LayoutManagerを拡張して曲線上にコンポーネントを配置

final double A2 = 4.0;
panel2.setLayout(new FlowLayout() {
  @Override public void layoutContainer(Container target) {
    synchronized(target.getTreeLock()) {
      Insets i = target.getInsets();
      int nmembers  = target.getComponentCount();
      if (nmembers <= 0) {
        return;
      }
      int vgap = getVgap();
      int hgap = getHgap();
      int rowh = (target.getHeight() - (i.top + i.bottom + vgap * 2)) / nmembers;
      int x = i.left + hgap;
      int y = i.top  + vgap;
      for (int i = 0; i < nmembers; i++) {
        Component m = target.getComponent(i);
        if (m.isVisible()) {
          Dimension d = m.getPreferredSize();
          m.setSize(d.width, d.height);
          m.setLocation(x, y);
          y += (vgap + Math.min(rowh, d.height));
          x = (int) (A2 * Math.sqrt(y));
        }
      }
    }
  }
});