I don't know if it makes sense to allow the o/s to do the handling of switching it off. The user is assuming they are providing user-input and that therefore they are operating the display, and therefore the screensaver should not show up. They assume that even if they have their screensaver switched on and set up to show only when there is no activity from the user, that the fact they are activating things means the screensaver won't show, which they trust from the o/s. So it makes sense that using our app should *override* the screensaver activating, but not mess with the default settings that the user chose. If the screensaver is switched on in the o/s, let us choose whether to disable it. You shouldn't have to get the user to mess with system settings to make your app work right.