Wipeアニメーションで画像を表示

class WipeImage extends JComponent implements ActionListener {
  private int ww = 0;
  public WipeImage() {
    super();
    setBackground(Color.BLACK);
  }

  @Override protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    int iw = (int) icon.getIconWidth();
    int ih = (int) icon.getIconHeight();
    if (direction) {
      if (ww < iw) {
        ww += 10;
      } else {
        animator.stop();
      }
    } else {
      if (ww > 0) {
        ww -= 10;
      } else {
        animator.stop();
      }
    }
    g.drawImage(icon.getImage(), 0, 0, iw, ih, this);
    g.fillRect(ww, 0, iw - ww, ih);
  }

  @Override public void actionPerformed(ActionEvent e) {
    repaint();
  }
}