Modalで透明なJDialogを使って親のJFrameへの入力をブロックする

JButton button = new JButton("Stop 5sec");
button.addActionListener(e -> {
  Window w = SwingUtilities.getWindowAncestor(getRootPane());
  JDialog dialog = new JDialog(w, Dialog.ModalityType.APPLICATION_MODAL);
  dialog.setUndecorated(true);
  dialog.setBounds(w.getBounds());
  dialog.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
  int color = check.isSelected() ? 0x22_FF_00_00 : 0x01_00_00_00;
  dialog.setBackground(new Color(color, true));
  new BackgroundTask() {
    @Override protected void done() {
      if (!isDisplayable()) {
        cancel(true);
        return;
      }
      dialog.setVisible(false);
    }
  }.execute();
  dialog.setVisible(true);
});
// ...
class BackgroundTask extends SwingWorker<String, Void> {
  @Override protected String doInBackground() throws InterruptedException {
    Thread.sleep(5_000);
    return "Done";
  }
}