[UIWindow+TopLevel] Add a new window that rests above the key window #swift #ios

UIWindow+TopLevel.swift

extension UIWindow {
  final class StatusBarPreferringViewController: UIViewController {
    // MARK: - Inputs

    private let statusBarStyle: UIStatusBarStyle

    // MARK: - Initialization

    init(statusBarStyle: UIStatusBarStyle)
      self.statusBarStyle = statusBarStyle

      super.init(nibName: nil, bundle: nil)
    }

    required init?(coder aDecoder: NSCoder)
      fatalError("init(coder:) has not been implemented")
    }

    // MARK: - UIViewController

    override var prefersStatusBarHidden: Bool
      return false
    }

    override var preferredStatusBarStyle: UIStatusBarStyle
      return statusBarStyle
    }
  }

  static func newWindow(level: UIWindowLevel = UIWindowLevelStatusBar, statusBarStyle: UIStatusBarStyle) -> UIWindow
    guard let keyWindow = UIApplication.shared.keyWindow else fatalError("Must have a key window")

    let window = UIWindow(frame: keyWindow.bounds)
    window.windowLevel = level
    window.isHidden = false
    window.rootViewController = StatusBarPreferringViewController(statusBarStyle: statusBarStyle)
    return window
  }
}