AppCoordinatorのやつ

AppCoordinator.swift

import UIKit

class AppCoordinator: Coordinator {

    let window: UIWindow
    lazy var feedCoordinator: FeedCoordinator = {
        return FeedCoordinator(viewController: self.window.rootViewController!)
    }()

    init(window: UIWindow) {
        self.window = window
    }

    func start() {
        let viewController = SplashViewController.instantiate()
        viewController.transitionsDelegate = self
        window.rootViewController = viewController
        window.makeKeyAndVisible()
    }

}

extension AppCoordinator: SplashTransions {

    func showHome() {
        feedCoordinator.start()
    }

    func showLogin() {
        window.rootViewController?.present(LoginViewController.instantiate(), animated: false, completion: nil)
    }

}

AppDelegate.swift

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    lazy var appCoordinator: AppCoordinator = {
        return AppCoordinator(window: self.window!)
    }()

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        window = UIWindow(frame: UIScreen.main.bounds)
        appCoordinator.start()
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
    }

    func applicationWillTerminate(_ application: UIApplication) {
    }

}

FeedCoordinator.swift

import Foundation
import UIKit

class FeedCoordinator: Coordinator {

    let presentingViewController: UIViewController
    lazy var rootViewController: UIViewController = {
        return FeedNavigationController.instantiate(storyboard: FeedViewController.className)
    }()

    init(viewController: UIViewController) {
        self.presentingViewController = viewController
    }

    func start() {
        presentingViewController.present(rootViewController, animated: false, completion: nil)
    }

}