann <sven@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "stdlib.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include "gdk/gdkkeysyms.h"
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpmarshal.h"
+
+#include "gimpscalecombobox.h"
+
+
+#define MAX_ITEMS  10
+
+enum
+{
+  COLUMN_SCALE,
+  COLUMN_LABEL,
+  COLUMN_PERSISTENT,
+  N_COLUMNS
+};
+
+enum
+{
+  ENTRY_ACTIVATED,
+  LAST_SIGNAL
+};
+
+
+static void      gimp_scale_combo_box_constructed     (GObject           *object);
+static void      gimp_scale_combo_box_finalize        (GObject           *object);
+
+static void      gimp_scale_combo_box_style_set       (GtkWidget         *widget,
+                                                       GtkStyle          *prev_style);
+
+static void      gimp_scale_combo_box_changed         (GimpScaleComboBox *combo_box);
+static void      gimp_scale_combo_box_entry_activate  (GtkWidget         *entry,
+                                                       GimpScaleComboBox *combo_box);
+static gboolean  gimp_scale_combo_box_entry_key_press (GtkWidget         *entry,
+                                                       GdkEventKey       *event,
+                                                       GimpScaleComboBox *combo_box);
+
+static void      gimp_scale_combo_box_scale_iter_set  (GtkListStore      *store,
+                                                       GtkTreeIter       *iter,
+                                                       gdouble            scale,
+                                                       gboolean           persistent);
+
+
+G_DEFINE_TYPE (GimpScaleComboBox, gimp_scale_combo_box,
+               GTK_TYPE_COMBO_BOX)
+
+#define parent_class gimp_scale_combo_box_parent_class
+
+static guint scale_combo_box_signals[LAST_SIGNAL] = { 0 };
+
+
+static void
+gimp_scale_combo_box_class_init (GimpScaleComboBoxClass *klass)
+{
+  GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  scale_combo_box_signals[ENTRY_ACTIVATED] =
+    g_signal_new ("entry-activated",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpScaleComboBoxClass, entry_activated),
+                  NULL, NULL,
+                  gimp_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  object_class->constructed = gimp_scale_combo_box_constructed;
+  object_class->finalize    = gimp_scale_combo_box_finalize;
+
+  widget_class->style_set   = gimp_scale_combo_box_style_set;
+
+  klass->entry_activated    = NULL;
+
+  gtk_widget_class_install_style_property (widget_class,
+                                           g_param_spec_double ("label-scale",
+                                                                NULL, NULL,
+                                                                0.0,
+                                                                G_MAXDOUBLE,
+                                                                1.0,
+                                                                GIMP_PARAM_READABLE));
+}
+
+static void
+gimp_scale_combo_box_init (GimpScaleComboBox *combo_box)
+{
+  combo_box->scale     = 1.0;
+  combo_box->last_path = NULL;
+}
+
+static void
+gimp_scale_combo_box_constructed (GObject *object)
+{
+  GimpScaleComboBox *combo_box = GIMP_SCALE_COMBO_BOX (object);
+  GtkWidget         *entry;
+  GtkListStore      *store;
+  GtkCellLayout     *layout;
+  GtkCellRenderer   *cell;
+  GtkTreeIter        iter;
+  GtkBorder          border = { 0, 0, 0, 0 };
+  gint               i;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  store = gtk_list_store_new (N_COLUMNS,
+                              G_TYPE_DOUBLE,    /* SCALE       */
+                              G_TYPE_STRING,    /* LABEL       */
+                              G_TYPE_BOOLEAN);  /* PERSISTENT  */
+
+  gtk_combo_box_set_model (GTK_COMBO_BOX (combo_box), GTK_TREE_MODEL (store));
+  g_object_unref (store);
+
+  gtk_combo_box_set_entry_text_column (GTK_COMBO_BOX (combo_box),
+                                       COLUMN_LABEL);
+
+  entry = gtk_bin_get_child (GTK_BIN (combo_box));
+
+  g_object_set (entry,
+                "xalign",             1.0,
+                "width-chars",        5,
+                "truncate-multiline", TRUE,
+                "inner-border",       &border,
+                NULL);
+
+  layout = GTK_CELL_LAYOUT (combo_box);
+
+  cell = g_object_new (GTK_TYPE_CELL_RENDERER_TEXT,
+                       "xalign", 1.0,
+                       NULL);
+
+  gtk_cell_layout_clear (layout);
+  gtk_cell_layout_pack_start (layout, cell, TRUE);
+  gtk_cell_layout_set_attributes (layout, cell,
+                                  "text", COLUMN_LABEL,
+                                  NULL);
+
+  for (i = 8; i > 0; i /= 2)
+    {
+      gtk_list_store_append (store, &iter);
+      gimp_scale_combo_box_scale_iter_set (store, &iter, i, TRUE);
+    }
+
+  for (i = 2; i <= 8; i *= 2)
+    {
+      gtk_list_store_append (store, &iter);
+      gimp_scale_combo_box_scale_iter_set (store, &iter, 1.0 / i, TRUE);
+    }
+
+  g_signal_connect (combo_box, "changed",
+                    G_CALLBACK (gimp_scale_combo_box_changed),
+                    NULL);
+
+  g_signal_connect (entry, "activate",
+                    G_CALLBACK (gimp_scale_combo_box_entry_activate),
+                    combo_box);
+  g_signal_connect (entry, "key-press-event",
+                    G_CALLBACK (gimp_scale_combo_box_entry_key_press),
+                    combo_box);
+}
+
+static void
+gimp_scale_combo_box_finalize (GObject *object)
+{
+  GimpScaleComboBox *combo_box = GIMP_SCALE_COMBO_BOX (object);
+
+  if (combo_box->last_path)
+    {
+      gtk_tree_path_free (combo_box->last_path);
+      combo_box->last_path = NULL;
+    }
+
+  if (combo_box->mru)
+    {
+      g_list_free_full (combo_box->mru,
+                        (GDestroyNotify) gtk_tree_row_reference_free);
+      combo_box->mru = NULL;
+    }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_scale_combo_box_style_set (GtkWidget *widget,
+                                GtkStyle  *prev_style)
+{
+  GtkWidget            *entry;
+  GtkRcStyle           *rc_style;
+  PangoContext         *context;
+  PangoFontDescription *font_desc;
+  gint                  font_size;
+  gdouble               label_scale;
+
+  GTK_WIDGET_CLASS (parent_class)->style_set (widget, prev_style);
+
+  gtk_widget_style_get (widget, "label-scale", &label_scale, NULL);
+
+  entry = gtk_bin_get_child (GTK_BIN (widget));
+
+  rc_style = gtk_widget_get_modifier_style (GTK_WIDGET (entry));
+
+  if (rc_style->font_desc)
+    pango_font_description_free (rc_style->font_desc);
+
+  context = gtk_widget_get_pango_context (widget);
+  font_desc = pango_context_get_font_description (context);
+  rc_style->font_desc = pango_font_description_copy (font_desc);
+
+  font_size = pango_font_description_get_size (rc_style->font_desc);
+  pango_font_description_set_size (rc_style->font_desc, label_scale * font_size);
+
+  gtk_widget_modify_style (GTK_WIDGET (entry), rc_style);
+}
+
+static void
+gimp_scale_combo_box_changed (GimpScaleComboBox *combo_box)
+{
+  GtkTreeIter iter;
+
+  if (gtk_combo_box_get_active_iter (GTK_COMBO_BOX (combo_box), &iter))
+    {
+      GtkTreeModel *model = gtk_combo_box_get_model (GTK_COMBO_BOX (combo_box));
+      gdouble       scale;
+
+      gtk_tree_model_get (model, &iter,
+                          COLUMN_SCALE, &scale,
+                          -1);
+      if (scale > 0.0)
+        {
+          combo_box->scale = scale;
+
+          if (combo_box->last_path)
+            gtk_tree_path_free (combo_box->last_path);
+
+          combo_box->last_path = gtk_tree_model_get_path (model, &iter);
+        }
+    }
+}
+
+static gboolean
+gimp_scale_combo_box_parse_text (const gchar *text,
+                                 gdouble     *scale)
+{
+  gchar   *end;
+  gdouble  left_number;
+  gdouble  right_number;
+
+  /* try to parse a number */
+  left_number = strtod (text, &end);
+
+  if (end == text)
+    return FALSE;
+  else
+    text = end;
+
+  /* skip over whitespace */
+  while (g_unichar_isspace (g_utf8_get_char (text)))
+    text = g_utf8_next_char (text);
+
+  if (*text == '\0' || *text == '%')
+    {
+      *scale = left_number / 100.0;
+      return TRUE;
+    }
+
+  /* check for a valid separator */
+  if (*text != '/' && *text != ':')
+    {
+      *scale = left_number;
+      return TRUE;
+    }
+
+  text = g_utf8_next_char (text);
+
+  /* skip over whitespace */
+  while (g_unichar_isspace (g_utf8_get_char (text)))
+    text = g_utf8_next_char (text);
+
+  /* try to parse another number */
+  right_number = strtod (text, &end);
+
+  if (end == text)
+    return FALSE;
+
+  if (right_number == 0.0)
+    return FALSE;
+
+  *scale = left_number / right_number;
+  return TRUE;
+}
+
+static void
+gimp_scale_combo_box_entry_activate (GtkWidget         *entry,
+                                     GimpScaleComboBox *combo_box)
+{
+  const gchar *text = gtk_entry_get_text (GTK_ENTRY (entry));
+  gdouble      scale;
+
+  if (gimp_scale_combo_box_parse_text (text, &scale) &&
+      scale >= 1.0 / 256.0                           &&
+      scale <= 256.0)
+    {
+      gimp_scale_combo_box_set_scale (combo_box, scale);
+    }
+  else
+    {
+      gtk_widget_error_bell (entry);
+
+      gimp_scale_combo_box_set_scale (combo_box, combo_box->scale);
+    }
+
+  g_signal_emit (combo_box, scale_combo_box_signals[ENTRY_ACTIVATED], 0);
+}
+
+static gboolean
+gimp_scale_combo_box_entry_key_press (GtkWidget         *entry,
+                                      GdkEventKey       *event,
+                                      GimpScaleComboBox *combo_box)
+{
+  if (event->keyval == GDK_KEY_Escape)
+    {
+      gimp_scale_combo_box_set_scale (combo_box, combo_box->scale);
+
+      g_signal_emit (combo_box, scale_combo_box_signals[ENTRY_ACTIVATED], 0);
+
+      return TRUE;
+    }
+
+  if (event->keyval == GDK_KEY_Tab    ||
+      event->keyval == GDK_KEY_KP_Tab ||
+      event->keyval == GDK_KEY_ISO_Left_Tab)
+    {
+      gimp_scale_combo_box_entry_activate (entry, combo_box);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_scale_combo_box_scale_iter_set (GtkListStore *store,
+                                     GtkTreeIter  *iter,
+                                     gdouble       scale,
+                                     gboolean      persistent)
+{
+  gchar label[32];
+
+#ifdef G_OS_WIN32
+
+  /*  use a normal space until pango's windows backend uses harfbuzz,
+   *  see bug #735505
+   */
+#define PERCENT_SPACE " "
+
+#else
+
+  /*  use U+2009 THIN SPACE to separate the percent sign from the number */
+#define PERCENT_SPACE "\342\200\211"
+
+#endif
+
+  if (scale > 1.0)
+    g_snprintf (label, sizeof (label),
+                "%d" PERCENT_SPACE "%%", (gint) ROUND (100.0 * scale));
+  else
+    g_snprintf (label, sizeof (label),
+                "%.3g" PERCENT_SPACE "%%", 100.0 * scale);
+
+  gtk_list_store_set (store, iter,
+                      COLUMN_SCALE,      scale,
+                      COLUMN_LABEL,      label,
+                      COLUMN_PERSISTENT, persistent,
+                      -1);
+}
+
+static void
+gimp_scale_combo_box_mru_add (GimpScaleComboBox *combo_box,
+                              GtkTreeIter       *iter)
+{
+  GtkTreeModel *model = gtk_combo_box_get_model (GTK_COMBO_BOX (combo_box));
+  GtkTreePath  *path  = gtk_tree_model_get_path (model, iter);
+  GList        *list;
+  gboolean      found;
+
+  for (list = combo_box->mru, found = FALSE; list && !found; list = list->next)
+    {
+      GtkTreePath *this = gtk_tree_row_reference_get_path (list->data);
+
+      if (gtk_tree_path_compare (this, path) == 0)
+        {
+          if (list->prev)
+            {
+              combo_box->mru = g_list_remove_link (combo_box->mru, list);
+              combo_box->mru = g_list_concat (list, combo_box->mru);
+            }
+
+          found = TRUE;
+        }
+
+      gtk_tree_path_free (this);
+    }
+
+  if (! found)
+    combo_box->mru = g_list_prepend (combo_box->mru,
+                                     gtk_tree_row_reference_new (model, path));
+
+  gtk_tree_path_free (path);
+}
+
+static void
+gimp_scale_combo_box_mru_remove_last (GimpScaleComboBox *combo_box)
+{
+  GtkTreeModel *model;
+  GtkTreePath  *path;
+  GList        *last;
+  GtkTreeIter   iter;
+
+  if (! combo_box->mru)
+    return;
+
+  model = gtk_combo_box_get_model (GTK_COMBO_BOX (combo_box));
+
+  last = g_list_last (combo_box->mru);
+  path = gtk_tree_row_reference_get_path (last->data);
+
+  if (gtk_tree_model_get_iter (model, &iter, path))
+    {
+      gtk_list_store_remove (GTK_LIST_STORE (model), &iter);
+      gtk_tree_row_reference_free (last->data);
+      combo_box->mru = g_list_delete_link (combo_box->mru, last);
+    }
+
+  gtk_tree_path_free (path);
+}
+
+
+/**
+ * gimp_scale_combo_box_new:
+ *
+ * Return value: a new #GimpScaleComboBox.
+ **/
+GtkWidget *
+gimp_scale_combo_box_new (void)
+{
+  return g_object_new (GIMP_TYPE_SCALE_COMBO_BOX,
+                       "has-entry", TRUE,
+                       NULL);
+}
+
+void
+gimp_scale_combo_box_set_scale (GimpScaleComboBox *combo_box,
+                                gdouble            scale)
+{
+  GtkTreeModel *model;
+  GtkListStore *store;
+  GtkWidget    *entry;
+  GtkTreeIter   iter;
+  gboolean      iter_valid;
+  gboolean      persistent;
+  gint          n_digits;
+
+  g_return_if_fail (GIMP_IS_SCALE_COMBO_BOX (combo_box));
+  g_return_if_fail (scale > 0.0);
+
+  model = gtk_combo_box_get_model (GTK_COMBO_BOX (combo_box));
+  store = GTK_LIST_STORE (model);
+
+  for (iter_valid = gtk_tree_model_get_iter_first (model, &iter);
+       iter_valid;
+       iter_valid = gtk_tree_model_iter_next (model, &iter))
+    {
+      gdouble  this;
+
+      gtk_tree_model_get (model, &iter,
+                          COLUMN_SCALE, &this,
+                          -1);
+
+      if (fabs (this - scale) < 0.0001)
+        break;
+    }
+
+  if (! iter_valid)
+    {
+      GtkTreeIter  sibling;
+
+      for (iter_valid = gtk_tree_model_get_iter_first (model, &sibling);
+           iter_valid;
+           iter_valid = gtk_tree_model_iter_next (model, &sibling))
+        {
+          gdouble this;
+
+          gtk_tree_model_get (model, &sibling,
+                              COLUMN_SCALE, &this,
+                              -1);
+
+          if (this < scale)
+            break;
+        }
+
+      gtk_list_store_insert_before (store, &iter, iter_valid ? &sibling : NULL);
+      gimp_scale_combo_box_scale_iter_set (store, &iter, scale, FALSE);
+    }
+
+  gtk_combo_box_set_active_iter (GTK_COMBO_BOX (combo_box), &iter);
+
+  gtk_tree_model_get (model, &iter,
+                      COLUMN_PERSISTENT, &persistent,
+                      -1);
+  if (! persistent)
+    {
+      gimp_scale_combo_box_mru_add (combo_box, &iter);
+
+      if (gtk_tree_model_iter_n_children (model, NULL) > MAX_ITEMS)
+        gimp_scale_combo_box_mru_remove_last (combo_box);
+    }
+
+  /* Update entry size appropriately. */
+  entry = gtk_bin_get_child (GTK_BIN (combo_box));
+  n_digits = (gint) floor (log10 (scale) + 1);
+
+  g_object_set (entry,
+                "width-chars", MAX (5, n_digits + 4),
+                NULL);
+}
+
+gdouble
+gimp_scale_combo_box_get_scale (GimpScaleComboBox *combo_box)
+{
+  g_return_val_if_fail (GIMP_IS_SCALE_COMBO_BOX (combo_box), 1.0);
+
+  return combo_box->scale;
+}
diff --git a/app/display/gimpscalecombobox.h b/app/display/gimpscalecombobox.h
new file mode 100644
index 0000000..1c35e2f
--- /dev/null
+++ b/app/display/gimpscalecombobox.h
@@ -0,0 +1,60 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpscalecombobox.h
+ * Copyright (C) 2004, 2008  Sven Neumann <sven@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_SCALE_COMBO_BOX_H__
+#define __GIMP_SCALE_COMBO_BOX_H__
+
+
+#define GIMP_TYPE_SCALE_COMBO_BOX            (gimp_scale_combo_box_get_type ())
+#define GIMP_SCALE_COMBO_BOX(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_SCALE_COMBO_BOX, GimpScaleComboBox))
+#define GIMP_SCALE_COMBO_BOX_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_SCALE_COMBO_BOX, GimpScaleComboBoxClass))
+#define GIMP_IS_SCALE_COMBO_BOX(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_SCALE_COMBO_BOX))
+#define GIMP_IS_SCALE_COMBO_BOX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_SCALE_COMBO_BOX))
+#define GIMP_SCALE_COMBO_BOX_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_SCALE_COMBO_BOX, GimpScaleComboBoxClass))
+
+
+typedef struct _GimpScaleComboBoxClass  GimpScaleComboBoxClass;
+
+struct _GimpScaleComboBoxClass
+{
+  GtkComboBoxClass  parent_instance;
+
+  void (* entry_activated) (GimpScaleComboBox *combo_box);
+};
+
+struct _GimpScaleComboBox
+{
+  GtkComboBox  parent_instance;
+
+  gdouble      scale;
+  GtkTreePath *last_path;
+  GList       *mru;
+};
+
+
+GType       gimp_scale_combo_box_get_type   (void) G_GNUC_CONST;
+
+GtkWidget * gimp_scale_combo_box_new        (void);
+void        gimp_scale_combo_box_set_scale  (GimpScaleComboBox *combo_box,
+                                             gdouble            scale);
+gdouble     gimp_scale_combo_box_get_scale  (GimpScaleComboBox *combo_box);
+
+
+#endif  /* __GIMP_SCALE_COMBO_BOX_H__ */
diff --git a/app/display/gimpsinglewindowstrategy.c b/app/display/gimpsinglewindowstrategy.c
new file mode 100644
index 0000000..e840dfa
--- /dev/null
+++ b/app/display/gimpsinglewindowstrategy.c
@@ -0,0 +1,157 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpsinglewindowstrategy.c
+ * Copyright (C) 2011 Martin Nordholts <martinn@src.gnome.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+
+#include "widgets/gimpdialogfactory.h"
+#include "widgets/gimpdock.h"
+#include "widgets/gimpdockbook.h"
+#include "widgets/gimpdockcolumns.h"
+#include "widgets/gimpwindowstrategy.h"
+
+#include "gimpimagewindow.h"
+#include "gimpsinglewindowstrategy.h"
+
+
+static void        gimp_single_window_strategy_window_strategy_iface_init (GimpWindowStrategyInterface *iface);
+static GtkWidget * gimp_single_window_strategy_show_dockable_dialog       (GimpWindowStrategy          *strategy,
+                                                                           Gimp                        *gimp,
+                                                                           GimpDialogFactory           *factory,
+                                                                           GdkScreen                   *screen,
+                                                                           gint                         monitor,
+                                                                           const gchar                 *identifiers);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpSingleWindowStrategy, gimp_single_window_strategy, GIMP_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_WINDOW_STRATEGY,
+                                                gimp_single_window_strategy_window_strategy_iface_init))
+
+#define parent_class gimp_single_window_strategy_parent_class
+
+
+static void
+gimp_single_window_strategy_class_init (GimpSingleWindowStrategyClass *klass)
+{
+}
+
+static void
+gimp_single_window_strategy_init (GimpSingleWindowStrategy *strategy)
+{
+}
+
+static void
+gimp_single_window_strategy_window_strategy_iface_init (GimpWindowStrategyInterface *iface)
+{
+  iface->show_dockable_dialog = gimp_single_window_strategy_show_dockable_dialog;
+}
+
+static GtkWidget *
+gimp_single_window_strategy_show_dockable_dialog (GimpWindowStrategy *strategy,
+                                                  Gimp               *gimp,
+                                                  GimpDialogFactory  *factory,
+                                                  GdkScreen          *screen,
+                                                  gint                monitor,
+                                                  const gchar        *identifiers)
+{
+  GList           *windows = gimp_get_image_windows (gimp);
+  GtkWidget       *widget  = NULL;
+  GimpImageWindow *window;
+
+  g_return_val_if_fail (windows != NULL, NULL);
+
+  /* In single-window mode, there should only be one window... */
+  window = GIMP_IMAGE_WINDOW (windows->data);
+
+  if (strcmp ("gimp-toolbox", identifiers) == 0)
+    {
+      /* Only allow one toolbox... */
+      if (! gimp_image_window_has_toolbox (window))
+        {
+          GimpDockColumns *columns;
+          GimpUIManager   *ui_manager = gimp_image_window_get_ui_manager (window);
+
+          widget = gimp_dialog_factory_dialog_new (factory,
+                                                   screen,
+                                                   monitor,
+                                                   ui_manager,
+                                                   "gimp-toolbox",
+                                                   -1 /*view_size*/,
+                                                   FALSE /*present*/);
+          gtk_widget_show (widget);
+
+          columns = gimp_image_window_get_left_docks (window);
+          gimp_dock_columns_add_dock (columns,
+                                      GIMP_DOCK (widget),
+                                      -1 /*index*/);
+        }
+    }
+  else if (gimp_dialog_factory_find_widget (factory, identifiers))
+    {
+      /* if the dialog is already open, simply raise it */
+      return gimp_dialog_factory_dialog_raise (factory, screen, monitor,
+                                               identifiers, -1);
+   }
+  else
+    {
+      GtkWidget *dockbook;
+
+      dockbook = gimp_image_window_get_default_dockbook (window);
+
+      if (! dockbook)
+        {
+          GimpDockColumns *dock_columns;
+
+          /* No dock, need to add one */
+          dock_columns = gimp_image_window_get_right_docks (window);
+          gimp_dock_columns_prepare_dockbook (dock_columns,
+                                              -1 /*index*/,
+                                              &dockbook);
+        }
+
+      widget = gimp_dockbook_add_from_dialog_factory (GIMP_DOCKBOOK (dockbook),
+                                                      identifiers,
+                                                      -1 /*index*/);
+    }
+
+
+  g_list_free (windows);
+
+  return widget;
+}
+
+GimpObject *
+gimp_single_window_strategy_get_singleton (void)
+{
+  static GimpObject *singleton = NULL;
+
+  if (! singleton)
+    singleton = g_object_new (GIMP_TYPE_SINGLE_WINDOW_STRATEGY, NULL);
+
+  return singleton;
+}
diff --git a/app/display/gimpsinglewindowstrategy.h b/app/display/gimpsinglewindowstrategy.h
new file mode 100644
index 0000000..5b145c7
--- /dev/null
+++ b/app/display/gimpsinglewindowstrategy.h
@@ -0,0 +1,54 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpsinglewindowstrategy.h
+ * Copyright (C) 2011 Martin Nordholts <martinn@src.gnome.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_SINGLE_WINDOW_STRATEGY_H__
+#define __GIMP_SINGLE_WINDOW_STRATEGY_H__
+
+
+#include "core/gimpobject.h"
+
+
+#define GIMP_TYPE_SINGLE_WINDOW_STRATEGY            (gimp_single_window_strategy_get_type ())
+#define GIMP_SINGLE_WINDOW_STRATEGY(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_SINGLE_WINDOW_STRATEGY, GimpSingleWindowStrategy))
+#define GIMP_SINGLE_WINDOW_STRATEGY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_SINGLE_WINDOW_STRATEGY, GimpSingleWindowStrategyClass))
+#define GIMP_IS_SINGLE_WINDOW_STRATEGY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_SINGLE_WINDOW_STRATEGY))
+#define GIMP_IS_SINGLE_WINDOW_STRATEGY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_SINGLE_WINDOW_STRATEGY))
+#define GIMP_SINGLE_WINDOW_STRATEGY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_SINGLE_WINDOW_STRATEGY, GimpSingleWindowStrategyClass))
+
+
+typedef struct _GimpSingleWindowStrategyClass GimpSingleWindowStrategyClass;
+
+struct _GimpSingleWindowStrategy
+{
+  GimpObject  parent_instance;
+};
+
+struct _GimpSingleWindowStrategyClass
+{
+  GimpObjectClass  parent_class;
+};
+
+
+GType        gimp_single_window_strategy_get_type          (void) G_GNUC_CONST;
+
+GimpObject * gimp_single_window_strategy_get_singleton     (void);
+
+
+#endif /* __GIMP_SINGLE_WINDOW_STRATEGY_H__ */
diff --git a/app/display/gimpstatusbar.c b/app/display/gimpstatusbar.c
new file mode 100644
index 0000000..0c0ca14
--- /dev/null
+++ b/app/display/gimpstatusbar.c
@@ -0,0 +1,1747 @@
+/* GIMP - The GNU Image Manipulation Program Copyright (C) 1995
+ * Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "config/gimpdisplayconfig.h"
+
+#include "core/gimpimage.h"
+#include "core/gimpprogress.h"
+
+#include "widgets/gimpuimanager.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scale.h"
+#include "gimpimagewindow.h"
+#include "gimpscalecombobox.h"
+#include "gimpstatusbar.h"
+
+#include "gimp-intl.h"
+
+
+/*  maximal width of the string holding the cursor-coordinates   */
+#define CURSOR_LEN                      256
+
+/*  the spacing of the hbox                                      */
+#define HBOX_SPACING                      1
+
+/*  spacing between the icon and the statusbar label             */
+#define ICON_SPACING                      2
+
+/*  timeout (in milliseconds) for temporary statusbar messages   */
+#define MESSAGE_TIMEOUT                8000
+
+/*  minimal interval (in microseconds) between progress updates  */
+#define MIN_PROGRESS_UPDATE_INTERVAL  50000
+
+
+typedef struct _GimpStatusbarMsg GimpStatusbarMsg;
+
+struct _GimpStatusbarMsg
+{
+  guint  context_id;
+  gchar *icon_name;
+  gchar *text;
+};
+
+
+static void     gimp_statusbar_progress_iface_init (GimpProgressInterface *iface);
+
+static void     gimp_statusbar_dispose            (GObject           *object);
+static void     gimp_statusbar_finalize           (GObject           *object);
+
+static void     gimp_statusbar_screen_changed     (GtkWidget         *widget,
+                                                   GdkScreen         *previous);
+static void     gimp_statusbar_style_set          (GtkWidget         *widget,
+                                                   GtkStyle          *prev_style);
+
+static void     gimp_statusbar_hbox_size_request  (GtkWidget         *widget,
+                                                   GtkRequisition    *requisition,
+                                                   GimpStatusbar     *statusbar);
+
+static GimpProgress *
+                gimp_statusbar_progress_start     (GimpProgress      *progress,
+                                                   gboolean           cancellable,
+                                                   const gchar       *message);
+static void     gimp_statusbar_progress_end       (GimpProgress      *progress);
+static gboolean gimp_statusbar_progress_is_active (GimpProgress      *progress);
+static void     gimp_statusbar_progress_set_text  (GimpProgress      *progress,
+                                                   const gchar       *message);
+static void     gimp_statusbar_progress_set_value (GimpProgress      *progress,
+                                                   gdouble            percentage);
+static gdouble  gimp_statusbar_progress_get_value (GimpProgress      *progress);
+static void     gimp_statusbar_progress_pulse     (GimpProgress      *progress);
+static gboolean gimp_statusbar_progress_message   (GimpProgress      *progress,
+                                                   Gimp              *gimp,
+                                                   GimpMessageSeverity severity,
+                                                   const gchar       *domain,
+                                                   const gchar       *message);
+static void     gimp_statusbar_progress_canceled  (GtkWidget         *button,
+                                                   GimpStatusbar     *statusbar);
+
+static gboolean gimp_statusbar_label_expose       (GtkWidget         *widget,
+                                                   GdkEventExpose    *event,
+                                                   GimpStatusbar     *statusbar);
+
+static void     gimp_statusbar_update             (GimpStatusbar     *statusbar);
+static void     gimp_statusbar_unit_changed       (GimpUnitComboBox  *combo,
+                                                   GimpStatusbar     *statusbar);
+static void     gimp_statusbar_scale_changed      (GimpScaleComboBox *combo,
+                                                   GimpStatusbar     *statusbar);
+static void     gimp_statusbar_scale_activated    (GimpScaleComboBox *combo,
+                                                   GimpStatusbar     *statusbar);
+static gboolean gimp_statusbar_rotate_pressed     (GtkWidget         *event_box,
+                                                   GdkEvent          *event,
+                                                   GimpStatusbar     *statusbar);
+static gboolean gimp_statusbar_horiz_flip_pressed (GtkWidget         *event_box,
+                                                   GdkEvent          *event,
+                                                   GimpStatusbar     *statusbar);
+static gboolean gimp_statusbar_vert_flip_pressed  (GtkWidget         *event_box,
+                                                   GdkEvent          *event,
+                                                   GimpStatusbar     *statusbar);
+static void     gimp_statusbar_shell_scaled       (GimpDisplayShell  *shell,
+                                                   GimpStatusbar     *statusbar);
+static void     gimp_statusbar_shell_rotated      (GimpDisplayShell  *shell,
+                                                   GimpStatusbar     *statusbar);
+static void     gimp_statusbar_shell_status_notify(GimpDisplayShell  *shell,
+                                                   const GParamSpec  *pspec,
+                                                   GimpStatusbar     *statusbar);
+static guint    gimp_statusbar_get_context_id     (GimpStatusbar     *statusbar,
+                                                   const gchar       *context);
+static gboolean gimp_statusbar_temp_timeout       (GimpStatusbar     *statusbar);
+
+static void     gimp_statusbar_add_message        (GimpStatusbar     *statusbar,
+                                                   guint              context_id,
+                                                   const gchar       *icon_name,
+                                                   const gchar       *format,
+                                                   va_list            args,
+                                                   gboolean           move_to_front) G_GNUC_PRINTF (4, 0);
+static void     gimp_statusbar_remove_message     (GimpStatusbar     *statusbar,
+                                                   guint              context_id);
+static void     gimp_statusbar_msg_free           (GimpStatusbarMsg  *msg);
+
+static gchar *  gimp_statusbar_vprintf            (const gchar       *format,
+                                                   va_list            args) G_GNUC_PRINTF (1, 0);
+
+static GdkPixbuf * gimp_statusbar_load_icon       (GimpStatusbar     *statusbar,
+                                                   const gchar       *icon_name);
+
+
+G_DEFINE_TYPE_WITH_CODE (GimpStatusbar, gimp_statusbar, GTK_TYPE_STATUSBAR,
+                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_PROGRESS,
+                                                gimp_statusbar_progress_iface_init))
+
+#define parent_class gimp_statusbar_parent_class
+
+
+static void
+gimp_statusbar_class_init (GimpStatusbarClass *klass)
+{
+  GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  object_class->dispose        = gimp_statusbar_dispose;
+  object_class->finalize       = gimp_statusbar_finalize;
+
+  widget_class->screen_changed = gimp_statusbar_screen_changed;
+  widget_class->style_set      = gimp_statusbar_style_set;
+}
+
+static void
+gimp_statusbar_progress_iface_init (GimpProgressInterface *iface)
+{
+  iface->start     = gimp_statusbar_progress_start;
+  iface->end       = gimp_statusbar_progress_end;
+  iface->is_active = gimp_statusbar_progress_is_active;
+  iface->set_text  = gimp_statusbar_progress_set_text;
+  iface->set_value = gimp_statusbar_progress_set_value;
+  iface->get_value = gimp_statusbar_progress_get_value;
+  iface->pulse     = gimp_statusbar_progress_pulse;
+  iface->message   = gimp_statusbar_progress_message;
+}
+
+static void
+gimp_statusbar_init (GimpStatusbar *statusbar)
+{
+  GtkWidget     *hbox;
+  GtkWidget     *hbox2;
+  GtkWidget     *image;
+  GtkWidget     *label;
+  GimpUnitStore *store;
+  GList         *children;
+
+  statusbar->shell          = NULL;
+  statusbar->messages       = NULL;
+  statusbar->context_ids    = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                                     g_free, NULL);
+  statusbar->seq_context_id = 1;
+
+  statusbar->temp_context_id =
+    gimp_statusbar_get_context_id (statusbar, "gimp-statusbar-temp");
+
+  statusbar->cursor_format_str[0]   = '\0';
+  statusbar->cursor_format_str_f[0] = '\0';
+  statusbar->length_format_str[0]   = '\0';
+
+  statusbar->progress_active      = FALSE;
+  statusbar->progress_shown       = FALSE;
+
+  /*  remove the message label from the message area  */
+  hbox = gtk_statusbar_get_message_area (GTK_STATUSBAR (statusbar));
+  gtk_box_set_spacing (GTK_BOX (hbox), HBOX_SPACING);
+
+  children = gtk_container_get_children (GTK_CONTAINER (hbox));
+  statusbar->label = g_object_ref (children->data);
+  g_list_free (children);
+
+  gtk_container_remove (GTK_CONTAINER (hbox), statusbar->label);
+
+  g_signal_connect (hbox, "size-request",
+                    G_CALLBACK (gimp_statusbar_hbox_size_request),
+                    statusbar);
+
+  statusbar->cursor_label = gtk_label_new ("8888, 8888");
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->cursor_label, FALSE, FALSE, 0);
+  gtk_widget_show (statusbar->cursor_label);
+
+  store = gimp_unit_store_new (2);
+  statusbar->unit_combo = gimp_unit_combo_box_new_with_model (store);
+  g_object_unref (store);
+
+  /* see issue #2642 */
+  gtk_combo_box_set_wrap_width (GTK_COMBO_BOX (statusbar->unit_combo), 1);
+
+  gtk_widget_set_can_focus (statusbar->unit_combo, FALSE);
+  g_object_set (statusbar->unit_combo, "focus-on-click", FALSE, NULL);
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->unit_combo, FALSE, FALSE, 0);
+  gtk_widget_show (statusbar->unit_combo);
+
+  g_signal_connect (statusbar->unit_combo, "changed",
+                    G_CALLBACK (gimp_statusbar_unit_changed),
+                    statusbar);
+
+  statusbar->scale_combo = gimp_scale_combo_box_new ();
+  gtk_widget_set_can_focus (statusbar->scale_combo, FALSE);
+  g_object_set (statusbar->scale_combo, "focus-on-click", FALSE, NULL);
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->scale_combo, FALSE, FALSE, 0);
+  gtk_widget_show (statusbar->scale_combo);
+
+  g_signal_connect (statusbar->scale_combo, "changed",
+                    G_CALLBACK (gimp_statusbar_scale_changed),
+                    statusbar);
+
+  g_signal_connect (statusbar->scale_combo, "entry-activated",
+                    G_CALLBACK (gimp_statusbar_scale_activated),
+                    statusbar);
+
+  /* Shell transform status */
+  statusbar->rotate_widget = gtk_event_box_new ();
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->rotate_widget,
+                      FALSE, FALSE, 1);
+  gtk_widget_show (statusbar->rotate_widget);
+
+  statusbar->rotate_label = gtk_label_new (NULL);
+  gtk_container_add (GTK_CONTAINER (statusbar->rotate_widget),
+                     statusbar->rotate_label);
+  gtk_widget_show (statusbar->rotate_label);
+
+  g_signal_connect (statusbar->rotate_widget, "button-press-event",
+                    G_CALLBACK (gimp_statusbar_rotate_pressed),
+                    statusbar);
+
+  statusbar->horizontal_flip_icon = gtk_event_box_new ();
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->horizontal_flip_icon,
+                      FALSE, FALSE, 1);
+  gtk_widget_show (statusbar->horizontal_flip_icon);
+
+  image = gtk_image_new_from_icon_name ("gimp-flip-horizontal",
+                                        GTK_ICON_SIZE_MENU);
+  gtk_container_add (GTK_CONTAINER (statusbar->horizontal_flip_icon), image);
+  gtk_widget_show (image);
+
+  g_signal_connect (statusbar->horizontal_flip_icon, "button-press-event",
+                    G_CALLBACK (gimp_statusbar_horiz_flip_pressed),
+                    statusbar);
+
+  statusbar->vertical_flip_icon = gtk_event_box_new ();
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->vertical_flip_icon,
+                      FALSE, FALSE, 1);
+  gtk_widget_show (statusbar->vertical_flip_icon);
+
+  image = gtk_image_new_from_icon_name ("gimp-flip-vertical",
+                                        GTK_ICON_SIZE_MENU);
+  gtk_container_add (GTK_CONTAINER (statusbar->vertical_flip_icon), image);
+  gtk_widget_show (image);
+
+  g_signal_connect (statusbar->vertical_flip_icon, "button-press-event",
+                    G_CALLBACK (gimp_statusbar_vert_flip_pressed),
+                    statusbar);
+
+  /*  put the label back into the message area  */
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->label, TRUE, TRUE, 1);
+
+  g_object_unref (statusbar->label);
+
+  g_signal_connect_after (statusbar->label, "expose-event",
+                          G_CALLBACK (gimp_statusbar_label_expose),
+                          statusbar);
+
+  statusbar->progressbar = g_object_new (GTK_TYPE_PROGRESS_BAR,
+                                         "text-xalign", 0.0,
+                                         "text-yalign", 0.5,
+                                         "ellipsize",   PANGO_ELLIPSIZE_END,
+                                         NULL);
+  gtk_box_pack_start (GTK_BOX (hbox), statusbar->progressbar, TRUE, TRUE, 0);
+  /*  don't show the progress bar  */
+
+  /*  construct the cancel button's contents manually because we
+   *  always want image and label regardless of settings, and we want
+   *  a menu size image.
+   */
+  statusbar->cancel_button = gtk_button_new ();
+  gtk_widget_set_can_focus (statusbar->cancel_button, FALSE);
+  gtk_button_set_relief (GTK_BUTTON (statusbar->cancel_button),
+                         GTK_RELIEF_NONE);
+  gtk_widget_set_sensitive (statusbar->cancel_button, FALSE);
+  gtk_box_pack_end (GTK_BOX (hbox),
+                    statusbar->cancel_button, FALSE, FALSE, 0);
+  /*  don't show the cancel button  */
+
+  hbox2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+  gtk_container_add (GTK_CONTAINER (statusbar->cancel_button), hbox2);
+  gtk_widget_show (hbox2);
+
+  image = gtk_image_new_from_icon_name ("gtk-cancel", GTK_ICON_SIZE_MENU);
+  gtk_box_pack_start (GTK_BOX (hbox2), image, FALSE, FALSE, 2);
+  gtk_widget_show (image);
+
+  label = gtk_label_new ("Cancel");
+  gtk_box_pack_start (GTK_BOX (hbox2), label, FALSE, FALSE, 2);
+  gtk_widget_show (label);
+
+  g_signal_connect (statusbar->cancel_button, "clicked",
+                    G_CALLBACK (gimp_statusbar_progress_canceled),
+                    statusbar);
+}
+
+static void
+gimp_statusbar_dispose (GObject *object)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (object);
+
+  if (statusbar->temp_timeout_id)
+    {
+      g_source_remove (statusbar->temp_timeout_id);
+      statusbar->temp_timeout_id = 0;
+    }
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_statusbar_finalize (GObject *object)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (object);
+
+  g_clear_object (&statusbar->icon);
+  g_clear_pointer (&statusbar->icon_hash, g_hash_table_unref);
+
+  g_slist_free_full (statusbar->messages,
+                     (GDestroyNotify) gimp_statusbar_msg_free);
+  statusbar->messages = NULL;
+
+  g_clear_pointer (&statusbar->context_ids, g_hash_table_destroy);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_statusbar_screen_changed (GtkWidget *widget,
+                               GdkScreen *previous)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (widget);
+
+  if (GTK_WIDGET_CLASS (parent_class)->screen_changed)
+    GTK_WIDGET_CLASS (parent_class)->screen_changed (widget, previous);
+
+  g_clear_pointer (&statusbar->icon_hash, g_hash_table_unref);
+}
+
+static void
+gimp_statusbar_style_set (GtkWidget *widget,
+                          GtkStyle  *prev_style)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (widget);
+
+  GTK_WIDGET_CLASS (parent_class)->style_set (widget, prev_style);
+
+  g_clear_pointer (&statusbar->icon_hash, g_hash_table_unref);
+}
+
+static void
+gimp_statusbar_hbox_size_request (GtkWidget      *widget,
+                                  GtkRequisition *requisition,
+                                  GimpStatusbar  *statusbar)
+{
+  GtkRequisition child_requisition;
+  gint           width = 0;
+
+  /*  also consider the children which can be invisible  */
+
+  gtk_widget_size_request (statusbar->cursor_label, &child_requisition);
+  width += child_requisition.width;
+  requisition->height = MAX (requisition->height,
+                             child_requisition.height);
+
+  gtk_widget_size_request (statusbar->unit_combo, &child_requisition);
+  width += child_requisition.width;
+  requisition->height = MAX (requisition->height,
+                             child_requisition.height);
+
+  gtk_widget_size_request (statusbar->scale_combo, &child_requisition);
+  width += child_requisition.width;
+  requisition->height = MAX (requisition->height,
+                             child_requisition.height);
+
+  gtk_widget_size_request (statusbar->progressbar, &child_requisition);
+  requisition->height = MAX (requisition->height,
+                             child_requisition.height);
+
+  gtk_widget_size_request (statusbar->label, &child_requisition);
+  requisition->height = MAX (requisition->height,
+                             child_requisition.height);
+
+  gtk_widget_size_request (statusbar->cancel_button, &child_requisition);
+  requisition->height = MAX (requisition->height,
+                             child_requisition.height);
+
+  requisition->width = MAX (requisition->width, width + 32);
+}
+
+static GimpProgress *
+gimp_statusbar_progress_start (GimpProgress *progress,
+                               gboolean      cancellable,
+                               const gchar  *message)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (progress);
+
+  if (! statusbar->progress_active)
+    {
+      GtkWidget     *bar = statusbar->progressbar;
+      GtkAllocation  allocation;
+
+      statusbar->progress_active           = TRUE;
+      statusbar->progress_value            = 0.0;
+      statusbar->progress_last_update_time = g_get_monotonic_time ();
+
+      gimp_statusbar_push (statusbar, "progress", NULL, "%s", message);
+      gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR (bar), 0.0);
+      gtk_widget_set_sensitive (statusbar->cancel_button, cancellable);
+
+      if (cancellable)
+        {
+          if (message)
+            {
+              gchar *tooltip = g_strdup_printf (_("Cancel <i>%s</i>"), message);
+
+              gimp_help_set_help_data_with_markup (statusbar->cancel_button,
+                                                   tooltip, NULL);
+              g_free (tooltip);
+            }
+
+          gtk_widget_show (statusbar->cancel_button);
+        }
+
+      gtk_widget_get_allocation (statusbar->label, &allocation);
+
+      gtk_widget_show (statusbar->progressbar);
+      gtk_widget_hide (statusbar->label);
+
+      /*  This shit is needed so that the progress bar is drawn in the
+       *  correct place in the cases where we suck completely and run
+       *  an operation that blocks the GUI and doesn't let the main
+       *  loop run.
+       */
+      gtk_container_resize_children (GTK_CONTAINER (statusbar));
+      gtk_widget_size_allocate (statusbar->progressbar, &allocation);
+
+      if (! gtk_widget_get_visible (GTK_WIDGET (statusbar)))
+        {
+          gtk_widget_show (GTK_WIDGET (statusbar));
+          statusbar->progress_shown = TRUE;
+        }
+
+      gimp_widget_flush_expose (bar);
+
+      gimp_statusbar_override_window_title (statusbar);
+
+      return progress;
+    }
+
+  return NULL;
+}
+
+static void
+gimp_statusbar_progress_end (GimpProgress *progress)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (progress);
+
+  if (statusbar->progress_active)
+    {
+      GtkWidget *bar = statusbar->progressbar;
+
+      if (statusbar->progress_shown)
+        {
+          gtk_widget_hide (GTK_WIDGET (statusbar));
+          statusbar->progress_shown = FALSE;
+        }
+
+      statusbar->progress_active = FALSE;
+      statusbar->progress_value  = 0.0;
+
+      gtk_widget_hide (bar);
+      gtk_widget_show (statusbar->label);
+
+      gimp_statusbar_pop (statusbar, "progress");
+
+      gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR (bar), 0.0);
+      gtk_widget_set_sensitive (statusbar->cancel_button, FALSE);
+      gtk_widget_hide (statusbar->cancel_button);
+
+      gimp_statusbar_restore_window_title (statusbar);
+    }
+}
+
+static gboolean
+gimp_statusbar_progress_is_active (GimpProgress *progress)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (progress);
+
+  return statusbar->progress_active;
+}
+
+static void
+gimp_statusbar_progress_set_text (GimpProgress *progress,
+                                  const gchar  *message)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (progress);
+
+  if (statusbar->progress_active)
+    {
+      GtkWidget *bar = statusbar->progressbar;
+
+      gimp_statusbar_replace (statusbar, "progress", NULL, "%s", message);
+
+      gimp_widget_flush_expose (bar);
+
+      gimp_statusbar_override_window_title (statusbar);
+    }
+}
+
+static void
+gimp_statusbar_progress_set_value (GimpProgress *progress,
+                                   gdouble       percentage)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (progress);
+
+  if (statusbar->progress_active)
+    {
+      guint64 time = g_get_monotonic_time ();
+
+      if (time - statusbar->progress_last_update_time >=
+          MIN_PROGRESS_UPDATE_INTERVAL)
+        {
+          GtkWidget     *bar = statusbar->progressbar;
+          GtkAllocation  allocation;
+          gdouble        diff;
+
+          gtk_widget_get_allocation (bar, &allocation);
+
+          statusbar->progress_value = percentage;
+
+          diff = fabs (percentage -
+                       gtk_progress_bar_get_fraction (GTK_PROGRESS_BAR (bar)));
+
+          /* only update the progress bar if this causes a visible change */
+          if (allocation.width * diff >= 1.0)
+            {
+              statusbar->progress_last_update_time = time;
+
+              gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR (bar),
+                                             percentage);
+
+              gimp_widget_flush_expose (bar);
+            }
+        }
+    }
+}
+
+static gdouble
+gimp_statusbar_progress_get_value (GimpProgress *progress)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (progress);
+
+  if (statusbar->progress_active)
+    return statusbar->progress_value;
+
+  return 0.0;
+}
+
+static void
+gimp_statusbar_progress_pulse (GimpProgress *progress)
+{
+  GimpStatusbar *statusbar = GIMP_STATUSBAR (progress);
+
+  if (statusbar->progress_active)
+    {
+      guint64 time = g_get_monotonic_time ();
+
+      if (time - statusbar->progress_last_update_time >=
+          MIN_PROGRESS_UPDATE_INTERVAL)
+        {
+          GtkWidget *bar = statusbar->progressbar;
+
+          statusbar->progress_last_update_time = time;
+
+          gtk_progress_bar_pulse (GTK_PROGRESS_BAR (bar));
+
+          gimp_widget_flush_expose (bar);
+        }
+    }
+}
+
+static gboolean
+gimp_statusbar_progress_message (GimpProgress        *progress,
+                                 Gimp                *gimp,
+                                 GimpMessageSeverity  severity,
+                                 const gchar         *domain,
+                                 const gchar         *message)
+{
+  GimpStatusbar *statusbar  = GIMP_STATUSBAR (progress);
+  PangoLayout   *layout;
+  const gchar   *icon_name;
+  gboolean       handle_msg = FALSE;
+
+  /*  don't accept a message if we are already displaying a more severe one  */
+  if (statusbar->temp_timeout_id && statusbar->temp_severity > severity)
+    return FALSE;
+
+  /*  we can only handle short one-liners  */
+  layout = gtk_widget_create_pango_layout (statusbar->label, message);
+
+  icon_name = gimp_get_message_icon_name (severity);
+
+  if (pango_layout_get_line_count (layout) == 1)
+    {
+      GtkAllocation label_allocation;
+      gint          width;
+
+      gtk_widget_get_allocation (statusbar->label, &label_allocation);
+
+      pango_layout_get_pixel_size (layout, &width, NULL);
+
+      if (width < label_allocation.width)
+        {
+          if (icon_name)
+            {
+              GdkPixbuf *pixbuf;
+
+              pixbuf = gimp_statusbar_load_icon (statusbar, icon_name);
+
+              width += ICON_SPACING + gdk_pixbuf_get_width (pixbuf);
+
+              g_object_unref (pixbuf);
+
+              handle_msg = (width < label_allocation.width);
+            }
+          else
+            {
+              handle_msg = TRUE;
+            }
+        }
+    }
+
+  g_object_unref (layout);
+
+  if (handle_msg)
+    gimp_statusbar_push_temp (statusbar, severity, icon_name, "%s", message);
+
+  return handle_msg;
+}
+
+static void
+gimp_statusbar_progress_canceled (GtkWidget     *button,
+                                  GimpStatusbar *statusbar)
+{
+  if (statusbar->progress_active)
+    gimp_progress_cancel (GIMP_PROGRESS (statusbar));
+}
+
+static void
+gimp_statusbar_set_text (GimpStatusbar *statusbar,
+                         const gchar   *icon_name,
+                         const gchar   *text)
+{
+  if (statusbar->progress_active)
+    {
+      gtk_progress_bar_set_text (GTK_PROGRESS_BAR (statusbar->progressbar),
+                                 text);
+    }
+  else
+    {
+      g_clear_object (&statusbar->icon);
+
+      if (icon_name)
+        statusbar->icon = gimp_statusbar_load_icon (statusbar, icon_name);
+
+      if (statusbar->icon)
+        {
+          PangoAttrList  *attrs;
+          PangoAttribute *attr;
+          PangoRectangle  rect;
+          gchar          *tmp;
+
+          tmp = g_strconcat (" ", text, NULL);
+          gtk_label_set_text (GTK_LABEL (statusbar->label), tmp);
+          g_free (tmp);
+
+          rect.x      = 0;
+          rect.y      = 0;
+          rect.width  = PANGO_SCALE * (gdk_pixbuf_get_width (statusbar->icon) +
+                                       ICON_SPACING);
+          rect.height = 0;
+
+          attrs = pango_attr_list_new ();
+
+          attr = pango_attr_shape_new (&rect, &rect);
+          attr->start_index = 0;
+          attr->end_index   = 1;
+          pango_attr_list_insert (attrs, attr);
+
+          gtk_label_set_attributes (GTK_LABEL (statusbar->label), attrs);
+          pango_attr_list_unref (attrs);
+        }
+      else
+        {
+          gtk_label_set_text (GTK_LABEL (statusbar->label), text);
+          gtk_label_set_attributes (GTK_LABEL (statusbar->label), NULL);
+        }
+    }
+}
+
+static void
+gimp_statusbar_update (GimpStatusbar *statusbar)
+{
+  GimpStatusbarMsg *msg = NULL;
+
+  if (statusbar->messages)
+    msg = statusbar->messages->data;
+
+  if (msg && msg->text)
+    {
+      gimp_statusbar_set_text (statusbar, msg->icon_name, msg->text);
+    }
+  else
+    {
+      gimp_statusbar_set_text (statusbar, NULL, "");
+    }
+}
+
+
+/*  public functions  */
+
+GtkWidget *
+gimp_statusbar_new (void)
+{
+  return g_object_new (GIMP_TYPE_STATUSBAR, NULL);
+}
+
+void
+gimp_statusbar_set_shell (GimpStatusbar    *statusbar,
+                          GimpDisplayShell *shell)
+{
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell == statusbar->shell)
+    return;
+
+  if (statusbar->shell)
+    {
+      g_signal_handlers_disconnect_by_func (statusbar->shell,
+                                            gimp_statusbar_shell_scaled,
+                                            statusbar);
+      g_signal_handlers_disconnect_by_func (statusbar->shell,
+                                            gimp_statusbar_shell_rotated,
+                                            statusbar);
+      g_signal_handlers_disconnect_by_func (statusbar->shell,
+                                            gimp_statusbar_shell_status_notify,
+                                            statusbar);
+    }
+
+  statusbar->shell = shell;
+
+  g_signal_connect_object (statusbar->shell, "scaled",
+                           G_CALLBACK (gimp_statusbar_shell_scaled),
+                           statusbar, 0);
+  g_signal_connect_object (statusbar->shell, "rotated",
+                           G_CALLBACK (gimp_statusbar_shell_rotated),
+                           statusbar, 0);
+  g_signal_connect_object (statusbar->shell, "notify::status",
+                           G_CALLBACK (gimp_statusbar_shell_status_notify),
+                           statusbar, 0);
+  gimp_statusbar_shell_rotated (shell, statusbar);
+}
+
+gboolean
+gimp_statusbar_get_visible (GimpStatusbar *statusbar)
+{
+  g_return_val_if_fail (GIMP_IS_STATUSBAR (statusbar), FALSE);
+
+  if (statusbar->progress_shown)
+    return FALSE;
+
+  return gtk_widget_get_visible (GTK_WIDGET (statusbar));
+}
+
+void
+gimp_statusbar_set_visible (GimpStatusbar *statusbar,
+                            gboolean       visible)
+{
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+
+  if (statusbar->progress_shown)
+    {
+      if (visible)
+        {
+          statusbar->progress_shown = FALSE;
+          return;
+        }
+    }
+
+  gtk_widget_set_visible (GTK_WIDGET (statusbar), visible);
+}
+
+void
+gimp_statusbar_empty (GimpStatusbar *statusbar)
+{
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+
+  gtk_widget_hide (statusbar->cursor_label);
+  gtk_widget_hide (statusbar->unit_combo);
+  gtk_widget_hide (statusbar->scale_combo);
+  gtk_widget_hide (statusbar->rotate_widget);
+  gtk_widget_hide (statusbar->horizontal_flip_icon);
+  gtk_widget_hide (statusbar->vertical_flip_icon);
+}
+
+void
+gimp_statusbar_fill (GimpStatusbar *statusbar)
+{
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+
+  gtk_widget_show (statusbar->cursor_label);
+  gtk_widget_show (statusbar->unit_combo);
+  gtk_widget_show (statusbar->scale_combo);
+  gtk_widget_show (statusbar->rotate_widget);
+  gimp_statusbar_shell_rotated (statusbar->shell, statusbar);
+}
+
+void
+gimp_statusbar_override_window_title (GimpStatusbar *statusbar)
+{
+  GtkWidget *toplevel;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+
+  toplevel = gtk_widget_get_toplevel (GTK_WIDGET (statusbar));
+
+  if (gimp_image_window_is_iconified (GIMP_IMAGE_WINDOW (toplevel)))
+    {
+      const gchar *message = gimp_statusbar_peek (statusbar, "progress");
+
+      if (message)
+        gtk_window_set_title (GTK_WINDOW (toplevel), message);
+    }
+}
+
+void
+gimp_statusbar_restore_window_title (GimpStatusbar *statusbar)
+{
+  GtkWidget *toplevel;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+
+  toplevel = gtk_widget_get_toplevel (GTK_WIDGET (statusbar));
+
+  if (gimp_image_window_is_iconified (GIMP_IMAGE_WINDOW (toplevel)))
+    {
+      g_object_notify (G_OBJECT (statusbar->shell), "title");
+    }
+}
+
+void
+gimp_statusbar_push (GimpStatusbar *statusbar,
+                     const gchar   *context,
+                     const gchar   *icon_name,
+                     const gchar   *format,
+                     ...)
+{
+  va_list args;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (context != NULL);
+  g_return_if_fail (format != NULL);
+
+  va_start (args, format);
+  gimp_statusbar_push_valist (statusbar, context, icon_name, format, args);
+  va_end (args);
+}
+
+void
+gimp_statusbar_push_valist (GimpStatusbar *statusbar,
+                            const gchar   *context,
+                            const gchar   *icon_name,
+                            const gchar   *format,
+                            va_list        args)
+{
+  guint context_id;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (context != NULL);
+  g_return_if_fail (format != NULL);
+
+  context_id = gimp_statusbar_get_context_id (statusbar, context);
+
+  gimp_statusbar_add_message (statusbar,
+                              context_id,
+                              icon_name, format, args,
+                              /*  move_to_front =  */ TRUE);
+}
+
+void
+gimp_statusbar_push_coords (GimpStatusbar       *statusbar,
+                            const gchar         *context,
+                            const gchar         *icon_name,
+                            GimpCursorPrecision  precision,
+                            const gchar         *title,
+                            gdouble              x,
+                            const gchar         *separator,
+                            gdouble              y,
+                            const gchar         *help)
+{
+  GimpDisplayShell *shell;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (title != NULL);
+  g_return_if_fail (separator != NULL);
+
+  if (help == NULL)
+    help = "";
+
+  shell = statusbar->shell;
+
+  switch (precision)
+    {
+    case GIMP_CURSOR_PRECISION_PIXEL_CENTER:
+      x = (gint) x;
+      y = (gint) y;
+      break;
+
+    case GIMP_CURSOR_PRECISION_PIXEL_BORDER:
+      x = RINT (x);
+      y = RINT (y);
+      break;
+
+    case GIMP_CURSOR_PRECISION_SUBPIXEL:
+      break;
+    }
+
+  if (shell->unit == GIMP_UNIT_PIXEL)
+    {
+      if (precision == GIMP_CURSOR_PRECISION_SUBPIXEL)
+        {
+          gimp_statusbar_push (statusbar, context,
+                               icon_name,
+                               statusbar->cursor_format_str_f,
+                               title,
+                               x,
+                               separator,
+                               y,
+                               help);
+        }
+      else
+        {
+          gimp_statusbar_push (statusbar, context,
+                               icon_name,
+                               statusbar->cursor_format_str,
+                               title,
+                               (gint) RINT (x),
+                               separator,
+                               (gint) RINT (y),
+                               help);
+        }
+    }
+  else /* show real world units */
+    {
+      gdouble xres;
+      gdouble yres;
+
+      gimp_image_get_resolution (gimp_display_get_image (shell->display),
+                                 &xres, &yres);
+
+      gimp_statusbar_push (statusbar, context,
+                           icon_name,
+                           statusbar->cursor_format_str,
+                           title,
+                           gimp_pixels_to_units (x, shell->unit, xres),
+                           separator,
+                           gimp_pixels_to_units (y, shell->unit, yres),
+                           help);
+    }
+}
+
+void
+gimp_statusbar_push_length (GimpStatusbar       *statusbar,
+                            const gchar         *context,
+                            const gchar         *icon_name,
+                            const gchar         *title,
+                            GimpOrientationType  axis,
+                            gdouble              value,
+                            const gchar         *help)
+{
+  GimpDisplayShell *shell;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (title != NULL);
+
+  if (help == NULL)
+    help = "";
+
+  shell = statusbar->shell;
+
+  if (shell->unit == GIMP_UNIT_PIXEL)
+    {
+      gimp_statusbar_push (statusbar, context,
+                           icon_name,
+                           statusbar->length_format_str,
+                           title,
+                           (gint) RINT (value),
+                           help);
+    }
+  else /* show real world units */
+    {
+      gdouble xres;
+      gdouble yres;
+      gdouble resolution;
+
+      gimp_image_get_resolution (gimp_display_get_image (shell->display),
+                                 &xres, &yres);
+
+      switch (axis)
+        {
+        case GIMP_ORIENTATION_HORIZONTAL:
+          resolution = xres;
+          break;
+
+        case GIMP_ORIENTATION_VERTICAL:
+          resolution = yres;
+          break;
+
+        default:
+          g_return_if_reached ();
+          break;
+        }
+
+      gimp_statusbar_push (statusbar, context,
+                           icon_name,
+                           statusbar->length_format_str,
+                           title,
+                           gimp_pixels_to_units (value, shell->unit, resolution),
+                           help);
+    }
+}
+
+void
+gimp_statusbar_replace (GimpStatusbar *statusbar,
+                        const gchar   *context,
+                        const gchar   *icon_name,
+                        const gchar   *format,
+                        ...)
+{
+  va_list args;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (context != NULL);
+  g_return_if_fail (format != NULL);
+
+  va_start (args, format);
+  gimp_statusbar_replace_valist (statusbar, context, icon_name, format, args);
+  va_end (args);
+}
+
+void
+gimp_statusbar_replace_valist (GimpStatusbar *statusbar,
+                               const gchar   *context,
+                               const gchar   *icon_name,
+                               const gchar   *format,
+                               va_list        args)
+{
+  guint context_id;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (context != NULL);
+  g_return_if_fail (format != NULL);
+
+  context_id = gimp_statusbar_get_context_id (statusbar, context);
+
+  gimp_statusbar_add_message (statusbar,
+                              context_id,
+                              icon_name, format, args,
+                              /*  move_to_front =  */ FALSE);
+}
+
+const gchar *
+gimp_statusbar_peek (GimpStatusbar *statusbar,
+                     const gchar   *context)
+{
+  GSList *list;
+  guint   context_id;
+
+  g_return_val_if_fail (GIMP_IS_STATUSBAR (statusbar), NULL);
+  g_return_val_if_fail (context != NULL, NULL);
+
+  context_id = gimp_statusbar_get_context_id (statusbar, context);
+
+  for (list = statusbar->messages; list; list = list->next)
+    {
+      GimpStatusbarMsg *msg = list->data;
+
+      if (msg->context_id == context_id)
+        {
+          return msg->text;
+        }
+    }
+
+  return NULL;
+}
+
+void
+gimp_statusbar_pop (GimpStatusbar *statusbar,
+                    const gchar   *context)
+{
+  guint context_id;
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (context != NULL);
+
+  context_id = gimp_statusbar_get_context_id (statusbar, context);
+
+  gimp_statusbar_remove_message (statusbar,
+                                 context_id);
+}
+
+void
+gimp_statusbar_push_temp (GimpStatusbar       *statusbar,
+                          GimpMessageSeverity  severity,
+                          const gchar         *icon_name,
+                          const gchar         *format,
+                          ...)
+{
+  va_list args;
+
+  va_start (args, format);
+  gimp_statusbar_push_temp_valist (statusbar, severity, icon_name, format, args);
+  va_end (args);
+}
+
+void
+gimp_statusbar_push_temp_valist (GimpStatusbar       *statusbar,
+                                 GimpMessageSeverity  severity,
+                                 const gchar         *icon_name,
+                                 const gchar         *format,
+                                 va_list              args)
+{
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+  g_return_if_fail (severity <= GIMP_MESSAGE_WARNING);
+  g_return_if_fail (format != NULL);
+
+  /*  don't accept a message if we are already displaying a more severe one  */
+  if (statusbar->temp_timeout_id && statusbar->temp_severity > severity)
+    return;
+
+  if (statusbar->temp_timeout_id)
+    g_source_remove (statusbar->temp_timeout_id);
+
+  statusbar->temp_timeout_id =
+    g_timeout_add (MESSAGE_TIMEOUT,
+                   (GSourceFunc) gimp_statusbar_temp_timeout, statusbar);
+
+  statusbar->temp_severity = severity;
+
+  gimp_statusbar_add_message (statusbar,
+                              statusbar->temp_context_id,
+                              icon_name, format, args,
+                              /*  move_to_front =  */ TRUE);
+
+  if (severity >= GIMP_MESSAGE_WARNING)
+    gimp_widget_blink (statusbar->label);
+}
+
+void
+gimp_statusbar_pop_temp (GimpStatusbar *statusbar)
+{
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+
+  if (statusbar->temp_timeout_id)
+    {
+      g_source_remove (statusbar->temp_timeout_id);
+      statusbar->temp_timeout_id = 0;
+
+      gimp_statusbar_remove_message (statusbar,
+                                     statusbar->temp_context_id);
+    }
+}
+
+void
+gimp_statusbar_update_cursor (GimpStatusbar       *statusbar,
+                              GimpCursorPrecision  precision,
+                              gdouble              x,
+                              gdouble              y)
+{
+  GimpDisplayShell *shell;
+  GimpImage        *image;
+  gchar             buffer[CURSOR_LEN];
+
+  g_return_if_fail (GIMP_IS_STATUSBAR (statusbar));
+
+  shell = statusbar->shell;
+  image = gimp_display_get_image (shell->display);
+
+  if (! image                            ||
+      x <  0                             ||
+      y <  0                             ||
+      x >= gimp_image_get_width  (image) ||
+      y >= gimp_image_get_height (image))
+    {
+      gtk_widget_set_sensitive (statusbar->cursor_label, FALSE);
+    }
+  else
+    {
+      gtk_widget_set_sensitive (statusbar->cursor_label, TRUE);
+    }
+
+  switch (precision)
+    {
+    case GIMP_CURSOR_PRECISION_PIXEL_CENTER:
+      x = (gint) x;
+      y = (gint) y;
+      break;
+
+    case GIMP_CURSOR_PRECISION_PIXEL_BORDER:
+      x = RINT (x);
+      y = RINT (y);
+      break;
+
+    case GIMP_CURSOR_PRECISION_SUBPIXEL:
+      break;
+    }
+
+  if (shell->unit == GIMP_UNIT_PIXEL)
+    {
+      if (precision == GIMP_CURSOR_PRECISION_SUBPIXEL)
+        {
+          g_snprintf (buffer, sizeof (buffer),
+                      statusbar->cursor_format_str_f,
+                      "", x, ", ", y, "");
+        }
+      else
+        {
+          g_snprintf (buffer, sizeof (buffer),
+                      statusbar->cursor_format_str,
+                      "", (gint) RINT (x), ", ", (gint) RINT (y), "");
+        }
+    }
+  else /* show real world units */
+    {
+      GtkTreeModel  *model;
+      GimpUnitStore *store;
+
+      model = gtk_combo_box_get_model (GTK_COMBO_BOX (statusbar->unit_combo));
+      store = GIMP_UNIT_STORE (model);
+
+      gimp_unit_store_set_pixel_values (store, x, y);
+      gimp_unit_store_get_values (store, shell->unit, &x, &y);
+
+      g_snprintf (buffer, sizeof (buffer),
+                  statusbar->cursor_format_str,
+                  "", x, ", ", y, "");
+    }
+
+  gtk_label_set_text (GTK_LABEL (statusbar->cursor_label), buffer);
+}
+
+void
+gimp_statusbar_clear_cursor (GimpStatusbar *statusbar)
+{
+  gtk_label_set_text (GTK_LABEL (statusbar->cursor_label), "");
+  gtk_widget_set_sensitive (statusbar->cursor_label, TRUE);
+}
+
+
+/*  private functions  */
+
+static gboolean
+gimp_statusbar_label_expose (GtkWidget      *widget,
+                             GdkEventExpose *event,
+                             GimpStatusbar  *statusbar)
+{
+  if (statusbar->icon)
+    {
+      cairo_t        *cr;
+      PangoRectangle  rect;
+      gint            x, y;
+
+      cr = gdk_cairo_create (event->window);
+
+      gdk_cairo_region (cr, event->region);
+      cairo_clip (cr);
+
+      gtk_label_get_layout_offsets (GTK_LABEL (widget), &x, &y);
+
+      pango_layout_index_to_pos (gtk_label_get_layout (GTK_LABEL (widget)), 0,
+                                 &rect);
+
+      /*  the rectangle width is negative when rendering right-to-left  */
+      x += PANGO_PIXELS (rect.x) + (rect.width < 0 ?
+                                    PANGO_PIXELS (rect.width) : 0);
+      y += PANGO_PIXELS (rect.y);
+
+      gdk_cairo_set_source_pixbuf (cr, statusbar->icon, x, y);
+      cairo_paint (cr);
+
+      cairo_destroy (cr);
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_statusbar_shell_scaled (GimpDisplayShell *shell,
+                             GimpStatusbar    *statusbar)
+{
+  static PangoLayout *layout = NULL;
+
+  GimpImage    *image = gimp_display_get_image (shell->display);
+  GtkTreeModel *model;
+  const gchar  *text;
+  gint          image_width;
+  gint          image_height;
+  gdouble       image_xres;
+  gdouble       image_yres;
+  gint          width;
+
+  if (image)
+    {
+      image_width  = gimp_image_get_width  (image);
+      image_height = gimp_image_get_height (image);
+      gimp_image_get_resolution (image, &image_xres, &image_yres);
+    }
+  else
+    {
+      image_width  = shell->disp_width;
+      image_height = shell->disp_height;
+      image_xres   = shell->display->config->monitor_xres;
+      image_yres   = shell->display->config->monitor_yres;
+    }
+
+  g_signal_handlers_block_by_func (statusbar->scale_combo,
+                                   gimp_statusbar_scale_changed, statusbar);
+  gimp_scale_combo_box_set_scale (GIMP_SCALE_COMBO_BOX (statusbar->scale_combo),
+                                  gimp_zoom_model_get_factor (shell->zoom));
+  g_signal_handlers_unblock_by_func (statusbar->scale_combo,
+                                     gimp_statusbar_scale_changed, statusbar);
+
+  model = gtk_combo_box_get_model (GTK_COMBO_BOX (statusbar->unit_combo));
+  gimp_unit_store_set_resolutions (GIMP_UNIT_STORE (model),
+                                   image_xres, image_yres);
+
+  g_signal_handlers_block_by_func (statusbar->unit_combo,
+                                   gimp_statusbar_unit_changed, statusbar);
+  gimp_unit_combo_box_set_active (GIMP_UNIT_COMBO_BOX (statusbar->unit_combo),
+                                  shell->unit);
+  g_signal_handlers_unblock_by_func (statusbar->unit_combo,
+                                     gimp_statusbar_unit_changed, statusbar);
+
+  if (shell->unit == GIMP_UNIT_PIXEL)
+    {
+      g_snprintf (statusbar->cursor_format_str,
+                  sizeof (statusbar->cursor_format_str),
+                  "%%s%%d%%s%%d%%s");
+      g_snprintf (statusbar->cursor_format_str_f,
+                  sizeof (statusbar->cursor_format_str_f),
+                  "%%s%%.1f%%s%%.1f%%s");
+      g_snprintf (statusbar->length_format_str,
+                  sizeof (statusbar->length_format_str),
+                  "%%s%%d%%s");
+    }
+  else /* show real world units */
+    {
+      gint w_digits;
+      gint h_digits;
+
+      w_digits = gimp_unit_get_scaled_digits (shell->unit, image_xres);
+      h_digits = gimp_unit_get_scaled_digits (shell->unit, image_yres);
+
+      g_snprintf (statusbar->cursor_format_str,
+                  sizeof (statusbar->cursor_format_str),
+                  "%%s%%.%df%%s%%.%df%%s",
+                  w_digits, h_digits);
+      strcpy (statusbar->cursor_format_str_f, statusbar->cursor_format_str);
+      g_snprintf (statusbar->length_format_str,
+                  sizeof (statusbar->length_format_str),
+                  "%%s%%.%df%%s", MAX (w_digits, h_digits));
+    }
+
+  gimp_statusbar_update_cursor (statusbar, GIMP_CURSOR_PRECISION_SUBPIXEL,
+                                -image_width, -image_height);
+
+  text = gtk_label_get_text (GTK_LABEL (statusbar->cursor_label));
+
+  /* one static layout for all displays should be fine */
+  if (! layout)
+    layout = gtk_widget_create_pango_layout (statusbar->cursor_label, NULL);
+
+  pango_layout_set_text (layout, text, -1);
+  pango_layout_get_pixel_size (layout, &width, NULL);
+
+  gtk_widget_set_size_request (statusbar->cursor_label, width, -1);
+
+  gimp_statusbar_clear_cursor (statusbar);
+}
+
+static void
+gimp_statusbar_shell_rotated (GimpDisplayShell *shell,
+                              GimpStatusbar    *statusbar)
+{
+  if (shell->rotate_angle != 0.0)
+    {
+      /* Degree symbol U+00B0. There are no spaces between the value and the
+       * unit for angular rotation.
+       */
+      gchar *text = g_strdup_printf (" %.2f\xC2\xB0", shell->rotate_angle);
+
+      gtk_label_set_text (GTK_LABEL (statusbar->rotate_label), text);
+      g_free (text);
+
+      gtk_widget_show (statusbar->rotate_widget);
+    }
+  else
+    {
+      gtk_widget_hide (statusbar->rotate_widget);
+    }
+
+  if (shell->flip_horizontally)
+    gtk_widget_show (statusbar->horizontal_flip_icon);
+  else
+    gtk_widget_hide (statusbar->horizontal_flip_icon);
+
+  if (shell->flip_vertically)
+    gtk_widget_show (statusbar->vertical_flip_icon);
+  else
+    gtk_widget_hide (statusbar->vertical_flip_icon);
+}
+
+static void
+gimp_statusbar_shell_status_notify (GimpDisplayShell *shell,
+                                    const GParamSpec *pspec,
+                                    GimpStatusbar    *statusbar)
+{
+  gimp_statusbar_replace (statusbar, "title",
+                          NULL, "%s", shell->status);
+}
+
+static void
+gimp_statusbar_unit_changed (GimpUnitComboBox *combo,
+                             GimpStatusbar    *statusbar)
+{
+  gimp_display_shell_set_unit (statusbar->shell,
+                               gimp_unit_combo_box_get_active (combo));
+}
+
+static void
+gimp_statusbar_scale_changed (GimpScaleComboBox *combo,
+                              GimpStatusbar     *statusbar)
+{
+  gimp_display_shell_scale (statusbar->shell,
+                            GIMP_ZOOM_TO,
+                            gimp_scale_combo_box_get_scale (combo),
+                            GIMP_ZOOM_FOCUS_BEST_GUESS);
+}
+
+static void
+gimp_statusbar_scale_activated (GimpScaleComboBox *combo,
+                                GimpStatusbar     *statusbar)
+{
+  gtk_widget_grab_focus (statusbar->shell->canvas);
+}
+
+static gboolean
+gimp_statusbar_rotate_pressed (GtkWidget     *event_box,
+                               GdkEvent      *event,
+                               GimpStatusbar *statusbar)
+{
+  GimpImageWindow *window = gimp_display_shell_get_window (statusbar->shell);
+  GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+
+  gimp_ui_manager_activate_action (manager, "view", "view-rotate-other");
+  return FALSE;
+}
+
+static gboolean
+gimp_statusbar_horiz_flip_pressed (GtkWidget     *event_box,
+                                   GdkEvent      *event,
+                                   GimpStatusbar *statusbar)
+{
+  GimpImageWindow *window = gimp_display_shell_get_window (statusbar->shell);
+  GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+
+  gimp_ui_manager_activate_action (manager, "view", "view-flip-horizontally");
+
+  return FALSE;
+}
+
+static gboolean
+gimp_statusbar_vert_flip_pressed (GtkWidget     *event_box,
+                                  GdkEvent      *event,
+                                  GimpStatusbar *statusbar)
+{
+  GimpImageWindow *window = gimp_display_shell_get_window (statusbar->shell);
+  GimpUIManager   *manager = gimp_image_window_get_ui_manager (window);
+
+  gimp_ui_manager_activate_action (manager, "view", "view-flip-vertically");
+
+  return FALSE;
+}
+
+static guint
+gimp_statusbar_get_context_id (GimpStatusbar *statusbar,
+                               const gchar   *context)
+{
+  guint id = GPOINTER_TO_UINT (g_hash_table_lookup (statusbar->context_ids,
+                                                    context));
+
+  if (! id)
+    {
+      id = statusbar->seq_context_id++;
+
+      g_hash_table_insert (statusbar->context_ids,
+                           g_strdup (context), GUINT_TO_POINTER (id));
+    }
+
+  return id;
+}
+
+static gboolean
+gimp_statusbar_temp_timeout (GimpStatusbar *statusbar)
+{
+  gimp_statusbar_pop_temp (statusbar);
+
+  return FALSE;
+}
+
+static void
+gimp_statusbar_add_message (GimpStatusbar *statusbar,
+                            guint          context_id,
+                            const gchar   *icon_name,
+                            const gchar   *format,
+                            va_list        args,
+                            gboolean       move_to_front)
+{
+  gchar            *message;
+  GSList           *list;
+  GimpStatusbarMsg *msg;
+  gint              position;
+
+  message = gimp_statusbar_vprintf (format, args);
+
+  for (list = statusbar->messages; list; list = g_slist_next (list))
+    {
+      msg = list->data;
+
+      if (msg->context_id == context_id)
+        {
+          gboolean is_front_message = (list == statusbar->messages);
+
+          if ((is_front_message || ! move_to_front) &&
+              strcmp (msg->text, message) == 0      &&
+              g_strcmp0 (msg->icon_name, icon_name) == 0)
+            {
+              g_free (message);
+              return;
+            }
+
+          if (move_to_front)
+            {
+              statusbar->messages = g_slist_remove (statusbar->messages, msg);
+              gimp_statusbar_msg_free (msg);
+
+              break;
+            }
+          else
+            {
+              g_free (msg->icon_name);
+              msg->icon_name = g_strdup (icon_name);
+
+              g_free (msg->text);
+              msg->text = message;
+
+              if (is_front_message)
+                gimp_statusbar_update (statusbar);
+
+              return;
+            }
+        }
+    }
+
+  msg = g_slice_new (GimpStatusbarMsg);
+
+  msg->context_id = context_id;
+  msg->icon_name  = g_strdup (icon_name);
+  msg->text       = message;
+
+  /*  find the position at which to insert the new message  */
+  position = 0;
+  /*  progress messages are always at the front of the list  */
+  if (! (statusbar->progress_active &&
+         context_id == gimp_statusbar_get_context_id (statusbar, "progress")))
+    {
+      if (statusbar->progress_active)
+        position++;
+
+      /*  temporary messages are in front of all other non-progress messages  */
+      if (statusbar->temp_timeout_id &&
+          context_id != statusbar->temp_context_id)
+        position++;
+    }
+
+  statusbar->messages = g_slist_insert (statusbar->messages, msg, position);
+
+  if (position == 0)
+    gimp_statusbar_update (statusbar);
+}
+
+static void
+gimp_statusbar_remove_message (GimpStatusbar *statusbar,
+                               guint          context_id)
+{
+  GSList   *list;
+  gboolean  needs_update = FALSE;
+
+  for (list = statusbar->messages; list; list = g_slist_next (list))
+    {
+      GimpStatusbarMsg *msg = list->data;
+
+      if (msg->context_id == context_id)
+        {
+          needs_update = (list == statusbar->messages);
+
+          statusbar->messages = g_slist_remove (statusbar->messages, msg);
+          gimp_statusbar_msg_free (msg);
+
+          break;
+        }
+    }
+
+  if (needs_update)
+    gimp_statusbar_update (statusbar);
+}
+
+static void
+gimp_statusbar_msg_free (GimpStatusbarMsg *msg)
+{
+  g_free (msg->icon_name);
+  g_free (msg->text);
+
+  g_slice_free (GimpStatusbarMsg, msg);
+}
+
+static gchar *
+gimp_statusbar_vprintf (const gchar *format,
+                        va_list      args)
+{
+  gchar *message;
+  gchar *newline;
+
+  message = g_strdup_vprintf (format, args);
+
+  /*  guard us from multi-line strings  */
+  newline = strchr (message, '\r');
+  if (newline)
+    *newline = '\0';
+
+  newline = strchr (message, '\n');
+  if (newline)
+    *newline = '\0';
+
+  return message;
+}
+
+static GdkPixbuf *
+gimp_statusbar_load_icon (GimpStatusbar *statusbar,
+                          const gchar   *icon_name)
+{
+  GdkPixbuf *icon;
+
+  if (G_UNLIKELY (! statusbar->icon_hash))
+    {
+      statusbar->icon_hash =
+        g_hash_table_new_full (g_str_hash,
+                               g_str_equal,
+                               (GDestroyNotify) g_free,
+                               (GDestroyNotify) g_object_unref);
+    }
+
+  icon = g_hash_table_lookup (statusbar->icon_hash, icon_name);
+
+  if (icon)
+    return g_object_ref (icon);
+
+  icon = gimp_widget_load_icon (statusbar->label, icon_name, 16);
+
+  /* this is not optimal but so what */
+  if (g_hash_table_size (statusbar->icon_hash) > 16)
+    g_hash_table_remove_all (statusbar->icon_hash);
+
+  g_hash_table_insert (statusbar->icon_hash,
+                       g_strdup (icon_name), g_object_ref (icon));
+
+  return icon;
+}
diff --git a/app/display/gimpstatusbar.h b/app/display/gimpstatusbar.h
new file mode 100644
index 0000000..7d5f279
--- /dev/null
+++ b/app/display/gimpstatusbar.h
@@ -0,0 +1,158 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_STATUSBAR_H__
+#define __GIMP_STATUSBAR_H__
+
+G_BEGIN_DECLS
+
+
+/*  maximal length of the format string for the cursor-coordinates  */
+#define CURSOR_FORMAT_LENGTH 32
+
+
+#define GIMP_TYPE_STATUSBAR            (gimp_statusbar_get_type ())
+#define GIMP_STATUSBAR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_STATUSBAR, GimpStatusbar))
+#define GIMP_STATUSBAR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_STATUSBAR, GimpStatusbarClass))
+#define GIMP_IS_STATUSBAR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_STATUSBAR))
+#define GIMP_IS_STATUSBAR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_STATUSBAR))
+#define GIMP_STATUSBAR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_STATUSBAR, GimpStatusbarClass))
+
+typedef struct _GimpStatusbarClass GimpStatusbarClass;
+
+struct _GimpStatusbar
+{
+  GtkStatusbar         parent_instance;
+
+  GimpDisplayShell    *shell;
+
+  GSList              *messages;
+  GHashTable          *context_ids;
+  guint                seq_context_id;
+
+  GdkPixbuf           *icon;
+  GHashTable          *icon_hash;
+
+  guint                temp_context_id;
+  guint                temp_timeout_id;
+  GimpMessageSeverity  temp_severity;
+
+  gchar                cursor_format_str[CURSOR_FORMAT_LENGTH];
+  gchar                cursor_format_str_f[CURSOR_FORMAT_LENGTH];
+  gchar                length_format_str[CURSOR_FORMAT_LENGTH];
+
+  GtkWidget           *cursor_label;
+  GtkWidget           *unit_combo;
+  GtkWidget           *scale_combo;
+  GtkWidget           *rotate_widget;
+  GtkWidget           *rotate_label;
+  GtkWidget           *horizontal_flip_icon;
+  GtkWidget           *vertical_flip_icon;
+  GtkWidget           *label; /* same as GtkStatusbar->label */
+
+  GtkWidget           *progressbar;
+  GtkWidget           *cancel_button;
+  gboolean             progress_active;
+  gboolean             progress_shown;
+  gdouble              progress_value;
+  guint64              progress_last_update_time;
+};
+
+struct _GimpStatusbarClass
+{
+  GtkStatusbarClass parent_class;
+};
+
+
+GType       gimp_statusbar_get_type              (void) G_GNUC_CONST;
+GtkWidget * gimp_statusbar_new                   (void);
+
+void        gimp_statusbar_set_shell             (GimpStatusbar       *statusbar,
+                                                  GimpDisplayShell    *shell);
+
+gboolean    gimp_statusbar_get_visible           (GimpStatusbar       *statusbar);
+void        gimp_statusbar_set_visible           (GimpStatusbar       *statusbar,
+                                                  gboolean             visible);
+void        gimp_statusbar_empty                 (GimpStatusbar       *statusbar);
+void        gimp_statusbar_fill                  (GimpStatusbar       *statusbar);
+
+void        gimp_statusbar_override_window_title (GimpStatusbar       *statusbar);
+void        gimp_statusbar_restore_window_title  (GimpStatusbar       *statusbar);
+
+void        gimp_statusbar_push                  (GimpStatusbar       *statusbar,
+                                                  const gchar         *context,
+                                                  const gchar         *icon_name,
+                                                  const gchar         *format,
+                                                  ...) G_GNUC_PRINTF (4, 5);
+void        gimp_statusbar_push_valist           (GimpStatusbar       *statusbar,
+                                                  const gchar         *context,
+                                                  const gchar         *icon_name,
+                                                  const gchar         *format,
+                                                  va_list              args) G_GNUC_PRINTF (4, 0);
+void        gimp_statusbar_push_coords           (GimpStatusbar       *statusbar,
+                                                  const gchar         *context,
+                                                  const gchar         *icon_name,
+                                                  GimpCursorPrecision  precision,
+                                                  const gchar         *title,
+                                                  gdouble              x,
+                                                  const gchar         *separator,
+                                                  gdouble              y,
+                                                  const gchar         *help);
+void        gimp_statusbar_push_length           (GimpStatusbar       *statusbar,
+                                                  const gchar         *context,
+                                                  const gchar         *icon_name,
+                                                  const gchar         *title,
+                                                  GimpOrientationType  axis,
+                                                  gdouble              value,
+                                                  const gchar         *help);
+void        gimp_statusbar_replace               (GimpStatusbar       *statusbar,
+                                                  const gchar         *context,
+                                                  const gchar         *icon_name,
+                                                  const gchar         *format,
+                                                  ...) G_GNUC_PRINTF (4, 5);
+void        gimp_statusbar_replace_valist        (GimpStatusbar       *statusbar,
+                                                  const gchar         *context,
+                                                  const gchar         *icon_name,
+                                                  const gchar         *format,
+                                                  va_list              args) G_GNUC_PRINTF (4, 0);
+const gchar * gimp_statusbar_peek                (GimpStatusbar       *statusbar,
+                                                  const gchar         *context);
+void        gimp_statusbar_pop                   (GimpStatusbar       *statusbar,
+                                                  const gchar         *context);
+
+void        gimp_statusbar_push_temp             (GimpStatusbar       *statusbar,
+                                                  GimpMessageSeverity  severity,
+                                                  const gchar         *icon_name,
+                                                  const gchar         *format,
+                                                  ...) G_GNUC_PRINTF (4, 5);
+void        gimp_statusbar_push_temp_valist      (GimpStatusbar       *statusbar,
+                                                  GimpMessageSeverity  severity,
+                                                  const gchar         *icon_name,
+                                                  const gchar         *format,
+                                                  va_list              args) G_GNUC_PRINTF (4, 0);
+void        gimp_statusbar_pop_temp              (GimpStatusbar       *statusbar);
+
+void        gimp_statusbar_update_cursor         (GimpStatusbar       *statusbar,
+                                                  GimpCursorPrecision  precision,
+                                                  gdouble              x,
+                                                  gdouble              y);
+void        gimp_statusbar_clear_cursor          (GimpStatusbar       *statusbar);
+
+
+G_END_DECLS
+
+#endif /* __GIMP_STATUSBAR_H__ */
diff --git a/app/display/gimptoolcompass.c b/app/display/gimptoolcompass.c
new file mode 100644
index 0000000..3d9045b
--- /dev/null
+++ b/app/display/gimptoolcompass.c
@@ -0,0 +1,1218 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolcompass.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Measure tool
+ * Copyright (C) 1999-2003 Sven Neumann <sven@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-utils.h"
+#include "core/gimpimage.h"
+#include "core/gimpmarshal.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvashandle.h"
+#include "gimpcanvasline.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-appearance.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpdisplayshell-utils.h"
+#include "gimptoolcompass.h"
+
+#include "gimp-intl.h"
+
+
+#define ARC_RADIUS 30
+#define ARC_GAP    (ARC_RADIUS / 2)
+#define EPSILON    1e-6
+
+
+/*  possible measure functions  */
+typedef enum
+{
+  CREATING,
+  ADDING,
+  MOVING,
+  MOVING_ALL,
+  GUIDING,
+  FINISHED
+} CompassFunction;
+
+enum
+{
+  PROP_0,
+  PROP_ORIENTATION,
+  PROP_N_POINTS,
+  PROP_X1,
+  PROP_Y1,
+  PROP_X2,
+  PROP_Y2,
+  PROP_X3,
+  PROP_Y3,
+  PROP_PIXEL_ANGLE,
+  PROP_UNIT_ANGLE,
+  PROP_EFFECTIVE_ORIENTATION
+};
+
+enum
+{
+  CREATE_GUIDES,
+  LAST_SIGNAL
+};
+
+struct _GimpToolCompassPrivate
+{
+  GimpCompassOrientation  orientation;
+  gint                    n_points;
+  gint                    x[3];
+  gint                    y[3];
+
+  GimpVector2             radius1;
+  GimpVector2             radius2;
+  gdouble                 display_angle;
+  gdouble                 pixel_angle;
+  gdouble                 unit_angle;
+  GimpCompassOrientation  effective_orientation;
+
+  CompassFunction         function;
+  gdouble                 mouse_x;
+  gdouble                 mouse_y;
+  gint                    last_x;
+  gint                    last_y;
+  gint                    point;
+
+  GimpCanvasItem         *line1;
+  GimpCanvasItem         *line2;
+  GimpCanvasItem         *arc;
+  GimpCanvasItem         *arc_line;
+  GimpCanvasItem         *handles[3];
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_compass_constructed     (GObject                *object);
+static void     gimp_tool_compass_set_property    (GObject                *object,
+                                                   guint                   property_id,
+                                                   const GValue           *value,
+                                                   GParamSpec             *pspec);
+static void     gimp_tool_compass_get_property    (GObject                *object,
+                                                   guint                   property_id,
+                                                   GValue                 *value,
+                                                   GParamSpec             *pspec);
+
+static void     gimp_tool_compass_changed         (GimpToolWidget         *widget);
+static gint     gimp_tool_compass_button_press    (GimpToolWidget         *widget,
+                                                   const GimpCoords       *coords,
+                                                   guint32                 time,
+                                                   GdkModifierType         state,
+                                                   GimpButtonPressType     press_type);
+static void     gimp_tool_compass_button_release  (GimpToolWidget         *widget,
+                                                   const GimpCoords       *coords,
+                                                   guint32                 time,
+                                                   GdkModifierType         state,
+                                                   GimpButtonReleaseType   release_type);
+static void     gimp_tool_compass_motion          (GimpToolWidget         *widget,
+                                                   const GimpCoords       *coords,
+                                                   guint32                 time,
+                                                   GdkModifierType         state);
+static GimpHit  gimp_tool_compass_hit             (GimpToolWidget         *widget,
+                                                   const GimpCoords       *coords,
+                                                   GdkModifierType         state,
+                                                   gboolean                proximity);
+static void     gimp_tool_compass_hover           (GimpToolWidget         *widget,
+                                                   const GimpCoords       *coords,
+                                                   GdkModifierType         state,
+                                                   gboolean                proximity);
+static void     gimp_tool_compass_leave_notify    (GimpToolWidget         *widget);
+static void     gimp_tool_compass_motion_modifier (GimpToolWidget         *widget,
+                                                   GdkModifierType         key,
+                                                   gboolean                press,
+                                                   GdkModifierType         state);
+static gboolean gimp_tool_compass_get_cursor      (GimpToolWidget         *widget,
+                                                   const GimpCoords       *coords,
+                                                   GdkModifierType         state,
+                                                   GimpCursorType         *cursor,
+                                                   GimpToolCursorType     *tool_cursor,
+                                                   GimpCursorModifier     *modifier);
+
+static gint     gimp_tool_compass_get_point       (GimpToolCompass        *compass,
+                                                   const GimpCoords       *coords);
+static void     gimp_tool_compass_update_hilight  (GimpToolCompass        *compass);
+static void     gimp_tool_compass_update_angle    (GimpToolCompass        *compass,
+                                                   GimpCompassOrientation  orientation,
+                                                   gboolean                flip);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolCompass, gimp_tool_compass,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_compass_parent_class
+
+static guint compass_signals[LAST_SIGNAL] = { 0 };
+
+
+static void
+gimp_tool_compass_class_init (GimpToolCompassClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed      = gimp_tool_compass_constructed;
+  object_class->set_property     = gimp_tool_compass_set_property;
+  object_class->get_property     = gimp_tool_compass_get_property;
+
+  widget_class->changed          = gimp_tool_compass_changed;
+  widget_class->button_press     = gimp_tool_compass_button_press;
+  widget_class->button_release   = gimp_tool_compass_button_release;
+  widget_class->motion           = gimp_tool_compass_motion;
+  widget_class->hit              = gimp_tool_compass_hit;
+  widget_class->hover            = gimp_tool_compass_hover;
+  widget_class->leave_notify     = gimp_tool_compass_leave_notify;
+  widget_class->motion_modifier  = gimp_tool_compass_motion_modifier;
+  widget_class->get_cursor       = gimp_tool_compass_get_cursor;
+  widget_class->update_on_scale  = TRUE;
+  widget_class->update_on_rotate = TRUE;
+
+  compass_signals[CREATE_GUIDES] =
+    g_signal_new ("create-guides",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolCompassClass, create_guides),
+                  NULL, NULL,
+                  gimp_marshal_VOID__INT_INT_BOOLEAN_BOOLEAN,
+                  G_TYPE_NONE, 4,
+                  G_TYPE_INT,
+                  G_TYPE_INT,
+                  G_TYPE_BOOLEAN,
+                  G_TYPE_BOOLEAN);
+
+  g_object_class_install_property (object_class, PROP_ORIENTATION,
+                                   g_param_spec_enum ("orientation", NULL, NULL,
+                                                      GIMP_TYPE_COMPASS_ORIENTATION,
+                                                      GIMP_COMPASS_ORIENTATION_AUTO,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_N_POINTS,
+                                   g_param_spec_int ("n-points", NULL, NULL,
+                                                     1, 3, 1,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X1,
+                                   g_param_spec_int ("x1", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y1,
+                                   g_param_spec_int ("y1", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X2,
+                                   g_param_spec_int ("x2", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y2,
+                                   g_param_spec_int ("y2", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X3,
+                                   g_param_spec_int ("x3", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y3,
+                                   g_param_spec_int ("y3", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIXEL_ANGLE,
+                                   g_param_spec_double ("pixel-angle", NULL, NULL,
+                                                        -G_PI, G_PI, 0.0,
+                                                        GIMP_PARAM_READABLE));
+
+  g_object_class_install_property (object_class, PROP_UNIT_ANGLE,
+                                   g_param_spec_double ("unit-angle", NULL, NULL,
+                                                        -G_PI, G_PI, 0.0,
+                                                        GIMP_PARAM_READABLE));
+
+  g_object_class_install_property (object_class, PROP_EFFECTIVE_ORIENTATION,
+                                   g_param_spec_enum ("effective-orientation", NULL, NULL,
+                                                      GIMP_TYPE_COMPASS_ORIENTATION,
+                                                      GIMP_COMPASS_ORIENTATION_AUTO,
+                                                      GIMP_PARAM_READABLE));
+}
+
+static void
+gimp_tool_compass_init (GimpToolCompass *compass)
+{
+  compass->private = gimp_tool_compass_get_instance_private (compass);
+
+  compass->private->point = -1;
+}
+
+static void
+gimp_tool_compass_constructed (GObject *object)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (object);
+  GimpToolWidget         *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolCompassPrivate *private = compass->private;
+  GimpCanvasGroup        *stroke_group;
+  gint                    i;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  stroke_group = gimp_tool_widget_add_stroke_group (widget);
+
+  gimp_tool_widget_push_group (widget, stroke_group);
+
+  private->line1 = gimp_tool_widget_add_line (widget,
+                                              private->x[0],
+                                              private->y[0],
+                                              private->x[1],
+                                              private->y[1]);
+
+  private->line2 = gimp_tool_widget_add_line (widget,
+                                              private->x[0],
+                                              private->y[0],
+                                              private->x[2],
+                                              private->y[2]);
+
+  private->arc = gimp_tool_widget_add_handle (widget,
+                                              GIMP_HANDLE_CIRCLE,
+                                              private->x[0],
+                                              private->y[0],
+                                              ARC_RADIUS * 2 + 1,
+                                              ARC_RADIUS * 2 + 1,
+                                              GIMP_HANDLE_ANCHOR_CENTER);
+
+  private->arc_line = gimp_tool_widget_add_line (widget,
+                                                 private->x[0],
+                                                 private->y[0],
+                                                 private->x[0] + 10,
+                                                 private->y[0]);
+
+  gimp_tool_widget_pop_group (widget);
+
+  for (i = 0; i < 3; i++)
+    {
+      private->handles[i] =
+        gimp_tool_widget_add_handle (widget,
+                                     i == 0 ?
+                                     GIMP_HANDLE_CIRCLE : GIMP_HANDLE_CROSS,
+                                     private->x[i],
+                                     private->y[i],
+                                     GIMP_CANVAS_HANDLE_SIZE_CROSS,
+                                     GIMP_CANVAS_HANDLE_SIZE_CROSS,
+                                     GIMP_HANDLE_ANCHOR_CENTER);
+    }
+
+  gimp_tool_compass_changed (widget);
+}
+
+static void
+gimp_tool_compass_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (object);
+  GimpToolCompassPrivate *private = compass->private;
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      private->orientation = g_value_get_enum (value);
+      break;
+    case PROP_N_POINTS:
+      private->n_points = g_value_get_int (value);
+      break;
+    case PROP_X1:
+      private->x[0] = g_value_get_int (value);
+      break;
+    case PROP_Y1:
+      private->y[0] = g_value_get_int (value);
+      break;
+    case PROP_X2:
+      private->x[1] = g_value_get_int (value);
+      break;
+    case PROP_Y2:
+      private->y[1] = g_value_get_int (value);
+      break;
+    case PROP_X3:
+      private->x[2] = g_value_get_int (value);
+      break;
+    case PROP_Y3:
+      private->y[2] = g_value_get_int (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_compass_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (object);
+  GimpToolCompassPrivate *private = compass->private;
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      g_value_set_enum (value, private->orientation);
+      break;
+    case PROP_N_POINTS:
+      g_value_set_int (value, private->n_points);
+      break;
+    case PROP_X1:
+      g_value_set_int (value, private->x[0]);
+      break;
+    case PROP_Y1:
+      g_value_set_int (value, private->y[0]);
+      break;
+    case PROP_X2:
+      g_value_set_int (value, private->x[1]);
+      break;
+    case PROP_Y2:
+      g_value_set_int (value, private->y[1]);
+      break;
+    case PROP_X3:
+      g_value_set_int (value, private->x[2]);
+      break;
+    case PROP_Y3:
+      g_value_set_int (value, private->y[2]);
+      break;
+    case PROP_PIXEL_ANGLE:
+      g_value_set_double (value, private->pixel_angle);
+      break;
+    case PROP_UNIT_ANGLE:
+      g_value_set_double (value, private->unit_angle);
+      break;
+    case PROP_EFFECTIVE_ORIENTATION:
+      g_value_set_enum (value, private->effective_orientation);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_compass_changed (GimpToolWidget *widget)
+{
+  GimpToolCompass        *compass       = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private       = compass->private;
+  GimpDisplayShell       *shell         = gimp_tool_widget_get_shell (widget);
+  gdouble                 angle1;
+  gdouble                 angle2;
+  gint                    draw_arc      = 0;
+  gboolean                draw_arc_line = FALSE;
+  gdouble                 arc_line_display_length;
+  gdouble                 arc_line_length;
+
+  gimp_tool_compass_update_angle (compass, private->orientation, FALSE);
+
+  angle1 = -atan2 (private->radius1.y * shell->scale_y,
+                   private->radius1.x * shell->scale_x);
+  angle2 = -private->display_angle;
+
+  gimp_canvas_line_set (private->line1,
+                        private->x[0],
+                        private->y[0],
+                        private->x[1],
+                        private->y[1]);
+  gimp_canvas_item_set_visible (private->line1, private->n_points > 1);
+  if (private->n_points > 1 &&
+      gimp_canvas_item_transform_distance (private->line1,
+                                           private->x[0],
+                                           private->y[0],
+                                           private->x[1],
+                                           private->y[1]) > ARC_RADIUS)
+    {
+      draw_arc++;
+    }
+
+
+  arc_line_display_length = ARC_RADIUS                           +
+                            (GIMP_CANVAS_HANDLE_SIZE_CROSS >> 1) +
+                            ARC_GAP;
+  arc_line_length         = arc_line_display_length              /
+                            hypot (private->radius2.x * shell->scale_x,
+                                  private->radius2.y * shell->scale_y);
+
+  if (private->n_points > 2)
+    {
+      gdouble length = gimp_canvas_item_transform_distance (private->line2,
+                                                            private->x[0],
+                                                            private->y[0],
+                                                            private->x[2],
+                                                            private->y[2]);
+
+      if (length > ARC_RADIUS)
+        {
+          draw_arc++;
+          draw_arc_line = TRUE;
+
+          if (length > arc_line_display_length)
+            {
+              gimp_canvas_line_set (
+                private->line2,
+                private->x[0] + private->radius2.x * arc_line_length,
+                private->y[0] + private->radius2.y * arc_line_length,
+                private->x[2],
+                private->y[2]);
+              gimp_canvas_item_set_visible (private->line2, TRUE);
+            }
+          else
+            {
+              gimp_canvas_item_set_visible (private->line2, FALSE);
+            }
+        }
+      else
+        {
+          gimp_canvas_line_set (private->line2,
+                                private->x[0],
+                                private->y[0],
+                                private->x[2],
+                                private->y[2]);
+          gimp_canvas_item_set_visible (private->line2, TRUE);
+        }
+    }
+  else
+    {
+      gimp_canvas_item_set_visible (private->line2, FALSE);
+    }
+
+  gimp_canvas_handle_set_position (private->arc,
+                                   private->x[0], private->y[0]);
+  gimp_canvas_handle_set_angles (private->arc, angle1, angle2);
+  gimp_canvas_item_set_visible (private->arc,
+                                private->n_points > 1             &&
+                                draw_arc == private->n_points - 1 &&
+                                fabs (angle2) > EPSILON);
+
+  arc_line_length = (ARC_RADIUS + (GIMP_CANVAS_HANDLE_SIZE_CROSS >> 1)) /
+                    hypot (private->radius2.x * shell->scale_x,
+                           private->radius2.y * shell->scale_y);
+
+  gimp_canvas_line_set (private->arc_line,
+                        private->x[0],
+                        private->y[0],
+                        private->x[0] + private->radius2.x * arc_line_length,
+                        private->y[0] + private->radius2.y * arc_line_length);
+  gimp_canvas_item_set_visible (private->arc_line,
+                                (private->n_points == 2 || draw_arc_line) &&
+                                fabs (angle2) > EPSILON);
+
+  gimp_canvas_handle_set_position (private->handles[0],
+                                   private->x[0], private->y[0]);
+  gimp_canvas_item_set_visible (private->handles[0],
+                                private->n_points > 0);
+
+  gimp_canvas_handle_set_position (private->handles[1],
+                                   private->x[1], private->y[1]);
+  gimp_canvas_item_set_visible (private->handles[1],
+                                private->n_points > 1);
+
+  gimp_canvas_handle_set_position (private->handles[2],
+                                   private->x[2], private->y[2]);
+  gimp_canvas_item_set_visible (private->handles[2],
+                                private->n_points > 2);
+
+  gimp_tool_compass_update_hilight (compass);
+}
+
+gint
+gimp_tool_compass_button_press (GimpToolWidget      *widget,
+                                const GimpCoords    *coords,
+                                guint32              time,
+                                GdkModifierType      state,
+                                GimpButtonPressType  press_type)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private = compass->private;
+
+  private->function = CREATING;
+
+  private->mouse_x = coords->x;
+  private->mouse_y = coords->y;
+
+  /*  if the cursor is in one of the handles, the new function will be
+   *  moving or adding a new point or guide
+   */
+  if (private->point != -1)
+    {
+      GdkModifierType extend_mask = gimp_get_extend_selection_mask ();
+      GdkModifierType toggle_mask = gimp_get_toggle_behavior_mask ();
+
+      if (state & (toggle_mask | GDK_MOD1_MASK))
+        {
+          gboolean create_hguide = (state & toggle_mask);
+          gboolean create_vguide = (state & GDK_MOD1_MASK);
+
+          g_signal_emit (compass, compass_signals[CREATE_GUIDES], 0,
+                         private->x[private->point],
+                         private->y[private->point],
+                         create_hguide,
+                         create_vguide);
+
+          private->function = GUIDING;
+        }
+      else
+        {
+          if (private->n_points == 1 || (state & extend_mask))
+            private->function = ADDING;
+          else
+            private->function = MOVING;
+        }
+    }
+
+  /*  adding to the middle point makes no sense  */
+  if (private->point    == 0      &&
+      private->function == ADDING &&
+      private->n_points == 3)
+    {
+      private->function = MOVING;
+    }
+
+  /*  if the function is still CREATING, we are outside the handles  */
+  if (private->function == CREATING)
+    {
+      if (private->n_points > 1 && (state & GDK_MOD1_MASK))
+        {
+          private->function = MOVING_ALL;
+
+          private->last_x = coords->x;
+          private->last_y = coords->y;
+        }
+    }
+
+  if (private->function == CREATING)
+    {
+      /*  set the first point and go into ADDING mode  */
+      g_object_set (compass,
+                    "n-points", 1,
+                    "x1",       (gint) (coords->x + 0.5),
+                    "y1",       (gint) (coords->y + 0.5),
+                    "x2",       0,
+                    "y2",       0,
+                    "x3",       0,
+                    "y3",       0,
+                    NULL);
+
+      private->point    = 0;
+      private->function = ADDING;
+    }
+
+  return 1;
+}
+
+void
+gimp_tool_compass_button_release (GimpToolWidget        *widget,
+                                  const GimpCoords      *coords,
+                                  guint32                time,
+                                  GdkModifierType        state,
+                                  GimpButtonReleaseType  release_type)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private = compass->private;
+
+  private->function = FINISHED;
+}
+
+void
+gimp_tool_compass_motion (GimpToolWidget   *widget,
+                          const GimpCoords *coords,
+                          guint32           time,
+                          GdkModifierType   state)
+{
+  GimpToolCompass        *compass  = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private  = compass->private;
+  gint                    new_n_points;
+  gint                    new_x[3];
+  gint                    new_y[3];
+  gint                    dx, dy;
+  gint                    tmp;
+
+  private->mouse_x = coords->x;
+  private->mouse_y = coords->y;
+
+  /*  A few comments here, because this routine looks quite weird at first ...
+   *
+   *  The goal is to keep point 0, called the start point, to be
+   *  always the one in the middle or, if there are only two points,
+   *  the one that is fixed.  The angle is then always measured at
+   *  this point.
+   */
+
+  new_n_points = private->n_points;
+  new_x[0]     = private->x[0];
+  new_y[0]     = private->y[0];
+  new_x[1]     = private->x[1];
+  new_y[1]     = private->y[1];
+  new_x[2]     = private->x[2];
+  new_y[2]     = private->y[2];
+
+  switch (private->function)
+    {
+    case ADDING:
+      switch (private->point)
+        {
+        case 0:
+          /*  we are adding to the start point  */
+          break;
+
+        case 1:
+          /*  we are adding to the end point, make it the new start point  */
+          new_x[0] = private->x[1];
+          new_y[0] = private->y[1];
+
+          new_x[1] = private->x[0];
+          new_y[1] = private->y[0];
+          break;
+
+        case 2:
+          /*  we are adding to the third point, make it the new start point  */
+          new_x[1] = private->x[0];
+          new_y[1] = private->y[0];
+          new_x[0] = private->x[2];
+          new_y[0] = private->y[2];
+          break;
+
+        default:
+          break;
+        }
+
+      new_n_points = MIN (new_n_points + 1, 3);
+
+      private->point    = new_n_points - 1;
+      private->function = MOVING;
+      /*  don't break here!  */
+
+    case MOVING:
+      /*  if we are moving the start point and only have two, make it
+       *  the end point
+       */
+      if (new_n_points == 2 && private->point == 0)
+        {
+          tmp = new_x[0];
+          new_x[0] = new_x[1];
+          new_x[1] = tmp;
+
+          tmp = new_y[0];
+          new_y[0] = new_y[1];
+          new_y[1] = tmp;
+
+          private->point = 1;
+        }
+
+      new_x[private->point] = ROUND (coords->x);
+      new_y[private->point] = ROUND (coords->y);
+
+      if (state & gimp_get_constrain_behavior_mask ())
+        {
+          gdouble  x = new_x[private->point];
+          gdouble  y = new_y[private->point];
+
+          gimp_display_shell_constrain_line (gimp_tool_widget_get_shell (widget),
+                                             new_x[0], new_y[0],
+                                             &x, &y,
+                                             GIMP_CONSTRAIN_LINE_15_DEGREES);
+
+          new_x[private->point] = ROUND (x);
+          new_y[private->point] = ROUND (y);
+        }
+
+      g_object_set (compass,
+                    "n-points", new_n_points,
+                    "x1",       new_x[0],
+                    "y1",       new_y[0],
+                    "x2",       new_x[1],
+                    "y2",       new_y[1],
+                    "x3",       new_x[2],
+                    "y3",       new_y[2],
+                    NULL);
+      break;
+
+    case MOVING_ALL:
+      dx = ROUND (coords->x) - private->last_x;
+      dy = ROUND (coords->y) - private->last_y;
+
+      g_object_set (compass,
+                    "x1", new_x[0] + dx,
+                    "y1", new_y[0] + dy,
+                    "x2", new_x[1] + dx,
+                    "y2", new_y[1] + dy,
+                    "x3", new_x[2] + dx,
+                    "y3", new_y[2] + dy,
+                    NULL);
+
+      private->last_x = ROUND (coords->x);
+      private->last_y = ROUND (coords->y);
+      break;
+
+    default:
+      break;
+    }
+}
+
+GimpHit
+gimp_tool_compass_hit (GimpToolWidget   *widget,
+                       const GimpCoords *coords,
+                       GdkModifierType   state,
+                       gboolean          proximity)
+{
+  GimpToolCompass *compass = GIMP_TOOL_COMPASS (widget);
+
+  if (gimp_tool_compass_get_point (compass, coords) >= 0)
+    return GIMP_HIT_DIRECT;
+  else
+    return GIMP_HIT_INDIRECT;
+}
+
+void
+gimp_tool_compass_hover (GimpToolWidget   *widget,
+                         const GimpCoords *coords,
+                         GdkModifierType   state,
+                         gboolean          proximity)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private = compass->private;
+  gint                    point;
+
+  private->mouse_x = coords->x;
+  private->mouse_y = coords->y;
+
+  point = gimp_tool_compass_get_point (compass, coords);
+
+  if (point >= 0)
+    {
+      GdkModifierType  extend_mask = gimp_get_extend_selection_mask ();
+      GdkModifierType  toggle_mask = gimp_get_toggle_behavior_mask ();
+      gchar           *status;
+
+      if (state & toggle_mask)
+        {
+          if (state & GDK_MOD1_MASK)
+            {
+              status = gimp_suggest_modifiers (_("Click to place "
+                                                 "vertical and "
+                                                 "horizontal guides"),
+                                               0,
+                                               NULL, NULL, NULL);
+            }
+          else
+            {
+              status = gimp_suggest_modifiers (_("Click to place a "
+                                                 "horizontal guide"),
+                                               GDK_MOD1_MASK & ~state,
+                                               NULL, NULL, NULL);
+            }
+        }
+      else if (state & GDK_MOD1_MASK)
+        {
+          status = gimp_suggest_modifiers (_("Click to place a "
+                                             "vertical guide"),
+                                           toggle_mask & ~state,
+                                           NULL, NULL, NULL);
+        }
+      else if ((state & extend_mask) &&
+               ! ((point == 0) && (private->n_points == 3)))
+        {
+          status = gimp_suggest_modifiers (_("Click-Drag to add a "
+                                             "new point"),
+                                           (toggle_mask |
+                                            GDK_MOD1_MASK) & ~state,
+                                           NULL, NULL, NULL);
+        }
+      else
+        {
+          if ((point == 0) && (private->n_points == 3))
+            state |= extend_mask;
+
+          status = gimp_suggest_modifiers (_("Click-Drag to move this "
+                                             "point"),
+                                           (extend_mask |
+                                            toggle_mask |
+                                            GDK_MOD1_MASK) & ~state,
+                                           NULL, NULL, NULL);
+        }
+
+      gimp_tool_widget_set_status (widget, status);
+
+      g_free (status);
+    }
+  else
+    {
+      if ((private->n_points > 1) && (state & GDK_MOD1_MASK))
+        {
+          gimp_tool_widget_set_status (widget,
+                                       _("Click-Drag to move all points"));
+        }
+      else
+        {
+          gimp_tool_widget_set_status (widget, NULL);
+        }
+    }
+
+  if (point != private->point)
+    {
+      private->point = point;
+
+      gimp_tool_compass_update_hilight (compass);
+    }
+}
+
+void
+gimp_tool_compass_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private = compass->private;
+
+  if (private->point != -1)
+    {
+      private->point = -1;
+
+      gimp_tool_compass_update_hilight (compass);
+    }
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
+}
+
+static void
+gimp_tool_compass_motion_modifier (GimpToolWidget  *widget,
+                                   GdkModifierType  key,
+                                   gboolean         press,
+                                   GdkModifierType  state)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private = compass->private;
+
+  if (key == gimp_get_constrain_behavior_mask () &&
+      private->function == MOVING)
+    {
+      gint    new_x[3];
+      gint    new_y[3];
+      gdouble x = private->mouse_x;
+      gdouble y = private->mouse_y;
+
+      new_x[0] = private->x[0];
+      new_y[0] = private->y[0];
+      new_x[1] = private->x[1];
+      new_y[1] = private->y[1];
+      new_x[2] = private->x[2];
+      new_y[2] = private->y[2];
+
+      if (press)
+        {
+          gimp_display_shell_constrain_line (gimp_tool_widget_get_shell (widget),
+                                             private->x[0], private->y[0],
+                                             &x, &y,
+                                             GIMP_CONSTRAIN_LINE_15_DEGREES);
+        }
+
+      new_x[private->point] = ROUND (x);
+      new_y[private->point] = ROUND (y);
+
+      g_object_set (compass,
+                    "x1", new_x[0],
+                    "y1", new_y[0],
+                    "x2", new_x[1],
+                    "y2", new_y[1],
+                    "x3", new_x[2],
+                    "y3", new_y[2],
+                    NULL);
+    }
+}
+
+static gboolean
+gimp_tool_compass_get_cursor (GimpToolWidget     *widget,
+                              const GimpCoords   *coords,
+                              GdkModifierType     state,
+                              GimpCursorType     *cursor,
+                              GimpToolCursorType *tool_cursor,
+                              GimpCursorModifier *modifier)
+{
+  GimpToolCompass        *compass = GIMP_TOOL_COMPASS (widget);
+  GimpToolCompassPrivate *private = compass->private;
+
+  if (private->point != -1)
+    {
+      GdkModifierType extend_mask = gimp_get_extend_selection_mask ();
+      GdkModifierType toggle_mask = gimp_get_toggle_behavior_mask ();
+
+      if (state & toggle_mask)
+        {
+          if (state & GDK_MOD1_MASK)
+            {
+              *cursor = GIMP_CURSOR_CORNER_BOTTOM_RIGHT;
+              return TRUE;
+            }
+          else
+            {
+              *cursor = GIMP_CURSOR_SIDE_BOTTOM;
+              return TRUE;
+            }
+        }
+      else if (state & GDK_MOD1_MASK)
+        {
+          *cursor = GIMP_CURSOR_SIDE_RIGHT;
+          return TRUE;
+        }
+      else if ((state & extend_mask) &&
+               ! ((private->point == 0) &&
+                  (private->n_points == 3)))
+        {
+          *modifier = GIMP_CURSOR_MODIFIER_PLUS;
+          return TRUE;
+        }
+      else
+        {
+          *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+          return TRUE;
+        }
+    }
+  else
+    {
+      if ((private->n_points > 1) && (state & GDK_MOD1_MASK))
+        {
+          *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}
+
+static gint
+gimp_tool_compass_get_point (GimpToolCompass  *compass,
+                             const GimpCoords *coords)
+{
+  GimpToolCompassPrivate *private = compass->private;
+  gint                    i;
+
+  for (i = 0; i < private->n_points; i++)
+    {
+      if (gimp_canvas_item_hit (private->handles[i],
+                                coords->x, coords->y))
+        {
+          return i;
+        }
+    }
+
+  return -1;
+}
+
+static void
+gimp_tool_compass_update_hilight (GimpToolCompass *compass)
+{
+  GimpToolCompassPrivate *private = compass->private;
+  gint                    i;
+
+  for (i = 0; i < private->n_points; i++)
+    {
+      if (private->handles[i])
+        {
+          gimp_canvas_item_set_highlight (private->handles[i],
+                                          private->point == i);
+        }
+    }
+}
+
+static void
+gimp_tool_compass_update_angle (GimpToolCompass        *compass,
+                                GimpCompassOrientation  orientation,
+                                gboolean                flip)
+{
+  GimpToolWidget         *widget  = GIMP_TOOL_WIDGET (compass);
+  GimpToolCompassPrivate *private = compass->private;
+  GimpDisplayShell       *shell   = gimp_tool_widget_get_shell (widget);
+  GimpImage              *image   = gimp_display_get_image (shell->display);
+  GimpVector2             radius1;
+  GimpVector2             radius2;
+  gdouble                 pixel_angle;
+  gdouble                 unit_angle;
+  gdouble                 xres;
+  gdouble                 yres;
+
+  gimp_image_get_resolution (image, &xres, &yres);
+
+  private->radius1.x = private->x[1] - private->x[0];
+  private->radius1.y = private->y[1] - private->y[0];
+
+  if (private->n_points == 3)
+    {
+      orientation = GIMP_COMPASS_ORIENTATION_AUTO;
+
+      private->radius2.x = private->x[2] - private->x[0];
+      private->radius2.y = private->y[2] - private->y[0];
+    }
+  else
+    {
+      gdouble angle = -shell->rotate_angle * G_PI / 180.0;
+
+      if (orientation == GIMP_COMPASS_ORIENTATION_VERTICAL)
+        angle -= G_PI / 2.0;
+
+      if (flip)
+        angle += G_PI;
+
+      if (shell->flip_horizontally)
+        angle = G_PI - angle;
+      if (shell->flip_vertically)
+        angle = -angle;
+
+      private->radius2.x = cos (angle);
+      private->radius2.y = sin (angle);
+
+      if (! shell->dot_for_dot)
+        {
+          private->radius2.x *= xres;
+          private->radius2.y *= yres;
+
+          gimp_vector2_normalize (&private->radius2);
+        }
+    }
+
+  radius1 = private->radius1;
+  radius2 = private->radius2;
+
+  pixel_angle = atan2 (gimp_vector2_cross_product (&radius1, &radius2).x,
+                       gimp_vector2_inner_product (&radius1, &radius2));
+
+  radius1.x /= xres;
+  radius1.y /= yres;
+
+  radius2.x /= xres;
+  radius2.y /= yres;
+
+  unit_angle = atan2 (gimp_vector2_cross_product (&radius1, &radius2).x,
+                      gimp_vector2_inner_product (&radius1, &radius2));
+
+  if (shell->dot_for_dot)
+    private->display_angle = pixel_angle;
+  else
+    private->display_angle = unit_angle;
+
+  if (private->n_points == 2)
+    {
+      if (! flip && fabs (private->display_angle) > G_PI / 2.0 + EPSILON)
+        {
+          gimp_tool_compass_update_angle (compass, orientation, TRUE);
+
+          return;
+        }
+      else if (orientation == GIMP_COMPASS_ORIENTATION_AUTO)
+        {
+          if (fabs (private->display_angle) <= G_PI / 4.0 + EPSILON)
+            {
+              orientation = GIMP_COMPASS_ORIENTATION_HORIZONTAL;
+            }
+          else
+            {
+              gimp_tool_compass_update_angle (compass,
+                                              GIMP_COMPASS_ORIENTATION_VERTICAL,
+                                              FALSE);
+
+              return;
+            }
+        }
+    }
+
+  if (fabs (pixel_angle - private->pixel_angle) > EPSILON)
+    {
+      private->pixel_angle = pixel_angle;
+
+      g_object_notify (G_OBJECT (compass), "pixel-angle");
+    }
+
+  if (fabs (unit_angle - private->unit_angle) > EPSILON)
+    {
+      private->unit_angle = unit_angle;
+
+      g_object_notify (G_OBJECT (compass), "unit-angle");
+    }
+
+  if (orientation != private->effective_orientation)
+    {
+      private->effective_orientation = orientation;
+
+      g_object_notify (G_OBJECT (compass), "effective-orientation");
+    }
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_compass_new (GimpDisplayShell       *shell,
+                       GimpCompassOrientation  orientation,
+                       gint                    n_points,
+                       gint                    x1,
+                       gint                    y1,
+                       gint                    x2,
+                       gint                    y2,
+                       gint                    x3,
+                       gint                    y3)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_COMPASS,
+                       "shell",       shell,
+                       "orientation", orientation,
+                       "n-points",    n_points,
+                       "x1",          x1,
+                       "y1",          y1,
+                       "x2",          x2,
+                       "y2",          y2,
+                       NULL);
+}
diff --git a/app/display/gimptoolcompass.h b/app/display/gimptoolcompass.h
new file mode 100644
index 0000000..8e6fdfe
--- /dev/null
+++ b/app/display/gimptoolcompass.h
@@ -0,0 +1,72 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolcompass.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_COMPASS_H__
+#define __GIMP_TOOL_COMPASS_H__
+
+
+#include "gimptoolwidget.h"
+
+
+#define GIMP_TYPE_TOOL_COMPASS            (gimp_tool_compass_get_type ())
+#define GIMP_TOOL_COMPASS(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_COMPASS, GimpToolCompass))
+#define GIMP_TOOL_COMPASS_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_COMPASS, GimpToolCompassClass))
+#define GIMP_IS_TOOL_COMPASS(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_COMPASS))
+#define GIMP_IS_TOOL_COMPASS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_COMPASS))
+#define GIMP_TOOL_COMPASS_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_COMPASS, GimpToolCompassClass))
+
+
+typedef struct _GimpToolCompass        GimpToolCompass;
+typedef struct _GimpToolCompassPrivate GimpToolCompassPrivate;
+typedef struct _GimpToolCompassClass   GimpToolCompassClass;
+
+struct _GimpToolCompass
+{
+  GimpToolWidget          parent_instance;
+
+  GimpToolCompassPrivate *private;
+};
+
+struct _GimpToolCompassClass
+{
+  GimpToolWidgetClass  parent_class;
+
+  void (* create_guides) (GimpToolCompass *compass,
+                          gint             x,
+                          gint             y,
+                          gboolean         horizontal,
+                          gboolean         vertical);
+};
+
+
+GType            gimp_tool_compass_get_type (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_compass_new      (GimpDisplayShell       *shell,
+                                             GimpCompassOrientation  orinetation,
+                                             gint                    n_points,
+                                             gint                    x1,
+                                             gint                    y1,
+                                             gint                    x2,
+                                             gint                    y2,
+                                             gint                    y3,
+                                             gint                    x3);
+
+
+#endif /* __GIMP_TOOL_COMPASS_H__ */
diff --git a/app/display/gimptooldialog.c b/app/display/gimptooldialog.c
new file mode 100644
index 0000000..e0bc082
--- /dev/null
+++ b/app/display/gimptooldialog.c
@@ -0,0 +1,208 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptooldialog.c
+ * Copyright (C) 2003  Sven Neumann <sven@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimpobject.h"
+#include "core/gimptoolinfo.h"
+
+#include "widgets/gimpdialogfactory.h"
+
+#include "gimpdisplayshell.h"
+#include "gimptooldialog.h"
+
+
+typedef struct _GimpToolDialogPrivate GimpToolDialogPrivate;
+
+struct _GimpToolDialogPrivate
+{
+  GimpDisplayShell *shell;
+};
+
+#define GET_PRIVATE(dialog) ((GimpToolDialogPrivate *) gimp_tool_dialog_get_instance_private ((GimpToolDialog *) (dialog)))
+
+
+static void   gimp_tool_dialog_dispose     (GObject          *object);
+
+static void   gimp_tool_dialog_shell_unmap (GimpDisplayShell *shell,
+                                            GimpToolDialog   *dialog);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolDialog, gimp_tool_dialog,
+                            GIMP_TYPE_VIEWABLE_DIALOG)
+
+
+static void
+gimp_tool_dialog_class_init (GimpToolDialogClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gimp_tool_dialog_dispose;
+}
+
+static void
+gimp_tool_dialog_init (GimpToolDialog *dialog)
+{
+}
+
+static void
+gimp_tool_dialog_dispose (GObject *object)
+{
+  GimpToolDialogPrivate *private = GET_PRIVATE (object);
+
+  if (private->shell)
+    {
+      g_object_remove_weak_pointer (G_OBJECT (private->shell),
+                                    (gpointer) &private->shell);
+      private->shell = NULL;
+    }
+
+  G_OBJECT_CLASS (gimp_tool_dialog_parent_class)->dispose (object);
+}
+
+
+/**
+ * gimp_tool_dialog_new:
+ * @tool_info: a #GimpToolInfo
+ * @desc:      a string to use in the dialog header or %NULL to use the help
+ *             field from #GimpToolInfo
+ * @...:       a %NULL-terminated valist of button parameters as described in
+ *             gtk_dialog_new_with_buttons().
+ *
+ * This function conveniently creates a #GimpViewableDialog using the
+ * information stored in @tool_info. It also registers the tool with
+ * the "toplevel" dialog factory.
+ *
+ * Return value: a new #GimpViewableDialog
+ **/
+GtkWidget *
+gimp_tool_dialog_new (GimpToolInfo *tool_info,
+                      GdkScreen    *screen,
+                      gint          monitor,
+                      const gchar  *title,
+                      const gchar  *description,
+                      const gchar  *icon_name,
+                      const gchar  *help_id,
+                      ...)
+{
+  GtkWidget *dialog;
+  gchar     *identifier;
+  va_list    args;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_INFO (tool_info), NULL);
+
+  if (! title)
+    title = tool_info->label;
+
+  if (! description)
+    description = tool_info->tooltip;
+
+  if (! help_id)
+    help_id = tool_info->help_id;
+
+  if (! icon_name)
+    icon_name = gimp_viewable_get_icon_name (GIMP_VIEWABLE (tool_info));
+
+  dialog = g_object_new (GIMP_TYPE_TOOL_DIALOG,
+                         "title",        title,
+                         "role",         gimp_object_get_name (tool_info),
+                         "description",  description,
+                         "icon-name",    icon_name,
+                         "help-func",    gimp_standard_help_func,
+                         "help-id",      help_id,
+                         NULL);
+
+  va_start (args, help_id);
+  gimp_dialog_add_buttons_valist (GIMP_DIALOG (dialog), args);
+  va_end (args);
+
+  identifier = g_strconcat (gimp_object_get_name (tool_info), "-dialog", NULL);
+
+  gimp_dialog_factory_add_foreign (gimp_dialog_factory_get_singleton (),
+                                   identifier,
+                                   dialog,
+                                   screen,
+                                   monitor);
+
+  g_free (identifier);
+
+  return dialog;
+}
+
+void
+gimp_tool_dialog_set_shell (GimpToolDialog   *tool_dialog,
+                            GimpDisplayShell *shell)
+{
+  GimpToolDialogPrivate *private = GET_PRIVATE (tool_dialog);
+
+  g_return_if_fail (GIMP_IS_TOOL_DIALOG (tool_dialog));
+  g_return_if_fail (shell == NULL || GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell == private->shell)
+    return;
+
+  if (private->shell)
+    {
+      g_object_remove_weak_pointer (G_OBJECT (private->shell),
+                                    (gpointer) &private->shell);
+      g_signal_handlers_disconnect_by_func (private->shell,
+                                            gimp_tool_dialog_shell_unmap,
+                                            tool_dialog);
+
+      gtk_window_set_transient_for (GTK_WINDOW (tool_dialog), NULL);
+    }
+
+  private->shell = shell;
+
+  if (private->shell)
+    {
+      GtkWidget *toplevel = gtk_widget_get_toplevel (GTK_WIDGET (shell));
+
+      gtk_window_set_transient_for (GTK_WINDOW (tool_dialog),
+                                    GTK_WINDOW (toplevel));
+
+      g_signal_connect_object (private->shell, "unmap",
+                               G_CALLBACK (gimp_tool_dialog_shell_unmap),
+                               tool_dialog, 0);
+      g_object_add_weak_pointer (G_OBJECT (private->shell),
+                                 (gpointer) &private->shell);
+    }
+}
+
+
+/*  private functions  */
+
+static void
+gimp_tool_dialog_shell_unmap (GimpDisplayShell *shell,
+                              GimpToolDialog   *dialog)
+{
+  /*  the dialog being mapped while the shell is being unmapped
+   *  happens when switching images in GimpImageWindow
+   */
+  if (gtk_widget_get_mapped (GTK_WIDGET (dialog)))
+    g_signal_emit_by_name (dialog, "close");
+}
diff --git a/app/display/gimptooldialog.h b/app/display/gimptooldialog.h
new file mode 100644
index 0000000..13f437d
--- /dev/null
+++ b/app/display/gimptooldialog.h
@@ -0,0 +1,58 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptooldialog.h
+ * Copyright (C) 2003  Sven Neumann <sven@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_DIALOG_H__
+#define __GIMP_TOOL_DIALOG_H__
+
+#include "widgets/gimpviewabledialog.h"
+
+
+#define GIMP_TYPE_TOOL_DIALOG            (gimp_tool_dialog_get_type ())
+#define GIMP_TOOL_DIALOG(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_DIALOG, GimpToolDialog))
+#define GIMP_TOOL_DIALOG_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_DIALOG, GimpToolDialogClass))
+#define GIMP_IS_TOOL_DIALOG(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_DIALOG))
+#define GIMP_IS_TOOL_DIALOG_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_DIALOG))
+#define GIMP_TOOL_DIALOG_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_DIALOG, GimpToolDialogClass))
+
+
+typedef struct _GimpViewableDialogClass GimpToolDialogClass;
+
+struct _GimpToolDialog
+{
+  GimpViewableDialog  parent_instance;
+};
+
+
+GType       gimp_tool_dialog_get_type (void) G_GNUC_CONST;
+
+GtkWidget * gimp_tool_dialog_new       (GimpToolInfo     *tool_info,
+                                        GdkScreen        *screen,
+                                        gint              monitor,
+                                        const gchar      *title,
+                                        const gchar      *description,
+                                        const gchar      *icon_name,
+                                        const gchar      *help_id,
+                                        ...) G_GNUC_NULL_TERMINATED;
+
+void        gimp_tool_dialog_set_shell (GimpToolDialog   *tool_dialog,
+                                        GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_TOOL_DIALOG_H__ */
diff --git a/app/display/gimptoolfocus.c b/app/display/gimptoolfocus.c
new file mode 100644
index 0000000..a607f06
--- /dev/null
+++ b/app/display/gimptoolfocus.c
@@ -0,0 +1,1209 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolfocus.c
+ * Copyright (C) 2020 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvasgroup.h"
+#include "gimpcanvashandle.h"
+#include "gimpcanvaslimit.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimpdisplayshell-utils.h"
+#include "gimptoolfocus.h"
+
+#include "gimp-intl.h"
+
+
+#define HANDLE_SIZE   12.0
+#define SNAP_DISTANCE 12.0
+
+#define EPSILON       1e-6
+
+
+enum
+{
+  PROP_0,
+  PROP_TYPE,
+  PROP_X,
+  PROP_Y,
+  PROP_RADIUS,
+  PROP_ASPECT_RATIO,
+  PROP_ANGLE,
+  PROP_INNER_LIMIT,
+  PROP_MIDPOINT
+};
+
+enum
+{
+  LIMIT_OUTER,
+  LIMIT_INNER,
+  LIMIT_MIDDLE,
+
+  N_LIMITS
+};
+
+
+typedef enum
+{
+  HOVER_NONE,
+  HOVER_LIMIT,
+  HOVER_HANDLE,
+  HOVER_MOVE,
+  HOVER_ROTATE
+} Hover;
+
+
+typedef struct
+{
+  GimpCanvasItem *item;
+
+  GtkOrientation  orientation;
+  GimpVector2     dir;
+} GimpToolFocusHandle;
+
+typedef struct
+{
+  GimpCanvasGroup     *group;
+  GimpCanvasItem      *item;
+
+  gint                 n_handles;
+  GimpToolFocusHandle  handles[4];
+} GimpToolFocusLimit;
+
+struct _GimpToolFocusPrivate
+{
+  GimpLimitType       type;
+
+  gdouble             x;
+  gdouble             y;
+  gdouble             radius;
+  gdouble             aspect_ratio;
+  gdouble             angle;
+
+  gdouble             inner_limit;
+  gdouble             midpoint;
+
+  GimpToolFocusLimit  limits[N_LIMITS];
+
+  Hover               hover;
+  gint                hover_limit;
+  gint                hover_handle;
+  GimpCanvasItem     *hover_item;
+
+  GimpCanvasItem     *last_hover_item;
+
+  gdouble             saved_x;
+  gdouble             saved_y;
+  gdouble             saved_radius;
+  gdouble             saved_aspect_ratio;
+  gdouble             saved_angle;
+
+  gdouble             saved_inner_limit;
+  gdouble             saved_midpoint;
+
+  gdouble             orig_x;
+  gdouble             orig_y;
+};
+
+
+/*  local function prototypes  */
+
+static void       gimp_tool_focus_constructed      (GObject               *object);
+static void       gimp_tool_focus_set_property     (GObject               *object,
+                                                    guint                  property_id,
+                                                    const GValue          *value,
+                                                    GParamSpec            *pspec);
+static void       gimp_tool_focus_get_property     (GObject               *object,
+                                                    guint                  property_id,
+                                                    GValue                *value,
+                                                    GParamSpec            *pspec);
+
+static void       gimp_tool_focus_changed          (GimpToolWidget        *widget);
+static gint       gimp_tool_focus_button_press     (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    guint32                time,
+                                                    GdkModifierType        state,
+                                                    GimpButtonPressType    press_type);
+static void       gimp_tool_focus_button_release   (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    guint32                time,
+                                                    GdkModifierType        state,
+                                                    GimpButtonReleaseType  release_type);
+static void       gimp_tool_focus_motion           (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    guint32                time,
+                                                    GdkModifierType        state);
+static GimpHit    gimp_tool_focus_hit              (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    GdkModifierType        state,
+                                                    gboolean               proximity);
+static void       gimp_tool_focus_hover            (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    GdkModifierType        state,
+                                                    gboolean               proximity);
+static void       gimp_tool_focus_leave_notify     (GimpToolWidget        *widget);
+static void       gimp_tool_focus_motion_modifier  (GimpToolWidget        *widget,
+                                                    GdkModifierType        key,
+                                                    gboolean               press,
+                                                    GdkModifierType        state);
+static void       gimp_tool_focus_hover_modifier   (GimpToolWidget        *widget,
+                                                    GdkModifierType        key,
+                                                    gboolean               press,
+                                                    GdkModifierType        state);
+static gboolean   gimp_tool_focus_get_cursor       (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    GdkModifierType        state,
+                                                    GimpCursorType        *cursor,
+                                                    GimpToolCursorType    *tool_cursor,
+                                                    GimpCursorModifier    *modifier);
+
+static void       gimp_tool_focus_update_hover     (GimpToolFocus         *focus,
+                                                    const GimpCoords      *coords,
+                                                    gboolean               proximity);
+
+static void       gimp_tool_focus_update_highlight (GimpToolFocus         *focus);
+static void       gimp_tool_focus_update_status    (GimpToolFocus         *focus,
+                                                    GdkModifierType        state);
+
+static void       gimp_tool_focus_save             (GimpToolFocus         *focus);
+static void       gimp_tool_focus_restore          (GimpToolFocus         *focus);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolFocus, gimp_tool_focus,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_focus_parent_class
+
+
+/*  private functions  */
+
+static void
+gimp_tool_focus_class_init (GimpToolFocusClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_focus_constructed;
+  object_class->set_property    = gimp_tool_focus_set_property;
+  object_class->get_property    = gimp_tool_focus_get_property;
+
+  widget_class->changed         = gimp_tool_focus_changed;
+  widget_class->button_press    = gimp_tool_focus_button_press;
+  widget_class->button_release  = gimp_tool_focus_button_release;
+  widget_class->motion          = gimp_tool_focus_motion;
+  widget_class->hit             = gimp_tool_focus_hit;
+  widget_class->hover           = gimp_tool_focus_hover;
+  widget_class->leave_notify    = gimp_tool_focus_leave_notify;
+  widget_class->motion_modifier = gimp_tool_focus_motion_modifier;
+  widget_class->hover_modifier  = gimp_tool_focus_hover_modifier;
+  widget_class->get_cursor      = gimp_tool_focus_get_cursor;
+  widget_class->update_on_scale = TRUE;
+
+  g_object_class_install_property (object_class, PROP_TYPE,
+                                   g_param_spec_enum ("type", NULL, NULL,
+                                                      GIMP_TYPE_LIMIT_TYPE,
+                                                      GIMP_LIMIT_CIRCLE,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_RADIUS,
+                                   g_param_spec_double ("radius", NULL, NULL,
+                                                        0.0,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ASPECT_RATIO,
+                                   g_param_spec_double ("aspect-ratio", NULL, NULL,
+                                                        -1.0,
+                                                        +1.0,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ANGLE,
+                                   g_param_spec_double ("angle", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_INNER_LIMIT,
+                                   g_param_spec_double ("inner-limit", NULL, NULL,
+                                                        0.0,
+                                                        1.0,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_MIDPOINT,
+                                   g_param_spec_double ("midpoint", NULL, NULL,
+                                                        0.0,
+                                                        1.0,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_focus_init (GimpToolFocus *focus)
+{
+  GimpToolFocusPrivate *priv;
+
+  priv = gimp_tool_focus_get_instance_private (focus);
+
+  focus->priv = priv;
+
+  priv->hover = HOVER_NONE;
+}
+
+static void
+gimp_tool_focus_constructed (GObject *object)
+{
+  GimpToolFocus        *focus  = GIMP_TOOL_FOCUS (object);
+  GimpToolWidget       *widget = GIMP_TOOL_WIDGET (object);
+  GimpToolFocusPrivate *priv   = focus->priv;
+  gint                  i;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  for (i = N_LIMITS - 1; i >= 0; i--)
+    {
+      priv->limits[i].group = gimp_tool_widget_add_group (widget);
+
+      gimp_tool_widget_push_group (widget, priv->limits[i].group);
+
+      priv->limits[i].item = gimp_tool_widget_add_limit (
+        widget,
+        GIMP_LIMIT_CIRCLE,
+        0.0, 0.0,
+        0.0,
+        1.0,
+        0.0,
+        /* dashed = */ i == LIMIT_MIDDLE);
+
+      if (i == LIMIT_OUTER || i == LIMIT_INNER)
+        {
+          gint j;
+
+          priv->limits[i].n_handles = 4;
+
+          for (j = priv->limits[i].n_handles - 1; j >= 0; j--)
+            {
+              priv->limits[i].handles[j].item = gimp_tool_widget_add_handle (
+                widget,
+                GIMP_HANDLE_FILLED_CIRCLE,
+                0.0, 0.0, HANDLE_SIZE, HANDLE_SIZE,
+                GIMP_HANDLE_ANCHOR_CENTER);
+
+              priv->limits[i].handles[j].orientation =
+                j % 2 == 0 ? GTK_ORIENTATION_HORIZONTAL :
+                             GTK_ORIENTATION_VERTICAL;
+
+              priv->limits[i].handles[j].dir.x = cos (j * G_PI / 2.0);
+              priv->limits[i].handles[j].dir.y = sin (j * G_PI / 2.0);
+            }
+        }
+
+      gimp_tool_widget_pop_group (widget);
+    }
+
+  gimp_tool_focus_changed (widget);
+}
+
+static void
+gimp_tool_focus_set_property (GObject      *object,
+                              guint         property_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
+{
+  GimpToolFocus        *focus = GIMP_TOOL_FOCUS (object);
+  GimpToolFocusPrivate *priv  = focus->priv;
+
+  switch (property_id)
+    {
+    case PROP_TYPE:
+      priv->type = g_value_get_enum (value);
+      break;
+
+    case PROP_X:
+      priv->x = g_value_get_double (value);
+      break;
+
+    case PROP_Y:
+      priv->y = g_value_get_double (value);
+      break;
+
+    case PROP_RADIUS:
+      priv->radius = g_value_get_double (value);
+      break;
+
+    case PROP_ASPECT_RATIO:
+      priv->aspect_ratio = g_value_get_double (value);
+      break;
+
+    case PROP_ANGLE:
+      priv->angle = g_value_get_double (value);
+      break;
+
+    case PROP_INNER_LIMIT:
+      priv->inner_limit = g_value_get_double (value);
+      break;
+
+    case PROP_MIDPOINT:
+      priv->midpoint = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_focus_get_property (GObject    *object,
+                              guint       property_id,
+                              GValue     *value,
+                              GParamSpec *pspec)
+{
+  GimpToolFocus        *focus = GIMP_TOOL_FOCUS (object);
+  GimpToolFocusPrivate *priv  = focus->priv;
+
+  switch (property_id)
+    {
+    case PROP_TYPE:
+      g_value_set_enum (value, priv->type);
+      break;
+
+    case PROP_X:
+      g_value_set_double (value, priv->x);
+      break;
+
+    case PROP_Y:
+      g_value_set_double (value, priv->y);
+      break;
+
+    case PROP_RADIUS:
+      g_value_set_double (value, priv->radius);
+      break;
+
+    case PROP_ASPECT_RATIO:
+      g_value_set_double (value, priv->aspect_ratio);
+      break;
+
+    case PROP_ANGLE:
+      g_value_set_double (value, priv->angle);
+      break;
+
+    case PROP_INNER_LIMIT:
+      g_value_set_double (value, priv->inner_limit);
+      break;
+
+    case PROP_MIDPOINT:
+      g_value_set_double (value, priv->midpoint);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_focus_changed (GimpToolWidget *widget)
+{
+  GimpToolFocus        *focus = GIMP_TOOL_FOCUS (widget);
+  GimpToolFocusPrivate *priv  = focus->priv;
+  gint                  i;
+
+  for (i = 0; i < N_LIMITS; i++)
+    {
+      gimp_canvas_item_begin_change (priv->limits[i].item);
+
+      g_object_set (priv->limits[i].item,
+                    "type",         priv->type,
+                    "x",            priv->x,
+                    "y",            priv->y,
+                    "aspect-ratio", priv->aspect_ratio,
+                    "angle",        priv->angle,
+                    NULL);
+    }
+
+  g_object_set (priv->limits[LIMIT_OUTER].item,
+                "radius", priv->radius,
+                NULL);
+
+  g_object_set (priv->limits[LIMIT_INNER].item,
+                "radius", priv->radius * priv->inner_limit,
+                NULL);
+
+  g_object_set (priv->limits[LIMIT_MIDDLE].item,
+                "radius", priv->radius * (priv->inner_limit         +
+                                          (1.0 - priv->inner_limit) *
+                                          priv->midpoint),
+                NULL);
+
+  for (i = 0; i < N_LIMITS; i++)
+    {
+      gdouble rx, ry;
+      gdouble max_r = 0.0;
+      gint    j;
+
+      gimp_canvas_limit_get_radii (GIMP_CANVAS_LIMIT (priv->limits[i].item),
+                                   &rx, &ry);
+
+      for (j = 0; j < priv->limits[i].n_handles; j++)
+        {
+          GimpVector2 p = priv->limits[i].handles[j].dir;
+          gdouble     r;
+
+          p.x *= rx;
+          p.y *= ry;
+
+          gimp_vector2_rotate (&p, -priv->angle);
+
+          p.x += priv->x;
+          p.y += priv->y;
+
+          gimp_canvas_handle_set_position (priv->limits[i].handles[j].item,
+                                           p.x, p.y);
+
+          r = gimp_canvas_item_transform_distance (
+            priv->limits[i].handles[j].item,
+            priv->x, priv->y,
+            p.x,     p.y);
+
+          max_r = MAX (max_r, r);
+        }
+
+      for (j = 0; j < priv->limits[i].n_handles; j++)
+        {
+          gimp_canvas_item_set_visible (priv->limits[i].handles[j].item,
+                                        priv->type != GIMP_LIMIT_HORIZONTAL &&
+                                        priv->type != GIMP_LIMIT_VERTICAL   &&
+                                        max_r >= 1.5 * HANDLE_SIZE);
+        }
+
+      gimp_canvas_item_end_change (priv->limits[i].item);
+    }
+}
+
+static gint
+gimp_tool_focus_button_press (GimpToolWidget      *widget,
+                              const GimpCoords    *coords,
+                              guint32              time,
+                              GdkModifierType      state,
+                              GimpButtonPressType  press_type)
+{
+  GimpToolFocus        *focus = GIMP_TOOL_FOCUS (widget);
+  GimpToolFocusPrivate *priv  = focus->priv;
+
+  if (press_type == GIMP_BUTTON_PRESS_NORMAL)
+    {
+      gimp_tool_focus_save (focus);
+
+      priv->orig_x = coords->x;
+      priv->orig_y = coords->y;
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_tool_focus_button_release (GimpToolWidget        *widget,
+                                const GimpCoords      *coords,
+                                guint32                time,
+                                GdkModifierType        state,
+                                GimpButtonReleaseType  release_type)
+{
+  GimpToolFocus *focus = GIMP_TOOL_FOCUS (widget);
+
+  if (release_type == GIMP_BUTTON_RELEASE_CANCEL)
+    gimp_tool_focus_restore (focus);
+}
+
+static void
+gimp_tool_focus_motion (GimpToolWidget   *widget,
+                        const GimpCoords *coords,
+                        guint32           time,
+                        GdkModifierType   state)
+{
+  GimpToolFocus        *focus = GIMP_TOOL_FOCUS (widget);
+  GimpToolFocusPrivate *priv  = focus->priv;
+  GimpDisplayShell     *shell = gimp_tool_widget_get_shell (widget);
+  gboolean              extend;
+  gboolean              constrain;
+
+  extend    = state & gimp_get_extend_selection_mask ();
+  constrain = state & gimp_get_constrain_behavior_mask ();
+
+  switch (priv->hover)
+    {
+    case HOVER_NONE:
+      break;
+
+    case HOVER_LIMIT:
+      {
+        GimpCanvasItem *limit = priv->limits[priv->hover_limit].item;
+        gdouble         radius;
+        gdouble         outer_radius;
+        gdouble         inner_radius;
+        gdouble         x,  y;
+        gdouble         cx, cy;
+
+        x = coords->x;
+        y = coords->y;
+
+        gimp_canvas_limit_center_point (GIMP_CANVAS_LIMIT (limit),
+                                        x,   y,
+                                        &cx, &cy);
+
+        if (gimp_canvas_item_transform_distance (limit,
+                                                 x,  y,
+                                                 cx, cy) <= SNAP_DISTANCE)
+          {
+            x = cx;
+            y = cy;
+          }
+
+        if (fabs (fabs (priv->aspect_ratio) - 1.0) <= EPSILON)
+          {
+            if (priv->radius <= EPSILON)
+              {
+                g_object_set (focus,
+                              "aspect-ratio", 0.0,
+                              NULL);
+              }
+            else
+              {
+                break;
+              }
+          }
+
+        radius = gimp_canvas_limit_boundary_radius (GIMP_CANVAS_LIMIT (limit),
+                                                    x, y);
+
+        outer_radius = priv->radius;
+        inner_radius = priv->radius * priv->inner_limit;
+
+        switch (priv->hover_limit)
+          {
+          case LIMIT_OUTER:
+            {
+              outer_radius = radius;
+
+              if (extend)
+                inner_radius = priv->inner_limit * radius;
+              else
+                outer_radius = MAX (outer_radius, inner_radius);
+            }
+            break;
+
+          case LIMIT_INNER:
+            {
+              inner_radius = radius;
+
+              if (extend)
+                {
+                  if (priv->inner_limit > EPSILON)
+                    outer_radius = inner_radius / priv->inner_limit;
+                  else
+                    inner_radius = 0.0;
+                }
+              else
+                {
+                  inner_radius = MIN (inner_radius, outer_radius);
+                }
+            }
+            break;
+
+          case LIMIT_MIDDLE:
+            {
+              if (extend)
+                {
+                  if (priv->inner_limit > EPSILON || priv->midpoint > EPSILON)
+                    {
+                      outer_radius = radius / (priv->inner_limit         +
+                                               (1.0 - priv->inner_limit) *
+                                               priv->midpoint);
+                      inner_radius = priv->inner_limit * outer_radius;
+                    }
+                  else
+                    {
+                      radius = 0.0;
+                    }
+                }
+              else
+                {
+                  radius = CLAMP (radius, inner_radius, outer_radius);
+                }
+
+              if (fabs (outer_radius - inner_radius) > EPSILON)
+                {
+                  g_object_set (focus,
+                                "midpoint", MAX ((radius       - inner_radius) /
+                                                 (outer_radius - inner_radius),
+                                                 0.0),
+                                NULL);
+                }
+            }
+            break;
+          }
+
+        g_object_set (focus,
+                      "radius", outer_radius,
+                      NULL);
+
+        if (outer_radius > EPSILON)
+          {
+            g_object_set (focus,
+                          "inner-limit", inner_radius / outer_radius,
+                          NULL);
+          }
+      }
+      break;
+
+    case HOVER_HANDLE:
+      {
+        GimpToolFocusHandle *handle;
+        GimpVector2          e;
+        GimpVector2          s;
+        GimpVector2          p;
+        gdouble              rx, ry;
+        gdouble              r;
+
+        handle = &priv->limits[priv->hover_limit].handles[priv->hover_handle];
+
+        e = handle->dir;
+
+        gimp_vector2_rotate (&e, -priv->angle);
+
+        s = e;
+
+        gimp_canvas_limit_get_radii (
+          GIMP_CANVAS_LIMIT (priv->limits[priv->hover_limit].item),
+          &rx, &ry);
+
+        if (handle->orientation == GTK_ORIENTATION_HORIZONTAL)
+          gimp_vector2_mul (&s, ry);
+        else
+          gimp_vector2_mul (&s, rx);
+
+        p.x = coords->x - priv->x;
+        p.y = coords->y - priv->y;
+
+        r = gimp_vector2_inner_product (&p, &e);
+        r = MAX (r, 0.0);
+
+        p = e;
+
+        gimp_vector2_mul (&p, r);
+
+        if (extend)
+          {
+            if (handle->orientation == GTK_ORIENTATION_HORIZONTAL)
+              {
+                if (rx <= EPSILON && ry > EPSILON)
+                  break;
+
+                ry = r * (1.0 - priv->aspect_ratio);
+              }
+            else
+              {
+                if (ry <= EPSILON && rx > EPSILON)
+                  break;
+
+                rx = r * (1.0 + priv->aspect_ratio);
+              }
+          }
+        else
+          {
+            if (gimp_canvas_item_transform_distance (
+                  priv->limits[priv->hover_limit].item,
+                  s.x, s.y,
+                  p.x, p.y) <= SNAP_DISTANCE * 0.75)
+              {
+                if (handle->orientation == GTK_ORIENTATION_HORIZONTAL)
+                  r = ry;
+                else
+                  r = rx;
+              }
+          }
+
+        if (handle->orientation == GTK_ORIENTATION_HORIZONTAL)
+          rx = r;
+        else
+          ry = r;
+
+        r = MAX (rx, ry);
+
+        if (priv->hover_limit == LIMIT_INNER)
+          r /= priv->inner_limit;
+
+        g_object_set (focus,
+                      "radius", r,
+                      NULL);
+
+        if (! extend)
+          {
+            gdouble aspect_ratio;
+
+            if (fabs (rx - ry) <= EPSILON)
+              aspect_ratio = 0.0;
+            else if (rx > ry)
+              aspect_ratio = 1.0 - ry / rx;
+            else
+              aspect_ratio = rx / ry - 1.0;
+
+            g_object_set (focus,
+                          "aspect-ratio", aspect_ratio,
+                          NULL);
+          }
+      }
+      break;
+
+    case HOVER_MOVE:
+      g_object_set (focus,
+                    "x", priv->saved_x + (coords->x - priv->orig_x),
+                    "y", priv->saved_y + (coords->y - priv->orig_y),
+                    NULL);
+      break;
+
+    case HOVER_ROTATE:
+      {
+        gdouble angle;
+        gdouble orig_angle;
+
+        angle      = atan2 (coords->y    - priv->y, coords->x    - priv->x);
+        orig_angle = atan2 (priv->orig_y - priv->y, priv->orig_x - priv->x);
+
+        angle = priv->saved_angle + (angle - orig_angle);
+
+        if (constrain)
+          angle = gimp_display_shell_constrain_angle (shell, angle, 12);
+
+        g_object_set (focus,
+                      "angle", angle,
+                      NULL);
+      }
+      break;
+    }
+}
+
+static GimpHit
+gimp_tool_focus_hit (GimpToolWidget   *widget,
+                     const GimpCoords *coords,
+                     GdkModifierType   state,
+                     gboolean          proximity)
+{
+  GimpToolFocus        *focus = GIMP_TOOL_FOCUS (widget);
+  GimpToolFocusPrivate *priv  = focus->priv;
+
+  gimp_tool_focus_update_hover (focus, coords, proximity);
+
+  switch (priv->hover)
+    {
+    case HOVER_NONE:
+      return GIMP_HIT_NONE;
+
+    case HOVER_LIMIT:
+    case HOVER_HANDLE:
+      return GIMP_HIT_DIRECT;
+
+    case HOVER_MOVE:
+    case HOVER_ROTATE:
+      return GIMP_HIT_INDIRECT;
+    }
+
+  g_return_val_if_reached (GIMP_HIT_NONE);
+}
+
+static void
+gimp_tool_focus_hover (GimpToolWidget   *widget,
+                       const GimpCoords *coords,
+                       GdkModifierType   state,
+                       gboolean          proximity)
+{
+  GimpToolFocus *focus = GIMP_TOOL_FOCUS (widget);
+
+  gimp_tool_focus_update_hover (focus, coords, proximity);
+
+  gimp_tool_focus_update_highlight (focus);
+  gimp_tool_focus_update_status    (focus, state);
+}
+
+static void
+gimp_tool_focus_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolFocus *focus = GIMP_TOOL_FOCUS (widget);
+
+  gimp_tool_focus_update_hover (focus, NULL, FALSE);
+
+  gimp_tool_focus_update_highlight (focus);
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
+}
+
+static void
+gimp_tool_focus_motion_modifier (GimpToolWidget  *widget,
+                                 GdkModifierType  key,
+                                 gboolean         press,
+                                 GdkModifierType  state)
+{
+  GimpToolFocus *focus = GIMP_TOOL_FOCUS (widget);
+
+  gimp_tool_focus_update_status (focus, state);
+}
+
+static void
+gimp_tool_focus_hover_modifier (GimpToolWidget  *widget,
+                                GdkModifierType  key,
+                                gboolean         press,
+                                GdkModifierType  state)
+{
+  GimpToolFocus *focus = GIMP_TOOL_FOCUS (widget);
+
+  gimp_tool_focus_update_status (focus, state);
+}
+
+static gboolean
+gimp_tool_focus_get_cursor (GimpToolWidget     *widget,
+                            const GimpCoords   *coords,
+                            GdkModifierType     state,
+                            GimpCursorType     *cursor,
+                            GimpToolCursorType *tool_cursor,
+                            GimpCursorModifier *modifier)
+{
+  GimpToolFocus        *focus = GIMP_TOOL_FOCUS (widget);
+  GimpToolFocusPrivate *priv  = focus->priv;
+
+  switch (priv->hover)
+    {
+    case HOVER_NONE:
+      return FALSE;
+
+    case HOVER_LIMIT:
+    case HOVER_HANDLE:
+      *modifier = GIMP_CURSOR_MODIFIER_RESIZE;
+      return TRUE;
+
+    case HOVER_MOVE:
+      *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+      return TRUE;
+
+    case HOVER_ROTATE:
+      *modifier = GIMP_CURSOR_MODIFIER_ROTATE;
+      return TRUE;
+    }
+
+  g_return_val_if_reached (FALSE);
+}
+
+static void
+gimp_tool_focus_update_hover (GimpToolFocus    *focus,
+                              const GimpCoords *coords,
+                              gboolean          proximity)
+{
+  GimpToolFocusPrivate *priv            = focus->priv;
+  gdouble               min_handle_dist = HANDLE_SIZE;
+  gint                  i;
+
+  priv->hover      = HOVER_NONE;
+  priv->hover_item = NULL;
+
+  if (! proximity)
+    return;
+
+  for (i = 0; i < N_LIMITS; i++)
+    {
+      gint j;
+
+      for (j = 0; j < priv->limits[i].n_handles; j++)
+        {
+          GimpCanvasItem *handle = priv->limits[i].handles[j].item;
+
+          if (gimp_canvas_item_get_visible (handle))
+            {
+              gdouble x, y;
+              gdouble dist;
+
+              g_object_get (handle,
+                            "x", &x,
+                            "y", &y,
+                            NULL);
+
+              dist = gimp_canvas_item_transform_distance (handle,
+                                                          x,         y,
+                                                          coords->x, coords->y);
+
+              if (dist < min_handle_dist)
+                {
+                  min_handle_dist = dist;
+
+                  priv->hover        = HOVER_HANDLE;
+                  priv->hover_limit  = i;
+                  priv->hover_handle = j;
+                  priv->hover_item   = handle;
+                }
+            }
+        }
+    }
+
+  if (priv->hover != HOVER_NONE)
+    return;
+
+  if (  gimp_canvas_limit_is_inside (
+          GIMP_CANVAS_LIMIT (priv->limits[LIMIT_OUTER].item),
+          coords->x, coords->y) &&
+      ! gimp_canvas_limit_is_inside (
+          GIMP_CANVAS_LIMIT (priv->limits[LIMIT_INNER].item),
+          coords->x, coords->y))
+    {
+      if (gimp_canvas_item_hit (priv->limits[LIMIT_MIDDLE].item,
+                                coords->x, coords->y))
+        {
+          priv->hover       = HOVER_LIMIT;
+          priv->hover_limit = LIMIT_MIDDLE;
+          priv->hover_item  = priv->limits[LIMIT_MIDDLE].item;
+
+          return;
+        }
+    }
+
+  if (! gimp_canvas_limit_is_inside (
+          GIMP_CANVAS_LIMIT (priv->limits[LIMIT_INNER].item),
+          coords->x, coords->y))
+    {
+      if (gimp_canvas_item_hit (priv->limits[LIMIT_OUTER].item,
+                                coords->x, coords->y))
+        {
+          priv->hover       = HOVER_LIMIT;
+          priv->hover_limit = LIMIT_OUTER;
+          priv->hover_item  = priv->limits[LIMIT_OUTER].item;
+
+          return;
+        }
+    }
+
+  if (gimp_canvas_item_hit (priv->limits[LIMIT_INNER].item,
+                            coords->x, coords->y))
+    {
+      priv->hover       = HOVER_LIMIT;
+      priv->hover_limit = LIMIT_INNER;
+      priv->hover_item  = priv->limits[LIMIT_INNER].item;
+
+      return;
+    }
+
+  if (gimp_canvas_limit_is_inside (
+        GIMP_CANVAS_LIMIT (priv->limits[LIMIT_OUTER].item),
+        coords->x, coords->y))
+    {
+      priv->hover = HOVER_MOVE;
+    }
+  else
+    {
+      priv->hover = HOVER_ROTATE;
+    }
+}
+
+static void
+gimp_tool_focus_update_highlight (GimpToolFocus *focus)
+{
+  GimpToolWidget       *widget = GIMP_TOOL_WIDGET (focus);
+  GimpToolFocusPrivate *priv   = focus->priv;
+  gint                  i;
+
+  if (priv->hover_item == priv->last_hover_item)
+    return;
+
+  if (priv->last_hover_item)
+    gimp_canvas_item_set_highlight (priv->last_hover_item, FALSE);
+
+  #define RAISE_ITEM(item)                           \
+    G_STMT_START                                     \
+      {                                              \
+        g_object_ref (item);                         \
+                                                     \
+        gimp_tool_widget_remove_item (widget, item); \
+        gimp_tool_widget_add_item    (widget, item); \
+                                                     \
+        g_object_unref (item);                       \
+      }                                              \
+    G_STMT_END
+
+  for (i = N_LIMITS - 1; i >= 0; i--)
+    RAISE_ITEM (GIMP_CANVAS_ITEM (priv->limits[i].group));
+
+  if (priv->hover_item)
+    {
+      gimp_canvas_item_set_highlight (priv->hover_item, TRUE);
+
+      RAISE_ITEM (GIMP_CANVAS_ITEM (priv->limits[priv->hover_limit].group));
+    }
+
+  #undef RAISE_ITEM
+
+  priv->last_hover_item = priv->hover_item;
+}
+
+static void
+gimp_tool_focus_update_status (GimpToolFocus   *focus,
+                               GdkModifierType  state)
+{
+  GimpToolFocusPrivate *priv                    = focus->priv;
+  GdkModifierType       state_mask              = 0;
+  const gchar          *message                 = NULL;
+  const gchar          *extend_selection_format = NULL;
+  const gchar          *toggle_behavior_format  = NULL;
+  gchar                *status;
+
+  switch (priv->hover)
+    {
+    case HOVER_NONE:
+      break;
+
+    case HOVER_LIMIT:
+      if (! (state & gimp_get_extend_selection_mask ()))
+        {
+          if (priv->hover_limit == LIMIT_MIDDLE)
+            message                = _("Click-Drag to change the midpoint");
+          else
+            message                = _("Click-Drag to resize the limit");
+
+          extend_selection_format  = _("%s to resize the focus");
+          state_mask              |= gimp_get_extend_selection_mask ();
+        }
+      else
+        {
+          message                  = _("Click-Drag to resize the focus");
+        }
+      break;
+
+    case HOVER_HANDLE:
+      if (! (state & gimp_get_extend_selection_mask ()))
+        {
+          message                  = _("Click-Drag to change the aspect ratio");
+          extend_selection_format  = _("%s to resize the focus");
+          state_mask              |= gimp_get_extend_selection_mask ();
+        }
+      else
+        {
+          message                  = _("Click-Drag to resize the focus");
+        }
+      break;
+
+    case HOVER_MOVE:
+      message                      = _("Click-Drag to move the focus");
+      break;
+
+    case HOVER_ROTATE:
+      message                      = _("Click-Drag to rotate the focus");
+      toggle_behavior_format       = _("%s for constrained angles");
+      state_mask                  |= gimp_get_constrain_behavior_mask ();
+      break;
+    }
+
+  status = gimp_suggest_modifiers (message,
+                                   ~state & state_mask,
+                                   extend_selection_format,
+                                   toggle_behavior_format,
+                                   NULL);
+
+  gimp_tool_widget_set_status (GIMP_TOOL_WIDGET (focus), status);
+
+  g_free (status);
+}
+
+static void
+gimp_tool_focus_save (GimpToolFocus *focus)
+{
+  GimpToolFocusPrivate *priv = focus->priv;
+
+  priv->saved_x            = priv->x;
+  priv->saved_y            = priv->y;
+  priv->saved_radius       = priv->radius;
+  priv->saved_aspect_ratio = priv->aspect_ratio;
+  priv->saved_angle        = priv->angle;
+
+  priv->saved_inner_limit  = priv->inner_limit;
+  priv->saved_midpoint     = priv->midpoint;
+}
+
+static void
+gimp_tool_focus_restore (GimpToolFocus *focus)
+{
+  GimpToolFocusPrivate *priv = focus->priv;
+
+  g_object_set (focus,
+                "x",            priv->saved_x,
+                "y",            priv->saved_y,
+                "radius",       priv->saved_radius,
+                "aspect-ratio", priv->saved_aspect_ratio,
+                "angle",        priv->saved_angle,
+
+                "inner_limit",  priv->saved_inner_limit,
+                "midpoint",     priv->saved_midpoint,
+
+                NULL);
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_focus_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_FOCUS,
+                       "shell", shell,
+                       NULL);
+}
diff --git a/app/display/gimptoolfocus.h b/app/display/gimptoolfocus.h
new file mode 100644
index 0000000..e2fc5bd
--- /dev/null
+++ b/app/display/gimptoolfocus.h
@@ -0,0 +1,58 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolfocus.h
+ * Copyright (C) 2020 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_FOCUS_H__
+#define __GIMP_TOOL_FOCUS_H__
+
+
+#include "gimptoolwidget.h"
+
+
+#define GIMP_TYPE_TOOL_FOCUS            (gimp_tool_focus_get_type ())
+#define GIMP_TOOL_FOCUS(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_FOCUS, GimpToolFocus))
+#define GIMP_TOOL_FOCUS_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_FOCUS, GimpToolFocusClass))
+#define GIMP_IS_TOOL_FOCUS(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_FOCUS))
+#define GIMP_IS_TOOL_FOCUS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_FOCUS))
+#define GIMP_TOOL_FOCUS_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_FOCUS, GimpToolFocusClass))
+
+
+typedef struct _GimpToolFocus        GimpToolFocus;
+typedef struct _GimpToolFocusPrivate GimpToolFocusPrivate;
+typedef struct _GimpToolFocusClass   GimpToolFocusClass;
+
+struct _GimpToolFocus
+{
+  GimpToolWidget        parent_instance;
+
+  GimpToolFocusPrivate *priv;
+};
+
+struct _GimpToolFocusClass
+{
+  GimpToolWidgetClass  parent_class;
+};
+
+
+GType            gimp_tool_focus_get_type (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_focus_new      (GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_TOOL_FOCUS_H__ */
diff --git a/app/display/gimptoolgui.c b/app/display/gimptoolgui.c
new file mode 100644
index 0000000..28c40bf
--- /dev/null
+++ b/app/display/gimptoolgui.c
@@ -0,0 +1,1037 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolgui.c
+ * Copyright (C) 2013  Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "display-types.h"
+
+#include "core/gimpcontext.h"
+#include "core/gimpmarshal.h"
+#include "core/gimptoolinfo.h"
+
+#include "widgets/gimpdialogfactory.h"
+#include "widgets/gimpoverlaybox.h"
+#include "widgets/gimpoverlaydialog.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpdisplayshell.h"
+#include "gimptooldialog.h"
+#include "gimptoolgui.h"
+
+
+enum
+{
+  RESPONSE,
+  LAST_SIGNAL
+};
+
+
+typedef struct _ResponseEntry ResponseEntry;
+
+struct _ResponseEntry
+{
+  gint      response_id;
+  gchar    *button_text;
+  gint      alternative_position;
+  gboolean  sensitive;
+};
+
+typedef struct _GimpToolGuiPrivate GimpToolGuiPrivate;
+
+struct _GimpToolGuiPrivate
+{
+  GimpToolInfo     *tool_info;
+  gchar            *title;
+  gchar            *description;
+  gchar            *icon_name;
+  gchar            *help_id;
+  GList            *response_entries;
+  gint              default_response;
+  gboolean          focus_on_map;
+
+  gboolean          overlay;
+  gboolean          auto_overlay;
+
+  GimpDisplayShell *shell;
+  GimpViewable     *viewable;
+
+  GtkWidget        *dialog;
+  GtkWidget        *vbox;
+};
+
+#define GET_PRIVATE(gui) ((GimpToolGuiPrivate *) gimp_tool_gui_get_instance_private ((GimpToolGui *) (gui)))
+
+
+static void            gimp_tool_gui_dispose           (GObject       *object);
+static void            gimp_tool_gui_finalize          (GObject       *object);
+
+static void            gimp_tool_gui_create_dialog     (GimpToolGui   *gui,
+                                                        GdkScreen     *screen,
+                                                        gint           monitor);
+static void            gimp_tool_gui_add_dialog_button (GimpToolGui   *gui,
+                                                        ResponseEntry *entry);
+static void            gimp_tool_gui_update_buttons    (GimpToolGui   *gui);
+static void            gimp_tool_gui_update_shell      (GimpToolGui   *gui);
+static void            gimp_tool_gui_update_viewable   (GimpToolGui   *gui);
+
+static void            gimp_tool_gui_dialog_response   (GtkWidget     *dialog,
+                                                        gint           response_id,
+                                                        GimpToolGui   *gui);
+static void            gimp_tool_gui_canvas_resized    (GtkWidget     *canvas,
+                                                        GtkAllocation *allocation,
+                                                        GimpToolGui   *gui);
+
+static ResponseEntry * response_entry_new              (gint           response_id,
+                                                        const gchar   *button_text);
+static void            response_entry_free             (ResponseEntry *entry);
+static ResponseEntry * response_entry_find             (GList         *entries,
+                                                        gint           response_id);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolGui, gimp_tool_gui, GIMP_TYPE_OBJECT)
+
+static guint signals[LAST_SIGNAL] = { 0, };
+
+#define parent_class gimp_tool_gui_parent_class
+
+
+static void
+gimp_tool_gui_class_init (GimpToolGuiClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose  = gimp_tool_gui_dispose;
+  object_class->finalize = gimp_tool_gui_finalize;
+
+  signals[RESPONSE] =
+    g_signal_new ("response",
+                  G_OBJECT_CLASS_TYPE (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GimpToolGuiClass, response),
+                  NULL, NULL,
+                  gimp_marshal_VOID__INT,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_INT);
+}
+
+static void
+gimp_tool_gui_init (GimpToolGui *gui)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (gui);
+
+  private->default_response = -1;
+  private->focus_on_map     = TRUE;
+
+  private->vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
+  g_object_ref_sink (private->vbox);
+}
+
+static void
+gimp_tool_gui_dispose (GObject *object)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (object);
+
+  g_clear_object (&private->tool_info);
+
+  if (private->shell)
+    gimp_tool_gui_set_shell (GIMP_TOOL_GUI (object), NULL);
+
+  if (private->viewable)
+    gimp_tool_gui_set_viewable (GIMP_TOOL_GUI (object), NULL);
+
+  g_clear_object (&private->vbox);
+
+  if (private->dialog)
+    {
+      if (gtk_widget_get_visible (private->dialog))
+        gimp_tool_gui_hide (GIMP_TOOL_GUI (object));
+
+      if (private->overlay)
+        g_object_unref (private->dialog);
+      else
+        gtk_widget_destroy (private->dialog);
+
+      private->dialog = NULL;
+    }
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_tool_gui_finalize (GObject *object)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (object);
+
+  g_clear_pointer (&private->title,       g_free);
+  g_clear_pointer (&private->description, g_free);
+  g_clear_pointer (&private->icon_name,   g_free);
+  g_clear_pointer (&private->help_id,     g_free);
+
+  if (private->response_entries)
+    {
+      g_list_free_full (private->response_entries,
+                        (GDestroyNotify) response_entry_free);
+      private->response_entries = NULL;
+    }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+
+/**
+ * gimp_tool_gui_new:
+ * @tool_info:   a #GimpToolInfo
+ * @description: a string to use in the gui header or %NULL to use the help
+ *               field from #GimpToolInfo
+ * @...:         a %NULL-terminated valist of button parameters as described in
+ *               gtk_gui_new_with_buttons().
+ *
+ * This function creates a #GimpToolGui using the information stored
+ * in @tool_info.
+ *
+ * Return value: a new #GimpToolGui
+ **/
+GimpToolGui *
+gimp_tool_gui_new (GimpToolInfo *tool_info,
+                   const gchar  *title,
+                   const gchar  *description,
+                   const gchar  *icon_name,
+                   const gchar  *help_id,
+                   GdkScreen    *screen,
+                   gint          monitor,
+                   gboolean      overlay,
+                   ...)
+{
+  GimpToolGui        *gui;
+  GimpToolGuiPrivate *private;
+  va_list             args;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_INFO (tool_info), NULL);
+
+  gui = g_object_new (GIMP_TYPE_TOOL_GUI, NULL);
+
+  private = GET_PRIVATE (gui);
+
+  if (! title)
+    title = tool_info->label;
+
+  if (! description)
+    description = tool_info->label;
+
+  if (! icon_name)
+    icon_name = gimp_viewable_get_icon_name (GIMP_VIEWABLE (tool_info));
+
+  if (! help_id)
+    help_id = tool_info->help_id;
+
+  private->tool_info   = g_object_ref (tool_info);
+  private->title       = g_strdup (title);
+  private->description = g_strdup (description);
+  private->icon_name   = g_strdup (icon_name);
+  private->help_id     = g_strdup (help_id);
+  private->overlay     = overlay;
+
+  va_start (args, overlay);
+
+  gimp_tool_gui_add_buttons_valist (gui, args);
+
+  va_end (args);
+
+  gimp_tool_gui_create_dialog (gui, screen, monitor);
+
+  return gui;
+}
+
+void
+gimp_tool_gui_set_title (GimpToolGui *gui,
+                         const gchar *title)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (title == private->title)
+    return;
+
+  g_free (private->title);
+  private->title = g_strdup (title);
+
+  if (! title)
+    title = private->tool_info->label;
+
+  g_object_set (private->dialog, "title", title, NULL);
+}
+
+void
+gimp_tool_gui_set_description (GimpToolGui *gui,
+                               const gchar *description)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (description == private->description)
+    return;
+
+  g_free (private->description);
+  private->description = g_strdup (description);
+
+  if (! description)
+    description = private->tool_info->tooltip;
+
+  if (private->overlay)
+    {
+      /* TODO */
+    }
+  else
+    {
+      g_object_set (private->dialog, "description", description, NULL);
+    }
+}
+
+void
+gimp_tool_gui_set_icon_name (GimpToolGui *gui,
+                             const gchar *icon_name)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (icon_name == private->icon_name)
+    return;
+
+  g_free (private->icon_name);
+  private->icon_name = g_strdup (icon_name);
+
+  if (! icon_name)
+    icon_name = gimp_viewable_get_icon_name (GIMP_VIEWABLE (private->tool_info));
+
+  g_object_set (private->dialog, "icon-name", icon_name, NULL);
+}
+
+void
+gimp_tool_gui_set_help_id (GimpToolGui *gui,
+                           const gchar *help_id)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (help_id == private->help_id)
+    return;
+
+  g_free (private->help_id);
+  private->help_id = g_strdup (help_id);
+
+  if (! help_id)
+    help_id = private->tool_info->help_id;
+
+  if (private->overlay)
+    {
+      /* TODO */
+    }
+  else
+    {
+      g_object_set (private->dialog, "help-id", help_id, NULL);
+    }
+}
+
+void
+gimp_tool_gui_set_shell (GimpToolGui      *gui,
+                         GimpDisplayShell *shell)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+  g_return_if_fail (shell == NULL || GIMP_IS_DISPLAY_SHELL (shell));
+
+  private = GET_PRIVATE (gui);
+
+  if (shell == private->shell)
+    return;
+
+  if (private->shell)
+    {
+      g_object_remove_weak_pointer (G_OBJECT (private->shell),
+                                    (gpointer) &private->shell);
+      g_signal_handlers_disconnect_by_func (private->shell->canvas,
+                                            gimp_tool_gui_canvas_resized,
+                                            gui);
+    }
+
+  private->shell = shell;
+
+  if (private->shell)
+    {
+      g_signal_connect (private->shell->canvas, "size-allocate",
+                        G_CALLBACK (gimp_tool_gui_canvas_resized),
+                        gui);
+      g_object_add_weak_pointer (G_OBJECT (private->shell),
+                                 (gpointer) &private->shell);
+    }
+
+  gimp_tool_gui_update_shell (gui);
+}
+
+void
+gimp_tool_gui_set_viewable (GimpToolGui  *gui,
+                            GimpViewable *viewable)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+  g_return_if_fail (viewable == NULL || GIMP_IS_VIEWABLE (viewable));
+
+  private = GET_PRIVATE (gui);
+
+  if (private->viewable == viewable)
+    return;
+
+  if (private->viewable)
+    g_object_remove_weak_pointer (G_OBJECT (private->viewable),
+                                  (gpointer) &private->viewable);
+
+  private->viewable = viewable;
+
+  if (private->viewable)
+    g_object_add_weak_pointer (G_OBJECT (private->viewable),
+                               (gpointer) &private->viewable);
+
+  gimp_tool_gui_update_viewable (gui);
+}
+
+GtkWidget *
+gimp_tool_gui_get_dialog (GimpToolGui *gui)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_GUI (gui), NULL);
+
+  return GET_PRIVATE (gui)->dialog;
+}
+
+GtkWidget *
+gimp_tool_gui_get_vbox (GimpToolGui *gui)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_GUI (gui), NULL);
+
+  return GET_PRIVATE (gui)->vbox;
+}
+
+gboolean
+gimp_tool_gui_get_visible (GimpToolGui *gui)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_GUI (gui), FALSE);
+
+  private = GET_PRIVATE (gui);
+
+  if (private->overlay)
+    return gtk_widget_get_parent (private->dialog) != NULL;
+  else
+    return gtk_widget_get_visible (private->dialog);
+}
+
+void
+gimp_tool_gui_show (GimpToolGui *gui)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  g_return_if_fail (private->shell != NULL);
+
+  if (private->overlay)
+    {
+      if (! gtk_widget_get_parent (private->dialog))
+        {
+          gimp_overlay_box_add_child (GIMP_OVERLAY_BOX (private->shell->canvas),
+                                      private->dialog, 1.0, 0.0);
+          gtk_widget_show (private->dialog);
+        }
+    }
+  else
+    {
+      if (gtk_widget_get_visible (private->dialog))
+        gdk_window_show (gtk_widget_get_window (private->dialog));
+      else
+        gtk_widget_show (private->dialog);
+    }
+}
+
+void
+gimp_tool_gui_hide (GimpToolGui *gui)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (private->overlay)
+    {
+      if (gtk_widget_get_parent (private->dialog))
+        {
+          gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (private->dialog)),
+                                private->dialog);
+          gtk_widget_hide (private->dialog);
+        }
+    }
+  else
+    {
+      if (gimp_dialog_factory_from_widget (private->dialog, NULL))
+        {
+          gimp_dialog_factory_hide_dialog (private->dialog);
+        }
+      else
+        {
+          gtk_widget_hide (private->dialog);
+        }
+    }
+}
+
+void
+gimp_tool_gui_set_overlay (GimpToolGui *gui,
+                           GdkScreen   *screen,
+                           gint         monitor,
+                           gboolean     overlay)
+{
+  GimpToolGuiPrivate *private;
+  gboolean            visible;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (private->overlay == overlay)
+    return;
+
+  if (! private->dialog)
+    {
+      private->overlay = overlay;
+      return;
+    }
+
+  visible = gtk_widget_get_visible (private->dialog);
+
+  if (visible)
+    gimp_tool_gui_hide (gui);
+
+  gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (private->vbox)),
+                        private->vbox);
+
+  if (private->overlay)
+    g_object_unref (private->dialog);
+  else
+    gtk_widget_destroy (private->dialog);
+
+  private->overlay = overlay;
+
+  gimp_tool_gui_create_dialog (gui, screen, monitor);
+
+  if (visible)
+    gimp_tool_gui_show (gui);
+}
+
+gboolean
+gimp_tool_gui_get_overlay (GimpToolGui *gui)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_GUI (gui), FALSE);
+
+  return GET_PRIVATE (gui)->overlay;
+}
+
+void
+gimp_tool_gui_set_auto_overlay (GimpToolGui *gui,
+                                gboolean     auto_overlay)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (private->auto_overlay != auto_overlay)
+    {
+      private->auto_overlay = auto_overlay;
+
+      if (private->shell)
+        gimp_tool_gui_canvas_resized (private->shell->canvas, NULL, gui);
+    }
+}
+
+gboolean
+gimp_tool_gui_get_auto_overlay (GimpToolGui *gui)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_GUI (gui), FALSE);
+
+  return GET_PRIVATE (gui)->auto_overlay;
+}
+
+void
+gimp_tool_gui_set_focus_on_map (GimpToolGui *gui,
+                                gboolean     focus_on_map)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  if (private->focus_on_map == focus_on_map)
+    return;
+
+  private->focus_on_map = focus_on_map ? TRUE : FALSE;
+
+  if (! private->overlay)
+    {
+      gtk_window_set_focus_on_map (GTK_WINDOW (private->dialog),
+                                   private->focus_on_map);
+    }
+}
+
+gboolean
+gimp_tool_gui_get_focus_on_map (GimpToolGui *gui)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_GUI (gui), FALSE);
+
+  return GET_PRIVATE (gui)->focus_on_map;
+}
+
+void
+gimp_tool_gui_add_buttons_valist (GimpToolGui *gui,
+                                  va_list      args)
+{
+  const gchar *button_text;
+  gint         response_id;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  while ((button_text = va_arg (args, const gchar *)))
+    {
+      response_id = va_arg (args, gint);
+
+      gimp_tool_gui_add_button (gui, button_text, response_id);
+    }
+}
+
+void
+gimp_tool_gui_add_button (GimpToolGui *gui,
+                          const gchar *button_text,
+                          gint         response_id)
+{
+  GimpToolGuiPrivate *private;
+  ResponseEntry     *entry;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+  g_return_if_fail (button_text != NULL);
+
+  private = GET_PRIVATE (gui);
+
+  entry = response_entry_new (response_id, button_text);
+
+  private->response_entries = g_list_append (private->response_entries,
+                                             entry);
+
+  if (private->dialog)
+    gimp_tool_gui_add_dialog_button (gui, entry);
+}
+
+void
+gimp_tool_gui_set_default_response (GimpToolGui *gui,
+                                    gint         response_id)
+{
+  GimpToolGuiPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  g_return_if_fail (response_entry_find (private->response_entries,
+                                         response_id) != NULL);
+
+  private->default_response = response_id;
+
+  if (private->overlay)
+    {
+      gimp_overlay_dialog_set_default_response (GIMP_OVERLAY_DIALOG (private->dialog),
+                                                response_id);
+    }
+  else
+    {
+      gtk_dialog_set_default_response (GTK_DIALOG (private->dialog),
+                                       response_id);
+    }
+}
+
+void
+gimp_tool_gui_set_response_sensitive (GimpToolGui *gui,
+                                      gint         response_id,
+                                      gboolean     sensitive)
+{
+  GimpToolGuiPrivate *private;
+  ResponseEntry      *entry;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  entry = response_entry_find (private->response_entries, response_id);
+
+  if (! entry)
+    return;
+
+  entry->sensitive = sensitive;
+
+  if (private->overlay)
+    {
+      gimp_overlay_dialog_set_response_sensitive (GIMP_OVERLAY_DIALOG (private->dialog),
+                                                  response_id, sensitive);
+    }
+  else
+    {
+      gtk_dialog_set_response_sensitive (GTK_DIALOG (private->dialog),
+                                         response_id, sensitive);
+    }
+}
+
+void
+gimp_tool_gui_set_alternative_button_order (GimpToolGui *gui,
+                                            ...)
+{
+  GimpToolGuiPrivate *private;
+  va_list             args;
+  gint                response_id;
+  gint                i;
+
+  g_return_if_fail (GIMP_IS_TOOL_GUI (gui));
+
+  private = GET_PRIVATE (gui);
+
+  va_start (args, gui);
+
+  for (response_id = va_arg (args, gint), i = 0;
+       response_id != -1;
+       response_id = va_arg (args, gint), i++)
+    {
+      ResponseEntry *entry = response_entry_find (private->response_entries,
+                                                  response_id);
+
+      if (entry)
+        entry->alternative_position = i;
+    }
+
+  va_end (args);
+
+  gimp_tool_gui_update_buttons (gui);
+}
+
+
+/*  private functions  */
+
+static void
+gimp_tool_gui_create_dialog (GimpToolGui *gui,
+                             GdkScreen   *screen,
+                             gint         monitor)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (gui);
+  GList              *list;
+
+  if (private->overlay)
+    {
+      private->dialog = gimp_overlay_dialog_new (private->tool_info,
+                                                 private->description,
+                                                 NULL);
+      g_object_ref_sink (private->dialog);
+
+      for (list = private->response_entries; list; list = g_list_next (list))
+        {
+          ResponseEntry *entry = list->data;
+
+          gimp_tool_gui_add_dialog_button (gui, entry);
+        }
+
+      if (private->default_response != -1)
+        gimp_overlay_dialog_set_default_response (GIMP_OVERLAY_DIALOG (private->dialog),
+                                                  private->default_response);
+
+      gtk_container_set_border_width (GTK_CONTAINER (private->dialog), 6);
+
+      gtk_container_set_border_width (GTK_CONTAINER (private->vbox), 0);
+      gtk_container_add (GTK_CONTAINER (private->dialog), private->vbox);
+      gtk_widget_show (private->vbox);
+    }
+  else
+    {
+      private->dialog = gimp_tool_dialog_new (private->tool_info,
+                                              screen, monitor,
+                                              private->title,
+                                              private->description,
+                                              private->icon_name,
+                                              private->help_id,
+                                              NULL);
+
+      for (list = private->response_entries; list; list = g_list_next (list))
+        {
+          ResponseEntry *entry = list->data;
+
+          gimp_tool_gui_add_dialog_button (gui, entry);
+        }
+
+      if (private->default_response != -1)
+        gtk_dialog_set_default_response (GTK_DIALOG (private->dialog),
+                                         private->default_response);
+
+      gtk_window_set_focus_on_map (GTK_WINDOW (private->dialog),
+                                   private->focus_on_map);
+
+      gtk_container_set_border_width (GTK_CONTAINER (private->vbox), 6);
+      gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (private->dialog))),
+                          private->vbox, TRUE, TRUE, 0);
+      gtk_widget_show (private->vbox);
+    }
+
+  gimp_tool_gui_update_buttons (gui);
+
+  if (private->shell)
+    gimp_tool_gui_update_shell (gui);
+
+  if (private->viewable)
+    gimp_tool_gui_update_viewable (gui);
+
+  g_signal_connect_object (private->dialog, "response",
+                           G_CALLBACK (gimp_tool_gui_dialog_response),
+                           G_OBJECT (gui), 0);
+}
+
+static void
+gimp_tool_gui_add_dialog_button (GimpToolGui   *gui,
+                                 ResponseEntry *entry)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (gui);
+
+  if (private->overlay)
+    {
+      gimp_overlay_dialog_add_button (GIMP_OVERLAY_DIALOG (private->dialog),
+                                      entry->button_text,
+                                      entry->response_id);
+
+      if (! entry->sensitive)
+        {
+          gimp_overlay_dialog_set_response_sensitive (
+            GIMP_OVERLAY_DIALOG (private->dialog),
+            entry->response_id, FALSE);
+        }
+    }
+  else
+    {
+      gimp_dialog_add_button (GIMP_DIALOG (private->dialog),
+                              entry->button_text,
+                              entry->response_id);
+
+      if (! entry->sensitive)
+        gtk_dialog_set_response_sensitive (GTK_DIALOG (private->dialog),
+                                           entry->response_id,
+                                           FALSE);
+    }
+}
+
+static void
+gimp_tool_gui_update_buttons (GimpToolGui *gui)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (gui);
+  GList              *list;
+  gint               *ids;
+  gint                n_ids;
+  gint                n_alternatives = 0;
+  gint                i;
+
+  n_ids = g_list_length (private->response_entries);
+  ids   = g_new0 (gint, n_ids);
+
+  for (list = private->response_entries, i = 0;
+       list;
+       list = g_list_next (list), i++)
+    {
+      ResponseEntry *entry = list->data;
+
+      if (entry->alternative_position >= 0 &&
+          entry->alternative_position < n_ids)
+        {
+          ids[entry->alternative_position] = entry->response_id;
+          n_alternatives++;
+        }
+    }
+
+  if (n_ids == n_alternatives)
+    {
+      if (private->overlay)
+        {
+          gimp_overlay_dialog_set_alternative_button_order (GIMP_OVERLAY_DIALOG (private->dialog),
+                                                            n_ids, ids);
+        }
+      else
+        {
+          gtk_dialog_set_alternative_button_order_from_array (GTK_DIALOG (private->dialog),
+                                                              n_ids, ids);
+        }
+    }
+
+  g_free (ids);
+}
+
+static void
+gimp_tool_gui_update_shell (GimpToolGui *gui)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (gui);
+
+  if (private->overlay)
+    {
+      if (gtk_widget_get_parent (private->dialog))
+        {
+          gimp_tool_gui_hide (gui);
+
+          if (private->shell)
+            gimp_tool_gui_show (gui);
+        }
+    }
+  else
+    {
+      gimp_tool_dialog_set_shell (GIMP_TOOL_DIALOG (private->dialog),
+                                  private->shell);
+    }
+}
+
+static void
+gimp_tool_gui_update_viewable (GimpToolGui *gui)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (gui);
+
+  if (! private->overlay)
+    {
+      GimpContext *context = NULL;
+
+      if (private->tool_info)
+        context = GIMP_CONTEXT (private->tool_info->tool_options);
+
+      gimp_viewable_dialog_set_viewable (GIMP_VIEWABLE_DIALOG (private->dialog),
+                                         private->viewable, context);
+    }
+}
+
+static void
+gimp_tool_gui_dialog_response (GtkWidget   *dialog,
+                               gint         response_id,
+                               GimpToolGui *gui)
+{
+  if (response_id == GIMP_RESPONSE_DETACH)
+    {
+      gimp_tool_gui_set_auto_overlay (gui, FALSE);
+      gimp_tool_gui_set_overlay (gui,
+                                 gtk_widget_get_screen (dialog),
+                                 gimp_widget_get_monitor (dialog),
+                                 FALSE);
+    }
+  else
+    {
+      g_signal_emit (gui, signals[RESPONSE], 0,
+                     response_id);
+    }
+}
+
+static void
+gimp_tool_gui_canvas_resized (GtkWidget     *canvas,
+                              GtkAllocation *unused,
+                              GimpToolGui   *gui)
+{
+  GimpToolGuiPrivate *private = GET_PRIVATE (gui);
+
+  if (private->auto_overlay)
+    {
+      GtkRequisition requisition;
+      GtkAllocation  allocation;
+      gboolean       overlay = FALSE;
+
+      gtk_widget_size_request (private->vbox, &requisition);
+      gtk_widget_get_allocation (canvas, &allocation);
+
+      if (allocation.width  > 2 * requisition.width &&
+          allocation.height > 3 * requisition.height)
+        {
+          overlay = TRUE;
+        }
+
+      gimp_tool_gui_set_overlay (gui,
+                                 gtk_widget_get_screen (private->dialog),
+                                 gimp_widget_get_monitor (private->dialog),
+                                 overlay);
+    }
+}
+
+static ResponseEntry *
+response_entry_new (gint         response_id,
+                    const gchar *button_text)
+{
+  ResponseEntry *entry = g_slice_new0 (ResponseEntry);
+
+  entry->response_id          = response_id;
+  entry->button_text          = g_strdup (button_text);
+  entry->alternative_position = -1;
+  entry->sensitive            = TRUE;
+
+  return entry;
+}
+
+static void
+response_entry_free (ResponseEntry *entry)
+{
+  g_free (entry->button_text);
+
+  g_slice_free (ResponseEntry, entry);
+}
+
+static ResponseEntry *
+response_entry_find (GList *entries,
+                     gint   response_id)
+{
+  for (; entries; entries = g_list_next (entries))
+    {
+      ResponseEntry *entry = entries->data;
+
+      if (entry->response_id == response_id)
+        return entry;
+    }
+
+  return NULL;
+}
diff --git a/app/display/gimptoolgui.h b/app/display/gimptoolgui.h
new file mode 100644
index 0000000..7b099a5
--- /dev/null
+++ b/app/display/gimptoolgui.h
@@ -0,0 +1,115 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolgui.h
+ * Copyright (C) 2013  Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_GUI_H__
+#define __GIMP_TOOL_GUI_H__
+
+
+#include "core/gimpobject.h"
+
+
+#define GIMP_TYPE_TOOL_GUI            (gimp_tool_gui_get_type ())
+#define GIMP_TOOL_GUI(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_GUI, GimpToolGui))
+#define GIMP_TOOL_GUI_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_GUI, GimpToolGuiClass))
+#define GIMP_IS_TOOL_GUI(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_GUI))
+#define GIMP_IS_TOOL_GUI_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_GUI))
+#define GIMP_TOOL_GUI_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_GUI, GimpToolGuiClass))
+
+
+typedef struct _GimpToolGuiClass GimpToolGuiClass;
+
+struct _GimpToolGui
+{
+  GimpObject  parent_instance;
+};
+
+struct _GimpToolGuiClass
+{
+  GimpObjectClass  parent_instance;
+
+  void (* response) (GimpToolGui *gui,
+                     gint         response_id);
+
+};
+
+
+GType         gimp_tool_gui_get_type               (void) G_GNUC_CONST;
+
+GimpToolGui * gimp_tool_gui_new                    (GimpToolInfo     *tool_info,
+                                                    const gchar      *title,
+                                                    const gchar      *description,
+                                                    const gchar      *icon_name,
+                                                    const gchar      *help_id,
+                                                    GdkScreen        *screen,
+                                                    gint              monitor,
+                                                    gboolean          overlay,
+                                                    ...) G_GNUC_NULL_TERMINATED;
+
+void          gimp_tool_gui_set_title              (GimpToolGui      *gui,
+                                                    const gchar      *title);
+void          gimp_tool_gui_set_description        (GimpToolGui      *gui,
+                                                    const gchar      *description);
+void          gimp_tool_gui_set_icon_name          (GimpToolGui      *gui,
+                                                    const gchar      *icon_name);
+void          gimp_tool_gui_set_help_id            (GimpToolGui      *gui,
+                                                    const gchar      *help_id);
+
+void          gimp_tool_gui_set_shell              (GimpToolGui      *gui,
+                                                    GimpDisplayShell *shell);
+void          gimp_tool_gui_set_viewable           (GimpToolGui      *gui,
+                                                    GimpViewable     *viewable);
+
+GtkWidget   * gimp_tool_gui_get_dialog             (GimpToolGui      *gui);
+GtkWidget   * gimp_tool_gui_get_vbox               (GimpToolGui      *gui);
+
+gboolean      gimp_tool_gui_get_visible            (GimpToolGui      *gui);
+void          gimp_tool_gui_show                   (GimpToolGui      *gui);
+void          gimp_tool_gui_hide                   (GimpToolGui      *gui);
+
+void          gimp_tool_gui_set_overlay            (GimpToolGui      *gui,
+                                                    GdkScreen        *screen,
+                                                    gint              monitor,
+                                                    gboolean          overlay);
+gboolean      gimp_tool_gui_get_overlay            (GimpToolGui      *gui);
+
+void          gimp_tool_gui_set_auto_overlay       (GimpToolGui      *gui,
+                                                    gboolean          auto_overlay);
+gboolean      gimp_tool_gui_get_auto_overlay       (GimpToolGui      *gui);
+
+void          gimp_tool_gui_set_focus_on_map       (GimpToolGui      *gui,
+                                                    gboolean          focus_on_map);
+gboolean      gimp_tool_gui_get_focus_on_map       (GimpToolGui      *gui);
+
+
+void          gimp_tool_gui_add_buttons_valist     (GimpToolGui      *gui,
+                                                    va_list           args);
+void          gimp_tool_gui_add_button             (GimpToolGui      *gui,
+                                                    const gchar      *button_text,
+                                                    gint              response_id);
+void          gimp_tool_gui_set_default_response   (GimpToolGui      *gui,
+                                                    gint              response_id);
+void          gimp_tool_gui_set_response_sensitive (GimpToolGui      *gui,
+                                                    gint              response_id,
+                                                    gboolean          sensitive);
+void    gimp_tool_gui_set_alternative_button_order (GimpToolGui      *gui,
+                                                    ...);
+
+
+#endif /* __GIMP_TOOL_GUI_H__ */
diff --git a/app/display/gimptoolgyroscope.c b/app/display/gimptoolgyroscope.c
new file mode 100644
index 0000000..4d6b175
--- /dev/null
+++ b/app/display/gimptoolgyroscope.c
@@ -0,0 +1,879 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolgyroscope.c
+ * Copyright (C) 2018 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimptoolgyroscope.h"
+
+#include "gimp-intl.h"
+
+
+#define EPSILON    1e-6
+#define DEG_TO_RAD (G_PI / 180.0)
+
+
+typedef enum
+{
+  MODE_NONE,
+  MODE_PAN,
+  MODE_ROTATE,
+  MODE_ZOOM
+} Mode;
+
+typedef enum
+{
+  CONSTRAINT_NONE,
+  CONSTRAINT_UNKNOWN,
+  CONSTRAINT_HORIZONTAL,
+  CONSTRAINT_VERTICAL
+} Constraint;
+
+enum
+{
+  PROP_0,
+  PROP_YAW,
+  PROP_PITCH,
+  PROP_ROLL,
+  PROP_ZOOM,
+  PROP_INVERT,
+  PROP_SPEED,
+  PROP_PIVOT_X,
+  PROP_PIVOT_Y
+};
+
+struct _GimpToolGyroscopePrivate
+{
+  gdouble    yaw;
+  gdouble    pitch;
+  gdouble    roll;
+  gdouble    zoom;
+
+  gdouble    orig_yaw;
+  gdouble    orig_pitch;
+  gdouble    orig_roll;
+  gdouble    orig_zoom;
+
+  gboolean   invert;
+
+  gdouble    speed;
+
+  gdouble    pivot_x;
+  gdouble    pivot_y;
+
+  Mode       mode;
+  Constraint constraint;
+
+  gdouble    last_x;
+  gdouble    last_y;
+
+  gdouble    last_angle;
+  gdouble    curr_angle;
+
+  gdouble    last_zoom;
+};
+
+
+/*  local function prototypes  */
+
+static void       gimp_tool_gyroscope_set_property    (GObject               *object,
+                                                       guint                  property_id,
+                                                       const GValue          *value,
+                                                       GParamSpec            *pspec);
+static void       gimp_tool_gyroscope_get_property    (GObject               *object,
+                                                       guint                  property_id,
+                                                       GValue                *value,
+                                                       GParamSpec            *pspec);
+
+static gint       gimp_tool_gyroscope_button_press    (GimpToolWidget        *widget,
+                                                       const GimpCoords      *coords,
+                                                       guint32                time,
+                                                       GdkModifierType        state,
+                                                       GimpButtonPressType    press_type);
+static void       gimp_tool_gyroscope_button_release  (GimpToolWidget        *widget,
+                                                       const GimpCoords      *coords,
+                                                       guint32                time,
+                                                       GdkModifierType        state,
+                                                       GimpButtonReleaseType  release_type);
+static void       gimp_tool_gyroscope_motion          (GimpToolWidget        *widget,
+                                                       const GimpCoords      *coords,
+                                                       guint32                time,
+                                                       GdkModifierType        state);
+static GimpHit    gimp_tool_gyroscope_hit             (GimpToolWidget        *widget,
+                                                       const GimpCoords      *coords,
+                                                       GdkModifierType        state,
+                                                       gboolean               proximity);
+static void       gimp_tool_gyroscope_hover           (GimpToolWidget        *widget,
+                                                       const GimpCoords      *coords,
+                                                       GdkModifierType        state,
+                                                       gboolean               proximity);
+static gboolean   gimp_tool_gyroscope_key_press       (GimpToolWidget        *widget,
+                                                       GdkEventKey           *kevent);
+static void       gimp_tool_gyroscope_motion_modifier (GimpToolWidget        *widget,
+                                                       GdkModifierType        key,
+                                                       gboolean               press,
+                                                       GdkModifierType        state);
+static gboolean   gimp_tool_gyroscope_get_cursor      (GimpToolWidget        *widget,
+                                                       const GimpCoords      *coords,
+                                                       GdkModifierType        state,
+                                                       GimpCursorType        *cursor,
+                                                       GimpToolCursorType    *tool_cursor,
+                                                       GimpCursorModifier    *modifier);
+
+static void       gimp_tool_gyroscope_update_status   (GimpToolGyroscope      *gyroscope,
+                                                       GdkModifierType         state);
+
+static void       gimp_tool_gyroscope_save            (GimpToolGyroscope      *gyroscope);
+static void       gimp_tool_gyroscope_restore         (GimpToolGyroscope      *gyroscope);
+
+static void       gimp_tool_gyroscope_rotate          (GimpToolGyroscope      *gyroscope,
+                                                       const GimpVector3      *axis);
+static void       gimp_tool_gyroscope_rotate_vector   (GimpVector3            *vector,
+                                                       const GimpVector3      *axis);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolGyroscope, gimp_tool_gyroscope,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_gyroscope_parent_class
+
+
+static void
+gimp_tool_gyroscope_class_init (GimpToolGyroscopeClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->set_property    = gimp_tool_gyroscope_set_property;
+  object_class->get_property    = gimp_tool_gyroscope_get_property;
+
+  widget_class->button_press    = gimp_tool_gyroscope_button_press;
+  widget_class->button_release  = gimp_tool_gyroscope_button_release;
+  widget_class->motion          = gimp_tool_gyroscope_motion;
+  widget_class->hit             = gimp_tool_gyroscope_hit;
+  widget_class->hover           = gimp_tool_gyroscope_hover;
+  widget_class->key_press       = gimp_tool_gyroscope_key_press;
+  widget_class->motion_modifier = gimp_tool_gyroscope_motion_modifier;
+  widget_class->get_cursor      = gimp_tool_gyroscope_get_cursor;
+
+  g_object_class_install_property (object_class, PROP_YAW,
+                                   g_param_spec_double ("yaw", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PITCH,
+                                   g_param_spec_double ("pitch", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ROLL,
+                                   g_param_spec_double ("roll", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ZOOM,
+                                   g_param_spec_double ("zoom", NULL, NULL,
+                                                        0.0,
+                                                        +G_MAXDOUBLE,
+                                                        1.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_INVERT,
+                                   g_param_spec_boolean ("invert", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_SPEED,
+                                   g_param_spec_double ("speed", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        1.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIVOT_X,
+                                   g_param_spec_double ("pivot-x", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIVOT_Y,
+                                   g_param_spec_double ("pivot-y", NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        +G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_gyroscope_init (GimpToolGyroscope *gyroscope)
+{
+  gyroscope->private = gimp_tool_gyroscope_get_instance_private (gyroscope);
+}
+
+static void
+gimp_tool_gyroscope_set_property (GObject      *object,
+                                  guint         property_id,
+                                  const GValue *value,
+                                  GParamSpec   *pspec)
+{
+  GimpToolGyroscope        *gyroscope = GIMP_TOOL_GYROSCOPE (object);
+  GimpToolGyroscopePrivate *private = gyroscope->private;
+
+  switch (property_id)
+    {
+    case PROP_YAW:
+      private->yaw = g_value_get_double (value);
+      break;
+    case PROP_PITCH:
+      private->pitch = g_value_get_double (value);
+      break;
+    case PROP_ROLL:
+      private->roll = g_value_get_double (value);
+      break;
+    case PROP_ZOOM:
+      private->zoom = g_value_get_double (value);
+      break;
+    case PROP_INVERT:
+      private->invert = g_value_get_boolean (value);
+      break;
+    case PROP_SPEED:
+      private->speed = g_value_get_double (value);
+      break;
+    case PROP_PIVOT_X:
+      private->pivot_x = g_value_get_double (value);
+      break;
+    case PROP_PIVOT_Y:
+      private->pivot_y = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_gyroscope_get_property (GObject    *object,
+                                  guint       property_id,
+                                  GValue     *value,
+                                  GParamSpec *pspec)
+{
+  GimpToolGyroscope        *gyroscope = GIMP_TOOL_GYROSCOPE (object);
+  GimpToolGyroscopePrivate *private = gyroscope->private;
+
+  switch (property_id)
+    {
+    case PROP_YAW:
+      g_value_set_double (value, private->yaw);
+      break;
+    case PROP_PITCH:
+      g_value_set_double (value, private->pitch);
+      break;
+    case PROP_ROLL:
+      g_value_set_double (value, private->roll);
+      break;
+    case PROP_ZOOM:
+      g_value_set_double (value, private->zoom);
+      break;
+    case PROP_INVERT:
+      g_value_set_boolean (value, private->invert);
+      break;
+    case PROP_SPEED:
+      g_value_set_double (value, private->speed);
+      break;
+    case PROP_PIVOT_X:
+      g_value_set_double (value, private->pivot_x);
+      break;
+    case PROP_PIVOT_Y:
+      g_value_set_double (value, private->pivot_y);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static gint
+gimp_tool_gyroscope_button_press (GimpToolWidget      *widget,
+                                  const GimpCoords    *coords,
+                                  guint32              time,
+                                  GdkModifierType      state,
+                                  GimpButtonPressType  press_type)
+{
+  GimpToolGyroscope        *gyroscope = GIMP_TOOL_GYROSCOPE (widget);
+  GimpToolGyroscopePrivate *private   = gyroscope->private;
+
+  gimp_tool_gyroscope_save (gyroscope);
+
+  if (state & GDK_MOD1_MASK)
+    {
+      private->mode = MODE_ZOOM;
+
+      private->last_zoom = private->zoom;
+    }
+  else if (state & gimp_get_extend_selection_mask ())
+    {
+      private->mode = MODE_ROTATE;
+
+      private->last_angle = atan2 (coords->y - private->pivot_y,
+                                   coords->x - private->pivot_x);
+      private->curr_angle = private->last_angle;
+    }
+  else
+    {
+      private->mode = MODE_PAN;
+
+      if (state & gimp_get_constrain_behavior_mask ())
+        private->constraint = CONSTRAINT_UNKNOWN;
+      else
+        private->constraint = CONSTRAINT_NONE;
+    }
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+
+  gimp_tool_gyroscope_update_status (gyroscope, state);
+
+  return 1;
+}
+
+static void
+gimp_tool_gyroscope_button_release (GimpToolWidget        *widget,
+                                    const GimpCoords      *coords,
+                                    guint32                time,
+                                    GdkModifierType        state,
+                                    GimpButtonReleaseType  release_type)
+{
+  GimpToolGyroscope        *gyroscope = GIMP_TOOL_GYROSCOPE (widget);
+  GimpToolGyroscopePrivate *private   = gyroscope->private;
+
+  if (release_type == GIMP_BUTTON_RELEASE_CANCEL)
+    gimp_tool_gyroscope_restore (gyroscope);
+
+  private->mode = MODE_NONE;
+
+  gimp_tool_gyroscope_update_status (gyroscope, state);
+}
+
+static void
+gimp_tool_gyroscope_motion (GimpToolWidget   *widget,
+                            const GimpCoords *coords,
+                            guint32           time,
+                            GdkModifierType   state)
+{
+  GimpToolGyroscope        *gyroscope = GIMP_TOOL_GYROSCOPE (widget);
+  GimpToolGyroscopePrivate *private   = gyroscope->private;
+  GimpDisplayShell         *shell     = gimp_tool_widget_get_shell (widget);
+  GimpVector3               axis      = {};
+
+  switch (private->mode)
+    {
+      case MODE_PAN:
+        {
+          gdouble x1     = private->last_x;
+          gdouble y1     = private->last_y;
+          gdouble x2     = coords->x;
+          gdouble y2     = coords->y;
+          gdouble factor = 1.0 / private->zoom;
+
+          if (private->constraint != CONSTRAINT_NONE)
+            {
+              gimp_display_shell_rotate_xy_f (shell, x1, y1, &x1, &y1);
+              gimp_display_shell_rotate_xy_f (shell, x2, y2, &x2, &y2);
+
+              if (private->constraint == CONSTRAINT_UNKNOWN)
+                {
+                  if (fabs (x2 - x1) > fabs (y2 - y1))
+                    private->constraint = CONSTRAINT_HORIZONTAL;
+                  else if (fabs (y2 - y1) > fabs (x2 - x1))
+                    private->constraint = CONSTRAINT_VERTICAL;
+                }
+
+              if (private->constraint == CONSTRAINT_HORIZONTAL)
+                y2 = y1;
+              else if (private->constraint == CONSTRAINT_VERTICAL)
+                x2 = x1;
+
+              gimp_display_shell_unrotate_xy_f (shell, x1, y1, &x1, &y1);
+              gimp_display_shell_unrotate_xy_f (shell, x2, y2, &x2, &y2);
+            }
+
+          if (private->invert)
+            factor = 1.0 / factor;
+
+          gimp_vector3_set (&axis, y2 - y1, x2 - x1, 0.0);
+          gimp_vector3_mul (&axis, factor * private->speed);
+        }
+      break;
+
+    case MODE_ROTATE:
+      {
+        gdouble angle;
+
+        angle = atan2 (coords->y - private->pivot_y,
+                       coords->x - private->pivot_x);
+
+        private->curr_angle = angle;
+
+        angle -= private->last_angle;
+
+        if (state & gimp_get_constrain_behavior_mask ())
+          angle = RINT (angle / (G_PI / 6.0)) * (G_PI / 6.0);
+
+        gimp_vector3_set (&axis, 0.0, 0.0, angle);
+
+        private->last_angle += angle;
+      }
+    break;
+
+    case MODE_ZOOM:
+      {
+        gdouble x1, y1;
+        gdouble x2, y2;
+        gdouble zoom;
+
+        gimp_display_shell_transform_xy_f (shell,
+                                           private->last_x, private->last_y,
+                                           &x1,             &y1);
+        gimp_display_shell_transform_xy_f (shell,
+                                           coords->x,       coords->y,
+                                           &x2,             &y2);
+
+        zoom = (y1 - y2) * shell->scale_y / 128.0;
+
+        if (private->invert)
+          zoom = -zoom;
+
+        private->last_zoom *= pow (2.0, zoom);
+
+        zoom = log (private->last_zoom / private->zoom) / G_LN2;
+
+        if (state & gimp_get_constrain_behavior_mask ())
+          zoom = RINT (zoom * 2.0) / 2.0;
+
+        g_object_set (gyroscope,
+                      "zoom", private->zoom * pow (2.0, zoom),
+                      NULL);
+      }
+      break;
+
+    case MODE_NONE:
+      g_return_if_reached ();
+  }
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+
+  gimp_tool_gyroscope_rotate (gyroscope, &axis);
+}
+
+static GimpHit
+gimp_tool_gyroscope_hit (GimpToolWidget   *widget,
+                         const GimpCoords *coords,
+                         GdkModifierType   state,
+                         gboolean          proximity)
+{
+  return GIMP_HIT_INDIRECT;
+}
+
+static void
+gimp_tool_gyroscope_hover (GimpToolWidget   *widget,
+                           const GimpCoords *coords,
+                           GdkModifierType   state,
+                           gboolean          proximity)
+{
+  gimp_tool_gyroscope_update_status (GIMP_TOOL_GYROSCOPE (widget), state);
+}
+
+static gboolean
+gimp_tool_gyroscope_key_press (GimpToolWidget *widget,
+                               GdkEventKey    *kevent)
+{
+  GimpToolGyroscope        *gyroscope = GIMP_TOOL_GYROSCOPE (widget);
+  GimpToolGyroscopePrivate *private   = gyroscope->private;
+  GimpDisplayShell         *shell     = gimp_tool_widget_get_shell (widget);
+  GimpVector3               axis      = {};
+  gboolean                  fast;
+  gboolean                  result    = FALSE;
+
+  fast = (kevent->state & gimp_get_constrain_behavior_mask ());
+
+  if (kevent->state & GDK_MOD1_MASK)
+    {
+      /* zoom */
+      gdouble zoom = 0.0;
+
+      switch (kevent->keyval)
+        {
+        case GDK_KEY_Up:
+          zoom   = fast ? +1.0 : +1.0 / 8.0;
+          result = TRUE;
+          break;
+
+        case GDK_KEY_Down:
+          zoom   = fast ? -1.0 : -1.0 / 8.0;
+          result = TRUE;
+          break;
+        }
+
+      if (private->invert)
+        zoom = -zoom;
+
+      if (zoom)
+        {
+          g_object_set (gyroscope,
+                        "zoom", private->zoom * pow (2.0, zoom),
+                        NULL);
+        }
+    }
+  else if (kevent->state & gimp_get_extend_selection_mask ())
+    {
+      /* rotate */
+      gdouble angle = 0.0;
+
+      switch (kevent->keyval)
+        {
+        case GDK_KEY_Left:
+          angle  = fast ? +15.0 : +1.0;
+          result = TRUE;
+          break;
+
+        case GDK_KEY_Right:
+          angle  = fast ? -15.0 : -1.0;
+          result = TRUE;
+          break;
+        }
+
+      if (shell->flip_horizontally ^ shell->flip_vertically)
+        angle = -angle;
+
+      gimp_vector3_set (&axis, 0.0, 0.0, angle * DEG_TO_RAD);
+    }
+  else
+    {
+      /* pan */
+      gdouble x0     = 0.0;
+      gdouble y0     = 0.0;
+      gdouble x      = 0.0;
+      gdouble y      = 0.0;
+      gdouble factor = 1.0 / private->zoom;
+
+      if (private->invert)
+        factor = 1.0 / factor;
+
+      switch (kevent->keyval)
+        {
+        case GDK_KEY_Left:
+          x      = fast ? +15.0 : +1.0;
+          result = TRUE;
+          break;
+
+        case GDK_KEY_Right:
+          x      = fast ? -15.0 : -1.0;
+          result = TRUE;
+          break;
+
+        case GDK_KEY_Up:
+          y      = fast ? +15.0 : +1.0;
+          result = TRUE;
+          break;
+
+        case GDK_KEY_Down:
+          y      = fast ? -15.0 : -1.0;
+          result = TRUE;
+          break;
+        }
+
+      gimp_display_shell_unrotate_xy_f (shell, x0, y0, &x0, &y0);
+      gimp_display_shell_unrotate_xy_f (shell, x,  y,  &x,  &y);
+
+      gimp_vector3_set (&axis,
+                        (y - y0) * DEG_TO_RAD,
+                        (x - x0) * DEG_TO_RAD,
+                        0.0);
+      gimp_vector3_mul (&axis, factor);
+    }
+
+  gimp_tool_gyroscope_rotate (gyroscope, &axis);
+
+  return result;
+}
+
+static void
+gimp_tool_gyroscope_motion_modifier (GimpToolWidget  *widget,
+                                     GdkModifierType  key,
+                                     gboolean         press,
+                                     GdkModifierType  state)
+{
+  GimpToolGyroscope        *gyroscope = GIMP_TOOL_GYROSCOPE (widget);
+  GimpToolGyroscopePrivate *private   = gyroscope->private;
+
+  gimp_tool_gyroscope_update_status (gyroscope, state);
+
+  if (key == gimp_get_constrain_behavior_mask ())
+    {
+      switch (private->mode)
+      {
+        case MODE_PAN:
+          if (state & gimp_get_constrain_behavior_mask ())
+            private->constraint = CONSTRAINT_UNKNOWN;
+          else
+            private->constraint = CONSTRAINT_NONE;
+          break;
+
+        case MODE_ROTATE:
+          if (! (state & gimp_get_constrain_behavior_mask ()))
+            private->last_angle = private->curr_angle;
+          break;
+
+        case MODE_ZOOM:
+          if (! (state & gimp_get_constrain_behavior_mask ()))
+            private->last_zoom = private->zoom;
+          break;
+
+        case MODE_NONE:
+          break;
+      }
+    }
+}
+
+static gboolean
+gimp_tool_gyroscope_get_cursor (GimpToolWidget     *widget,
+                                const GimpCoords   *coords,
+                                GdkModifierType     state,
+                                GimpCursorType     *cursor,
+                                GimpToolCursorType *tool_cursor,
+                                GimpCursorModifier *modifier)
+{
+  if (state & GDK_MOD1_MASK)
+    *modifier = GIMP_CURSOR_MODIFIER_ZOOM;
+  else if (state & gimp_get_extend_selection_mask ())
+    *modifier = GIMP_CURSOR_MODIFIER_ROTATE;
+  else
+    *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+
+  return TRUE;
+}
+
+static void
+gimp_tool_gyroscope_update_status (GimpToolGyroscope *gyroscope,
+                                   GdkModifierType    state)
+{
+  GimpToolGyroscopePrivate *private = gyroscope->private;
+  gchar                    *status;
+
+  if (private->mode == MODE_ZOOM ||
+      (private->mode == MODE_NONE &&
+       state & GDK_MOD1_MASK))
+    {
+      status = gimp_suggest_modifiers (_("Click-Drag to zoom"),
+                                       gimp_get_toggle_behavior_mask () &
+                                       ~state,
+                                       NULL,
+                                       _("%s for constrained steps"),
+                                       NULL);
+    }
+  else if (private->mode == MODE_ROTATE ||
+           (private->mode == MODE_NONE &&
+            state & gimp_get_extend_selection_mask ()))
+    {
+      status = gimp_suggest_modifiers (_("Click-Drag to rotate"),
+                                       gimp_get_toggle_behavior_mask () &
+                                       ~state,
+                                       NULL,
+                                       _("%s for constrained angles"),
+                                       NULL);
+    }
+  else
+    {
+      status = gimp_suggest_modifiers (_("Click-Drag to pan"),
+                                       (((gimp_get_extend_selection_mask () |
+                                          GDK_MOD1_MASK)                    *
+                                         (private->mode == MODE_NONE))      |
+                                        gimp_get_toggle_behavior_mask  ())  &
+                                        ~state,
+                                       _("%s to rotate"),
+                                       _("%s for a constrained axis"),
+                                       _("%s to zoom"));
+    }
+
+  gimp_tool_widget_set_status (GIMP_TOOL_WIDGET (gyroscope), status);
+
+  g_free (status);
+}
+
+static void
+gimp_tool_gyroscope_save (GimpToolGyroscope *gyroscope)
+{
+  GimpToolGyroscopePrivate *private = gyroscope->private;
+
+  private->orig_yaw   = private->yaw;
+  private->orig_pitch = private->pitch;
+  private->orig_roll  = private->roll;
+  private->orig_zoom  = private->zoom;
+}
+
+static void
+gimp_tool_gyroscope_restore (GimpToolGyroscope *gyroscope)
+{
+  GimpToolGyroscopePrivate *private = gyroscope->private;
+
+  g_object_set (gyroscope,
+                "yaw",   private->orig_yaw,
+                "pitch", private->orig_pitch,
+                "roll",  private->orig_roll,
+                "zoom",  private->orig_zoom,
+                NULL);
+}
+
+static void
+gimp_tool_gyroscope_rotate (GimpToolGyroscope *gyroscope,
+                            const GimpVector3 *axis)
+{
+  GimpToolGyroscopePrivate *private = gyroscope->private;
+  GimpVector3               real_axis;
+  GimpVector3               basis[2];
+  gdouble                   yaw;
+  gdouble                   pitch;
+  gdouble                   roll;
+  gint                      i;
+
+  if (gimp_vector3_length (axis) < EPSILON)
+    return;
+
+  real_axis = *axis;
+
+  if (private->invert)
+    gimp_vector3_neg (&real_axis);
+
+  for (i = 0; i < 2; i++)
+    {
+      gimp_vector3_set (&basis[i], i == 0, i == 1, 0.0);
+
+      if (private->invert)
+        gimp_tool_gyroscope_rotate_vector (&basis[i], &real_axis);
+
+      gimp_tool_gyroscope_rotate_vector (
+        &basis[i], &(GimpVector3) {0.0, private->yaw * DEG_TO_RAD, 0.0});
+      gimp_tool_gyroscope_rotate_vector (
+        &basis[i], &(GimpVector3) {private->pitch * DEG_TO_RAD, 0.0, 0.0});
+      gimp_tool_gyroscope_rotate_vector (
+        &basis[i], &(GimpVector3) {0.0, 0.0, private->roll * DEG_TO_RAD});
+
+      if (! private->invert)
+        gimp_tool_gyroscope_rotate_vector (&basis[i], &real_axis);
+    }
+
+  roll = atan2 (basis[1].x, basis[1].y);
+
+  for (i = 0; i < 2; i++)
+    {
+      gimp_tool_gyroscope_rotate_vector (
+        &basis[i], &(GimpVector3) {0.0, 0.0, -roll});
+    }
+
+  pitch = atan2 (-basis[1].z, basis[1].y);
+
+  for (i = 0; i < 1; i++)
+    {
+      gimp_tool_gyroscope_rotate_vector (
+        &basis[i], &(GimpVector3) {-pitch, 0.0, 0.0});
+    }
+
+  yaw = atan2 (basis[0].z, basis[0].x);
+
+  g_object_set (gyroscope,
+                "yaw",   yaw   / DEG_TO_RAD,
+                "pitch", pitch / DEG_TO_RAD,
+                "roll",  roll  / DEG_TO_RAD,
+                NULL);
+}
+
+static void
+gimp_tool_gyroscope_rotate_vector (GimpVector3       *vector,
+                                   const GimpVector3 *axis)
+{
+  GimpVector3 normalized_axis;
+  GimpVector3 projection;
+  GimpVector3 u;
+  GimpVector3 v;
+  gdouble     angle;
+
+  angle = gimp_vector3_length (axis);
+
+  if (angle < EPSILON)
+    return;
+
+  normalized_axis = gimp_vector3_mul_val (*axis, 1.0 / angle);
+
+  projection = gimp_vector3_mul_val (
+    normalized_axis,
+    gimp_vector3_inner_product (vector, &normalized_axis));
+
+  u = gimp_vector3_sub_val (*vector, projection);
+  v = gimp_vector3_cross_product (&u, &normalized_axis);
+
+  gimp_vector3_mul (&u, cos (angle));
+  gimp_vector3_mul (&v, sin (angle));
+
+  gimp_vector3_add (vector, &u, &v);
+  gimp_vector3_add (vector, vector, &projection);
+}
+
+
+/*  public functions  */
+
+
+GimpToolWidget *
+gimp_tool_gyroscope_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_GYROSCOPE,
+                       "shell", shell,
+                       NULL);
+}
diff --git a/app/display/gimptoolgyroscope.h b/app/display/gimptoolgyroscope.h
new file mode 100644
index 0000000..3d89648
--- /dev/null
+++ b/app/display/gimptoolgyroscope.h
@@ -0,0 +1,58 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolgyroscope.h
+ * Copyright (C) 2018 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_GYROSCOPE_H__
+#define __GIMP_TOOL_GYROSCOPE_H__
+
+
+#include "gimptoolwidget.h"
+
+
+#define GIMP_TYPE_TOOL_GYROSCOPE            (gimp_tool_gyroscope_get_type ())
+#define GIMP_TOOL_GYROSCOPE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_GYROSCOPE, GimpToolGyroscope))
+#define GIMP_TOOL_GYROSCOPE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_GYROSCOPE, GimpToolGyroscopeClass))
+#define GIMP_IS_TOOL_GYROSCOPE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_GYROSCOPE))
+#define GIMP_IS_TOOL_GYROSCOPE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_GYROSCOPE))
+#define GIMP_TOOL_GYROSCOPE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_GYROSCOPE, GimpToolGyroscopeClass))
+
+
+typedef struct _GimpToolGyroscope        GimpToolGyroscope;
+typedef struct _GimpToolGyroscopePrivate GimpToolGyroscopePrivate;
+typedef struct _GimpToolGyroscopeClass   GimpToolGyroscopeClass;
+
+struct _GimpToolGyroscope
+{
+  GimpToolWidget            parent_instance;
+
+  GimpToolGyroscopePrivate *private;
+};
+
+struct _GimpToolGyroscopeClass
+{
+  GimpToolWidgetClass  parent_class;
+};
+
+
+GType            gimp_tool_gyroscope_get_type (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_gyroscope_new      (GimpDisplayShell *shell);
+
+
+#endif /* __GIMP_TOOL_GYROSCOPE_H__ */
diff --git a/app/display/gimptoolhandlegrid.c b/app/display/gimptoolhandlegrid.c
new file mode 100644
index 0000000..cb5b53d
--- /dev/null
+++ b/app/display/gimptoolhandlegrid.c
@@ -0,0 +1,1186 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolhandlegrid.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Based on GimpHandleTransformTool
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-transform-utils.h"
+#include "core/gimp-utils.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvashandle.h"
+#include "gimpdisplayshell.h"
+#include "gimptoolhandlegrid.h"
+
+#include "gimp-intl.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_HANDLE_MODE,
+  PROP_N_HANDLES,
+  PROP_ORIG_X1,
+  PROP_ORIG_Y1,
+  PROP_ORIG_X2,
+  PROP_ORIG_Y2,
+  PROP_ORIG_X3,
+  PROP_ORIG_Y3,
+  PROP_ORIG_X4,
+  PROP_ORIG_Y4,
+  PROP_TRANS_X1,
+  PROP_TRANS_Y1,
+  PROP_TRANS_X2,
+  PROP_TRANS_Y2,
+  PROP_TRANS_X3,
+  PROP_TRANS_Y3,
+  PROP_TRANS_X4,
+  PROP_TRANS_Y4
+};
+
+
+struct _GimpToolHandleGridPrivate
+{
+  GimpTransformHandleMode  handle_mode; /* enum to be renamed */
+
+  gint        n_handles;
+  GimpVector2 orig[4];
+  GimpVector2 trans[4];
+
+  gint     handle;
+  gdouble  last_x;
+  gdouble  last_y;
+
+  gboolean hover;
+  gdouble  mouse_x;
+  gdouble  mouse_y;
+
+  GimpCanvasItem *handles[5];
+};
+
+
+/*  local function prototypes  */
+
+static void   gimp_tool_handle_grid_constructed    (GObject               *object);
+static void   gimp_tool_handle_grid_set_property   (GObject               *object,
+                                                    guint                  property_id,
+                                                    const GValue          *value,
+                                                    GParamSpec            *pspec);
+static void   gimp_tool_handle_grid_get_property   (GObject               *object,
+                                                    guint                  property_id,
+                                                    GValue                *value,
+                                                    GParamSpec            *pspec);
+
+static void   gimp_tool_handle_grid_changed        (GimpToolWidget        *widget);
+static gint   gimp_tool_handle_grid_button_press   (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    guint32                time,
+                                                    GdkModifierType        state,
+                                                    GimpButtonPressType    press_type);
+static void   gimp_tool_handle_grid_button_release (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    guint32                time,
+                                                    GdkModifierType        state,
+                                                    GimpButtonReleaseType  release_type);
+static void   gimp_tool_handle_grid_motion         (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    guint32                time,
+                                                    GdkModifierType        state);
+static GimpHit  gimp_tool_handle_grid_hit          (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    GdkModifierType        state,
+                                                    gboolean               proximity);
+static void     gimp_tool_handle_grid_hover        (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    GdkModifierType        state,
+                                                    gboolean               proximity);
+static void     gimp_tool_handle_grid_leave_notify (GimpToolWidget        *widget);
+static gboolean gimp_tool_handle_grid_get_cursor   (GimpToolWidget        *widget,
+                                                    const GimpCoords      *coords,
+                                                    GdkModifierType        state,
+                                                    GimpCursorType        *cursor,
+                                                    GimpToolCursorType    *tool_cursor,
+                                                    GimpCursorModifier    *modifier);
+
+static gint     gimp_tool_handle_grid_get_handle     (GimpToolHandleGrid  *grid,
+                                                      const GimpCoords    *coords);
+static void     gimp_tool_handle_grid_update_hilight (GimpToolHandleGrid  *grid);
+static void     gimp_tool_handle_grid_update_matrix  (GimpToolHandleGrid  *grid);
+
+static gboolean is_handle_position_valid           (GimpToolHandleGrid    *grid,
+                                                    gint                   handle);
+static void     handle_micro_move                  (GimpToolHandleGrid    *grid,
+                                                    gint                   handle);
+
+static inline gdouble calc_angle               (gdouble ax,
+                                                gdouble ay,
+                                                gdouble bx,
+                                                gdouble by);
+static inline gdouble calc_len                 (gdouble a,
+                                                gdouble b);
+static inline gdouble calc_lineintersect_ratio (gdouble p1x,
+                                                gdouble p1y,
+                                                gdouble p2x,
+                                                gdouble p2y,
+                                                gdouble q1x,
+                                                gdouble q1y,
+                                                gdouble q2x,
+                                                gdouble q2y);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolHandleGrid, gimp_tool_handle_grid,
+                            GIMP_TYPE_TOOL_TRANSFORM_GRID)
+
+#define parent_class gimp_tool_handle_grid_parent_class
+
+
+static void
+gimp_tool_handle_grid_class_init (GimpToolHandleGridClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_handle_grid_constructed;
+  object_class->set_property    = gimp_tool_handle_grid_set_property;
+  object_class->get_property    = gimp_tool_handle_grid_get_property;
+
+  widget_class->changed         = gimp_tool_handle_grid_changed;
+  widget_class->button_press    = gimp_tool_handle_grid_button_press;
+  widget_class->button_release  = gimp_tool_handle_grid_button_release;
+  widget_class->motion          = gimp_tool_handle_grid_motion;
+  widget_class->hit             = gimp_tool_handle_grid_hit;
+  widget_class->hover           = gimp_tool_handle_grid_hover;
+  widget_class->leave_notify    = gimp_tool_handle_grid_leave_notify;
+  widget_class->get_cursor      = gimp_tool_handle_grid_get_cursor;
+
+  g_object_class_install_property (object_class, PROP_HANDLE_MODE,
+                                   g_param_spec_enum ("handle-mode",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_TRANSFORM_HANDLE_MODE,
+                                                      GIMP_HANDLE_MODE_ADD_TRANSFORM,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_N_HANDLES,
+                                   g_param_spec_int ("n-handles",
+                                                     NULL, NULL,
+                                                     0, 4, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_X1,
+                                   g_param_spec_double ("orig-x1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_Y1,
+                                   g_param_spec_double ("orig-y1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_X2,
+                                   g_param_spec_double ("orig-x2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_Y2,
+                                   g_param_spec_double ("orig-y2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_X3,
+                                   g_param_spec_double ("orig-x3",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_Y3,
+                                   g_param_spec_double ("orig-y3",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_X4,
+                                   g_param_spec_double ("orig-x4",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ORIG_Y4,
+                                   g_param_spec_double ("orig-y4",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_X1,
+                                   g_param_spec_double ("trans-x1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_Y1,
+                                   g_param_spec_double ("trans-y1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_X2,
+                                   g_param_spec_double ("trans-x2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_Y2,
+                                   g_param_spec_double ("trans-y2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_X3,
+                                   g_param_spec_double ("trans-x3",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_Y3,
+                                   g_param_spec_double ("trans-y3",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_X4,
+                                   g_param_spec_double ("trans-x4",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_TRANS_Y4,
+                                   g_param_spec_double ("trans-y4",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_handle_grid_init (GimpToolHandleGrid *grid)
+{
+  grid->private = gimp_tool_handle_grid_get_instance_private (grid);
+}
+
+static void
+gimp_tool_handle_grid_constructed (GObject *object)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (object);
+  GimpToolWidget            *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolHandleGridPrivate *private = grid->private;
+  gint                       i;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  for (i = 0; i < 4; i++)
+    {
+      private->handles[i + 1] =
+        gimp_tool_widget_add_handle (widget,
+                                     GIMP_HANDLE_CIRCLE,
+                                     0, 0,
+                                     GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                     GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                     GIMP_HANDLE_ANCHOR_CENTER);
+    }
+
+  gimp_tool_handle_grid_changed (widget);
+}
+
+static void
+gimp_tool_handle_grid_set_property (GObject      *object,
+                                    guint         property_id,
+                                    const GValue *value,
+                                    GParamSpec   *pspec)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (object);
+  GimpToolHandleGridPrivate *private = grid->private;
+
+  switch (property_id)
+    {
+    case PROP_HANDLE_MODE:
+      private->handle_mode = g_value_get_enum (value);
+      break;
+
+    case PROP_N_HANDLES:
+      private->n_handles = g_value_get_int (value);
+      break;
+
+    case PROP_ORIG_X1:
+      private->orig[0].x = g_value_get_double (value);
+      break;
+    case PROP_ORIG_Y1:
+      private->orig[0].y = g_value_get_double (value);
+      break;
+    case PROP_ORIG_X2:
+      private->orig[1].x = g_value_get_double (value);
+      break;
+    case PROP_ORIG_Y2:
+      private->orig[1].y = g_value_get_double (value);
+      break;
+    case PROP_ORIG_X3:
+      private->orig[2].x = g_value_get_double (value);
+      break;
+    case PROP_ORIG_Y3:
+      private->orig[2].y = g_value_get_double (value);
+      break;
+    case PROP_ORIG_X4:
+      private->orig[3].x = g_value_get_double (value);
+      break;
+    case PROP_ORIG_Y4:
+      private->orig[3].y = g_value_get_double (value);
+      break;
+
+    case PROP_TRANS_X1:
+      private->trans[0].x = g_value_get_double (value);
+      break;
+    case PROP_TRANS_Y1:
+      private->trans[0].y = g_value_get_double (value);
+      break;
+    case PROP_TRANS_X2:
+      private->trans[1].x = g_value_get_double (value);
+      break;
+    case PROP_TRANS_Y2:
+      private->trans[1].y = g_value_get_double (value);
+      break;
+    case PROP_TRANS_X3:
+      private->trans[2].x = g_value_get_double (value);
+      break;
+    case PROP_TRANS_Y3:
+      private->trans[2].y = g_value_get_double (value);
+      break;
+    case PROP_TRANS_X4:
+      private->trans[3].x = g_value_get_double (value);
+      break;
+    case PROP_TRANS_Y4:
+      private->trans[3].y = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_handle_grid_get_property (GObject    *object,
+                                    guint       property_id,
+                                    GValue     *value,
+                                    GParamSpec *pspec)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (object);
+  GimpToolHandleGridPrivate *private = grid->private;
+
+  switch (property_id)
+    {
+    case PROP_N_HANDLES:
+      g_value_set_int (value, private->n_handles);
+      break;
+
+    case PROP_HANDLE_MODE:
+      g_value_set_enum (value, private->handle_mode);
+      break;
+
+    case PROP_ORIG_X1:
+      g_value_set_double (value, private->orig[0].x);
+      break;
+    case PROP_ORIG_Y1:
+      g_value_set_double (value, private->orig[0].y);
+      break;
+    case PROP_ORIG_X2:
+      g_value_set_double (value, private->orig[1].x);
+      break;
+    case PROP_ORIG_Y2:
+      g_value_set_double (value, private->orig[1].y);
+      break;
+    case PROP_ORIG_X3:
+      g_value_set_double (value, private->orig[2].x);
+      break;
+    case PROP_ORIG_Y3:
+      g_value_set_double (value, private->orig[2].y);
+      break;
+    case PROP_ORIG_X4:
+      g_value_set_double (value, private->orig[3].x);
+      break;
+    case PROP_ORIG_Y4:
+      g_value_set_double (value, private->orig[3].y);
+      break;
+
+    case PROP_TRANS_X1:
+      g_value_set_double (value, private->trans[0].x);
+      break;
+    case PROP_TRANS_Y1:
+      g_value_set_double (value, private->trans[0].y);
+      break;
+    case PROP_TRANS_X2:
+      g_value_set_double (value, private->trans[1].x);
+      break;
+    case PROP_TRANS_Y2:
+      g_value_set_double (value, private->trans[1].y);
+      break;
+    case PROP_TRANS_X3:
+      g_value_set_double (value, private->trans[2].x);
+      break;
+    case PROP_TRANS_Y3:
+      g_value_set_double (value, private->trans[2].y);
+      break;
+    case PROP_TRANS_X4:
+      g_value_set_double (value, private->trans[3].x);
+      break;
+    case PROP_TRANS_Y4:
+      g_value_set_double (value, private->trans[3].y);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_handle_grid_changed (GimpToolWidget *widget)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private = grid->private;
+  gint                       i;
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->changed (widget);
+
+  for (i = 0; i < 4; i++)
+    {
+      gimp_canvas_handle_set_position (private->handles[i + 1],
+                                       private->trans[i].x,
+                                       private->trans[i].y);
+      gimp_canvas_item_set_visible (private->handles[i + 1],
+                                    i < private->n_handles);
+    }
+
+  gimp_tool_handle_grid_update_hilight (grid);
+}
+
+static gint
+gimp_tool_handle_grid_button_press (GimpToolWidget      *widget,
+                                    const GimpCoords    *coords,
+                                    guint32              time,
+                                    GdkModifierType      state,
+                                    GimpButtonPressType  press_type)
+{
+  GimpToolHandleGrid        *grid          = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private       = grid->private;
+  gint                       n_handles     = private->n_handles;
+  gint                       active_handle = private->handle - 1;
+
+  switch (private->handle_mode)
+    {
+    case GIMP_HANDLE_MODE_ADD_TRANSFORM:
+      if (n_handles < 4 && active_handle == -1)
+        {
+          /* add handle */
+
+          GimpMatrix3 *matrix;
+
+          active_handle = n_handles;
+
+          private->trans[active_handle].x = coords->x;
+          private->trans[active_handle].y = coords->y;
+          private->n_handles++;
+
+          if (! is_handle_position_valid (grid, active_handle))
+            {
+              handle_micro_move (grid, active_handle);
+            }
+
+          /* handle was added, calculate new original position */
+          g_object_get (grid,
+                        "transform", &matrix,
+                        NULL);
+
+          gimp_matrix3_invert (matrix);
+          gimp_matrix3_transform_point (matrix,
+                                        private->trans[active_handle].x,
+                                        private->trans[active_handle].y,
+                                        &private->orig[active_handle].x,
+                                        &private->orig[active_handle].y);
+
+          g_free (matrix);
+
+          private->handle = active_handle + 1;
+
+          g_object_notify (G_OBJECT (grid), "n-handles");
+        }
+      break;
+
+    case GIMP_HANDLE_MODE_MOVE:
+      /* check for valid position and calculating of OX0...OY3 is
+       * done on button release
+       */
+      break;
+
+    case GIMP_HANDLE_MODE_REMOVE:
+      if (n_handles > 0      &&
+          active_handle >= 0 &&
+          active_handle < 4)
+        {
+          /* remove handle */
+
+          GimpVector2 temp  = private->trans[active_handle];
+          GimpVector2 tempo = private->orig[active_handle];
+          gint        i;
+
+          n_handles--;
+          private->n_handles--;
+
+          for (i = active_handle; i < n_handles; i++)
+            {
+              private->trans[i] = private->trans[i + 1];
+              private->orig[i]  = private->orig[i + 1];
+            }
+
+          private->trans[n_handles] = temp;
+          private->orig[n_handles]  = tempo;
+
+          g_object_notify (G_OBJECT (grid), "n-handles");
+        }
+      break;
+    }
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+
+  return private->handle;
+}
+
+static void
+gimp_tool_handle_grid_button_release (GimpToolWidget        *widget,
+                                      const GimpCoords      *coords,
+                                      guint32                time,
+                                      GdkModifierType        state,
+                                      GimpButtonReleaseType  release_type)
+{
+  GimpToolHandleGrid        *grid          = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private       = grid->private;
+  gint                       active_handle = private->handle - 1;
+
+  if (private->handle_mode == GIMP_HANDLE_MODE_MOVE &&
+      active_handle >= 0 &&
+      active_handle < 4)
+    {
+      GimpMatrix3 *matrix;
+
+      if (! is_handle_position_valid (grid, active_handle))
+        {
+          handle_micro_move (grid, active_handle);
+        }
+
+      /* handle was moved, calculate new original position */
+      g_object_get (grid,
+                    "transform", &matrix,
+                    NULL);
+
+      gimp_matrix3_invert (matrix);
+      gimp_matrix3_transform_point (matrix,
+                                    private->trans[active_handle].x,
+                                    private->trans[active_handle].y,
+                                    &private->orig[active_handle].x,
+                                    &private->orig[active_handle].y);
+
+      g_free (matrix);
+
+      gimp_tool_handle_grid_update_matrix (grid);
+    }
+}
+
+void
+gimp_tool_handle_grid_motion (GimpToolWidget   *widget,
+                              const GimpCoords *coords,
+                              guint32           time,
+                              GdkModifierType   state)
+{
+  GimpToolHandleGrid        *grid          = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private       = grid->private;
+  gint                       n_handles     = private->n_handles;
+  gint                       active_handle = private->handle - 1;
+  gdouble                    diff_x        = coords->x - private->last_x;
+  gdouble                    diff_y        = coords->y - private->last_y;
+
+  private->mouse_x = coords->x;
+  private->mouse_y = coords->y;
+
+  if (active_handle >= 0 && active_handle < 4)
+    {
+      if (private->handle_mode == GIMP_HANDLE_MODE_MOVE)
+        {
+          private->trans[active_handle].x += diff_x;
+          private->trans[active_handle].y += diff_y;
+
+          /* check for valid position and calculating of OX0...OY3 is
+           * done on button release hopefully this makes the code run
+           * faster Moving could be even faster if there was caching
+           * for the image preview
+           */
+          gimp_canvas_handle_set_position (private->handles[active_handle + 1],
+                                           private->trans[active_handle].x,
+                                           private->trans[active_handle].y);
+        }
+      else if (private->handle_mode == GIMP_HANDLE_MODE_ADD_TRANSFORM)
+        {
+          gdouble angle, angle_sin, angle_cos, scale;
+          GimpVector2 fixed_handles[3];
+          GimpVector2 oldpos[4];
+          GimpVector2 newpos[4];
+          gint    i, j;
+
+          for (i = 0, j = 0; i < 4; i++)
+            {
+              /* Find all visible handles that are not being moved */
+              if (i < n_handles && i != active_handle)
+                {
+                  fixed_handles[j] = private->trans[i];
+                  j++;
+                }
+
+              newpos[i] = oldpos[i] = private->trans[i];
+            }
+
+          newpos[active_handle].x = oldpos[active_handle].x + diff_x;
+          newpos[active_handle].y = oldpos[active_handle].y + diff_y;
+
+          switch (n_handles)
+            {
+            case 1:
+              /* move */
+              for (i = 0; i < 4; i++)
+                {
+                  newpos[i].x = oldpos[i].x + diff_x;
+                  newpos[i].y = oldpos[i].y + diff_y;
+                }
+              break;
+
+            case 2:
+              /* rotate and keep-aspect-scale */
+              scale =
+                calc_len (newpos[active_handle].x - fixed_handles[0].x,
+                          newpos[active_handle].y - fixed_handles[0].y) /
+                calc_len (oldpos[active_handle].x - fixed_handles[0].x,
+                          oldpos[active_handle].y - fixed_handles[0].y);
+
+              angle = calc_angle (oldpos[active_handle].x - fixed_handles[0].x,
+                                  oldpos[active_handle].y - fixed_handles[0].y,
+                                  newpos[active_handle].x - fixed_handles[0].x,
+                                  newpos[active_handle].y - fixed_handles[0].y);
+
+              angle_sin = sin (angle);
+              angle_cos = cos (angle);
+
+              for (i = 2; i < 4; i++)
+                {
+                  newpos[i].x =
+                    fixed_handles[0].x +
+                    scale * (angle_cos * (oldpos[i].x - fixed_handles[0].x) +
+                             angle_sin * (oldpos[i].y - fixed_handles[0].y));
+
+                  newpos[i].y =
+                    fixed_handles[0].y +
+                    scale * (-angle_sin * (oldpos[i].x - fixed_handles[0].x) +
+                              angle_cos * (oldpos[i].y - fixed_handles[0].y));
+                }
+              break;
+
+            case 3:
+              /* shear and non-aspect-scale */
+              scale = calc_lineintersect_ratio (oldpos[3].x,
+                                                oldpos[3].y,
+                                                oldpos[active_handle].x,
+                                                oldpos[active_handle].y,
+                                                fixed_handles[0].x,
+                                                fixed_handles[0].y,
+                                                fixed_handles[1].x,
+                                                fixed_handles[1].y);
+
+              newpos[3].x = oldpos[3].x + scale * diff_x;
+              newpos[3].y = oldpos[3].y + scale * diff_y;
+              break;
+            }
+
+          for (i = 0; i < 4; i++)
+            {
+              private->trans[i] = newpos[i];
+            }
+
+          gimp_tool_handle_grid_update_matrix (grid);
+        }
+    }
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+}
+
+static GimpHit
+gimp_tool_handle_grid_hit (GimpToolWidget   *widget,
+                           const GimpCoords *coords,
+                           GdkModifierType   state,
+                           gboolean          proximity)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private = grid->private;
+
+  if (proximity)
+    {
+      gint handle = gimp_tool_handle_grid_get_handle (grid, coords);
+
+      switch (private->handle_mode)
+        {
+        case GIMP_HANDLE_MODE_ADD_TRANSFORM:
+          if (handle > 0)
+            return GIMP_HIT_DIRECT;
+          else
+            return GIMP_HIT_INDIRECT;
+          break;
+
+        case GIMP_HANDLE_MODE_MOVE:
+        case GIMP_HANDLE_MODE_REMOVE:
+          if (private->handle > 0)
+            return GIMP_HIT_DIRECT;
+          break;
+        }
+    }
+
+  return GIMP_HIT_NONE;
+}
+
+static void
+gimp_tool_handle_grid_hover (GimpToolWidget   *widget,
+                             const GimpCoords *coords,
+                             GdkModifierType   state,
+                             gboolean          proximity)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private = grid->private;
+  gchar                     *status  = NULL;
+
+  private->hover   = TRUE;
+  private->mouse_x = coords->x;
+  private->mouse_y = coords->y;
+
+  private->handle = gimp_tool_handle_grid_get_handle (grid, coords);
+
+  if (proximity)
+    {
+      GdkModifierType extend_mask = gimp_get_extend_selection_mask ();
+      GdkModifierType toggle_mask = gimp_get_toggle_behavior_mask ();
+
+      switch (private->handle_mode)
+        {
+        case GIMP_HANDLE_MODE_ADD_TRANSFORM:
+          if (private->handle > 0)
+            {
+              const gchar *s = NULL;
+
+              switch (private->n_handles)
+                {
+                case 1:
+                  s = _("Click-Drag to move");
+                  break;
+                case 2:
+                  s = _("Click-Drag to rotate and scale");
+                  break;
+                case 3:
+                  s = _("Click-Drag to shear and scale");
+                  break;
+                case 4:
+                  s = _("Click-Drag to change perspective");
+                  break;
+                }
+
+              status = gimp_suggest_modifiers (s,
+                                               extend_mask | toggle_mask,
+                                               NULL, NULL, NULL);
+            }
+          else
+            {
+              if (private->n_handles < 4)
+                status = g_strdup (_("Click to add a handle"));
+            }
+          break;
+
+        case GIMP_HANDLE_MODE_MOVE:
+          if (private->handle > 0)
+            status = g_strdup (_("Click-Drag to move this handle"));
+          break;
+
+        case GIMP_HANDLE_MODE_REMOVE:
+          if (private->handle > 0)
+            status = g_strdup (_("Click-Drag to remove this handle"));
+          break;
+        }
+    }
+
+  gimp_tool_widget_set_status (widget, status);
+  g_free (status);
+
+  gimp_tool_handle_grid_update_hilight (grid);
+}
+
+static void
+gimp_tool_handle_grid_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private = grid->private;
+
+  private->hover  = FALSE;
+  private->handle = 0;
+
+  gimp_tool_handle_grid_update_hilight (grid);
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
+}
+
+static gboolean
+gimp_tool_handle_grid_get_cursor (GimpToolWidget     *widget,
+                                  const GimpCoords   *coords,
+                                  GdkModifierType     state,
+                                  GimpCursorType     *cursor,
+                                  GimpToolCursorType *tool_cursor,
+                                  GimpCursorModifier *modifier)
+{
+  GimpToolHandleGrid        *grid    = GIMP_TOOL_HANDLE_GRID (widget);
+  GimpToolHandleGridPrivate *private = grid->private;
+
+  *cursor      = GIMP_CURSOR_CROSSHAIR_SMALL;
+  *tool_cursor = GIMP_TOOL_CURSOR_NONE;
+  *modifier    = GIMP_CURSOR_MODIFIER_NONE;
+
+  switch (private->handle_mode)
+    {
+    case GIMP_HANDLE_MODE_ADD_TRANSFORM:
+      if (private->handle > 0)
+        {
+          switch (private->n_handles)
+            {
+            case 1:
+              *tool_cursor = GIMP_TOOL_CURSOR_MOVE;
+              break;
+            case 2:
+              *tool_cursor = GIMP_TOOL_CURSOR_ROTATE;
+              break;
+            case 3:
+              *tool_cursor = GIMP_TOOL_CURSOR_SHEAR;
+              break;
+            case 4:
+              *tool_cursor = GIMP_TOOL_CURSOR_PERSPECTIVE;
+              break;
+            }
+        }
+      else
+        {
+          if (private->n_handles < 4)
+            *modifier = GIMP_CURSOR_MODIFIER_PLUS;
+          else
+            *modifier = GIMP_CURSOR_MODIFIER_BAD;
+        }
+      break;
+
+    case GIMP_HANDLE_MODE_MOVE:
+      if (private->handle > 0)
+        *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+      else
+        *modifier = GIMP_CURSOR_MODIFIER_BAD;
+      break;
+
+    case GIMP_HANDLE_MODE_REMOVE:
+      if (private->handle > 0)
+        *modifier = GIMP_CURSOR_MODIFIER_MINUS;
+      else
+        *modifier = GIMP_CURSOR_MODIFIER_BAD;
+      break;
+    }
+
+  return TRUE;
+}
+
+static gint
+gimp_tool_handle_grid_get_handle (GimpToolHandleGrid *grid,
+                                  const GimpCoords   *coords)
+{
+  GimpToolHandleGridPrivate *private = grid->private;
+  gint                       i;
+
+  for (i = 0; i < 4; i++)
+    {
+      if (private->handles[i + 1] &&
+          gimp_canvas_item_hit (private->handles[i + 1],
+                                coords->x, coords->y))
+        {
+          return i + 1;
+        }
+    }
+
+  return 0;
+}
+
+static void
+gimp_tool_handle_grid_update_hilight (GimpToolHandleGrid *grid)
+{
+  GimpToolHandleGridPrivate *private = grid->private;
+  gint                       i;
+
+  for (i = 0; i < 4; i++)
+    {
+      GimpCanvasItem *item = private->handles[i + 1];
+
+      if (item)
+        {
+          gdouble diameter = GIMP_CANVAS_HANDLE_SIZE_CIRCLE;
+
+          if (private->hover)
+            {
+              diameter = gimp_canvas_handle_calc_size (
+                item,
+                private->mouse_x,
+                private->mouse_y,
+                GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                2 * GIMP_CANVAS_HANDLE_SIZE_CIRCLE);
+            }
+
+          gimp_canvas_handle_set_size (item, diameter, diameter);
+          gimp_canvas_item_set_highlight (item, (i + 1) == private->handle);
+        }
+    }
+}
+
+static void
+gimp_tool_handle_grid_update_matrix (GimpToolHandleGrid *grid)
+{
+  GimpToolHandleGridPrivate *private = grid->private;
+  GimpMatrix3                transform;
+  gboolean                   transform_valid;
+
+  gimp_matrix3_identity (&transform);
+  transform_valid = gimp_transform_matrix_generic (&transform,
+                                                   private->orig,
+                                                   private->trans);
+
+  g_object_set (grid,
+                "transform",   &transform,
+                "show-guides", transform_valid,
+                NULL);
+}
+
+/* check if a handle is not on the connection line of two other handles */
+static gboolean
+is_handle_position_valid (GimpToolHandleGrid *grid,
+                          gint                handle)
+{
+  GimpToolHandleGridPrivate *private = grid->private;
+  gint                       i, j, k;
+
+  for (i = 0; i < 2; i++)
+    {
+      for (j = i + 1; j < 3; j++)
+        {
+          for (k = j + 1; i < 4; i++)
+            {
+              if (handle == i ||
+                  handle == j ||
+                  handle == k)
+                {
+                  if ((private->trans[i].x -
+                       private->trans[j].x) *
+                      (private->trans[j].y -
+                       private->trans[k].y) ==
+
+                      (private->trans[j].x -
+                       private->trans[k].x) *
+                      (private->trans[i].y -
+                       private->trans[j].y))
+                    {
+                      return FALSE;
+                    }
+                }
+            }
+        }
+    }
+
+  return TRUE;
+}
+
+/* three handles on a line causes problems.
+ * Let's move the new handle around a bit to find a better position */
+static void
+handle_micro_move (GimpToolHandleGrid *grid,
+                   gint                handle)
+{
+  GimpToolHandleGridPrivate *private = grid->private;
+  gdouble                    posx    = private->trans[handle].x;
+  gdouble                    posy    = private->trans[handle].y;
+  gdouble                    dx, dy;
+
+  for (dx = -0.1; dx < 0.11; dx += 0.1)
+    {
+      private->trans[handle].x = posx + dx;
+
+      for (dy = -0.1; dy < 0.11; dy += 0.1)
+        {
+          private->trans[handle].y = posy + dy;
+
+          if (is_handle_position_valid (grid, handle))
+            {
+              return;
+            }
+        }
+    }
+}
+
+/* finds the clockwise angle between the vectors given, 0-2π */
+static inline gdouble
+calc_angle (gdouble ax,
+            gdouble ay,
+            gdouble bx,
+            gdouble by)
+{
+  gdouble angle;
+  gdouble direction;
+  gdouble length = sqrt ((ax * ax + ay * ay) * (bx * bx + by * by));
+
+  angle = acos ((ax * bx + ay * by) / length);
+  direction = ax * by - ay * bx;
+
+  return ((direction < 0) ? angle : 2 * G_PI - angle);
+}
+
+static inline gdouble
+calc_len  (gdouble a,
+           gdouble b)
+{
+  return sqrt (a * a + b * b);
+}
+
+/* imagine two lines, one through the points p1 and p2, the other one
+ * through the points q1 and q2. Find the intersection point r.
+ * Calculate (distance p1 to r)/(distance p2 to r)
+ */
+static inline gdouble
+calc_lineintersect_ratio (gdouble p1x, gdouble p1y,
+                          gdouble p2x, gdouble p2y,
+                          gdouble q1x, gdouble q1y,
+                          gdouble q2x, gdouble q2y)
+{
+  gdouble denom, u;
+
+  denom = (q2y - q1y) * (p2x - p1x) - (q2x - q1x) * (p2y - p1y);
+  if (denom == 0.0)
+    {
+      /* u is infinite, so u/(u-1) is 1 */
+      return 1.0;
+    }
+
+  u = (q2y - q1y) * (q1x - p1x) - (q1y - p1y) * (q2x - q1x);
+  u /= denom;
+
+  return u / (u - 1);
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_handle_grid_new (GimpDisplayShell *shell,
+                           gdouble           x1,
+                           gdouble           y1,
+                           gdouble           x2,
+                           gdouble           y2)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_HANDLE_GRID,
+                       "shell",       shell,
+                       "x1",          x1,
+                       "y1",          y1,
+                       "x2",          x2,
+                       "y2",          y2,
+                       "clip-guides", TRUE,
+                       NULL);
+}
diff --git a/app/display/gimptoolhandlegrid.h b/app/display/gimptoolhandlegrid.h
new file mode 100644
index 0000000..77d31dc
--- /dev/null
+++ b/app/display/gimptoolhandlegrid.h
@@ -0,0 +1,62 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolhandlegrid.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_HANDLE_GRID_H__
+#define __GIMP_TOOL_HANDLE_GRID_H__
+
+
+#include "gimptooltransformgrid.h"
+
+
+#define GIMP_TYPE_TOOL_HANDLE_GRID            (gimp_tool_handle_grid_get_type ())
+#define GIMP_TOOL_HANDLE_GRID(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_HANDLE_GRID, GimpToolHandleGrid))
+#define GIMP_TOOL_HANDLE_GRID_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_HANDLE_GRID, GimpToolHandleGridClass))
+#define GIMP_IS_TOOL_HANDLE_GRID(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_HANDLE_GRID))
+#define GIMP_IS_TOOL_HANDLE_GRID_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_HANDLE_GRID))
+#define GIMP_TOOL_HANDLE_GRID_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_HANDLE_GRID, GimpToolHandleGridClass))
+
+
+typedef struct _GimpToolHandleGrid        GimpToolHandleGrid;
+typedef struct _GimpToolHandleGridPrivate GimpToolHandleGridPrivate;
+typedef struct _GimpToolHandleGridClass   GimpToolHandleGridClass;
+
+struct _GimpToolHandleGrid
+{
+  GimpToolTransformGrid      parent_instance;
+
+  GimpToolHandleGridPrivate *private;
+};
+
+struct _GimpToolHandleGridClass
+{
+  GimpToolTransformGridClass  parent_class;
+};
+
+
+GType            gimp_tool_handle_grid_get_type (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_handle_grid_new      (GimpDisplayShell  *shell,
+                                                 gdouble            x1,
+                                                 gdouble            y1,
+                                                 gdouble            x2,
+                                                 gdouble            y2);
+
+
+#endif /* __GIMP_TOOL_HANDLE_GRID_H__ */
diff --git a/app/display/gimptoolline.c b/app/display/gimptoolline.c
new file mode 100644
index 0000000..271f926
--- /dev/null
+++ b/app/display/gimptoolline.c
@@ -0,0 +1,1796 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolline.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Major improvements for interactivity
+ * Copyright (C) 2014 Michael Henning <drawoc@darkrefraction.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-utils.h"
+#include "core/gimpmarshal.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvasgroup.h"
+#include "gimpcanvashandle.h"
+#include "gimpcanvasline.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-cursor.h"
+#include "gimpdisplayshell-utils.h"
+#include "gimptoolline.h"
+
+#include "gimp-intl.h"
+
+
+#define SHOW_LINE            TRUE
+#define GRAB_LINE_MASK       GDK_MOD1_MASK
+#define ENDPOINT_HANDLE_TYPE GIMP_HANDLE_CROSS
+#define ENDPOINT_HANDLE_SIZE GIMP_CANVAS_HANDLE_SIZE_CROSS
+#define SLIDER_HANDLE_TYPE   GIMP_HANDLE_FILLED_DIAMOND
+#define SLIDER_HANDLE_SIZE   (ENDPOINT_HANDLE_SIZE * 2 / 3)
+#define HANDLE_CIRCLE_SCALE  1.8
+#define LINE_VICINITY        ((gint) (SLIDER_HANDLE_SIZE * HANDLE_CIRCLE_SCALE) / 2)
+#define SLIDER_TEAR_DISTANCE (5 * LINE_VICINITY)
+
+
+/* hover-only "handles" */
+#define HOVER_NEW_SLIDER     (GIMP_TOOL_LINE_HANDLE_NONE - 1)
+
+
+typedef enum
+{
+  GRAB_NONE,
+  GRAB_SELECTION,
+  GRAB_LINE
+} GimpToolLineGrab;
+
+enum
+{
+  PROP_0,
+  PROP_X1,
+  PROP_Y1,
+  PROP_X2,
+  PROP_Y2,
+  PROP_SLIDERS,
+  PROP_SELECTION,
+  PROP_STATUS_TITLE,
+};
+
+enum
+{
+  CAN_ADD_SLIDER,
+  ADD_SLIDER,
+  PREPARE_TO_REMOVE_SLIDER,
+  REMOVE_SLIDER,
+  SELECTION_CHANGED,
+  HANDLE_CLICKED,
+  LAST_SIGNAL
+};
+
+struct _GimpToolLinePrivate
+{
+  gdouble            x1;
+  gdouble            y1;
+  gdouble            x2;
+  gdouble            y2;
+  GArray            *sliders;
+  gint               selection;
+  gchar             *status_title;
+
+  gdouble            saved_x1;
+  gdouble            saved_y1;
+  gdouble            saved_x2;
+  gdouble            saved_y2;
+  gdouble            saved_slider_value;
+
+  gdouble            mouse_x;
+  gdouble            mouse_y;
+  gint               hover;
+  gdouble            new_slider_value;
+  gboolean           remove_slider;
+  GimpToolLineGrab   grab;
+
+  GimpCanvasItem    *line;
+  GimpCanvasItem    *start_handle;
+  GimpCanvasItem    *end_handle;
+  GimpCanvasItem    *slider_group;
+  GArray            *slider_handles;
+  GimpCanvasItem    *handle_circle;
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_line_constructed     (GObject               *object);
+static void     gimp_tool_line_finalize        (GObject               *object);
+static void     gimp_tool_line_set_property    (GObject               *object,
+                                                guint                  property_id,
+                                                const GValue          *value,
+                                                GParamSpec            *pspec);
+static void     gimp_tool_line_get_property    (GObject               *object,
+                                                guint                  property_id,
+                                                GValue                *value,
+                                                GParamSpec            *pspec);
+
+static void     gimp_tool_line_changed         (GimpToolWidget        *widget);
+static void     gimp_tool_line_focus_changed   (GimpToolWidget        *widget);
+static gint     gimp_tool_line_button_press    (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                guint32                time,
+                                                GdkModifierType        state,
+                                                GimpButtonPressType    press_type);
+static void     gimp_tool_line_button_release  (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                guint32                time,
+                                                GdkModifierType        state,
+                                                GimpButtonReleaseType  release_type);
+static void     gimp_tool_line_motion          (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                guint32                time,
+                                                GdkModifierType        state);
+static GimpHit  gimp_tool_line_hit             (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state,
+                                                gboolean               proximity);
+static void     gimp_tool_line_hover           (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state,
+                                                gboolean               proximity);
+static void     gimp_tool_line_leave_notify    (GimpToolWidget        *widget);
+static gboolean gimp_tool_line_key_press       (GimpToolWidget        *widget,
+                                                GdkEventKey           *kevent);
+static void     gimp_tool_line_motion_modifier (GimpToolWidget        *widget,
+                                                GdkModifierType        key,
+                                                gboolean               press,
+                                                GdkModifierType        state);
+static gboolean gimp_tool_line_get_cursor      (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state,
+                                                GimpCursorType        *cursor,
+                                                GimpToolCursorType    *tool_cursor,
+                                                GimpCursorModifier    *modifier);
+
+static gint     gimp_tool_line_get_hover       (GimpToolLine          *line,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state);
+static GimpControllerSlider *
+                gimp_tool_line_get_slider      (GimpToolLine          *line,
+                                                gint                   slider);
+static GimpCanvasItem *
+                gimp_tool_line_get_handle      (GimpToolLine          *line,
+                                                gint                   handle);
+static gdouble  gimp_tool_line_project_point   (GimpToolLine          *line,
+                                                gdouble                x,
+                                                gdouble                y,
+                                                gboolean               constrain,
+                                                gdouble               *dist);
+
+static gboolean
+               gimp_tool_line_selection_motion (GimpToolLine          *line,
+                                                gboolean               constrain);
+
+static void     gimp_tool_line_update_handles  (GimpToolLine          *line);
+static void     gimp_tool_line_update_circle   (GimpToolLine          *line);
+static void     gimp_tool_line_update_hilight  (GimpToolLine          *line);
+static void     gimp_tool_line_update_status   (GimpToolLine          *line,
+                                                GdkModifierType        state,
+                                                gboolean               proximity);
+
+static gboolean gimp_tool_line_handle_hit      (GimpCanvasItem        *handle,
+                                                gdouble                x,
+                                                gdouble                y,
+                                                gdouble               *min_dist);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolLine, gimp_tool_line, GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_line_parent_class
+
+static guint line_signals[LAST_SIGNAL] = { 0, };
+
+
+static void
+gimp_tool_line_class_init (GimpToolLineClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_line_constructed;
+  object_class->finalize        = gimp_tool_line_finalize;
+  object_class->set_property    = gimp_tool_line_set_property;
+  object_class->get_property    = gimp_tool_line_get_property;
+
+  widget_class->changed         = gimp_tool_line_changed;
+  widget_class->focus_changed   = gimp_tool_line_focus_changed;
+  widget_class->button_press    = gimp_tool_line_button_press;
+  widget_class->button_release  = gimp_tool_line_button_release;
+  widget_class->motion          = gimp_tool_line_motion;
+  widget_class->hit             = gimp_tool_line_hit;
+  widget_class->hover           = gimp_tool_line_hover;
+  widget_class->leave_notify    = gimp_tool_line_leave_notify;
+  widget_class->key_press       = gimp_tool_line_key_press;
+  widget_class->motion_modifier = gimp_tool_line_motion_modifier;
+  widget_class->get_cursor      = gimp_tool_line_get_cursor;
+
+  line_signals[CAN_ADD_SLIDER] =
+    g_signal_new ("can-add-slider",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GimpToolLineClass, can_add_slider),
+                  NULL, NULL,
+                  gimp_marshal_BOOLEAN__DOUBLE,
+                  G_TYPE_BOOLEAN, 1,
+                  G_TYPE_DOUBLE);
+
+  line_signals[ADD_SLIDER] =
+    g_signal_new ("add-slider",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GimpToolLineClass, add_slider),
+                  NULL, NULL,
+                  gimp_marshal_INT__DOUBLE,
+                  G_TYPE_INT, 1,
+                  G_TYPE_DOUBLE);
+
+  line_signals[PREPARE_TO_REMOVE_SLIDER] =
+    g_signal_new ("prepare-to-remove-slider",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolLineClass, prepare_to_remove_slider),
+                  NULL, NULL,
+                  gimp_marshal_VOID__INT_BOOLEAN,
+                  G_TYPE_NONE, 2,
+                  G_TYPE_INT,
+                  G_TYPE_BOOLEAN);
+
+  line_signals[REMOVE_SLIDER] =
+    g_signal_new ("remove-slider",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolLineClass, remove_slider),
+                  NULL, NULL,
+                  gimp_marshal_VOID__INT,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_INT);
+
+  line_signals[SELECTION_CHANGED] =
+    g_signal_new ("selection-changed",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolLineClass, selection_changed),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  line_signals[HANDLE_CLICKED] =
+    g_signal_new ("handle-clicked",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GimpToolLineClass, handle_clicked),
+                  NULL, NULL,
+                  gimp_marshal_BOOLEAN__INT_UINT_ENUM,
+                  G_TYPE_BOOLEAN, 3,
+                  G_TYPE_INT,
+                  G_TYPE_UINT,
+                  GIMP_TYPE_BUTTON_PRESS_TYPE);
+
+  g_object_class_install_property (object_class, PROP_X1,
+                                   g_param_spec_double ("x1", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y1,
+                                   g_param_spec_double ("y1", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X2,
+                                   g_param_spec_double ("x2", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y2,
+                                   g_param_spec_double ("y2", NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE, 0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_SLIDERS,
+                                   g_param_spec_boxed ("sliders", NULL, NULL,
+                                                       G_TYPE_ARRAY,
+                                                       GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_SELECTION,
+                                   g_param_spec_int ("selection", NULL, NULL,
+                                                     GIMP_TOOL_LINE_HANDLE_NONE,
+                                                     G_MAXINT,
+                                                     GIMP_TOOL_LINE_HANDLE_NONE,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_STATUS_TITLE,
+                                   g_param_spec_string ("status-title",
+                                                        NULL, NULL,
+                                                        _("Line: "),
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_line_init (GimpToolLine *line)
+{
+  GimpToolLinePrivate *private;
+
+  private = line->private = gimp_tool_line_get_instance_private (line);
+
+  private->sliders = g_array_new (FALSE, FALSE, sizeof (GimpControllerSlider));
+
+  private->selection = GIMP_TOOL_LINE_HANDLE_NONE;
+  private->hover     = GIMP_TOOL_LINE_HANDLE_NONE;
+  private->grab      = GRAB_NONE;
+
+  private->slider_handles = g_array_new (FALSE, TRUE,
+                                         sizeof (GimpCanvasItem *));
+}
+
+static void
+gimp_tool_line_constructed (GObject *object)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (object);
+  GimpToolWidget      *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolLinePrivate *private = line->private;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  private->line = gimp_tool_widget_add_line (widget,
+                                             private->x1,
+                                             private->y1,
+                                             private->x2,
+                                             private->y2);
+
+  gimp_canvas_item_set_visible (private->line, SHOW_LINE);
+
+  private->start_handle =
+    gimp_tool_widget_add_handle (widget,
+                                 ENDPOINT_HANDLE_TYPE,
+                                 private->x1,
+                                 private->y1,
+                                 ENDPOINT_HANDLE_SIZE,
+                                 ENDPOINT_HANDLE_SIZE,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+  private->end_handle =
+    gimp_tool_widget_add_handle (widget,
+                                 ENDPOINT_HANDLE_TYPE,
+                                 private->x2,
+                                 private->y2,
+                                 ENDPOINT_HANDLE_SIZE,
+                                 ENDPOINT_HANDLE_SIZE,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+  private->slider_group =
+    gimp_canvas_group_new (gimp_tool_widget_get_shell (widget));
+  gimp_tool_widget_add_item (widget, private->slider_group);
+  g_object_unref (private->slider_group);
+
+  private->handle_circle =
+    gimp_tool_widget_add_handle (widget,
+                                 GIMP_HANDLE_CIRCLE,
+                                 private->x1,
+                                 private->y1,
+                                 ENDPOINT_HANDLE_SIZE * HANDLE_CIRCLE_SCALE,
+                                 ENDPOINT_HANDLE_SIZE * HANDLE_CIRCLE_SCALE,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+  gimp_tool_line_changed (widget);
+}
+
+static void
+gimp_tool_line_finalize (GObject *object)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (object);
+  GimpToolLinePrivate *private = line->private;
+
+  g_clear_pointer (&private->sliders, g_array_unref);
+  g_clear_pointer (&private->status_title, g_free);
+  g_clear_pointer (&private->slider_handles, g_array_unref);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_tool_line_set_property (GObject      *object,
+                             guint         property_id,
+                             const GValue *value,
+                             GParamSpec   *pspec)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (object);
+  GimpToolLinePrivate *private = line->private;
+
+  switch (property_id)
+    {
+    case PROP_X1:
+      private->x1 = g_value_get_double (value);
+      break;
+    case PROP_Y1:
+      private->y1 = g_value_get_double (value);
+      break;
+    case PROP_X2:
+      private->x2 = g_value_get_double (value);
+      break;
+    case PROP_Y2:
+      private->y2 = g_value_get_double (value);
+      break;
+
+    case PROP_SLIDERS:
+      {
+        GArray   *sliders = g_value_dup_boxed (value);
+        gboolean  deselect;
+
+        g_return_if_fail (sliders != NULL);
+
+        deselect =
+          GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->selection) &&
+          (sliders->len != private->sliders->len               ||
+           ! gimp_tool_line_get_slider (line, private->selection)->selectable);
+
+        g_array_unref (private->sliders);
+        private->sliders = sliders;
+
+        if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->hover))
+          private->hover = GIMP_TOOL_LINE_HANDLE_NONE;
+
+        if (deselect)
+          gimp_tool_line_set_selection (line, GIMP_TOOL_LINE_HANDLE_NONE);
+      }
+      break;
+
+    case PROP_SELECTION:
+      {
+        gint selection = g_value_get_int (value);
+
+        g_return_if_fail (selection < (gint) private->sliders->len);
+        g_return_if_fail (selection < 0 ||
+                          gimp_tool_line_get_slider (line,
+                                                     selection)->selectable);
+
+        if (selection != private->selection)
+          {
+            private->selection = selection;
+
+            if (private->grab == GRAB_SELECTION)
+              private->grab = GRAB_NONE;
+
+            g_signal_emit (line, line_signals[SELECTION_CHANGED], 0);
+          }
+      }
+      break;
+
+    case PROP_STATUS_TITLE:
+      g_free (private->status_title);
+      private->status_title = g_value_dup_string (value);
+      if (! private->status_title)
+        private->status_title = g_strdup (_("Line: "));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_line_get_property (GObject    *object,
+                             guint       property_id,
+                             GValue     *value,
+                             GParamSpec *pspec)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (object);
+  GimpToolLinePrivate *private = line->private;
+
+  switch (property_id)
+    {
+    case PROP_X1:
+      g_value_set_double (value, private->x1);
+      break;
+    case PROP_Y1:
+      g_value_set_double (value, private->y1);
+      break;
+    case PROP_X2:
+      g_value_set_double (value, private->x2);
+      break;
+    case PROP_Y2:
+      g_value_set_double (value, private->y2);
+      break;
+
+    case PROP_SLIDERS:
+      g_value_set_boxed (value, private->sliders);
+      break;
+
+    case PROP_SELECTION:
+      g_value_set_int (value, private->selection);
+      break;
+
+    case PROP_STATUS_TITLE:
+      g_value_set_string (value, private->status_title);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_line_changed (GimpToolWidget *widget)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+  gint                 i;
+
+  gimp_canvas_line_set (private->line,
+                        private->x1,
+                        private->y1,
+                        private->x2,
+                        private->y2);
+
+  gimp_canvas_handle_set_position (private->start_handle,
+                                   private->x1,
+                                   private->y1);
+
+  gimp_canvas_handle_set_position (private->end_handle,
+                                   private->x2,
+                                   private->y2);
+
+  /* remove excessive slider handles */
+  for (i = private->sliders->len; i < private->slider_handles->len; i++)
+    {
+      gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (private->slider_group),
+                                     gimp_tool_line_get_handle (line, i));
+    }
+
+  g_array_set_size (private->slider_handles, private->sliders->len);
+
+  for (i = 0; i < private->sliders->len; i++)
+    {
+      gdouble          value;
+      gdouble          x;
+      gdouble          y;
+      GimpCanvasItem **handle;
+
+      value = gimp_tool_line_get_slider (line, i)->value;
+
+      x = private->x1 + (private->x2 - private->x1) * value;
+      y = private->y1 + (private->y2 - private->y1) * value;
+
+      handle = &g_array_index (private->slider_handles, GimpCanvasItem *, i);
+
+      if (*handle)
+        {
+          gimp_canvas_handle_set_position (*handle, x, y);
+        }
+      else
+        {
+          *handle = gimp_canvas_handle_new (gimp_tool_widget_get_shell (widget),
+                                            SLIDER_HANDLE_TYPE,
+                                            GIMP_HANDLE_ANCHOR_CENTER,
+                                            x,
+                                            y,
+                                            SLIDER_HANDLE_SIZE,
+                                            SLIDER_HANDLE_SIZE);
+
+          gimp_canvas_group_add_item (GIMP_CANVAS_GROUP (private->slider_group),
+                                      *handle);
+          g_object_unref (*handle);
+        }
+    }
+
+  gimp_tool_line_update_handles (line);
+  gimp_tool_line_update_circle (line);
+  gimp_tool_line_update_hilight (line);
+}
+
+static void
+gimp_tool_line_focus_changed (GimpToolWidget *widget)
+{
+  GimpToolLine *line = GIMP_TOOL_LINE (widget);
+
+  gimp_tool_line_update_hilight (line);
+}
+
+gboolean
+gimp_tool_line_button_press (GimpToolWidget      *widget,
+                             const GimpCoords    *coords,
+                             guint32              time,
+                             GdkModifierType      state,
+                             GimpButtonPressType  press_type)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+  gboolean             result  = FALSE;
+
+  private->grab          = GRAB_NONE;
+  private->remove_slider = FALSE;
+
+  private->saved_x1 = private->x1;
+  private->saved_y1 = private->y1;
+  private->saved_x2 = private->x2;
+  private->saved_y2 = private->y2;
+
+  if (press_type         != GIMP_BUTTON_PRESS_NORMAL   &&
+      private->hover      > GIMP_TOOL_LINE_HANDLE_NONE &&
+      private->selection  > GIMP_TOOL_LINE_HANDLE_NONE)
+    {
+      g_signal_emit (line, line_signals[HANDLE_CLICKED], 0,
+                     private->selection, state, press_type, &result);
+
+      if (! result)
+        gimp_tool_widget_hover (widget, coords, state, TRUE);
+    }
+
+  if (press_type == GIMP_BUTTON_PRESS_NORMAL || ! result)
+    {
+      private->saved_x1 = private->x1;
+      private->saved_y1 = private->y1;
+      private->saved_x2 = private->x2;
+      private->saved_y2 = private->y2;
+
+      if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->hover))
+        {
+          private->saved_slider_value =
+            gimp_tool_line_get_slider (line, private->hover)->value;
+        }
+
+      if (private->hover > GIMP_TOOL_LINE_HANDLE_NONE)
+        {
+          gimp_tool_line_set_selection (line, private->hover);
+
+          private->grab = GRAB_SELECTION;
+        }
+      else if (private->hover == HOVER_NEW_SLIDER)
+        {
+          gint slider;
+
+          g_signal_emit (line, line_signals[ADD_SLIDER], 0,
+                         private->new_slider_value, &slider);
+
+          g_return_val_if_fail (slider < (gint) private->sliders->len, FALSE);
+
+          if (slider >= 0)
+            {
+              gimp_tool_line_set_selection (line, slider);
+
+              private->saved_slider_value =
+                gimp_tool_line_get_slider (line, private->selection)->value;
+
+              private->grab = GRAB_SELECTION;
+            }
+        }
+      else if (state & GRAB_LINE_MASK)
+        {
+          private->grab = GRAB_LINE;
+        }
+
+      result = (private->grab != GRAB_NONE);
+    }
+
+  if (! result)
+    {
+      private->hover = GIMP_TOOL_LINE_HANDLE_NONE;
+
+      gimp_tool_line_set_selection (line, GIMP_TOOL_LINE_HANDLE_NONE);
+    }
+
+  gimp_tool_line_update_handles (line);
+  gimp_tool_line_update_circle (line);
+  gimp_tool_line_update_status (line, state, TRUE);
+
+  return result;
+}
+
+void
+gimp_tool_line_button_release (GimpToolWidget        *widget,
+                               const GimpCoords      *coords,
+                               guint32                time,
+                               GdkModifierType        state,
+                               GimpButtonReleaseType  release_type)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+  GimpToolLineGrab     grab    = private->grab;
+
+  private->grab = GRAB_NONE;
+
+  if (release_type == GIMP_BUTTON_RELEASE_CANCEL)
+    {
+      if (grab != GRAB_NONE)
+        {
+          if (grab == GRAB_SELECTION &&
+              GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->selection))
+            {
+              gimp_tool_line_get_slider (line, private->selection)->value =
+                private->saved_slider_value;
+
+              if (private->remove_slider)
+                {
+                  private->remove_slider = FALSE;
+
+                  g_signal_emit (line, line_signals[PREPARE_TO_REMOVE_SLIDER], 0,
+                                 private->selection, FALSE);
+                }
+            }
+
+          g_object_set (line,
+                        "x1", private->saved_x1,
+                        "y1", private->saved_y1,
+                        "x2", private->saved_x2,
+                        "y2", private->saved_y2,
+                        NULL);
+        }
+    }
+  else if (grab == GRAB_SELECTION)
+    {
+      if (private->remove_slider)
+        {
+          private->remove_slider = FALSE;
+
+          g_signal_emit (line, line_signals[REMOVE_SLIDER], 0,
+                         private->selection);
+        }
+      else if (release_type == GIMP_BUTTON_RELEASE_CLICK)
+        {
+          gboolean result;
+
+          g_signal_emit (line, line_signals[HANDLE_CLICKED], 0,
+                         private->selection, state, GIMP_BUTTON_PRESS_NORMAL,
+                         &result);
+        }
+    }
+}
+
+void
+gimp_tool_line_motion (GimpToolWidget   *widget,
+                       const GimpCoords *coords,
+                       guint32           time,
+                       GdkModifierType   state)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+  gdouble              diff_x  = coords->x - private->mouse_x;
+  gdouble              diff_y  = coords->y - private->mouse_y;
+
+  private->mouse_x = coords->x;
+  private->mouse_y = coords->y;
+
+  if (private->grab == GRAB_LINE)
+    {
+      g_object_set (line,
+                    "x1", private->x1 + diff_x,
+                    "y1", private->y1 + diff_y,
+                    "x2", private->x2 + diff_x,
+                    "y2", private->y2 + diff_y,
+                    NULL);
+    }
+  else
+    {
+      gboolean constrain = (state & gimp_get_constrain_behavior_mask ()) != 0;
+
+      gimp_tool_line_selection_motion (line, constrain);
+    }
+
+  gimp_tool_line_update_status (line, state, TRUE);
+}
+
+GimpHit
+gimp_tool_line_hit (GimpToolWidget   *widget,
+                    const GimpCoords *coords,
+                    GdkModifierType   state,
+                    gboolean          proximity)
+{
+  GimpToolLine *line = GIMP_TOOL_LINE (widget);
+
+  if (! (state & GRAB_LINE_MASK))
+    {
+      gint hover = gimp_tool_line_get_hover (line, coords, state);
+
+      if (hover != GIMP_TOOL_LINE_HANDLE_NONE)
+        return GIMP_HIT_DIRECT;
+    }
+  else
+    {
+      return GIMP_HIT_INDIRECT;
+    }
+
+  return GIMP_HIT_NONE;
+}
+
+void
+gimp_tool_line_hover (GimpToolWidget   *widget,
+                      const GimpCoords *coords,
+                      GdkModifierType   state,
+                      gboolean          proximity)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+
+  private->mouse_x = coords->x;
+  private->mouse_y = coords->y;
+
+  if (! (state & GRAB_LINE_MASK))
+    private->hover = gimp_tool_line_get_hover (line, coords, state);
+  else
+    private->hover = GIMP_TOOL_LINE_HANDLE_NONE;
+
+  gimp_tool_line_update_handles (line);
+  gimp_tool_line_update_circle (line);
+  gimp_tool_line_update_status (line, state, proximity);
+}
+
+static void
+gimp_tool_line_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+
+  private->hover = GIMP_TOOL_LINE_HANDLE_NONE;
+
+  gimp_tool_line_update_handles (line);
+  gimp_tool_line_update_circle (line);
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
+}
+
+static gboolean
+gimp_tool_line_key_press (GimpToolWidget *widget,
+                          GdkEventKey    *kevent)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+  GimpDisplayShell    *shell;
+  gdouble              pixels  = 1.0;
+  gboolean             move_line;
+
+  move_line = kevent->state & GRAB_LINE_MASK;
+
+  if (private->selection == GIMP_TOOL_LINE_HANDLE_NONE && ! move_line)
+    return GIMP_TOOL_WIDGET_CLASS (parent_class)->key_press (widget, kevent);
+
+  shell = gimp_tool_widget_get_shell (widget);
+
+  if (kevent->state & gimp_get_extend_selection_mask ())
+    pixels = 10.0;
+
+  if (kevent->state & gimp_get_toggle_behavior_mask ())
+    pixels = 50.0;
+
+  switch (kevent->keyval)
+    {
+    case GDK_KEY_Left:
+    case GDK_KEY_Right:
+    case GDK_KEY_Up:
+    case GDK_KEY_Down:
+      /* move an endpoint (or both endpoints) */
+      if (private->selection < 0 || move_line)
+        {
+          gdouble xdist, ydist;
+          gdouble dx,    dy;
+
+          xdist = FUNSCALEX (shell, pixels);
+          ydist = FUNSCALEY (shell, pixels);
+
+          dx = 0.0;
+          dy = 0.0;
+
+          switch (kevent->keyval)
+            {
+            case GDK_KEY_Left:  dx = -xdist; break;
+            case GDK_KEY_Right: dx = +xdist; break;
+            case GDK_KEY_Up:    dy = -ydist; break;
+            case GDK_KEY_Down:  dy = +ydist; break;
+            }
+
+          if (private->selection == GIMP_TOOL_LINE_HANDLE_START || move_line)
+            {
+              g_object_set (line,
+                            "x1", private->x1 + dx,
+                            "y1", private->y1 + dy,
+                            NULL);
+            }
+
+          if (private->selection == GIMP_TOOL_LINE_HANDLE_END || move_line)
+            {
+              g_object_set (line,
+                            "x2", private->x2 + dx,
+                            "y2", private->y2 + dy,
+                            NULL);
+            }
+        }
+      /* move a slider */
+      else
+        {
+          GimpControllerSlider *slider;
+          gdouble               dist;
+          gdouble               dvalue;
+
+          slider = gimp_tool_line_get_slider (line, private->selection);
+
+          if (! slider->movable)
+            break;
+
+          dist = gimp_canvas_item_transform_distance (private->line,
+                                                      private->x1, private->y1,
+                                                      private->x2, private->y2);
+
+          if (dist > 0.0)
+            dist = pixels / dist;
+
+          dvalue = 0.0;
+
+          switch (kevent->keyval)
+            {
+            case GDK_KEY_Left:
+              if      (private->x1 < private->x2) dvalue = -dist;
+              else if (private->x1 > private->x2) dvalue = +dist;
+              break;
+
+            case GDK_KEY_Right:
+              if      (private->x1 < private->x2) dvalue = +dist;
+              else if (private->x1 > private->x2) dvalue = -dist;
+              break;
+
+            case GDK_KEY_Up:
+              if      (private->y1 < private->y2) dvalue = -dist;
+              else if (private->y1 > private->y2) dvalue = +dist;
+              break;
+
+            case GDK_KEY_Down:
+              if      (private->y1 < private->y2) dvalue = +dist;
+              else if (private->y1 > private->y2) dvalue = -dist;
+              break;
+            }
+
+          if (dvalue != 0.0)
+            {
+              slider->value += dvalue;
+              slider->value  = CLAMP (slider->value, slider->min, slider->max);
+              slider->value  = CLAMP (slider->value, 0.0, 1.0);
+
+              g_object_set (line,
+                            "sliders", private->sliders,
+                            NULL);
+            }
+        }
+      return TRUE;
+
+    case GDK_KEY_BackSpace:
+    case GDK_KEY_Delete:
+      if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->selection))
+        {
+          if (gimp_tool_line_get_slider (line, private->selection)->removable)
+            {
+              g_signal_emit (line, line_signals[REMOVE_SLIDER], 0,
+                             private->selection);
+            }
+        }
+      return TRUE;
+    }
+
+  return GIMP_TOOL_WIDGET_CLASS (parent_class)->key_press (widget, kevent);
+}
+
+static void
+gimp_tool_line_motion_modifier (GimpToolWidget  *widget,
+                                GdkModifierType  key,
+                                gboolean         press,
+                                GdkModifierType  state)
+{
+  GimpToolLine *line = GIMP_TOOL_LINE (widget);
+
+  if (key == gimp_get_constrain_behavior_mask ())
+    {
+      gimp_tool_line_selection_motion (line, press);
+
+      gimp_tool_line_update_status (line, state, TRUE);
+    }
+}
+
+static gboolean
+gimp_tool_line_get_cursor (GimpToolWidget     *widget,
+                           const GimpCoords   *coords,
+                           GdkModifierType     state,
+                           GimpCursorType     *cursor,
+                           GimpToolCursorType *tool_cursor,
+                           GimpCursorModifier *modifier)
+{
+  GimpToolLine        *line    = GIMP_TOOL_LINE (widget);
+  GimpToolLinePrivate *private = line->private;
+
+  if (private->grab ==GRAB_LINE || (state & GRAB_LINE_MASK))
+    {
+      *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+
+      return TRUE;
+    }
+  else if (private->grab  == GRAB_SELECTION ||
+           private->hover >  GIMP_TOOL_LINE_HANDLE_NONE)
+    {
+      const GimpControllerSlider *slider = NULL;
+
+      if (private->grab == GRAB_SELECTION)
+        {
+          if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->selection))
+            slider = gimp_tool_line_get_slider (line, private->selection);
+        }
+      else if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->hover))
+        {
+          slider = gimp_tool_line_get_slider (line, private->hover);
+        }
+
+      if (private->grab == GRAB_SELECTION && slider && private->remove_slider)
+        {
+          *modifier = GIMP_CURSOR_MODIFIER_MINUS;
+
+          return TRUE;
+        }
+      else if (! slider || slider->movable)
+        {
+          *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+
+          return TRUE;
+        }
+    }
+  else if (private->hover == HOVER_NEW_SLIDER)
+    {
+      *modifier = GIMP_CURSOR_MODIFIER_PLUS;
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static gint
+gimp_tool_line_get_hover (GimpToolLine     *line,
+                          const GimpCoords *coords,
+                          GdkModifierType   state)
+{
+  GimpToolLinePrivate *private = line->private;
+  gint                 hover   = GIMP_TOOL_LINE_HANDLE_NONE;
+  gdouble              min_dist;
+  gint                 first_handle;
+  gint                 i;
+
+  /* find the closest handle to the cursor */
+  min_dist     = G_MAXDOUBLE;
+  first_handle = private->sliders->len - 1;
+
+  /* skip the sliders if the two endpoints are the same, in particular so
+   * that if the line is created during a button-press event (as in the
+   * blend tool), the end endpoint is dragged, instead of a slider.
+   */
+  if (private->x1 == private->x2 && private->y1 == private->y2)
+    first_handle = -1;
+
+  for (i = first_handle; i > GIMP_TOOL_LINE_HANDLE_NONE; i--)
+    {
+      GimpCanvasItem *handle;
+
+      if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (i))
+        {
+          const GimpControllerSlider *slider;
+
+          slider = gimp_tool_line_get_slider (line, i);
+
+          if (! slider->visible || ! slider->selectable)
+            continue;
+        }
+
+      handle = gimp_tool_line_get_handle (line, i);
+
+      if (gimp_tool_line_handle_hit (handle,
+                                     private->mouse_x,
+                                     private->mouse_y,
+                                     &min_dist))
+        {
+          hover = i;
+        }
+    }
+
+  if (hover == GIMP_TOOL_LINE_HANDLE_NONE)
+    {
+      gboolean constrain;
+      gdouble  value;
+      gdouble  dist;
+
+      constrain = (state & gimp_get_constrain_behavior_mask ()) != 0;
+
+      value = gimp_tool_line_project_point (line,
+                                            private->mouse_x,
+                                            private->mouse_y,
+                                            constrain,
+                                            &dist);
+
+      if (value >= 0.0 && value <= 1.0 && dist <= LINE_VICINITY)
+        {
+          gboolean can_add;
+
+          g_signal_emit (line, line_signals[CAN_ADD_SLIDER], 0,
+                         value, &can_add);
+
+          if (can_add)
+            {
+              hover                     = HOVER_NEW_SLIDER;
+              private->new_slider_value = value;
+            }
+        }
+    }
+
+  return hover;
+}
+
+static GimpControllerSlider *
+gimp_tool_line_get_slider (GimpToolLine *line,
+                           gint          slider)
+{
+  GimpToolLinePrivate *private = line->private;
+
+  gimp_assert (slider >= 0 && slider < private->sliders->len);
+
+  return &g_array_index (private->sliders, GimpControllerSlider, slider);
+}
+
+static GimpCanvasItem *
+gimp_tool_line_get_handle (GimpToolLine *line,
+                           gint          handle)
+{
+  GimpToolLinePrivate *private = line->private;
+
+  switch (handle)
+    {
+    case GIMP_TOOL_LINE_HANDLE_NONE:
+      return NULL;
+
+    case GIMP_TOOL_LINE_HANDLE_START:
+      return private->start_handle;
+
+    case GIMP_TOOL_LINE_HANDLE_END:
+      return private->end_handle;
+
+    default:
+      gimp_assert (handle >= 0 &&
+                   handle <  (gint) private->slider_handles->len);
+
+      return g_array_index (private->slider_handles,
+                            GimpCanvasItem *, handle);
+    }
+}
+
+static gdouble
+gimp_tool_line_project_point (GimpToolLine *line,
+                              gdouble       x,
+                              gdouble       y,
+                              gboolean      constrain,
+                              gdouble      *dist)
+{
+  GimpToolLinePrivate *private = line->private;
+  gdouble              length_sqr;
+  gdouble              value   = 0.0;
+
+  length_sqr = SQR (private->x2 - private->x1) +
+               SQR (private->y2 - private->y1);
+
+  /* don't calculate the projection for 0-length lines, since we'll just get
+   * NaN.
+   */
+  if (length_sqr > 0.0)
+    {
+      value  = (private->x2 - private->x1) * (x - private->x1) +
+               (private->y2 - private->y1) * (y - private->y1);
+      value /= length_sqr;
+
+      if (dist)
+        {
+          gdouble px;
+          gdouble py;
+
+          px = private->x1 + (private->x2 - private->x1) * value;
+          py = private->y1 + (private->y2 - private->y1) * value;
+
+          *dist = gimp_canvas_item_transform_distance (private->line,
+                                                       x,  y,
+                                                       px, py);
+        }
+
+      if (constrain)
+        value = RINT (12.0 * value) / 12.0;
+    }
+  else
+    {
+      if (dist)
+        {
+          *dist = gimp_canvas_item_transform_distance (private->line,
+                                                       x,           y,
+                                                       private->x1, private->y1);
+        }
+    }
+
+  return value;
+}
+
+static gboolean
+gimp_tool_line_selection_motion (GimpToolLine *line,
+                                 gboolean      constrain)
+{
+  GimpToolLinePrivate *private = line->private;
+  gdouble              x       = private->mouse_x;
+  gdouble              y       = private->mouse_y;
+
+  if (private->grab != GRAB_SELECTION)
+    return FALSE;
+
+  switch (private->selection)
+    {
+    case GIMP_TOOL_LINE_HANDLE_NONE:
+      gimp_assert_not_reached ();
+
+    case GIMP_TOOL_LINE_HANDLE_START:
+      if (constrain)
+        {
+          gimp_display_shell_constrain_line (
+            gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (line)),
+            private->x2, private->y2,
+            &x, &y,
+            GIMP_CONSTRAIN_LINE_15_DEGREES);
+        }
+
+      g_object_set (line,
+                    "x1", x,
+                    "y1", y,
+                    NULL);
+      return TRUE;
+
+    case GIMP_TOOL_LINE_HANDLE_END:
+      if (constrain)
+        {
+          gimp_display_shell_constrain_line (
+            gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (line)),
+            private->x1, private->y1,
+            &x, &y,
+            GIMP_CONSTRAIN_LINE_15_DEGREES);
+        }
+
+      g_object_set (line,
+                    "x2", x,
+                    "y2", y,
+                    NULL);
+      return TRUE;
+
+    default:
+      {
+        GimpDisplayShell     *shell;
+        GimpControllerSlider *slider;
+        gdouble               value;
+        gdouble               dist;
+        gboolean              remove_slider;
+
+        shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (line));
+
+        slider = gimp_tool_line_get_slider (line, private->selection);
+
+        /* project the cursor position onto the line */
+        value = gimp_tool_line_project_point (line, x, y, constrain, &dist);
+
+        /* slider dragging */
+        if (slider->movable)
+          {
+            value = CLAMP (value, slider->min, slider->max);
+            value = CLAMP (value, 0.0,         1.0);
+
+            value = fabs (value); /* avoid negative zero */
+
+            slider->value = value;
+
+            g_object_set (line,
+                          "sliders", private->sliders,
+                          NULL);
+          }
+
+        /* slider tearing */
+        remove_slider = slider->removable && dist > SLIDER_TEAR_DISTANCE;
+
+        if (remove_slider != private->remove_slider)
+          {
+            private->remove_slider = remove_slider;
+
+            g_signal_emit (line, line_signals[PREPARE_TO_REMOVE_SLIDER], 0,
+                           private->selection, remove_slider);
+
+            /* set the cursor modifier to a minus by talking to the shell
+             * directly -- eek!
+             */
+            {
+              GimpCursorType     cursor;
+              GimpToolCursorType tool_cursor;
+              GimpCursorModifier modifier;
+
+              cursor      = shell->current_cursor;
+              tool_cursor = shell->tool_cursor;
+              modifier    = GIMP_CURSOR_MODIFIER_NONE;
+
+              gimp_tool_line_get_cursor (GIMP_TOOL_WIDGET (line), NULL, 0,
+                                         &cursor, &tool_cursor, &modifier);
+
+              gimp_display_shell_set_cursor (shell, cursor, tool_cursor, modifier);
+            }
+
+            gimp_tool_line_update_handles (line);
+            gimp_tool_line_update_circle (line);
+            gimp_tool_line_update_status (line,
+                                          constrain ?
+                                            gimp_get_constrain_behavior_mask () :
+                                            0,
+                                          TRUE);
+          }
+
+        return TRUE;
+      }
+    }
+}
+
+static void
+gimp_tool_line_update_handles (GimpToolLine *line)
+{
+  GimpToolLinePrivate *private = line->private;
+  gdouble              value;
+  gdouble              dist;
+  gint                 i;
+
+  value = gimp_tool_line_project_point (line,
+                                        private->mouse_x,
+                                        private->mouse_y,
+                                        FALSE,
+                                        &dist);
+
+  for (i = 0; i < private->sliders->len; i++)
+    {
+      const GimpControllerSlider *slider;
+      GimpCanvasItem             *handle;
+      gint                        size;
+      gint                        hit_radius;
+      gboolean                    show_autohidden;
+      gboolean                    visible;
+
+      slider = gimp_tool_line_get_slider (line, i);
+      handle = gimp_tool_line_get_handle (line, i);
+
+      size = slider->size * SLIDER_HANDLE_SIZE;
+      size = MAX (size, 1);
+
+      hit_radius = (MAX (size, SLIDER_HANDLE_SIZE) * HANDLE_CIRCLE_SCALE) / 2;
+
+      /* show a autohidden slider if it's selected, or if no other handle is
+       * grabbed or hovered-over, and the cursor is close enough to the line,
+       * between the slider's min and max values.
+       */
+      show_autohidden = private->selection == i                        ||
+                        (private->grab == GRAB_NONE                    &&
+                         (private->hover <= GIMP_TOOL_LINE_HANDLE_NONE ||
+                          private->hover == i)                         &&
+                         dist <= hit_radius                            &&
+                         value >= slider->min                          &&
+                         value <= slider->max);
+
+      visible = slider->visible                         &&
+                (! slider->autohide || show_autohidden) &&
+                ! (private->selection == i && private->remove_slider);
+
+      handle = gimp_tool_line_get_handle (line, i);
+
+      if (visible)
+        {
+          g_object_set (handle,
+                        "type",   slider->type,
+                        "width",  size,
+                        "height", size,
+                        NULL);
+        }
+
+      gimp_canvas_item_set_visible (handle, visible);
+    }
+}
+
+static void
+gimp_tool_line_update_circle (GimpToolLine *line)
+{
+  GimpToolLinePrivate *private = line->private;
+  gboolean             visible;
+
+  visible = (private->grab == GRAB_NONE                    &&
+             private->hover != GIMP_TOOL_LINE_HANDLE_NONE) ||
+            (private->grab == GRAB_SELECTION               &&
+             private->remove_slider);
+
+  if (visible)
+    {
+      gdouble  x;
+      gdouble  y;
+      gint     width;
+      gint     height;
+      gboolean dashed;
+
+      if (private->grab == GRAB_NONE && private->hover == HOVER_NEW_SLIDER)
+        {
+          /* new slider */
+          x = private->x1 +
+              (private->x2 - private->x1) * private->new_slider_value;
+          y = private->y1 +
+              (private->y2 - private->y1) * private->new_slider_value;
+
+          width = height = SLIDER_HANDLE_SIZE;
+
+          dashed = TRUE;
+        }
+      else
+        {
+          GimpCanvasItem *handle;
+
+          if (private->grab == GRAB_SELECTION)
+            {
+              /* tear slider */
+              handle = gimp_tool_line_get_handle (line, private->selection);
+              dashed = TRUE;
+            }
+          else
+            {
+              /* hover over handle */
+              handle = gimp_tool_line_get_handle (line, private->hover);
+              dashed = FALSE;
+            }
+
+          gimp_canvas_handle_get_position (handle, &x,     &y);
+          gimp_canvas_handle_get_size     (handle, &width, &height);
+        }
+
+      width   = MAX (width,  SLIDER_HANDLE_SIZE);
+      height  = MAX (height, SLIDER_HANDLE_SIZE);
+
+      width  *= HANDLE_CIRCLE_SCALE;
+      height *= HANDLE_CIRCLE_SCALE;
+
+      gimp_canvas_handle_set_position (private->handle_circle, x,     y);
+      gimp_canvas_handle_set_size     (private->handle_circle, width, height);
+
+      g_object_set (private->handle_circle,
+                    "type", dashed ? GIMP_HANDLE_DASHED_CIRCLE :
+                                     GIMP_HANDLE_CIRCLE,
+                    NULL);
+    }
+
+  gimp_canvas_item_set_visible (private->handle_circle, visible);
+}
+
+static void
+gimp_tool_line_update_hilight (GimpToolLine *line)
+{
+  GimpToolLinePrivate *private = line->private;
+  gboolean             focus;
+  gint                 i;
+
+  focus = gimp_tool_widget_get_focus (GIMP_TOOL_WIDGET (line));
+
+  for (i = GIMP_TOOL_LINE_HANDLE_NONE + 1;
+       i < (gint) private->sliders->len;
+       i++)
+    {
+      GimpCanvasItem *handle;
+
+      handle = gimp_tool_line_get_handle (line, i);
+
+      gimp_canvas_item_set_highlight (handle, focus && i == private->selection);
+    }
+}
+
+static void
+gimp_tool_line_update_status (GimpToolLine    *line,
+                              GdkModifierType  state,
+                              gboolean         proximity)
+{
+  GimpToolLinePrivate *private = line->private;
+
+  if (proximity)
+    {
+      GimpDisplayShell *shell;
+      const gchar      *toggle_behavior_format = NULL;
+      const gchar      *message                = NULL;
+      gchar            *line_status            = NULL;
+      gchar            *status;
+      gint              handle;
+
+      shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (line));
+
+      if (private->grab == GRAB_SELECTION)
+        handle = private->selection;
+      else
+        handle = private->hover;
+
+      if (handle == GIMP_TOOL_LINE_HANDLE_START ||
+          handle == GIMP_TOOL_LINE_HANDLE_END)
+        {
+          line_status = gimp_display_shell_get_line_status (shell,
+                                                            _("Click-Drag to move the endpoint"),
+                                                            ". ",
+                                                            private->x1,
+                                                            private->y1,
+                                                            private->x2,
+                                                            private->y2);
+          toggle_behavior_format = _("%s for constrained angles");
+        }
+      else if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (handle) ||
+               handle == HOVER_NEW_SLIDER)
+        {
+          if (private->grab == GRAB_SELECTION && private->remove_slider)
+            {
+              message = _("Release to remove the slider");
+            }
+          else
+            {
+              toggle_behavior_format = _("%s for constrained values");
+
+              if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (handle))
+                {
+                  if (gimp_tool_line_get_slider (line, handle)->movable)
+                    {
+                      if (gimp_tool_line_get_slider (line, handle)->removable)
+                        {
+                          if (private->grab == GRAB_SELECTION)
+                            {
+                              message = _("Click-Drag to move the slider; "
+                                          "drag away to remove the slider");
+                            }
+                          else
+                            {
+                              message = _("Click-Drag to move or remove the slider");
+                            }
+                        }
+                      else
+                        {
+                          message = _("Click-Drag to move the slider");
+                        }
+                    }
+                  else
+                    {
+                      toggle_behavior_format = NULL;
+
+                      if (gimp_tool_line_get_slider (line, handle)->removable)
+                        {
+                          if (private->grab == GRAB_SELECTION)
+                            {
+                              message = _("Click-Drag away to remove the slider");
+                            }
+                          else
+                            {
+                              message = _("Click-Drag to remove the slider");
+                            }
+                        }
+                      else
+                        {
+                          message = NULL;
+                        }
+                    }
+                }
+              else
+                {
+                  message = _("Click or Click-Drag to add a new slider");
+                }
+            }
+        }
+      else if (state & GDK_MOD1_MASK)
+        {
+          message = _("Click-Drag to move the line");
+        }
+
+      status =
+        gimp_suggest_modifiers (message ? message : (line_status ? line_status : ""),
+                                ((toggle_behavior_format ?
+                                   gimp_get_constrain_behavior_mask () : 0) |
+                                 (private->grab == GRAB_NONE ?
+                                   GDK_MOD1_MASK : 0)) &
+                                ~state,
+                                NULL,
+                                toggle_behavior_format,
+                                _("%s to move the whole line"));
+
+      if (message || line_status)
+        {
+          gimp_tool_widget_set_status (GIMP_TOOL_WIDGET (line), status);
+        }
+      else
+        {
+          line_status = gimp_display_shell_get_line_status (shell,
+                                                            private->status_title,
+                                                            ". ",
+                                                            private->x1,
+                                                            private->y1,
+                                                            private->x2,
+                                                            private->y2);
+          gimp_tool_widget_set_status_coords (GIMP_TOOL_WIDGET (line),
+                                              line_status,
+                                              private->x2 - private->x1,
+                                              ", ",
+                                              private->y2 - private->y1,
+                                              status);
+        }
+
+      g_free (status);
+      if (line_status)
+        g_free (line_status);
+    }
+  else
+    {
+      gimp_tool_widget_set_status (GIMP_TOOL_WIDGET (line), NULL);
+    }
+}
+
+static gboolean
+gimp_tool_line_handle_hit (GimpCanvasItem *handle,
+                           gdouble         x,
+                           gdouble         y,
+                           gdouble        *min_dist)
+{
+  gdouble handle_x;
+  gdouble handle_y;
+  gint    handle_width;
+  gint    handle_height;
+  gint    radius;
+  gdouble dist;
+
+  gimp_canvas_handle_get_position (handle, &handle_x,     &handle_y);
+  gimp_canvas_handle_get_size     (handle, &handle_width, &handle_height);
+
+  handle_width  = MAX (handle_width,  SLIDER_HANDLE_SIZE);
+  handle_height = MAX (handle_height, SLIDER_HANDLE_SIZE);
+
+  radius = ((gint) (handle_width * HANDLE_CIRCLE_SCALE)) / 2;
+  radius = MAX (radius, LINE_VICINITY);
+
+  dist = gimp_canvas_item_transform_distance (handle,
+                                              x, y, handle_x, handle_y);
+
+  if (dist <= radius && dist < *min_dist)
+    {
+      *min_dist = dist;
+
+      return TRUE;
+    }
+  else
+    {
+      return FALSE;
+    }
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_line_new (GimpDisplayShell *shell,
+                    gdouble           x1,
+                    gdouble           y1,
+                    gdouble           x2,
+                    gdouble           y2)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_LINE,
+                       "shell", shell,
+                       "x1",    x1,
+                       "y1",    y1,
+                       "x2",    x2,
+                       "y2",    y2,
+                       NULL);
+}
+
+void
+gimp_tool_line_set_sliders (GimpToolLine               *line,
+                            const GimpControllerSlider *sliders,
+                            gint                        n_sliders)
+{
+  GimpToolLinePrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_LINE (line));
+  g_return_if_fail (n_sliders == 0 || (n_sliders > 0 && sliders != NULL));
+
+  private = line->private;
+
+  if (GIMP_TOOL_LINE_HANDLE_IS_SLIDER (private->selection) &&
+      private->sliders->len != n_sliders)
+    {
+      gimp_tool_line_set_selection (line, GIMP_TOOL_LINE_HANDLE_NONE);
+    }
+
+  g_array_set_size (private->sliders, n_sliders);
+
+  memcpy (private->sliders->data, sliders,
+          n_sliders * sizeof (GimpControllerSlider));
+
+  g_object_set (line,
+                "sliders", private->sliders,
+                NULL);
+}
+
+const GimpControllerSlider *
+gimp_tool_line_get_sliders (GimpToolLine *line,
+                            gint         *n_sliders)
+{
+  GimpToolLinePrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_LINE (line), NULL);
+
+  private = line->private;
+
+  if (n_sliders) *n_sliders = private->sliders->len;
+
+  return (const GimpControllerSlider *) private->sliders->data;
+}
+
+void
+gimp_tool_line_set_selection (GimpToolLine *line,
+                              gint          handle)
+{
+  GimpToolLinePrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_LINE (line));
+
+  private = line->private;
+
+  g_return_if_fail (handle >= GIMP_TOOL_LINE_HANDLE_NONE &&
+                    handle <  (gint) private->sliders->len);
+
+  g_object_set (line,
+                "selection", handle,
+                NULL);
+}
+
+gint
+gimp_tool_line_get_selection (GimpToolLine *line)
+{
+  GimpToolLinePrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_LINE (line), GIMP_TOOL_LINE_HANDLE_NONE);
+
+  private = line->private;
+
+  return private->selection;
+}
diff --git a/app/display/gimptoolline.h b/app/display/gimptoolline.h
new file mode 100644
index 0000000..80d046d
--- /dev/null
+++ b/app/display/gimptoolline.h
@@ -0,0 +1,99 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolline.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_LINE_H__
+#define __GIMP_TOOL_LINE_H__
+
+
+#include "gimptoolwidget.h"
+
+
+/* in the context of GimpToolLine, "handle" is a collective term for either an
+ * endpoint or a slider.  a handle value may be either a (nonnegative) slider
+ * index, or one of the values below:
+ */
+#define GIMP_TOOL_LINE_HANDLE_NONE  (-3)
+#define GIMP_TOOL_LINE_HANDLE_START (-2)
+#define GIMP_TOOL_LINE_HANDLE_END   (-1)
+
+#define GIMP_TOOL_LINE_HANDLE_IS_SLIDER(handle) ((handle) >= 0)
+
+
+#define GIMP_TYPE_TOOL_LINE            (gimp_tool_line_get_type ())
+#define GIMP_TOOL_LINE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_LINE, GimpToolLine))
+#define GIMP_TOOL_LINE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_LINE, GimpToolLineClass))
+#define GIMP_IS_TOOL_LINE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_LINE))
+#define GIMP_IS_TOOL_LINE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_LINE))
+#define GIMP_TOOL_LINE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_LINE, GimpToolLineClass))
+
+
+typedef struct _GimpToolLine        GimpToolLine;
+typedef struct _GimpToolLinePrivate GimpToolLinePrivate;
+typedef struct _GimpToolLineClass   GimpToolLineClass;
+
+struct _GimpToolLine
+{
+  GimpToolWidget       parent_instance;
+
+  GimpToolLinePrivate *private;
+};
+
+struct _GimpToolLineClass
+{
+  GimpToolWidgetClass  parent_class;
+
+  /*  signals  */
+  gboolean (* can_add_slider)           (GimpToolLine        *line,
+                                         gdouble              value);
+  gint     (* add_slider)               (GimpToolLine        *line,
+                                         gdouble              value);
+  void     (* prepare_to_remove_slider) (GimpToolLine        *line,
+                                         gint                 slider,
+                                         gboolean             remove);
+  void     (* remove_slider)            (GimpToolLine        *line,
+                                         gint                 slider);
+  void     (* selection_changed)        (GimpToolLine        *line);
+  gboolean (* handle_clicked)           (GimpToolLine        *line,
+                                         gint                 handle,
+                                         GdkModifierType      state,
+                                         GimpButtonPressType  press_type);
+};
+
+
+GType                        gimp_tool_line_get_type      (void) G_GNUC_CONST;
+
+GimpToolWidget             * gimp_tool_line_new           (GimpDisplayShell           *shell,
+                                                           gdouble                     x1,
+                                                           gdouble                     y1,
+                                                           gdouble                     x2,
+                                                           gdouble                     y2);
+
+void                         gimp_tool_line_set_sliders   (GimpToolLine               *line,
+                                                           const GimpControllerSlider *sliders,
+                                                           gint                        n_sliders);
+const GimpControllerSlider * gimp_tool_line_get_sliders   (GimpToolLine               *line,
+                                                           gint                       *n_sliders);
+
+void                         gimp_tool_line_set_selection (GimpToolLine               *line,
+                                                           gint                        handle);
+gint                         gimp_tool_line_get_selection (GimpToolLine               *line);
+
+
+#endif /* __GIMP_TOOL_LINE_H__ */
diff --git a/app/display/gimptoolpath.c b/app/display/gimptoolpath.c
new file mode 100644
index 0000000..9e2cf54
--- /dev/null
+++ b/app/display/gimptoolpath.c
@@ -0,0 +1,1904 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolpath.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Vector tool
+ * Copyright (C) 2003 Simon Budig  <simon@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpbase/gimpbase.h"
+
+#include "display-types.h"
+
+#include "vectors/gimpanchor.h"
+#include "vectors/gimpbezierstroke.h"
+#include "vectors/gimpvectors.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "tools/gimptools-utils.h"
+
+#include "gimpcanvashandle.h"
+#include "gimpcanvasitem-utils.h"
+#include "gimpcanvasline.h"
+#include "gimpcanvaspath.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimptoolpath.h"
+
+#include "gimp-intl.h"
+
+
+#define TOGGLE_MASK  gimp_get_extend_selection_mask ()
+#define MOVE_MASK    GDK_MOD1_MASK
+#define INSDEL_MASK  gimp_get_toggle_behavior_mask ()
+
+
+/*  possible vector functions  */
+typedef enum
+{
+  VECTORS_SELECT_VECTOR,
+  VECTORS_CREATE_VECTOR,
+  VECTORS_CREATE_STROKE,
+  VECTORS_ADD_ANCHOR,
+  VECTORS_MOVE_ANCHOR,
+  VECTORS_MOVE_ANCHORSET,
+  VECTORS_MOVE_HANDLE,
+  VECTORS_MOVE_CURVE,
+  VECTORS_MOVE_STROKE,
+  VECTORS_MOVE_VECTORS,
+  VECTORS_INSERT_ANCHOR,
+  VECTORS_DELETE_ANCHOR,
+  VECTORS_CONNECT_STROKES,
+  VECTORS_DELETE_SEGMENT,
+  VECTORS_CONVERT_EDGE,
+  VECTORS_FINISHED
+} GimpVectorFunction;
+
+enum
+{
+  PROP_0,
+  PROP_VECTORS,
+  PROP_EDIT_MODE,
+  PROP_POLYGONAL
+};
+
+enum
+{
+  BEGIN_CHANGE,
+  END_CHANGE,
+  ACTIVATE,
+  LAST_SIGNAL
+};
+
+struct _GimpToolPathPrivate
+{
+  GimpVectors          *vectors;        /* the current Vector data           */
+  GimpVectorMode        edit_mode;
+  gboolean              polygonal;
+
+  GimpVectorFunction    function;       /* function we're performing         */
+  GimpAnchorFeatureType restriction;    /* movement restriction              */
+  gboolean              modifier_lock;  /* can we toggle the Shift key?      */
+  GdkModifierType       saved_state;    /* modifier state at button_press    */
+  gdouble               last_x;         /* last x coordinate                 */
+  gdouble               last_y;         /* last y coordinate                 */
+  gboolean              undo_motion;    /* we need a motion to have an undo  */
+  gboolean              have_undo;      /* did we push an undo at            */
+                                        /* ..._button_press?                 */
+
+  GimpAnchor           *cur_anchor;     /* the current Anchor                */
+  GimpAnchor           *cur_anchor2;    /* secondary Anchor (end on_curve)   */
+  GimpStroke           *cur_stroke;     /* the current Stroke                */
+  gdouble               cur_position;   /* the current Position on a segment */
+
+  gint                  sel_count;      /* number of selected anchors        */
+  GimpAnchor           *sel_anchor;     /* currently selected anchor, NULL   */
+                                        /* if multiple anchors are selected  */
+  GimpStroke           *sel_stroke;     /* selected stroke                   */
+
+  GimpVectorMode        saved_mode;     /* used by modifier_key()            */
+
+  GimpCanvasItem       *path;
+  GList                *items;
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_path_constructed     (GObject               *object);
+static void     gimp_tool_path_dispose         (GObject               *object);
+static void     gimp_tool_path_set_property    (GObject               *object,
+                                                guint                  property_id,
+                                                const GValue          *value,
+                                                GParamSpec            *pspec);
+static void     gimp_tool_path_get_property    (GObject               *object,
+                                                guint                  property_id,
+                                                GValue                *value,
+                                                GParamSpec            *pspec);
+
+static void     gimp_tool_path_changed         (GimpToolWidget        *widget);
+static gint     gimp_tool_path_button_press    (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                guint32                time,
+                                                GdkModifierType        state,
+                                                GimpButtonPressType    press_type);
+static void     gimp_tool_path_button_release  (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                guint32                time,
+                                                GdkModifierType        state,
+                                                GimpButtonReleaseType  release_type);
+static void     gimp_tool_path_motion          (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                guint32                time,
+                                                GdkModifierType        state);
+static GimpHit  gimp_tool_path_hit             (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state,
+                                                gboolean               proximity);
+static void     gimp_tool_path_hover           (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state,
+                                                gboolean               proximity);
+static gboolean gimp_tool_path_key_press       (GimpToolWidget        *widget,
+                                                GdkEventKey           *kevent);
+static gboolean gimp_tool_path_get_cursor      (GimpToolWidget        *widget,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state,
+                                                GimpCursorType        *cursor,
+                                                GimpToolCursorType    *tool_cursor,
+                                                GimpCursorModifier    *modifier);
+
+static GimpVectorFunction
+                   gimp_tool_path_get_function (GimpToolPath          *path,
+                                                const GimpCoords      *coords,
+                                                GdkModifierType        state);
+                                                
+static void     gimp_tool_path_update_status   (GimpToolPath          *path,
+                                                GdkModifierType        state,
+                                                gboolean               proximity);
+
+static void     gimp_tool_path_begin_change    (GimpToolPath          *path,
+                                                const gchar           *desc);
+static void     gimp_tool_path_end_change      (GimpToolPath          *path,
+                                                gboolean               success);
+
+static void     gimp_tool_path_vectors_visible (GimpVectors           *vectors,
+                                                GimpToolPath          *path);
+static void     gimp_tool_path_vectors_freeze  (GimpVectors           *vectors,
+                                                GimpToolPath          *path);
+static void     gimp_tool_path_vectors_thaw    (GimpVectors           *vectors,
+                                                GimpToolPath          *path);
+static void     gimp_tool_path_verify_state    (GimpToolPath          *path);
+
+static void     gimp_tool_path_move_selected_anchors
+                                               (GimpToolPath          *path,
+                                                gdouble                x,
+                                                gdouble                y);
+static void     gimp_tool_path_delete_selected_anchors
+                                               (GimpToolPath          *path);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolPath, gimp_tool_path, GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_path_parent_class
+
+static guint path_signals[LAST_SIGNAL] = { 0 };
+
+
+static void
+gimp_tool_path_class_init (GimpToolPathClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_path_constructed;
+  object_class->dispose         = gimp_tool_path_dispose;
+  object_class->set_property    = gimp_tool_path_set_property;
+  object_class->get_property    = gimp_tool_path_get_property;
+
+  widget_class->changed         = gimp_tool_path_changed;
+  widget_class->focus_changed   = gimp_tool_path_changed;
+  widget_class->button_press    = gimp_tool_path_button_press;
+  widget_class->button_release  = gimp_tool_path_button_release;
+  widget_class->motion          = gimp_tool_path_motion;
+  widget_class->hit             = gimp_tool_path_hit;
+  widget_class->hover           = gimp_tool_path_hover;
+  widget_class->key_press       = gimp_tool_path_key_press;
+  widget_class->get_cursor      = gimp_tool_path_get_cursor;
+
+  path_signals[BEGIN_CHANGE] =
+    g_signal_new ("begin-change",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolPathClass, begin_change),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__STRING,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_STRING);
+
+  path_signals[END_CHANGE] =
+    g_signal_new ("end-change",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolPathClass, end_change),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__BOOLEAN,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_BOOLEAN);
+
+  path_signals[ACTIVATE] =
+    g_signal_new ("activate",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolPathClass, activate),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__FLAGS,
+                  G_TYPE_NONE, 1,
+                  GDK_TYPE_MODIFIER_TYPE);
+
+  g_object_class_install_property (object_class, PROP_VECTORS,
+                                   g_param_spec_object ("vectors", NULL, NULL,
+                                                        GIMP_TYPE_VECTORS,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_EDIT_MODE,
+                                   g_param_spec_enum ("edit-mode",
+                                                      _("Edit Mode"),
+                                                      NULL,
+                                                      GIMP_TYPE_VECTOR_MODE,
+                                                      GIMP_VECTOR_MODE_DESIGN,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_POLYGONAL,
+                                   g_param_spec_boolean ("polygonal",
+                                                         _("Polygonal"),
+                                                         _("Restrict editing to polygons"),
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_path_init (GimpToolPath *path)
+{
+  path->private = gimp_tool_path_get_instance_private (path);
+}
+
+static void
+gimp_tool_path_constructed (GObject *object)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (object);
+  GimpToolWidget      *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolPathPrivate *private = path->private;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  private->path = gimp_tool_widget_add_path (widget, NULL);
+
+  gimp_tool_path_changed (widget);
+}
+
+static void
+gimp_tool_path_dispose (GObject *object)
+{
+  GimpToolPath *path = GIMP_TOOL_PATH (object);
+
+  gimp_tool_path_set_vectors (path, NULL);
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_tool_path_set_property (GObject      *object,
+                             guint         property_id,
+                             const GValue *value,
+                             GParamSpec   *pspec)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (object);
+  GimpToolPathPrivate *private = path->private;
+
+  switch (property_id)
+    {
+    case PROP_VECTORS:
+      gimp_tool_path_set_vectors (path, g_value_get_object (value));
+      break;
+    case PROP_EDIT_MODE:
+      private->edit_mode = g_value_get_enum (value);
+      break;
+    case PROP_POLYGONAL:
+      private->polygonal = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_path_get_property (GObject    *object,
+                             guint       property_id,
+                             GValue     *value,
+                             GParamSpec *pspec)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (object);
+  GimpToolPathPrivate *private = path->private;
+
+  switch (property_id)
+    {
+    case PROP_VECTORS:
+      g_value_set_object (value, private->vectors);
+      break;
+    case PROP_EDIT_MODE:
+      g_value_set_enum (value, private->edit_mode);
+      break;
+    case PROP_POLYGONAL:
+      g_value_set_boolean (value, private->polygonal);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+item_remove_func (GimpCanvasItem *item,
+                  GimpToolWidget *widget)
+{
+  gimp_tool_widget_remove_item (widget, item);
+}
+
+static void
+gimp_tool_path_changed (GimpToolWidget *widget)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (widget);
+  GimpToolPathPrivate *private = path->private;
+  GimpVectors         *vectors = private->vectors;
+
+  if (private->items)
+    {
+      g_list_foreach (private->items, (GFunc) item_remove_func, widget);
+      g_list_free (private->items);
+      private->items = NULL;
+    }
+
+  if (vectors && gimp_vectors_get_bezier (vectors))
+    {
+      GimpStroke *cur_stroke;
+
+      gimp_canvas_path_set (private->path,
+                            gimp_vectors_get_bezier (vectors));
+      gimp_canvas_item_set_visible (private->path,
+                                    ! gimp_item_get_visible (GIMP_ITEM (vectors)));
+
+      for (cur_stroke = gimp_vectors_stroke_get_next (vectors, NULL);
+           cur_stroke;
+           cur_stroke = gimp_vectors_stroke_get_next (vectors, cur_stroke))
+        {
+          GimpCanvasItem *item;
+          GArray         *coords;
+          GList          *draw_anchors;
+          GList          *list;
+
+          /* anchor handles */
+          draw_anchors = gimp_stroke_get_draw_anchors (cur_stroke);
+
+          for (list = draw_anchors; list; list = g_list_next (list))
+            {
+              GimpAnchor *cur_anchor = GIMP_ANCHOR (list->data);
+
+              if (cur_anchor->type == GIMP_ANCHOR_ANCHOR)
+                {
+                  item =
+                    gimp_tool_widget_add_handle (widget,
+                                                 cur_anchor->selected ?
+                                                 GIMP_HANDLE_CIRCLE :
+                                                 GIMP_HANDLE_FILLED_CIRCLE,
+                                                 cur_anchor->position.x,
+                                                 cur_anchor->position.y,
+                                                 GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                 GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+                  private->items = g_list_prepend (private->items, item);
+                }
+            }
+
+          g_list_free (draw_anchors);
+
+          if (private->sel_count <= 2)
+            {
+              /* the lines to the control handles */
+              coords = gimp_stroke_get_draw_lines (cur_stroke);
+
+              if (coords)
+                {
+                  if (coords->len % 2 == 0)
+                    {
+                      gint i;
+
+                      for (i = 0; i < coords->len; i += 2)
+                        {
+                          item = gimp_tool_widget_add_line
+                            (widget,
+                             g_array_index (coords, GimpCoords, i).x,
+                             g_array_index (coords, GimpCoords, i).y,
+                             g_array_index (coords, GimpCoords, i + 1).x,
+                             g_array_index (coords, GimpCoords, i + 1).y);
+
+                          if (gimp_tool_widget_get_focus (widget))
+                            gimp_canvas_item_set_highlight (item, TRUE);
+
+                          private->items = g_list_prepend (private->items, item);
+                        }
+                    }
+
+                  g_array_free (coords, TRUE);
+                }
+
+              /* control handles */
+              draw_anchors = gimp_stroke_get_draw_controls (cur_stroke);
+
+              for (list = draw_anchors; list; list = g_list_next (list))
+                {
+                  GimpAnchor *cur_anchor = GIMP_ANCHOR (list->data);
+
+                  item =
+                    gimp_tool_widget_add_handle (widget,
+                                                 GIMP_HANDLE_SQUARE,
+                                                 cur_anchor->position.x,
+                                                 cur_anchor->position.y,
+                                                 GIMP_CANVAS_HANDLE_SIZE_CIRCLE - 3,
+                                                 GIMP_CANVAS_HANDLE_SIZE_CIRCLE - 3,
+                                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+                  private->items = g_list_prepend (private->items, item);
+                }
+
+              g_list_free (draw_anchors);
+            }
+        }
+    }
+  else
+    {
+      gimp_canvas_path_set (private->path, NULL);
+    }
+}
+
+static gboolean
+gimp_tool_path_check_writable (GimpToolPath *path)
+{
+  GimpToolPathPrivate *private = path->private;
+  GimpToolWidget      *widget  = GIMP_TOOL_WIDGET (path);
+  GimpDisplayShell    *shell   = gimp_tool_widget_get_shell (widget);
+
+  if (gimp_item_is_content_locked (GIMP_ITEM (private->vectors)) ||
+      gimp_item_is_position_locked (GIMP_ITEM (private->vectors)))
+    {
+      gimp_tool_widget_message_literal (GIMP_TOOL_WIDGET (path),
+                                        _("The active path is locked."));
+
+      /* FIXME: this should really be done by the tool */
+      gimp_tools_blink_lock_box (shell->display->gimp,
+                                 GIMP_ITEM (private->vectors));
+
+      private->function = VECTORS_FINISHED;
+
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+gboolean
+gimp_tool_path_button_press (GimpToolWidget      *widget,
+                             const GimpCoords    *coords,
+                             guint32              time,
+                             GdkModifierType      state,
+                             GimpButtonPressType  press_type)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (widget);
+  GimpToolPathPrivate *private = path->private;
+
+  /* do nothing if we are in a FINISHED state */
+  if (private->function == VECTORS_FINISHED)
+    return 0;
+
+  g_return_val_if_fail (private->vectors  != NULL                  ||
+                        private->function == VECTORS_SELECT_VECTOR ||
+                        private->function == VECTORS_CREATE_VECTOR, 0);
+
+  private->undo_motion = FALSE;
+
+  /* save the current modifier state */
+
+  private->saved_state = state;
+
+
+  /* select a vectors object */
+
+  if (private->function == VECTORS_SELECT_VECTOR)
+    {
+      GimpVectors *vectors;
+
+      if (gimp_canvas_item_on_vectors (private->path,
+                                       coords,
+                                       GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                       GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                       NULL, NULL, NULL, NULL, NULL, &vectors))
+        {
+          gimp_tool_path_set_vectors (path, vectors);
+        }
+
+      private->function = VECTORS_FINISHED;
+    }
+
+
+  /* create a new vector from scratch */
+
+  if (private->function == VECTORS_CREATE_VECTOR)
+    {
+      GimpDisplayShell *shell = gimp_tool_widget_get_shell (widget);
+      GimpImage        *image = gimp_display_get_image (shell->display);
+      GimpVectors      *vectors;
+
+      vectors = gimp_vectors_new (image, _("Unnamed"));
+      g_object_ref_sink (vectors);
+
+      /* Undo step gets added implicitly */
+      private->have_undo = TRUE;
+
+      private->undo_motion = TRUE;
+
+      gimp_tool_path_set_vectors (path, vectors);
+      g_object_unref (vectors);
+
+      private->function = VECTORS_CREATE_STROKE;
+    }
+
+
+  gimp_vectors_freeze (private->vectors);
+
+  /* create a new stroke */
+
+  if (private->function == VECTORS_CREATE_STROKE &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Add Stroke"));
+      private->undo_motion = TRUE;
+
+      private->cur_stroke = gimp_bezier_stroke_new ();
+      gimp_vectors_stroke_add (private->vectors, private->cur_stroke);
+      g_object_unref (private->cur_stroke);
+
+      private->sel_stroke = private->cur_stroke;
+      private->cur_anchor = NULL;
+      private->sel_anchor = NULL;
+      private->function   = VECTORS_ADD_ANCHOR;
+    }
+
+
+  /* add an anchor to an existing stroke */
+
+  if (private->function == VECTORS_ADD_ANCHOR &&
+      gimp_tool_path_check_writable (path))
+    {
+      GimpCoords position = GIMP_COORDS_DEFAULT_VALUES;
+
+      position.x = coords->x;
+      position.y = coords->y;
+
+      gimp_tool_path_begin_change (path, _("Add Anchor"));
+      private->undo_motion = TRUE;
+
+      private->cur_anchor = gimp_bezier_stroke_extend (private->sel_stroke,
+                                                       &position,
+                                                       private->sel_anchor,
+                                                       EXTEND_EDITABLE);
+
+      private->restriction = GIMP_ANCHOR_FEATURE_SYMMETRIC;
+
+      if (! private->polygonal)
+        private->function = VECTORS_MOVE_HANDLE;
+      else
+        private->function = VECTORS_MOVE_ANCHOR;
+
+      private->cur_stroke = private->sel_stroke;
+    }
+
+
+  /* insertion of an anchor in a curve segment */
+
+  if (private->function == VECTORS_INSERT_ANCHOR &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Insert Anchor"));
+      private->undo_motion = TRUE;
+
+      private->cur_anchor = gimp_stroke_anchor_insert (private->cur_stroke,
+                                                       private->cur_anchor,
+                                                       private->cur_position);
+      if (private->cur_anchor)
+        {
+          if (private->polygonal)
+            {
+              gimp_stroke_anchor_convert (private->cur_stroke,
+                                          private->cur_anchor,
+                                          GIMP_ANCHOR_FEATURE_EDGE);
+            }
+
+          private->function = VECTORS_MOVE_ANCHOR;
+        }
+      else
+        {
+          private->function = VECTORS_FINISHED;
+        }
+    }
+
+
+  /* move a handle */
+
+  if (private->function == VECTORS_MOVE_HANDLE &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Drag Handle"));
+
+      if (private->cur_anchor->type == GIMP_ANCHOR_ANCHOR)
+        {
+          if (! private->cur_anchor->selected)
+            {
+              gimp_vectors_anchor_select (private->vectors,
+                                          private->cur_stroke,
+                                          private->cur_anchor,
+                                          TRUE, TRUE);
+              private->undo_motion = TRUE;
+            }
+
+          gimp_canvas_item_on_vectors_handle (private->path,
+                                              private->vectors, coords,
+                                              GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                              GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                              GIMP_ANCHOR_CONTROL, TRUE,
+                                              &private->cur_anchor,
+                                              &private->cur_stroke);
+          if (! private->cur_anchor)
+            private->function = VECTORS_FINISHED;
+        }
+    }
+
+
+  /* move an anchor */
+
+  if (private->function == VECTORS_MOVE_ANCHOR &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Drag Anchor"));
+
+      if (! private->cur_anchor->selected)
+        {
+          gimp_vectors_anchor_select (private->vectors,
+                                      private->cur_stroke,
+                                      private->cur_anchor,
+                                      TRUE, TRUE);
+          private->undo_motion = TRUE;
+        }
+    }
+
+
+  /* move multiple anchors */
+
+  if (private->function == VECTORS_MOVE_ANCHORSET &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Drag Anchors"));
+
+      if (state & TOGGLE_MASK)
+        {
+          gimp_vectors_anchor_select (private->vectors,
+                                      private->cur_stroke,
+                                      private->cur_anchor,
+                                      !private->cur_anchor->selected,
+                                      FALSE);
+          private->undo_motion = TRUE;
+
+          if (private->cur_anchor->selected == FALSE)
+            private->function = VECTORS_FINISHED;
+        }
+    }
+
+
+  /* move a curve segment directly */
+
+  if (private->function == VECTORS_MOVE_CURVE &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Drag Curve"));
+
+      /* the magic numbers are taken from the "feel good" parameter
+       * from gimp_bezier_stroke_point_move_relative in gimpbezierstroke.c. */
+      if (private->cur_position < 5.0 / 6.0)
+        {
+          gimp_vectors_anchor_select (private->vectors,
+                                      private->cur_stroke,
+                                      private->cur_anchor, TRUE, TRUE);
+          private->undo_motion = TRUE;
+        }
+
+      if (private->cur_position > 1.0 / 6.0)
+        {
+          gimp_vectors_anchor_select (private->vectors,
+                                      private->cur_stroke,
+                                      private->cur_anchor2, TRUE,
+                                      (private->cur_position >= 5.0 / 6.0));
+          private->undo_motion = TRUE;
+        }
+
+    }
+
+
+  /* connect two strokes */
+
+  if (private->function == VECTORS_CONNECT_STROKES &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Connect Strokes"));
+      private->undo_motion = TRUE;
+
+      gimp_stroke_connect_stroke (private->sel_stroke,
+                                  private->sel_anchor,
+                                  private->cur_stroke,
+                                  private->cur_anchor);
+
+      if (private->cur_stroke != private->sel_stroke &&
+          gimp_stroke_is_empty (private->cur_stroke))
+        {
+          gimp_vectors_stroke_remove (private->vectors,
+                                      private->cur_stroke);
+        }
+
+      private->sel_anchor = private->cur_anchor;
+      private->cur_stroke = private->sel_stroke;
+
+      gimp_vectors_anchor_select (private->vectors,
+                                  private->sel_stroke,
+                                  private->sel_anchor, TRUE, TRUE);
+
+      private->function = VECTORS_FINISHED;
+    }
+
+
+  /* move a stroke or all strokes of a vectors object */
+
+  if ((private->function == VECTORS_MOVE_STROKE ||
+       private->function == VECTORS_MOVE_VECTORS) &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Drag Path"));
+
+      /* Work is being done in gimp_tool_path_motion()... */
+    }
+
+
+  /* convert an anchor to something that looks like an edge */
+
+  if (private->function == VECTORS_CONVERT_EDGE &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Convert Edge"));
+      private->undo_motion = TRUE;
+
+      gimp_stroke_anchor_convert (private->cur_stroke,
+                                  private->cur_anchor,
+                                  GIMP_ANCHOR_FEATURE_EDGE);
+
+      if (private->cur_anchor->type == GIMP_ANCHOR_ANCHOR)
+        {
+          gimp_vectors_anchor_select (private->vectors,
+                                      private->cur_stroke,
+                                      private->cur_anchor, TRUE, TRUE);
+
+          private->function = VECTORS_MOVE_ANCHOR;
+        }
+      else
+        {
+          private->cur_stroke = NULL;
+          private->cur_anchor = NULL;
+
+          /* avoid doing anything stupid */
+          private->function = VECTORS_FINISHED;
+        }
+    }
+
+
+  /* removal of a node in a stroke */
+
+  if (private->function == VECTORS_DELETE_ANCHOR &&
+      gimp_tool_path_check_writable (path))
+    {
+      gimp_tool_path_begin_change (path, _("Delete Anchor"));
+      private->undo_motion = TRUE;
+
+      gimp_stroke_anchor_delete (private->cur_stroke,
+                                 private->cur_anchor);
+
+      if (gimp_stroke_is_empty (private->cur_stroke))
+        gimp_vectors_stroke_remove (private->vectors,
+                                    private->cur_stroke);
+
+      private->cur_stroke = NULL;
+      private->cur_anchor = NULL;
+      private->function = VECTORS_FINISHED;
+    }
+
+
+  /* deleting a segment (opening up a stroke) */
+
+  if (private->function == VECTORS_DELETE_SEGMENT &&
+      gimp_tool_path_check_writable (path))
+    {
+      GimpStroke *new_stroke;
+
+      gimp_tool_path_begin_change (path, _("Delete Segment"));
+      private->undo_motion = TRUE;
+
+      new_stroke = gimp_stroke_open (private->cur_stroke,
+                                     private->cur_anchor);
+      if (new_stroke)
+        {
+          gimp_vectors_stroke_add (private->vectors, new_stroke);
+          g_object_unref (new_stroke);
+        }
+
+      private->cur_stroke = NULL;
+      private->cur_anchor = NULL;
+      private->function   = VECTORS_FINISHED;
+    }
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+
+  gimp_vectors_thaw (private->vectors);
+
+  return 1;
+}
+
+void
+gimp_tool_path_button_release (GimpToolWidget        *widget,
+                               const GimpCoords      *coords,
+                               guint32                time,
+                               GdkModifierType        state,
+                               GimpButtonReleaseType  release_type)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (widget);
+  GimpToolPathPrivate *private = path->private;
+
+  private->function = VECTORS_FINISHED;
+
+  if (private->have_undo)
+    {
+      if (! private->undo_motion ||
+          release_type == GIMP_BUTTON_RELEASE_CANCEL)
+        {
+          gimp_tool_path_end_change (path, FALSE);
+        }
+      else
+        {
+          gimp_tool_path_end_change (path, TRUE);
+        }
+    }
+}
+
+void
+gimp_tool_path_motion (GimpToolWidget   *widget,
+                       const GimpCoords *coords,
+                       guint32           time,
+                       GdkModifierType   state)
+{
+  GimpToolPath        *path     = GIMP_TOOL_PATH (widget);
+  GimpToolPathPrivate *private  = path->private;
+  GimpCoords           position = GIMP_COORDS_DEFAULT_VALUES;
+  GimpAnchor          *anchor;
+
+  if (private->function == VECTORS_FINISHED)
+    return;
+
+  position.x = coords->x;
+  position.y = coords->y;
+
+  gimp_vectors_freeze (private->vectors);
+
+  if ((private->saved_state & TOGGLE_MASK) != (state & TOGGLE_MASK))
+    private->modifier_lock = FALSE;
+
+  if (! private->modifier_lock)
+    {
+      if (state & TOGGLE_MASK)
+        {
+          private->restriction = GIMP_ANCHOR_FEATURE_SYMMETRIC;
+        }
+      else
+        {
+          private->restriction = GIMP_ANCHOR_FEATURE_NONE;
+        }
+    }
+
+  switch (private->function)
+    {
+    case VECTORS_MOVE_ANCHOR:
+    case VECTORS_MOVE_HANDLE:
+      anchor = private->cur_anchor;
+
+      if (anchor)
+        {
+          gimp_stroke_anchor_move_absolute (private->cur_stroke,
+                                            private->cur_anchor,
+                                            &position,
+                                            private->restriction);
+          private->undo_motion = TRUE;
+        }
+      break;
+
+    case VECTORS_MOVE_CURVE:
+      if (private->polygonal)
+        {
+          gimp_tool_path_move_selected_anchors (path,
+                                                coords->x - private->last_x,
+                                                coords->y - private->last_y);
+          private->undo_motion = TRUE;
+        }
+      else
+        {
+          gimp_stroke_point_move_absolute (private->cur_stroke,
+                                           private->cur_anchor,
+                                           private->cur_position,
+                                           &position,
+                                           private->restriction);
+          private->undo_motion = TRUE;
+        }
+      break;
+
+    case VECTORS_MOVE_ANCHORSET:
+      gimp_tool_path_move_selected_anchors (path,
+                                            coords->x - private->last_x,
+                                            coords->y - private->last_y);
+      private->undo_motion = TRUE;
+      break;
+
+    case VECTORS_MOVE_STROKE:
+      if (private->cur_stroke)
+        {
+          gimp_stroke_translate (private->cur_stroke,
+                                 coords->x - private->last_x,
+                                 coords->y - private->last_y);
+          private->undo_motion = TRUE;
+        }
+      else if (private->sel_stroke)
+        {
+          gimp_stroke_translate (private->sel_stroke,
+                                 coords->x - private->last_x,
+                                 coords->y - private->last_y);
+          private->undo_motion = TRUE;
+        }
+      break;
+
+    case VECTORS_MOVE_VECTORS:
+      gimp_item_translate (GIMP_ITEM (private->vectors),
+                           coords->x - private->last_x,
+                           coords->y - private->last_y, FALSE);
+      private->undo_motion = TRUE;
+      break;
+
+    default:
+      break;
+    }
+
+  gimp_vectors_thaw (private->vectors);
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+}
+
+GimpHit
+gimp_tool_path_hit (GimpToolWidget   *widget,
+                    const GimpCoords *coords,
+                    GdkModifierType   state,
+                    gboolean          proximity)
+{
+  GimpToolPath *path = GIMP_TOOL_PATH (widget);
+
+  switch (gimp_tool_path_get_function (path, coords, state))
+    {
+    case VECTORS_SELECT_VECTOR:
+    case VECTORS_MOVE_ANCHOR:
+    case VECTORS_MOVE_ANCHORSET:
+    case VECTORS_MOVE_HANDLE:
+    case VECTORS_MOVE_CURVE:
+    case VECTORS_MOVE_STROKE:
+    case VECTORS_DELETE_ANCHOR:
+    case VECTORS_DELETE_SEGMENT:
+    case VECTORS_INSERT_ANCHOR:
+    case VECTORS_CONNECT_STROKES:
+    case VECTORS_CONVERT_EDGE:
+      return GIMP_HIT_DIRECT;
+
+    case VECTORS_CREATE_VECTOR:
+    case VECTORS_CREATE_STROKE:
+    case VECTORS_ADD_ANCHOR:
+    case VECTORS_MOVE_VECTORS:
+      return GIMP_HIT_INDIRECT;
+    
+    case VECTORS_FINISHED:
+      return GIMP_HIT_NONE;
+    }
+
+  return GIMP_HIT_NONE;
+}
+
+void
+gimp_tool_path_hover (GimpToolWidget   *widget,
+                      const GimpCoords *coords,
+                      GdkModifierType   state,
+                      gboolean          proximity)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (widget);
+  GimpToolPathPrivate *private = path->private;
+
+  private->function = gimp_tool_path_get_function (path, coords, state);
+
+  gimp_tool_path_update_status (path, state, proximity);
+}
+
+static gboolean
+gimp_tool_path_key_press (GimpToolWidget *widget,
+                          GdkEventKey    *kevent)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (widget);
+  GimpToolPathPrivate *private = path->private;
+  GimpDisplayShell    *shell;
+  gdouble              xdist, ydist;
+  gdouble              pixels = 1.0;
+
+  if (! private->vectors)
+    return FALSE;
+
+  shell = gimp_tool_widget_get_shell (widget);
+
+  if (kevent->state & gimp_get_extend_selection_mask ())
+    pixels = 10.0;
+
+  if (kevent->state & gimp_get_toggle_behavior_mask ())
+    pixels = 50.0;
+
+  switch (kevent->keyval)
+    {
+    case GDK_KEY_Return:
+    case GDK_KEY_KP_Enter:
+    case GDK_KEY_ISO_Enter:
+      g_signal_emit (path, path_signals[ACTIVATE], 0,
+                     kevent->state);
+      break;
+
+    case GDK_KEY_BackSpace:
+    case GDK_KEY_Delete:
+      gimp_tool_path_delete_selected_anchors (path);
+      break;
+
+    case GDK_KEY_Left:
+    case GDK_KEY_Right:
+    case GDK_KEY_Up:
+    case GDK_KEY_Down:
+      xdist = FUNSCALEX (shell, pixels);
+      ydist = FUNSCALEY (shell, pixels);
+
+      gimp_tool_path_begin_change (path, _("Move Anchors"));
+      gimp_vectors_freeze (private->vectors);
+
+      switch (kevent->keyval)
+        {
+        case GDK_KEY_Left:
+          gimp_tool_path_move_selected_anchors (path, -xdist, 0);
+          break;
+
+        case GDK_KEY_Right:
+          gimp_tool_path_move_selected_anchors (path, xdist, 0);
+          break;
+
+        case GDK_KEY_Up:
+          gimp_tool_path_move_selected_anchors (path, 0, -ydist);
+          break;
+
+        case GDK_KEY_Down:
+          gimp_tool_path_move_selected_anchors (path, 0, ydist);
+          break;
+
+        default:
+          break;
+        }
+
+      gimp_vectors_thaw (private->vectors);
+      gimp_tool_path_end_change (path, TRUE);
+      break;
+
+    case GDK_KEY_Escape:
+      if (private->edit_mode != GIMP_VECTOR_MODE_DESIGN)
+        g_object_set (private,
+                      "vectors-edit-mode", GIMP_VECTOR_MODE_DESIGN,
+                      NULL);
+      break;
+
+    default:
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+static gboolean
+gimp_tool_path_get_cursor (GimpToolWidget     *widget,
+                           const GimpCoords   *coords,
+                           GdkModifierType     state,
+                           GimpCursorType     *cursor,
+                           GimpToolCursorType *tool_cursor,
+                           GimpCursorModifier *modifier)
+{
+  GimpToolPath        *path    = GIMP_TOOL_PATH (widget);
+  GimpToolPathPrivate *private = path->private;
+
+  *tool_cursor = GIMP_TOOL_CURSOR_PATHS;
+  *modifier    = GIMP_CURSOR_MODIFIER_NONE;
+
+  switch (private->function)
+    {
+    case VECTORS_SELECT_VECTOR:
+      *tool_cursor = GIMP_TOOL_CURSOR_HAND;
+      break;
+
+    case VECTORS_CREATE_VECTOR:
+    case VECTORS_CREATE_STROKE:
+      *modifier = GIMP_CURSOR_MODIFIER_CONTROL;
+      break;
+
+    case VECTORS_ADD_ANCHOR:
+    case VECTORS_INSERT_ANCHOR:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_ANCHOR;
+      *modifier    = GIMP_CURSOR_MODIFIER_PLUS;
+      break;
+
+    case VECTORS_DELETE_ANCHOR:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_ANCHOR;
+      *modifier    = GIMP_CURSOR_MODIFIER_MINUS;
+      break;
+
+    case VECTORS_DELETE_SEGMENT:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_SEGMENT;
+      *modifier    = GIMP_CURSOR_MODIFIER_MINUS;
+      break;
+
+    case VECTORS_MOVE_HANDLE:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_CONTROL;
+      *modifier    = GIMP_CURSOR_MODIFIER_MOVE;
+      break;
+
+    case VECTORS_CONVERT_EDGE:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_CONTROL;
+      *modifier    = GIMP_CURSOR_MODIFIER_MINUS;
+      break;
+
+    case VECTORS_MOVE_ANCHOR:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_ANCHOR;
+      *modifier    = GIMP_CURSOR_MODIFIER_MOVE;
+      break;
+
+    case VECTORS_MOVE_CURVE:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_SEGMENT;
+      *modifier    = GIMP_CURSOR_MODIFIER_MOVE;
+      break;
+
+    case VECTORS_MOVE_STROKE:
+    case VECTORS_MOVE_VECTORS:
+      *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+      break;
+
+    case VECTORS_MOVE_ANCHORSET:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_ANCHOR;
+      *modifier    = GIMP_CURSOR_MODIFIER_MOVE;
+      break;
+
+    case VECTORS_CONNECT_STROKES:
+      *tool_cursor = GIMP_TOOL_CURSOR_PATHS_SEGMENT;
+      *modifier    = GIMP_CURSOR_MODIFIER_JOIN;
+      break;
+
+    default:
+      *modifier = GIMP_CURSOR_MODIFIER_BAD;
+      break;
+    }
+
+  return TRUE;
+}
+
+static GimpVectorFunction
+gimp_tool_path_get_function (GimpToolPath     *path,
+                             const GimpCoords *coords,
+                             GdkModifierType   state)
+{
+  GimpToolPathPrivate *private    = path->private;
+  GimpAnchor          *anchor     = NULL;
+  GimpAnchor          *anchor2    = NULL;
+  GimpStroke          *stroke     = NULL;
+  gdouble              position   = -1;
+  gboolean             on_handle  = FALSE;
+  gboolean             on_curve   = FALSE;
+  gboolean             on_vectors = FALSE;
+  GimpVectorFunction   function   = VECTORS_FINISHED;
+
+  private->modifier_lock = FALSE;
+
+  /* are we hovering the current vectors on the current display? */
+  if (private->vectors)
+    {
+      on_handle = gimp_canvas_item_on_vectors_handle (private->path,
+                                                      private->vectors,
+                                                      coords,
+                                                      GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                      GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                      GIMP_ANCHOR_ANCHOR,
+                                                      private->sel_count > 2,
+                                                      &anchor, &stroke);
+
+      if (! on_handle)
+        on_curve = gimp_canvas_item_on_vectors_curve (private->path,
+                                                      private->vectors,
+                                                      coords,
+                                                      GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                      GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                      NULL,
+                                                      &position, &anchor,
+                                                      &anchor2, &stroke);
+    }
+
+  if (! on_handle && ! on_curve)
+    {
+      on_vectors = gimp_canvas_item_on_vectors (private->path,
+                                                coords,
+                                                GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                NULL, NULL, NULL, NULL, NULL,
+                                                NULL);
+    }
+
+  private->cur_position = position;
+  private->cur_anchor   = anchor;
+  private->cur_anchor2  = anchor2;
+  private->cur_stroke   = stroke;
+
+  switch (private->edit_mode)
+    {
+    case GIMP_VECTOR_MODE_DESIGN:
+      if (! private->vectors)
+        {
+          if (on_vectors)
+            {
+              function = VECTORS_SELECT_VECTOR;
+            }
+          else
+            {
+              function               = VECTORS_CREATE_VECTOR;
+              private->restriction   = GIMP_ANCHOR_FEATURE_SYMMETRIC;
+              private->modifier_lock = TRUE;
+            }
+        }
+      else if (on_handle)
+        {
+          if (anchor->type == GIMP_ANCHOR_ANCHOR)
+            {
+              if (state & TOGGLE_MASK)
+                {
+                  function = VECTORS_MOVE_ANCHORSET;
+                }
+              else
+                {
+                  if (private->sel_count >= 2 && anchor->selected)
+                    function = VECTORS_MOVE_ANCHORSET;
+                  else
+                    function = VECTORS_MOVE_ANCHOR;
+                }
+            }
+          else
+            {
+              function = VECTORS_MOVE_HANDLE;
+
+              if (state & TOGGLE_MASK)
+                private->restriction = GIMP_ANCHOR_FEATURE_SYMMETRIC;
+              else
+                private->restriction = GIMP_ANCHOR_FEATURE_NONE;
+            }
+        }
+      else if (on_curve)
+        {
+          if (gimp_stroke_point_is_movable (stroke, anchor, position))
+            {
+              function = VECTORS_MOVE_CURVE;
+
+              if (state & TOGGLE_MASK)
+                private->restriction = GIMP_ANCHOR_FEATURE_SYMMETRIC;
+              else
+                private->restriction = GIMP_ANCHOR_FEATURE_NONE;
+            }
+          else
+            {
+              function = VECTORS_FINISHED;
+            }
+        }
+      else
+        {
+          if (private->sel_stroke &&
+              private->sel_anchor &&
+              gimp_stroke_is_extendable (private->sel_stroke,
+                                         private->sel_anchor) &&
+              ! (state & TOGGLE_MASK))
+            function = VECTORS_ADD_ANCHOR;
+          else
+            function = VECTORS_CREATE_STROKE;
+
+          private->restriction   = GIMP_ANCHOR_FEATURE_SYMMETRIC;
+          private->modifier_lock = TRUE;
+        }
+
+      break;
+
+    case GIMP_VECTOR_MODE_EDIT:
+      if (! private->vectors)
+        {
+          if (on_vectors)
+            {
+              function = VECTORS_SELECT_VECTOR;
+            }
+          else
+            {
+              function = VECTORS_FINISHED;
+            }
+        }
+      else if (on_handle)
+        {
+          if (anchor->type == GIMP_ANCHOR_ANCHOR)
+            {
+              if (! (state & TOGGLE_MASK) &&
+                  private->sel_anchor &&
+                  private->sel_anchor != anchor &&
+                  gimp_stroke_is_extendable (private->sel_stroke,
+                                             private->sel_anchor) &&
+                  gimp_stroke_is_extendable (stroke, anchor))
+                {
+                  function = VECTORS_CONNECT_STROKES;
+                }
+              else
+                {
+                  if (state & TOGGLE_MASK)
+                    {
+                      function = VECTORS_DELETE_ANCHOR;
+                    }
+                  else
+                    {
+                      if (private->polygonal)
+                        function = VECTORS_MOVE_ANCHOR;
+                      else
+                        function = VECTORS_MOVE_HANDLE;
+                    }
+                }
+            }
+          else
+            {
+              if (state & TOGGLE_MASK)
+                function = VECTORS_CONVERT_EDGE;
+              else
+                function = VECTORS_MOVE_HANDLE;
+            }
+        }
+      else if (on_curve)
+        {
+          if (state & TOGGLE_MASK)
+            {
+              function = VECTORS_DELETE_SEGMENT;
+            }
+          else if (gimp_stroke_anchor_is_insertable (stroke, anchor, position))
+            {
+              function = VECTORS_INSERT_ANCHOR;
+            }
+          else
+            {
+              function = VECTORS_FINISHED;
+            }
+        }
+      else
+        {
+          function = VECTORS_FINISHED;
+        }
+
+      break;
+
+    case GIMP_VECTOR_MODE_MOVE:
+      if (! private->vectors)
+        {
+          if (on_vectors)
+            {
+              function = VECTORS_SELECT_VECTOR;
+            }
+          else
+            {
+              function = VECTORS_FINISHED;
+            }
+        }
+      else if (on_handle || on_curve)
+        {
+          if (state & TOGGLE_MASK)
+            {
+              function = VECTORS_MOVE_VECTORS;
+            }
+          else
+            {
+              function = VECTORS_MOVE_STROKE;
+            }
+        }
+      else
+        {
+          if (on_vectors)
+            {
+              function = VECTORS_SELECT_VECTOR;
+            }
+          else
+            {
+              function = VECTORS_MOVE_VECTORS;
+            }
+        }
+      break;
+    }
+
+  return function;
+}
+
+static void
+gimp_tool_path_update_status (GimpToolPath    *path,
+                              GdkModifierType  state,
+                              gboolean         proximity)
+{
+  GimpToolPathPrivate *private     = path->private;
+  GdkModifierType      extend_mask = gimp_get_extend_selection_mask ();
+  GdkModifierType      toggle_mask = gimp_get_toggle_behavior_mask ();
+  const gchar         *status      = NULL;
+  gboolean             free_status = FALSE;
+
+  if (! proximity)
+    {
+      gimp_tool_widget_set_status (GIMP_TOOL_WIDGET (path), NULL);
+      return;
+    }
+
+  switch (private->function)
+    {
+    case VECTORS_SELECT_VECTOR:
+      status = _("Click to pick path to edit");
+      break;
+
+    case VECTORS_CREATE_VECTOR:
+      status = _("Click to create a new path");
+      break;
+
+    case VECTORS_CREATE_STROKE:
+      status = _("Click to create a new component of the path");
+      break;
+
+    case VECTORS_ADD_ANCHOR:
+      status = gimp_suggest_modifiers (_("Click or Click-Drag to create "
+                                         "a new anchor"),
+                                       extend_mask & ~state,
+                                       NULL, NULL, NULL);
+      free_status = TRUE;
+      break;
+
+    case VECTORS_MOVE_ANCHOR:
+      if (private->edit_mode != GIMP_VECTOR_MODE_EDIT)
+        {
+          status = gimp_suggest_modifiers (_("Click-Drag to move the "
+                                             "anchor around"),
+                                           toggle_mask & ~state,
+                                           NULL, NULL, NULL);
+          free_status = TRUE;
+        }
+      else
+        status = _("Click-Drag to move the anchor around");
+      break;
+
+    case VECTORS_MOVE_ANCHORSET:
+      status = _("Click-Drag to move the anchors around");
+      break;
+
+    case VECTORS_MOVE_HANDLE:
+      if (private->restriction != GIMP_ANCHOR_FEATURE_SYMMETRIC)
+        {
+          status = gimp_suggest_modifiers (_("Click-Drag to move the "
+                                             "handle around"),
+                                           extend_mask & ~state,
+                                           NULL, NULL, NULL);
+        }
+      else
+        {
+          status = gimp_suggest_modifiers (_("Click-Drag to move the "
+                                             "handles around symmetrically"),
+                                           extend_mask & ~state,
+                                           NULL, NULL, NULL);
+        }
+      free_status = TRUE;
+      break;
+
+    case VECTORS_MOVE_CURVE:
+      if (private->polygonal)
+        status = gimp_suggest_modifiers (_("Click-Drag to move the "
+                                           "anchors around"),
+                                         extend_mask & ~state,
+                                         NULL, NULL, NULL);
+      else
+        status = gimp_suggest_modifiers (_("Click-Drag to change the "
+                                           "shape of the curve"),
+                                         extend_mask & ~state,
+                                         _("%s: symmetrical"), NULL, NULL);
+      free_status = TRUE;
+      break;
+
+    case VECTORS_MOVE_STROKE:
+      status = gimp_suggest_modifiers (_("Click-Drag to move the "
+                                         "component around"),
+                                       extend_mask & ~state,
+                                       NULL, NULL, NULL);
+      free_status = TRUE;
+      break;
+
+    case VECTORS_MOVE_VECTORS:
+      status = _("Click-Drag to move the path around");
+      break;
+
+    case VECTORS_INSERT_ANCHOR:
+      status = gimp_suggest_modifiers (_("Click-Drag to insert an anchor "
+                                         "on the path"),
+                                       extend_mask & ~state,
+                                       NULL, NULL, NULL);
+      free_status = TRUE;
+      break;
+
+    case VECTORS_DELETE_ANCHOR:
+      status = _("Click to delete this anchor");
+      break;
+
+    case VECTORS_CONNECT_STROKES:
+      status = _("Click to connect this anchor "
+                 "with the selected endpoint");
+      break;
+
+    case VECTORS_DELETE_SEGMENT:
+      status = _("Click to open up the path");
+      break;
+
+    case VECTORS_CONVERT_EDGE:
+      status = _("Click to make this node angular");
+      break;
+
+    case VECTORS_FINISHED:
+      status = _("Clicking here does nothing, try clicking on path elements.");
+      break;
+    }
+
+  gimp_tool_widget_set_status (GIMP_TOOL_WIDGET (path), status);
+
+  if (free_status)
+    g_free ((gchar *) status);
+}
+
+static void
+gimp_tool_path_begin_change (GimpToolPath *path,
+                             const gchar  *desc)
+{
+  GimpToolPathPrivate *private = path->private;
+
+  g_return_if_fail (private->vectors != NULL);
+
+  /* don't push two undos */
+  if (private->have_undo)
+    return;
+
+  g_signal_emit (path, path_signals[BEGIN_CHANGE], 0,
+                 desc);
+
+  private->have_undo = TRUE;
+}
+
+static void
+gimp_tool_path_end_change (GimpToolPath *path,
+                           gboolean      success)
+{
+  GimpToolPathPrivate *private = path->private;
+
+  private->have_undo   = FALSE;
+  private->undo_motion = FALSE;
+
+  g_signal_emit (path, path_signals[END_CHANGE], 0,
+                 success);
+}
+
+static void
+gimp_tool_path_vectors_visible (GimpVectors  *vectors,
+                                GimpToolPath *path)
+{
+  GimpToolPathPrivate *private = path->private;
+
+  gimp_canvas_item_set_visible (private->path,
+                                ! gimp_item_get_visible (GIMP_ITEM (vectors)));
+}
+
+static void
+gimp_tool_path_vectors_freeze (GimpVectors  *vectors,
+                               GimpToolPath *path)
+{
+}
+
+static void
+gimp_tool_path_vectors_thaw (GimpVectors  *vectors,
+                             GimpToolPath *path)
+{
+  /*  Ok, the vector might have changed externally (e.g. Undo) we need
+   *  to validate our internal state.
+   */
+  gimp_tool_path_verify_state (path);
+  gimp_tool_path_changed (GIMP_TOOL_WIDGET (path));
+}
+
+static void
+gimp_tool_path_verify_state (GimpToolPath *path)
+{
+  GimpToolPathPrivate *private          = path->private;
+  GimpStroke          *cur_stroke       = NULL;
+  gboolean             cur_anchor_valid = FALSE;
+  gboolean             cur_stroke_valid = FALSE;
+
+  private->sel_count  = 0;
+  private->sel_anchor = NULL;
+  private->sel_stroke = NULL;
+
+  if (! private->vectors)
+    {
+      private->cur_position = -1;
+      private->cur_anchor   = NULL;
+      private->cur_stroke   = NULL;
+      return;
+    }
+
+  while ((cur_stroke = gimp_vectors_stroke_get_next (private->vectors,
+                                                     cur_stroke)))
+    {
+      GList *anchors;
+      GList *list;
+
+      /* anchor handles */
+      anchors = gimp_stroke_get_draw_anchors (cur_stroke);
+
+      if (cur_stroke == private->cur_stroke)
+        cur_stroke_valid = TRUE;
+
+      for (list = anchors; list; list = g_list_next (list))
+        {
+          GimpAnchor *cur_anchor = list->data;
+
+          if (cur_anchor == private->cur_anchor)
+            cur_anchor_valid = TRUE;
+
+          if (cur_anchor->type == GIMP_ANCHOR_ANCHOR &&
+              cur_anchor->selected)
+            {
+              private->sel_count++;
+              if (private->sel_count == 1)
+                {
+                  private->sel_anchor = cur_anchor;
+                  private->sel_stroke = cur_stroke;
+                }
+              else
+                {
+                  private->sel_anchor = NULL;
+                  private->sel_stroke = NULL;
+                }
+            }
+        }
+
+      g_list_free (anchors);
+
+      anchors = gimp_stroke_get_draw_controls (cur_stroke);
+
+      for (list = anchors; list; list = g_list_next (list))
+        {
+          GimpAnchor *cur_anchor = list->data;
+
+          if (cur_anchor == private->cur_anchor)
+            cur_anchor_valid = TRUE;
+        }
+
+      g_list_free (anchors);
+    }
+
+  if (! cur_stroke_valid)
+    private->cur_stroke = NULL;
+
+  if (! cur_anchor_valid)
+    private->cur_anchor = NULL;
+}
+
+static void
+gimp_tool_path_move_selected_anchors (GimpToolPath *path,
+                                      gdouble       x,
+                                      gdouble       y)
+{
+  GimpToolPathPrivate *private = path->private;
+  GimpAnchor          *cur_anchor;
+  GimpStroke          *cur_stroke = NULL;
+  GList               *anchors;
+  GList               *list;
+  GimpCoords           offset = { 0.0, };
+
+  offset.x = x;
+  offset.y = y;
+
+  while ((cur_stroke = gimp_vectors_stroke_get_next (private->vectors,
+                                                     cur_stroke)))
+    {
+      /* anchors */
+      anchors = gimp_stroke_get_draw_anchors (cur_stroke);
+
+      for (list = anchors; list; list = g_list_next (list))
+        {
+          cur_anchor = GIMP_ANCHOR (list->data);
+
+          if (cur_anchor->selected)
+            gimp_stroke_anchor_move_relative (cur_stroke,
+                                              cur_anchor,
+                                              &offset,
+                                              GIMP_ANCHOR_FEATURE_NONE);
+        }
+
+      g_list_free (anchors);
+    }
+}
+
+static void
+gimp_tool_path_delete_selected_anchors (GimpToolPath *path)
+{
+  GimpToolPathPrivate *private = path->private;
+  GimpAnchor          *cur_anchor;
+  GimpStroke          *cur_stroke = NULL;
+  GList               *anchors;
+  GList               *list;
+  gboolean             have_undo = FALSE;
+
+  gimp_vectors_freeze (private->vectors);
+
+  while ((cur_stroke = gimp_vectors_stroke_get_next (private->vectors,
+                                                     cur_stroke)))
+    {
+      /* anchors */
+      anchors = gimp_stroke_get_draw_anchors (cur_stroke);
+
+      for (list = anchors; list; list = g_list_next (list))
+        {
+          cur_anchor = GIMP_ANCHOR (list->data);
+
+          if (cur_anchor->selected)
+            {
+              if (! have_undo)
+                {
+                  gimp_tool_path_begin_change (path, _("Delete Anchors"));
+                  have_undo = TRUE;
+                }
+
+              gimp_stroke_anchor_delete (cur_stroke, cur_anchor);
+
+              if (gimp_stroke_is_empty (cur_stroke))
+                {
+                  gimp_vectors_stroke_remove (private->vectors, cur_stroke);
+                  cur_stroke = NULL;
+                }
+            }
+        }
+
+      g_list_free (anchors);
+    }
+
+  if (have_undo)
+    gimp_tool_path_end_change (path, TRUE);
+
+  gimp_vectors_thaw (private->vectors);
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_path_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_PATH,
+                       "shell", shell,
+                       NULL);
+}
+
+void
+gimp_tool_path_set_vectors (GimpToolPath *path,
+                            GimpVectors  *vectors)
+{
+  GimpToolPathPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_PATH (path));
+  g_return_if_fail (vectors == NULL || GIMP_IS_VECTORS (vectors));
+
+  private = path->private;
+
+  if (vectors == private->vectors)
+    return;
+
+  if (private->vectors)
+    {
+      g_signal_handlers_disconnect_by_func (private->vectors,
+                                            gimp_tool_path_vectors_visible,
+                                            path);
+      g_signal_handlers_disconnect_by_func (private->vectors,
+                                            gimp_tool_path_vectors_freeze,
+                                            path);
+      g_signal_handlers_disconnect_by_func (private->vectors,
+                                            gimp_tool_path_vectors_thaw,
+                                            path);
+
+      g_object_unref (private->vectors);
+    }
+
+  private->vectors  = vectors;
+  private->function = VECTORS_FINISHED;
+  gimp_tool_path_verify_state (path);
+
+  if (private->vectors)
+    {
+      g_object_ref (private->vectors);
+
+      g_signal_connect_object (private->vectors, "visibility-changed",
+                               G_CALLBACK (gimp_tool_path_vectors_visible),
+                               path, 0);
+      g_signal_connect_object (private->vectors, "freeze",
+                               G_CALLBACK (gimp_tool_path_vectors_freeze),
+                               path, 0);
+      g_signal_connect_object (private->vectors, "thaw",
+                               G_CALLBACK (gimp_tool_path_vectors_thaw),
+                               path, 0);
+    }
+
+  g_object_notify (G_OBJECT (path), "vectors");
+}
diff --git a/app/display/gimptoolpath.h b/app/display/gimptoolpath.h
new file mode 100644
index 0000000..861d5e8
--- /dev/null
+++ b/app/display/gimptoolpath.h
@@ -0,0 +1,68 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolpath.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_PATH_H__
+#define __GIMP_TOOL_PATH_H__
+
+
+#include "gimptoolwidget.h"
+
+
+#define GIMP_TYPE_TOOL_PATH            (gimp_tool_path_get_type ())
+#define GIMP_TOOL_PATH(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_PATH, GimpToolPath))
+#define GIMP_TOOL_PATH_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_PATH, GimpToolPathClass))
+#define GIMP_IS_TOOL_PATH(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_PATH))
+#define GIMP_IS_TOOL_PATH_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_PATH))
+#define GIMP_TOOL_PATH_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_PATH, GimpToolPathClass))
+
+
+typedef struct _GimpToolPath        GimpToolPath;
+typedef struct _GimpToolPathPrivate GimpToolPathPrivate;
+typedef struct _GimpToolPathClass   GimpToolPathClass;
+
+struct _GimpToolPath
+{
+  GimpToolWidget       parent_instance;
+
+  GimpToolPathPrivate *private;
+};
+
+struct _GimpToolPathClass
+{
+  GimpToolWidgetClass  parent_class;
+
+  void (* begin_change) (GimpToolPath    *path,
+                         const gchar     *desc);
+  void (* end_change)   (GimpToolPath    *path,
+                         gboolean         success);
+  void (* activate)     (GimpToolPath    *path,
+                         GdkModifierType  state);
+};
+
+
+GType            gimp_tool_path_get_type    (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_path_new         (GimpDisplayShell *shell);
+
+void             gimp_tool_path_set_vectors (GimpToolPath     *path,
+                                             GimpVectors      *vectors);
+
+
+#endif /* __GIMP_TOOL_PATH_H__ */
diff --git a/app/display/gimptoolpolygon.c b/app/display/gimptoolpolygon.c
new file mode 100644
index 0000000..4f2c20b
--- /dev/null
+++ b/app/display/gimptoolpolygon.c
@@ -0,0 +1,1495 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolpolygon.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Based on GimpFreeSelectTool
+ *
+ * Major improvement to support polygonal segments
+ * Copyright (C) 2008 Martin Nordholts
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-utils.h"
+#include "core/gimpmarshal.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvashandle.h"
+#include "gimpcanvasline.h"
+#include "gimpcanvaspolygon.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-utils.h"
+#include "gimptoolpolygon.h"
+
+#include "gimp-intl.h"
+
+
+#define POINT_GRAB_THRESHOLD_SQ SQR (GIMP_CANVAS_HANDLE_SIZE_CIRCLE / 2)
+#define POINT_SHOW_THRESHOLD_SQ SQR (GIMP_CANVAS_HANDLE_SIZE_CIRCLE * 7)
+#define N_ITEMS_PER_ALLOC       1024
+#define INVALID_INDEX           (-1)
+#define NO_CLICK_TIME_AVAILABLE 0
+
+
+enum
+{
+  CHANGE_COMPLETE,
+  LAST_SIGNAL
+};
+
+
+struct _GimpToolPolygonPrivate
+{
+  /* Index of grabbed segment index. */
+  gint               grabbed_segment_index;
+
+  /* We need to keep track of a number of points when we move a
+   * segment vertex
+   */
+  GimpVector2       *saved_points_lower_segment;
+  GimpVector2       *saved_points_higher_segment;
+  gint               max_n_saved_points_lower_segment;
+  gint               max_n_saved_points_higher_segment;
+
+  /* Keeps track whether or not a modification of the polygon has been
+   * made between _button_press and _button_release
+   */
+  gboolean           polygon_modified;
+
+  /* Point which is used to draw the polygon but which is not part of
+   * it yet
+   */
+  GimpVector2        pending_point;
+  gboolean           show_pending_point;
+
+  /* The points of the polygon */
+  GimpVector2       *points;
+  gint               max_n_points;
+
+  /* The number of points actually in use */
+  gint               n_points;
+
+
+  /* Any int array containing the indices for the points in the
+   * polygon that connects different segments together
+   */
+  gint              *segment_indices;
+  gint               max_n_segment_indices;
+
+  /* The number of segment indices actually in use */
+  gint               n_segment_indices;
+
+  /* Is the polygon closed? */
+  gboolean           polygon_closed;
+
+  /* Whether or not to constrain the angle for newly created polygonal
+   * segments.
+   */
+  gboolean           constrain_angle;
+
+  /* Whether or not to suppress handles (so that new segments can be
+   * created immediately after an existing segment vertex.
+   */
+  gboolean           suppress_handles;
+
+  /* Last _oper_update or _motion coords */
+  gboolean           hover;
+  GimpVector2        last_coords;
+
+  /* A double-click commits the selection, keep track of last
+   * click-time and click-position.
+   */
+  guint32            last_click_time;
+  GimpCoords         last_click_coord;
+
+  /* Are we in a click-drag-release? */
+  gboolean           button_down;
+
+  GimpCanvasItem    *polygon;
+  GimpCanvasItem    *pending_line;
+  GimpCanvasItem    *closing_line;
+  GPtrArray         *handles;
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_polygon_constructed     (GObject               *object);
+static void     gimp_tool_polygon_finalize        (GObject               *object);
+static void     gimp_tool_polygon_set_property    (GObject               *object,
+                                                   guint                  property_id,
+                                                   const GValue          *value,
+                                                   GParamSpec            *pspec);
+static void     gimp_tool_polygon_get_property    (GObject               *object,
+                                                   guint                  property_id,
+                                                   GValue                *value,
+                                                   GParamSpec            *pspec);
+
+static void     gimp_tool_polygon_changed         (GimpToolWidget        *widget);
+static gint     gimp_tool_polygon_button_press    (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   guint32                time,
+                                                   GdkModifierType        state,
+                                                   GimpButtonPressType    press_type);
+static void     gimp_tool_polygon_button_release  (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   guint32                time,
+                                                   GdkModifierType        state,
+                                                   GimpButtonReleaseType  release_type);
+static void     gimp_tool_polygon_motion          (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   guint32                time,
+                                                   GdkModifierType        state);
+static GimpHit  gimp_tool_polygon_hit             (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   GdkModifierType        state,
+                                                   gboolean               proximity);
+static void     gimp_tool_polygon_hover           (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   GdkModifierType        state,
+                                                   gboolean               proximity);
+static void     gimp_tool_polygon_leave_notify    (GimpToolWidget        *widget);
+static gboolean gimp_tool_polygon_key_press       (GimpToolWidget        *widget,
+                                                   GdkEventKey           *kevent);
+static void     gimp_tool_polygon_motion_modifier (GimpToolWidget        *widget,
+                                                   GdkModifierType        key,
+                                                   gboolean               press,
+                                                   GdkModifierType        state);
+static void     gimp_tool_polygon_hover_modifier  (GimpToolWidget        *widget,
+                                                   GdkModifierType        key,
+                                                   gboolean               press,
+                                                   GdkModifierType        state);
+static gboolean gimp_tool_polygon_get_cursor      (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   GdkModifierType        state,
+                                                   GimpCursorType        *cursor,
+                                                   GimpToolCursorType    *tool_cursor,
+                                                   GimpCursorModifier    *modifier);
+
+static void     gimp_tool_polygon_change_complete (GimpToolPolygon       *polygon);
+
+static gint   gimp_tool_polygon_get_segment_index (GimpToolPolygon       *polygon,
+                                                   const GimpCoords      *coords);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolPolygon, gimp_tool_polygon,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_polygon_parent_class
+
+static guint polygon_signals[LAST_SIGNAL] = { 0, };
+
+static const GimpVector2 vector2_zero = { 0.0, 0.0 };
+
+
+static void
+gimp_tool_polygon_class_init (GimpToolPolygonClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_polygon_constructed;
+  object_class->finalize        = gimp_tool_polygon_finalize;
+  object_class->set_property    = gimp_tool_polygon_set_property;
+  object_class->get_property    = gimp_tool_polygon_get_property;
+
+  widget_class->changed         = gimp_tool_polygon_changed;
+  widget_class->button_press    = gimp_tool_polygon_button_press;
+  widget_class->button_release  = gimp_tool_polygon_button_release;
+  widget_class->motion          = gimp_tool_polygon_motion;
+  widget_class->hit             = gimp_tool_polygon_hit;
+  widget_class->hover           = gimp_tool_polygon_hover;
+  widget_class->leave_notify    = gimp_tool_polygon_leave_notify;
+  widget_class->key_press       = gimp_tool_polygon_key_press;
+  widget_class->motion_modifier = gimp_tool_polygon_motion_modifier;
+  widget_class->hover_modifier  = gimp_tool_polygon_hover_modifier;
+  widget_class->get_cursor      = gimp_tool_polygon_get_cursor;
+
+  polygon_signals[CHANGE_COMPLETE] =
+    g_signal_new ("change-complete",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolPolygonClass, change_complete),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+}
+
+static void
+gimp_tool_polygon_init (GimpToolPolygon *polygon)
+{
+  polygon->private = gimp_tool_polygon_get_instance_private (polygon);
+
+  polygon->private->grabbed_segment_index = INVALID_INDEX;
+  polygon->private->last_click_time       = NO_CLICK_TIME_AVAILABLE;
+}
+
+static void
+gimp_tool_polygon_constructed (GObject *object)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (object);
+  GimpToolWidget         *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolPolygonPrivate *private = polygon->private;
+  GimpCanvasGroup        *stroke_group;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  stroke_group = gimp_tool_widget_add_stroke_group (widget);
+
+  gimp_tool_widget_push_group (widget, stroke_group);
+
+  private->polygon = gimp_tool_widget_add_polygon (widget, NULL,
+                                                   NULL, 0, FALSE);
+
+  private->pending_line = gimp_tool_widget_add_line (widget, 0, 0, 0, 0);
+  private->closing_line = gimp_tool_widget_add_line (widget, 0, 0, 0, 0);
+
+  gimp_tool_widget_pop_group (widget);
+
+  private->handles = g_ptr_array_new ();
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static void
+gimp_tool_polygon_finalize (GObject *object)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (object);
+  GimpToolPolygonPrivate *private = polygon->private;
+
+  g_free (private->points);
+  g_free (private->segment_indices);
+  g_free (private->saved_points_lower_segment);
+  g_free (private->saved_points_higher_segment);
+
+  g_clear_pointer (&private->handles, g_ptr_array_unref);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_tool_polygon_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_polygon_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_polygon_get_segment (GimpToolPolygon  *polygon,
+                               GimpVector2     **points,
+                               gint             *n_points,
+                               gint              segment_start,
+                               gint              segment_end)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  *points   = &priv->points[priv->segment_indices[segment_start]];
+  *n_points = priv->segment_indices[segment_end] -
+              priv->segment_indices[segment_start] +
+              1;
+}
+
+static void
+gimp_tool_polygon_get_segment_point (GimpToolPolygon *polygon,
+                                     gdouble         *start_point_x,
+                                     gdouble         *start_point_y,
+                                     gint             segment_index)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  *start_point_x = priv->points[priv->segment_indices[segment_index]].x;
+  *start_point_y = priv->points[priv->segment_indices[segment_index]].y;
+}
+
+static gboolean
+gimp_tool_polygon_should_close (GimpToolPolygon  *polygon,
+                                guint32           time,
+                                const GimpCoords *coords)
+{
+  GimpToolWidget         *widget       = GIMP_TOOL_WIDGET (polygon);
+  GimpToolPolygonPrivate *priv         = polygon->private;
+  gboolean                double_click = FALSE;
+  gdouble                 dist;
+
+  if (priv->polygon_modified      ||
+      priv->n_segment_indices < 1 ||
+      priv->n_points          < 3 ||
+      priv->polygon_closed)
+    return FALSE;
+
+  dist = gimp_canvas_item_transform_distance_square (priv->polygon,
+                                                     coords->x,
+                                                     coords->y,
+                                                     priv->points[0].x,
+                                                     priv->points[0].y);
+
+  /* Handle double-click. It must be within GTK+ global double-click
+   * time since last click, and it must be within GTK+ global
+   * double-click distance away from the last point
+   */
+  if (time != NO_CLICK_TIME_AVAILABLE)
+    {
+      GimpDisplayShell *shell    = gimp_tool_widget_get_shell (widget);
+      GtkSettings      *settings = gtk_widget_get_settings (GTK_WIDGET (shell));
+      gint              double_click_time;
+      gint              double_click_distance;
+      gint              click_time_passed;
+      gdouble           dist_from_last_point;
+
+      click_time_passed = time - priv->last_click_time;
+
+      dist_from_last_point =
+        gimp_canvas_item_transform_distance_square (priv->polygon,
+                                                    coords->x,
+                                                    coords->y,
+                                                    priv->last_click_coord.x,
+                                                    priv->last_click_coord.y);
+
+      g_object_get (settings,
+                    "gtk-double-click-time",     &double_click_time,
+                    "gtk-double-click-distance", &double_click_distance,
+                    NULL);
+
+      double_click = click_time_passed    < double_click_time &&
+                     dist_from_last_point < double_click_distance;
+    }
+
+  return ((! priv->suppress_handles && dist < POINT_GRAB_THRESHOLD_SQ) ||
+          double_click);
+}
+
+static void
+gimp_tool_polygon_revert_to_last_segment (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  priv->n_points = priv->segment_indices[priv->n_segment_indices - 1] + 1;
+}
+
+static void
+gimp_tool_polygon_remove_last_segment (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (priv->polygon_closed)
+    {
+      priv->polygon_closed = FALSE;
+
+      gimp_tool_polygon_changed (GIMP_TOOL_WIDGET (polygon));
+
+      return;
+    }
+
+  if (priv->n_segment_indices > 0)
+    {
+      GimpCanvasItem *handle;
+
+      priv->n_segment_indices--;
+
+      handle = g_ptr_array_index (priv->handles,
+                                  priv->n_segment_indices);
+
+      gimp_tool_widget_remove_item (GIMP_TOOL_WIDGET (polygon), handle);
+      g_ptr_array_remove (priv->handles, handle);
+    }
+
+  if (priv->n_segment_indices <= 0)
+    {
+      priv->grabbed_segment_index = INVALID_INDEX;
+      priv->show_pending_point    = FALSE;
+      priv->n_points              = 0;
+      priv->n_segment_indices     = 0;
+
+      gimp_tool_widget_response (GIMP_TOOL_WIDGET (polygon),
+                                 GIMP_TOOL_WIDGET_RESPONSE_CANCEL);
+    }
+  else
+    {
+      gimp_tool_polygon_revert_to_last_segment (polygon);
+
+      gimp_tool_polygon_changed (GIMP_TOOL_WIDGET (polygon));
+    }
+}
+
+static void
+gimp_tool_polygon_add_point (GimpToolPolygon *polygon,
+                             gdouble          x,
+                             gdouble          y)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (priv->n_points >= priv->max_n_points)
+    {
+      priv->max_n_points += N_ITEMS_PER_ALLOC;
+
+      priv->points = g_realloc (priv->points,
+                                sizeof (GimpVector2) * priv->max_n_points);
+    }
+
+  priv->points[priv->n_points].x = x;
+  priv->points[priv->n_points].y = y;
+
+  priv->n_points++;
+}
+
+static void
+gimp_tool_polygon_add_segment_index (GimpToolPolygon *polygon,
+                                     gint             index)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (priv->n_segment_indices >= priv->max_n_segment_indices)
+    {
+      priv->max_n_segment_indices += N_ITEMS_PER_ALLOC;
+
+      priv->segment_indices = g_realloc (priv->segment_indices,
+                                         sizeof (GimpVector2) *
+                                         priv->max_n_segment_indices);
+    }
+
+  priv->segment_indices[priv->n_segment_indices] = index;
+
+  g_ptr_array_add (priv->handles,
+                   gimp_tool_widget_add_handle (GIMP_TOOL_WIDGET (polygon),
+                                                GIMP_HANDLE_CROSS,
+                                                0, 0,
+                                                GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                GIMP_HANDLE_ANCHOR_CENTER));
+
+  priv->n_segment_indices++;
+}
+
+static gboolean
+gimp_tool_polygon_is_point_grabbed (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  return priv->grabbed_segment_index != INVALID_INDEX;
+}
+
+static void
+gimp_tool_polygon_fit_segment (GimpToolPolygon   *polygon,
+                               GimpVector2       *dest_points,
+                               GimpVector2        dest_start_target,
+                               GimpVector2        dest_end_target,
+                               const GimpVector2 *source_points,
+                               gint               n_points)
+{
+  GimpVector2 origo_translation_offset;
+  GimpVector2 untranslation_offset;
+  gdouble     rotation;
+  gdouble     scale;
+
+  /* Handle some quick special cases */
+  if (n_points <= 0)
+    {
+      return;
+    }
+  else if (n_points == 1)
+    {
+      dest_points[0] = dest_end_target;
+      return;
+    }
+  else if (n_points == 2)
+    {
+      dest_points[0] = dest_start_target;
+      dest_points[1] = dest_end_target;
+      return;
+    }
+
+  /* Copy from source to dest; we work on the dest data */
+  memcpy (dest_points, source_points, sizeof (GimpVector2) * n_points);
+
+  /* Transform the destination end point */
+  {
+    GimpVector2 *dest_end;
+    GimpVector2  origo_translated_end_target;
+    gdouble      target_rotation;
+    gdouble      current_rotation;
+    gdouble      target_length;
+    gdouble      current_length;
+
+    dest_end = &dest_points[n_points - 1];
+
+    /* Transate to origin */
+    gimp_vector2_sub (&origo_translation_offset,
+                      &vector2_zero,
+                      &dest_points[0]);
+    gimp_vector2_add (dest_end,
+                      dest_end,
+                      &origo_translation_offset);
+
+    /* Calculate origo_translated_end_target */
+    gimp_vector2_sub (&origo_translated_end_target,
+                      &dest_end_target,
+                      &dest_start_target);
+
+    /* Rotate */
+    target_rotation  = atan2 (vector2_zero.y - origo_translated_end_target.y,
+                              vector2_zero.x - origo_translated_end_target.x);
+    current_rotation = atan2 (vector2_zero.y - dest_end->y,
+                              vector2_zero.x - dest_end->x);
+    rotation         = current_rotation - target_rotation;
+
+    gimp_vector2_rotate (dest_end, rotation);
+
+
+    /* Scale */
+    target_length  = gimp_vector2_length (&origo_translated_end_target);
+    current_length = gimp_vector2_length (dest_end);
+    scale          = target_length / current_length;
+
+    gimp_vector2_mul (dest_end, scale);
+
+
+    /* Untranslate */
+    gimp_vector2_sub (&untranslation_offset,
+                      &dest_end_target,
+                      dest_end);
+    gimp_vector2_add (dest_end,
+                      dest_end,
+                      &untranslation_offset);
+  }
+
+  /* Do the same transformation for the rest of the points */
+  {
+    gint i;
+
+    for (i = 0; i < n_points - 1; i++)
+      {
+        /* Translate */
+        gimp_vector2_add (&dest_points[i],
+                          &origo_translation_offset,
+                          &dest_points[i]);
+
+        /* Rotate */
+        gimp_vector2_rotate (&dest_points[i],
+                             rotation);
+
+        /* Scale */
+        gimp_vector2_mul (&dest_points[i],
+                          scale);
+
+        /* Untranslate */
+        gimp_vector2_add (&dest_points[i],
+                          &dest_points[i],
+                          &untranslation_offset);
+      }
+  }
+}
+
+static void
+gimp_tool_polygon_move_segment_vertex_to (GimpToolPolygon *polygon,
+                                          gint             segment_index,
+                                          gdouble          new_x,
+                                          gdouble          new_y)
+{
+  GimpToolPolygonPrivate *priv         = polygon->private;
+  GimpVector2             cursor_point = { new_x, new_y };
+  GimpVector2            *dest;
+  GimpVector2            *dest_start_target;
+  GimpVector2            *dest_end_target;
+  gint                    n_points;
+
+  /* Handle the segment before the grabbed point */
+  if (segment_index > 0)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index - 1,
+                                     priv->grabbed_segment_index);
+
+      dest_start_target = &dest[0];
+      dest_end_target   = &cursor_point;
+
+      gimp_tool_polygon_fit_segment (polygon,
+                                     dest,
+                                     *dest_start_target,
+                                     *dest_end_target,
+                                     priv->saved_points_lower_segment,
+                                     n_points);
+    }
+
+  /* Handle the segment after the grabbed point */
+  if (segment_index < priv->n_segment_indices - 1)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index,
+                                     priv->grabbed_segment_index + 1);
+
+      dest_start_target = &cursor_point;
+      dest_end_target   = &dest[n_points - 1];
+
+      gimp_tool_polygon_fit_segment (polygon,
+                                     dest,
+                                     *dest_start_target,
+                                     *dest_end_target,
+                                     priv->saved_points_higher_segment,
+                                     n_points);
+    }
+
+  /* Handle when there only is one point */
+  if (segment_index == 0 &&
+      priv->n_segment_indices == 1)
+    {
+      priv->points[0].x = new_x;
+      priv->points[0].y = new_y;
+    }
+}
+
+static void
+gimp_tool_polygon_revert_to_saved_state (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+  GimpVector2            *dest;
+  gint                    n_points;
+
+  /* Without a point grab we have no sensible information to fall back
+   * on, bail out
+   */
+  if (! gimp_tool_polygon_is_point_grabbed (polygon))
+    {
+      return;
+    }
+
+  if (priv->grabbed_segment_index > 0)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index - 1,
+                                     priv->grabbed_segment_index);
+
+      memcpy (dest,
+              priv->saved_points_lower_segment,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  if (priv->grabbed_segment_index < priv->n_segment_indices - 1)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index,
+                                     priv->grabbed_segment_index + 1);
+
+      memcpy (dest,
+              priv->saved_points_higher_segment,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  if (priv->grabbed_segment_index == 0 &&
+      priv->n_segment_indices     == 1)
+    {
+      priv->points[0] = *priv->saved_points_lower_segment;
+    }
+}
+
+static void
+gimp_tool_polygon_prepare_for_move (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+  GimpVector2            *source;
+  gint                    n_points;
+
+  if (priv->grabbed_segment_index > 0)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &source,
+                                     &n_points,
+                                     priv->grabbed_segment_index - 1,
+                                     priv->grabbed_segment_index);
+
+      if (n_points > priv->max_n_saved_points_lower_segment)
+        {
+          priv->max_n_saved_points_lower_segment = n_points;
+
+          priv->saved_points_lower_segment =
+            g_realloc (priv->saved_points_lower_segment,
+                       sizeof (GimpVector2) * n_points);
+        }
+
+      memcpy (priv->saved_points_lower_segment,
+              source,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  if (priv->grabbed_segment_index < priv->n_segment_indices - 1)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &source,
+                                     &n_points,
+                                     priv->grabbed_segment_index,
+                                     priv->grabbed_segment_index + 1);
+
+      if (n_points > priv->max_n_saved_points_higher_segment)
+        {
+          priv->max_n_saved_points_higher_segment = n_points;
+
+          priv->saved_points_higher_segment =
+            g_realloc (priv->saved_points_higher_segment,
+                       sizeof (GimpVector2) * n_points);
+        }
+
+      memcpy (priv->saved_points_higher_segment,
+              source,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  /* A special-case when there only is one point */
+  if (priv->grabbed_segment_index == 0 &&
+      priv->n_segment_indices     == 1)
+    {
+      if (priv->max_n_saved_points_lower_segment == 0)
+        {
+          priv->max_n_saved_points_lower_segment = 1;
+
+          priv->saved_points_lower_segment = g_new0 (GimpVector2, 1);
+        }
+
+      *priv->saved_points_lower_segment = priv->points[0];
+    }
+}
+
+static void
+gimp_tool_polygon_update_motion (GimpToolPolygon *polygon,
+                                 gdouble          new_x,
+                                 gdouble          new_y)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (gimp_tool_polygon_is_point_grabbed (polygon))
+    {
+      priv->polygon_modified = TRUE;
+
+      if (priv->constrain_angle &&
+          priv->n_segment_indices > 1)
+        {
+          gdouble start_point_x;
+          gdouble start_point_y;
+          gint    segment_index;
+
+          /* Base constraints on the last segment vertex if we move
+           * the first one, otherwise base on the previous segment
+           * vertex
+           */
+          if (priv->grabbed_segment_index == 0)
+            {
+              segment_index = priv->n_segment_indices - 1;
+            }
+          else
+            {
+              segment_index = priv->grabbed_segment_index - 1;
+            }
+
+          gimp_tool_polygon_get_segment_point (polygon,
+                                               &start_point_x,
+                                               &start_point_y,
+                                               segment_index);
+
+          gimp_display_shell_constrain_line (
+            gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (polygon)),
+            start_point_x,
+            start_point_y,
+            &new_x,
+            &new_y,
+            GIMP_CONSTRAIN_LINE_15_DEGREES);
+        }
+
+      gimp_tool_polygon_move_segment_vertex_to (polygon,
+                                                priv->grabbed_segment_index,
+                                                new_x,
+                                                new_y);
+
+      /* We also must update the pending point if we are moving the
+       * first point
+       */
+      if (priv->grabbed_segment_index == 0)
+        {
+          priv->pending_point.x = new_x;
+          priv->pending_point.y = new_y;
+        }
+    }
+  else
+    {
+      /* Don't show the pending point while we are adding points */
+      priv->show_pending_point = FALSE;
+
+      gimp_tool_polygon_add_point (polygon, new_x, new_y);
+    }
+}
+
+static void
+gimp_tool_polygon_status_update (GimpToolPolygon  *polygon,
+                                 const GimpCoords *coords,
+                                 gboolean          proximity)
+{
+  GimpToolWidget         *widget = GIMP_TOOL_WIDGET (polygon);
+  GimpToolPolygonPrivate *priv   = polygon->private;
+
+  if (proximity)
+    {
+      const gchar *status_text = NULL;
+
+      if (gimp_tool_polygon_is_point_grabbed (polygon))
+        {
+          if (gimp_tool_polygon_should_close (polygon,
+                                              NO_CLICK_TIME_AVAILABLE,
+                                              coords))
+            {
+              status_text = _("Click to close shape");
+            }
+          else
+            {
+              status_text = _("Click-Drag to move segment vertex");
+            }
+        }
+      else if (priv->polygon_closed)
+        {
+          status_text = _("Return commits, Escape cancels, Backspace re-opens shape");
+        }
+      else if (priv->n_segment_indices >= 3)
+        {
+          status_text = _("Return commits, Escape cancels, Backspace removes last segment");
+        }
+      else
+        {
+          status_text = _("Click-Drag adds a free segment, Click adds a polygonal segment");
+        }
+
+      if (status_text)
+        {
+          gimp_tool_widget_set_status (widget, status_text);
+        }
+    }
+  else
+    {
+      gimp_tool_widget_set_status (widget, NULL);
+    }
+}
+
+static void
+gimp_tool_polygon_changed (GimpToolWidget *widget)
+{
+  GimpToolPolygon        *polygon               = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *private               = polygon->private;
+  gboolean                hovering_first_point  = FALSE;
+  gboolean                handles_wants_to_show = FALSE;
+  GimpCoords              coords                = { private->last_coords.x,
+                                                    private->last_coords.y,
+                                                    /* pad with 0 */ };
+  gint                    i;
+
+  gimp_canvas_polygon_set_points (private->polygon,
+                                  private->points, private->n_points);
+
+  if (private->show_pending_point)
+    {
+      GimpVector2 last = private->points[private->n_points - 1];
+
+      gimp_canvas_line_set (private->pending_line,
+                            last.x,
+                            last.y,
+                            private->pending_point.x,
+                            private->pending_point.y);
+    }
+
+  gimp_canvas_item_set_visible (private->pending_line,
+                                private->show_pending_point);
+
+  if (private->polygon_closed)
+    {
+      GimpVector2 first = private->points[0];
+      GimpVector2 last  = private->points[private->n_points - 1];
+
+      gimp_canvas_line_set (private->closing_line,
+                            first.x, first.y,
+                            last.x,  last.y);
+    }
+
+  gimp_canvas_item_set_visible (private->closing_line,
+                                private->polygon_closed);
+
+  hovering_first_point =
+    gimp_tool_polygon_should_close (polygon,
+                                    NO_CLICK_TIME_AVAILABLE,
+                                    &coords);
+
+  /* We always show the handle for the first point, even with button1
+   * down, since releasing the button on the first point will close
+   * the polygon, so it's a significant state which we must give
+   * feedback for
+   */
+  handles_wants_to_show = (hovering_first_point || ! private->button_down);
+
+  for (i = 0; i < private->n_segment_indices; i++)
+    {
+      GimpCanvasItem *handle;
+      GimpVector2    *point;
+
+      handle = g_ptr_array_index (private->handles, i);
+      point  = &private->points[private->segment_indices[i]];
+
+      if (private->hover             &&
+          handles_wants_to_show      &&
+          ! private->suppress_handles &&
+
+          /* If the first point is hovered while button1 is held down,
+           * only draw the first handle, the other handles are not
+           * relevant (see comment a few lines up)
+           */
+          (i == 0 ||
+           ! (private->button_down || hovering_first_point)))
+        {
+          gdouble         dist;
+          GimpHandleType  handle_type = -1;
+
+          dist =
+            gimp_canvas_item_transform_distance_square (handle,
+                                                        private->last_coords.x,
+                                                        private->last_coords.y,
+                                                        point->x,
+                                                        point->y);
+
+          /* If the cursor is over the point, fill, if it's just
+           * close, draw an outline
+           */
+          if (dist < POINT_GRAB_THRESHOLD_SQ)
+            handle_type = GIMP_HANDLE_FILLED_CIRCLE;
+          else if (dist < POINT_SHOW_THRESHOLD_SQ)
+            handle_type = GIMP_HANDLE_CIRCLE;
+
+          if (handle_type != -1)
+            {
+              gint size;
+
+              gimp_canvas_item_begin_change (handle);
+
+              gimp_canvas_handle_set_position (handle, point->x, point->y);
+
+              g_object_set (handle,
+                            "type", handle_type,
+                            NULL);
+
+              size = gimp_canvas_handle_calc_size (handle,
+                                                   private->last_coords.x,
+                                                   private->last_coords.y,
+                                                   GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                   2 * GIMP_CANVAS_HANDLE_SIZE_CIRCLE);
+              if (FALSE)
+                gimp_canvas_handle_set_size (handle, size, size);
+
+              if (dist < POINT_GRAB_THRESHOLD_SQ)
+                gimp_canvas_item_set_highlight (handle, TRUE);
+              else
+                gimp_canvas_item_set_highlight (handle, FALSE);
+
+              gimp_canvas_item_set_visible (handle, TRUE);
+
+              gimp_canvas_item_end_change (handle);
+            }
+          else
+            {
+              gimp_canvas_item_set_visible (handle, FALSE);
+            }
+        }
+      else
+        {
+          gimp_canvas_item_set_visible (handle, FALSE);
+       }
+    }
+}
+
+static gboolean
+gimp_tool_polygon_button_press (GimpToolWidget      *widget,
+                                const GimpCoords    *coords,
+                                guint32              time,
+                                GdkModifierType      state,
+                                GimpButtonPressType  press_type)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  if (gimp_tool_polygon_is_point_grabbed (polygon))
+    {
+      gimp_tool_polygon_prepare_for_move (polygon);
+    }
+  else if (priv->polygon_closed)
+    {
+      if (press_type == GIMP_BUTTON_PRESS_DOUBLE &&
+          gimp_canvas_item_hit (priv->polygon, coords->x, coords->y))
+        {
+          gimp_tool_widget_response (widget, GIMP_TOOL_WIDGET_RESPONSE_CONFIRM);
+        }
+
+      return 0;
+    }
+  else
+    {
+      GimpVector2 point_to_add;
+
+      /* Note that we add the pending point (unless it is the first
+       * point we add) because the pending point is setup correctly
+       * with regards to angle constraints.
+       */
+      if (priv->n_points > 0)
+        {
+          point_to_add = priv->pending_point;
+        }
+      else
+        {
+          point_to_add.x = coords->x;
+          point_to_add.y = coords->y;
+        }
+
+      /* No point was grabbed, add a new point and mark this as a
+       * segment divider. For a line segment, this will be the only
+       * new point. For a free segment, this will be the first point
+       * of the free segment.
+       */
+      gimp_tool_polygon_add_point (polygon,
+                                   point_to_add.x,
+                                   point_to_add.y);
+      gimp_tool_polygon_add_segment_index (polygon, priv->n_points - 1);
+    }
+
+  priv->button_down = TRUE;
+
+  gimp_tool_polygon_changed (widget);
+
+  return 1;
+}
+
+static void
+gimp_tool_polygon_button_release (GimpToolWidget        *widget,
+                                  const GimpCoords      *coords,
+                                  guint32                time,
+                                  GdkModifierType        state,
+                                  GimpButtonReleaseType  release_type)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  g_object_ref (widget);
+
+  priv->button_down = FALSE;
+
+  switch (release_type)
+    {
+    case GIMP_BUTTON_RELEASE_CLICK:
+    case GIMP_BUTTON_RELEASE_NO_MOTION:
+      /* If a click was made, we don't consider the polygon modified */
+      priv->polygon_modified = FALSE;
+
+      /* First finish of the line segment if no point was grabbed */
+      if (! gimp_tool_polygon_is_point_grabbed (polygon))
+        {
+          /* Revert any free segment points that might have been added */
+          gimp_tool_polygon_revert_to_last_segment (polygon);
+        }
+
+      /* After the segments are up to date and we have handled
+       * double-click, see if it's committing time
+       */
+      if (gimp_tool_polygon_should_close (polygon, time, coords))
+        {
+          /* We can get a click notification even though the end point
+           * has been moved a few pixels. Since a move will change the
+           * free selection, revert it before doing the commit.
+           */
+          gimp_tool_polygon_revert_to_saved_state (polygon);
+
+          priv->polygon_closed = TRUE;
+
+          gimp_tool_polygon_change_complete (polygon);
+        }
+
+      priv->last_click_time  = time;
+      priv->last_click_coord = *coords;
+      break;
+
+    case GIMP_BUTTON_RELEASE_NORMAL:
+      /* First finish of the free segment if no point was grabbed */
+      if (! gimp_tool_polygon_is_point_grabbed (polygon))
+        {
+          /* The points are all setup, just make a segment */
+          gimp_tool_polygon_add_segment_index (polygon, priv->n_points - 1);
+        }
+
+      /* After the segments are up to date, see if it's committing time */
+      if (gimp_tool_polygon_should_close (polygon,
+                                          NO_CLICK_TIME_AVAILABLE,
+                                          coords))
+        {
+          priv->polygon_closed = TRUE;
+        }
+
+      gimp_tool_polygon_change_complete (polygon);
+      break;
+
+    case GIMP_BUTTON_RELEASE_CANCEL:
+      if (gimp_tool_polygon_is_point_grabbed (polygon))
+        gimp_tool_polygon_revert_to_saved_state (polygon);
+      else
+        gimp_tool_polygon_remove_last_segment (polygon);
+      break;
+
+    default:
+      break;
+    }
+
+  /* Reset */
+  priv->polygon_modified = FALSE;
+
+  gimp_tool_polygon_changed (widget);
+
+  g_object_unref (widget);
+}
+
+static void
+gimp_tool_polygon_motion (GimpToolWidget   *widget,
+                          const GimpCoords *coords,
+                          guint32           time,
+                          GdkModifierType   state)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->last_coords.x = coords->x;
+  priv->last_coords.y = coords->y;
+
+  gimp_tool_polygon_update_motion (polygon,
+                                   coords->x,
+                                   coords->y);
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static GimpHit
+gimp_tool_polygon_hit (GimpToolWidget   *widget,
+                       const GimpCoords *coords,
+                       GdkModifierType   state,
+                       gboolean          proximity)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  if ((priv->n_points > 0 && ! priv->polygon_closed) ||
+      gimp_tool_polygon_get_segment_index (polygon, coords) != INVALID_INDEX)
+    {
+      return GIMP_HIT_DIRECT;
+    }
+  else if (priv->polygon_closed &&
+           gimp_canvas_item_hit (priv->polygon, coords->x, coords->y))
+    {
+      return GIMP_HIT_INDIRECT;
+    }
+
+  return GIMP_HIT_NONE;
+}
+
+static void
+gimp_tool_polygon_hover (GimpToolWidget   *widget,
+                         const GimpCoords *coords,
+                         GdkModifierType   state,
+                         gboolean          proximity)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+  gboolean                hovering_first_point;
+
+  priv->grabbed_segment_index = gimp_tool_polygon_get_segment_index (polygon,
+                                                                     coords);
+  priv->hover                 = TRUE;
+
+  hovering_first_point =
+    gimp_tool_polygon_should_close (polygon,
+                                    NO_CLICK_TIME_AVAILABLE,
+                                    coords);
+
+  priv->last_coords.x = coords->x;
+  priv->last_coords.y = coords->y;
+
+  if (priv->n_points == 0  ||
+      priv->polygon_closed ||
+      (gimp_tool_polygon_is_point_grabbed (polygon) &&
+       ! hovering_first_point) ||
+      ! proximity)
+    {
+      priv->show_pending_point = FALSE;
+    }
+  else
+    {
+      priv->show_pending_point = TRUE;
+
+      if (hovering_first_point)
+        {
+          priv->pending_point = priv->points[0];
+        }
+      else
+        {
+          priv->pending_point.x = coords->x;
+          priv->pending_point.y = coords->y;
+
+          if (priv->constrain_angle && priv->n_points > 0)
+            {
+              gdouble start_point_x;
+              gdouble start_point_y;
+
+              /*  the last point is the line's start point  */
+              gimp_tool_polygon_get_segment_point (polygon,
+                                                   &start_point_x,
+                                                   &start_point_y,
+                                                   priv->n_segment_indices - 1);
+
+              gimp_display_shell_constrain_line (
+                gimp_tool_widget_get_shell (widget),
+                start_point_x, start_point_y,
+                &priv->pending_point.x,
+                &priv->pending_point.y,
+                GIMP_CONSTRAIN_LINE_15_DEGREES);
+            }
+        }
+    }
+
+  gimp_tool_polygon_status_update (polygon, coords, proximity);
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static void
+gimp_tool_polygon_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->grabbed_segment_index = INVALID_INDEX;
+  priv->hover                 = FALSE;
+  priv->show_pending_point    = FALSE;
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static gboolean
+gimp_tool_polygon_key_press (GimpToolWidget *widget,
+                             GdkEventKey    *kevent)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  switch (kevent->keyval)
+    {
+    case GDK_KEY_BackSpace:
+      gimp_tool_polygon_remove_last_segment (polygon);
+
+      if (priv->n_segment_indices > 0)
+        gimp_tool_polygon_change_complete (polygon);
+      return TRUE;
+
+    default:
+      break;
+    }
+
+  return GIMP_TOOL_WIDGET_CLASS (parent_class)->key_press (widget, kevent);
+}
+
+static void
+gimp_tool_polygon_motion_modifier (GimpToolWidget  *widget,
+                                   GdkModifierType  key,
+                                   gboolean         press,
+                                   GdkModifierType  state)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->constrain_angle = ((state & gimp_get_constrain_behavior_mask ()) ?
+                           TRUE : FALSE);
+
+  /* If we didn't came here due to a mouse release, immediately update
+   * the position of the thing we move.
+   */
+  if (state & GDK_BUTTON1_MASK)
+    {
+      gimp_tool_polygon_update_motion (polygon,
+                                       priv->last_coords.x,
+                                       priv->last_coords.y);
+    }
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static void
+gimp_tool_polygon_hover_modifier (GimpToolWidget  *widget,
+                                  GdkModifierType  key,
+                                  gboolean         press,
+                                  GdkModifierType  state)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->constrain_angle = ((state & gimp_get_constrain_behavior_mask ()) ?
+                           TRUE : FALSE);
+
+  priv->suppress_handles = ((state & gimp_get_extend_selection_mask ()) ?
+                           TRUE : FALSE);
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static gboolean
+gimp_tool_polygon_get_cursor (GimpToolWidget     *widget,
+                              const GimpCoords   *coords,
+                              GdkModifierType     state,
+                              GimpCursorType     *cursor,
+                              GimpToolCursorType *tool_cursor,
+                              GimpCursorModifier *modifier)
+{
+  GimpToolPolygon *polygon = GIMP_TOOL_POLYGON (widget);
+
+  if (gimp_tool_polygon_is_point_grabbed (polygon) &&
+      ! gimp_tool_polygon_should_close (polygon,
+                                        NO_CLICK_TIME_AVAILABLE,
+                                        coords))
+    {
+      *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_tool_polygon_change_complete (GimpToolPolygon *polygon)
+{
+  g_signal_emit (polygon, polygon_signals[CHANGE_COMPLETE], 0);
+}
+
+static gint
+gimp_tool_polygon_get_segment_index (GimpToolPolygon  *polygon,
+                                     const GimpCoords *coords)
+{
+  GimpToolPolygonPrivate *priv          = polygon->private;
+  gint                    segment_index = INVALID_INDEX;
+
+  if (! priv->suppress_handles)
+    {
+      gdouble shortest_dist = POINT_GRAB_THRESHOLD_SQ;
+      gint    i;
+
+      for (i = 0; i < priv->n_segment_indices; i++)
+        {
+          gdouble      dist;
+          GimpVector2 *point;
+
+          point = &priv->points[priv->segment_indices[i]];
+
+          dist = gimp_canvas_item_transform_distance_square (priv->polygon,
+                                                             coords->x,
+                                                             coords->y,
+                                                             point->x,
+                                                             point->y);
+
+          if (dist < shortest_dist)
+            {
+              shortest_dist = dist;
+
+              segment_index = i;
+            }
+        }
+    }
+
+  return segment_index;
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_polygon_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_POLYGON,
+                       "shell", shell,
+                       NULL);
+}
+
+gboolean
+gimp_tool_polygon_is_closed (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_POLYGON (polygon), FALSE);
+
+  private = polygon->private;
+
+  return private->polygon_closed;
+}
+
+void
+gimp_tool_polygon_get_points (GimpToolPolygon    *polygon,
+                              const GimpVector2 **points,
+                              gint               *n_points)
+{
+  GimpToolPolygonPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_POLYGON (polygon));
+
+  private = polygon->private;
+
+  if (points)   *points   = private->points;
+  if (n_points) *n_points = private->n_points;
+}
diff --git a/app/display/gimptoolpolygon.h b/app/display/gimptoolpolygon.h
new file mode 100644
index 0000000..fa3560a
--- /dev/null
+++ b/app/display/gimptoolpolygon.h
@@ -0,0 +1,66 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolpolygon.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_POLYGON_H__
+#define __GIMP_TOOL_POLYGON_H__
+
+
+#include "gimptoolwidget.h"
+
+
+#define GIMP_TYPE_TOOL_POLYGON            (gimp_tool_polygon_get_type ())
+#define GIMP_TOOL_POLYGON(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_POLYGON, GimpToolPolygon))
+#define GIMP_TOOL_POLYGON_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_POLYGON, GimpToolPolygonClass))
+#define GIMP_IS_TOOL_POLYGON(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_POLYGON))
+#define GIMP_IS_TOOL_POLYGON_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_POLYGON))
+#define GIMP_TOOL_POLYGON_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_POLYGON, GimpToolPolygonClass))
+
+
+typedef struct _GimpToolPolygon        GimpToolPolygon;
+typedef struct _GimpToolPolygonPrivate GimpToolPolygonPrivate;
+typedef struct _GimpToolPolygonClass   GimpToolPolygonClass;
+
+struct _GimpToolPolygon
+{
+  GimpToolWidget          parent_instance;
+
+  GimpToolPolygonPrivate *private;
+};
+
+struct _GimpToolPolygonClass
+{
+  GimpToolWidgetClass  parent_class;
+
+  /*  signals  */
+  void (* change_complete) (GimpToolPolygon *polygon);
+};
+
+
+GType            gimp_tool_polygon_get_type   (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_polygon_new        (GimpDisplayShell   *shell);
+
+gboolean         gimp_tool_polygon_is_closed  (GimpToolPolygon    *polygon);
+void             gimp_tool_polygon_get_points (GimpToolPolygon    *polygon,
+                                               const GimpVector2 **points,
+                                               gint               *n_points);
+
+
+#endif /* __GIMP_TOOL_POLYGON_H__ */
diff --git a/app/display/gimptoolrectangle.c b/app/display/gimptoolrectangle.c
new file mode 100644
index 0000000..c1192db
--- /dev/null
+++ b/app/display/gimptoolrectangle.c
@@ -0,0 +1,4256 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolrectangle.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Based on GimpRectangleTool
+ * Copyright (C) 2007 Martin Nordholts
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontext.h"
+#include "core/gimpimage.h"
+#include "core/gimpitem.h"
+#include "core/gimpmarshal.h"
+#include "core/gimppickable.h"
+#include "core/gimppickable-auto-shrink.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvasarc.h"
+#include "gimpcanvascorner.h"
+#include "gimpcanvashandle.h"
+#include "gimpcanvasitem-utils.h"
+#include "gimpcanvasrectangle.h"
+#include "gimpcanvasrectangleguides.h"
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimptoolrectangle.h"
+
+#include "gimp-intl.h"
+
+
+/*  speed of key movement  */
+#define ARROW_VELOCITY   25
+
+#define MAX_HANDLE_SIZE         50
+#define MIN_HANDLE_SIZE         15
+#define NARROW_MODE_HANDLE_SIZE 15
+#define NARROW_MODE_THRESHOLD   45
+
+
+enum
+{
+  PROP_0,
+  PROP_X1,
+  PROP_Y1,
+  PROP_X2,
+  PROP_Y2,
+  PROP_CONSTRAINT,
+  PROP_PRECISION,
+  PROP_NARROW_MODE,
+  PROP_FORCE_NARROW_MODE,
+  PROP_DRAW_ELLIPSE,
+  PROP_ROUND_CORNERS,
+  PROP_CORNER_RADIUS,
+  PROP_STATUS_TITLE,
+
+  PROP_HIGHLIGHT,
+  PROP_HIGHLIGHT_OPACITY,
+  PROP_GUIDE,
+  PROP_X,
+  PROP_Y,
+  PROP_WIDTH,
+  PROP_HEIGHT,
+  PROP_FIXED_RULE_ACTIVE,
+  PROP_FIXED_RULE,
+  PROP_DESIRED_FIXED_WIDTH,
+  PROP_DESIRED_FIXED_HEIGHT,
+  PROP_DESIRED_FIXED_SIZE_WIDTH,
+  PROP_DESIRED_FIXED_SIZE_HEIGHT,
+  PROP_ASPECT_NUMERATOR,
+  PROP_ASPECT_DENOMINATOR,
+  PROP_FIXED_CENTER
+};
+
+enum
+{
+  CHANGE_COMPLETE,
+  LAST_SIGNAL
+};
+
+typedef enum
+{
+  CLAMPED_NONE   = 0,
+  CLAMPED_LEFT   = 1 << 0,
+  CLAMPED_RIGHT  = 1 << 1,
+  CLAMPED_TOP    = 1 << 2,
+  CLAMPED_BOTTOM = 1 << 3
+} ClampedSide;
+
+typedef enum
+{
+  SIDE_TO_RESIZE_NONE,
+  SIDE_TO_RESIZE_LEFT,
+  SIDE_TO_RESIZE_RIGHT,
+  SIDE_TO_RESIZE_TOP,
+  SIDE_TO_RESIZE_BOTTOM,
+  SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY,
+  SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY,
+} SideToResize;
+
+
+#define FEQUAL(a,b)       (fabs ((a) - (b)) < 0.0001)
+#define PIXEL_FEQUAL(a,b) (fabs ((a) - (b)) < 0.5)
+
+
+struct _GimpToolRectanglePrivate
+{
+  /* The following members are "constants", that is, variables that are setup
+   * during gimp_tool_rectangle_button_press and then only read.
+   */
+
+  /* Whether or not the rectangle currently being rubber-banded is the
+   * first one created with this instance, this determines if we can
+   * undo it on button_release.
+   */
+  gboolean                is_first;
+
+  /* Whether or not the rectangle currently being rubber-banded was
+   * created from scratch.
+   */
+  gboolean                is_new;
+
+  /* Holds the coordinate that should be used as the "other side" when
+   * fixed-center is turned off.
+   */
+  gdouble                 other_side_x;
+  gdouble                 other_side_y;
+
+  /* Holds the coordinate to be used as center when fixed-center is used. */
+  gdouble                 center_x_on_fixed_center;
+  gdouble                 center_y_on_fixed_center;
+
+  /* True when the rectangle is being adjusted (moved or
+   * rubber-banded).
+   */
+  gboolean                rect_adjusting;
+
+
+  /* The rest of the members are internal state variables, that is, variables
+   * that might change during the manipulation session of the rectangle. Make
+   * sure these variables are in consistent states.
+   */
+
+  /* Coordinates of upper left and lower right rectangle corners. */
+  gdouble                 x1, y1;
+  gdouble                 x2, y2;
+
+  /* Integer coordinats of upper left corner and size. We must
+   * calculate this separately from the gdouble ones because sometimes
+   * we don't want to affect the integer size (e.g. when moving the
+   * rectangle), but that will be the case if we always calculate the
+   * integer coordinates based on rounded values of the gdouble
+   * coordinates even if the gdouble width remains constant.
+   *
+   * TODO: Change the internal double-representation of the rectangle
+   * to x,y width,height instead of x1,y1 x2,y2. That way we don't
+   * need to keep a separate representation of the integer version of
+   * the rectangle; rounding width an height will yield consistent
+   * results and not depend on position of the rectangle.
+   */
+  gint                    x1_int,    y1_int;
+  gint                    width_int, height_int;
+
+  /* How to constrain the rectangle. */
+  GimpRectangleConstraint constraint;
+
+  /* What precision the rectangle will appear to have externally (it
+   * will always be double internally)
+   */
+  GimpRectanglePrecision  precision;
+
+  /* Previous coordinate applied to the rectangle. */
+  gdouble                 lastx;
+  gdouble                 lasty;
+
+  /* Width and height of corner handles. */
+  gint                    corner_handle_w;
+  gint                    corner_handle_h;
+
+  /* Width and height of side handles. */
+  gint                    top_and_bottom_handle_w;
+  gint                    left_and_right_handle_h;
+
+  /* Whether or not the rectangle is in a 'narrow situation' i.e. it is
+   * too small for reasonable sized handle to be inside. In this case
+   * we put handles on the outside.
+   */
+  gboolean                narrow_mode;
+
+  /* This boolean allows to always set narrow mode */
+  gboolean                force_narrow_mode;
+
+  /* Whether or not to draw an ellipse inside the rectangle */
+  gboolean                draw_ellipse;
+
+  /* Whether to draw round corners */
+  gboolean                round_corners;
+  gdouble                 corner_radius;
+
+  /* The title for the statusbar coords */
+  gchar                  *status_title;
+
+  /* For saving in case of cancellation. */
+  gdouble                 saved_x1;
+  gdouble                 saved_y1;
+  gdouble                 saved_x2;
+  gdouble                 saved_y2;
+
+  gint                    suppress_updates;
+
+  GimpRectangleFunction   function;
+
+  /* The following values are externally synced with GimpRectangleOptions */
+
+  gboolean                highlight;
+  gdouble                 highlight_opacity;
+  GimpGuidesType          guide;
+
+  gdouble                 x;
+  gdouble                 y;
+  gdouble                 width;
+  gdouble                 height;
+
+  gboolean                fixed_rule_active;
+  GimpRectangleFixedRule  fixed_rule;
+  gdouble                 desired_fixed_width;
+  gdouble                 desired_fixed_height;
+  gdouble                 desired_fixed_size_width;
+  gdouble                 desired_fixed_size_height;
+  gdouble                 aspect_numerator;
+  gdouble                 aspect_denominator;
+  gboolean                fixed_center;
+
+  /* Canvas items for drawing the GUI */
+
+  GimpCanvasItem         *guides;
+  GimpCanvasItem         *rectangle;
+  GimpCanvasItem         *ellipse;
+  GimpCanvasItem         *corners[4];
+  GimpCanvasItem         *center;
+  GimpCanvasItem         *creating_corners[4];
+  GimpCanvasItem         *handles[GIMP_N_TOOL_RECTANGLE_FUNCTIONS];
+  GimpCanvasItem         *highlight_handles[GIMP_N_TOOL_RECTANGLE_FUNCTIONS];
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_rectangle_constructed     (GObject               *object);
+static void     gimp_tool_rectangle_finalize        (GObject               *object);
+static void     gimp_tool_rectangle_set_property    (GObject               *object,
+                                                     guint                  property_id,
+                                                     const GValue          *value,
+                                                     GParamSpec            *pspec);
+static void     gimp_tool_rectangle_get_property    (GObject               *object,
+                                                     guint                  property_id,
+                                                     GValue                *value,
+                                                     GParamSpec            *pspec);
+static void     gimp_tool_rectangle_notify          (GObject               *object,
+                                                     GParamSpec            *pspec);
+
+static void     gimp_tool_rectangle_changed         (GimpToolWidget        *widget);
+static gint     gimp_tool_rectangle_button_press    (GimpToolWidget        *widget,
+                                                     const GimpCoords      *coords,
+                                                     guint32                time,
+                                                     GdkModifierType        state,
+                                                     GimpButtonPressType    press_type);
+static void     gimp_tool_rectangle_button_release  (GimpToolWidget        *widget,
+                                                     const GimpCoords      *coords,
+                                                     guint32                time,
+                                                     GdkModifierType        state,
+                                                     GimpButtonReleaseType  release_type);
+static void     gimp_tool_rectangle_motion          (GimpToolWidget        *widget,
+                                                     const GimpCoords      *coords,
+                                                     guint32                time,
+                                                     GdkModifierType        state);
+static GimpHit  gimp_tool_rectangle_hit             (GimpToolWidget        *widget,
+                                                     const GimpCoords      *coords,
+                                                     GdkModifierType        state,
+                                                     gboolean               proximity);
+static void     gimp_tool_rectangle_hover           (GimpToolWidget        *widget,
+                                                     const GimpCoords      *coords,
+                                                     GdkModifierType        state,
+                                                     gboolean               proximity);
+static void     gimp_tool_rectangle_leave_notify    (GimpToolWidget        *widget);
+static gboolean gimp_tool_rectangle_key_press       (GimpToolWidget        *widget,
+                                                     GdkEventKey           *kevent);
+static void     gimp_tool_rectangle_motion_modifier (GimpToolWidget        *widget,
+                                                     GdkModifierType        key,
+                                                     gboolean               press,
+                                                     GdkModifierType        state);
+static gboolean gimp_tool_rectangle_get_cursor      (GimpToolWidget        *widget,
+                                                     const GimpCoords      *coords,
+                                                     GdkModifierType        state,
+                                                     GimpCursorType        *cursor,
+                                                     GimpToolCursorType    *tool_cursor,
+                                                     GimpCursorModifier    *modifier);
+
+static void     gimp_tool_rectangle_change_complete (GimpToolRectangle     *rectangle);
+
+static void     gimp_tool_rectangle_update_options  (GimpToolRectangle     *rectangle);
+static void     gimp_tool_rectangle_update_handle_sizes
+                                                    (GimpToolRectangle     *rectangle);
+static void     gimp_tool_rectangle_update_status   (GimpToolRectangle     *rectangle);
+
+static void     gimp_tool_rectangle_synthesize_motion
+                                                    (GimpToolRectangle     *rectangle,
+                                                     gint               function,
+                                                     gdouble            new_x,
+                                                     gdouble            new_y);
+
+static GimpRectangleFunction
+                gimp_tool_rectangle_calc_function   (GimpToolRectangle     *rectangle,
+                                                     const GimpCoords      *coords,
+                                                     gboolean               proximity);
+static void     gimp_tool_rectangle_check_function  (GimpToolRectangle     *rectangle);
+
+static gboolean gimp_tool_rectangle_coord_outside   (GimpToolRectangle     *rectangle,
+                                                     const GimpCoords      *coords);
+
+static gboolean gimp_tool_rectangle_coord_on_handle (GimpToolRectangle     *rectangle,
+                                                     const GimpCoords      *coords,
+                                                     GimpHandleAnchor       anchor);
+
+static GimpHandleAnchor gimp_tool_rectangle_get_anchor
+                                                    (GimpRectangleFunction  function);
+static gboolean gimp_tool_rectangle_rect_rubber_banding_func
+                                                    (GimpToolRectangle     *rectangle);
+static gboolean gimp_tool_rectangle_rect_adjusting_func
+                                                    (GimpToolRectangle     *rectangle);
+
+static void     gimp_tool_rectangle_get_other_side  (GimpToolRectangle     *rectangle,
+                                                     gdouble              **other_x,
+                                                     gdouble              **other_y);
+static void     gimp_tool_rectangle_get_other_side_coord
+                                                    (GimpToolRectangle     *rectangle,
+                                                     gdouble               *other_side_x,
+                                                     gdouble               *other_side_y);
+static void     gimp_tool_rectangle_set_other_side_coord
+                                                    (GimpToolRectangle     *rectangle,
+                                                     gdouble                other_side_x,
+                                                     gdouble                other_side_y);
+
+static void     gimp_tool_rectangle_apply_coord     (GimpToolRectangle     *rectangle,
+                                                     gdouble                coord_x,
+                                                     gdouble                coord_y);
+static void     gimp_tool_rectangle_setup_snap_offsets
+                                                    (GimpToolRectangle     *rectangle,
+                                                     const GimpCoords      *coords);
+
+static void     gimp_tool_rectangle_clamp           (GimpToolRectangle     *rectangle,
+                                                     ClampedSide           *clamped_sides,
+                                                     GimpRectangleConstraint constraint,
+                                                     gboolean               symmetrically);
+static void     gimp_tool_rectangle_clamp_width     (GimpToolRectangle     *rectangle,
+                                                     ClampedSide           *clamped_sides,
+                                                     GimpRectangleConstraint constraint,
+                                                     gboolean               symmetrically);
+static void     gimp_tool_rectangle_clamp_height    (GimpToolRectangle     *rectangle,
+                                                     ClampedSide           *clamped_sides,
+                                                     GimpRectangleConstraint constraint,
+                                                     gboolean               symmetrically);
+
+static void     gimp_tool_rectangle_keep_inside     (GimpToolRectangle     *rectangle,
+                                                     GimpRectangleConstraint constraint);
+static void     gimp_tool_rectangle_keep_inside_horizontally
+                                                    (GimpToolRectangle     *rectangle,
+                                                     GimpRectangleConstraint constraint);
+static void     gimp_tool_rectangle_keep_inside_vertically
+                                                    (GimpToolRectangle     *rectangle,
+                                                     GimpRectangleConstraint constraint);
+
+static void     gimp_tool_rectangle_apply_fixed_width
+                                                    (GimpToolRectangle     *rectangle,
+                                                     GimpRectangleConstraint constraint,
+                                                     gdouble                width);
+static void     gimp_tool_rectangle_apply_fixed_height
+                                                    (GimpToolRectangle     *rectangle,
+                                                     GimpRectangleConstraint constraint,
+                                                     gdouble                height);
+
+static void     gimp_tool_rectangle_apply_aspect    (GimpToolRectangle     *rectangle,
+                                                     gdouble                aspect,
+                                                     gint                   clamped_sides);
+
+static void     gimp_tool_rectangle_update_with_coord
+                                                    (GimpToolRectangle     *rectangle,
+                                                     gdouble                new_x,
+                                                     gdouble                new_y);
+static void     gimp_tool_rectangle_apply_fixed_rule(GimpToolRectangle     *rectangle);
+
+static void     gimp_tool_rectangle_get_constraints (GimpToolRectangle     *rectangle,
+                                                     gint                  *min_x,
+                                                     gint                  *min_y,
+                                                     gint                  *max_x,
+                                                     gint                  *max_y,
+                                                     GimpRectangleConstraint constraint);
+
+static void     gimp_tool_rectangle_handle_general_clamping
+                                                    (GimpToolRectangle     *rectangle);
+static void     gimp_tool_rectangle_update_int_rect (GimpToolRectangle     *rectangle);
+static void     gimp_tool_rectangle_adjust_coord    (GimpToolRectangle     *rectangle,
+                                                     gdouble                coord_x_input,
+                                                     gdouble                coord_y_input,
+                                                     gdouble               *coord_x_output,
+                                                     gdouble               *coord_y_output);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolRectangle, gimp_tool_rectangle,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_rectangle_parent_class
+
+static guint rectangle_signals[LAST_SIGNAL] = { 0, };
+
+
+static void
+gimp_tool_rectangle_class_init (GimpToolRectangleClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_rectangle_constructed;
+  object_class->finalize        = gimp_tool_rectangle_finalize;
+  object_class->set_property    = gimp_tool_rectangle_set_property;
+  object_class->get_property    = gimp_tool_rectangle_get_property;
+  object_class->notify          = gimp_tool_rectangle_notify;
+
+  widget_class->changed         = gimp_tool_rectangle_changed;
+  widget_class->button_press    = gimp_tool_rectangle_button_press;
+  widget_class->button_release  = gimp_tool_rectangle_button_release;
+  widget_class->motion          = gimp_tool_rectangle_motion;
+  widget_class->hit             = gimp_tool_rectangle_hit;
+  widget_class->hover           = gimp_tool_rectangle_hover;
+  widget_class->leave_notify    = gimp_tool_rectangle_leave_notify;
+  widget_class->key_press       = gimp_tool_rectangle_key_press;
+  widget_class->motion_modifier = gimp_tool_rectangle_motion_modifier;
+  widget_class->get_cursor      = gimp_tool_rectangle_get_cursor;
+  widget_class->update_on_scale = TRUE;
+
+  rectangle_signals[CHANGE_COMPLETE] =
+    g_signal_new ("change-complete",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolRectangleClass, change_complete),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  g_object_class_install_property (object_class, PROP_X1,
+                                   g_param_spec_double ("x1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y1,
+                                   g_param_spec_double ("y1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X2,
+                                   g_param_spec_double ("x2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y2,
+                                   g_param_spec_double ("y2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CONSTRAINT,
+                                   g_param_spec_enum ("constraint",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_RECTANGLE_CONSTRAINT,
+                                                      GIMP_RECTANGLE_CONSTRAIN_NONE,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PRECISION,
+                                   g_param_spec_enum ("precision",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_RECTANGLE_PRECISION,
+                                                      GIMP_RECTANGLE_PRECISION_INT,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_NARROW_MODE,
+                                   g_param_spec_boolean ("narrow-mode",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FORCE_NARROW_MODE,
+                                   g_param_spec_boolean ("force-narrow-mode",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_DRAW_ELLIPSE,
+                                   g_param_spec_boolean ("draw-ellipse",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ROUND_CORNERS,
+                                   g_param_spec_boolean ("round-corners",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CORNER_RADIUS,
+                                   g_param_spec_double ("corner-radius",
+                                                        NULL, NULL,
+                                                        0.0, 10000.0, 10.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_STATUS_TITLE,
+                                   g_param_spec_string ("status-title",
+                                                        NULL, NULL,
+                                                        _("Rectangle: "),
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_HIGHLIGHT,
+                                   g_param_spec_boolean ("highlight",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_HIGHLIGHT_OPACITY,
+                                   g_param_spec_double ("highlight-opacity",
+                                                        NULL, NULL,
+                                                        0.0, 1.0, 0.5,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_GUIDE,
+                                   g_param_spec_enum ("guide",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_GUIDES_TYPE,
+                                                      GIMP_GUIDES_NONE,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X,
+                                   g_param_spec_double ("x",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y,
+                                   g_param_spec_double ("y",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_WIDTH,
+                                   g_param_spec_double ("width",
+                                                        NULL, NULL,
+                                                        0.0,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_HEIGHT,
+                                   g_param_spec_double ("height",
+                                                        NULL, NULL,
+                                                        0.0,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FIXED_RULE_ACTIVE,
+                                   g_param_spec_boolean ("fixed-rule-active",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FIXED_RULE,
+                                   g_param_spec_enum ("fixed-rule",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_RECTANGLE_FIXED_RULE,
+                                                      GIMP_RECTANGLE_FIXED_ASPECT,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_WIDTH,
+                                   g_param_spec_double ("desired-fixed-width",
+                                                        NULL, NULL,
+                                                        0.0, GIMP_MAX_IMAGE_SIZE,
+                                                        100.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_HEIGHT,
+                                   g_param_spec_double ("desired-fixed-height",
+                                                        NULL, NULL,
+                                                        0.0, GIMP_MAX_IMAGE_SIZE,
+                                                        100.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_SIZE_WIDTH,
+                                   g_param_spec_double ("desired-fixed-size-width",
+                                                        NULL, NULL,
+                                                        0.0, GIMP_MAX_IMAGE_SIZE,
+                                                        100.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_SIZE_HEIGHT,
+                                   g_param_spec_double ("desired-fixed-size-height",
+                                                        NULL, NULL,
+                                                        0.0, GIMP_MAX_IMAGE_SIZE,
+                                                        100.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ASPECT_NUMERATOR,
+                                   g_param_spec_double ("aspect-numerator",
+                                                        NULL, NULL,
+                                                        0.0, GIMP_MAX_IMAGE_SIZE,
+                                                        1.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ASPECT_DENOMINATOR,
+                                   g_param_spec_double ("aspect-denominator",
+                                                        NULL, NULL,
+                                                        0.0, GIMP_MAX_IMAGE_SIZE,
+                                                        1.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FIXED_CENTER,
+                                   g_param_spec_boolean ("fixed-center",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_rectangle_init (GimpToolRectangle *rectangle)
+{
+  rectangle->private = gimp_tool_rectangle_get_instance_private (rectangle);
+
+  rectangle->private->function = GIMP_TOOL_RECTANGLE_CREATING;
+  rectangle->private->is_first = TRUE;
+}
+
+static void
+gimp_tool_rectangle_constructed (GObject *object)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
+  GimpToolWidget           *widget    = GIMP_TOOL_WIDGET (object);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  GimpCanvasGroup          *stroke_group;
+  gint                      i;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  stroke_group = gimp_tool_widget_add_stroke_group (widget);
+
+  gimp_tool_widget_push_group (widget, stroke_group);
+
+  private->guides = gimp_tool_widget_add_rectangle_guides (widget,
+                                                           0, 0, 10, 10,
+                                                           GIMP_GUIDES_NONE);
+
+  private->rectangle = gimp_tool_widget_add_rectangle (widget,
+                                                       0, 0, 10, 10,
+                                                       FALSE);
+
+  private->ellipse = gimp_tool_widget_add_arc (widget,
+                                               0, 0, 10, 10,
+                                               0.0, 2 * G_PI,
+                                               FALSE);
+
+  for (i = 0; i < 4; i++)
+    private->corners[i] = gimp_tool_widget_add_arc (widget,
+                                                    0, 0, 10, 10,
+                                                    0.0, 2 * G_PI,
+                                                    FALSE);
+
+  gimp_tool_widget_pop_group (widget);
+
+  private->center = gimp_tool_widget_add_handle (widget,
+                                                 GIMP_HANDLE_CROSS,
+                                                 0, 0,
+                                                 GIMP_CANVAS_HANDLE_SIZE_SMALL,
+                                                 GIMP_CANVAS_HANDLE_SIZE_SMALL,
+                                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+  gimp_tool_widget_push_group (widget, stroke_group);
+
+  private->creating_corners[0] =
+    gimp_tool_widget_add_corner (widget,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_NORTH_WEST,
+                                 10, 10,
+                                 FALSE);
+
+  private->creating_corners[1] =
+    gimp_tool_widget_add_corner (widget,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_NORTH_EAST,
+                                 10, 10,
+                                 FALSE);
+
+  private->creating_corners[2] =
+    gimp_tool_widget_add_corner (widget,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_SOUTH_WEST,
+                                 10, 10,
+                                 FALSE);
+
+  private->creating_corners[3] =
+    gimp_tool_widget_add_corner (widget,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_SOUTH_EAST,
+                                 10, 10,
+                                 FALSE);
+
+  gimp_tool_widget_pop_group (widget);
+
+  for (i = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
+       i <= GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
+       i++)
+    {
+      GimpHandleAnchor anchor;
+
+      anchor = gimp_tool_rectangle_get_anchor (i);
+
+      gimp_tool_widget_push_group (widget, stroke_group);
+
+      private->handles[i] = gimp_tool_widget_add_corner (widget,
+                                                         0, 0, 10, 10,
+                                                         anchor,
+                                                         10, 10,
+                                                         FALSE);
+
+      gimp_tool_widget_pop_group (widget);
+
+      private->highlight_handles[i] = gimp_tool_widget_add_corner (widget,
+                                                                   0, 0, 10, 10,
+                                                                   anchor,
+                                                                   10, 10,
+                                                                   FALSE);
+      gimp_canvas_item_set_highlight (private->highlight_handles[i], TRUE);
+    }
+
+  gimp_tool_rectangle_changed (widget);
+}
+
+static void
+gimp_tool_rectangle_finalize (GObject *object)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+
+  g_clear_pointer (&private->status_title, g_free);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_tool_rectangle_set_property (GObject      *object,
+                                  guint         property_id,
+                                  const GValue *value,
+                                  GParamSpec   *pspec)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+
+  switch (property_id)
+    {
+    case PROP_X1:
+      private->x1 = g_value_get_double (value);
+      break;
+    case PROP_Y1:
+      private->y1 = g_value_get_double (value);
+      break;
+    case PROP_X2:
+      private->x2 = g_value_get_double (value);
+      break;
+    case PROP_Y2:
+      private->y2 = g_value_get_double (value);
+      break;
+
+    case PROP_CONSTRAINT:
+      private->constraint = g_value_get_enum (value);
+      break;
+    case PROP_PRECISION:
+      private->precision = g_value_get_enum (value);
+      break;
+
+    case PROP_NARROW_MODE:
+      private->narrow_mode = g_value_get_boolean (value);
+      break;
+    case PROP_FORCE_NARROW_MODE:
+      private->force_narrow_mode = g_value_get_boolean (value);
+      break;
+    case PROP_DRAW_ELLIPSE:
+      private->draw_ellipse = g_value_get_boolean (value);
+      break;
+    case PROP_ROUND_CORNERS:
+      private->round_corners = g_value_get_boolean (value);
+      break;
+    case PROP_CORNER_RADIUS:
+      private->corner_radius = g_value_get_double (value);
+      break;
+
+    case PROP_STATUS_TITLE:
+      g_free (private->status_title);
+      private->status_title = g_value_dup_string (value);
+      if (! private->status_title)
+        private->status_title = g_strdup (_("Rectangle: "));
+      break;
+
+    case PROP_HIGHLIGHT:
+      private->highlight = g_value_get_boolean (value);
+      break;
+    case PROP_HIGHLIGHT_OPACITY:
+      private->highlight_opacity = g_value_get_double (value);
+      break;
+    case PROP_GUIDE:
+      private->guide = g_value_get_enum (value);
+      break;
+
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+    case PROP_WIDTH:
+      private->width = g_value_get_double (value);
+      break;
+    case PROP_HEIGHT:
+      private->height = g_value_get_double (value);
+      break;
+
+    case PROP_FIXED_RULE_ACTIVE:
+      private->fixed_rule_active = g_value_get_boolean (value);
+      break;
+    case PROP_FIXED_RULE:
+      private->fixed_rule = g_value_get_enum (value);
+      break;
+    case PROP_DESIRED_FIXED_WIDTH:
+      private->desired_fixed_width = g_value_get_double (value);
+      break;
+    case PROP_DESIRED_FIXED_HEIGHT:
+      private->desired_fixed_height = g_value_get_double (value);
+      break;
+    case PROP_DESIRED_FIXED_SIZE_WIDTH:
+      private->desired_fixed_size_width = g_value_get_double (value);
+      break;
+    case PROP_DESIRED_FIXED_SIZE_HEIGHT:
+      private->desired_fixed_size_height = g_value_get_double (value);
+      break;
+    case PROP_ASPECT_NUMERATOR:
+      private->aspect_numerator = g_value_get_double (value);
+      break;
+    case PROP_ASPECT_DENOMINATOR:
+      private->aspect_denominator = g_value_get_double (value);
+      break;
+
+    case PROP_FIXED_CENTER:
+      private->fixed_center = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_rectangle_get_property (GObject    *object,
+                                  guint       property_id,
+                                  GValue     *value,
+                                  GParamSpec *pspec)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+
+  switch (property_id)
+    {
+    case PROP_X1:
+      g_value_set_double (value, private->x1);
+      break;
+    case PROP_Y1:
+      g_value_set_double (value, private->y1);
+      break;
+    case PROP_X2:
+      g_value_set_double (value, private->x2);
+      break;
+    case PROP_Y2:
+      g_value_set_double (value, private->y2);
+      break;
+
+    case PROP_CONSTRAINT:
+      g_value_set_enum (value, private->constraint);
+      break;
+    case PROP_PRECISION:
+      g_value_set_enum (value, private->precision);
+      break;
+
+    case PROP_NARROW_MODE:
+      g_value_set_boolean (value, private->narrow_mode);
+      break;
+    case PROP_FORCE_NARROW_MODE:
+      g_value_set_boolean (value, private->force_narrow_mode);
+      break;
+    case PROP_DRAW_ELLIPSE:
+      g_value_set_boolean (value, private->draw_ellipse);
+      break;
+    case PROP_ROUND_CORNERS:
+      g_value_set_boolean (value, private->round_corners);
+      break;
+    case PROP_CORNER_RADIUS:
+      g_value_set_double (value, private->corner_radius);
+      break;
+
+    case PROP_STATUS_TITLE:
+      g_value_set_string (value, private->status_title);
+      break;
+
+    case PROP_HIGHLIGHT:
+      g_value_set_boolean (value, private->highlight);
+      break;
+    case PROP_HIGHLIGHT_OPACITY:
+      g_value_set_double (value, private->highlight_opacity);
+      break;
+    case PROP_GUIDE:
+      g_value_set_enum (value, private->guide);
+      break;
+
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+    case PROP_WIDTH:
+      g_value_set_double (value, private->width);
+      break;
+    case PROP_HEIGHT:
+      g_value_set_double (value, private->height);
+      break;
+
+    case PROP_FIXED_RULE_ACTIVE:
+      g_value_set_boolean (value, private->fixed_rule_active);
+      break;
+    case PROP_FIXED_RULE:
+      g_value_set_enum (value, private->fixed_rule);
+      break;
+    case PROP_DESIRED_FIXED_WIDTH:
+      g_value_set_double (value, private->desired_fixed_width);
+      break;
+    case PROP_DESIRED_FIXED_HEIGHT:
+      g_value_set_double (value, private->desired_fixed_height);
+      break;
+    case PROP_DESIRED_FIXED_SIZE_WIDTH:
+      g_value_set_double (value, private->desired_fixed_size_width);
+      break;
+    case PROP_DESIRED_FIXED_SIZE_HEIGHT:
+      g_value_set_double (value, private->desired_fixed_size_height);
+      break;
+    case PROP_ASPECT_NUMERATOR:
+      g_value_set_double (value, private->aspect_numerator);
+      break;
+    case PROP_ASPECT_DENOMINATOR:
+      g_value_set_double (value, private->aspect_denominator);
+      break;
+
+    case PROP_FIXED_CENTER:
+      g_value_set_boolean (value, private->fixed_center);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_rectangle_notify (GObject    *object,
+                            GParamSpec *pspec)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+
+  if (G_OBJECT_CLASS (parent_class)->notify)
+    G_OBJECT_CLASS (parent_class)->notify (object, pspec);
+
+  if (! strcmp (pspec->name, "x1") ||
+      ! strcmp (pspec->name, "y1") ||
+      ! strcmp (pspec->name, "x2") ||
+      ! strcmp (pspec->name, "y2"))
+    {
+      gimp_tool_rectangle_update_int_rect (rectangle);
+
+      gimp_tool_rectangle_update_options (rectangle);
+    }
+  else if (! strcmp  (pspec->name, "x") &&
+           ! PIXEL_FEQUAL (private->x1, private->x))
+    {
+      gimp_tool_rectangle_synthesize_motion (rectangle,
+                                             GIMP_TOOL_RECTANGLE_MOVING,
+                                             private->x,
+                                             private->y1);
+    }
+  else if (! strcmp  (pspec->name, "y") &&
+           ! PIXEL_FEQUAL (private->y1, private->y))
+    {
+      gimp_tool_rectangle_synthesize_motion (rectangle,
+                                             GIMP_TOOL_RECTANGLE_MOVING,
+                                             private->x1,
+                                             private->y);
+    }
+  else if (! strcmp  (pspec->name, "width") &&
+           ! PIXEL_FEQUAL (private->x2 - private->x1, private->width))
+    {
+      /* Calculate x2, y2 that will create a rectangle of given width,
+       * for the current options.
+       */
+      gdouble x2;
+
+      if (private->fixed_center)
+        {
+          x2 = private->center_x_on_fixed_center +
+               private->width / 2;
+        }
+      else
+        {
+          x2 = private->x1 + private->width;
+        }
+
+      gimp_tool_rectangle_synthesize_motion (rectangle,
+                                             GIMP_TOOL_RECTANGLE_RESIZING_RIGHT,
+                                             x2,
+                                             private->y2);
+    }
+  else if (! strcmp  (pspec->name, "height") &&
+           ! PIXEL_FEQUAL (private->y2 - private->y1, private->height))
+    {
+      /* Calculate x2, y2 that will create a rectangle of given
+       * height, for the current options.
+       */
+      gdouble y2;
+
+      if (private->fixed_center)
+        {
+          y2 = private->center_y_on_fixed_center +
+               private->height / 2;
+        }
+      else
+        {
+          y2 = private->y1 + private->height;
+        }
+
+      gimp_tool_rectangle_synthesize_motion (rectangle,
+                                             GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM,
+                                             private->x2,
+                                             y2);
+    }
+  else if (! strcmp (pspec->name, "desired-fixed-size-width"))
+    {
+      /* We are only interested in when width and height swaps, so
+       * it's enough to only check e.g. for width.
+       */
+
+      gdouble width  = private->x2 - private->x1;
+      gdouble height = private->y2 - private->y1;
+
+      /* Depending on a bunch of conditions, we might want to
+       * immedieately switch width and height of the pending
+       * rectangle.
+       */
+      if (private->fixed_rule_active                          &&
+#if 0
+          tool->button_press_state                            == 0    &&
+          tool->active_modifier_state                         == 0    &&
+#endif
+          FEQUAL (private->desired_fixed_size_width,  height) &&
+          FEQUAL (private->desired_fixed_size_height, width))
+        {
+          gdouble x = private->x1;
+          gdouble y = private->y1;
+
+          gimp_tool_rectangle_synthesize_motion (rectangle,
+                                                 GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT,
+                                                 private->x2,
+                                                 private->y2);
+
+          /* For some reason these needs to be set separately... */
+          g_object_set (rectangle,
+                        "x", x,
+                        NULL);
+          g_object_set (rectangle,
+                        "y", y,
+                        NULL);
+        }
+    }
+  else if (! strcmp (pspec->name, "aspect-numerator"))
+    {
+      /* We are only interested in when numerator and denominator
+       * swaps, so it's enough to only check e.g. for numerator.
+       */
+
+      double    width             = private->x2 - private->x1;
+      double    height            = private->y2 - private->y1;
+      gdouble   new_inverse_ratio = private->aspect_denominator /
+                                    private->aspect_numerator;
+      gdouble   lower_ratio;
+      gdouble   higher_ratio;
+
+      /* The ratio of the Fixed: Aspect ratio rule and the pending
+       * rectangle is very rarely exactly the same so use an
+       * interval. For small rectangles the below code will
+       * automatically yield a more generous accepted ratio interval
+       * which is exactly what we want.
+       */
+      if (width > height && height > 1.0)
+        {
+          lower_ratio  = width / (height + 1.0);
+          higher_ratio = width / (height - 1.0);
+        }
+      else
+        {
+          lower_ratio  = (width - 1.0) / height;
+          higher_ratio = (width + 1.0) / height;
+        }
+
+      /* Depending on a bunch of conditions, we might want to
+       * immedieately switch width and height of the pending
+       * rectangle.
+       */
+      if (private->fixed_rule_active               &&
+#if 0
+          tool->button_press_state    == 0                 &&
+          tool->active_modifier_state == 0                 &&
+#endif
+          lower_ratio                 <  new_inverse_ratio &&
+          higher_ratio                >  new_inverse_ratio)
+        {
+          gdouble new_x2 = private->x1 + private->y2 - private->y1;
+          gdouble new_y2 = private->y1 + private->x2 - private->x1;
+
+          gimp_tool_rectangle_synthesize_motion (rectangle,
+                                                 GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT,
+                                                 new_x2,
+                                                 new_y2);
+        }
+    }
+}
+
+static void
+gimp_tool_rectangle_changed (GimpToolWidget *widget)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  GimpDisplayShell         *shell     = gimp_tool_widget_get_shell (widget);
+  gdouble                   x1, y1, x2, y2;
+  gint                      handle_width;
+  gint                      handle_height;
+  gint                      i;
+
+  gimp_tool_rectangle_update_handle_sizes (rectangle);
+
+  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
+
+  gimp_canvas_rectangle_guides_set (private->guides,
+                                    x1, y1,
+                                    x2 - x1,
+                                    y2 - y1,
+                                    private->guide, 4);
+
+  gimp_canvas_rectangle_set (private->rectangle,
+                             x1, y1,
+                             x2 - x1,
+                             y2 - y1);
+
+  if (private->draw_ellipse)
+    {
+      gimp_canvas_arc_set (private->ellipse,
+                           (x1 + x2) / 2.0,
+                           (y1 + y2) / 2.0,
+                           (x2 - x1) / 2.0,
+                           (y2 - y1) / 2.0,
+                           0.0, 2 * G_PI);
+      gimp_canvas_item_set_visible (private->ellipse, TRUE);
+    }
+  else
+    {
+      gimp_canvas_item_set_visible (private->ellipse, FALSE);
+    }
+
+  if (private->round_corners && private->corner_radius > 0.0)
+    {
+      gdouble radius;
+
+      radius = MIN (private->corner_radius,
+                    MIN ((x2 - x1) / 2.0, (y2 - y1) / 2.0));
+
+      gimp_canvas_arc_set (private->corners[0],
+                           x1 + radius,
+                           y1 + radius,
+                           radius, radius,
+                           G_PI / 2.0, G_PI / 2.0);
+
+      gimp_canvas_arc_set (private->corners[1],
+                           x2 - radius,
+                           y1 + radius,
+                           radius, radius,
+                           0.0, G_PI / 2.0);
+
+      gimp_canvas_arc_set (private->corners[2],
+                           x1 + radius,
+                           y2 - radius,
+                           radius, radius,
+                           G_PI, G_PI / 2.0);
+
+      gimp_canvas_arc_set (private->corners[3],
+                           x2 - radius,
+                           y2 - radius,
+                           radius, radius,
+                           G_PI * 1.5, G_PI / 2.0);
+
+      for (i = 0; i < 4; i++)
+        gimp_canvas_item_set_visible (private->corners[i], TRUE);
+    }
+  else
+    {
+      for (i = 0; i < 4; i++)
+        gimp_canvas_item_set_visible (private->corners[i], FALSE);
+    }
+
+  gimp_canvas_item_set_visible (private->center, FALSE);
+
+  for (i = 0; i < 4; i++)
+    {
+      gimp_canvas_item_set_visible (private->creating_corners[i], FALSE);
+      gimp_canvas_item_set_highlight (private->creating_corners[i], FALSE);
+    }
+
+  for (i = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
+       i <= GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
+       i++)
+    {
+      gimp_canvas_item_set_visible (private->handles[i], FALSE);
+      gimp_canvas_item_set_visible (private->highlight_handles[i], FALSE);
+    }
+
+  handle_width  = private->corner_handle_w;
+  handle_height = private->corner_handle_h;
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_MOVING:
+      if (private->rect_adjusting)
+        {
+          /* Mark the center because we snap to it */
+          gimp_canvas_handle_set_position (private->center,
+                                           (x1 + x2) / 2.0,
+                                           (y1 + y2) / 2.0);
+          gimp_canvas_item_set_visible (private->center, TRUE);
+          break;
+        }
+
+      /* else fallthrough */
+
+    case GIMP_TOOL_RECTANGLE_DEAD:
+    case GIMP_TOOL_RECTANGLE_CREATING:
+    case GIMP_TOOL_RECTANGLE_AUTO_SHRINK:
+      for (i = 0; i < 4; i++)
+        {
+          gimp_canvas_corner_set (private->creating_corners[i],
+                                  x1, y1, x2 - x1, y2 - y1,
+                                  handle_width, handle_height,
+                                  private->narrow_mode);
+          gimp_canvas_item_set_visible (private->creating_corners[i], TRUE);
+        }
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      handle_width = private->top_and_bottom_handle_w;
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      handle_height = private->left_and_right_handle_h;
+      break;
+
+    default:
+      break;
+    }
+
+  if (handle_width  >= 3                                           &&
+      handle_height >= 3                                           &&
+      private->function >= GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT &&
+      private->function <= GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM)
+    {
+      GimpCanvasItem *corner;
+
+      if (private->rect_adjusting)
+        corner = private->handles[private->function];
+      else
+        corner = private->highlight_handles[private->function];
+
+      gimp_canvas_corner_set (corner,
+                              x1, y1, x2 - x1, y2 - y1,
+                              handle_width, handle_height,
+                              private->narrow_mode);
+      gimp_canvas_item_set_visible (corner, TRUE);
+    }
+
+  if (private->highlight && ! private->rect_adjusting)
+    {
+      GdkRectangle rect;
+
+      rect.x      = x1;
+      rect.y      = y1;
+      rect.width  = x2 - x1;
+      rect.height = y2 - y1;
+
+      gimp_display_shell_set_highlight (shell, &rect, private->highlight_opacity);
+    }
+  else
+    {
+      gimp_display_shell_set_highlight (shell, NULL, 0.0);
+    }
+}
+
+gint
+gimp_tool_rectangle_button_press (GimpToolWidget      *widget,
+                                  const GimpCoords    *coords,
+                                  guint32              time,
+                                  GdkModifierType      state,
+                                  GimpButtonPressType  press_type)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  gdouble                   snapped_x, snapped_y;
+  gint                      snap_x, snap_y;
+
+  /* save existing shape in case of cancellation */
+  private->saved_x1 = private->x1;
+  private->saved_y1 = private->y1;
+  private->saved_x2 = private->x2;
+  private->saved_y2 = private->y2;
+
+  gimp_tool_rectangle_setup_snap_offsets (rectangle, coords);
+  gimp_tool_widget_get_snap_offsets (widget, &snap_x, &snap_y, NULL, NULL);
+
+  snapped_x = coords->x + snap_x;
+  snapped_y = coords->y + snap_y;
+
+  private->lastx = snapped_x;
+  private->lasty = snapped_y;
+
+  if (private->function == GIMP_TOOL_RECTANGLE_CREATING)
+    {
+      /* Remember that this rectangle was created from scratch. */
+      private->is_new = TRUE;
+
+      private->x1 = private->x2 = snapped_x;
+      private->y1 = private->y2 = snapped_y;
+
+      /* Unless forced, created rectangles should not be started in
+       * narrow-mode
+       */
+      if (private->force_narrow_mode)
+        private->narrow_mode = TRUE;
+      else
+        private->narrow_mode = FALSE;
+
+      /* If the rectangle is being modified we want the center on
+       * fixed_center to be at the center of the currently existing
+       * rectangle, otherwise we want the point where the user clicked
+       * to be the center on fixed_center.
+       */
+      private->center_x_on_fixed_center = snapped_x;
+      private->center_y_on_fixed_center = snapped_y;
+
+      /* When the user toggles modifier keys, we want to keep track of
+       * what coordinates the "other side" should have. If we are
+       * creating a rectangle, use the current mouse coordinates as
+       * the coordinate of the "other side", otherwise use the
+       * immediate "other side" for that.
+       */
+      private->other_side_x = snapped_x;
+      private->other_side_y = snapped_y;
+    }
+  else
+    {
+      /* This rectangle was not created from scratch. */
+      private->is_new = FALSE;
+
+      private->center_x_on_fixed_center = (private->x1 + private->x2) / 2;
+      private->center_y_on_fixed_center = (private->y1 + private->y2) / 2;
+
+      gimp_tool_rectangle_get_other_side_coord (rectangle,
+                                                &private->other_side_x,
+                                                &private->other_side_y);
+    }
+
+  gimp_tool_rectangle_update_int_rect (rectangle);
+
+  /* Is the rectangle being rubber-banded? */
+  private->rect_adjusting = gimp_tool_rectangle_rect_adjusting_func (rectangle);
+
+  gimp_tool_rectangle_changed (widget);
+
+  gimp_tool_rectangle_update_status (rectangle);
+
+  return 1;
+}
+
+void
+gimp_tool_rectangle_button_release (GimpToolWidget        *widget,
+                                    const GimpCoords      *coords,
+                                    guint32                time,
+                                    GdkModifierType        state,
+                                    GimpButtonReleaseType  release_type)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  gint                      response  = 0;
+
+  gimp_tool_widget_set_status (widget, NULL);
+
+  /* On button release, we are not rubber-banding the rectangle any longer. */
+  private->rect_adjusting = FALSE;
+
+  gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);
+
+  switch (release_type)
+    {
+    case GIMP_BUTTON_RELEASE_NO_MOTION:
+      /* If the first created rectangle was not expanded, halt the
+       * tool...
+       */
+      if (gimp_tool_rectangle_rectangle_is_first (rectangle))
+        {
+          response = GIMP_TOOL_WIDGET_RESPONSE_CANCEL;
+          break;
+        }
+
+      /* ...else fallthrough and treat a long click without movement
+       * like a normal change
+       */
+
+    case GIMP_BUTTON_RELEASE_NORMAL:
+      /* If a normal click-drag-release actually created a rectangle
+       * with content...
+       */
+      if (private->x1 != private->x2 &&
+          private->y1 != private->y2)
+        {
+          gimp_tool_rectangle_change_complete (rectangle);
+          break;
+        }
+
+      /* ...else fallthrough and undo the operation, we can't have
+       * zero-extent rectangles
+       */
+
+    case GIMP_BUTTON_RELEASE_CANCEL:
+      private->x1 = private->saved_x1;
+      private->y1 = private->saved_y1;
+      private->x2 = private->saved_x2;
+      private->y2 = private->saved_y2;
+
+      gimp_tool_rectangle_update_int_rect (rectangle);
+
+      /* If the first created rectangle was canceled, halt the tool */
+      if (gimp_tool_rectangle_rectangle_is_first (rectangle))
+        response = GIMP_TOOL_WIDGET_RESPONSE_CANCEL;
+      break;
+
+    case GIMP_BUTTON_RELEASE_CLICK:
+      /* When a dead area is clicked, don't execute. */
+      if (private->function != GIMP_TOOL_RECTANGLE_DEAD)
+        response = GIMP_TOOL_WIDGET_RESPONSE_CONFIRM;
+      break;
+    }
+
+  /* We must update this. */
+  private->center_x_on_fixed_center = (private->x1 + private->x2) / 2;
+  private->center_y_on_fixed_center = (private->y1 + private->y2) / 2;
+
+  gimp_tool_rectangle_update_options (rectangle);
+
+  gimp_tool_rectangle_changed (widget);
+
+  private->is_first = FALSE;
+
+  /*  emit response at the end, so everything is up to date even if
+   *  a signal handler decides hot to shut down the rectangle
+   */
+  if (response != 0)
+    gimp_tool_widget_response (widget, response);
+}
+
+void
+gimp_tool_rectangle_motion (GimpToolWidget   *widget,
+                            const GimpCoords *coords,
+                            guint32           time,
+                            GdkModifierType   state)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  gdouble                   snapped_x;
+  gdouble                   snapped_y;
+  gint                      snap_x, snap_y;
+
+  /* Motion events should be ignored when we're just waiting for the
+   * button release event to execute or if the user has grabbed a dead
+   * area of the rectangle.
+   */
+  if (private->function == GIMP_TOOL_RECTANGLE_EXECUTING ||
+      private->function == GIMP_TOOL_RECTANGLE_DEAD)
+    return;
+
+  /* Handle snapping. */
+  gimp_tool_widget_get_snap_offsets (widget, &snap_x, &snap_y, NULL, NULL);
+
+  snapped_x = coords->x + snap_x;
+  snapped_y = coords->y + snap_y;
+
+  /* This is the core rectangle shape updating function: */
+  gimp_tool_rectangle_update_with_coord (rectangle, snapped_x, snapped_y);
+
+  gimp_tool_rectangle_update_status (rectangle);
+
+  if (private->function == GIMP_TOOL_RECTANGLE_CREATING)
+    {
+      GimpRectangleFunction function = GIMP_TOOL_RECTANGLE_CREATING;
+      gdouble               dx       = snapped_x - private->lastx;
+      gdouble               dy       = snapped_y - private->lasty;
+
+      /* When the user starts to move the cursor, set the current
+       * function to one of the corner-grabbed functions, depending on
+       * in what direction the user starts dragging the rectangle.
+       */
+      if (dx < 0)
+        {
+          function = (dy < 0 ?
+                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT :
+                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT);
+        }
+      else if (dx > 0)
+        {
+          function = (dy < 0 ?
+                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT :
+                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT);
+        }
+      else if (dy < 0)
+        {
+          function = (dx < 0 ?
+                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT :
+                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT);
+        }
+      else if (dy > 0)
+        {
+          function = (dx < 0 ?
+                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT :
+                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT);
+        }
+
+      gimp_tool_rectangle_set_function (rectangle, function);
+
+      if (private->fixed_rule_active &&
+          private->fixed_rule == GIMP_RECTANGLE_FIXED_SIZE)
+        {
+          /* For fixed size, set the function to moving immediately since the
+           * rectangle can not be resized anyway.
+           */
+
+          /* We fake a coord update to get the right size. */
+          gimp_tool_rectangle_update_with_coord (rectangle,
+                                                 snapped_x,
+                                                 snapped_y);
+
+          gimp_tool_widget_set_snap_offsets (widget,
+                                             -(private->x2 - private->x1) / 2,
+                                             -(private->y2 - private->y1) / 2,
+                                             private->x2 - private->x1,
+                                             private->y2 - private->y1);
+
+          gimp_tool_rectangle_set_function (rectangle,
+                                            GIMP_TOOL_RECTANGLE_MOVING);
+        }
+    }
+
+  gimp_tool_rectangle_update_options (rectangle);
+
+  private->lastx = snapped_x;
+  private->lasty = snapped_y;
+}
+
+GimpHit
+gimp_tool_rectangle_hit (GimpToolWidget   *widget,
+                         const GimpCoords *coords,
+                         GdkModifierType   state,
+                         gboolean          proximity)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  GimpRectangleFunction     function;
+
+  if (private->suppress_updates)
+    {
+      function = gimp_tool_rectangle_get_function (rectangle);
+    }
+  else
+    {
+      function = gimp_tool_rectangle_calc_function (rectangle,
+                                                    coords, proximity);
+    }
+
+  switch (function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      return GIMP_HIT_DIRECT;
+
+    case GIMP_TOOL_RECTANGLE_CREATING:
+    case GIMP_TOOL_RECTANGLE_MOVING:
+      return GIMP_HIT_INDIRECT;
+
+    case GIMP_TOOL_RECTANGLE_DEAD:
+    case GIMP_TOOL_RECTANGLE_AUTO_SHRINK:
+    case GIMP_TOOL_RECTANGLE_EXECUTING:
+    default:
+      return GIMP_HIT_NONE;
+    }
+}
+
+void
+gimp_tool_rectangle_hover (GimpToolWidget   *widget,
+                           const GimpCoords *coords,
+                           GdkModifierType   state,
+                           gboolean          proximity)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  GimpRectangleFunction     function;
+
+  if (private->suppress_updates)
+    {
+      private->suppress_updates--;
+      return;
+    }
+
+  function = gimp_tool_rectangle_calc_function (rectangle, coords, proximity);
+
+  gimp_tool_rectangle_set_function (rectangle, function);
+}
+
+static void
+gimp_tool_rectangle_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolRectangle *rectangle = GIMP_TOOL_RECTANGLE (widget);
+
+  gimp_tool_rectangle_set_function (rectangle, GIMP_TOOL_RECTANGLE_DEAD);
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
+}
+
+static gboolean
+gimp_tool_rectangle_key_press (GimpToolWidget *widget,
+                               GdkEventKey    *kevent)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  gint                      dx        = 0;
+  gint                      dy        = 0;
+  gdouble                   new_x     = 0;
+  gdouble                   new_y     = 0;
+
+  switch (kevent->keyval)
+    {
+    case GDK_KEY_Up:
+      dy = -1;
+      break;
+    case GDK_KEY_Left:
+      dx = -1;
+      break;
+    case GDK_KEY_Right:
+      dx = 1;
+      break;
+    case GDK_KEY_Down:
+      dy = 1;
+      break;
+
+    default:
+      return GIMP_TOOL_WIDGET_CLASS (parent_class)->key_press (widget, kevent);
+    }
+
+  /*  If the shift key is down, move by an accelerated increment  */
+  if (kevent->state & gimp_get_extend_selection_mask ())
+    {
+      dx *= ARROW_VELOCITY;
+      dy *= ARROW_VELOCITY;
+    }
+
+  gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);
+
+  /*  Resize the rectangle if the mouse is over a handle, otherwise move it  */
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_MOVING:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+      new_x = private->x1 + dx;
+      new_y = private->y1 + dy;
+      private->lastx = new_x;
+      private->lasty = new_y;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+      new_x = private->x2 + dx;
+      new_y = private->y1 + dy;
+      private->lastx = new_x;
+      private->lasty = new_y;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+      new_x = private->x1 + dx;
+      new_y = private->y2 + dy;
+      private->lastx = new_x;
+      private->lasty = new_y;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+      new_x = private->x2 + dx;
+      new_y = private->y2 + dy;
+      private->lastx = new_x;
+      private->lasty = new_y;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+      new_x = private->x1 + dx;
+      private->lastx = new_x;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      new_x = private->x2 + dx;
+      private->lastx = new_x;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+      new_y = private->y1 + dy;
+      private->lasty = new_y;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      new_y = private->y2 + dy;
+      private->lasty = new_y;
+      break;
+
+    default:
+      return TRUE;
+    }
+
+  gimp_tool_rectangle_update_with_coord (rectangle, new_x, new_y);
+
+  private->center_x_on_fixed_center = (private->x1 + private->x2) / 2;
+  private->center_y_on_fixed_center = (private->y1 + private->y2) / 2;
+
+  gimp_tool_rectangle_update_options (rectangle);
+
+  gimp_tool_rectangle_change_complete (rectangle);
+
+  /*  Evil hack to suppress oper updates. We do this because we don't
+   *  want the rectangle tool to change function while the rectangle
+   *  is being resized or moved using the keyboard.
+   */
+  private->suppress_updates = 2;
+
+  return TRUE;
+}
+
+static void
+gimp_tool_rectangle_motion_modifier (GimpToolWidget  *widget,
+                                     GdkModifierType  key,
+                                     gboolean         press,
+                                     GdkModifierType  state)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+  gboolean                  button1_down;
+
+  button1_down = (state & GDK_BUTTON1_MASK);
+
+  if (key == gimp_get_extend_selection_mask ())
+    {
+#if 0
+      /* Here we want to handle manually when to update the rectangle, so we
+       * don't want gimp_tool_rectangle_options_notify to do anything.
+       */
+      g_signal_handlers_block_by_func (options,
+                                       gimp_tool_rectangle_options_notify,
+                                       rectangle);
+#endif
+
+      g_object_set (rectangle,
+                    "fixed-rule-active", ! private->fixed_rule_active,
+                    NULL);
+
+#if 0
+      g_signal_handlers_unblock_by_func (options,
+                                         gimp_tool_rectangle_options_notify,
+                                         rectangle);
+#endif
+
+      /* Only change the shape if the mouse is still down (i.e. the user is
+       * still editing the rectangle.
+       */
+      if (button1_down)
+        {
+          if (! private->fixed_rule_active)
+            {
+              /* Reset anchor point */
+              gimp_tool_rectangle_set_other_side_coord (rectangle,
+                                                        private->other_side_x,
+                                                        private->other_side_y);
+            }
+
+          gimp_tool_rectangle_update_with_coord (rectangle,
+                                                 private->lastx,
+                                                 private->lasty);
+        }
+    }
+
+  if (key == gimp_get_toggle_behavior_mask ())
+    {
+      g_object_set (rectangle,
+                    "fixed-center", ! private->fixed_center,
+                    NULL);
+
+      if (private->fixed_center)
+        {
+          gimp_tool_rectangle_update_with_coord (rectangle,
+                                                 private->lastx,
+                                                 private->lasty);
+
+          /* Only emit the rectangle-changed signal if the button is
+           * not down. If it is down, the signal will and shall be
+           * emitted on _button_release instead.
+           */
+          if (! button1_down)
+            {
+              gimp_tool_rectangle_change_complete (rectangle);
+            }
+        }
+      else if (button1_down)
+        {
+          /* If we are leaving fixed_center mode we want to set the
+           * "other side" where it should be. Don't do anything if we
+           * came here by a mouse-click though, since then the user
+           * has confirmed the shape and we don't want to modify it
+           * afterwards.
+           */
+          gimp_tool_rectangle_set_other_side_coord (rectangle,
+                                                    private->other_side_x,
+                                                    private->other_side_y);
+        }
+    }
+
+  gimp_tool_rectangle_update_options (rectangle);
+}
+
+static gboolean
+gimp_tool_rectangle_get_cursor (GimpToolWidget     *widget,
+                                const GimpCoords   *coords,
+                                GdkModifierType     state,
+                                GimpCursorType     *cursor,
+                                GimpToolCursorType *tool_cursor,
+                                GimpCursorModifier *modifier)
+{
+  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
+  GimpToolRectanglePrivate *private   = rectangle->private;
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_CREATING:
+      *cursor = GIMP_CURSOR_CROSSHAIR_SMALL;
+      break;
+    case GIMP_TOOL_RECTANGLE_MOVING:
+      *cursor   = GIMP_CURSOR_MOVE;
+      *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+      *cursor = GIMP_CURSOR_CORNER_TOP_LEFT;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+      *cursor = GIMP_CURSOR_CORNER_TOP_RIGHT;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+      *cursor = GIMP_CURSOR_CORNER_BOTTOM_LEFT;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+      *cursor = GIMP_CURSOR_CORNER_BOTTOM_RIGHT;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+      *cursor = GIMP_CURSOR_SIDE_LEFT;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      *cursor = GIMP_CURSOR_SIDE_RIGHT;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+      *cursor = GIMP_CURSOR_SIDE_TOP;
+      break;
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      *cursor = GIMP_CURSOR_SIDE_BOTTOM;
+      break;
+
+    default:
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+static void
+gimp_tool_rectangle_change_complete (GimpToolRectangle *rectangle)
+{
+  g_signal_emit (rectangle, rectangle_signals[CHANGE_COMPLETE], 0);
+}
+
+static void
+gimp_tool_rectangle_update_options (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gdouble                   x1, y1;
+  gdouble                   x2, y2;
+
+  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
+
+#if 0
+  g_signal_handlers_block_by_func (options,
+                                   gimp_tool_rectangle_options_notify,
+                                   rect_tool);
+#endif
+
+  g_object_freeze_notify (G_OBJECT (rectangle));
+
+  if (! FEQUAL (private->x, x1))
+    g_object_set (rectangle, "x", x1, NULL);
+
+  if (! FEQUAL (private->y, y1))
+    g_object_set (rectangle, "y", y1, NULL);
+
+  if (! FEQUAL (private->width, x2 - x1))
+    g_object_set (rectangle, "width", x2 - x1, NULL);
+
+  if (! FEQUAL (private->height, y2 - y1))
+    g_object_set (rectangle, "height", y2 - y1, NULL);
+
+  g_object_thaw_notify (G_OBJECT (rectangle));
+
+#if 0
+  g_signal_handlers_unblock_by_func (options,
+                                     gimp_tool_rectangle_options_notify,
+                                     rect_tool);
+#endif
+}
+
+static void
+gimp_tool_rectangle_update_handle_sizes (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  GimpDisplayShell         *shell;
+  gint                      visible_rectangle_width;
+  gint                      visible_rectangle_height;
+  gint                      rectangle_width;
+  gint                      rectangle_height;
+  gdouble                   pub_x1, pub_y1;
+  gdouble                   pub_x2, pub_y2;
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+
+  gimp_tool_rectangle_get_public_rect (rectangle,
+                                       &pub_x1, &pub_y1, &pub_x2, &pub_y2);
+  {
+    /* Calculate rectangles of the selection rectangle and the display
+     * shell, with origin at (0, 0) of image, and in screen coordinate
+     * scale.
+     */
+    gint x1 =  pub_x1 * shell->scale_x;
+    gint y1 =  pub_y1 * shell->scale_y;
+    gint w1 = (pub_x2 - pub_x1) * shell->scale_x;
+    gint h1 = (pub_y2 - pub_y1) * shell->scale_y;
+
+    gint x2, y2, w2, h2;
+
+    gimp_display_shell_scroll_get_scaled_viewport (shell, &x2, &y2, &w2, &h2);
+
+    rectangle_width  = w1;
+    rectangle_height = h1;
+
+    /* Handle size calculations shall be based on the visible part of
+     * the rectangle, so calculate the size for the visible rectangle
+     * by intersecting with the viewport rectangle.
+     */
+    gimp_rectangle_intersect (x1, y1,
+                              w1, h1,
+                              x2, y2,
+                              w2, h2,
+                              NULL, NULL,
+                              &visible_rectangle_width,
+                              &visible_rectangle_height);
+
+    /* Determine if we are in narrow-mode or not. */
+    if (private->force_narrow_mode)
+      private->narrow_mode = TRUE;
+    else
+      private->narrow_mode = (visible_rectangle_width  < NARROW_MODE_THRESHOLD ||
+                              visible_rectangle_height < NARROW_MODE_THRESHOLD);
+  }
+
+  if (private->narrow_mode)
+    {
+      /* Corner handles always have the same (on-screen) size in
+       * narrow-mode.
+       */
+      private->corner_handle_w = NARROW_MODE_HANDLE_SIZE;
+      private->corner_handle_h = NARROW_MODE_HANDLE_SIZE;
+
+      private->top_and_bottom_handle_w = CLAMP (rectangle_width,
+                                                MIN (rectangle_width - 2,
+                                                     NARROW_MODE_HANDLE_SIZE),
+                                                G_MAXINT);
+      private->left_and_right_handle_h = CLAMP (rectangle_height,
+                                                MIN (rectangle_height - 2,
+                                                     NARROW_MODE_HANDLE_SIZE),
+                                                G_MAXINT);
+    }
+  else
+    {
+      /* Calculate and clamp corner handle size. */
+
+      private->corner_handle_w = visible_rectangle_width  / 4;
+      private->corner_handle_h = visible_rectangle_height / 4;
+
+      private->corner_handle_w = CLAMP (private->corner_handle_w,
+                                        MIN_HANDLE_SIZE,
+                                        MAX_HANDLE_SIZE);
+      private->corner_handle_h = CLAMP (private->corner_handle_h,
+                                        MIN_HANDLE_SIZE,
+                                        MAX_HANDLE_SIZE);
+
+      /* Calculate and clamp side handle size. */
+
+      private->top_and_bottom_handle_w = rectangle_width  - 3 * private->corner_handle_w;
+      private->left_and_right_handle_h = rectangle_height - 3 * private->corner_handle_h;
+
+      private->top_and_bottom_handle_w = CLAMP (private->top_and_bottom_handle_w,
+                                                MIN_HANDLE_SIZE,
+                                                G_MAXINT);
+      private->left_and_right_handle_h = CLAMP (private->left_and_right_handle_h,
+                                                MIN_HANDLE_SIZE,
+                                                G_MAXINT);
+    }
+}
+
+static void
+gimp_tool_rectangle_update_status (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gdouble                   x1, y1, x2, y2;
+
+  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
+
+  if (private->function == GIMP_TOOL_RECTANGLE_MOVING)
+    {
+      gimp_tool_widget_set_status_coords (GIMP_TOOL_WIDGET (rectangle),
+                                          _("Position: "),
+                                          x1, ", ", y1,
+                                          NULL);
+    }
+  else
+    {
+      gchar *aspect_text = NULL;
+      gint   width       = x2 - x1;
+      gint   height      = y2 - y1;
+
+      if (width > 0.0 && height > 0.0)
+        {
+          aspect_text = g_strdup_printf ("  (%.2f:1)",
+                                         (gdouble) width / (gdouble) height);
+        }
+
+      gimp_tool_widget_set_status_coords (GIMP_TOOL_WIDGET (rectangle),
+                                          private->status_title,
+                                          width, " × ", height,
+                                          aspect_text);
+      g_free (aspect_text);
+    }
+}
+
+static void
+gimp_tool_rectangle_synthesize_motion (GimpToolRectangle *rectangle,
+                                       gint               function,
+                                       gdouble            new_x,
+                                       gdouble            new_y)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  GimpRectangleFunction     old_function;
+
+  /* We don't want to synthesize motions if the tool control is active
+   * since that means the mouse button is down and the rectangle will
+   * get updated in _motion anyway. The reason we want to prevent this
+   * function from executing is that is emits the
+   * rectangle-changed-complete signal which we don't want in the
+   * middle of a rectangle change.
+   *
+   * In addition to that, we don't want to synthesize a motion if
+   * there is no pending rectangle because that doesn't make any
+   * sense.
+   */
+  if (private->rect_adjusting)
+    return;
+
+  old_function = private->function;
+
+  gimp_tool_rectangle_set_function (rectangle, function);
+
+  gimp_tool_rectangle_update_with_coord (rectangle, new_x, new_y);
+
+  /* We must update this. */
+  private->center_x_on_fixed_center = (private->x1 + private->x2) / 2;
+  private->center_y_on_fixed_center = (private->y1 + private->y2) / 2;
+
+  gimp_tool_rectangle_update_options (rectangle);
+
+  gimp_tool_rectangle_set_function (rectangle, old_function);
+
+  gimp_tool_rectangle_change_complete (rectangle);
+}
+
+static void
+swap_doubles (gdouble *i,
+              gdouble *j)
+{
+  gdouble tmp;
+
+  tmp = *i;
+  *i = *j;
+  *j = tmp;
+}
+
+static GimpRectangleFunction
+gimp_tool_rectangle_calc_function (GimpToolRectangle *rectangle,
+                                   const GimpCoords  *coords,
+                                   gboolean           proximity)
+{
+  if (! proximity)
+    {
+      return GIMP_TOOL_RECTANGLE_DEAD;
+    }
+  else if (gimp_tool_rectangle_coord_outside (rectangle, coords))
+    {
+      /* The cursor is outside of the rectangle, clicking should
+       * create a new rectangle.
+       */
+      return GIMP_TOOL_RECTANGLE_CREATING;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_NORTH_WEST))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_SOUTH_EAST))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT;
+    }
+  else if  (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                 coords,
+                                                 GIMP_HANDLE_ANCHOR_NORTH_EAST))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_SOUTH_WEST))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_WEST))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_LEFT;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_EAST))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_RIGHT;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_NORTH))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_TOP;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_SOUTH))
+    {
+      return GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
+    }
+  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
+                                                coords,
+                                                GIMP_HANDLE_ANCHOR_CENTER))
+    {
+      return GIMP_TOOL_RECTANGLE_MOVING;
+    }
+  else
+    {
+      return GIMP_TOOL_RECTANGLE_DEAD;
+    }
+}
+
+/* gimp_tool_rectangle_check_function() is needed to deal with
+ * situations where the user drags a corner or edge across one of the
+ * existing edges, thereby changing its function.  Ugh.
+ */
+static void
+gimp_tool_rectangle_check_function (GimpToolRectangle *rectangle)
+
+{
+  GimpToolRectanglePrivate *private  = rectangle->private;
+  GimpRectangleFunction     function = private->function;
+
+  if (private->x2 < private->x1)
+    {
+      swap_doubles (&private->x1, &private->x2);
+
+      switch (function)
+        {
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_RIGHT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_LEFT;
+          break;
+          /* avoid annoying warnings about unhandled enums */
+        default:
+          break;
+        }
+    }
+
+  if (private->y2 < private->y1)
+    {
+      swap_doubles (&private->y1, &private->y2);
+
+      switch (function)
+        {
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
+          break;
+        case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+          function = GIMP_TOOL_RECTANGLE_RESIZING_TOP;
+          break;
+        default:
+          break;
+        }
+    }
+
+  gimp_tool_rectangle_set_function (rectangle, function);
+}
+
+/**
+ * gimp_tool_rectangle_coord_outside:
+ *
+ * Returns: %TRUE if the coord is outside the rectangle bounds
+ *          including any outside handles.
+ */
+static gboolean
+gimp_tool_rectangle_coord_outside (GimpToolRectangle *rectangle,
+                                   const GimpCoords  *coord)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  GimpDisplayShell         *shell;
+  gboolean                  narrow_mode = private->narrow_mode;
+  gdouble                   x1, y1, x2, y2;
+  gdouble                   x1_b, y1_b, x2_b, y2_b;
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+
+  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
+
+  x1_b = x1 - (narrow_mode ? private->corner_handle_w / shell->scale_x : 0);
+  x2_b = x2 + (narrow_mode ? private->corner_handle_w / shell->scale_x : 0);
+  y1_b = y1 - (narrow_mode ? private->corner_handle_h / shell->scale_y : 0);
+  y2_b = y2 + (narrow_mode ? private->corner_handle_h / shell->scale_y : 0);
+
+  return (coord->x < x1_b ||
+          coord->x > x2_b ||
+          coord->y < y1_b ||
+          coord->y > y2_b);
+}
+
+/**
+ * gimp_tool_rectangle_coord_on_handle:
+ *
+ * Returns: %TRUE if the coord is on the handle that corresponds to
+ *          @anchor.
+ */
+static gboolean
+gimp_tool_rectangle_coord_on_handle (GimpToolRectangle *rectangle,
+                                     const GimpCoords  *coords,
+                                     GimpHandleAnchor   anchor)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  GimpDisplayShell         *shell;
+  gdouble                   x1, y1, x2, y2;
+  gdouble                   rect_w, rect_h;
+  gdouble                   handle_x          = 0;
+  gdouble                   handle_y          = 0;
+  gdouble                   handle_width      = 0;
+  gdouble                   handle_height     = 0;
+  gint                      narrow_mode_x_dir = 0;
+  gint                      narrow_mode_y_dir = 0;
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+
+  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
+
+  rect_w = x2 - x1;
+  rect_h = y2 - y1;
+
+  switch (anchor)
+    {
+    case GIMP_HANDLE_ANCHOR_NORTH_WEST:
+      handle_x      = x1;
+      handle_y      = y1;
+      handle_width  = private->corner_handle_w;
+      handle_height = private->corner_handle_h;
+
+      narrow_mode_x_dir = -1;
+      narrow_mode_y_dir = -1;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_EAST:
+      handle_x      = x2;
+      handle_y      = y2;
+      handle_width  = private->corner_handle_w;
+      handle_height = private->corner_handle_h;
+
+      narrow_mode_x_dir =  1;
+      narrow_mode_y_dir =  1;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH_EAST:
+      handle_x      = x2;
+      handle_y      = y1;
+      handle_width  = private->corner_handle_w;
+      handle_height = private->corner_handle_h;
+
+      narrow_mode_x_dir =  1;
+      narrow_mode_y_dir = -1;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH_WEST:
+      handle_x      = x1;
+      handle_y      = y2;
+      handle_width  = private->corner_handle_w;
+      handle_height = private->corner_handle_h;
+
+      narrow_mode_x_dir = -1;
+      narrow_mode_y_dir =  1;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_WEST:
+      handle_x      = x1;
+      handle_y      = y1 + rect_h / 2;
+      handle_width  = private->corner_handle_w;
+      handle_height = private->left_and_right_handle_h;
+
+      narrow_mode_x_dir = -1;
+      narrow_mode_y_dir =  0;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_EAST:
+      handle_x      = x2;
+      handle_y      = y1 + rect_h / 2;
+      handle_width  = private->corner_handle_w;
+      handle_height = private->left_and_right_handle_h;
+
+      narrow_mode_x_dir =  1;
+      narrow_mode_y_dir =  0;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_NORTH:
+      handle_x      = x1 + rect_w / 2;
+      handle_y      = y1;
+      handle_width  = private->top_and_bottom_handle_w;
+      handle_height = private->corner_handle_h;
+
+      narrow_mode_x_dir =  0;
+      narrow_mode_y_dir = -1;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_SOUTH:
+      handle_x      = x1 + rect_w / 2;
+      handle_y      = y2;
+      handle_width  = private->top_and_bottom_handle_w;
+      handle_height = private->corner_handle_h;
+
+      narrow_mode_x_dir =  0;
+      narrow_mode_y_dir =  1;
+      break;
+
+    case GIMP_HANDLE_ANCHOR_CENTER:
+      handle_x      = x1 + rect_w / 2;
+      handle_y      = y1 + rect_h / 2;
+
+      if (private->narrow_mode)
+        {
+          handle_width  = rect_w * shell->scale_x;
+          handle_height = rect_h * shell->scale_y;
+        }
+      else
+        {
+          handle_width  = rect_w * shell->scale_x - private->corner_handle_w * 2;
+          handle_height = rect_h * shell->scale_y - private->corner_handle_h * 2;
+        }
+
+      narrow_mode_x_dir =  0;
+      narrow_mode_y_dir =  0;
+      break;
+    }
+
+  if (private->narrow_mode)
+    {
+      handle_x += narrow_mode_x_dir * handle_width  / shell->scale_x;
+      handle_y += narrow_mode_y_dir * handle_height / shell->scale_y;
+    }
+
+  return gimp_canvas_item_on_handle (private->rectangle,
+                                     coords->x, coords->y,
+                                     GIMP_HANDLE_SQUARE,
+                                     handle_x,     handle_y,
+                                     handle_width, handle_height,
+                                     anchor);
+}
+
+static GimpHandleAnchor
+gimp_tool_rectangle_get_anchor (GimpRectangleFunction function)
+{
+  switch (function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+      return GIMP_HANDLE_ANCHOR_NORTH_WEST;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+      return GIMP_HANDLE_ANCHOR_NORTH_EAST;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+      return GIMP_HANDLE_ANCHOR_SOUTH_WEST;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+      return GIMP_HANDLE_ANCHOR_SOUTH_EAST;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+      return GIMP_HANDLE_ANCHOR_WEST;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      return GIMP_HANDLE_ANCHOR_EAST;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+      return GIMP_HANDLE_ANCHOR_NORTH;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      return GIMP_HANDLE_ANCHOR_SOUTH;
+
+    default:
+      return GIMP_HANDLE_ANCHOR_CENTER;
+    }
+}
+
+static gboolean
+gimp_tool_rectangle_rect_rubber_banding_func (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_CREATING:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_AUTO_SHRINK:
+      return TRUE;
+
+    case GIMP_TOOL_RECTANGLE_MOVING:
+    case GIMP_TOOL_RECTANGLE_DEAD:
+    default:
+      break;
+    }
+
+  return FALSE;
+}
+
+/**
+ * gimp_tool_rectangle_rect_adjusting_func:
+ * @rectangle:
+ *
+ * Returns: %TRUE if the current function is a rectangle adjusting
+ *          function.
+ */
+static gboolean
+gimp_tool_rectangle_rect_adjusting_func (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  return (gimp_tool_rectangle_rect_rubber_banding_func (rectangle) ||
+          private->function == GIMP_TOOL_RECTANGLE_MOVING);
+}
+
+/**
+ * gimp_tool_rectangle_get_other_side:
+ * @rectangle: A #GimpToolRectangle.
+ * @other_x:   Pointer to double of the other-x double.
+ * @other_y:   Pointer to double of the other-y double.
+ *
+ * Calculates pointers to member variables that hold the coordinates
+ * of the opposite side (either the opposite corner or literally the
+ * opposite side), based on the current function. The opposite of a
+ * corner needs two coordinates, the opposite of a side only needs
+ * one.
+ */
+static void
+gimp_tool_rectangle_get_other_side (GimpToolRectangle  *rectangle,
+                                    gdouble           **other_x,
+                                    gdouble           **other_y)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      *other_x = &private->x1;
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+      *other_x = &private->x2;
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+    default:
+      *other_x = NULL;
+      break;
+    }
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      *other_y = &private->y1;
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+      *other_y = &private->y2;
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+    default:
+      *other_y = NULL;
+      break;
+    }
+}
+
+static void
+gimp_tool_rectangle_get_other_side_coord (GimpToolRectangle *rectangle,
+                                          gdouble           *other_side_x,
+                                          gdouble           *other_side_y)
+{
+  gdouble *other_x = NULL;
+  gdouble *other_y = NULL;
+
+  gimp_tool_rectangle_get_other_side (rectangle, &other_x, &other_y);
+
+  if (other_x)
+    *other_side_x = *other_x;
+  if (other_y)
+    *other_side_y = *other_y;
+}
+
+static void
+gimp_tool_rectangle_set_other_side_coord (GimpToolRectangle *rectangle,
+                                          gdouble            other_side_x,
+                                          gdouble            other_side_y)
+{
+  gdouble *other_x = NULL;
+  gdouble *other_y = NULL;
+
+  gimp_tool_rectangle_get_other_side (rectangle, &other_x, &other_y);
+
+  if (other_x)
+    *other_x = other_side_x;
+  if (other_y)
+    *other_y = other_side_y;
+
+  gimp_tool_rectangle_check_function (rectangle);
+
+  gimp_tool_rectangle_update_int_rect (rectangle);
+}
+
+/**
+ * gimp_tool_rectangle_apply_coord:
+ * @param:     A #GimpToolRectangle.
+ * @coord_x:   X of coord.
+ * @coord_y:   Y of coord.
+ *
+ * Adjust the rectangle to the new position specified by passed
+ * coordinate, taking fixed_center into account, which means it
+ * expands the rectangle around the center point.
+ */
+static void
+gimp_tool_rectangle_apply_coord (GimpToolRectangle *rectangle,
+                                 gdouble            coord_x,
+                                 gdouble            coord_y)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  if (private->function == GIMP_TOOL_RECTANGLE_MOVING)
+    {
+      /* Preserve width and height while moving the grab-point to where the
+       * cursor is.
+       */
+      gdouble w = private->x2 - private->x1;
+      gdouble h = private->y2 - private->y1;
+
+      private->x1 = coord_x;
+      private->y1 = coord_y;
+
+      private->x2 = private->x1 + w;
+      private->y2 = private->y1 + h;
+
+      /* We are done already. */
+      return;
+    }
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+      private->x1 = coord_x;
+
+      if (private->fixed_center)
+        private->x2 = 2 * private->center_x_on_fixed_center - private->x1;
+
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      private->x2 = coord_x;
+
+      if (private->fixed_center)
+        private->x1 = 2 * private->center_x_on_fixed_center - private->x2;
+
+      break;
+
+    default:
+      break;
+    }
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+      private->y1 = coord_y;
+
+      if (private->fixed_center)
+        private->y2 = 2 * private->center_y_on_fixed_center - private->y1;
+
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      private->y2 = coord_y;
+
+      if (private->fixed_center)
+        private->y1 = 2 * private->center_y_on_fixed_center - private->y2;
+
+      break;
+
+    default:
+      break;
+    }
+}
+
+static void
+gimp_tool_rectangle_setup_snap_offsets (GimpToolRectangle *rectangle,
+                                        const GimpCoords  *coords)
+{
+  GimpToolWidget           *widget  = GIMP_TOOL_WIDGET (rectangle);
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gdouble                   x1, y1, x2, y2;
+  gdouble                   coord_x, coord_y;
+
+  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
+  gimp_tool_rectangle_adjust_coord (rectangle,
+                                    coords->x, coords->y,
+                                    &coord_x, &coord_y);
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_CREATING:
+      gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         x1 - coord_x,
+                                         y1 - coord_y,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         x2 - coord_x,
+                                         y1 - coord_y,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         x1 - coord_x,
+                                         y2 - coord_y,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         x2 - coord_x,
+                                         y2 - coord_y,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         x1 - coord_x, 0,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         x2 - coord_x, 0,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         0, y1 - coord_y,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         0, y2 - coord_y,
+                                         0, 0);
+      break;
+
+    case GIMP_TOOL_RECTANGLE_MOVING:
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         x1 - coord_x,
+                                         y1 - coord_y,
+                                         x2 - x1,
+                                         y2 - y1);
+      break;
+
+    default:
+      break;
+    }
+}
+
+/**
+ * gimp_tool_rectangle_clamp:
+ * @rectangle:      A #GimpToolRectangle.
+ * @clamped_sides:  Where to put contrainment information.
+ * @constraint:     Constraint to use.
+ * @symmetrically:  Whether or not to clamp symmetrically.
+ *
+ * Clamps rectangle inside specified bounds, providing information of
+ * where clamping was done. Can also clamp symmetrically.
+ */
+static void
+gimp_tool_rectangle_clamp (GimpToolRectangle       *rectangle,
+                           ClampedSide             *clamped_sides,
+                           GimpRectangleConstraint  constraint,
+                           gboolean                 symmetrically)
+{
+  gimp_tool_rectangle_clamp_width (rectangle,
+                                   clamped_sides,
+                                   constraint,
+                                   symmetrically);
+
+  gimp_tool_rectangle_clamp_height (rectangle,
+                                    clamped_sides,
+                                    constraint,
+                                    symmetrically);
+}
+
+/**
+ * gimp_tool_rectangle_clamp_width:
+ * @rectangle:      A #GimpToolRectangle.
+ * @clamped_sides:  Where to put contrainment information.
+ * @constraint:     Constraint to use.
+ * @symmetrically:  Whether or not to clamp symmetrically.
+ *
+ * Clamps height of rectangle. Set symmetrically to true when using
+ * for fixed_center:ed rectangles, since that will clamp symmetrically
+ * which is just what is needed.
+ *
+ * When this function constrains, it puts what it constrains in
+ * @constraint. This information is essential when an aspect ratio is
+ * to be applied.
+ */
+static void
+gimp_tool_rectangle_clamp_width (GimpToolRectangle       *rectangle,
+                                 ClampedSide             *clamped_sides,
+                                 GimpRectangleConstraint  constraint,
+                                 gboolean                 symmetrically)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gint                      min_x;
+  gint                      max_x;
+
+  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
+    return;
+
+  gimp_tool_rectangle_get_constraints (rectangle,
+                                       &min_x, NULL,
+                                       &max_x, NULL,
+                                       constraint);
+  if (private->x1 < min_x)
+    {
+      gdouble dx = min_x - private->x1;
+
+      private->x1 += dx;
+
+      if (symmetrically)
+        private->x2 -= dx;
+
+      if (private->x2 < min_x)
+        private->x2 = min_x;
+
+      if (clamped_sides)
+        *clamped_sides |= CLAMPED_LEFT;
+    }
+
+  if (private->x2 > max_x)
+    {
+      gdouble dx = max_x - private->x2;
+
+      private->x2 += dx;
+
+      if (symmetrically)
+        private->x1 -= dx;
+
+      if (private->x1 > max_x)
+        private->x1 = max_x;
+
+      if (clamped_sides)
+        *clamped_sides |= CLAMPED_RIGHT;
+    }
+}
+
+/**
+ * gimp_tool_rectangle_clamp_height:
+ * @rectangle:      A #GimpToolRectangle.
+ * @clamped_sides:  Where to put contrainment information.
+ * @constraint:     Constraint to use.
+ * @symmetrically:  Whether or not to clamp symmetrically.
+ *
+ * Clamps height of rectangle. Set symmetrically to true when using for
+ * fixed_center:ed rectangles, since that will clamp symmetrically which is just
+ * what is needed.
+ *
+ * When this function constrains, it puts what it constrains in
+ * @constraint. This information is essential when an aspect ratio is to be
+ * applied.
+ */
+static void
+gimp_tool_rectangle_clamp_height (GimpToolRectangle       *rectangle,
+                                  ClampedSide             *clamped_sides,
+                                  GimpRectangleConstraint  constraint,
+                                  gboolean                 symmetrically)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gint                      min_y;
+  gint                      max_y;
+
+  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
+    return;
+
+  gimp_tool_rectangle_get_constraints (rectangle,
+                                       NULL, &min_y,
+                                       NULL, &max_y,
+                                       constraint);
+  if (private->y1 < min_y)
+    {
+      gdouble dy = min_y - private->y1;
+
+      private->y1 += dy;
+
+      if (symmetrically)
+        private->y2 -= dy;
+
+      if (private->y2 < min_y)
+        private->y2 = min_y;
+
+      if (clamped_sides)
+        *clamped_sides |= CLAMPED_TOP;
+    }
+
+  if (private->y2 > max_y)
+    {
+      gdouble dy = max_y - private->y2;
+
+      private->y2 += dy;
+
+      if (symmetrically)
+        private->y1 -= dy;
+
+      if (private->y1 > max_y)
+        private->y1 = max_y;
+
+      if (clamped_sides)
+        *clamped_sides |= CLAMPED_BOTTOM;
+    }
+}
+
+/**
+ * gimp_tool_rectangle_keep_inside:
+ * @rectangle: A #GimpToolRectangle.
+ *
+ * If the rectangle is outside of the canvas, move it into it. If the rectangle is
+ * larger than the canvas in any direction, make it fill the canvas in that direction.
+ */
+static void
+gimp_tool_rectangle_keep_inside (GimpToolRectangle      *rectangle,
+                                 GimpRectangleConstraint constraint)
+{
+  gimp_tool_rectangle_keep_inside_horizontally (rectangle, constraint);
+  gimp_tool_rectangle_keep_inside_vertically   (rectangle, constraint);
+}
+
+/**
+ * gimp_tool_rectangle_keep_inside_horizontally:
+ * @rectangle:      A #GimpToolRectangle.
+ * @constraint:     Constraint to use.
+ *
+ * If the rectangle is outside of the given constraint horizontally, move it
+ * inside. If it is too big to fit inside, make it just as big as the width
+ * limit.
+ */
+static void
+gimp_tool_rectangle_keep_inside_horizontally (GimpToolRectangle       *rectangle,
+                                              GimpRectangleConstraint  constraint)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gint                      min_x;
+  gint                      max_x;
+
+  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
+    return;
+
+  gimp_tool_rectangle_get_constraints (rectangle,
+                                       &min_x, NULL,
+                                       &max_x, NULL,
+                                       constraint);
+
+  if (max_x - min_x < private->x2 - private->x1)
+    {
+      private->x1 = min_x;
+      private->x2 = max_x;
+    }
+  else
+    {
+      if (private->x1 < min_x)
+        {
+          gdouble dx = min_x - private->x1;
+
+          private->x1 += dx;
+          private->x2 += dx;
+        }
+      if (private->x2 > max_x)
+        {
+          gdouble dx = max_x - private->x2;
+
+          private->x1 += dx;
+          private->x2 += dx;
+        }
+    }
+}
+
+/**
+ * gimp_tool_rectangle_keep_inside_vertically:
+ * @rectangle:      A #GimpToolRectangle.
+ * @constraint:     Constraint to use.
+ *
+ * If the rectangle is outside of the given constraint vertically,
+ * move it inside. If it is too big to fit inside, make it just as big
+ * as the width limit.
+ */
+static void
+gimp_tool_rectangle_keep_inside_vertically (GimpToolRectangle       *rectangle,
+                                            GimpRectangleConstraint  constraint)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gint                      min_y;
+  gint                      max_y;
+
+  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
+    return;
+
+  gimp_tool_rectangle_get_constraints (rectangle,
+                                       NULL, &min_y,
+                                       NULL, &max_y,
+                                       constraint);
+
+  if (max_y - min_y < private->y2 - private->y1)
+    {
+      private->y1 = min_y;
+      private->y2 = max_y;
+    }
+  else
+    {
+      if (private->y1 < min_y)
+        {
+          gdouble dy = min_y - private->y1;
+
+          private->y1 += dy;
+          private->y2 += dy;
+        }
+      if (private->y2 > max_y)
+        {
+          gdouble dy = max_y - private->y2;
+
+          private->y1 += dy;
+          private->y2 += dy;
+        }
+    }
+}
+
+/**
+ * gimp_tool_rectangle_apply_fixed_width:
+ * @rectangle:      A #GimpToolRectangle.
+ * @constraint:     Constraint to use.
+ * @width:
+ *
+ * Makes the rectangle have a fixed_width, following the constrainment
+ * rules of fixed widths as well. Please refer to the rectangle tools
+ * spec.
+ */
+static void
+gimp_tool_rectangle_apply_fixed_width (GimpToolRectangle      *rectangle,
+                                       GimpRectangleConstraint constraint,
+                                       gdouble                 width)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+      /* We always want to center around fixed_center here, since we want the
+       * anchor point to be directly on the opposite side.
+       */
+      private->x1 = private->center_x_on_fixed_center -
+                    width / 2;
+      private->x2 = private->x1 + width;
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+      /* We always want to center around fixed_center here, since we want the
+       * anchor point to be directly on the opposite side.
+       */
+      private->x1 = private->center_x_on_fixed_center -
+                    width / 2;
+      private->x2 = private->x1 + width;
+      break;
+
+    default:
+      break;
+    }
+
+  /* Width shall be kept even after constraints, so we move the
+   * rectangle sideways rather than adjusting a side.
+   */
+  gimp_tool_rectangle_keep_inside_horizontally (rectangle, constraint);
+}
+
+/**
+ * gimp_tool_rectangle_apply_fixed_height:
+ * @rectangle:      A #GimpToolRectangle.
+ * @constraint:     Constraint to use.
+ * @height:
+ *
+ * Makes the rectangle have a fixed_height, following the
+ * constrainment rules of fixed heights as well. Please refer to the
+ * rectangle tools spec.
+ */
+static void
+gimp_tool_rectangle_apply_fixed_height (GimpToolRectangle      *rectangle,
+                                        GimpRectangleConstraint constraint,
+                                        gdouble                 height)
+
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  switch (private->function)
+    {
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+      /* We always want to center around fixed_center here, since we
+       * want the anchor point to be directly on the opposite side.
+       */
+      private->y1 = private->center_y_on_fixed_center -
+                    height / 2;
+      private->y2 = private->y1 + height;
+      break;
+
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+      /* We always want to center around fixed_center here, since we
+       * want the anchor point to be directly on the opposite side.
+       */
+      private->y1 = private->center_y_on_fixed_center -
+                    height / 2;
+      private->y2 = private->y1 + height;
+      break;
+
+    default:
+      break;
+    }
+
+  /* Width shall be kept even after constraints, so we move the
+   * rectangle sideways rather than adjusting a side.
+   */
+  gimp_tool_rectangle_keep_inside_vertically (rectangle, constraint);
+}
+
+/**
+ * gimp_tool_rectangle_apply_aspect:
+ * @rectangle:      A #GimpToolRectangle.
+ * @aspect:         The desired aspect.
+ * @clamped_sides:  Bitfield of sides that have been clamped.
+ *
+ * Adjust the rectangle to the desired aspect.
+ *
+ * Sometimes, a side must not be moved outwards, for example if a the
+ * RIGHT side has been clamped previously, we must not move the RIGHT
+ * side to the right, since that would violate the constraint
+ * again. The clamped_sides bitfield keeps track of sides that have
+ * previously been clamped.
+ *
+ * If fixed_center is used, the function adjusts the aspect by
+ * symmetrically adjusting the left and right, or top and bottom side.
+ */
+static void
+gimp_tool_rectangle_apply_aspect (GimpToolRectangle *rectangle,
+                                  gdouble            aspect,
+                                  gint               clamped_sides)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  gdouble                   current_w;
+  gdouble                   current_h;
+  gdouble                   current_aspect;
+  SideToResize              side_to_resize = SIDE_TO_RESIZE_NONE;
+
+  current_w = private->x2 - private->x1;
+  current_h = private->y2 - private->y1;
+
+  current_aspect = (gdouble) current_w / (gdouble) current_h;
+
+  /* Do we have to do anything? */
+  if (current_aspect == aspect)
+    return;
+
+  if (private->fixed_center)
+    {
+      /* We may only adjust the sides symmetrically to get desired aspect. */
+      if (current_aspect > aspect)
+        {
+          /* We prefer to use top and bottom (since that will make the
+           * cursor remain on the rectangle edge), unless that is what
+           * the user has grabbed.
+           */
+          switch (private->function)
+            {
+            case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+              if (! (clamped_sides & CLAMPED_TOP) &&
+                  ! (clamped_sides & CLAMPED_BOTTOM))
+                {
+                  side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
+                }
+              else
+                {
+                  side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
+                }
+              break;
+
+            case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+            case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+            default:
+              side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
+              break;
+            }
+        }
+      else /* (current_aspect < aspect) */
+        {
+          /* We prefer to use left and right (since that will make the
+           * cursor remain on the rectangle edge), unless that is what
+           * the user has grabbed.
+           */
+          switch (private->function)
+            {
+            case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+            case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+              if (! (clamped_sides & CLAMPED_LEFT) &&
+                  ! (clamped_sides & CLAMPED_RIGHT))
+                {
+                  side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
+                }
+              else
+                {
+                  side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
+                }
+              break;
+
+            case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+            case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+            default:
+              side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
+              break;
+            }
+        }
+    }
+  else if (current_aspect > aspect)
+    {
+      /* We can safely pick LEFT or RIGHT, since using those sides
+       * will make the rectangle smaller, so we don't need to check
+       * for clamped_sides. We may only use TOP and BOTTOM if not
+       * those sides have been clamped, since using them will make the
+       * rectangle bigger.
+       */
+      switch (private->function)
+        {
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+          if (! (clamped_sides & CLAMPED_TOP))
+            side_to_resize = SIDE_TO_RESIZE_TOP;
+          else
+            side_to_resize = SIDE_TO_RESIZE_LEFT;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+          if (! (clamped_sides & CLAMPED_TOP))
+            side_to_resize = SIDE_TO_RESIZE_TOP;
+          else
+            side_to_resize = SIDE_TO_RESIZE_RIGHT;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+          if (! (clamped_sides & CLAMPED_BOTTOM))
+            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
+          else
+            side_to_resize = SIDE_TO_RESIZE_LEFT;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+          if (! (clamped_sides & CLAMPED_BOTTOM))
+            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
+          else
+            side_to_resize = SIDE_TO_RESIZE_RIGHT;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+          if (! (clamped_sides & CLAMPED_TOP) &&
+              ! (clamped_sides & CLAMPED_BOTTOM))
+            side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
+          else
+            side_to_resize = SIDE_TO_RESIZE_LEFT;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+          if (! (clamped_sides & CLAMPED_TOP) &&
+              ! (clamped_sides & CLAMPED_BOTTOM))
+            side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
+          else
+            side_to_resize = SIDE_TO_RESIZE_RIGHT;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+        case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+          side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_MOVING:
+        default:
+          if (! (clamped_sides & CLAMPED_BOTTOM))
+            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
+          else if (! (clamped_sides & CLAMPED_RIGHT))
+            side_to_resize = SIDE_TO_RESIZE_RIGHT;
+          else if (! (clamped_sides & CLAMPED_TOP))
+            side_to_resize = SIDE_TO_RESIZE_TOP;
+          else if (! (clamped_sides & CLAMPED_LEFT))
+            side_to_resize = SIDE_TO_RESIZE_LEFT;
+          break;
+        }
+    }
+  else /* (current_aspect < aspect) */
+    {
+      /* We can safely pick TOP or BOTTOM, since using those sides
+       * will make the rectangle smaller, so we don't need to check
+       * for clamped_sides. We may only use LEFT and RIGHT if not
+       * those sides have been clamped, since using them will make the
+       * rectangle bigger.
+       */
+      switch (private->function)
+        {
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
+          if (! (clamped_sides & CLAMPED_LEFT))
+            side_to_resize = SIDE_TO_RESIZE_LEFT;
+          else
+            side_to_resize = SIDE_TO_RESIZE_TOP;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
+          if (! (clamped_sides & CLAMPED_RIGHT))
+            side_to_resize = SIDE_TO_RESIZE_RIGHT;
+          else
+            side_to_resize = SIDE_TO_RESIZE_TOP;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
+          if (! (clamped_sides & CLAMPED_LEFT))
+            side_to_resize = SIDE_TO_RESIZE_LEFT;
+          else
+            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
+          if (! (clamped_sides & CLAMPED_RIGHT))
+            side_to_resize = SIDE_TO_RESIZE_RIGHT;
+          else
+            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
+          if (! (clamped_sides & CLAMPED_LEFT) &&
+              ! (clamped_sides & CLAMPED_RIGHT))
+            side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
+          else
+            side_to_resize = SIDE_TO_RESIZE_TOP;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
+          if (! (clamped_sides & CLAMPED_LEFT) &&
+              ! (clamped_sides & CLAMPED_RIGHT))
+            side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
+          else
+            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
+        case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
+          side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
+          break;
+
+        case GIMP_TOOL_RECTANGLE_MOVING:
+        default:
+          if (! (clamped_sides & CLAMPED_BOTTOM))
+            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
+          else if (! (clamped_sides & CLAMPED_RIGHT))
+            side_to_resize = SIDE_TO_RESIZE_RIGHT;
+          else if (! (clamped_sides & CLAMPED_TOP))
+            side_to_resize = SIDE_TO_RESIZE_TOP;
+          else if (! (clamped_sides & CLAMPED_LEFT))
+            side_to_resize = SIDE_TO_RESIZE_LEFT;
+          break;
+        }
+    }
+
+  /* We now know what side(s) we should resize, so now we just solve
+   * the aspect equation for that side(s).
+   */
+  switch (side_to_resize)
+    {
+    case SIDE_TO_RESIZE_NONE:
+      return;
+
+    case SIDE_TO_RESIZE_LEFT:
+      private->x1 = private->x2 - aspect * current_h;
+      break;
+
+    case SIDE_TO_RESIZE_RIGHT:
+      private->x2 = private->x1 + aspect * current_h;
+      break;
+
+    case SIDE_TO_RESIZE_TOP:
+      private->y1 = private->y2 - current_w / aspect;
+      break;
+
+    case SIDE_TO_RESIZE_BOTTOM:
+      private->y2 = private->y1 + current_w / aspect;
+      break;
+
+    case SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY:
+      {
+        gdouble correct_h = current_w / aspect;
+
+        private->y1 = private->center_y_on_fixed_center - correct_h / 2;
+        private->y2 = private->y1 + correct_h;
+      }
+      break;
+
+    case SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY:
+      {
+        gdouble correct_w = current_h * aspect;
+
+        private->x1 = private->center_x_on_fixed_center - correct_w / 2;
+        private->x2 = private->x1 + correct_w;
+      }
+      break;
+    }
+}
+
+/**
+ * gimp_tool_rectangle_update_with_coord:
+ * @rectangle:      A #GimpToolRectangle.
+ * @new_x:          New X-coordinate in the context of the current function.
+ * @new_y:          New Y-coordinate in the context of the current function.
+ *
+ * The core rectangle adjustment function. It updates the rectangle
+ * for the passed cursor coordinate, taking current function and tool
+ * options into account.  It also updates the current
+ * private->function if necessary.
+ */
+static void
+gimp_tool_rectangle_update_with_coord (GimpToolRectangle *rectangle,
+                                       gdouble            new_x,
+                                       gdouble            new_y)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  /* Move the corner or edge the user currently has grabbed. */
+  gimp_tool_rectangle_apply_coord (rectangle, new_x, new_y);
+
+  /* Update private->function. The function changes if the user
+   * "flips" the rectangle.
+   */
+  gimp_tool_rectangle_check_function (rectangle);
+
+  /* Clamp the rectangle if necessary */
+  gimp_tool_rectangle_handle_general_clamping (rectangle);
+
+  /* If the rectangle is being moved, do not run through any further
+   * rectangle adjusting functions since it's shape should not change
+   * then.
+   */
+  if (private->function != GIMP_TOOL_RECTANGLE_MOVING)
+    {
+      gimp_tool_rectangle_apply_fixed_rule (rectangle);
+    }
+
+  gimp_tool_rectangle_update_int_rect (rectangle);
+}
+
+static void
+gimp_tool_rectangle_apply_fixed_rule (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate    *private = rectangle->private;
+  GimpRectangleConstraint      constraint_to_use;
+  GimpDisplayShell            *shell;
+  GimpImage                   *image;
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+  image = gimp_display_get_image (shell->display);
+
+  /* Calculate what constraint to use when needed. */
+  constraint_to_use = gimp_tool_rectangle_get_constraint (rectangle);
+
+  if (private->fixed_rule_active &&
+      private->fixed_rule == GIMP_RECTANGLE_FIXED_ASPECT)
+    {
+      gdouble aspect;
+
+      aspect = CLAMP (private->aspect_numerator /
+                      private->aspect_denominator,
+                      1.0 / gimp_image_get_height (image),
+                      gimp_image_get_width (image));
+
+      if (constraint_to_use == GIMP_RECTANGLE_CONSTRAIN_NONE)
+        {
+          gimp_tool_rectangle_apply_aspect (rectangle,
+                                            aspect,
+                                            CLAMPED_NONE);
+        }
+      else
+        {
+          if (private->function != GIMP_TOOL_RECTANGLE_MOVING)
+            {
+              ClampedSide clamped_sides = CLAMPED_NONE;
+
+              gimp_tool_rectangle_apply_aspect (rectangle,
+                                                aspect,
+                                                clamped_sides);
+
+              /* After we have applied aspect, we might have taken the
+               * rectangle outside of constraint, so clamp and apply
+               * aspect again. We will get the right result this time,
+               * since 'clamped_sides' will be setup correctly now.
+               */
+              gimp_tool_rectangle_clamp (rectangle,
+                                         &clamped_sides,
+                                         constraint_to_use,
+                                         private->fixed_center);
+
+              gimp_tool_rectangle_apply_aspect (rectangle,
+                                                aspect,
+                                                clamped_sides);
+            }
+          else
+            {
+              gimp_tool_rectangle_apply_aspect (rectangle,
+                                                aspect,
+                                                CLAMPED_NONE);
+
+              gimp_tool_rectangle_keep_inside (rectangle,
+                                               constraint_to_use);
+            }
+        }
+    }
+  else if (private->fixed_rule_active &&
+           private->fixed_rule == GIMP_RECTANGLE_FIXED_SIZE)
+    {
+      gimp_tool_rectangle_apply_fixed_width (rectangle,
+                                             constraint_to_use,
+                                             private->desired_fixed_size_width);
+      gimp_tool_rectangle_apply_fixed_height (rectangle,
+                                              constraint_to_use,
+                                              private->desired_fixed_size_height);
+    }
+  else if (private->fixed_rule_active &&
+           private->fixed_rule == GIMP_RECTANGLE_FIXED_WIDTH)
+    {
+      gimp_tool_rectangle_apply_fixed_width (rectangle,
+                                             constraint_to_use,
+                                             private->desired_fixed_width);
+    }
+  else if (private->fixed_rule_active &&
+           private->fixed_rule == GIMP_RECTANGLE_FIXED_HEIGHT)
+    {
+      gimp_tool_rectangle_apply_fixed_height (rectangle,
+                                              constraint_to_use,
+                                              private->desired_fixed_height);
+    }
+}
+
+/**
+ * gimp_tool_rectangle_get_constraints:
+ * @rectangle:      A #GimpToolRectangle.
+ * @min_x:
+ * @min_y:
+ * @max_x:
+ * @max_y:          Pointers of where to put constraints. NULL allowed.
+ * @constraint:     Whether to return image or layer constraints.
+ *
+ * Calculates constraint coordinates for image or layer.
+ */
+static void
+gimp_tool_rectangle_get_constraints (GimpToolRectangle       *rectangle,
+                                     gint                    *min_x,
+                                     gint                    *min_y,
+                                     gint                    *max_x,
+                                     gint                    *max_y,
+                                     GimpRectangleConstraint  constraint)
+{
+  GimpDisplayShell *shell;
+  GimpImage        *image;
+  gint              min_x_dummy;
+  gint              min_y_dummy;
+  gint              max_x_dummy;
+  gint              max_y_dummy;
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+  image = gimp_display_get_image (shell->display);
+
+  if (! min_x) min_x = &min_x_dummy;
+  if (! min_y) min_y = &min_y_dummy;
+  if (! max_x) max_x = &max_x_dummy;
+  if (! max_y) max_y = &max_y_dummy;
+
+  *min_x = 0;
+  *min_y = 0;
+  *max_x = 0;
+  *max_y = 0;
+
+  switch (constraint)
+    {
+    case GIMP_RECTANGLE_CONSTRAIN_IMAGE:
+      if (image)
+        {
+          *min_x = 0;
+          *min_y = 0;
+          *max_x = gimp_image_get_width  (image);
+          *max_y = gimp_image_get_height (image);
+        }
+      break;
+
+    case GIMP_RECTANGLE_CONSTRAIN_DRAWABLE:
+      if (image)
+        {
+          GimpItem *item = GIMP_ITEM (gimp_image_get_active_drawable (image));
+
+          if (item)
+            {
+              gimp_item_get_offset (item, min_x, min_y);
+              *max_x = *min_x + gimp_item_get_width  (item);
+              *max_y = *min_y + gimp_item_get_height (item);
+            }
+        }
+      break;
+
+    default:
+      g_warning ("Invalid rectangle constraint.\n");
+      return;
+    }
+}
+
+/**
+ * gimp_tool_rectangle_handle_general_clamping:
+ * @rectangle: A #GimpToolRectangle.
+ *
+ * Make sure that constraints are applied to the rectangle, either by
+ * manually doing it, or by looking at the rectangle tool options and
+ * concluding it will be done later.
+ */
+static void
+gimp_tool_rectangle_handle_general_clamping (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+  GimpRectangleConstraint   constraint;
+
+  constraint = gimp_tool_rectangle_get_constraint (rectangle);
+
+  /* fixed_aspect takes care of clamping by it self, so just return in
+   * case that is in use. Also return if no constraints should be
+   * enforced.
+   */
+  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
+    return;
+
+  if (private->function != GIMP_TOOL_RECTANGLE_MOVING)
+    {
+      gimp_tool_rectangle_clamp (rectangle,
+                                 NULL,
+                                 constraint,
+                                 private->fixed_center);
+    }
+  else
+    {
+      gimp_tool_rectangle_keep_inside (rectangle, constraint);
+    }
+}
+
+/**
+ * gimp_tool_rectangle_update_int_rect:
+ * @rectangle:
+ *
+ * Update integer representation of rectangle.
+ **/
+static void
+gimp_tool_rectangle_update_int_rect (GimpToolRectangle *rectangle)
+{
+  GimpToolRectanglePrivate *private = rectangle->private;
+
+  private->x1_int = SIGNED_ROUND (private->x1);
+  private->y1_int = SIGNED_ROUND (private->y1);
+
+  if (gimp_tool_rectangle_rect_rubber_banding_func (rectangle))
+    {
+      private->width_int  = (gint) SIGNED_ROUND (private->x2) - private->x1_int;
+      private->height_int = (gint) SIGNED_ROUND (private->y2) - private->y1_int;
+    }
+}
+
+/**
+ * gimp_tool_rectangle_adjust_coord:
+ * @rectangle:
+ * @ccoord_x_input:
+ * @ccoord_x_input:
+ * @ccoord_x_output:
+ * @ccoord_x_output:
+ *
+ * Transforms a coordinate to better fit the public behaviour of the
+ * rectangle.
+ */
+static void
+gimp_tool_rectangle_adjust_coord (GimpToolRectangle *rectangle,
+                                  gdouble            coord_x_input,
+                                  gdouble            coord_y_input,
+                                  gdouble           *coord_x_output,
+                                  gdouble           *coord_y_output)
+{
+  GimpToolRectanglePrivate *priv = rectangle->private;
+
+  switch (priv->precision)
+    {
+    case GIMP_RECTANGLE_PRECISION_INT:
+      *coord_x_output = RINT (coord_x_input);
+      *coord_y_output = RINT (coord_y_input);
+      break;
+
+    case GIMP_RECTANGLE_PRECISION_DOUBLE:
+    default:
+      *coord_x_output = coord_x_input;
+      *coord_y_output = coord_y_input;
+      break;
+    }
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_rectangle_new (GimpDisplayShell  *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_RECTANGLE,
+                       "shell",      shell,
+                       NULL);
+}
+
+GimpRectangleFunction
+gimp_tool_rectangle_get_function (GimpToolRectangle *rectangle)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle),
+                        GIMP_TOOL_RECTANGLE_DEAD);
+
+  return rectangle->private->function;
+}
+
+void
+gimp_tool_rectangle_set_function (GimpToolRectangle     *rectangle,
+                                  GimpRectangleFunction  function)
+{
+  GimpToolRectanglePrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
+
+  private = rectangle->private;
+
+  if (private->function != function)
+    {
+      private->function = function;
+
+      gimp_tool_rectangle_changed (GIMP_TOOL_WIDGET (rectangle));
+    }
+}
+
+void
+gimp_tool_rectangle_set_constraint (GimpToolRectangle       *rectangle,
+                                    GimpRectangleConstraint  constraint)
+{
+  GimpToolRectanglePrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
+
+  private = rectangle->private;
+
+  if (constraint != private->constraint)
+    {
+      g_object_freeze_notify (G_OBJECT (rectangle));
+
+      private->constraint = constraint;
+      g_object_notify (G_OBJECT (rectangle), "constraint");
+
+      gimp_tool_rectangle_clamp (rectangle, NULL, constraint, FALSE);
+
+      g_object_thaw_notify (G_OBJECT (rectangle));
+
+      gimp_tool_rectangle_change_complete (rectangle);
+    }
+}
+
+GimpRectangleConstraint
+gimp_tool_rectangle_get_constraint (GimpToolRectangle *rectangle)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), 0);
+
+  return rectangle->private->constraint;
+}
+
+/**
+ * gimp_tool_rectangle_get_public_rect:
+ * @rectangle:
+ * @x1:
+ * @y1:
+ * @x2:
+ * @y2:
+ *
+ * This function returns the rectangle as it appears to be publicly
+ * (based on integer or double precision-mode).
+ **/
+void
+gimp_tool_rectangle_get_public_rect (GimpToolRectangle *rectangle,
+                                     gdouble           *x1,
+                                     gdouble           *y1,
+                                     gdouble           *x2,
+                                     gdouble           *y2)
+{
+  GimpToolRectanglePrivate *priv;
+
+  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
+  g_return_if_fail (x1 != NULL);
+  g_return_if_fail (y1 != NULL);
+  g_return_if_fail (x2 != NULL);
+  g_return_if_fail (y2 != NULL);
+
+  priv = rectangle->private;
+
+  switch (priv->precision)
+    {
+    case GIMP_RECTANGLE_PRECISION_INT:
+      *x1 = priv->x1_int;
+      *y1 = priv->y1_int;
+      *x2 = priv->x1_int + priv->width_int;
+      *y2 = priv->y1_int + priv->height_int;
+      break;
+
+    case GIMP_RECTANGLE_PRECISION_DOUBLE:
+    default:
+      *x1 = priv->x1;
+      *y1 = priv->y1;
+      *x2 = priv->x2;
+      *y2 = priv->y2;
+      break;
+    }
+}
+
+/**
+ * gimp_tool_rectangle_pending_size_set:
+ * @width_property:  Option property to set to pending rectangle width.
+ * @height_property: Option property to set to pending rectangle height.
+ *
+ * Sets specified rectangle tool options properties to the width and
+ * height of the current pending rectangle.
+ */
+void
+gimp_tool_rectangle_pending_size_set (GimpToolRectangle *rectangle,
+                                      GObject           *object,
+                                      const gchar       *width_property,
+                                      const gchar       *height_property)
+{
+  GimpToolRectanglePrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
+  g_return_if_fail (width_property  != NULL);
+  g_return_if_fail (height_property != NULL);
+
+  private = rectangle->private;
+
+  g_object_set (object,
+                width_property,  MAX (private->x2 - private->x1, 1.0),
+                height_property, MAX (private->y2 - private->y1, 1.0),
+                NULL);
+}
+
+/**
+ * gimp_tool_rectangle_constraint_size_set:
+ * @width_property:  Option property to set to current constraint width.
+ * @height_property: Option property to set to current constraint height.
+ *
+ * Sets specified rectangle tool options properties to the width and
+ * height of the current constraint size.
+ */
+void
+gimp_tool_rectangle_constraint_size_set (GimpToolRectangle *rectangle,
+                                         GObject           *object,
+                                         const gchar       *width_property,
+                                         const gchar       *height_property)
+{
+  GimpDisplayShell *shell;
+  GimpContext      *context;
+  GimpImage        *image;
+  gdouble           width;
+  gdouble           height;
+
+  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
+
+  shell   = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+  context = gimp_get_user_context (shell->display->gimp);
+  image   = gimp_context_get_image (context);
+
+  if (! image)
+    {
+      width  = 1.0;
+      height = 1.0;
+    }
+  else
+    {
+      GimpRectangleConstraint constraint;
+
+      constraint = gimp_tool_rectangle_get_constraint (rectangle);
+
+      switch (constraint)
+        {
+        case GIMP_RECTANGLE_CONSTRAIN_DRAWABLE:
+          {
+            GimpItem *item = GIMP_ITEM (gimp_image_get_active_layer (image));
+
+            if (! item)
+              {
+                width  = 1.0;
+                height = 1.0;
+              }
+            else
+              {
+                width  = gimp_item_get_width  (item);
+                height = gimp_item_get_height (item);
+              }
+          }
+          break;
+
+        case GIMP_RECTANGLE_CONSTRAIN_IMAGE:
+        default:
+          {
+            width  = gimp_image_get_width  (image);
+            height = gimp_image_get_height (image);
+          }
+          break;
+        }
+    }
+
+  g_object_set (object,
+                width_property,  width,
+                height_property, height,
+                NULL);
+}
+
+/**
+ * gimp_tool_rectangle_rectangle_is_first:
+ * @rectangle:
+ *
+ * Returns: %TRUE if the user is creating the first rectangle with
+ * this instance from scratch, %FALSE if modifying an existing
+ * rectangle, or creating a new rectangle, discarding the existing
+ * one. This function is only meaningful in _motion and
+ * _button_release.
+ */
+gboolean
+gimp_tool_rectangle_rectangle_is_first (GimpToolRectangle *rectangle)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), FALSE);
+
+  return rectangle->private->is_first;
+}
+
+/**
+ * gimp_tool_rectangle_rectangle_is_new:
+ * @rectangle:
+ *
+ * Returns: %TRUE if the user is creating a new rectangle from
+ * scratch, %FALSE if modifying n previously existing rectangle. This
+ * function is only meaningful in _motion and _button_release.
+ */
+gboolean
+gimp_tool_rectangle_rectangle_is_new (GimpToolRectangle *rectangle)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), FALSE);
+
+  return rectangle->private->is_new;
+}
+
+/**
+ * gimp_tool_rectangle_point_in_rectangle:
+ * @rectangle:
+ * @x:         X-coord of point to test (in image coordinates)
+ * @y:         Y-coord of point to test (in image coordinates)
+ *
+ * Returns: %TRUE if the passed point was within the rectangle
+ **/
+gboolean
+gimp_tool_rectangle_point_in_rectangle (GimpToolRectangle *rectangle,
+                                        gdouble            x,
+                                        gdouble            y)
+{
+  gdouble  x1, y1, x2, y2;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), FALSE);
+
+  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
+
+  return (x >= x1 && x <= x2 &&
+          y >= y1 && y <= y2);
+}
+
+/**
+ * gimp_tool_rectangle_frame_item:
+ * @rectangle: a #GimpToolRectangle interface
+ * @item:      a #GimpItem attached to the image on which a
+ *             rectangle is being shown.
+ *
+ * Convenience function to set the corners of the rectangle to
+ * match the bounds of the specified item.  The rectangle interface
+ * must be active (i.e., showing a rectangle), and the item must be
+ * attached to the image on which the rectangle is active.
+ **/
+void
+gimp_tool_rectangle_frame_item (GimpToolRectangle *rectangle,
+                                GimpItem          *item)
+{
+  GimpDisplayShell *shell;
+  gint              offset_x;
+  gint              offset_y;
+  gint              width;
+  gint              height;
+
+  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
+  g_return_if_fail (GIMP_IS_ITEM (item));
+  g_return_if_fail (gimp_item_is_attached (item));
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+
+  g_return_if_fail (gimp_display_get_image (shell->display) ==
+                    gimp_item_get_image (item));
+
+  width  = gimp_item_get_width  (item);
+  height = gimp_item_get_height (item);
+
+  gimp_item_get_offset (item, &offset_x, &offset_y);
+
+  gimp_tool_rectangle_set_function (rectangle, GIMP_TOOL_RECTANGLE_CREATING);
+
+  g_object_set (rectangle,
+                "x1", (gdouble) offset_x,
+                "y1", (gdouble) offset_y,
+                "x2", (gdouble) (offset_x + width),
+                "y2", (gdouble) (offset_y + height),
+                NULL);
+
+  /* kludge to force handle sizes to update.  This call may be harmful
+   * if this function is ever moved out of the text tool code.
+   */
+  gimp_tool_rectangle_set_constraint (rectangle, GIMP_RECTANGLE_CONSTRAIN_NONE);
+}
+
+void
+gimp_tool_rectangle_auto_shrink (GimpToolRectangle *rectangle,
+                                 gboolean           shrink_merged)
+{
+  GimpToolRectanglePrivate *private;
+  GimpDisplayShell         *shell;
+  GimpImage                *image;
+  GimpPickable             *pickable;
+  gint                      offset_x = 0;
+  gint                      offset_y = 0;
+  gint                      x1, y1;
+  gint                      x2, y2;
+  gint                      shrunk_x;
+  gint                      shrunk_y;
+  gint                      shrunk_width;
+  gint                      shrunk_height;
+
+  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
+
+  private = rectangle->private;
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
+  image = gimp_display_get_image (shell->display);
+
+  if (shrink_merged)
+    {
+      pickable = GIMP_PICKABLE (image);
+
+      x1 = private->x1;
+      y1 = private->y1;
+      x2 = private->x2;
+      y2 = private->y2;
+    }
+  else
+    {
+      pickable = GIMP_PICKABLE (gimp_image_get_active_drawable (image));
+
+      if (! pickable)
+        return;
+
+      gimp_item_get_offset (GIMP_ITEM (pickable), &offset_x, &offset_y);
+
+      x1 = private->x1 - offset_x;
+      y1 = private->y1 - offset_y;
+      x2 = private->x2 - offset_x;
+      y2 = private->y2 - offset_y;
+    }
+
+  switch (gimp_pickable_auto_shrink (pickable,
+                                     x1, y1, x2 - x1, y2 - y1,
+                                     &shrunk_x,
+                                     &shrunk_y,
+                                     &shrunk_width,
+                                     &shrunk_height))
+    {
+    case GIMP_AUTO_SHRINK_SHRINK:
+      {
+        GimpRectangleFunction original_function = private->function;
+
+        private->function = GIMP_TOOL_RECTANGLE_AUTO_SHRINK;
+
+        private->x1 = offset_x + shrunk_x;
+        private->y1 = offset_y + shrunk_y;
+        private->x2 = offset_x + shrunk_x + shrunk_width;
+        private->y2 = offset_y + shrunk_y + shrunk_height;
+
+        gimp_tool_rectangle_update_int_rect (rectangle);
+
+        gimp_tool_rectangle_change_complete (rectangle);
+
+        private->function = original_function;
+
+        gimp_tool_rectangle_update_options (rectangle);
+      }
+      break;
+
+    default:
+      break;
+    }
+}
diff --git a/app/display/gimptoolrectangle.h b/app/display/gimptoolrectangle.h
new file mode 100644
index 0000000..361839a
--- /dev/null
+++ b/app/display/gimptoolrectangle.h
@@ -0,0 +1,124 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolrectangle.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Based on GimpRectangleTool
+ * Copyright (C) 2007 Martin Nordholts
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_RECTANGLE_H__
+#define __GIMP_TOOL_RECTANGLE_H__
+
+
+#include "gimptoolwidget.h"
+
+
+typedef enum
+{
+  GIMP_TOOL_RECTANGLE_DEAD,
+  GIMP_TOOL_RECTANGLE_CREATING,
+  GIMP_TOOL_RECTANGLE_MOVING,
+  GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT,
+  GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT,
+  GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT,
+  GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT,
+  GIMP_TOOL_RECTANGLE_RESIZING_LEFT,
+  GIMP_TOOL_RECTANGLE_RESIZING_RIGHT,
+  GIMP_TOOL_RECTANGLE_RESIZING_TOP,
+  GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM,
+  GIMP_TOOL_RECTANGLE_AUTO_SHRINK,
+  GIMP_TOOL_RECTANGLE_EXECUTING,
+  GIMP_N_TOOL_RECTANGLE_FUNCTIONS
+} GimpRectangleFunction;
+
+
+#define GIMP_TYPE_TOOL_RECTANGLE            (gimp_tool_rectangle_get_type ())
+#define GIMP_TOOL_RECTANGLE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_RECTANGLE, GimpToolRectangle))
+#define GIMP_TOOL_RECTANGLE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_RECTANGLE, GimpToolRectangleClass))
+#define GIMP_IS_TOOL_RECTANGLE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_RECTANGLE))
+#define GIMP_IS_TOOL_RECTANGLE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_RECTANGLE))
+#define GIMP_TOOL_RECTANGLE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_RECTANGLE, GimpToolRectangleClass))
+
+
+typedef struct _GimpToolRectangle        GimpToolRectangle;
+typedef struct _GimpToolRectanglePrivate GimpToolRectanglePrivate;
+typedef struct _GimpToolRectangleClass   GimpToolRectangleClass;
+
+struct _GimpToolRectangle
+{
+  GimpToolWidget            parent_instance;
+
+  GimpToolRectanglePrivate *private;
+};
+
+struct _GimpToolRectangleClass
+{
+  GimpToolWidgetClass  parent_class;
+
+  /*  signals  */
+
+  gboolean (* change_complete) (GimpToolRectangle *rectangle);
+};
+
+
+GType    gimp_tool_rectangle_get_type         (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_rectangle_new      (GimpDisplayShell       *shell);
+
+GimpRectangleFunction
+         gimp_tool_rectangle_get_function     (GimpToolRectangle      *rectangle);
+void     gimp_tool_rectangle_set_function     (GimpToolRectangle      *rectangle,
+                                               GimpRectangleFunction   function);
+
+void     gimp_tool_rectangle_set_constraint   (GimpToolRectangle      *rectangle,
+                                               GimpRectangleConstraint constraint);
+GimpRectangleConstraint
+         gimp_tool_rectangle_get_constraint   (GimpToolRectangle      *rectangle);
+
+void     gimp_tool_rectangle_get_public_rect  (GimpToolRectangle      *rectangle,
+                                               gdouble                *pub_x1,
+                                               gdouble                *pub_y1,
+                                               gdouble                *pub_x2,
+                                               gdouble                *pub_y2);
+
+void     gimp_tool_rectangle_pending_size_set (GimpToolRectangle      *rectangle,
+                                               GObject                *object,
+                                               const gchar            *width_property,
+                                               const gchar            *height_property);
+
+void     gimp_tool_rectangle_constraint_size_set
+                                              (GimpToolRectangle      *rectangle,
+                                               GObject                *object,
+                                               const gchar            *width_property,
+                                               const gchar            *height_property);
+
+gboolean gimp_tool_rectangle_rectangle_is_first
+                                              (GimpToolRectangle      *rectangle);
+gboolean gimp_tool_rectangle_rectangle_is_new (GimpToolRectangle      *rectangle);
+gboolean gimp_tool_rectangle_point_in_rectangle
+                                              (GimpToolRectangle      *rectangle,
+                                               gdouble                 x,
+                                               gdouble                 y);
+
+void     gimp_tool_rectangle_frame_item       (GimpToolRectangle      *rectangle,
+                                               GimpItem               *item);
+void     gimp_tool_rectangle_auto_shrink      (GimpToolRectangle      *rectrectangle,
+                                               gboolean                shrink_merged);
+
+
+#endif /* __GIMP_TOOL_RECTANGLE_H__ */
diff --git a/app/display/gimptoolrotategrid.c b/app/display/gimptoolrotategrid.c
new file mode 100644
index 0000000..c583490
--- /dev/null
+++ b/app/display/gimptoolrotategrid.c
@@ -0,0 +1,330 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolrotategrid.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-transform-utils.h"
+#include "core/gimp-utils.h"
+
+#include "gimpdisplayshell.h"
+#include "gimptoolrotategrid.h"
+
+#include "gimp-intl.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_ANGLE
+};
+
+
+struct _GimpToolRotateGridPrivate
+{
+  gdouble  angle;
+
+  gboolean rotate_grab;
+  gdouble  real_angle;
+  gdouble  last_x;
+  gdouble  last_y;
+};
+
+
+/*  local function prototypes  */
+
+static void   gimp_tool_rotate_grid_set_property (GObject             *object,
+                                                  guint                property_id,
+                                                  const GValue        *value,
+                                                  GParamSpec          *pspec);
+static void   gimp_tool_rotate_grid_get_property (GObject             *object,
+                                                  guint                property_id,
+                                                  GValue              *value,
+                                                  GParamSpec          *pspec);
+
+static gint   gimp_tool_rotate_grid_button_press (GimpToolWidget      *widget,
+                                                  const GimpCoords    *coords,
+                                                  guint32              time,
+                                                  GdkModifierType      state,
+                                                  GimpButtonPressType  press_type);
+static void   gimp_tool_rotate_grid_motion       (GimpToolWidget      *widget,
+                                                  const GimpCoords    *coords,
+                                                  guint32              time,
+                                                  GdkModifierType      state);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolRotateGrid, gimp_tool_rotate_grid,
+                            GIMP_TYPE_TOOL_TRANSFORM_GRID)
+
+#define parent_class gimp_tool_rotate_grid_parent_class
+
+
+static void
+gimp_tool_rotate_grid_class_init (GimpToolRotateGridClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->set_property    = gimp_tool_rotate_grid_set_property;
+  object_class->get_property    = gimp_tool_rotate_grid_get_property;
+
+  widget_class->button_press    = gimp_tool_rotate_grid_button_press;
+  widget_class->motion          = gimp_tool_rotate_grid_motion;
+
+  g_object_class_install_property (object_class, PROP_ANGLE,
+                                   g_param_spec_double ("angle",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_rotate_grid_init (GimpToolRotateGrid *grid)
+{
+  grid->private = gimp_tool_rotate_grid_get_instance_private (grid);
+}
+
+static void
+gimp_tool_rotate_grid_set_property (GObject      *object,
+                                    guint         property_id,
+                                    const GValue *value,
+                                    GParamSpec   *pspec)
+{
+  GimpToolRotateGrid        *grid    = GIMP_TOOL_ROTATE_GRID (object);
+  GimpToolRotateGridPrivate *private = grid->private;
+
+  switch (property_id)
+    {
+    case PROP_ANGLE:
+      private->angle = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_rotate_grid_get_property (GObject    *object,
+                                    guint       property_id,
+                                    GValue     *value,
+                                    GParamSpec *pspec)
+{
+  GimpToolRotateGrid        *grid    = GIMP_TOOL_ROTATE_GRID (object);
+  GimpToolRotateGridPrivate *private = grid->private;
+
+  switch (property_id)
+    {
+    case PROP_ANGLE:
+      g_value_set_double (value, private->angle);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static gint
+gimp_tool_rotate_grid_button_press (GimpToolWidget      *widget,
+                                    const GimpCoords    *coords,
+                                    guint32              time,
+                                    GdkModifierType      state,
+                                    GimpButtonPressType  press_type)
+{
+  GimpToolRotateGrid        *grid    = GIMP_TOOL_ROTATE_GRID (widget);
+  GimpToolRotateGridPrivate *private = grid->private;
+  GimpTransformHandle        handle;
+
+  handle = GIMP_TOOL_WIDGET_CLASS (parent_class)->button_press (widget,
+                                                                coords, time,
+                                                                state,
+                                                                press_type);
+
+  if (handle == GIMP_TRANSFORM_HANDLE_ROTATION)
+    {
+      private->rotate_grab = TRUE;
+      private->real_angle  = private->angle;
+      private->last_x      = coords->x;
+      private->last_y      = coords->y;
+    }
+  else
+    {
+      private->rotate_grab = FALSE;
+    }
+
+  return handle;
+}
+
+void
+gimp_tool_rotate_grid_motion (GimpToolWidget   *widget,
+                              const GimpCoords *coords,
+                              guint32           time,
+                              GdkModifierType   state)
+{
+  GimpToolRotateGrid        *grid    = GIMP_TOOL_ROTATE_GRID (widget);
+  GimpToolRotateGridPrivate *private = grid->private;
+  gdouble                    angle1, angle2, angle;
+  gdouble                    pivot_x, pivot_y;
+  gdouble                    x1, y1, x2, y2;
+  gboolean                   constrain;
+  GimpMatrix3                transform;
+
+  if (! private->rotate_grab)
+    {
+      gdouble old_pivot_x;
+      gdouble old_pivot_y;
+
+      g_object_get (widget,
+                    "pivot-x", &old_pivot_x,
+                    "pivot-y", &old_pivot_y,
+                    NULL);
+
+      g_object_freeze_notify (G_OBJECT (widget));
+
+      GIMP_TOOL_WIDGET_CLASS (parent_class)->motion (widget,
+                                                     coords, time, state);
+
+      g_object_get (widget,
+                    "pivot-x", &pivot_x,
+                    "pivot-y", &pivot_y,
+                    NULL);
+
+      if (old_pivot_x != pivot_x ||
+          old_pivot_y != pivot_y)
+        {
+          gimp_matrix3_identity (&transform);
+          gimp_transform_matrix_rotate_center (&transform,
+                                               pivot_x, pivot_y,
+                                               private->angle);
+
+          g_object_set (widget,
+                        "transform", &transform,
+                        NULL);
+       }
+
+      g_object_thaw_notify (G_OBJECT (widget));
+
+      return;
+    }
+
+  g_object_get (widget,
+                "pivot-x",          &pivot_x,
+                "pivot-y",          &pivot_y,
+                "constrain-rotate", &constrain,
+                NULL);
+
+  x1 = coords->x       - pivot_x;
+  x2 = private->last_x - pivot_x;
+  y1 = pivot_y - coords->y;
+  y2 = pivot_y - private->last_y;
+
+  /*  find the first angle  */
+  angle1 = atan2 (y1, x1);
+
+  /*  find the angle  */
+  angle2 = atan2 (y2, x2);
+
+  angle = angle2 - angle1;
+
+  if (angle > G_PI || angle < -G_PI)
+    angle = angle2 - ((angle1 < 0) ? 2.0 * G_PI + angle1 : angle1 - 2.0 * G_PI);
+
+  /*  increment the transform tool's angle  */
+  private->real_angle += angle;
+
+  /*  limit the angle to between -180 and 180 degrees  */
+  if (private->real_angle < - G_PI)
+    {
+      private->real_angle += 2.0 * G_PI;
+    }
+  else if (private->real_angle > G_PI)
+    {
+      private->real_angle -= 2.0 * G_PI;
+    }
+
+  /*  constrain the angle to 15-degree multiples if ctrl is held down  */
+#define FIFTEEN_DEG (G_PI / 12.0)
+
+  if (constrain)
+    {
+      angle = FIFTEEN_DEG * (gint) ((private->real_angle +
+                                     FIFTEEN_DEG / 2.0) / FIFTEEN_DEG);
+    }
+  else
+    {
+      angle = private->real_angle;
+    }
+
+  gimp_matrix3_identity (&transform);
+  gimp_transform_matrix_rotate_center (&transform, pivot_x, pivot_y, angle);
+
+  g_object_set (widget,
+                "transform", &transform,
+                "angle",     angle,
+                NULL);
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_rotate_grid_new (GimpDisplayShell *shell,
+                           gdouble           x1,
+                           gdouble           y1,
+                           gdouble           x2,
+                           gdouble           y2,
+                           gdouble           pivot_x,
+                           gdouble           pivot_y,
+                           gdouble           angle)
+{
+  GimpMatrix3 transform;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  gimp_matrix3_identity (&transform);
+  gimp_transform_matrix_rotate_center (&transform, pivot_x, pivot_y, angle);
+
+  return g_object_new (GIMP_TYPE_TOOL_ROTATE_GRID,
+                       "shell",     shell,
+                       "transform", &transform,
+                       "x1",        x1,
+                       "y1",        y1,
+                       "x2",        x2,
+                       "y2",        y2,
+                       "pivot-x",   pivot_x,
+                       "pivot-y",   pivot_y,
+                       "angle",     angle,
+                       NULL);
+}
diff --git a/app/display/gimptoolrotategrid.h b/app/display/gimptoolrotategrid.h
new file mode 100644
index 0000000..2254c8d
--- /dev/null
+++ b/app/display/gimptoolrotategrid.h
@@ -0,0 +1,65 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolrotategrid.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_ROTATE_GRID_H__
+#define __GIMP_TOOL_ROTATE_GRID_H__
+
+
+#include "gimptooltransformgrid.h"
+
+
+#define GIMP_TYPE_TOOL_ROTATE_GRID            (gimp_tool_rotate_grid_get_type ())
+#define GIMP_TOOL_ROTATE_GRID(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_ROTATE_GRID, GimpToolRotateGrid))
+#define GIMP_TOOL_ROTATE_GRID_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_ROTATE_GRID, GimpToolRotateGridClass))
+#define GIMP_IS_TOOL_ROTATE_GRID(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_ROTATE_GRID))
+#define GIMP_IS_TOOL_ROTATE_GRID_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_ROTATE_GRID))
+#define GIMP_TOOL_ROTATE_GRID_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_ROTATE_GRID, GimpToolRotateGridClass))
+
+
+typedef struct _GimpToolRotateGrid        GimpToolRotateGrid;
+typedef struct _GimpToolRotateGridPrivate GimpToolRotateGridPrivate;
+typedef struct _GimpToolRotateGridClass   GimpToolRotateGridClass;
+
+struct _GimpToolRotateGrid
+{
+  GimpToolTransformGrid      parent_instance;
+
+  GimpToolRotateGridPrivate *private;
+};
+
+struct _GimpToolRotateGridClass
+{
+  GimpToolTransformGridClass  parent_class;
+};
+
+
+GType            gimp_tool_rotate_grid_get_type (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_rotate_grid_new      (GimpDisplayShell  *shell,
+                                                 gdouble            x1,
+                                                 gdouble            y1,
+                                                 gdouble            x2,
+                                                 gdouble            y2,
+                                                 gdouble            pivot_x,
+                                                 gdouble            pivot_y,
+                                                 gdouble            angle);
+
+
+#endif /* __GIMP_TOOL_ROTATE_GRID_H__ */
diff --git a/app/display/gimptoolsheargrid.c b/app/display/gimptoolsheargrid.c
new file mode 100644
index 0000000..878c549
--- /dev/null
+++ b/app/display/gimptoolsheargrid.c
@@ -0,0 +1,360 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolsheargrid.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-transform-utils.h"
+#include "core/gimp-utils.h"
+
+#include "gimpdisplayshell.h"
+#include "gimptoolsheargrid.h"
+
+#include "gimp-intl.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_ORIENTATION,
+  PROP_SHEAR_X,
+  PROP_SHEAR_Y
+};
+
+
+struct _GimpToolShearGridPrivate
+{
+  GimpOrientationType orientation;
+  gdouble             shear_x;
+  gdouble             shear_y;
+
+  gdouble             last_x;
+  gdouble             last_y;
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_shear_grid_set_property (GObject             *object,
+                                                   guint                property_id,
+                                                   const GValue        *value,
+                                                   GParamSpec          *pspec);
+static void     gimp_tool_shear_grid_get_property (GObject             *object,
+                                                   guint                property_id,
+                                                   GValue              *value,
+                                                   GParamSpec          *pspec);
+
+static gint     gimp_tool_shear_grid_button_press (GimpToolWidget      *widget,
+                                                   const GimpCoords    *coords,
+                                                   guint32              time,
+                                                   GdkModifierType      state,
+                                                   GimpButtonPressType  press_type);
+static void     gimp_tool_shear_grid_motion        (GimpToolWidget      *widget,
+                                                    const GimpCoords    *coords,
+                                                    guint32              time,
+                                                    GdkModifierType      state);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolShearGrid, gimp_tool_shear_grid,
+                            GIMP_TYPE_TOOL_TRANSFORM_GRID)
+
+#define parent_class gimp_tool_shear_grid_parent_class
+
+
+static void
+gimp_tool_shear_grid_class_init (GimpToolShearGridClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->set_property    = gimp_tool_shear_grid_set_property;
+  object_class->get_property    = gimp_tool_shear_grid_get_property;
+
+  widget_class->button_press    = gimp_tool_shear_grid_button_press;
+  widget_class->motion          = gimp_tool_shear_grid_motion;
+
+  g_object_class_install_property (object_class, PROP_ORIENTATION,
+                                   g_param_spec_enum ("orientation",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_ORIENTATION_TYPE,
+                                                      GIMP_ORIENTATION_UNKNOWN,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_SHEAR_X,
+                                   g_param_spec_double ("shear-x",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_SHEAR_Y,
+                                   g_param_spec_double ("shear-y",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_shear_grid_init (GimpToolShearGrid *grid)
+{
+  grid->private = gimp_tool_shear_grid_get_instance_private (grid);
+
+  g_object_set (grid,
+                "inside-function",         GIMP_TRANSFORM_FUNCTION_SHEAR,
+                "outside-function",        GIMP_TRANSFORM_FUNCTION_SHEAR,
+                "use-corner-handles",      FALSE,
+                "use-perspective-handles", FALSE,
+                "use-side-handles",        FALSE,
+                "use-shear-handles",       FALSE,
+                "use-center-handle",       FALSE,
+                "use-pivot-handle",        FALSE,
+                NULL);
+}
+
+static void
+gimp_tool_shear_grid_set_property (GObject      *object,
+                                   guint         property_id,
+                                   const GValue *value,
+                                   GParamSpec   *pspec)
+{
+  GimpToolShearGrid        *grid    = GIMP_TOOL_SHEAR_GRID (object);
+  GimpToolShearGridPrivate *private = grid->private;
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      private->orientation = g_value_get_enum (value);
+      break;
+    case PROP_SHEAR_X:
+      private->shear_x = g_value_get_double (value);
+      break;
+    case PROP_SHEAR_Y:
+      private->shear_y = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_shear_grid_get_property (GObject    *object,
+                                   guint       property_id,
+                                   GValue     *value,
+                                   GParamSpec *pspec)
+{
+  GimpToolShearGrid        *grid    = GIMP_TOOL_SHEAR_GRID (object);
+  GimpToolShearGridPrivate *private = grid->private;
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      g_value_set_enum (value, private->orientation);
+      break;
+    case PROP_SHEAR_X:
+      g_value_set_double (value, private->shear_x);
+      break;
+    case PROP_SHEAR_Y:
+      g_value_set_double (value, private->shear_y);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static gint
+gimp_tool_shear_grid_button_press (GimpToolWidget      *widget,
+                                   const GimpCoords    *coords,
+                                   guint32              time,
+                                   GdkModifierType      state,
+                                   GimpButtonPressType  press_type)
+{
+  GimpToolShearGrid        *grid    = GIMP_TOOL_SHEAR_GRID (widget);
+  GimpToolShearGridPrivate *private = grid->private;
+
+  private->last_x = coords->x;
+  private->last_y = coords->y;
+
+  return 1;
+}
+
+void
+gimp_tool_shear_grid_motion (GimpToolWidget   *widget,
+                             const GimpCoords *coords,
+                             guint32           time,
+                             GdkModifierType   state)
+{
+  GimpToolShearGrid        *grid    = GIMP_TOOL_SHEAR_GRID (widget);
+  GimpToolShearGridPrivate *private = grid->private;
+  gdouble                   diffx   = coords->x - private->last_x;
+  gdouble                   diffy   = coords->y - private->last_y;
+  gdouble                   amount  = 0.0;
+  GimpMatrix3               transform;
+  GimpMatrix3              *t;
+  gdouble                   x1, y1;
+  gdouble                   x2, y2;
+  gdouble                   tx1, ty1;
+  gdouble                   tx2, ty2;
+  gdouble                   tx3, ty3;
+  gdouble                   tx4, ty4;
+  gdouble                   current_x;
+  gdouble                   current_y;
+
+  g_object_get (widget,
+                "transform", &t,
+                "x1",        &x1,
+                "y1",        &y1,
+                "x2",        &x2,
+                "y2",        &y2,
+                NULL);
+
+  gimp_matrix3_transform_point (t, x1, y1, &tx1, &ty1);
+  gimp_matrix3_transform_point (t, x2, y1, &tx2, &ty2);
+  gimp_matrix3_transform_point (t, x1, y2, &tx3, &ty3);
+  gimp_matrix3_transform_point (t, x2, y2, &tx4, &ty4);
+
+  g_free (t);
+
+  current_x = coords->x;
+  current_y = coords->y;
+
+  diffx = current_x - private->last_x;
+  diffy = current_y - private->last_y;
+
+  /*  If we haven't yet decided on which way to control shearing
+   *  decide using the maximum differential
+   */
+  if (private->orientation == GIMP_ORIENTATION_UNKNOWN)
+    {
+#define MIN_MOVE 5
+
+      if (ABS (diffx) > MIN_MOVE || ABS (diffy) > MIN_MOVE)
+        {
+          if (ABS (diffx) > ABS (diffy))
+            {
+              private->orientation = GIMP_ORIENTATION_HORIZONTAL;
+              private->shear_x     = 0.0;
+            }
+          else
+            {
+              private->orientation = GIMP_ORIENTATION_VERTICAL;
+              private->shear_y     = 0.0;
+            }
+        }
+      /*  set the current coords to the last ones  */
+      else
+        {
+          current_x = private->last_x;
+          current_y = private->last_y;
+        }
+    }
+
+  /*  if the direction is known, keep track of the magnitude  */
+  if (private->orientation == GIMP_ORIENTATION_HORIZONTAL)
+    {
+      if (current_y > (ty1 + ty3) / 2)
+        private->shear_x += diffx;
+      else
+        private->shear_x -= diffx;
+
+      amount = private->shear_x;
+    }
+  else if (private->orientation == GIMP_ORIENTATION_VERTICAL)
+    {
+      if (current_x > (tx1 + tx2) / 2)
+        private->shear_y += diffy;
+      else
+        private->shear_y -= diffy;
+
+      amount = private->shear_y;
+    }
+
+  gimp_matrix3_identity (&transform);
+  gimp_transform_matrix_shear (&transform,
+                               x1, y1, x2 - x1, y2 - y1,
+                               private->orientation, amount);
+
+  g_object_set (widget,
+                "transform",   &transform,
+                "orientation", private->orientation,
+                "shear-x",     private->shear_x,
+                "shear_y",     private->shear_y,
+                NULL);
+
+  private->last_x = current_x;
+  private->last_y = current_y;
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_shear_grid_new (GimpDisplayShell    *shell,
+                          gdouble              x1,
+                          gdouble              y1,
+                          gdouble              x2,
+                          gdouble              y2,
+                          GimpOrientationType  orientation,
+                          gdouble              shear_x,
+                          gdouble              shear_y)
+{
+  GimpMatrix3 transform;
+  gdouble     amount;
+
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  if (orientation == GIMP_ORIENTATION_HORIZONTAL)
+    amount = shear_x;
+  else
+    amount = shear_y;
+
+  gimp_matrix3_identity (&transform);
+  gimp_transform_matrix_shear (&transform,
+                               x1, y1, x2 - x1, y2 - y1,
+                               orientation, amount);
+
+  return g_object_new (GIMP_TYPE_TOOL_SHEAR_GRID,
+                       "shell",       shell,
+                       "transform",   &transform,
+                       "x1",          x1,
+                       "y1",          y1,
+                       "x2",          x2,
+                       "y2",          y2,
+                       "orientation", orientation,
+                       "shear-x",     shear_x,
+                       "shear-y",     shear_y,
+                       NULL);
+}
diff --git a/app/display/gimptoolsheargrid.h b/app/display/gimptoolsheargrid.h
new file mode 100644
index 0000000..dab96d5
--- /dev/null
+++ b/app/display/gimptoolsheargrid.h
@@ -0,0 +1,65 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolsheargrid.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_SHEAR_GRID_H__
+#define __GIMP_TOOL_SHEAR_GRID_H__
+
+
+#include "gimptooltransformgrid.h"
+
+
+#define GIMP_TYPE_TOOL_SHEAR_GRID            (gimp_tool_shear_grid_get_type ())
+#define GIMP_TOOL_SHEAR_GRID(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_SHEAR_GRID, GimpToolShearGrid))
+#define GIMP_TOOL_SHEAR_GRID_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_SHEAR_GRID, GimpToolShearGridClass))
+#define GIMP_IS_TOOL_SHEAR_GRID(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_SHEAR_GRID))
+#define GIMP_IS_TOOL_SHEAR_GRID_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_SHEAR_GRID))
+#define GIMP_TOOL_SHEAR_GRID_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_SHEAR_GRID, GimpToolShearGridClass))
+
+
+typedef struct _GimpToolShearGrid        GimpToolShearGrid;
+typedef struct _GimpToolShearGridPrivate GimpToolShearGridPrivate;
+typedef struct _GimpToolShearGridClass   GimpToolShearGridClass;
+
+struct _GimpToolShearGrid
+{
+  GimpToolTransformGrid     parent_instance;
+
+  GimpToolShearGridPrivate *private;
+};
+
+struct _GimpToolShearGridClass
+{
+  GimpToolTransformGridClass  parent_class;
+};
+
+
+GType            gimp_tool_shear_grid_get_type (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_shear_grid_new      (GimpDisplayShell    *shell,
+                                                gdouble              x1,
+                                                gdouble              y1,
+                                                gdouble              x2,
+                                                gdouble              y2,
+                                                GimpOrientationType  orientation,
+                                                gdouble              shear_x,
+                                                gdouble              shear_y);
+
+
+#endif /* __GIMP_TOOL_SHEAR_GRID_H__ */
diff --git a/app/display/gimptooltransform3dgrid.c b/app/display/gimptooltransform3dgrid.c
new file mode 100644
index 0000000..06cd955
--- /dev/null
+++ b/app/display/gimptooltransform3dgrid.c
@@ -0,0 +1,1162 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptool3dtransformgrid.c
+ * Copyright (C) 2019 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "core/gimp-transform-3d-utils.h"
+#include "core/gimp-utils.h"
+
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+#include "gimptooltransform3dgrid.h"
+
+#include "gimp-intl.h"
+
+
+#define CONSTRAINT_MIN_DIST   8.0
+#define PIXELS_PER_REVOLUTION 1000
+
+
+enum
+{
+  PROP_0,
+  PROP_MODE,
+  PROP_UNIFIED,
+  PROP_CONSTRAIN_AXIS,
+  PROP_Z_AXIS,
+  PROP_LOCAL_FRAME,
+  PROP_CAMERA_X,
+  PROP_CAMERA_Y,
+  PROP_CAMERA_Z,
+  PROP_OFFSET_X,
+  PROP_OFFSET_Y,
+  PROP_OFFSET_Z,
+  PROP_ROTATION_ORDER,
+  PROP_ANGLE_X,
+  PROP_ANGLE_Y,
+  PROP_ANGLE_Z,
+  PROP_PIVOT_3D_X,
+  PROP_PIVOT_3D_Y,
+  PROP_PIVOT_3D_Z
+};
+
+typedef enum
+{
+  AXIS_NONE,
+  AXIS_X,
+  AXIS_Y
+} Axis;
+
+struct _GimpToolTransform3DGridPrivate
+{
+  GimpTransform3DMode mode;
+  gboolean            unified;
+
+  gboolean            constrain_axis;
+  gboolean            z_axis;
+  gboolean            local_frame;
+
+  gdouble             camera_x;
+  gdouble             camera_y;
+  gdouble             camera_z;
+
+  gdouble             offset_x;
+  gdouble             offset_y;
+  gdouble             offset_z;
+
+  gint                rotation_order;
+  gdouble             angle_x;
+  gdouble             angle_y;
+  gdouble             angle_z;
+
+  gdouble             pivot_x;
+  gdouble             pivot_y;
+  gdouble             pivot_z;
+
+  GimpTransformHandle handle;
+
+  gdouble             orig_x;
+  gdouble             orig_y;
+  gdouble             orig_offset_x;
+  gdouble             orig_offset_y;
+  gdouble             orig_offset_z;
+  GimpMatrix3         orig_transform;
+
+  gdouble             last_x;
+  gdouble             last_y;
+
+  Axis                constrained_axis;
+};
+
+
+/*  local function prototypes  */
+
+static void       gimp_tool_transform_3d_grid_constructed            (GObject                 *object);
+static void       gimp_tool_transform_3d_grid_set_property           (GObject                 *object,
+                                                                      guint                    property_id,
+                                                                      const GValue            *value,
+                                                                      GParamSpec              *pspec);
+static void       gimp_tool_transform_3d_grid_get_property           (GObject                 *object,
+                                                                      guint                    property_id,
+                                                                      GValue                  *value,
+                                                                      GParamSpec              *pspec);
+
+static gint       gimp_tool_transform_3d_grid_button_press           (GimpToolWidget          *widget,
+                                                                      const GimpCoords        *coords,
+                                                                      guint32                  time,
+                                                                      GdkModifierType          state,
+                                                                      GimpButtonPressType      press_type);
+static void       gimp_tool_transform_3d_grid_motion                 (GimpToolWidget          *widget,
+                                                                      const GimpCoords        *coords,
+                                                                      guint32                  time,
+                                                                      GdkModifierType          state);
+static void       gimp_tool_transform_3d_grid_hover                  (GimpToolWidget          *widget,
+                                                                      const GimpCoords        *coords,
+                                                                      GdkModifierType          state,
+                                                                      gboolean                 proximity);
+static void       gimp_tool_transform_3d_grid_hover_modifier         (GimpToolWidget          *widget,
+                                                                      GdkModifierType          key,
+                                                                      gboolean                 press,
+                                                                      GdkModifierType          state);
+static gboolean   gimp_tool_transform_3d_grid_get_cursor              (GimpToolWidget          *widget,
+                                                                      const GimpCoords        *coords,
+                                                                      GdkModifierType          state,
+                                                                      GimpCursorType          *cursor,
+                                                                      GimpToolCursorType      *tool_cursor,
+                                                                      GimpCursorModifier      *modifier);
+
+static void       gimp_tool_transform_3d_grid_update_mode            (GimpToolTransform3DGrid *grid);
+static void       gimp_tool_transform_3d_grid_reset_motion           (GimpToolTransform3DGrid *grid);
+static gboolean   gimp_tool_transform_3d_grid_constrain              (GimpToolTransform3DGrid *grid,
+                                                                      gdouble                  x,
+                                                                      gdouble                  y,
+                                                                      gdouble                  ox,
+                                                                      gdouble                  oy,
+                                                                      gdouble                 *tx,
+                                                                      gdouble                 *ty);
+
+static gboolean   gimp_tool_transform_3d_grid_motion_vanishing_point (GimpToolTransform3DGrid *grid,
+                                                                      gdouble                  x,
+                                                                      gdouble                  y);
+static gboolean   gimp_tool_transform_3d_grid_motion_move            (GimpToolTransform3DGrid *grid,
+                                                                      gdouble                  x,
+                                                                      gdouble                  y);
+static gboolean   gimp_tool_transform_3d_grid_motion_rotate          (GimpToolTransform3DGrid *grid,
+                                                                      gdouble                  x,
+                                                                      gdouble                  y);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolTransform3DGrid, gimp_tool_transform_3d_grid,
+                            GIMP_TYPE_TOOL_TRANSFORM_GRID)
+
+#define parent_class gimp_tool_transform_3d_grid_parent_class
+
+
+static void
+gimp_tool_transform_3d_grid_class_init (GimpToolTransform3DGridClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_transform_3d_grid_constructed;
+  object_class->set_property    = gimp_tool_transform_3d_grid_set_property;
+  object_class->get_property    = gimp_tool_transform_3d_grid_get_property;
+
+  widget_class->button_press    = gimp_tool_transform_3d_grid_button_press;
+  widget_class->motion          = gimp_tool_transform_3d_grid_motion;
+  widget_class->hover           = gimp_tool_transform_3d_grid_hover;
+  widget_class->hover_modifier  = gimp_tool_transform_3d_grid_hover_modifier;
+  widget_class->get_cursor      = gimp_tool_transform_3d_grid_get_cursor;
+
+  g_object_class_install_property (object_class, PROP_MODE,
+                                   g_param_spec_enum ("mode",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_TRANSFORM_3D_MODE,
+                                                      GIMP_TRANSFORM_3D_MODE_CAMERA,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_UNIFIED,
+                                   g_param_spec_boolean ("unified",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CONSTRAIN_AXIS,
+                                   g_param_spec_boolean ("constrain-axis",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Z_AXIS,
+                                   g_param_spec_boolean ("z-axis",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_LOCAL_FRAME,
+                                   g_param_spec_boolean ("local-frame",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CAMERA_X,
+                                   g_param_spec_double ("camera-x",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CAMERA_Y,
+                                   g_param_spec_double ("camera-y",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CAMERA_Z,
+                                   g_param_spec_double ("camera-z",
+                                                        NULL, NULL,
+                                                        -(1.0 / 0.0),
+                                                        1.0 / 0.0,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_OFFSET_X,
+                                   g_param_spec_double ("offset-x",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_OFFSET_Y,
+                                   g_param_spec_double ("offset-y",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_OFFSET_Z,
+                                   g_param_spec_double ("offset-z",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ROTATION_ORDER,
+                                   g_param_spec_int ("rotation-order",
+                                                     NULL, NULL,
+                                                     0, 6, 0,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ANGLE_X,
+                                   g_param_spec_double ("angle-x",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ANGLE_Y,
+                                   g_param_spec_double ("angle-y",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_ANGLE_Z,
+                                   g_param_spec_double ("angle-z",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIVOT_3D_X,
+                                   g_param_spec_double ("pivot-3d-x",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIVOT_3D_Y,
+                                   g_param_spec_double ("pivot-3d-y",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIVOT_3D_Z,
+                                   g_param_spec_double ("pivot-3d-z",
+                                                        NULL, NULL,
+                                                        -G_MAXDOUBLE,
+                                                        G_MAXDOUBLE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_transform_3d_grid_init (GimpToolTransform3DGrid *grid)
+{
+  grid->priv = gimp_tool_transform_3d_grid_get_instance_private (grid);
+}
+
+static void
+gimp_tool_transform_3d_grid_constructed (GObject *object)
+{
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  g_object_set (object,
+                "clip-guides",         TRUE,
+                "dynamic-handle-size", FALSE,
+                NULL);
+}
+
+static void
+gimp_tool_transform_3d_grid_set_property (GObject      *object,
+                                          guint         property_id,
+                                          const GValue *value,
+                                          GParamSpec   *pspec)
+{
+  GimpToolTransform3DGrid        *grid = GIMP_TOOL_TRANSFORM_3D_GRID (object);
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+
+  switch (property_id)
+    {
+    case PROP_MODE:
+      priv->mode = g_value_get_enum (value);
+      gimp_tool_transform_3d_grid_update_mode (grid);
+      break;
+
+    case PROP_UNIFIED:
+      priv->unified = g_value_get_boolean (value);
+      gimp_tool_transform_3d_grid_update_mode (grid);
+      break;
+
+    case PROP_CONSTRAIN_AXIS:
+      priv->constrain_axis = g_value_get_boolean (value);
+      gimp_tool_transform_3d_grid_reset_motion (grid);
+      break;
+    case PROP_Z_AXIS:
+      priv->z_axis = g_value_get_boolean (value);
+      gimp_tool_transform_3d_grid_reset_motion (grid);
+      break;
+    case PROP_LOCAL_FRAME:
+      priv->local_frame = g_value_get_boolean (value);
+      gimp_tool_transform_3d_grid_reset_motion (grid);
+      break;
+
+    case PROP_CAMERA_X:
+      priv->camera_x = g_value_get_double (value);
+      g_object_set (grid,
+                    "pivot-x", priv->camera_x,
+                    NULL);
+      break;
+    case PROP_CAMERA_Y:
+      priv->camera_y = g_value_get_double (value);
+      g_object_set (grid,
+                    "pivot-y", priv->camera_y,
+                    NULL);
+      break;
+    case PROP_CAMERA_Z:
+      priv->camera_z = g_value_get_double (value);
+      break;
+
+    case PROP_OFFSET_X:
+      priv->offset_x = g_value_get_double (value);
+      break;
+    case PROP_OFFSET_Y:
+      priv->offset_y = g_value_get_double (value);
+      break;
+    case PROP_OFFSET_Z:
+      priv->offset_z = g_value_get_double (value);
+      break;
+
+    case PROP_ROTATION_ORDER:
+      priv->rotation_order = g_value_get_int (value);
+      break;
+    case PROP_ANGLE_X:
+      priv->angle_x = g_value_get_double (value);
+      break;
+    case PROP_ANGLE_Y:
+      priv->angle_y = g_value_get_double (value);
+      break;
+    case PROP_ANGLE_Z:
+      priv->angle_z = g_value_get_double (value);
+      break;
+
+    case PROP_PIVOT_3D_X:
+      priv->pivot_x = g_value_get_double (value);
+      break;
+    case PROP_PIVOT_3D_Y:
+      priv->pivot_y = g_value_get_double (value);
+      break;
+    case PROP_PIVOT_3D_Z:
+      priv->pivot_z = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_transform_3d_grid_get_property (GObject    *object,
+                                          guint       property_id,
+                                          GValue     *value,
+                                          GParamSpec *pspec)
+{
+  GimpToolTransform3DGrid        *grid = GIMP_TOOL_TRANSFORM_3D_GRID (object);
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+
+  switch (property_id)
+    {
+    case PROP_MODE:
+      g_value_set_enum (value, priv->mode);
+      break;
+    case PROP_UNIFIED:
+      g_value_set_boolean (value, priv->unified);
+      break;
+
+    case PROP_CONSTRAIN_AXIS:
+      g_value_set_boolean (value, priv->constrain_axis);
+      break;
+    case PROP_Z_AXIS:
+      g_value_set_boolean (value, priv->z_axis);
+      break;
+    case PROP_LOCAL_FRAME:
+      g_value_set_boolean (value, priv->local_frame);
+      break;
+
+    case PROP_CAMERA_X:
+      g_value_set_double (value, priv->camera_x);
+      break;
+    case PROP_CAMERA_Y:
+      g_value_set_double (value, priv->camera_y);
+      break;
+    case PROP_CAMERA_Z:
+      g_value_set_double (value, priv->camera_z);
+      break;
+
+    case PROP_OFFSET_X:
+      g_value_set_double (value, priv->offset_x);
+      break;
+    case PROP_OFFSET_Y:
+      g_value_set_double (value, priv->offset_y);
+      break;
+    case PROP_OFFSET_Z:
+      g_value_set_double (value, priv->offset_z);
+      break;
+
+    case PROP_ROTATION_ORDER:
+      g_value_set_int (value, priv->rotation_order);
+      break;
+    case PROP_ANGLE_X:
+      g_value_set_double (value, priv->angle_x);
+      break;
+    case PROP_ANGLE_Y:
+      g_value_set_double (value, priv->angle_y);
+      break;
+    case PROP_ANGLE_Z:
+      g_value_set_double (value, priv->angle_z);
+      break;
+
+    case PROP_PIVOT_3D_X:
+      g_value_set_double (value, priv->pivot_x);
+      break;
+    case PROP_PIVOT_3D_Y:
+      g_value_set_double (value, priv->pivot_y);
+      break;
+    case PROP_PIVOT_3D_Z:
+      g_value_set_double (value, priv->pivot_z);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static gint
+gimp_tool_transform_3d_grid_button_press (GimpToolWidget      *widget,
+                                          const GimpCoords    *coords,
+                                          guint32              time,
+                                          GdkModifierType      state,
+                                          GimpButtonPressType  press_type)
+{
+  GimpToolTransform3DGrid        *grid = GIMP_TOOL_TRANSFORM_3D_GRID (widget);
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+
+  priv->handle = GIMP_TOOL_WIDGET_CLASS (parent_class)->button_press (
+    widget, coords, time, state, press_type);
+
+  priv->orig_x           = coords->x;
+  priv->orig_y           = coords->y;
+  priv->orig_offset_x    = priv->offset_x;
+  priv->orig_offset_y    = priv->offset_y;
+  priv->orig_offset_z    = priv->offset_z;
+  priv->last_x           = coords->x;
+  priv->last_y           = coords->y;
+
+  gimp_tool_transform_3d_grid_reset_motion (grid);
+
+  return priv->handle;
+}
+
+void
+gimp_tool_transform_3d_grid_motion (GimpToolWidget   *widget,
+                                    const GimpCoords *coords,
+                                    guint32           time,
+                                    GdkModifierType   state)
+{
+  GimpToolTransform3DGrid        *grid = GIMP_TOOL_TRANSFORM_3D_GRID (widget);
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+  GimpMatrix3                     transform;
+  gboolean                        update = TRUE;
+
+  switch (priv->handle)
+    {
+    case GIMP_TRANSFORM_HANDLE_PIVOT:
+      update = gimp_tool_transform_3d_grid_motion_vanishing_point (
+        grid, coords->x, coords->y);
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_CENTER:
+      update = gimp_tool_transform_3d_grid_motion_move (
+        grid, coords->x, coords->y);
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_ROTATION:
+      update = gimp_tool_transform_3d_grid_motion_rotate (
+        grid, coords->x, coords->y);
+    break;
+
+    default:
+      g_return_if_reached ();
+    }
+
+  if (update)
+    {
+      gimp_transform_3d_matrix (&transform,
+
+                                priv->camera_x,
+                                priv->camera_y,
+                                priv->camera_z,
+
+                                priv->offset_x,
+                                priv->offset_y,
+                                priv->offset_z,
+
+                                priv->rotation_order,
+                                priv->angle_x,
+                                priv->angle_y,
+                                priv->angle_z,
+
+                                priv->pivot_x,
+                                priv->pivot_y,
+                                priv->pivot_z);
+
+      g_object_set (widget,
+                    "transform", &transform,
+                    NULL);
+    }
+}
+
+static void
+gimp_tool_transform_3d_grid_hover (GimpToolWidget   *widget,
+                                   const GimpCoords *coords,
+                                   GdkModifierType   state,
+                                   gboolean          proximity)
+{
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->hover (widget,
+                                                coords, state, proximity);
+
+  if (proximity &&
+      gimp_tool_transform_grid_get_handle (GIMP_TOOL_TRANSFORM_GRID (widget)) ==
+      GIMP_TRANSFORM_HANDLE_PIVOT)
+    {
+      gimp_tool_widget_set_status (widget,
+                                   _("Click-Drag to move the vanishing point"));
+    }
+}
+
+static void
+gimp_tool_transform_3d_grid_hover_modifier (GimpToolWidget  *widget,
+                                            GdkModifierType  key,
+                                            gboolean         press,
+                                            GdkModifierType  state)
+{
+  GimpToolTransform3DGrid        *grid = GIMP_TOOL_TRANSFORM_3D_GRID (widget);
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->hover_modifier (widget,
+                                                         key, press, state);
+
+  priv->local_frame = (state & gimp_get_extend_selection_mask ()) != 0;
+}
+
+static gboolean
+gimp_tool_transform_3d_grid_get_cursor (GimpToolWidget     *widget,
+                                        const GimpCoords   *coords,
+                                        GdkModifierType     state,
+                                        GimpCursorType     *cursor,
+                                        GimpToolCursorType *tool_cursor,
+                                        GimpCursorModifier *modifier)
+{
+  if (! GIMP_TOOL_WIDGET_CLASS (parent_class)->get_cursor (widget,
+                                                           coords,
+                                                           state,
+                                                           cursor,
+                                                           tool_cursor,
+                                                           modifier))
+    {
+      return FALSE;
+    }
+
+  if (gimp_tool_transform_grid_get_handle (GIMP_TOOL_TRANSFORM_GRID (widget)) ==
+      GIMP_TRANSFORM_HANDLE_PIVOT)
+    {
+      *tool_cursor = GIMP_TOOL_CURSOR_TRANSFORM_3D_CAMERA;
+    }
+
+  return TRUE;
+}
+
+static void
+gimp_tool_transform_3d_grid_update_mode (GimpToolTransform3DGrid *grid)
+{
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+
+  if (priv->unified)
+    {
+      g_object_set (grid,
+                    "inside-function",  GIMP_TRANSFORM_FUNCTION_MOVE,
+                    "outside-function", GIMP_TRANSFORM_FUNCTION_ROTATE,
+                    "use-pivot-handle", TRUE,
+                    NULL);
+    }
+  else
+    {
+      switch (priv->mode)
+        {
+        case GIMP_TRANSFORM_3D_MODE_CAMERA:
+          g_object_set (grid,
+                        "inside-function",  GIMP_TRANSFORM_FUNCTION_NONE,
+                        "outside-function", GIMP_TRANSFORM_FUNCTION_NONE,
+                        "use-pivot-handle", TRUE,
+                        NULL);
+          break;
+
+        case GIMP_TRANSFORM_3D_MODE_MOVE:
+          g_object_set (grid,
+                        "inside-function",  GIMP_TRANSFORM_FUNCTION_MOVE,
+                        "outside-function", GIMP_TRANSFORM_FUNCTION_MOVE,
+                        "use-pivot-handle", FALSE,
+                        NULL);
+          break;
+
+        case GIMP_TRANSFORM_3D_MODE_ROTATE:
+          g_object_set (grid,
+                        "inside-function",  GIMP_TRANSFORM_FUNCTION_ROTATE,
+                        "outside-function", GIMP_TRANSFORM_FUNCTION_ROTATE,
+                        "use-pivot-handle", FALSE,
+                        NULL);
+          break;
+        }
+    }
+}
+
+static void
+gimp_tool_transform_3d_grid_reset_motion (GimpToolTransform3DGrid *grid)
+{
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+  GimpMatrix3                    *transform;
+
+  priv->constrained_axis = AXIS_NONE;
+
+  g_object_get (grid,
+                "transform", &transform,
+                NULL);
+
+  priv->orig_transform = *transform;
+
+  g_free (transform);
+}
+
+static gboolean
+gimp_tool_transform_3d_grid_constrain (GimpToolTransform3DGrid *grid,
+                                       gdouble                  x,
+                                       gdouble                  y,
+                                       gdouble                  ox,
+                                       gdouble                  oy,
+                                       gdouble                 *tx,
+                                       gdouble                 *ty)
+{
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+
+  if (! priv->constrain_axis)
+    return TRUE;
+
+  if (priv->constrained_axis == AXIS_NONE)
+    {
+      GimpDisplayShell *shell;
+      gdouble           x1, y1;
+      gdouble           x2, y2;
+
+      shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (grid));
+
+      gimp_display_shell_transform_xy_f (shell,
+                                         priv->last_x, priv->last_y,
+                                         &x1,          &y1);
+      gimp_display_shell_transform_xy_f (shell,
+                                         x,            y,
+                                         &x2,          &y2);
+
+      if (hypot (x2 - x1, y2 - y1) < CONSTRAINT_MIN_DIST)
+        return FALSE;
+
+      if (fabs (*tx - ox) >= fabs (*ty - oy))
+        priv->constrained_axis = AXIS_X;
+      else
+        priv->constrained_axis = AXIS_Y;
+    }
+
+  if (priv->constrained_axis == AXIS_X)
+    *ty = oy;
+  else
+    *tx = ox;
+
+  return TRUE;
+}
+
+static gboolean
+gimp_tool_transform_3d_grid_motion_vanishing_point (GimpToolTransform3DGrid *grid,
+                                                    gdouble                  x,
+                                                    gdouble                  y)
+{
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+  GimpCoords                      c    = {};
+  gdouble                         pivot_x;
+  gdouble                         pivot_y;
+
+  if (! gimp_tool_transform_3d_grid_constrain (grid,
+                                               x,            y,
+                                               priv->last_x, priv->last_y,
+                                               &x,           &y))
+    {
+      return FALSE;
+    }
+
+  c.x = x;
+  c.y = y;
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->motion (GIMP_TOOL_WIDGET (grid),
+                                                 &c, 0, 0);
+
+  g_object_get (grid,
+                "pivot-x", &pivot_x,
+                "pivot-y", &pivot_y,
+                NULL);
+
+  g_object_set (grid,
+                "camera-x", pivot_x,
+                "camera-y", pivot_y,
+                NULL);
+
+  priv->last_x = c.x;
+  priv->last_y = c.y;
+
+  return TRUE;
+}
+
+static gboolean
+gimp_tool_transform_3d_grid_motion_move (GimpToolTransform3DGrid *grid,
+                                         gdouble                  x,
+                                         gdouble                  y)
+{
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+  GimpMatrix4                     matrix;
+
+  if (! priv->z_axis)
+    {
+      gdouble x1, y1, z1, w1;
+      gdouble x2, y2, z2, w2;
+
+      if (! priv->local_frame)
+        {
+          gimp_matrix4_identity (&matrix);
+        }
+      else
+        {
+          GimpMatrix3 transform_inv = priv->orig_transform;;
+
+          gimp_matrix3_invert (&transform_inv);
+
+          gimp_transform_3d_matrix3_to_matrix4 (&transform_inv, &matrix, 2);
+        }
+
+      w1 = gimp_matrix4_transform_point (&matrix,
+                                         priv->last_x, priv->last_y, 0.0,
+                                         &x1,          &y1,          &z1);
+      w2 = gimp_matrix4_transform_point (&matrix,
+                                         x,            y,            0.0,
+                                         &x2,          &y2,          &z2);
+
+      if (w1 <= 0.0)
+        return FALSE;
+
+      if (! gimp_tool_transform_3d_grid_constrain (grid,
+                                                   x,   y,
+                                                   x1,  y1,
+                                                   &x2, &y2))
+        {
+          return FALSE;
+        }
+
+      if (priv->local_frame)
+        {
+          gimp_matrix4_identity (&matrix);
+
+          gimp_transform_3d_matrix4_rotate_euler (&matrix,
+                                                  priv->rotation_order,
+                                                  priv->angle_x,
+                                                  priv->angle_y,
+                                                  priv->angle_z,
+                                                  0.0, 0.0, 0.0);
+
+          gimp_matrix4_transform_point (&matrix,
+                                        x1,  y1,  z1,
+                                        &x1, &y1, &z1);
+          gimp_matrix4_transform_point (&matrix,
+                                        x2,  y2,  z2,
+                                        &x2, &y2, &z2);
+        }
+
+      if (w2 > 0.0)
+        {
+          g_object_set (grid,
+                        "offset-x", priv->offset_x + (x2 - x1),
+                        "offset-y", priv->offset_y + (y2 - y1),
+                        "offset-z", priv->offset_z + (z2 - z1),
+                        NULL);
+
+          priv->last_x = x;
+          priv->last_y = y;
+        }
+      else
+        {
+          g_object_set (grid,
+                        "offset-x", priv->orig_offset_x,
+                        "offset-y", priv->orig_offset_y,
+                        "offset-z", priv->orig_offset_z,
+                        NULL);
+
+          priv->last_x = priv->orig_x;
+          priv->last_y = priv->orig_y;
+        }
+    }
+  else
+    {
+      GimpVector3 axis;
+      gdouble     amount;
+
+      if (! priv->local_frame)
+        {
+          axis.x = 0.0;
+          axis.y = 0.0;
+          axis.z = 1.0;
+        }
+      else
+        {
+          gimp_matrix4_identity (&matrix);
+
+          gimp_transform_3d_matrix4_rotate_euler (&matrix,
+                                                  priv->rotation_order,
+                                                  priv->angle_x,
+                                                  priv->angle_y,
+                                                  priv->angle_z,
+                                                  0.0, 0.0, 0.0);
+
+          axis.x = matrix.coeff[0][2];
+          axis.y = matrix.coeff[1][2];
+          axis.z = matrix.coeff[2][2];
+
+          if (axis.x < 0.0)
+            gimp_vector3_neg (&axis);
+        }
+
+      amount = x - priv->last_x;
+
+      g_object_set (grid,
+                    "offset-x", priv->offset_x + axis.x * amount,
+                    "offset-y", priv->offset_y + axis.y * amount,
+                    "offset-z", priv->offset_z + axis.z * amount,
+                    NULL);
+
+      priv->last_x = x;
+      priv->last_y = y;
+    }
+
+  return TRUE;
+}
+
+static gboolean
+gimp_tool_transform_3d_grid_motion_rotate (GimpToolTransform3DGrid *grid,
+                                           gdouble                  x,
+                                           gdouble                  y)
+{
+  GimpToolTransform3DGridPrivate *priv = grid->priv;
+  GimpDisplayShell               *shell;
+  GimpMatrix4                     matrix;
+  GimpMatrix2                     basis_inv;
+  GimpVector3                     omega;
+  gdouble                         z_sign;
+  gboolean                        local_frame;
+
+  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (grid));
+
+  local_frame = priv->local_frame && (priv->constrain_axis || priv->z_axis);
+
+  if (! local_frame)
+    {
+      gimp_matrix2_identity (&basis_inv);
+      z_sign = 1.0;
+    }
+  else
+    {
+      {
+        GimpVector3 o, n, c;
+
+        gimp_matrix4_identity (&matrix);
+
+        gimp_transform_3d_matrix4_rotate_euler (&matrix,
+                                                priv->rotation_order,
+                                                priv->angle_x,
+                                                priv->angle_y,
+                                                priv->angle_z,
+                                                priv->pivot_x,
+                                                priv->pivot_y,
+                                                priv->pivot_z);
+
+        gimp_transform_3d_matrix4_translate (&matrix,
+                                             priv->offset_x,
+                                             priv->offset_y,
+                                             priv->offset_z);
+
+        gimp_matrix4_transform_point (&matrix,
+                                      0.0,  0.0,  0.0,
+                                      &o.x, &o.y, &o.z);
+        gimp_matrix4_transform_point (&matrix,
+                                      0.0,  0.0,  1.0,
+                                      &n.x, &n.y, &n.z);
+
+        c.x = priv->camera_x;
+        c.y = priv->camera_y;
+        c.z = priv->camera_z;
+
+        gimp_vector3_sub (&n, &n, &o);
+        gimp_vector3_sub (&c, &c, &o);
+
+        z_sign = gimp_vector3_inner_product (&c, &n) <= 0.0 ? +1.0 : -1.0;
+      }
+
+      {
+        GimpVector2 o, u, v;
+
+        gimp_matrix3_transform_point (&priv->orig_transform,
+                                      priv->pivot_x, priv->pivot_y,
+                                      &o.x, &o.y);
+        gimp_matrix3_transform_point (&priv->orig_transform,
+                                      priv->pivot_x + 1.0, priv->pivot_y,
+                                      &u.x, &u.y);
+        gimp_matrix3_transform_point (&priv->orig_transform,
+                                      priv->pivot_x, priv->pivot_y + 1.0,
+                                      &v.x, &v.y);
+
+        gimp_vector2_sub (&u, &u, &o);
+        gimp_vector2_sub (&v, &v, &o);
+
+        gimp_vector2_normalize (&u);
+        gimp_vector2_normalize (&v);
+
+        basis_inv.coeff[0][0] = u.x;
+        basis_inv.coeff[1][0] = u.y;
+        basis_inv.coeff[0][1] = v.x;
+        basis_inv.coeff[1][1] = v.y;
+
+        gimp_matrix2_invert (&basis_inv);
+      }
+    }
+
+  if (! priv->z_axis)
+    {
+      GimpVector2 scale;
+      gdouble     norm;
+
+      gimp_matrix2_transform_point (&basis_inv,
+                                    -(y - priv->last_y),
+                                    x - priv->last_x,
+                                    &omega.x, &omega.y);
+
+      omega.z = 0.0;
+
+      if (! gimp_tool_transform_3d_grid_constrain (grid,
+                                                   x,        y,
+                                                   0.0,      0.0,
+                                                   &omega.x, &omega.y))
+        {
+          return FALSE;
+        }
+
+      norm = gimp_vector3_length (&omega);
+
+      if (norm > 0.0)
+        {
+          scale.x = shell->scale_x * omega.y / norm;
+          scale.y = shell->scale_y * omega.x / norm;
+
+          gimp_vector3_mul (&omega, gimp_vector2_length (&scale));
+          gimp_vector3_mul (&omega, 2.0 * G_PI / PIXELS_PER_REVOLUTION);
+        }
+    }
+  else
+    {
+      GimpVector2 o;
+      GimpVector2 v1 = {priv->last_x,  priv->last_y};
+      GimpVector2 v2 = {x,             y};
+
+      g_warn_if_fail (priv->pivot_z == 0.0);
+
+      gimp_matrix3_transform_point (&priv->orig_transform,
+                                    priv->pivot_x, priv->pivot_y,
+                                    &o.x,          &o.y);
+
+      gimp_vector2_sub (&v1, &v1, &o);
+      gimp_vector2_sub (&v2, &v2, &o);
+
+      gimp_vector2_normalize (&v1);
+      gimp_vector2_normalize (&v2);
+
+      omega.x = 0.0;
+      omega.y = 0.0;
+      omega.z = atan2 (gimp_vector2_cross_product (&v1, &v2).y,
+                       gimp_vector2_inner_product (&v1, &v2));
+
+      omega.z *= z_sign;
+    }
+
+  gimp_matrix4_identity (&matrix);
+
+  if (local_frame)
+    gimp_transform_3d_matrix4_rotate (&matrix, &omega);
+
+  gimp_transform_3d_matrix4_rotate_euler (&matrix,
+                                          priv->rotation_order,
+                                          priv->angle_x,
+                                          priv->angle_y,
+                                          priv->angle_z,
+                                          0.0, 0.0, 0.0);
+
+  if (! local_frame)
+    gimp_transform_3d_matrix4_rotate (&matrix, &omega);
+
+  gimp_transform_3d_matrix4_rotate_euler_decompose (&matrix,
+                                                    priv->rotation_order,
+                                                    &priv->angle_x,
+                                                    &priv->angle_y,
+                                                    &priv->angle_z);
+
+  priv->last_x = x;
+  priv->last_y = y;
+
+  g_object_set (grid,
+                "angle-x", priv->angle_x,
+                "angle-y", priv->angle_y,
+                "angle-z", priv->angle_z,
+                NULL);
+
+  return TRUE;
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_transform_3d_grid_new (GimpDisplayShell *shell,
+                                 gdouble           x1,
+                                 gdouble           y1,
+                                 gdouble           x2,
+                                 gdouble           y2,
+                                 gdouble           camera_x,
+                                 gdouble           camera_y,
+                                 gdouble           camera_z)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_TRANSFORM_3D_GRID,
+                       "shell",      shell,
+                       "x1",         x1,
+                       "y1",         y1,
+                       "x2",         x2,
+                       "y2",         y2,
+                       "camera-x",   camera_x,
+                       "camera-y",   camera_y,
+                       "camera-z",   camera_z,
+                       "pivot-3d-x", (x1 + x2) / 2.0,
+                       "pivot-3d-y", (y1 + y2) / 2.0,
+                       "pivot-3d-z", 0.0,
+                       NULL);
+}
diff --git a/app/display/gimptooltransform3dgrid.h b/app/display/gimptooltransform3dgrid.h
new file mode 100644
index 0000000..42ac3ea
--- /dev/null
+++ b/app/display/gimptooltransform3dgrid.h
@@ -0,0 +1,65 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptool3dtransformgrid.h
+ * Copyright (C) 2019 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_TRANSFORM_3D_GRID_H__
+#define __GIMP_TOOL_TRANSFORM_3D_GRID_H__
+
+
+#include "gimptooltransformgrid.h"
+
+
+#define GIMP_TYPE_TOOL_TRANSFORM_3D_GRID            (gimp_tool_transform_3d_grid_get_type ())
+#define GIMP_TOOL_TRANSFORM_3D_GRID(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_TRANSFORM_3D_GRID, GimpToolTransform3DGrid))
+#define GIMP_TOOL_TRANSFORM_3D_GRID_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_TRANSFORM_3D_GRID, GimpToolTransform3DGridClass))
+#define GIMP_IS_TOOL_TRANSFORM_3D_GRID(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_TRANSFORM_3D_GRID))
+#define GIMP_IS_TOOL_TRANSFORM_3D_GRID_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_TRANSFORM_3D_GRID))
+#define GIMP_TOOL_TRANSFORM_3D_GRID_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_TRANSFORM_3D_GRID, GimpToolTransform3DGridClass))
+
+
+typedef struct _GimpToolTransform3DGrid        GimpToolTransform3DGrid;
+typedef struct _GimpToolTransform3DGridPrivate GimpToolTransform3DGridPrivate;
+typedef struct _GimpToolTransform3DGridClass   GimpToolTransform3DGridClass;
+
+struct _GimpToolTransform3DGrid
+{
+  GimpToolTransformGrid     parent_instance;
+
+  GimpToolTransform3DGridPrivate *priv;
+};
+
+struct _GimpToolTransform3DGridClass
+{
+  GimpToolTransformGridClass  parent_class;
+};
+
+
+GType            gimp_tool_transform_3d_grid_get_type (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_transform_3d_grid_new      (GimpDisplayShell    *shell,
+                                                       gdouble              x1,
+                                                       gdouble              y1,
+                                                       gdouble              x2,
+                                                       gdouble              y2,
+                                                       gdouble              camera_x,
+                                                       gdouble              camera_y,
+                                                       gdouble              camera_z);
+
+
+#endif /* __GIMP_TOOL_TRANSFORM_3D_GRID_H__ */
diff --git a/app/display/gimptooltransformgrid.c b/app/display/gimptooltransformgrid.c
new file mode 100644
index 0000000..b186b91
--- /dev/null
+++ b/app/display/gimptooltransformgrid.c
@@ -0,0 +1,2494 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptooltransformgrid.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Based on GimpUnifiedTransformTool
+ * Copyright (C) 2011 Mikael Magnusson <mikachu@src.gnome.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-transform-utils.h"
+#include "core/gimp-utils.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvashandle.h"
+#include "gimpcanvastransformguides.h"
+#include "gimpdisplayshell.h"
+#include "gimptooltransformgrid.h"
+
+#include "gimp-intl.h"
+
+
+#define MIN_HANDLE_SIZE 6
+
+
+enum
+{
+  PROP_0,
+  PROP_TRANSFORM,
+  PROP_X1,
+  PROP_Y1,
+  PROP_X2,
+  PROP_Y2,
+  PROP_PIVOT_X,
+  PROP_PIVOT_Y,
+  PROP_GUIDE_TYPE,
+  PROP_N_GUIDES,
+  PROP_CLIP_GUIDES,
+  PROP_SHOW_GUIDES,
+  PROP_INSIDE_FUNCTION,
+  PROP_OUTSIDE_FUNCTION,
+  PROP_USE_CORNER_HANDLES,
+  PROP_USE_PERSPECTIVE_HANDLES,
+  PROP_USE_SIDE_HANDLES,
+  PROP_USE_SHEAR_HANDLES,
+  PROP_USE_CENTER_HANDLE,
+  PROP_USE_PIVOT_HANDLE,
+  PROP_DYNAMIC_HANDLE_SIZE,
+  PROP_CONSTRAIN_MOVE,
+  PROP_CONSTRAIN_SCALE,
+  PROP_CONSTRAIN_ROTATE,
+  PROP_CONSTRAIN_SHEAR,
+  PROP_CONSTRAIN_PERSPECTIVE,
+  PROP_FROMPIVOT_SCALE,
+  PROP_FROMPIVOT_SHEAR,
+  PROP_FROMPIVOT_PERSPECTIVE,
+  PROP_CORNERSNAP,
+  PROP_FIXEDPIVOT
+};
+
+
+struct _GimpToolTransformGridPrivate
+{
+  GimpMatrix3            transform;
+  gdouble                x1, y1;
+  gdouble                x2, y2;
+  gdouble                pivot_x;
+  gdouble                pivot_y;
+  GimpGuidesType         guide_type;
+  gint                   n_guides;
+  gboolean               clip_guides;
+  gboolean               show_guides;
+  GimpTransformFunction  inside_function;
+  GimpTransformFunction  outside_function;
+  gboolean               use_corner_handles;
+  gboolean               use_perspective_handles;
+  gboolean               use_side_handles;
+  gboolean               use_shear_handles;
+  gboolean               use_center_handle;
+  gboolean               use_pivot_handle;
+  gboolean               dynamic_handle_size;
+  gboolean               constrain_move;
+  gboolean               constrain_scale;
+  gboolean               constrain_rotate;
+  gboolean               constrain_shear;
+  gboolean               constrain_perspective;
+  gboolean               frompivot_scale;
+  gboolean               frompivot_shear;
+  gboolean               frompivot_perspective;
+  gboolean               cornersnap;
+  gboolean               fixedpivot;
+
+  gdouble                curx;         /*  current x coord                    */
+  gdouble                cury;         /*  current y coord                    */
+
+  gdouble                button_down;  /*  is the mouse button pressed        */
+  gdouble                mousex;       /*  x coord where mouse was clicked    */
+  gdouble                mousey;       /*  y coord where mouse was clicked    */
+
+  gdouble                cx, cy;       /*  center point (for moving)          */
+
+  /*  transformed handle coords */
+  gdouble                tx1, ty1;
+  gdouble                tx2, ty2;
+  gdouble                tx3, ty3;
+  gdouble                tx4, ty4;
+  gdouble                tcx, tcy;
+  gdouble                tpx, tpy;
+
+  /*  previous transformed handle coords */
+  gdouble                prev_tx1, prev_ty1;
+  gdouble                prev_tx2, prev_ty2;
+  gdouble                prev_tx3, prev_ty3;
+  gdouble                prev_tx4, prev_ty4;
+  gdouble                prev_tcx, prev_tcy;
+  gdouble                prev_tpx, prev_tpy;
+
+  GimpTransformHandle    handle;        /*  current tool activity              */
+
+  GimpCanvasItem        *guides;
+  GimpCanvasItem        *handles[GIMP_N_TRANSFORM_HANDLES];
+  GimpCanvasItem        *center_items[2];
+  GimpCanvasItem        *pivot_items[2];
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_transform_grid_constructed    (GObject               *object);
+static void     gimp_tool_transform_grid_set_property   (GObject               *object,
+                                                         guint                  property_id,
+                                                         const GValue          *value,
+                                                         GParamSpec            *pspec);
+static void     gimp_tool_transform_grid_get_property   (GObject               *object,
+                                                         guint                  property_id,
+                                                         GValue                *value,
+                                                         GParamSpec            *pspec);
+
+static void     gimp_tool_transform_grid_changed        (GimpToolWidget        *widget);
+static gint     gimp_tool_transform_grid_button_press   (GimpToolWidget        *widget,
+                                                         const GimpCoords      *coords,
+                                                         guint32                time,
+                                                         GdkModifierType        state,
+                                                         GimpButtonPressType    press_type);
+static void     gimp_tool_transform_grid_button_release (GimpToolWidget        *widget,
+                                                         const GimpCoords      *coords,
+                                                         guint32                time,
+                                                         GdkModifierType        state,
+                                                         GimpButtonReleaseType  release_type);
+static void     gimp_tool_transform_grid_motion         (GimpToolWidget        *widget,
+                                                         const GimpCoords      *coords,
+                                                         guint32                time,
+                                                         GdkModifierType        state);
+static GimpHit  gimp_tool_transform_grid_hit            (GimpToolWidget        *widget,
+                                                         const GimpCoords      *coords,
+                                                         GdkModifierType        state,
+                                                         gboolean               proximity);
+static void     gimp_tool_transform_grid_hover          (GimpToolWidget        *widget,
+                                                         const GimpCoords      *coords,
+                                                         GdkModifierType        state,
+                                                         gboolean               proximity);
+static void     gimp_tool_transform_grid_leave_notify   (GimpToolWidget        *widget);
+static void     gimp_tool_transform_grid_hover_modifier (GimpToolWidget        *widget,
+                                                         GdkModifierType        key,
+                                                         gboolean               press,
+                                                         GdkModifierType        state);
+static gboolean gimp_tool_transform_grid_get_cursor     (GimpToolWidget        *widget,
+                                                         const GimpCoords      *coords,
+                                                         GdkModifierType        state,
+                                                         GimpCursorType        *cursor,
+                                                         GimpToolCursorType    *tool_cursor,
+                                                         GimpCursorModifier    *modifier);
+
+static GimpTransformHandle
+                gimp_tool_transform_grid_get_handle_for_coords
+                                                        (GimpToolTransformGrid *grid,
+                                                         const GimpCoords      *coords);
+static void     gimp_tool_transform_grid_update_hilight (GimpToolTransformGrid *grid);
+static void     gimp_tool_transform_grid_update_box     (GimpToolTransformGrid *grid);
+static void     gimp_tool_transform_grid_update_matrix  (GimpToolTransformGrid *grid);
+static void     gimp_tool_transform_grid_calc_handles   (GimpToolTransformGrid *grid,
+                                                         gint                  *handle_w,
+                                                         gint                  *handle_h);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolTransformGrid, gimp_tool_transform_grid,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_transform_grid_parent_class
+
+
+static void
+gimp_tool_transform_grid_class_init (GimpToolTransformGridClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_transform_grid_constructed;
+  object_class->set_property    = gimp_tool_transform_grid_set_property;
+  object_class->get_property    = gimp_tool_transform_grid_get_property;
+
+  widget_class->changed         = gimp_tool_transform_grid_changed;
+  widget_class->button_press    = gimp_tool_transform_grid_button_press;
+  widget_class->button_release  = gimp_tool_transform_grid_button_release;
+  widget_class->motion          = gimp_tool_transform_grid_motion;
+  widget_class->hit             = gimp_tool_transform_grid_hit;
+  widget_class->hover           = gimp_tool_transform_grid_hover;
+  widget_class->leave_notify    = gimp_tool_transform_grid_leave_notify;
+  widget_class->hover_modifier  = gimp_tool_transform_grid_hover_modifier;
+  widget_class->get_cursor      = gimp_tool_transform_grid_get_cursor;
+  widget_class->update_on_scale = TRUE;
+
+  g_object_class_install_property (object_class, PROP_TRANSFORM,
+                                   gimp_param_spec_matrix3 ("transform",
+                                                            NULL, NULL,
+                                                            NULL,
+                                                            GIMP_PARAM_READWRITE |
+                                                            G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X1,
+                                   g_param_spec_double ("x1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y1,
+                                   g_param_spec_double ("y1",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_X2,
+                                   g_param_spec_double ("x2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_Y2,
+                                   g_param_spec_double ("y2",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIVOT_X,
+                                   g_param_spec_double ("pivot-x",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_PIVOT_Y,
+                                   g_param_spec_double ("pivot-y",
+                                                        NULL, NULL,
+                                                        -GIMP_MAX_IMAGE_SIZE,
+                                                        GIMP_MAX_IMAGE_SIZE,
+                                                        0.0,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_GUIDE_TYPE,
+                                   g_param_spec_enum ("guide-type", NULL, NULL,
+                                                      GIMP_TYPE_GUIDES_TYPE,
+                                                      GIMP_GUIDES_NONE,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_N_GUIDES,
+                                   g_param_spec_int ("n-guides", NULL, NULL,
+                                                     1, 128, 4,
+                                                     GIMP_PARAM_READWRITE |
+                                                     G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CLIP_GUIDES,
+                                   g_param_spec_boolean ("clip-guides", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_SHOW_GUIDES,
+                                   g_param_spec_boolean ("show-guides", NULL, NULL,
+                                                         TRUE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_INSIDE_FUNCTION,
+                                   g_param_spec_enum ("inside-function",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_TRANSFORM_FUNCTION,
+                                                      GIMP_TRANSFORM_FUNCTION_MOVE,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_OUTSIDE_FUNCTION,
+                                   g_param_spec_enum ("outside-function",
+                                                      NULL, NULL,
+                                                      GIMP_TYPE_TRANSFORM_FUNCTION,
+                                                      GIMP_TRANSFORM_FUNCTION_ROTATE,
+                                                      GIMP_PARAM_READWRITE |
+                                                      G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_USE_CORNER_HANDLES,
+                                   g_param_spec_boolean ("use-corner-handles",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_USE_PERSPECTIVE_HANDLES,
+                                   g_param_spec_boolean ("use-perspective-handles",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_USE_SIDE_HANDLES,
+                                   g_param_spec_boolean ("use-side-handles",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_USE_SHEAR_HANDLES,
+                                   g_param_spec_boolean ("use-shear-handles",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_USE_CENTER_HANDLE,
+                                   g_param_spec_boolean ("use-center-handle",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_USE_PIVOT_HANDLE,
+                                   g_param_spec_boolean ("use-pivot-handle",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_DYNAMIC_HANDLE_SIZE,
+                                   g_param_spec_boolean ("dynamic-handle-size",
+                                                         NULL, NULL,
+                                                         TRUE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CONSTRAIN_MOVE,
+                                   g_param_spec_boolean ("constrain-move",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CONSTRAIN_SCALE,
+                                   g_param_spec_boolean ("constrain-scale",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CONSTRAIN_ROTATE,
+                                   g_param_spec_boolean ("constrain-rotate",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CONSTRAIN_SHEAR,
+                                   g_param_spec_boolean ("constrain-shear",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CONSTRAIN_PERSPECTIVE,
+                                   g_param_spec_boolean ("constrain-perspective",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FROMPIVOT_SCALE,
+                                   g_param_spec_boolean ("frompivot-scale",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FROMPIVOT_SHEAR,
+                                   g_param_spec_boolean ("frompivot-shear",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FROMPIVOT_PERSPECTIVE,
+                                   g_param_spec_boolean ("frompivot-perspective",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_CORNERSNAP,
+                                   g_param_spec_boolean ("cornersnap",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+
+  g_object_class_install_property (object_class, PROP_FIXEDPIVOT,
+                                   g_param_spec_boolean ("fixedpivot",
+                                                         NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE |
+                                                         G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_tool_transform_grid_init (GimpToolTransformGrid *grid)
+{
+  grid->private = gimp_tool_transform_grid_get_instance_private (grid);
+}
+
+static void
+gimp_tool_transform_grid_constructed (GObject *object)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (object);
+  GimpToolWidget               *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolTransformGridPrivate *private = grid->private;
+  GimpCanvasGroup              *stroke_group;
+  gint                          i;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  private->guides = gimp_tool_widget_add_transform_guides (widget,
+                                                           &private->transform,
+                                                           private->x1,
+                                                           private->y1,
+                                                           private->x2,
+                                                           private->y2,
+                                                           private->guide_type,
+                                                           private->n_guides,
+                                                           private->clip_guides);
+
+  for (i = 0; i < 4; i++)
+    {
+      /*  draw the scale handles  */
+      private->handles[GIMP_TRANSFORM_HANDLE_NW + i] =
+        gimp_tool_widget_add_handle (widget,
+                                     GIMP_HANDLE_SQUARE,
+                                     0, 0, 10, 10,
+                                     GIMP_HANDLE_ANCHOR_CENTER);
+
+      /*  draw the perspective handles  */
+      private->handles[GIMP_TRANSFORM_HANDLE_NW_P + i] =
+        gimp_tool_widget_add_handle (widget,
+                                     GIMP_HANDLE_DIAMOND,
+                                     0, 0, 10, 10,
+                                     GIMP_HANDLE_ANCHOR_CENTER);
+
+      /*  draw the side handles  */
+      private->handles[GIMP_TRANSFORM_HANDLE_N + i] =
+        gimp_tool_widget_add_handle (widget,
+                                     GIMP_HANDLE_SQUARE,
+                                     0, 0, 10, 10,
+                                     GIMP_HANDLE_ANCHOR_CENTER);
+
+      /*  draw the shear handles  */
+      private->handles[GIMP_TRANSFORM_HANDLE_N_S + i] =
+        gimp_tool_widget_add_handle (widget,
+                                     GIMP_HANDLE_FILLED_DIAMOND,
+                                     0, 0, 10, 10,
+                                     GIMP_HANDLE_ANCHOR_CENTER);
+    }
+
+  /*  draw the rotation center axis handle  */
+  stroke_group = gimp_tool_widget_add_stroke_group (widget);
+
+  private->handles[GIMP_TRANSFORM_HANDLE_PIVOT] =
+    GIMP_CANVAS_ITEM (stroke_group);
+
+  gimp_tool_widget_push_group (widget, stroke_group);
+
+  private->pivot_items[0] =
+    gimp_tool_widget_add_handle (widget,
+                                 GIMP_HANDLE_CIRCLE,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+  private->pivot_items[1] =
+    gimp_tool_widget_add_handle (widget,
+                                 GIMP_HANDLE_CROSS,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+  gimp_tool_widget_pop_group (widget);
+
+  /*  draw the center handle  */
+  stroke_group = gimp_tool_widget_add_stroke_group (widget);
+
+  private->handles[GIMP_TRANSFORM_HANDLE_CENTER] =
+    GIMP_CANVAS_ITEM (stroke_group);
+
+  gimp_tool_widget_push_group (widget, stroke_group);
+
+  private->center_items[0] =
+    gimp_tool_widget_add_handle (widget,
+                                 GIMP_HANDLE_SQUARE,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+  private->center_items[1] =
+    gimp_tool_widget_add_handle (widget,
+                                 GIMP_HANDLE_CROSS,
+                                 0, 0, 10, 10,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+
+  gimp_tool_widget_pop_group (widget);
+
+  gimp_tool_transform_grid_changed (widget);
+}
+
+static void
+gimp_tool_transform_grid_set_property (GObject      *object,
+                                       guint         property_id,
+                                       const GValue *value,
+                                       GParamSpec   *pspec)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (object);
+  GimpToolTransformGridPrivate *private = grid->private;
+  gboolean                      box     = FALSE;
+
+  switch (property_id)
+    {
+    case PROP_TRANSFORM:
+      {
+        GimpMatrix3 *transform = g_value_get_boxed (value);
+
+        if (transform)
+          private->transform = *transform;
+        else
+          gimp_matrix3_identity (&private->transform);
+      }
+      break;
+
+    case PROP_X1:
+      private->x1 = g_value_get_double (value);
+      box = TRUE;
+      break;
+    case PROP_Y1:
+      private->y1 = g_value_get_double (value);
+      box = TRUE;
+      break;
+    case PROP_X2:
+      private->x2 = g_value_get_double (value);
+      box = TRUE;
+      break;
+    case PROP_Y2:
+      private->y2 = g_value_get_double (value);
+      box = TRUE;
+      break;
+
+    case PROP_PIVOT_X:
+      private->pivot_x = g_value_get_double (value);
+      break;
+    case PROP_PIVOT_Y:
+      private->pivot_y = g_value_get_double (value);
+      break;
+
+    case PROP_GUIDE_TYPE:
+      private->guide_type = g_value_get_enum (value);
+      break;
+    case PROP_N_GUIDES:
+      private->n_guides = g_value_get_int (value);
+      break;
+    case PROP_CLIP_GUIDES:
+      private->clip_guides = g_value_get_boolean (value);
+      break;
+    case PROP_SHOW_GUIDES:
+      private->show_guides = g_value_get_boolean (value);
+      break;
+
+    case PROP_INSIDE_FUNCTION:
+      private->inside_function = g_value_get_enum (value);
+      break;
+    case PROP_OUTSIDE_FUNCTION:
+      private->outside_function = g_value_get_enum (value);
+      break;
+
+    case PROP_USE_CORNER_HANDLES:
+      private->use_corner_handles = g_value_get_boolean (value);
+      break;
+    case PROP_USE_PERSPECTIVE_HANDLES:
+      private->use_perspective_handles = g_value_get_boolean (value);
+      break;
+    case PROP_USE_SIDE_HANDLES:
+      private->use_side_handles = g_value_get_boolean (value);
+      break;
+    case PROP_USE_SHEAR_HANDLES:
+      private->use_shear_handles = g_value_get_boolean (value);
+      break;
+    case PROP_USE_CENTER_HANDLE:
+      private->use_center_handle = g_value_get_boolean (value);
+      break;
+    case PROP_USE_PIVOT_HANDLE:
+      private->use_pivot_handle = g_value_get_boolean (value);
+      break;
+
+    case PROP_DYNAMIC_HANDLE_SIZE:
+      private->dynamic_handle_size = g_value_get_boolean (value);
+      break;
+
+    case PROP_CONSTRAIN_MOVE:
+      private->constrain_move = g_value_get_boolean (value);
+      break;
+    case PROP_CONSTRAIN_SCALE:
+      private->constrain_scale = g_value_get_boolean (value);
+      break;
+    case PROP_CONSTRAIN_ROTATE:
+      private->constrain_rotate = g_value_get_boolean (value);
+      break;
+    case PROP_CONSTRAIN_SHEAR:
+      private->constrain_shear = g_value_get_boolean (value);
+      break;
+    case PROP_CONSTRAIN_PERSPECTIVE:
+      private->constrain_perspective = g_value_get_boolean (value);
+      break;
+
+    case PROP_FROMPIVOT_SCALE:
+      private->frompivot_scale = g_value_get_boolean (value);
+      break;
+    case PROP_FROMPIVOT_SHEAR:
+      private->frompivot_shear = g_value_get_boolean (value);
+      break;
+    case PROP_FROMPIVOT_PERSPECTIVE:
+      private->frompivot_perspective = g_value_get_boolean (value);
+      break;
+
+    case PROP_CORNERSNAP:
+      private->cornersnap = g_value_get_boolean (value);
+      break;
+    case PROP_FIXEDPIVOT:
+      private->fixedpivot = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+
+  if (box)
+    {
+      private->cx = (private->x1 + private->x2) / 2.0;
+      private->cy = (private->y1 + private->y2) / 2.0;
+    }
+}
+
+static void
+gimp_tool_transform_grid_get_property (GObject    *object,
+                                       guint       property_id,
+                                       GValue     *value,
+                                       GParamSpec *pspec)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (object);
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  switch (property_id)
+    {
+    case PROP_TRANSFORM:
+      g_value_set_boxed (value, &private->transform);
+      break;
+
+    case PROP_X1:
+      g_value_set_double (value, private->x1);
+      break;
+    case PROP_Y1:
+      g_value_set_double (value, private->y1);
+      break;
+    case PROP_X2:
+      g_value_set_double (value, private->x2);
+      break;
+    case PROP_Y2:
+      g_value_set_double (value, private->y2);
+      break;
+
+    case PROP_PIVOT_X:
+      g_value_set_double (value, private->pivot_x);
+      break;
+    case PROP_PIVOT_Y:
+      g_value_set_double (value, private->pivot_y);
+      break;
+
+    case PROP_GUIDE_TYPE:
+      g_value_set_enum (value, private->guide_type);
+      break;
+    case PROP_N_GUIDES:
+      g_value_set_int (value, private->n_guides);
+      break;
+    case PROP_CLIP_GUIDES:
+      g_value_set_boolean (value, private->clip_guides);
+      break;
+    case PROP_SHOW_GUIDES:
+      g_value_set_boolean (value, private->show_guides);
+      break;
+
+    case PROP_INSIDE_FUNCTION:
+      g_value_set_enum (value, private->inside_function);
+      break;
+    case PROP_OUTSIDE_FUNCTION:
+      g_value_set_enum (value, private->outside_function);
+      break;
+
+    case PROP_USE_CORNER_HANDLES:
+      g_value_set_boolean (value, private->use_corner_handles);
+      break;
+    case PROP_USE_PERSPECTIVE_HANDLES:
+      g_value_set_boolean (value, private->use_perspective_handles);
+      break;
+    case PROP_USE_SIDE_HANDLES:
+      g_value_set_boolean (value, private->use_side_handles);
+      break;
+    case PROP_USE_SHEAR_HANDLES:
+      g_value_set_boolean (value, private->use_shear_handles);
+      break;
+    case PROP_USE_CENTER_HANDLE:
+      g_value_set_boolean (value, private->use_center_handle);
+      break;
+    case PROP_USE_PIVOT_HANDLE:
+      g_value_set_boolean (value, private->use_pivot_handle);
+      break;
+
+    case PROP_DYNAMIC_HANDLE_SIZE:
+      g_value_set_boolean (value, private->dynamic_handle_size);
+      break;
+
+    case PROP_CONSTRAIN_MOVE:
+      g_value_set_boolean (value, private->constrain_move);
+      break;
+    case PROP_CONSTRAIN_SCALE:
+      g_value_set_boolean (value, private->constrain_scale);
+      break;
+    case PROP_CONSTRAIN_ROTATE:
+      g_value_set_boolean (value, private->constrain_rotate);
+      break;
+    case PROP_CONSTRAIN_SHEAR:
+      g_value_set_boolean (value, private->constrain_shear);
+      break;
+    case PROP_CONSTRAIN_PERSPECTIVE:
+      g_value_set_boolean (value, private->constrain_perspective);
+      break;
+
+    case PROP_FROMPIVOT_SCALE:
+      g_value_set_boolean (value, private->frompivot_scale);
+      break;
+    case PROP_FROMPIVOT_SHEAR:
+      g_value_set_boolean (value, private->frompivot_shear);
+      break;
+    case PROP_FROMPIVOT_PERSPECTIVE:
+      g_value_set_boolean (value, private->frompivot_perspective);
+      break;
+
+    case PROP_CORNERSNAP:
+      g_value_set_boolean (value, private->cornersnap);
+      break;
+    case PROP_FIXEDPIVOT:
+      g_value_set_boolean (value, private->fixedpivot);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static gboolean
+transform_is_convex (GimpVector2 *pos)
+{
+  return gimp_transform_polygon_is_convex (pos[0].x, pos[0].y,
+                                           pos[1].x, pos[1].y,
+                                           pos[2].x, pos[2].y,
+                                           pos[3].x, pos[3].y);
+}
+
+static gboolean
+transform_grid_is_convex (GimpToolTransformGrid *grid)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  return gimp_transform_polygon_is_convex (private->tx1, private->ty1,
+                                           private->tx2, private->ty2,
+                                           private->tx3, private->ty3,
+                                           private->tx4, private->ty4);
+}
+
+static inline gboolean
+vectorisnull (GimpVector2 v)
+{
+  return ((v.x == 0.0) && (v.y == 0.0));
+}
+
+static inline gdouble
+dotprod (GimpVector2 a,
+         GimpVector2 b)
+{
+  return a.x * b.x + a.y * b.y;
+}
+
+static inline gdouble
+norm (GimpVector2 a)
+{
+  return sqrt (dotprod (a, a));
+}
+
+static inline GimpVector2
+vectorsubtract (GimpVector2 a,
+                GimpVector2 b)
+{
+  GimpVector2 c;
+
+  c.x = a.x - b.x;
+  c.y = a.y - b.y;
+
+  return c;
+}
+
+static inline GimpVector2
+vectoradd (GimpVector2 a,
+           GimpVector2 b)
+{
+  GimpVector2 c;
+
+  c.x = a.x + b.x;
+  c.y = a.y + b.y;
+
+  return c;
+}
+
+static inline GimpVector2
+scalemult (GimpVector2 a,
+           gdouble     b)
+{
+  GimpVector2 c;
+
+  c.x = a.x * b;
+  c.y = a.y * b;
+
+  return c;
+}
+
+static inline GimpVector2
+vectorproject (GimpVector2 a,
+               GimpVector2 b)
+{
+  return scalemult (b, dotprod (a, b) / dotprod (b, b));
+}
+
+/* finds the clockwise angle between the vectors given, 0-2π */
+static inline gdouble
+calcangle (GimpVector2 a,
+           GimpVector2 b)
+{
+  gdouble angle, angle2;
+  gdouble length;
+
+  if (vectorisnull (a) || vectorisnull (b))
+    return 0.0;
+
+  length = norm (a) * norm (b);
+
+  angle = acos (SAFE_CLAMP (dotprod (a, b) / length, -1.0, +1.0));
+  angle2 = b.y;
+  b.y = -b.x;
+  b.x = angle2;
+  angle2 = acos (SAFE_CLAMP (dotprod (a, b) / length, -1.0, +1.0));
+
+  return ((angle2 > G_PI / 2.0) ? angle : 2.0 * G_PI - angle);
+}
+
+static inline GimpVector2
+rotate2d (GimpVector2 p,
+          gdouble     angle)
+{
+  GimpVector2 ret;
+
+  ret.x = cos (angle) * p.x-sin (angle) * p.y;
+  ret.y = sin (angle) * p.x+cos (angle) * p.y;
+
+  return ret;
+}
+
+static inline GimpVector2
+lineintersect (GimpVector2 p1, GimpVector2 p2,
+               GimpVector2 q1, GimpVector2 q2)
+{
+  gdouble     denom, u;
+  GimpVector2 p;
+
+  denom = (q2.y - q1.y) * (p2.x - p1.x) - (q2.x - q1.x) * (p2.y - p1.y);
+  if (denom == 0.0)
+    {
+      p.x = (p1.x + p2.x + q1.x + q2.x) / 4;
+      p.y = (p1.y + p2.y + q1.y + q2.y) / 4;
+    }
+  else
+    {
+      u = (q2.x - q1.x) * (p1.y - q1.y) - (q2.y - q1.y) * (p1.x - q1.x);
+      u /= denom;
+
+      p.x = p1.x + u * (p2.x - p1.x);
+      p.y = p1.y + u * (p2.y - p1.y);
+    }
+
+  return p;
+}
+
+static inline GimpVector2
+get_pivot_delta (GimpToolTransformGrid *grid,
+                 GimpVector2           *oldpos,
+                 GimpVector2           *newpos,
+                 GimpVector2            pivot)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+  GimpMatrix3                   transform_before;
+  GimpMatrix3                   transform_after;
+  GimpVector2                   delta;
+
+  gimp_matrix3_identity (&transform_before);
+  gimp_matrix3_identity (&transform_after);
+
+  gimp_transform_matrix_perspective (&transform_before,
+                                     private->x1,
+                                     private->y1,
+                                     private->x2 - private->x1,
+                                     private->y2 - private->y1,
+                                     oldpos[0].x, oldpos[0].y,
+                                     oldpos[1].x, oldpos[1].y,
+                                     oldpos[2].x, oldpos[2].y,
+                                     oldpos[3].x, oldpos[3].y);
+  gimp_transform_matrix_perspective (&transform_after,
+                                     private->x1,
+                                     private->y1,
+                                     private->x2 - private->x1,
+                                     private->y2 - private->y1,
+                                     newpos[0].x, newpos[0].y,
+                                     newpos[1].x, newpos[1].y,
+                                     newpos[2].x, newpos[2].y,
+                                     newpos[3].x, newpos[3].y);
+  gimp_matrix3_invert (&transform_before);
+  gimp_matrix3_mult (&transform_after, &transform_before);
+  gimp_matrix3_transform_point (&transform_before,
+                                pivot.x, pivot.y, &delta.x, &delta.y);
+
+  delta = vectorsubtract (delta, pivot);
+
+  return delta;
+}
+
+static gboolean
+point_is_inside_polygon (gint     n,
+                         gdouble *x,
+                         gdouble *y,
+                         gdouble  px,
+                         gdouble  py)
+{
+  gint     i, j;
+  gboolean odd = FALSE;
+
+  for (i = 0, j = n - 1; i < n; j = i++)
+    {
+      if ((y[i] < py && y[j] >= py) ||
+          (y[j] < py && y[i] >= py))
+        {
+          if (x[i] + (py - y[i]) / (y[j] - y[i]) * (x[j] - x[i]) < px)
+            odd = !odd;
+        }
+    }
+
+  return odd;
+}
+
+static gboolean
+point_is_inside_polygon_pos (GimpVector2 *pos,
+                             GimpVector2  point)
+{
+  return point_is_inside_polygon (4,
+                                  (gdouble[4]){ pos[0].x, pos[1].x,
+                                                pos[3].x, pos[2].x },
+                                  (gdouble[4]){ pos[0].y, pos[1].y,
+                                                pos[3].y, pos[2].y },
+                                  point.x, point.y);
+}
+
+static void
+get_handle_geometry (GimpToolTransformGrid *grid,
+                     GimpVector2           *position,
+                     gdouble               *angle)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  GimpVector2 o[] = { { .x = private->tx1, .y = private->ty1 },
+                      { .x = private->tx2, .y = private->ty2 },
+                      { .x = private->tx3, .y = private->ty3 },
+                      { .x = private->tx4, .y = private->ty4 } };
+  GimpVector2 right = { .x = 1.0, .y = 0.0 };
+  GimpVector2 up    = { .x = 0.0, .y = 1.0 };
+
+  if (position)
+    {
+      position[0] = o[0];
+      position[1] = o[1];
+      position[2] = o[2];
+      position[3] = o[3];
+    }
+
+  angle[0] = calcangle (vectorsubtract (o[1], o[0]), right);
+  angle[1] = calcangle (vectorsubtract (o[3], o[2]), right);
+  angle[2] = calcangle (vectorsubtract (o[3], o[1]), up);
+  angle[3] = calcangle (vectorsubtract (o[2], o[0]), up);
+
+  angle[4] = (angle[0] + angle[3]) / 2.0;
+  angle[5] = (angle[0] + angle[2]) / 2.0;
+  angle[6] = (angle[1] + angle[3]) / 2.0;
+  angle[7] = (angle[1] + angle[2]) / 2.0;
+
+  angle[8] = (angle[0] + angle[1] + angle[2] + angle[3]) / 4.0;
+}
+
+static void
+gimp_tool_transform_grid_changed (GimpToolWidget *widget)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+  gdouble                       angle[9];
+  GimpVector2                   o[4], t[4];
+  gint                          handle_w;
+  gint                          handle_h;
+  gint                          d, i;
+
+  gimp_tool_transform_grid_update_box (grid);
+
+  gimp_canvas_transform_guides_set (private->guides,
+                                    &private->transform,
+                                    private->x1,
+                                    private->y1,
+                                    private->x2,
+                                    private->y2,
+                                    private->guide_type,
+                                    private->n_guides,
+                                    private->clip_guides);
+  gimp_canvas_item_set_visible (private->guides, private->show_guides);
+
+  get_handle_geometry (grid, o, angle);
+  gimp_tool_transform_grid_calc_handles (grid, &handle_w, &handle_h);
+
+  for (i = 0; i < 4; i++)
+    {
+      GimpCanvasItem *h;
+      gdouble         factor;
+
+      /*  the scale handles  */
+      factor = 1.0;
+      if (private->use_perspective_handles)
+        factor = 1.5;
+
+      h = private->handles[GIMP_TRANSFORM_HANDLE_NW + i];
+      gimp_canvas_item_set_visible (h, private->use_corner_handles);
+
+      if (private->use_corner_handles)
+        {
+          gimp_canvas_handle_set_position (h, o[i].x, o[i].y);
+          gimp_canvas_handle_set_size (h, handle_w * factor, handle_h * factor);
+          gimp_canvas_handle_set_angles (h, angle[i + 4], 0.0);
+        }
+
+      /*  the perspective handles  */
+      factor = 1.0;
+      if (private->use_corner_handles)
+        factor = 0.8;
+
+      h = private->handles[GIMP_TRANSFORM_HANDLE_NW_P + i];
+      gimp_canvas_item_set_visible (h, private->use_perspective_handles);
+
+      if (private->use_perspective_handles)
+        {
+          gimp_canvas_handle_set_position (h, o[i].x, o[i].y);
+          gimp_canvas_handle_set_size (h, handle_w * factor, handle_h * factor);
+          gimp_canvas_handle_set_angles (h, angle[i + 4], 0.0);
+        }
+    }
+
+  /*  draw the side handles  */
+  t[0] = scalemult (vectoradd (o[0], o[1]), 0.5);
+  t[1] = scalemult (vectoradd (o[2], o[3]), 0.5);
+  t[2] = scalemult (vectoradd (o[1], o[3]), 0.5);
+  t[3] = scalemult (vectoradd (o[2], o[0]), 0.5);
+
+  for (i = 0; i < 4; i++)
+    {
+      GimpCanvasItem *h;
+
+      h = private->handles[GIMP_TRANSFORM_HANDLE_N + i];
+      gimp_canvas_item_set_visible (h, private->use_side_handles);
+
+      if (private->use_side_handles)
+        {
+          gimp_canvas_handle_set_position (h, t[i].x, t[i].y);
+          gimp_canvas_handle_set_size (h, handle_w, handle_h);
+          gimp_canvas_handle_set_angles (h, angle[i], 0.0);
+        }
+    }
+
+  /*  draw the shear handles  */
+  t[0] = scalemult (vectoradd (           o[0]      , scalemult (o[1], 3.0)),
+                    0.25);
+  t[1] = scalemult (vectoradd (scalemult (o[2], 3.0),            o[3]      ),
+                    0.25);
+  t[2] = scalemult (vectoradd (           o[1]      , scalemult (o[3], 3.0)),
+                    0.25);
+  t[3] = scalemult (vectoradd (scalemult (o[0], 3.0),            o[2]      ),
+                    0.25);
+
+  for (i = 0; i < 4; i++)
+    {
+      GimpCanvasItem *h;
+
+      h = private->handles[GIMP_TRANSFORM_HANDLE_N_S + i];
+      gimp_canvas_item_set_visible (h, private->use_shear_handles);
+
+      if (private->use_shear_handles)
+        {
+          gimp_canvas_handle_set_position (h, t[i].x, t[i].y);
+          gimp_canvas_handle_set_size (h, handle_w, handle_h);
+          gimp_canvas_handle_set_angles (h, angle[i], 0.0);
+        }
+    }
+
+  d = MIN (handle_w, handle_h);
+  if (private->use_center_handle)
+    d *= 2; /* so you can grab it from under the center handle */
+
+  gimp_canvas_item_set_visible (private->handles[GIMP_TRANSFORM_HANDLE_PIVOT],
+                                private->use_pivot_handle);
+
+  if (private->use_pivot_handle)
+    {
+      gimp_canvas_handle_set_position (private->pivot_items[0],
+                                       private->tpx, private->tpy);
+      gimp_canvas_handle_set_size (private->pivot_items[0], d, d);
+
+      gimp_canvas_handle_set_position (private->pivot_items[1],
+                                       private->tpx, private->tpy);
+      gimp_canvas_handle_set_size (private->pivot_items[1], d, d);
+    }
+
+  d = MIN (handle_w, handle_h);
+
+  gimp_canvas_item_set_visible (private->handles[GIMP_TRANSFORM_HANDLE_CENTER],
+                                private->use_center_handle);
+
+  if (private->use_center_handle)
+    {
+      gimp_canvas_handle_set_position (private->center_items[0],
+                                       private->tcx, private->tcy);
+      gimp_canvas_handle_set_size (private->center_items[0], d, d);
+      gimp_canvas_handle_set_angles (private->center_items[0], angle[8], 0.0);
+
+      gimp_canvas_handle_set_position (private->center_items[1],
+                                       private->tcx, private->tcy);
+      gimp_canvas_handle_set_size (private->center_items[1], d, d);
+      gimp_canvas_handle_set_angles (private->center_items[1], angle[8], 0.0);
+    }
+
+  gimp_tool_transform_grid_update_hilight (grid);
+}
+
+gint
+gimp_tool_transform_grid_button_press (GimpToolWidget      *widget,
+                                       const GimpCoords    *coords,
+                                       guint32              time,
+                                       GdkModifierType      state,
+                                       GimpButtonPressType  press_type)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  private->button_down = TRUE;
+  private->mousex      = coords->x;
+  private->mousey      = coords->y;
+
+  if (private->handle != GIMP_TRANSFORM_HANDLE_NONE)
+    {
+      if (private->handles[private->handle])
+        {
+          GimpCanvasItem *handle;
+          gdouble         x, y;
+
+          switch (private->handle)
+            {
+            case GIMP_TRANSFORM_HANDLE_CENTER:
+              handle = private->center_items[0];
+              break;
+
+            case GIMP_TRANSFORM_HANDLE_PIVOT:
+              handle = private->pivot_items[0];
+              break;
+
+             default:
+              handle = private->handles[private->handle];
+              break;
+            }
+
+          gimp_canvas_handle_get_position (handle, &x, &y);
+
+          gimp_tool_widget_set_snap_offsets (widget,
+                                             SIGNED_ROUND (x - coords->x),
+                                             SIGNED_ROUND (y - coords->y),
+                                             0, 0);
+        }
+      else
+        {
+          gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);
+        }
+
+      private->prev_tx1 = private->tx1;
+      private->prev_ty1 = private->ty1;
+      private->prev_tx2 = private->tx2;
+      private->prev_ty2 = private->ty2;
+      private->prev_tx3 = private->tx3;
+      private->prev_ty3 = private->ty3;
+      private->prev_tx4 = private->tx4;
+      private->prev_ty4 = private->ty4;
+      private->prev_tpx = private->tpx;
+      private->prev_tpy = private->tpy;
+      private->prev_tcx = private->tcx;
+      private->prev_tcy = private->tcy;
+
+      return private->handle;
+    }
+
+  gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);
+
+  return 0;
+}
+
+void
+gimp_tool_transform_grid_button_release (GimpToolWidget        *widget,
+                                         const GimpCoords      *coords,
+                                         guint32                time,
+                                         GdkModifierType        state,
+                                         GimpButtonReleaseType  release_type)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  private->button_down = FALSE;
+}
+
+void
+gimp_tool_transform_grid_motion (GimpToolWidget   *widget,
+                                 const GimpCoords *coords,
+                                 guint32           time,
+                                 GdkModifierType   state)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+  gdouble                      *x[4], *y[4];
+  gdouble                      *newpivot_x, *newpivot_y;
+
+  GimpVector2                  oldpos[5], newpos[4];
+  GimpVector2                  cur   = { .x = coords->x,
+                                         .y = coords->y };
+  GimpVector2                  mouse = { .x = private->mousex,
+                                         .y = private->mousey };
+  GimpVector2                  d;
+  GimpVector2                  pivot;
+
+  gboolean                     fixedpivot = private->fixedpivot;
+  GimpTransformHandle          handle     = private->handle;
+  gint                         i;
+
+  private->curx = coords->x;
+  private->cury = coords->y;
+
+  x[0] = &private->tx1;
+  y[0] = &private->ty1;
+  x[1] = &private->tx2;
+  y[1] = &private->ty2;
+  x[2] = &private->tx3;
+  y[2] = &private->ty3;
+  x[3] = &private->tx4;
+  y[3] = &private->ty4;
+
+  newpos[0].x = oldpos[0].x = private->prev_tx1;
+  newpos[0].y = oldpos[0].y = private->prev_ty1;
+  newpos[1].x = oldpos[1].x = private->prev_tx2;
+  newpos[1].y = oldpos[1].y = private->prev_ty2;
+  newpos[2].x = oldpos[2].x = private->prev_tx3;
+  newpos[2].y = oldpos[2].y = private->prev_ty3;
+  newpos[3].x = oldpos[3].x = private->prev_tx4;
+  newpos[3].y = oldpos[3].y = private->prev_ty4;
+
+  /* put center point in this array too */
+  oldpos[4].x = private->prev_tcx;
+  oldpos[4].y = private->prev_tcy;
+
+  d = vectorsubtract (cur, mouse);
+
+  newpivot_x = &private->tpx;
+  newpivot_y = &private->tpy;
+
+  if (private->use_pivot_handle)
+    {
+      pivot.x = private->prev_tpx;
+      pivot.y = private->prev_tpy;
+    }
+  else
+    {
+      /* when the transform grid doesn't use a pivot handle, use the center
+       * point as the pivot instead.
+       */
+      pivot.x = private->prev_tcx;
+      pivot.y = private->prev_tcy;
+
+      fixedpivot = TRUE;
+    }
+
+  /* move */
+  if (handle == GIMP_TRANSFORM_HANDLE_CENTER)
+    {
+      if (private->constrain_move)
+        {
+          /* snap to 45 degree vectors from starting point */
+          gdouble angle = 16.0 * calcangle ((GimpVector2) { 1.0, 0.0 },
+                                            d) / (2.0 * G_PI);
+          gdouble dist  = norm (d) / sqrt (2);
+
+          if (angle < 1.0 || angle >= 15.0)
+            d.y = 0;
+          else if (angle < 3.0)
+            d.y = -(d.x = dist);
+          else if (angle < 5.0)
+            d.x = 0;
+          else if (angle < 7.0)
+            d.x = d.y = -dist;
+          else if (angle < 9.0)
+            d.y = 0;
+          else if (angle < 11.0)
+            d.x = -(d.y = dist);
+          else if (angle < 13.0)
+            d.x = 0;
+          else if (angle < 15.0)
+            d.x = d.y = dist;
+        }
+
+      for (i = 0; i < 4; i++)
+        newpos[i] = vectoradd (oldpos[i], d);
+    }
+
+  /* rotate */
+  if (handle == GIMP_TRANSFORM_HANDLE_ROTATION)
+    {
+      gdouble angle = calcangle (vectorsubtract (cur, pivot),
+                                 vectorsubtract (mouse, pivot));
+
+      if (private->constrain_rotate)
+        {
+          /* round to 15 degree multiple */
+          angle /= 2 * G_PI / 24.0;
+          angle = round (angle);
+          angle *= 2 * G_PI / 24.0;
+        }
+
+      for (i = 0; i < 4; i++)
+        newpos[i] = vectoradd (pivot,
+                               rotate2d (vectorsubtract (oldpos[i], pivot),
+                                         angle));
+
+      fixedpivot = TRUE;
+    }
+
+  /* move rotation axis */
+  if (handle == GIMP_TRANSFORM_HANDLE_PIVOT)
+    {
+      pivot = vectoradd (pivot, d);
+
+      if (private->cornersnap)
+        {
+          /* snap to corner points and center */
+          gint    closest = 0;
+          gdouble closest_dist = G_MAXDOUBLE, dist;
+
+          for (i = 0; i < 5; i++)
+            {
+              dist = norm (vectorsubtract (pivot, oldpos[i]));
+              if (dist < closest_dist)
+                {
+                  closest_dist = dist;
+                  closest = i;
+                }
+            }
+
+          if (closest_dist *
+              gimp_tool_widget_get_shell (widget)->scale_x < 50)
+            {
+              pivot = oldpos[closest];
+            }
+        }
+
+      fixedpivot = TRUE;
+    }
+
+  /* scaling via corner */
+  if (handle == GIMP_TRANSFORM_HANDLE_NW ||
+      handle == GIMP_TRANSFORM_HANDLE_NE ||
+      handle == GIMP_TRANSFORM_HANDLE_SE ||
+      handle == GIMP_TRANSFORM_HANDLE_SW)
+    {
+      /* Scaling through scale handles means translating one corner point,
+       * with all sides at constant angles.
+       */
+
+      gint this, left, right, opposite;
+
+      /* 0: northwest, 1: northeast, 2: southwest, 3: southeast */
+      if (handle == GIMP_TRANSFORM_HANDLE_NW)
+        {
+          this = 0; left = 1; right = 2; opposite = 3;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_NE)
+        {
+          this = 1; left = 3; right = 0; opposite = 2;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_SW)
+        {
+          this = 2; left = 0; right = 3; opposite = 1;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_SE)
+        {
+          this = 3; left = 2; right = 1; opposite = 0;
+        }
+      else
+        gimp_assert_not_reached ();
+
+      /* when the keep aspect transformation constraint is enabled,
+       * the translation shall only be along the diagonal that runs
+       * trough this corner point.
+       */
+      if (private->constrain_scale)
+        {
+          /* restrict to movement along the diagonal */
+          GimpVector2 diag = vectorsubtract (oldpos[this], oldpos[opposite]);
+
+          d = vectorproject (d, diag);
+        }
+
+      /* Move the corner being interacted with */
+      /*    rp---------tp
+       *   /           /\ <- d, the interaction vector
+       *  /           /  tp
+       * op----------/
+       *
+       */
+      newpos[this] = vectoradd (oldpos[this], d);
+
+      /* Where the corner to the right and left would go, need these to form
+       * lines to intersect with the sides */
+      /*    rp----------/
+       *   /\          /\
+       *  /  nr       /  nt
+       * op----------lp
+       *              \
+       *               nl
+       */
+
+      newpos[right] = vectoradd (oldpos[right], d);
+      newpos[left]  = vectoradd (oldpos[left], d);
+
+      /* Now we just need to find the intersection of op-rp and nr-nt.
+       *    rp----------/
+       *   /           /
+       *  /  nr==========nt
+       * op----------/
+       *
+       */
+      newpos[right] = lineintersect (newpos[right], newpos[this],
+                                     oldpos[opposite], oldpos[right]);
+      newpos[left]  = lineintersect (newpos[left], newpos[this],
+                                     oldpos[opposite], oldpos[left]);
+      /*    /-----------/
+       *   /           /
+       *  rp============nt
+       * op----------/
+       *
+       */
+
+      /*
+       *
+       *  /--------------/
+       * /--------------/
+       *
+       */
+
+      if (private->frompivot_scale &&
+          transform_is_convex (newpos) &&
+          transform_is_convex (oldpos))
+        {
+          /* transform the pivot point before the interaction and
+           * after, and move everything by this difference
+           */
+          //TODO the handle doesn't actually end up where the mouse cursor is
+          GimpVector2 delta = get_pivot_delta (grid, oldpos, newpos, pivot);
+          for (i = 0; i < 4; i++)
+            newpos[i] = vectorsubtract (newpos[i], delta);
+
+          fixedpivot = TRUE;
+        }
+    }
+
+  /* scaling via sides */
+  if (handle == GIMP_TRANSFORM_HANDLE_N ||
+      handle == GIMP_TRANSFORM_HANDLE_E ||
+      handle == GIMP_TRANSFORM_HANDLE_S ||
+      handle == GIMP_TRANSFORM_HANDLE_W)
+    {
+      gint        this_l, this_r, opp_l, opp_r;
+      GimpVector2 side_l, side_r, midline;
+
+      /* 0: northwest, 1: northeast, 2: southwest, 3: southeast */
+      if (handle == GIMP_TRANSFORM_HANDLE_N)
+        {
+          this_l = 1; this_r = 0;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_E)
+        {
+          this_l = 3; this_r = 1;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_S)
+        {
+          this_l = 2; this_r = 3;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_W)
+        {
+          this_l = 0; this_r = 2;
+        }
+      else
+        gimp_assert_not_reached ();
+
+      opp_l = 3 - this_r; opp_r = 3 - this_l;
+
+      side_l = vectorsubtract (oldpos[opp_l], oldpos[this_l]);
+      side_r = vectorsubtract (oldpos[opp_r], oldpos[this_r]);
+      midline = vectoradd (side_l, side_r);
+
+      /* restrict to movement along the midline */
+      d = vectorproject (d, midline);
+
+      if (private->constrain_scale)
+        {
+          GimpVector2 before, after, effective_pivot = pivot;
+          gdouble     distance;
+
+          if (! private->frompivot_scale)
+            {
+              /* center of the opposite side is pivot */
+              effective_pivot = scalemult (vectoradd (oldpos[opp_l],
+                                                      oldpos[opp_r]), 0.5);
+            }
+
+          /* get the difference between the distance from the pivot to
+           * where interaction started and the distance from the pivot
+           * to where cursor is now, and scale all corners distance
+           * from the pivot with this factor
+           */
+          before = vectorsubtract (effective_pivot, mouse);
+          after = vectorsubtract (effective_pivot, cur);
+          after = vectorproject (after, before);
+
+          distance = 0.5 * (after.x / before.x + after.y / before.y);
+
+          for (i = 0; i < 4; i++)
+            newpos[i] = vectoradd (effective_pivot,
+                                   scalemult (vectorsubtract (oldpos[i],
+                                                              effective_pivot),
+                                              distance));
+        }
+      else
+        {
+          /* just move the side */
+          newpos[this_l] = vectoradd (oldpos[this_l], d);
+          newpos[this_r] = vectoradd (oldpos[this_r], d);
+        }
+
+      if (! private->constrain_scale   &&
+          private->frompivot_scale     &&
+          transform_is_convex (newpos) &&
+          transform_is_convex (oldpos))
+        {
+          GimpVector2 delta = get_pivot_delta (grid, oldpos, newpos, pivot);
+          for (i = 0; i < 4; i++)
+            newpos[i] = vectorsubtract (newpos[i], delta);
+
+          fixedpivot = TRUE;
+        }
+    }
+
+  /* shear */
+  if (handle == GIMP_TRANSFORM_HANDLE_N_S ||
+      handle == GIMP_TRANSFORM_HANDLE_E_S ||
+      handle == GIMP_TRANSFORM_HANDLE_S_S ||
+      handle == GIMP_TRANSFORM_HANDLE_W_S)
+    {
+      gint this_l, this_r;
+
+      /* set up indices for this edge and the opposite edge */
+      if (handle == GIMP_TRANSFORM_HANDLE_N_S)
+        {
+          this_l = 1; this_r = 0;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_W_S)
+        {
+          this_l = 0; this_r = 2;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_S_S)
+        {
+          this_l = 2; this_r = 3;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_E_S)
+        {
+          this_l = 3; this_r = 1;
+        }
+      else
+        gimp_assert_not_reached ();
+
+      if (private->constrain_shear)
+        {
+          /* restrict to movement along the side */
+          GimpVector2 side = vectorsubtract (oldpos[this_r], oldpos[this_l]);
+
+          d = vectorproject (d, side);
+        }
+
+      newpos[this_l] = vectoradd (oldpos[this_l], d);
+      newpos[this_r] = vectoradd (oldpos[this_r], d);
+
+      if (private->frompivot_shear     &&
+          transform_is_convex (newpos) &&
+          transform_is_convex (oldpos))
+        {
+          GimpVector2 delta = get_pivot_delta (grid, oldpos, newpos, pivot);
+          for (i = 0; i < 4; i++)
+            newpos[i] = vectorsubtract (newpos[i], delta);
+
+          fixedpivot = TRUE;
+        }
+    }
+
+  /* perspective transform */
+  if (handle == GIMP_TRANSFORM_HANDLE_NW_P ||
+      handle == GIMP_TRANSFORM_HANDLE_NE_P ||
+      handle == GIMP_TRANSFORM_HANDLE_SE_P ||
+      handle == GIMP_TRANSFORM_HANDLE_SW_P)
+    {
+      gint this, left, right, opposite;
+
+      /* 0: northwest, 1: northeast, 2: southwest, 3: southeast */
+      if (handle == GIMP_TRANSFORM_HANDLE_NW_P)
+        {
+          this = 0; left = 1; right = 2; opposite = 3;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_NE_P)
+        {
+          this = 1; left = 3; right = 0; opposite = 2;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_SW_P)
+        {
+          this = 2; left = 0; right = 3; opposite = 1;
+        }
+      else if (handle == GIMP_TRANSFORM_HANDLE_SE_P)
+        {
+          this = 3; left = 2; right = 1; opposite = 0;
+        }
+      else
+        gimp_assert_not_reached ();
+
+      if (private->constrain_perspective)
+        {
+          /* when the constrain transformation constraint is enabled,
+           * the translation shall only be either along the side
+           * angles of the two sides that run to this corner point, or
+           * along the diagonal that runs trough this corner point.
+           */
+          GimpVector2 proj[4];
+          gdouble     rej[4];
+
+          for (i = 0; i < 4; i++)
+            {
+              if (i == this)
+                continue;
+
+              /* get the vectors along the sides and the diagonal */
+              proj[i] = vectorsubtract (oldpos[this], oldpos[i]);
+
+              /* project d on each candidate vector and see which has
+               * the shortest rejection
+               */
+              proj[i] = vectorproject (d, proj[i]);
+              rej[i] = norm (vectorsubtract (d, proj[i]));
+            }
+
+          if (rej[left] < rej[right] && rej[left] < rej[opposite])
+            d = proj[left];
+          else if (rej[right] < rej[opposite])
+            d = proj[right];
+          else
+            d = proj[opposite];
+        }
+
+      newpos[this] = vectoradd (oldpos[this], d);
+
+      if (private->frompivot_perspective &&
+          transform_is_convex (newpos)   &&
+          transform_is_convex (oldpos))
+        {
+          GimpVector2 delta = get_pivot_delta (grid, oldpos, newpos, pivot);
+
+          for (i = 0; i < 4; i++)
+            newpos[i] = vectorsubtract (newpos[i], delta);
+
+          fixedpivot = TRUE;
+        }
+    }
+
+  /* this will have been set to TRUE if an operation used the pivot in
+   * addition to being a user option
+   */
+  if (! fixedpivot                 &&
+      transform_is_convex (newpos) &&
+      transform_is_convex (oldpos) &&
+      point_is_inside_polygon_pos (oldpos, pivot))
+    {
+      GimpVector2 delta = get_pivot_delta (grid, oldpos, newpos, pivot);
+      pivot = vectoradd (pivot, delta);
+    }
+
+  /* make sure the new coordinates are valid */
+  for (i = 0; i < 4; i++)
+    {
+      if (! isfinite (newpos[i].x) || ! isfinite (newpos[i].y))
+        return;
+    }
+
+  if (! isfinite (pivot.x) || ! isfinite (pivot.y))
+    return;
+
+  for (i = 0; i < 4; i++)
+    {
+      *x[i] = newpos[i].x;
+      *y[i] = newpos[i].y;
+    }
+
+  /* set unconditionally: if options get toggled during operation, we
+   * have to move pivot back
+   */
+  *newpivot_x = pivot.x;
+  *newpivot_y = pivot.y;
+
+  gimp_tool_transform_grid_update_matrix (grid);
+}
+
+static const gchar *
+get_friendly_operation_name (GimpTransformHandle handle)
+{
+  switch (handle)
+    {
+    case GIMP_TRANSFORM_HANDLE_NONE:
+      return "";
+    case GIMP_TRANSFORM_HANDLE_NW_P:
+    case GIMP_TRANSFORM_HANDLE_NE_P:
+    case GIMP_TRANSFORM_HANDLE_SW_P:
+    case GIMP_TRANSFORM_HANDLE_SE_P:
+      return _("Click-Drag to change perspective");
+    case GIMP_TRANSFORM_HANDLE_NW:
+    case GIMP_TRANSFORM_HANDLE_NE:
+    case GIMP_TRANSFORM_HANDLE_SW:
+    case GIMP_TRANSFORM_HANDLE_SE:
+      return _("Click-Drag to scale");
+    case GIMP_TRANSFORM_HANDLE_N:
+    case GIMP_TRANSFORM_HANDLE_S:
+    case GIMP_TRANSFORM_HANDLE_E:
+    case GIMP_TRANSFORM_HANDLE_W:
+      return _("Click-Drag to scale");
+    case GIMP_TRANSFORM_HANDLE_CENTER:
+      return _("Click-Drag to move");
+    case GIMP_TRANSFORM_HANDLE_PIVOT:
+      return _("Click-Drag to move the pivot point");
+    case GIMP_TRANSFORM_HANDLE_N_S:
+    case GIMP_TRANSFORM_HANDLE_S_S:
+    case GIMP_TRANSFORM_HANDLE_E_S:
+    case GIMP_TRANSFORM_HANDLE_W_S:
+      return _("Click-Drag to shear");
+    case GIMP_TRANSFORM_HANDLE_ROTATION:
+      return _("Click-Drag to rotate");
+    default:
+      gimp_assert_not_reached ();
+    }
+}
+
+static GimpTransformHandle
+gimp_tool_transform_get_area_handle (GimpToolTransformGrid *grid,
+                                     const GimpCoords      *coords,
+                                     GimpTransformFunction  function)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+  GimpTransformHandle           handle  = GIMP_TRANSFORM_HANDLE_NONE;
+
+  switch (function)
+    {
+    case GIMP_TRANSFORM_FUNCTION_NONE:
+      break;
+
+    case GIMP_TRANSFORM_FUNCTION_MOVE:
+      handle = GIMP_TRANSFORM_HANDLE_CENTER;
+      break;
+
+    case GIMP_TRANSFORM_FUNCTION_ROTATE:
+      handle = GIMP_TRANSFORM_HANDLE_ROTATION;
+      break;
+
+    case GIMP_TRANSFORM_FUNCTION_SCALE:
+    case GIMP_TRANSFORM_FUNCTION_PERSPECTIVE:
+      {
+        gdouble closest_dist;
+        gdouble dist;
+
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           private->tx1,
+                                                           private->ty1);
+        closest_dist = dist;
+        if (function == GIMP_TRANSFORM_FUNCTION_PERSPECTIVE)
+          handle = GIMP_TRANSFORM_HANDLE_NW_P;
+        else
+          handle = GIMP_TRANSFORM_HANDLE_NW;
+
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           private->tx2,
+                                                           private->ty2);
+        if (dist < closest_dist)
+          {
+            closest_dist = dist;
+            if (function == GIMP_TRANSFORM_FUNCTION_PERSPECTIVE)
+              handle = GIMP_TRANSFORM_HANDLE_NE_P;
+            else
+              handle = GIMP_TRANSFORM_HANDLE_NE;
+          }
+
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           private->tx3,
+                                                           private->ty3);
+        if (dist < closest_dist)
+          {
+            closest_dist = dist;
+            if (function == GIMP_TRANSFORM_FUNCTION_PERSPECTIVE)
+              handle = GIMP_TRANSFORM_HANDLE_SW_P;
+            else
+              handle = GIMP_TRANSFORM_HANDLE_SW;
+          }
+
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           private->tx4,
+                                                           private->ty4);
+        if (dist < closest_dist)
+          {
+            closest_dist = dist;
+            if (function == GIMP_TRANSFORM_FUNCTION_PERSPECTIVE)
+              handle = GIMP_TRANSFORM_HANDLE_SE_P;
+            else
+              handle = GIMP_TRANSFORM_HANDLE_SE;
+          }
+      }
+      break;
+
+    case GIMP_TRANSFORM_FUNCTION_SHEAR:
+      {
+        gdouble handle_x;
+        gdouble handle_y;
+        gdouble closest_dist;
+        gdouble dist;
+
+        gimp_canvas_handle_get_position (private->handles[GIMP_TRANSFORM_HANDLE_N],
+                                         &handle_x, &handle_y);
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           handle_x, handle_y);
+        closest_dist = dist;
+        handle = GIMP_TRANSFORM_HANDLE_N_S;
+
+        gimp_canvas_handle_get_position (private->handles[GIMP_TRANSFORM_HANDLE_W],
+                                         &handle_x, &handle_y);
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           handle_x, handle_y);
+        if (dist < closest_dist)
+          {
+            closest_dist = dist;
+            handle = GIMP_TRANSFORM_HANDLE_W_S;
+          }
+
+        gimp_canvas_handle_get_position (private->handles[GIMP_TRANSFORM_HANDLE_E],
+                                         &handle_x, &handle_y);
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           handle_x, handle_y);
+        if (dist < closest_dist)
+          {
+            closest_dist = dist;
+            handle = GIMP_TRANSFORM_HANDLE_E_S;
+          }
+
+        gimp_canvas_handle_get_position (private->handles[GIMP_TRANSFORM_HANDLE_S],
+                                         &handle_x, &handle_y);
+        dist = gimp_canvas_item_transform_distance_square (private->guides,
+                                                           coords->x, coords->y,
+                                                           handle_x, handle_y);
+        if (dist < closest_dist)
+          {
+            closest_dist = dist;
+            handle = GIMP_TRANSFORM_HANDLE_S_S;
+          }
+      }
+      break;
+    }
+
+  return handle;
+}
+
+GimpHit
+gimp_tool_transform_grid_hit (GimpToolWidget   *widget,
+                              const GimpCoords *coords,
+                              GdkModifierType   state,
+                              gboolean          proximity)
+{
+  GimpToolTransformGrid *grid = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpTransformHandle    handle;
+
+  handle = gimp_tool_transform_grid_get_handle_for_coords (grid, coords);
+
+  if (handle != GIMP_TRANSFORM_HANDLE_NONE)
+    return GIMP_HIT_DIRECT;
+
+  return GIMP_HIT_INDIRECT;
+}
+
+void
+gimp_tool_transform_grid_hover (GimpToolWidget   *widget,
+                                const GimpCoords *coords,
+                                GdkModifierType   state,
+                                gboolean          proximity)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+  GimpTransformHandle           handle;
+
+  handle = gimp_tool_transform_grid_get_handle_for_coords (grid, coords);
+
+  if (handle == GIMP_TRANSFORM_HANDLE_NONE)
+    {
+      /* points passed in clockwise order */
+      if (point_is_inside_polygon (4,
+                                   (gdouble[4]){ private->tx1, private->tx2,
+                                                 private->tx4, private->tx3 },
+                                   (gdouble[4]){ private->ty1, private->ty2,
+                                                 private->ty4, private->ty3 },
+                                   coords->x, coords->y))
+        {
+          handle = gimp_tool_transform_get_area_handle (grid, coords,
+                                                        private->inside_function);
+        }
+      else
+        {
+          handle = gimp_tool_transform_get_area_handle (grid, coords,
+                                                        private->outside_function);
+        }
+    }
+
+  if (handle != GIMP_TRANSFORM_HANDLE_NONE && proximity)
+    {
+      gimp_tool_widget_set_status (widget,
+                                   get_friendly_operation_name (handle));
+    }
+  else
+    {
+      gimp_tool_widget_set_status (widget, NULL);
+    }
+
+  private->handle = handle;
+
+  gimp_tool_transform_grid_update_hilight (grid);
+}
+
+void
+gimp_tool_transform_grid_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  private->handle = GIMP_TRANSFORM_HANDLE_NONE;
+
+  gimp_tool_transform_grid_update_hilight (grid);
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
+}
+
+static void
+gimp_tool_transform_grid_modifier (GimpToolWidget  *widget,
+                                   GdkModifierType  key)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  if (key == gimp_get_constrain_behavior_mask ())
+    {
+      g_object_set (widget,
+                    "frompivot-scale",       ! private->frompivot_scale,
+                    "frompivot-shear",       ! private->frompivot_shear,
+                    "frompivot-perspective", ! private->frompivot_perspective,
+                    NULL);
+    }
+  else if (key == gimp_get_extend_selection_mask ())
+    {
+      g_object_set (widget,
+                    "cornersnap",            ! private->cornersnap,
+                    "constrain-move",        ! private->constrain_move,
+                    "constrain-scale",       ! private->constrain_scale,
+                    "constrain-rotate",      ! private->constrain_rotate,
+                    "constrain-shear",       ! private->constrain_shear,
+                    "constrain-perspective", ! private->constrain_perspective,
+                    NULL);
+    }
+}
+
+static void
+gimp_tool_transform_grid_hover_modifier (GimpToolWidget  *widget,
+                                         GdkModifierType  key,
+                                         gboolean         press,
+                                         GdkModifierType  state)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+  GimpCoords                    coords  = { 0.0, };
+
+  gimp_tool_transform_grid_modifier (widget, key);
+
+  if (private->button_down)
+    {
+      /*  send a non-motion to update the grid with the new constraints  */
+      coords.x = private->curx;
+      coords.y = private->cury;
+      gimp_tool_transform_grid_motion (widget, &coords, 0, state);
+    }
+}
+
+static gboolean
+gimp_tool_transform_grid_get_cursor (GimpToolWidget     *widget,
+                                     const GimpCoords   *coords,
+                                     GdkModifierType     state,
+                                     GimpCursorType     *cursor,
+                                     GimpToolCursorType *tool_cursor,
+                                     GimpCursorModifier *modifier)
+{
+  GimpToolTransformGrid        *grid    = GIMP_TOOL_TRANSFORM_GRID (widget);
+  GimpToolTransformGridPrivate *private = grid->private;
+  gdouble                       angle[9];
+  gint                          i;
+  GimpCursorType                map[8];
+  GimpVector2                   pos[4], this, that;
+  gboolean                      flip       = FALSE;
+  gboolean                      side       = FALSE;
+  gboolean                      set_cursor = TRUE;
+
+  map[0] = GIMP_CURSOR_CORNER_TOP_LEFT;
+  map[1] = GIMP_CURSOR_CORNER_TOP;
+  map[2] = GIMP_CURSOR_CORNER_TOP_RIGHT;
+  map[3] = GIMP_CURSOR_CORNER_RIGHT;
+  map[4] = GIMP_CURSOR_CORNER_BOTTOM_RIGHT;
+  map[5] = GIMP_CURSOR_CORNER_BOTTOM;
+  map[6] = GIMP_CURSOR_CORNER_BOTTOM_LEFT;
+  map[7] = GIMP_CURSOR_CORNER_LEFT;
+
+  get_handle_geometry (grid, pos, angle);
+
+  for (i = 0; i < 8; i++)
+    angle[i] = round (angle[i] * 180.0 / G_PI / 45.0);
+
+  switch (private->handle)
+    {
+    case GIMP_TRANSFORM_HANDLE_NW_P:
+    case GIMP_TRANSFORM_HANDLE_NW:
+      i = (gint) angle[4] + 0;
+      this = pos[0];
+      that = pos[3];
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_NE_P:
+    case GIMP_TRANSFORM_HANDLE_NE:
+      i = (gint) angle[5] + 2;
+      this = pos[1];
+      that = pos[2];
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_SW_P:
+    case GIMP_TRANSFORM_HANDLE_SW:
+      i = (gint) angle[6] + 6;
+      this = pos[2];
+      that = pos[1];
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_SE_P:
+    case GIMP_TRANSFORM_HANDLE_SE:
+      i = (gint) angle[7] + 4;
+      this = pos[3];
+      that = pos[0];
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_N:
+    case GIMP_TRANSFORM_HANDLE_N_S:
+      i = (gint) angle[0] + 1;
+      this = vectoradd (pos[0], pos[1]);
+      that = vectoradd (pos[2], pos[3]);
+      side = TRUE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_S:
+    case GIMP_TRANSFORM_HANDLE_S_S:
+      i = (gint) angle[1] + 5;
+      this = vectoradd (pos[2], pos[3]);
+      that = vectoradd (pos[0], pos[1]);
+      side = TRUE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_E:
+    case GIMP_TRANSFORM_HANDLE_E_S:
+      i = (gint) angle[2] + 3;
+      this = vectoradd (pos[1], pos[3]);
+      that = vectoradd (pos[0], pos[2]);
+      side = TRUE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_W:
+    case GIMP_TRANSFORM_HANDLE_W_S:
+      i = (gint) angle[3] + 7;
+      this = vectoradd (pos[0], pos[2]);
+      that = vectoradd (pos[1], pos[3]);
+      side = TRUE;
+      break;
+
+    default:
+      set_cursor = FALSE;
+      break;
+    }
+
+  if (set_cursor)
+    {
+      i %= 8;
+
+      switch (map[i])
+        {
+        case GIMP_CURSOR_CORNER_TOP_LEFT:
+          if (this.x + this.y > that.x + that.y)
+            flip = TRUE;
+          break;
+        case GIMP_CURSOR_CORNER_TOP:
+          if (this.y > that.y)
+            flip = TRUE;
+          break;
+        case GIMP_CURSOR_CORNER_TOP_RIGHT:
+          if (this.x - this.y < that.x - that.y)
+            flip = TRUE;
+          break;
+        case GIMP_CURSOR_CORNER_RIGHT:
+          if (this.x < that.x)
+            flip = TRUE;
+          break;
+        case GIMP_CURSOR_CORNER_BOTTOM_RIGHT:
+          if (this.x + this.y < that.x + that.y)
+            flip = TRUE;
+          break;
+        case GIMP_CURSOR_CORNER_BOTTOM:
+          if (this.y < that.y)
+            flip = TRUE;
+          break;
+        case GIMP_CURSOR_CORNER_BOTTOM_LEFT:
+          if (this.x - this.y > that.x - that.y)
+            flip = TRUE;
+          break;
+        case GIMP_CURSOR_CORNER_LEFT:
+          if (this.x > that.x)
+            flip = TRUE;
+          break;
+        default:
+          gimp_assert_not_reached ();
+        }
+
+      if (flip)
+        *cursor = map[(i + 4) % 8];
+      else
+        *cursor = map[i];
+
+      if (side)
+        *cursor += 8;
+    }
+
+  /* parent class handles *cursor and *modifier for most handles */
+  switch (private->handle)
+    {
+    case GIMP_TRANSFORM_HANDLE_NONE:
+      *tool_cursor = GIMP_TOOL_CURSOR_NONE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_NW_P:
+    case GIMP_TRANSFORM_HANDLE_NE_P:
+    case GIMP_TRANSFORM_HANDLE_SW_P:
+    case GIMP_TRANSFORM_HANDLE_SE_P:
+      *tool_cursor = GIMP_TOOL_CURSOR_PERSPECTIVE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_NW:
+    case GIMP_TRANSFORM_HANDLE_NE:
+    case GIMP_TRANSFORM_HANDLE_SW:
+    case GIMP_TRANSFORM_HANDLE_SE:
+    case GIMP_TRANSFORM_HANDLE_N:
+    case GIMP_TRANSFORM_HANDLE_S:
+    case GIMP_TRANSFORM_HANDLE_E:
+    case GIMP_TRANSFORM_HANDLE_W:
+      *tool_cursor = GIMP_TOOL_CURSOR_RESIZE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_CENTER:
+      *tool_cursor = GIMP_TOOL_CURSOR_MOVE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_PIVOT:
+      *tool_cursor = GIMP_TOOL_CURSOR_ROTATE;
+      *modifier    = GIMP_CURSOR_MODIFIER_MOVE;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_N_S:
+    case GIMP_TRANSFORM_HANDLE_S_S:
+    case GIMP_TRANSFORM_HANDLE_E_S:
+    case GIMP_TRANSFORM_HANDLE_W_S:
+      *tool_cursor = GIMP_TOOL_CURSOR_SHEAR;
+      break;
+
+    case GIMP_TRANSFORM_HANDLE_ROTATION:
+      *tool_cursor = GIMP_TOOL_CURSOR_ROTATE;
+      break;
+
+    default:
+      g_return_val_if_reached (FALSE);
+    }
+
+  return TRUE;
+}
+
+static GimpTransformHandle
+gimp_tool_transform_grid_get_handle_for_coords (GimpToolTransformGrid *grid,
+                                                const GimpCoords      *coords)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+  GimpTransformHandle           i;
+
+  for (i = GIMP_TRANSFORM_HANDLE_NONE + 1; i < GIMP_N_TRANSFORM_HANDLES; i++)
+    {
+      if (private->handles[i] &&
+          gimp_canvas_item_hit (private->handles[i], coords->x, coords->y))
+        {
+          return i;
+        }
+    }
+
+  return GIMP_TRANSFORM_HANDLE_NONE;
+}
+
+static void
+gimp_tool_transform_grid_update_hilight (GimpToolTransformGrid *grid)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+  GimpTransformHandle           handle;
+
+  for (handle = GIMP_TRANSFORM_HANDLE_NONE;
+       handle < GIMP_N_TRANSFORM_HANDLES;
+       handle++)
+    {
+      if (private->handles[handle])
+        {
+          gimp_canvas_item_set_highlight (private->handles[handle],
+                                          handle == private->handle);
+        }
+    }
+}
+
+static void
+gimp_tool_transform_grid_update_box (GimpToolTransformGrid  *grid)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  gimp_matrix3_transform_point (&private->transform,
+                                private->x1, private->y1,
+                                &private->tx1, &private->ty1);
+  gimp_matrix3_transform_point (&private->transform,
+                                private->x2, private->y1,
+                                &private->tx2, &private->ty2);
+  gimp_matrix3_transform_point (&private->transform,
+                                private->x1, private->y2,
+                                &private->tx3, &private->ty3);
+  gimp_matrix3_transform_point (&private->transform,
+                                private->x2, private->y2,
+                                &private->tx4, &private->ty4);
+
+  /* don't transform pivot */
+  private->tpx = private->pivot_x;
+  private->tpy = private->pivot_y;
+
+  if (transform_grid_is_convex (grid))
+    {
+      gimp_matrix3_transform_point (&private->transform,
+                                    (private->x1 + private->x2) / 2.0,
+                                    (private->y1 + private->y2) / 2.0,
+                                    &private->tcx, &private->tcy);
+    }
+  else
+    {
+      private->tcx = (private->tx1 +
+                      private->tx2 +
+                      private->tx3 +
+                      private->tx4) / 4.0;
+      private->tcy = (private->ty1 +
+                      private->ty2 +
+                      private->ty3 +
+                      private->ty4) / 4.0;
+    }
+}
+
+static void
+gimp_tool_transform_grid_update_matrix (GimpToolTransformGrid *grid)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+
+  gimp_matrix3_identity (&private->transform);
+  gimp_transform_matrix_perspective (&private->transform,
+                                     private->x1,
+                                     private->y1,
+                                     private->x2 - private->x1,
+                                     private->y2 - private->y1,
+                                     private->tx1,
+                                     private->ty1,
+                                     private->tx2,
+                                     private->ty2,
+                                     private->tx3,
+                                     private->ty3,
+                                     private->tx4,
+                                     private->ty4);
+
+  private->pivot_x = private->tpx;
+  private->pivot_y = private->tpy;
+
+  g_object_freeze_notify (G_OBJECT (grid));
+  g_object_notify (G_OBJECT (grid), "transform");
+  g_object_notify (G_OBJECT (grid), "pivot-x");
+  g_object_notify (G_OBJECT (grid), "pivot-x");
+  g_object_thaw_notify (G_OBJECT (grid));
+}
+
+static void
+gimp_tool_transform_grid_calc_handles (GimpToolTransformGrid *grid,
+                                       gint                  *handle_w,
+                                       gint                  *handle_h)
+{
+  GimpToolTransformGridPrivate *private = grid->private;
+  gint                          dx1, dy1;
+  gint                          dx2, dy2;
+  gint                          dx3, dy3;
+  gint                          dx4, dy4;
+  gint                          x1, y1;
+  gint                          x2, y2;
+
+  if (! private->dynamic_handle_size)
+    {
+      *handle_w = GIMP_CANVAS_HANDLE_SIZE_LARGE;
+      *handle_h = GIMP_CANVAS_HANDLE_SIZE_LARGE;
+
+      return;
+    }
+
+  gimp_canvas_item_transform_xy (private->guides,
+                                 private->tx1, private->ty1,
+                                 &dx1, &dy1);
+  gimp_canvas_item_transform_xy (private->guides,
+                                 private->tx2, private->ty2,
+                                 &dx2, &dy2);
+  gimp_canvas_item_transform_xy (private->guides,
+                                 private->tx3, private->ty3,
+                                 &dx3, &dy3);
+  gimp_canvas_item_transform_xy (private->guides,
+                                 private->tx4, private->ty4,
+                                 &dx4, &dy4);
+
+  x1 = MIN4 (dx1, dx2, dx3, dx4);
+  y1 = MIN4 (dy1, dy2, dy3, dy4);
+  x2 = MAX4 (dx1, dx2, dx3, dx4);
+  y2 = MAX4 (dy1, dy2, dy3, dy4);
+
+  *handle_w = CLAMP ((x2 - x1) / 3,
+                     MIN_HANDLE_SIZE, GIMP_CANVAS_HANDLE_SIZE_LARGE);
+  *handle_h = CLAMP ((y2 - y1) / 3,
+                     MIN_HANDLE_SIZE, GIMP_CANVAS_HANDLE_SIZE_LARGE);
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_transform_grid_new (GimpDisplayShell  *shell,
+                              const GimpMatrix3 *transform,
+                              gdouble            x1,
+                              gdouble            y1,
+                              gdouble            x2,
+                              gdouble            y2)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_TRANSFORM_GRID,
+                       "shell",      shell,
+                       "transform",  transform,
+                       "x1",         x1,
+                       "y1",         y1,
+                       "x2",         x2,
+                       "y2",         y2,
+                       NULL);
+}
+
+
+/*  protected functions  */
+
+GimpTransformHandle
+gimp_tool_transform_grid_get_handle (GimpToolTransformGrid *grid)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_TRANSFORM_GRID (grid),
+                        GIMP_TRANSFORM_HANDLE_NONE);
+
+  return grid->private->handle;
+}
diff --git a/app/display/gimptooltransformgrid.h b/app/display/gimptooltransformgrid.h
new file mode 100644
index 0000000..949beb2
--- /dev/null
+++ b/app/display/gimptooltransformgrid.h
@@ -0,0 +1,99 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptooltransformgrid.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_TRANSFORM_GRID_H__
+#define __GIMP_TOOL_TRANSFORM_GRID_H__
+
+
+#include "gimpcanvashandle.h"
+#include "gimptoolwidget.h"
+
+
+#define GIMP_TOOL_TRANSFORM_GRID_MAX_HANDLE_SIZE \
+  (1.5 * GIMP_CANVAS_HANDLE_SIZE_LARGE)
+
+
+typedef enum
+{
+  GIMP_TRANSFORM_HANDLE_NONE,
+  GIMP_TRANSFORM_HANDLE_NW_P,     /* north west perspective         */
+  GIMP_TRANSFORM_HANDLE_NE_P,     /* north east perspective         */
+  GIMP_TRANSFORM_HANDLE_SW_P,     /* south west perspective         */
+  GIMP_TRANSFORM_HANDLE_SE_P,     /* south east perspective         */
+  GIMP_TRANSFORM_HANDLE_NW,       /* north west                     */
+  GIMP_TRANSFORM_HANDLE_NE,       /* north east                     */
+  GIMP_TRANSFORM_HANDLE_SW,       /* south west                     */
+  GIMP_TRANSFORM_HANDLE_SE,       /* south east                     */
+  GIMP_TRANSFORM_HANDLE_N,        /* north                          */
+  GIMP_TRANSFORM_HANDLE_S,        /* south                          */
+  GIMP_TRANSFORM_HANDLE_E,        /* east                           */
+  GIMP_TRANSFORM_HANDLE_W,        /* west                           */
+  GIMP_TRANSFORM_HANDLE_CENTER,   /* center for moving              */
+  GIMP_TRANSFORM_HANDLE_PIVOT,    /* pivot for rotation and scaling */
+  GIMP_TRANSFORM_HANDLE_N_S,      /* north shearing                 */
+  GIMP_TRANSFORM_HANDLE_S_S,      /* south shearing                 */
+  GIMP_TRANSFORM_HANDLE_E_S,      /* east shearing                  */
+  GIMP_TRANSFORM_HANDLE_W_S,      /* west shearing                  */
+  GIMP_TRANSFORM_HANDLE_ROTATION, /* rotation                       */
+
+  GIMP_N_TRANSFORM_HANDLES /* keep this last so *handles[] is the right size */
+} GimpTransformHandle;
+
+
+#define GIMP_TYPE_TOOL_TRANSFORM_GRID            (gimp_tool_transform_grid_get_type ())
+#define GIMP_TOOL_TRANSFORM_GRID(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_TRANSFORM_GRID, GimpToolTransformGrid))
+#define GIMP_TOOL_TRANSFORM_GRID_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_TRANSFORM_GRID, GimpToolTransformGridClass))
+#define GIMP_IS_TOOL_TRANSFORM_GRID(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_TRANSFORM_GRID))
+#define GIMP_IS_TOOL_TRANSFORM_GRID_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_TRANSFORM_GRID))
+#define GIMP_TOOL_TRANSFORM_GRID_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_TRANSFORM_GRID, GimpToolTransformGridClass))
+
+
+typedef struct _GimpToolTransformGrid        GimpToolTransformGrid;
+typedef struct _GimpToolTransformGridPrivate GimpToolTransformGridPrivate;
+typedef struct _GimpToolTransformGridClass   GimpToolTransformGridClass;
+
+struct _GimpToolTransformGrid
+{
+  GimpToolWidget                parent_instance;
+
+  GimpToolTransformGridPrivate *private;
+};
+
+struct _GimpToolTransformGridClass
+{
+  GimpToolWidgetClass  parent_class;
+};
+
+
+GType                 gimp_tool_transform_grid_get_type   (void) G_GNUC_CONST;
+
+GimpToolWidget      * gimp_tool_transform_grid_new        (GimpDisplayShell      *shell,
+                                                           const GimpMatrix3     *transform,
+                                                           gdouble                x1,
+                                                           gdouble                y1,
+                                                           gdouble                x2,
+                                                           gdouble                y2);
+
+/*  protected functions  */
+
+GimpTransformHandle   gimp_tool_transform_grid_get_handle (GimpToolTransformGrid *grid);
+
+
+#endif /* __GIMP_TOOL_TRANSFORM_GRID_H__ */
diff --git a/app/display/gimptoolwidget.c b/app/display/gimptoolwidget.c
new file mode 100644
index 0000000..516f366
--- /dev/null
+++ b/app/display/gimptoolwidget.c
@@ -0,0 +1,1117 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolwidget.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdarg.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "display-types.h"
+
+#include "core/gimpmarshal.h"
+
+#include "gimpcanvasarc.h"
+#include "gimpcanvascorner.h"
+#include "gimpcanvasgroup.h"
+#include "gimpcanvashandle.h"
+#include "gimpcanvaslimit.h"
+#include "gimpcanvasline.h"
+#include "gimpcanvaspath.h"
+#include "gimpcanvaspolygon.h"
+#include "gimpcanvasrectangle.h"
+#include "gimpcanvasrectangleguides.h"
+#include "gimpcanvastransformguides.h"
+#include "gimpdisplayshell.h"
+#include "gimptoolwidget.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_SHELL,
+  PROP_ITEM
+};
+
+enum
+{
+  CHANGED,
+  RESPONSE,
+  SNAP_OFFSETS,
+  STATUS,
+  STATUS_COORDS,
+  MESSAGE,
+  FOCUS_CHANGED,
+  LAST_SIGNAL
+};
+
+struct _GimpToolWidgetPrivate
+{
+  GimpDisplayShell *shell;
+  GimpCanvasItem   *item;
+  GList            *group_stack;
+
+  gint              snap_offset_x;
+  gint              snap_offset_y;
+  gint              snap_width;
+  gint              snap_height;
+
+  gboolean          visible;
+  gboolean          focus;
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_widget_finalize           (GObject         *object);
+static void     gimp_tool_widget_constructed        (GObject         *object);
+static void     gimp_tool_widget_set_property       (GObject         *object,
+                                                     guint            property_id,
+                                                     const GValue    *value,
+                                                     GParamSpec      *pspec);
+static void     gimp_tool_widget_get_property       (GObject         *object,
+                                                     guint            property_id,
+                                                     GValue          *value,
+                                                     GParamSpec      *pspec);
+static void     gimp_tool_widget_properties_changed (GObject         *object,
+                                                     guint            n_pspecs,
+                                                     GParamSpec     **pspecs);
+
+static void     gimp_tool_widget_real_leave_notify  (GimpToolWidget  *widget);
+static gboolean gimp_tool_widget_real_key_press     (GimpToolWidget  *widget,
+                                                     GdkEventKey     *kevent);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolWidget, gimp_tool_widget, GIMP_TYPE_OBJECT)
+
+#define parent_class gimp_tool_widget_parent_class
+
+static guint widget_signals[LAST_SIGNAL] = { 0 };
+
+
+static void
+gimp_tool_widget_class_init (GimpToolWidgetClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize                    = gimp_tool_widget_finalize;
+  object_class->constructed                 = gimp_tool_widget_constructed;
+  object_class->set_property                = gimp_tool_widget_set_property;
+  object_class->get_property                = gimp_tool_widget_get_property;
+  object_class->dispatch_properties_changed = gimp_tool_widget_properties_changed;
+
+  klass->leave_notify                       = gimp_tool_widget_real_leave_notify;
+  klass->key_press                          = gimp_tool_widget_real_key_press;
+
+  widget_signals[CHANGED] =
+    g_signal_new ("changed",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolWidgetClass, changed),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  widget_signals[RESPONSE] =
+    g_signal_new ("response",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolWidgetClass, response),
+                  NULL, NULL,
+                  gimp_marshal_VOID__INT,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_INT);
+
+  widget_signals[SNAP_OFFSETS] =
+    g_signal_new ("snap-offsets",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolWidgetClass, snap_offsets),
+                  NULL, NULL,
+                  gimp_marshal_VOID__INT_INT_INT_INT,
+                  G_TYPE_NONE, 4,
+                  G_TYPE_INT,
+                  G_TYPE_INT,
+                  G_TYPE_INT,
+                  G_TYPE_INT);
+
+  widget_signals[STATUS] =
+    g_signal_new ("status",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolWidgetClass, status),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__STRING,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_STRING);
+
+  widget_signals[STATUS_COORDS] =
+    g_signal_new ("status-coords",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolWidgetClass, status_coords),
+                  NULL, NULL,
+                  gimp_marshal_VOID__STRING_DOUBLE_STRING_DOUBLE_STRING,
+                  G_TYPE_NONE, 5,
+                  G_TYPE_STRING,
+                  G_TYPE_DOUBLE,
+                  G_TYPE_STRING,
+                  G_TYPE_DOUBLE,
+                  G_TYPE_STRING);
+
+  widget_signals[MESSAGE] =
+    g_signal_new ("message",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolWidgetClass, message),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__STRING,
+                  G_TYPE_NONE, 1,
+                  G_TYPE_STRING);
+
+  widget_signals[FOCUS_CHANGED] =
+    g_signal_new ("focus-changed",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolWidgetClass, focus_changed),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  g_object_class_install_property (object_class, PROP_SHELL,
+                                   g_param_spec_object ("shell",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_DISPLAY_SHELL,
+                                                        GIMP_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT_ONLY));
+
+  g_object_class_install_property (object_class, PROP_ITEM,
+                                   g_param_spec_object ("item",
+                                                        NULL, NULL,
+                                                        GIMP_TYPE_CANVAS_ITEM,
+                                                        GIMP_PARAM_READABLE));
+}
+
+static void
+gimp_tool_widget_init (GimpToolWidget *widget)
+{
+  widget->private = gimp_tool_widget_get_instance_private (widget);
+
+  widget->private->visible = TRUE;
+}
+
+static void
+gimp_tool_widget_constructed (GObject *object)
+{
+  GimpToolWidget        *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolWidgetPrivate *private = widget->private;
+  GimpToolWidgetClass   *klass   = GIMP_TOOL_WIDGET_GET_CLASS (widget);
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  gimp_assert (GIMP_IS_DISPLAY_SHELL (private->shell));
+
+  private->item = gimp_canvas_group_new (private->shell);
+
+  gimp_canvas_item_set_visible (private->item, private->visible);
+
+  if (klass->changed)
+    {
+      if (klass->update_on_scale)
+        {
+          g_signal_connect_object (private->shell, "scaled",
+                                   G_CALLBACK (klass->changed),
+                                   widget,
+                                   G_CONNECT_SWAPPED);
+        }
+
+      if (klass->update_on_scroll)
+        {
+          g_signal_connect_object (private->shell, "scrolled",
+                                   G_CALLBACK (klass->changed),
+                                   widget,
+                                   G_CONNECT_SWAPPED);
+        }
+
+      if (klass->update_on_rotate)
+        {
+          g_signal_connect_object (private->shell, "rotated",
+                                   G_CALLBACK (klass->changed),
+                                   widget,
+                                   G_CONNECT_SWAPPED);
+        }
+    }
+}
+
+static void
+gimp_tool_widget_finalize (GObject *object)
+{
+  GimpToolWidget        *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolWidgetPrivate *private = widget->private;
+
+  g_clear_object (&private->item);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_tool_widget_set_property (GObject      *object,
+                               guint         property_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GimpToolWidget        *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolWidgetPrivate *private = widget->private;
+
+  switch (property_id)
+    {
+    case PROP_SHELL:
+      private->shell = g_value_get_object (value); /* don't ref */
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_widget_get_property (GObject    *object,
+                               guint       property_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GimpToolWidget        *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolWidgetPrivate *private = widget->private;
+
+  switch (property_id)
+    {
+    case PROP_SHELL:
+      g_value_set_object (value, private->shell);
+      break;
+
+    case PROP_ITEM:
+      g_value_set_object (value, private->item);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_widget_properties_changed (GObject     *object,
+                                     guint        n_pspecs,
+                                     GParamSpec **pspecs)
+{
+  GimpToolWidget *widget = GIMP_TOOL_WIDGET (object);
+
+  G_OBJECT_CLASS (parent_class)->dispatch_properties_changed (object,
+                                                              n_pspecs,
+                                                              pspecs);
+
+  gimp_tool_widget_changed (widget);
+}
+
+static void
+gimp_tool_widget_real_leave_notify (GimpToolWidget *widget)
+{
+  gimp_tool_widget_set_status (widget, NULL);
+}
+
+static gboolean
+gimp_tool_widget_real_key_press (GimpToolWidget *widget,
+                                 GdkEventKey    *kevent)
+{
+  switch (kevent->keyval)
+    {
+    case GDK_KEY_Return:
+    case GDK_KEY_KP_Enter:
+    case GDK_KEY_ISO_Enter:
+      gimp_tool_widget_response (widget, GIMP_TOOL_WIDGET_RESPONSE_CONFIRM);
+      return TRUE;
+
+    case GDK_KEY_Escape:
+      gimp_tool_widget_response (widget, GIMP_TOOL_WIDGET_RESPONSE_CANCEL);
+      return TRUE;
+
+    case GDK_KEY_BackSpace:
+      gimp_tool_widget_response (widget, GIMP_TOOL_WIDGET_RESPONSE_RESET);
+      return TRUE;
+
+    default:
+      break;
+    }
+
+  return FALSE;
+}
+
+
+/*  public functions  */
+
+GimpDisplayShell *
+gimp_tool_widget_get_shell (GimpToolWidget *widget)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  return widget->private->shell;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_get_item (GimpToolWidget *widget)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  return widget->private->item;
+}
+
+void
+gimp_tool_widget_set_visible (GimpToolWidget *widget,
+                              gboolean        visible)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  if (visible != widget->private->visible)
+    {
+      widget->private->visible = visible;
+
+      if (widget->private->item)
+        gimp_canvas_item_set_visible (widget->private->item, visible);
+
+      if (! visible)
+        gimp_tool_widget_set_status (widget, NULL);
+    }
+}
+
+gboolean
+gimp_tool_widget_get_visible (GimpToolWidget *widget)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), FALSE);
+
+  return widget->private->visible;
+}
+
+void
+gimp_tool_widget_set_focus (GimpToolWidget *widget,
+                            gboolean        focus)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  if (focus != widget->private->focus)
+    {
+      widget->private->focus = focus;
+
+      g_signal_emit (widget, widget_signals[FOCUS_CHANGED], 0);
+    }
+}
+
+gboolean
+gimp_tool_widget_get_focus (GimpToolWidget *widget)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), FALSE);
+
+  return widget->private->focus;
+}
+
+void
+gimp_tool_widget_changed (GimpToolWidget *widget)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  g_signal_emit (widget, widget_signals[CHANGED], 0);
+}
+
+void
+gimp_tool_widget_response (GimpToolWidget *widget,
+                           gint            response_id)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  g_signal_emit (widget, widget_signals[RESPONSE], 0,
+                 response_id);
+}
+
+void
+gimp_tool_widget_set_snap_offsets (GimpToolWidget *widget,
+                                   gint            offset_x,
+                                   gint            offset_y,
+                                   gint            width,
+                                   gint            height)
+{
+  GimpToolWidgetPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  private = widget->private;
+
+  if (offset_x != private->snap_offset_x ||
+      offset_y != private->snap_offset_y ||
+      width    != private->snap_width    ||
+      height   != private->snap_height)
+    {
+      private->snap_offset_x = offset_x;
+      private->snap_offset_y = offset_y;
+      private->snap_width    = width;
+      private->snap_height   = height;
+
+      g_signal_emit (widget, widget_signals[SNAP_OFFSETS], 0,
+                 offset_x, offset_y, width, height);
+    }
+}
+
+void
+gimp_tool_widget_get_snap_offsets (GimpToolWidget *widget,
+                                   gint           *offset_x,
+                                   gint           *offset_y,
+                                   gint           *width,
+                                   gint           *height)
+{
+  GimpToolWidgetPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  private = widget->private;
+
+  if (offset_x) *offset_x = private->snap_offset_x;
+  if (offset_y) *offset_y = private->snap_offset_y;
+  if (width)    *width    = private->snap_width;
+  if (height)   *height   = private->snap_height;
+}
+
+void
+gimp_tool_widget_set_status (GimpToolWidget *widget,
+                             const gchar    *status)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  g_signal_emit (widget, widget_signals[STATUS], 0,
+                 status);
+}
+
+void
+gimp_tool_widget_set_status_coords (GimpToolWidget *widget,
+                                    const gchar    *title,
+                                    gdouble         x,
+                                    const gchar    *separator,
+                                    gdouble         y,
+                                    const gchar    *help)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  g_signal_emit (widget, widget_signals[STATUS_COORDS], 0,
+                 title, x, separator, y, help);
+}
+
+void
+gimp_tool_widget_message (GimpToolWidget *widget,
+                          const gchar    *format,
+                          ...)
+{
+  va_list  args;
+  gchar   *message;
+
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (format != NULL);
+
+  va_start (args, format);
+
+  message = g_strdup_vprintf (format, args);
+
+  va_end (args);
+
+  gimp_tool_widget_message_literal (widget, message);
+
+  g_free (message);
+}
+
+void
+gimp_tool_widget_message_literal (GimpToolWidget *widget,
+                                  const gchar    *message)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (message != NULL);
+
+  g_signal_emit (widget, widget_signals[MESSAGE], 0,
+                 message);
+}
+
+void
+gimp_tool_widget_add_item (GimpToolWidget *widget,
+                           GimpCanvasItem *item)
+{
+  GimpCanvasGroup *group;
+
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  group = GIMP_CANVAS_GROUP (widget->private->item);
+
+  if (widget->private->group_stack)
+    group = widget->private->group_stack->data;
+
+  gimp_canvas_group_add_item (group, item);
+}
+
+void
+gimp_tool_widget_remove_item (GimpToolWidget *widget,
+                              GimpCanvasItem *item)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (widget->private->item),
+                                 item);
+}
+
+GimpCanvasGroup *
+gimp_tool_widget_add_group (GimpToolWidget *widget)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_group_new (widget->private->shell);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return GIMP_CANVAS_GROUP (item);
+}
+
+GimpCanvasGroup *
+gimp_tool_widget_add_stroke_group (GimpToolWidget *widget)
+{
+  GimpCanvasGroup *group;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  group = gimp_tool_widget_add_group (widget);
+  gimp_canvas_group_set_group_stroking (group, TRUE);
+
+  return group;
+}
+
+GimpCanvasGroup *
+gimp_tool_widget_add_fill_group (GimpToolWidget *widget)
+{
+  GimpCanvasGroup *group;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  group = gimp_tool_widget_add_group (widget);
+  gimp_canvas_group_set_group_filling (group, TRUE);
+
+  return group;
+}
+
+void
+gimp_tool_widget_push_group (GimpToolWidget  *widget,
+                             GimpCanvasGroup *group)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
+
+  widget->private->group_stack = g_list_prepend (widget->private->group_stack,
+                                                 group);
+}
+
+void
+gimp_tool_widget_pop_group (GimpToolWidget *widget)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (widget->private->group_stack != NULL);
+
+  widget->private->group_stack = g_list_remove (widget->private->group_stack,
+                                                widget->private->group_stack->data);
+}
+
+/**
+ * gimp_tool_widget_add_line:
+ * @widget: the #GimpToolWidget
+ * @x1:     start point X in image coordinates
+ * @y1:     start point Y in image coordinates
+ * @x2:     end point X in image coordinates
+ * @y2:     end point Y in image coordinates
+ *
+ * This function adds a #GimpCanvasLine to @widget.
+ **/
+GimpCanvasItem *
+gimp_tool_widget_add_line (GimpToolWidget *widget,
+                           gdouble         x1,
+                           gdouble         y1,
+                           gdouble         x2,
+                           gdouble         y2)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_line_new (widget->private->shell,
+                               x1, y1, x2, y2);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_rectangle (GimpToolWidget *widget,
+                                gdouble         x,
+                                gdouble         y,
+                                gdouble         width,
+                                gdouble         height,
+                                gboolean        filled)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_rectangle_new (widget->private->shell,
+                                    x, y, width, height, filled);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_arc (GimpToolWidget *widget,
+                          gdouble         center_x,
+                          gdouble         center_y,
+                          gdouble         radius_x,
+                          gdouble         radius_y,
+                          gdouble         start_angle,
+                          gdouble         slice_angle,
+                          gboolean        filled)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_arc_new (widget->private->shell,
+                              center_x, center_y,
+                              radius_x, radius_y,
+                              start_angle, slice_angle,
+                              filled);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_limit (GimpToolWidget *widget,
+                            GimpLimitType   type,
+                            gdouble         x,
+                            gdouble         y,
+                            gdouble         radius,
+                            gdouble         aspect_ratio,
+                            gdouble         angle,
+                            gboolean        dashed)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_limit_new (widget->private->shell,
+                                type,
+                                x, y,
+                                radius,
+                                aspect_ratio,
+                                angle,
+                                dashed);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_polygon (GimpToolWidget    *widget,
+                              GimpMatrix3       *transform,
+                              const GimpVector2 *points,
+                              gint               n_points,
+                              gboolean           filled)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+  g_return_val_if_fail (points == NULL || n_points > 0, NULL);
+
+  item = gimp_canvas_polygon_new (widget->private->shell,
+                                  points, n_points,
+                                  transform, filled);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_polygon_from_coords (GimpToolWidget    *widget,
+                                          GimpMatrix3       *transform,
+                                          const GimpCoords  *points,
+                                          gint               n_points,
+                                          gboolean           filled)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+  g_return_val_if_fail (points == NULL || n_points > 0, NULL);
+
+  item = gimp_canvas_polygon_new_from_coords (widget->private->shell,
+                                              points, n_points,
+                                              transform, filled);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_path (GimpToolWidget       *widget,
+                           const GimpBezierDesc *desc)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_path_new (widget->private->shell,
+                               desc, 0, 0, FALSE, GIMP_PATH_STYLE_DEFAULT);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_handle (GimpToolWidget   *widget,
+                             GimpHandleType    type,
+                             gdouble           x,
+                             gdouble           y,
+                             gint              width,
+                             gint              height,
+                             GimpHandleAnchor  anchor)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_handle_new (widget->private->shell,
+                                 type, anchor, x, y, width, height);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_corner (GimpToolWidget   *widget,
+                             gdouble           x,
+                             gdouble           y,
+                             gdouble           width,
+                             gdouble           height,
+                             GimpHandleAnchor  anchor,
+                             gint              corner_width,
+                             gint              corner_height,
+                             gboolean          outside)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_corner_new (widget->private->shell,
+                                 x, y, width, height,
+                                 anchor, corner_width, corner_height,
+                                 outside);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_rectangle_guides (GimpToolWidget *widget,
+                                       gdouble         x,
+                                       gdouble         y,
+                                       gdouble         width,
+                                       gdouble         height,
+                                       GimpGuidesType  type)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_rectangle_guides_new (widget->private->shell,
+                                           x, y, width, height, type, 4);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+GimpCanvasItem *
+gimp_tool_widget_add_transform_guides (GimpToolWidget    *widget,
+                                       const GimpMatrix3 *transform,
+                                       gdouble            x1,
+                                       gdouble            y1,
+                                       gdouble            x2,
+                                       gdouble            y2,
+                                       GimpGuidesType     type,
+                                       gint               n_guides,
+                                       gboolean           clip)
+{
+  GimpCanvasItem *item;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), NULL);
+
+  item = gimp_canvas_transform_guides_new (widget->private->shell,
+                                           transform, x1, y1, x2, y2,
+                                           type, n_guides, clip);
+
+  gimp_tool_widget_add_item (widget, item);
+  g_object_unref (item);
+
+  return item;
+}
+
+gint
+gimp_tool_widget_button_press (GimpToolWidget      *widget,
+                               const GimpCoords    *coords,
+                               guint32              time,
+                               GdkModifierType      state,
+                               GimpButtonPressType  press_type)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), 0);
+  g_return_val_if_fail (coords != NULL, 0);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->button_press)
+    {
+      return GIMP_TOOL_WIDGET_GET_CLASS (widget)->button_press (widget,
+                                                                coords, time,
+                                                                state,
+                                                                press_type);
+    }
+
+  return 0;
+}
+
+void
+gimp_tool_widget_button_release (GimpToolWidget        *widget,
+                                 const GimpCoords      *coords,
+                                 guint32                time,
+                                 GdkModifierType        state,
+                                 GimpButtonReleaseType  release_type)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (coords != NULL);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->button_release)
+    {
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->button_release (widget,
+                                                           coords, time, state,
+                                                           release_type);
+    }
+}
+
+void
+gimp_tool_widget_motion (GimpToolWidget   *widget,
+                         const GimpCoords *coords,
+                         guint32           time,
+                         GdkModifierType   state)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (coords != NULL);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->motion)
+    {
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->motion (widget,
+                                                   coords, time, state);
+    }
+}
+
+GimpHit
+gimp_tool_widget_hit (GimpToolWidget   *widget,
+                      const GimpCoords *coords,
+                      GdkModifierType   state,
+                      gboolean          proximity)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), GIMP_HIT_NONE);
+  g_return_val_if_fail (coords != NULL, GIMP_HIT_NONE);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->hit)
+    {
+      return GIMP_TOOL_WIDGET_GET_CLASS (widget)->hit (widget,
+                                                       coords, state,
+                                                       proximity);
+    }
+
+  return GIMP_HIT_NONE;
+}
+
+void
+gimp_tool_widget_hover (GimpToolWidget   *widget,
+                        const GimpCoords *coords,
+                        GdkModifierType   state,
+                        gboolean          proximity)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+  g_return_if_fail (coords != NULL);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->hover)
+    {
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->hover (widget,
+                                                  coords, state, proximity);
+    }
+}
+
+void
+gimp_tool_widget_leave_notify (GimpToolWidget *widget)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->leave_notify)
+    {
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->leave_notify (widget);
+    }
+}
+
+gboolean
+gimp_tool_widget_key_press (GimpToolWidget *widget,
+                            GdkEventKey    *kevent)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), FALSE);
+  g_return_val_if_fail (kevent != NULL, FALSE);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->key_press)
+    {
+      return GIMP_TOOL_WIDGET_GET_CLASS (widget)->key_press (widget, kevent);
+    }
+
+  return FALSE;
+}
+
+gboolean
+gimp_tool_widget_key_release (GimpToolWidget *widget,
+                              GdkEventKey    *kevent)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), FALSE);
+  g_return_val_if_fail (kevent != NULL, FALSE);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->key_release)
+    {
+      return GIMP_TOOL_WIDGET_GET_CLASS (widget)->key_release (widget, kevent);
+    }
+
+  return FALSE;
+}
+
+void
+gimp_tool_widget_motion_modifier (GimpToolWidget  *widget,
+                                  GdkModifierType  key,
+                                  gboolean         press,
+                                  GdkModifierType  state)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->motion_modifier)
+    {
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->motion_modifier (widget,
+                                                            key, press, state);
+    }
+}
+
+void
+gimp_tool_widget_hover_modifier (GimpToolWidget  *widget,
+                                 GdkModifierType  key,
+                                 gboolean         press,
+                                 GdkModifierType  state)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET (widget));
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->hover_modifier)
+    {
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->hover_modifier (widget,
+                                                           key, press, state);
+    }
+}
+
+gboolean
+gimp_tool_widget_get_cursor (GimpToolWidget      *widget,
+                             const GimpCoords    *coords,
+                             GdkModifierType      state,
+                             GimpCursorType      *cursor,
+                             GimpToolCursorType  *tool_cursor,
+                             GimpCursorModifier  *modifier)
+
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET (widget), FALSE);
+  g_return_val_if_fail (coords != NULL, FALSE);
+
+  if (widget->private->visible &&
+      GIMP_TOOL_WIDGET_GET_CLASS (widget)->get_cursor)
+    {
+      GimpCursorType     my_cursor;
+      GimpToolCursorType my_tool_cursor;
+      GimpCursorModifier my_modifier;
+
+      if (cursor)      my_cursor      = *cursor;
+      if (tool_cursor) my_tool_cursor = *tool_cursor;
+      if (modifier)    my_modifier    = *modifier;
+
+      if (GIMP_TOOL_WIDGET_GET_CLASS (widget)->get_cursor (widget, coords,
+                                                           state,
+                                                           &my_cursor,
+                                                           &my_tool_cursor,
+                                                           &my_modifier))
+        {
+          if (cursor)      *cursor      = my_cursor;
+          if (tool_cursor) *tool_cursor = my_tool_cursor;
+          if (modifier)    *modifier    = my_modifier;
+
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}
diff --git a/app/display/gimptoolwidget.h b/app/display/gimptoolwidget.h
new file mode 100644
index 0000000..742aa2a
--- /dev/null
+++ b/app/display/gimptoolwidget.h
@@ -0,0 +1,318 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolwidget.h
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_WIDGET_H__
+#define __GIMP_TOOL_WIDGET_H__
+
+
+#include "core/gimpobject.h"
+
+
+#define GIMP_TOOL_WIDGET_RESPONSE_CONFIRM -1
+#define GIMP_TOOL_WIDGET_RESPONSE_CANCEL  -2
+#define GIMP_TOOL_WIDGET_RESPONSE_RESET   -3
+
+
+#define GIMP_TYPE_TOOL_WIDGET            (gimp_tool_widget_get_type ())
+#define GIMP_TOOL_WIDGET(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_WIDGET, GimpToolWidget))
+#define GIMP_TOOL_WIDGET_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_WIDGET, GimpToolWidgetClass))
+#define GIMP_IS_TOOL_WIDGET(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_WIDGET))
+#define GIMP_IS_TOOL_WIDGET_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_WIDGET))
+#define GIMP_TOOL_WIDGET_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_WIDGET, GimpToolWidgetClass))
+
+
+typedef struct _GimpToolWidgetPrivate GimpToolWidgetPrivate;
+typedef struct _GimpToolWidgetClass   GimpToolWidgetClass;
+
+struct _GimpToolWidget
+{
+  GimpObject             parent_instance;
+
+  GimpToolWidgetPrivate *private;
+};
+
+struct _GimpToolWidgetClass
+{
+  GimpObjectClass  parent_class;
+
+  /*  signals  */
+  void     (* changed)         (GimpToolWidget        *widget);
+  void     (* response)        (GimpToolWidget        *widget,
+                                gint                   response_id);
+  void     (* snap_offsets)    (GimpToolWidget        *widget,
+                                gint                   offset_x,
+                                gint                   offset_y,
+                                gint                   width,
+                                gint                   height);
+  void     (* status)          (GimpToolWidget        *widget,
+                                const gchar           *status);
+  void     (* status_coords)   (GimpToolWidget        *widget,
+                                const gchar           *title,
+                                gdouble                x,
+                                const gchar           *separator,
+                                gdouble                y,
+                                const gchar           *help);
+  void     (* message)         (GimpToolWidget        *widget,
+                                const gchar           *message);
+  void     (* focus_changed)   (GimpToolWidget        *widget);
+
+  /*  virtual functions  */
+  gint     (* button_press)    (GimpToolWidget        *widget,
+                                const GimpCoords      *coords,
+                                guint32                time,
+                                GdkModifierType        state,
+                                GimpButtonPressType    press_type);
+  void     (* button_release)  (GimpToolWidget        *widget,
+                                const GimpCoords      *coords,
+                                guint32                time,
+                                GdkModifierType        state,
+                                GimpButtonReleaseType  release_type);
+  void     (* motion)          (GimpToolWidget        *widget,
+                                const GimpCoords      *coords,
+                                guint32                time,
+                                GdkModifierType        state);
+
+  GimpHit  (* hit)             (GimpToolWidget        *widget,
+                                const GimpCoords      *coords,
+                                GdkModifierType        state,
+                                gboolean               proximity);
+  void     (* hover)           (GimpToolWidget        *widget,
+                                const GimpCoords      *coords,
+                                GdkModifierType        state,
+                                gboolean               proximity);
+  void     (* leave_notify)    (GimpToolWidget        *widget);
+
+  gboolean (* key_press)       (GimpToolWidget        *widget,
+                                GdkEventKey           *kevent);
+  gboolean (* key_release)     (GimpToolWidget        *widget,
+                                GdkEventKey           *kevent);
+
+  void     (* motion_modifier) (GimpToolWidget        *widget,
+                                GdkModifierType        key,
+                                gboolean               press,
+                                GdkModifierType        state);
+  void     (* hover_modifier)  (GimpToolWidget        *widget,
+                                GdkModifierType        key,
+                                gboolean               press,
+                                GdkModifierType        state);
+
+  gboolean (* get_cursor)      (GimpToolWidget        *widget,
+                                const GimpCoords      *coords,
+                                GdkModifierType        state,
+                                GimpCursorType        *cursor,
+                                GimpToolCursorType    *tool_cursor,
+                                GimpCursorModifier    *modifier);
+
+  gboolean update_on_scale;
+  gboolean update_on_scroll;
+  gboolean update_on_rotate;
+};
+
+
+GType              gimp_tool_widget_get_type          (void) G_GNUC_CONST;
+
+GimpDisplayShell * gimp_tool_widget_get_shell         (GimpToolWidget  *widget);
+GimpCanvasItem   * gimp_tool_widget_get_item          (GimpToolWidget  *widget);
+
+void               gimp_tool_widget_set_visible       (GimpToolWidget  *widget,
+                                                       gboolean         visible);
+gboolean           gimp_tool_widget_get_visible       (GimpToolWidget  *widget);
+
+void               gimp_tool_widget_set_focus         (GimpToolWidget  *widget,
+                                                       gboolean         focus);
+gboolean           gimp_tool_widget_get_focus         (GimpToolWidget  *widget);
+
+/*  for subclasses, to notify the handling tool
+ */
+void               gimp_tool_widget_changed           (GimpToolWidget  *widget);
+
+void               gimp_tool_widget_response          (GimpToolWidget  *widget,
+                                                       gint             response_id);
+
+void               gimp_tool_widget_set_snap_offsets  (GimpToolWidget  *widget,
+                                                       gint             offset_x,
+                                                       gint             offset_y,
+                                                       gint             width,
+                                                       gint             height);
+void               gimp_tool_widget_get_snap_offsets  (GimpToolWidget  *widget,
+                                                       gint            *offset_x,
+                                                       gint            *offset_y,
+                                                       gint            *width,
+                                                       gint            *height);
+
+void               gimp_tool_widget_set_status        (GimpToolWidget  *widget,
+                                                       const gchar     *status);
+void               gimp_tool_widget_set_status_coords (GimpToolWidget  *widget,
+                                                       const gchar     *title,
+                                                       gdouble          x,
+                                                       const gchar     *separator,
+                                                       gdouble          y,
+                                                       const gchar     *help);
+
+void               gimp_tool_widget_message           (GimpToolWidget  *widget,
+                                                       const gchar     *format,
+                                                       ...) G_GNUC_PRINTF (2, 3);
+void               gimp_tool_widget_message_literal   (GimpToolWidget  *widget,
+                                                       const gchar     *message);
+
+/*  for subclasses, to add and manage their items
+ */
+void               gimp_tool_widget_add_item         (GimpToolWidget  *widget,
+                                                      GimpCanvasItem  *item);
+void               gimp_tool_widget_remove_item      (GimpToolWidget  *widget,
+                                                      GimpCanvasItem  *item);
+
+GimpCanvasGroup  * gimp_tool_widget_add_group        (GimpToolWidget  *widget);
+GimpCanvasGroup  * gimp_tool_widget_add_stroke_group (GimpToolWidget  *widget);
+GimpCanvasGroup  * gimp_tool_widget_add_fill_group   (GimpToolWidget  *widget);
+
+void               gimp_tool_widget_push_group       (GimpToolWidget  *widget,
+                                                      GimpCanvasGroup *group);
+void               gimp_tool_widget_pop_group        (GimpToolWidget  *widget);
+
+/*  for subclasses, convenience functions to add specific items
+ */
+GimpCanvasItem * gimp_tool_widget_add_line      (GimpToolWidget       *widget,
+                                                 gdouble               x1,
+                                                 gdouble               y1,
+                                                 gdouble               x2,
+                                                 gdouble               y2);
+GimpCanvasItem * gimp_tool_widget_add_rectangle (GimpToolWidget       *widget,
+                                                 gdouble               x,
+                                                 gdouble               y,
+                                                 gdouble               width,
+                                                 gdouble               height,
+                                                 gboolean              filled);
+GimpCanvasItem * gimp_tool_widget_add_arc       (GimpToolWidget       *widget,
+                                                 gdouble               center_x,
+                                                 gdouble               center_y,
+                                                 gdouble               radius_x,
+                                                 gdouble               radius_y,
+                                                 gdouble               start_angle,
+                                                 gdouble               slice_angle,
+                                                 gboolean              filled);
+GimpCanvasItem * gimp_tool_widget_add_limit     (GimpToolWidget       *widget,
+                                                 GimpLimitType         type,
+                                                 gdouble               x,
+                                                 gdouble               y,
+                                                 gdouble               radius,
+                                                 gdouble               aspect_ratio,
+                                                 gdouble               angle,
+                                                 gboolean              dashed);
+GimpCanvasItem * gimp_tool_widget_add_polygon   (GimpToolWidget       *widget,
+                                                 GimpMatrix3          *transform,
+                                                 const GimpVector2    *points,
+                                                 gint                  n_points,
+                                                 gboolean              filled);
+GimpCanvasItem * gimp_tool_widget_add_polygon_from_coords
+                                                (GimpToolWidget       *widget,
+                                                 GimpMatrix3          *transform,
+                                                 const GimpCoords     *points,
+                                                 gint                  n_points,
+                                                 gboolean              filled);
+GimpCanvasItem * gimp_tool_widget_add_path      (GimpToolWidget       *widget,
+                                                 const GimpBezierDesc *desc);
+
+GimpCanvasItem * gimp_tool_widget_add_handle    (GimpToolWidget       *widget,
+                                                 GimpHandleType        type,
+                                                 gdouble               x,
+                                                 gdouble               y,
+                                                 gint                  width,
+                                                 gint                  height,
+                                                 GimpHandleAnchor      anchor);
+GimpCanvasItem * gimp_tool_widget_add_corner    (GimpToolWidget       *widget,
+                                                 gdouble               x,
+                                                 gdouble               y,
+                                                 gdouble               width,
+                                                 gdouble               height,
+                                                 GimpHandleAnchor      anchor,
+                                                 gint                  corner_width,
+                                                 gint                  corner_height,
+                                                 gboolean              outside);
+
+GimpCanvasItem * gimp_tool_widget_add_rectangle_guides
+                                                (GimpToolWidget       *widget,
+                                                 gdouble               x,
+                                                 gdouble               y,
+                                                 gdouble               width,
+                                                 gdouble               height,
+                                                 GimpGuidesType        type);
+GimpCanvasItem * gimp_tool_widget_add_transform_guides
+                                                (GimpToolWidget       *widget,
+                                                 const GimpMatrix3    *transform,
+                                                 gdouble               x1,
+                                                 gdouble               y1,
+                                                 gdouble               x2,
+                                                 gdouble               y2,
+                                                 GimpGuidesType        type,
+                                                 gint                  n_guides,
+                                                 gboolean              clip);
+
+/*  for tools, to be called from the respective GimpTool method
+ *  implementations
+ */
+gint       gimp_tool_widget_button_press    (GimpToolWidget        *widget,
+                                             const GimpCoords      *coords,
+                                             guint32                time,
+                                             GdkModifierType        state,
+                                             GimpButtonPressType    press_type);
+void       gimp_tool_widget_button_release  (GimpToolWidget        *widget,
+                                             const GimpCoords      *coords,
+                                             guint32                time,
+                                             GdkModifierType        state,
+                                             GimpButtonReleaseType  release_type);
+void       gimp_tool_widget_motion          (GimpToolWidget        *widget,
+                                             const GimpCoords      *coords,
+                                             guint32                time,
+                                             GdkModifierType        state);
+
+GimpHit    gimp_tool_widget_hit             (GimpToolWidget        *widget,
+                                             const GimpCoords      *coords,
+                                             GdkModifierType        state,
+                                             gboolean               proximity);
+void       gimp_tool_widget_hover           (GimpToolWidget        *widget,
+                                             const GimpCoords      *coords,
+                                             GdkModifierType        state,
+                                             gboolean               proximity);
+void       gimp_tool_widget_leave_notify    (GimpToolWidget        *widget);
+
+gboolean   gimp_tool_widget_key_press       (GimpToolWidget        *widget,
+                                             GdkEventKey           *kevent);
+gboolean   gimp_tool_widget_key_release     (GimpToolWidget        *widget,
+                                             GdkEventKey           *kevent);
+
+void       gimp_tool_widget_motion_modifier (GimpToolWidget        *widget,
+                                             GdkModifierType        key,
+                                             gboolean               press,
+                                             GdkModifierType        state);
+void       gimp_tool_widget_hover_modifier  (GimpToolWidget        *widget,
+                                             GdkModifierType        key,
+                                             gboolean               press,
+                                             GdkModifierType        state);
+
+gboolean   gimp_tool_widget_get_cursor      (GimpToolWidget        *widget,
+                                             const GimpCoords      *coords,
+                                             GdkModifierType        state,
+                                             GimpCursorType        *cursor,
+                                             GimpToolCursorType    *tool_cursor,
+                                             GimpCursorModifier    *modifier);
+
+
+#endif /* __GIMP_TOOL_WIDGET_H__ */
diff --git a/app/display/gimptoolwidgetgroup.c b/app/display/gimptoolwidgetgroup.c
new file mode 100644
index 0000000..d62f4c9
--- /dev/null
+++ b/app/display/gimptoolwidgetgroup.c
@@ -0,0 +1,731 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolwidgetgroup.c
+ * Copyright (C) 2018 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "core/gimpcontainer.h"
+#include "core/gimplist.h"
+
+#include "gimpcanvasgroup.h"
+#include "gimpdisplayshell.h"
+#include "gimptoolwidgetgroup.h"
+
+
+struct _GimpToolWidgetGroupPrivate
+{
+  GimpContainer  *children;
+
+  GimpToolWidget *focus_widget;
+  GimpToolWidget *hover_widget;
+
+  gboolean        auto_raise;
+};
+
+
+/*  local function prototypes  */
+
+static void             gimp_tool_widget_group_finalize            (GObject               *object);
+
+static void             gimp_tool_widget_group_focus_changed       (GimpToolWidget        *widget);
+static gint             gimp_tool_widget_group_button_press        (GimpToolWidget        *widget,
+                                                                    const GimpCoords      *coords,
+                                                                    guint32                time,
+                                                                    GdkModifierType        state,
+                                                                    GimpButtonPressType    press_type);
+static void             gimp_tool_widget_group_button_release      (GimpToolWidget        *widget,
+                                                                    const GimpCoords      *coords,
+                                                                    guint32                time,
+                                                                    GdkModifierType        state,
+                                                                    GimpButtonReleaseType  release_type);
+static void             gimp_tool_widget_group_motion              (GimpToolWidget        *widget,
+                                                                    const GimpCoords      *coords,
+                                                                    guint32                time,
+                                                                    GdkModifierType        state);
+static GimpHit          gimp_tool_widget_group_hit                 (GimpToolWidget        *widget,
+                                                                    const GimpCoords      *coords,
+                                                                    GdkModifierType        state,
+                                                                    gboolean               proximity);
+static void             gimp_tool_widget_group_hover               (GimpToolWidget        *widget,
+                                                                    const GimpCoords      *coords,
+                                                                    GdkModifierType        state,
+                                                                    gboolean               proximity);
+static void             gimp_tool_widget_group_leave_notify        (GimpToolWidget        *widget);
+static gboolean         gimp_tool_widget_group_key_press           (GimpToolWidget        *widget,
+                                                                    GdkEventKey           *kevent);
+static gboolean         gimp_tool_widget_group_key_release         (GimpToolWidget        *widget,
+                                                                    GdkEventKey           *kevent);
+static void             gimp_tool_widget_group_motion_modifier     (GimpToolWidget        *widget,
+                                                                    GdkModifierType        key,
+                                                                    gboolean               press,
+                                                                    GdkModifierType        state);
+static void             gimp_tool_widget_group_hover_modifier      (GimpToolWidget        *widget,
+                                                                    GdkModifierType        key,
+                                                                    gboolean               press,
+                                                                    GdkModifierType        state);
+static gboolean         gimp_tool_widget_group_get_cursor          (GimpToolWidget        *widget,
+                                                                    const GimpCoords      *coords,
+                                                                    GdkModifierType        state,
+                                                                    GimpCursorType        *cursor,
+                                                                    GimpToolCursorType    *tool_cursor,
+                                                                    GimpCursorModifier    *modifier);
+
+static void             gimp_tool_widget_group_children_add        (GimpContainer         *container,
+                                                                    GimpToolWidget        *child,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_children_remove     (GimpContainer         *container,
+                                                                    GimpToolWidget        *child,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_children_reorder    (GimpContainer         *container,
+                                                                    GimpToolWidget        *child,
+                                                                    gint                   new_index,
+                                                                    GimpToolWidgetGroup   *group);
+
+static void             gimp_tool_widget_group_child_changed       (GimpToolWidget        *child,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_child_response      (GimpToolWidget        *child,
+                                                                    gint                   response_id,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_child_snap_offsets  (GimpToolWidget        *child,
+                                                                    gint                   offset_x,
+                                                                    gint                   offset_y,
+                                                                    gint                   width,
+                                                                    gint                   height,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_child_status        (GimpToolWidget        *child,
+                                                                    const gchar           *status,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_child_status_coords (GimpToolWidget        *child,
+                                                                    const gchar           *title,
+                                                                    gdouble                x,
+                                                                    const gchar           *separator,
+                                                                    gdouble                y,
+                                                                    const gchar           *help,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_child_message       (GimpToolWidget        *child,
+                                                                    const gchar           *message,
+                                                                    GimpToolWidgetGroup   *group);
+static void             gimp_tool_widget_group_child_focus_changed (GimpToolWidget        *child,
+                                                                    GimpToolWidgetGroup   *group);
+
+static GimpToolWidget * gimp_tool_widget_group_get_hover_widget    (GimpToolWidgetGroup   *group,
+                                                                    const GimpCoords      *coords,
+                                                                    GdkModifierType        state,
+                                                                    gboolean               proximity,
+                                                                    GimpHit               *hit);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolWidgetGroup, gimp_tool_widget_group,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_widget_group_parent_class
+
+
+/*  priv functions  */
+
+
+static void
+gimp_tool_widget_group_class_init (GimpToolWidgetGroupClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->finalize        = gimp_tool_widget_group_finalize;
+
+  widget_class->focus_changed   = gimp_tool_widget_group_focus_changed;
+  widget_class->button_press    = gimp_tool_widget_group_button_press;
+  widget_class->button_release  = gimp_tool_widget_group_button_release;
+  widget_class->motion          = gimp_tool_widget_group_motion;
+  widget_class->hit             = gimp_tool_widget_group_hit;
+  widget_class->hover           = gimp_tool_widget_group_hover;
+  widget_class->leave_notify    = gimp_tool_widget_group_leave_notify;
+  widget_class->key_press       = gimp_tool_widget_group_key_press;
+  widget_class->key_release     = gimp_tool_widget_group_key_release;
+  widget_class->motion_modifier = gimp_tool_widget_group_motion_modifier;
+  widget_class->hover_modifier  = gimp_tool_widget_group_hover_modifier;
+  widget_class->get_cursor      = gimp_tool_widget_group_get_cursor;
+}
+
+static void
+gimp_tool_widget_group_init (GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv;
+
+  priv = group->priv = gimp_tool_widget_group_get_instance_private (group);
+
+  priv->children = g_object_new (GIMP_TYPE_LIST,
+                                 "children-type", GIMP_TYPE_TOOL_WIDGET,
+                                 "append",        TRUE,
+                                 NULL);
+
+  g_signal_connect (priv->children, "add",
+                    G_CALLBACK (gimp_tool_widget_group_children_add),
+                    group);
+  g_signal_connect (priv->children, "remove",
+                    G_CALLBACK (gimp_tool_widget_group_children_remove),
+                    group);
+  g_signal_connect (priv->children, "reorder",
+                    G_CALLBACK (gimp_tool_widget_group_children_reorder),
+                    group);
+
+  gimp_container_add_handler (priv->children, "changed",
+                              G_CALLBACK (gimp_tool_widget_group_child_changed),
+                              group);
+  gimp_container_add_handler (priv->children, "response",
+                              G_CALLBACK (gimp_tool_widget_group_child_response),
+                              group);
+  gimp_container_add_handler (priv->children, "snap-offsets",
+                              G_CALLBACK (gimp_tool_widget_group_child_snap_offsets),
+                              group);
+  gimp_container_add_handler (priv->children, "status",
+                              G_CALLBACK (gimp_tool_widget_group_child_status),
+                              group);
+  gimp_container_add_handler (priv->children, "status-coords",
+                              G_CALLBACK (gimp_tool_widget_group_child_status_coords),
+                              group);
+  gimp_container_add_handler (priv->children, "message",
+                              G_CALLBACK (gimp_tool_widget_group_child_message),
+                              group);
+  gimp_container_add_handler (priv->children, "focus-changed",
+                              G_CALLBACK (gimp_tool_widget_group_child_focus_changed),
+                              group);
+}
+
+static void
+gimp_tool_widget_group_finalize (GObject *object)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (object);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  g_clear_object (&priv->children);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static gint
+gimp_tool_widget_group_button_press (GimpToolWidget      *widget,
+                                     const GimpCoords    *coords,
+                                     guint32              time,
+                                     GdkModifierType      state,
+                                     GimpButtonPressType  press_type)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  gimp_tool_widget_group_hover (widget, coords, state, TRUE);
+
+  if (priv->focus_widget != priv->hover_widget)
+    {
+      if (priv->hover_widget)
+        gimp_tool_widget_set_focus (priv->hover_widget, TRUE);
+      else if (priv->focus_widget)
+        gimp_tool_widget_set_focus (priv->focus_widget, FALSE);
+    }
+
+  if (priv->hover_widget)
+    {
+      if (priv->auto_raise)
+        {
+          gimp_container_reorder (priv->children,
+                                  GIMP_OBJECT (priv->hover_widget), -1);
+        }
+
+      return gimp_tool_widget_button_press (priv->hover_widget,
+                                            coords, time, state, press_type);
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_tool_widget_group_focus_changed (GimpToolWidget *widget)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  if (priv->focus_widget)
+    {
+      GimpToolWidget *focus_widget = priv->focus_widget;
+
+      gimp_tool_widget_set_focus (priv->focus_widget,
+                                  gimp_tool_widget_get_focus (widget));
+
+      priv->focus_widget = focus_widget;
+    }
+}
+
+static void
+gimp_tool_widget_group_button_release (GimpToolWidget        *widget,
+                                       const GimpCoords      *coords,
+                                       guint32                time,
+                                       GdkModifierType        state,
+                                       GimpButtonReleaseType  release_type)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  if (priv->hover_widget)
+    {
+      gimp_tool_widget_button_release (priv->hover_widget,
+                                       coords, time, state, release_type);
+    }
+}
+
+static void
+gimp_tool_widget_group_motion (GimpToolWidget   *widget,
+                        const GimpCoords *coords,
+                        guint32           time,
+                        GdkModifierType   state)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv = group->priv;
+
+  if (priv->hover_widget)
+    gimp_tool_widget_motion (priv->hover_widget, coords, time, state);
+}
+
+static GimpHit
+gimp_tool_widget_group_hit (GimpToolWidget   *widget,
+                            const GimpCoords *coords,
+                            GdkModifierType   state,
+                            gboolean          proximity)
+{
+  GimpToolWidgetGroup *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpHit              hit;
+
+  gimp_tool_widget_group_get_hover_widget (group,
+                                           coords, state, proximity,
+                                           &hit);
+
+  return hit;
+}
+
+static void
+gimp_tool_widget_group_hover (GimpToolWidget   *widget,
+                              const GimpCoords *coords,
+                              GdkModifierType   state,
+                              gboolean          proximity)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+  GimpToolWidget             *hover_widget;
+
+  hover_widget =
+    gimp_tool_widget_group_get_hover_widget (group,
+                                             coords, state, proximity,
+                                             NULL);
+
+  if (priv->hover_widget && priv->hover_widget != hover_widget)
+    gimp_tool_widget_leave_notify (priv->hover_widget);
+
+  priv->hover_widget = hover_widget;
+
+  if (priv->hover_widget)
+    gimp_tool_widget_hover (priv->hover_widget, coords, state, proximity);
+}
+
+static void
+gimp_tool_widget_group_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  if (priv->hover_widget)
+    {
+      gimp_tool_widget_leave_notify (priv->hover_widget);
+
+      priv->hover_widget = NULL;
+    }
+
+  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
+}
+
+static gboolean
+gimp_tool_widget_group_key_press (GimpToolWidget *widget,
+                                  GdkEventKey    *kevent)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  if (priv->focus_widget)
+    return gimp_tool_widget_key_press (priv->focus_widget, kevent);
+
+  return GIMP_TOOL_WIDGET_CLASS (parent_class)->key_press (widget, kevent);
+}
+
+static gboolean
+gimp_tool_widget_group_key_release (GimpToolWidget *widget,
+                                    GdkEventKey    *kevent)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  if (priv->focus_widget)
+    return gimp_tool_widget_key_release (priv->focus_widget, kevent);
+
+  return FALSE;
+}
+
+static void
+gimp_tool_widget_group_motion_modifier (GimpToolWidget  *widget,
+                                        GdkModifierType  key,
+                                        gboolean         press,
+                                        GdkModifierType  state)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  if (priv->hover_widget)
+    gimp_tool_widget_motion_modifier (priv->hover_widget, key, press, state);
+}
+
+static void
+gimp_tool_widget_group_hover_modifier (GimpToolWidget  *widget,
+                                       GdkModifierType  key,
+                                       gboolean         press,
+                                       GdkModifierType  state)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+  GList                      *iter;
+
+  for (iter = g_queue_peek_head_link (GIMP_LIST (priv->children)->queue);
+       iter;
+       iter = g_list_next (iter))
+    {
+      gimp_tool_widget_hover_modifier (iter->data, key, press, state);
+    }
+}
+
+static gboolean
+gimp_tool_widget_group_get_cursor (GimpToolWidget     *widget,
+                                   const GimpCoords   *coords,
+                                   GdkModifierType     state,
+                                   GimpCursorType     *cursor,
+                                   GimpToolCursorType *tool_cursor,
+                                   GimpCursorModifier *modifier)
+{
+  GimpToolWidgetGroup        *group = GIMP_TOOL_WIDGET_GROUP (widget);
+  GimpToolWidgetGroupPrivate *priv  = group->priv;
+
+  if (priv->hover_widget)
+    {
+      return gimp_tool_widget_get_cursor (priv->hover_widget,
+                                          coords, state,
+                                          cursor, tool_cursor, modifier);
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_tool_widget_group_children_add (GimpContainer       *container,
+                                     GimpToolWidget      *child,
+                                     GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+  GimpCanvasGroup            *canvas_group;
+
+  canvas_group = GIMP_CANVAS_GROUP (gimp_tool_widget_get_item (widget));
+
+  gimp_canvas_group_add_item (canvas_group,
+                              gimp_tool_widget_get_item (child));
+
+  if (gimp_tool_widget_get_focus (child) && priv->focus_widget)
+    {
+      gimp_tool_widget_set_focus (priv->focus_widget, FALSE);
+
+      priv->focus_widget = NULL;
+    }
+
+  if (! priv->focus_widget)
+    {
+      priv->focus_widget = child;
+
+      gimp_tool_widget_set_focus (child, gimp_tool_widget_get_focus (widget));
+    }
+
+  gimp_tool_widget_changed (widget);
+}
+
+static void
+gimp_tool_widget_group_children_remove (GimpContainer       *container,
+                                        GimpToolWidget      *child,
+                                        GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+  GimpCanvasGroup            *canvas_group;
+
+  canvas_group = GIMP_CANVAS_GROUP (gimp_tool_widget_get_item (widget));
+
+  if (priv->focus_widget == child)
+    {
+      gimp_tool_widget_set_focus (child, FALSE);
+
+      priv->focus_widget = NULL;
+    }
+
+  if (priv->hover_widget == child)
+    {
+      gimp_tool_widget_leave_notify (child);
+
+      priv->hover_widget = NULL;
+    }
+
+  if (! priv->focus_widget)
+    {
+      priv->focus_widget =
+        GIMP_TOOL_WIDGET (gimp_container_get_last_child (container));
+
+      if (priv->focus_widget)
+        gimp_tool_widget_set_focus (priv->focus_widget, TRUE);
+    }
+
+  gimp_canvas_group_remove_item (canvas_group,
+                                 gimp_tool_widget_get_item (child));
+
+  gimp_tool_widget_changed (widget);
+}
+
+static void
+gimp_tool_widget_group_children_reorder (GimpContainer       *container,
+                                         GimpToolWidget      *child,
+                                         gint                 new_index,
+                                         GimpToolWidgetGroup *group)
+{
+  GimpToolWidget  *widget = GIMP_TOOL_WIDGET (group);
+  GimpCanvasGroup *canvas_group;
+  GList           *iter;
+
+  canvas_group = GIMP_CANVAS_GROUP (gimp_tool_widget_get_item (widget));
+
+  for (iter = g_queue_peek_head_link (GIMP_LIST (container)->queue);
+       iter;
+       iter = g_list_next (iter))
+    {
+      GimpCanvasItem *item = gimp_tool_widget_get_item (iter->data);
+
+      gimp_canvas_group_remove_item (canvas_group, item);
+      gimp_canvas_group_add_item    (canvas_group, item);
+    }
+
+  gimp_tool_widget_changed (widget);
+}
+
+static void
+gimp_tool_widget_group_child_changed (GimpToolWidget      *child,
+                                      GimpToolWidgetGroup *group)
+{
+  GimpToolWidget *widget = GIMP_TOOL_WIDGET (group);
+
+  gimp_tool_widget_changed (widget);
+}
+
+static void
+gimp_tool_widget_group_child_response (GimpToolWidget      *child,
+                                       gint                 response_id,
+                                       GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+
+  if (priv->focus_widget == child)
+    gimp_tool_widget_response (widget, response_id);
+}
+
+static void
+gimp_tool_widget_group_child_snap_offsets (GimpToolWidget      *child,
+                                           gint                 offset_x,
+                                           gint                 offset_y,
+                                           gint                 width,
+                                           gint                 height,
+                                           GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+
+  if (priv->hover_widget == child)
+    {
+      gimp_tool_widget_set_snap_offsets (widget,
+                                         offset_x, offset_y, width, height);
+    }
+}
+
+static void
+gimp_tool_widget_group_child_status (GimpToolWidget      *child,
+                                     const gchar         *status,
+                                     GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+
+  if (priv->hover_widget == child)
+    gimp_tool_widget_set_status (widget, status);
+}
+
+static void
+gimp_tool_widget_group_child_status_coords (GimpToolWidget      *child,
+                                            const gchar         *title,
+                                            gdouble              x,
+                                            const gchar         *separator,
+                                            gdouble              y,
+                                            const gchar         *help,
+                                            GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+
+  if (priv->hover_widget == child)
+    gimp_tool_widget_set_status_coords (widget, title, x, separator, y, help);
+}
+
+static void
+gimp_tool_widget_group_child_message (GimpToolWidget      *child,
+                                      const gchar         *message,
+                                      GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+
+  if (priv->focus_widget == child)
+    gimp_tool_widget_message_literal (widget, message);
+}
+
+static void
+gimp_tool_widget_group_child_focus_changed (GimpToolWidget      *child,
+                                            GimpToolWidgetGroup *group)
+{
+  GimpToolWidgetGroupPrivate *priv   = group->priv;
+  GimpToolWidget             *widget = GIMP_TOOL_WIDGET (group);
+
+  if (gimp_tool_widget_get_focus (child))
+    {
+      if (priv->focus_widget && priv->focus_widget != child)
+        gimp_tool_widget_set_focus (priv->focus_widget, FALSE);
+
+      priv->focus_widget = child;
+
+      gimp_tool_widget_set_focus (widget, TRUE);
+    }
+  else
+    {
+      if (priv->focus_widget == child)
+        priv->focus_widget = NULL;
+    }
+}
+
+static GimpToolWidget *
+gimp_tool_widget_group_get_hover_widget (GimpToolWidgetGroup *group,
+                                         const GimpCoords    *coords,
+                                         GdkModifierType      state,
+                                         gboolean             proximity,
+                                         GimpHit             *hit)
+{
+  GimpToolWidgetGroupPrivate *priv           = group->priv;
+  GimpToolWidget             *indirect_child = NULL;
+  gboolean                    indirect       = FALSE;
+  GList                      *iter;
+
+  for (iter = g_queue_peek_tail_link (GIMP_LIST (priv->children)->queue);
+       iter;
+       iter = g_list_previous (iter))
+    {
+      GimpToolWidget *child = iter->data;
+
+      switch (gimp_tool_widget_hit (child, coords, state, proximity))
+        {
+        case GIMP_HIT_DIRECT:
+          if (hit) *hit = GIMP_HIT_DIRECT;
+
+          return child;
+
+        case GIMP_HIT_INDIRECT:
+          if (! indirect || child == priv->focus_widget)
+            indirect_child = child;
+          else if (indirect_child != priv->focus_widget)
+            indirect_child = NULL;
+
+          indirect = TRUE;
+
+          break;
+
+        case GIMP_HIT_NONE:
+          break;
+        }
+    }
+
+  if (hit) *hit = indirect_child ? GIMP_HIT_INDIRECT : GIMP_HIT_NONE;
+
+  return indirect_child;
+}
+
+
+/*  public functions  */
+
+
+GimpToolWidget *
+gimp_tool_widget_group_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_WIDGET_GROUP,
+                       "shell", shell,
+                       NULL);
+}
+
+GimpContainer *
+gimp_tool_widget_group_get_children (GimpToolWidgetGroup *group)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET_GROUP (group), NULL);
+
+  return group->priv->children;
+}
+
+GimpToolWidget *
+gimp_tool_widget_group_get_focus_widget (GimpToolWidgetGroup *group)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET_GROUP (group), NULL);
+
+  return group->priv->focus_widget;
+}
+
+void
+gimp_tool_widget_group_set_auto_raise (GimpToolWidgetGroup *group,
+                                       gboolean             auto_raise)
+{
+  g_return_if_fail (GIMP_IS_TOOL_WIDGET_GROUP (group));
+
+  group->priv->auto_raise = auto_raise;
+}
+
+gboolean
+gimp_tool_widget_group_get_auto_raise (GimpToolWidgetGroup *group)
+{
+  g_return_val_if_fail (GIMP_IS_TOOL_WIDGET_GROUP (group), FALSE);
+
+  return group->priv->auto_raise;
+}
+
diff --git a/app/display/gimptoolwidgetgroup.h b/app/display/gimptoolwidgetgroup.h
new file mode 100644
index 0000000..0a8331f
--- /dev/null
+++ b/app/display/gimptoolwidgetgroup.h
@@ -0,0 +1,65 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolwidgetgroup.h
+ * Copyright (C) 2018 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_TOOL_WIDGET_GROUP_H__
+#define __GIMP_TOOL_WIDGET_GROUP_H__
+
+
+#include "gimptoolwidget.h"
+
+
+#define GIMP_TYPE_TOOL_WIDGET_GROUP            (gimp_tool_widget_group_get_type ())
+#define GIMP_TOOL_WIDGET_GROUP(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_TOOL_WIDGET_GROUP, GimpToolWidgetGroup))
+#define GIMP_TOOL_WIDGET_GROUP_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_TOOL_WIDGET_GROUP, GimpToolWidgetGroupClass))
+#define GIMP_IS_TOOL_WIDGET_GROUP(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_TOOL_WIDGET_GROUP))
+#define GIMP_IS_TOOL_WIDGET_GROUP_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_TOOL_WIDGET_GROUP))
+#define GIMP_TOOL_WIDGET_GROUP_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_TOOL_WIDGET_GROUP, GimpToolWidgetGroupClass))
+
+
+typedef struct _GimpToolWidgetGroupPrivate GimpToolWidgetGroupPrivate;
+typedef struct _GimpToolWidgetGroupClass   GimpToolWidgetGroupClass;
+
+struct _GimpToolWidgetGroup
+{
+  GimpToolWidget              parent_instance;
+
+  GimpToolWidgetGroupPrivate *priv;
+};
+
+struct _GimpToolWidgetGroupClass
+{
+  GimpToolWidgetClass  parent_class;
+};
+
+
+GType            gimp_tool_widget_group_get_type         (void) G_GNUC_CONST;
+
+GimpToolWidget * gimp_tool_widget_group_new              (GimpDisplayShell    *shell);
+
+GimpContainer  * gimp_tool_widget_group_get_children     (GimpToolWidgetGroup *group);
+
+GimpToolWidget * gimp_tool_widget_group_get_focus_widget (GimpToolWidgetGroup *group);
+
+void             gimp_tool_widget_group_set_auto_raise   (GimpToolWidgetGroup *group,
+                                                          gboolean             auto_raise);
+gboolean         gimp_tool_widget_group_get_auto_raise   (GimpToolWidgetGroup *group);
+
+
+#endif /* __GIMP_TOOL_WIDGET_GROUP_H__ */