Explore the various UI frameworks available for building app interfaces. Discuss the use cases for different frameworks, share best practices, and get help with specific framework-related questions.

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Scroll offset incorrectly resets when animating insertion of ScrollView using .geometryGroup()
Hey, I've been having a problem with scroll views in combination with the .geometryGroup() modifier. I have filed a Feedback (FB17698293) but I also wanted to post this here in case someone maybe has a better workaround for the problem. Problem Whenever you conditionally insert a ScrollView inside a VStack that is modified with a .geometryGroup() modifier, the scroll view content offset resets itself after the insertion animation is done, even if you started scrolling inside the scroll view during the animation and haven't let go of the screen. This happens consistently and is fully reproducible (see below), both using a simulator and a real device. Unfortunately, this is a very annoying glitch that ruins a lot of cool UX components that rely on .geometryGroup(). The weird thing is that the glitch entirely disappears, if you add a simple, non-zero (but greater than 1) .padding() modifier to the VStack (.padding().geometryGroup()). I have no idea why this fixes the glitch, but it does. However, adding a padding is not feasible in many situations, so this workaround is not ideal. Steps to reproduce Launch the code below (using a simulator or a real device) and tap "Toggle Expansion" to insert the scroll view. As the view is animating in, drag the scroll content and hold it scrolled away from the top. Wait for the animation to complete. The scroll view will reset the content offset, even though the drag gesture is still active (i.e. you haven't lifted your finger to release the scroll view) On a real device, this sometimes even leads to an even worse visual artifact where the scroll view is rendered twice for a few frames; once with the correct offset, and once with the reset offset. I wanted to include a link to a gif/video showing the glitch, but it tells me that imgur is not allowed on the forums. Expected Behavior I want the scroll view to respect the content offset, even if I started changing it mid-animation. Xcode Version I am using Xcode 16.4 (16F6) but this problem has been occurring since the .geometryGroup() modifier has been release. I was only now able to pinpoint this problem exactly, so I'm filing this feedback. Code The entire code that reproduces the problem: import SwiftUI struct ContentView: View { @State private var isExpanded: Bool = false var body: some View { VStack { if isExpanded { ScrollView { Text(loremIpsum) } } Button("Toggle Expansion") { isExpanded.toggle() } } // .padding(10) // Adding a non-zero padding makes the glitch disappear .frame(maxWidth: .infinity) .geometryGroup() .animation(.default, value: isExpanded) } } #Preview { ContentView().preferredColorScheme(.dark) } // MARK: - Mock Data let loremIpsum = """ Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt \ ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco \ laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla \ pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt \ mollit anim id est laborum. """
Topic: UI Frameworks SubTopic: SwiftUI
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134
May ’25
Use Custom UIApplication Subclass with SwiftUI
I have a SwiftUI app which needs the Ivanti AppConnect SDK. The docs only show how to integrate it into a Swift/UIKit app. But I need it to work with SwiftUI. I probably could make a UIKit base app and then load my existing SwiftUI views and code through a SwiftUI component host or something. But I'd like to avoid that if possible. Here is where I'm stuck: The AppConnect framework loads through a custom UIApplication subclass in the main.swift file: import Foundation import AppConnect UIApplicationMain( CommandLine.argc, CommandLine.unsafeArgv, ACUIApplicationClassName, NSStringFromClass(AppDelegate.self) ) The startup works as expected, and the expected function is called in the AppDelegate class: func application( _ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {...} However, the SwiftUI view is not loaded and the scree stays blank. I implemented a SceneDelegate.swift class which doesn't seem to be called. Also, the following function in the AppDelegate doesn't get called either: func application( _ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {...} So how do I bootstrap SwiftUI with a custom UIApplication class? can that be done with the @main macro somehow? I'm still pretty new to Swift and iOS development. Any help is appreciated
Topic: UI Frameworks SubTopic: SwiftUI Tags:
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71
May ’25
brightnessDidChangeNotification does not seem to work on Mac Catalyst 15.5
Hi, I have been trying to subscribe to brightnessDidChangeNotification (https://developer.apple.com/documentation/uikit/uiscreen/brightnessdidchangenotification) with my code: var publisher = NotificationCenter.default.publisher(for: UIScreen.brightnessDidChangeNotification) .map { _ -> Double in return UIScreen.main.brightness } But it does seem that no such event is fired on Mac Catalyst 15.5. https://developer.apple.com/documentation/uikit/uiscreen/brightnessdidchangenotification claims that API is available since 13.1. Could anybody tell me if I'm doing something wrong or if the API is not supported at the moment? Thank you!
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168
May ’25
Can We Detect When Running Behind a Slide Over Window?
I'm trying to determine if it’s possible to detect when a user interacts with a Slide Over window while my app is running in the background on iPadOS. I've explored lifecycle methods such as scenePhase and various UIApplication notifications (e.g., willResignActiveNotification) to detect focus loss, but these approaches don't seem to capture the event reliably. Has anyone found an alternative solution or workaround for detecting this specific state change? Any insights or recommended practices would be greatly appreciated.
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123
Mar ’25
CPTabBarTemplate in CarPlay Simulator: Tab Becomes Inactive on Re-selection
I am facing an issue in my CarPlay app using CPTabBarTemplate. The app has two tabs, and on launch, the first tab is correctly selected. However, when I tap on the first tab again, instead of staying active, it becomes inactive. This behavior is unexpected, as re-selecting the active tab should typically maintain its selected state. Has anyone else encountered this issue or found a workaround to prevent the tab from becoming inactive?
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59
May ’25
Live Activity resets to initial state after 8+ hours in background
Hi Apple team and community, We’re encountering a strange issue with Live Activity that seems related to memory management or background lifecycle. ❓ Issue: Our app updates a Live Activity regularly (every 3 minutes) using .update(...). However, after the app remains in the background for around 8 hours, the Live Activity reverts to the initial state that was passed into .request(...). Even though the app continues sending updates in the background, the UI on the Lock Screen and Dynamic Island resets to the original state.
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69
Apr ’25
tvOS Remote Control Entitlements
I've been looking for a solution to configure the Apple TV remote(s) from the 5th generation and upwards. Some of the basic functionalities are disabling buttons on the physical remote control while maintaining proper functionality on remote controller apps on iOS devices. There seems to be a lack of relevant entitlements in that category, and without it I can't seem to figure out a way to make it work. Any ideas on the matter? Maybe a workaround that allows to configure the Apple TV to work with other remotes? Thank you in advance to anyone that put in thought to my query.
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103
May ’25
How to make app for iPhone and iPad separatly
I released an app for iPhone (and it's could be downloaded for iPad also), and now I developered another app for iPad version with the same code and logic but I modified the layout to fit bigger screen and make better user experience and appearance. Howevert the app review rejected my release due to the duplicate content, how can I solve it?
Topic: UI Frameworks SubTopic: General
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47
Mar ’25
openURL:options:completionHandler: Not Opening tel:// Link on iPad with Cellular Data
We are using openURL:options:completionHandler: to open a tel:// number in the dialer to place a call. This works on iPhones and WiFi-only iPads (tested with a iPad Mini 6th Gen), but it is failing to open on an iPad 8th Gen (WiFi + Cellular) running iPadOS 18.5 being used by a customer. Prior to updating the iPad to iPadOS 18, the call worked on iPadOS 15.2 and opened the call in FaceTime as expected. Despite not opening the dialer in iPadOS 18, the completionHandler returns the success parameter as true. canOpenUrl also returns true. We created a small test application that reproduces the issue using the code snippet below in a new application, with the tel schema added to the info.plist Queried URL Schemes. We are currently using Xcode 16.3. Test Steps: Create a new blank application and replace ContentView.swift with the code snippet below Run the test app on a physical iPad 8th Gen (WiFi + Cellular) Tap the "place a test call" button Expected Results: The user is prompted to call the number and is taken to FaceTime to attempt the call. The user may then receive an alert telling them an iPhone must be paired if not already. Alternatively: return success = false in the completionHandler. Actual Results: No action occurs that is visible to the user, and the completionHandler returns success = true. Separately, we should be able to have some method of checking if the device can actually complete a call, i.e. if an iPhone is paired, so that we can correctly show or hide a phone icon in the app based on if the user can place a call. canOpenUrl returns true even if there is not a device paired and the call cannot actually be placed, and there doesn't seem to be a proper method for making that check. Code Snippet: import SwiftUI struct ContentView: View { @State private var showAlert = false var body: some View { VStack { Image(systemName: "globe") .imageScale(.large) .foregroundStyle(.tint) Text("Hello, world!") Button("Place a test call") { if let url = URL(string: "tel://5555554567") { UIApplication.shared.open(url) { success in if success { print("Call initiated successfully.") } else { showAlert = true } } } } } .padding() .alert("Call Failed", isPresented: $showAlert) { Button("OK") { showAlert = false } } message: { Text("The call could not be initiated.") } } } #Preview { ContentView() }
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Jun ’25
iOS 18.4.1 Keyboard Extension Dark Mode Background Issue
Background Color Issue in Custom Keyboard Extension in Dark Mode for iOS 18.4.1 Issue Description I'm developing a custom keyboard extension for iOS 18.4.1 and experiencing an issue with background colors when using Dark Mode. After a user makes a selection from a menu in the keyboard, the background color of a view unexpectedly changes to white instead of maintaining the dark theme color. Steps to Reproduce Enable Dark Mode on the device Activate the custom keyboard in any text field Perform a specific interaction (selecting an item from a menu) After selection, the background of the view turns white instead of remaining dark Technical Details The issue appears to be related to UIScrollView's background color behavior The problem doesn't occur on initial display of the menu, only after user interaction I've attempted to set background colors explicitly on the view hierarchy, but the issue persists Environment iOS 18.4.1 Xcode 16.0 Custom keyboard extension Questions Has anyone encountered similar issues with view background colors changing after user interactions in keyboard extensions on iOS 18.4.1? Is there a recommended approach to maintain dark background colors in keyboard extensions after user selections? Could this be related to a change in how UIScrollView handles background colors in recent iOS versions? Thank you for any assistance or insights.
Topic: UI Frameworks SubTopic: UIKit
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104
May ’25
memory leak upon mouse down in a NSTextField
Dear all, Sorry if the topic has already been commented but I could not be able to find it in over 10,000 picks using the forum search field... My problem is that with any NSTextField in my app, a click will result in a memory leak. There is no code attached, just bindings to NSNumber properties. How can I fix this ? Thanks for your help. Best regards Chris
Topic: UI Frameworks SubTopic: AppKit
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70
May ’25
Remove persistent bottom gray bar at the bottom when using hardware keyboard
DESCRIPTION OF PROBLEM When using SwiftUI’s TextField or TextEditor on iPadOS, a persistent gray or default system material bar appears at the bottom of the screen. This gray bar is not present in Apple’s native apps (such as Notes, Mail, Messages) or in third-party apps like ChatGPT and Beeper STEPS TO REPRODUCE Create a TextField or TextEditor. Run the code, click on it, without software keyboard enabled.
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125
May ’25
How to create a QuickTime recording like panel?
QuickTime recording palette behaves in a way which I want to replicate in my desktop app - specifically the behaviour when switching spaces, it appears on top. Currently, my app appears on all spaces, and even over fullscreen applications BUT it already exists when I switch to the space, this feels disjointed. I can't find a solution to this behaviour. Here's the Window Collection Behaviours I've tried (on an NSPanel): FullScreenAuxiliary - appears over fullscreen apps. CanJoinAllSpaces - appears on all spaces. These two options make the dock show up on all spaces in the same position, but on each space they already exists. I've tried this behaviour too: MoveToActiveSpace - which as per docs would move the window into active space only when its reopened, mine stays open all the time. I can't find any more information on how QuickTime achieves this.
Topic: UI Frameworks SubTopic: SwiftUI
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73
May ’25
cannot save event
iOS 18.4.1 When I change a Google type event to an iCloud type, a "Cannot Save Event" prompt box pops up. We have also received user feedback that recurring events also fail to save. After updating to iOS 18.4 when trying to save changes to an existing repeating event, the message "Cannot Save Event" will appear. EventKitUI
Topic: UI Frameworks SubTopic: UIKit
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65
May ’25
What is the proper way to format a generic subview view when hoping to have it work with both an @State and an @Bindable?
Let's say you have a protocol that can work with both classes and structs but you want to have a uniform UI to make edits. What is the recommended way to have one view that will take both? App import SwiftUI @main struct ObservationTesterApp: App { var body: some Scene { WindowGroup { ContentView(existence: Existence()) } } } Types import Foundation protocol Dateable { var timestamp:Date { get set } } struct Arrival:Dateable { var timestamp:Date } @Observable class Existence:Dateable { var timestamp:Date init(timestamp: Date) { self.timestamp = timestamp } } extension Existence { convenience init() { self.init(timestamp: Date()) } } ContentView, etc // // ContentView.swift // ObservationTester // // import SwiftUI struct EditDateableView<TimedThing:Dateable>:View { @Binding var timed:TimedThing //note that this currently JUST a date picker //but it's possible the protocol would have more var body:some View { DatePicker("Time To Change", selection: $timed.timestamp) } } #Preview { @Previewable @State var tt = Arrival(timestamp: Date()) EditDateableView<Arrival>(timed: $tt) } struct ContentView: View { @State var arrival = Arrival(timestamp: Date()) @Bindable var existence:Existence var body: some View { //this work around also not allowed. "self is immutable" // let existBinding = Binding<Existence>(get: { existence }, set: { existence = $0 }) VStack { EditDateableView(timed: $arrival) //a Binding cant take a Bindable //EditDateableView<Existence>(timed: $existence) } .padding() } } #Preview { ContentView(existence: Existence()) }
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147
May ’25
AppKit: presentAsModalWindow doesn't center the presented window on macOS 15
When I present a view controller, whose view is a SwiftUI View, via presentAsModalWindow(_:) the presented window is no longer centered horizontally to the screen, but rather its origin is there. I know this issue occurs for macOS 15.2+, but can't tell if it is from 15.0+. I couldn't find any documentation on why was this changed. Here's an example code that represents my architecture: class RootViewController: NSViewController { private lazy var button: NSButton = NSButton( title: "Present", target: self, action: #selector(presentView)) override func viewDidLoad() { super.viewDidLoad() // Add button to tree } @objc func presentView() { presentAsModalWindow(PresentedViewController()) } } class PresentedViewController: NSViewController { override loadView() { view = NSHostingView(rootView: MyView()) } } struct MyView: View { /* impl */ }
Topic: UI Frameworks SubTopic: AppKit Tags:
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195
Mar ’25
Is it reasonable to vend an NSView from a "ViewModel" when using NSViewRepresentable instead of implementing the Coordinator pattern?
I'm currently integrating SwiftUI into an AppKit based application and was curious if the design pattern below was viable or not. In order to "bridge" between AppKit and SwiftUI, most of my SwiftUI "root" views have aViewModel that is accessible to the SwiftUI view via @ObservedObject. When a SwiftUI views need to use NSViewRepresentable I'm finding the use of a ViewModel and a Coordinator to be an unnecessary layer of indirection. In cases where it makes sense, I've just used the ViewModel as the Coordinator and it all appears to be working ok, but I'm curious if this is reasonable design pattern or if I'm overlooking something. Consider the following pseudo code: // 1. A normal @ObservedObject acting as the ViewModel that also owns and manages an NSTableView. @MainActor final class ViewModel: ObservedObject, NSTableView... { let scrollView: NSScrollView let tableView: NSTableView @Published var selectedTitle: String init() { // ViewModel manages tableView as its dataSource and delegate. tableView.dataSource = self tableView.delegate = self } func reload() { tableView.reloadData() } // Update view model properties. // Simpler than passing back up through a Coordinator. func tableViewSelectionDidChange(_ notification: Notification) { selectedTitle = tableView.selectedItem.title } } // 2. A normal SwiftUI view, mostly driven by the ViewModel. struct ContentView: View { @ObservedObject model: ViewModel var body: some View { Text(model.selectedTitle) // No need to pass anything down other than the view model. MyTableView(model: model) Button("Reload") { model.reload() } Button("Delete") { model.deleteRow(...) } } } // 3. A barebones NSViewRepresentable that just vends the required NSView. No other state is required as the ViewModel handles all interactions with the view. struct MyTableView: NSViewRepresentable { // Can this even be an NSView? let model: ViewModel func makeNSView(context: Context) -> some NSView { return model.scrollView } func updateNSView(_ nsView: NSViewType, context: Context) { // Not needed, all updates are driven through the ViewModel. } } From what I can tell, the above is working as expected, but I'm curious if there are some situations where this could "break", particularly around the lifecycle of NSViewRepresentable Would love to know if overall pattern is "ok" from a SwiftUI perspective.
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66
Apr ’25
iOS 17 Bug? Adding a .sheet to a .fullscreencover makes background opaque
I am working on creating a custom Popup View based on a .fullscreenCover. The .fullscreenCover is used to place the Popup content on screen on a semi-transparent background. While this works on iOS 18, there is a problem on iOS 17: When the Popup content contains a .sheet, the background is not transparent any more but opaque. Image: iOS 17. When showing the Popup an opaque background covers the main content. When tapping on the background it turns transparent. Image: iOS 18. Everything works as intended. When showing the Popup the main background is covered with a semi-transparent background. Removing the .sheet(...) from the Popup content solves the problem. It does not matter if the sheet is used or not. Adding it to the view code is enough to trigger the problem. Using a .sheet within a .fullscreenCover should not be a problem as far as I know. Is this a bug in iOS 17 or is there something wrong with my code? Code: struct SwiftUIView: View { @State var isPresented: Bool = false @State var sheetPresented: Bool = false var body: some View { ZStack { VStack { Color.red.frame(maxHeight: .infinity) Color.green.frame(maxHeight: .infinity) Color.yellow.frame(maxHeight: .infinity) Color.blue.frame(maxHeight: .infinity) } Button("Show") { isPresented = true } .padding() .background(.white) Popup(isPresented: $isPresented) { VStack { Button("Dismiss") { isPresented = false } } .frame(maxWidth: 300) .padding() .background( RoundedRectangle(cornerRadius: 20) .fill(.white) ) .sheet(isPresented: $sheetPresented) { Text("Hallo") } } } } } struct Popup<Content: View>: View { @Binding var isPresented: Bool let content: () -> Content init(isPresented: Binding<Bool>, @ViewBuilder _ content: @escaping () -> Content) { _isPresented = isPresented self.content = content } @State private var internalIsPresented: Bool = false @State private var isShowing: Bool = false let transitionDuration: TimeInterval = 0.5 var body: some View { ZStack { } .fullScreenCover(isPresented: $internalIsPresented) { VStack { content() } .frame(maxWidth: .infinity, maxHeight: .infinity) .background( Color.black.opacity(0.5) .opacity(isShowing ? 1 : 0) .animation(.easeOut(duration: transitionDuration), value: isShowing) .ignoresSafeArea() ) .presentationBackground(.clear) .onAppear { isShowing = true } .onDisappear { isShowing = false } } .onChange(of: isPresented) { _ in withoutAnimation { internalIsPresented = isPresented } } } } extension View { func withoutAnimation(action: @escaping () -> Void) { var transaction = Transaction() transaction.disablesAnimations = true withTransaction(transaction) { action() } } }
Topic: UI Frameworks SubTopic: SwiftUI
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98
May ’25