I have an application that communicates with custom external hardware on the network (using UDP). I have a thread that receives and process the UDP data and then signals a waiting thread by releasing a semaphore when data is available. A have a asyncSendAndReceive and asyncReceive function that just begs to use async/await. But I cannot simply switch because of the use of the semaphore. Various forums and discussions said that semaphores should no longer be used for signalling. If not semaphores, then what else? Note that my two async functions may not always block. If data was received before they were called, then it is queued (and the semaphore is signalled).

The example code below shows what I am trying to achieve: When the user types a '*', it should be replaced with a '×'. It looks like it works, but the cursor position is corrupted, even though it looks OK, and the diagnostics that is printed below shows a valid index. If you type "12*34" you get "12×43" because the cursor is inserting before the shown cursor instead of after. How can I fix this? struct ContentView: View { @State private var input: String = "" @State private var selection: TextSelection? = nil var body: some View { VStack { TextField("Type 12*34", text: $input, selection: $selection) .onKeyPress(action: {keyPress in handleKeyPress(keyPress) }) Text("Selection: \(selectionAsString())") }.padding() } func handleKeyPress(_ keyPress: KeyPress) -> KeyPress.Result { if (keyPress.key.character == "*") { insertAtCursor(text: "×") moveCursor(offset: 1) return KeyPress.Result.handled } return KeyPress.Result.ignored } func moveCursor(offset: Int) { guard let selection else { return } if case let .selection(range) = selection.indices { print("Moving cursor from \(range.lowerBound)") let newIndex = input.index(range.lowerBound, offsetBy: offset, limitedBy: input.endIndex)! let newSelection : TextSelection.Indices = .selection(newIndex..<newIndex) if case let .selection(range) = newSelection { print("Moved to \(range.lowerBound)") } self.selection!.indices = newSelection } } func insertAtCursor(text: String) { guard let selection else { return } if case let .selection(range) = selection.indices { input.insert(contentsOf: text, at: range.lowerBound) } } func selectionAsString() -> String { guard let selection else { return "None" } switch selection.indices { case .selection(let range): if (range.lowerBound == range.upperBound) { return ("No selection, cursor at \(range.lowerBound)") } let lower = range.lowerBound.utf16Offset(in: input) let upper = range.upperBound.utf16Offset(in: input) return "\(lower) - \(upper)" case .multiSelection(let rangeSet): return "Multi selection \(rangeSet)" @unknown default: fatalError("Unknown selection") } } }

I have a SwiftUI sandbox app that uses userDefaults. I would like to verify that the data is correctly saved and also modify it during development to check that my app behaves correctly. I can see the data in ~/Library/Containers//Data/Library/Preferences/.plist. My problem is that when I delete this file to check that my app will behave correctly, then it is re-created with old data. It contains entries that I used for development testing, and not in use any longer. I am unable to get a clean file again. Where is the original data saved, and how do I access it? I've looked in: ~/Library/Preferences ~/Library/Preferences/By Host ~/Library/Caches ~/Library/Saved Application State It is not in one of those locations unless it is named differently. Even a search on my mac did not find it.

I have a class that I cannot change to ObservableObject with Published members. I tried getting around this by writing my own Binding. Although the value is updated correctly, the UI is not. Why is this. Below is a simple demo view. When it is run and the toggle is clicked, it will print out correctly that the value is changed, but the UI does not update. Why? import SwiftUI class BoolWrapper {   public var value = false {     didSet {       print("Value changed to \(value)")     }   } } let boolWrapper = BoolWrapper() struct ContentView: View {   var body: some View {     Toggle(isOn: Binding(get: {       return boolWrapper.value     }, set: { value in       boolWrapper.value = value     }), label: { Text("Toggle") })   } } struct ContentView_Previews: PreviewProvider {   static var previews: some View {     ContentView()   } }

My question is slightly broader, but hopefully this simple use case states the point.I ofthen run in to the problem where my source of truth is a custom type (struct, array of bytes, int, etc.) that I want to edit. I would like to write a view that has a binding to this type so that all the editing logic lives inside this view without the views outside having to worry how it is edited.The simplest example of this is a view that takes a binding to an Int where the user edits it with a TextField. Up to now I've only been able to do this with a custom UI- or NSViewRepresentable implementation. I thought I had a solution today, but it too does not work. It is close enough, that I thought maybe someone can see a path going further.Below is my code. It has an IntView that takes a binding to an Int, and uses state for the strValue. When it first apears, it updates the local state. It then has a method that can be called to update the binding value (this because I cannot get updates as the text field is changing).My contentView creates this view and stores updateValue so that it can be called when the button is pressed. The problem is that view is a value (not a reference), so the intView created in body() is not the same one as that in the .async call (I double-checked this with the print that prints the pointer to each). When updateValue() is called, I get an exception, because I am using the wrong view. The reason for using an .async call is so that I do not change state when body is computed.Can this code somehow be made to work, or is there another solution to writing IntView that takes a binding to an Int?My problem is often more complicated for example when I want to bind to a struct. If I write a custom __ViewRepresentable solution, then I lose a lot of the ease-of-use of swift, and goes back to manual layout, etc.struct IntView: View { @Binding var value: Int @State private var strValue: String = "" var body: some View { return TextField("Type here", text: $strValue) .onAppear(perform: { self.strValue = "\(self.value)" }) } func updateValue() { value = Int(strValue)! } } struct ContentView: View { @State var intValue: Int = 12 @State var updateValue: (() -&gt; Void)? var body: some View { let intView = IntView(value: $intValue) withUnsafePointer(to: intView) { print("value at first @\($0)") } DispatchQueue.main.async { withUnsafePointer(to: intView) { print("value in async @\($0)") } self.updateValue = intView.updateValue } return VStack { Text("\(intValue)") intView Button(action: { self.updateValue!() }, label: { Text("Get Value") }) } .padding() .frame(maxWidth: .infinity, maxHeight: .infinity) } } struct ContentView_Previews: PreviewProvider { static var previews: some View { ContentView() } }

I am trying out the new TextField selection ability on macOS but it crashes in various different ways with extremely large stack traces. Looks like it is getting into re-entrant function calls. A similar problem is described on the SwiftUI forums with no responses yet. Here is my simple example struct ContentView: View { @State private var text: String = "" @State private var selection: TextSelection? var body: some View { TextField("Message", text: $text, selection: $selection) .padding() } } Setting text to a value like "Hallo World" causes an instant crash as soon as you start typing in the TextField. Setting text empty (as in example above) lets you edit the text but as it crashes as soon as you commit it (press enter). Any workarounds or fixes?

I am trying to get access to raw audio samples from mic. I've written a simple example application that writes the values to a text file. Below is my sample application. All the input samples from the buffers connected to the input tap is zero. What am I doing wrong? I did add the Privacy - Microphone Usage Description key to my application target properties and I am allowing microphone access when the application launches. I do find it strange that I have to provide permission every time even though in Settings > Privacy, my application is listed as one of the applications allowed to access the microphone. class AudioRecorder { private let audioEngine = AVAudioEngine() private var fileHandle: FileHandle? func startRecording() { let inputNode = audioEngine.inputNode let audioFormat: AVAudioFormat #if os(iOS) let hardwareSampleRate = AVAudioSession.sharedInstance().sampleRate audioFormat = AVAudioFormat(standardFormatWithSampleRate: hardwareSampleRate, channels: 1)! #elseif os(macOS) audioFormat = inputNode.inputFormat(forBus: 0) // Use input node's current format #endif setupTextFile() inputNode.installTap(onBus: 0, bufferSize: 1024, format: audioFormat) { [weak self] buffer, _ in self!.processAudioBuffer(buffer: buffer) } do { try audioEngine.start() print("Recording started with format: \(audioFormat)") } catch { print("Failed to start audio engine: \(error.localizedDescription)") } } func stopRecording() { audioEngine.stop() audioEngine.inputNode.removeTap(onBus: 0) print("Recording stopped.") } private func setupTextFile() { let tempDir = FileManager.default.temporaryDirectory let textFileURL = tempDir.appendingPathComponent("audioData.txt") FileManager.default.createFile(atPath: textFileURL.path, contents: nil, attributes: nil) fileHandle = try? FileHandle(forWritingTo: textFileURL) } private func processAudioBuffer(buffer: AVAudioPCMBuffer) { guard let channelData = buffer.floatChannelData else { return } let channelSamples = channelData[0] let frameLength = Int(buffer.frameLength) var textData = "" var allZero = true for i in 0..<frameLength { let sample = channelSamples[i] if sample != 0 { allZero = false } textData += "\(sample)\n" } if allZero { print("Got \(frameLength) worth of audio data on \(buffer.stride) channels. All data is zero.") } else { print("Got \(frameLength) worth of audio data on \(buffer.stride) channels.") } // Write to file if let data = textData.data(using: .utf8) { fileHandle!.write(data) } } }

I have a program where I need to handle Edit>Copy when the first responder cannot. I've added the following to my AppDelegate: @IBAction @objc func copy(_ sender: Any?) {     // My code here...   } But Edit>Copy is greyed out on the menu unless a TextField has focus and it has text selected. How do I get my copy function called when the text field has focus but does not have text selected (or any other case where the current view with focus cannot handle copy)?

I have some code that used to work but is failing to bind to a local UDP port saying it is already in use. lsof does not show that the port is being used. Below is my receive function that fails. bindResult is "-1" when calling bind, and the error printed out contains "Address already in use (48)". I am trying to bind to 127.0.0.1:6000. This has been working for a very long time, but I've not used it for one or two months, so not sure if a macOS upgrade or something else broke it. func receive(handleRxData: @escaping (UdpSocket, IpAddress, ArraySlice&lt;UInt8&gt;) -&gt; Void,                withError error: (_ msg: String) -&gt; Void) {          self.handleRxData = handleRxData          var cfSocketContext = CFSocketContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil)     cfSocketContext.info = Unmanaged.passRetained(self).toOpaque()          cfSock = CFSocketCreate(kCFAllocatorDefault,                             PF_INET,                             SOCK_DGRAM,                             IPPROTO_UDP, CFSocketCallBackType.readCallBack.rawValue,                             { (socket: CFSocket?, callBackType: CFSocketCallBackType, address: CFData?, data: UnsafeRawPointer?, info: UnsafeMutableRawPointer?) -&gt; Void in                               let udpSocket = Unmanaged&lt;UdpSocket&gt;.fromOpaque(info!).takeUnretainedValue()                               udpSocket.receiveCallback()     },                             UnsafeMutablePointer&lt;CFSocketContext&gt;(&amp;cfSocketContext))     let sock = CFSocketGetNative(cfSock)          // Create ipv4 addr struct:     var sin = sockaddr_in()     if (local.type == .ipv4) {       sin.sin_len = __uint8_t(MemoryLayout.size(ofValue: sin))       sin.sin_family = sa_family_t(AF_INET)       sin.sin_addr.s_addr = local.ipv4.bigEndian       sin.sin_port = local.port.bigEndian     }          let bindResult = withUnsafeMutablePointer(to: &amp;sin) {       $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {         bind(sock, UnsafeMutablePointer&lt;sockaddr&gt;($0), socklen_t(MemoryLayout&lt;sockaddr_in&gt;.size))       }     }     if bindResult &lt; 0 {       error("Could not bind to socket \(sin) ( \(String(cString: strerror(errno)!)) (\(errno)).")       return     }          // Change socket to non-blocking:     let flags = fcntl(sock, F_GETFL);     let fcntlResult = fcntl(sock, F_SETFL, flags | O_NONBLOCK);     if (fcntlResult &lt; 0) {       print("Could not change socket to non-blocking ( \(String(cString: strerror(errno)!)) (\(errno)).")     }     // Add to run loop:     let rls = CFSocketCreateRunLoopSource(nil, cfSock, 0);     if (rls == nil) {       error("Could not get run loop source.")       return     }     CFRunLoopAddSource(CFRunLoopGetCurrent(), rls, CFRunLoopMode.commonModes)// CFRunLoopMode.defaultMode);   }

I have a SwiftUI app with a class that conforms to ObservableObject that contains state that I would like to preserve between application launches. How do I do this in swiftUI? I need something similar to @SceneStorage but for reference types. Below is an example showing what I am trying to accomplish. This app shows statistics for a specific network port. I would like to have the StreamStats parameters preserved. I can save the lastPort value using the @SceneStorage property wrapper but this is just to demonstrate the intent. Note: Although this example does not show it, the port member in StreamStats could be changed by code in the class itself. It must not only be reflected correctly the the GUI, but also be saved as part of the state. import SwiftUI @main struct SceneStorageTest: App { var body: some Scene { WindowGroup("Port Statistics", id: "statsView") { ContentView() } } } class StreamStats: ObservableObject { @Published public var port: Int = 60000 init() { startListening() } public func startListening() { print("Gathering stats for port \(port)") } } struct ContentView: View { @SceneStorage("lastPort") var lastPort: Int = 0 @StateObject var streamStats = StreamStats() @Environment(\.openWindow) private var openWindow var body: some View { VStack { Text("Last port: \(lastPort)") TextField("port", value: $streamStats.port, format: .number) Button("Open") { lastPort = streamStats.port streamStats.startListening() } Divider() Button("New Port Statistics Window") { openWindow(id: "statsView") } }.padding() } }

How does one remove the focus border for a TextField in SwiftUI?In Cocoa, setting the border to "None" in interface builder would remove the border.I've tried using .border with a width of zero, but that does not work. The .border adds another border on top of the focus border.Setting the style also does not do the trick.

I am trying to create a standard stepper with text field in swiftUI, but it does not seem to exist.I need something that looks like this:Do I have to create my own view, or is something already available?I tried an HStack with Text, TextField and stepper, but this does not align properly when placed in a form, and the stepper and text field cannot have a binding to the same value.Any ideas on how to implement this?

I would like to keep my layout the same, and only rotate views in-place when the screen orientation changes.Below is a simple example of what I am trying to acieve. It shows to TestViews horizontally when in portrait mode, and vertically when in landscape mode.I've made sure that the views themselve does not get re-created in the hope that it would only animate the difference in layout between portrait and landscape, but it makes the views very small, and then animate them in from the corner of the screen.What I am trying to acieve, is for each view to effectively rotate by 90 degrees when the orientation changes. Is it possible in swiftUI?[In my example below, I've hacked my AppDelegate to be my model to get rotation notifications from a publisher in it. This needs to be added for the example to work.]struct TestView: View { var text: String var body: some View { ZStack { RoundedRectangle(cornerRadius: 25.0, style: .continuous) .foregroundColor(Color(red: 0.2, green: 0.2, blue: 0.2)) Text(verbatim: text) .font(.system(size: 95)) .foregroundColor(.white) }.aspectRatio(1.0, contentMode: .fit) } } struct ContentView: View { @EnvironmentObject var model : AppDelegate private let testViews: [TestView] = (0...1).map { TestView(text: "\($0)") } var body: some View { ZStack { if !model.isPotrait { HStack { VStack { testViews[0] testViews[1] } } } else { VStack { HStack { testViews[0] testViews[1] } } } }.padding() } }

I used to get an e-mail when people replied to my posts but that is no longer working (I do not know when it broke). I cannot find where it needs to be enabled. Has it been removed? If not, where is it enabled?

The new SwiftUI introduces the new Menu - https://developer.apple.com/documentation/swiftui/menu item but I cannot find any complete examples showing how to use it. I did find an article (cannot link to it here) on how to use Menu but it is connected to a toolbar item only and does not change the menubar. I would like to add a menu item to the menubar in macOS using a SwiftUI App. Any examples of how to do this would be great.