ios - Detect UITabBar Selected Index/ Item Changes that is set Programmatically

Question

I would like to know how do we detect when the selected TabBar Item or Index is changed when the changes is done programmatically?

self.tabBarController.selectedIndex = 1;

This two delegate function only detect changes when the tabBar Item was selected by user. It does not fire when the changes to the selectedIndex was done programmatically.

func tabBarController(tabBarController: UITabBarController, didSelectViewController viewController: UIViewController) {
    println("tabBarController didSelectViewController")
}

override func tabBar(tabBar: UITabBar, didSelectItem item: UITabBarItem!) {
    println("tabBar didSelectItem")
}

Answer 1

Along all answers here, if you subclassed UITabBarController already, here's a simple solution for all tab bar changes (User initiated and programmatic ):

// Override selectedViewController for User initiated changes
override var selectedViewController: UIViewController? {
    didSet {
        tabChangedTo(selectedIndex: selectedIndex)
    }
}
// Override selectedIndex for Programmatic changes    
override var selectedIndex: Int {
    didSet {
        tabChangedTo(selectedIndex: selectedIndex)
    }
}

// handle new selection
 func tabChangedTo(selectedIndex: Int) {}