Component上に重ねて配置したダイアログの表示状態をアニメーション付きで切り替える

JPanel p = new JPanel() {
  @Override public boolean isOptimizedDrawingEnabled() {
    return false;
  }
};
p.setLayout(new BorderLayout(0, 0) {
  @Override public void layoutContainer(Container parent) {
    synchronized (parent.getTreeLock()) {
      Insets insets = parent.getInsets();
      int width = parent.getWidth();
      int height = parent.getHeight();
      int top = insets.top;
      int bottom = height - insets.bottom;
      int left = insets.left;
      int right = width - insets.right;
      Component nc = getLayoutComponent(parent, BorderLayout.NORTH);
      if (Objects.nonNull(nc)) {
        Dimension d = nc.getPreferredSize();
        int vsw = UIManager.getInt("ScrollBar.width");
        nc.setBounds(right - d.width - vsw, yy - d.height, d.width, d.height);
      }
      Component cc = getLayoutComponent(parent, BorderLayout.CENTER);
      if (Objects.nonNull(cc)) {
        cc.setBounds(left, top, right - left, bottom - top);
      }
    }
  }
});
p.add(searchBox, BorderLayout.NORTH);
p.add(new JScrollPane(tree));