PopupView in MenuItem

I would like to have a PopupView show when a user selects a menu item. It does not look like MenuBar.MenuItem is flexible enough for this. I have also tried just creating the popup dynamically when the menu item is selected


PopupView popup = new PopupView(feedback);
popup.setHideOnMouseOut(false);
popup.setWidth("500px");
popup.setHeight("500px");
popup.setPopupVisible(true);

but this does not work either. If I want this kind of functionality, where should I look?

Please help point me in the right direction.

Thanks