Custom segue transition animation - swift

Question

I'm working on an app that utilizes the navigation controller. I have a certain view controller that has a left and right button in the navigation bar and each button segues to a different view controller. When I press the right button, I just call self.performSegue(withIdentifier: "ToDestination", sender: nil) and when I pop back I call _ = self.navigationController?.popViewController(animated: true).
My issue is when I press the left button. I can push and pop, but I want the transition to work opposite of the right button. Since I'm pressing the left button, I want the segue to transition from left to right, and when I pop, I want the segue to transition from right to left.
I can get the transitions to work the way I want by doing:
//push
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "SearchController") as! SearchController
let transition: CATransition = CATransition()
let timeFunc : CAMediaTimingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.duration = 0.5
transition.timingFunction = timeFunc
transition.type = kCATransitionPush
transition.subtype = kCATransitionFromLeft
self.navigationController!.view.layer.add(transition, forKey: kCATransition)
self.navigationController!.pushViewController(vc, animated: true)
//pop
let transition: CATransition = CATransition()
let timeFunc : CAMediaTimingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.duration = 0.5
transition.timingFunction = timeFunc
transition.type = kCATransitionPush
transition.subtype = kCATransitionFromRight
self.navigationController!.view.layer.add(transition, forKey: kCATransition)
_ = self.navigationController?.popViewController(animated: true)
This works, but there is a black flash when transitioning between view controllers. Is there a better way to get the default transition animation?

Answer 1

The best way to achieve that is to create custom push and pop animation by conforming UIViewControllerAnimatedTransitioning protocol:-
//CustomPushAnimation class
import UIKit
class CustomPushAnimation: NSObject, UIViewControllerAnimatedTransitioning {
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.2
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerVw = transitionContext.containerView
let fromViewController = transitionContext.viewController(forKey: .from)
let toViewController = transitionContext.viewController(forKey: .to)
guard let fromVc = fromViewController, let toVc = toViewController else { return }
let finalFrame = transitionContext.finalFrame(for: toVc)
//Below line will start from left
toVc.view.frame = finalFrame.offsetBy(dx: -finalFrame.size.width/2, dy: 0)
containerVw.addSubview(toVc.view)
UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
toVc.view.frame = finalFrame
fromVc.view.alpha = 0.5
}, completion: {(finished) in
transitionContext.completeTransition(finished)
fromVc.view.alpha = 1.0
})
}
}
//CustomPopAnimation class
import UIKit
class CustomPopAnimation: NSObject, UIViewControllerAnimatedTransitioning {
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.2
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerView = transitionContext.containerView
let fromViewController = transitionContext.viewController(forKey: .from)
let toViewController = transitionContext.viewController(forKey: .to)
guard let fromVc = fromViewController,
let toVc = toViewController,
let snapshotView = fromVc.view.snapshotView(afterScreenUpdates: false)
else { return }
let finalFrame = transitionContext.finalFrame(for: fromVc)
toVc.view.frame = finalFrame
containerView.addSubview(toVc.view)
containerView.sendSubview(toBack: toVc.view)
snapshotView.frame = fromVc.view.frame
containerView.addSubview(snapshotView)
fromVc.view.removeFromSuperview()
UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
//Below line will start from right
snapshotView.frame = finalFrame.offsetBy(dx: -finalFrame.size.width, dy: 0)
}, completion: {(finished) in
snapshotView.removeFromSuperview()
transitionContext.completeTransition(finished)
})
}
}
And last you need to present the new View controller with setting
animation flag to true otherwise it will not work
//Below code should be inside YourViewController
let vc = UIStoryboard(name: "storyboardName", bundle: nil).instantiateViewController(withIdentifier: "ViewControllerIdentifier") let navigationController = BaseNavigationController(rootViewController: vc)
navigationController.transitioningDelegate = self
present(navigationController, animated: true, completion: nil)
You also need to conform UIViewControllerTransitioningDelegate
protocol in order to work animation
extension YourViewController: UIViewControllerTransitioningDelegate {
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
return customPushAnimation
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
return customPopAnimation
}
}