Device control based on another devices status

Is it possible to do something like
If projector is on and there is motion then do not turn on the lights? This would prevent the lights from turning on automatically if we are watching a movie and someone gets up for some reason.
I was thinking I could add this inline with the power for the projector to get the state of the projector:!/products/smartpower-outlet

This is a great idea for many different scenarios. I think you could simply do this with a mode rather than a custom SmartApp. What happens if you created a Movie mode that would not do anything when motion was detected?

Yup do this ^

You could set the projector power on to activate the movie mode automatically

The problem with the projector being the trigger is that it takes the projector like 30 seconds to warm up. Until that time the room would be dark. Can you set a delay on an event or judge the level of light coming from the projector and then dim the room lights when the projector actually displays an image?

Can a raspberry pie be integrated with ST? Maybe something can be done with that and an ambient light sensor.