LibWebView+UI: Add an option to toggle a menu's visibility

This requires setting up an observer interface akin to menu actions.

Libraries/LibWebView/Menu.cpp

@@ -134,4 +134,28 @@ void Menu::add_action(NonnullRefPtr<Action> action)
     m_items.append(move(action));
 }
 
+void Menu::set_visible(bool visible)
+{
+    if (m_visible == visible)
+        return;
+    m_visible = visible;
+
+    for (auto& observer : m_observers)
+        observer->on_visible_state_changed(*this);
+}
+
+void Menu::add_observer(NonnullOwnPtr<Observer> observer)
+{
+    observer->on_visible_state_changed(*this);
+
+    m_observers.append(move(observer));
+}
+
+void Menu::remove_observer(Observer const& observer)
+{
+    m_observers.remove_first_matching([&](auto const& candidate) {
+        return candidate.ptr() == &observer;
+    });
+}
+
 }

Libraries/LibWebView/Menu.h

@@ -224,6 +224,9 @@ public:
     void set_render_group_icon(bool render_group_icon) { m_render_group_icon = render_group_icon; }
     bool render_group_icon() const { return m_render_group_icon; }
 
+    bool visible() const { return m_visible; }
+    void set_visible(bool);
+
     template<typename Callback>
     void for_each_action(Callback const& callback)
     {
@@ -235,6 +238,15 @@ public:
         }
     }
 
+    struct Observer {
+        virtual ~Observer() = default;
+
+        virtual void on_visible_state_changed(Menu&) { }
+    };
+
+    void add_observer(NonnullOwnPtr<Observer>);
+    void remove_observer(Observer const& observer);
+
     Function<void(Gfx::IntPoint)> on_activation;
 
 private:
@@ -247,9 +259,11 @@ private:
     Vector<MenuItem> m_items;
 
     HashMap<StringView, String> m_properties;
+    Vector<NonnullOwnPtr<Observer>, 1> m_observers;
 
     bool m_is_group { false };
     bool m_render_group_icon { false };
+    bool m_visible { true };
 };
 
 }

UI/AppKit/Interface/Menu.mm

@@ -187,6 +187,27 @@ private:
     __weak id m_control { nil };
 };
 
+class MenuObserver final : public WebView::Menu::Observer {
+public:
+    static NonnullOwnPtr<MenuObserver> create(NSMenuItem* item)
+    {
+        return adopt_own(*new MenuObserver(item));
+    }
+
+    virtual void on_visible_state_changed(WebView::Menu& menu) override
+    {
+        [m_item setHidden:!menu.visible()];
+    }
+
+private:
+    explicit MenuObserver(NSMenuItem* item)
+        : m_item(item)
+    {
+    }
+
+    __weak NSMenuItem* m_item { nil };
+};
+
 static void initialize_native_icon(WebView::Action& action, id control)
 {
     static constexpr CGFloat const MENU_ICON_SIZE = 16;
@@ -357,6 +378,21 @@ static void initialize_native_control(WebView::Action& action, id control)
     action.add_observer(move(observer));
 }
 
+static void initialize_native_menu(WebView::Menu& menu, NSMenuItem* item)
+{
+    auto observer = MenuObserver::create(item);
+
+    auto* guard = [[DeallocGuard alloc] init:[menu = menu.make_weak_ptr(), observer = observer.ptr()]() {
+        if (menu)
+            menu->remove_observer(*observer);
+    }];
+
+    static char guard_key = 0;
+    objc_setAssociatedObject(item, &guard_key, guard, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+
+    menu.add_observer(move(observer));
+}
+
 static void add_items_to_menu(NSMenu* nsmenu, WebView::Menu& menu)
 {
     for (auto& menu_item : menu.items()) {
@@ -421,6 +457,7 @@ NSMenuItem* create_application_menu_item(WebView::Menu& menu)
                                             action:nil
                                      keyEquivalent:@""];
     [item setSubmenu:create_application_menu(menu)];
+    initialize_native_menu(menu, item);
 
     if (menu.render_group_icon())
         set_control_image(item, @"folder");

UI/Qt/Menu.cpp

@@ -97,6 +97,28 @@ private:
     IncludeActionIcon m_include_action_icon { IncludeActionIcon::Yes };
 };
 
+class MenuObserver final : public WebView::Menu::Observer {
+public:
+    static NonnullOwnPtr<MenuObserver> create(QMenu& qmenu)
+    {
+        return adopt_own(*new MenuObserver(qmenu));
+    }
+
+    virtual void on_visible_state_changed(WebView::Menu& menu) override
+    {
+        if (m_menu && m_menu->menuAction())
+            m_menu->menuAction()->setVisible(menu.visible());
+    }
+
+private:
+    explicit MenuObserver(QMenu& qmenu)
+        : m_menu(&qmenu)
+    {
+    }
+
+    QPointer<QMenu> m_menu;
+};
+
 template<typename T>
 static void add_properties(QObject& object, T& menu_or_action)
 {
@@ -224,6 +246,7 @@ static void initialize_native_control(WebView::Action& action, QAction& qaction,
 
 static void add_items_to_menu(QMenu& qmenu, QWidget& parent, WebView::Menu& menu)
 {
+    menu.add_observer(MenuObserver::create(qmenu));
     add_properties(qmenu, menu);
 
     for (auto& menu_item : menu.items()) {