JPasswordFieldのエコー文字を変更

class MyPasswordFieldUI extends BasicPasswordFieldUI {
  private static final StarIcon ICON = new StarIcon();
  public static MyPasswordFieldUI createUI(JPasswordField c) {
    c.setEchoChar('\u25A0'); // As wide as a CJK character cell (fullwidth)
    return new MyPasswordFieldUI();
  }

  @Override public View create(Element elem) {
    return new MyPasswordView(elem);
  }

  private static class MyPasswordView extends PasswordView {
    @Override protected int drawEchoCharacter(Graphics g, int x, int y, char c) {
      FontMetrics fm = g.getFontMetrics();
      ICON.paintIcon(null, g, x, y - fm.getAscent());
      return x + ICON.getIconWidth(); // fm.charWidth(c);
    }

    public MyPasswordView(Element element) {
      super(element);
    }
  }
}