Xcode / Swift | Use UIViewController transition for UINavigationController - swift

Question

Storyboard cutting
The steps that I did were:
Create the + and x buttons in the Controllers
Create simple outlets in the Controllers
Create an action in the Controller for the x (dismiss)-button
#IBAction func button_close_pressed(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
}
Create a segue on the Storyboard from the + button to the targetViewController.
Create the transition class.
import UIKit
class CircularTransition: NSObject {
var circle = UIView()
var startingPoint = CGPoint.zero {
didSet {
circle.center = startingPoint
}
}
var circleColor = UIColor.red
var duration = 3.0
enum CircularTransitionMode: Int {
case present, dismiss, pop
}
var transitionMode: CircularTransitionMode = .present
}
extension CircularTransition: UIViewControllerAnimatedTransitioning {
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return duration
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerView = transitionContext.containerView
if transitionMode == .present {
if let presentedView = transitionContext.view(forKey: UITransitionContextViewKey.to) {
let viewCenter = presentedView.center
let viewSize = presentedView.frame.size
circle = UIView()
circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
circle.layer.cornerRadius = circle.frame.size.height / 2
circle.center = startingPoint
circle.backgroundColor = circleColor
circle.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
containerView.addSubview(circle)
presentedView.center = startingPoint
presentedView.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
presentedView.alpha = 0
containerView.addSubview(presentedView)
UIView.animate(withDuration: duration, animations: {
self.circle.transform = CGAffineTransform.identity
presentedView.transform = CGAffineTransform.identity
presentedView.alpha = 1
presentedView.center = viewCenter
}, completion: { (success: Bool) in
transitionContext.completeTransition(success)
})
}
} else {
let transitionModeKey = (transitionMode == .pop) ? UITransitionContextViewKey.to : UITransitionContextViewKey.from
if let returningView = transitionContext.view(forKey: transitionModeKey) {
let viewCenter = returningView.center
let viewSize = returningView.frame.size
circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
circle.layer.cornerRadius = circle.frame.size.height / 2
circle.center = startingPoint
UIView.animate(withDuration: duration, animations: {
self.circle.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
returningView.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
returningView.center = self.startingPoint
returningView.alpha = 0
if self.transitionMode == .pop {
containerView.insertSubview(returningView, belowSubview: returningView)
containerView.insertSubview(self.circle, belowSubview: returningView)
}
}, completion: { (success: Bool) in
returningView.center = viewCenter
returningView.removeFromSuperview()
self.circle.removeFromSuperview()
transitionContext.completeTransition(success)
})
}
}
}
func frameForCircle(withViewCenter viewCenter: CGPoint, size viewSize: CGSize, startPoint: CGPoint) -> CGRect {
let xLength = fmax(startPoint.x, viewSize.width - startPoint.x)
let yLength = fmax(startPoint.y, viewSize.height - startPoint.y)
let offsetVector = sqrt(xLength * xLength + yLength * yLength) * 2
let size = CGSize(width: offsetVector, height: offsetVector)
return CGRect(origin: CGPoint.zero, size: size)
}
}
In the source Controller I added ... to the class
UIViewControllerTransitioningDelegate
Then
let transition = CircularTransition()
And last but not least
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let eventVC = segue.destination as! EventViewController
eventVC.transitioningDelegate = self
eventVC.modalPresentationStyle = .custom
}
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.transitionMode = .present
transition.startingPoint = self.button_addEvent.center
transition.circleColor = self.button_addEvent.backgroundColor!
return transition
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.transitionMode = .dismiss
transition.startingPoint = self.button_addEvent.center
transition.circleColor = self.button_addEvent.backgroundColor!
return transition
}
Now, why doesn't that work? I only can think of that the problem comes with the Navigation Controller instead of a normal ViewController, because with a normal one it works fine. But I really have no idea hwo to change the code to match with the Navigation Controller (source Controller).
Kind regards and thank you!

Answer 1

You need to implement UINavigationControllerDelegate in your viewController
func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
switch operation {
case .push:
transition.transitionMode = .present
transition.startingPoint = self.button_addEvent.center
transition.circleColor = self.button_addEvent.backgroundColor!
return transition
default:
transition.transitionMode = .dismiss
transition.startingPoint = self.button_addEvent.center
transition.circleColor = self.button_addEvent.backgroundColor!
return transition
}
}