How get current keywindow equivalent for multi window SceneDelegate Xcode 11?

Question

I'm converting my iOS13 app for iPadOS to SceneDelegate (multi window).

How can I get the current UIWindow from the current SceneDelegate?

I know that a can access the current scene using UIView.window or UIViewController.view.window, but I have a non UI class (AppDelegate) where I need to get the window (keyWindow until iOS12) to show a snack bar on top of everything.

I used to do [UIApplication sharedApplication].keyWindow but now, of course, that's wrong.

Answer 1

Swift 5.x / iOS 13.x

Inspired by many solutions, to get back my old window property (searching it inside the connectedScenes) I've realized a little extension:

extension UIApplication {
    var currentWindow: UIWindow? {
        connectedScenes
        .filter({$0.activationState == .foregroundActive})
        .map({$0 as? UIWindowScene})
        .compactMap({$0})
        .first?.windows
        .filter({$0.isKeyWindow}).first
    }
}

---

Usage:

if let window = UIApplication.shared.currentWindow { 
   // do whatever you want with window
}

Answer 2

You'll want to simply iterate through all your windows and find the key window manually.

for (UIWindow *window in [UIApplication sharedApplication].windows) {
    if (window.isKeyWindow) {
        // you have the key window
        break;
    }
}

DO NOT use UISceneActivationStateForegroundActive as the check. That means something different and folks are introducing bugs by using logic to find the first UISceneActivationStateForegroundActive window scene.