[Swift] iOS ViewController present to top most

UIViewController+presentToTop.swift

//
//  UIViewController+presentToTop.swift
//
//  Created by 홍경표 on 2021/06/01.
//

import UIKit

extension UIViewController {
    func presentToTop() {
        let currentTop = UIApplication.shared.keyWindowCurrentScene?.topViewController
        currentTop?.present(self, animated: true, completion: nil)
    }
}

extension UIWindow {
    var topViewController: UIViewController? {
        var top = self.rootViewController
        while true {
            if let presented = top?.presentedViewController {
                top = presented
            } else if let nav = top as? UINavigationController {
                top = nav.visibleViewController
            } else if let tab = top as? UITabBarController {
                top = tab.selectedViewController
            } else {
                break
            }
        }
        return top
    }
}

extension UIApplication {
    class var keyWindowOfCurrentScene: UIWindow? {
        shared.windows.first(where: { $0.isKeyWindow })
    }
}