public IDisposable Subscribe(IObserver <ListChange <T> > observer)
{
var mapper = new WhereChangeMapper();
var gate = new object();
return(_source.Subscribe(
Observer.Create <ListChange <T> >(
onNext: change =>
{
lock (gate)
{
var newChanges = new List <ListChange <T> >();
change(
insert: (index, item) => newChanges.AddRange(mapper.Insert(index, item, _predicate(item))),
replace: (index, item) => newChanges.AddRange(mapper.Replace(index, item, _predicate(item))),
remove: index => newChanges.AddRange(mapper.Remove <T>(index)),
clear: () => newChanges.AddRange(mapper.Clear <T>()));
if (newChanges.Count > 0)
{
observer.OnNext(ListChange.Combine(newChanges));
}
}
},
onCompleted: observer.OnCompleted,
onError: observer.OnError)));
}
public void OnNext(ListChange <IObservable <T> > changes)
{
lock (_gate)
{
changes(
insert: (index, obs) =>
{
var indexedItem = new IndexTrackerList <SingleAssignmentDisposable> .IndexedItem(new SingleAssignmentDisposable());
_innerSubscriptions.Insert(index, indexedItem);
_changeMapper.InsertFalse(index);
_innerCompleted = _innerCompleted.Insert(index, false);
indexedItem.Value.Disposable = SubscribeInner(obs, indexedItem);
},
replace: (index, obs) =>
{
_innerSubscriptions[index].Dispose();
var indexedItem = new IndexTrackerList <SingleAssignmentDisposable> .IndexedItem(new SingleAssignmentDisposable());
_innerSubscriptions.Replace(index, indexedItem);
_innerCompleted = _innerCompleted.ReplaceAt(index, false);
indexedItem.Value.Disposable = SubscribeInner(obs, indexedItem);
// The new observable hasn't produced any values left, so remove any leftover old values
foreach (var change in _changeMapper.ReplaceFalse <T>(index))
{
_observer.OnNext(change);
}
},
remove: (index) =>
{
_innerSubscriptions[index].Dispose();
_innerSubscriptions.Remove(index);
_innerCompleted = _innerCompleted.RemoveAt(index);
foreach (var change in _changeMapper.Remove <T>(index))
{
_observer.OnNext(change);
}
},
clear: () =>
{
Disposable.Combine(_innerSubscriptions).Dispose();
_innerSubscriptions.Clear();
_innerCompleted = SumTree <bool> .Empty(false, (d1, d2) => d1 && d2);
foreach (var change in _changeMapper.Clear <T>())
{
_observer.OnNext(change);
}
});
}
}