JTableのセルに複数配置したコンポーネントのJToolTip

JTable table = new JTable(model) {
  @Override public String getToolTipText(MouseEvent e) {
    Point pt = e.getPoint();
    int vrow = rowAtPoint(pt);
    int vcol = columnAtPoint(pt);
    int mcol = convertColumnIndexToModel(vcol);
    if (mcol == 1) {
      TableCellRenderer tcr = getCellRenderer(vrow, vcol);
      Component c = prepareRenderer(tcr, vrow, vcol);
      if (c instanceof JPanel) {
        Rectangle r = getCellRect(vrow, vcol, true);
        c.setBounds(r);
        c.doLayout();
        pt.translate(-r.x, -r.y);
        Component l = SwingUtilities.getDeepestComponentAt(c, pt.x, pt.y);
        if (l instanceof JLabel) {
          ImageIcon icon = (ImageIcon) ((JLabel) l).getIcon();
          return icon.getDescription();
        }
      }
    }
    return super.getToolTipText(e);
  }
};