Ask HN: Is there a reliable way in Linux to know if a monitor is on/off?

I am developing a kiosk-ish application with raspberry to be managed remotely. So far I have managed to get to know if a monitor is connected to the HDMI, but in no way I can now if it has been switched off or has lost power. Also I have no way to know if someone has just pressed the off button. It is just that xset and xrandr (the option talked in numerous SO posts) doesn't get that information.

Is there any way?