title: Detect user proximity from the screen
body: <p>I'm working on a BB10 app that needs to be able to <a href="https://stackoverflow.com/questions/29545315/disable-screen-during-call/29545316">disable the screen</a> when the user holds the phone up to his/her face during a call.</p>
  
  <p>How can I tell when the user is holding the phone up to his/her face?</p>