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()));
}
/// <summary>
/// Initializes a new instance of the <see cref="NavigationViewModel"/> class.
/// </summary>
public NavigationViewModel()
{
history = new ReactiveList <IPanePageViewModel>();
history.Changing.Subscribe(CollectionChanging);
history.Changed.Subscribe(CollectionChanged);
var pos = this.WhenAnyValue(
x => x.Index,
x => x.History.Count,
(i, c) => new { Index = i, Count = c });
content = pos
.Where(x => x.Index < x.Count)
.Select(x => x.Index != -1 ? history[x.Index] : null)
.StartWith((IPanePageViewModel)null)
.ToProperty(this, x => x.Content);
this.WhenAnyValue(x => x.Content)
.Buffer(2, 1)
.Subscribe(x => {
if (x[0] != null && history.Contains(x[0]))
{
x[0].Deactivated();
}
x[1]?.Activated();
});
NavigateBack = ReactiveCommand.Create(() => { }, pos.Select(x => x.Index > 0));
NavigateBack.Subscribe(_ => Back());
NavigateForward = ReactiveCommand.Create(() => { }, pos.Select(x => x.Index < x.Count - 1));
NavigateForward.Subscribe(_ => Forward());
}
/// <summary>
/// Initializes a new instance of the <see cref="NavigationViewModel"/> class.
/// </summary>
public NavigationViewModel()
{
history = new ReactiveList <IPanePageViewModel>();
history.BeforeItemsAdded.Subscribe(BeforeItemAdded);
history.CollectionChanged += CollectionChanged;
var pos = this.WhenAnyValue(
x => x.Index,
x => x.History.Count,
(i, c) => new { Index = i, Count = c });
content = pos
.Where(x => x.Index < x.Count)
.Select(x => x.Index != -1 ? history[x.Index] : null)
.StartWith((IPanePageViewModel)null)
.ToProperty(this, x => x.Content);
NavigateBack = ReactiveCommand.Create(pos.Select(x => x.Index > 0));
NavigateBack.Subscribe(_ => Back());
NavigateForward = ReactiveCommand.Create(pos.Select(x => x.Index < x.Count - 1));
NavigateForward.Subscribe(_ => Forward());
}