ChatCollectionView

ChatCollectionView.swift

class ChatViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        collectionView.transform = CGAffineTransform.reversed
        // .........
    }
    
}

class ChatCollectionViewCell: UICollectionViewCell {
    
    override func apply(_ layoutAttributes: UICollectionViewLayoutAttributes) {
        super.apply(layoutAttributes)
        guard transform.isIdentity else { return }
        UIView.performWithoutAnimation { transform = CGAffineTransform.reversed }
    }
    
}

extension CGAffineTransform {
    static let reversed = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: 0)
}