Add UseGlobalMenuByDefault flag. Update examples

docs/src/content/docs/guides/menus.mdx

@@ -284,11 +284,36 @@ fileMenu.AddRole(application.Quit)
 
 Application menus are the menus that appear at the top of your application window (Windows/Linux) or at the top of the screen (macOS).
 
+### Global Menu Inheritance: `UseGlobalMenuByDefault`
+
+On Windows and Linux, menus are usually set per window. However, if you want all windows to use the global application menu by default (unless a window-specific menu is provided), you can enable this behaviour with the `UseGlobalMenuByDefault` option:
+
+```go
+app := application.New(application.Options{
+    Name: "MyApp",
+    UseGlobalMenuByDefault: true, // All windows will use the global menu unless overridden
+})
+
+menu := app.NewMenu()
+// ... add items/roles ...
+app.SetMenu(menu)
+
+app.NewWebviewWindow().SetTitle("Window 1").Show()
+app.NewWebviewWindow().SetTitle("Window 2").Show()
+```
+
+- When `UseGlobalMenuByDefault` is `true`, any window created without an explicit menu will inherit the global application menu.
+- If you set a menu directly on a window (via `WebviewWindowOptions.Menu` or `window.SetMenu()`), that menu takes precedence for that window.
+- This flag has no effect on macOS, where the application menu is always global.
+
+**When to use:**
+- Use this option if you want a consistent application menu across all windows on Windows/Linux, without having to set it for each window individually.
+- Omit this option or set it to `false` if you want to control menus per window.
 
 ### Application Menu Behaviour
 
 When you set an application menu using `app.SetMenu()`, it becomes the main menu on macOS.
-Menus are set on a pre-window basis for Windows/Linux.
+Menus are set on a pre-window basis for Windows/Linux (unless `UseGlobalMenuByDefault` is enabled).
 
 ```go
 app.NewWebviewWindowWithOptions(application.WebviewWindowOptions{

v3/examples/menu-fixes/main.go

@@ -14,9 +14,10 @@ var clickBitmap []byte
 func main() {
 
 	app := application.New(application.Options{
-		Name:        "Menu Demo",
-		Description: "A demo of the menu system",
-		Assets:      application.AlphaAssets,
+		UseGlobalMenuByDefault: true,
+		Name:                   "Menu Demo",
+		Description:            "A demo of the menu system",
+		Assets:                 application.AlphaAssets,
 		Mac: application.MacOptions{
 			ApplicationShouldTerminateAfterLastWindowClosed: true,
 		},

v3/examples/menu/main.go

@@ -14,9 +14,10 @@ var clickBitmap []byte
 func main() {
 
 	app := application.New(application.Options{
-		Name:        "Menu Demo",
-		Description: "A demo of the menu system",
-		Assets:      application.AlphaAssets,
+		UseGlobalMenuByDefault: true,
+		Name:                   "Menu Demo",
+		Description:            "A demo of the menu system",
+		Assets:                 application.AlphaAssets,
 		Mac: application.MacOptions{
 			ApplicationShouldTerminateAfterLastWindowClosed: true,
 		},

v3/pkg/application/application_linux.go

@@ -84,12 +84,10 @@ func (r rnr) run() {
 }
 
 func (a *linuxApp) setApplicationMenu(menu *Menu) {
-	// FIXME: How do we avoid putting a menu?
 	if menu == nil {
-		// Create a default menu
 		menu = DefaultApplicationMenu()
-		globalApplication.ApplicationMenu = menu
 	}
+	globalApplication.ApplicationMenu = menu
 }
 
 func (a *linuxApp) run() error {

v3/pkg/application/application_options.go

@@ -28,6 +28,10 @@ type Options struct {
 	// Linux is the Linux specific configuration for Linux builds
 	Linux LinuxOptions
 
+	// UseGlobalMenuByDefault determines if the global application menu set via SetMenu should be used by default for all windows on Windows and Linux.
+	// If false (default), windows do not inherit the global menu unless explicitly set. If true, all windows inherit the global menu unless they opt out.
+	UseGlobalMenuByDefault bool
+
 	// Services allows you to bind Go methods to the frontend.
 	Services []Service
 

v3/pkg/application/webview_window_linux.go

@@ -275,6 +275,12 @@ func (w *linuxWebviewWindow) run() {
 			menu.Update()
 		})
 		w.gtkmenu = (menu.impl).(*linuxMenu).native
+	} else if !w.parent.options.Frameless && globalApplication.options.UseGlobalMenuByDefault && globalApplication.ApplicationMenu != nil {
+		// Use the global application menu if the flag is set and no explicit window menu is provided
+		InvokeSync(func() {
+			globalApplication.ApplicationMenu.Update()
+		})
+		w.gtkmenu = (globalApplication.ApplicationMenu.impl).(*linuxMenu).native
 	}
 
 	w.window, w.webview, w.vbox = windowNew(app.application, w.gtkmenu, w.parent.id, w.parent.options.Linux.WebviewGpuPolicy)

v3/pkg/application/webview_window_windows.go

@@ -322,6 +322,12 @@ func (w *windowsWebviewWindow) run() {
 			w.menu = NewApplicationMenu(w, userMenu)
 			w.menu.parentWindow = w
 			appMenu = w.menu.menu
+		} else if globalApplication.options.UseGlobalMenuByDefault && globalApplication.ApplicationMenu != nil {
+			// Use the global application menu if the flag is set and no explicit window menu is provided
+			globalApplication.ApplicationMenu.Update()
+			w.menu = NewApplicationMenu(w, globalApplication.ApplicationMenu)
+			w.menu.parentWindow = w
+			appMenu = w.menu.menu
 		}
 	}