public static IObservable <bool> ConstructCanNavigateBack(this IBackNavigatingVM vm)
{
return(vm.WhenAny(x => x.NavigateBackTarget)
.Select(x => x != null));
}
public static IObservable <bool> ConstructIsActive(this IBackNavigatingVM vm, MainWindowVM mwvm)
{
return(mwvm.WhenAny(x => x.ActivePane)
.Select(x => object.ReferenceEquals(vm, x)));
}
public static IObservable <bool> ConstructCanNavigateBack(this IBackNavigatingVM vm)
{
return(vm.WhenAny(x => x.NavigateBackTarget)
.CombineLatest(vm.IsBackEnabled)
.Select(x => x.First != null && x.Second));
}