Interactive Delegate Methods Never Called

Question

I want to make an interactive transition between a ViewController (1) and a NavigationViewController (2).

The NavigationController is called by a button, so there's no interactive transition when presenting. It can be dismissed by a button or a UIPanGestureRecognizer, so it can be dismissed interactively or not.

I have an object named TransitionManager for the transition, subclass of UIPercentDrivenInteractiveTransition.

The problem with the code below is that the two delegate methods interactionControllerFor... are never called.

Moreover, when I press the buttons or swip (UIPanGestureRecognizer), the basic animation of the modal segue is done. So the two delegate methods animationControllerFor... don't work either.

Any Ideas ? Thanks

ViewController.swift

let transitionManager = TransitionManager()

override func viewDidLoad() {
    super.viewDidLoad()

    self.transitioningDelegate = transitionManager
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

        let dest = segue.destinationViewController as UIViewController
        dest.transitioningDelegate = transitionManager
        dest.modalPresentationStyle = .Custom
}

TransitionManager.swift

class TransitionPushManager: UIPercentDrivenInteractiveTransition,
 UINavigationControllerDelegate, UIViewControllerTransitioningDelegate {


@IBOutlet var navigationController: UINavigationController!

var animation : Animator! // Implement UIViewControllerAnimatedTransitioning protocol


override func awakeFromNib() {
    var panGesture = UIPanGestureRecognizer(target: self, action: "gestureHandler:")
    navigationController.view.addGestureRecognizer(panGesture)

    animation = Animator()
}

func gestureHandler(pan : UIPanGestureRecognizer) {

    switch pan.state {

    case .Began :

        interactive = true

            navigationController.presentingViewController?.dismissViewControllerAnimated(true, completion:nil)


    case .Changed :

        ...            

    default :

        ...

        interactive = false

    }

}


func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return animation
}

func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return animation
}

func interactionControllerForPresentation(animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
    return nil
}

func interactionControllerForDismissal(animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
    return self.interactive ? self : nil
}

Main.storyboard

• The button on the ViewController triggered a modal segue to presenting the NavigationController

• The NavigationController's delegate outlet is linked to an object of the TransitionManager class

• The NavigationController is referenced in the TransitionManager class by the property "navigationController"