Я переписал его в UIViewControllerRepresentable, и теперь он работает нормально
struct CollectionView<Section: Hashable & CaseIterable, Item: Hashable>: UIViewControllerRepresentable {
// MARK: - Properties
let layout: UICollectionViewLayout
let sections: [Section]
let items: [Section: [Item]]
// MARK: - Actions
let snapshot: (() -> NSDiffableDataSourceSnapshot<Section, Item>)?
let content: (_ indexPath: IndexPath, _ item: Item) -> AnyView
// MARK: - Init
init(layout: UICollectionViewLayout,
sections: [Section],
items: [Section: [Item]],
snapshot: (() -> NSDiffableDataSourceSnapshot<Section, Item>)? = nil,
@ViewBuilder content: @escaping (_ indexPath: IndexPath, _ item: Item) -> AnyView) {
self.layout = layout
self.sections = sections
self.items = items
self.snapshot = snapshot
self.content = content
}
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIViewController(context: Context) -> CollectionViewController<Section, Item> {
let controller = CollectionViewController<Section, Item>()
controller.layout = self.layout
controller.snapshotForCurrentState = {
if let snapshot = self.snapshot {
return snapshot()
}
var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
snapshot.appendSections(self.sections)
self.sections.forEach { section in
snapshot.appendItems(self.items[section]!, toSection: section)
}
return snapshot
}
controller.content = content
controller.collectionView.delegate = context.coordinator
return controller
}
func updateUIViewController(_ uiViewController: CollectionViewController<Section, Item>, context: Context) {
uiViewController.updateUI()
}
class Coordinator: NSObject, UICollectionViewDelegate {
// MARK: - Properties
let parent: CollectionView
// MARK: - Init
init(_ parent: CollectionView) {
self.parent = parent
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Did select item at \(indexPath)")
}
}
}
struct CollectionView_Previews: PreviewProvider {
enum Section: CaseIterable {
case features
case categories
}
enum Item: Hashable {
case feature(feature: Feature)
case category(category: Category)
}
class Feature: Hashable{
let id: String
let title: String
init(id: String, title: String) {
self.id = id
self.title = title
}
func hash(into hasher: inout Hasher) {
hasher.combine(self.id)
}
static func ==(lhs: Feature, rhs: Feature) -> Bool {
lhs.id == rhs.id
}
}
class Category: Hashable {
let id: String
let title: String
init(id: String, title: String) {
self.id = id
self.title = title
}
func hash(into hasher: inout Hasher) {
hasher.combine(self.id)
}
static func ==(lhs: Category, rhs: Category) -> Bool {
lhs.id == rhs.id
}
}
static let items: [Section: [Item]] = {
return [
.features : [
.feature(feature: Feature(id: "1", title: "Feature 1")),
.feature(feature: Feature(id: "2", title: "Feature 2")),
.feature(feature: Feature(id: "3", title: "Feature 3"))
],
.categories : [
.category(category: Category(id: "1", title: "Category 1")),
.category(category: Category(id: "2", title: "Category 2")),
.category(category: Category(id: "3", title: "Category 3"))
]
]
}()
static var previews: some View {
func generateLayout() -> UICollectionViewLayout {
let itemHeightDimension = NSCollectionLayoutDimension.absolute(44)
let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(0.5), heightDimension: itemHeightDimension)
let item = NSCollectionLayoutItem(layoutSize: itemSize)
let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(0.5), heightDimension: itemHeightDimension)
let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitem: item, count: 2)
let section = NSCollectionLayoutSection(group: group)
section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 0, bottom: 0, trailing: 0)
let layout = UICollectionViewCompositionalLayout(section: section)
return layout
}
return CollectionView(layout: generateLayout(), sections: [.features], items: items, snapshot: {
var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
snapshot.appendSections(Section.allCases)
items.forEach { (section, items) in
snapshot.appendItems(items, toSection: section)
}
return snapshot
}) { (indexPath, item) -> AnyView in
switch item {
case .feature(let item):
return AnyView(Text("Feature \(item.title)"))
case .category(let item):
return AnyView(Text("Category \(item.title)"))
}
}
}
}
class CollectionViewController<Section, Item>: UIViewController
where Section : Hashable & CaseIterable, Item : Hashable {
var layout: UICollectionViewLayout! = nil
var snapshotForCurrentState: (() -> NSDiffableDataSourceSnapshot<Section, Item>)! = nil
var content: ((_ indexPath: IndexPath, _ item: Item) -> AnyView)! = nil
lazy var dataSource: UICollectionViewDiffableDataSource<Section, Item> = {
let dataSource = UICollectionViewDiffableDataSource<Section, Item>(collectionView: collectionView, cellProvider: cellProvider)
return dataSource
}()
lazy var collectionView: UICollectionView = {
let collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: layout)
collectionView.autoresizingMask = [.flexibleHeight, .flexibleWidth]
collectionView.backgroundColor = .clear
return collectionView
}()
override func viewDidLoad() {
super.viewDidLoad()
configureCollectionView()
configureDataSource()
}
}
extension CollectionViewController {
private func configureCollectionView() {
view.addSubview(collectionView)
collectionView.register(HostingControllerCollectionViewCell<AnyView>.self, forCellWithReuseIdentifier: HostingControllerCollectionViewCell<AnyView>.reuseIdentifier)
}
private func configureDataSource() {
// load initial data
let snapshot : NSDiffableDataSourceSnapshot<Section, Item> = snapshotForCurrentState()
dataSource.apply(snapshot, animatingDifferences: false)
}
private func cellProvider(collectionView: UICollectionView, indexPath: IndexPath, item: Item) -> UICollectionViewCell? {
print("Providing cell for \(indexPath)")
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: HostingControllerCollectionViewCell<AnyView>.reuseIdentifier, for: indexPath) as? HostingControllerCollectionViewCell<AnyView> else {
fatalError("Coult not load cell!")
}
cell.host(content(indexPath, item))
return cell
}
}
extension CollectionViewController {
func updateUI() {
let snapshot : NSDiffableDataSourceSnapshot<Section, Item> = snapshotForCurrentState()
dataSource.apply(snapshot, animatingDifferences: true)
}
}