Adding upstream version 2.10.22.upstream/2.10.22upstream

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

1 files changed, 959 insertions, 0 deletions

diff --git a/app/widgets/gimppanedbox.c b/app/widgets/gimppanedbox.c
new file mode 100644
index 0000000..15e8b54
--- /dev/null
+++ b/app/widgets/gimppanedbox.c
@@ -0,0 +1,959 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimppanedbox.c
+ * Copyright (C) 2001-2005 Michael Natterer <mitch@gimp.org>
+ * Copyright (C) 2009-2011 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>
+#ifdef GDK_DISABLE_DEPRECATED
+#undef GDK_DISABLE_DEPRECATED
+#endif
+#include <gtk/gtk.h>
+
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "widgets-types.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontext.h"
+#include "core/gimpmarshal.h"
+
+#include "gimpdialogfactory.h"
+#include "gimpdnd.h"
+#include "gimpdockable.h"
+#include "gimpdockbook.h"
+#include "gimpmenudock.h"
+#include "gimppanedbox.h"
+#include "gimptoolbox.h"
+
+#include "gimp-log.h"
+
+
+/**
+ * Defines the size of the area that dockables can be dropped on in
+ * order to be inserted and get space on their own (rather than
+ * inserted among others and sharing space)
+ */
+#define DROP_AREA_SIZE                  6
+
+#define DROP_HIGHLIGHT_MIN_SIZE         32
+#define DROP_HIGHLIGHT_COLOR            "#215d9c"
+#define DROP_HIGHLIGHT_OPACITY_ACTIVE   1.0
+#define DROP_HIGHLIGHT_OPACITY_INACTIVE 0.5
+
+#define INSERT_INDEX_UNUSED             G_MININT
+
+
+struct _GimpPanedBoxPrivate
+{
+  /* Widgets that are separated by panes */
+  GList                  *widgets;
+
+  /* Windows used for drag-and-drop output */
+  GdkWindow              *dnd_windows[3];
+  GdkDragContext         *dnd_context;
+  gint                    dnd_paned_position;
+  gint                    dnd_idle_id;
+
+  /* The insert index to use on drop */
+  gint                    insert_index;
+
+  /* Callback on drop */
+  GimpPanedBoxDroppedFunc dropped_cb;
+  gpointer                dropped_cb_data;
+
+  /* A drag handler offered to handle drag events */
+  GimpPanedBox           *drag_handler;
+};
+
+
+static void      gimp_paned_box_dispose                 (GObject        *object);
+
+static void      gimp_paned_box_drag_leave              (GtkWidget      *widget,
+                                                         GdkDragContext *context,
+                                                         guint           time);
+static gboolean  gimp_paned_box_drag_motion             (GtkWidget      *widget,
+                                                         GdkDragContext *context,
+                                                         gint            x,
+                                                         gint            y,
+                                                         guint           time);
+static gboolean  gimp_paned_box_drag_drop               (GtkWidget      *widget,
+                                                         GdkDragContext *context,
+                                                         gint            x,
+                                                         gint            y,
+                                                         guint           time);
+static void      gimp_paned_box_realize                 (GtkWidget      *widget);
+static void      gimp_paned_box_unrealize               (GtkWidget      *widget);
+static void      gimp_paned_box_set_widget_drag_handler (GtkWidget      *widget,
+                                                         GimpPanedBox   *handler);
+static gint      gimp_paned_box_get_drop_area_size      (GimpPanedBox   *paned_box);
+
+static void      gimp_paned_box_drag_callback           (GdkDragContext *context,
+                                                         gboolean        begin,
+                                                         GimpPanedBox   *paned_box);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpPanedBox, gimp_paned_box, GTK_TYPE_BOX)
+
+#define parent_class gimp_paned_box_parent_class
+
+static const GtkTargetEntry dialog_target_table[] = { GIMP_TARGET_DIALOG };
+
+
+static void
+gimp_paned_box_class_init (GimpPanedBoxClass *klass)
+{
+  GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  object_class->dispose     = gimp_paned_box_dispose;
+
+  widget_class->drag_leave  = gimp_paned_box_drag_leave;
+  widget_class->drag_motion = gimp_paned_box_drag_motion;
+  widget_class->drag_drop   = gimp_paned_box_drag_drop;
+  widget_class->realize     = gimp_paned_box_realize;
+  widget_class->unrealize   = gimp_paned_box_unrealize;
+}
+
+static void
+gimp_paned_box_init (GimpPanedBox *paned_box)
+{
+  paned_box->p = gimp_paned_box_get_instance_private (paned_box);
+
+  /* Setup DND */
+  gtk_drag_dest_set (GTK_WIDGET (paned_box),
+                     0,
+                     dialog_target_table, G_N_ELEMENTS (dialog_target_table),
+                     GDK_ACTION_MOVE);
+
+  gimp_dockbook_add_drag_callback (
+    (GimpDockbookDragCallback) gimp_paned_box_drag_callback,
+    paned_box);
+}
+
+static void
+gimp_paned_box_dispose (GObject *object)
+{
+  GimpPanedBox *paned_box = GIMP_PANED_BOX (object);
+
+  if (paned_box->p->dnd_idle_id)
+    {
+      g_source_remove (paned_box->p->dnd_idle_id);
+
+      paned_box->p->dnd_idle_id = 0;
+    }
+
+  while (paned_box->p->widgets)
+    {
+      GtkWidget *widget = paned_box->p->widgets->data;
+
+      g_object_ref (widget);
+      gimp_paned_box_remove_widget (paned_box, widget);
+      gtk_widget_destroy (widget);
+      g_object_unref (widget);
+    }
+
+  gimp_dockbook_remove_drag_callback (
+    (GimpDockbookDragCallback) gimp_paned_box_drag_callback,
+    paned_box);
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_paned_box_realize (GtkWidget *widget)
+{
+  GTK_WIDGET_CLASS (parent_class)->realize (widget);
+
+  /* We realize() dnd_window on demand in
+   * gimp_paned_box_show_separators()
+   */
+}
+
+static void
+gimp_paned_box_unrealize (GtkWidget *widget)
+{
+  GimpPanedBox *paned_box = GIMP_PANED_BOX (widget);
+  gint          i;
+
+  for (i = 0; i < G_N_ELEMENTS (paned_box->p->dnd_windows); i++)
+    {
+      GdkWindow *window = paned_box->p->dnd_windows[i];
+
+      if (window)
+        {
+          gdk_window_set_user_data (window, NULL);
+          gdk_window_destroy (window);
+
+          paned_box->p->dnd_windows[i] = NULL;
+        }
+    }
+
+  GTK_WIDGET_CLASS (parent_class)->unrealize (widget);
+}
+
+static void
+gimp_paned_box_set_widget_drag_handler (GtkWidget    *widget,
+                                        GimpPanedBox *drag_handler)
+{
+  /* Hook us in for drag events. We could abstract this properly and
+   * put gimp_paned_box_will_handle_drag() in an interface for
+   * example, but it doesn't feel worth it at this point
+   *
+   * Note that we don't have 'else if's because a widget can be both a
+   * dock and a toolbox for example, in which case we want to set a
+   * drag handler in two ways
+   *
+   * We so need to introduce some abstractions here...
+   */
+
+  if (GIMP_IS_DOCKBOOK (widget))
+    {
+      gimp_dockbook_set_drag_handler (GIMP_DOCKBOOK (widget),
+                                      drag_handler);
+    }
+
+  if (GIMP_IS_DOCK (widget))
+    {
+      GimpPanedBox *dock_paned_box = NULL;
+      dock_paned_box = GIMP_PANED_BOX (gimp_dock_get_vbox (GIMP_DOCK (widget)));
+      gimp_paned_box_set_drag_handler (dock_paned_box, drag_handler);
+    }
+
+  if (GIMP_IS_TOOLBOX (widget))
+    {
+      GimpToolbox *toolbox = GIMP_TOOLBOX (widget);
+      gimp_toolbox_set_drag_handler (toolbox, drag_handler);
+    }
+}
+
+static gint
+gimp_paned_box_get_drop_area_size (GimpPanedBox *paned_box)
+{
+  gint drop_area_size = 0;
+
+  if (! paned_box->p->widgets)
+    {
+      GtkAllocation  allocation;
+      GtkOrientation orientation;
+
+      gtk_widget_get_allocation (GTK_WIDGET (paned_box), &allocation);
+      orientation = gtk_orientable_get_orientation (GTK_ORIENTABLE (paned_box));
+
+      if (orientation == GTK_ORIENTATION_HORIZONTAL)
+        drop_area_size = allocation.width;
+      else if (orientation == GTK_ORIENTATION_VERTICAL)
+        drop_area_size = allocation.height;
+    }
+
+  drop_area_size = MAX (drop_area_size, DROP_AREA_SIZE);
+
+  return drop_area_size;
+}
+
+static gboolean
+gimp_paned_box_get_handle_drag (GimpPanedBox   *paned_box,
+                                GdkDragContext *context,
+                                gint            x,
+                                gint            y,
+                                guint           time,
+                                gint           *insert_index,
+                                GeglRectangle  *area)
+{
+  gint           index          = INSERT_INDEX_UNUSED;
+  GtkAllocation  allocation     = { 0, };
+  gint           area_x         = 0;
+  gint           area_y         = 0;
+  gint           area_w         = 0;
+  gint           area_h         = 0;
+  GtkOrientation orientation    = 0;
+  gint           drop_area_size = gimp_paned_box_get_drop_area_size (paned_box);
+
+  if (gimp_paned_box_will_handle_drag (paned_box->p->drag_handler,
+                                       GTK_WIDGET (paned_box),
+                                       context,
+                                       x, y,
+                                       time))
+    {
+      return FALSE;
+    }
+
+  if (gtk_drag_dest_find_target (GTK_WIDGET (paned_box), context, NULL) ==
+      GDK_NONE)
+    {
+      return FALSE;
+    }
+
+  gtk_widget_get_allocation (GTK_WIDGET (paned_box), &allocation);
+
+  /* See if we're at the edge of the dock If there are no dockables,
+   * the entire paned box is a drop area
+   */
+  orientation = gtk_orientable_get_orientation (GTK_ORIENTABLE (paned_box));
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    {
+      area_y = 0;
+      area_h = allocation.height;
+
+      /* If there are no widgets, the drop area is as big as the paned
+       * box
+       */
+      if (! paned_box->p->widgets)
+        area_w = allocation.width;
+      else
+        area_w = drop_area_size;
+
+      if (x < drop_area_size)
+        {
+          index = 0;
+          area_x = 0;
+        }
+      if (x > allocation.width - drop_area_size)
+        {
+          index = -1;
+          area_x = allocation.width - drop_area_size;
+        }
+    }
+  else /* if (orientation = GTK_ORIENTATION_VERTICAL) */
+    {
+      area_x = 0;
+      area_w = allocation.width;
+
+      /* If there are no widgets, the drop area is as big as the paned
+       * box
+       */
+      if (! paned_box->p->widgets)
+        area_h = allocation.height;
+      else
+        area_h = drop_area_size;
+
+      if (y < drop_area_size)
+        {
+          index = 0;
+          area_y = 0;
+        }
+      if (y > allocation.height - drop_area_size)
+        {
+          index = -1;
+          area_y = allocation.height - drop_area_size;
+        }
+    }
+
+  if (area)
+    {
+      area->x      = allocation.x + area_x;
+      area->y      = allocation.y + area_y;
+      area->width  = area_w;
+      area->height = area_h;
+    }
+
+  if (insert_index)
+    *insert_index = index;
+
+  return index != INSERT_INDEX_UNUSED;
+}
+
+static void
+gimp_paned_box_position_drop_indicator (GimpPanedBox *paned_box,
+                                        gint          index,
+                                        gint          x,
+                                        gint          y,
+                                        gint          width,
+                                        gint          height,
+                                        gdouble       opacity)
+{
+  GtkWidget    *widget = GTK_WIDGET (paned_box);
+  GdkWindow    *window = paned_box->p->dnd_windows[index];
+  GtkStyle     *style  = gtk_widget_get_style (widget);
+  GtkStateType  state  = gtk_widget_get_state (widget);
+  GimpRGB       bg;
+  GimpRGB       fg;
+  GdkColor      color;
+
+  if (! gtk_widget_is_drawable (widget))
+    return;
+
+  /* Create or move the GdkWindow in place */
+  if (! window)
+    {
+      GtkAllocation allocation;
+      GdkWindowAttr attributes;
+
+      gtk_widget_get_allocation (widget, &allocation);
+
+      attributes.x           = x;
+      attributes.y           = y;
+      attributes.width       = width;
+      attributes.height      = height;
+      attributes.window_type = GDK_WINDOW_CHILD;
+      attributes.wclass      = GDK_INPUT_OUTPUT;
+      attributes.event_mask  = gtk_widget_get_events (widget);
+
+      window = gdk_window_new (gtk_widget_get_window (widget),
+                               &attributes,
+                               GDK_WA_X | GDK_WA_Y);
+      gdk_window_set_user_data (window, widget);
+
+      paned_box->p->dnd_windows[index] = window;
+    }
+  else
+    {
+      gdk_window_move_resize (window,
+                              x, y,
+                              width, height);
+    }
+
+  gimp_rgb_set_uchar (&bg,
+                      style->bg[state].red   >> 8,
+                      style->bg[state].green >> 8,
+                      style->bg[state].blue  >> 8);
+  bg.a = 1.0;
+
+  gimp_rgb_parse_hex (&fg, DROP_HIGHLIGHT_COLOR, -1);
+  fg.a = opacity;
+
+  gimp_rgb_composite (&bg, &fg, GIMP_RGB_COMPOSITE_NORMAL);
+
+  color.red   = bg.r * 0xffff;
+  color.green = bg.g * 0xffff;
+  color.blue  = bg.b * 0xffff;
+
+  gdk_rgb_find_color (gtk_widget_get_colormap (widget), &color);
+
+  gdk_window_set_background (window, &color);
+
+  gdk_window_show (window);
+}
+
+static void
+gimp_paned_box_hide_drop_indicator (GimpPanedBox *paned_box,
+                                    gint          index)
+{
+  if (! paned_box->p->dnd_windows[index])
+    return;
+
+  gdk_window_hide (paned_box->p->dnd_windows[index]);
+}
+
+static void
+gimp_paned_box_drag_leave (GtkWidget      *widget,
+                           GdkDragContext *context,
+                           guint           time)
+{
+  GimpPanedBox *paned_box = GIMP_PANED_BOX (widget);
+
+  gimp_paned_box_hide_drop_indicator (paned_box, 0);
+}
+
+static gboolean
+gimp_paned_box_drag_motion (GtkWidget      *widget,
+                            GdkDragContext *context,
+                            gint            x,
+                            gint            y,
+                            guint           time)
+{
+  GimpPanedBox  *paned_box = GIMP_PANED_BOX (widget);
+  gint           insert_index;
+  GeglRectangle  area;
+  gboolean       handle;
+
+  handle = gimp_paned_box_get_handle_drag (paned_box, context, x, y, time,
+                                           &insert_index, &area);
+
+  /* If we are at the edge, show a GdkWindow to communicate that a
+   * drop will create a new dock column
+   */
+  if (handle)
+    {
+      gimp_paned_box_position_drop_indicator (paned_box,
+                                              0,
+                                              area.x,
+                                              area.y,
+                                              area.width,
+                                              area.height,
+                                              DROP_HIGHLIGHT_OPACITY_ACTIVE);
+    }
+  else
+    {
+      gimp_paned_box_hide_drop_indicator (paned_box, 0);
+    }
+
+  /* Save the insert index for drag-drop */
+  paned_box->p->insert_index = insert_index;
+
+  gdk_drag_status (context, handle ? GDK_ACTION_MOVE : 0, time);
+
+  /* Return TRUE so drag_leave() is called */
+  return handle;
+}
+
+static gboolean
+gimp_paned_box_drag_drop (GtkWidget      *widget,
+                          GdkDragContext *context,
+                          gint            x,
+                          gint            y,
+                          guint           time)
+{
+  GimpPanedBox *paned_box = GIMP_PANED_BOX (widget);
+  gboolean      dropped   = FALSE;
+
+  if (gimp_paned_box_will_handle_drag (paned_box->p->drag_handler,
+                                       widget,
+                                       context,
+                                       x, y,
+                                       time))
+    {
+      return FALSE;
+    }
+
+  if (paned_box->p->dropped_cb)
+    {
+      GtkWidget *source = gtk_drag_get_source_widget (context);
+
+      if (source)
+        dropped = paned_box->p->dropped_cb (source,
+                                            paned_box->p->insert_index,
+                                            paned_box->p->dropped_cb_data);
+    }
+
+  gtk_drag_finish (context, dropped, TRUE, time);
+
+  return TRUE;
+}
+
+static gboolean
+gimp_paned_box_drag_callback_idle (GimpPanedBox *paned_box)
+{
+  GtkAllocation  allocation;
+  GtkOrientation orientation;
+  GeglRectangle  area;
+
+  paned_box->p->dnd_idle_id = 0;
+
+  gtk_widget_get_allocation (GTK_WIDGET (paned_box), &allocation);
+  orientation = gtk_orientable_get_orientation (GTK_ORIENTABLE (paned_box));
+
+  #define ADD_AREA(index, left, top)               \
+    if (gimp_paned_box_get_handle_drag (           \
+        paned_box,                                 \
+        paned_box->p->dnd_context,                 \
+        (left), (top),                             \
+        0,                                         \
+        NULL, &area))                              \
+      {                                            \
+        gimp_paned_box_position_drop_indicator (   \
+          paned_box,                               \
+          index,                                   \
+          area.x, area.y, area.width, area.height, \
+          DROP_HIGHLIGHT_OPACITY_INACTIVE);        \
+      }
+
+  if (! paned_box->p->widgets)
+    {
+      ADD_AREA (1, allocation.width / 2, allocation.height / 2)
+    }
+  else if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    {
+      ADD_AREA (1, 0,                    allocation.height / 2)
+      ADD_AREA (2, allocation.width - 1, allocation.height / 2)
+    }
+  else
+    {
+      ADD_AREA (1, allocation.width / 2, 0)
+      ADD_AREA (2, allocation.width / 2, allocation.height - 1)
+    }
+
+  #undef ADD_AREA
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+gimp_paned_box_drag_callback (GdkDragContext *context,
+                              gboolean        begin,
+                              GimpPanedBox   *paned_box)
+{
+  GtkWidget *paned;
+  gint       position;
+
+  if (! gtk_widget_get_sensitive (GTK_WIDGET (paned_box)))
+    return;
+
+  paned = gtk_widget_get_ancestor (GTK_WIDGET (paned_box),
+                                   GTK_TYPE_PANED);
+
+  /* apparently, we can be called multiple times when beginning a drag
+   * (possibly a gtk bug); make sure not to leak the idle.
+   *
+   * see issue #4895.
+   */
+  if (begin && ! paned_box->p->dnd_context)
+    {
+      paned_box->p->dnd_context = context;
+
+      if (paned)
+        {
+          GtkAllocation allocation;
+
+          gtk_widget_get_allocation (paned, &allocation);
+
+          position = gtk_paned_get_position (GTK_PANED (paned));
+
+          paned_box->p->dnd_paned_position = position;
+
+          if (position < 0)
+            {
+              position = 0;
+            }
+          else if (gtk_widget_is_ancestor (
+                     GTK_WIDGET (paned_box),
+                     gtk_paned_get_child2 (GTK_PANED (paned))))
+            {
+              position = allocation.width - position;
+            }
+
+          if (position < DROP_HIGHLIGHT_MIN_SIZE)
+            {
+              position = DROP_HIGHLIGHT_MIN_SIZE;
+
+              if (gtk_widget_is_ancestor (
+                    GTK_WIDGET (paned_box),
+                    gtk_paned_get_child2 (GTK_PANED (paned))))
+                {
+                  position = allocation.width - position;
+                }
+
+              gtk_paned_set_position (GTK_PANED (paned), position);
+            }
+        }
+
+      paned_box->p->dnd_idle_id = g_idle_add (
+        (GSourceFunc) gimp_paned_box_drag_callback_idle,
+        paned_box);
+    }
+  else if (! begin && paned_box->p->dnd_context)
+    {
+      if (paned_box->p->dnd_idle_id)
+        {
+          g_source_remove (paned_box->p->dnd_idle_id);
+
+          paned_box->p->dnd_idle_id = 0;
+        }
+
+      paned_box->p->dnd_context = NULL;
+
+      gimp_paned_box_hide_drop_indicator (paned_box, 1);
+      gimp_paned_box_hide_drop_indicator (paned_box, 2);
+
+      if (paned)
+        {
+          gtk_paned_set_position (GTK_PANED (paned),
+                                  paned_box->p->dnd_paned_position);
+        }
+    }
+}
+
+
+GtkWidget *
+gimp_paned_box_new (gboolean       homogeneous,
+                    gint           spacing,
+                    GtkOrientation orientation)
+{
+  return g_object_new (GIMP_TYPE_PANED_BOX,
+                       "homogeneous",  homogeneous,
+                       "spacing",      0,
+                       "orientation",  orientation,
+                       NULL);
+}
+
+void
+gimp_paned_box_set_dropped_cb (GimpPanedBox            *paned_box,
+                               GimpPanedBoxDroppedFunc  dropped_cb,
+                               gpointer                 dropped_cb_data)
+{
+  g_return_if_fail (GIMP_IS_PANED_BOX (paned_box));
+
+  paned_box->p->dropped_cb      = dropped_cb;
+  paned_box->p->dropped_cb_data = dropped_cb_data;
+}
+
+/**
+ * gimp_paned_box_add_widget:
+ * @paned_box: A #GimpPanedBox
+ * @widget:    The #GtkWidget to add
+ * @index:     Where to add the @widget
+ *
+ * Add a #GtkWidget to the #GimpPanedBox in a hierarchy of #GtkPaned:s
+ * so the space can be manually distributed between the widgets.
+ **/
+void
+gimp_paned_box_add_widget (GimpPanedBox *paned_box,
+                           GtkWidget    *widget,
+                           gint          index)
+{
+  gint old_length = 0;
+
+  g_return_if_fail (GIMP_IS_PANED_BOX (paned_box));
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  GIMP_LOG (DND, "Adding GtkWidget %p to GimpPanedBox %p", widget, paned_box);
+
+  /* Calculate length */
+  old_length = g_list_length (paned_box->p->widgets);
+
+  /* If index is invalid append at the end */
+  if (index >= old_length || index < 0)
+    {
+      index = old_length;
+    }
+
+  /* Insert into the list */
+  paned_box->p->widgets = g_list_insert (paned_box->p->widgets, widget, index);
+
+  /* Hook us in for drag events. We could abstract this but it doesn't
+   * seem worth it at this point
+   */
+  gimp_paned_box_set_widget_drag_handler (widget, paned_box);
+
+  /* Insert into the GtkPaned hierarchy */
+  if (old_length == 0)
+    {
+      gtk_box_pack_start (GTK_BOX (paned_box), widget, TRUE, TRUE, 0);
+    }
+  else
+    {
+      GtkWidget      *old_widget;
+      GtkWidget      *parent;
+      GtkWidget      *paned;
+      GtkOrientation  orientation;
+
+      /* Figure out what widget to detach */
+      if (index == 0)
+        {
+          old_widget = g_list_nth_data (paned_box->p->widgets, index + 1);
+        }
+      else
+        {
+          old_widget = g_list_nth_data (paned_box->p->widgets, index - 1);
+        }
+
+      parent = gtk_widget_get_parent (old_widget);
+
+      if (old_length > 1 && index > 0)
+        {
+          GtkWidget *grandparent = gtk_widget_get_parent (parent);
+
+          old_widget = parent;
+          parent     = grandparent;
+        }
+
+      /* Detach the widget and build up a new hierarchy */
+      g_object_ref (old_widget);
+      gtk_container_remove (GTK_CONTAINER (parent), old_widget);
+
+      /* GtkPaned is abstract :( */
+      orientation = gtk_orientable_get_orientation (GTK_ORIENTABLE (paned_box));
+      paned = gtk_paned_new (orientation);
+
+      if (GTK_IS_PANED (parent))
+        {
+          gtk_paned_pack1 (GTK_PANED (parent), paned, TRUE, FALSE);
+        }
+      else
+        {
+          gtk_box_pack_start (GTK_BOX (parent), paned, TRUE, TRUE, 0);
+        }
+      gtk_widget_show (paned);
+
+      if (index == 0)
+        {
+          gtk_paned_pack1 (GTK_PANED (paned), widget,
+                           TRUE, FALSE);
+          gtk_paned_pack2 (GTK_PANED (paned), old_widget,
+                           TRUE, FALSE);
+        }
+      else
+        {
+          gtk_paned_pack1 (GTK_PANED (paned), old_widget,
+                           TRUE, FALSE);
+          gtk_paned_pack2 (GTK_PANED (paned), widget,
+                           TRUE, FALSE);
+        }
+
+      g_object_unref (old_widget);
+    }
+}
+
+/**
+ * gimp_paned_box_remove_widget:
+ * @paned_box: A #GimpPanedBox
+ * @widget:    The #GtkWidget to remove
+ *
+ * Remove a #GtkWidget from a #GimpPanedBox added with
+ * gimp_widgets_add_paned_widget().
+ **/
+void
+gimp_paned_box_remove_widget (GimpPanedBox *paned_box,
+                              GtkWidget    *widget)
+{
+  gint       old_length   = 0;
+  gint       index        = 0;
+  GtkWidget *other_widget = NULL;
+  GtkWidget *parent       = NULL;
+  GtkWidget *grandparent  = NULL;
+
+  g_return_if_fail (GIMP_IS_PANED_BOX (paned_box));
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  GIMP_LOG (DND, "Removing GtkWidget %p from GimpPanedBox %p", widget, paned_box);
+
+  /* Calculate length and index */
+  old_length = g_list_length (paned_box->p->widgets);
+  index      = g_list_index (paned_box->p->widgets, widget);
+
+  /* Remove from list */
+  paned_box->p->widgets = g_list_remove (paned_box->p->widgets, widget);
+
+  /* Reset the drag events hook */
+  gimp_paned_box_set_widget_drag_handler (widget, NULL);
+
+  /* Remove from widget hierarchy */
+  if (old_length == 1)
+    {
+      /* The widget might already be parent-less if we are in
+       * destruction, .e.g when closing a dock window.
+       */
+      if (gtk_widget_get_parent (widget) != NULL)
+        gtk_container_remove (GTK_CONTAINER (paned_box), widget);
+    }
+  else
+    {
+      g_object_ref (widget);
+
+      parent      = gtk_widget_get_parent (GTK_WIDGET (widget));
+      grandparent = gtk_widget_get_parent (parent);
+
+      if (index == 0)
+        other_widget = gtk_paned_get_child2 (GTK_PANED (parent));
+      else
+        other_widget = gtk_paned_get_child1 (GTK_PANED (parent));
+
+      g_object_ref (other_widget);
+
+      gtk_container_remove (GTK_CONTAINER (parent), other_widget);
+      gtk_container_remove (GTK_CONTAINER (parent), GTK_WIDGET (widget));
+
+      gtk_container_remove (GTK_CONTAINER (grandparent), parent);
+
+      if (GTK_IS_PANED (grandparent))
+        gtk_paned_pack1 (GTK_PANED (grandparent), other_widget, TRUE, FALSE);
+      else
+        gtk_box_pack_start (GTK_BOX (paned_box), other_widget, TRUE, TRUE, 0);
+
+      g_object_unref (other_widget);
+
+      g_object_unref (widget);
+    }
+}
+
+/**
+ * gimp_paned_box_will_handle_drag:
+ * @paned_box: A #GimpPanedBox
+ * @widget:    The widget that got the drag event
+ * @context:   Context from drag event
+ * @x:         x from drag event
+ * @y:         y from drag event
+ * @time:      time from drag event
+ *
+ * Returns: %TRUE if the drag event on @widget will be handled by
+ *          @paned_box.
+ **/
+gboolean
+gimp_paned_box_will_handle_drag (GimpPanedBox   *paned_box,
+                                 GtkWidget      *widget,
+                                 GdkDragContext *context,
+                                 gint            x,
+                                 gint            y,
+                                 gint            time)
+{
+  gint           paned_box_x    = 0;
+  gint           paned_box_y    = 0;
+  GtkAllocation  allocation     = { 0, };
+  GtkOrientation orientation    = 0;
+  gboolean       will_handle    = FALSE;
+  gint           drop_area_size = 0;
+
+  g_return_val_if_fail (paned_box == NULL ||
+                        GIMP_IS_PANED_BOX (paned_box), FALSE);
+
+  /* Check for NULL to allow cleaner client code */
+  if (paned_box == NULL)
+    return FALSE;
+
+  /* Our handler might handle it */
+  if (gimp_paned_box_will_handle_drag (paned_box->p->drag_handler,
+                                       widget,
+                                       context,
+                                       x, y,
+                                       time))
+    {
+      /* Return TRUE so the client will pass on the drag event */
+      return TRUE;
+    }
+
+  /* If we don't have a common ancenstor we will not handle it */
+  if (! gtk_widget_translate_coordinates (widget,
+                                          GTK_WIDGET (paned_box),
+                                          x, y,
+                                          &paned_box_x, &paned_box_y))
+    {
+      /* Return FALSE so the client can take care of the drag event */
+      return FALSE;
+    }
+
+  /* We now have paned_box coordinates, see if the paned_box will
+   * handle the event
+   */
+  gtk_widget_get_allocation (GTK_WIDGET (paned_box), &allocation);
+  orientation    = gtk_orientable_get_orientation (GTK_ORIENTABLE (paned_box));
+  drop_area_size = gimp_paned_box_get_drop_area_size (paned_box);
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    {
+      will_handle = (paned_box_x < drop_area_size ||
+                     paned_box_x > allocation.width - drop_area_size);
+    }
+  else /*if (orientation = GTK_ORIENTATION_VERTICAL)*/
+    {
+      will_handle = (paned_box_y < drop_area_size ||
+                     paned_box_y > allocation.height - drop_area_size);
+    }
+
+  return will_handle;
+}
+
+void
+gimp_paned_box_set_drag_handler (GimpPanedBox *paned_box,
+                                 GimpPanedBox *drag_handler)
+{
+  g_return_if_fail (GIMP_IS_PANED_BOX (paned_box));
+
+  paned_box->p->drag_handler = drag_handler;
+}