/// <summary>
/// Observes collectionchanged events for <paramref name="source"/>.
/// </summary>
public static IObservable <NotifyCollectionChangedEventArgs> ObserveCollectionChangedSlim(
this INotifyCollectionChanged source,
bool signalInitial)
{
if (signalInitial)
{
return(Observable.Return(CachedEventArgs.NotifyCollectionReset)
.Concat(source.ObserveCollectionChangedSlim(signalInitial: false)));
}
return(Observable.Create <NotifyCollectionChangedEventArgs>(o =>
{
NotifyCollectionChangedEventHandler handler = (_, e) => o.OnNext(e);
source.CollectionChanged += handler;
return Disposable.Create(() => source.CollectionChanged -= handler);
}));
}
/// <summary>
/// Observes collection changed events for <paramref name="source"/>.
/// </summary>
/// <param name="source">The source collection.</param>
/// <param name="signalInitial">When true a reset is signaled on subscribe.</param>
/// <returns>An <see cref="IObservable{NotifyCollectionChangedEventArgs}"/>.</returns>
public static IObservable <NotifyCollectionChangedEventArgs> ObserveCollectionChangedSlim(this INotifyCollectionChanged source, bool signalInitial)
{
if (source is null)
{
throw new ArgumentNullException(nameof(source));
}
if (signalInitial)
{
return(Observable.Return(CachedEventArgs.NotifyCollectionReset)
.Concat(source.ObserveCollectionChangedSlim(signalInitial: false)));
}
return(Observable.Create <NotifyCollectionChangedEventArgs>(o =>
{
source.CollectionChanged += Handler;
return Disposable.Create(() => source.CollectionChanged -= Handler);
void Handler(object _, NotifyCollectionChangedEventArgs e)
{
o.OnNext(e);
}
}));
}
