/// <summary>
/// Observe changes to the AppState of a class derived from ISuspensionHost.
/// </summary>
/// <typeparam name="T">The observable type.</typeparam>
/// <param name="item">The suspension host.</param>
/// <returns>An observable of the app state.</returns>
public static IObservable <T> ObserveAppState <T>(this ISuspensionHost item)
where T : class
{
return(item.WhenAny(suspensionHost => suspensionHost.AppState, observedChange => observedChange.Value)
.Where(x => x != null)
.Cast <T>());
}
/// <summary>
/// Observe changes to the AppState of a class derived from ISuspensionHost.
/// </summary>
/// <typeparam name="T">The observable type.</typeparam>
/// <param name="item">The suspension host.</param>
/// <returns>An observable of the app state.</returns>
public static IObservable <T> ObserveAppState <T>(this ISuspensionHost item)
where T : class
{
if (item is null)
{
throw new ArgumentNullException(nameof(item));
}
return(item.WhenAny(suspensionHost => suspensionHost.AppState, observedChange => observedChange.Value)
.WhereNotNull()
.Cast <T>());
}
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="This"></param>
/// <returns></returns>
public static IObservable <T> ObserveAppState <T>(this ISuspensionHost This)
{
return(This.WhenAny(x => x.AppState, x => (T)x.Value)
.Where(x => x != null));
}
/// <summary>
/// Observe changes to the AppState of a class derived from ISuspensionHost.
/// </summary>
/// <typeparam name="T">The observable type.</typeparam>
/// <param name="item">The suspension host.</param>
/// <returns>An observable of the app state.</returns>
public static IObservable <T> ObserveAppState <T>(this ISuspensionHost item)
where T : class
{
return(item.WhenAny(x => x.AppState, x => (T)x.Value)
.Where(x => x != null));
}