I can't find any documentation on this. I've tried adding png files to my project and adding them with the "+" button here, but Xcode just ignores me. No error message. Is it looking for a specific file format? This is Xcode 13.

This appears to severely limit the usefulness of hierarchical lists in SwiftUI. I want to use the new hierarchical list/outline to display a filesystem tree. For data to pass to OutlineGroup, I created a class named FileSystemNode, and gave it a computed children property. When the getter is first called, it will read its directory contents to return a list (if it is a directory). Problem is, when the OutlineGroup is first displayed, even though it is collapsed on-screen to a single node, it calls children and recurses over the entire filesystem. Is there a way to stop this? If not, I hope it gets fixed before release. (This is on macOS Big Sur beta)

My app crashes and Xcode shows no stack trace. It just pops up some line of assembly language in __pthread_kill, and shows this in the console: [error] precondition failure: invalid value type for attribute: 230424 (saw PreferenceKeys, expected ViewList) AttributeGraph precondition failure: invalid value type for attribute: 230424 (saw PreferenceKeys, expected ViewList). Seems like a bug in SwiftUI. Any ideas? This is on macOS 11.

Simple code like this gives an error. struct MyView: View {     @State private var test: Bool = false     var body: some View {           Text("Hello. \(test)") The error: Instance method 'appendInterpolation(_:formatter:)' requires that 'Bool' inherit from 'NSObject' What is going on?

I think they are, but I got myself into a situation with this error: // Inside a SwiftUI View struct... let cancelled: @MainActor () -> Void var body: some View { ... Button(action: self.cancelled) { Text("Cancel") } // Error here The compiler reports: Converting function value of type '@MainActor () -> Void' to '() -> Void' loses global actor 'MainActor' I originally put that attribute on the cancelled property, because in the passed-in closure, I was doing something that gave me an error about how I had to be on the MainActor.

I created a simple app in Xcode. Installed and ran it in the iOS Simulator. I can also start it from command line like this: % xcrun simctl launch booted com.example.TestBuildCommands --console com.example.TestBuildCommands: 52877 % It just prints that one line and returns my shell prompt. But the help for launch says that --console should: "Block and print the application's stdout and stderr to the current terminal." In my main() function I have: int main(int argc, char * argv[]) { printf("In main.\n"); ... Shouldn't I be seeing that message in my terminal screen? % xcrun simctl help launch Launch an application by identifier on a device. Usage: simctl launch [-w | --wait-for-debugger] [--console|--console-pty] [--stdout=<path>] [--stderr=<path>] [--terminate-running-process] <device> <app bundle identifier> [<argv 1> <argv 2> ... <argv n>] --console Block and print the application's stdout and stderr to the current terminal. Signals received by simctl are passed through to the application. (Cannot be combined with --stdout or --stderr) [...] ps. Anyone know how to turn off syntax highlighting in those triple-backquoted code blocks that are meant to be just terminal text, not highlighted code?

This method on UIEvent gets you more touch positions, and I think it's useful for a drawing app, to respond with greater precision to the position of the Pencil stylus. Is there a similar thing in macOS, for mouse or tablet events? I found this property mouseCoalescingEnabled, but the docs there don't describe how to get the extra events.

I'd like to use the new localization screenshots and test plans feature to take screenshots in different languages, for the app store. I end up with images that are half one screen and half another, like it's some kind of timing issue. My test code is below. Is it missing something that would give it the right timing on the screenshots?I wrote a UI test and set "Localization Screenshots" to "On" in the test plan's settings. The UI test walks through a few screens and the resulting test report has a few image files attached labeled "Localization screenshot". Some images are are split so that the left side is one view controller and the right side is another, like it captured a push navigation transition. Another image has two overlaid screens, each half faded.I'm running in the simulator. My test code looks like: func testTakeScreenshots() { let app = XCUIApplication() app.launch() // At workouts page app.tables["workouts"].cells.element(boundBy: 0).tap() // At first workout app.navigationBars.buttons["edit"].tap() // At workout edit screen, click first exercise app.tables.cells.element(boundBy: 0).tap() ... }

I have some code that used to run on my iPad Pro. Today I compiled it for iOS 13, with Xcode 11, and I get errors like this: validateComputeFunctionArguments:834: failed assertion `Compute Function(merge_layer): Shader uses texture(outTexture[1]) as read-write, but hardware does not support read-write texture of this pixel format.'The pixel format is showing as `MTLPixelFormatBGRA8Unorm`. That's what I expected.The debugger says the device has no support for writeable textures. (lldb) p device.readWriteTextureSupport (MTLReadWriteTextureTier) $R25 = tierNoneDid some devices lose support for texture writing in iOS 13?Rob

Hi, I want something like sandbox-exec, so I can run things that I don't trust, and restrict their ability to read or write files to only certain locations. Like most software devs I have to download and run lots of code from the internet and the danger of this really annoys me. Unfortunately sandbox-exec is marked as deprecated and the APIs in sandbox.h say "No longer supported". I notice there is some new stuff in the Apple docs about "hypervisors" and "virtualization". https://developer.apple.com/documentation/hypervisor https://developer.apple.com/documentation/virtualization Would these APIs allow me to start and control a virtual copy of my macOS, to serve like a sandbox? Are there other solutions that people use? As an example, say that I need to download and run a copy of memcached. It's a typical open source project – you unpack a source tgz, then run configure; make and get a binary. Now I want to run that without worrying that some hacker injected a piece of evil code to copy my files and send them somewhere. So I want to say "run this binary, while disallowing file reads and writes, except for directories X,Y,Z, and disallowing network connections, except for listening on port 1234."

Hi, If I change the AppIcon in Xcode's Assets.xcassets, and rerun my app, the image used in the dock and app switcher does not update. If I "Clean Build Folder", and re-run, then it updates. This is annoying when I keep tweaking the colors in the icon and want to see how they look. A full rebuild takes a while, because I have a few Swift Package dependencies. Anyone know a trick to get the AppIcon to stop caching (or whatever it's doing)? I tried killall Dock and killall Finder, but that didn't help. (macOS 11.2.3) Rob

You used to be able to put two wheel Pickers side-by-side in an HStack, if you used .frame(...) to set the width, along with .clipped(). Example code from previous question here: https://developer.apple.com/forums/thread/127028 HStack(spacing: 0) { Picker(selection: $choice1, label: Text("C1")) { ForEach(0..<10) { n in Text("\(n) a").tag(n) } } .pickerStyle(.wheel) .frame(minWidth: 0) .clipped() // repeat with second Picker } This is not working for me now in iOS 15. The views still appear side by side, but the touch area seems to overlap. When you try to adjust the first wheel, it spins the second one. I can move the first wheel, if I touch way over to the leading side of the screen. (I had to add the explicit Picker style. It seems like defaulting to .menu also started in iOS 15. ?)

I want to show a custom confirmation dialog on my iPad. It pops up looking utterly ridiculous because the size is way bigger than it needs - inches of padding on all sides. Is there still no way to control a sheet size on iPad? Example code: struct ContentView: View {     @State var showSheet = false     var body: some View {         Button("Show sheet") {             showSheet = true         }.sheet(isPresented: $showSheet) {             VStack(spacing: 0) {                 Text("Title")                 Divider()                 Text("Line 1")                 Text("Line 2. Blah blah blah blah.")                 Divider()                 HStack {                     Button("Cancel") { showSheet = false }                     Divider()                     Button("OK") { showSheet = false }                 }.fixedSize(horizontal: false, vertical: true)             }             .frame(minWidth: 0, minHeight: 0)             .fixedSize()         }     } } The result:

I watched a WWDC talk on LLDB, and they showed a nice trick of calling CATransaction.flush() from the debugger, to push changes to a UIView to the screen, even when the program was paused. Is there is a similar thing we can do with Metal? I'm using MTKView, but I can change to a lower level if that's required. The MTKView is paused, so I'm using setNeedsDisplay. As usual, I implement the draw delegate method to encode and commit a command buffer. If I do this from LLDB: metalView.setNeedsDisplay() CATransaction.flush() I can see that causes my draw function to run, but nothing shows up on screen. Is there something else we can do to flush those metal commands to the GPU and see them on screen while stepping through the program with the debugger?

I'm working on a macOS app that I want to give "Full Disk Access". When I run from Xcode, I get "permission denied" errors when reading a file in my home directory. What can I do so that I can run and debug from Xcode? I dragged the binary from the derived data folder to the System Preferences list for Full Disk Access, but that seems to do nothing.