private void OnAdd(object sender, int index, IEnumerable <TSource> newItems)
{
IEnumerable <TSource> addedItems = GetAddedItems(index, newItems);
ItemsIndex <TSource>? removedItems = GetRemovedItemsFromAdd(index, newItems.Count());
if (addedItems != null)
{
if (removedItems != null)
{
FireRemove(removedItems.Value.Items, removedItems.Value.Index);
}
FireAdd(addedItems, index);
}
}
private void OnRemove(object sender, int index, IEnumerable <TSource> oldItems)
{
IEnumerable <TSource> removed = GetRemovedItems(index, oldItems);
if (removed != null)
{
FireRemove(removed, index);
ItemsIndex <TSource>?addedItems = GetAddedItemsFromRemove(index, oldItems.Count());
if (addedItems != null)
{
FireAdd(addedItems.Value.Items, addedItems.Value.Index);
}
}
}
