Adding upstream version 2.10.22.upstream/2.10.22upstream

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

1 files changed, 1396 insertions, 0 deletions

diff --git a/app/tools/gimpforegroundselecttool.c b/app/tools/gimpforegroundselecttool.c
new file mode 100644
index 0000000..480cff1
--- /dev/null
+++ b/app/tools/gimpforegroundselecttool.c
@@ -0,0 +1,1396 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * GimpForegroundSelectTool
+ * Copyright (C) 2005  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 <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpbase/gimpbase.h"
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "tools-types.h"
+
+#include "config/gimpguiconfig.h"
+
+#include "gegl/gimp-gegl-loops.h"
+#include "gegl/gimp-gegl-mask.h"
+#include "gegl/gimp-gegl-utils.h"
+
+#include "core/gimp.h"
+#include "core/gimpchannel-select.h"
+#include "core/gimpdrawable-foreground-extract.h"
+#include "core/gimperror.h"
+#include "core/gimpimage.h"
+#include "core/gimplayer.h"
+#include "core/gimplayermask.h"
+#include "core/gimpprogress.h"
+#include "core/gimpscanconvert.h"
+
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "display/gimpcanvasitem.h"
+#include "display/gimpcanvasbufferpreview.h"
+#include "display/gimpdisplay.h"
+#include "display/gimpdisplayshell.h"
+#include "display/gimptoolgui.h"
+
+#include "gimpforegroundselecttool.h"
+#include "gimpforegroundselectoptions.h"
+#include "gimptoolcontrol.h"
+
+#include "gimp-intl.h"
+
+
+#define FAR_OUTSIDE -10000
+
+
+typedef struct _StrokeUndo StrokeUndo;
+
+struct _StrokeUndo
+{
+  GeglBuffer          *saved_trimap;
+  gint                 trimap_x;
+  gint                 trimap_y;
+  GimpMattingDrawMode  draw_mode;
+  gint                 stroke_width;
+};
+
+
+static void   gimp_foreground_select_tool_finalize       (GObject          *object);
+
+static gboolean  gimp_foreground_select_tool_initialize  (GimpTool         *tool,
+                                                          GimpDisplay      *display,
+                                                          GError          **error);
+static void   gimp_foreground_select_tool_control        (GimpTool         *tool,
+                                                          GimpToolAction    action,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_button_press   (GimpTool         *tool,
+                                                          const GimpCoords *coords,
+                                                          guint32           time,
+                                                          GdkModifierType   state,
+                                                          GimpButtonPressType press_type,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_button_release (GimpTool         *tool,
+                                                          const GimpCoords *coords,
+                                                          guint32           time,
+                                                          GdkModifierType   state,
+                                                          GimpButtonReleaseType release_type,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_motion         (GimpTool         *tool,
+                                                          const GimpCoords *coords,
+                                                          guint32           time,
+                                                          GdkModifierType   state,
+                                                          GimpDisplay      *display);
+static gboolean  gimp_foreground_select_tool_key_press   (GimpTool         *tool,
+                                                          GdkEventKey      *kevent,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_modifier_key   (GimpTool         *tool,
+                                                          GdkModifierType   key,
+                                                          gboolean          press,
+                                                          GdkModifierType   state,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_active_modifier_key
+                                                         (GimpTool         *tool,
+                                                          GdkModifierType   key,
+                                                          gboolean          press,
+                                                          GdkModifierType   state,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_oper_update    (GimpTool         *tool,
+                                                          const GimpCoords *coords,
+                                                          GdkModifierType   state,
+                                                          gboolean          proximity,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_cursor_update  (GimpTool         *tool,
+                                                          const GimpCoords *coords,
+                                                          GdkModifierType   state,
+                                                          GimpDisplay      *display);
+static const gchar * gimp_foreground_select_tool_can_undo
+                                                         (GimpTool         *tool,
+                                                          GimpDisplay      *display);
+static const gchar * gimp_foreground_select_tool_can_redo
+                                                         (GimpTool         *tool,
+                                                          GimpDisplay      *display);
+static gboolean   gimp_foreground_select_tool_undo       (GimpTool         *tool,
+                                                          GimpDisplay      *display);
+static gboolean   gimp_foreground_select_tool_redo       (GimpTool         *tool,
+                                                          GimpDisplay      *display);
+static void   gimp_foreground_select_tool_options_notify (GimpTool         *tool,
+                                                          GimpToolOptions  *options,
+                                                          const GParamSpec *pspec);
+
+static void   gimp_foreground_select_tool_draw           (GimpDrawTool     *draw_tool);
+
+static void   gimp_foreground_select_tool_confirm        (GimpPolygonSelectTool *poly_sel,
+                                                          GimpDisplay           *display);
+
+static void   gimp_foreground_select_tool_halt           (GimpForegroundSelectTool *fg_select);
+static void   gimp_foreground_select_tool_commit         (GimpForegroundSelectTool *fg_select);
+
+static void   gimp_foreground_select_tool_set_trimap     (GimpForegroundSelectTool *fg_select);
+static void   gimp_foreground_select_tool_set_preview    (GimpForegroundSelectTool *fg_select);
+static void   gimp_foreground_select_tool_preview        (GimpForegroundSelectTool *fg_select);
+
+static void   gimp_foreground_select_tool_stroke_paint   (GimpForegroundSelectTool *fg_select);
+static void   gimp_foreground_select_tool_cancel_paint   (GimpForegroundSelectTool *fg_select);
+
+static void   gimp_foreground_select_tool_response       (GimpToolGui              *gui,
+                                                          gint                      response_id,
+                                                          GimpForegroundSelectTool *fg_select);
+static void   gimp_foreground_select_tool_preview_toggled(GtkToggleButton          *button,
+                                                          GimpForegroundSelectTool *fg_select);
+
+static void   gimp_foreground_select_tool_update_gui     (GimpForegroundSelectTool *fg_select);
+
+static StrokeUndo * gimp_foreground_select_undo_new      (GeglBuffer               *trimap,
+                                                          GArray                   *stroke,
+                                                          GimpMattingDrawMode       draw_mode,
+                                                          gint                      stroke_width);
+static void         gimp_foreground_select_undo_pop      (StrokeUndo               *undo,
+                                                          GeglBuffer               *trimap);
+static void         gimp_foreground_select_undo_free     (StrokeUndo               *undo);
+
+
+G_DEFINE_TYPE (GimpForegroundSelectTool, gimp_foreground_select_tool,
+               GIMP_TYPE_POLYGON_SELECT_TOOL)
+
+#define parent_class gimp_foreground_select_tool_parent_class
+
+
+void
+gimp_foreground_select_tool_register (GimpToolRegisterCallback  callback,
+                                      gpointer                  data)
+{
+  (* callback) (GIMP_TYPE_FOREGROUND_SELECT_TOOL,
+                GIMP_TYPE_FOREGROUND_SELECT_OPTIONS,
+                gimp_foreground_select_options_gui,
+                GIMP_CONTEXT_PROP_MASK_FOREGROUND |
+                GIMP_CONTEXT_PROP_MASK_BACKGROUND,
+                "gimp-foreground-select-tool",
+                _("Foreground Select"),
+                _("Foreground Select Tool: Select a region containing foreground objects"),
+                N_("F_oreground Select"), NULL,
+                NULL, GIMP_HELP_TOOL_FOREGROUND_SELECT,
+                GIMP_ICON_TOOL_FOREGROUND_SELECT,
+                data);
+}
+
+static void
+gimp_foreground_select_tool_class_init (GimpForegroundSelectToolClass *klass)
+{
+  GObjectClass               *object_class    = G_OBJECT_CLASS (klass);
+  GimpToolClass              *tool_class      = GIMP_TOOL_CLASS (klass);
+  GimpDrawToolClass          *draw_tool_class = GIMP_DRAW_TOOL_CLASS (klass);
+  GimpPolygonSelectToolClass *polygon_select_tool_class;
+
+  polygon_select_tool_class = GIMP_POLYGON_SELECT_TOOL_CLASS (klass);
+
+  object_class->finalize             = gimp_foreground_select_tool_finalize;
+
+  tool_class->initialize             = gimp_foreground_select_tool_initialize;
+  tool_class->control                = gimp_foreground_select_tool_control;
+  tool_class->button_press           = gimp_foreground_select_tool_button_press;
+  tool_class->button_release         = gimp_foreground_select_tool_button_release;
+  tool_class->motion                 = gimp_foreground_select_tool_motion;
+  tool_class->key_press              = gimp_foreground_select_tool_key_press;
+  tool_class->modifier_key           = gimp_foreground_select_tool_modifier_key;
+  tool_class->active_modifier_key    = gimp_foreground_select_tool_active_modifier_key;
+  tool_class->oper_update            = gimp_foreground_select_tool_oper_update;
+  tool_class->cursor_update          = gimp_foreground_select_tool_cursor_update;
+  tool_class->can_undo               = gimp_foreground_select_tool_can_undo;
+  tool_class->can_redo               = gimp_foreground_select_tool_can_redo;
+  tool_class->undo                   = gimp_foreground_select_tool_undo;
+  tool_class->redo                   = gimp_foreground_select_tool_redo;
+  tool_class->options_notify         = gimp_foreground_select_tool_options_notify;
+
+  draw_tool_class->draw              = gimp_foreground_select_tool_draw;
+
+  polygon_select_tool_class->confirm = gimp_foreground_select_tool_confirm;
+}
+
+static void
+gimp_foreground_select_tool_init (GimpForegroundSelectTool *fg_select)
+{
+  GimpTool *tool = GIMP_TOOL (fg_select);
+
+  gimp_tool_control_set_motion_mode (tool->control, GIMP_MOTION_MODE_EXACT);
+  gimp_tool_control_set_scroll_lock (tool->control, FALSE);
+  gimp_tool_control_set_preserve    (tool->control, FALSE);
+  gimp_tool_control_set_dirty_mask  (tool->control,
+                                     GIMP_DIRTY_IMAGE_SIZE |
+                                     GIMP_DIRTY_ACTIVE_DRAWABLE);
+  gimp_tool_control_set_precision   (tool->control,
+                                     GIMP_CURSOR_PRECISION_SUBPIXEL);
+  gimp_tool_control_set_tool_cursor (tool->control,
+                                     GIMP_TOOL_CURSOR_FREE_SELECT);
+
+  gimp_tool_control_set_action_size (tool->control,
+                                     "tools/tools-foreground-select-brush-size-set");
+
+  fg_select->state = MATTING_STATE_FREE_SELECT;
+  fg_select->grayscale_preview = NULL;
+}
+
+static void
+gimp_foreground_select_tool_finalize (GObject *object)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (object);
+
+  g_clear_object (&fg_select->gui);
+  fg_select->preview_toggle = NULL;
+
+  if (fg_select->stroke)
+    g_warning ("%s: stroke should be NULL at this point", G_STRLOC);
+
+  if (fg_select->mask)
+    g_warning ("%s: mask should be NULL at this point", G_STRLOC);
+
+  if (fg_select->trimap)
+    g_warning ("%s: mask should be NULL at this point", G_STRLOC);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static gboolean
+gimp_foreground_select_tool_initialize (GimpTool     *tool,
+                                        GimpDisplay  *display,
+                                        GError      **error)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  GimpGuiConfig            *config    = GIMP_GUI_CONFIG (display->gimp->config);
+  GimpImage                *image     = gimp_display_get_image (display);
+  GimpDrawable             *drawable  = gimp_image_get_active_drawable (image);
+  GimpDisplayShell         *shell     = gimp_display_get_shell (display);
+
+  if (! drawable)
+    return FALSE;
+
+  if (! gimp_item_is_visible (GIMP_ITEM (drawable)) &&
+      ! config->edit_non_visible)
+    {
+      g_set_error_literal (error, GIMP_ERROR, GIMP_FAILED,
+                           _("The active layer is not visible."));
+      return FALSE;
+    }
+
+  tool->display = display;
+
+  /*  enable double click for the FreeSelectTool, because it may have been
+   *  disabled if the tool has switched to MATTING_STATE_PAINT_TRIMAP,
+   *  in gimp_foreground_select_tool_set_trimap().
+   */
+  gimp_tool_control_set_wants_double_click (tool->control, TRUE);
+
+  fg_select->state = MATTING_STATE_FREE_SELECT;
+
+  if (! fg_select->gui)
+    {
+      fg_select->gui =
+        gimp_tool_gui_new (tool->tool_info,
+                           NULL,
+                           _("Dialog for foreground select"),
+                           NULL, NULL,
+                           gtk_widget_get_screen (GTK_WIDGET (shell)),
+                           gimp_widget_get_monitor (GTK_WIDGET (shell)),
+                           TRUE,
+
+                           _("_Cancel"), GTK_RESPONSE_CANCEL,
+                           _("_Select"), GTK_RESPONSE_APPLY,
+
+                           NULL);
+
+      gimp_tool_gui_set_auto_overlay (fg_select->gui, TRUE);
+
+      g_signal_connect (fg_select->gui, "response",
+                        G_CALLBACK (gimp_foreground_select_tool_response),
+                        fg_select);
+
+      fg_select->preview_toggle =
+        gtk_check_button_new_with_mnemonic (_("_Preview mask"));
+      gtk_box_pack_start (GTK_BOX (gimp_tool_gui_get_vbox (fg_select->gui)),
+                          fg_select->preview_toggle, FALSE, FALSE, 0);
+      gtk_widget_show (fg_select->preview_toggle);
+
+      g_signal_connect (fg_select->preview_toggle, "toggled",
+                        G_CALLBACK (gimp_foreground_select_tool_preview_toggled),
+                        fg_select);
+    }
+
+  gimp_tool_gui_set_description (fg_select->gui,
+                                 _("Select foreground pixels"));
+
+  gimp_tool_gui_set_response_sensitive (fg_select->gui, GTK_RESPONSE_APPLY,
+                                        FALSE);
+  gtk_widget_set_sensitive (fg_select->preview_toggle, FALSE);
+
+  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (fg_select->preview_toggle),
+                                FALSE);
+
+  gimp_tool_gui_set_shell (fg_select->gui, shell);
+  gimp_tool_gui_set_viewable (fg_select->gui, GIMP_VIEWABLE (drawable));
+
+  gimp_tool_gui_show (fg_select->gui);
+
+  return TRUE;
+}
+
+static void
+gimp_foreground_select_tool_control (GimpTool       *tool,
+                                     GimpToolAction  action,
+                                     GimpDisplay    *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  switch (action)
+    {
+    case GIMP_TOOL_ACTION_PAUSE:
+    case GIMP_TOOL_ACTION_RESUME:
+      break;
+
+    case GIMP_TOOL_ACTION_HALT:
+      gimp_foreground_select_tool_halt (fg_select);
+      break;
+
+    case GIMP_TOOL_ACTION_COMMIT:
+      gimp_foreground_select_tool_commit (fg_select);
+      break;
+    }
+
+  GIMP_TOOL_CLASS (parent_class)->control (tool, action, display);
+}
+
+static void
+gimp_foreground_select_tool_button_press (GimpTool            *tool,
+                                          const GimpCoords    *coords,
+                                          guint32              time,
+                                          GdkModifierType      state,
+                                          GimpButtonPressType  press_type,
+                                          GimpDisplay         *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  GimpDrawTool             *draw_tool = GIMP_DRAW_TOOL (tool);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      GIMP_TOOL_CLASS (parent_class)->button_press (tool, coords, time, state,
+                                                    press_type, display);
+    }
+  else
+    {
+      GimpVector2 point = gimp_vector2_new (coords->x, coords->y);
+
+      gimp_draw_tool_pause (draw_tool);
+
+      if (gimp_draw_tool_is_active (draw_tool) && draw_tool->display != display)
+        gimp_draw_tool_stop (draw_tool);
+
+      gimp_tool_control_activate (tool->control);
+
+      fg_select->last_coords = *coords;
+
+      g_return_if_fail (fg_select->stroke == NULL);
+      fg_select->stroke = g_array_new (FALSE, FALSE, sizeof (GimpVector2));
+
+      g_array_append_val (fg_select->stroke, point);
+
+      if (! gimp_draw_tool_is_active (draw_tool))
+        gimp_draw_tool_start (draw_tool, display);
+
+      gimp_draw_tool_resume (draw_tool);
+    }
+}
+
+static void
+gimp_foreground_select_tool_button_release (GimpTool              *tool,
+                                            const GimpCoords      *coords,
+                                            guint32                time,
+                                            GdkModifierType        state,
+                                            GimpButtonReleaseType  release_type,
+                                            GimpDisplay           *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      GIMP_TOOL_CLASS (parent_class)->button_release (tool, coords, time, state,
+                                                      release_type, display);
+    }
+  else
+    {
+      gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
+
+      gimp_tool_control_halt (tool->control);
+
+      if (release_type == GIMP_BUTTON_RELEASE_CANCEL)
+        {
+          gimp_foreground_select_tool_cancel_paint (fg_select);
+        }
+      else
+        {
+          gimp_foreground_select_tool_stroke_paint (fg_select);
+
+          if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+            gimp_foreground_select_tool_preview (fg_select);
+          else
+            gimp_foreground_select_tool_set_trimap (fg_select);
+        }
+
+      gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
+    }
+}
+
+static void
+gimp_foreground_select_tool_motion (GimpTool         *tool,
+                                    const GimpCoords *coords,
+                                    guint32           time,
+                                    GdkModifierType   state,
+                                    GimpDisplay      *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      GIMP_TOOL_CLASS (parent_class)->motion (tool, coords, time, state,
+                                              display);
+    }
+  else
+    {
+      GimpVector2 *last = &g_array_index (fg_select->stroke,
+                                          GimpVector2,
+                                          fg_select->stroke->len - 1);
+
+      gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
+
+      fg_select->last_coords = *coords;
+
+      if (last->x != (gint) coords->x || last->y != (gint) coords->y)
+        {
+          GimpVector2 point = gimp_vector2_new (coords->x, coords->y);
+
+          g_array_append_val (fg_select->stroke, point);
+        }
+
+      gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
+    }
+}
+
+static gboolean
+gimp_foreground_select_tool_key_press (GimpTool    *tool,
+                                       GdkEventKey *kevent,
+                                       GimpDisplay *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      return GIMP_TOOL_CLASS (parent_class)->key_press (tool, kevent, display);
+    }
+  else
+    {
+      if (display != tool->display)
+        return FALSE;
+
+      switch (kevent->keyval)
+        {
+        case GDK_KEY_Return:
+        case GDK_KEY_KP_Enter:
+        case GDK_KEY_ISO_Enter:
+          if (fg_select->state == MATTING_STATE_PAINT_TRIMAP)
+            gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (fg_select->preview_toggle),
+                                          TRUE);
+          else
+            gimp_foreground_select_tool_response (fg_select->gui,
+                                                  GTK_RESPONSE_APPLY, fg_select);
+          return TRUE;
+
+        case GDK_KEY_Escape:
+          if (fg_select->state == MATTING_STATE_PAINT_TRIMAP)
+            gimp_foreground_select_tool_response (fg_select->gui,
+                                                  GTK_RESPONSE_CANCEL, fg_select);
+          else
+            gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (fg_select->preview_toggle),
+                                          FALSE);
+          return TRUE;
+
+        default:
+          return FALSE;
+        }
+    }
+}
+
+static void
+gimp_foreground_select_tool_modifier_key (GimpTool        *tool,
+                                          GdkModifierType  key,
+                                          gboolean         press,
+                                          GdkModifierType  state,
+                                          GimpDisplay     *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      GIMP_TOOL_CLASS (parent_class)->modifier_key (tool, key, press, state,
+                                                    display);
+    }
+  else
+    {
+#if 0
+      if (key == gimp_get_toggle_behavior_mask ())
+        {
+          GimpForegroundSelectOptions *options;
+
+          options = GIMP_FOREGROUND_SELECT_TOOL_GET_OPTIONS (tool);
+
+          g_object_set (options,
+                        "background", ! options->background,
+                        NULL);
+        }
+#endif
+    }
+}
+
+static void
+gimp_foreground_select_tool_active_modifier_key (GimpTool        *tool,
+                                                 GdkModifierType  key,
+                                                 gboolean         press,
+                                                 GdkModifierType  state,
+                                                 GimpDisplay     *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      GIMP_TOOL_CLASS (parent_class)->active_modifier_key (tool, key, press,
+                                                           state, display);
+    }
+}
+
+static void
+gimp_foreground_select_tool_oper_update (GimpTool         *tool,
+                                         const GimpCoords *coords,
+                                         GdkModifierType   state,
+                                         gboolean          proximity,
+                                         GimpDisplay      *display)
+{
+  GimpForegroundSelectTool    *fg_select    = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  GimpForegroundSelectOptions *options;
+  const gchar                 *status_stage = NULL;
+  const gchar                 *status_mode  = NULL;
+
+  options = GIMP_FOREGROUND_SELECT_TOOL_GET_OPTIONS (fg_select);
+
+  GIMP_TOOL_CLASS (parent_class)->oper_update (tool, coords, state, proximity,
+                                               display);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      if (GIMP_SELECTION_TOOL (tool)->function == SELECTION_SELECT)
+        {
+          gint n_points;
+
+          gimp_polygon_select_tool_get_points (GIMP_POLYGON_SELECT_TOOL (tool),
+                                               NULL, &n_points);
+
+          if (n_points > 2)
+            {
+              status_mode = _("Roughly outline the object to extract");
+              status_stage = _("press Enter to refine.");
+            }
+          else
+            {
+              status_stage = _("Roughly outline the object to extract");
+            }
+        }
+    }
+  else
+    {
+      GimpDrawTool *draw_tool = GIMP_DRAW_TOOL (tool);
+
+      gimp_draw_tool_pause (draw_tool);
+
+      if (proximity)
+        {
+          fg_select->last_coords = *coords;
+        }
+      else
+        {
+          fg_select->last_coords.x = FAR_OUTSIDE;
+          fg_select->last_coords.y = FAR_OUTSIDE;
+        }
+
+      gimp_draw_tool_resume (draw_tool);
+
+      if (options->draw_mode == GIMP_MATTING_DRAW_MODE_FOREGROUND)
+        status_mode = _("Selecting foreground");
+      else if (options->draw_mode == GIMP_MATTING_DRAW_MODE_BACKGROUND)
+        status_mode = _("Selecting background");
+      else
+        status_mode = _("Selecting unknown");
+
+      if (fg_select->state == MATTING_STATE_PAINT_TRIMAP)
+        status_stage = _("press Enter to preview.");
+      else
+        status_stage = _("press Escape to exit preview or Enter to apply.");
+    }
+
+  if (proximity && status_stage)
+    {
+      if (status_mode)
+        gimp_tool_replace_status (tool, display, "%s, %s", status_mode, status_stage);
+      else
+        gimp_tool_replace_status (tool, display, "%s", status_stage);
+    }
+}
+
+static void
+gimp_foreground_select_tool_cursor_update (GimpTool         *tool,
+                                           const GimpCoords *coords,
+                                           GdkModifierType   state,
+                                           GimpDisplay      *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->state == MATTING_STATE_PAINT_TRIMAP)
+    {
+      switch (GIMP_SELECTION_TOOL (tool)->function)
+        {
+        case SELECTION_MOVE_MASK:
+        case SELECTION_MOVE:
+        case SELECTION_MOVE_COPY:
+        case SELECTION_ANCHOR:
+          return;
+        default:
+          break;
+        }
+    }
+
+  GIMP_TOOL_CLASS (parent_class)->cursor_update (tool, coords, state, display);
+}
+
+static const gchar *
+gimp_foreground_select_tool_can_undo (GimpTool    *tool,
+                                      GimpDisplay *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->undo_stack)
+    {
+      StrokeUndo  *undo = fg_select->undo_stack->data;
+      const gchar *desc;
+
+      if (gimp_enum_get_value (GIMP_TYPE_MATTING_DRAW_MODE, undo->draw_mode,
+                               NULL, NULL, &desc, NULL))
+        {
+          return desc;
+        }
+    }
+
+  return NULL;
+}
+
+static const gchar *
+gimp_foreground_select_tool_can_redo (GimpTool    *tool,
+                                      GimpDisplay *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+
+  if (fg_select->redo_stack)
+    {
+      StrokeUndo  *undo = fg_select->redo_stack->data;
+      const gchar *desc;
+
+      if (gimp_enum_get_value (GIMP_TYPE_MATTING_DRAW_MODE, undo->draw_mode,
+                               NULL, NULL, &desc, NULL))
+        {
+          return desc;
+        }
+    }
+
+  return NULL;
+}
+
+static gboolean
+gimp_foreground_select_tool_undo (GimpTool    *tool,
+                                  GimpDisplay *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  StrokeUndo               *undo      = fg_select->undo_stack->data;
+
+  gimp_foreground_select_undo_pop (undo, fg_select->trimap);
+
+  fg_select->undo_stack = g_list_remove (fg_select->undo_stack, undo);
+  fg_select->redo_stack = g_list_prepend (fg_select->redo_stack, undo);
+
+  if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+    gimp_foreground_select_tool_preview (fg_select);
+  else
+    gimp_foreground_select_tool_set_trimap (fg_select);
+
+  return TRUE;
+}
+
+static gboolean
+gimp_foreground_select_tool_redo (GimpTool    *tool,
+                                  GimpDisplay *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  StrokeUndo               *undo      = fg_select->redo_stack->data;
+
+  gimp_foreground_select_undo_pop (undo, fg_select->trimap);
+
+  fg_select->redo_stack = g_list_remove (fg_select->redo_stack, undo);
+  fg_select->undo_stack = g_list_prepend (fg_select->undo_stack, undo);
+
+  if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+    gimp_foreground_select_tool_preview (fg_select);
+  else
+    gimp_foreground_select_tool_set_trimap (fg_select);
+
+  return TRUE;
+}
+
+static void
+gimp_foreground_select_tool_options_notify (GimpTool         *tool,
+                                            GimpToolOptions  *options,
+                                            const GParamSpec *pspec)
+{
+  GimpForegroundSelectTool    *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  GimpForegroundSelectOptions *fg_options;
+
+  fg_options = GIMP_FOREGROUND_SELECT_OPTIONS (options);
+
+  if (! tool->display)
+    return;
+
+  if (! strcmp (pspec->name, "mask-color") ||
+      ! strcmp (pspec->name, "preview-mode"))
+    {
+      if (fg_select->state == MATTING_STATE_PAINT_TRIMAP)
+        {
+          gimp_foreground_select_tool_set_trimap (fg_select);
+        }
+      else if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+        {
+          gimp_foreground_select_tool_set_preview (fg_select);
+        }
+    }
+  else if (! strcmp (pspec->name, "engine"))
+    {
+      if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+        {
+          gimp_foreground_select_tool_preview (fg_select);
+        }
+    }
+  else if (! strcmp (pspec->name, "iterations"))
+    {
+      if (fg_options->engine == GIMP_MATTING_ENGINE_GLOBAL &&
+          fg_select->state   == MATTING_STATE_PREVIEW_MASK)
+        {
+          gimp_foreground_select_tool_preview (fg_select);
+        }
+    }
+  else if (! strcmp (pspec->name, "levels") ||
+           ! strcmp (pspec->name, "active-levels"))
+    {
+      if (fg_options->engine == GIMP_MATTING_ENGINE_LEVIN &&
+          fg_select->state   == MATTING_STATE_PREVIEW_MASK)
+        {
+          gimp_foreground_select_tool_preview (fg_select);
+        }
+    }
+}
+
+static void
+gimp_foreground_select_tool_get_area (GeglBuffer *mask,
+                                      gint       *x1,
+                                      gint       *y1,
+                                      gint       *x2,
+                                      gint       *y2)
+{
+  gint width;
+  gint height;
+
+  gimp_gegl_mask_bounds (mask, x1, y1, x2, y2);
+
+  width  = *x2 - *x1;
+  height = *y2 - *y1;
+
+  *x1 = MAX (*x1 - width  / 2, 0);
+  *y1 = MAX (*y1 - height / 2, 0);
+  *x2 = MIN (*x2 + width  / 2, gimp_item_get_width  (GIMP_ITEM (mask)));
+  *y2 = MIN (*y2 + height / 2, gimp_item_get_height (GIMP_ITEM (mask)));
+}
+
+static void
+gimp_foreground_select_tool_draw (GimpDrawTool *draw_tool)
+{
+  GimpTool                    *tool      = GIMP_TOOL (draw_tool);
+  GimpForegroundSelectTool    *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  GimpForegroundSelectOptions *options;
+
+  options = GIMP_FOREGROUND_SELECT_TOOL_GET_OPTIONS (tool);
+
+  if (fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      GIMP_DRAW_TOOL_CLASS (parent_class)->draw (draw_tool);
+      return;
+    }
+  else
+    {
+      gint    x      = fg_select->last_coords.x;
+      gint    y      = fg_select->last_coords.y;
+      gdouble radius = options->stroke_width / 2.0f;
+
+      if (fg_select->stroke)
+        {
+          GimpDisplayShell *shell = gimp_display_get_shell (draw_tool->display);
+
+          gimp_draw_tool_add_pen (draw_tool,
+                                  (const GimpVector2 *) fg_select->stroke->data,
+                                  fg_select->stroke->len,
+                                  GIMP_CONTEXT (options),
+                                  GIMP_ACTIVE_COLOR_FOREGROUND,
+                                  options->stroke_width * shell->scale_y);
+        }
+
+      /*  warn if the user is drawing outside of the working area  */
+      if (FALSE)
+        {
+          gint x1, y1;
+          gint x2, y2;
+
+          gimp_foreground_select_tool_get_area (fg_select->mask,
+                                                &x1, &y1, &x2, &y2);
+
+          if (x < x1 + radius || x > x2 - radius ||
+              y < y1 + radius || y > y2 - radius)
+            {
+              gimp_draw_tool_add_rectangle (draw_tool, FALSE,
+                                            x1, y1,
+                                            x2 - x1, y2 - y1);
+            }
+        }
+
+      if (x > FAR_OUTSIDE && y > FAR_OUTSIDE)
+        gimp_draw_tool_add_arc (draw_tool, FALSE,
+                                x - radius, y - radius,
+                                2 * radius, 2 * radius,
+                                0.0, 2.0 * G_PI);
+
+      if (fg_select->grayscale_preview)
+        gimp_draw_tool_add_preview (draw_tool, fg_select->grayscale_preview);
+    }
+}
+
+static void
+gimp_foreground_select_tool_confirm (GimpPolygonSelectTool *poly_sel,
+                                     GimpDisplay           *display)
+{
+  GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (poly_sel);
+  GimpImage                *image     = gimp_display_get_image (display);
+  GimpDrawable             *drawable  = gimp_image_get_active_drawable (image);
+  GimpItem                 *item      = GIMP_ITEM (drawable);
+
+  if (drawable && fg_select->state == MATTING_STATE_FREE_SELECT)
+    {
+      GimpScanConvert   *scan_convert = gimp_scan_convert_new ();
+      const GimpVector2 *points;
+      gint               n_points;
+
+      gimp_polygon_select_tool_get_points (poly_sel, &points, &n_points);
+
+      gimp_scan_convert_add_polyline (scan_convert, n_points, points, TRUE);
+
+      fg_select->trimap =
+        gegl_buffer_new (GEGL_RECTANGLE (gimp_item_get_offset_x (item),
+                                         gimp_item_get_offset_y (item),
+                                         gimp_item_get_width    (item),
+                                         gimp_item_get_height   (item)),
+                         gimp_image_get_mask_format (image));
+
+      gimp_scan_convert_render_value (scan_convert, fg_select->trimap,
+                                      0, 0, 0.5);
+      gimp_scan_convert_free (scan_convert);
+
+      fg_select->grayscale_preview =
+          gimp_canvas_buffer_preview_new (gimp_display_get_shell (display),
+                                          fg_select->trimap);
+
+      gimp_foreground_select_tool_set_trimap (fg_select);
+    }
+}
+
+static void
+gimp_foreground_select_tool_halt (GimpForegroundSelectTool *fg_select)
+{
+  GimpTool     *tool = GIMP_TOOL (fg_select);
+  GimpDrawTool *draw_tool = GIMP_DRAW_TOOL (fg_select);
+
+  if (draw_tool->preview)
+    {
+      gimp_draw_tool_remove_preview (draw_tool, fg_select->grayscale_preview);
+    }
+
+  g_clear_object (&fg_select->grayscale_preview);
+  g_clear_object (&fg_select->trimap);
+  g_clear_object (&fg_select->mask);
+
+  if (fg_select->undo_stack)
+    {
+      g_list_free_full (fg_select->undo_stack,
+                        (GDestroyNotify) gimp_foreground_select_undo_free);
+      fg_select->undo_stack = NULL;
+    }
+
+  if (fg_select->redo_stack)
+    {
+      g_list_free_full (fg_select->redo_stack,
+                        (GDestroyNotify) gimp_foreground_select_undo_free);
+      fg_select->redo_stack = NULL;
+    }
+
+  if (tool->display)
+    gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                 NULL, 0, 0, NULL, FALSE);
+
+  gimp_tool_control_set_tool_cursor        (tool->control,
+                                            GIMP_TOOL_CURSOR_FREE_SELECT);
+  gimp_tool_control_set_toggle_tool_cursor (tool->control,
+                                            GIMP_TOOL_CURSOR_FREE_SELECT);
+
+  gimp_tool_control_set_toggled (tool->control, FALSE);
+
+  /*  set precision to SUBPIXEL, because it may have been changed to
+   *  PIXEL_CENTER if the tool has switched to MATTING_STATE_PAINT_TRIMAP,
+   *  in gimp_foreground_select_tool_set_trimap().
+   */
+  gimp_tool_control_set_precision (tool->control,
+                                   GIMP_CURSOR_PRECISION_SUBPIXEL);
+
+  fg_select->state = MATTING_STATE_FREE_SELECT;
+
+  /*  update the undo actions / menu items  */
+  if (tool->display)
+    gimp_image_flush (gimp_display_get_image (tool->display));
+
+  tool->display  = NULL;
+  tool->drawable = NULL;
+
+  if (fg_select->gui)
+    gimp_tool_gui_hide (fg_select->gui);
+}
+
+static void
+gimp_foreground_select_tool_commit (GimpForegroundSelectTool *fg_select)
+{
+  GimpTool             *tool    = GIMP_TOOL (fg_select);
+  GimpSelectionOptions *options = GIMP_SELECTION_TOOL_GET_OPTIONS (fg_select);
+
+  if (tool->display && fg_select->state != MATTING_STATE_FREE_SELECT)
+    {
+      GimpImage *image = gimp_display_get_image (tool->display);
+
+      if (fg_select->state != MATTING_STATE_PREVIEW_MASK)
+        gimp_foreground_select_tool_preview (fg_select);
+
+      gimp_channel_select_buffer (gimp_image_get_mask (image),
+                                  C_("command", "Foreground Select"),
+                                  fg_select->mask,
+                                  0, /* x offset */
+                                  0, /* y offset */
+                                  options->operation,
+                                  options->feather,
+                                  options->feather_radius,
+                                  options->feather_radius);
+
+      gimp_image_flush (image);
+    }
+}
+
+static void
+gimp_foreground_select_tool_set_trimap (GimpForegroundSelectTool *fg_select)
+{
+  GimpTool                    *tool = GIMP_TOOL (fg_select);
+  GimpForegroundSelectOptions *options;
+
+  g_return_if_fail (fg_select->trimap != NULL);
+
+  options = GIMP_FOREGROUND_SELECT_TOOL_GET_OPTIONS (tool);
+
+  gimp_polygon_select_tool_halt (GIMP_POLYGON_SELECT_TOOL (fg_select));
+
+  if (options->preview_mode == GIMP_MATTING_PREVIEW_MODE_ON_COLOR)
+    {
+      if (fg_select->grayscale_preview)
+        gimp_canvas_item_set_visible (fg_select->grayscale_preview, FALSE);
+
+      gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                   fg_select->trimap, 0, 0,
+                                   &options->mask_color, TRUE);
+    }
+  else
+    {
+      gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                   NULL, 0, 0, NULL, FALSE);
+
+      if (fg_select->grayscale_preview)
+        {
+          g_object_set (fg_select->grayscale_preview, "buffer",
+                        fg_select->trimap, NULL);
+
+          gimp_canvas_item_set_visible (fg_select->grayscale_preview, TRUE);
+        }
+    }
+
+  gimp_tool_control_set_tool_cursor        (tool->control,
+                                            GIMP_TOOL_CURSOR_PAINTBRUSH);
+  gimp_tool_control_set_toggle_tool_cursor (tool->control,
+                                            GIMP_TOOL_CURSOR_PAINTBRUSH);
+
+  gimp_tool_control_set_toggled (tool->control, FALSE);
+
+  /* disable double click in paint trimap state */
+  gimp_tool_control_set_wants_double_click (tool->control, FALSE);
+
+  /* set precision to PIXEL_CENTER in paint trimap state */
+  gimp_tool_control_set_precision (tool->control,
+                                   GIMP_CURSOR_PRECISION_PIXEL_CENTER);
+
+  fg_select->state = MATTING_STATE_PAINT_TRIMAP;
+
+  gimp_foreground_select_tool_update_gui (fg_select);
+}
+
+static void
+gimp_foreground_select_tool_set_preview (GimpForegroundSelectTool *fg_select)
+{
+
+  GimpTool                    *tool = GIMP_TOOL (fg_select);
+  GimpForegroundSelectOptions *options;
+
+  g_return_if_fail (fg_select->mask != NULL);
+
+  options = GIMP_FOREGROUND_SELECT_TOOL_GET_OPTIONS (tool);
+
+  if (options->preview_mode == GIMP_MATTING_PREVIEW_MODE_ON_COLOR)
+    {
+      if (fg_select->grayscale_preview)
+        gimp_canvas_item_set_visible (fg_select->grayscale_preview, FALSE);
+
+      gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                   fg_select->mask, 0, 0,
+                                   &options->mask_color, TRUE);
+    }
+  else
+    {
+      gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                   NULL, 0, 0, NULL, FALSE);
+
+      if (fg_select->grayscale_preview)
+        {
+          g_object_set (fg_select->grayscale_preview, "buffer",
+                    fg_select->mask, NULL);
+          gimp_canvas_item_set_visible (fg_select->grayscale_preview, TRUE);
+        }
+    }
+
+  gimp_tool_control_set_tool_cursor        (tool->control,
+                                            GIMP_TOOL_CURSOR_PAINTBRUSH);
+  gimp_tool_control_set_toggle_tool_cursor (tool->control,
+                                            GIMP_TOOL_CURSOR_PAINTBRUSH);
+
+  gimp_tool_control_set_toggled (tool->control, FALSE);
+
+  fg_select->state = MATTING_STATE_PREVIEW_MASK;
+
+  gimp_foreground_select_tool_update_gui (fg_select);
+}
+
+static void
+gimp_foreground_select_tool_preview (GimpForegroundSelectTool *fg_select)
+{
+  GimpTool                    *tool     = GIMP_TOOL (fg_select);
+  GimpForegroundSelectOptions *options;
+  GimpImage                   *image    = gimp_display_get_image (tool->display);
+  GimpDrawable                *drawable = gimp_image_get_active_drawable (image);
+
+  options  = GIMP_FOREGROUND_SELECT_TOOL_GET_OPTIONS (tool);
+
+  g_clear_object (&fg_select->mask);
+
+  fg_select->mask = gimp_drawable_foreground_extract (drawable,
+                                                      options->engine,
+                                                      options->iterations,
+                                                      options->levels,
+                                                      options->active_levels,
+                                                      fg_select->trimap,
+                                                      GIMP_PROGRESS (fg_select));
+
+  gimp_foreground_select_tool_set_preview (fg_select);
+}
+
+static void
+gimp_foreground_select_tool_stroke_paint (GimpForegroundSelectTool *fg_select)
+{
+  GimpForegroundSelectOptions *options;
+  GimpScanConvert             *scan_convert;
+  StrokeUndo                  *undo;
+  gint                         width;
+  gdouble                      opacity;
+
+  options = GIMP_FOREGROUND_SELECT_TOOL_GET_OPTIONS (fg_select);
+
+  g_return_if_fail (fg_select->stroke != NULL);
+
+  width = ROUND ((gdouble) options->stroke_width);
+
+  if (fg_select->redo_stack)
+    {
+      g_list_free_full (fg_select->redo_stack,
+                        (GDestroyNotify) gimp_foreground_select_undo_free);
+      fg_select->redo_stack = NULL;
+    }
+
+  undo = gimp_foreground_select_undo_new (fg_select->trimap,
+                                          fg_select->stroke,
+                                          options->draw_mode, width);
+  if (! undo)
+    {
+      g_array_free (fg_select->stroke, TRUE);
+      fg_select->stroke = NULL;
+      return;
+    }
+
+  fg_select->undo_stack = g_list_prepend (fg_select->undo_stack, undo);
+
+  scan_convert = gimp_scan_convert_new ();
+
+  if (fg_select->stroke->len == 1)
+    {
+      GimpVector2 points[2];
+
+      points[0] = points[1] = ((GimpVector2 *) fg_select->stroke->data)[0];
+
+      points[1].x += 0.01;
+      points[1].y += 0.01;
+
+      gimp_scan_convert_add_polyline (scan_convert, 2, points, FALSE);
+    }
+  else
+    {
+      gimp_scan_convert_add_polyline (scan_convert,
+                                      fg_select->stroke->len,
+                                      (GimpVector2 *) fg_select->stroke->data,
+                                      FALSE);
+    }
+
+  gimp_scan_convert_stroke (scan_convert,
+                            width,
+                            GIMP_JOIN_ROUND, GIMP_CAP_ROUND, 10.0,
+                            0.0, NULL);
+
+  if (options->draw_mode == GIMP_MATTING_DRAW_MODE_FOREGROUND)
+    opacity = 1.0;
+  else if (options->draw_mode == GIMP_MATTING_DRAW_MODE_BACKGROUND)
+    opacity = 0.0;
+  else
+    opacity = 0.5;
+
+  gimp_scan_convert_compose_value (scan_convert, fg_select->trimap,
+                                   0, 0,
+                                   opacity);
+
+  gimp_scan_convert_free (scan_convert);
+
+  g_array_free (fg_select->stroke, TRUE);
+  fg_select->stroke = NULL;
+
+  /*  update the undo actions / menu items  */
+  gimp_image_flush (gimp_display_get_image (GIMP_TOOL (fg_select)->display));
+}
+
+static void
+gimp_foreground_select_tool_cancel_paint (GimpForegroundSelectTool *fg_select)
+{
+  g_return_if_fail (fg_select->stroke != NULL);
+
+  g_array_free (fg_select->stroke, TRUE);
+  fg_select->stroke = NULL;
+}
+
+static void
+gimp_foreground_select_tool_response (GimpToolGui              *gui,
+                                      gint                      response_id,
+                                      GimpForegroundSelectTool *fg_select)
+{
+  GimpTool *tool = GIMP_TOOL (fg_select);
+
+  switch (response_id)
+    {
+    case GTK_RESPONSE_APPLY:
+      gimp_tool_control (tool, GIMP_TOOL_ACTION_COMMIT, tool->display);
+      break;
+
+    default:
+      gimp_tool_control (tool, GIMP_TOOL_ACTION_HALT, tool->display);
+      break;
+    }
+}
+
+static void
+gimp_foreground_select_tool_preview_toggled (GtkToggleButton          *button,
+                                             GimpForegroundSelectTool *fg_select)
+{
+  if (fg_select->state != MATTING_STATE_FREE_SELECT)
+    {
+      if (gtk_toggle_button_get_active (button))
+        {
+          if (fg_select->state == MATTING_STATE_PAINT_TRIMAP)
+            gimp_foreground_select_tool_preview (fg_select);
+        }
+      else
+        {
+          if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+            gimp_foreground_select_tool_set_trimap (fg_select);
+        }
+    }
+}
+
+static void
+gimp_foreground_select_tool_update_gui (GimpForegroundSelectTool *fg_select)
+{
+  if (fg_select->state == MATTING_STATE_PAINT_TRIMAP)
+    {
+      gimp_tool_gui_set_description (fg_select->gui, _("Paint mask"));
+    }
+  else if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+    {
+      gimp_tool_gui_set_description (fg_select->gui, _("Preview"));
+    }
+
+  gimp_tool_gui_set_response_sensitive (fg_select->gui, GTK_RESPONSE_APPLY,
+                                        TRUE);
+  gtk_widget_set_sensitive (fg_select->preview_toggle, TRUE);
+}
+
+static StrokeUndo *
+gimp_foreground_select_undo_new (GeglBuffer          *trimap,
+                                 GArray              *stroke,
+                                 GimpMattingDrawMode draw_mode,
+                                 gint                stroke_width)
+
+{
+  StrokeUndo          *undo;
+  const GeglRectangle *extent;
+  gint                 x1, y1, x2, y2;
+  gint                 width, height;
+  gint                 i;
+
+  extent = gegl_buffer_get_extent (trimap);
+
+  x1 = G_MAXINT;
+  y1 = G_MAXINT;
+  x2 = G_MININT;
+  y2 = G_MININT;
+
+  for (i = 0; i < stroke->len; i++)
+    {
+      GimpVector2 *point = &g_array_index (stroke, GimpVector2, i);
+
+      x1 = MIN (x1, floor (point->x));
+      y1 = MIN (y1, floor (point->y));
+      x2 = MAX (x2, ceil (point->x));
+      y2 = MAX (y2, ceil (point->y));
+    }
+
+  x1 -= (stroke_width + 1) / 2;
+  y1 -= (stroke_width + 1) / 2;
+  x2 += (stroke_width + 1) / 2;
+  y2 += (stroke_width + 1) / 2;
+
+  x1 = MAX (x1, extent->x);
+  y1 = MAX (y1, extent->y);
+  x2 = MIN (x2, extent->x + extent->width);
+  y2 = MIN (y2, extent->x + extent->height);
+
+  width  = x2 - x1;
+  height = y2 - y1;
+
+  if (width <= 0 || height <= 0)
+    return NULL;
+
+  undo = g_slice_new0 (StrokeUndo);
+  undo->saved_trimap = gegl_buffer_new (GEGL_RECTANGLE (x1, y1, width, height),
+                                        gegl_buffer_get_format (trimap));
+
+  gimp_gegl_buffer_copy (
+    trimap,             GEGL_RECTANGLE (x1, y1, width, height),
+    GEGL_ABYSS_NONE,
+    undo->saved_trimap, NULL);
+
+  undo->trimap_x = x1;
+  undo->trimap_y = y1;
+
+  undo->draw_mode    = draw_mode;
+  undo->stroke_width = stroke_width;
+
+  return undo;
+}
+
+static void
+gimp_foreground_select_undo_pop (StrokeUndo *undo,
+                                 GeglBuffer *trimap)
+{
+  GeglBuffer *buffer;
+  gint        width, height;
+
+  buffer = gimp_gegl_buffer_dup (undo->saved_trimap);
+
+  width  = gegl_buffer_get_width  (buffer);
+  height = gegl_buffer_get_height (buffer);
+
+  gimp_gegl_buffer_copy (trimap,
+                         GEGL_RECTANGLE (undo->trimap_x, undo->trimap_y,
+                                         width, height),
+                         GEGL_ABYSS_NONE,
+                         undo->saved_trimap, NULL);
+
+  gimp_gegl_buffer_copy (buffer,
+                         GEGL_RECTANGLE (undo->trimap_x, undo->trimap_y,
+                                         width, height),
+                         GEGL_ABYSS_NONE,
+                         trimap, NULL);
+
+  g_object_unref (buffer);
+}
+
+static void
+gimp_foreground_select_undo_free (StrokeUndo *undo)
+{
+  g_clear_object (&undo->saved_trimap);
+
+  g_slice_free (StrokeUndo, undo);
+}