JLayerを使用して無効時のコンポーネントの文字色を変更する

class DisableInputLayerUI extends LayerUI<JComponent> {
  private static final String CMD_BLOCKING = "lock";
  private static final boolean DEBUG_POPUP_BLOCK = false;
  private final MouseAdapter emptyMouseListener = new MouseAdapter() {};
  private final KeyAdapter emptyKeyListener = new KeyAdapter() {};
  private boolean isBlocking;

  @Override public void installUI(JComponent c) {
    super.installUI(c);
    if (c instanceof JLayer) {
      JLayer jlayer = (JLayer) c;
      if (DEBUG_POPUP_BLOCK) {
        jlayer.getGlassPane().addMouseListener(emptyMouseListener);
        jlayer.getGlassPane().addKeyListener(emptyKeyListener);
      }
      jlayer.setLayerEventMask(
          AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK
        | AWTEvent.MOUSE_WHEEL_EVENT_MASK | AWTEvent.KEY_EVENT_MASK
        | AWTEvent.FOCUS_EVENT_MASK | AWTEvent.COMPONENT_EVENT_MASK);
    }
  }

  @Override public void uninstallUI(JComponent c) {
    if (c instanceof JLayer) {
      JLayer jlayer = (JLayer) c;
      jlayer.setLayerEventMask(0);
      if (DEBUG_POPUP_BLOCK) {
        jlayer.getGlassPane().removeMouseListener(emptyMouseListener);
        jlayer.getGlassPane().removeKeyListener(emptyKeyListener);
      }
    }
    super.uninstallUI(c);
  }

  @Override protected void processComponentEvent(
      ComponentEvent e, JLayer<? extends JComponent> l) {
    System.out.println("processComponentEvent");
  }

  @Override protected void processKeyEvent(
      KeyEvent e, JLayer<? extends JComponent> l) {
    System.out.println("processKeyEvent");
  }

  @Override protected void processFocusEvent(
      FocusEvent e, JLayer<? extends JComponent> l) {
    System.out.println("processFocusEvent");
  }

  @Override public void eventDispatched(
      AWTEvent e, JLayer<? extends JComponent> l) {
    if (isBlocking && e instanceof InputEvent) {
      ((InputEvent) e).consume();
    }
  }

  public void setLocked(boolean flag) {
    boolean oldv = isBlocking;
    isBlocking = flag;
    firePropertyChange(CMD_BLOCKING, oldv, isBlocking);
  }

  @Override public void applyPropertyChange(
      PropertyChangeEvent pce, JLayer<? extends JComponent> l) {
    String cmd = pce.getPropertyName();
    if (CMD_BLOCKING.equals(cmd)) {
      JButton b = (JButton) l.getView();
      b.setFocusable(!isBlocking);
      b.setMnemonic(isBlocking ? 0 : b.getText().charAt(0));
      b.setForeground(isBlocking ? Color.RED : Color.BLACK);
      l.getGlassPane().setVisible((Boolean) pce.getNewValue());
    }
  }
}