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.

All subtopics
Posts under UI Frameworks topic

Post

Replies

Boosts

Views

Activity

A Summary of the WWDC25 Group Lab - UI Frameworks
At WWDC25 we launched a new type of Lab event for the developer community - Group Labs. A Group Lab is a panel Q&A designed for a large audience of developers. Group Labs are a unique opportunity for the community to submit questions directly to a panel of Apple engineers and designers. Here are the highlights from the WWDC25 Group Lab for UI Frameworks. How would you recommend developers start adopting the new design? Start by focusing on the foundational structural elements of your application, working from the "top down" or "bottom up" based on your application's hierarchy. These structural changes, like edge-to-edge content and updated navigation and controls, often require corresponding code modifications. As a first step, recompile your application with the new SDK to see what updates are automatically applied, especially if you've been using standard controls. Then, carefully analyze where the new design elements can be applied to your UI, paying particular attention to custom controls or UI that could benefit from a refresh. Address the large structural items first then focus on smaller details is recommended. Will we need to migrate our UI code to Swift and SwiftUI to adopt the new design? No, you will not need to migrate your UI code to Swift and SwiftUI to adopt the new design. The UI frameworks fully support the new design, allowing you to migrate your app with as little effort as possible, especially if you've been using standard controls. The goal is to make it easy to adopt the new design, regardless of your current UI framework, to achieve a cohesive look across the operating system. What was the reason for choosing Liquid Glass over frosted glass, as used in visionOS? The choice of Liquid Glass was driven by the desire to bring content to life. The see-through nature of Liquid Glass enhances this effect. The appearance of Liquid Glass adapts based on its size; larger glass elements look more frosted, which aligns with the design of visionOS, where everything feels larger and benefits from the frosted look. What are best practices for apps that use customized navigation bars? The new design emphasizes behavior and transitions as much as static appearance. Consider whether you truly need a custom navigation bar, or if the system-provided controls can meet your needs. Explore new APIs for subtitles and custom views in navigation bars, designed to support common use cases. If you still require a custom solution, ensure you're respecting safe areas using APIs like SwiftUI's safeAreaInset. When working with Liquid Glass, group related buttons in shared containers to maintain design consistency. Finally, mark glass containers as interactive. For branding, instead of coloring the navigation bar directly, consider incorporating branding colors into the content area behind the Liquid Glass controls. This creates a dynamic effect where the color is visible through the glass and moves with the content as the user scrolls. I want to know why new UI Framework APIs aren’t backward compatible, specifically in SwiftUI? It leads to code with lots of if-else statements. Existing APIs have been updated to work with the new design where possible, ensuring that apps using those APIs will adopt the new design and function on both older and newer operating systems. However, new APIs often depend on deep integration across the framework and graphics stack, making backward compatibility impractical. When using these new APIs, it's important to consider how they fit within the context of the latest OS. The use of if-else statements allows you to maintain compatibility with older systems while taking full advantage of the new APIs and design features on newer systems. If you are using new APIs, it likely means you are implementing something very specific to the new design language. Using conditional code allows you to intentionally create different code paths for the new design versus older operating systems. Prefer to use if #available where appropriate to intentionally adopt new design elements. Are there any Liquid Glass materials in iOS or macOS that are only available as part of dedicated components? Or are all those materials available through new UIKit and AppKit views? Yes, some variations of the Liquid Glass material are exclusively available through dedicated components like sliders, segmented controls, and tab bars. However, the "regular" and "clear" glass materials should satisfy most application requirements. If you encounter situations where these options are insufficient, please file feedback. If I were to create an app today, how should I design it to make it future proof using Liquid Glass? The best approach to future-proof your app is to utilize standard system controls and design your UI to align with the standard system look and feel. Using the framework-provided declarative API generally leads to easier adoption of future design changes, as you're expressing intent rather than specifying pixel-perfect visuals. Pay close attention to the design sessions offered this year, which cover the design motivation behind the Liquid Glass material and best practices for its use. Is it possible to implement your own sidebar on macOS without NSSplitViewController, but still provide the Liquid Glass appearance? While technically possible to create a custom sidebar that approximates the Liquid Glass appearance without using NSSplitViewController, it is not recommended. The system implementation of the sidebar involves significant unseen complexity, including interlayering with scroll edge effects and fullscreen behaviors. NSSplitViewController provides the necessary level of abstraction for the framework to handle these details correctly. Regarding the SceneDelagate and scene based life-cycle, I would like to confirm that AppDelegate is not going away. Also if the above is a correct understanding, is there any advice as to what should, and should not, be moved to the SceneDelegate? UIApplicationDelegate is not going away and still serves a purpose for application-level interactions with the system and managing scenes at a higher level. Move code related to your app's scene or UI into the UISceneDelegate. Remember that adopting scenes doesn't necessarily mean supporting multiple scenes; an app can be scene-based but still support only one scene. Refer to the tech note Migrating to the UIKit scene-based life cycle and the Make your UIKit app more flexible WWDC25 session for more information.
Topic: UI Frameworks SubTopic: General
0
0
688
Jun ’25
SwiftUI Text is larger when empty
I have a simple SwiftUI Text: Text(t) .font(Font.system(size: 9)) Strangely its ideal height seems to be larger when it is empty. I initially observed this in a custom Layout container that wasn't working quite right. Eventually I looked at the height returned by v.dimensions(in:), and found that when t is non-empty the height is 11; when empty, it's 14. Subsequently I observed similar behaviour in a regular VStack container. Has anyone seen anything similar? Are there any properties that could affect this behaviour? (This is on a watch - I don't know if that matters.)
0
0
308
Jan ’25
AppIntents - Choosing a default Measurement<UnitMass> for body weight based on locale
Here’s a clearer and more concise version of your question: I’m creating an AppIntent to allow users to log their body weight. My intent includes a @Parameter defined as: @Parameter( title: "Weight", description: "Current Weight", defaultUnit: .pounds, supportsNegativeNumbers: false ) var weight: Measurement<UnitMass> This works but doesn’t respect the user’s Locale and its measurementSystem. When I add defaultUnitAdjustForLocale: true to the @Parameter macro, the default always switches to kilograms, regardless of the locale. How can I correctly set the default unit to match the user’s locale for the purpose of entering a users body weight?
0
0
379
Jan ’25
How to truncate text from head with multi line?
I want to truncate text from head with max 2 lines. I try the following code import SwiftUI struct ContentView: View { @State var content: String = "Hello world! wef wefwwfe wfewe weweffwefwwfwe wfwe" var body: some View { VStack { Text(content) .lineLimit(nil) .truncationMode(.head) .frame(height: 50) Button { content += content } label: { Text("Double") } .buttonStyle(.borderedProminent) } .frame(width: 200, height: 1000) .padding() } } #Preview { ContentView() } It show result like this, this is not what I want.
0
0
242
Mar ’25
Application threw exception NSInternalInconsistencyException: Multi layer delegate table missing.
I recently detected a special crash on 18.0, 18.1, 18.1.1, 18.2,18.3 which cannot be repeated, and the page logs are related to the keyboard, is there any idea to deal with this problem? Exception Category: nsexception Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x00000000 at 0x0000000000000000 Crashed Thread: 0 CrashDoctor Diagnosis: Application threw exception NSInternalInconsistencyException: Multi layer delegate table missing. Thread 0 Crashed: 0 CoreFoundation 0x00000001869d87cc __exceptionPreprocess + [ : 164] 1 libobjc.A.dylib 0x0000000183cab2e4 objc_exception_throw + [ : 88] 2 Foundation 0x0000000185da88d8 _userInfoForFileAndLine 3 UIKitCore 0x0000000189e78074 -[UIView _multiLayerDelegatesTableCreateIfNecessary:] + [ : 208] 4 UIKitCore 0x0000000189e780c4 -[UIView _registerMultiLayerDelegate:] + [ : 36] 5 UIKitCore 0x00000001894874c0 -[_UIPortalView setSourceView:] + [ : 132] 6 UIKitCore 0x000000018a1eb6bc -[_UIPortalView initWithSourceView:] + [ : 68] 7 UIKitCore 0x000000018a213ea4 -[_UITextMagnifiedLoupeView initWithSourceView:] + [ : 444] 8 UIKitCore 0x000000018a6c461c +[UITextLoupeSession _makeLoupeViewForSourceView:selectionWidget:orientation:] + [ : 84] 9 UIKitCore 0x000000018a6c47bc +[UITextLoupeSession _beginLoupeSessionAtPoint:fromSelectionWidgetView:inView:orientation:] + [ : 304] 10 UIKitCore 0x0000000189d50ce0 -[UITextRefinementTouchBehavior textLoupeInteraction:gestureChangedWithState:location:translation:velocity:modifierFlags:shouldCancel:] + [ : 1756] 11 UIKit 0x0000000240e309e0 -[UITextRefinementTouchBehaviorAccessibility textLoupeInteraction:gestureChangedWithState:location:translation:velocity:modifierFlags:shouldCancel:] + [ : 216] 12 UIKitCore 0x000000018a4d45b4 -[UITextRefinementInteraction loupeGestureWithState:location:translation:velocity:modifierFlags:shouldCancel:] + [ : 124] 13 UIKitCore 0x000000018a4d3f74 -[UITextRefinementInteraction loupeGesture:] + [ : 548] 14 UIKitCore 0x000000018952eac4 -[UIGestureRecognizerTarget _sendActionWithGestureRecognizer:] + [ : 128] 15 UIKitCore 0x000000018952e934 _UIGestureRecognizerSendTargetActions + [ : 92] 16 UIKitCore 0x000000018952e6f4 _UIGestureRecognizerSendActions + [ : 284] 17 UIKitCore 0x00000001891e1b28 -[UIGestureRecognizer _updateGestureForActiveEvents] + [ : 572] 18 UIKitCore 0x00000001891b3724 _UIGestureEnvironmentUpdate + [ : 2488] 19 CoreFoundation 0x000000018697a1f4 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + [ : 36] 20 CoreFoundation 0x0000000186979f98 __CFRunLoopDoObservers + [ : 552] 21 CoreFoundation 0x00000001869a9028 __CFRunLoopRun + [ : 948] 22 CoreFoundation 0x00000001869a8830 CFRunLoopRunSpecific + [ : 588] 23 GraphicsServices 0x00000001d29881c4 GSEventRunModal + [ : 164] 24 UIKitCore 0x000000018950eeb0 -[UIApplication _run] + [ : 816] 25 UIKitCore 0x00000001895bd5b4 UIApplicationMain + [ : 340] 26 顺丰小哥 0x0000000104423cc0 main + [main.m : 13] 27 (null) 0x00000001ac396ec8 0x0 + 7184412360
Topic: UI Frameworks SubTopic: UIKit
0
0
290
Dec ’24
SwiftUI Canvas Text - scale to fill rectangle
How do I draw a single line of text in a SwiftUI Canvas, scaled to fill a given rectangle? Example: Canvas { context, size in let r = CGRect(origin: CGPointZero, size: size); // Whole canvas let t = Text("Hello World"); context.draw(t, in: r); } Outside of Canvas I'd add .minimumScaleFactor(0) .lineLimit(1), and I guess set a large default font size, and I'd get the result I want. But inside Canvas, .minimumScaleFactor and .lineLimit don't seem to be available; they return some View, not Text, which can't be used in context.draw. (Is there a trick to make that work?) I have written the following to do this, but I think there must be an easier way to achieve this! Suggestions? extension GraphicsContext { mutating func draw_text_in_rect(string: String, rect: CGRect) { let text = Text(string) .font(.system(size: 25)); // The font size used here does matter, because e.g. letter spacing // varies with the font size. let resolved = resolve(text); let text_size = resolved.measure(in: CGSize(width: CGFloat.infinity, height: CGFloat.infinity)); let text_aspect = text_size.width / text_size.height; let fit_size = CGSize(width: min(rect.size.width, rect.size.height*text_aspect), height: min(rect.size.height, rect.size.width/text_aspect)); let fit_rect = CGRect(x: rect.origin.x + (rect.size.width-fit_size.width)/2, y: rect.origin.y + (rect.size.height-fit_size.height)/2, width: fit_size.width, height: fit_size.height); let scale = fit_size.width / text_size.width; // For debug: // var p = Path(); // p.addRect(fit_rect); // stroke(p, with: GraphicsContext.Shading.color(.red), lineWidth: 1); translateBy(x: fit_rect.minX, y: fit_rect.minY); scaleBy(x:scale, y:scale); draw(resolved, at: CGPointZero, anchor: UnitPoint.topLeading); transform = CGAffineTransformIdentity; } };
0
0
371
Jan ’25
Dynamically Update Complex UI Views in SwiftUI
I am working on a SwiftUI project where I need to dynamically update the UI by adding or removing components based on some event. The challenge is handling complex UI structures efficiently while ensuring smooth animations and state management. Example Scenario: I have a screen displaying a list of items. When a user taps an item, additional details (like a subview or expanded section) should appear dynamically. If the user taps again, the additional content should disappear. The UI should animate these changes smoothly without causing unnecessary re-renders. My Current Approach: I have tried using @State and if conditions to toggle views, like this: struct ContentView: View { @State private var showDetails = false var body: some View { VStack { Button("Toggle Details") { showDetails.toggle() } if showDetails { Text("Additional Information") .transition(.slide) // Using animation } } .animation(.easeInOut, value: showDetails) } } However, in complex UI scenarios where multiple components need to be shown/hidden dynamically, this approach is not maintainable and could cause performance issues. I need help with the below questions. Questions: State Management: Should I use @State, @Binding, or @ObservedObject for handling dynamic UI updates efficiently? Best Practices: What are the best practices for structuring SwiftUI views to handle dynamic updates without excessive re-renders? Performance Optimization: How can I prevent unnecessary recomputations when updating only specific UI sections? Animations & Transitions: What is the best way to apply animations smoothly while toggling visibility of multiple components? Advanced Approaches: Are there better techniques using @EnvironmentObject, ViewBuilder, or even GeometryReader for dynamically adjusting UI layouts? Any insights, code examples, or resources would be greatly appreciated.
0
0
348
Jan ’25
MVVM design and data dependency
According to the MVVM design pattern, one of my views depends on many properties in my model. Can I use logic like @published var model = MyModel()? Will there be a large performance loss? Will the UI be refreshed when other unrelated properties in the model are modified? What is the best practice in this case?
Topic: UI Frameworks SubTopic: General
0
0
248
Jan ’25
detecting modifier keys using UITextFieldDelegate protocol
I have a UITextField in my application, and I want to detect all the keys uniquely to perform all relevant task. However, there is some problem in cleanly identifying some of the keys. I m not able to identify the backspace key press in the textField(_:shouldChangeCharactersIn:replacementString:) method. Also I don't know how to detect the Caps Lock key. I am intending to so this because I want to perform some custom handling for some keys. Can someone help me with what is the way of detecting it under the recommendation from apple. Thanks in advance. Note: checking for replacementString parameter in shouldChangeCharactersIn method for empty does not help for backspace detection as it overlaps with other cases.
Topic: UI Frameworks SubTopic: UIKit Tags:
0
0
145
Mar ’25
How does UIScene know whether it has the main key window and when it changes on iPad's multi-scene?
Hi. I know to know which window gets hardware keyboard events (such as shortcut key) currently on iPad. Until iPadOS 15.0, UIApplication.shared.keyWindow, which was deprecated on iPadOS 13.0 and didBecomeKeyNotification/didResignKeyNotification. But after iPadOS 15.0, a keyWindow is managed by UIScene, not by UIApplication. Each scene of my app always has just one window. For my purpose, checking deprecated UIApplication.shared.keyWindow is still effective but didBecomeKeyNotification and didResignKeyNotification don't work because they are fired when a change happens only inside the scene. So my questions are, What is the new alternative of UIApplication.shared.keyWindow? I know a wrong hack like UIApplication.shared.connectedScenes.compactMap { $0 as? UIWindowScene }.first?.windows.filter { $0.isKeyWindow }.first does not work since the order of connectedScenes is not related with getting hardware keyboard events. What are the new alternatives of didBecomeKeyNotification/didResignKeyNotification which work on inter-scene? The second question is more crucial. Because about the first question, I can still use deprecated UIApplication.shared.keyWindow. Thanks.
Topic: UI Frameworks SubTopic: General Tags:
0
0
244
Feb ’25
Do the coordinates obtained by scanning a QR code with VNDetectBarcodesRequest match the coordinates of the finder pattern?
I am creating an application that uses VNDetectBarcodesRequest to read QR codes from images and adjust the image orientation to match that of the QR code finder pattern. The QR code was successfully read, and the coordinates of the QR code were obtained.Upon checking the obtained topLeft, topRight, and bottomLeft coordinates, they always seem to match the topLeft, topRight, and bottomLeft coordinates of the finder pattern. Is it specified that the coordinates of topLeft, topRight, and bottomLeft obtained with VNDetectBarcodesRequest match the topLeft, topRight, and bottomLeft of the finder pattern? Or do they just happen to match? I would appreciate it if you could tell me if the matching of coordinates is a specification. Thank you for your help.
0
0
324
Feb ’25
[SwiftUI] SecureEntry Autofill in Dark Mode
When using New Password Autofill in Dark Mode, it appears that SecureEntry sets the background color to white and applies a yellow-ish overlay, but doesn't adapt the foreground text color accordingly. This gives the illusion that the SecureEntry field is empty, as we have white text on a white background. Is there a holistic and SwiftUI-native way of fixing this?
0
0
54
Apr ’25
LazyHstack in SwiftUI not supporting varying height views
In SwiftUI I want to create a list with LazyVstack and each row item in the LazyVstack is a LazyHstack of horizontally scrollable list of images with some description with line limit of 3 and width of every item is fixed to 100 but height of every item is variable as per description text content. But in any of the rows if the first item has image description of 1 line and the remaining items in the same row has image description of 3 lines then the LazyHStack is truncating all the image descriptions in the same row to one line making all the items in that row of same height. Why LazyHStack is not supporting items of varying height ? Expected behaviour should be that height of every LazyHStack should automatically adjust as per item content height. But it seems SwiftUI is not supporting LazyHstack with items of varying height. Will SwiftUI ever support this feature?
Topic: UI Frameworks SubTopic: SwiftUI
0
0
260
Feb ’25
Translate extension bahvior
DESCRIPTION OF PROBLEM We need to add an implementation that will have the same swipe/scroll behavior as the Apple Translator extension, here is the code that we are currently using: import SwiftUI import TranslationUIProvider @main class TranslationProviderExtension: TranslationUIProviderExtension { required init() {} var body: some TranslationUIProviderExtensionScene { TranslationUIProviderSelectedTextScene { context in VStack { TranslationProviderView(context: context) } } } } struct TranslationProviderView: View { @State var context: TranslationUIProviderContext init(context c: TranslationUIProviderContext) { context = c } var body: some View { ScrollableSheetView() } } struct ScrollableSheetView: View { var body: some View { ScrollView { VStack(spacing: 20) { ForEach(0..<50) { index in Text("Item (index)") .padding() .frame(maxWidth: .infinity) .background(Color.blue.opacity(0.1)) .cornerRadius(8) } } .padding() } .padding() } } Using this code, on the first extension run, swipe up will expand the extension (which is OK) but swiping down on the expanded state of the extension works only as a scroll instead of swiping the extension from expanded mode back to compact mode. STEPS TO REPRODUCE Select a text in Safari Tap on Translate in the contextual menu Swipe up on the text ->the extension expands into full mode Swipe down->only scrolls work, I cannot swipe the extension from full mode to compact mode. Expected behavior: when i swipe down on the expanded extension, the extension should get into compact mode, not continuously scroll down.
Topic: UI Frameworks SubTopic: SwiftUI
0
0
67
Apr ’25
Longtime UIStackView Bug
There has been a long lasting UIStackView bug dating back to 2016 that still exists in the latest Xcode 16.3 and SDKs, where calling setHidden:true multiple times (lets say twice) on a subview of that stack view requires calling setHidden:false twice before the subview shows up again. This was originally documented via Radar #25087688. Hopefully a Frameworks Engineer here on the forums can raise it to the attention of the appropriate engineers. It would be really nice if this eventually gets fixed, because it's one of those odd issues where you end up wasting a lot of time trying to debug because everything looks correct.
Topic: UI Frameworks SubTopic: UIKit Tags:
0
1
78
Apr ’25
UICalendarView with decorations - change day height
Is there any way to change the height of the "day" cells in the UICalendarView? The view is very tall on the screen and I'd like to shorten it so I can put more content below it without using a scroll view. I'm using SwiftUI with a UICalendarView with UIViewRepresentable. The calendar will have default decorations to indicate a date with events.
Topic: UI Frameworks SubTopic: SwiftUI
0
0
209
Feb ’25
SFSafariViewController's preferred colors are invalidated after rotation
There are two issues about SFSafariViewController. After rotate from landscape to portrait, The topAnchor is destroyed. The specified bar tint color and control tint color are invalidated.(Returns to system color) Regarding the second issue, I’ve found a temporary workaround. Override the viewWillTransition(to:with:) and keep it empty. Don't call super.viewWillTransition(to:with:). Since UIKit is not open source, I don’t know the exact cause, but I found something that could be the key to the issue. So, I reported it to Apple Feedback Assistant. You can check the details and the sample project in the GitHub repository below. https://github.com/ueunli/SafariViewer
0
0
303
Feb ’25
iOS 18.4 App updates crashes the widget and the only solution is to restart the device or change the device language
App update in which there were no changes regarding the widget. Just after it updated, the widget turns black in some cases. It also appears black in the widget gallery. Removing and adding it again did not work in this case, only after an iOS restart it works fine again This is the log 2025-03-20 02:14:05.961611 +0800 Content load failed: unable to find or unarchive file for key: [com.aa.bb::com.aa.bb.widget:cc_widget:systemMedium::360.00/169.00/23.00:(null)~(null)] on no host. The session may still produce one shortly. Error: Using url file:///private/var/mobile/Containers/Data/PluginKitPlugin/51C5E4F2-6F1F-4466-A428-73C73B9CC887/SystemData/com.apple.chrono/placeholders/cc_widget/systemMedium----360.00w--169.00h--23.00r--1f--0.00t-0.00l-0.00b0.00t.chrono-timeline ... Error Domain=NSCocoaErrorDomain Code=4 "file“systemMedium----360.00w--169.00h--23.00r--1f--0.00t-0.00l-0.00b0.00t.chrono-timeline”not exist。" UserInfo={NSFilePath=/private/var/mobile/Containers/Data/PluginKitPlugin/51C5E4F2-6F1F-4466-A428-73C73B9CC887/SystemData/com.apple.chrono/placeholders/cc_widget/systemMedium----360.00w--169.00h--23.00r--1f--0.00t-0.00l-0.00b0.00t.chrono-timeline, NSUnderlyingError=0xa693d3a80 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}
0
0
104
Mar ’25
Conflict between offerCodeRedemption and Camera
Hello, I implemented offerCodeRedemption recently on my app in my subscription/onboarding flow. When I did, it broke my camera functionality (elsewhere in the app; totally unrelated code). I was able to fix the issue when implementing the old "AppStore.presentOfferCodeRedeemSheet" code with UIKit. I'm not sure why this is happening, but it seemed like a bug to me.
Topic: UI Frameworks SubTopic: SwiftUI
0
0
142
Feb ’25