Swing/MouseDrivenImageRotation のバックアップ(No.9)

class DraggableImageMouseListener extends MouseAdapter {
  private static final Color HOVER_COLOR = new Color(100, 255, 200, 100);
  private static final int IR = 40;
  private static final int OR = IR * 3;
  private static final BasicStroke BORDER_STROKE = new BasicStroke(4f);
  private final RoundRectangle2D.Double border;
  private final Ellipse2D.Double inner = new Ellipse2D.Double(0, 0, IR, IR);
  private final Ellipse2D.Double outer = new Ellipse2D.Double(0, 0, OR, OR);
  public final Image image;
  public final int width;
  public final int height;
  public final double centerX, centerY;
  public double x = 10d, y = 50d, radian = 45d * (Math.PI / 180d);
  public double startX, startY, startA;
  private boolean moverHover, rotatorHover;
  public DraggableImageMouseListener(ImageIcon ii) {
    super();
    image = ii.getImage();
    width = ii.getIconWidth();
    height = ii.getIconHeight();
    centerX = width / 2.0;
    centerY = height / 2.0;
    inner.x = x + centerX - IR / 2;
    inner.y = y + centerY - IR / 2;
    outer.x = x + centerX - OR / 2;
    outer.y = y + centerY - OR / 2;
    border = new RoundRectangle2D.Double(0d, 0d, width, height, 10d, 10d);
  }
  public void paint(Graphics g, ImageObserver ior) {
    Graphics2D g2d = (Graphics2D) g.create();
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                         RenderingHints.VALUE_ANTIALIAS_ON);
    AffineTransform at = AffineTransform.getTranslateInstance(x, y);
    at.rotate(radian, centerX, centerY);
    g2d.setPaint(Color.WHITE);
    g2d.setStroke(BORDER_STROKE);
    Shape s = new Rectangle2D.Double(
        border.x - 2, border.y - 2, border.width + 4, border.height + 20);
    g2d.fill(at.createTransformedShape(s));
    g2d.draw(at.createTransformedShape(s));
    g2d.drawImage(image, at, ior);
    if (rotatorHover) {
      Area donut = new Area(outer);
      donut.subtract(new Area(inner));
      g2d.setPaint(HOVER_COLOR);
      g2d.fill(donut);
    } else if (moverHover) {
      g2d.setPaint(HOVER_COLOR);
      g2d.fill(inner);
    }
    g2d.setStroke(BORDER_STROKE);
    g2d.setPaint(Color.WHITE);
    g2d.draw(at.createTransformedShape(border));
    g2d.dispose();
  }
  @Override public void mouseMoved(MouseEvent e) {
    if (outer.contains(e.getX(), e.getY()) && !inner.contains(e.getX(), e.getY())) {
      moverHover = false;
      rotatorHover = true;
    } else if (inner.contains(e.getX(), e.getY())) {
      moverHover = true;
      rotatorHover = false;
    } else {
      moverHover = false;
      rotatorHover = false;
    }
    e.getComponent().repaint();
  }
  @Override public void mouseReleased(MouseEvent e) {
    rotatorHover = false;
    moverHover = false;
    e.getComponent().repaint();
  }
  @Override public void mousePressed(MouseEvent e) {
    if (outer.contains(e.getX(), e.getY()) && !inner.contains(e.getX(), e.getY())) {
      rotatorHover = true;
      startA = radian - Math.atan2(e.getY() - y - centerY, e.getX() - x - centerX);
      e.getComponent().repaint();
    } else if (inner.contains(e.getX(), e.getY())) {
      moverHover = true;
      startX = e.getX();
      startY = e.getY();
      e.getComponent().repaint();
    }
  }
  @Override public void mouseDragged(MouseEvent e) {
    if (rotatorHover) {
      radian = startA + Math.atan2(e.getY() - y - centerY, e.getX() - x - centerX);
      e.getComponent().repaint();
    } else if (moverHover) {
      x += e.getX() - startX;
      y += e.getY() - startY;
      inner.x = x + centerX - IR / 2;
      inner.y = y + centerY - IR / 2;
      outer.x = x + centerX - OR / 2;
      outer.y = y + centerY - OR / 2;
      startX = e.getX();
      startY = e.getY();
      e.getComponent().repaint();
    }
  }
}