LibGUI: Add support for changing window title

userspace/programs/WindowServer/Window.h

@@ -52,6 +52,8 @@ public:
 	LibGUI::Window::Attributes get_attributes() const { return m_attributes; };
 	void set_attributes(LibGUI::Window::Attributes attributes) { m_attributes = attributes; };
 
+	BAN::ErrorOr<void> set_title(BAN::StringView title) { m_title.clear(); TRY(m_title.append(title)); TRY(prepare_title_bar()); return {}; }
+
 	const uint32_t* framebuffer() const { return m_fb_addr; }
 
 	uint32_t title_bar_pixel(int32_t abs_x, int32_t abs_y, Position cursor) const

userspace/programs/WindowServer/WindowServer.cpp

@@ -307,7 +307,7 @@ void WindowServer::on_window_set_fullscreen(int fd, const LibGUI::WindowPacket::
 
 	if (!target_window)
 	{
-		dwarnln("client tried to set window size while not owning a window");
+		dwarnln("client tried to set window fullscreen while not owning a window");
 		return;
 	}
 
@@ -316,6 +316,32 @@ void WindowServer::on_window_set_fullscreen(int fd, const LibGUI::WindowPacket::
 	invalidate(m_framebuffer.area());
 }
 
+void WindowServer::on_window_set_title(int fd, const LibGUI::WindowPacket::WindowSetTitle& packet)
+{
+	BAN::RefPtr<Window> target_window;
+	for (auto& window : m_client_windows)
+	{
+		if (window->client_fd() != fd)
+			continue;
+		target_window = window;
+		break;
+	}
+
+	if (!target_window)
+	{
+		dwarnln("client tried to set window title while not owning a window");
+		return;
+	}
+
+	if (auto ret = target_window->set_title(packet.title); ret.is_error())
+	{
+		dwarnln("failed to set window title: {}", ret.error());
+		return;
+	}
+
+	invalidate(target_window->title_bar_area());
+}
+
 void WindowServer::on_key_event(LibInput::KeyEvent event)
 {
 	// Mod key is not passed to clients

userspace/programs/WindowServer/WindowServer.h

@@ -38,6 +38,7 @@ public:
 	void on_window_set_mouse_capture(int fd, const LibGUI::WindowPacket::WindowSetMouseCapture&);
 	void on_window_set_size(int fd, const LibGUI::WindowPacket::WindowSetSize&);
 	void on_window_set_fullscreen(int fd, const LibGUI::WindowPacket::WindowSetFullscreen&);
+	void on_window_set_title(int fd, const LibGUI::WindowPacket::WindowSetTitle&);
 
 	void on_key_event(LibInput::KeyEvent event);
 	void on_mouse_button(LibInput::MouseButtonEvent event);

userspace/programs/WindowServer/main.cpp

@@ -379,6 +379,10 @@ int main()
 						if (auto ret = LibGUI::WindowPacket::WindowSetFullscreen::deserialize(client_data.packet_buffer.span()); !ret.is_error())
 							window_server.on_window_set_fullscreen(fd, ret.release_value());
 						break;
+					case LibGUI::PacketType::WindowSetTitle:
+						if (auto ret = LibGUI::WindowPacket::WindowSetTitle::deserialize(client_data.packet_buffer.span()); !ret.is_error())
+							window_server.on_window_set_title(fd, ret.release_value());
+						break;
 					default:
 						dprintln("unhandled packet type: {}", *reinterpret_cast<uint32_t*>(client_data.packet_buffer.data()));
 				}