Dear random Apple UIKit engineer. This is a question for you. Today let's speak about keyboard notifications. In particular, UIResponder.keyboardWillShowNotification and UIResponder.keyboardWillHideNotification. While working with those, I noticed some undocumented behaviour. First, let me give you some context: extension UIViewController { func registerForKeyboardNotifications() { NotificationCenter.default.addObserver(self, selector: #selector(keyboardNotification), name: UIResponder.keyboardWillShowNotification, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(keyboardNotification), name: UIResponder.keyboardWillHideNotification, object: nil) } /// Override this method to handle keyboard notifications. @objc func keyboardNotification(_ notification: Notification) { ... } } Eventually, I found that latter method with 3 dots has an implicit animation inside it's scope. Here is the [proof.](https://medium.com /uptech-team/why-does-uiresponder-keyboard-notification-handler-animate-10cc96bce372) Another thing I noticed, is that this property definition is perfectly valid let curve = UIView.AnimationCurve(rawValue: 7)!. The 7 btw comes from UIResponder.keyboardAnimationCurveUserInfoKey as a default value during my tests. So, the enum with 4 possible values (0...3) can be initialized with a value out of enum's cases range. Also, how can I initialize UIView.AnimationOption from 7? I will pollute my OptionSet which I feed to options parameter on UIView.animate(...) My questions: Why implicit animation is not documented and can I trust it or it's a subject to change. Why UIView.AnimationCurve(rawValue: 7)! does not crash. How can I convert UIResponder.keyboardAnimationCurveUserInfoKey's value into UIView.AnimationOption properly if I don't want to use implicit value. I don't encroach on UIKit secrets. I just need to know how to work with the API. Thank you!

I want to support Genmoji input in my SwiftUI TextField or TextEditor, but looking around, it seems there's no SwiftUI only way to do it? If none, it's kind of disappointing that they're saying SwiftUI is the path forward, but not updating it with support for new technologies. Going back, does this mean we can only support Genmoji through UITextField and UIViewRepresentable? or there more direct options? Btw, I'm also using SwiftData for storage.

Hello! What UIKit API enables you to add a view below the navigation bar and extend the scroll edge effect below it in iOS 26? safeAreaBar is how you do it in SwiftUI but I need to achieve this design in my UIKit app (which has a collection view in a view controller in a navigation controller). struct ContentView: View { let segments = ["First", "Second", "Third"] @State private var selectedSegment = "First" var body: some View { NavigationStack { List(0..<50, id: \.self) { i in Text("Row \(i + 1)") } .safeAreaBar(edge: .top) { Picker("Segment", selection: $selectedSegment) { ForEach(segments, id: \.self) { Text($0) } } .pickerStyle(.segmented) .padding(.horizontal) .padding(.bottom, 8) } .navigationTitle("Title") .navigationBarTitleDisplayMode(.inline) } } }

Hello. I have an 12 year old app that still has some objective-c code in it. I have a place where i have a flip animation between 2 view controllers that looks like this: [UIView transitionFromView:origView toView:newViewController.view duration:0.5 options:UIViewAnimationOptionTransitionFlipFromRight completion:nil]; It has looked like this since 2012 at least. In our production release, it works prior to 26.1, but in 26.1 and 26.2, the flip is off-center and looks weird. it's like both edges flip the same way. It's a little bit hard to explain. If seen at least 2 other app store apps that i have installed behave this way too, from 26.1 and onwards. Anyone else seen this? Is there anything that can be done about it? Thankful for thoughts.

I have an app where I create UIToolbars and add them to UIViews programatically. I've never used autolayout for anything, I've never assigned any constraints to anything, etc. This worked fine pre-iOS 26. Now I'm trying to build for iOS 26 (liquid glass) and my toolbars are spamming my debug pane with hundreds of lines of autolayout warnings. Here are some key phrases from the warnings: Unable to simultaneously satisfy constraints. Will attempt to recover by breaking constraint Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) Does anybody know what happened and how I can get it to stop? The way things are, I can't use the debug pane for anything because of this spam.

When a UIVisualEffect with glass effect view is added with opacity 0, it remains hidden as expected. But when changing it back to 1 should make it visible, but currently it stays hidden forever. The bug is only reproducible on iOS 26.1 and iOS 26.2. It does not happen on iOS 26.0. The issue is also not reproducible with UIBlurEffect. Only happens for Glass effect Here is the repro link

Hello! I'm creating a settings page for my app and I want it to look as native as possible. I want to know if it's possible to add constraints that make the second label go to the bottom when the text size gets really large (see Picture1) instead of having to force it to be on the right (see Picture 2). I've left my constraint code for this cell down below, too. I'm still learning constraints and best practices, so if there's any feedback, I'd love to hear it. Thank you! Picture 1 Picture 2 - (void) setConstraints { [NSLayoutConstraint activateConstraints:@[ // Cell Title Label [self.themeColorLabel.leadingAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.leadingAnchor], [self.themeColorLabel.trailingAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.trailingAnchor], [self.themeColorLabel.topAnchor constraintEqualToAnchor: self.contentView.layoutMarginsGuide.topAnchor], [self.themeColorLabel.bottomAnchor constraintEqualToAnchor: self.contentView.layoutMarginsGuide.bottomAnchor], // Selected Theme Color Label [self.selectedColorLabel.trailingAnchor constraintEqualToAnchor: self.contentView.layoutMarginsGuide.trailingAnchor], [self.selectedColorLabel.topAnchor constraintEqualToAnchor: self.contentView.layoutMarginsGuide.topAnchor], [self.selectedColorLabel.bottomAnchor constraintEqualToAnchor: self.contentView.layoutMarginsGuide.bottomAnchor], ]]; }

After switching our iOS app project from Swift 5 to Swift 6 and publishing an update, we started seeing a large number of crashes in Firebase Crashlytics. The crashes are triggered by NotificationCenter methods (post, addObserver, removeObserver) and show the following error: BUG IN CLIENT OF LIBDISPATCH: Assertion failed: Block was expected to execute on queue [com.apple.main-thread (0x1f9dc1580)] All scopes to related calls are already explicitly marked with @MainActor. This issue never occurred with Swift 5, but appeared immediately after moving to Swift 6. Has anyone else encountered this problem? Is there a known solution or workaround? Thanks in advance!

I was trying to figure out why my bottom sheet looks weird and doesn't have the "proper glass" look. I found that this issue seems to be new to iOS 26.1. See the images below, they show the same view hierarchy (in this case UIHostingController configured as bottom sheet that has NavigationStack and content. On iOS 26.1 there seems to be extra two layers of background - even though I am no adding any. iOS 26: iOS 26.1 Has anyone experienced something similar? Any workarounds? I am happy to completely disable the glass effect for this bottom sheet if it helps. The screenshots show one sheet, but the same thing happens for another ones.

I have a Catalyst app on the App Store and I'm starting to get messages from users that the popover bubbles all over the app are without content. I see the error locally as well, but I don't know how to fix it. I get the following warning in XCode when opening a popup: UIScene property of UINSSceneViewController was accessed before it was set.

When UIStatusBarHidden is set to YES, the navigation bar is displayed in the wrong vertical position immediately after app launch. The layout only corrects itself after the device orientation changes (e.g., rotation). Steps to Reproduce: Create a new app with a navigation controller. Set UIStatusBarHidden = YES in Info.plist. Launch the app. Expected Result: The navigation bar should appear in the correct position immediately after launch. Actual Result: The navigation bar is misaligned on first launch, and only moves to the correct position after rotating the device.

Does iOS 26 support HDR images for app icons to be rendered in High Dynamic Range for Springboard or not?

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?

I am using a common UI pattern: UITabBarController as window root, each tab with a separate UINavigationController stack. I want the (bottom!) tab bar to be only visible when the user is at the root of the app and hide it when a detail page is opened. To do that, I used hidesBottomBarWhenPushed on any view controller that would be pushed on my navigation stacks and that worked fine in the past. But with iOS 26, I am seeing several issues: On iOS where when the bottom tab bar is used, when in a details page and navigating back, the tab bar becomes fully visible immediately instead of slowly animating in as it has been in the past. This is particular visible and annoying when using the "swipe to go back" gesture On iPad, the situation is even worse: On iPadOS 18, the tab bar appeared in the navigation controller's navigation bar - no matter if hidesBottomBarWhenPushed was set or not - fine. But now, with iPadOS 26, this top tab bar disappears when a child is pushed. Not only that, it disappears abruptly, without animation, and the Liquid Glass effect on the UIBarButtonItems is broken as well. There is no transition whatsoever, buttons are simply replaced with the new UIBarButtonItems of the pushed view controller once it became fully visible. It gets even worse when swipe-back navigating on iPadOS: As soon as the back transition starts, the tab bar becomes visible again (without animation), covering the title (view) of the UINavigationController. If the swipe-back transition is not completed the tab bar suddenly stays visible When the swipe-back transition is interrupted close to the end of the transition and it goes back to the pushed view controller, the top UIBarButtonItems are showing a visual glitch where the content (text or icon) stays on the area where the tab bar is, while their container (the glass effect) are on the vertically aligned to the title view. I am surprised that I have not found any similar reports of these problems, so I am wondering if I am doing anything wrong or using hidesBottomBarWhenPushed simply isn't recommended or supported any more.

After the iOS 26 update, unwanted animations appear on UIButton. I'm using the attributedTitle property of UIButton.Configuration to change the button's text, and an animation appears after iOS 26. (It's unclear whether it's after iOS 26.0 or iOS 26.1, but it likely started with 26.1.) The peculiar thing is that the animation only starts appearing on buttons that have been pressed once. I tried using UIView.performWithoutAnimation and CATransaction's begin(), setDisableActions(true), commit(), but it didn't work. How should I solve this? Below is the code for changing the button's text. func updateTitle() { let keys = type.keys if keys.count == 1 { guard let key = keys.first else { return } if key.count == 1 { if Character(key).isLowercase { self.configuration?.attributedTitle = AttributedString(key, attributes: AttributeContainer([.font: UIFont.systemFont(ofSize: 24, weight: .regular), .foregroundColor: UIColor.label])) } else if Character(key).isUppercase { self.configuration?.attributedTitle = AttributedString(key, attributes: AttributeContainer([.font: UIFont.systemFont(ofSize: 22, weight: .regular), .foregroundColor: UIColor.label])) } else { self.configuration?.attributedTitle = AttributedString(key, attributes: AttributeContainer([.font: UIFont.systemFont(ofSize: 22, weight: .regular), .foregroundColor: UIColor.label])) } } else { self.configuration?.attributedTitle = AttributedString(key, attributes: AttributeContainer([.font: UIFont.systemFont(ofSize: 18, weight: .regular), .foregroundColor: UIColor.label])) } } else { let joined = keys.joined(separator: "") self.configuration?.attributedTitle = AttributedString(joined, attributes: AttributeContainer([.font: UIFont.systemFont(ofSize: 22, weight: .regular), .foregroundColor: UIColor.label])) } }

Device: iPhone 11 iOS Version: 17.2.1 Frameworks: UIKit, Auto Layout App Behavior: App supports Arabic (RTL). User can switch language in-app. When language is switched, the app sets UIView.appearance().semanticContentAttribute and fully rebuilds the window’s rootViewController. Problem Summary I update the global semantic direction only when the user explicitly switches language inside the app — e.g.: // Only run when user switches language inside the app UIView.appearance().semanticContentAttribute = .forceRightToLeft // or .forceLeftToRight // then rebuild the window's rootViewController I do not change UIView.appearance().semanticContentAttribute during navigation transitions. Despite that, after switching the language (and rebuilding the root), the app sometimes crashes during a subsequent UINavigationController push/pop animation. The crash appears to be caused by UIKit’s Auto Layout engine removing or updating directional constraints while a navigation transition is running. Crash Log (most relevant portion) Crashed: com.apple.main-thread 0 CoreAutoLayout 0x1372c -[NSISEngine positiveErrorVarForBrokenConstraintWithMarker:errorVar:] + 212 1 CoreAutoLayout 0x121d4 -[NSISEngine removeConstraintWithMarker:] + 1028 2 CoreAutoLayout 0x11d78 -[NSLayoutConstraint _removeFromEngine:] + 148 3 UIKitCore 0x124ba9c __58-[UIView _updateDirectionalConstraintsIfNeededWasFlipped:]_block_invoke_2 + 56 4 UIKitCore 0x484d4 ___UIViewEnumerateLayoutConstraintsAndAdjustForSelectedLayoutVariables_block_invoke + 296 5 UIKitCore 0x4801c -[UIView(AdditionalLayoutSupport) _withUnsatisfiableConstraintsLoggingSuspendedIfEngineDelegateExists:] + 112 6 UIKitCore 0x60830 -[UIView _updateDirectionalConstraintsIfNeededWasFlipped:] + 356 7 UIKitCore 0x60494 -[UIView setSemanticContentAttribute:] + 148 8 CoreFoundation 0x31794 __invoking___ + 148 9 CoreFoundation 0xe6360 -[NSInvocation invokeUsingIMP:] + 332 10 UIKitCore 0x1d93ec __workaround10030904InvokeWithTarget_block_invoke + 68 11 UIKitCore 0x250ec +[UIView _performSystemAppearanceModifications:] + 72 12 UIKitCore 0x3f008 applyInvocationsToTarget + 1004 13 UIKitCore 0x3dcd4 +[_UIAppearance _applyInvocationsTo:window:matchingSelector:onlySystemInvocations:] + 1180 14 UIKitCore 0x3d744 __88-[UIView(Internal) _performUpdatesForPossibleChangesOfIdiom:orScreen:traverseHierarchy:]_block_invoke + 68 15 UIKitCore 0x3d6c4 -[UIView _performUpdatesForPossibleChangesOfIdiom:orScreen:traverseHierarchy:] + 216 16 UIKitCore 0x3d5a0 -[UIView _didChangeFromIdiomOnScreen:traverseHierarchy:] + 112 17 UIKitCore 0x11644 -[UIView(Internal) _didMoveFromWindow:toWindow:] + 1220 18 UIKitCore 0x1142c -[UIView(Internal) _didMoveFromWindow:toWindow:] + 684 19 UIKitCore 0x1142c -[UIView(Internal) _didMoveFromWindow:toWindow:] + 684 20 UIKitCore 0x1142c -[UIView(Internal) _didMoveFromWindow:toWindow:] + 684 21 UIKitCore 0x10eb4 __45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke + 124 22 CoreAutoLayout 0xa514 -[NSISEngine withBehaviors:performModifications:] + 84 23 UIKitCore 0x10ddc -[UIView _postMovedFromSuperview:] + 504 24 UIKitCore 0xfa24 -[UIView(Internal) _addSubview:positioned:relativeTo:] + 2200 25 UIKitCore 0x7a63b8 __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke_2 + 1252 26 UIKitCore 0x41a70 +[UIView(Animation) performWithoutAnimation:] + 76 27 UIKitCore 0x7a5e84 __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke + 240 28 UIKitCore 0x12749c +[UIView _performBlockDelayingTriggeringResponderEvents:forScene:] + 176 29 UIKitCore 0x7a5990 -[_UINavigationParallaxTransition animateTransition:] + 952 30 UIKitCore 0x291098 ___UIViewControllerTransitioningRunCustomTransition_block_invoke_3 + 52 31 UIKitCore 0x29100c +[UIKeyboardSceneDelegate _pinInputViewsForKeyboardSceneDelegate:onBehalfOfResponder:duringBlock:] + 96 32 UIKitCore 0x290f70 ___UIViewControllerTransitioningRunCustomTransition_block_invoke_2 + 196 33 UIKitCore 0x1d8c8c +[UIView(Animation) _setAlongsideAnimations:toRunByEndOfBlock:] + 180 34 UIKitCore 0x1d851c _UIViewControllerTransitioningRunCustomTransition + 484 35 UIKitCore 0x6f5a84 -[UINavigationController _startCustomTransition:] + 3292 36 UIKitCore 0x1182a8 -[UINavigationController _startDeferredTransitionIfNeeded:] + 496 37 UIKitCore 0x1179a0 -[UINavigationController __viewWillLayoutSubviews] + 96 38 UIKitCore 0x117904 -[UILayoutContainerView layoutSubviews] + 172 39 UIKitCore 0x3297c -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1528 40 QuartzCore 0x66aa8 CA::Layer::layout_if_needed(CA::Transaction*) + 500 41 QuartzCore 0x66630 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 144 42 QuartzCore 0x6cb60 CA::Context::commit_transaction(CA::Transaction*, double, double*) + 464 43 QuartzCore 0x65e3c CA::Transaction::commit() + 648 44 QuartzCore 0x65ae4 CA::Transaction::flush_as_runloop_observer(bool) + 88 45 CoreFoundation 0x3583c __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 36 46 CoreFoundation 0x34244 __CFRunLoopDoObservers + 548 47 CoreFoundation 0x33960 __CFRunLoopRun + 1028 48 CoreFoundation 0x33478 CFRunLoopRunSpecific + 608 49 GraphicsServices 0x34f8 GSEventRunModal + 164 50 UIKitCore 0x22c62c -[UIApplication _run] + 888 51 UIKitCore 0x22bc68 UIApplicationMain + 340 52 MyApp 0x46a040 main + 44 (AppDelegate.swift:44) 53 ??? 0x1c8d52dcc (缺少) Questions / Requests Recommended patterns for in-app language switching (LTR ⇄ RTL) to avoid direction/constraint races during animations? For example: Should semantic direction be applied to the window/root view controller only? Should we avoid rebuilding root during an active transition? Any suggested synchronization (e.g., wait for transitions to finish) or APIs to call after rebuilding?

My app start up has became horrid. It takes 1 minute to open SQLlite database for my rust core. Impossible to work... I have Address Sanitizer, Thread Perf Checker and Thread Sanitizer disabled...

This is a problem from Beta 1, but since there is no fix yet in Beta 3, I'd like to raise it. The app is built with macCatalyst, and we have pretty simple tab bar controller setup: viewController = UITabBarController() viewController.tabBar.tintColor = .buttonForegroundColor importWorkflow = ModelImportWorkflow( userInterfaceIdiom: userInterfaceIdiom, workspace: workspace) mergeWorkflow = ModelMergeWorkflow(userInterfaceIdiom: userInterfaceIdiom, workspace: workspace) listWorkflow = ModelListWorkflow(workspace: workspace, userInterfaceIdiom: userInterfaceIdiom) viewController.viewControllers = [ listWorkflow.viewControllable, importWorkflow.viewControllable, mergeWorkflow.viewControllable, ] viewController.modalPresentationStyle = .formSheet We don't do any customizations on the tab bar and in Beta 3 (26.2), there is no way to found the tab bar (attached a user reported image). Please advise what's the course of action. Thanks.

When I run my Mac Catalyst app I'm getting unacceptable performance when resizing the window. Window resizing is very unresponsive/laggy. Configuration: The root view controller is a UISplitViewController (three pane split using UISplitViewControllerStyleTripleColumn). Sidebar is configured. It's using a UICollectionView sidebar style (so it looks like NSOutlineView in AppKit). On initial launch there is no selection and the second and third view controllers in the split have empty placeholder view controllers. At this point window resizing is fine. Now I make a selection in the sidebar. This populates the supplementary view controller with a view controller that uses a UITableView. Now resizing the window performance is awful. Basically this is unusable. When resizing the window a bunch what looks to be Core Animation related logs flood the console during window resize: cannot add handler to 3 from 1 - dropping Library: QuartzCore | Subsystem: com.apple.coreanimation Now if I go to my app's Info.plist and add: UIDesignRequiresCompatibility entry with a value of TRUE and follow the same steps described above window resizing works as expected and I do not experience performance issues. Also with UIDesignRequiresCompatibility there is no "cannot add handlers" error logs flooding the console on window resize.

Returning to a Mac Catalyst app that I put to the side for awhile..when running it on Xcode 26.1 it crashes at launch with: Assertion failure in -[NSToolbarItemGroupView _layoutWrapperViewsWithAttributes:], NSToolbarItemGroupView.m:599 No attributes were found for item Call stack has a bunch of Autolayout code in AppKit like: [NSWindow(NSConstraintBasedLayoutInternal) _layoutViewTree] + 120 50 AppKit 0x00000001911e8a10 -[NSWindow(NSConstraintBasedLayoutInternal) layoutIfNeeded] + 240 51 UIKitMacHelper 0x00000001a98f293c -[UINSWindow layoutIfNeeded] + 56 A few unnamed symbols mixed in maybe that's that Swiftness beneath the surface. App is just murdered on launch. I assume this is related to using NSToolbarItemGroup when building an NSToolbar... I do see this log out: NSToolbarItemGroup does not support selectionMode. Create the group with one of the class constructors to support selection. Which is an interesting log so I commented out all calls to setSelectionMode: but still the same crash. I do set the groups subitems property directly (I do not use the class constructors as the logging statement above indicates). I have no idea if using the class constructors will workaround this issue or not but I'm not particularly excited about that idea because I have items in the same toolbar group with different actions.