WindowServer+LibGUI: Notify clients when menus become visible/hidden

This will allow clients to react to these events.

Userland/Libraries/LibGUI/Menu.cpp

@@ -162,4 +162,13 @@ Action* Menu::action_at(size_t index)
     return m_items[index].action();
 }
 
+void Menu::visibility_did_change(Badge<WindowServerConnection>, bool visible)
+{
+    if (m_visible == visible)
+        return;
+    m_visible = visible;
+    if (on_visibility_change)
+        on_visibility_change(visible);
+}
+
 }

Userland/Libraries/LibGUI/Menu.h

@@ -59,6 +59,12 @@ public:
     void popup(const Gfx::IntPoint& screen_position, const RefPtr<Action>& default_action = nullptr);
     void dismiss();
 
+    void visibility_did_change(Badge<WindowServerConnection>, bool visible);
+
+    Function<void(bool)> on_visibility_change;
+
+    bool is_visible() const { return m_visible; }
+
 private:
     friend class MenuBar;
 
@@ -71,6 +77,7 @@ private:
     RefPtr<Gfx::Bitmap> m_icon;
     NonnullOwnPtrVector<MenuItem> m_items;
     WeakPtr<Action> m_last_default_action;
+    bool m_visible { false };
 };
 
 }

Userland/Libraries/LibGUI/WindowServerConnection.cpp

@@ -252,6 +252,16 @@ void WindowServerConnection::handle(const Messages::WindowClient::MouseWheel& me
         Core::EventLoop::current().post_event(*window, make<MouseEvent>(Event::MouseWheel, message.mouse_position(), message.buttons(), to_gmousebutton(message.button()), message.modifiers(), message.wheel_delta()));
 }
 
+void WindowServerConnection::handle(const Messages::WindowClient::MenuVisibilityDidChange& message)
+{
+    auto* menu = Menu::from_menu_id(message.menu_id());
+    if (!menu) {
+        dbgln("EventLoop received visibility change event for invalid menu ID {}", message.menu_id());
+        return;
+    }
+    menu->visibility_did_change({}, message.visible());
+}
+
 void WindowServerConnection::handle(const Messages::WindowClient::MenuItemActivated& message)
 {
     auto* menu = Menu::from_menu_id(message.menu_id());

Userland/Libraries/LibGUI/WindowServerConnection.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -64,6 +64,7 @@ private:
     virtual void handle(const Messages::WindowClient::WindowCloseRequest&) override;
     virtual void handle(const Messages::WindowClient::WindowResized&) override;
     virtual void handle(const Messages::WindowClient::MenuItemActivated&) override;
+    virtual void handle(const Messages::WindowClient::MenuVisibilityDidChange&) override;
     virtual void handle(const Messages::WindowClient::ScreenRectChanged&) override;
     virtual void handle(const Messages::WindowClient::WM_WindowRemoved&) override;
     virtual void handle(const Messages::WindowClient::WM_WindowStateChanged&) override;

Userland/Services/WindowServer/Menu.cpp

@@ -151,10 +151,10 @@ Window& Menu::ensure_menu_window()
     }
 
     auto window = Window::construct(*this, WindowType::Menu);
+    window->set_visible(false);
     window->set_rect(0, 0, width, window_height);
     m_menu_window = move(window);
     draw();
-
     return *m_menu_window;
 }
 
@@ -291,7 +291,8 @@ void Menu::update_for_new_hovered_item(bool make_input)
         hovered_item()->submenu()->do_popup(hovered_item()->rect().top_right().translated(menu_window()->rect().location()), make_input, true);
     } else {
         MenuManager::the().close_everyone_not_in_lineage(*this);
-        ensure_menu_window().set_visible(true);
+        ensure_menu_window();
+        set_visible(true);
     }
     redraw();
 }
@@ -593,7 +594,7 @@ void Menu::do_popup(const Gfx::IntPoint& position, bool make_input, bool as_subm
     }
 
     window.move_to(adjusted_pos);
-    window.set_visible(true);
+    set_visible(true);
     MenuManager::the().open_menu(*this, make_input);
     WindowManager::the().did_popup_a_menu({});
 }
@@ -612,4 +613,15 @@ bool Menu::is_menu_ancestor_of(const Menu& other) const
     return false;
 }
 
+void Menu::set_visible(bool visible)
+{
+    if (!menu_window())
+        return;
+    if (visible == menu_window()->is_visible())
+        return;
+    menu_window()->set_visible(visible);
+    if (m_client)
+        m_client->post_message(Messages::WindowClient::MenuVisibilityDidChange(m_menu_id, visible));
+}
+
 }

Userland/Services/WindowServer/Menu.h

@@ -111,6 +111,8 @@ public:
 
     void close();
 
+    void set_visible(bool);
+
     void popup(const Gfx::IntPoint&);
     void do_popup(const Gfx::IntPoint&, bool make_input, bool as_submenu = false);
 

Userland/Services/WindowServer/MenuManager.cpp

@@ -242,8 +242,7 @@ void MenuManager::close_everyone()
 {
     for (auto& menu : m_open_menu_stack) {
         VERIFY(menu);
-        if (menu->menu_window())
-            menu->menu_window()->set_visible(false);
+        menu->set_visible(false);
         menu->clear_hovered_item();
     }
     m_open_menu_stack.clear();
@@ -270,8 +269,7 @@ void MenuManager::close_menus(const Vector<Menu*>& menus)
     for (auto& menu : menus) {
         if (menu == m_current_menu)
             clear_current_menu();
-        if (menu->menu_window())
-            menu->menu_window()->set_visible(false);
+        menu->set_visible(false);
         menu->clear_hovered_item();
         m_open_menu_stack.remove_first_matching([&](auto& entry) {
             return entry == menu;
@@ -332,7 +330,7 @@ void MenuManager::open_menu(Menu& menu, bool as_current_menu)
         menu.redraw_if_theme_changed();
         if (!menu.menu_window())
             menu.ensure_menu_window();
-        menu.menu_window()->set_visible(true);
+        menu.set_visible(true);
     }
 
     if (m_open_menu_stack.find_if([&menu](auto& other) { return &menu == other.ptr(); }).is_end())

Userland/Services/WindowServer/WindowClient.ipc

@@ -19,6 +19,7 @@ endpoint WindowClient = 4
     WindowResized(i32 window_id, Gfx::IntRect new_rect) =|
 
     MenuItemActivated(i32 menu_id, i32 identifier) =|
+    MenuVisibilityDidChange(i32 menu_id, bool visible) =|
 
     ScreenRectChanged(Gfx::IntRect rect) =|