public static CompositeDisposable TrackChangesOfType <T, T2>(this IReactiveList <T2> list, Action <T2> add,
Action <T2> remove,
Action <IEnumerable <T2> > reset, Func <T, bool> filter = null)
where T2 : class
where T : class, T2
{
if (list == null)
{
throw new ArgumentNullException(nameof(list));
}
var disposables = new CompositeDisposable();
if (add != null)
{
var o = list.ItemsAdded.OfType <T>();
if (filter != null)
{
o = o.Where(filter);
}
disposables.Add(o.Subscribe(add));
}
if (remove != null)
{
var o = list.ItemsRemoved.OfType <T>();
if (filter != null)
{
o = o.Where(filter);
}
disposables.Add(o.Subscribe(remove));
}
if (reset != null)
{
disposables.Add(list.ShouldReset
.Subscribe(
x =>
reset(filter == null
? list.OfType <T>().ToArray()
: list.OfType <T>().Where(filter).ToArray())));
}
return(disposables);
}