public PlayingEventViewmodel(Engine engine)
 {
     _engine = engine;
     _engine.EngineOperation += _onEngineOperation;
     _engine.EngineTick += _onEngineTick;
     PlayingEvent = _engine.PlayingEvent();
     _sliderTimer = new DispatcherTimer();
     _sliderTimer.Interval = TimeSpan.FromMilliseconds(200);
     _sliderTimer.Tick += SliderPositionDelayedUpdate;
 }