Portlet mode change, handleResourceRequest vs handleRenderRequest?

I was under the impression that portlet mode changes were handled in the render request (e.g. in
GenericPortlet
).

However, according to the
Book of Vaadin
, the portlet mode are received as resource requests. Is that just for Vaadin portlets?

Portlet mode changes are communicated via the handleRenderRequest method of the PortletListener interface … at least in Vaadin 6 and Liferay 6.1.