Emmanuele Bassi

              ebassi@linux.intel.com

# Migrating from ClutterBehaviour

The #ClutterBehaviour class and its sub-classes have been deprecated since Clutter 1.6. The animation framework provided by #ClutterAnimation, #ClutterAnimator and #ClutterState fully replaces all functionality from the #ClutterBehaviour classes.

Generally, animations using #ClutterBehaviour sub-classes can be effectively re-implemented just by using #ClutterActor properties.

Here is an example of an animation using a #ClutterBehaviourOpacity instance:

      ClutterTimeline *timeline = clutter_timeline_new (250);
      ClutterAlpha *alpha = clutter_alpha_new_full (timeline, CLUTTER_LINEAR);
      ClutterBehaviour *behaviour = clutter_behaviour_opacity_new (alpha, 255, 0);

      clutter_behaviour_apply (behaviour, some_actor);

      clutter_timeline_start (timeline);

The same effect can be achieved by using clutter_actor_animate() and the #ClutterActor:opacity property:

      clutter_actor_set_opacity (some_actor, 255);
      clutter_actor_animate (some_actor, CLUTTER_LINEAR, 250,
                             "opacity", 0,
                             NULL);

#ClutterBehaviours used for continuous animations with looping timelines can still be effectively replaced by looping animations; for instance, the following example of a "pulsating" actor using #ClutterBehaviourScale:

    static void
    reverse_timeline (ClutterTimeline *timeline)
    {
      ClutterTimelineDirection dir = clutter_timeline_get_direction (timeline);

      if (dir == CLUTTER_TIMELINE_FORWARD)
        dir = CLUTTER_TIMELINE_BACKWARD;
      else
        dir = CLUTTER_TIMELINE_FORWARD;

      clutter_timeline_set_direction (timeline, dir);
    }

      ClutterTimeline *timeline = clutter_timeline_new (500);
      ClutterAlpha *alpha = clutter_alpha_new_full (timeline, CLUTTER_LINEAR);
      ClutterBehaviour *behaviour;

      g_object_set (some_actor, "scale-gravity", CLUTTER_GRAVITY_CENTER, NULL);
      behaviour = clutter_behaviour_scale_new (alpha,
                                               1.0, 2.0,
                                               1.0, 2.0);
      clutter_behaviour_apply (behaviour, some_actor);

      g_signal_connect (timeline,
                        "completed", G_CALLBACK (reverse_timeline),
                        NULL);

      clutter_timeline_set_loop (timeline);
      clutter_timeline_start (timeline);

The same effect can be achieved using a #ClutterAnimation:

      ClutterAnimation *animation =
        clutter_actor_animate (some_actor, CLUTTER_LINEAR, 500,
                               "scale-x", 2.0,
                               "scale-y", 2.0,
                               "fixed::scale-gravity", CLUTTER_GRAVITY_CENTER,
                               NULL);

      ClutterTimeline *timeline = clutter_animation_get_timeline (animation);
      clutter_timeline_set_repeat_count (timeline, -1);
      clutter_timeline_set_auto_reverse (timeline, TRUE);

#ClutterBehaviour sub-classes can be applied to multiple actors, in order to share the duration and the easing mode. It is possible to use the same underlying #ClutterTimeline and #ClutterAlpha instances with #ClutterAnimation to achieve the same effect. Complex animations, spanning multiple actors, should use the #ClutterAnimator and #ClutterState classes instead.