private void MoveEnd(object sender, MouseEventArgs e)
 {
     if (_moving)
     {
         IMoveable c = (IMoveable)_control;
         c.OnDragEnd(e);
         _moving = false;
     }
 }
 protected virtual void MoveEnd(object sender, MouseEventArgs e)
 {
     //TODO: May need to implement Viewport check
     if (_movingItem != null)
     {
         _movingItem.OnDragEnd(e);
         _movingItem = null;
     }
 }