VitNX_DockGroup.OnMouseUp Method

protected override void OnMouseUp(MouseEventArgs e)
 {
     base.OnMouseUp(e);
     _dragTab = null;
     if (_tabArea.DropdownRectangle.Contains(e.Location))
     {
         if (_tabArea.DropdownHot)
             _tabArea.ShowMenu(this, new Point(_tabArea.DropdownRectangle.Left,
                 _tabArea.DropdownRectangle.Bottom - 2));
         return;
     }
     if (_tabArea.ClickedCloseButton == null)
         return;
     var closeRect = RectangleToTabArea(_tabArea.ClickedCloseButton.CloseButtonRectangle);
     if (closeRect.Contains(e.Location))
         _tabArea.ClickedCloseButton.DockContent.Close();
 }