VitNX_ToolWindow.OnMouseUp Method

protected override void OnMouseUp(MouseEventArgs e)
 {
     base.OnMouseUp(e);
     if (_closeButtonRect.Contains(e.Location) && _closeButtonPressed)
         Close();
     _closeButtonPressed = false;
     _closeButtonHot = false;
     _shouldDrag = false;
     Invalidate();
 }