UIViewControllerAnimatedTransitioning not firing

Question

Doing a simpel transition but it is not getting called I am not getting what I missed here.Can anyone help me out .Not getting any error or warning.

Animation Class -:

import UIKit

class CustomPresentAnimationController: NSObject,UIViewControllerAnimatedTransitioning {

    public func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval
    {
      return 2.5
    }
    // This method can only  be a nop if the transition is interactive and not a percentDriven interactive transition.
    public func animateTransition(using transitionContext: UIViewControllerContextTransitioning)

    {
       let fromViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)
        let toViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)
        let finalViewcontroller = transitionContext.finalFrame(for: toViewController!)
        let bounds = UIScreen.main.bounds
        toViewController?.view.frame = finalViewcontroller.offsetBy(dx: 0, dy: bounds.size.height)
        print(transitionDuration(using: transitionContext))
        let containerView = transitionContext.containerView
        containerView.addSubview((toViewController?.view)!)

        UIView.animate(withDuration: transitionDuration(using: transitionContext),delay: 0.1,options: UIViewAnimationOptions.curveEaseIn,animations: { () -> Void in
            fromViewController?.view.alpha = 0.5
            toViewController?.view.frame = finalViewcontroller
        },completion: { (finished) -> Void in

            transitionContext.completeTransition(true)
            fromViewController?.view.alpha = 1.0
        })
    }


}

From view controller-:

import UIKit

class ItemsTableViewController: UITableViewController,UIViewControllerTransitioningDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

    }
    let customPresentAnimationController = CustomPresentAnimationController()

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "showAction" {
            let toViewController = segue.destination as! ActionViewController
            toViewController.transitioningDelegate = self
        }
    }
    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 5
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "ItemCell", for: indexPath) as UITableViewCell
        cell.textLabel?.text = "Item 0\(indexPath.row + 1)"
        return cell
    }

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

}

ToViewcontroller-:

import UIKit

class ActionViewController: UIViewController {

    @IBAction func dismiss(_ sender: UIButton) {
        self.dismiss(animated: true, completion: nil)
    }

}

Answer 1

Looks like you have copy/pasted the swift 2 version of the method and now the signature is different:

func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return Transition()
}

func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return Transition()
}

EDIT: also probably best to return a new instance of the transition and get rid of the let at the top.