IGListKit/Examples/Examples-iOS/IGListKitExamples/ViewControllers/SingleSectionViewController.swift

/**
 Copyright (c) Facebook, Inc. and its affiliates.
 
 The examples provided by Facebook are for non-commercial testing and evaluation
 purposes only. Facebook reserves all rights not expressly granted.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

import IGListKit
import UIKit

final class SingleSectionViewController: UIViewController, ListAdapterDataSource, ListSingleSectionControllerDelegate {

    lazy var adapter: ListAdapter = {
        return ListAdapter(updater: ListAdapterUpdater(), viewController: self)
    }()

    let collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())

    let data = Array(0..<20)

    // MARK: - Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()

        view.addSubview(collectionView)
        adapter.collectionView = collectionView
        adapter.dataSource = self
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        collectionView.frame = view.bounds
    }

    // MARK: - ListAdapterDataSource

    func objects(for listAdapter: ListAdapter) -> [ListDiffable] {
        return data as [ListDiffable]
    }

    func listAdapter(_ listAdapter: ListAdapter, sectionControllerFor object: Any) -> ListSectionController {
        let configureBlock = { (item: Any, cell: UICollectionViewCell) in
            guard let cell = cell as? NibCell, let number = item as? Int else { return }
            cell.text = "Cell: \(number + 1)"
        }

        let sizeBlock = { (item: Any, context: ListCollectionContext?) -> CGSize in
            guard let context = context else { return CGSize() }
            return CGSize(width: context.containerSize.width, height: 44)
        }
        let sectionController = ListSingleSectionController(nibName: NibCell.nibName,
                                                            bundle: nil,
                                                            configureBlock: configureBlock,
                                                            sizeBlock: sizeBlock)
        sectionController.selectionDelegate = self

        return sectionController
    }

    func emptyView(for listAdapter: ListAdapter) -> UIView? { return nil }

    // MARK: - ListSingleSectionControllerDelegate

    func didSelect(_ sectionController: ListSingleSectionController, with object: Any) {
        let section = adapter.section(for: sectionController) + 1
        let alert = UIAlertController(
            title: "Section \(section) was selected \u{1F389}",
            message: "Cell Object: " + String(describing: object),
            preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "Dismiss", style: .default, handler: nil))
        present(alert, animated: true, completion: nil)
    }

}