Emmanuele
Bassi

              ebassi@gnome.org

# Migrating from ClutterAnimation

The #ClutterAnimation class, along with the #ClutterActor wrappers clutter_actor_animate(), clutter_actor_animate_with_timeline() and clutter_actor_animate_with_alpha(), has been deprecated in Clutter 1.12, and should not be used in newly written code.

The direct replacement for a #ClutterAnimation is the #ClutterPropertyTransition class, which allows the transition of a single #GObject property from an initial value to a final value over a user-defined time using a user-defined easing curve.

The #ClutterPropertyTransition class inherits from #ClutterTransition, which allows setting the transition interval, as well as the animatable instance to be transitioned; and from #ClutterTimeline, which allows setting the duration and easing curve of the transition.

For instance, the following #ClutterAnimation set up:

      ClutterAnimation *animation = clutter_animation_new ();

      clutter_animation_set_mode (animation, CLUTTER_EASE_OUT_CUBIC);
      clutter_animation_set_duration (animation, 2500);

      /* object_to_animate is set elsewhere */
      clutter_animation_set_object (animation, object_to_animate);

      ClutterInterval *interval = clutter_interval_new (G_TYPE_FLOAT, 0.0, 100.0);

      /* property_name is set elsewhere */
      clutter_animation_bind_interval (animation, property_name, interval);

      ClutterTimeline *timeline = clutter_animation_get_timeline (animation);
      clutter_timeline_start (timeline);

Can be replaced by #ClutterPropertyTransition:

      ClutterTransition *transition = clutter_property_transition_new (property_name);

      clutter_timeline_set_progress_mode (CLUTTER_TIMELINE (transition),
                                          CLUTTER_EASE_OUT_CUBIC);
      clutter_timeline_set_duration (CLUTTER_TIMELINE (transition), 2000);

      clutter_transition_set_animatable (transition, object_to_animate);

      clutter_transition_set_from (transition, G_TYPE_FLOAT, 0.0);
      clutter_transition_set_to (transition, G_TYPE_FLOAT, 100.0);

      clutter_timeline_start (CLUTTER_TIMELINE (transition));

It is important to note that only #ClutterAnimatable implementations can be used directly with #ClutterTransition.

A #ClutterPropertyTransition can only animate a single property; if more than one property transition is required, you can use the #ClutterTransitionGroup class to group the transitions together.

## Migrating clutter_actor_animate()

#ClutterActor animatable properties can use implicit transitions through their setter functions. The duration and easing curve of the animation is controlled by clutter_actor_set_easing_duration() and by clutter_actor_set_easing_mode(), respectively; for instance, the equivalent of the following clutter_actor_animate() call:

      clutter_actor_animate (actor, CLUTTER_EASE_OUT_BOUNCE, 500,
                             "x", new_x_position,
                             "y", new_y_position,
                             "opacity", 255,
                             NULL);

Can be replaced by the following:

      clutter_actor_set_easing_mode (actor, CLUTTER_EASE_OUT_BOUNCE);
      clutter_actor_set_easing_duration (actor, 500);
      clutter_actor_set_position (actor, new_x_position, new_y_position);
      clutter_actor_set_opacity (actor, 255);

The default easing duration for the 1.0 API series is set to 0, which means no transition at all.

It is possible to set the easing state of a #ClutterActor to its default values by using clutter_actor_save_easing_state(), and return to the previous values by calling clutter_actor_restore_easing_state() instead. The easing state affects all the animatable properties that are modified after changing it; so, for instance:

      clutter_actor_save_easing_state (actor);
      clutter_actor_set_easing_duration (actor, 500);
      clutter_actor_set_opacity (actor, 255);

      clutter_actor_save_easing_state (actor);
      clutter_actor_set_easing_delay (actor, 500);
      clutter_actor_set_easing_duration (actor, 500);
      clutter_actor_set_size (actor, width, height);
      clutter_actor_restore_easing_state (actor);

      clutter_actor_restore_easing_state (actor);

The animation above will implicitly transition the opacity from its current value to 255 in 500 milliseconds using the default easing curve; at the same time, the size of the actor will be transitioned in 500 milliseconds after a delay of 500 milliseconds to the new size stored in the variables width and height.