public override void OnDeactivate()
 {
     if (_circularPatternWindow != null)
     {
         _circularPatternWindow.Close();
         _circularPatternWindow = null;
     }
     base.OnDeactivate();
 }
 protected override void BuildDialog(string dialogTitle)
 {
     if (_circularPatternWindow != null)
     {
         return;
     }
     _builder = new NodeBuilder(_selectedNodes[0]);
     _axis    = GeomUtils.ExtractAxis(new NodeBuilder(_selectedNodes[1]).Shape);
     _circularPatternWindow = new CircularPatternWindow(dialogTitle, AxisLength());
     _circularPatternWindow.OnValueChange  += PreviewCircularPattern;
     _circularPatternWindow.OnDialogClosed += OnClosed;
     _circularPatternWindow.Show();
     PreviewCircularPattern();
 }