UICollectionViewFlowLayout that aligns all the UICollectionViewCells to the top-left

UICollectionViewLeftAlignmentFlowLayout.swift

//
//  UICollectionViewLeftAlignmentFlowLayout.swift
//
//  Created by Rigoberto Sáenz Imbacuán (https://www.linkedin.com/in/rsaenzi/)
//  Copyright © 2021. All rights reserved.
//

class UICollectionViewLeftAlignmentFlowLayout: UICollectionViewFlowLayout {

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {

        let allCells = super.layoutAttributesForElements(in: rect)

        // This locator is used to calculate the position of each cell
        var locator = CGPoint.zero

        allCells?.forEach { cell in

            // Determine if the locator should be located in a new row
            if (locator.x + cell.frame.width) > rect.width, cell.indexPath.row > 0 {
                locator.x = 0
                locator.y += cell.frame.height + minimumLineSpacing
            }

            // Cell is positioned where the locator is
            cell.frame.origin = locator

            // Move the locator right next to the previous cell
            locator.x += cell.frame.width + minimumInteritemSpacing
        }

        return allCells
    }
}