UIWindow Presentation Context - Get top most presented UIViewController of UIWindow

uiwindow-presentation-context.swift

// https://hashaam.com/2017/08/31/uiwindow-presentation-context/

extension UIWindow {
    
    func presentationContext(context: UIViewController? = nil) -> UIViewController? {
        
        var presentationContextViewController = rootViewController
        if let context = context  {
            presentationContextViewController = context
        }
        
        if presentationContextViewController?.presentedViewController == nil {
            
            if let navigationController = presentationContextViewController as? UINavigationController {
                return navigationController.topViewController
            }
            
            return presentationContextViewController
            
        }
        
        return presentationContext(context: presentationContextViewController?.presentedViewController)
        
    }
    
}