Presenting a specific view controller once immediately after launch screen closes

Question

I have a 1-screen tutorial View Controller. I want this tutorial VC to show only once (userdefaults), but I want a smooth transition from when the launch screen finishes -> tutorial VC.

Right now - the launch screen finishes, then the main interface of the App shows for a split second, then the tutorial VC shows up. I want to remove this "flashing" of the main interface.

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    if !didShowTut {
        fireTutorial()
        didShowTut = true
    }
}

func fireTutorial() {
    let tutVC = UIStoryboard(name: "FirstTutorial", bundle: nil).instantiateViewController(withIdentifier: "TutorialSBID") as UIViewController
    tutVC.modalPresentationStyle = .overCurrentContext
    self.present(tutVC, animated: false, completion: nil)
}

Any help to create a smooth transition from Launch screen -> Tutorial VC would be appreciated.

@Joe on first time, set the tutorial VC as window's root view controller. when tutorial finishes, change window's root view controller again with your app's main interface. — Shebin Koshy, Feb 28 '18 at 06:04
@ShebinKoshy - Currently working on your suggestion as a solution. — Joe, Feb 28 '18 at 06:18
Possible duplicate: https://stackoverflow.com/questions/26355847/ios-present-modal-view-controller-on-startup-without-flash — Vladimir Grigorov, May 28 '19 at 11:46

score 0 · Answer 1 · answered Feb 28 '18 at 05:57

0

You are presenting the tutVC on the viewDidAppear func which is executed after the screen has been loaded.

try calling the fireTutorial() on override func viewDidLoad() or on the override func viewWillAppear(_ animated: Bool) methods that get executed before the screen is loaded.

answered Feb 28 '18 at 05:57

Patrick Haralabidis

1
1

I did try that; the VC never loads up if i put fireTutorial() in either viewDidLoad or viewWillAppear. – Joe Feb 28 '18 at 06:02
@Joe which one is the app root view controller? – Patrick Haralabidis Feb 28 '18 at 06:17
The main VC is the root. I suppose for the very first App load, the tutorial VC should be root, as suggested above by Shebin? – Joe Feb 28 '18 at 06:19
@Joe this is probably because you are not using a navigation controller and the main VC is set as the root in the storyboard. You can add a navigation controller, set it as the entry point of your app and set the main VC as the root VC of the Navigation controller. After that you will be able to call fireTutorial in the ViewWillAppear or set up a modal segue. – Patrick Haralabidis Feb 28 '18 at 06:44
I've embedded my main VC in a navigation controller (in storyboard.) The TutorialVC now shows up when it's presented in viewWillAppear, but the 'flashing' is still occurring. (same result when presented in viewDidLoad). – Joe Feb 28 '18 at 07:04
@joe Are both view controllers in the same storyboard? If so, have you tried presenting with a seque? – Patrick Haralabidis Feb 28 '18 at 07:12
No, the main App interface and tutorial each have their own storyboards. – Joe Feb 28 '18 at 07:15
I got this working. Check my answer. Thank you for your help! You jived some ideas to try, which ultimately worked. – Joe Feb 28 '18 at 07:50

score 0 · Accepted Answer · answered Feb 28 '18 at 07:49

I went with a slightly different approach to solve this.

I embedded the main app VC in a navigation controller, then pushing the tutorialVC in App Delegate didFinishLaunchingWithOptions.

let tutorialVC = UIStoryboard(name: "FirstTutorial", bundle: nil)
let firstVC = tutorialVC.instantiateViewController(withIdentifier: "TutorialSBID") as UIViewController
if let navigationController = self.window?.rootViewController as? UINavigationController
{
    navigationController.pushViewController(firstVC, animated: false)
}
return true

Bilal Awan · Answer 3 · 2018-02-28T06:04:20.533

-1

Write this code in viewWillAppear or viewWillLayoutSubviews() instead of viewDidAppear

edited Feb 28 '18 at 06:04

answered Feb 28 '18 at 05:56

Bilal Awan

4,730
1
8
15

The tutorial VC does not load if I put it in viewWillAppear. It just goes straight into the main App interface. – Joe Feb 28 '18 at 06:02
Then try writing the code in viewWillLayoutSubviews() – Bilal Awan Feb 28 '18 at 06:04

Presenting a specific view controller once immediately after launch screen closes

3 Answers3