When the guy was talking about structural identity, starting at about 8:53, he mentioned how the swiftui needs to guarantee that the two views can't swap places, and it does this by looking at the views type structure. It guarantees that the true view will always be an A, and the false view will always be a B.
Not sure exactly what he means because views can't "swap places" like dogs. Why isn't just knowing that some View is shown in true, and another is shown in false, enough for its identity? e.g. The identity could be "The view on true" vs
"The view on false", same as his example with "The dog on the left" vs "The dog on the right"
Explore the various UI frameworks available for building app interfaces. Discuss the use cases for different frameworks, share best practices, and get help with specific framework-related questions.
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I have a UIHostingController on which I have set:
hostingController.sizingOptions = [.intrinsicContentSize]
The size of my SwiftUI content changes with animation (I update a @Published property on an ObservableObject inside a withAnimation block). However, I notice that my hostingController.view just jumps to the new frame without animating the change.
Question: how can I animate the frame changes in UIHostingController that are caused by sizingOptions = [.intrinsicContentSize]
We noticed in multiple apps that readableContentGuide is way too wide on iOS 26.x.
Here are changes between iPad 13inch iOS 18.3 and the same device iOS 26.2 (but this affects also iOS 26.0 and iOS 26.1):
13 inch iOS 18
Landscape ContentSizeCategory:
XS, Width: 1376.0 , Readable Width: 560.0
S, Width: 1376.0 , Readable Width: 600.0
M, Width: 1376.0 , Readable Width: 632.0
L, Width: 1376.0 , Readable Width: 664.0
XL, Width: 1376.0 , Readable Width: 744.0
XXL, Width: 1376.0 , Readable Width: 816.0
XXXL,Width: 1376.0 , Readable Width: 896.0
A_M, Width: 1376.0 , Readable Width: 1096.0
A_L, Width: 1376.0 , Readable Width: 1280.0
A_XL,Width: 1376.0 , Readable Width: 1336.0
13 inch iOS 26
Landscape ContentSizeCategory:
XS, Width: 1376.0 , Readable Width: 752.0
S, Width: 1376.0 , Readable Width: 800.0
M, Width: 1376.0 , Readable Width: 848.0
L, Width: 1376.0 , Readable Width: 896.0
XL, Width: 1376.0 , Readable Width: 1000.0
XXL, Width: 1376.0 , Readable Width: 1096.0
XXXL,Width: 1376.0 , Readable Width: 1200.0
A_M, Width: 1376.0 , Readable Width: 1336.0
The code I used:
class ViewController: UIViewController {
lazy var readableView: UIView = {
let view = UIView()
view.backgroundColor = .systemBlue
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(readableView)
NSLayoutConstraint.activate([
readableView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
readableView.leadingAnchor.constraint(equalTo: view.readableContentGuide.leadingAnchor),
readableView.trailingAnchor.constraint(equalTo: view.readableContentGuide.trailingAnchor),
readableView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor)
])
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if readableView.frame.width > 0 {
let orientation = UIDevice.current.orientation
print("""
ContentSizeCategory: \(preferredContentSizeCategoryAsString())
Width: \(view.frame.width) , Readable Width: \(readableView.frame.width), Ratio: \(String(format: "%.1f", (readableView.frame.width / view.frame.width) * 100))%
""")
}
}
func preferredContentSizeCategoryAsString() -> String {
switch UIApplication.shared.preferredContentSizeCategory {
case UIContentSizeCategory.accessibilityExtraExtraExtraLarge:
return "A_XXXL"
case UIContentSizeCategory.accessibilityExtraExtraLarge:
return "A_XXL"
case UIContentSizeCategory.accessibilityExtraLarge:
return "A_XL"
case UIContentSizeCategory.accessibilityLarge:
return "A_L"
case UIContentSizeCategory.accessibilityMedium:
return "A_M"
case UIContentSizeCategory.extraExtraExtraLarge:
return "XXXL"
case UIContentSizeCategory.extraExtraLarge:
return "XXL"
case UIContentSizeCategory.extraLarge:
return "XL"
case UIContentSizeCategory.large:
return "L"
case UIContentSizeCategory.medium:
return "M"
case UIContentSizeCategory.small:
return "S"
case UIContentSizeCategory.extraSmall:
return "XS"
case UIContentSizeCategory.unspecified:
return "U"
default:
return "D"
}
}
}
Please advise, it feels completely broken.
Thank you.
既然 iOS 26 必须启用 UIScene 生命周期，那么 UIAlertView/UIActionSheet 就实际已经无法使用了，所以为什么不直接将它们标记为不可用，或者直接移除？
When I navigate to a player controller and switch to landscape mode, and then pop it and choose portrait mode, the tabBar encounters an issue
Topic:
UI Frameworks
SubTopic:
UIKit
I've integrated PencilKit into my app, but I've noticed that shape recognition isn't working during drawing, even though it works perfectly in the Notes app. Is this a bug, or is shape recognition simply not supported in PencilKit for Swift?
I just found a weird bug:
If you place a Text view using .foregroundStyle(.secondary), .tertiary, or other semantic colors inside a ScrollView, and apply a Material background clipped to an UnevenRoundedRectangle, the text becomes invisible. This issue does not occur when:
The text uses .primary or explicit colors (e.g., .red, Color.blue), or
The background is clipped to a standard shape (e.g., RoundedRectangle).
A minimal reproducible example is shown below:
ScrollView{
VStack {
Image(systemName: "globe")
.imageScale(.large)
.foregroundStyle(.tint)
Text("Hello World.")
.font(.system(size: 15))
.foregroundStyle(.quinary)
}
}
.padding()
.frame(height: 100)
.background(Material.regular)
.clipShape(UnevenRoundedRectangle(topLeadingRadius: 10,bottomLeadingRadius: 8,bottomTrailingRadius:8, topTrailingRadius: 8))
I have a text editor where I replace the selected text when a button is tapped. Most of the time it works, but sometimes the new text is inserted at the end of the text instead of at the selected position. Is this a bug?
@Bindable var note: Richnote
@State private var selection = AttributedTextSelection()
var body: some View {
VStack {
TextEditor(text: $note.content, selection: $selection)
Button("Replace text") {
let textToInsert = "A long text that makes me think lalala"
note.content.replaceSelection(&selection, withCharacters: textToInsert)
}
Topic:
UI Frameworks
SubTopic:
SwiftUI
I have an existing iOS app with MapKit. It always shows the current user location with UserAnnotation. But the same isn't true for macOS. I have this sample macOS application in SwiftUI. In the following, the current user location with a large blue dot appears only occasionally. It won't, 19 of 20 times. Why is that? I do have a location privacy key in Info.plist. And the Location checkbox is on under Signing & Capabilities.
import SwiftUI
import MapKit
struct ContentView: View {
@State private var markerItems: [MarkerItem] = [
MarkerItem(name: "Farmers Market 1", lat: 35.681, lon: 139.691),
MarkerItem(name: "Farmers Market 2", lat: 35.685, lon: 139.695),
MarkerItem(name: "Farmers Market 3", lat: 35.689, lon: 139.699)
]
@State private var position: MapCameraPosition = .automatic
var body: some View {
Map(position: $position) {
UserAnnotation()
ForEach(markerItems, id: \.self) { item in
Marker(item.name, coordinate: CLLocationCoordinate2D(latitude: item.lat, longitude: item.lon))
}
}
.mapControlVisibility(.hidden)
.mapStyle(.standard(elevation: .realistic))
.ignoresSafeArea()
}
}
#Preview {
ContentView()
}
struct MarkerItem: Hashable {
let name: String
let lat: Double
let lon: Double
}
Hi,
I am looking to display (in SwiftUI) the Tabview page dots like in the weather app in the toolbar, an important thing is I want to keep page controls by tapping and scrubbing.
Actually, I want to do what's on Apple Design's Page Controls page; here's the link and a photo of what I'd like to do.
Could you help me?
https://developer.apple.com/design/human-interface-guidelines/page-controls
I'm looking to support toggleable bullet and numbered lists in my IOS 26 app. currently my text editor looks like this
@Binding var text: AttributedString
var requestFocus: Bool = false
@State private var selection = AttributedTextSelection()
@FocusState private var isFocused: Bool
var body: some View {
TextEditor(text: $text, selection: $selection)
.scrollContentBackground(.hidden)
.background(Color.clear)
.focused($isFocused)
.safeAreaInset(edge: .bottom) {
if isFocused {
FormattingToolbar(text: $text, selection: $selection)
.padding(.horizontal)
.padding(.vertical, 8)
.background(Color(UIColor.systemBackground))
}
}
.onChange(of: requestFocus) { _, newValue in
if newValue {
isFocused = true
}
}
}
}
i cant find any useful docs on how to best implement this. anything helps, thanks
Topic:
UI Frameworks
SubTopic:
SwiftUI
I have (had) a view controller that does a bit of manual layout in a -viewDidLayout override.
This was pretty easy to manage - however since introducing NSGlassEffectView into the view hierarchy I sometimes am getting hit with "Unable to simultaneously satisfy constraints" and Appkit would break a constraint to 'recover.' It appears translatesAutoresizingMaskIntoConstraints is creating some really weird fixed width and height constraints. Here I wasn't doing any autolayout - just add the glass view and set its frame in -viewDidLayout.
At runtime since I do manual layout in -viewDidLayout the frames are fixed and there is no real "error" in my app in practice though I wanted to get rid of the constraint breaking warning being logged because I know Autolayout can be aggressive about 'correctness' who knows if they decide to throw and not catch in the future.
In my perfect world I would probably just prefer a view.doesManualLayout = YES here - the subviews are big containers no labels so localization is not an issue for me. Rather than playing with autoresizing masks to get better translated constraints I decided to set translatesAutoresizingMaskIntoConstraints to NO and make the constraints myself. Now I get hit with the following exception:
"The window has been marked as needing another Layout Window pass, but it has already had more Layout Window passes than there are views in the window"
So this happens because the view which now has constraints -- I adjusted the frame of it one point in -viewDidLayout. My question is - is not legal to make changes in -viewDidLayout - which seems like the AppKit version of -viewDidLayoutSubviews.
In UIKit I always thought it was fine to make changes in -viewDidLayoutSubviews to frames - even if constraints were used - this is a place where you could override things in complex layouts that cannot be easily described in constraints. But in AppKit if you touch certain frames in -viewDidLayout it can now cause this exception (also related: https://developer.apple.com/forums/thread/806471)
I will change the constant of one of the constraints to account for the 1 point adjustment but my question still stands - is it not legal to touch frames in -viewDidLayout when autolayout constraints are used on that subview? It is (or at least was if I remember correctly) permitted to change the layout in -viewDidLayoutSubviews in UIKit but AppKit seems to be more aggressive in its checking for layout correctness).
What about calling -sizeToFit on a control in viewDidLayout or some method that has side effect of invalidating layout in a non obvious way, is doing things like this now 'dangerous?'
Shouldn't AppKit just block the layout from being invalidated from within -viewDidLayout - and leave whatever the layout is as is when viewDidLayout returns (thus making -viewDidLayout a useful place to override layout in the rare cases where you need a sledgehammer?)
Views placed inside tabViewBottomAccessory that access @Environment values or contain @State properties experience unstable identity, as shown by Self._printChanges(). The identity changes on every structural update to the TabView, even though the view's actual identity should remain stable. This causes unnecessary view recreation and breaks SwiftUI's expected identity and lifecycle behavior.
Environment
Xcode Version 26.2 (17C52)
iOS 26.2 simulator and device
struct ContentView: View {
@State var showMoreTabs = true
struct DemoTab: View {
var body: some View { Text(String(describing: type(of: self))) }
}
var body: some View {
TabView {
Tab("Home", systemImage: "house") { DemoTab() }
Tab("Alerts", systemImage: "bell") { DemoTab() }
if showMoreTabs {
TabSection("Categories") {
Tab("Climate", systemImage: "fan") { DemoTab() }
Tab("Lights", systemImage: "lightbulb") { DemoTab() }
}
}
Tab("Settings", systemImage: "gear") {
List {
Toggle("Show more Tabs", isOn: $showMoreTabs)
}
}
}
.tabViewBottomAccessory {
AccessoryView()
}
.task {
while true {
try? await Task.sleep(for: .seconds(5))
if Task.isCancelled { break }
print("toggling showMoreTabs")
showMoreTabs.toggle()
}
}
.tabBarMinimizeBehavior(.onScrollDown)
}
}
struct AccessoryView: View {
var body: some View {
HStack {
EnvironmentAccess()
WithState()
Stateless()
}
}
}
struct EnvironmentAccess: View {
@Environment(\.tabViewBottomAccessoryPlacement) var placement
var body: some View {
// FIXME: EnvironmentAccess: @self, @identity, _placement changed.
// Identity should be stable
let _ = Self._printChanges()
Text(String(describing: type(of: self))) }
}
struct WithState: View {
@State var int = Int.random(in: 0...100)
var body: some View {
// FIXME: WithState: @self, @identity, _id changed.
// Identity should be stable
let _ = Self._printChanges()
Text(String(describing: type(of: self)))
}
}
struct Stateless: View {
var body: some View {
// Works as expected: Stateless: @self changed.
let _ = Self._printChanges()
Text(String(describing: type(of: self)))
}
}
This bug seems to make accessing TabViewBottomAccessoryPlacement impossible without losing view identity; the demo code is affected by the bug. Accessing a value like @Environment(\.colorScheme) is similarly affected, making visually adapting the contents of the accessory to the TabView content without losing identity challenging if not impossible.
Submitted as FB21627918.
I have no idea how to do it: on MacOS, in Document.init(configuration: ReadConfiguration) I decode file, and restore objects from data, which in some cases could take a long time. Document isn't fully inited, so I have no access to it. But would like to have a progress bar on screen (easier to wait for done, for now). I know size, progress value, but no idea how to make view from object during init.
I know, this question may be very stupid.
init(configuration: ReadConfiguration) throws {
guard let data = configuration.file.regularFileContents
else {
throw CocoaError(.fileReadCorruptFile)
}
let decoder = JSONDecoder()
let flat = try decoder.decode(FlatDoc.self, from: data)
print ("reverting \(flat.objects.count) objects...")
///This takes time, a lot of time, need progress bar
///Total is `flat.objects.count`, current is `objects.count`
/// `Show me a way to the (next) progress bar!`
revertObjects(from: flat.objects)
print ("...done")
}
update: I defined var flatObjects in Document, and I can convert in .onAppear.
struct TestApp: App {
@State var isLoading = false
...
ContentView(document: file.$document)
.onAppear {
isLoading = true
Task {file.document.revertObjects()}
isLoading = false
}
if isLoading {
ProgressView()
}
...
}
But progress bar never shows, only rainbow ball
Do you know if there is a work around to animate the reorder of a table without generating ghost rows?
here is the code:
var id = UUID()
var name: String
var value: Int
}
struct ContentView: View {
@State var selectedNumber: UUID?
@State var sortedBy: [KeyPathComparator<MyNumbers>] = [KeyPathComparator(\.name, order: .reverse)]
@State var numbers: [MyNumbers] = {
var numbersArray = [MyNumbers]()
for i in 0..<100 {
numbersArray.append(MyNumbers(name: "\(i)", value: i))
}
return numbersArray
}()
var body: some View {
Table(numbers, selection: $selectedNumber, sortOrder: $sortedBy) {
TableColumn("names", value: \.name){ number in
Text(number.name)
}
TableColumn("names", value: \.name){ number in
Text(number.name)
}
}.onChange(of: sortedBy) { oldValue, newValue in
withAnimation {
numbers.sort(using: newValue)
}
}
}
}
it generates ghost rows when the top row is selected and reorders twice, as you can see in the screenshot, the first six rows has two labels overlapped.
Topic:
UI Frameworks
SubTopic:
SwiftUI
When I use UIScrollView to Browse photos, sometime was crash.
Issue Details:
App: 美信 (Midea Connect)
Problem: Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Feedback generator was deactivated by its client more times than it was activated: <_UIZoomEdgeFeedbackGenerator: 0x33527cdc0>' First throw call stack
Affected: 4 user out of thousands
iOS Version: 18.0.1、26.1、26.2
What Works:
All other users has no crash
Same iOS version, no issues
User Has Tried:
The user experienced two crashes after opening the page hundreds of times
Topic:
UI Frameworks
SubTopic:
UIKit
Our app works fine on iOS 26 on other platforms but on iphone17, the text on the popovers is so light it is unreadable when the device is in Light mode. Is anyone else having this issue and if so, do you have any recommendations?
Topic:
UI Frameworks
SubTopic:
General
I found an issue related to Gmail and Email apps. When I try to fetch text using
controller.textDocumentProxy.documentContext, it works fine every time in my original app and in the Messages app. However, in Gmail or Email apps, after pasting text, controller.textDocumentProxy.documentContext returns nil until the pasted text is edited. The same scenario works correctly in Messages and my original app. i'm trying it from my keyboard extension and my keyboard builded bases on KeyboardKit SDK when i jump to text Document Proxy it's referring me to UITextDocumentProxy
Topic:
UI Frameworks
SubTopic:
UIKit
Since Callkit is not supported in mainland China, 'LiveCommunicationKit' is currently being used. When a VoIP push notification is received, the banner does not display correctly, but the phone icon in the top left corner, the ringtone, and vibration are present. I followed the solution in "https://developer.apple.com/forums/thread/774958?answerId=827083022#827083022" to resolve the crash issue, but the banner is still not displayed.
Topic:
UI Frameworks
SubTopic:
General
Hello,
I'm currently working on an app that will have a different name (and UI) depending on an environment variable that is set by that app's custom installer that I also wrote.
I'm trying to change the app name that is displayed in the menu bar (top left) programmatically. I've done some research and found that it's probably not possible to do so because it's fetched from the app's Info.plist
The answer is probably already there but I'll ask the question: Is it possible to change the app's name in the menu bar without tampering with the Info.plist (as it will break the signature at runtime, and it can't be done at compile time)
The use case here is that I'm shipping a single app with multiple installers, because the app will be the same for all sets of users but it will have minor UI changes (which in my opinion, don't need an entire separate release), the installers will set a flag that the app will, based on, change its UI to the corresponding set of users. For the most part it's been successful but only small issue remain like this one.
The reason it's done like that is when updating I'll ship 1 release for all users to update rather than having to ship multiple releases with no difference between them