[gimp] app: switch off double buffering on the entire offscreen widget tree

[Michael Natterer <mitch src gnome org>]

commit 27ec3aa81283431c1ec458c8b41993975acf2d09
Author: Michael Natterer <mitch gimp org>
Date:   Fri Jun 18 13:45:03 2010 +0200

    app: switch off double buffering on the entire offscreen widget tree
    
    Also always return FALSE from the expose and damage event handlers.

 app/widgets/gimpoverlaybox.c |   25 ++++++++++++++++++++++---
 1 files changed, 22 insertions(+), 3 deletions(-)
---
diff --git a/app/widgets/gimpoverlaybox.c b/app/widgets/gimpoverlaybox.c
index 98353a9..dda04c0 100644
--- a/app/widgets/gimpoverlaybox.c
+++ b/app/widgets/gimpoverlaybox.c
@@ -235,7 +235,7 @@ gimp_overlay_box_expose (GtkWidget      *widget,
       for (list = box->children; list; list = g_list_next (list))
         {
           if (gimp_overlay_child_expose (box, list->data, event))
-            return TRUE;
+            return FALSE;
         }
     }
 
@@ -252,7 +252,7 @@ gimp_overlay_box_damage (GtkWidget      *widget,
   for (list = box->children; list; list = g_list_next (list))
     {
       if (gimp_overlay_child_damage (box, list->data, event))
-        return TRUE;
+        return FALSE;
     }
 
   return FALSE;
@@ -344,6 +344,25 @@ gimp_overlay_box_new (void)
   return g_object_new (GIMP_TYPE_OVERLAY_BOX, NULL);
 }
 
+static void
+unset_double_buffered (GtkWidget *widget)
+{
+  gtk_widget_set_double_buffered (widget, FALSE);
+
+  if (GTK_IS_CONTAINER (widget))
+    {
+      GList *children = gtk_container_get_children (GTK_CONTAINER (widget));
+      GList *list;
+
+      for (list = children; list; list = g_list_next (list))
+        {
+          unset_double_buffered (list->data);
+        }
+
+      g_list_free (children);
+    }
+}
+
 void
 gimp_overlay_box_add_child (GimpOverlayBox *box,
                             GtkWidget      *widget,
@@ -355,7 +374,7 @@ gimp_overlay_box_add_child (GimpOverlayBox *box,
   g_return_if_fail (GIMP_IS_OVERLAY_BOX (box));
   g_return_if_fail (GTK_IS_WIDGET (widget));
 
-  gtk_widget_set_double_buffered (widget, FALSE);
+  unset_double_buffered (widget);
 
   child = gimp_overlay_child_new (box, widget, xalign, yalign, 0.0, 0.7);