Please note that for this app to be able show you your location on the map you need to enable it to ask for permission to track the user's location, in the project's targets' info: Here's also a video that illustrates the lag: https://youtube.com/shorts/DSl-umGxs20?feature=share. That being said, if you run this SwiftUI app and allow it to track your location, tap the MapUserLocationButton and press the buttons at the bottom, you'll see that the map lags: import SwiftUI import MapKit import CoreLocation struct ContentView: View { let currentLocationManager = CurrentUserLocationManager() let mapLocationsManager = MapLocationsManager() @State private var mapCameraPosition: MapCameraPosition = .automatic var body: some View { Map( position: $mapCameraPosition ) .safeAreaInset(edge: .bottom) { VStack { if mapLocationsManager.shouldAllowSearches { Button("First button") { mapLocationsManager.shouldAllowSearches = false } } Button("Second button") { mapLocationsManager.shouldAllowSearches = true } } .frame(maxWidth: .infinity) .padding() } .mapControls { MapUserLocationButton() } } } @Observable class MapLocationsManager { var shouldAllowSearches = false } // MARK: - Location related code - class CurrentUserLocationManager: NSObject { var locationManager: CLLocationManager? override init() { super.init() startIfNecessary() } func startIfNecessary() { if locationManager == nil { locationManager = .init() locationManager?.delegate = self } else { print(">> \(Self.self).\(#function): method called redundantly: locationManager had already been initialized") } } }; extension CurrentUserLocationManager: CLLocationManagerDelegate { func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) { checkLocationAuthorization() } }; extension CurrentUserLocationManager { private func checkLocationAuthorization() { guard let locationManager else { return } switch locationManager.authorizationStatus { case .notDetermined: locationManager.requestWhenInUseAuthorization() case .restricted: print("Your location is restricted") case .denied: print("Go into setting to change it") case .authorizedAlways, .authorizedWhenInUse, .authorized: // locationManager.startUpdatingLocation() break @unknown default: break } } } I've also tried in a UIKit app (by just embedding ContentView in a view controller), with the same results: import UIKit import MapKit import SwiftUI import CoreLocation class ViewController: UIViewController { let currentLocationManager = CurrentUserLocationManager() override func viewDidLoad() { super.viewDidLoad() currentLocationManager.startIfNecessary() let hostingController = UIHostingController( rootView: MapView() ) addChild(hostingController) hostingController.view.frame = view.bounds hostingController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight] view.addSubview(hostingController.view) hostingController.didMove(toParent: self) } } extension ViewController { struct MapView: View { let mapLocationsManager = MapLocationsManager() @State private var mapCameraPosition: MapCameraPosition = .automatic var body: some View { Map( position: $mapCameraPosition ) .safeAreaInset(edge: .bottom) { VStack { if mapLocationsManager.shouldAllowSearches { Button("First button") { mapLocationsManager.shouldAllowSearches = false } } Button("Second button") { mapLocationsManager.shouldAllowSearches = true } } .frame(maxWidth: .infinity) .padding() } .mapControls { MapUserLocationButton() } } } } extension ViewController { @Observable class MapLocationsManager { var shouldAllowSearches = false } } class CurrentUserLocationManager: NSObject { var locationManager: CLLocationManager? func startIfNecessary() { if locationManager == nil { locationManager = .init() locationManager?.delegate = self } else { print(">> \(Self.self).\(#function): method called redundantly: locationManager had already been initialized") } } }; extension CurrentUserLocationManager: CLLocationManagerDelegate { func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) { checkLocationAuthorization() } }; extension CurrentUserLocationManager { private func checkLocationAuthorization() { guard let locationManager else { return } switch locationManager.authorizationStatus { case .notDetermined: locationManager.requestWhenInUseAuthorization() case .restricted: print("Your location is restricted") case .denied: print("Go into setting to change it") case .authorizedAlways, .authorizedWhenInUse, .authorized: // locationManager.startUpdatingLocation() break @unknown default: break } } } If you don't center the map in the user's location, you might see an occasiona lag, but it seems to me that this only happens once. How do I avoid these lags altogether? Xcode 15.4

If you run the following UIKit app and tap on the button, you can see that it only updates its color if you hold on it for a bit, instead of immediately (as happens in the second app) (iOS 17.5, iPhone 15 Pro simulator, Xcode 15.4). This app consists of a view controller with a table view with one cell, which has a CheckoutButton instance constrained to its contentView top, bottom, leading and trailing anchors. The checkout button uses UIButton.Configuration to set its appearance, and update it based on its state. import UIKit class ViewController: UIViewController { let tableView = UITableView() let checkoutButton = CheckoutButton() override func viewDidLoad() { super.viewDidLoad() // table view setup view.addSubview(tableView) tableView.frame = view.bounds tableView.autoresizingMask = [.flexibleHeight, .flexibleWidth] tableView.dataSource = self tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell") } } 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.contentView.addSubview(checkoutButton) checkoutButton.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ checkoutButton.topAnchor.constraint(equalTo: cell.contentView.topAnchor), checkoutButton.bottomAnchor.constraint(equalTo: cell.contentView.bottomAnchor), checkoutButton.leadingAnchor.constraint(equalTo: cell.contentView.leadingAnchor), checkoutButton.trailingAnchor.constraint(equalTo: cell.contentView.trailingAnchor) ]) return cell } } class CheckoutButton: UIButton { override init(frame: CGRect) { super.init(frame: frame) var configuration = UIButton.Configuration.plain() var attributeContainer = AttributeContainer() attributeContainer.font = .preferredFont(forTextStyle: .headline) attributeContainer.foregroundColor = .label configuration.attributedTitle = .init("Checkout", attributes: attributeContainer) self.configuration = configuration let configHandler: UIButton.ConfigurationUpdateHandler = { button in switch button.state { case .selected, .highlighted: button.configuration?.background.backgroundColor = .systemCyan case .disabled: button.configuration?.background.backgroundColor = .systemGray4 default: button.configuration?.background.backgroundColor = .systemBlue } } self.configurationUpdateHandler = configHandler } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } } In this second app, instead, the selection of the button is immediately reflected in its appearance: import UIKit class ViewController: UIViewController { let button = CheckoutButton() override func viewDidLoad() { super.viewDidLoad() view.addSubview(button) button.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ button.centerXAnchor.constraint(equalTo: view.centerXAnchor), button.centerYAnchor.constraint(equalTo: view.centerYAnchor), button.widthAnchor.constraint(equalToConstant: 300), button.heightAnchor.constraint(equalToConstant: 44) ]) } } class CheckoutButton: UIButton { override init(frame: CGRect) { super.init(frame: frame) var configuration = UIButton.Configuration.plain() var attributeContainer = AttributeContainer() attributeContainer.font = .preferredFont(forTextStyle: .headline) attributeContainer.foregroundColor = .label configuration.attributedTitle = .init("Checkout", attributes: attributeContainer) self.configuration = configuration let configHandler: UIButton.ConfigurationUpdateHandler = { button in switch button.state { case .selected, .highlighted: button.configuration?.background.backgroundColor = .systemCyan case .disabled: button.configuration?.background.backgroundColor = .systemGray4 default: button.configuration?.background.backgroundColor = .systemBlue } } self.configurationUpdateHandler = configHandler } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } } This app consists of a view controller with just a button: no table view unlike in the first app. How do I make the button show its selection as soon as it's tapped, no matter if it's in a table view cell or on its own?

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 a 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 as well allow the UI to adjust to changes to the text view frame on iOS 16+ only. Recommended, modern, approach: Not recommended, old, approach: Here's what I've tried and didn’t work on the Xcode 15.3 iPhone 15 Pro simulator with iOS 17.4 and on my iPhone SE with iOS 15.8: view.keyboardLayoutGuide.topAnchor.constraint(equalTo: textView.bottomAnchor).isActive = true in the text view cell registration view.keyboardLayoutGuide.topAnchor.constraint(equalTo: collectionView.bottomAnchor).isActive = true in viewDidLoad() pinning the bottom of the collection view to the top of the keyboard: func configureHierarchy() { collectionView = UICollectionView(frame: .zero, collectionViewLayout: createLayout()) view.addSubview(collectionView) collectionView.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ collectionView.topAnchor.constraint(equalTo: view.topAnchor), collectionView.bottomAnchor.constraint(equalTo: view.keyboardLayoutGuide.topAnchor), collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor), collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor) ]) } To be more specific, I only tried this last approach on the simulator, and it moved the UI seemingly twice as much as it should have, and the tab bar of my tab bar controller was black, which discouraged me although there might be a proper (non-workaround) solution for iOS 17 only (i.e. saying view.keyboardLayoutGuide.usesBottomSafeArea = false). The first 2 approaches just didn't work instead. Setting the constraints priority to .defaultHigh doesn't do it.

Here is a screenshot of the app: And here follows the code: it's a view controller with a collection view with plain list layout and a diffable data source. It has 1 section with 2 rows. The 1st row's content configuration is UIListContentConfiguration.cell(), and it has some text. The 2nd row has an empty content configuration instead. As you can see, if you run the app, the separator insets are different for the two rows. Did I make a mistake? If this is expected behavior instead, is there an easy fix? import UIKit class ViewController: UIViewController { var collectionView: UICollectionView! var dataSource: UICollectionViewDiffableDataSource<String, String>! var snapshot: NSDiffableDataSourceSnapshot<String, String> { var snapshot = NSDiffableDataSourceSnapshot<String, String>() snapshot.appendSections(["main"]) snapshot.appendItems(["one", "two"]) return snapshot } override func viewDidLoad() { super.viewDidLoad() configureHierarchy() configureDataSource() } func configureHierarchy() { collectionView = .init( frame: view.bounds, collectionViewLayout: createLayout() ) view.addSubview(collectionView) collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight] } func createLayout() -> UICollectionViewLayout { return UICollectionViewCompositionalLayout { section, layoutEnvironment in let config = UICollectionLayoutListConfiguration(appearance: .plain) return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } func configureDataSource() { let firstCellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in var contentConfiguration = UIListContentConfiguration.cell() contentConfiguration.text = "Hello" cell.contentConfiguration = contentConfiguration } let secondCellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in } let emptyCellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in switch itemIdentifier { case "one": collectionView.dequeueConfiguredReusableCell(using: firstCellRegistration, for: indexPath, item: itemIdentifier) case "two": collectionView.dequeueConfiguredReusableCell(using: secondCellRegistration, for: indexPath, item: itemIdentifier) default: collectionView.dequeueConfiguredReusableCell(using: emptyCellRegistration, for: indexPath, item: itemIdentifier) } } dataSource.apply(self.snapshot, animatingDifferences: false) } } Xcode 15.4, iPhone 15 Pro simulator, iOS 17.5, MacBook Air M1 8GB, macOS 14.5.

I'm making a UIKit app with no storyboard. This is my scene delegate: import UIKit class SceneDelegate: UIResponder, UIWindowSceneDelegate { var window: UIWindow? func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) { guard let windowScene = (scene as? UIWindowScene) else { return } let window = UIWindow(windowScene: windowScene) window.makeKeyAndVisible() window.rootViewController = UINavigationController(rootViewController: ViewController()) self.window = window } } I've noticed that if I subclass ViewController to UICollectionViewController, the app crashes with message "Thread 1: "UICollectionView must be initialized with a non-nil layout parameter"": import UIKit class ViewController: UICollectionViewController { } It looks like I necessarily need to override the initializer: import UIKit class ViewController: UICollectionViewController { init() { super.init(collectionViewLayout: .init()) } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } } I would indeed like to pass the final collection view layout in super.init(collectionViewLayout:), but defining the trailing actions before that isn't possible since self hasn't been initialized yet. So this is what I'm stuck with: import UIKit class ViewController: UICollectionViewController { init() { super.init(collectionViewLayout: .init()) var configuration = UICollectionLayoutListConfiguration(appearance: .insetGrouped) var layout = UICollectionViewCompositionalLayout.list(using: configuration) configuration.trailingSwipeActionsConfigurationProvider = { [weak self] indexPath -> UISwipeActionsConfiguration? in // access a property of self return .init(actions: [.init(style: .destructive, title: "Hello", handler: { _,_,_ in print("Handled") })]) } layout = UICollectionViewCompositionalLayout.list(using: configuration) collectionView.collectionViewLayout = layout } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } } Is this all valid?

Sample app 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) } } Problem If you tap on the row, it doesn't look like it gets selected: the line backgroundConfiguration.backgroundColor = .systemBlue breaks the cell's default background color transformer. Question Given that my goal is to have my cell manifest its selection exactly like usual (meaning exactly as it would without the line backgroundConfiguration.backgroundColor = .systemBlue), that the details of how a cell usually does so are likely not public, that I would like to set a custom background color for my cell and that I would want to configure its appearance using configurations, since I seem to understand that that is the way to go from iOS 14 onwards, does anybody know how to achieve my goal by resetting something to whatever it was before I said backgroundConfiguration.backgroundColor = .systemBlue? 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 cell's backgroundConfiguration to UIBackgroundConfiguration.listGroupedCell().updated(for: cell.configurationState) Setting the color transformer to cell.defaultBackgroundConfiguration().backgroundColorTransformer Using collection view controllers (and setting collectionView.clearsSelectionOnViewWillAppear to false) Setting the cell's automaticallyUpdatesBackgroundConfiguration to false and then back to true Putting the cell's configuration code inside a configurationUpdateHandler Combinations of the approaches above Setting the color transformer to UIBackgroundConfiguration.listGroupedCell().backgroundColorTransformer and cell.backgroundConfiguration?.backgroundColorTransformer (they're both nil) Workaround 1: use a custom color transformer var backgroundConfiguration = UIBackgroundConfiguration.listGroupedCell() backgroundConfiguration.backgroundColorTransformer = .init { _ in if cell.configurationState.isSelected || cell.configurationState.isHighlighted || cell.configurationState.isFocused { .systemRed } else { .systemBlue } } cell.backgroundConfiguration = backgroundConfiguration Workaround 2: don't use a background configuration You can set the cell's selectedBackgroundView, like so: let v = UIView() v.backgroundColor = .systemBlue cell.selectedBackgroundView = v You won't be able to use custom background content configurations though and might want to use background views instead: var contentConfiguration = UIListContentConfiguration.cell() contentConfiguration.text = "Hello" cell.contentConfiguration = contentConfiguration let v = UIView() v.backgroundColor = .systemBlue cell.backgroundView = v let bv = UIView() bv.backgroundColor = .systemRed cell.selectedBackgroundView = bv Consideration on the workarounds Both workarounds seem to also not break this code, which deselects cells on viewWillAppear(_:) and was taken and slightly adapted from Apple's Modern Collection Views project (e.g. EmojiExplorerViewController.swift): override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) deselectSelectedItems(animated: animated) } func deselectSelectedItems(animated: Bool) { if let indexPath = collectionView.indexPathsForSelectedItems?.first { if let coordinator = transitionCoordinator { coordinator.animate(alongsideTransition: { [weak self] context in self?.collectionView.deselectItem(at: indexPath, animated: true) }) { [weak self] (context) in if context.isCancelled { self?.collectionView.selectItem(at: indexPath, animated: false, scrollPosition: []) } } } else { collectionView.deselectItem(at: indexPath, animated: animated) } } } (Collection view controllers don't sport all of that logic out of the box, even though their clearsSelectionOnViewWillAppear property is true by default.)

Problem When I reconfigure a collection view snapshot and apply it to my complex production collection view with list layout, the UI updates slowly, unless I don't animate the differences, even though I'm only reconfiguring the specific item identifiers of the cells that should be updated. I thought that maybe I could speed up the animations of the UI updates by applying the snapshot to a specific section (dataSource?.apply(sectionSnapshot, to: .main)) instead of to the whole collection view (dataSource?.apply(wholeSnapshot)). The problem is that I can't reconfigure the item identifiers of a single section snapshot to then apply the updated snapshot. Question Given the following sample app, can anybody edit reconfigureMainSection() so that, when invoked, the .main section cell registrations are called, consequently invoking print("Reconfiguring")? Sample app This collection view with list layout and diffable data source has 1 section and 2 rows. You can tap the right bar button item to call reconfigureMainSection(). class ViewController: UICollectionViewController { var snapshot: NSDiffableDataSourceSnapshot<Section, String> { var snapshot = NSDiffableDataSourceSnapshot<Section, String>() snapshot.appendSections([.main]) snapshot.appendItems(["one", "two"], toSection: .main) return snapshot } var dataSource: UICollectionViewDiffableDataSource<Section, String>? enum Section { case main } init() { super.init(collectionViewLayout: .init()) collectionView.collectionViewLayout = createLayout() configureDataSource() } override func viewDidLoad() { super.viewDidLoad() navigationItem.rightBarButtonItem = .init( title: "Reconfigure", style: .plain, target: self, action: #selector(reconfigureMainSection) ) } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in print("Reconfiguring") } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } dataSource?.apply(self.snapshot, animatingDifferences: false) } func createLayout() -> UICollectionViewLayout { return UICollectionViewCompositionalLayout { section, layoutEnvironment in let config = UICollectionLayoutListConfiguration(appearance: .plain) return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } @objc func reconfigureMainSection() { var sectionSnapshot = NSDiffableDataSourceSectionSnapshot<String>() sectionSnapshot.append(snapshot.itemIdentifiers(inSection: .main)) // reconfigure the section snapshot dataSource?.apply(sectionSnapshot, to: .main) } } Environment MacBook Air M1 8GB macOS Sonoma 14.5 Xcode 15.4 iPhone 15 Pro simulator on iOS 17.5

Sample app A collection view controller with list layout, 1 section and 1 row. The cell's content view contains a text view. class ViewController: UICollectionViewController { var snapshot: NSDiffableDataSourceSnapshot<Section, String> { var snapshot = NSDiffableDataSourceSnapshot<Section, String>() snapshot.appendSections([.main]) snapshot.appendItems(["one", "two"], toSection: .main) return snapshot } var dataSource: UICollectionViewDiffableDataSource<Section, String>? enum Section { case main } init() { super.init(collectionViewLayout: .init()) collectionView.collectionViewLayout = createLayout() configureDataSource() // more likely and automatically avoid unpleasant animations on iOS 15 by configuring the data source in the init rather than in view did load } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in let textView = UITextView() textView.font = .systemFont(ofSize: UIFont.labelFontSize) cell.contentView.addSubview(textView) textView.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ textView.topAnchor.constraint(equalTo: cell.contentView.topAnchor, constant: 8), textView.bottomAnchor.constraint(equalTo: cell.contentView.bottomAnchor, constant: -8), textView.leadingAnchor.constraint(equalTo: cell.contentView.leadingAnchor, constant: cell.directionalLayoutMargins.leading), textView.trailingAnchor.constraint(equalTo: cell.contentView.trailingAnchor, constant: -cell.directionalLayoutMargins.trailing) ]) } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } dataSource?.apply(self.snapshot, animatingDifferences: false) } func createLayout() -> UICollectionViewLayout { return UICollectionViewCompositionalLayout { section, layoutEnvironment in let config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } } Question 1 Can anybody edit the provided sample code so that the text view's vertical indicator inset is not cut off at the top? Question 2 It seems to me that Apple has successfully implemented text views inside table view cells: can anybody provide Apple documentation as per how to do so? What I've tried and didn't work textView.verticalScrollIndicatorInsets.top = 30 // does nothing Adding the text view to a custom view and the view to the cell's content view textView.contentInset = .zero textView.scrollIndicatorInsets = .zero textView.textContainerInset = .zero textView.textContainer.lineFragmentPadding = 0 Centering the text view vertically and constraining its height to that of the content view with an 8 points constant to leave some padding Constraining the top and bottom anchors of the text view to the cell's layout margins guide's top and bottom anchors Constraint I need the text view to have some padding from the top and bottom of the cell for aesthetic reasons.

Code that reproduces the issue import SwiftUI @main struct TextFieldsGridApp: App { @State private var controller = Controller() var body: some Scene { WindowGroup { GridView() .environment(controller) } } } struct GridView: View { @Environment(Controller.self) private var c var body: some View { VStack { ForEach(0..<c.strings.count, id: \.self) { r in HStack { ForEach(0..<4, id: \.self) { c in TextField( "", text: c.strings[r][c] ) .textFieldStyle(.roundedBorder) } } } } .padding() } } #Preview { GridView() .environment(Controller()) } @Observable class Controller { private(set) var strings: [[String]] = Array( repeating: Array(repeating: "A", count: 4), count: 4, ) } Error Cannot convert value of type 'Range<Int>' to expected argument type 'Binding<C>', caused by ForEach(0..<4, id: \.self) { c in. Which I do not get if I say, for example: struct GridView: View { @State private var text = "H" // ... TextField("", text: $text) Environment MacBook Air M1 8GB iOS Sequoia 15.5 Xcode 16.4 Preview: iPhone 16 Pro, iOS 18.5.

I used to be able to do that by clicking on main, as the documentation says, whereas now nothing happens. I believe this is Xcode 26 Beta 3. MacBook Air M1 8GB, macOS 15.5. I need to get to 220 characters, so I may as well say I've also tried double clicking etc. Does anyone kindly have any suggestions?

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?