context : Ubuntu 11.04 + shipped xfce 4.8 + shipped xfce-power-mamager 1.0.10 Xfce-power-manager is activated while listening music with quodlibet (http://code.google.com/p/quodlibet/) or watching video with parole. I don't know if xfce-power-manager should detect that quodlibet/parole are playing (not simply running) or if quodlibet/parole should provide themselves the relevant signal (inhibition via dbus ?) I've found something about dbus inhibition in the documentation but I don't know how to use theses informations.
This should be handled by the mediaplayers, the power manager cannot detect by itself when it should inhibit the screensaver etc.