Summary On iOS 18 and later, Chinese text rendering shows a noticeable performance regression related to the HVF (Hierarchical Variable Font) pipeline. Environment iOS Version: iOS 18+ Framework: libhvf.dylib (Hierarchical Variable Font) Affected Font: PingFangUI.ttc (private system font, automatically used for Chinese text) Related Frameworks: CoreText, CoreGraphics, FontParser Devices: All iOS devices (more noticeable on older hardware) Background iOS 18 Change: PingFang.ttc was removed from /System/Library/Fonts/ Private PingFangUI.ttc was added (inaccessible via normal font APIs) System automatically uses PingFangUI.ttc for all Chinese text rendering PingFangUI.ttc contains HVF tables → utilizes libhvf.dylib HVF Architecture: HVF (Hierarchical Variable Font) organizes glyphs as tree structures Each glyph = Composite → multiple Parts → nested hierarchy Rendering a single character requires traversing this tree Key Observation A single Chinese glyph typically triggers ~20 calls to HVF::LoaderHVGL::loadPartAtIndex. Cache invalidation is triggered via IncrementRenderCount after every 18 glyphs: __ZNK27THierVariationsDataForkFont20IncrementRenderCountEv: ldr w8, [x0, #0x12c] add w8, w8, #0x1 str w8, [x0, #0x12c] cmp w8, #0x12 b.lo return ldr x0, [x0, #0x120] bl HVF_clear_part_cache str wzr, [x19, #0x12c] return: ret This causes the cache to be cleared before a typical sentence finishes rendering. Complete Call Stack (Rendering Hot Path) #0-1 HVF::LoaderHVGL::loadPartAtIndex #2 HVF::FlatPartCache::partAtIndex #3 HVF::PartTransformRenderer::renderComposite #4 HVF::PartTransformRenderer::render #5 HVF::PartTransformRenderer::renderToContext #6 _HVF_render_current_part #7 THierVariationsFontHandler::GetOutlinePath #8 TFontHandler::CopyGlyphPath #9 THierVariationsFontHandler::CopyGlyphPath #10 TFPFont::CopyGlyphPath #11-12 TFPFont::CopyGlyphPath / _FPFontCopyGlyphPath #13 _CGFontCreateGlyphPath #14 _CGGlyphBuilderLockBitmaps #15 _render_glyphs #16 _draw_glyph_bitmaps #17 _ripc_DrawGlyphs #18 CG::DisplayList::executeEntries #19 _CGDisplayListDrawInContextDelegate #20 _CABackingStoreUpdate_ #21-22 CALayer display/layout #23-24 CA::Transaction::commit #25-30 UIApplicationMain / RunLoop HVF::LoaderHVGL::loadPartAtIndex is consistently observed as a hot function in Instruments and in production. Cache Clear Call Stack #0 HVF::FlatPartCache::clear #1 HVF_clear_part_cache #2 THierVariationsDataForkFont::IncrementRenderCount #3 THierVariationsFontHandler::GetOutlinePath #4 TFontHandler::CopyGlyphPath #5 FPFontCopyGlyphPath #6 CGFontCreateGlyphPath #7 _render_glyphs #8 _draw_glyph_bitmaps #9 _ripc_DrawGlyphs This shows that cache clearing occurs within the glyph rendering path. Impact For a typical Chinese sentence (~20 characters): Each glyph requires multiple part loads (~20 per glyph) Cache is cleared before rendering completes Previously loaded parts cannot be reused Observed effects: Increased loadPartAtIndex invocation count Low cache hit rate Increased CPU usage in glyph rendering Main-thread blocking during Core Animation commit Regression iOS 17 and earlier: Rendering is smooth under similar workloads. iOS 18+: Increased rendering cost and visible frame drops. The issue is more pronounced on older devices such as iPhone XS and iPhone 11. Reproduction Render a Chinese text string longer than 18 characters, for example: 刷新测试中文文本用于验证渲染性能问题需要超过十八个字 Observe: Repeated loadPartAtIndex calls Frequent cache clearing Request It would be helpful to review the cache eviction strategy for HVF, particularly for complex scripts such as Chinese. Potential considerations: Adjusting or scaling the cache threshold Avoiding full cache clears during continuous rendering Improving reuse of parts across glyphs within the same rendering batch

The app becomes unresponsive when pushing a new page. The screen is covered by the _UIParallaxOverlayView class, blocking all gestures. Are there any scenarios where the transition animation might suddenly stop mid-process? Or could you provide more information to help me troubleshoot this issue? I noticed: When the issue occurs, the FromViewController is displayed on the screen. The ToViewController also exists in the view tree, but it's not visible on the screen. _UIParallaxOverlayView only appears on iOS 18 and above. The animation appears to be controlled by +[UIView _fluidParallaxTransitionsEnabledWithTraitCollection:], which is _os_feature_enabled_impl("UIKit", "fluid_parallax_transitions"). Reference

Hi, I have a SwiftUI "work time" screen with a rotating ring (60 tick marks, Canvas-based). While the app stays in foreground, rotation is fine. After the app is in background for a while and comes back to foreground, I consistently see one visual glitch: the ring makes one very short step in the opposite direction once then continues rotating clockwise normally So this is not a crash, only a visual reverse tick on resume. What I expect: no direction change after foreground resume continuous clockwise motion What I already tried: withAnimation(.linear(...).repeatForever(...)) + restart on scenePhase TimelineView (.animation and .periodic) with time-based angle angle with and without modulo wrapping wall-clock and monotonic time sources rotation via rotationEffect and also via Canvas geometry warmup delays after resume restoring original ring visuals (long/short tick marks) The effect is still reproducible. Question: What is the correct SwiftUI approach to implement a continuously rotating ring that stays direction-stable across background/foreground transitions, with no one-frame reverse step on resume? Any pattern that is robust on current iOS versions and avoids visual artifacts on scene phase changes would be appreciated. Minimal repro: import SwiftUI struct ReproClockView: View { @Environment(\.scenePhase) private var scenePhase private let tickCount = 60 private let rotationDuration: Double = 120 @State private var rotationDegrees: Double = 0 @State private var hasAppeared = false var body: some View { ZStack { Canvas { context, size in let center = CGPoint(x: size.width / 2, y: size.height / 2) let radius = min(size.width, size.height) / 2 - 8 for index in 0..<tickCount { let angle = Double(index) * (360.0 / Double(tickCount)) - 90 let radians = angle * .pi / 180 let isLongTick = index % 5 == 0 let length: CGFloat = isLongTick ? 22 : 14 let outerRadius = radius let innerRadius = radius - length let startPoint = CGPoint( x: center.x + cos(radians) * outerRadius, y: center.y + sin(radians) * outerRadius ) let endPoint = CGPoint( x: center.x + cos(radians) * innerRadius, y: center.y + sin(radians) * innerRadius ) var path = Path() path.move(to: startPoint) path.addLine(to: endPoint) context.stroke( path, with: .color(.red), style: StrokeStyle(lineWidth: 2.5, lineCap: .round) ) } } .rotationEffect(.degrees(rotationDegrees)) .drawingGroup() } .frame(width: 340, height: 340) .onAppear { guard !hasAppeared else { return } hasAppeared = true startRotation() } .onChange(of: scenePhase) { oldPhase, newPhase in if oldPhase == .background && newPhase == .active { withAnimation(.linear(duration: 0)) { rotationDegrees = 0 } DispatchQueue.main.asyncAfter(deadline: .now() + 0.05) { startRotation() } } } } private func startRotation() { rotationDegrees = 0 withAnimation(.linear(duration: rotationDuration).repeatForever(autoreverses: false)) { rotationDegrees = 360 } } }

If you use .navigationTransition(.zoom(sourceID: zoomID, in: namespace)) with a carousel or a card view, which uses : .stroke(Color.secondary.opacity(0.5), lineWidth: 5) It causes the border stroke to render incorrectly, and even in some cases, the card glitches out and disappears from the screen. The card is clickable but there is no entity in the placeholder of that place.

My app doesn't respond on iPhone Air iOS 26.1. After startup, my app shows the main view with a tab bar controller containing 4 navigation controllers. However, when a second-level view controller is pushed onto any navigation controller, the UI freezes and becomes unresponsive. The iPhone simulator running iOS 26.1 exhibits the same problem. The debug profile shows CPU usage at 100%. However, other devices and simulators do not have this problem.

Hello every developers. I need your help. Do you know how to attach animation to appearance, like a smooth transition from dark to light and vise versa. My code here: @main struct The_Library_of_BabelonApp: App { @AppStorage("selectedAppearance") private var selectedAppearance = 0 @StateObject private var router = AppRouter() var scheme: ColorScheme? { if selectedAppearance == 1 { return .light } if selectedAppearance == 2 { return .dark } return nil } var body: some Scene { WindowGroup { RootView() .preferredColorScheme(scheme) .environmentObject(router) // this is doesn't work correctly .animation(.smooth(duration: 2), value: selectedAppearance) } } } And my appearance switching looks: struct SettingsView: View { @AppStorage("selectedAppearance") private var selectedAppearance = 0 var body: some View { List { Section(header: Text("Appearance")) { HStack(spacing: 20) { ThemePreview(title: "Light", imageName: "lightTheme", tag: 1, selection: $selectedAppearance) ThemePreview(title: "Dark", imageName: "darkTheme", tag: 2, selection: $selectedAppearance) ThemePreview(title: "System", imageName: "systemMode", tag: 0, selection: $selectedAppearance) } .padding(.vertical, 10) .frame(maxWidth: .infinity) } } } } struct ThemePreview: View { let title: String let imageName: String let tag: Int @Binding var selection: Int var body: some View { Button { selection = tag } label: { VStack { Image(imageName) .resizable() .aspectRatio(contentMode: .fill) .frame(width: 120, height: 80) .clipShape(RoundedRectangle(cornerRadius: 12)) .overlay( RoundedRectangle(cornerRadius: 12) .stroke(selection == tag ? Color.blue : Color.clear, lineWidth: 3) ) Text(title) .font(.caption) .foregroundColor(selection == tag ? .blue : .primary) } } .buttonStyle(.plain) } } I guess my code works but animation working another way, its turn my Section, I don't know.... Thank you in advance

During editing in Pages (or Word) I am getting these glitches (see attachment). Started after the last update to Mac OS 26.3 (beta) Also removed 2 recent instalments (Blackhole audio driver and kDrive/Infomaniak, but trouble is still there. 27" iMac 2020 (Intel) i7 3,8 Ghz AMD Radeon Pro 5500 XT 8 GB 24 GB RAM macOS Tahoe 26.3 (=beta) Tried restart in safe mode, checked fonts. Talked to aissistent to get a solution, but no ...) Thx for any advice, Pieter (not a developer so please kee pit simple 🙏🏻)

Hello, I am trying to use matchedGeometryEffect to animate between an item in a list view and the item's detail view. Right now, I am getting an unwanted cross-fade animation as the view transitions. So the list item moves into place as it should with the modifier, but it fades out as its detail version fades in, which I do not want. I do not want any fading at all, just the movement from one component to the other. How do I stop this? Thanks.

On iOS Devices with ProMotion (120HZ) if you animate Elements on your Page with animation-timeline you get Ghosting Effects. You can not see the Ghosting with a Simulator or on Screenshots, only on real Devices. To Reproduce I made a Minimal Example: https://codesandbox.io/p/sandbox/120hztest-xrwgtc When you scroll quickly on the Page with an iOS 120HZ Device (https://en.wikipedia.org/wiki/List_of_smartphones_with_a_high_refresh_rate_display) you will see ghosting on the Top of the right Element (animation-timeline) and no ghosting on the other animated Element. (I edited the Screenshot, to Illustrate how the Effect looks like, since it is only visible on the real Display)

We have an UIViewController called InfoPlayerViewController. Its main subview is from a child view controller backed by SwiftUI via UIHostingController. The InfoPlayerViewController conforms to UIViewControllerTransitioningDelegate. The animation controller for dismissing is DismissPlayerAnimationController. It runs UIKit keyframe animations via UIViewPropertyAnimator. When the keyframe animation is executed there’s an occasional crash for end users in production. It only happens on iOS 26. FB Radar: FB20871547 An example crash is below. Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Exception Reason: +[_SwiftUILayerDelegate _screen]: unrecognized selector sent to class 0x20c95da08 Termination Reason: SIGNAL 6 Abort trap: 6 Triggered by Thread: 0 Last Exception Backtrace: 0 CoreFoundation 0x1a23828c8 __exceptionPreprocess + 164 (NSException.m:249) 1 libobjc.A.dylib 0x19f2f97c4 objc_exception_throw + 88 (objc-exception.mm:356) 2 CoreFoundation 0x1a241e6cc +[NSObject(NSObject) doesNotRecognizeSelector:] + 364 (NSObject.m:158) 3 CoreFoundation 0x1a22ff4f8 ___forwarding___ + 1472 (NSForwarding.m:3616) 4 CoreFoundation 0x1a23073a0 _CF_forwarding_prep_0 + 96 (:-1) 5 UIKitCore 0x1a948e880 __35-[UIViewKeyframeAnimationState pop]_block_invoke + 300 (UIView.m:2973) 6 CoreFoundation 0x1a22cb170 __NSDICTIONARY_IS_CALLING_OUT_TO_A_BLOCK__ + 24 (NSDictionaryHelpers.m:10) 7 CoreFoundation 0x1a245d7cc -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 288 (NSDictionaryM.m:271) 8 UIKitCore 0x1a948e6bc -[UIViewKeyframeAnimationState pop] + 376 (UIView.m:2955) 9 UIKitCore 0x1a7bc40e8 +[UIViewAnimationState popAnimationState] + 60 (UIView.m:1250) 10 UIKitCore 0x1a94acc44 +[UIView(UIViewAnimationWithBlocks) _setupAnimationWithDuration:delay:view:options:factory:animations:start:animationStateGenerator:completion:] + 684 (UIView.m:17669) 11 UIKitCore 0x1a94ae334 +[UIView(UIViewKeyframeAnimations) animateKeyframesWithDuration:delay:options:animations:completion:] + 224 (UIView.m:17945) 12 MyApp 0x102c78dec static UIView.animateNestedKeyframe(withRelativeStartTime:relativeDuration:animations:) + 208 (UIView+AnimateNestedKeyframe.swift:10) 13 MyApp 0x102aef3c0 closure #1 in DismissPlayerAnimationController.slideDownBelowTabBarTransitionAnimator(using:) + 156 (DismissPlayerAnimationController.swift:229) 14 MyApp 0x102a2d3d4 <deduplicated_symbol> + 28 15 UIKitCore 0x1a7d5ae5c -[UIViewPropertyAnimator _runAnimations] + 172 (UIViewPropertyAnimator.m:2123) 16 UIKitCore 0x1a83e1594 __49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke_3 + 92 (UIViewPropertyAnimator.m:3557) 17 UIKitCore 0x1a83e1464 __49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke + 96 (UIViewPropertyAnimator.m:3547) 18 UIKitCore 0x1a83e1518 __49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke_2 + 144 (UIViewPropertyAnimator.m:3553) 19 UIKitCore 0x1a83e0e64 -[UIViewPropertyAnimator _setupAnimationTracking:] + 100 (UIViewPropertyAnimator.m:3510) 20 UIKitCore 0x1a83e1264 -[UIViewPropertyAnimator startAnimationAsPaused:] + 728 (UIViewPropertyAnimator.m:3610) 21 UIKitCore 0x1a83de42c -[UIViewPropertyAnimator pauseAnimation] + 68 (UIViewPropertyAnimator.m:2753) 22 UIKitCore 0x1a87d5328 -[UIPercentDrivenInteractiveTransition _startInterruptibleTransition:] + 244 (UIViewControllerTransitioning.m:982) 23 UIKitCore 0x1a87d5514 -[UIPercentDrivenInteractiveTransition startInteractiveTransition:] + 184 (UIViewControllerTransitioning.m:1012) 24 UIKitCore 0x1a7c7931c ___UIViewControllerTransitioningRunCustomTransitionWithRequest_block_invoke_3 + 152 (UIViewControllerTransitioning.m:1579) 25 UIKitCore 0x1a892aefc +[UIKeyboardSceneDelegate _pinInputViewsForKeyboardSceneDelegate:onBehalfOfResponder:duringBlock:] + 96 (UIKeyboardSceneDelegate.m:3518) 26 UIKitCore 0x1a7c79238 ___UIViewControllerTransitioningRunCustomTransitionWithRequest_block_invoke_2 + 236 (UIViewControllerTransitioning.m:1571) 27 UIKitCore 0x1a94ab4b8 +[UIView(Animation) _setAlongsideAnimations:toRunByEndOfBlock:animated:] + 188 (UIView.m:17089) 28 UIKitCore 0x1a7c79070 _UIViewControllerTransitioningRunCustomTransitionWithRequest + 556 (UIViewControllerTransitioning.m:1560) 29 UIKitCore 0x1a86cb7cc __77-[UIPresentationController runTransitionForCurrentStateAnimated:handoffData:]_block_invoke_3 + 1784 (UIPresentationController.m:1504) 30 UIKitCore 0x1a7c43888 -[_UIAfterCACommitBlock run] + 72 (_UIAfterCACommitQueue.m:137) 31 UIKitCore 0x1a7c437c0 -[_UIAfterCACommitQueue flush] + 168 (_UIAfterCACommitQueue.m:228) 32 UIKitCore 0x1a7c436d0 _runAfterCACommitDeferredBlocks + 260 (UIApplication.m:3297) 33 UIKitCore 0x1a7c43c34 _cleanUpAfterCAFlushAndRunDeferredBlocks + 80 (UIApplication.m:3275) 34 UIKitCore 0x1a7c1f104 _UIApplicationFlushCATransaction + 72 (UIApplication.m:3338) 35 UIKitCore 0x1a7c1f024 __setupUpdateSequence_block_invoke_2 + 352 (_UIUpdateScheduler.m:1634) 36 UIKitCore 0x1a7c2cee8 _UIUpdateSequenceRunNext + 128 (_UIUpdateSequence.mm:189) 37 UIKitCore 0x1a7c2c378 schedulerStepScheduledMainSectionContinue + 60 (_UIUpdateScheduler.m:1185) 38 UpdateCycle 0x28c58f5f8 UC::DriverCore::continueProcessing() + 84 (UCDriver.cc:288) 39 CoreFoundation 0x1a2323230 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 (CFRunLoop.c:2021) 40 CoreFoundation 0x1a23231a4 __CFRunLoopDoSource0 + 172 (CFRunLoop.c:2065) 41 CoreFoundation 0x1a2300c6c __CFRunLoopDoSources0 + 232 (CFRunLoop.c:2102) 42 CoreFoundation 0x1a22d68b0 __CFRunLoopRun + 820 (CFRunLoop.c:2983) 43 CoreFoundation 0x1a22d5c44 _CFRunLoopRunSpecificWithOptions + 532 (CFRunLoop.c:3462) 44 GraphicsServices 0x2416a2498 GSEventRunModal + 120 (GSEvent.c:2049) 45 UIKitCore 0x1a7c50ddc -[UIApplication _run] + 792 (UIApplication.m:3899) 46 UIKitCore 0x1a7bf5b0c UIApplicationMain + 336 (UIApplication.m:5574) // ...

Is the pseudocode below thread-safe? Imagine that the Main thread sets the CAMetalLayer's drawableSize to a new size meanwhile the rendering thread is in the middle of rendering into an existing MTLDrawable which does still have the old size. Is the change of metalLayer.drawableSize thread-safe in the sense that I can present an old MTLDrawable which has a different resolution than the current value of metalLayer.drawableSize? I assume that setting the drawableSize property informs Metal that the next MTLDrawable offered by the CAMetalLayer should have the new size, right? Is it valid to assume that "metalLayer.drawableSize = newSize" and "metalLayer.nextDrawable()" are internally synchronized, so it cannot happen that metalLayer.nextDrawable() would produce e.g. a MTLDrawable with the old width but with the new height (or a completely invalid resolution due to potential race conditions)? func onWindowResized(newSize: CGSize) { // Called on the Main thread metalLayer.drawableSize = newSize } func onVsync(drawable: MTLDrawable) { // Called on a background rendering thread renderer.renderInto(drawable: drawable) }

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() } } }

On devices and simulators with iOS 26.1, the animation does not work correctly (the initial and final screens are distorted). I use open class func transition(with view: UIView, duration: TimeInterval, options: UIView.AnimationOptions = [], animations: (() -> Void)?, completion: ((Bool) -> Void)? = nil) with options: .transitionFlipFromRight

I'm Trying to add an NSProgressIndicator on the unlock (first lock screen ) in macOS ( the screen with the lock icon ) I already added a label and it works fine and after entering the password on the second (authentication) page I can able to add ProgressIndicator but not on first screen. But Whenever I try to add a Progress indicator, the entire screen turns Black and nothing is displayed Is NSProgressIndicator supported on the first unlock Screen ? Or does macOS block animated UI on this screen Any Guidance would be helpful Thanks

please fix!

Good day! Have anyone experienced sudden crashes increase cause by CALayerInvalidGeometry · CALayer position contains NaN: [nan 5] that gets set via -[AVMobileGlassVolumeControlsView layoutSubviews]? 94% of crashes belong to iOS 26.0.1, while rest to 26.0. What's weird, though, is that it is caused by some AVKit internal logic and cant' understand how to track it down, neither how to reproduce. Stack trace looks as follows: 0 CoreFoundation +0xc98c4 ___exceptionPreprocess 1 libobjc.A.dylib +0x317c0 _objc_exception_throw 2 CoreFoundation +0x1548d0 +[NSException raise:format:] 3 QuartzCore +0x909b4 CA::Layer::set_position(CA::Vec2<double> const&, bool) 4 QuartzCore +0x2af294 -[CALayer setPosition:] 5 UIKitCore +0xe9fc18 -[UIView _backing_setPosition:] 6 UIKitCore +0x18f6158 -[UIView setCenter:] 7 UIKitCore +0x1eb704 0x188b5e704 (0x188b5e5f4 + 272) 8 UIKitCore +0x1eb56c 0x188b5e56c (0x188b5e4f0 + 124) 9 UIKitCore +0x18fd318 -[UIView(Geometry) _resizeWithOldSuperviewSize:] 10 CoreFoundation +0x1514c ___NSARRAY_IS_CALLING_OUT_TO_A_BLOCK__ 11 CoreFoundation +0xdd18c -[__NSArrayM enumerateObjectsWithOptions:usingBlock:] 12 UIKitCore +0x18fc6dc -[UIView(Geometry) resizeSubviewsWithOldSize:] 13 UIKitCore +0x18fabd0 -[UIView(Geometry) setFrame:] 14 AVKit +0x1b5a88 -[AVMobileGlassVolumeControlsView layoutSubviews] 15 UIKitCore +0x27074 0x18899a074 (0x188999d3c + 824) 16 UIKitCore +0x27b34 0x18899ab34 (0x18899ab14 + 32) 17 UIKitCore +0x190df64 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] 18 QuartzCore +0xac9a4 CA::Layer::perform_update_(CA::Layer*, CALayer*, unsigned int, CA::Transaction*) 19 QuartzCore +0x8f2f8 CA::Layer::update_if_needed(CA::Transaction*, unsigned int, unsigned int) 20 UIKitCore +0x57b0 -[UIView(Hierarchy) layoutBelowIfNeeded] 21 AVKit +0x1b6634 ___74-[AVMobileGlassVolumeControlsView _updateVolumeFluidSliderEmphasizedScale]_block_invoke 22 UIKitCore +0x1b3e58 -[UIViewPropertyAnimator _runAnimations] 23 UIKitCore +0x19025f0 +[UIView(Animation) _performWithState:trackingIdentifier:duration:delay:animations:] 24 UIKitCore +0x83a650 ___49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke_4 25 UIKitCore +0x83a460 ___49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke 26 UIKitCore +0x83a210 -[UIViewPropertyAnimator startAnimationAsPaused:] 27 AVKit +0x1b6574 -[AVMobileGlassVolumeControlsView setEmphasized:] 28 AVKit +0x127510 ___64-[AVMobileGlassControlsViewController _animateVolumeEmphasisTo:]_block_invoke 29 UIKitCore +0x1b3e58 -[UIViewPropertyAnimator _runAnimations] 30 UIKitCore +0x83a590 ___49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke_3 31 UIKitCore +0x83a460 ___49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke 32 UIKitCore +0x83a514 ___49-[UIViewPropertyAnimator startAnimationAsPaused:]_block_invoke_2 33 UIKitCore +0x839e60 -[UIViewPropertyAnimator _setupAnimationTracking:] 34 UIKitCore +0x83a260 -[UIViewPropertyAnimator startAnimationAsPaused:] 35 AVKit +0x127480 -[AVMobileGlassControlsViewController _animateVolumeEmphasisTo:] 36 AVKit +0x12ea2c ___56-[AVMobileGlassControlsViewController _observationSetup]_block_invoke_5 37 AVKit +0xcbcd0 ___106-[AVObservationController startObservingNotificationForName:object:notificationCenter:observationHandler:]_block_invoke 38 CoreFoundation +0x519ec ___CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ 39 CoreFoundation +0x51ab0 ____CFXRegistrationPost_block_invoke 40 CoreFoundation +0x5190c __CFXRegistrationPost 41 CoreFoundation +0x520ac __CFXNotificationPost 42 Foundation +0x94fc2c -[NSNotificationCenter postNotificationName:object:userInfo:] 43 AVKit +0x1b9bd8 -[AVSystemVolumeController _postNotificationForNameIfFullyInitialized:userInfo:] 44 AVKit +0x1b9dc0 -[AVSystemVolumeController setVolume:shouldShowHUD:] 45 AVKit +0x1b965c ___69-[AVSystemVolumeController _handleSystemVolumeDidChangeNotification:]_block_invoke 46 AVKit +0x1b8da4 -[AVSystemVolumeController _performOnMainThread:] 47 AVKit +0x1b95c0 -[AVSystemVolumeController _handleSystemVolumeDidChangeNotification:] 48 CoreFoundation +0x51a00 ___CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ 49 CoreFoundation +0x51ab0 ____CFXRegistrationPost_block_invoke 50 CoreFoundation +0x5190c __CFXRegistrationPost 51 CoreFoundation +0x520ac __CFXNotificationPost 52 Foundation +0x94fc2c -[NSNotificationCenter postNotificationName:object:userInfo:] 53 MediaExperience +0x1039b0 ___76+[AVSystemControllerCommon postNotificationOnMainQueue:notification:object:]_block_invoke 54 MediaExperience +0x6b64 ___MXDispatchAsync_block_invoke 55 libdispatch.dylib +0x1ad8 __dispatch_call_block_and_release 56 libdispatch.dylib +0x1b7e8 __dispatch_client_callout 57 libdispatch.dylib +0x38b20 __dispatch_main_queue_drain.cold.5 58 libdispatch.dylib +0x10ec4 __dispatch_main_queue_drain 59 libdispatch.dylib +0x10e00 __dispatch_main_queue_callback_4CF 60 CoreFoundation +0x6b51c ___CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ 61 CoreFoundation +0x1dd10 ___CFRunLoopRun 62 CoreFoundation +0x1cc40 __CFRunLoopRunSpecificWithOptions 63 GraphicsServices +0x1494 _GSEventRunModal 64 UIKitCore +0xa9dd8 -[UIApplication _run] 65 UIKitCore +0x4eb08 _UIApplicationMain 66 TuneIn Radio +0x1b318 main (main.m:28:22) 67 dyld +0x4e24 start

Hi. Since Xcode 16 and/or iOS 18.0 (I upgraded at the same time), I have an strange effect in the lower (let's say) 20% section of the Navigation Bar when changing to another tab, and this independently if large titles are used or not. Mentioned section is brighter or darker than the rest of the Navigation Bar background, depending on which background tint is used. This effect lasts about 0.3 seconds, but is clearly visible, quite disturbing and new as of Xcode 16 and/or iOS 18.0. I use the code below in AppDelegate to get a gradient coloured Navigation Bar background. let appearance = UINavigationBarAppearance() UINavigationBar.appearance().standardAppearance = appearance UINavigationBar.appearance().compactAppearance = appearance UINavigationBar.appearance().scrollEdgeAppearance = appearance UINavigationBar.appearance().compactScrollEdgeAppearance = appearance If I don't use above code., the background color is filled and without gradient. Subject effect doesn't show in this case. The effect basically looks like when changing tab, the new Navigation Bar background doesn't clear right away, and keeps the background from the previous Navigation Bar for 0.3 seconds before new one Navigation Bar background is rendered. I spent quite some time on changing every possible setting, in code as well as storyboard ... no success so far. Any ideas how to disable this undesired animation?

Hi everyone, After upgrading to macOS 26 (Tahoe) I’ve run into an issue: NSTextField becomes noticeably blurry when its parent layer is transformed (CATransform3D or CGAffineTransform). On macOS 15 (Sequoia) the exact same code worked fine — text stayed sharp. Interestingly, an NSImage backed by a PDF representation transforms without any problem and remains perfectly crisp, but labels do not. What I’ve tried so far Checked the contentsScale of the layers Setting magnificationFilter = .nearest Toggled shouldRasterize on/off and adjusted rasterizationScale Have there been any Core Animation or AppKit changes in macOS 26 that affect text rendering when transforming layers? What’s the recommended way now to keep NSTextField text sharp (similar to how vector PDF images behave) when scaling its parent layer? Any insights, best practices, or workarounds would be greatly appreciated. Thanks in advance!

From what I’ve seen, this issue has been around since macOS 13 and can be reproduced reliably. It happens with some apps like Music, Notes, and Google Chrome. Here’s how to see it: 1.Make sure “Minimize windows into application” is enabled in System Settings, or just open a minimized app later directly from its application icon. 2.Open one of the apps mentioned above. 3.Minimize it. 4.Click the minimized app in the Dock to restore it. You’ll notice the GUI flashes for a moment and the minimize animation plays again. Some additional info here: https://forums.macrumors.com/threads/weird-glitches-during-restore-from-minimalization-of-any-app.2370260/ A video clipped from another GitHub issue: https://private-user-images.githubusercontent.com/13177224/445474477-36d8c784-9588-4186-8b6a-875c4077ce1c.mp4?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.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.xbAxdTgxadCVCZPsnZkhx9HnVbjP-D5w1GfPTBatIWQ

Hi all, After upgrading to the iOS 26 beta, the scrolling in my SwiftUI chat view is completely broken. The exact same code works perfectly on iOS 18. Context: I have a chat view using ScrollViewReader and a vertically-reversed ScrollView (with .rotationEffect(.degrees(180))). Each message row (MessageBubble) uses multiple simultaneousGesture handlers: Horizontal drag for swipe-to-reply (and other actions: pin, delete) Long press for showing popover/actions Vertical scroll for normal chat scrolling This was working great on iOS 18. In iOS 26 beta, the vertical scroll is either completely disabled, jittery, or hijacked by the message row’s drag gestures, even though .simultaneousGesture is used (see code below). Minimal Repro Sample MessageListView.swift swift Copy Edit ScrollViewReader { proxy in ScrollView(.vertical, showsIndicators: false) { LazyVStack(spacing: 0) { // ... grouped messages ForEach(...) { ... MessageBubble(...) // see below } Color.clear.frame(height: 8).id("BOTTOM_ANCHOR") } .padding(.horizontal, 4) .rotationEffect(.degrees(180)) } .rotationEffect(.degrees(180)) } MessageBubble.swift struct MessageBubble: View { // ... var body: some View { // horizontal swipe-to-reply gesture let dragGesture = DragGesture(minimumDistance: 10) // ... ZStack { // ... HStack { ... } // ... .simultaneousGesture( DragGesture(minimumDistance: 0) // for long press // ... ) .simultaneousGesture(dragGesture) // for horizontal swipe } // ... } }