title: Swipe to go back is disabled if the navigation bar is hidden
body: <p>My iOS 7 app uses <code>UINavigationController</code> with a hidden navigation bar. The top of my main screen includes a custom tab bar. I want to rely exclusively on the swipe to go back gesture, or the navigation buttons in the tab bar, without displaying the navigation bar and its back button.</p>
  
  <p>What I'm observing is that setting <code>self.navigationController.navigationBarHidden = YES</code> hides the navigation bar and disables the gesture recognizer. Swiping left to right from the screen edge does nothing when I've descended a level in the navigation controller.</p>
  
  <p>With this code:</p>
  
  <pre><code>- (void)viewWillAppear:(BOOL)animated
  {
      [super viewWillAppear:animated];
      self.navigationController.navigationBarHidden = YES;
  }
  
  - (void)viewDidAppear:(BOOL)animated
  {
      [super viewDidAppear:animated];
      NSLog(@"%@", self.navigationController.interactivePopGestureRecognizer);
      NSLog(@"%@", self.navigationController.interactivePopGestureRecognizer.delegate);
  }
  </code></pre>
  
  <p>I get:</p>
  
  <blockquote>
    <p>2013-12-09 22:18:32.082 Redacted[496:60b]
    ;
    target= &lt;(action=handleNavigationTransition:,
    target=&lt;_UINavigationInteractiveTransition 0x146612f0>)>></p>
    
    <p>2013-12-09 22:18:36.795 Redacted[496:60b]
    &lt;_UINavigationInteractiveTransition: 0x146612f0></p>
  </blockquote>
  
  <p>...which is the same regardless if I'm setting navigationBarHidden to <code>YES</code> or <code>NO</code>. So, the gesture recognizer, and its delegate, are both valid.</p>
  
  <p>So why is this gesture recognizer not working when the navigation bar is hidden, and how do I fix that?</p>
  
  <p>This is an iOS 7 app for iPhone/iPod touch screens.</p>