/// <summary>
/// This is invoked when the collection changes.
/// </summary>
/// <param name="sender">Collection</param>
/// <param name="e">Change event</param>
void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (IgnoreChanges)
{
return;
}
var undoList = new List <CollectionChangeUndo>();
IList collection = (IList)sender;
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
undoList.AddRange(e.NewItems.Cast <object>().Select((item, i) => new CollectionChangeUndo(collection, CollectionChangeType.Add, -1, e.NewStartingIndex + i, null, item)));
break;
case NotifyCollectionChangedAction.Remove:
undoList.AddRange(e.OldItems.Cast <object>().Select((item, i) => new CollectionChangeUndo(collection, CollectionChangeType.Remove, e.OldStartingIndex + i, -1, item, null)));
break;
case NotifyCollectionChangedAction.Replace:
undoList.Add(new CollectionChangeUndo(collection, CollectionChangeType.Replace, e.OldStartingIndex, e.NewStartingIndex, e.OldItems[0], e.NewItems[0]));
break;
case NotifyCollectionChangedAction.Move:
undoList.Add(new CollectionChangeUndo(collection, CollectionChangeType.Move, e.OldStartingIndex, e.NewStartingIndex, e.NewItems[0], e.NewItems[0]));
break;
}
// If tracking undos, then add them to our list.
if (_trackedUndoSet != null)
{
_trackedUndoSet.AddRange(undoList.Cast <ISupportUndo>());
}
// Or add them directly to the undo manager
else
{
var undoService = _undoService;
if (undoService != null)
{
undoList.ForEach(ccu => undoService.Add(ccu));
}
}
}
