We have submitted a feedback for this issue: FB21230723 We're building a note-taking app for iOS and macOS that uses both UITextView and NSTextView. When performing text input that involves a marked range (such as Japanese input) in a UITextView or NSTextView with a UITextViewDelegate or NSTextViewDelegate set, the text view's marked range (markedTextRange / markedRange()) has not yet been updated at the moment when shouldChangeTextIn is invoked. UITextViewDelegate.textView(_:shouldChangeTextIn:replacementText:) NSTextViewDelegate.textView(_:shouldChangeTextIn:replacementString:) The current behavior is this when entering text in Japanese: (same for NSTextView) func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool { print(textView.markedTextRange != nil) // prints out false DispatchQueue.main.async { print(textView.markedTextRange != nil) // prints out true } } However, we need the value of markedTextRange right away in order to determine whether to return true or false from this method. Is there any workaround for this issue?

We have crash reports as shown below that we haven't yet been able to repro and could use some help deubgging. My guess is that the app is giving a label or text view an attributed string with an invalid attribute range, but attributed strings are used in many places throughout the app, and I don't know an efficient way to track this down. I'm posting the stack trace here in hopes that someone more familiar with the internals of the system frameworks mentioned will be able to provide a clue to help narrow where I should look. Fatal Exception: NSRangeException NSMutableRLEArray objectAtIndex:effectiveRange:: Out of bounds 0 CoreFoundation 0x2d5fc __exceptionPreprocess 1 libobjc.A.dylib 0x31244 objc_exception_throw 2 Foundation 0x47130 blockForLocation 3 UIFoundation 0x2589c -[NSTextLineFragment _defaultRenderingAttributesAtCharacterIndex:effectiveRange:] 4 UIFoundation 0x25778 __53-[NSTextLineFragment initWithAttributedString:range:]_block_invoke 5 CoreText 0x58964 TLine::DrawGlyphsWithAttributeOverrides(TLineDrawContext const&, __CFDictionary const* (long, CFRange*) block_pointer, TDecoratorObserver*) const 6 CoreText 0x58400 CTLineDrawWithAttributeOverrides 7 UIFoundation 0x25320 _NSCoreTypesetterRenderLine 8 UIFoundation 0x24b10 -[NSTextLineFragment drawAtPoint:graphicsContext:] 9 UIFoundation 0x3e634 -[NSTextLineFragment drawAtPoint:inContext:] 10 UIFoundation 0x3e450 -[NSTextLayoutFragment drawAtPoint:inContext:] 11 UIKitCore 0x3e3098 __38-[_UITextLayoutFragmentView drawRect:]_block_invoke 12 UIKitCore 0x3e31cc _UITextCanvasDrawWithFadedEdgesInContext 13 UIKitCore 0x3e3040 -[_UITextLayoutFragmentView drawRect:] 14 UIKitCore 0xd7a98 -[UIView(CALayerDelegate) drawLayer:inContext:] 15 QuartzCore 0x109340 CABackingStoreUpdate_ 16 QuartzCore 0x109224 invocation function for block in CA::Layer::display_() 17 QuartzCore 0x917f0 -[CALayer _display] 18 QuartzCore 0x90130 CA::Layer::layout_and_display_if_needed(CA::Transaction*) 19 QuartzCore 0xe50c4 CA::Context::commit_transaction(CA::Transaction*, double, double*) 20 QuartzCore 0x5bd8c CA::Transaction::commit() 21 UIKitCore 0x9f3f0 _UIApplicationFlushCATransaction 22 UIKitCore 0x9c89c __setupUpdateSequence_block_invoke_2 23 UIKitCore 0x9c710 _UIUpdateSequenceRun 24 UIKitCore 0x9f040 schedulerStepScheduledMainSection 25 UIKitCore 0x9cc5c runloopSourceCallback 26 CoreFoundation 0x73f4c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ 27 CoreFoundation 0x73ee0 __CFRunLoopDoSource0 28 CoreFoundation 0x76b40 __CFRunLoopDoSources0 29 CoreFoundation 0x75d3c __CFRunLoopRun 30 CoreFoundation 0xc8284 CFRunLoopRunSpecific 31 GraphicsServices 0x14c0 GSEventRunModal 32 UIKitCore 0x3ee674 -[UIApplication _run] 33 UIKitCore 0x14e88 UIApplicationMain also filed as FB16905066

With iOS 26.1 we started seeing a bug that only appears on iPhone Air. This bug is visible with simulators too. I have tried so many different ways to fix the issue, but Instruments Profiler is pointing at UIKitCore. We load a tab bar, when the user attempts to switch a tab, the app hangs and never recovers. It happens right as the animation of the Glass bubble is in progress. I have tried a UIKit Tab bar, a SwiftUI Tab bar. I tore out AppDelegate and did a direct @main SwiftUI entry for my application. This issue appears with every tab bar instance I try. I attempted to disable LiquidGlass by utilizing this flag UIDesignRequiresCompatibility in my plist, but the flag seems to be ignored by the system. I am not sure what else to try. I have a trace file if that is helpful. What else can I upload? Here is what the code looks like. struct ContentView: View { @State private var selectedTab = 2 var body: some View { TabView(selection: $selectedTab) { Text("Profile") .tabItem { Label("Me", systemImage: "person") } .tag(0) Text("Training") .tabItem { Label("Training", systemImage: "calendar") } .tag(1) Text("Home") .tabItem { Label("Home", systemImage: "house") } .tag(2) Text("Goals") .tabItem { Label("Goals", systemImage: "target") } .tag(3) Text("Coach") .tabItem { Label("Coach", systemImage: "person.2") } .tag(4) } } } #Preview { ContentView() } and AppView entry point import SwiftUI @main struct RunCoachApp: App { var body: some Scene { WindowGroup { ContentView() } } }

I'm unable to find the right combination modifiers to get drag and drop to work using the new .draggable(containerItemID:) and dragContainer(for:in:selection:_:) modifiers. The drag is initiated with the item's ID, the item is requested from the .dragContainer modifier, but the drop closure is never triggered. Minimal repro: struct Item: Identifiable, Codable, Transferable { var id = UUID() var value: String static var transferRepresentation: some TransferRepresentation { CodableRepresentation(contentType: .tab) } } struct DragDrop: View { @State var items: [Item] = [ Item(value: "Hello"), Item(value: "world"), Item(value: "something"), Item(value: "else") ] var body: some View { List(items) { item in HStack { Text(item.value) Spacer() } .contentShape(Rectangle()) .draggable(containerItemID: item.id) .dropDestination(for: Item.self) { items, session in print("Drop: \(items)") } } .dragContainer(for: Item.self) { itemID in print("Drag: \(itemID)") return items.filter { itemID == $0.id } } } } #Preview("Simple") { DragDrop() }

I’m using the new preferredTransition = .zoom(...) API introduced in iOS 18. Here’s a simplified version of what I do on app startup: let listVC = CollectionViewController(collectionViewLayout: layout) let detailVC = DetailViewController() detailVC.preferredTransition = .zoom(sourceViewProvider: { context in let indexPath = IndexPath(row: 0, section: 0) let cell = listVC.collectionView.cellForItem(at: indexPath) return cell }) let nav = UINavigationController() nav.setViewControllers([listVC, detailVC], animated: false) window?.rootViewController = nav window?.makeKeyAndVisible() This is meant to restore the UI state from a previous session — the app should launch directly into the DetailViewController. The Problem When I launch the app with setViewControllers([listVC, detailVC], animated: false), the transition from listVC to detailVC appears correctly (i.e., no animation, as intended), but the drag-to-dismiss gesture does not work. The back button appears, and tapping it correctly triggers the zoom-out transition back to the cell, so the preferredTransition = .zoom(...) itself is properly configured. Interestingly, if I delay the push with a DispatchQueue.main.async and instead do: nav.setViewControllers([listVC], animated: false) DispatchQueue.main.async { nav.pushViewController(detailVC, animated: true) } …then everything works perfectly — including the interactive swipe-to-dismiss gesture — but that introduces an unwanted visual artifact: the user briefly sees the listVC, and then it pushes to detailVC, which I’m trying to avoid. My Question Is there a way to enable the swipe-to-dismiss gesture when using setViewControllers([listVC, detailVC], animated: false) It can be very confusing for users if swipe-to-dismiss only works in certain cases inconsistently. Thanks

We're seeing a sharp uptick in BaseBoard/FrontBoardServices crashes since we migrated from UIApplicationDelegate to UIWindowSceneDelegate. Having exhausted everything on my end short of reverse engineering BaseBoard or making changes without being able to know if they work, I need help. I think all I need to get unstuck is an answer to these questions, if possible: What does -[BSSettings initWithSettings:] enumerate over? If I know what's being enumerated, I'll know what to look for in our app. What triggers FrontBoardServices to do this update? If I can reproduce the crash--or at least better understand when it may happen--I will be better able to fix it Here's two similar stack traces: App_(iOS)-crashreport-07-30-2025_1040-0600-redacted.crash App_(iOS)-crashreport-07-30-2025_1045-0600-redacted.crash Since these are private trameworks, there is no documentation or information on their behavior that I can find. There are other forum posts regarding this crash, on here and on other sites. However, I did not find any that shed any insight on the cause or conditions of the crash. Additionally, this is on iPhone, not macOS, and not iPad. This post is different, because I'm asking specific questions that can be answered by someone with familiarity on how these internal frameworks work. I'm not asking for help debugging my application, though I'd gladly take any suggestions/tips! Here's the long version, in case anyone finds it useful: In our application, we have seen a sharp rise in crashes in BaseBoard and FrontBoardServices, which are internal iOS frameworks, since we migrated our app to use UIWindowSceneDelegate. We were using exclusively UIApplicationDelegate before. The stack traces haven't proven very useful yet, because we haven't been able to reproduce the crashes ourselves. Upon searching online, we have learned that Baseboard/Frontsoardservices are probably copying scene settings upon something in the scene changing. Based on our crash reports, we know that most of our users are on an iPhone, not an iPad or macOS, so we can rule out split screen or window resizing. Our app is locked to portrait as well, so we can also rule out orientation changes. And considering the stack trace is in the middle of an objc_retain_x2 call, which is itself inside of a collection enumeration, we are assuming that whatever is being enumerated probably was changed or deallocated during enumeration. Sometimes it's objc_retain_x2, and sometimes it's a release call. And sometimes it's a completely different stack trace, but still within BaseBoard/FrontBoardServices. I suspect these all share the same cause. Because it's thread 0 that crashed, we know that BaseBoard/FrontBoardServices were running on the main thread, which means that for this crash to occur, something might be changing on a background thread. This is what leads me to suspect a race condition. There are many places in our app where we accidentally update the UI from a background thread. We've fixed many of them, but I'm sure there are more. Our app is large. Because of this, I think background UI are the most likely cause. However, since I can't reproduce the crash, and because none of our stack traces clearly show UI updates happening on another thread at the same time, I am not certain. And here's the stack trace inline, in case the attachments expire or search engines can't read them: Thread 0 name: Thread 0 Crashed: objc_retain_x2 (libobjc.A.dylib) BSIntegerMapEnumerateWithBlock (BaseBoard) -[BSSettings initWithSettings:] (BaseBoard) -[BSKeyedSettings initWithSettings:] (BaseBoard) -[FBSSettings _settings:] (FrontBoardServices) -[FBSSettings _settings] (FrontBoardServices) -[FBSSettingsDiff applyToMutableSettings:] (FrontBoardServices) -[FBSSettingsDiff settingsByApplyingToMutableCopyOfSettings:] (FrontBoardServices) -[FBSSceneSettingsDiff settingsByApplyingToMutableCopyOfSettings:] (FrontBoardServices) -[FBSScene updater:didUpdateSettings:withDiff:transitionContext:completion:] (FrontBoardServices) __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke_2 (FrontBoardServices) -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] (FrontBoardServices) __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke.cold.1 (FrontBoardServices) __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke (FrontBoardServices) _dispatch_client_callout (libdispatch.dylib) _dispatch_block_invoke_direct (libdispatch.dylib) __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ (FrontBoardServices) -[FBSMainRunLoopSerialQueue _targetQueue_performNextIfPossible] (FrontBoardServices) -[FBSMainRunLoopSerialQueue _performNextFromRunLoopSource] (FrontBoardServices) __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (CoreFoundation) __CFRunLoopDoSource0 (CoreFoundation) __CFRunLoopDoSources0 (CoreFoundation) __CFRunLoopRun (CoreFoundation) CFRunLoopRunSpecific (CoreFoundation) GSEventRunModal (GraphicsServices) -[UIApplication _run] (UIKitCore) UIApplicationMain (UIKitCore) (null) (UIKitCore) main (AppDelegate.swift:0) 0x1ab8cbf08 + 0

Right now, the traffic light buttons overlapped on my iPad app top corner on windows mode (full screen is fine). How do I properly design my app to avoid the traffic light buttons? Detect that it is iPadOS 26?

Dear Apple Customer Support, I’m developing a new Swift iPadOS app and I want the app to run in landscape only (portrait disabled). In Xcode, under Target > General > Deployment Info > Device Orientation, if I select only Landscape Left and Landscape Right, the app builds successfully, but during upload/validation I receive this message and the upload is blocked: “Update the Info.plist: Support for all orientations will soon be required.” Could you please advise what the correct/recommended way is to keep an iPad app locked to landscape only while complying with the current App Store upload requirements? Is there a specific Info.plist configuration (e.g., UISupportedInterfaceOrientations~ipad) or another setting that should be used? Thank you,

I have a PDF which contains geocoordinates. I'm extracting out that image with the following code (this is for an iOS application): guard let cgDocument = CGPDFDocument(overlay.pdfUrl as CFURL) else { return } guard let cgPage = cgDocument.page(at: 1) else { return } var boundingRect = self.rect(for: overlay.boundingMapRect) let pdfPageRect = cgPage.getBoxRect(.mediaBox) let renderer = UIGraphicsImageRenderer(size: pdfPageRect.size) var img = renderer.image { ctx in UIColor.white.set() ctx.fill(pdfPageRect) ctx.cgContext.translateBy(x: 0.0, y: pdfPageRect.size.height) ctx.cgContext.scaleBy(x: 1.0, y: -1.0) ctx.cgContext.drawPDFPage(cgPage) } Once I have that image, I then need to adjust it to fit the specific coordinate corners. For that, I'm doing the following using a perspectiveTransform: let ciImg = CIImage(image: img)! let perspectiveTransformFilter = CIFilter.perspectiveTransform() perspectiveTransformFilter.inputImage = ciImg perspectiveTransformFilter.topRight = cartesianForPoint(point: ur, extent: boundingRect) perspectiveTransformFilter.topLeft = cartesianForPoint(point: ul, extent: boundingRect) perspectiveTransformFilter.bottomRight = cartesianForPoint(point: lr, extent: boundingRect) perspectiveTransformFilter.bottomLeft = cartesianForPoint(point: ll, extent: boundingRect) let txImg = perspectiveTransformFilter.outputImage! img = UIImage(ciImage: txImg) The original image is 792 x 612 (a landscape PDF) but the boundingRect covering the coordinates is 25625 x 20030. Obviously when I try to draw the image into that bounding box the app runs out of memory (25625 x 20030 x 4 is around 2GB of memory). What I'm struggling with is - how do I correctly scale this image to fit into the bounding box even though the bounding box is, oh, 10x the resolution of the actual device? There's some key CoreGraphics thing I'm sure I'm missing here.

Sidebars for mac Catalyst apps running with UIDesignRequiresCompatibility flag render their active items with a white bg tint – resulting in labels and icons being not visible. mac OS Tahoe 26.1 Beta 3 (25B5062e) FB20765036 Example (Apple Developer App):

In iOS 26, the Slider control no longer respects the step parameter. For example, import SwiftUI struct ContentView: View { @State private var sliderValue: CGFloat = 16 var body: some View { Slider( value: $sliderValue, in: 0...100, step: 5, onEditingChanged: { editing in print(sliderValue) } ) } } In iOS 18, this prints values like 5, 35, 60, 95, etc. In iOS 26.0 (release version), this prints floats that are not rounded to the nearest 5, and the slider does not snap to values ending in 5. Feedback report number: FB20320542

Since iPadOS 26.1 I notice a new annoying bug when changing the dark mode option of the system. The appearance of the UI changes, but no longer for view controllers which are presented as Popover. For these view controllers the method "traitCollectionDidChange()" is still called (though sometimes with a very large delay), but checking the traitCollection property of the view controller in there does no longer return the correct appearance (which is probably why the visual appearance of the popover doesn't change anymore). So if the dark mode was just switched on, traitCollectionDidChange() is called, but the "traitCollection.userInterfaceStyle" property still tells me that the system is in normal mode. More concrete, traitCollection.userInterfaceStyle seems to be set correctly only(!) when opening the popover, and while the popover is open, it is never updated anymore when the dark mode changes. This is also visible in the standard Apps of the iPad, like the Apple Maps App: just tap on the "map" icon at the top right to open the "Map mode" view. While the view is open, change the dark mode. All of the Maps App will change its appearance, with the exception of this "Map mode" view. Does anyone know an easy workaround? Or do I really need to manually change the colors for all popup view controllers whenever the dark mode changes? Using dynamic UIColors won't help, because these rely on the "userInterfaceStyle" property, and this is no longer correct. Bugreport: FB20928471

Hello, While integrating the Liquid Glass UI introduced in iOS 26 into my existing app, I encountered an unexpected issue. My app uses a UITabBarController, where each tab contains a UINavigationController, and the actual content resides in each UIViewController. Typically, I perform navigation using navigationController?.pushViewController(...) and hide the TabBar by setting vc.hidesBottomBarWhenPushed = true when needed. This structure worked perfectly fine prior to iOS 26, and I believe many apps use a similar approach. However, after enabling Liquid Glass UI, a problem occurs. Problem Description From AViewController, I push BViewController with hidesBottomBarWhenPushed = true. BViewController appears, and the TabBar is hidden as expected. When performing a swipe-back gesture, as soon as AViewController becomes visible, the TabBar immediately reappears (likely due to A’s viewWillAppear). The TabBar remains visible for a short moment even if the gesture is canceled — during that time, it is also interactable. Before iOS 26, the TabBar appeared synchronized with AViewController and did not prematurely show during the swipe transition. Tried using the new iOS 18 API: tabBarController?.setTabBarHidden(false, animated: true) It slightly improves the animation behavior, but the issue persists. If hidesBottomBarWhenPushed is now deprecated or discouraged, migrating entirely to setTabBarHidden would require significant refactoring, which is not practical for many existing apps. Is this caused by a misuse of hidesBottomBarWhenPushed, or could this be a regression or design change in iOS 26’s Liquid Glass UI?

The following is verbatim of a feedback report (FB19809442) I submitted, shared here as someone else might be interested to see it (I hate the fact that we can't see each other's feedbacks). On iOS 16, TextKit 2 calls NSTextLayoutFragment's draw(at:in:) method once for the first paragraph, but for every other paragraph, it calls it continuously on every scroll step in the UITextView. (The first paragraph is not cached; its draw is called again when it is about to be displayed again, but then it is again called only once per its lifecycle.) On iOS 17, the behavior is similar; the draw method gets called once for the 1st and 2nd paragraph, and for every other paragraph it again gets called continuously as a user scrolls a UITextView. On iOS 18 (and iOS 26 beta 4), TextKit 2 calls the layout fragment's draw(at:in:) on every scroll step in the UITextView, for all paragraphs. This results in terrible performance. TextKit 2 is promised to bring many performance benefits by utilizing the viewport - a new concept that represents the visible area of a text view, along with a small overscroll. However, having the draw method being constantly called almost negates all the performance benefits that viewport brings. Imagine what could happen if someone needs to add just a bit of logic to that draw method. FPS drops significantly and UX is terribly degraded. I tried optimizing this by only rendering those text line fragments which are in the viewport, by using NSTextViewportLayoutController.viewportBounds and converting NSTextLineFragment.typographicBounds to the viewport-relative coordinate space (i.e. the coordinate space of the UITextView itself). However, this patch only works on iOS 18 where the draw method is called too many times, as the viewport changes. (I may have some other problems in my implementation, but I gave up on improving those, as this can't work reliably on all OS versions since the underlying framework isn't calling the method consistently.) Is this expected? What are our options for improving performance in these areas?

On an iPad running iOS26, there is an issue with the numberPad keyboard I have a UITextField with a keyboard type of .numberPad When I first tap in the field, a new number pad with just numbers (similar to the one that shows up on iPhone) shows up. When I tap again in the field, that number pad goes away. When I tap in the field again, the full keyboard with numbers etc shows up (this is the one that used to always show up pre-iOS26)

Hello, I have a number of UIViewControllers that are presented as follows: vc.modalPresentationStyle = UIModalPresentationStyle.popover vc.modalTransitionStyle = UIModalTransitionStyle.coverVertical self.present(vc, animated: true, completion: nil) The VC is designed from a Storyboard where I set the 'view' of the VC to have a .clear 'backgroundColor', I have a smaller 'Alert View' added as a subview which is what the user interacts with. In iOS 13 - iOS 18 this would present modally, not take up the entire screen and allow the user to see relevant context from the screen underneath. In iOS 26 Beta 5 and every beta prior the system injects a 'UIDropShadowView' in the View Hierarchy, this view has a solid color backdrop, either white/black depending on light/dark mode. This causes all underlying content to be blocked and essentially forces a full screen modal presentation despite the existing design. I am looking for a way to remove this solid color. I'm not sure if it's intentional or a bug / oversight. I have been able to remove it in a hacky way, I cycle the view hierarchy to find 'UIDropShadowView' and set it's backdrop to transparent. However when you swipe down to partially dismiss the view it turns to Liquid Glass when it is around 75% dismissed and then resets the background color to white/black. I tried creating a custom UIViewControllerTransitioningDelegate so that I could re-implement the existing behaviour but it's incredibly difficult to mimic the partial dismiss swipe down effect on the VC. I have also tried changing my presentation to: vc.modalPresentationStyle = UIModalPresentationStyle.overFullScreen vc.modalTransitionStyle = UIModalTransitionStyle.crossDissolve This works but then the user loses the ability to interactively swipe to dismiss. Any help would be appreciated. Thank you!

I have an iOS Widget that also can load on the Mac when the Use iPhone Widgets setting is turned on on the Mac in Desktop & Dock. I want to use a different url scheme to open video clips from the widget if it is being clicked on iOS or the Mac. I tried using ProcessInfo.processInfo.isiOSAppOnMac but it always thinks it is on iOS. I also tried looking for the user document path to see if it was /var/mobile/ or /Users/. but it always thinks it is /var/mobile. I assume this is as it is not really a catalyst app but a WidgetKit extension from the phone. Is there anyway I can figure out when the widget is running on the mac? Thanks!

I have some apps using SwiftData document based. They work as expected under iOS17, but not under iOS18: install the app on a iPad 11 pro (first gen) from my MacBook open the app and open an existing fils (perfect under iOS17) it shows a blank, white screen, no data I can create a new document, blank screen, no data When I open that newly created file on a iOS 17 iPad pro, it works perfect, as expected The apps were created from scratch under macOS 14.7 with the corresponding Xcode/Swift/UI version. iOS devices under iOS17 Are there any known problems with document based SwiftData-apps under iOS18, are there any changes one has to made? Thank You so much for any help!

Here is a simple view to demonstrate the issue struct ContentView: View { @State private var isPresented = false var body: some View { VStack { Button("Test") { isPresented = true } } .alert("Test", isPresented: $isPresented, actions: { Button("Delete All", role: .destructive) {} }, message: { Text("Are You Sure?") }) .padding() } }``` Which results in ![example alert]("https://developer.apple.com/forums/content/attachment/c6210120-d82e-4df5-a01a-fc5cb168e1bf" "title=Screenshot 2025-09-08 at 08.57.21.png;width=546;height=442") The destructive button is almost unreadable. WCAG score is 1.4, far below the minimum recommended 4.5. I found [this post](https://stackoverflow.com/q/66448869) on SO going back to Big Sur, but not on this forum. Any known workarounds (except for building my own dialogs, which I am trying to avoid)? Using confirmationDialog instead of alert does not make a difference.

I'm implementing infinite scrolling with Swift Charts where additional historical data loads when scrolling near the beginning of the dataset. However, when new data is loaded, the chart's scroll position jumps unexpectedly. Current behavior: Initially loads 10 data points, displaying the latest 5 When scrolling backwards with only 3 points remaining off-screen, triggers loading of 10 more historical points After loading, the scroll position jumps to the 3rd position of the new dataset instead of maintaining the current view Expected behavior: Scroll position should remain stable when new data is loaded User's current view should not change during data loading Here's my implementation logic using some mock data: import SwiftUI import Charts struct DataPoint: Identifiable { let id = UUID() let date: Date let value: Double } class ChartViewModel: ObservableObject { @Published var dataPoints: [DataPoint] = [] private var isLoading = false init() { loadMoreData() } func loadMoreData() { guard !isLoading else { return } isLoading = true let newData = self.generateDataPoints( endDate: self.dataPoints.first?.date ?? Date(), count: 10 ) self.dataPoints.insert(contentsOf: newData, at: 0) self.isLoading = false print("\(dataPoints.count) data points.") } private func generateDataPoints(endDate: Date, count: Int) -> [DataPoint] { var points: [DataPoint] = [] let calendar = Calendar.current for i in 0..<count { let date = calendar.date( byAdding: .day, value: -i, to: endDate ) ?? endDate let value = Double.random(in: 0...100) points.append(DataPoint(date: date, value: value)) } return points.sorted { $0.date < $1.date } } } struct ScrollableChart: View { @StateObject private var viewModel = ChartViewModel() @State private var scrollPosition: Date @State private var scrollDebounceTask: Task<Void, Never>? init() { self.scrollPosition = .now.addingTimeInterval(-4*24*3600) } var body: some View { Chart(viewModel.dataPoints) { point in BarMark( x: .value("Time", point.date, unit: .day), y: .value("Value", point.value) ) } .chartScrollableAxes(.horizontal) .chartXVisibleDomain(length: 5 * 24 * 3600) .chartScrollPosition(x: $scrollPosition) .chartXScale(domain: .automatic(includesZero: false)) .frame(height: 300) .onChange(of: scrollPosition) { oldPosition, newPosition in scrollDebounceTask?.cancel() scrollDebounceTask = Task { try? await Task.sleep(for: .milliseconds(300)) if !Task.isCancelled { checkAndLoadMoreData(currentPosition: newPosition) } } } } private func checkAndLoadMoreData(currentPosition: Date?) { guard let currentPosition, let earliestDataPoint = viewModel.dataPoints.first?.date else { return } let timeInterval = currentPosition.timeIntervalSince(earliestDataPoint) if timeInterval <= 3 * 24 * 3600 { viewModel.loadMoreData() } } } I attempted to compensate for this jump by adding: scrollPosition = scrollPosition.addingTimeInterval(10 * 24 * 3600) after viewModel.loadMoreData(). However, this caused the chart to jump in the opposite direction by 10 days, rather than maintaining the current position. What's the problem with my code and how to fix it?