Animate navigation bar barTintColor change in iOS10 not working

Question

I upgraded to XCode 8.0 / iOS 10 and now the color change animation of my navigation bar is not working anymore, it changes the color directly without any animation.

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Answer 1

Interactive animation

Define a protocol:

/// Navigation bar colors for `ColorableNavigationController`, called on `push` & `pop` actions
public protocol NavigationBarColorable: UIViewController {
    var navigationTintColor: UIColor? { get }
    var navigationBarTintColor: UIColor? { get }
}

public extension NavigationBarColorable {
    var navigationTintColor: UIColor? { return nil }
}

Define a custom NavigationController subclass:

class AppNavigationController: UINavigationController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        navigationBar.shadowImage = UIImage()
        if let colors = rootViewController as? NavigationBarColorable {
            setNavigationBarColors(colors)            
        }
    }
    
    private var previousViewController: UIViewController? {
        guard viewControllers.count > 1 else {
            return nil
        }
        return viewControllers[viewControllers.count - 2]
    }
    
    override open func pushViewController(_ viewController: UIViewController, animated: Bool) {
        if let colors = viewController as? NavigationBarColorable {
            setNavigationBarColors(colors)
        }
               
        super.pushViewController(viewController, animated: animated)
    }
    
    override open func popViewController(animated: Bool) -> UIViewController? {
        if let colors = previousViewController as? NavigationBarColorable {
            setNavigationBarColors(colors)
        }
                        
        // Let's start pop action or we can't get transitionCoordinator()
        let popViewController = super.popViewController(animated: animated)
        
        // Secure situation if user cancelled transition
        transitionCoordinator?.animate(alongsideTransition: nil, completion: { [weak self] context in
            guard let `self` = self else { return }

            guard let colors = self.topViewController as? NavigationBarColorable else { return }
            self.setNavigationBarColors(colors)
        })
        
        return popViewController
    }
    
    override func popToRootViewController(animated: Bool) -> [UIViewController]? {
        if let colors = rootViewController as? NavigationBarColorable {
            setNavigationBarColors(colors)
        }
        
        let controllers = super.popToRootViewController(animated: animated)
        
        return controllers
    }
    
    private func setNavigationBarColors(_ colors: NavigationBarColorable) {
        
        if let tintColor = colors.navigationTintColor {
            navigationBar.titleTextAttributes = [
                .foregroundColor : tintColor
            ]
            navigationBar.tintColor = tintColor
        }
        
        navigationBar.barTintColor = colors.navigationBarTintColor
    }
}

Now you can conform to NavigationBarColorable in any controller inside the AppNavigationController and give it any color you want.

extension FirstViewController: NavigationBarColorable {
    public var navigationBarTintColor: UIColor? { UIColor.red }
    public var navigationTintColor: UIColor? { UIColor.white }
}

extension SecondViewController: NavigationBarColorable {
    public var navigationBarTintColor: UIColor? { UIColor.blue }
    public var navigationTintColor: UIColor? { UIColor.orange }
}

Don't forget to implement this useful extension:

extension UINavigationController {
    var rootViewController: UIViewController? {
        return viewControllers.first
    }
}