Rotation only in one ViewController

Question

I am trying to rotate one view while all other views (5) are fixed to portrait. The reason is that in that one view I want the user to watch pictures which he saved before.

Answer 1

With everyone's ideas I wrote the most elegant way to do it I think.

Result:

    func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        return (UIApplication.getTopViewController() as? Rotatable == nil) ? .portrait : .allButUpsideDown
    }

Add this extension to your project which will always be useful not only for this:

extension UIApplication {

    class func getTopViewController(base: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
        if let nav = base as? UINavigationController {
            return getTopViewController(base: nav.visibleViewController)
        }

        if let tab = base as? UITabBarController {
            if let selected = tab.selectedViewController {
                return getTopViewController(base: selected)
            }
        }

        if let presented = base?.presentedViewController {
            return getTopViewController(base: presented)
        }

        return base
    }

}

Create the protocol:

protocol Rotatable {}

And implement it:

class ViewController: UIViewController, Rotatable {
}