Is it possible to ctrl-drag in Storyboard to set a UINavigationControllerDelegate?

In Xcode 5.0.2 I've created an app for iPhone with a navigation controller and 3 further view controllers (here fullscreen):

xcode screenshot

I'd like the LoginViewController (with the "Login" title in the above screenshot) be the delegate for the navigation controller, so that its method

- (void)navigationController:(UINavigationController *)navigationController
       didShowViewController:(UIViewController *)viewController
                    animated:(BOOL)animated

is called - so I have added the following code to its viewDidLoad:

UINavigationController *nc = self.navigationController;
[nc setDelegate:self];

This works, but I wonder if setting the delegate for the navigation controller is also possible in the Interface Builder?

I've tried ctrl-dragging from the yellow cube sign of the navigation controller to the LoginViewController scene and vice versa - but I'm only offered a popup to create a segue...

Solution

EDIT: this answer might be outdated as of Dec 2015. This answer is probably more accurate for XCode 6 and newer.

Long long ago, before storyboards existed, setting delegates was possible using outlets (although I don't remember if it was possible for UINavigationController, I only remember that I did it with UITableView). You would just right-click on Navigation Controller and drag from the outlet to the target:

outlets

However, according to this answer, it's not possible anymore. You can do it programatically in viewDidLoad as you did, or using prepareForSegue:.