How to synchronize cells animation - ios

Question

I'm trying to simulate a shimmering animation in each cell of a UICollectionView.
When I start the app it works fine:
But when I scroll to the left each cell gets itself animation:
What I want is when I to scroll it to left, it works like the first image. For a while, I've just put this code below to do the animation:
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
guard let cell = cell as? ShimmeringCell else { return }
UIView.animate(withDuration: 1.0, delay: 0, options: [.autoreverse, .repeat], animations: {
cell.alpha = 0.4
}, completion: nil)
}
This is the full code: Github
Can anyone help me?

Answer 1

I found the answer.
To solve this issue, I had to create a new UIView and add this in a subview of UICollectionView:
let newCollectionView: UICollectionView = {
// Here was creating a collectionView
return collection
}()
let viewExample: UIView = {
// Here was creating a new view
return view
}()
override func viewDidLoad() {
super.viewDidLoad()
newCollectionView.delegate = self
newCollectionView.dataSource = self
newCollectionView.register(ShimmeringCell.self, forCellWithReuseIdentifier: cellId)
self.view.addSubview(self.newCollectionView)
setupCollection()
}
private func setupCollection() {
// Constraints...
self.newCollectionView.addSubview(self.viewExample)
setupViewExample()
}
private func setupViewExample() {
// Constraints...
}
After that, I just put the animation in this view:
override func viewDidLoad() {
super.viewDidLoad()
newCollectionView.delegate = self
newCollectionView.dataSource = self
newCollectionView.register(ShimmeringCell.self, forCellWithReuseIdentifier: cellId)
self.view.addSubview(self.newCollectionView)
setupCollection()
self.viewExample.alpha = 0.6
UIView.animate(withDuration: 1.0, delay: 0, options: [.repeat, .autoreverse, .allowUserInteraction], animations: {
self.viewExample.alpha = 0
}, completion: nil)
}
It's resulted:
Thanks for all and see you somewhere on the world.
Github with this solution: Github