Swing/MouseDrivenImageRotation のバックアップ(No.10)

class DraggableImageMouseListener extends MouseAdapter {
  private static final BasicStroke BORDER_STROKE = new BasicStroke(4f);
  private static final Color BORDER_COLOR = Color.WHITE;
  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 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);
  private final Point2D.Double imagePt = new Point2D.Double(10d, 50d);
  private final Point2D.Double startPt = new Point2D.Double(); //drag start point
  private final Point2D.Double centerPt = new Point2D.Double();
  private final Image image;
  private double radian = 45d * (Math.PI / 180d);
  private double startRadian; //drag start radian
  private boolean moverHover;
  private boolean rotatorHover;

  protected DraggableImageMouseListener(ImageIcon ii) {
    super();
    image = ii.getImage();
    int width  = ii.getIconWidth();
    int height = ii.getIconHeight();
    centerPt.x = width / 2d;
    centerPt.y = height / 2d;
    inner.x = imagePt.x + centerPt.x - IR / 2;
    inner.y = imagePt.y + centerPt.y - IR / 2;
    outer.x = imagePt.x + centerPt.x - OR / 2;
    outer.y = imagePt.y + centerPt.y - OR / 2;
    border  = new RoundRectangle2D.Double(0d, 0d, width, height, 10d, 10d);
  }
  public void paint(Graphics g, ImageObserver ior) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    AffineTransform at = AffineTransform.getTranslateInstance(imagePt.x, imagePt.y);
    at.rotate(radian, centerPt.x, centerPt.y);

    g2.setPaint(BORDER_COLOR);
    g2.setStroke(BORDER_STROKE);
    Shape s = new Rectangle2D.Double(
        border.x - 2, border.y - 2, border.width + 4, border.height + 20);
    g2.fill(at.createTransformedShape(s));
    g2.draw(at.createTransformedShape(s));

    g2.drawImage(image, at, ior);
    if (rotatorHover) {
      Area donut = new Area(outer);
      donut.subtract(new Area(inner));
      g2.setPaint(HOVER_COLOR);
      g2.fill(donut);
    } else if (moverHover) {
      g2.setPaint(HOVER_COLOR);
      g2.fill(inner);
    }
    g2.setStroke(BORDER_STROKE);
    g2.setPaint(BORDER_COLOR);
    g2.draw(at.createTransformedShape(border));
    g2.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;
      startRadian = radian - Math.atan2(
          e.getY() - imagePt.y - centerPt.y, e.getX() - imagePt.x - centerPt.x);
      e.getComponent().repaint();
    } else if (inner.contains(e.getX(), e.getY())) {
      moverHover = true;
      startPt.x = e.getX();
      startPt.y = e.getY();
      e.getComponent().repaint();
    }
  }
  @Override public void mouseDragged(MouseEvent e) {
    if (rotatorHover) {
      radian = startRadian + Math.atan2(
          e.getY() - imagePt.y - centerPt.y, e.getX() - imagePt.x - centerPt.x);
      e.getComponent().repaint();
    } else if (moverHover) {
      imagePt.x += e.getX() - startPt.x;
      imagePt.y += e.getY() - startPt.y;
      inner.x = imagePt.x + centerPt.x - IR / 2;
      inner.y = imagePt.y + centerPt.y - IR / 2;
      outer.x = imagePt.x + centerPt.x - OR / 2;
      outer.y = imagePt.y + centerPt.y - OR / 2;
      startPt.x = e.getX();
      startPt.y = e.getY();
      e.getComponent().repaint();
    }
  }
}