macos: confirm on quit

macos/Sources/ContentView.swift

@@ -0,0 +1,48 @@
+import SwiftUI
+import GhosttyKit
+
+struct ContentView: View {
+    let ghostty: Ghostty.AppState
+    
+    @EnvironmentObject private var appDelegate: AppDelegate
+    
+    var body: some View {
+        switch ghostty.readiness {
+        case .loading:
+            Text("Loading")
+                .onChange(of: appDelegate.confirmQuit) { value in
+                    guard value else { return }
+                    NSApplication.shared.reply(toApplicationShouldTerminate: true)
+                }
+        case .error:
+            ErrorView()
+                .onChange(of: appDelegate.confirmQuit) { value in
+                    guard value else { return }
+                    NSApplication.shared.reply(toApplicationShouldTerminate: true)
+                }
+        case .ready:
+            Ghostty.TerminalSplit(onClose: Self.closeWindow)
+                .ghosttyApp(ghostty.app!)
+                .confirmationDialog(
+                    "Quit Ghostty?",
+                    isPresented: $appDelegate.confirmQuit) {
+                        Button("Close Ghostty", role: .destructive) {
+                            NSApplication.shared.reply(toApplicationShouldTerminate: true)
+                        }
+                        .keyboardShortcut(.defaultAction)
+                        
+                        Button("Cancel", role: .cancel) {
+                            NSApplication.shared.reply(toApplicationShouldTerminate: false)
+                        }
+                        .keyboardShortcut(.cancelAction)
+                    } message: {
+                        Text("All terminal sessions will be terminated.")
+                    }
+        }
+    }
+    
+    static func closeWindow() {
+        guard let currentWindow = NSApp.keyWindow else { return }
+        currentWindow.close()
+    }
+}

macos/Sources/GhosttyApp.swift

@@ -18,15 +18,7 @@ struct GhosttyApp: App {
     
     var body: some Scene {
         WindowGroup {
-            switch ghostty.readiness {
-            case .loading:
-                Text("Loading")
-            case .error:
-                ErrorView()
-            case .ready:
-                Ghostty.TerminalSplit(onClose: Self.closeWindow)
-                    .ghosttyApp(ghostty.app!)
-            }
+            ContentView(ghostty: ghostty)
         }
         .backport.defaultSize(width: 800, height: 600)
         .commands {
@@ -110,7 +102,9 @@ struct GhosttyApp: App {
     }
 }
 
-class AppDelegate: NSObject, NSApplicationDelegate {
+class AppDelegate: NSObject, NSApplicationDelegate, ObservableObject {
+    @Published var confirmQuit: Bool = false
+    
     // See CursedMenuManager for more information.
     private var menuManager: CursedMenuManager?
     
@@ -124,6 +118,11 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         // we can't create from SwiftUI.
         menuManager = CursedMenuManager()
     }
+    
+    func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
+        confirmQuit = true
+        return .terminateLater
+    }
 }
 
 /// SwiftUI as of macOS 13.x provides no way to manage the default menu items that are created