Visible ViewController UIViewController extension

UIViewController+VisibleViewController.swift

//
//  UIViewController+VisibleViewController.swift
//

import Foundation

extension UIViewController {
	func currentlyDisplayedViewController() -> UIViewController? {
		if isKind(of: UINavigationController.self) {
			let navigationController = self as! UINavigationController
			return navigationController.visibleViewController?.currentlyDisplayedViewController()
		}
		if isKind(of: UITabBarController.self) {
			let tabBarController = self as! UITabBarController
			return tabBarController.selectedViewController?.currentlyDisplayedViewController()
		}
		if let presentedVC = presentedViewController {
			return presentedVC.currentlyDisplayedViewController()
		}
		return self
	}
}