macos: take over menu bar, separate close and close window

macos/Sources/GhosttyApp.swift

@@ -13,6 +13,9 @@ struct GhosttyApp: App {
     @StateObject private var ghostty = Ghostty.AppState()
     @NSApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate
     
+    /// The current focused Ghostty surface in this app
+    @FocusedValue(\.ghosttySurfaceView) private var focusedSurface
+    
     var body: some Scene {
         WindowGroup {
             switch ghostty.readiness {
@@ -27,7 +30,10 @@ struct GhosttyApp: App {
         }.commands {
             CommandGroup(after: .newItem) {
                 Button("New Tab", action: newTab).keyboardShortcut("t", modifiers: [.command])
-            }
+                Divider()
+                Button("Close", action: close).keyboardShortcut("w", modifiers: [.command])
+                Button("Close Window", action: closeWindow).keyboardShortcut("w", modifiers: [.command, .shift])
+             }
         }
         
         Settings {
@@ -44,13 +50,72 @@ struct GhosttyApp: App {
             currentWindow.addTabbedWindow(newWindow, ordered: .above)
         }
     }
+    
+    func close() {
+        guard let surfaceView = focusedSurface else { return }
+        guard let surface = surfaceView.surface else { return }
+        ghostty.requestClose(surface: surface)
+    }
+    
+    func closeWindow() {
+        guard let currentWindow = NSApp.keyWindow else { return }
+        currentWindow.close()
+    }
 }
 
 class AppDelegate: NSObject, NSApplicationDelegate {
+    // See CursedMenuManager for more information.
+    private var menuManager: CursedMenuManager?
+    
     func applicationDidFinishLaunching(_ notification: Notification) {
         UserDefaults.standard.register(defaults: [
             // Disable this so that repeated key events make it through to our terminal views.
             "ApplePressAndHoldEnabled": false,
         ])
+        
+        // Create our menu manager to create some custom menu items that
+        // we can't create from SwiftUI.
+        menuManager = CursedMenuManager()
+    }
+}
+
+/// SwiftUI as of macOS 13.x provides no way to manage the default menu items that are created
+/// as part of a WindowGroup. This class is prefixed with "Cursed" because this is a truly cursed
+/// solution to the problem and I think its quite brittle. As soon as SwiftUI supports a better option
+/// we should conditionally compile for that when supported.
+///
+/// The way this works is by setting up KVO on various menu objects and reacting to it. For example,
+/// when SwiftUI tries to add a "Close" menu, we intercept it and delete it. Nice try!
+private class CursedMenuManager {
+    var mainToken: NSKeyValueObservation?
+    var fileToken: NSKeyValueObservation?
+    
+    init() {
+        // If the whole menu changed we want to setup our new KVO
+        self.mainToken = NSApp.observe(\.mainMenu, options: .new) { app, change in
+            self.onNewMenu()
+        }
+        
+        // Initial setup
+        onNewMenu()
+    }
+    
+    private func onNewMenu() {
+         guard let menu = NSApp.mainMenu else { return }
+         guard let file = menu.item(withTitle: "File") else { return }
+         guard let submenu = file.submenu else { return }
+         fileToken = submenu.observe(\.items) { (_, _) in
+             let remove = ["Close", "Close All"]
+             
+             // We look for the items in reverse since we're removing only the
+             // ones SwiftUI inserts which are at the end. We make replacements
+             // which we DON'T want deleted.
+             let items = submenu.items.reversed()
+             remove.forEach { title in
+                 if let item = items.first(where: { $0.title.caseInsensitiveCompare(title) == .orderedSame }) {
+                     submenu.removeItem(item)
+                 }
+             }
+         }
     }
 }