cancel method
void
cancel()
Implementation
void cancel() {
if (!_inEffect) return;
_inEffect = false;
_isIdle = true;
_isPaused = false;
_finishedFlag = true;
_currentTime = 0;
_startTime = null;
_effect!._calculateTiming(null);
timeline?._removeAnimation(this);
if (oncancel != null) {
var event = AnimationPlaybackEvent(EVENT_CANCEL);
event.timelineTime = _timeline!.currentTime;
oncancel!(event);
}
}