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

App Crash with CarPlay & UIScene
My app crashed on iOS 18.1 only, here is the crash log: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'BUG IN CLIENT OF UIKIT: <CPTemplateApplicationScene: 0x1114bb780> -[UIScene _registerSettingsDiffActionArray:forKey:]: Registering the scene itself results in a retain cycle.' And I found this post: https://mastodon.social/@marcoarment/113280078320422999 Is this a system bug in iOS 18.1 beta 5?
1
0
120
Apr ’25
Does MKLookAroundViewController work on macOS?
Trying to incorporate a LookAroundView into my macOS application but unable to make the LookAroundView interactive at all. I can get it to display a static image, but there's no interactivity at all and no controls visible. This is using the SwiftUI LookAroundPreview view as well as trying to wrap MKLookAroundViewController inside an NSViewRepresentable. The navigation properties are set to true but that doesn't seem to make a difference. Would love to incorporate this feature but without interactivity its value is limited. macOS 15.4.1 (24E263), Xcode Version 16.3 (16E140)
1
0
117
Apr ’25
📍 Inconsistent POI Visibility Between Apple Maps and MKLocalSearch / CLGeocoder
Summary: Hi! I'm experiencing an issue between what Apple Maps displays in the UI and what is accessible via MapKit APIs such as MKLocalSearch and CLGeocoder. Specifically, some verified and publicly visible businesses (with proper POI categories like .cafe) are not returned by coordinate-based POI searches or reverse geocoding, even when their exact address and coordinates are known. Repro Steps: In Apple Maps (iOS), search for Rustic Knead located at: 1130 State St, Lemont, IL 60439 Note that: The business appears visually on the map It is categorized as a cafe The address is 1130 State St Now in code, attempt both: A coordinate-based POI search using MKLocalSearch.Request(region:) A reverse geocoding lookup via CLGeocoder.reverseGeocodeLocation Example coordinates: latitude: 41.673604, longitude: -88.002295 Expected Behavior: Given the precise coordinates and Apple Maps showing the POI publicly, I expect either or both of the following: MKLocalSearch should return the POI (Rustic Knead) within a reasonable radius and appropriate .pointOfInterestFilter. CLGeocoder should return a CLPlacemark with either name = "Rustic Knead" or an areasOfInterest value containing it. Actual Behavior: MKLocalSearch returns 0 POIs at that location, even with filters removed and radius increased to 500+ meters. CLGeocoder.reverseGeocodeLocation returns a valid postal address but does not include the business name in .name or areasOfInterest. Searching by business name (e.g., "Rustic Knead") does work, but coordinate/address-only lookups do not. Questions: Are there known limitations in how MapKit surfaces POIs by coordinate or reverse geocode? Is there a way to ensure public, categorized POIs are accessible programmatically via MapKit APIs? Is there a better strategy to provide coordinates and return a business name?
1
0
108
Apr ’25
How to make a UIButton resize its custom font text using `configurationUpdateHandler`?
I've read in this post that in order to make the configuration of UIButton adjust my custom font's size automatically I need to add implementation to recalculate the font's size inside configurationUpdateHandler. But how would this look like? I also read something about matching the font's text style. But at this point I'm just guessing. Here's the code: let loginButton = UIButton(configuration: config, primaryAction: nil) loginButton.configurationUpdateHandler = { button in guard var config = button.configuration else { return } let traits = button.traitCollection let baseTitleFont = UIFont.customFont(ofSize: 18, weight: .semibold) let baseSubtitleFont = UIFont.customFont(ofSize: 18, weight: .regular) let scaledTitleFont = UIFontMetrics(forTextStyle: .body).scaledFont(for: baseTitleFont, compatibleWith: traits) let scaledSubtitleFont = UIFontMetrics(forTextStyle: .body).scaledFont(for: baseSubtitleFont, compatibleWith: traits) config.titleTextAttributesTransformer = UIConfigurationTextAttributesTransformer { incoming in var outgoing = incoming outgoing.font = scaledTitleFont return outgoing } config.subtitleTextAttributesTransformer = UIConfigurationTextAttributesTransformer { incoming in var outgoing = incoming outgoing.font = baseSubtitleFont return outgoing } button.configuration = config } Thanks in advance!
3
0
176
Apr ’25
VisionOS custom hover effect and click sound
I have created a custom hover effect per this WWDC video and many other examples on the Net: https://developer.apple.com/videos/play/wwdc2024/10152/ I can get the button to expand when looked at within a VisionOS device and it will invoke a tap event when tapped but there is no click sound like a normal SwiftUI button does in VisionOS! I can't for the life of me figure out why. Any help would be appreciated!
2
0
305
Apr ’25
How to match Status/Menu Bar font (Date and Time)
Hello, I am trying to match the font and the position of the date and time displayed. This is what it looks like: .font: NSFont.systemFont(ofSize: NSFont.systemFontSize, weight: .regular), .foregroundColor: NSColor.labelColor, .baselineOffset: 0.5 It looks great on built-in display, but on external 4K it is incorrect. The baselineOffest is unnecessary, and the font looks skinny in comparison. Can anyone comment on such issue?
5
0
245
Apr ’25
Using the UIPasteControl
Hello 👋🏽 I am a new iOS developer and I am having a hard time understanding the behavior of the new UIPasteControl to avoid showing the system prompt. Does anyone has any example code I could look at to understand the behavior. Idk how to set the target of the button to the general pasteboard. also I am using objective-c . thanks cristian
5
0
4.1k
Apr ’25
SwiftUI Button fade animation happens with a delay when in ScrollView
When we place a Button inside a ScrollView , the fade animation of the button is delayed, so most users won't see it I think. You can see this in the trivial example struct ContentView: View { var body: some View { ScrollView { Button { // empty } label: { Text("Fade animation test") } } } } Is there any way to opt out of this behavior? In UIKit, this was also the default behavior, but you could always change it by overriding touchesShouldCancel method. I think I can probably do that by rewriting an animation completely with some custom ButtonStyle or by rewriting a Button component completely, but it doesn't seem like a good solution to me, as I want the native look and feel (in case of button animation it is pretty easy to mimic though). And also for some components, like lists, Apple has already implemented the correct behavior by themselves somehow.
3
0
102
Apr ’25
SwiftUI ScrollView Jittery/Glitchy Scrolling in iOS 17
Evening All and hope you had a good weekend. I'm experiencing significant scrolling issues in my SwiftUI weather app running on iOS 17. When scrolling through the main content, the scrolling is glitchy and not smooth, particularly around transitions between different subviews in the scroll view. The Issue The scrolling behavior has these problems: Stuttering/jittery movement during normal scrolling The issue seems most noticeable around the transitions between the header sections and the content sections (WindDetailsView and WeatherDataView) Smooth deceleration is affected, with visible "jumps" during momentum scrolling The problem appears to be worse on devices with iOS 17 compared to previous iOS versions Current Implementation My app uses a standard SwiftUI ScrollView with offset tracking to create a parallax effect for the header when scrolling. I'm calculating offset values to animate the header and adjust its opacity as the user scrolls. Here's the core structure:
Topic: UI Frameworks SubTopic: SwiftUI
2
0
127
Apr ’25
Not Showing FileOpen with Document-
I have developed several document-based (NSDocument) applications for macOS is Cocoa. Now, I'm playing with a document app project in SwiftUI. If I launch the application out of box, a file-select panel will open just as you see in TextEdit. (Please see the picture below) How do we prevent it from appearing? I would rather show a blank window, which in fact appears if I just press Command + N. Thanks.
2
0
111
Apr ’25
Using handleExternalEvents scene modifier to route external events to the correct scene
In an iPadOS SwiftUI app supporting multiple scenes, each Scene responds to a particular way in which the app was launched. If app was launched by tapping an associated file or a deep link (custom URL), then, the URLHandlerScene is invoked. If app was launched by QuickAction (long tap on the app icon), then another Scene is invoked etc. Each Scene has a purpose and responds to a particular launch. But after defining handlesExternlEvents(matching:) scene modifier, the scene was not getting launched when user taps the associated file or the app's Deeplinks was invoked. @main struct IOSSwiftUIScenesApp: App { var body: some Scene { DefaultScene() URLHandlerScene() .handlesExternalEvents(matching: ["file://"]) // Launched by an associated file .handlesExternalEvents(matching: ["Companion://"]) // Launched by Deeplink. // Other scenes } } struct URLHandlerScene: Scene { @State private var inputURL: URL // Store the incoming URL init() { self.inputURL = URL(string: "Temp://")! } var body: some Scene { WindowGroup { URLhandlerView(inputURL: $inputURL) .onOpenURL(perform: { (fileURL: URL) in log(String(format: "URLhandlerView().onOpenURL | Thread.current = %@", String(describing: Thread.current))) log("fileURL = " + String(describing: fileURL)) inputURL = fileURL }) } } } As shown above, I've attached handlesExternalEvents(matching:) modifier with "file://" for the associate file and "Companion" is my custom URL scheme. As per the scene matching rules documented here, my URLHandlerScene should get launched, but every time I launch the app using associated file or 'open' a Deeplink, the DefaultScene is always launched. What is missing here? Can someone please help?
1
0
152
Apr ’25
How to screenshot?
Is there anything to make a one off screenshot? like cmd+shift+3. But with code? There is ScreenCaptureKit - but it seems to be more for video / audio streams. I thought of trying to get the first frame from the video stream. But it seems to be rather a complex workaround for a simple problem.
3
0
144
Apr ’25
How to detect iPad trackpad touch-down (indirectPointer) to immediately stop coasting animation
Hello, I have a custom 3D object viewer on iOS that lets users spin the model using the touchscreen or a trackpad and supports coasting (momentum spinning). I need to stop the coasting animation as soon as the user touches down, but I can only immediately detect touches on the screen itself - on the trackpad I can't get an immediate notification of the touches. So far I’ve tried: State.began on my UIPanGestureRecognizer. It only fires after a small movement on both touchscreen and trackpad. .possible on the pan gesture; this state never occurs during the gesture cycle. UIApplicationSupportsIndirectInputEvents = YES in Info.plist; it didn’t make touchesBegan fire for indirectPointer touches. Since UITableView (and other UIScrollView subclasses) clearly detect trackpad “touch-down” to cancel scrolling, there must be a way to receive that event. Does anyone know how to catch the initial trackpad contact—before any movement—on an indirect input device? Below is a minimal code snippet demonstrating the issue. On the touchscreen you'll see a message the moment you touch the view, but the trackpad doesn't trigger any messages until your fingers move. Any advice would be greatly appreciated. Thanks in advance, John import UIKit class ViewController: UIViewController { private let debugView = DebugView() override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .white // Fill the screen with our debug view debugView.frame = view.bounds debugView.autoresizingMask = [.flexibleWidth, .flexibleHeight] debugView.backgroundColor = UIColor(white: 0.95, alpha: 1) view.addSubview(debugView) // Attach a pan recognizer that logs its state let panGR = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:))) panGR.allowedScrollTypesMask = .all debugView.addGestureRecognizer(panGR) } @objc private func handlePan(_ gr: UIPanGestureRecognizer) { switch gr.state { case .possible: print("Pan state: possible") case .began: print("Pan state: began") case .changed: print("Pan state: changed – translation = \(gr.translation(in: debugView))") case .ended: print("Pan state: ended – velocity = \(gr.velocity(in: debugView))") case .cancelled: print("Pan state: cancelled") case .failed: print("Pan state: failed") @unknown default: print("Pan state: unknown") } } } class DebugView: UIView { override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { super.touchesBegan(touches, with: event) for t in touches { let typeDesc: String switch t.type { case .direct: typeDesc = "direct (finger)" case .indirectPointer: typeDesc = "indirectPointer (trackpad/mouse)" case .indirect: typeDesc = "indirect (Apple TV remote)" case .pencil: typeDesc = "pencil (Apple Pencil)" @unknown default: typeDesc = "unknown" } print("touchesBegan on DebugView – touch type: \(typeDesc), location: \(t.location(in: self))") } } }
Topic: UI Frameworks SubTopic: UIKit Tags:
2
0
115
Apr ’25
searchable isPresented set too late in a sheet
I have a popover/sheet in iOS which allows users to search and add items to a list. When the sheet is shown, the search should always be active. I am using searchable on a NavigationStack inside the sheet. I am using the isPresented parameter to activate search. My issue is with the animation of the search activation. Even if I use... isPresented: .constant(true) ...the search isn't activated until the sheet has completed it's entrance animation, resulting in two stages of animation. I can't add a video here, but the two images below show the steps I am seeing. First a slide up animation, with the search in the navigation drawer, then a second animation, once the sheet is fully in place, as the search becomes active. Is it possible to merge these two animations, so search is in place when the sheet animates up?
Topic: UI Frameworks SubTopic: SwiftUI
0
0
55
Apr ’25
Setting UserDefaults in Preview
Hello, I've got a View that loads data from UserDefaults. I want to set the value of the UserDefault in the preview so i can see how it looks while developing. However when i am trying to set it in preview, i get the following error when i try set it in preview. 'buildExpression' is unavailable: this expression does not conform to 'View' What is the correct way to set the user defaults in preview? import Foundation class PreferencesViewModel: ObservableObject { @Published var maximumDistance: Double = UserDefaults.standard.value(for: .maximumDistance) as? Double ?? PreferencesViewModel.maximumDistanceOptions[0] { didSet { UserDefaults.standard.set(maximumDistance, for: .maximumDistance) } } #Preview { let preferencesViewModel = PreferencesViewModel() preferencesViewModel.maximumDistance = 5.0 PreferencesView() .environmentObject(PreferencesViewModel()) }
2
0
138
Apr ’25
App Crashes on Paper Selection After Background Printer Connection
Description: When initiating the print flow via UIPrintInteractionController, and no printer is initially connected, iOS displays all possible paper sizes in the paper selection UI. However, if a printer connects in the background after this view is shown, the list of paper sizes does not automatically refresh to reflect only the options supported by the connected printer. If the user selects an incompatible paper size (one not supported by the printer that has just connected), the app crashes due to an invalid configuration. Steps to Reproduce: Launch the app and navigate to the print functionality. Tap the Print button to invoke UIPrintInteractionController. At this point, no printer is yet connected. iOS displays all available paper sizes. While the paper selection UI is visible, the AirPrint-compatible printer connects in the background. Without dismissing the controller, the user selects a paper size (e.g., one that is not supported by the printer). The app crashes. Expected Result: App should not crash Once the printer becomes available (connected in the background), the paper size options should refresh automatically. The list should be filtered to only include sizes that are compatible with the connected printer. This prevents the user from selecting an invalid option, avoiding crashes. Actual Result: App crashes The paper size list remains unfiltered. The user can still select unsupported paper sizes. Selecting an incompatible option causes the app to crash, due to a mismatch between UI selection and printer capability.
Topic: UI Frameworks SubTopic: UIKit
0
0
97
Apr ’25
RealityView in UIHostingController/UIKit transparency
I'm experimenting with RealityView in the UI of an AUv3 plug-in. The plug-in UI is implemented in a UIKitViewController with a UIHostingController hosting a RealityView. When i run the standalone app on visionOS I want the background to be transparent, and the reality view content. how can i achieve that? I've tried turning off opaque in many views and and setting background colors to .clear.
1
0
75
Apr ’25
SwiftUI Button is not tappable if an Image is followed in a VStack
Here is the code: import SwiftUI struct ContentView: View { var body: some View { VStack(alignment: .leading, spacing: 8) { Button(action: { print("Tapped the button") }, label: { Text("Button") .foregroundStyle(Color.white) .padding() .background(Color.gray) }) .border(Color.green, width: 2) Image(systemName: "square.and.arrow.up") .resizable() .aspectRatio(contentMode: .fill) .foregroundStyle(Color.black) .frame(height: 240) .border(Color.blue, width: 2) .clipped() } .padding() .border(Color.black, width: 2) } } #Preview { ContentView() } The problem is that the button is not tappable. Test environment: macOS 15.3.2 (24D81), Xcode Version 16.2 (16C5032a), Simulator: iPhone 16 (18.3.1) However, if we change the code from ".aspectRatio(contentMode: .fill)" to ".aspectRatio(contentMode: .fit)" then the problem goes away. Any suggestions to fix the problem?
Topic: UI Frameworks SubTopic: SwiftUI
3
0
126
Apr ’25
NSTableView.clickedRow sometimes is greater than number of rows
Xcode has been downloading many similar crash reports for my app for some time now, related to an index out of range runtime exception when accessing a Swift array. The crashes always happen in methods triggered by user input or during menu item validation when I try to access the data source array by using the following code to determine the indexes of the relevant table rows: let indexes = clickedRow == -1 || selectedRowIndexes.contains(clickedRow) ? selectedRowIndexes : IndexSet(integer: clickedRow) I was never able to reproduce the crash until today. When the app crashed in the Xcode debugger, I examined the variables clickedRow and selectedRowIndexes.first, which were 1 and 0 respectively. What's interesting: the table view only contained one row, so clickedRow was effectively invalid. I tried to reproduce the issue several times afterwards, but it never happened again. What could cause this issue? What are the circumstances where it is invalid? Do I always have to explicitly check if clickedRow is within the data source range?
Topic: UI Frameworks SubTopic: AppKit Tags:
4
0
104
Apr ’25
App Crash with CarPlay & UIScene
My app crashed on iOS 18.1 only, here is the crash log: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'BUG IN CLIENT OF UIKIT: <CPTemplateApplicationScene: 0x1114bb780> -[UIScene _registerSettingsDiffActionArray:forKey:]: Registering the scene itself results in a retain cycle.' And I found this post: https://mastodon.social/@marcoarment/113280078320422999 Is this a system bug in iOS 18.1 beta 5?
Replies
1
Boosts
0
Views
120
Activity
Apr ’25
Does MKLookAroundViewController work on macOS?
Trying to incorporate a LookAroundView into my macOS application but unable to make the LookAroundView interactive at all. I can get it to display a static image, but there's no interactivity at all and no controls visible. This is using the SwiftUI LookAroundPreview view as well as trying to wrap MKLookAroundViewController inside an NSViewRepresentable. The navigation properties are set to true but that doesn't seem to make a difference. Would love to incorporate this feature but without interactivity its value is limited. macOS 15.4.1 (24E263), Xcode Version 16.3 (16E140)
Replies
1
Boosts
0
Views
117
Activity
Apr ’25
📍 Inconsistent POI Visibility Between Apple Maps and MKLocalSearch / CLGeocoder
Summary: Hi! I'm experiencing an issue between what Apple Maps displays in the UI and what is accessible via MapKit APIs such as MKLocalSearch and CLGeocoder. Specifically, some verified and publicly visible businesses (with proper POI categories like .cafe) are not returned by coordinate-based POI searches or reverse geocoding, even when their exact address and coordinates are known. Repro Steps: In Apple Maps (iOS), search for Rustic Knead located at: 1130 State St, Lemont, IL 60439 Note that: The business appears visually on the map It is categorized as a cafe The address is 1130 State St Now in code, attempt both: A coordinate-based POI search using MKLocalSearch.Request(region:) A reverse geocoding lookup via CLGeocoder.reverseGeocodeLocation Example coordinates: latitude: 41.673604, longitude: -88.002295 Expected Behavior: Given the precise coordinates and Apple Maps showing the POI publicly, I expect either or both of the following: MKLocalSearch should return the POI (Rustic Knead) within a reasonable radius and appropriate .pointOfInterestFilter. CLGeocoder should return a CLPlacemark with either name = "Rustic Knead" or an areasOfInterest value containing it. Actual Behavior: MKLocalSearch returns 0 POIs at that location, even with filters removed and radius increased to 500+ meters. CLGeocoder.reverseGeocodeLocation returns a valid postal address but does not include the business name in .name or areasOfInterest. Searching by business name (e.g., "Rustic Knead") does work, but coordinate/address-only lookups do not. Questions: Are there known limitations in how MapKit surfaces POIs by coordinate or reverse geocode? Is there a way to ensure public, categorized POIs are accessible programmatically via MapKit APIs? Is there a better strategy to provide coordinates and return a business name?
Replies
1
Boosts
0
Views
108
Activity
Apr ’25
Is there a way to present a fullscreen view controller and keep drawing the presenting view controller?
Looking for a solution that keeps the presented view controller fullscreen. The background is that I need to take some screenshots of the presenting view controller while the modal is onscreen. It's a pretty messy operation and we don't want to distract and delay the user by doing it before the modal is presented.
Topic: UI Frameworks SubTopic: UIKit
Replies
1
Boosts
0
Views
45
Activity
Apr ’25
How to make a UIButton resize its custom font text using `configurationUpdateHandler`?
I've read in this post that in order to make the configuration of UIButton adjust my custom font's size automatically I need to add implementation to recalculate the font's size inside configurationUpdateHandler. But how would this look like? I also read something about matching the font's text style. But at this point I'm just guessing. Here's the code: let loginButton = UIButton(configuration: config, primaryAction: nil) loginButton.configurationUpdateHandler = { button in guard var config = button.configuration else { return } let traits = button.traitCollection let baseTitleFont = UIFont.customFont(ofSize: 18, weight: .semibold) let baseSubtitleFont = UIFont.customFont(ofSize: 18, weight: .regular) let scaledTitleFont = UIFontMetrics(forTextStyle: .body).scaledFont(for: baseTitleFont, compatibleWith: traits) let scaledSubtitleFont = UIFontMetrics(forTextStyle: .body).scaledFont(for: baseSubtitleFont, compatibleWith: traits) config.titleTextAttributesTransformer = UIConfigurationTextAttributesTransformer { incoming in var outgoing = incoming outgoing.font = scaledTitleFont return outgoing } config.subtitleTextAttributesTransformer = UIConfigurationTextAttributesTransformer { incoming in var outgoing = incoming outgoing.font = baseSubtitleFont return outgoing } button.configuration = config } Thanks in advance!
Replies
3
Boosts
0
Views
176
Activity
Apr ’25
VisionOS custom hover effect and click sound
I have created a custom hover effect per this WWDC video and many other examples on the Net: https://developer.apple.com/videos/play/wwdc2024/10152/ I can get the button to expand when looked at within a VisionOS device and it will invoke a tap event when tapped but there is no click sound like a normal SwiftUI button does in VisionOS! I can't for the life of me figure out why. Any help would be appreciated!
Replies
2
Boosts
0
Views
305
Activity
Apr ’25
How to match Status/Menu Bar font (Date and Time)
Hello, I am trying to match the font and the position of the date and time displayed. This is what it looks like: .font: NSFont.systemFont(ofSize: NSFont.systemFontSize, weight: .regular), .foregroundColor: NSColor.labelColor, .baselineOffset: 0.5 It looks great on built-in display, but on external 4K it is incorrect. The baselineOffest is unnecessary, and the font looks skinny in comparison. Can anyone comment on such issue?
Replies
5
Boosts
0
Views
245
Activity
Apr ’25
Using the UIPasteControl
Hello 👋🏽 I am a new iOS developer and I am having a hard time understanding the behavior of the new UIPasteControl to avoid showing the system prompt. Does anyone has any example code I could look at to understand the behavior. Idk how to set the target of the button to the general pasteboard. also I am using objective-c . thanks cristian
Replies
5
Boosts
0
Views
4.1k
Activity
Apr ’25
SwiftUI Button fade animation happens with a delay when in ScrollView
When we place a Button inside a ScrollView , the fade animation of the button is delayed, so most users won't see it I think. You can see this in the trivial example struct ContentView: View { var body: some View { ScrollView { Button { // empty } label: { Text("Fade animation test") } } } } Is there any way to opt out of this behavior? In UIKit, this was also the default behavior, but you could always change it by overriding touchesShouldCancel method. I think I can probably do that by rewriting an animation completely with some custom ButtonStyle or by rewriting a Button component completely, but it doesn't seem like a good solution to me, as I want the native look and feel (in case of button animation it is pretty easy to mimic though). And also for some components, like lists, Apple has already implemented the correct behavior by themselves somehow.
Replies
3
Boosts
0
Views
102
Activity
Apr ’25
SwiftUI ScrollView Jittery/Glitchy Scrolling in iOS 17
Evening All and hope you had a good weekend. I'm experiencing significant scrolling issues in my SwiftUI weather app running on iOS 17. When scrolling through the main content, the scrolling is glitchy and not smooth, particularly around transitions between different subviews in the scroll view. The Issue The scrolling behavior has these problems: Stuttering/jittery movement during normal scrolling The issue seems most noticeable around the transitions between the header sections and the content sections (WindDetailsView and WeatherDataView) Smooth deceleration is affected, with visible "jumps" during momentum scrolling The problem appears to be worse on devices with iOS 17 compared to previous iOS versions Current Implementation My app uses a standard SwiftUI ScrollView with offset tracking to create a parallax effect for the header when scrolling. I'm calculating offset values to animate the header and adjust its opacity as the user scrolls. Here's the core structure:
Topic: UI Frameworks SubTopic: SwiftUI
Replies
2
Boosts
0
Views
127
Activity
Apr ’25
Not Showing FileOpen with Document-
I have developed several document-based (NSDocument) applications for macOS is Cocoa. Now, I'm playing with a document app project in SwiftUI. If I launch the application out of box, a file-select panel will open just as you see in TextEdit. (Please see the picture below) How do we prevent it from appearing? I would rather show a blank window, which in fact appears if I just press Command + N. Thanks.
Replies
2
Boosts
0
Views
111
Activity
Apr ’25
Using handleExternalEvents scene modifier to route external events to the correct scene
In an iPadOS SwiftUI app supporting multiple scenes, each Scene responds to a particular way in which the app was launched. If app was launched by tapping an associated file or a deep link (custom URL), then, the URLHandlerScene is invoked. If app was launched by QuickAction (long tap on the app icon), then another Scene is invoked etc. Each Scene has a purpose and responds to a particular launch. But after defining handlesExternlEvents(matching:) scene modifier, the scene was not getting launched when user taps the associated file or the app's Deeplinks was invoked. @main struct IOSSwiftUIScenesApp: App { var body: some Scene { DefaultScene() URLHandlerScene() .handlesExternalEvents(matching: ["file://"]) // Launched by an associated file .handlesExternalEvents(matching: ["Companion://"]) // Launched by Deeplink. // Other scenes } } struct URLHandlerScene: Scene { @State private var inputURL: URL // Store the incoming URL init() { self.inputURL = URL(string: "Temp://")! } var body: some Scene { WindowGroup { URLhandlerView(inputURL: $inputURL) .onOpenURL(perform: { (fileURL: URL) in log(String(format: "URLhandlerView().onOpenURL | Thread.current = %@", String(describing: Thread.current))) log("fileURL = " + String(describing: fileURL)) inputURL = fileURL }) } } } As shown above, I've attached handlesExternalEvents(matching:) modifier with "file://" for the associate file and "Companion" is my custom URL scheme. As per the scene matching rules documented here, my URLHandlerScene should get launched, but every time I launch the app using associated file or 'open' a Deeplink, the DefaultScene is always launched. What is missing here? Can someone please help?
Replies
1
Boosts
0
Views
152
Activity
Apr ’25
How to screenshot?
Is there anything to make a one off screenshot? like cmd+shift+3. But with code? There is ScreenCaptureKit - but it seems to be more for video / audio streams. I thought of trying to get the first frame from the video stream. But it seems to be rather a complex workaround for a simple problem.
Replies
3
Boosts
0
Views
144
Activity
Apr ’25
How to detect iPad trackpad touch-down (indirectPointer) to immediately stop coasting animation
Hello, I have a custom 3D object viewer on iOS that lets users spin the model using the touchscreen or a trackpad and supports coasting (momentum spinning). I need to stop the coasting animation as soon as the user touches down, but I can only immediately detect touches on the screen itself - on the trackpad I can't get an immediate notification of the touches. So far I’ve tried: State.began on my UIPanGestureRecognizer. It only fires after a small movement on both touchscreen and trackpad. .possible on the pan gesture; this state never occurs during the gesture cycle. UIApplicationSupportsIndirectInputEvents = YES in Info.plist; it didn’t make touchesBegan fire for indirectPointer touches. Since UITableView (and other UIScrollView subclasses) clearly detect trackpad “touch-down” to cancel scrolling, there must be a way to receive that event. Does anyone know how to catch the initial trackpad contact—before any movement—on an indirect input device? Below is a minimal code snippet demonstrating the issue. On the touchscreen you'll see a message the moment you touch the view, but the trackpad doesn't trigger any messages until your fingers move. Any advice would be greatly appreciated. Thanks in advance, John import UIKit class ViewController: UIViewController { private let debugView = DebugView() override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .white // Fill the screen with our debug view debugView.frame = view.bounds debugView.autoresizingMask = [.flexibleWidth, .flexibleHeight] debugView.backgroundColor = UIColor(white: 0.95, alpha: 1) view.addSubview(debugView) // Attach a pan recognizer that logs its state let panGR = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:))) panGR.allowedScrollTypesMask = .all debugView.addGestureRecognizer(panGR) } @objc private func handlePan(_ gr: UIPanGestureRecognizer) { switch gr.state { case .possible: print("Pan state: possible") case .began: print("Pan state: began") case .changed: print("Pan state: changed – translation = \(gr.translation(in: debugView))") case .ended: print("Pan state: ended – velocity = \(gr.velocity(in: debugView))") case .cancelled: print("Pan state: cancelled") case .failed: print("Pan state: failed") @unknown default: print("Pan state: unknown") } } } class DebugView: UIView { override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { super.touchesBegan(touches, with: event) for t in touches { let typeDesc: String switch t.type { case .direct: typeDesc = "direct (finger)" case .indirectPointer: typeDesc = "indirectPointer (trackpad/mouse)" case .indirect: typeDesc = "indirect (Apple TV remote)" case .pencil: typeDesc = "pencil (Apple Pencil)" @unknown default: typeDesc = "unknown" } print("touchesBegan on DebugView – touch type: \(typeDesc), location: \(t.location(in: self))") } } }
Topic: UI Frameworks SubTopic: UIKit Tags:
Replies
2
Boosts
0
Views
115
Activity
Apr ’25
searchable isPresented set too late in a sheet
I have a popover/sheet in iOS which allows users to search and add items to a list. When the sheet is shown, the search should always be active. I am using searchable on a NavigationStack inside the sheet. I am using the isPresented parameter to activate search. My issue is with the animation of the search activation. Even if I use... isPresented: .constant(true) ...the search isn't activated until the sheet has completed it's entrance animation, resulting in two stages of animation. I can't add a video here, but the two images below show the steps I am seeing. First a slide up animation, with the search in the navigation drawer, then a second animation, once the sheet is fully in place, as the search becomes active. Is it possible to merge these two animations, so search is in place when the sheet animates up?
Topic: UI Frameworks SubTopic: SwiftUI
Replies
0
Boosts
0
Views
55
Activity
Apr ’25
Setting UserDefaults in Preview
Hello, I've got a View that loads data from UserDefaults. I want to set the value of the UserDefault in the preview so i can see how it looks while developing. However when i am trying to set it in preview, i get the following error when i try set it in preview. 'buildExpression' is unavailable: this expression does not conform to 'View' What is the correct way to set the user defaults in preview? import Foundation class PreferencesViewModel: ObservableObject { @Published var maximumDistance: Double = UserDefaults.standard.value(for: .maximumDistance) as? Double ?? PreferencesViewModel.maximumDistanceOptions[0] { didSet { UserDefaults.standard.set(maximumDistance, for: .maximumDistance) } } #Preview { let preferencesViewModel = PreferencesViewModel() preferencesViewModel.maximumDistance = 5.0 PreferencesView() .environmentObject(PreferencesViewModel()) }
Replies
2
Boosts
0
Views
138
Activity
Apr ’25
App Crashes on Paper Selection After Background Printer Connection
Description: When initiating the print flow via UIPrintInteractionController, and no printer is initially connected, iOS displays all possible paper sizes in the paper selection UI. However, if a printer connects in the background after this view is shown, the list of paper sizes does not automatically refresh to reflect only the options supported by the connected printer. If the user selects an incompatible paper size (one not supported by the printer that has just connected), the app crashes due to an invalid configuration. Steps to Reproduce: Launch the app and navigate to the print functionality. Tap the Print button to invoke UIPrintInteractionController. At this point, no printer is yet connected. iOS displays all available paper sizes. While the paper selection UI is visible, the AirPrint-compatible printer connects in the background. Without dismissing the controller, the user selects a paper size (e.g., one that is not supported by the printer). The app crashes. Expected Result: App should not crash Once the printer becomes available (connected in the background), the paper size options should refresh automatically. The list should be filtered to only include sizes that are compatible with the connected printer. This prevents the user from selecting an invalid option, avoiding crashes. Actual Result: App crashes The paper size list remains unfiltered. The user can still select unsupported paper sizes. Selecting an incompatible option causes the app to crash, due to a mismatch between UI selection and printer capability.
Topic: UI Frameworks SubTopic: UIKit
Replies
0
Boosts
0
Views
97
Activity
Apr ’25
RealityView in UIHostingController/UIKit transparency
I'm experimenting with RealityView in the UI of an AUv3 plug-in. The plug-in UI is implemented in a UIKitViewController with a UIHostingController hosting a RealityView. When i run the standalone app on visionOS I want the background to be transparent, and the reality view content. how can i achieve that? I've tried turning off opaque in many views and and setting background colors to .clear.
Replies
1
Boosts
0
Views
75
Activity
Apr ’25
SwiftUI Button is not tappable if an Image is followed in a VStack
Here is the code: import SwiftUI struct ContentView: View { var body: some View { VStack(alignment: .leading, spacing: 8) { Button(action: { print("Tapped the button") }, label: { Text("Button") .foregroundStyle(Color.white) .padding() .background(Color.gray) }) .border(Color.green, width: 2) Image(systemName: "square.and.arrow.up") .resizable() .aspectRatio(contentMode: .fill) .foregroundStyle(Color.black) .frame(height: 240) .border(Color.blue, width: 2) .clipped() } .padding() .border(Color.black, width: 2) } } #Preview { ContentView() } The problem is that the button is not tappable. Test environment: macOS 15.3.2 (24D81), Xcode Version 16.2 (16C5032a), Simulator: iPhone 16 (18.3.1) However, if we change the code from ".aspectRatio(contentMode: .fill)" to ".aspectRatio(contentMode: .fit)" then the problem goes away. Any suggestions to fix the problem?
Topic: UI Frameworks SubTopic: SwiftUI
Replies
3
Boosts
0
Views
126
Activity
Apr ’25
NSTableView.clickedRow sometimes is greater than number of rows
Xcode has been downloading many similar crash reports for my app for some time now, related to an index out of range runtime exception when accessing a Swift array. The crashes always happen in methods triggered by user input or during menu item validation when I try to access the data source array by using the following code to determine the indexes of the relevant table rows: let indexes = clickedRow == -1 || selectedRowIndexes.contains(clickedRow) ? selectedRowIndexes : IndexSet(integer: clickedRow) I was never able to reproduce the crash until today. When the app crashed in the Xcode debugger, I examined the variables clickedRow and selectedRowIndexes.first, which were 1 and 0 respectively. What's interesting: the table view only contained one row, so clickedRow was effectively invalid. I tried to reproduce the issue several times afterwards, but it never happened again. What could cause this issue? What are the circumstances where it is invalid? Do I always have to explicitly check if clickedRow is within the data source range?
Topic: UI Frameworks SubTopic: AppKit Tags:
Replies
4
Boosts
0
Views
104
Activity
Apr ’25