SYNOPSIS

    my $animation = Clutter::Animation->new();

    # 500 milliseconds of duration
    $animation->set_duration(500);

    # cubic easing mode
    $animation->set_mode('ease-out-cubic');

    # set the object we want to animate
    $animation->set_object($texture);

    # bind the properties we want to animate on the object; bind()
    # calls can be chained up to
    $animation->bind('scale-x', 2.0)
              ->bind('scale-y', 2.0)
              ->bind('opacity', 255);

    # start the animation
    $animation->get_timeline()->start();

    # set the object as reactive when the animation ends
    $animation->signal_connect(completed => sub {
        $animation->get_object()->set_reactive(TRUE);
    })

DESCRIPTION

Clutter::Animation is an class providing simple, implicit animations for Glib::Object instances.

Clutter::Animation instances will bind one or more object properties belonging to a Glib::Object to a Clutter::Interval, and will then use a Clutter::Alpha to interpolate the property between the initial and final values of the interval.

The duration of the animation is set using Clutter::Animation::set_duration(). The easing mode of the animation is set using Clutter::Animation::set_mode().

Controlling the Animation

If you want to control the animation you should retrieve the Clutter::Timeline using Clutter::Animation::get_timeline() and then use Clutter::Timeline methods like Clutter::Timeline::start(), Clutter::Timeline::pause() or Clutter::Timeline::stop().

A Clutter::Animation will emit the Clutter::Animation::completed signal when the Clutter::Timeline used by the animation is completed; unlike Clutter::Timeline, though, the Clutter::Animation::completed will not be emitted if Clutter::Animation:loop is set to %TRUE - that is, a looping animation never completes.

If your animation depends on user control you can force its completion using Clutter::Animation::completed().

If the Glib::Object instance bound to a Clutter::Animation implements the Clutter::Animatable interface it is possible for that instance to control the way the initial and final states are interpolated.

Changing the Animation

The initial and final value of a property bound to the Animation are controlled by a Clutter::Interval instance. You can retrieve the Interval instance and change the values, or you can change the Interval instance itself:

    # increase the scaling factor
    $animation->get_interval('scale-x')->set_final_value(2.5);
    $animation->get_interval('scale-y')->set_final_value(2.5);

    # change the opacity interval
    $cur_value = $animation->get_object()->get_opacity();
    $interval = Clutter::Interval->new('Glib::Uchar');
    $interval->set_interval($cur_value, 128);
    $animation->update_interval('opacity', $interval);

Differences between Animation and Behaviour

Clutter::Animation is distinguished from Clutter::Behaviour because the former can only control Glib::Object properties of a single Glib::Object instance, while the latter can control multiple properties using accessor functions inside the Clutter::Behaviour::ALPHA_NOTIFY virtual function, and can control multiple Clutter::Actors at the same time.

Convenience API

For convenience, it is possible to use the Clutter::Actor::animate() method which will take care of setting up and tearing down a Clutter::Animation instance and animate an actor between its current state and the specified final state:

    $texture->animate(
        'ease-out-cubic', 500,
        scale_x => 2.0,
        scale_y => 2.0,
        opacity => 255
    )->signal_connect(completed => sub { $texture->set_reactive(TRUE) })

The example above reproduces the same animation as the one in the Synopsis.

The Clutter::Animation instance created by Clutter::Actor::animate() is managed by the animate() method itself and it is guaranteed to be valid for as long as the animation is running; once the animation emits the completed signal, the animation will still be valid from within handlers connected to that signal, until the default signal handler is executed.

CPAN RT