gtkframe: Don't queue a redraw on the entire widget every size allocate

Lots of applications often use GtkFrame as a giant toplevel container,
and that means that they get size allocated often. When frames get size
allocated, they invalidate their entire widget tree, even if they
haven't changed size or anything like that happens at all. This is
because the shadow / label needs to be redrawn if the child changes
size. We can optimize this out and only mark ourselves for a redraw if
the child has actually changed its size.

diff --git a/gtk/gtkframe.c b/gtk/gtkframe.c
index 7c82e3ad6f2d6b2fa62f77a0fcd15120c01076b4..421b0515ffe61b14d082cfa6b418f39ba0434a72 100644 (file)
--- a/gtk/gtkframe.c
+++ b/gtk/gtkframe.c
@@ -706,6 +706,16 @@ gtk_frame_draw (GtkWidget *widget,
   return FALSE;
 }
 
+static gboolean
+rectangle_equal (const GdkRectangle *a,
+                 const GdkRectangle *b)
+{
+  return a->x == b->x
+      && a->y == b->y
+      && a->width == b->width
+      && a->height == b->height;
+}
+
 static void
 gtk_frame_size_allocate (GtkWidget     *widget,
                         GtkAllocation *allocation)
@@ -719,11 +729,11 @@ gtk_frame_size_allocate (GtkWidget     *widget,
   gtk_widget_set_allocation (widget, allocation);
 
   gtk_frame_compute_child_allocation (frame, &new_allocation);
-  
+
   /* If the child allocation changed, that means that the frame is drawn
    * in a new place, so we must redraw the entire widget.
    */
-  if (gtk_widget_get_mapped (widget))
+  if (gtk_widget_get_mapped (widget) && !rectangle_equal (&priv->child_allocation, &new_allocation))
     {
       gdk_window_invalidate_rect (gtk_widget_get_window (widget), allocation, FALSE);
     }