!7

cmodule NestedDesktopPane {
  transient JDesktopPane desktopPane;
  L<Win> windows = syncL();

  sclass Win {
    Rect rect;
    S title;
    transient JInternalFrame frame;
  }

  visual withCenteredButtons(desktopPane = jDesktopPane(),
    "Add frame", rThreadEnter addAFrame);
  
  void addAFrame {
    JInternalFrame f = showInternalFrame(desktopPane, "Hello world");
    new Win win;
    win.rect = boundsAsRect(f);
    win.title = getTitle(f);
    win.frame = f;
    windows.add(win);
    change():
  }

  void restoreFrames {
    for (Win win : windows)
      win.frame = setBounds(win.rect, showInternalFrame(desktopPane, win.title));
  }
}