How to show two view controllers as modal but animate transition only for the second one?

Question

I have three controllers (FirstVC, SecondVC, ThirdVC) inside storyboad, and navigation is sequential: a user can present modally SecondVC from FirstVC. and then present modally ThirdVC from SecondVC. Now, I need to make some button that will open ThirdVC from FirstVC but will also put SecondVC on in between, so when a user will press back/Cross from ThirdVC he will be returned to SecondVC. So, I don’t need animation from FirstVC to SecondVC, just need to go SecondVC and then animate only transition to ThirdVC.

I found same question for push sague How to push two view controllers but animate transition only for the second one?. I need same behaviour with present modally.

present the second with animation false and in completion handler present the third one with animation on ? — Mohmmad S, Dec 19 '18 at 11:09
Its working but for split of second, SecondVC is visible in the background. — Muhammad Usman Aleem, Dec 19 '18 at 11:23
mmmmmm think about work around because presenting has to be done like that idk if there is a way to achieve that or is it possible however think out of the box like maybe set the View in the second one alpha to 0 or something — Mohmmad S, Dec 19 '18 at 11:24
like its has to be presented to be added to the stack of views, else its not existed, it has to be initialised first so you can go back to it — Mohmmad S, Dec 19 '18 at 11:26

score 1 · Answer 1 · answered Dec 19 '18 at 12:20

You cannot present a view controller until the view of the presenting view controller has rendered. Therefore, it's not possible to present two view controllers simultaneously where the second presentation originates from the first--the first must first render its view.

But the solution is still rather basic. If the user is going from A to B, you present B from A like normal. If the user is going from A to C, you present C from A but C is a container view controller with two children (B and C, C obviously on top). Therefore, when the user dismisses C, he is not really dismissing anything, but rather animating C out of view to show B (using the same animation as the dismiss). To the user, it looks all the same.

Habib Ali · Accepted Answer · 2018-12-20T09:04:13.637

Here will be the hierarchy First VC presents second VC

let vc = UIStoryboard.init(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "SecondVC") as! SecondVC
    present(vc, animated: true, completion: nil)
present(vc, animated: true, completion: nil)

second VC will add third VC as subview and make it visible

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.

    let vc = UIStoryboard.init(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ThirdVC") as! ThirdVC
    self.addChild(vc)
    self.view.addSubview(vc.view)
}

when dismiss third VC remove it from super view with animation and reveal second VC

UIView.animate(withDuration: 0.5, animations: { [weak self] in
        self?.view.frame = CGRect(x: 0, y: self?.view.frame.height ?? 0.0, width: self?.view.frame.width ?? 0.0, height: self?.view.frame.height ?? 0.0)
    }, completion: { [weak self] _ in
        self?.view.removeFromSuperview()
    })

dismiss second VC and reveal first VC

dismiss(animated: true, completion: nil)

How to show two view controllers as modal but animate transition only for the second one?

2 Answers2