Avoid lots of unnecessary computation when moving toplevel windows

There is no need to do all these computations when moving toplevels
as that can't really change any visible regions. Nor will it cause
any exposes we need to handle.

diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 50cc817aa86e73b2c9b791c8fa318e548a55c403..416b7dd5e2a9e31194ddf35b05d12e55e1bc030d 100644 (file)
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -5803,6 +5803,7 @@ gdk_window_move_resize_internal (GdkWindow *window,
   int old_x, old_y, old_abs_x, old_abs_y;
   int dx, dy;
   gboolean do_move_native_children;
+  gboolean is_toplevel, is_resize;
 
   g_return_if_fail (GDK_IS_WINDOW (window));
 
@@ -5818,29 +5819,30 @@ gdk_window_move_resize_internal (GdkWindow *window,
 
   old_x = private->x;
   old_y = private->y;
+
+  is_toplevel =
+    private->parent == NULL ||
+    GDK_WINDOW_TYPE (private->parent) == GDK_WINDOW_ROOT;
+
+  is_resize = (width != -1) || (height != -1);
+
+  if (GDK_WINDOW_IS_MAPPED (window) &&
+      (!is_toplevel || is_resize) &&
+      !private->input_only)
+    {
+      expose = TRUE;
+      
+      old_region = gdk_region_copy (private->clip_region);
+      /* Adjust region to parent window coords */
+      gdk_region_offset (old_region, private->x, private->y);
+    }
   
   if (gdk_window_has_impl (private))
     {
-      if (GDK_WINDOW_IS_MAPPED (window))
-       {
-         expose = !private->input_only;
-         old_region = gdk_region_copy (private->clip_region);
-         /* Adjust region to parent window coords */
-         gdk_region_offset (old_region, private->x, private->y);
-       }
-      
       GDK_WINDOW_IMPL_GET_IFACE (private->impl)->move_resize (window, with_move, x, y, width, height);
     }
   else
     {
-      if (GDK_WINDOW_IS_MAPPED (window))
-       {
-         expose = !private->input_only;
-         old_region = gdk_region_copy (private->clip_region);
-         /* Adjust region to parent window coords */
-         gdk_region_offset (old_region, private->x, private->y);
-       }
-
       if (with_move)
        {
          private->x = x;
@@ -5861,16 +5863,18 @@ gdk_window_move_resize_internal (GdkWindow *window,
 
   dx = private->x - old_x;
   dy = private->y - old_y;
-
+  
   old_abs_x = private->abs_x;
   old_abs_y = private->abs_y;
-  
-  recompute_visible_regions (private, TRUE, FALSE);
 
+  /* Avoid recomputing for pure toplevel moves, for performance reasons */
+  if (!is_toplevel || is_resize)
+    recompute_visible_regions (private, TRUE, FALSE);
+  
   if (do_move_native_children &&
       (old_abs_x != private->abs_x ||
        old_abs_y != private->abs_y))
-      move_native_children (private);
+    move_native_children (private);
   
   if (expose)
     {