updatePlayState method
      
void
updatePlayState()
      
     
    
    
Implementation
void updatePlayState() {
  if (isPlaying && attached) {
    markNeedsPaint();
  } else {
    _lastFrameTime = _notPlayingFlag;
    if (_frameCallbackID != -1) {
      SchedulerBinding.instance?.cancelFrameCallbackWithId(_frameCallbackID);
    }
  }
}