Swift -Transition to SceneDelegate

Question

Before iOS 13 I would use a transition to go from my LoginVC to my TabBarController. How would I accomplish the following for SceneDelegate? This app has only 1 scene/window

@objc func buttonTapped() {

    let transition = CATransition()
    transition.duration = 0.4
    transition.type = CATransitionType.moveIn
    transition.subtype = CATransitionSubtype.fromTop
    transition.timingFunction = CAMediaTimingFunction(name:CAMediaTimingFunctionName.default)

    let appDelegate = UIApplication.shared.delegate as? AppDelegate
    appDelegate?.window?.rootViewController?.view.removeFromSuperview()
    appDelegate?.window?.rootViewController?.dismiss(animated: false, completion: nil)
    appDelegate?.window?.layer.add(transition, forKey: kCATransition)
    appDelegate?.window?.rootViewController = //instance of my TabBarController() and selected index
    appDelegate?.window?.isHidden = false
}

Answer 1

@objc func buttonTapped() {

    let transition = CATransition()
    transition.duration = 0.4
    transition.type = CATransitionType.moveIn
    transition.subtype = CATransitionSubtype.fromTop
    transition.timingFunction = CAMediaTimingFunction(name:CAMediaTimingFunctionName.default)

    if #available(iOS 13, *) {

        UIApplication.shared.windows.first?.rootViewController?.view.removeFromSuperview()
        UIApplication.shared.windows.first?.rootViewController?.dismiss(animated: false, completion: nil)
        UIApplication.shared.windows.first?.layer.add(transition, forKey: kCATransition)
        UIApplication.shared.windows.first?.rootViewController = // instance of my TabBarController() and selected index
        UIApplication.shared.windows.first?.isHidden = false

    } else {

        let appDelegate = UIApplication.shared.delegate as? AppDelegate
        appDelegate?.window?.rootViewController?.view.removeFromSuperview()
        appDelegate?.window?.rootViewController?.dismiss(animated: false, completion: nil)
        appDelegate?.window?.layer.add(transition, forKey: kCATransition)
        appDelegate?.window?.rootViewController = //instance of my TabBarController() and selected index
        appDelegate?.window?.isHidden = false
    }
}