Is there a generic way to enable window activation by mouse hovering? Some of my users benefit from a mode where the keyboard focus automatically follows the mouse -- moving over a window activates that window and it starts receiving keyboard events.

I know I can do this simply by watching mouse events, but I also recall this used to be a standard interface behaviour on some systems. Thus I was wondering if QT had a toggle to enable such a mode without me having to code it on every window specially.