JCheckBoxのチェックアイコンを変更

class CheckBoxIcon2 implements Icon {
  private final Icon orgIcon = UIManager.getIcon("CheckBox.icon");
  @Override public void paintIcon(Component c, Graphics g, int x, int y) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.translate(x, y);
    orgIcon.paintIcon(c, g2, 0, 0);
    if (c instanceof AbstractButton) {
      AbstractButton b = (AbstractButton) c;
      ButtonModel model = b.getModel();
      g2.setColor(new Color(255, 155, 155, 100));
      g2.fillRect(2, 2, getIconWidth() - 4, getIconHeight() - 4);
      if (model.isSelected()) {
        g2.setColor(Color.RED);
        g2.drawLine(9, 3, 9, 3);
        g2.drawLine(8, 4, 9, 4);
        g2.drawLine(7, 5, 9, 5);
        g2.drawLine(6, 6, 8, 6);
        g2.drawLine(3, 7, 7, 7);
        g2.drawLine(4, 8, 6, 8);
        g2.drawLine(5, 9, 5, 9);
        g2.drawLine(3, 5, 3, 5);
        g2.drawLine(3, 6, 4, 6);
      }
    }
    g2.dispose();
  }

  @Override public int getIconWidth() {
    return orgIcon.getIconWidth();
  }

  @Override public int getIconHeight() {
    return orgIcon.getIconHeight();
  }
}