How to Push a ViewController with a ModalView? - ios

Question

How can I push a UIViewController (VC) presenting a modal view (MV) to screen with a single left-to-right transition animation?
I have tried:
Setting the modal transition style of MV, and then adding both controllers to the viewControllers of the navigation controller. This however results in MV just being a controller dismissed as any other controller in the stack.
I have tried presenting MV from VC with no animation, then adding VC to the viewControllers and presenting the stack as above. This resulted in MV being instantly presented when the transition to VC starts, while VC itself animates to screen as expected. E.g. the MV doesn't follow VC when it slides in.
I have tried presenting MV from VC with animation enabled, but that results in two transitions: first VC animates to screen, then VC slides up.
I'm out of ideas, yet I would like a native and clean solution: How to transition to VC with a single normal left-to-right push, when VC is entirely covered by MV?
Key point is that MV animates together with VC; MV would appear and behave like a full screen subview, but when dismissed it animates off screen like any other modal view controller.

Answer 1

There are many solutions to this issue. I think UIPresentationController can provide an important clue here.
I try to make the answer as simple as possible here. You may change parameters or even subclass UIPresentationController to achieve a full animation as you wish.
import UIKit
//Green
class TransViewController: UIViewController {
// MARK: - Navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
let dest = segue.destination
let nextVC = storyboard?.instantiateViewController(withIdentifier: "modelViewController")
if let myPresenter = dest.presentationController{
myPresenter.presentedView!.addSubview(nextVC!.view)
nextVC!.view.center = CGPoint.init(x: nextVC!.view.center.x + nextVC!.view.frame.width , y: nextVC!.view.center.y)
UIView.animate(withDuration: 0.5, animations: {
nextVC!.view.center = self.view.center
}) { (success) in
dest.present(nextVC!, animated: false, completion: nil)
}
}
}
}
//Yellow ; "modelViewController"
class ModelViewController: UIViewController {
#IBAction func click(_ sender : UIButton){
self.dismiss(animated: true, completion: nil)
}
}