public OperationViewModel(IScheduler scheduler)
{
dialogService = Locator.CurrentMutable.GetService <IDialogService>();
stopWatch = new Stopwatch();
Start = ReactiveCommand.Create(this.WhenAny(m => m.TimerState, m => m.Value != TimerState.Running));
Start.Subscribe(_ => StartImpl());
Stop = ReactiveCommand.Create(this.WhenAny(m => m.TimerState, m => m.Value != TimerState.Initial));
Stop.Subscribe(_ => StopImpl());
LapTimes = new ReactiveList <LapTime>();
Lap = ReactiveCommand.CreateAsyncObservable(this.WhenAny(m => m.TimerState, m => m.Value == TimerState.Running), _ => Observable.Return(stopWatch.Elapsed));
Lap.Subscribe(x => LapTimes.Add(new LapTime(x, x - (LapTimes.LastOrDefault()?.Elapsed ?? TimeSpan.Zero))));
this.WhenAny(vm => vm.TimerState, oc => oc.Value == TimerState.Initial).Subscribe(_ => LapTimes.Reset());
Observable.Interval(TimeSpan.FromMilliseconds(10d))
.Select(_ => GetFormattedElapsed(stopWatch.Elapsed))
.ToProperty(this, vm => vm.Elapsed, out elapsed, GetFormattedElapsed(TimeSpan.Zero), scheduler);
}
