by andrewj » 09 Aug 2015, 05:30
This is somewhat an OS issue, where events like a mouse click are treated as "yes the user is still at the computer, so don't start the screensaver", but other events like mousewheel are ignored. It often happens to me when reading a long webpage, using just the mousewheel to scroll through it, and suddenly the screensaver decides to kick in. This issue has existed in Linux for a long long time.
It is possible this is not something which can be fixed within an application, ideally should to fix the X server or screensaver protocol to regard joystick events (etc) as "proof-of-life".
OTOH, movie players like VLC need to inhibit the screensaver, so there probably is some code around to look at for this.