I'm looking for a way to detect that the screen attached to the HDMI out has been turned off, or is in sleep mode, either through a command-line tool or a Java app. So far, I've figured out how to detect whether there is something connected by checking the contents of this node in sysfs: /sys/class/display/display0.HDMI/connect
However, this only reports whether something is connected, not whether it's on or off.
I also tried using the isScreenOn() method in Android's PowerManager API to check the power on state, but it always returns true, regardless of whether the screen is on or off.
Does anyone know if getting the external HDMI's power state?
Thanks!
