final GraphicsDevice gd = frame.getGraphicsConfiguration().getDevice();

  if (doFullscreen) {
        frame.setUndecorated( true );
      if (gd.isFullScreenSupported()) {
          System.out.println("- Creating UI window (native fullscreen)");
          gd.setFullScreenWindow( frame );
      }
      else {
          final Rectangle bounds = frame.getGraphicsConfiguration().getBounds(); 
          System.out.println("- Creating UI window (fullscreen fallback for " + bounds + ")");
          frame.setAlwaysOnTop( true );
          frame.setBounds( bounds );
          frame.setVisible( true );
      }
  }
  else {
      System.out.println("- Creating UI window");
      frame.setVisible( true );
  }