Swift macOS Skill

Native macOS application development with AppKit, system integration, and distribution.

Prerequisites

• Xcode 15+ on macOS Sonoma+
• Apple Developer account (for distribution)
• Understanding of AppKit fundamentals

Parameters

parameters:
  distribution_method:
    type: string
    enum: [app_store, developer_id, none]
    default: developer_id
  sandbox_enabled:
    type: boolean
    default: true
  min_macos_version:
    type: string
    default: "13.0"
  app_type:
    type: string
    enum: [document_based, single_window, menu_bar, agent]
    default: single_window

Topics Covered

AppKit Components

Window Types

Distribution Methods

Code Examples

Menu Bar Application

import AppKit
import SwiftUI

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

    var body: some Scene {
        Settings {
            SettingsView()
        }
    }
}

final class AppDelegate: NSObject, NSApplicationDelegate {
    private var statusItem: NSStatusItem!
    private var popover: NSPopover!

    func applicationDidFinishLaunching(_ notification: Notification) {
        setupStatusItem()
        setupPopover()

        // Hide dock icon for menu bar only app
        NSApp.setActivationPolicy(.accessory)
    }

    private func setupStatusItem() {
        statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)

        if let button = statusItem.button {
            button.image = NSImage(systemSymbolName: "star.fill", accessibilityDescription: "App")
            button.action = #selector(togglePopover)
        }
    }

    private func setupPopover() {
        popover = NSPopover()
        popover.contentSize = NSSize(width: 300, height: 400)
        popover.behavior = .transient
        popover.contentViewController = NSHostingController(rootView: PopoverView())
    }

    @objc private func togglePopover() {
        guard let button = statusItem.button else { return }

        if popover.isShown {
            popover.performClose(nil)
        } else {
            popover.show(relativeTo: button.bounds, of: button, preferredEdge: .minY)
            popover.contentViewController?.view.window?.makeKey()
        }
    }
}

struct PopoverView: View {
    @Environment(\.openSettings) private var openSettings

    var body: some View {
        VStack(spacing: 16) {
            Text("Menu Bar App")
                .font(.headline)

            Button("Settings") {
                openSettings()
            }

            Button("Quit") {
                NSApp.terminate(nil)
            }
        }
        .padding()
    }
}

NSDocument-Based App

import AppKit

final class Document: NSDocument {
    var content: String = ""

    override class var autosavesInPlace: Bool { true }

    override func makeWindowControllers() {
        let contentVC = ContentViewController(document: self)
        let window = NSWindow(contentViewController: contentVC)
        window.setContentSize(NSSize(width: 800, height: 600))

        let windowController = NSWindowController(window: window)
        addWindowController(windowController)
    }

    override func data(ofType typeName: String) throws -> Data {
        guard let data = content.data(using: .utf8) else {
            throw NSError(domain: NSOSStatusErrorDomain, code: writErr)
        }
        return data
    }

    override func read(from data: Data, ofType typeName: String) throws {
        guard let content = String(data: data, encoding: .utf8) else {
            throw NSError(domain: NSOSStatusErrorDomain, code: readErr)
        }
        self.content = content
    }
}

final class ContentViewController: NSViewController {
    private let document: Document

    init(document: Document) {
        self.document = document
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) not implemented")
    }

    override func loadView() {
        let scrollView = NSScrollView()
        let textView = NSTextView()

        textView.isEditable = true
        textView.isRichText = false
        textView.font = .monospacedSystemFont(ofSize: 13, weight: .regular)
        textView.string = document.content

        scrollView.documentView = textView
        scrollView.hasVerticalScroller = true

        view = scrollView
    }
}

Sandboxing with Security-Scoped Bookmarks

final class SandboxedFileAccess {
    private static let bookmarksKey = "securityScopedBookmarks"

    static func requestAccess(to url: URL) throws -> URL {
        let bookmark = try url.bookmarkData(
            options: .withSecurityScope,
            includingResourceValuesForKeys: nil,
            relativeTo: nil
        )

        var bookmarks = UserDefaults.standard.dictionary(forKey: bookmarksKey) as? [String: Data] ?? [:]
        bookmarks[url.path] = bookmark
        UserDefaults.standard.set(bookmarks, forKey: bookmarksKey)

        return url
    }

    static func accessBookmarkedURL(_ path: String) throws -> URL {
        guard let bookmarks = UserDefaults.standard.dictionary(forKey: bookmarksKey) as? [String: Data],
              let bookmarkData = bookmarks[path] else {
            throw SandboxError.noBookmark
        }

        var isStale = false
        let url = try URL(
            resolvingBookmarkData: bookmarkData,
            options: .withSecurityScope,
            relativeTo: nil,
            bookmarkDataIsStale: &isStale
        )

        if isStale {
            _ = try requestAccess(to: url)
        }

        return url
    }

    static func withAccess<T>(to url: URL, perform: (URL) throws -> T) throws -> T {
        guard url.startAccessingSecurityScopedResource() else {
            throw SandboxError.accessDenied
        }
        defer { url.stopAccessingSecurityScopedResource() }
        return try perform(url)
    }
}

enum SandboxError: Error {
    case noBookmark
    case accessDenied
}

Notarization Script

#!/bin/bash
set -e

APP_PATH="$1"
DEVELOPER_ID="Developer ID Application: Your Name (TEAMID)"
KEYCHAIN_PROFILE="notary-profile"

echo "Signing..."
codesign --force --options runtime --sign "$DEVELOPER_ID" \
    --deep --strict "$APP_PATH"

echo "Creating ZIP..."
ditto -c -k --keepParent "$APP_PATH" "app.zip"

echo "Submitting for notarization..."
xcrun notarytool submit "app.zip" \
    --keychain-profile "$KEYCHAIN_PROFILE" \
    --wait

echo "Stapling..."
xcrun stapler staple "$APP_PATH"

echo "Verifying..."
spctl --assess --type execute --verbose=2 "$APP_PATH"

echo "Done!"
rm "app.zip"

Troubleshooting

Common Issues

Debug Tips

# Check code signing
codesign -dv --verbose=4 App.app

# Check entitlements
codesign -d --entitlements :- App.app

# Check notarization
spctl --assess --type execute App.app

# View sandbox violations
log show --predicate 'subsystem == "com.apple.sandbox"' --last 1h

Validation Rules

validation:
  - rule: hardened_runtime
    severity: error
    check: Enable hardened runtime for notarization
  - rule: sandbox_entitlements
    severity: warning
    check: Only request necessary sandbox entitlements
  - rule: code_signing
    severity: error
    check: Sign with Developer ID for distribution

Usage

Skill("swift-macos")

Related Skills

• swift-swiftui - SwiftUI on macOS
• swift-architecture - App architecture
• swift-testing - Testing macOS apps