Implement freezing of updates during resize

Replace the unused meta_compositor_set_updates() with
a reversed-meaning meta_compositor_set_updates_frozen(), and use
it to implement freezing application window updates during
interactive resizing. This avoids drawing new areas of the window
with blank content before the application has a chance to repaint.

https://bugzilla.gnome.org/show_bug.cgi?id=685463

src/compositor/compositor.c

@@ -721,10 +721,18 @@ meta_compositor_remove_window (MetaCompositor *compositor,
 }
 
 void
-meta_compositor_set_updates (MetaCompositor *compositor,
-                             MetaWindow     *window,
-                             gboolean        updates)
+meta_compositor_set_updates_frozen (MetaCompositor *compositor,
+                                    MetaWindow     *window,
+                                    gboolean        updates_frozen)
 {
+  MetaWindowActor *window_actor;
+
+  DEBUG_TRACE ("meta_compositor_set_updates_frozen\n");
+  window_actor = META_WINDOW_ACTOR (meta_window_get_compositor_private (window));
+  if (!window_actor)
+    return;
+
+  meta_window_actor_set_updates_frozen (window_actor, updates_frozen);
 }
 
 static gboolean

src/compositor/meta-window-actor-private.h

@@ -45,6 +45,8 @@ void     meta_window_actor_update_shape        (MetaWindowActor *self);
 void     meta_window_actor_update_opacity      (MetaWindowActor *self);
 void     meta_window_actor_mapped              (MetaWindowActor *self);
 void     meta_window_actor_unmapped            (MetaWindowActor *self);
+void     meta_window_actor_set_updates_frozen  (MetaWindowActor *self,
+                                                gboolean         updates_frozen);
 
 cairo_region_t *meta_window_actor_get_obscured_region (MetaWindowActor *self);
 

src/compositor/meta-window-actor.c

@@ -111,6 +111,7 @@ struct _MetaWindowActorPrivate
   guint             recompute_focused_shadow   : 1;
   guint             recompute_unfocused_shadow : 1;
   guint		    size_changed           : 1;
+  guint             updates_frozen         : 1;
 
   guint		    needs_destroy	   : 1;
 
@@ -925,10 +926,16 @@ meta_window_actor_thaw (MetaWindowActor *self)
   if (self->priv->freeze_count)
     return;
 
+  /* We ignore moves and resizes on frozen windows */
+  meta_window_actor_sync_actor_position (self);
+
+  /* We do this now since we might be going right back into the
+   * frozen state */
+  meta_window_actor_pre_paint (self);
+
   /* Since we ignore damage events while a window is frozen for certain effects
    * we may need to issue an update_area() covering the whole pixmap if we
    * don't know what real damage has happened. */
-
   if (self->priv->needs_damage_all)
     meta_window_actor_damage_all (self);
 }
@@ -1291,6 +1298,12 @@ meta_window_actor_destroy (MetaWindowActor *self)
     clutter_actor_destroy (CLUTTER_ACTOR (self));
 }
 
+static gboolean
+is_frozen (MetaWindowActor *self)
+{
+  return self->priv->freeze_count ? TRUE : FALSE;
+}
+
 void
 meta_window_actor_sync_actor_position (MetaWindowActor *self)
 {
@@ -1299,6 +1312,9 @@ meta_window_actor_sync_actor_position (MetaWindowActor *self)
 
   meta_window_get_input_rect (priv->window, &window_rect);
 
+  if (is_frozen (self))
+    return;
+
   if (priv->last_width != window_rect.width ||
       priv->last_height != window_rect.height)
     {
@@ -1496,6 +1512,9 @@ meta_window_actor_new (MetaWindow *window)
   if (priv->mapped)
     meta_window_actor_queue_create_pixmap (self);
 
+  meta_window_actor_set_updates_frozen (self,
+                                        meta_window_updates_are_frozen (priv->window));
+
   meta_window_actor_sync_actor_position (self);
 
   /* Hang our compositor window state off the MetaWindow for fast retrieval */
@@ -1829,12 +1848,6 @@ check_needs_shadow (MetaWindowActor *self)
     meta_shadow_unref (old_shadow);
 }
 
-static gboolean
-is_frozen (MetaWindowActor *self)
-{
-  return self->priv->freeze_count ? TRUE : FALSE;
-}
-
 void
 meta_window_actor_process_damage (MetaWindowActor    *self,
                                   XDamageNotifyEvent *event)
@@ -2328,3 +2341,21 @@ meta_window_actor_update_opacity (MetaWindowActor *self)
   self->priv->opacity = opacity;
   clutter_actor_set_opacity (self->priv->actor, opacity);
 }
+
+void
+meta_window_actor_set_updates_frozen (MetaWindowActor *self,
+                                      gboolean         updates_frozen)
+{
+  MetaWindowActorPrivate *priv = self->priv;
+
+  updates_frozen = updates_frozen != FALSE;
+
+  if (priv->updates_frozen != updates_frozen)
+    {
+      priv->updates_frozen = updates_frozen;
+      if (updates_frozen)
+        meta_window_actor_freeze (self);
+      else
+        meta_window_actor_thaw (self);
+    }
+}