gtk:application-screensaver-active (object)

object -- a gtk:application instance
active -- a boolean whether the screensaver is active

The accessor for the screensaver-active slot of the gtk:application class returns whether the screensaver is active.

The screensaver-active property is true if GTK believes that the screensaver is currently active. GTK only tracks session state, including this, when the register-session property is set to true. Tracking the screensaver state is supported on Linux.