Merge lp:~cimi/overlay-scrollbar/fix-746189 into lp:overlay-scrollbar

[Andrea Cimitan]

Check the right visual before saying the thumb should have rgba

[lp:~cimi/overlay-scrollbar/fix-746189]

189. By Andrea Cimitan on 2011-04-04

Better approach to composite-changed, always set it to false, and set to true only when the condition is verified

[Loïc Molinari (loic.molinari)]

review: Approve

=== modified file 'os/os-thumb.c'
--- os/os-thumb.c	2011-03-28 16:17:49 +0000
+++ os/os-thumb.c	2011-04-04 16:27:31 +0000
@@ -221,19 +221,25 @@
 static void
 os_thumb_composited_changed (GtkWidget *widget)
 {
-  GdkScreen *screen;
   OsThumb *thumb;
   OsThumbPrivate *priv;
 
   thumb = OS_THUMB (widget);
   priv = thumb->priv;
 
-  screen = gtk_widget_get_screen (widget);
-
-  if (gdk_screen_is_composited (screen))
-    priv->can_rgba = TRUE;
-  else
-    priv->can_rgba = FALSE;
+  priv->can_rgba = FALSE;
+
+  if (gdk_screen_is_composited (gtk_widget_get_screen (widget)))
+    {
+      GdkVisual *visual;
+
+      visual = gtk_widget_get_visual (widget);
+
+      if (visual->depth == 32 && (visual->red_mask   == 0xff0000 &&
+                                  visual->green_mask == 0x00ff00 &&
+                                  visual->blue_mask  == 0x0000ff))
+        priv->can_rgba = TRUE;
+    }
 
   gtk_widget_queue_draw (widget);
 }