Restore pre-iOS7 UINavigationController pushViewController animation

I managed to workaround the new transition type by creating a category for UINavigationController. In my case I needed to revert it to the old transition style because I have transparent viewControllers that slide over a static background.

• UINavigationController+Retro.h

  @interface UINavigationController (Retro)
  
  - (void)pushViewControllerRetro:(UIViewController *)viewController;
  - (void)popViewControllerRetro;
  
  @end
  

• UINavigationController+Retro.m

  #import "UINavigationController+Retro.h"
  
  @implementation UINavigationController (Retro)
  
  - (void)pushViewControllerRetro:(UIViewController *)viewController {
      CATransition *transition = [CATransition animation];
      transition.duration = 0.25;
      transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
      transition.type = kCATransitionPush;
      transition.subtype = kCATransitionFromRight;
      [self.view.layer addAnimation:transition forKey:nil];
  
      [self pushViewController:viewController animated:NO];
  }
  
  - (void)popViewControllerRetro {
      CATransition *transition = [CATransition animation];
      transition.duration = 0.25;
      transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
      transition.type = kCATransitionPush;
      transition.subtype = kCATransitionFromLeft;
      [self.view.layer addAnimation:transition forKey:nil];
  
      [self popViewControllerAnimated:NO];
  }
  
  @end