MyCollectionViewController #3

MyCollectionViewController3.swift

import UIKit

protocol CellController {
    func getCell(collectionView: UICollectionView, indexPath: IndexPath) -> UICollectionViewCell
}

struct TextItemModel {
    let title: String
}

struct ImageItemModel {
    let image: UIImage
}

struct TextCellController: CellController {
    var model: TextItemModel
    func getCell(collectionView: UICollectionView, indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "text", for: indexPath)
        cell.largeContentTitle = model.title
        return cell
    }
}

struct ImageCellController: CellController {
    var model: ImageItemModel
    func getCell(collectionView: UICollectionView, indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "text", for: indexPath)
        cell.largeContentImage = model.image
        return cell
    }
}


/// First set `model` and then present on screen.
final class MyCollectionViewController: UICollectionViewController {
    var cellControllers: [CellController]?
    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cellController = cellControllers?[indexPath.row]
        let cell = cellController?.getCell(collectionView: collectionView, indexPath: indexPath) ?? UICollectionViewCell()
        return cell
    }
}

func createMyCollectionViewController() -> MyCollectionViewController {
    let collectionViewController = MyCollectionViewController()
    let cellControllers: [CellController] = [
        ImageCellController(model: .init(image: UIImage(named: "what")!)),
        TextCellController(model: .init(title: "Text"))
    ]
    collectionViewController.cellControllers = cellControllers
    return collectionViewController
}