Currently, the RadPanelBar can only act as a tab strip (role="tabstrip"). (Actually, the current implementation is missing the role="tabstrip" attribute, so it's basically invalid and only a collection of incoherent tabs.)
The RadPanelBar, however, is rather a menu. It may, semantically, even rather be a tree view, too.
It depends on the usage on a web page what the RadPanelBar is actually supposed to represent.
So I suggest to add an enumeration property to the RadPanelBar enabling developers to designate it either
- as a tabstrip (containing tabs)
- as a menu (containing menu items)
- as a tree view (containing tree items)