Windowのフルスクリーン化

private void toggleFullScreenWindow() {
  GraphicsEnvironment graphicsEnvironment =
      GraphicsEnvironment.getLocalGraphicsEnvironment();
  GraphicsDevice graphicsDevice =
      graphicsEnvironment.getDefaultScreenDevice();
  if (Objects.isNull(graphicsDevice.getFullScreenWindow())) {
    dialog.dispose(); // destroy the native resources
    dialog.setUndecorated(true);
    dialog.setVisible(true); // rebuilding the native resources
    graphicsDevice.setFullScreenWindow(dialog);
  } else {
    graphicsDevice.setFullScreenWindow(null);
    dialog.dispose();
    dialog.setUndecorated(false);
    dialog.setVisible(true);
    dialog.repaint();
  }
  requestFocusInWindow();
}