private void collectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
addItems(e.NewItems);
break;
case NotifyCollectionChangedAction.Remove:
removeItems(e.OldItems);
// Explicitly reset scroll position here so that ScrollContainer doesn't retain our
// scroll position if we quickly add new items after calling a Clear().
if (Items.Count == 0)
{
ScrollContainer.ScrollToStart();
}
break;
case NotifyCollectionChangedAction.Reset:
currentlyDraggedItem = null;
ListContainer.Clear();
itemMap.Clear();
break;
case NotifyCollectionChangedAction.Replace:
removeItems(e.OldItems);
addItems(e.NewItems);
break;
}
}
private void removeItems(IList items)
{
foreach (var item in items.Cast <TModel>())
{
if (currentlyDraggedItem != null && EqualityComparer <TModel> .Default.Equals(currentlyDraggedItem.Model, item))
{
currentlyDraggedItem = null;
}
ListContainer.Remove(itemMap[item]);
itemMap.Remove(item);
}
reSort();
}
private void endArrangement(RearrangeableListItem <TModel> item, DragEndEvent e) => currentlyDraggedItem = null;
private void arrange(RearrangeableListItem <TModel> item, DragEvent e) => screenSpaceDragPosition = e.ScreenSpaceMousePosition;
private void startArrangement(RearrangeableListItem <TModel> item, DragStartEvent e)
{
currentlyDraggedItem = item;
screenSpaceDragPosition = e.ScreenSpaceMousePosition;
}