Use keyboard shortcuts for status bar app using SwiftUI

AppDelegate.swift

// https://github.com/sindresorhus/Preferences/issues/40
// https://lapcatsoftware.com/articles/working-without-a-nib-part-10.html

import Cocoa

@objc protocol EditMenuActions {
    func redo(_ sender: AnyObject)
    func undo(_ sender: AnyObject)
}

class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationWillFinishLaunching(_ notification: Notification) {
        let mainMenu = NSMenu(title: "MainMenu")
        let menuItem = mainMenu.addItem(withTitle: "", action: nil, keyEquivalent: "")
        
        let submenu = NSMenu()
        submenu.addItem(withTitle: "Close Window", action: #selector(NSWindow.performClose(_:)), keyEquivalent: "w")
        submenu.addItem(withTitle: "Undo", action: #selector(EditMenuActions.undo(_:)), keyEquivalent: "z")
        submenu.addItem(withTitle: "Redo", action: #selector(EditMenuActions.redo(_:)), keyEquivalent: "Z")
        submenu.addItem(withTitle: "Cut", action: #selector(NSText.cut(_:)), keyEquivalent: "x")
        submenu.addItem(withTitle: "Copy", action: #selector(NSText.copy(_:)), keyEquivalent: "c")
        submenu.addItem(withTitle: "Paste", action: #selector(NSText.paste(_:)), keyEquivalent: "v")
        submenu.addItem(withTitle: "Select All", action: #selector(NSText.selectAll(_:)), keyEquivalent: "a")
        
        mainMenu.setSubmenu(submenu, for: menuItem)
        NSApp.mainMenu = mainMenu
    }
}