Hide switching of storyboards - ios

Question

In my application I have 2 storyboards: Onboarding and Main. When user opens app for a first time - Onboarding storyboard is presented. After that, he presses a button and I show him Main Storyboard with such code:
let storyboard = UIStoryboard(name: "Shop", bundle: nil)
let navigationVc = storyboard.instantiateViewController(withIdentifier: "ShopScreens") as UIViewController
navigationVc.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
self.present(navigationVc, animated: false, completion: nil)
I wanted to make custom animation, when user switches storyboards. To do so - I've created simple view that I'm presenting on top of everything like this:
UIApplication.shared.keyWindow?.addSubview(self.containerViewForAnimatedView)
And this view is working fine, but only in terms of one Storyboard, it covers everything while app changes screens.
But when I try to switch storyboards - this view gets covered by newly presented storyboard.
I also tried presenting view in such way and brining it to front:
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.window?.addSubview(self.containerViewForAnimatedView)
But that din't work as well.
How can I hide switching of storyboards by presenting custom created view during that transition?
Would be grateful for any help.

Answer 1

Just played around some with it, no animations or anything special but this will give you the flow that you want:
class ViewController: UIViewController {
let viiew = UIView.init(frame: UIScreen.main.bounds)
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .red
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
self.viiew.backgroundColor = .blue
UIApplication.shared.keyWindowInConnectedScenes?.resignKey()
UIApplication.shared.keyWindowInConnectedScenes?.addSubview(self.viiew)
self.viiew.layer.zPosition = 1000
}
DispatchQueue.main.asyncAfter(deadline: .now() + 4) {
let vc = ViewController2()
UIApplication.shared.keyWindowInConnectedScenes?.rootViewController = vc
DispatchQueue.main.asyncAfter(deadline: .now() + 4) {
self.viiew.removeFromSuperview()
}
}
}
}
class ViewController2: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .green
}
}
extension UIApplication {
var keyWindowInConnectedScenes: UIWindow? {
return windows.first(where: { $0.isKeyWindow })
}
}