[gtk+] treeview: always pixelcache widget contents

[Christian Hergert <chergert src gnome org>]

commit fb06b6e4b8cc312f56322b38b91af5b4c726bc33
Author: Christian Hergert <christian hergert me>
Date:   Tue Jun 16 16:50:44 2015 -0700

    treeview: always pixelcache widget contents
    
    GtkTreeView has a particularly expensive drawing path. This can cause
    issues when part of animated widget sequences. Caching the content while
    a model is attached helps reduce the number of full redraws during
    exposure greatly.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=751082

 gtk/gtktreeview.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtktreeview.c b/gtk/gtktreeview.c
index 1e4779f..5eaed63 100644
--- a/gtk/gtktreeview.c
+++ b/gtk/gtktreeview.c
@@ -11540,6 +11540,8 @@ gtk_tree_view_set_model (GtkTreeView  *tree_view,
   if (tree_view->priv->selection)
   _gtk_tree_selection_emit_changed (tree_view->priv->selection);
 
+  _gtk_pixel_cache_set_always_cache (tree_view->priv->pixel_cache, (model != NULL));
+
   if (gtk_widget_get_realized (GTK_WIDGET (tree_view)))
     gtk_widget_queue_resize (GTK_WIDGET (tree_view));
 }