headless-browser: Add a mode to dump the layout tree after load finish

Userland/Utilities/headless-browser.cpp

@@ -13,6 +13,7 @@
 
 #include <AK/Badge.h>
 #include <AK/DeprecatedString.h>
+#include <AK/Function.h>
 #include <AK/LexicalPath.h>
 #include <AK/NonnullOwnPtr.h>
 #include <AK/String.h>
@@ -74,6 +75,13 @@ class HeadlessWebContentView final : public WebView::ViewImplementation {
  return client().take_document_screenshot().bitmap();
  }
 
+ ErrorOr<String> dump_layout_tree()
+ {
+ return String::from_deprecated_string(client().dump_layout_tree());
+ }
+
+ Function<void(const URL&)> on_load_finish;
+
 private:
  HeadlessWebContentView() = default;
 
@@ -93,7 +101,13 @@ class HeadlessWebContentView final : public WebView::ViewImplementation {
  void notify_server_did_click_link(Badge<WebView::WebContentClient>, const URL&, DeprecatedString const&, unsigned) override { }
  void notify_server_did_middle_click_link(Badge<WebView::WebContentClient>, const URL&, DeprecatedString const&, unsigned) override { }
  void notify_server_did_start_loading(Badge<WebView::WebContentClient>, const URL&, bool) override { }
- void notify_server_did_finish_loading(Badge<WebView::WebContentClient>, const URL&) override { }
+
+ void notify_server_did_finish_loading(Badge<WebView::WebContentClient>, const URL& url) override
+ {
+ if (on_load_finish)
+ on_load_finish(url);
+ }
+
  void notify_server_did_request_navigate_back(Badge<WebView::WebContentClient>) override { }
  void notify_server_did_request_navigate_forward(Badge<WebView::WebContentClient>) override { }
  void notify_server_did_request_refresh(Badge<WebView::WebContentClient>) override { }
@@ -195,10 +209,12 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
  StringView url;
  auto resources_folder = "/res"sv;
  StringView web_driver_ipc_path;
+ bool dump_layout_tree = false;
 
  Core::ArgsParser args_parser;
  args_parser.set_general_help("This utility runs the Browser in headless mode.");
  args_parser.add_option(screenshot_timeout, "Take a screenshot after [n] seconds (default: 1)", "screenshot", 's', "n");
+ args_parser.add_option(dump_layout_tree, "Dump layout tree and exit", "dump-layout-tree", 'd');
  args_parser.add_option(resources_folder, "Path of the base resources folder (defaults to /res)", "resources", 'r', "resources-root-path");
  args_parser.add_option(web_driver_ipc_path, "Path to the WebDriver IPC socket", "webdriver-ipc-path", 0, "path");
  args_parser.add_positional_argument(url, "URL to open", "url", Core::ArgsParser::Required::Yes);
@@ -218,11 +234,21 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
  static constexpr Gfx::IntSize window_size { 800, 600 };
 
  auto view = TRY(HeadlessWebContentView::create(move(theme), window_size, web_driver_ipc_path));
- view->load(TRY(format_url(url)));
-
  RefPtr<Core::Timer> timer;
- if (web_driver_ipc_path.is_empty())
+
+ if (dump_layout_tree) {
+ view->on_load_finish = [&](auto const&) {
+ auto layout_tree = view->dump_layout_tree().release_value_but_fixme_should_propagate_errors();
+
+ outln("{}", layout_tree);
+ fflush(stdout);
+
+ event_loop.quit(0);
+ };
+ } else if (web_driver_ipc_path.is_empty()) {
  timer = TRY(load_page_for_screenshot_and_exit(event_loop, *view, screenshot_timeout));
+ }
 
+ view->load(TRY(format_url(url)));
  return event_loop.exec();
 }