set_progress_func

Sets a custom progress function for this.

The progress function will be called by get_progress and will be used to compute the progress value based on the elapsed time and the total duration of the timeline.

If func is not null, the progress_mode property will be set to CUSTOM_MODE.

If func is null, any previously set progress function will be unset, and the progress_mode property will be set to LINEAR.

Parameters:

this	a Timeline
func	a progress function, or null
data	data to pass to func
notify	a function to be called when the progress function is removed or the timeline is disposed