I'm encountering a crash issue in my macOS application when clicking on the view generated by AppKit's showDefinition(for:at) function. I'm seeking assistance to resolve this issue.
**Problem Description: **
I'm developing a macOS application where I utilize the showDefinition(for:at) function provided by AppKit to display the definition view of words. However, whenever I click on this view, the application crashes abruptly.
**Error Message: **
The crash log reveals the following error message:
Fault: deferNSXPCInvocationOntoMainThread_block_invoke caught NSInternalInconsistencyException '_CPSSetFrontProcessWithOptions failed due to CGError -606 4294966690 fffffda2 (appIsDaemon)'
Attempts Made:
Tried wrapping relevant code blocks with DispatchQueue.main.async, suspecting a threading issue.
Making the DefinitionWindow variable a global one to manually control its lifecycle
Development Environment:
macOS Version: 14.3.1 Xcode Version: 15
Below is a complete and reproducible code snippet that can be directly executed within a terminal project template. Please note that it requires Accessibility permissions to be granted in the Privacy settings.
import Cocoa
import SwiftUI
import AppKit
class AppDelegate: NSObject, NSApplicationDelegate {
func applicationDidFinishLaunching(_ notification: Notification) {
NSEvent.addGlobalMonitorForEvents(matching: .keyDown) { [weak self] event in
guard let self = self else { return }
if event.modifierFlags.contains(.command) && event.charactersIgnoringModifiers == "c" {
self.ShowWordDefinition()
}
}
NSApp.servicesProvider = self
NSApp.registerServicesMenuSendTypes([.string], returnTypes: [])
}
func ShowWordDefinition(){
DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
let attributedString = NSAttributedString(string:NSPasteboard.general.string(forType: .string)!)
let DefinitionWindow = NSWindow(contentRect: NSRect(origin: .zero, size: NSSize(width: 1, height: 1)), styleMask: [.borderless], backing: .buffered, defer: false)
// on the top
DefinitionWindow.level = .floating
let pointInWindow = NSPoint(x:0,y:0); //default value
DefinitionWindow.contentView?.showDefinition(for: attributedString, at: pointInWindow)
DefinitionWindow.orderFront(nil)
}
}
}
let delegate = AppDelegate()
let app = NSApplication.shared
app.delegate = delegate
app.run()
full crash log reveals the following error message:
FAULT: deferNSXPCInvocationOntoMainThread_block_invoke caught NSInternalInconsistencyException '_CPSSetFrontProcessWithOptions failed due to CGError -606 4294966690 fffffda2 (appIsDaemon)' with backtrace (
"0 CoreFoundation __exceptionPreprocess + 176",
"1 libobjc.A.dylib objc_exception_throw + 60",
"2 CoreFoundation +[NSException exceptionWithName:reason:userInfo:] + 0",
"3 ViewBridge assertCGError + 80",
"4 ViewBridge -[NSRemoteView _serviceWindowWouldActivate] + 724",
"5 CoreFoundation __invoking___ + 148",
"6 CoreFoundation -[NSInvocation invoke] + 428",
"7 ViewBridge __deferNSXPCInvocationOntoMainThread_block_invoke + 120",
"8 ViewBridge __wrapBlockWithVoucher_block_invoke + 56",
"9 ViewBridge deferredBlockOpportunity_block_invoke_2 + 360",
"10 CoreFoundation __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 28",
"11 CoreFoundation __CFRunLoopDoBlocks + 356",
"12 CoreFoundation __CFRunLoopRun + 2440",
"13 CoreFoundation CFRunLoopRunSpecific + 608",
"14 HIToolbox RunCurrentEventLoopInMode + 292",
"15 HIToolbox ReceiveNextEventCommon + 648",
"16 HIToolbox _BlockUntilNextEventMatchingListInModeWithFilter + 76",
"17 AppKit _DPSNextEvent + 660",
"18 AppKit -[NSApplication(NSEventRouting) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 716",
"19 AppKit -[NSApplication run] + 476",
"20 try main + 160",
"21 dyld start + 2360"
)
Just a reminder, the application will crash when you click on the displayed definition window.
Potential Questions and Concerns:
Could there be an issue related to UI transitions or the main thread?
How exactly does the showDefinition(for:at) process work internally?
Maybe , the view's display level being raised when clicked caused conflict?
If anyone could provide any insights or guidance on resolving this issue, it would be greatly appreciated. Thank you!