reverse method
void
reverse()
Starts running this animation in reverse.
Implementation
void reverse() {
final currentRaw = rawProgress;
status = AnimationStatus.reverse;
if (_stopwatch == null) {
_stopwatch = clock.stopwatch()..start();
_transitionStartTimeMs = 0;
_lastFrameTimeMs = 0;
} else {
_stopwatch!.start();
_transitionStartTimeMs = _stopwatch!.elapsedMilliseconds;
}
_startProgress = currentRaw;
}