Kako implementirati prilagođeni animirani prelaz prilikom prelaska između ekrana u Navigation Controller-u?

Da biste implementirali prilagođeni animirani prelaz između ekrana u UINavigationController, morate koristiti protokole UIViewControllerAnimatedTransitioning i UINavigationControllerDelegate.

1. Kreirajte klasu koja implementira UIViewControllerAnimatedTransitioning, gde opisujete logiku animacije u sledećim metodama:

   • transitionDuration(using:) — trajanje animacije
   • animateTransition(using:) — sama animacija prelaza

2. Postavite kao delegata UINavigationController objekat koji implementira UINavigationControllerDelegate, i u metodi:

   func navigationController(_ navigationController: UINavigationController, 
                             animationControllerFor operation: UINavigationController.Operation, 
                             from fromVC: UIViewController, 
                             to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
       // vratite vaš objekat animacije
       return customAnimator
   }
   

Primer jednostavnog prilagođenog animatora:

class CustomAnimator: NSObject, UIViewControllerAnimatedTransitioning {
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.3
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        guard let toView = transitionContext.view(forKey: .to) else {
            transitionContext.completeTransition(false)
            return
        }
        let container = transitionContext.containerView
        toView.alpha = 0
        container.addSubview(toView)

        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
            toView.alpha = 1
        }) { finished in
            transitionContext.completeTransition(finished)
        }
    }
}