[gtk+] Optimize remove_child_area for children outside region

[Alexander Larsson <alexl src gnome org>]

commit a057c038893b7a9c84524796662de17a97e4437a
Author: Alexander Larsson <alexl redhat com>
Date:   Sun Jul 19 22:35:25 2009 +0200

    Optimize remove_child_area for children outside region
    
    If a child is totally outside the current region, bail early instead
    of doing costly calculations to subtract the child region.

 gdk/gdkwindow.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index eeb8932..a1fa450 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -636,6 +636,10 @@ remove_child_area (GdkWindowObject *private,
       r.width = child->width;
       r.height = child->height;
 
+      /* Bail early if child totally outside region */
+      if (gdk_region_rect_in (region, &r) == GDK_OVERLAP_RECTANGLE_OUT)
+	continue;
+
       child_region = gdk_region_rectangle (&r);
 
       if (child->shape)