void setupRx()
{
var countAsBehavior = Observable.Concat(
Observable.Defer(() => Observable.Return(_NavigationStack.Count)),
NavigationStack.CountChanged);
NavigateBack = ReactiveCommand.CreateAsyncObservable(
countAsBehavior.Select(x => x > 1),
_ => Observable.Return(Unit.Default));
NavigateBack.Subscribe(_ =>
NavigationStack.RemoveAt(NavigationStack.Count - 1));
Navigate = new ReactiveCommand <object>(Observable.Return(true), x => Observable.Return(x));
Navigate.Subscribe(x => {
var vm = x as IRoutableViewModel;
if (vm == null)
{
throw new Exception("Navigate must be called on an IRoutableViewModel");
}
NavigationStack.Add(vm);
});
NavigateAndReset = new ReactiveCommand <object>(Observable.Return(true), x => Observable.Return(x));
NavigateAndReset
.SelectMany(x => {
NavigationStack.Clear();
return(Navigate.ExecuteAsync(x));
}).Subscribe();
CurrentViewModel = Observable.Concat(
Observable.Defer(() => Observable.Return(NavigationStack.LastOrDefault())),
NavigationStack.Changed.Select(_ => NavigationStack.LastOrDefault()));
}