Action performed by UIViewController in UITabBar and Switched Back to Original View

Question

In have a UITabBarController with 3 view controller subviews. The default subview for the app is viewOne (with viewControllerOne). The other two are viewTwo and viewThree with the ordering in the UITabBar as expected.

My objective is to have an action be done when viewTwo is selected in the UITabBar while viewOne is active.

The viewTwo view is never shown but instead, when viewTwo is selected, an action is performed in viewTwoController, the UITabBar then shows viewOne as selected and the orignal view is shown again.

The UITabBarItem in the second slot must remain associated with the viewTwo nib.

Is it possible to associated a UITabBarItem with an action in its view controller and upon finishing that action, instruct its parent UITabBarController to switch to a different view?

Answer 1

UITabBarControllerDelegate got a method called tabBarController:shouldSelectViewController that you can override to do whatever you want to do when a tab switch has been triggered.

Here is the documentation: http://developer.apple.com/iphone/library/documentation/UIKit/Reference/UITabBarControllerDelegate%5FProtocol/Reference/Reference.html#//apple%5Fref/occ/intfm/UITabBarControllerDelegate/tabBarController%3AshouldSelectViewController: