title: React Native Router Flux Drawer
body: <p>I am trying to change the state of my app when the drawer is opened.
  onEnter and onOpen don't trigger at all.</p>
  
  <p>I am using a custom NavBar so the hamburger button isn't being displayed but if i swipe left on my IOS device the drawer opens.</p>
  
  <p>So how can i detect when the drawer is open?</p>