screen freezes if using modalPresentationStyle = .overCurrentContext swift 5

Question

I am presenting a navigation controller with modalPresentationStyle as overCurrentContext. After dismissing controller screen freezes.

I am presenting a FirstViewController with NAvigationController.

let firstVC = FirstViewController.controller()
let nvc = UINavigationController(rootViewController: firstVC)
nvc.modalPresentationStyle = .overCurrentContext
present(nvc, animated: true)

Then inside FirstViewController, I am passing navigationController to push SecondViewController

override func viewDidLoad() {
    super.viewDidLoad()
    guard let nav = navigationController else { return }
    showSecondViewController(parentController: nav)
}

func showSecondViewController(parentController: UINavigationController) {
    let secondVC = SecondViewController.controller()
    parentController.pushViewController(secondVC, animated: true)
}

Now first I am popping SecondViewcontroller on click action from SecondViewController

navigationController?.popViewController(animated: animated)

Then with some call back I am dismissing FirstViewController and NavigationControoler (nvc)

self.controller?.dismiss(animated: true)
self.nvc?.dismiss(animated: true)

Now after dismissing as above I am facing screen freeze issue. I need help to resolve this issue. Please help. Why screen is freezing. Please let me know if I am missing anything here? Thanks

Answer 1

Did you see any errors in the console? I'm not clear about "some call back" as you mentioned above. Can you elaborate?

I created a small project to replicate your issue. The approach below works fine in my case

• ViewController is the root view controller
• FirstViewController is the first controller presented on top of ViewController
• SecondViewController is pushed from the first view controller after the event "ViewDidLoad" happens in FirstViewController

I also created 1 onViewControllerDissmied callback in each ViewControllers (especially FirstViewController and SecondViewController)

In ViewController - I created a touch up inside event as below

    @objc func onButtonClicked() {
        let firstVC = FirstViewController()
        nvc = UINavigationController(rootViewController: firstVC)
        guard let nvc = nvc else { return }
        nvc.modalPresentationStyle = .overCurrentContext
        present(nvc, animated: true)
        mycontroller = firstVC
        firstVC.onViewControllerDimissed = { [weak self] in
            self?.mycontroller?.dismiss(animated: true)
            self?.nvc?.dismiss(animated: true)
        }
    }

FirstViewController

class FirstViewController: UIViewController {
    var label: UILabel = {
        let button = UILabel()
        button.translatesAutoresizingMaskIntoConstraints = false
        button.text = "First View Controller"
        button.textColor = .white
        return button
    }()
    var onViewControllerDimissed: (() -> Void)?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .purple
        guard let nav = navigationController else { return }
           showSecondViewController(parentController: nav)
    }

    func showSecondViewController(parentController: UINavigationController) {
        let secondVC = SecondViewController()
        parentController.pushViewController(secondVC, animated: true)
        secondVC.onViewControllerDimissed = { [weak self] in
            self?.onViewControllerDimissed?()
        }
    }
}

SecondViewController

class SecondViewController: UIViewController {
    var label: UILabel = {
        let button = UILabel()
        button.translatesAutoresizingMaskIntoConstraints = false
        button.text = "Second View Controller"
        return button
    }()
    
    var onViewControllerDimissed: (() -> Void)?
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
                let position = touch.location(in: view)
                let pnt: CGPoint = CGPoint(x: position.x, y: position.y)
                if (view.bounds.contains(pnt)) {
                    onScreenTouch()
                }
            }
    }
    
    func onScreenTouch() {
        navigationController?.popViewController(animated: true)
        onViewControllerDimissed?()
    }
}