When I simulate an app on an iOS device, the app gets installed, and is available for later use. When I do so on the mac and interrupt the simulation, I can still find the app afterwards, but, if I click on it, I get an alert that says that the app is not supported. My app's supported destinations are iPhone, iPad and Mac (designed for iPad). How do I install an Xcode app on a mac with an apple silicon chip?

Xcode's test scheme "info", "arguments", "options" and "diagnostics" tabs were once visible by pressing Command + Option + U, but they've been moved. Where do I find the corresponding sections, now? Here's the old UI (credit: https://betterprogramming.pub/easy-unit-testing-for-firebase-in-xcode-874842f79d84): Here is the new one:

Each time I run an app, which usually takes some 10 seconds, I normally go on working on it, but then I'm jumped to the simulator once the app has launched, which is especially annoying when I'm on full screen. Is there a way to stay on Xcode, instead?

In the following code, test 1 (test_postNotification) fails while test 2 (test_notificationsArePostedOnTheMainQueue) passes. What concerns me, though, is that if I substitute the lines "let result = XCTWaiter.wait(for: [expectation], timeout: 0); XCTAssertEqual(result, .timedOut)" of test 2 with "wait(for: [expectation], timeout: 0.1)", then test number 1 passes. I have cleaned the build folder and restarted Xcode and my computer, but the issue persists. This concerns me because I would have said that the tests of the NotificationPosterTests class were isolated, but apparently they are not, since changing test 2 makes test 1 go from failing to passing. Is this expected behavior? import Foundation import XCTest extension Notification.Name { static let menuPostRequest = Notification.Name("menuPostRequest") static let editingOrderError = Notification.Name("editingOrderError") } class NotificationPoster { let notificationCenter: NotificationCenter init(notificationCenter: NotificationCenter = .default) { self.notificationCenter = notificationCenter } func postNotification(_ notification: Notification) { let _notificationCenter = notificationCenter // you can't use optional chaining nor conditional unwrapping on self to reference self.notificationCenter in the dispatch block because self is nil when self.postNotification(_:) is called DispatchQueue.main.async { _notificationCenter.post(notification) } } } final class NotificationPosterTests: XCTestCase { private var sut: NotificationPoster! private var notificationCenter: NotificationCenter! override func setUp() { super.setUp() notificationCenter = NotificationCenter() sut = NotificationPoster(notificationCenter: notificationCenter) } override func tearDown() { notificationCenter = nil sut = nil super.tearDown() } func test_postNotification() { let notification = Notification(name: .menuPostRequest) let expectation = XCTNSNotificationExpectation( name: notification.name, object: notification.object, notificationCenter: notificationCenter ) sut.postNotification(notification) wait(for: [expectation], timeout: 0.1) // don't make it 0.01 } func test_notificationsArePostedOnTheMainQueue() { let notification = Notification(name: .editingOrderError) let expectation = XCTNSNotificationExpectation( name: notification.name, object: notification.object, notificationCenter: notificationCenter ) sut.postNotification(notification) let result = XCTWaiter.wait(for: [expectation], timeout: 0) XCTAssertEqual(result, .timedOut) } }

Hello, I am a UIKit developer and I would like to try out SwiftUI. Unfortunately, my previews don't load. My situation is like the one described in this blog post: https://forums.developer.apple.com/forums/thread/704036. Unfortunately I can't update Xcode like that developer did. What I've tried: quitting and restarting Xcode, restarting my computer, resetting the simulator, deleting the derived data folder, creating new projects without storage options, test bundles or source control, editing the content view of the initial Hello World file. To be clear, I've just started learning about SwiftUI, just yesterday evening, and the previews have never loaded. Is the problem solvable? If so, how?

For instance, executing the following code, in which a stepper is injected in a table view cell and the cell is reloaded when the user changes the stepper's value, causes the memory usage to grow pretty quickly (I stopped the simulation at 1GB) when you tap on the stepper. Also the CPU usage jumps straight at 99%, and the UI freezes. Note: I'd like to know exactly what I asked, not how to make a table view cell with a stepper in general. I know that calling reloadData() or reconfigureRows(at:) doesn't cause any of the mentioned issues. Also please don't reply with questions like "Have you tried to use weak references?". The code is short: please reply with a working solution if you can. class ViewController: UIViewController { let tableView = UITableView() let stepper = UIStepper() override func viewDidLoad() { super.viewDidLoad() view.addSubview(tableView) tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell") tableView.dataSource = self stepper.addTarget(self, action: #selector(stepperValueChanged), for: .valueChanged) } override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews() tableView.frame = view.bounds } @objc private func stepperValueChanged() { tableView.reloadRows(at: [IndexPath(row: 0, section: 0)], with: .automatic) } } extension ViewController: UITableViewDataSource { func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 1 } func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) cell.accessoryView = stepper var configuration = cell.defaultContentConfiguration() configuration.text = "\(stepper.value)" cell.contentConfiguration = configuration return cell } }

The following is a UIKit app that uses a collection view with list layout and a diffable data source. It displays one section that has 10 empty cells and then final cell whose content view contains a text view, that is pinned to the content view's layout margins guide. The text view's scrolling is set to false, so that the line collectionView.selfSizingInvalidation = .enabledIncludingConstraints will succeed at making the text view's cell resize automatically and animatedly as the text changes. import UIKit class ViewController: UIViewController { var collectionView: UICollectionView! var dataSource: UICollectionViewDiffableDataSource<String, Int>! let textView: UITextView = { let tv = UITextView() tv.text = "Text" tv.isScrollEnabled = false return tv }() override func viewDidLoad() { super.viewDidLoad() configureHierarchy() configureDataSource() if #available(iOS 16.0, *) { collectionView.selfSizingInvalidation = .enabledIncludingConstraints } } func configureHierarchy() { collectionView = .init(frame: .zero, collectionViewLayout: createLayout()) view.addSubview(collectionView) collectionView.frame = view.bounds collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight] } func createLayout() -> UICollectionViewLayout { let configuration = UICollectionLayoutListConfiguration(appearance: .insetGrouped) return UICollectionViewCompositionalLayout.list(using: configuration) } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, Int> { _, _, _ in } let textViewCellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, Int> { [weak self] cell, _, _ in guard let self else { return } cell.contentView.addSubview(textView) textView.pin(to: cell.contentView.layoutMarginsGuide) } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in if indexPath.row == 10 { collectionView.dequeueConfiguredReusableCell(using: textViewCellRegistration, for: indexPath, item: itemIdentifier) } else { collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } } var snapshot = NSDiffableDataSourceSnapshot<String, Int>() snapshot.appendSections(["section"]) snapshot.appendItems(Array(0...10)) dataSource.apply(snapshot) } } extension UIView { func pin( to object: CanBePinnedTo, top: CGFloat = 0, bottom: CGFloat = 0, leading: CGFloat = 0, trailing: CGFloat = 0 ) { self.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ self.topAnchor.constraint(equalTo: object.topAnchor, constant: top), self.bottomAnchor.constraint(equalTo: object.bottomAnchor, constant: bottom), self.leadingAnchor.constraint(equalTo: object.leadingAnchor, constant: leading), self.trailingAnchor.constraint(equalTo: object.trailingAnchor, constant: trailing), ]) } } @MainActor protocol CanBePinnedTo { var topAnchor: NSLayoutYAxisAnchor { get } var bottomAnchor: NSLayoutYAxisAnchor { get } var leadingAnchor: NSLayoutXAxisAnchor { get } var trailingAnchor: NSLayoutXAxisAnchor { get } } extension UIView: CanBePinnedTo { } extension UILayoutGuide: CanBePinnedTo { } How do I make the UI move to accomodate the keyboard once you tap on the text view and also when the text view changes size, by activating the view.keyboardLayoutGuide.topAnchor constraint, as shown in the WWDC21 video "Your guide to keyboard layout"? My code does not resize the text view on iOS 15, only on iOS 16+, so clearly the solution may allow the UI to adjust to text view changes on iOS 16+ only. Recommended, modern, approach: Not recommended, old, approach: I've tried to say view.keyboardLayoutGuide.topAnchor.constraint(equalTo: textView.bottomAnchor).isActive = true in the text view cell registration, as well as view.keyboardLayoutGuide.topAnchor.constraint(equalTo: collectionView.bottomAnchor).isActive = true in viewDidLoad(), but both of these approaches fail (Xcode 15.3 iPhone 15 Pro simulator with iOS 17.4, physical iPhone SE on iOS 15.8).

The following is a UIKit app with a collection view with one section, whose supplementary view sports a search bar. When you type, it often resigns first responder. import UIKit class ViewController: UIViewController { let words = ["foo", "bar"] var filteredWords = ["foo", "bar"] { didSet { dataSource.apply(self.snapshot) } } var collectionView: UICollectionView! var dataSource: UICollectionViewDiffableDataSource<String, String>! var snapshot: NSDiffableDataSourceSnapshot<String, String> { var snapshot = NSDiffableDataSourceSnapshot<String, String>() snapshot.appendSections(["main"]) snapshot.appendItems(filteredWords) return snapshot } override func viewDidLoad() { super.viewDidLoad() navigationItem.rightBarButtonItem = .init(title: "Apply", style: .plain, target: self, action: #selector(apply)) configureHierarchy() configureDataSource() } @objc func apply() { dataSource.apply(self.snapshot) } func configureHierarchy() { collectionView = .init(frame: .zero, collectionViewLayout: createLayout()) view.addSubview(collectionView) collectionView.frame = view.bounds collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight] } func createLayout() -> UICollectionViewLayout { UICollectionViewCompositionalLayout { section, layoutEnvironment in var config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) config.headerMode = .supplementary return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { _, _, _ in } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } let searchbarHeaderRegistration = UICollectionView.SupplementaryRegistration<SearchBarCell>(elementKind: UICollectionView.elementKindSectionHeader) { cell, elementKind, indexPath in cell.searchBar.delegate = self } dataSource.supplementaryViewProvider = { collectionView, kind, indexPath in collectionView.dequeueConfiguredReusableSupplementary(using: searchbarHeaderRegistration, for: indexPath) } dataSource.apply(self.snapshot, animatingDifferences: false) } } extension ViewController: UISearchBarDelegate { func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) { DispatchQueue.main.async { [weak self] in guard let self else { return } filteredWords = words.filter { $0.hasPrefix(searchText) } } } func searchBarTextDidEndEditing(_ searchBar: UISearchBar) { DispatchQueue.main.async { [weak self] in guard let self else { return } filteredWords = words } } } class SearchBarCell: UICollectionViewListCell { let searchBar = UISearchBar() override init(frame: CGRect) { super.init(frame: frame) contentView.addSubview(searchBar) searchBar.pinToSuperview() } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } } extension UIView { func pin( to object: CanBePinnedTo, top: CGFloat = 0, bottom: CGFloat = 0, leading: CGFloat = 0, trailing: CGFloat = 0 ) { self.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ self.topAnchor.constraint(equalTo: object.topAnchor, constant: top), self.bottomAnchor.constraint(equalTo: object.bottomAnchor, constant: bottom), self.leadingAnchor.constraint(equalTo: object.leadingAnchor, constant: leading), self.trailingAnchor.constraint(equalTo: object.trailingAnchor, constant: trailing), ]) } func pinToSuperview( top: CGFloat = 0, bottom: CGFloat = 0, leading: CGFloat = 0, trailing: CGFloat = 0, file: StaticString = #file, line: UInt = #line ) { guard let superview = self.superview else { print(">> \(#function) failed in file: \(String.localFilePath(from: file)), at line: \(line): could not find \(Self.self).superView.") return } self.pin(to: superview, top: top, bottom: bottom, leading: leading, trailing: trailing) } func pinToSuperview(constant c: CGFloat = 0, file: StaticString = #file, line: UInt = #line) { self.pinToSuperview(top: c, bottom: -c, leading: c, trailing: -c, file: file, line: line) } } @MainActor protocol CanBePinnedTo { var topAnchor: NSLayoutYAxisAnchor { get } var bottomAnchor: NSLayoutYAxisAnchor { get } var leadingAnchor: NSLayoutXAxisAnchor { get } var trailingAnchor: NSLayoutXAxisAnchor { get } } extension UIView: CanBePinnedTo { } extension UILayoutGuide: CanBePinnedTo { } extension String { static func localFilePath(from fullFilePath: StaticString = #file) -> Self { URL(fileURLWithPath: "\(fullFilePath)").lastPathComponent } } By the way if you remove the dispatch blocks, the app simply crashes complaining that you're trying to apply datasource snapshots from both the main queue and other queues. Xcode 15.3 iOS 17.4 simulator, MacBook Air M1 8GB macOS Sonoma 14.4.1

Please run the following UIKit app. It uses a collection view with compositional layout (list layout) and a diffable data source. It has one section with one row. The cell has an image view as a leading accessory. Unfortunately, as soon as I set an image for the image view, the accessory is no longer centered: import UIKit class ViewController: UIViewController { var collectionView: UICollectionView! var dataSource: UICollectionViewDiffableDataSource<String, String>! override func viewDidLoad() { super.viewDidLoad() configureHierarchy() configureDataSource() } func configureHierarchy() { collectionView = .init(frame: .zero, collectionViewLayout: createLayout()) view.addSubview(collectionView) collectionView.frame = view.bounds } func createLayout() -> UICollectionViewLayout { UICollectionViewCompositionalLayout { section, layoutEnvironment in let config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in let iv = UIImageView() iv.backgroundColor = .systemRed // iv.image = .init(systemName: "camera") iv.contentMode = .scaleAspectFit iv.frame.size = .init( width: 40, height: 40 ) cell.accessories = [.customView(configuration: .init( customView: iv, placement: .leading(), reservedLayoutWidth: .actual, maintainsFixedSize: true ))] } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } var snapshot = NSDiffableDataSourceSnapshot<String, String>() snapshot.appendSections(["main"]) snapshot.appendItems(["demo"]) dataSource.apply(snapshot, animatingDifferences: false) } } This seems like a bug but then if I set the image view's size to 100x100, even without giving it an image, the cell doesn't resize, which makes me think I'm making a mistake.

Apple's documentation pretty much only says this about ObservableObject: "A type of object with a publisher that emits before the object has changed. By default an ObservableObject synthesizes an objectWillChange publisher that emits the changed value before any of its @Published properties changes.". And this sample seems to behave the same way, with or without conformance to the protocol by Contact: import UIKit import Combine class ViewController: UIViewController { let john = Contact(name: "John Appleseed", age: 24) private var cancellables: Set<AnyCancellable> = [] override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. john.$age.sink { age in print("View controller's john's age is now \(age)") } .store(in: &cancellables) print(john.haveBirthday()) } } class Contact { @Published var name: String @Published var age: Int init(name: String, age: Int) { self.name = name self.age = age } func haveBirthday() -> Int { age += 1 return age } } Can I therefore omit conformance to ObservableObject every time I don't need the objectWillChange publisher?

The following is a UIKit app that displays a collection view with list layout and diffable data source (one section, one row). class ViewController: UIViewController { var collectionView: UICollectionView! var dataSource: UICollectionViewDiffableDataSource<String, String>! override func viewDidLoad() { super.viewDidLoad() configureHierarchy() configureDataSource() } func configureHierarchy() { collectionView = .init(frame: .zero, collectionViewLayout: createLayout()) view.addSubview(collectionView) collectionView.frame = view.bounds collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight] } func createLayout() -> UICollectionViewLayout { UICollectionViewCompositionalLayout { section, layoutEnvironment in let config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in var backgroundConfiguration = UIBackgroundConfiguration.listGroupedCell() backgroundConfiguration.backgroundColor = .systemBlue cell.backgroundConfiguration = backgroundConfiguration } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } var snapshot = NSDiffableDataSourceSnapshot<String, String>() snapshot.appendSections(["main"]) snapshot.appendItems(["demo"]) dataSource.apply(snapshot, animatingDifferences: false) } } If you tap on the row, it seems like selection doesn't happen: giving the cell a blue background broke its default background color transformer. Here's what I've tried and didn't work: Setting the collection view's delegate and specifying that you can select any row Setting the color transformer to .grayscale Setting the backgroundConfiguration to UIBackgroundConfiguration.listGroupedCell().updated(for: cell.configurationState) Combinations of the approaches above Setting the color transformer to UIBackgroundConfiguration.listGroupedCell().backgroundColorTransformer and cell.backgroundConfiguration?.backgroundColorTransformer (they're both nil) Setting the cell's backgroundColor directly I also considered using a custom color transformer: var backgroundConfiguration = UIBackgroundConfiguration.listGroupedCell() backgroundConfiguration.backgroundColorTransformer = UIConfigurationColorTransformer { _ in if cell.configurationState.isSelected || cell.configurationState.isHighlighted { .systemBlue.withAlphaComponent(0.7) } else { .systemBlue } } cell.backgroundConfiguration = backgroundConfiguration However, if you push a view controller when you select the row, the row gets deselected, which is unfortunate, giving that I like to deselect rows in viewWillAppear(_:) to keep users more oriented. There might be ways to circumvent this, but my custom color transformer might still differ from the default one in some other ways. So how do I assign the default one to my cell?

Code that reproduces the issue import SwiftUI @main struct KeyboardLayoutProblemApp: App { var body: some Scene { WindowGroup { iOSTabView() } } } struct iOSTabView: View { var body: some View { TabView { GameView() .frame(maxWidth: UIScreen.main.bounds.width, maxHeight: UIScreen.main.bounds.height) .tabItem { Label("Play", systemImage: "gamecontroller.fill") } } } } struct GameView: View { var body: some View { VStack { Text("Play") Spacer() KeyboardView() } .padding() } } struct KeyboardView: View { let firstRowLetters = "qwertyuiop".map { $0 } let secondRowLetters = "asdfghjkl".map { $0 } let thirdRowLetters = "zxcvbnm".map { $0 } var body: some View { VStack { HStack { ForEach(firstRowLetters, id: \.self) { LetterKeyView(character: $0) } } HStack { ForEach(secondRowLetters, id: \.self) { LetterKeyView(character: $0) } } HStack { ForEach(thirdRowLetters, id: \.self) { LetterKeyView(character: $0) } } } .padding() } } struct LetterKeyView: View { let character: Character var width: CGFloat { height*0.8 } @ScaledMetric(relativeTo: .title3) private var height = 35 var body: some View { Button { print("\(character) pressed") } label: { Text(String(character).capitalized) .font(.title3) .frame(width: self.width, height: self.height) .background { RoundedRectangle(cornerRadius: min(width, height)/4, style: .continuous) .stroke(.gray) } } .buttonStyle(PlainButtonStyle()) } } Problem GameView doesn't fit its parent view: Question How do I make GameView be at most as big as its parent view? What I've tried and didn't work GameView() .frame(maxWidth: .infinity, maxHeight: .infinity) GeometryReader { geometry in GameView() .frame(maxWidth: geometry.size.width, maxHeight: geometry.size.height) } GameView() .clipped() GameView() .layoutPriority(1) GameView() .scaledToFit() GameView() .minimumScaleFactor(0.01) GameView() .scaledToFill() .minimumScaleFactor(0.5) I'm not using UIScreen.main.bounds.width because I'm trying to build a multi-platform app.

The location of my derived data folder differs between Xcode and Finder. How do I change Xcode's path to match my Finder path? MacOS Sonoma 14.2.1, MacBook Air M1, 8GB Xcode 15.2

Note: I'd like the solution to work for iOS 15 as well. With the following implementation, tapping on the stepper from iPhone (iOS 15.8 (physical device) as well as iOS 17.2 (simulator and canvas)) presents ModalView, instead of changing the stepper's value as one would expect. It's a somewhat real-life example but still basic, as I felt that having a view with just a stepper would have made the problem unrealistically easy. struct CategoryView: View { @State private var modalIsPresented = false @State private var stepperValue = 0 var body: some View { List { StepperRow(value: self.$stepperValue) .onTapGesture { modalIsPresented = true } } .sheet(isPresented: $modalIsPresented) { modalIsPresented = false } content: { ModalView() } } } struct StepperRow: View { @Binding var value: Int var body: some View { VStack(alignment: .leading) { Stepper( "\(value) Name of the article", value: $value, in: 0...Int.max ) Text("Item description, which could be long and I'd like to go under the stepper.") .font(.caption) } } } What doesn't work: setting the stepper's style to .plain or BorderlessButtonStyle(), as might work for a button. The following code is a working solution, though it's ugly. struct CategoryView: View { @State private var stepperValue = 0 var body: some View { List { StepperRow(value: self.$stepperValue) } } } struct StepperRow: View { @Binding var value: Int @State private var modalIsPresented = false var body: some View { ZStack(alignment: .leading) { VStack(alignment: .leading) { HStack { Text("\(value) Name of the article") Spacer() Stepper( "", value: $value, in: 0...Int.max ) .labelsHidden() .hidden() } Text("Item description, which could be long and I'd like to go under the stepper.") .font(.caption) } .onTapGesture { modalIsPresented = true } VStack(alignment: .leading) { HStack { Text("\(value) Name of the article") .hidden() Spacer() Stepper( "", value: $value, in: 0...Int.max ) .labelsHidden() } Text("Item description, which could be long and I'd like to go under the stepper.") .font(.caption) .hidden() } } .sheet(isPresented: $modalIsPresented) { modalIsPresented = false } content: { ModalView() } } } Basically I've put the stepper above the view to which I've added the onTapGesture recognizer, but to do so I had to duplicate the view code, so that everything laid out correctly, and hide the appropriate subviews, so that VoiceOver would ignore the duplicates, and also because it felt right. Can anyone come up with a better solution?

Steppers overlap with the disclosure indicator if you try to add them to a UICollectionViewListCell using: cell.accessories = [.disclosureIndicator(), .customView(configuration: .init(customView: UIStepper(), placement: .trailing()))]. What's the correct way to add a stepper to the accessories of a cell then? Example that you can run: class GridViewController: UIViewController { enum Section { case main } var dataSource: UICollectionViewDiffableDataSource<Section, Int>! = nil var collectionView: UICollectionView! = nil override func viewDidLoad() { super.viewDidLoad() navigationItem.title = "VC" configureHierarchy() configureDataSource() } } extension GridViewController { private func createLayout() -> UICollectionViewLayout { let config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) return UICollectionViewCompositionalLayout.list(using: config) } } extension GridViewController { private func configureHierarchy() { collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout()) collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight] collectionView.backgroundColor = .black view.addSubview(collectionView) } private func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, Int> { (cell, indexPath, identifier) in cell.accessories = [.disclosureIndicator(), .customView(configuration: .init(customView: UIStepper(), placement: .trailing()))] } dataSource = UICollectionViewDiffableDataSource<Section, Int>(collectionView: collectionView) { (collectionView: UICollectionView, indexPath: IndexPath, identifier: Int) -> UICollectionViewCell? in return collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: identifier) } var snapshot = NSDiffableDataSourceSnapshot<Section, Int>() snapshot.appendSections([.main]) snapshot.appendItems([1]) dataSource.apply(snapshot, animatingDifferences: false) } }