Is there a mechanism in Qt to do selective signal emit?

Let's assume I have a Event class, which I pass across my objects with Qt signal-slot mechanism.
For new type of events, I add new classes,let's say AppEvent, which extends Event class. While I can still use the signal-slot mechanism to emit signal with AppEvent instance as parameter, all my slots which are interested in AppEvent are now required to check if the parameter is instance of AppEvent. Worse, all other slots, who are not potentially interested in AppEvent, get called, only to realize they have no interest in the event.

Does Qt support anything which would allow implementing this kind of signal selection?

Regards,
Jancsi Farkas