public function display()
    {
        if (!$this->visible) {
            return;
        }

        SwatWidget::display();

        $toolbar_ul = new SwatHtmlTag('ul');
        $toolbar_ul->id = $this->id;
        $toolbar_ul->class = $this->getCSSClassString();

        $toolbar_ul->open();
        $this->displayChildren();
        $toolbar_ul->close();
    }