Swift: best practices for Custom UICollectionView Layout Overlap guide on iPhone?
I'm currently working on a custom UICollectionView layout for my iOS app, which is built using Swift 5 and targets iOS 15. The layout is intended to display a grid of images, but I'm working with an scenario where the cells overlap each other inconsistently when scrolling. I suspect this might be due to my implementation of the `layoutAttributesForElements(in:)` method. Here's a simplified version of my layout class: ```swift class CustomGridLayout: UICollectionViewLayout { private var cache: [UICollectionViewLayoutAttributes] = [] private var contentHeight: CGFloat = 0 override func prepare() { guard let collectionView = collectionView else { return } cache.removeAll() contentHeight = 0 let itemWidth = collectionView.bounds.width / 2 let itemHeight: CGFloat = 100 for item in 0..<collectionView.numberOfItems(inSection: 0) { let indexPath = IndexPath(item: item, section: 0) let frame = CGRect(x: CGFloat(item % 2) * itemWidth, y: contentHeight, width: itemWidth, height: itemHeight) let attributes = UICollectionViewLayoutAttributes(forCellWith: indexPath) attributes.frame = frame cache.append(attributes) contentHeight += itemHeight } } override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? { return cache.filter { $0.frame.intersects(rect) } } override var collectionViewContentSize: CGSize { return CGSize(width: collectionView?.bounds.width ?? 0, height: contentHeight) } } ``` I have tried adjusting the `contentHeight` in the `prepare()` method and ensuring that the layout attributes are correctly calculated based on their position, but the scenario continues. When I scroll, I often see cells overlapping instead of being laid out properly in the grid format. Additionally, I noticed that the scenario is more pronounced on iPhone SE (2020) compared to larger devices. I've also checked that I am calling `invalidateLayout()` when the collection view's data source changes, but that doesn't seem to help as well. The debug output doesn't show any important errors, just the overlapping behavior. Is there something I might be missing in terms of layout invalidation or caching? Any insights into best practices for managing custom layouts in UICollectionView would be greatly appreciated! I'm using Swift 3.9 in this project. Any ideas how to fix this?