libui: Add Buttons

apps/CMakeLists.txt

@@ -49,3 +49,5 @@ luna_app(shmem-test.cpp shmem-test)
 luna_app(touch.cpp touch)
 luna_app(gclient.cpp gclient)
 target_link_libraries(gclient PUBLIC ui)
+luna_app(taskbar.cpp taskbar)
+target_link_libraries(taskbar PUBLIC ui)

apps/gclient.cpp

@@ -1,94 +1,75 @@
-#include <errno.h>
-#include <os/ArgumentParser.h>
-#include <os/File.h>
-#include <os/LocalClient.h>
-#include <sys/mman.h>
-#include <ui/Canvas.h>
-#include <ui/ipc/Server.h>
-#include <unistd.h>
+#include <ui/App.h>
+#include <ui/Layout.h>
 
-struct Window
+struct ColorWidget : public ui::Widget
 {
-    ui::Canvas canvas;
-    int id;
-
-    void set_title(os::LocalClient& client, const char* title)
+  public:
+    ColorWidget(ui::Color first, ui::Color second) : m_color(first), m_first_color(first), m_second_color(second)
     {
-        ui::SetWindowTitleRequest request;
-        request.window = id;
-        SET_IPC_STRING(request.title, title);
-        os::IPC::send_async(client, request);
     }
 
-    void redraw(os::LocalClient& client)
+    Result<ui::EventResult> handle_mouse_move(ui::Point) override
     {
-        ui::InvalidateRequest request;
-        request.window = id;
-        os::IPC::send_async(client, request);
+        m_color = m_second_color;
+        return ui::EventResult::DidHandle;
     }
+
+    Result<ui::EventResult> handle_mouse_leave(ui::Point) override
+    {
+        m_color = m_first_color;
+        return ui::EventResult::DidHandle;
+    }
+
+    Result<ui::EventResult> handle_mouse_down(ui::Point, int) override
+    {
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<ui::EventResult> handle_mouse_up(ui::Point, int) override
+    {
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<void> draw(ui::Canvas& canvas) override
+    {
+        canvas.fill(m_color);
+        return {};
+    }
+
+  private:
+    ui::Color m_color;
+    ui::Color m_first_color;
+    ui::Color m_second_color;
 };
 
-Result<void> handle_ipc_client_event(os::LocalClient&, u8)
-{
-    todo();
-}
-
-static Result<u32*> create_shm_region(const char* path, int* outfd, ui::Rect rect)
-{
-    int fd = shm_open(path, O_RDWR, 0600);
-    shm_unlink(path);
-    if (fd < 0) return err(errno);
-
-    usize size = rect.width * rect.height * 4; // 4 bytes per pixel
-
-    void* p = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-    if (p == MAP_FAILED)
-    {
-        shm_unlink(path);
-        close(fd);
-        return 0;
-    }
-
-    if (outfd) *outfd = fd;
-    else
-        close(fd);
-    return (u32*)p;
-}
-
-Result<Window> create_window(os::LocalClient& client, ui::Rect rect)
-{
-    ui::CreateWindowRequest request;
-    request.rect = rect;
-    auto response = TRY(os::IPC::send_sync<ui::CreateWindowResponse>(client, request));
-    u32* pixels = TRY(create_shm_region(response.shm_path, nullptr, rect));
-    return Window { ui::Canvas { rect.width, rect.height, rect.width, (u8*)pixels }, response.window };
-}
-
 Result<int> luna_main(int argc, char** argv)
 {
-    StringView socket_path = "/tmp/wind.sock";
+    ui::App app;
+    TRY(app.init(argc, argv));
 
-    os::ArgumentParser parser;
-    parser.add_description("A graphical user interface client."_sv);
-    parser.add_system_program_info("gclient"_sv);
-    parser.add_value_argument(socket_path, 's', "socket"_sv, "the path for the local IPC socket"_sv);
-    parser.parse(argc, argv);
+    auto* window = TRY(ui::Window::create(ui::Rect { 200, 200, 400, 300 }));
+    app.set_main_window(window);
 
-    auto client = TRY(os::LocalClient::connect(socket_path, false));
+    window->set_title("Main Window");
+    window->set_background(ui::CYAN);
 
-    Window window = TRY(create_window(*client, ui::Rect { 200, 200, 400, 300 }));
-    os::println("Created new window with id %d!", window.id);
+    ui::HorizontalLayout layout;
+    window->set_main_widget(layout);
 
-    sleep(3);
+    ColorWidget green(ui::GREEN, ui::WHITE);
+    layout.add_widget(green);
+    ColorWidget blue(ui::BLUE, ui::GRAY);
+    layout.add_widget(blue);
 
-    window.set_title(*client, "Example Window");
+    ui::VerticalLayout sublayout;
+    layout.add_widget(sublayout);
 
-    sleep(3);
+    ColorWidget red(ui::RED, ui::CYAN);
+    sublayout.add_widget(red);
+    ColorWidget white(ui::WHITE, ui::GREEN);
+    sublayout.add_widget(white);
 
-    window.canvas.fill(ui::CYAN);
-    window.redraw(*client);
+    window->draw();
 
-    sleep(3);
-
-    return 0;
+    return app.run();
 }

apps/taskbar.cpp

@@ -0,0 +1,40 @@
+#include <os/Process.h>
+#include <ui/App.h>
+#include <ui/Button.h>
+#include <ui/Container.h>
+#include <ui/Image.h>
+#include <ui/Layout.h>
+
+Result<int> luna_main(int argc, char** argv)
+{
+    ui::App app;
+    TRY(app.init(argc, argv));
+
+    ui::Rect screen = app.screen_rect();
+
+    ui::Rect bar = ui::Rect { ui::Point { 0, screen.height - 50 }, screen.width, 50 };
+
+    auto window = TRY(ui::Window::create(bar, false));
+    app.set_main_window(window);
+    window->set_background(ui::GRAY);
+
+    ui::HorizontalLayout layout(ui::AdjustHeight::Yes, ui::AdjustWidth::No);
+    window->set_main_widget(layout);
+
+    ui::Button button({ 0, 0, 50, 50 });
+    layout.add_widget(button);
+
+    ui::Container container({ 0, 0, 50, 50 }, ui::VerticalAlignment::Center, ui::HorizontalAlignment::Center);
+    button.set_widget(container);
+    button.set_action([] {
+        StringView args[] = { "/usr/bin/gclient" };
+        os::Process::spawn("/usr/bin/gclient", Slice<StringView> { args, 1 }, false);
+    });
+
+    auto image = TRY(ui::ImageWidget::load("/usr/share/icons/32x32/start-icon.tga"));
+    container.set_widget(*image);
+
+    window->draw();
+
+    return app.run();
+}

base/etc/user/00-taskbar

@@ -0,0 +1,4 @@
+Name=taskbar
+Description=Start the taskbar.
+Command=/usr/bin/taskbar
+Restart=true

libos/include/os/IPC.h

@@ -54,7 +54,7 @@ namespace os
          */
         template <typename Client, typename T> Result<void> send_async(Client& client, const T& message)
         {
-            u8 id = T::id;
+            u8 id = T::ID;
             TRY(client.send_typed(id));
             TRY(client.send_typed(message));
             return {};
@@ -90,7 +90,7 @@ namespace os
         Result<ResponseType> send_sync(os::LocalClient& client, const T& message,
                                        decltype(handle_ipc_client_event) handler = handle_ipc_client_event)
         {
-            u8 id = T::id;
+            u8 id = T::ID;
             TRY(client.send_typed(id));
             TRY(client.send_typed(message));
 
@@ -115,7 +115,7 @@ namespace os
                     }
                 }
 
-                if (response_id != ResponseType::id)
+                if (response_id != ResponseType::ID)
                 {
                     TRY(handler(client, response_id));
                     max_other_messages--;

libui/CMakeLists.txt

@@ -10,6 +10,12 @@ set(SOURCES
     src/Rect.cpp
     src/Font.cpp
     src/Image.cpp
+    src/App.cpp
+    src/Window.cpp
+    src/Layout.cpp
+    src/Alignment.cpp
+    src/Container.cpp
+    src/Button.cpp
 )
 
 add_library(ui ${SOURCES})

libui/include/ui/Alignment.h

@@ -0,0 +1,30 @@
+/**
+ * @file Alignment.h
+ * @author apio (cloudapio.eu)
+ * @brief UI component alignment.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <ui/Rect.h>
+
+namespace ui
+{
+    enum class VerticalAlignment
+    {
+        Top,
+        Center,
+        Bottom
+    };
+
+    enum class HorizontalAlignment
+    {
+        Left,
+        Center,
+        Right
+    };
+
+    Rect align(Rect container, Rect contained, VerticalAlignment valign, HorizontalAlignment halign);
+}

libui/include/ui/App.h

@@ -0,0 +1,65 @@
+/**
+ * @file App.h
+ * @author apio (cloudapio.eu)
+ * @brief UI application event loop.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <luna/HashMap.h>
+#include <os/LocalClient.h>
+#include <ui/Window.h>
+
+namespace ui
+{
+    class App
+    {
+      public:
+        App();
+        ~App();
+
+        Result<void> init(int, char**);
+        Result<int> run();
+
+        Rect screen_rect();
+
+        os::LocalClient& client()
+        {
+            return *m_client;
+        }
+
+        void set_should_close(bool b)
+        {
+            m_should_close = b;
+        }
+
+        void set_main_window(Window* window)
+        {
+            check(!m_main_window);
+            m_main_window = window;
+        }
+
+        Window* main_window()
+        {
+            return m_main_window;
+        }
+
+        Result<void> register_window(OwnedPtr<Window>&& window, Badge<Window>);
+        void unregister_window(Window* window, Badge<Window>);
+
+        Result<void> handle_ipc_event(u8 id);
+
+        static App& the();
+
+      private:
+        static App* s_app;
+        OwnedPtr<os::LocalClient> m_client;
+        Window* m_main_window { nullptr };
+        HashMap<int, OwnedPtr<Window>> m_windows;
+        bool m_should_close { false };
+
+        Window* find_window(int id);
+    };
+}

libui/include/ui/Button.h

@@ -0,0 +1,35 @@
+/**
+ * @file Button.h
+ * @author apio (cloudapio.eu)
+ * @brief A clickable component that triggers an action when pressed.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <ui/Widget.h>
+
+namespace ui
+{
+    class Button : public Widget
+    {
+      public:
+        Button(Rect rect);
+
+        void set_widget(Widget& widget);
+        void set_action(void (*action)(void));
+
+        Result<EventResult> handle_mouse_move(Point position) override;
+        Result<EventResult> handle_mouse_leave(Point position) override;
+        Result<EventResult> handle_mouse_down(Point position, int buttons) override;
+        Result<EventResult> handle_mouse_up(Point position, int buttons) override;
+        Result<void> draw(Canvas& canvas) override;
+
+      private:
+        bool m_hovered { false };
+        bool m_clicked { false };
+        Widget* m_child;
+        void (*m_action)(void);
+    };
+}

libui/include/ui/Container.h

@@ -0,0 +1,34 @@
+/**
+ * @file Container.h
+ * @author apio (cloudapio.eu)
+ * @brief A container widget to pad and align objects inside it.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <ui/Alignment.h>
+#include <ui/Widget.h>
+
+namespace ui
+{
+    class Container : public Widget
+    {
+      public:
+        Container(Rect rect, VerticalAlignment valign, HorizontalAlignment halign);
+
+        void set_widget(Widget& widget);
+
+        Result<EventResult> handle_mouse_move(Point position) override;
+        Result<EventResult> handle_mouse_leave(Point position) override;
+        Result<EventResult> handle_mouse_down(Point position, int buttons) override;
+        Result<EventResult> handle_mouse_up(Point position, int buttons) override;
+        Result<void> draw(Canvas& canvas) override;
+
+      private:
+        Widget* m_widget;
+        VerticalAlignment m_valign;
+        HorizontalAlignment m_halign;
+    };
+}

libui/include/ui/Image.h

@@ -11,6 +11,7 @@
 #include <luna/Buffer.h>
 #include <luna/SharedPtr.h>
 #include <os/Path.h>
+#include <ui/Widget.h>
 
 namespace ui
 {
@@ -77,4 +78,19 @@ namespace ui
         TGAHeader m_tga_header;
         Buffer m_image_data;
     };
+
+    class ImageWidget final : public Widget
+    {
+      public:
+        static Result<OwnedPtr<ImageWidget>> load(const os::Path& path);
+
+        Result<EventResult> handle_mouse_move(Point position) override;
+        Result<EventResult> handle_mouse_leave(Point position) override;
+        Result<EventResult> handle_mouse_down(Point position, int buttons) override;
+        Result<EventResult> handle_mouse_up(Point position, int buttons) override;
+        Result<void> draw(Canvas& canvas) override;
+
+      private:
+        SharedPtr<Image> m_image;
+    };
 }

libui/include/ui/Layout.h

@@ -0,0 +1,69 @@
+/**
+ * @file Layout.h
+ * @author apio (cloudapio.eu)
+ * @brief Layout widgets to organize content.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <luna/Vector.h>
+#include <ui/Widget.h>
+
+namespace ui
+{
+    enum class AdjustHeight
+    {
+        No,
+        Yes
+    };
+
+    enum class AdjustWidth
+    {
+        No,
+        Yes
+    };
+
+    class HorizontalLayout final : public Widget
+    {
+      public:
+        HorizontalLayout(AdjustHeight adjust_height = AdjustHeight::Yes, AdjustWidth adjust_width = AdjustWidth::Yes);
+
+        Result<EventResult> handle_mouse_move(Point position) override;
+        Result<EventResult> handle_mouse_leave(Point position) override;
+        Result<EventResult> handle_mouse_down(Point position, int buttons) override;
+        Result<EventResult> handle_mouse_up(Point position, int buttons) override;
+
+        Result<void> draw(Canvas& canvas) override;
+
+        Result<void> add_widget(Widget& widget);
+
+      private:
+        Vector<Widget*> m_widgets;
+        AdjustHeight m_adjust_height;
+        AdjustWidth m_adjust_width;
+        int m_used_width;
+    };
+
+    class VerticalLayout final : public Widget
+    {
+      public:
+        VerticalLayout(AdjustHeight adjust_height = AdjustHeight::Yes, AdjustWidth adjust_width = AdjustWidth::Yes);
+
+        Result<EventResult> handle_mouse_move(Point position) override;
+        Result<EventResult> handle_mouse_leave(Point position) override;
+        Result<EventResult> handle_mouse_down(Point position, int buttons) override;
+        Result<EventResult> handle_mouse_up(Point position, int buttons) override;
+
+        Result<void> draw(Canvas& canvas) override;
+
+        Result<void> add_widget(Widget& widget);
+
+      private:
+        Vector<Widget*> m_widgets;
+        AdjustHeight m_adjust_height;
+        AdjustWidth m_adjust_width;
+        int m_used_height;
+    };
+}

libui/include/ui/Mouse.h

@@ -0,0 +1,21 @@
+/**
+ * @file Mouse.h
+ * @author apio (cloudapio.eu)
+ * @brief Mouse buttons.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <moon/Mouse.h>
+
+namespace ui
+{
+    enum MouseButtons
+    {
+        LEFT = moon::Left,
+        MIDDLE = moon::Middle,
+        RIGHT = moon::Right,
+    };
+}

libui/include/ui/Widget.h

@@ -0,0 +1,68 @@
+/**
+ * @file Widget.h
+ * @author apio (cloudapio.eu)
+ * @brief Abstract widget class.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <luna/Result.h>
+#include <ui/Canvas.h>
+#include <ui/Point.h>
+#include <ui/Rect.h>
+
+namespace ui
+{
+    class Window;
+
+    enum class EventResult
+    {
+        DidHandle,
+        DidNotHandle,
+    };
+
+    class Widget
+    {
+      public:
+        virtual Result<EventResult> handle_mouse_move(Point position);
+        virtual Result<EventResult> handle_mouse_down(Point position, int buttons);
+        virtual Result<EventResult> handle_mouse_up(Point position, int buttons);
+        virtual Result<EventResult> handle_mouse_leave(Point position);
+
+        virtual Result<void> draw(Canvas& canvas);
+
+        void set_window(Window* window, Rect rect, Badge<Window>)
+        {
+            m_window = window;
+            m_rect = rect;
+        }
+
+        void set_parent(Widget* parent)
+        {
+            m_parent = parent;
+            m_window = parent->m_window;
+        }
+
+        Widget* parent()
+        {
+            return m_parent;
+        }
+
+        Window* window()
+        {
+            return m_window;
+        }
+
+        Rect& rect()
+        {
+            return m_rect;
+        }
+
+      protected:
+        Widget* m_parent { nullptr };
+        Window* m_window;
+        Rect m_rect { 0, 0, 50, 50 };
+    };
+}

libui/include/ui/Window.h

@@ -0,0 +1,66 @@
+/**
+ * @file Window.h
+ * @author apio (cloudapio.eu)
+ * @brief UI windows.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <luna/OwnedPtr.h>
+#include <luna/StringView.h>
+#include <ui/Canvas.h>
+#include <ui/Mouse.h>
+#include <ui/Rect.h>
+#include <ui/Widget.h>
+
+namespace ui
+{
+    class Window
+    {
+      public:
+        static Result<Window*> create(Rect rect, bool decorated = true);
+
+        void set_title(StringView title);
+
+        void set_background(Color color)
+        {
+            m_background = color;
+        }
+
+        void set_main_widget(Widget& widget)
+        {
+            check(!m_main_widget);
+            widget.set_window(this, m_canvas.rect(), {});
+            m_main_widget = &widget;
+        }
+
+        Canvas& canvas()
+        {
+            return m_canvas;
+        }
+
+        void update();
+
+        void close();
+
+        Result<void> draw();
+        Result<void> handle_mouse_move(ui::Point position);
+        Result<void> handle_mouse_buttons(ui::Point position, int buttons);
+
+        int id() const
+        {
+            return m_id;
+        }
+
+        ~Window();
+
+      private:
+        int m_id;
+        Canvas m_canvas;
+        Widget* m_main_widget { nullptr };
+        Color m_background { ui::BLACK };
+        Option<int> m_old_mouse_buttons;
+    };
+}

libui/include/ui/ipc/Client.h

@@ -9,6 +9,7 @@
 
 #pragma once
 #include <os/IPC.h>
+#include <ui/Point.h>
 
 namespace ui
 {
@@ -16,13 +17,39 @@ namespace ui
     {
         IPC_ENUM_CLIENT(ui),
         CREATE_WINDOW_RESPONSE_ID,
+        WINDOW_CLOSE_REQUEST_ID,
+        MOUSE_EVENT_REQUEST_ID,
+        GET_SCREEN_RECT_RESPONSE_ID
     };
 
     struct CreateWindowResponse
     {
-        static constexpr u8 id = CREATE_WINDOW_RESPONSE_ID;
+        static constexpr u8 ID = CREATE_WINDOW_RESPONSE_ID;
 
         int window;
         IPC_STRING(shm_path);
     };
+
+    struct WindowCloseRequest
+    {
+        static constexpr u8 ID = WINDOW_CLOSE_REQUEST_ID;
+
+        int window;
+    };
+
+    struct MouseEventRequest
+    {
+        static constexpr u8 ID = MOUSE_EVENT_REQUEST_ID;
+
+        int window;
+        Point position;
+        int buttons;
+    };
+
+    struct GetScreenRectResponse
+    {
+        static constexpr u8 ID = GET_SCREEN_RECT_RESPONSE_ID;
+
+        Rect rect;
+    };
 }

libui/include/ui/ipc/Server.h

@@ -21,19 +21,22 @@ namespace ui
         CREATE_WINDOW_ID,
         SET_WINDOW_TITLE_ID,
         INVALIDATE_ID,
+        CLOSE_WINDOW_ID,
+        GET_SCREEN_RECT_ID,
     };
 
     struct CreateWindowRequest
     {
         using ResponseType = CreateWindowResponse;
-        static constexpr u8 id = CREATE_WINDOW_ID;
+        static constexpr u8 ID = CREATE_WINDOW_ID;
 
         ui::Rect rect;
+        bool decorated;
     };
 
     struct SetWindowTitleRequest
     {
-        static constexpr u8 id = SET_WINDOW_TITLE_ID;
+        static constexpr u8 ID = SET_WINDOW_TITLE_ID;
 
         int window;
         IPC_STRING(title);
@@ -41,8 +44,23 @@ namespace ui
 
     struct InvalidateRequest
     {
-        static constexpr u8 id = INVALIDATE_ID;
+        static constexpr u8 ID = INVALIDATE_ID;
 
         int window;
     };
+
+    struct CloseWindowRequest
+    {
+        static constexpr u8 ID = CLOSE_WINDOW_ID;
+
+        int window;
+    };
+
+    struct GetScreenRectRequest
+    {
+        using ResponseType = GetScreenRectResponse;
+        static constexpr u8 ID = GET_SCREEN_RECT_ID;
+
+        int _shadow; // Unused.
+    };
 }

libui/src/Alignment.cpp

@@ -0,0 +1,40 @@
+/**
+ * @file Alignment.cpp
+ * @author apio (cloudapio.eu)
+ * @brief UI component alignment.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#include <ui/Alignment.h>
+
+namespace ui
+{
+    Rect align(Rect container, Rect contained, VerticalAlignment valign, HorizontalAlignment halign)
+    {
+        Rect result;
+        result.width = contained.width;
+        result.height = contained.height;
+        result.pos.y = container.pos.y;
+        result.pos.x = container.pos.x;
+
+        switch (valign)
+        {
+        case VerticalAlignment::Top: break;
+        case VerticalAlignment::Center: result.pos.y += (container.height - contained.height) / 2; break;
+        case VerticalAlignment::Bottom: result.pos.y += container.height - contained.height; break;
+        default: break;
+        }
+
+        switch (halign)
+        {
+        case HorizontalAlignment::Left: break;
+        case HorizontalAlignment::Center: result.pos.x += (container.width - contained.width) / 2; break;
+        case HorizontalAlignment::Right: result.pos.x += container.width - contained.width; break;
+        default: break;
+        }
+
+        return result;
+    }
+}

libui/src/App.cpp

@@ -0,0 +1,115 @@
+/**
+ * @file App.cpp
+ * @author apio (cloudapio.eu)
+ * @brief UI application event loop.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#include <os/ArgumentParser.h>
+#include <os/File.h>
+#include <os/IPC.h>
+#include <ui/App.h>
+#include <ui/ipc/Client.h>
+#include <ui/ipc/Server.h>
+
+Result<void> handle_ipc_client_event(os::LocalClient&, u8 id)
+{
+    return ui::App::the().handle_ipc_event(id);
+}
+
+namespace ui
+{
+    App* App::s_app { nullptr };
+
+    App::App()
+    {
+        s_app = this;
+    }
+
+    App::~App()
+    {
+        s_app = nullptr;
+    }
+
+    Result<void> App::init(int argc, char** argv)
+    {
+        StringView socket_path = "/tmp/wind.sock";
+
+        os::ArgumentParser parser;
+        parser.add_description("A UI application."_sv);
+        parser.add_system_program_info(argv[0]);
+        parser.add_value_argument(socket_path, 's', "socket"_sv, "the path for the local IPC socket"_sv);
+        parser.parse(argc, argv);
+
+        m_client = TRY(os::LocalClient::connect(socket_path, true));
+
+        return {};
+    }
+
+    Result<int> App::run()
+    {
+        check(m_main_window);
+        while (!m_should_close) { TRY(os::IPC::check_for_messages(*m_client)); }
+        return 0;
+    }
+
+    App& App::the()
+    {
+        check(s_app);
+        return *s_app;
+    }
+
+    Rect App::screen_rect()
+    {
+        ui::GetScreenRectRequest request {};
+        auto response = os::IPC::send_sync<ui::GetScreenRectResponse>(*m_client, request).release_value();
+        return response.rect;
+    }
+
+    Result<void> App::register_window(OwnedPtr<Window>&& window, Badge<Window>)
+    {
+        int id = window->id();
+        check(TRY(m_windows.try_set(id, move(window))));
+        return {};
+    }
+
+    void App::unregister_window(Window* window, Badge<Window>)
+    {
+        int id = window->id();
+        check(m_windows.try_remove(id));
+    }
+
+    Window* App::find_window(int id)
+    {
+        auto* window = m_windows.try_get_ref(id);
+        check(window);
+        return window->ptr();
+    }
+
+    Result<void> App::handle_ipc_event(u8 id)
+    {
+        switch (id)
+        {
+        case WINDOW_CLOSE_REQUEST_ID: {
+            WindowCloseRequest request;
+            TRY(m_client->recv_typed(request));
+            os::eprintln("ui: Window close request from server! Shall comply.");
+            auto* window = find_window(request.window);
+            window->close();
+            return {};
+        }
+        case MOUSE_EVENT_REQUEST_ID: {
+            MouseEventRequest request;
+            TRY(m_client->recv_typed(request));
+            auto* window = find_window(request.window);
+            window->handle_mouse_move(request.position);
+            window->handle_mouse_buttons(request.position, request.buttons);
+            window->draw();
+            return {};
+        }
+        default: fail("Unexpected IPC request from server!");
+        }
+    }
+}

libui/src/Button.cpp

@@ -0,0 +1,68 @@
+/**
+ * @file Button.cpp
+ * @author apio (cloudapio.eu)
+ * @brief A clickable component that triggers an action when pressed.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#include <ui/Button.h>
+#include <ui/Mouse.h>
+
+namespace ui
+{
+    Button::Button(Rect rect)
+    {
+        m_rect = rect;
+    }
+
+    void Button::set_widget(Widget& widget)
+    {
+        widget.rect() = m_rect;
+        m_child = &widget;
+        widget.set_parent(this);
+    }
+
+    void Button::set_action(void (*action)(void))
+    {
+        m_action = action;
+    }
+
+    Result<EventResult> Button::handle_mouse_move(Point position)
+    {
+        m_hovered = true;
+        return m_child->handle_mouse_move(position);
+    }
+
+    Result<EventResult> Button::handle_mouse_leave(Point position)
+    {
+        m_hovered = m_clicked = false;
+        return m_child->handle_mouse_leave(position);
+    }
+
+    Result<EventResult> Button::handle_mouse_down(Point position, int buttons)
+    {
+        auto result = TRY(m_child->handle_mouse_down(position, buttons));
+        if (result == EventResult::DidNotHandle)
+        {
+            if (!m_clicked && (buttons == ui::MouseButtons::LEFT))
+            {
+                m_clicked = true;
+                m_action();
+            }
+        }
+        return EventResult::DidHandle;
+    }
+
+    Result<EventResult> Button::handle_mouse_up(Point position, int buttons)
+    {
+        if (buttons & ui::MouseButtons::LEFT) m_clicked = false;
+        return m_child->handle_mouse_up(position, buttons);
+    }
+
+    Result<void> Button::draw(Canvas& canvas)
+    {
+        return m_child->draw(canvas);
+    }
+}

libui/src/Container.cpp

@@ -0,0 +1,55 @@
+/**
+ * @file Container.cpp
+ * @author apio (cloudapio.eu)
+ * @brief A container widget to pad and align objects inside it.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#include <ui/Container.h>
+
+namespace ui
+{
+    Container::Container(Rect rect, VerticalAlignment valign, HorizontalAlignment halign)
+        : m_valign(valign), m_halign(halign)
+    {
+        m_rect = rect;
+    }
+
+    void Container::set_widget(Widget& widget)
+    {
+        m_widget = &widget;
+        widget.rect() = ui::align(m_rect, widget.rect(), m_valign, m_halign);
+        widget.set_parent(this);
+    }
+
+    Result<EventResult> Container::handle_mouse_move(Point position)
+    {
+        return m_widget->handle_mouse_move(position);
+    }
+
+    Result<EventResult> Container::handle_mouse_leave(Point position)
+    {
+        return m_widget->handle_mouse_leave(position);
+    }
+
+    Result<EventResult> Container::handle_mouse_down(Point position, int buttons)
+    {
+        return m_widget->handle_mouse_down(position, buttons);
+    }
+
+    Result<EventResult> Container::handle_mouse_up(Point position, int buttons)
+    {
+        return m_widget->handle_mouse_up(position, buttons);
+    }
+
+    Result<void> Container::draw(Canvas& canvas)
+    {
+        auto rect = ui::Rect { m_widget->rect().pos.x - m_rect.pos.x, m_widget->rect().pos.y - m_rect.pos.y,
+                               m_widget->rect().width, m_widget->rect().height };
+        auto subcanvas = canvas.subcanvas(rect);
+        return m_widget->draw(subcanvas);
+    }
+
+}

libui/src/Image.cpp

@@ -8,6 +8,7 @@
  */
 
 #include <os/File.h>
+#include <ui/Alignment.h>
 #include <ui/Image.h>
 
 namespace ui
@@ -30,4 +31,38 @@ namespace ui
 
         return image;
     }
+
+    Result<OwnedPtr<ImageWidget>> ImageWidget::load(const os::Path& path)
+    {
+        auto widget = TRY(make_owned<ImageWidget>());
+        widget->m_image = TRY(Image::load(path));
+        widget->m_rect = { 0, 0, widget->m_image->width(), widget->m_image->height() };
+        return widget;
+    }
+
+    Result<EventResult> ImageWidget::handle_mouse_move(Point)
+    {
+        return EventResult::DidNotHandle;
+    }
+
+    Result<EventResult> ImageWidget::handle_mouse_leave(Point)
+    {
+        return EventResult::DidNotHandle;
+    }
+
+    Result<EventResult> ImageWidget::handle_mouse_up(Point, int)
+    {
+        return EventResult::DidNotHandle;
+    }
+
+    Result<EventResult> ImageWidget::handle_mouse_down(Point, int)
+    {
+        return EventResult::DidNotHandle;
+    }
+
+    Result<void> ImageWidget::draw(Canvas& canvas)
+    {
+        canvas.subcanvas({ 0, 0, m_image->width(), m_image->height() }).fill(m_image->pixels(), m_image->width());
+        return {};
+    }
 }

libui/src/Layout.cpp

@@ -0,0 +1,192 @@
+/**
+ * @file Layout.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Layout widgets to organize content.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#include <stdlib.h>
+#include <ui/Layout.h>
+
+namespace ui
+{
+    HorizontalLayout::HorizontalLayout(AdjustHeight adjust_height, AdjustWidth adjust_width)
+        : m_adjust_height(adjust_height), m_adjust_width(adjust_width)
+    {
+    }
+
+    Result<EventResult> HorizontalLayout::handle_mouse_move(Point position)
+    {
+        EventResult result = ui::EventResult::DidNotHandle;
+
+        for (auto widget : m_widgets)
+        {
+            if (widget->rect().contains(position)) result = TRY(widget->handle_mouse_move(position));
+            else
+                TRY(widget->handle_mouse_leave(position));
+        }
+
+        return result;
+    }
+
+    Result<EventResult> HorizontalLayout::handle_mouse_leave(Point position)
+    {
+        for (auto widget : m_widgets) TRY(widget->handle_mouse_leave(position));
+
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<EventResult> HorizontalLayout::handle_mouse_up(Point position, int buttons)
+    {
+        for (auto widget : m_widgets)
+        {
+            if (widget->rect().contains(position)) return widget->handle_mouse_up(position, buttons);
+        }
+
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<EventResult> HorizontalLayout::handle_mouse_down(Point position, int buttons)
+    {
+        for (auto widget : m_widgets)
+        {
+            if (widget->rect().contains(position)) return widget->handle_mouse_down(position, buttons);
+        }
+
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<void> HorizontalLayout::draw(Canvas& canvas)
+    {
+        for (auto widget : m_widgets)
+        {
+            ui::Rect rect = { m_rect.relative(widget->rect().pos), widget->rect().width, widget->rect().height };
+            auto subcanvas = canvas.subcanvas(rect);
+            TRY(widget->draw(subcanvas));
+        }
+
+        return {};
+    }
+
+    Result<void> HorizontalLayout::add_widget(Widget& widget)
+    {
+        TRY(m_widgets.try_append(&widget));
+
+        if (m_adjust_width == AdjustWidth::No)
+        {
+            widget.rect().pos.x = m_rect.pos.x + m_used_width;
+            m_used_width += widget.rect().width;
+        }
+        else
+        {
+            int used_width = 0;
+            div_t result = div(m_rect.width, (int)m_widgets.size());
+            for (auto w : m_widgets)
+            {
+                w->rect().pos.x = m_rect.pos.x + used_width;
+                w->rect().width = result.quot;
+                used_width += result.quot;
+            }
+            m_widgets[m_widgets.size() - 1]->rect().width += result.rem;
+        }
+
+        widget.rect().pos.y = m_rect.pos.y;
+
+        if (m_adjust_height == AdjustHeight::Yes) { widget.rect().height = m_rect.height; }
+
+        widget.set_parent(this);
+
+        return {};
+    }
+
+    VerticalLayout::VerticalLayout(AdjustHeight adjust_height, AdjustWidth adjust_width)
+        : m_adjust_height(adjust_height), m_adjust_width(adjust_width)
+    {
+    }
+
+    Result<EventResult> VerticalLayout::handle_mouse_move(Point position)
+    {
+        EventResult result = ui::EventResult::DidNotHandle;
+
+        for (auto widget : m_widgets)
+        {
+            if (widget->rect().contains(position)) result = TRY(widget->handle_mouse_move(position));
+            else
+                TRY(widget->handle_mouse_leave(position));
+        }
+
+        return result;
+    }
+
+    Result<EventResult> VerticalLayout::handle_mouse_leave(Point position)
+    {
+        for (auto widget : m_widgets) TRY(widget->handle_mouse_leave(position));
+
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<EventResult> VerticalLayout::handle_mouse_up(Point position, int buttons)
+    {
+        for (auto widget : m_widgets)
+        {
+            if (widget->rect().contains(position)) return widget->handle_mouse_up(position, buttons);
+        }
+
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<EventResult> VerticalLayout::handle_mouse_down(Point position, int buttons)
+    {
+        for (auto widget : m_widgets)
+        {
+            if (widget->rect().contains(position)) return widget->handle_mouse_down(position, buttons);
+        }
+
+        return ui::EventResult::DidNotHandle;
+    }
+
+    Result<void> VerticalLayout::draw(Canvas& canvas)
+    {
+        for (auto widget : m_widgets)
+        {
+            ui::Rect rect = { m_rect.relative(widget->rect().pos), widget->rect().width, widget->rect().height };
+            auto subcanvas = canvas.subcanvas(rect);
+            TRY(widget->draw(subcanvas));
+        }
+
+        return {};
+    }
+
+    Result<void> VerticalLayout::add_widget(Widget& widget)
+    {
+        TRY(m_widgets.try_append(&widget));
+
+        if (m_adjust_height == AdjustHeight::No)
+        {
+            widget.rect().pos.y = m_rect.pos.y + m_used_height;
+            m_used_height += widget.rect().height;
+        }
+        else
+        {
+            int used_height = 0;
+            div_t result = div(m_rect.height, (int)m_widgets.size());
+            for (auto w : m_widgets)
+            {
+                w->rect().pos.y = m_rect.pos.y + used_height;
+                w->rect().height = result.quot;
+                used_height += result.quot;
+            }
+            m_widgets[m_widgets.size() - 1]->rect().height += result.rem;
+        }
+
+        widget.rect().pos.x = m_rect.pos.x;
+
+        if (m_adjust_width == AdjustWidth::Yes) { widget.rect().width = m_rect.width; }
+
+        widget.set_parent(this);
+
+        return {};
+    }
+}

libui/src/Window.cpp

@@ -0,0 +1,124 @@
+/**
+ * @file Window.cpp
+ * @author apio (cloudapio.eu)
+ * @brief UI windows.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <ui/App.h>
+#include <ui/Window.h>
+#include <ui/ipc/Server.h>
+#include <unistd.h>
+
+static Result<u32*> create_shm_region(const char* path, int* outfd, ui::Rect rect)
+{
+    int fd = shm_open(path, O_RDWR, 0600);
+    shm_unlink(path);
+    if (fd < 0) return err(errno);
+
+    usize size = rect.width * rect.height * 4; // 4 bytes per pixel
+
+    void* p = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (p == MAP_FAILED)
+    {
+        shm_unlink(path);
+        close(fd);
+        return 0;
+    }
+
+    if (outfd) *outfd = fd;
+    else
+        close(fd);
+    return (u32*)p;
+}
+
+namespace ui
+{
+    Result<Window*> Window::create(Rect rect, bool decorated)
+    {
+        auto window = TRY(make_owned<Window>());
+
+        ui::CreateWindowRequest request;
+        request.rect = rect;
+        request.decorated = decorated;
+        auto response = TRY(os::IPC::send_sync<ui::CreateWindowResponse>(App::the().client(), request));
+
+        u32* pixels = TRY(create_shm_region(response.shm_path, nullptr, rect));
+
+        window->m_canvas = ui::Canvas { rect.width, rect.height, rect.width, (u8*)pixels };
+        window->m_id = response.window;
+
+        Window* p = window.ptr();
+
+        App::the().register_window(move(window), {});
+
+        return p;
+    }
+
+    Window::~Window()
+    {
+        if (m_canvas.ptr) munmap(m_canvas.ptr, ((usize)m_canvas.width) * ((usize)m_canvas.height) * 4);
+    }
+
+    void Window::set_title(StringView title)
+    {
+        ui::SetWindowTitleRequest request;
+        request.window = m_id;
+        SET_IPC_STRING(request.title, title.chars());
+        os::IPC::send_async(App::the().client(), request);
+    }
+
+    void Window::update()
+    {
+        ui::InvalidateRequest request;
+        request.window = m_id;
+        os::IPC::send_async(App::the().client(), request);
+    }
+
+    void Window::close()
+    {
+        App& app = App::the();
+
+        ui::CloseWindowRequest request;
+        request.window = m_id;
+        os::IPC::send_async(app.client(), request);
+
+        if (this == app.main_window()) app.set_should_close(true);
+
+        app.unregister_window(this, {});
+    }
+
+    Result<void> Window::draw()
+    {
+        m_canvas.fill(m_background);
+        if (m_main_widget) return m_main_widget->draw(m_canvas);
+        update();
+        return {};
+    }
+
+    Result<void> Window::handle_mouse_move(ui::Point position)
+    {
+        if (!m_main_widget) return {};
+        TRY(m_main_widget->handle_mouse_move(position));
+        return {};
+    }
+
+    Result<void> Window::handle_mouse_buttons(ui::Point position, int buttons)
+    {
+        if (!m_main_widget) return {};
+        if (buttons) TRY(m_main_widget->handle_mouse_down(position, buttons));
+        if (m_old_mouse_buttons.has_value())
+        {
+            int old_buttons = m_old_mouse_buttons.value();
+            int diff = old_buttons & ~buttons;
+            if (diff) TRY(m_main_widget->handle_mouse_up(position, diff));
+        }
+        m_old_mouse_buttons = buttons;
+        return {};
+    }
+}

wind/IPC.cpp

@@ -1,4 +1,5 @@
 #include "IPC.h"
+#include "Screen.h"
 #include <errno.h>
 #include <luna/Alignment.h>
 #include <luna/String.h>
@@ -64,7 +65,7 @@ static Result<u32*> create_shm_region(const char* path, int* outfd, ui::Rect rec
             if (rc.error() == EAGAIN)                                                                                  \
             {                                                                                                          \
                 client.rpc_in_progress = true;                                                                         \
-                client.rpc_id = decltype(request)::id;                                                                 \
+                client.rpc_id = decltype(request)::ID;                                                                 \
                 return {};                                                                                             \
             }                                                                                                          \
             else                                                                                                       \
@@ -72,17 +73,32 @@ static Result<u32*> create_shm_region(const char* path, int* outfd, ui::Rect rec
         }                                                                                                              \
     } while (0)
 
+#define CHECK_WINDOW_ID(request)                                                                                       \
+    do {                                                                                                               \
+        if ((usize)request.window >= client.windows.size() || !client.windows[request.window])                         \
+        {                                                                                                              \
+            os::eprintln("wind: Window id is invalid!");                                                               \
+            return {};                                                                                                 \
+        }                                                                                                              \
+    } while (0)
+
 static Result<void> handle_create_window_message(Client& client)
 {
     ui::CreateWindowRequest request;
     READ_MESSAGE(request);
 
     request.rect = request.rect.normalized();
-    request.rect.height += Window::titlebar_height(); // Make sure we provide the full contents rect that was asked for.
+
+    if (request.decorated)
+    {
+        request.rect.height +=
+            Window::titlebar_height(); // Make sure we provide the full contents rect that was asked for.
+        request.rect.pos.y -= Window::titlebar_height(); // Adjust it so the contents begin at the expected coordinates.
+    }
 
     auto name = TRY(String::from_cstring("Window"));
 
-    auto* window = new (std::nothrow) Window(request.rect, move(name));
+    auto* window = new (std::nothrow) Window(request.rect, move(name), request.decorated);
     if (!window)
     {
         os::IPC::send_error(client.conn, ENOMEM);
@@ -96,6 +112,9 @@ static Result<void> handle_create_window_message(Client& client)
     TRY_OR_IPC_ERROR(client.windows.try_append(window));
     int id = static_cast<int>(client.windows.size() - 1);
 
+    window->client = &client;
+    window->id = id;
+
     ui::CreateWindowResponse response;
     response.window = id;
     SET_IPC_STRING(response.shm_path, shm_path.chars());
@@ -112,11 +131,7 @@ static Result<void> handle_set_window_title_message(Client& client)
 
     os::println("wind: SetWindowTitle(\"%s\") for window %d", name.chars(), request.window);
 
-    if ((usize)request.window >= client.windows.size())
-    {
-        os::eprintln("wind: Window id out of range!");
-        return {};
-    }
+    CHECK_WINDOW_ID(request);
 
     client.windows[request.window]->name = move(name);
 
@@ -128,17 +143,40 @@ static Result<void> handle_invalidate_message(Client& client)
     ui::InvalidateRequest request;
     READ_MESSAGE(request);
 
-    if ((usize)request.window >= client.windows.size())
-    {
-        os::eprintln("wind: Window id out of range!");
-        return {};
-    }
+    CHECK_WINDOW_ID(request);
 
     client.windows[request.window]->dirty = true;
 
     return {};
 }
 
+static Result<void> handle_close_window_message(Client& client)
+{
+    ui::CloseWindowRequest request;
+    READ_MESSAGE(request);
+
+    CHECK_WINDOW_ID(request);
+
+    auto* window = client.windows[request.window];
+    client.windows[request.window] = nullptr;
+    g_windows.remove(window);
+    delete window;
+
+    return {};
+}
+
+static Result<void> handle_get_screen_rect_message(Client& client)
+{
+    ui::GetScreenRectRequest request;
+    READ_MESSAGE(request); // Kinda pointless, but required.
+
+    ui::GetScreenRectResponse response;
+    response.rect = Screen::the().canvas().rect();
+    os::IPC::send_async(client.conn, response);
+
+    return {};
+}
+
 namespace wind
 {
     Result<void> handle_ipc_message(Client& client, u8 id)
@@ -149,6 +187,8 @@ namespace wind
         case ui::CREATE_WINDOW_ID: return handle_create_window_message(client);
         case ui::SET_WINDOW_TITLE_ID: return handle_set_window_title_message(client);
         case ui::INVALIDATE_ID: return handle_invalidate_message(client);
+        case ui::CLOSE_WINDOW_ID: return handle_close_window_message(client);
+        case ui::GET_SCREEN_RECT_ID: return handle_get_screen_rect_message(client);
         default: os::eprintln("wind: Invalid IPC message from client!"); return err(EINVAL);
         }
     }

wind/Mouse.cpp

@@ -1,6 +1,9 @@
 #include "Mouse.h"
+#include "Client.h"
 #include <os/File.h>
+#include <os/IPC.h>
 #include <ui/Image.h>
+#include <ui/ipc/Client.h>
 
 static SharedPtr<ui::Image> g_mouse_cursor;
 
@@ -51,9 +54,10 @@ void Mouse::update(const moon::MousePacket& packet)
         {
             if (window->surface.absolute(window->close_button).contains(m_position))
             {
-                // Close button pressed
-                g_windows.remove(window);
-                delete window;
+                ui::WindowCloseRequest request;
+                request.window = window->id;
+                auto& client = *window->client;
+                os::IPC::send_async(client.conn, request);
                 break;
             }
             else if (window->surface.absolute(window->titlebar).contains(m_position))
@@ -74,4 +78,21 @@ void Mouse::update(const moon::MousePacket& packet)
             }
         }
     }
+
+    for (Window* window = g_windows.last().value_or(nullptr); window;
+         window = g_windows.previous(window).value_or(nullptr))
+    {
+        auto titlebar = window->surface.absolute(window->titlebar);
+        auto contents = window->surface.absolute(window->contents);
+        if (titlebar.contains(m_position)) break;
+        if (contents.contains(m_position))
+        {
+            ui::MouseEventRequest request;
+            request.window = window->id;
+            request.position = contents.relative(m_position);
+            request.buttons = packet.buttons;
+            os::IPC::send_async(window->client->conn, request);
+            break;
+        }
+    }
 }

wind/Screen.cpp

@@ -5,7 +5,9 @@
 #include <sys/mman.h>
 #include <unistd.h>
 
-Result<Screen> Screen::open()
+Screen Screen::s_the;
+
+Result<void> Screen::open()
 {
     int fd = ::open("/dev/fb0", O_RDWR);
     if (fd < 0) return err(errno);
@@ -23,7 +25,9 @@ Result<Screen> Screen::open()
     screen.m_canvas = ui::Canvas::create((u8*)p, width, height);
     screen.m_size = width * height * BYTES_PER_PIXEL;
 
-    return screen;
+    s_the = screen;
+
+    return {};
 }
 
 void Screen::sync()

wind/Screen.h

@@ -7,7 +7,7 @@ constexpr int BYTES_PER_PIXEL = 4;
 class Screen
 {
   public:
-    static Result<Screen> open();
+    static Result<void> open();
 
     ui::Canvas& canvas()
     {
@@ -19,9 +19,16 @@ class Screen
         return m_size;
     }
 
+    static Screen& the()
+    {
+        return s_the;
+    }
+
     void sync();
 
   private:
     ui::Canvas m_canvas;
     int m_size;
+
+    static Screen s_the;
 };

wind/Window.cpp

@@ -41,14 +41,15 @@ void Window::focus()
     g_windows.append(this);
 }
 
-Window::Window(ui::Rect r, String&& n) : surface(r), name(move(n))
+Window::Window(ui::Rect r, String&& n, bool d) : surface(r), name(move(n)), decorated(d)
 {
     auto font = ui::Font::default_font();
-    if (surface.width < 36) surface.width = 36;
-    if (surface.height < (font->height() + 20)) surface.height = font->height() + 20;
-    titlebar = ui::Rect { 0, 0, surface.width, font->height() + 20 };
-    close_button = ui::Rect { surface.width - 26, 10, 16, 16 };
-    contents = ui::Rect { 0, font->height() + 20, surface.width, surface.height - (font->height() + 20) };
+    if (decorated && surface.width < 36) surface.width = 36;
+    if (decorated && surface.height < (font->height() + 20)) surface.height = font->height() + 20;
+    titlebar = decorated ? ui::Rect { 0, 0, surface.width, font->height() + 20 } : ui::Rect { 0, 0, 0, 0 };
+    close_button = decorated ? ui::Rect { surface.width - 26, 10, 16, 16 } : ui::Rect { 0, 0, 0, 0 };
+    contents = decorated ? ui::Rect { 0, font->height() + 20, surface.width, surface.height - (font->height() + 20) }
+                         : ui::Rect { 0, 0, surface.width, surface.height };
     g_windows.append(this);
 }
 

wind/Window.h

@@ -5,6 +5,8 @@
 #include <ui/Color.h>
 #include <ui/Rect.h>
 
+struct Client;
+
 struct Window : public LinkedListNode<Window>
 {
     ui::Rect surface;
@@ -14,10 +16,13 @@ struct Window : public LinkedListNode<Window>
     u32* pixels;
     String name;
     bool dirty { false };
+    Client* client;
+    int id;
+    bool decorated;
 
     static int titlebar_height();
 
-    Window(ui::Rect, String&&);
+    Window(ui::Rect, String&&, bool);
     ~Window();
 
     void focus();

wind/main.cpp

@@ -49,7 +49,8 @@ Result<int> luna_main(int argc, char** argv)
     keyboard->set_buffer(os::File::NotBuffered);
     keyboard->set_close_on_exec();
 
-    auto screen = TRY(Screen::open());
+    TRY(Screen::open());
+    auto& screen = Screen::the();
 
     Mouse mouse_pointer { screen.canvas() };
 
@@ -127,12 +128,15 @@ Result<int> luna_main(int argc, char** argv)
                 auto client = clients.remove_at(i);
                 client.conn.disconnect();
                 for (auto& window : client.windows)
+                {
+                    if (window)
                     {
                         g_windows.remove(window);
                         delete window;
                     }
                 }
             }
+        }
         if (fds[2].revents & POLLIN)
         {
             auto client = TRY(server->accept());