Swing/TransformedShape のバックアップ(No.17)

class FontRotateAnimation extends JComponent implements ActionListener {
  private final Timer animator;
  private int rotate;
  private final Shape shape;
  private Shape s;
  public FontRotateAnimation(String str) {
    super();
    animator = new Timer(10, this);
    addHierarchyListener(new HierarchyListener() {
      @Override public void hierarchyChanged(HierarchyEvent e) {
        if ((e.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0
            && animator != null && !e.getComponent().isDisplayable()) {
          animator.stop();
        }
      }
    });
    Font font = new Font(Font.SERIF, Font.PLAIN, 200);
    FontRenderContext frc = new FontRenderContext(null, true, true);
    shape = new TextLayout(str, font, frc).getOutline(null);
    s = shape;
    animator.start();
  }
  @Override protected void paintComponent(Graphics g) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setPaint(Color.BLACK);
    g2.fill(s);
    g2.dispose();
  }
  @Override public void actionPerformed(ActionEvent e) {
    repaint(s.getBounds());
    Rectangle2D b = shape.getBounds2D();
    Point2D p = new Point2D.Double(
        b.getX() + b.getWidth() / 2d, b.getY() + b.getHeight() / 2d);
    AffineTransform at = AffineTransform.getRotateInstance(
        Math.toRadians(rotate), p.getX(), p.getY());
    AffineTransform toCenterAT = AffineTransform.getTranslateInstance(
        getWidth() / 2d - p.getX(), getHeight() / 2d - p.getY());
    Shape s1 = at.createTransformedShape(shape);
    s = toCenterAT.createTransformedShape(s1);
    repaint(s.getBounds());
    rotate = rotate >= 360 ? 0 : rotate + 2;
  }
}