LibWebView+WebDriver+UI: Migrate headless browsing to main Ladybird exe

We currently create a separate headless-browser application to serve two purposes: 1. Allow headless browsing to take a screenshot of a page or print its layout tree / internal text. 2. Run the LibWeb test framework. This patch migrates (1) to the main Ladybird executable. The --headless flag enables this mode. This matches the behavior of other browsers, and means we have one less executable to ship at distribution time. We want to avoid creating too many AppKit / Qt facilities in headless mode. So this involves some shuffling of application init to ensure we don't create them until after we've parsed the command line arguments. Namely, we avoid creating the NSApp in AppKit and QCoreApplication in Qt. Doing so also requires that we don't create the application event loop until we've parsed the command line as well, because the loop we create depends on whether we're creating those UI facilities.
Author: https://github.com/trflynn89 Commit: c011dc766f Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5026
2025-07-19 07:22:21 +00:00 · 2025-06-06 15:42:12 -04:00 · 2025-06-06 15:42:12 -04:00 · c011dc766f · 2025-06-10 16:06:04 +00:00
commit c011dc766f
parent 3894d8efec
28 changed files with 535 additions and 494 deletions
--- a/Libraries/LibWebView/Application.cpp
+++ b/Libraries/LibWebView/Application.cpp
@ -17,9 +17,11 @@
 #include <LibWebView/Application.h>
 #include <LibWebView/CookieJar.h>
 #include <LibWebView/Database.h>
+#include <LibWebView/HeadlessWebView.h>
 #include <LibWebView/HelperProcess.h>
 #include <LibWebView/URL.h>
 #include <LibWebView/UserAgent.h>
+#include <LibWebView/Utilities.h>
 #include <LibWebView/WebContentClient.h>

 namespace WebView {
@ -91,6 +93,9 @@ void Application::initialize(Main::Arguments const& arguments)

    Vector<ByteString> raw_urls;
    Vector<ByteString> certificates;
+    Optional<HeadlessMode> headless_mode;
+    Optional<int> window_width;
+    Optional<int> window_height;
    bool new_window = false;
    bool force_new_process = false;
    bool allow_popups = false;
@ -104,6 +109,7 @@ void Application::initialize(Main::Arguments const& arguments)
    Optional<StringView> dns_server_address;
    Optional<u16> dns_server_port;
    bool use_dns_over_tls = false;
+    bool layout_test_mode = false;
    bool log_all_js_exceptions = false;
    bool disable_site_isolation = false;
    bool enable_idl_tracing = false;
@ -118,6 +124,29 @@ void Application::initialize(Main::Arguments const& arguments)
    Core::ArgsParser args_parser;
    args_parser.set_general_help("The Ladybird web browser :^)");
    args_parser.add_positional_argument(raw_urls, "URLs to open", "url", Core::ArgsParser::Required::No);
+
+    args_parser.add_option(Core::ArgsParser::Option {
+        .argument_mode = Core::ArgsParser::OptionArgumentMode::Optional,
+        .help_string = "Run Ladybird without a browser window. Mode may be 'screenshot' (default), 'layout-tree', or 'text'.",
+        .long_name = "headless",
+        .value_name = "mode",
+        .accept_value = [&](StringView value) {
+            if (headless_mode.has_value())
+                return false;
+
+            if (value.is_empty() || value.equals_ignoring_ascii_case("screenshot"sv))
+                headless_mode = HeadlessMode::Screenshot;
+            else if (value.equals_ignoring_ascii_case("layout-tree"sv))
+                headless_mode = HeadlessMode::LayoutTree;
+            else if (value.equals_ignoring_ascii_case("text"sv))
+                headless_mode = HeadlessMode::Text;
+
+            return headless_mode.has_value();
+        },
+    });
+
+    args_parser.add_option(window_width, "Set viewport width in pixels (default: 800) (currently only supported for headless mode)", "window-width", 0, "pixels");
+    args_parser.add_option(window_height, "Set viewport height in pixels (default: 600) (currently only supported for headless mode)", "window-height", 0, "pixels");
    args_parser.add_option(certificates, "Path to a certificate file", "certificate", 'C', "certificate");
    args_parser.add_option(new_window, "Force opening in a new window", "new-window", 'n');
    args_parser.add_option(force_new_process, "Force creation of a new browser process", "force-new-process");
@ -128,6 +157,7 @@ void Application::initialize(Main::Arguments const& arguments)
    args_parser.add_option(profile_process, "Enable callgrind profiling of the given process name (WebContent, RequestServer, etc.)", "profile-process", 0, "process-name");
    args_parser.add_option(webdriver_content_ipc_path, "Path to WebDriver IPC for WebContent", "webdriver-content-path", 0, "path", Core::ArgsParser::OptionHideMode::CommandLineAndMarkdown);
    args_parser.add_option(devtools_port, "Set the Firefox DevTools server port ", "devtools-port", 0, "port");
+    args_parser.add_option(layout_test_mode, "Enable layout test mode", "layout-test-mode");
    args_parser.add_option(log_all_js_exceptions, "Log all JavaScript exceptions", "log-all-js-exceptions");
    args_parser.add_option(disable_site_isolation, "Disable site isolation", "disable-site-isolation");
    args_parser.add_option(enable_idl_tracing, "Enable IDL tracing", "enable-idl-tracing");
@ -141,6 +171,7 @@ void Application::initialize(Main::Arguments const& arguments)
    args_parser.add_option(dns_server_address, "Set the DNS server address", "dns-server", 0, "host|address");
    args_parser.add_option(dns_server_port, "Set the DNS server port", "dns-port", 0, "port (default: 53 or 853 if --dot)");
    args_parser.add_option(use_dns_over_tls, "Use DNS over TLS", "dot");
+
    args_parser.add_option(Core::ArgsParser::Option {
        .argument_mode = Core::ArgsParser::OptionArgumentMode::Required,
        .help_string = "Name of the User-Agent preset to use in place of the default User-Agent",
@ -178,6 +209,7 @@ void Application::initialize(Main::Arguments const& arguments)
    m_browser_options = {
        .urls = sanitize_urls(raw_urls, m_settings.new_tab_page_url()),
        .raw_urls = move(raw_urls),
+        .headless_mode = headless_mode,
        .certificates = move(certificates),
        .new_window = new_window ? NewWindow::Yes : NewWindow::No,
        .force_new_process = force_new_process ? ForceNewProcess::Yes : ForceNewProcess::No,
@ -194,6 +226,11 @@ void Application::initialize(Main::Arguments const& arguments)
        .devtools_port = devtools_port,
    };

+    if (window_width.has_value())
+        m_browser_options.window_width = *window_width;
+    if (window_height.has_value())
+        m_browser_options.window_height = *window_height;
+
    if (webdriver_content_ipc_path.has_value())
        m_browser_options.webdriver_content_ipc_path = *webdriver_content_ipc_path;

@ -201,6 +238,7 @@ void Application::initialize(Main::Arguments const& arguments)
        .command_line = MUST(String::join(' ', arguments.strings)),
        .executable_path = MUST(String::from_byte_string(MUST(Core::System::current_executable_path()))),
        .user_agent_preset = move(user_agent_preset),
+        .is_layout_test_mode = layout_test_mode ? IsLayoutTestMode::Yes : IsLayoutTestMode::No,
        .log_all_js_exceptions = log_all_js_exceptions ? LogAllJSExceptions::Yes : LogAllJSExceptions::No,
        .disable_site_isolation = disable_site_isolation ? DisableSiteIsolation::Yes : DisableSiteIsolation::No,
        .enable_idl_tracing = enable_idl_tracing ? EnableIDLTracing::Yes : EnableIDLTracing::No,
@ -215,12 +253,7 @@ void Application::initialize(Main::Arguments const& arguments)

    create_platform_options(m_browser_options, m_web_content_options);

-    if (m_browser_options.disable_sql_database == DisableSQLDatabase::No) {
-        m_database = Database::create().release_value_but_fixme_should_propagate_errors();
-        m_cookie_jar = CookieJar::create(*m_database).release_value_but_fixme_should_propagate_errors();
-    } else {
-        m_cookie_jar = CookieJar::create();
-    }
+    m_event_loop = create_platform_event_loop();
 }

 static ErrorOr<NonnullRefPtr<WebContentClient>> create_web_content_client(Optional<ViewImplementation&> view)
@ -278,6 +311,13 @@ void Application::launch_spare_web_content_process()

 ErrorOr<void> Application::launch_services()
 {
+    if (m_browser_options.disable_sql_database == DisableSQLDatabase::No) {
+        m_database = Database::create().release_value_but_fixme_should_propagate_errors();
+        m_cookie_jar = CookieJar::create(*m_database).release_value_but_fixme_should_propagate_errors();
+    } else {
+        m_cookie_jar = CookieJar::create();
+    }
+
    TRY(launch_request_server());
    TRY(launch_image_decoder_server());
    return {};
@ -329,13 +369,86 @@ ErrorOr<void> Application::launch_devtools_server()
    return {};
 }

-int Application::execute()
+static NonnullRefPtr<Core::Timer> load_page_for_screenshot_and_exit(Core::EventLoop& event_loop, HeadlessWebView& view, URL::URL const& url, int screenshot_timeout)
 {
-    int ret = m_event_loop.exec();
+    outln("Taking screenshot after {} seconds", screenshot_timeout);
+
+    auto timer = Core::Timer::create_single_shot(
+        screenshot_timeout * 1000,
+        [&]() {
+            view.take_screenshot(ViewImplementation::ScreenshotType::Full)
+                ->when_resolved([&event_loop](auto const& path) {
+                    outln("Saved screenshot to: {}", path);
+                    event_loop.quit(0);
+                })
+                .when_rejected([&event_loop](auto const& error) {
+                    warnln("Unable to take screenshot: {}", error);
+                    event_loop.quit(0);
+                });
+        });
+
+    view.load(url);
+    timer->start();
+
+    return timer;
+}
+
+static void load_page_for_info_and_exit(Core::EventLoop& event_loop, HeadlessWebView& view, URL::URL const& url, WebView::PageInfoType type)
+{
+    view.on_load_finish = [&view, &event_loop, url, type](auto const& loaded_url) {
+        if (!url.equals(loaded_url, URL::ExcludeFragment::Yes))
+            return;
+
+        view.request_internal_page_info(type)->when_resolved([&event_loop](auto const& text) {
+            outln("{}", text);
+            event_loop.quit(0);
+        });
+    };
+
+    view.load(url);
+}
+
+ErrorOr<int> Application::execute()
+{
+    OwnPtr<HeadlessWebView> view;
+    RefPtr<Core::Timer> screenshot_timer;
+
+    if (m_browser_options.headless_mode.has_value()) {
+        auto theme_path = LexicalPath::join(WebView::s_ladybird_resource_root, "themes"sv, "Default.ini"sv);
+        auto theme = TRY(Gfx::load_system_theme(theme_path.string()));
+
+        view = HeadlessWebView::create(move(theme), { m_browser_options.window_width, m_browser_options.window_height });
+
+        if (!m_browser_options.webdriver_content_ipc_path.has_value()) {
+            if (m_browser_options.urls.size() != 1)
+                return Error::from_string_literal("Headless mode currently only supports exactly one URL");
+
+            switch (*m_browser_options.headless_mode) {
+            case HeadlessMode::Screenshot:
+                screenshot_timer = load_page_for_screenshot_and_exit(*m_event_loop, *view, m_browser_options.urls.first(), 1);
+                break;
+            case HeadlessMode::LayoutTree:
+                load_page_for_info_and_exit(*m_event_loop, *view, m_browser_options.urls.first(), WebView::PageInfoType::LayoutTree | WebView::PageInfoType::PaintTree);
+                break;
+            case HeadlessMode::Text:
+                load_page_for_info_and_exit(*m_event_loop, *view, m_browser_options.urls.first(), WebView::PageInfoType::Text);
+                break;
+            case HeadlessMode::Test:
+                VERIFY_NOT_REACHED();
+            }
+        }
+    }
+
+    int ret = m_event_loop->exec();
    m_in_shutdown = true;
    return ret;
 }

+NonnullOwnPtr<Core::EventLoop> Application::create_platform_event_loop()
+{
+    return make<Core::EventLoop>();
+}
+
 void Application::add_child_process(WebView::Process&& process)
 {
    m_process_manager.add_process(move(process));