title: Browser FullScreen Event listener?
body: <p>Clarifications: </p>
  
  <ol>
  <li>By browser full screen I mean the browser window, NOT the DOM window.   </li>
  <li>I don't want a jQuery answer.  </li>
  <li>I really don't want to use the <code>setInterval()</code> method - I'm looking for some kind of event listener similar to <code>document.addEventListener('browserFullScreen', doStuff())</code>.</li>
  </ol>
  
  <p>I know the dom window can be detected if fullscreen through <a href="https://developer.mozilla.org/en-US/docs/Web/API/Fullscreen_API" rel="nofollow noreferrer">fullscreen API</a> - but this is for true fullscreen - i.e. F11. I need a way of detecting whether when a user would drag a browser window around a screen then "snap" it to the top of the screen which then causes the browser window to go to full screen.</p>
  
  <p>Any help would be greatly appreciated.</p>