title: How does Chromecast determine inactivity?
body: <p>I've made a Chromecast app that displays multiple quotes and the whole idea is to basically connect it to a spare tv/monitor you have lying around and use it to have inspirational quotes change on the screen.</p>
  
  <p>But the problem is, Chromecast automatically times out and goes back to the home screen after every few minutes of inactivity. I'd like to find out how it detects inactivity so I can prevent this behavior and allow my app to keep running on the Chromecast indefinitely, as a sort of replacement for the original photo screensaver.</p>