private void SourceCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (e.Action == NotifyCollectionChangedAction.Move)
{
return;
}
if (e.Action != NotifyCollectionChangedAction.Reset)
{
if (e.OldItems != null)
{
var removed = new List <T>();
foreach (T item in e.OldItems)
{
TaggedObservableValue <bool, ItemMultiplicity> lambdaResult;
if (isValueType || item != null)
{
if (lambdas.TryGetValue(item, out lambdaResult))
{
if (lambdaResult.Value)
{
removed.Add(lambdaResult.Tag.Item);
}
lambdaResult.Tag = lambdaResult.Tag.Decrease();
if (lambdaResult.Tag.Multiplicity == 0)
{
lambdaResult.ValueChanged -= LambdaChanged;
lambdaResult.Detach();
lambdas.Remove(item);
}
}
else
{
//throw new InvalidOperationException();
}
}
else
{
nulls--;
if (nulls == 0)
{
nullCheck.Detach();
nullCheck = null;
}
removed.Add(default(T));
}
}
OnRemoveItems(removed);
}
if (e.NewItems != null)
{
var added = new List <T>();
foreach (T item in e.NewItems)
{
var lambdaResult = AttachItem(item);
if (lambdaResult.Value)
{
added.Add(item);
}
}
OnAddItems(added);
}
}
else
{
DetachSource();
OnCleared();
}
}
protected virtual void DetachItem(TSource item, INotifyValue <TLambdaResult> lambdaValue)
{
lambdaValue.Detach();
}