hkAlium - UICollectionView with different cell sizes

What is it?

This lib allows you to set cells with different heights on the same UICollectionView vertical flow. See the picture below:

How it works?

The vertical flow follows a logic presented below determined by the number of specified columns, independent of the cell sizes.

How to import it?

Add the pod 'hkAlium' in your podfile or just copy the UICustomCollectionViewLayout.swift file in your project:

Example:

source 'https://github.com/CocoaPods/Specs.git'

use_frameworks!

target 'sample' do pod 'hkAlium' end

How to setup it?

First, you need to implement a UICollectionView and latter you must set a custom layout as you can see in the image below:

Complete example

If you want to see it running, clone the repo and execute the included sample project. The example is self-explained, you must implement a delegate CustomLayoutDelegate to specify the size of each item. Good luck!

// ViewController.swift
import UIKit
import hkAlium

class ViewController: UICollectionViewController, CustomLayoutDelegate {
    
    public var customCollectionViewLayout: UICustomCollectionViewLayout? {
        get {
            return collectionViewLayout as? UICustomCollectionViewLayout
        }
        set {
            if newValue != nil {
                self.collectionView?.collectionViewLayout = newValue!
            }
        }
    }
    
    struct Model {
        var index: Int
        var isBig: Bool
    }
    
    private let dataSet = [Model(index: 1, isBig: false), Model(index: 2, isBig: false), Model(index: 3, isBig: false),
                           Model(index: 4, isBig: true), Model(index: 5, isBig: false), Model(index: 6, isBig: false),
                           Model(index: 7, isBig: false), Model(index: 8, isBig: false), Model(index: 9, isBig: false),
                           Model(index: 10, isBig: false), Model(index: 11, isBig: false), Model(index: 12, isBig: false)]
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.customCollectionViewLayout?.delegate = self
        self.customCollectionViewLayout?.numberOfColumns = 2
        //self.customCollectionViewLayout?.cellPadding = 30
    }
    
    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return dataSet.count
    }
    
    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "UICustomCollectionViewCell", for: indexPath) as? UICustomCollectionViewCell
        cell?.label.text = "\(dataSet[indexPath.row].index)"
        
        return cell ?? UICollectionViewCell()
    }
    
    func collectionView(_ collectionView: UICollectionView,
                        heightForItemAt
                        indexPath: IndexPath,
                        with width: CGFloat) -> CGFloat {
        
        let heightSizes = [100,216]
        return CGFloat(heightSizes[dataSet[indexPath.row].isBig ? 1 : 0])
    }
}