[animation] Do not unref on ::complete by default

Bug 1535 - Complete animation always unrefs ClutterAnimation (even
           after g_object_ref_sink)

Animations created through clutter_animation_new() should not
automagically unref themselves by default on ::complete. We
only want that behaviour for Animations created by the
clutter_actor_animate* family of functions, since those provide
the automagic memory management.

clutter/clutter-animation.c

@@ -109,6 +109,7 @@ clutter_animation_finalize (GObject *gobject)
 {
   ClutterAnimationPrivate *priv = CLUTTER_ANIMATION (gobject)->priv;
 
+  CLUTTER_NOTE (ANIMATION, "Destroying properties hash table");
   g_hash_table_destroy (priv->properties);
 
   G_OBJECT_CLASS (clutter_animation_parent_class)->finalize (gobject);
@@ -237,19 +238,6 @@ clutter_animation_get_property (GObject    *gobject,
     }
 }
 
-static void
-clutter_animation_real_completed (ClutterAnimation *animation)
-{
-  CLUTTER_NOTE (ANIMATION, "Animation [%p] complete: unreffing",
-                animation);
-
-  /* the signal emission takes a reference on the animation, which
-   * means that even if we unref it here, it'll be valid for the
-   * whole duration of the emission chain
-   */
-  g_object_unref (animation);
-}
-
 static void
 clutter_animation_class_init (ClutterAnimationClass *klass)
 {
@@ -261,8 +249,6 @@ clutter_animation_class_init (ClutterAnimationClass *klass)
 
   g_type_class_add_private (klass, sizeof (ClutterAnimationPrivate));
 
-  klass->completed = clutter_animation_real_completed;
-
   gobject_class->set_property = clutter_animation_set_property;
   gobject_class->get_property = clutter_animation_get_property;
   gobject_class->dispose = clutter_animation_dispose;
@@ -1232,9 +1218,14 @@ clutter_animation_get_alpha (ClutterAnimation *animation)
  * clutter_animation_completed:
  * @animation: a #ClutterAnimation
  *
- * Emits the ::completed signal on @animation. After this function
+ * Emits the ::completed signal on @animation
- * terminates @animation will be unreferenced and it will not be
+ *
- * valid anymore, unless g_object_ref() was called before
+ * When using this function with a #ClutterAnimation created
+ * by the clutter_actor_animate() family of functions, @animation
+ * will be unreferenced and it will not be valid anymore,
+ * unless g_object_ref() was called before calling this function
+ * or unless a reference was taken inside a handler for the
+ * #ClutterAnimation::completed signal
  *
  * Since: 1.0
  */
@@ -1246,6 +1237,15 @@ clutter_animation_completed (ClutterAnimation *animation)
   g_signal_emit (animation, animation_signals[COMPLETED], 0);
 }
 
+static void
+on_animation_completed (ClutterAnimation *animation)
+{
+  CLUTTER_NOTE (ANIMATION, "Animation[%p] completed, unreferencing",
+                animation);
+
+  g_object_unref (animation);
+}
+
 /*
  * starts the timeline
  */
@@ -1401,6 +1401,10 @@ clutter_animation_setupv (ClutterAnimation    *animation,
                                         &values[i],
                                         pspec);
     }
+
+  g_signal_connect (animation, "completed",
+                    G_CALLBACK (on_animation_completed),
+                    NULL);
 }
 
 static void
@@ -1459,6 +1463,10 @@ clutter_animation_setup_valist (ClutterAnimation *animation,
 
       property_name = va_arg (var_args, gchar*);
     }
+
+  g_signal_connect (animation, "completed",
+                    G_CALLBACK (on_animation_completed),
+                    NULL);
 }
 
 /**
@@ -1637,9 +1645,9 @@ clutter_actor_animate_with_timeline (ClutterActor    *actor,
  * to control the animation or to know when the animation has been
  * completed.
  *
- * If a name argument starts with "signal::" the two following arguments are
+ * If a name argument starts with "signal::" the two following arguments
- * used as callback function and userdata for a signal handler installed on the
+ * are used as callback function and userdata for a signal handler installed
- * #ClutterAnimation object, for instance:
+ * on the #ClutterAnimation object, for instance:
  *
  * |[
  *
@@ -1656,7 +1664,6 @@ clutter_actor_animate_with_timeline (ClutterActor    *actor,
  *                          NULL);
  * ]|
  *
- *
  * Calling this function on an actor that is already being animated
  * will cause the current animation to change with the new final values,
  * the new easing mode and the new duration - that is, this code: