WindowServer: Give the desktop window the whole exact desktop rect

Servers/WindowServer/ClientConnection.cpp

@@ -447,7 +447,7 @@ OwnPtr<Messages::WindowServer::CreateWindowResponse> ClientConnection::handle(co
     if (!message.fullscreen())
         window->set_rect(message.rect());
     if (window->type() == WindowType::Desktop) {
-        window->set_rect(Screen::the().rect());
+        window->set_rect(WindowManager::the().desktop_rect());
         window->recalculate_rect();
     }
     window->set_show_titlebar(message.show_titlebar());

Servers/WindowServer/WindowManager.cpp

@@ -936,6 +936,18 @@ Gfx::Rect WindowManager::menubar_rect() const
     return MenuManager::the().menubar_rect();
 }
 
+Gfx::Rect WindowManager::desktop_rect() const
+{
+    if (active_fullscreen_window())
+        return {};
+    return {
+        0,
+        menubar_rect().bottom() + 1,
+        Screen::the().width(),
+        Screen::the().height() - menubar_rect().height() - 28
+    };
+}
+
 void WindowManager::event(Core::Event& event)
 {
     if (static_cast<Event&>(event).is_mouse_event()) {

Servers/WindowServer/WindowManager.h

@@ -119,6 +119,7 @@ public:
     void move_to_front_and_make_active(Window&);
 
     Gfx::Rect menubar_rect() const;
+    Gfx::Rect desktop_rect() const;
 
     const Cursor& active_cursor() const;
     const Cursor& arrow_cursor() const { return *m_arrow_cursor; }