Swing/PaintPanel のバックアップの現在との差分(No.16)

#spandel
class PaintPanel extends JPanel
#spanend
                 implements MouseMotionListener, MouseListener {
  private Point startPoint = new Point(-10, -10);
  private Point p = new Point(-10, -10);
  public PaintPanel() {
    super();
    addMouseMotionListener(this);
    addMouseListener(this);
#spanadd
class PaintPanel extends JPanel {
#spanend
  private static final Stroke STROKE = new BasicStroke(
      3f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
  private transient List<Shape> list;
  private transient Path2D path;
  private transient MouseAdapter handler;
#spanadd

#spanend
  @Override public void updateUI() {
    removeMouseMotionListener(handler);
    removeMouseListener(handler);
    super.updateUI();
    handler = new MouseAdapter() {
      @Override public void mousePressed(MouseEvent e) {
        path = new Path2D.Double();
        list.add(path);
        Point p = e.getPoint();
        path.moveTo(p.x, p.y);
        repaint();
      }
#spanadd

#spanend
      @Override public void mouseDragged(MouseEvent e) {
        Point p = e.getPoint();
        path.lineTo(p.x, p.y);
        repaint();
      }
    };
    addMouseMotionListener(handler);
    addMouseListener(handler);
    list = new ArrayList<Shape>();
  }
  @Override public void paintComponent(Graphics g) {
    //super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g.create();
    g2d.setStroke(new BasicStroke(3f));
    g2d.setPaint(Color.BLACK);
    g2d.drawLine(startPoint.x, startPoint.y, p.x, p.y);
    g2d.dispose();
    startPoint = p;
#spanadd

#spanend
  @Override protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    if (list != null) {
      Graphics2D g2 = (Graphics2D) g.create();
      g2.setPaint(Color.BLACK);
      g2.setStroke(STROKE);
      for (Shape s : list) {
        g2.draw(s);
      }
      g2.dispose();
    }
  }
  @Override public void mouseDragged(MouseEvent e) {
    p = e.getPoint();
    repaint();
  }
  @Override public void mouseMoved(MouseEvent e)    {}
  @Override public void mouseExited(MouseEvent e)   {}
  @Override public void mouseEntered(MouseEvent e)  {}
  @Override public void mouseReleased(MouseEvent e) {}
  @Override public void mouseClicked(MouseEvent e)  {}
}