Detect Session Lock

Is possible to detect if the session is locked only using QT?

Must be something cross-platform. This is possible or I'll produce a condition for each platform?

Thanks

I doubt that there is any cross-platform way of doing that.
But there could be libraries doing that.

Cheers,
_

Thanks anda_skoa

I'll search for different systems (different GUI, eg. gnome, kde, x11 and windows desktop) and trying to create my own, if I can do it in an acceptable time I share here via github.