Interactive Navigation: Segue Declaration

Theoretical question: in the code below, why, on the line "performSegue ....", the segue is not being executed completely? I mean, how does he know this is an interactive transition, and why does the "performSegue ..." method not have the same effect as if it were declared somewhere else?

FirstViewController.swift

let transitionManager = TransitionManager()


override func viewDidLoad() {
    super.viewDidLoad()

    transitionManager.sourceViewController = self

    // Do any additional setup after loading the view.
}

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

    let dest = segue.destinationViewController as UIViewController
    dest.transitioningDelegate = transitionManager
    transitionManager.destViewController = dest

}

      

        
        
        
      

    

Storyboard

Shogu from FirstViewController to SecondViewController.

• Identifier: "segueIdentifier"

• Segue: Modal

• Purpose: current

TransitionManager.swift

class TransitionManager: UIPercentDrivenInteractiveTransition,UIViewControllerAnimatedTransitioning, UIViewControllerTransitioningDelegate,UIViewControllerInteractiveTransitioning {

    var interactive = false
    var presenting = false

    var panGesture : UIPanGestureRecognizer!

    var sourceViewController : UIViewController! {
        didSet {

            panGesture = UIPanGestureRecognizer(target: self, action: "gestureHandler:")
            sourceViewController.view.addGestureRecognizer(panGesture)

        }
    }


    func gestureHandler(pan : UIPanGestureRecognizer) {

        let translation = pan.translationInView(pan.view!)

        let d =  translation.x / pan.view!.bounds.width * 0.5        

        switch pan.state {

        case UIGestureRecognizerState.Began :

            interactive = true

            sourceViewController.performSegueWithIdentifier("segueIdentifier", sender: self)


        case UIGestureRecognizerState.Changed :

            self.updateInteractiveTransition(d)

        default :

            interactive = false

            if d > 0.2 || velocity.x > 0 {
                self.finishInteractiveTransition()
            }
            else {
                self.cancelInteractiveTransition()
            }
        }

    }

    func animateTransition(transitionContext: UIViewControllerContextTransitioning) {

        //Something....


        UIView.animateWithDuration(1.0, animations: {

            //Something....

            }, completion: {}

        })

    }

    func transitionDuration(transitionContext: UIViewControllerContextTransitioning) -> NSTimeInterval {
        return 1
    }

    // MARK: UIViewControllerTransitioningDelegate protocol methods

    func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        self.presenting = true
        return self
    }

    func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        self.presenting = false
        return self
    }

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

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





}

      

        
        
        
      

    

In fact, I have a lot of code similar to this, this one works, but others do very similarly what I am explaining: the segue is simply executed without an interactive transition. Can someone explain to me?

thanks for the help