UIViewController: detecting drill-down and drill-up

iphone, uinavigationcontroller, uiviewcontroller

Solution

You could subclass UINavigationController, and add a property `didPushViewController`. Then you can override `pushViewController` and `popViewController` to correctly set the property to true or false respectively.

Problem

Is there a way for a UIViewController (inside a navigation stack) to detect whether it is appearing because a drill-down or a drill-up was performed? In viewWillAppear, the UINavigationController's topViewController and visibleViewController are already set to the new ViewController, unfortunately.

Original source