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.

I have a UIScrollView, and its subview inside needs to respond to some touchesMoved events without scrolling. I've got it mostly working, but with one sticking point that confuses the user: if I touch and quickly move my finger, then the UIScrollView takes the gesture as a scroll, and never calls the touchesBegan, touchesMoved, etc., of its subview. However, if I touch, then pause for a bit, then drag, then things work as intended: the subview gets touchesBegan, touchesMoved, etc., and things are handled without any scrolling. On my UIScrollView, I've set: delaysContentTouches = false canCancelContentTouches = true And I've overrode touchesShouldCancel(in view: UIView). But that does not get called in the case when I quickly drag my finger. Is there something else I need to do?

It's a simple question. I'm just trying to understand how these things fit together. Core Text doesn't seem to get updated much, but maybe that's because it's low level and doesn't need it. I assume it's still the recommended way to do low-level text things not handled by TextKit. ?

If I go to the Xcode documentation viewer and type simd_float3x3 in the search field, nothing comes up. I swear these things used to have documentation. Where is it? Is it a bug? (Xcode 13.4.1)

I've added an NSTrackingArea to my NSView because I want a certain rectangular area to show a different cursor. As expected, my view gets a call to it's cursorUpdate:(NSEvent*) method, but how do I tell whether it's an "enter" or "leave". - (void)cursorUpdate:(NSEvent *)event { // Do I push or pop my custom NSCursor? } I notice the event.modifierFlags changes from 8 to 9. But I don't see any public enum constants to test that, so I don't know if I can depend on that. The public enum contains stuff like this, in the higher bits. typedef NS_OPTIONS(NSUInteger, NSEventModifierFlags) { NSEventModifierFlagCapsLock = 1 << 16, NSEventModifierFlagShift = 1 << 17, ... The tracking area setup code: NSRect nsRect = ... NSTrackingAreaOptions options = NSTrackingCursorUpdate | NSTrackingActiveInKeyWindow; NSTrackingArea *trackingArea = [[NSTrackingArea alloc] initWithRect: nsRect options: options owner: owner userInfo: userInfo]; [myView addTrackingArea: trackingArea];

I had the following code in a program that I used to encrypt some important files. I haven't run it in a few years. It used to work, and now it seems the password is mysteriously gone from my Keychain! The return value is now errSecItemNotFound. I'm upset with myself for not backing up the key/password somewhere else. Is there anywhere this could be hiding? Did Apple move it somewhere? I know they created this "Passwords" app in recent years, but I don't see anything in there with the "account" string I used. I run the app from Xcode, so maybe it is in the "container" data somewhere? I do see keychain files under ~/Library. Maybe there is a way to look through old Time Machine backups. Ug. So stressful. Just looking for pointers on where the data might be, and why it might have disappeared. Unfortunately it was not a "guessable" password, it was a generated 256 bit key, base64 encoded. Perhaps I could crack that with brute force if I'm determined enough... public static func queryGenericPasswordAsString(account: String) throws -> String { let query: [String: Any] = [kSecClass as String: kSecClassGenericPassword, kSecMatchLimit as String: kSecMatchLimitOne, kSecAttrAccount as String: account, kSecReturnAttributes as String: true, kSecReturnData as String: true] var item: CFTypeRef? let status = SecItemCopyMatching(query as CFDictionary, &item) guard status != errSecItemNotFound else { throw KeychainError.noPassword } ... }

The sample code here, has code like: // Create a display link capable of being used with all active displays cvReturn = CVDisplayLinkCreateWithActiveCGDisplays(&_displayLink); But that function's doc says it's deprecated and to use NSView/NSWindow/NSScreen displayLink instead. That returns CADisplayLink, not CVDisplayLink. Also the documentation for that displayLink method is completely empty. I'm not sure if I'm supposed to add it to run loop, or what, after I get it. It would be nice to get an updated version of this sample project and/or have some documentation in NSView.displayLink

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.

I know how to add items to the main menu. But what if I want to connect a handler to one that is already there by default? (For example "Select All"). WindowGroup { ContentView() }.commands {     CommandGroup(after: CommandGroupPlacement.pasteboard) {   Button("Select All") { selectAll() } } That adds a second "Select All" menu item. If I use CommandGroup(replacing: ...) then it replaces others, not just the "Select All"

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?

Hi,I need to save and load metal textures to a file. Example code below is below. I'm noticing the RGB values are changing as it gets saved and reloaded again.metal texture pixel: RGBA: 42,79,12,95after save and reload: 66,88,37,95I thought it might be a colorspace issue, but the colorspaces I’ve tried all had the same problem. `genericRGBLinear` got close, but there’s got to be a way to save the RGB data and get it back exactly. ?thanks,RobCode:// saving... let ciCtx = CIContext() let ciImage = CIImage(mtlTexture: metalTexture, options: [:]) [ … transfrom to flip y-coordinate …] let colorSpace = CGColorSpaceCreateDeviceRGB() let cgImage = ciCtx.createCGImage(ciImage, from: fullRect, format: kCIFormatRGBA8, colorSpace: colorSpace)! let imageDest = CGImageDestinationCreateWithData(mData, kUTTypePNG, 1, nil)! CGImageDestinationAddImage(imageDest, cgImage, nil) CGImageDestinationFinalize(imageDest) // loading... let src = CGImageSourceCreateWithData(imgData, nil) let img = CGImageSourceCreateImageAtIndex(src, 0, nil) let loader = MTKTextureLoader(device: self.metalDevice) let texture = try! loader.newTexture(cgImage: img, options: [:])