simpletopbar/Sources/SimpleTopBar/App.swift

import SwiftUI
import AppKit
import ServiceManagement

@main
struct SimpleTopBarApp: App {
    @NSApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate

    var body: some Scene {
        MenuBarExtra("SimpleTopBar", systemImage: "menubar.rectangle") {
            TopBarView(model: AppListModel.shared)
        }
        .menuBarExtraStyle(.window)
    }
}

final class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationDidFinishLaunching(_ notification: Notification) {
        if CommandLine.arguments.contains("--self-test") {
            runSelfTest()
            return
        }

        // Single instance: stale copies keep a menu bar icon around after an
        // update and swallow clicks meant for the new instance.
        let myPid = ProcessInfo.processInfo.processIdentifier
        let others = NSRunningApplication.runningApplications(withBundleIdentifier: "dev.tzgyn.simpletopbar")
            .filter { $0.processIdentifier != myPid }
        for other in others {
            other.forceTerminate()
        }

        AppListModel.shared.start()
    }
}

enum LoginItem {
    static var isEnabled: Bool {
        SMAppService.mainApp.status == .enabled
    }

    static func toggle() -> Bool {
        let service = SMAppService.mainApp
        do {
            if service.status == .enabled {
                try service.unregister()
            } else {
                try service.register()
            }
            return true
        } catch {
            return false
        }
    }
}