/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    The application delegate. Creates and holds onto the main window, and implements the split view controller delegate.

*/

import UIKit

@UIApplicationMain

class AppDelegate: UIResponder, UIApplicationDelegate, UISplitViewControllerDelegate {

    // MARK: Properties

    var window: UIWindow?

    // MARK: App Delegate

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        guard let splitViewController = self.window!.rootViewController as? UISplitViewController else { fatalError("Unexpected view controller setup") }

        splitViewController.delegate = self

        return true

    }

    // MARK: Split View Delegate

    func splitViewController(_ splitViewController: UISplitViewController, collapseSecondary secondaryViewController: UIViewController, onto primaryViewController: UIViewController) -> Bool {

        guard let secondaryAsNavController = secondaryViewController as? UINavigationController else { return false }

        guard let topAsDetailController = secondaryAsNavController.topViewController as? DetailViewController else { return false }

        // Return true if the `sampleTitle` has not been set, collapsing the secondary controller.

        return topAsDetailController.sampleTitle == nil

    }

}