I'm trying to implement CardViews similar to the ones used in the iOS 11 App Store. In order to do so, I'm using a GitHub project (https://github.com/PaoloCuscela/Cards) and tweaked it a bit.
The problem is that when transitioning back from the presented Detail View to the initial view (which is placed inside a TabBarController) the card is drawn in front of the TabBar (see video https://youtu.be/qDb3JoISTdw) which gives the whole transition a kind of 'glitchy' look.
This is the Code of the transitioning class I use:
import UIKit
class Animator: NSObject, UIViewControllerAnimatedTransitioning {
fileprivate var presenting: Bool
fileprivate var velocity = 0.6
var bounceIntensity: CGFloat = 0.07
var card: Card
init(presenting: Bool, from card: Card) {
self.presenting = presenting
self.card = card
super.init()
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
// Animation Context Setup
let container = transitionContext.containerView
let to = transitionContext.viewController(forKey: .to)!
let from = transitionContext.viewController(forKey: .from)!
container.addSubview(to.view)
container.addSubview(from.view)
guard presenting else {
// Detail View Controller Dismiss Animations
card.isPresenting = false
let detailVC = from as! DetailViewController
let cardBackgroundFrame = detailVC.scrollView.convert(card.backgroundIV.frame, to: nil)
let bounce = self.bounceTransform(cardBackgroundFrame, to: card.originalFrame)
// Blur and fade with completion
UIView.animate(withDuration: velocity/2, delay: 0, options: .curveEaseOut, animations: {
detailVC.blurView.alpha = 0
}, completion: nil)
UIView.animate(withDuration: velocity, delay: 0, options: .curveEaseOut, animations: {
detailVC.snap.alpha = 0
self.card.backgroundIV.layer.cornerRadius = self.card.cardRadius
}, completion: { _ in
detailVC.layout(self.card.originalFrame, isPresenting: false, isAnimating: false)
self.card.addSubview(detailVC.card.backgroundIV)
transitionContext.completeTransition(true)
})
// Layout with bounce effect
UIView.animate(withDuration: velocity/2, delay: 0, options: .curveEaseOut, animations: {
detailVC.layout(self.card.originalFrame, isPresenting: false, transform: bounce)
self.card.delegate?.cardIsHidingDetail?(card: self.card)
}) { _ in UIView.animate(withDuration: self.velocity/2, delay: 0, options: .curveEaseOut, animations: {
detailVC.layout(self.card.originalFrame, isPresenting: false)
self.card.delegate?.cardIsHidingDetail?(card: self.card)
})
}
return
}
// Detail View Controller Present Animations
card.isPresenting = true
let detailVC = to as! DetailViewController
let bounce = self.bounceTransform(card.originalFrame, to: card.backgroundIV.frame)
container.bringSubview(toFront: detailVC.view)
detailVC.card = card
detailVC.layout(card.originalFrame, isPresenting: false)
// Blur and fade with completion
UIView.animate(withDuration: velocity/2, delay: 0, options: .curveEaseOut, animations: {
detailVC.blurView.alpha = 1
}, completion: nil)
UIView.animate(withDuration: velocity, delay: 0, options: .curveEaseOut, animations: {
self.card.transform = CGAffineTransform.identity // Reset card identity after push back on tap
detailVC.snap.alpha = 1
self.card.backgroundIV.layer.cornerRadius = 0
}, completion: { _ in
detailVC.layout(self.card.originalFrame, isPresenting: true, isAnimating: false, transform: .identity)
transitionContext.completeTransition(true)
})
// Layout with bounce effect
UIView.animate(withDuration: velocity/2, delay: 0, options: .curveEaseOut, animations: {
detailVC.layout(detailVC.view.frame, isPresenting: true, transform: bounce)
self.card.delegate?.cardIsShowingDetail?(card: self.card)
}) { _ in UIView.animate(withDuration: self.velocity/2, delay: 0, options: .curveEaseOut, animations: {
detailVC.layout(detailVC.view.frame, isPresenting: true)
self.card.delegate?.cardIsShowingDetail?(card: self.card)
})
}
}
private func bounceTransform(_ from: CGRect, to: CGRect ) -> CGAffineTransform {
let old = from.center
let new = to.center
let xDistance = old.x - new.x
let yDistance = old.y - new.y
let xMove = -( xDistance * bounceIntensity )
let yMove = -( yDistance * bounceIntensity )
return CGAffineTransform(translationX: xMove, y: yMove)
}
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return velocity
}
}
I haven't worked with transitioning in iOS and hope someone can tell me how to achieve what I want here.
