Chapter 6. Timelines

Table of Contents

Using Timelines

A Clutter::Timeline can be used to change the position or appearance of an actor over time. These can be used directly as described in this chapter, or together with an effect or behaviour, as you will see in the following chapters.

The timeline object emits its signal_new_frame() signal for each frame that should be drawn, for as many frames per second as specified. In your signal handler you can set the actor's properties. For instance, the actor might be moved and rotated over time, and its color might change while this is happening. You could even change the properties of several actors to animate the entire stage.

The Clutter::Timeline::create() constructor function takes a number of frames, and a number of frames per second, so the entire timeline will have a duration of n_frames / fps. You might therefore choose the number of frames based on a desired duration, by dividing the duration by the desired frames per second.

You may also use Clutter::Timeline::set_loop() to cause the timeline to repeat forever, or until you call Clutter::Timeline::stop(). The timeline does not start until you call Clutter::Timeline::start().

When a timeline has completed, it emits the signal_completed() signal.

Clutter::Timeline class reference