[mutter] plugins/default: Handle skipped animations

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 0545b932327d05cfe63222176bb2f6ba5e36a61c
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Nov 8 22:41:35 2019 +0100

    plugins/default: Handle skipped animations
    
    We currently assume that the actor_animate() helper function returns
    a timeline. However Clutter may skip implicit animations and simple
    set properties directly, for example when the actor is hidden.
    
    The returned timeline will be NULL in that case, and we abort when
    using it as instance parameter to g_signal_connect().
    
    Fix this by only setting up a completed handler when we are actually
    animating, and complete the effect directly otherwise.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/925

 src/compositor/plugins/default.c | 43 +++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 16 deletions(-)
---
diff --git a/src/compositor/plugins/default.c b/src/compositor/plugins/default.c
index 378009006..08ecf01ac 100644
--- a/src/compositor/plugins/default.c
+++ b/src/compositor/plugins/default.c
@@ -590,6 +590,7 @@ minimize (MetaPlugin *plugin, MetaWindowActor *window_actor)
   MetaWindowType type;
   MetaRectangle icon_geometry;
   MetaWindow *meta_window = meta_window_actor_get_meta_window (window_actor);
+  ClutterTimeline *timeline = NULL;
   ClutterActor *actor  = CLUTTER_ACTOR (window_actor);
 
 
@@ -602,24 +603,28 @@ minimize (MetaPlugin *plugin, MetaWindowActor *window_actor)
     }
 
   if (type == META_WINDOW_NORMAL)
+    {
+      timeline = actor_animate (actor,
+                                CLUTTER_EASE_IN_SINE,
+                                MINIMIZE_TIMEOUT,
+                                "scale-x", 0.0,
+                                "scale-y", 0.0,
+                                "x", (double)icon_geometry.x,
+                                "y", (double)icon_geometry.y,
+                                NULL);
+    }
+
+  if (timeline)
     {
       EffectCompleteData *data = g_new0 (EffectCompleteData, 1);
       ActorPrivate *apriv = get_actor_private (window_actor);
 
-      apriv->tml_minimize = actor_animate (actor,
-                                           CLUTTER_EASE_IN_SINE,
-                                           MINIMIZE_TIMEOUT,
-                                           "scale-x", 0.0,
-                                           "scale-y", 0.0,
-                                           "x", (double)icon_geometry.x,
-                                           "y", (double)icon_geometry.y,
-                                           NULL);
+      apriv->tml_minimize = timeline;
       data->plugin = plugin;
       data->actor = actor;
       g_signal_connect (apriv->tml_minimize, "completed",
                         G_CALLBACK (on_minimize_effect_complete),
                         data);
-
     }
   else
     meta_plugin_minimize_completed (plugin, window_actor);
@@ -708,21 +713,27 @@ destroy (MetaPlugin *plugin, MetaWindowActor *window_actor)
   MetaWindowType type;
   ClutterActor *actor = CLUTTER_ACTOR (window_actor);
   MetaWindow *meta_window = meta_window_actor_get_meta_window (window_actor);
+  ClutterTimeline *timeline = NULL;
 
   type = meta_window_get_window_type (meta_window);
 
   if (type == META_WINDOW_NORMAL)
+    {
+      timeline = actor_animate (actor,
+                                CLUTTER_EASE_OUT_QUAD,
+                                DESTROY_TIMEOUT,
+                                "opacity", 0,
+                                "scale-x", 0.8,
+                                "scale-y", 0.8,
+                                NULL);
+    }
+
+  if (timeline)
     {
       EffectCompleteData *data = g_new0 (EffectCompleteData, 1);
       ActorPrivate *apriv = get_actor_private (window_actor);
 
-      apriv->tml_destroy = actor_animate (actor,
-                                          CLUTTER_EASE_OUT_QUAD,
-                                          DESTROY_TIMEOUT,
-                                          "opacity", 0,
-                                          "scale-x", 0.8,
-                                          "scale-y", 0.8,
-                                          NULL);
+      apriv->tml_destroy = timeline;
       data->plugin = plugin;
       data->actor = actor;
       g_signal_connect (apriv->tml_destroy, "completed",