internal bool ClearCore ()
{
if (selection.Count == 0)
return false;
foreach (int index in selection)
owner.InvalidateItem (index);
selection.Clear ();
#if NET_2_0
// UIA Framework event: Selected items list updated
OnUIACollectionChangedEvent (new CollectionChangeEventArgs (CollectionChangeAction.Refresh, -1));
#endif
return true;
}