TIL80 ✨

🗓️23.08.11

compositional layout decoration Item

https://nemecek.be/blog/71/using-background-decoration-views-with-compositional-layout

URLProtocol

URLProtocol을 사용하면
mockURLProtocol 오브젝트를 만들면됨
테스트를 위해서 본코드를 바꾸면 안됨

DateFormatter

인스턴스 생성 제한
무거운 작업

서브스크립트

https://limjs-dev.tistory.com/105

Delegate

protocol ModelDelegate: class {
    
}

class Model {
    weak var delegate: ModelDelegate?
        deinit {
        print("deinit Model")
    }
}

class ViewController: ModelDelegate {
    var model: Model?
    func start() {
 
        model = Model()
        model?.delegate = self
    }
    deinit {
        print("deinit ViewController")
    }
}

var v: ViewController? = ViewController()
v?.start()
v = nil

decorationItem 예시코드

// MARK: setup Components
extension BoxOfficeViewController {
    
    // ...
    
    private func setupCollectionView() {
        let layout = verticalLayout()
        // BackgroundDecorationView 등록, collectionView가 아닌 layout에 등록
        layout.register(BackgroundDecorationView.self, forDecorationViewOfKind: "background")
        collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
        collectionView.translatesAutoresizingMaskIntoConstraints = false
        collectionView.register(BoxOfficeCollectionViewCell.self, forCellWithReuseIdentifier: BoxOfficeCollectionViewCell.identifier)
        collectionView.delegate = self
    }
    
    private func setupRefreshControl() {
        let refreshControl = UIRefreshControl()
        refreshControl.addTarget(self, action: #selector(fetchBoxOfficeData), for: .valueChanged)
        
        collectionView.refreshControl = refreshControl
    }
}

// MARK: CollectionView Layout
extension BoxOfficeViewController {
    private func verticalLayout() -> UICollectionViewCompositionalLayout {
        let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0), heightDimension: .fractionalHeight(0.1))
        let item = NSCollectionLayoutItem(layoutSize: itemSize)
        item.contentInsets = NSDirectionalEdgeInsets(top: 1, leading: 0, bottom: 0, trailing: 0)
        let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0), heightDimension: .fractionalHeight(1.2))
        let group = NSCollectionLayoutGroup.vertical(layoutSize: groupSize, subitems: [item])
        let section = NSCollectionLayoutSection(group: group)
        // orthogonalScrollingBehavior 세팅 특정 섹션 가로 스크롤
        section.orthogonalScrollingBehavior = .continuous
        // visibleItemsInvalidationHandler 클로져 블럭 구현, 아이템이 보이기 직전 아이템 설정
        section.visibleItemsInvalidationHandler = { [weak self] (visibleItems, offset, env) in
            guard let self = self else { return }
            visibleItems.forEach({ item in
                guard let cell = self.collectionView.cellForItem(at: item.indexPath) else { return }
                UIView.animate(withDuration: 0.3) {
                    cell.backgroundColor = .systemBackground
                }
            })
        }
        // decorationItems 설정, 섹션의 백그라운드 설정
        let backgroundItem = NSCollectionLayoutDecorationItem.background(elementKind: "background")
        section.decorationItems = [backgroundItem]
        
        return UICollectionViewCompositionalLayout(section: section)
    }
}

// 섹션에 넣을 UICollectionReusableView 구현
class BackgroundDecorationView: UICollectionReusableView {
    override init(frame: CGRect) {
        super.init(frame: frame)
        // Configure your decoration view's appearance here
        self.backgroundColor = .systemFill
//        self.layer.cornerRadius = 12
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}