WindowServer: Start implementing a menu system.

I'm going with a global top-of-the-screen menu instead of per-window menus.
The basic idea is that menus will live in the WindowServer and clients can
create menus via WindowServer requests.

Kernel/Makefile

@@ -63,6 +63,9 @@ WINDOWSERVER_OBJS = \
     ../WindowServer/WSWindow.o \
     ../WindowServer/WSWindowManager.o \
     ../WindowServer/WSScreen.o \
+    ../WindowServer/WSMenuBar.o \
+    ../WindowServer/WSMenu.o \
+    ../WindowServer/WSMenuItem.o \
     ../WindowServer/main.o
 
 AK_OBJS = \

SharedGraphics/Font.h

@@ -58,6 +58,7 @@ public:
 
     byte glyph_width() const { return m_glyph_width; }
     byte glyph_height() const { return m_glyph_height; }
+    int width(const String& string) const { return string.length() * glyph_width(); }
 
     String name() const { return m_name; }
     void set_name(const String& name) { m_name = name; }

SharedGraphics/GraphicsBitmap.cpp

@@ -39,6 +39,25 @@ GraphicsBitmap::GraphicsBitmap(Process& process, const Size& size)
 
     m_data = (RGBA32*)m_server_region->laddr().as_ptr();
 }
+
+RetainPtr<GraphicsBitmap> GraphicsBitmap::create_kernel_only(const Size& size)
+{
+    return adopt(*new GraphicsBitmap(size));
+}
+
+GraphicsBitmap::GraphicsBitmap(const Size& size)
+    : m_size(size)
+    , m_pitch(size.width() * sizeof(RGBA32))
+{
+    InterruptDisabler disabler;
+    size_t size_in_bytes = size.width() * size.height() * sizeof(RGBA32);
+    auto vmo = VMObject::create_anonymous(size_in_bytes);
+    auto& server = WSMessageLoop::the().server_process();
+    m_server_region = server.allocate_region_with_vmo(LinearAddress(), size_in_bytes, move(vmo), 0, "GraphicsBitmap (server)", true, false);
+    m_server_region->set_shared(true);
+    m_server_region->set_is_bitmap(true);
+    m_data = (RGBA32*)m_server_region->laddr().as_ptr();
+}
 #endif
 
 RetainPtr<GraphicsBitmap> GraphicsBitmap::create_wrapper(const Size& size, RGBA32* data)

SharedGraphics/GraphicsBitmap.h

@@ -15,6 +15,7 @@ class GraphicsBitmap : public Retainable<GraphicsBitmap> {
 public:
 #ifdef KERNEL
     static RetainPtr<GraphicsBitmap> create(Process&, const Size&);
+    static RetainPtr<GraphicsBitmap> create_kernel_only(const Size&);
 #endif
     static RetainPtr<GraphicsBitmap> create_wrapper(const Size&, RGBA32*);
     static RetainPtr<GraphicsBitmap> load_from_file(const String& path, const Size&);
@@ -37,6 +38,7 @@ public:
 private:
 #ifdef KERNEL
     GraphicsBitmap(Process&, const Size&);
+    GraphicsBitmap(const Size&);
 #endif
     GraphicsBitmap(const Size&, RGBA32*);
 

WindowServer/WSMenu.cpp

@@ -0,0 +1,111 @@
+#include "WSMenu.h"
+#include "WSMenuItem.h"
+#include "WSWindow.h"
+#include "WSMessage.h"
+#include "WSMessageLoop.h"
+#include <SharedGraphics/Painter.h>
+#include <SharedGraphics/Font.h>
+
+WSMenu::WSMenu(const String& name)
+    : m_name(name)
+{
+}
+
+WSMenu::~WSMenu()
+{
+}
+
+void WSMenu::set_menu_window(OwnPtr<WSWindow>&& menu_window)
+{
+    m_menu_window = move(menu_window);
+}
+
+const Font& WSMenu::font() const
+{
+    return Font::default_font();
+}
+
+int WSMenu::width() const
+{
+    int longest = 0;
+    for (auto& item : m_items) {
+        if (item->type() == WSMenuItem::Text)
+            longest = max(longest, font().width(item->text()));
+    }
+
+    return max(longest, 80) + padding() * 2;
+}
+
+int WSMenu::height() const
+{
+    if (m_items.is_empty())
+        return 0;
+    return (m_items.last()->rect().bottom() - 1) + padding();
+}
+
+WSWindow& WSMenu::ensure_menu_window()
+{
+    if (!m_menu_window) {
+        Point next_item_location(padding() / 2, padding() / 2);
+        for (auto& item : m_items) {
+            int height = 0;
+            if (item->type() == WSMenuItem::Text)
+                height = item_height();
+            else if (item->type() == WSMenuItem::Separator)
+                height = 7;
+            item->set_rect({ next_item_location, { width() - padding(), height } });
+            next_item_location.move_by(0, height);
+        }
+
+        auto window = make<WSWindow>(*this);
+        window->set_rect(0, 0, width(), height());
+        dbgprintf("Created menu window for menu '%s' (%u items) with rect %s\n", name().characters(), m_items.size(), window->rect().to_string().characters());
+        m_menu_window = move(window);
+        draw();
+    }
+    return *m_menu_window;
+}
+
+void WSMenu::draw()
+{
+    ASSERT(m_menu_window);
+    ASSERT(m_menu_window->backing());
+    Painter painter(*m_menu_window->backing());
+
+    Rect rect { { }, m_menu_window->size() };
+
+    painter.draw_rect(rect, Color::White);
+    painter.fill_rect(rect.shrunken(2, 2), Color::LightGray);
+
+    for (auto& item : m_items) {
+        if (item->type() == WSMenuItem::Text) {
+            Color text_color = Color::Black;
+            if (item.ptr() == m_hovered_item) {
+                painter.fill_rect(item->rect(), Color(0, 0, 128));
+                text_color = Color::White;
+            }
+            painter.draw_text(item->rect(), item->text(), Painter::TextAlignment::CenterLeft, text_color);
+        } else if (item->type() == WSMenuItem::Separator) {
+            Point p1(padding(), item->rect().center().y());
+            Point p2(width() - padding(), item->rect().center().y());
+            painter.draw_line(p1, p2, Color::MidGray);
+        }
+    }
+}
+
+void WSMenu::on_window_message(WSMessage& message)
+{
+    dbgprintf("WSMenu::on_window_message: %u\n", message.type());
+    if (message.type() == WSMessage::MouseMove) {
+        auto& mouse_event = static_cast<WSMouseEvent&>(message);
+        for (auto& item : m_items) {
+            if (item->rect().contains(mouse_event.position())) {
+                if (m_hovered_item == item.ptr())
+                    return;
+                m_hovered_item = item.ptr();
+                draw();
+                menu_window()->invalidate();
+            }
+        }
+    }
+}

WindowServer/WSMenu.h

@@ -0,0 +1,66 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/Vector.h>
+#include <SharedGraphics/Rect.h>
+#include "WSMenuItem.h"
+
+class WSMenuBar;
+class WSMessage;
+class WSWindow;
+class Font;
+
+class WSMenu {
+public:
+    WSMenu(const String& name);
+    ~WSMenu();
+
+    WSMenuBar* menu_bar() { return m_menubar; }
+    const WSMenuBar* menu_bar() const { return m_menubar; }
+
+    int item_count() const { return m_items.size(); }
+    WSMenuItem* item(int i) { return m_items[i].ptr(); }
+    const WSMenuItem* item(int i) const { return m_items[i].ptr(); }
+
+    void add_item(OwnPtr<WSMenuItem>&& item) { m_items.append(move(item)); }
+
+    String name() const { return m_name; }
+
+    template<typename Callback>
+    void for_each_item(Callback callback) const
+    {
+        for (auto& item : m_items)
+            callback(*item);
+    }
+
+    Rect text_rect_in_menubar() const { return m_text_rect_in_menubar; }
+    void set_text_rect_in_menubar(const Rect& rect) { m_text_rect_in_menubar = rect; }
+
+    Rect rect_in_menubar() const { return m_rect_in_menubar; }
+    void set_rect_in_menubar(const Rect& rect) { m_rect_in_menubar = rect; }
+
+    WSWindow* menu_window() { return m_menu_window.ptr(); }
+    void set_menu_window(OwnPtr<WSWindow>&&);
+
+    WSWindow& ensure_menu_window();
+
+    int width() const;
+    int height() const;
+
+    int item_height() const { return 16; }
+    int padding() const { return 4; }
+
+    void on_window_message(WSMessage&);
+    void draw();
+    const Font& font() const;
+
+private:
+    String m_name;
+    Rect m_rect_in_menubar;
+    Rect m_text_rect_in_menubar;
+    WSMenuBar* m_menubar { nullptr };
+    WSMenuItem* m_hovered_item { nullptr };
+    Vector<OwnPtr<WSMenuItem>> m_items;
+    OwnPtr<WSWindow> m_menu_window;
+};
+

WindowServer/WSMenuBar.cpp

@@ -0,0 +1,12 @@
+#include "WSMenuBar.h"
+#include "WSMenu.h"
+#include "WSMenuItem.h"
+
+WSMenuBar::WSMenuBar()
+{
+}
+
+WSMenuBar::~WSMenuBar()
+{
+}
+

WindowServer/WSMenuBar.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include "WSMenu.h"
+#include <AK/Vector.h>
+
+class WSMenuBar {
+public:
+    WSMenuBar();
+    ~WSMenuBar();
+
+    void add_menu(OwnPtr<WSMenu>&& menu) { m_menus.append(move(menu)); }
+
+    template<typename Callback>
+    void for_each_menu(Callback callback)
+    {
+        for (auto& menu : m_menus) {
+            if (!callback(*menu))
+                return;
+        }
+    }
+
+private:
+    Vector<OwnPtr<WSMenu>> m_menus;
+};

WindowServer/WSMenuItem.cpp

@@ -0,0 +1,16 @@
+#include "WSMenuItem.h"
+
+WSMenuItem::WSMenuItem(const String& text)
+    : m_type(Text)
+    , m_text(text)
+{
+}
+
+WSMenuItem::WSMenuItem(Type type)
+    : m_type(type)
+{
+}
+
+WSMenuItem::~WSMenuItem()
+{
+}

WindowServer/WSMenuItem.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <SharedGraphics/Rect.h>
+
+class WSMenuItem {
+public:
+    enum Type {
+        None,
+        Text,
+        Separator,
+    };
+
+    explicit WSMenuItem(const String& text);
+    explicit WSMenuItem(Type);
+    ~WSMenuItem();
+
+    Type type() const { return m_type; }
+    bool enabled() const { return m_enabled; }
+
+    String text() const { return m_text; }
+
+    void set_rect(const Rect& rect) { m_rect = rect; }
+    Rect rect() const { return m_rect; }
+
+private:
+    Type m_type { None };
+    bool m_enabled { true };
+    String m_text;
+    Rect m_rect;
+};
+

WindowServer/WSWindow.cpp

@@ -4,8 +4,15 @@
 #include "WSMessageLoop.h"
 #include "Process.h"
 
+WSWindow::WSWindow(WSMenu& menu)
+    : m_lock("WSWindow (menu)")
+    , m_menu(&menu)
+{
+    WSWindowManager::the().add_window(*this);
+}
+
 WSWindow::WSWindow(Process& process, int window_id)
-    : m_lock("WSWindow")
+    : m_lock("WSWindow (normal)")
     , m_process(&process)
     , m_window_id(window_id)
     , m_pid(process.pid())
@@ -35,13 +42,18 @@ void WSWindow::set_rect(const Rect& rect)
     Rect old_rect;
     {
         WSWindowLocker locker(*this);
-        if (!m_process)
+        if (!m_process && !m_menu)
             return;
         if (m_rect == rect)
             return;
         old_rect = m_rect;
         m_rect = rect;
-        m_backing = GraphicsBitmap::create(*m_process, m_rect.size());
+        if (!m_backing || old_rect.size() != rect.size()) {
+            if (m_process)
+                m_backing = GraphicsBitmap::create(*m_process, m_rect.size());
+            if (m_menu)
+                m_backing = GraphicsBitmap::create_kernel_only(m_rect.size());
+        }
     }
     WSWindowManager::the().notify_rect_changed(*this, old_rect, rect);
 }
@@ -59,6 +71,14 @@ static GUI_MouseButton to_api(MouseButton button)
 
 void WSWindow::on_message(WSMessage& message)
 {
+    if (m_menu) {
+        m_menu->on_window_message(message);
+        return;
+    }
+
+    if (!m_process)
+        return;
+
     GUI_Event gui_event;
     gui_event.window_id = window_id();
 
@@ -149,3 +169,16 @@ void WSWindow::set_global_cursor_tracking_enabled(bool enabled)
     dbgprintf("WSWindow{%p} global_cursor_tracking <- %u\n", enabled);
     m_global_cursor_tracking_enabled = enabled;
 }
+
+void WSWindow::set_visible(bool b)
+{
+    if (m_visible == b)
+        return;
+    m_visible = b;
+    invalidate();
+}
+
+void WSWindow::invalidate()
+{
+    WSWindowManager::the().invalidate(*this);
+}

WindowServer/WSWindow.h

@@ -10,13 +10,16 @@
 #include "WSMessageReceiver.h"
 
 class Process;
+class WSMenu;
 
 class WSWindow final : public WSMessageReceiver, public InlineLinkedListNode<WSWindow> {
     friend class WSWindowLocker;
 public:
     WSWindow(Process&, int window_id);
+    explicit WSWindow(WSMenu&);
     virtual ~WSWindow() override;
 
+    bool is_menu() const { return m_menu; }
     int window_id() const { return m_window_id; }
 
     String title() const { return m_title; }
@@ -27,14 +30,25 @@ public:
     int width() const { return m_rect.width(); }
     int height() const { return m_rect.height(); }
 
-    const Rect& rect() const { return m_rect; }
+    bool is_visible() const { return m_visible; }
+    void set_visible(bool);
+
+    Rect rect() const { return m_rect; }
     void set_rect(const Rect&);
+    void set_rect(int x, int y, int width, int height) { set_rect({ x, y, width, height }); }
     void set_rect_without_repaint(const Rect& rect) { m_rect = rect; }
 
+    void move_to(const Point& position) { set_rect({ position, size() }); }
+    void move_to(int x, int y) { move_to({ x, y }); }
+
     Point position() const { return m_rect.location(); }
     void set_position(const Point& position) { set_rect({ position.x(), position.y(), width(), height() }); }
     void set_position_without_repaint(const Point& position) { set_rect_without_repaint({ position.x(), position.y(), width(), height() }); }
 
+    Size size() const { return m_rect.size(); }
+
+    void invalidate();
+
     virtual void on_message(WSMessage&) override;
 
     bool is_being_dragged() const { return m_is_being_dragged; }
@@ -60,6 +74,9 @@ private:
     Rect m_rect;
     bool m_is_being_dragged { false };
     bool m_global_cursor_tracking_enabled { false };
+    bool m_visible { true };
+
+    WSMenu* m_menu { nullptr };
 
     RetainPtr<GraphicsBitmap> m_backing;
     Process* m_process { nullptr };

WindowServer/WSWindowManager.cpp

@@ -10,6 +10,9 @@
 #include <SharedGraphics/CharacterBitmap.h>
 #include <AK/StdLibExtras.h>
 #include <Kernel/BochsVGADevice.h>
+#include "WSMenu.h"
+#include "WSMenuBar.h"
+#include "WSMenuItem.h"
 
 //#define DEBUG_COUNTERS
 //#define DEBUG_WID_IN_TITLE_BAR
@@ -176,6 +179,32 @@ WSWindowManager::WSWindowManager()
         invalidate(m_screen_rect);
     });
 
+
+    {
+        auto menubar = make<WSMenuBar>();
+
+        {
+            auto menu = make<WSMenu>("Serenity");
+            menu->add_item(make<WSMenuItem>("Launch Terminal"));
+            menu->add_item(make<WSMenuItem>(WSMenuItem::Separator));
+            menu->add_item(make<WSMenuItem>("Hello again"));
+            menu->add_item(make<WSMenuItem>("To all my friends"));
+            menu->add_item(make<WSMenuItem>("Together we can play some rock&roll"));
+            menu->add_item(make<WSMenuItem>(WSMenuItem::Separator));
+            menu->add_item(make<WSMenuItem>("About..."));
+            menubar->add_menu(move(menu));
+        }
+        {
+            auto menu = make<WSMenu>("Application");
+            menu->add_item(make<WSMenuItem>("Bar!"));
+            menu->add_item(make<WSMenuItem>("Foo!"));
+            menubar->add_menu(move(menu));
+        }
+
+        set_current_menubar(menubar.ptr());
+        m_menubars.set(1, move(menubar));
+    }
+
     invalidate();
     compose();
 }
@@ -184,6 +213,24 @@ WSWindowManager::~WSWindowManager()
 {
 }
 
+void WSWindowManager::set_current_menubar(WSMenuBar* menubar)
+{
+    if (m_current_menubar == menubar)
+        return;
+    m_current_menubar = menubar;
+    if (!m_current_menubar)
+        return;
+    int menu_margin = 16;
+    Point next_menu_location { menu_margin / 2, 3 };
+    m_current_menubar->for_each_menu([&] (WSMenu& menu) {
+        int text_width = font().width(menu.name());
+        menu.set_rect_in_menubar({ next_menu_location.x() - menu_margin / 2, 0, text_width + menu_margin, menubar_rect().height() - 1 });
+        menu.set_text_rect_in_menubar({ next_menu_location, { text_width, font().glyph_height() } });
+        next_menu_location.move_by(menu.rect_in_menubar().width(), 0);
+        return true;
+    });
+}
+
 static const char* s_close_button_bitmap_data = {
     "##    ##"
     "###  ###"
@@ -205,6 +252,11 @@ void WSWindowManager::paint_window_frame(WSWindow& window)
     LOCKER(m_lock);
     //printf("[WM] paint_window_frame {%p}, rect: %d,%d %dx%d\n", &window, window.rect().x(), window.rect().y(), window.rect().width(), window.rect().height());
 
+    if (window.is_menu()) {
+        m_back_painter->draw_rect(window.rect().inflated(2, 2), Color::LightGray);
+        return;
+    }
+
     auto titlebar_rect = title_bar_rect(window.rect());
     auto titlebar_inner_rect = title_bar_text_rect(window.rect());
     auto outer_rect = outer_window_rect(window.rect());
@@ -318,6 +370,43 @@ void WSWindowManager::notify_rect_changed(WSWindow& window, const Rect& old_rect
     invalidate(outer_window_rect(new_rect));
 }
 
+void WSWindowManager::handle_menu_mouse_event(WSMenu& menu, WSMouseEvent& event)
+{
+    if (event.type() == WSMouseEvent::MouseDown && event.button() == MouseButton::Left) {
+        dbgprintf("[WM] MouseDown on menu '%s'\n", menu.name().characters());
+        if (m_current_menu == &menu)
+            return;
+        close_current_menu();
+        auto& menu_window = menu.ensure_menu_window();
+        menu_window.move_to({ menu.rect_in_menubar().x(), menu.rect_in_menubar().bottom() });
+        menu_window.set_visible(true);
+        m_current_menu = &menu;
+        return;
+    }
+    if (event.type() == WSMouseEvent::MouseUp && event.button() == MouseButton::Left) {
+        close_current_menu();
+        return;
+    }
+}
+
+void WSWindowManager::close_current_menu()
+{
+    if (m_current_menu && m_current_menu->menu_window())
+        m_current_menu->menu_window()->set_visible(false);
+    m_current_menu = nullptr;
+}
+
+void WSWindowManager::handle_menubar_mouse_event(WSMenuBar& menu, WSMouseEvent& event)
+{
+    m_current_menubar->for_each_menu([&] (WSMenu& menu) {
+        if (menu.rect_in_menubar().contains(event.position())) {
+            handle_menu_mouse_event(menu, event);
+            return false;
+        }
+        return true;
+    });
+}
+
 void WSWindowManager::handle_titlebar_mouse_event(WSWindow& window, WSMouseEvent& event)
 {
     if (event.type() == WSMessage::MouseDown && event.button() == MouseButton::Left) {
@@ -376,12 +465,23 @@ void WSWindowManager::process_mouse_event(WSMouseEvent& event)
     for (auto* window = m_windows_in_order.tail(); window; window = window->prev()) {
         if (!window->global_cursor_tracking())
             continue;
+        ASSERT(window->is_visible()); // Maybe this should be supported? Idk. Let's catch it and think about it later.
         Point position { event.x() - window->rect().x(), event.y() - window->rect().y() };
         auto local_event = make<WSMouseEvent>(event.type(), position, event.buttons(), event.button());
         window->on_message(*local_event);
     }
 
+    if (m_current_menubar && menubar_rect().contains(event.position())) {
+        handle_menubar_mouse_event(*m_current_menubar, event);
+        return;
+    }
+
+    if (m_current_menu && event.type() == WSMouseEvent::MouseUp && event.button() == MouseButton::Left)
+        close_current_menu();
+
     for (auto* window = m_windows_in_order.tail(); window; window = window->prev()) {
+        if (!window->is_visible())
+            continue;
         if (title_bar_rect(window->rect()).contains(event.position())) {
             if (event.type() == WSMessage::MouseDown) {
                 move_to_front(*window);
@@ -423,6 +523,8 @@ void WSWindowManager::compose()
 
     auto any_window_contains_rect = [this] (const Rect& r) {
         for (auto* window = m_windows_in_order.head(); window; window = window->next()) {
+            if (!window->is_visible())
+                continue;
             if (outer_window_rect(window->rect()).contains(r))
                 return true;
         }
@@ -449,6 +551,8 @@ void WSWindowManager::compose()
             m_back_painter->blit(dirty_rect.location(), *m_wallpaper, dirty_rect);
     }
     for (auto* window = m_windows_in_order.head(); window; window = window->next()) {
+        if (!window->is_visible())
+            continue;
         WSWindowLocker locker(*window);
         RetainPtr<GraphicsBitmap> backing = window->backing();
         if (!backing)
@@ -470,8 +574,9 @@ void WSWindowManager::compose()
         }
         m_back_painter->clear_clip_rect();
     }
-    draw_cursor();
 
+    draw_menubar();
+    draw_cursor();
 
     if (m_flash_flush.lock_and_copy()) {
         for (auto& rect : dirty_rects)
@@ -491,6 +596,28 @@ void WSWindowManager::invalidate_cursor()
     invalidate(cursor_rect);
 }
 
+Rect WSWindowManager::menubar_rect() const
+{
+    return { 0, 0, m_screen_rect.width(), 16 };
+}
+
+void WSWindowManager::draw_menubar()
+{
+    if (!m_current_menubar)
+        return;
+    m_back_painter->fill_rect(menubar_rect(), Color::LightGray);
+    m_back_painter->draw_line({ 0, menubar_rect().bottom() }, { menubar_rect().right(), menubar_rect().bottom() }, Color::White);
+    m_current_menubar->for_each_menu([&] (WSMenu& menu) {
+        Color text_color = Color::Black;
+        if (&menu == m_current_menu) {
+            m_back_painter->fill_rect(menu.rect_in_menubar(), Color(0, 0, 128));
+            text_color = Color::White;
+        }
+        m_back_painter->draw_text(menu.text_rect_in_menubar(), menu.name(), Painter::TextAlignment::CenterLeft, text_color);
+        return true;
+    });
+}
+
 void WSWindowManager::draw_cursor()
 {
     ASSERT_INTERRUPTS_ENABLED();
@@ -619,3 +746,4 @@ void WSWindowManager::flush(const Rect& a_rect)
         back_ptr = (RGBA32*)((byte*)back_ptr + pitch);
     }
 }
+

WindowServer/WSWindowManager.h

@@ -7,10 +7,12 @@
 #include <AK/InlineLinkedList.h>
 #include <AK/WeakPtr.h>
 #include <AK/Lock.h>
-#include <AK/CircularQueue.h>
+#include <AK/HashMap.h>
 #include "WSMessageReceiver.h"
+#include "WSMenuBar.h"
 
 class WSScreen;
+class WSMenuBar;
 class WSMouseEvent;
 class WSClientWantsToPaintMessage;
 class WSWindow;
@@ -32,6 +34,13 @@ public:
 
     void invalidate_cursor();
     void draw_cursor();
+    void draw_menubar();
+
+    Rect menubar_rect() const;
+    WSMenuBar* current_menubar() { return m_current_menubar; }
+    void set_current_menubar(WSMenuBar*);
+    WSMenu* current_menu() { return m_current_menu; }
+    void set_current_menu(WSMenu*);
 
     void invalidate(const WSWindow&);
     void invalidate(const WSWindow&, const Rect&);
@@ -47,10 +56,14 @@ private:
     virtual ~WSWindowManager() override;
 
     void process_mouse_event(WSMouseEvent&);
+    void handle_menu_mouse_event(WSMenu&, WSMouseEvent&);
+    void handle_menubar_mouse_event(WSMenuBar&, WSMouseEvent&);
     void handle_titlebar_mouse_event(WSWindow&, WSMouseEvent&);
     void handle_close_button_mouse_event(WSWindow&, WSMouseEvent&);
 
     void set_active_window(WSWindow*);
+
+    void close_current_menu();
     
     virtual void on_message(WSMessage&) override;
 
@@ -112,4 +125,8 @@ private:
 
     Lockable<bool> m_flash_flush;
     bool m_buffers_are_flipped { false };
+
+    WSMenuBar* m_current_menubar { nullptr };
+    WSMenu* m_current_menu { nullptr };
+    HashMap<int, OwnPtr<WSMenuBar>> m_menubars;
 };