From 0600d3d7e4c85eefa479d9735df37af707a31438 Mon Sep 17 00:00:00 2001
From: Alexander Larsson <alexl@redhat.com>
Date: Fri, 3 May 2013 10:42:40 +0200
Subject: [PATCH] GtkWidget: Use gdk_window_get_children_for_user_data

This makes iterating over the children a lot faster, as we're
not doing lots of intra-library calls and type checks. We're still
in some sence O(n^2) since we iterate over each child window for each
widget, but the profiles look much better.
---
 gtk/gtkwidget.c | 55 ++++++++++++++++++++++---------------------------
 1 file changed, 25 insertions(+), 30 deletions(-)

diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 19e026a401..2139d7badc 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -6402,7 +6402,7 @@ _gtk_widget_draw_windows (GdkWindow *window,
   cairo_pattern_t *pattern;
   gboolean do_clip;
   GtkWidget *widget = NULL;
-  GList *l;
+  GList *children, *l;
   int x, y;
 
   if (!gdk_window_is_viewable (window))
@@ -6438,29 +6438,26 @@ _gtk_widget_draw_windows (GdkWindow *window,
       _gtk_widget_draw_internal (widget, cr, do_clip, window);
       cairo_restore (cr);
 
-      for (l = g_list_last (gdk_window_peek_children (window));
-	   l != NULL;
-	   l = l->prev)
+      children = gdk_window_get_children_with_user_data (window, widget);
+      for (l = children; l != NULL; l = l->next)
 	{
 	  GdkWindow *child_window = l->data;
-	  gpointer child_data;
 	  GdkWindowType type;
 	  int wx, wy;
 
-	  type = gdk_window_get_window_type (child_window);
 	  if (!gdk_window_is_visible (child_window) ||
-	      gdk_window_is_input_only (child_window) ||
-	      type == GDK_WINDOW_OFFSCREEN ||
+	      gdk_window_is_input_only (child_window))
+	    continue;
+
+	  type = gdk_window_get_window_type (child_window);
+	  if (type == GDK_WINDOW_OFFSCREEN ||
 	      type == GDK_WINDOW_FOREIGN)
 	    continue;
 
-	  gdk_window_get_user_data (child_window, &child_data);
-	  if (child_data == (gpointer)widget)
-	    {
-	      gdk_window_get_position (child_window, &wx, &wy);
-	      _gtk_widget_draw_windows (child_window, cr, wx,wy);
-	    }
+	  gdk_window_get_position (child_window, &wx, &wy);
+	  _gtk_widget_draw_windows (child_window, cr, wx,wy);
 	}
+      g_list_free (children);
     }
 
   cairo_restore (cr);
@@ -6471,8 +6468,7 @@ _gtk_widget_draw (GtkWidget *widget,
 		  cairo_t   *cr)
 {
   GdkWindow *window, *child_window;
-  gpointer child_data;
-  GList *l;
+  GList *children, *l;
   int wx, wy;
   gboolean push_group;
   GdkWindowType type;
@@ -6520,27 +6516,26 @@ _gtk_widget_draw (GtkWidget *widget,
 
       /* But, it may also have child windows in the parent which we should
        * draw (after having drawn on the parent) */
-      for (l = g_list_last (gdk_window_peek_children (window));
-	   l != NULL;
-	   l = l->prev)
+      children = gdk_window_get_children_with_user_data (window, widget);
+      for (l = children; l != NULL; l = l->next)
 	{
 	  child_window = l->data;
-	  type = gdk_window_get_window_type (child_window);
+
 	  if (!gdk_window_is_visible (child_window) ||
-	      gdk_window_is_input_only (child_window) ||
-	      type == GDK_WINDOW_OFFSCREEN ||
+	      gdk_window_is_input_only (child_window))
+	    continue;
+
+	  type = gdk_window_get_window_type (child_window);
+	  if (type == GDK_WINDOW_OFFSCREEN ||
 	      type == GDK_WINDOW_FOREIGN)
 	    continue;
 
-	  gdk_window_get_user_data (child_window, &child_data);
-	  if (child_data == (gpointer)widget)
-	    {
-	      gdk_window_get_position (child_window, &wx, &wy);
-	      _gtk_widget_draw_windows (child_window, cr,
-					wx - widget->priv->allocation.x,
-					wy - widget->priv->allocation.y);
-	    }
+	  gdk_window_get_position (child_window, &wx, &wy);
+	  _gtk_widget_draw_windows (child_window, cr,
+				    wx - widget->priv->allocation.x,
+				    wy - widget->priv->allocation.y);
 	}
+      g_list_free (children);
     }
 
   if (push_group)
-- 
2.30.2