How to rotate a UITabBarController

I spent quite some time to try to understand how to rotate an application containing a tab bar controller. If you create a simple project (you can use the template Tab Bar Application offered in Xcode), you will not able to rotate the view as reported in the View Controller User Guide by Apple. I found the solution and I share it with you.

Let’s create a simple project. Open Xcode and chose the Tab Bar Application template in the iPhone OS group. Name it SimpleTab and save it where ever you like in your HD. Build and run it. If you rotate the iPhone (or the Simulator via Apple-Left or Right Arrow keys), it does not work: the interface keeps its portrait position.

Let’s add a new class to the project. Right-click the Classes group in the Groups & Files pane and choose Add… -> New File… Choose an NSObject subclass in the Cocoa Touch Classes group and name it MyTabBarController.

Open the MyTabBarController.h file and change it in this way:

#import <UIKit/UIKit.h>

@interface MyTabBarController : UITabBarController {

}
@end
 
Notice that I am subclassing UITabBarController. Now, edit the MyTabBarController.m file and add the following method:

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return YES;
}

Save it. We have simply created a subclass of UITabBarController able to rotate. Now, we need to tell Interface Builder to use this class, instead of its parent.

Double-click the MainWindow.xib file and select the Tab Bar Controller object in the MainWindow.xib window. Open the Identity Inspector and change the class name to MyTabBarController. Save it and close Interface Builder. Go back to Xcode and build and run. Now, if you try to rotate the view…… it works.

When you rotate the iPhone, the content of each view is not correctly displayed. You have to play with the autosizing mask in Interface Builder or programmatically. But I leave this to you.