Java graphic class proposition
I'm working a java+swing+miglayout project we settled on a class design for graphical classes that inherits from JPanel & JFrame, here is the skelletons :

    class GammaFrame : JFrame {
    private JPanel __pane__ = null;

    public static GammaFrame open(...) {

        _instance = GammaFrame()

        __pane__ = _instance.getContentPane();
        __pane__.setLayout(new MigLayout(...));

        _instance.__init__()
    
        # do logic job if any
   
        return _instance;
        }
    
        public static void main(String argv[]) {
            GammaFrame.open();
        }
    }

    class GammaPanel : JPanel {

    public static GammaPanel create(...) {

        _instance = GammaPanel()

        _instance.setLayout(new MigLayout(...));

        _instance.__init__()
    
        # do logic job if any
   
        return _instance;
        }
    
        public static void main(String argv[]) {
            JPanel panel = GammaPanel.create()
            JFrame frame = new JFrame()
            frame.getContentPane().add(panel)

            # 
            # more settings here
            # 

            frame.setVisible(true)
        }
    }

what may be the flaws of this design ?
Java graphic class proposition
===

I'm working a java+swing+miglayout project we settled on a class design for graphical classes that inherits from JPanel & JFrame, here is the skelletons :

    class GammaFrame : JFrame {
    private JPanel __pane__ = null;

    public static GammaFrame open(...) {

        _instance = GammaFrame()

        __pane__ = _instance.getContentPane();
        __pane__.setLayout(new MigLayout(...));

        _instance.__init__()
    
        # do logic job if any
   
        return _instance;
        }
    
        public static void main(String argv[]) {
            GammaFrame.open();
        }
    }

    class GammaPanel : JPanel {

    public static GammaPanel create(...) {

        _instance = GammaPanel()

        _instance.setLayout(new MigLayout(...));

        _instance.__init__()
    
        # do logic job if any
   
        return _instance;
        }
    
        public static void main(String argv[]) {
            JPanel panel = GammaPanel.create()
            JFrame frame = new JFrame()
            frame.getContentPane().add(panel)

            # 
            # more settings here
            # 

            frame.setVisible(true)
        }
    }

what may be the flaws of this design ?