add_tick_callback


Description:

public uint add_tick_callback (owned TickCallback callback)

Queues an animation frame update and adds a callback to be called before each frame.

Until the tick callback is removed, it will be called frequently (usually at the frame rate of the output device or as quickly as the application can be repainted, whichever is slower). For this reason, is most suitable for handling graphics that change every frame or every few frames. The tick callback does not automatically imply a relayout or repaint. If you want a repaint or relayout, and aren’t changing widget properties that would trigger that (for example, changing the text of a Label), then you will have to call queue_resize or queue_draw yourself.

get_frame_time should generally be used for timing continuous animations and get_predicted_presentation_time if you are trying to display isolated frames at particular times.

This is a more convenient alternative to connecting directly to the update signal of FrameClock, since you don't have to worry about when a FrameClock is assigned to a widget.

Parameters:

this

a Widget

callback

function to call for updating animations

notify

function to call to free user_data when the callback is removed.

user_data

data to pass to callback

Returns:

an id for the connection of this callback. Remove the callback by passing the id returned from this function to remove_tick_callback