How to get visible viewController from app delegate when using storyboard?

Question

I have some viewControllers, and I don\'t use NavigationController. How can I get visible view controller in app delegate methods (e.g. appli

Answer 1

Here is a recursive, protocol-oriented approach in Swift. Can be extended to custom types but any kind of UIViewController subclass should work with the code below.

public protocol ViewControllerContainer {

    var topMostViewController: UIViewController? { get }
}

extension UIViewController: ViewControllerContainer {

    public var topMostViewController: UIViewController? {

        if let presentedView = presentedViewController {

            return recurseViewController(presentedView)
        }

        return childViewControllers.last.map(recurseViewController)
    }
}

extension UITabBarController {

    public override var topMostViewController: UIViewController? {

        return selectedViewController.map(recurseViewController)
    }
}

extension UINavigationController {

    public override var topMostViewController: UIViewController? {

        return viewControllers.last.map(recurseViewController)
    }
}

extension UIWindow: ViewControllerContainer {

    public var topMostViewController: UIViewController? {

        return rootViewController.map(recurseViewController)
    }
}

func recurseViewController(viewController: UIViewController) -> UIViewController {

    return viewController.topMostViewController.map(recurseViewController) ?? viewController
}