How to make JFrame look and feel aware

Question

When I set a look and feel through the UIManager.setLookAndFeel the frame's content changes its look and feel as expected. E.g.

public static void main(String[] args) throws Exception {
  UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");

  JFrame frame = new JFrame();
  Container contentPane = frame.getContentPane();
  contentPane.setLayout(new FlowLayout());
  contentPane.add(new JButton("Some Button"));

  frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
  frame.setSize(200, 80);
  frame.setLocationRelativeTo(null);
  frame.setVisible(true);
}

But the frame is still painted using the OS default (Windows in my case).

How can I make the frame look and feel aware so that it looks like the e.g. the nimbus look and feel?

Usually look and feel is implemented using the ComponentUI, but a JFrame is not a JComponent so I can't implement an own ComponentUI and set it.

1. Solution

My first thought was to use an undecorated JFrame with a JInternalFrame as its main component.

public class LAFAwareJFrame extends JFrame {

  private JInternalFrame lafFrame = new JInternalFrame("", true, true, true, true);
  private JDesktopPane desktopPane = new JDesktopPane();


  public LAFAwareJFrame() {
    super.setUndecorated(true);
    desktopPane.add(lafFrame);
    lafFrame.setVisible(true);
    Container contentPane = super.getContentPane();
    contentPane.add(desktopPane);
  }

  @Override
  public void setUndecorated(boolean undecorated) {
    throw new UnsupportedOperationException("Can't change the undecorated property for a LAFAwareJFrame");
  }

  @Override
  public void setSize(int width, int height) {
    super.setSize(width, height);
    lafFrame.setSize(width, height);
  }

  @Override
  public Container getContentPane() {
    return lafFrame.getContentPane();
  }

  @Override
  public void setTitle(String title) {
    lafFrame.setTitle(title);
  }

    public static void main(String[] args) throws Exception {
      UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");

      JFrame frame = new LAFAwareJFrame();
      Container contentPane = frame.getContentPane();
      contentPane.setLayout(new FlowLayout());
      contentPane.add(new JButton("Some Button"));

      frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
      frame.setSize(200, 80);
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
    }
}

But then I have a lot to do with event handling and delegation. E.g when the JInternalFrame gets moved I don't really want to move the internal frame. Instead I want to move the undecorated frame.

2. Solution

Use the JInternalFrame only as a renderer. Like a ListCellRender.

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Since all solutions require a lot of work I want to ask you first if there is a better solution. E.g. a library or maybe it is already possible with standard Java and I missed something.

EDIT I tried to use setDefaultLookAndFeelDecorated but it doesn't work with nimbus and not with motif.