Question

What is the correct way to propagate shouldAutorotate into a deep modal viewcontroller in iOS6

Consider the following example:

1. Create a new sample Tabbed Application in XCode 4.5
2. In the Summary, select all orientations

3. Create a new simple UITabBarController, e.g. MyTabBarViewController and add the code

   - (BOOL)shouldAutorotate {
       return YES;
   }
   
   - (NSUInteger)supportedInterfaceOrientations {
       return UIInterfaceOrientationMaskAll;
   }
   

4. In the AppDelegate, replace with UITabBarController by MyTabBarViewController in order to hook the rotation

   self.tabBarController = [[MyTabBarViewController alloc] init];
   

5. Now the rotation should work, and in the FirstViewController, add the code to show a modal viewcontroller on click

   -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
   
       UIViewController * viewController2 = [[SecondViewController alloc] 
           initWithNibName:@"SecondViewController_iPhone" bundle:nil];
   
       [self presentViewController: [[UINavigationController alloc] 
           initWithRootViewController:viewController2] 
           animated:YES 
           completion:nil];
   }
   

Problem:

Now since the SecondViewController is wrapped by a UINavigationController, even I have added shouldAutorotate in SecondViewController and can’t make the upside down rotation done right.

The only fix is to create a custom UINavigationController and also implement shouldAutorotate and this should work.

But this approach sound stupid and it require me to fix all UI class by implementing the shouldAutorotate and I cannot use shorthands such as [UINavigationController alloc]
initWithRootViewController... anymore, I must implement all these UITabBarController and UINavigationController.

Are there any better approach?

Answer 1

Have you tried this:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didRotate:) name:UIDeviceOrientationDidChangeNotification object:nil];

It’s a notification sent by the device which tell the observer about the rotation. Do not forget to removeObserver when you don’t need anymore