LibWeb: Make preferred languages configurable

This also changes fetch to use the preferred languages for the
Accept-Language header.

Userland/Libraries/LibWeb/Fetch/Fetching/Fetching.cpp

@@ -235,7 +235,10 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Infrastructure::FetchController>> fetch(JS:
     // 14. If request’s header list does not contain `Accept-Language`, then user agents should append
     //     (`Accept-Language, an appropriate header value) to request’s header list.
     if (!request.header_list()->contains("Accept-Language"sv.bytes())) {
-        auto header = Infrastructure::Header::from_string_pair("Accept-Language"sv, "*"sv);
+        StringBuilder accept_language;
+        accept_language.join(","sv, ResourceLoader::the().preferred_languages());
+
+        auto header = Infrastructure::Header::from_string_pair("Accept-Language"sv, accept_language.string_view());
         request.header_list()->append(move(header));
     }
 

Userland/Libraries/LibWeb/HTML/NavigatorLanguage.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2022, Andrew Kaster <akaster@serenityos.org>
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -8,21 +9,17 @@
 
 #include <AK/String.h>
 #include <AK/Vector.h>
+#include <LibWeb/Loader/ResourceLoader.h>
 
 namespace Web::HTML {
 
 class NavigatorLanguageMixin {
 public:
     // https://html.spec.whatwg.org/multipage/system-state.html#dom-navigator-language
-    String language() const { return m_current_preferred_languages[0]; }
+    String language() const { return ResourceLoader::the().preferred_languages()[0]; }
 
     // https://html.spec.whatwg.org/multipage/system-state.html#dom-navigator-languages
-    // FIXME: The same object must be returned until the user agent needs to return different values, or values in a
-    //        different order.
-    Vector<String> languages() const { return m_current_preferred_languages; }
-
-protected:
-    Vector<String> m_current_preferred_languages = { "en-US"_string };
+    Vector<String> languages() const { return ResourceLoader::the().preferred_languages(); }
 };
 
 }

Userland/Libraries/LibWeb/Loader/ResourceLoader.cpp

@@ -59,6 +59,7 @@ ResourceLoader::ResourceLoader(NonnullRefPtr<ResourceLoaderConnector> connector)
     : m_connector(move(connector))
     , m_user_agent(MUST(String::from_utf8(default_user_agent)))
     , m_platform(MUST(String::from_utf8(default_platform)))
+    , m_preferred_languages({ "en-US"_string })
     , m_navigator_compatibility_mode(default_navigator_compatibility_mode)
 {
 }

Userland/Libraries/LibWeb/Loader/ResourceLoader.h

@@ -100,6 +100,9 @@ public:
     String const& platform() const { return m_platform; }
     void set_platform(String platform) { m_platform = move(platform); }
 
+    Vector<String> preferred_languages() const { return m_preferred_languages; }
+    void set_preferred_languages(Vector<String> preferred_languages) { m_preferred_languages = move(preferred_languages); }
+
     NavigatorCompatibilityMode navigator_compatibility_mode() { return m_navigator_compatibility_mode; }
     void set_navigator_compatibility_mode(NavigatorCompatibilityMode mode) { m_navigator_compatibility_mode = mode; }
 
@@ -123,6 +126,7 @@ private:
     NonnullRefPtr<ResourceLoaderConnector> m_connector;
     String m_user_agent;
     String m_platform;
+    Vector<String> m_preferred_languages;
     NavigatorCompatibilityMode m_navigator_compatibility_mode;
     bool m_enable_do_not_track { false };
     Optional<JS::GCPtr<Page>> m_page {};

Userland/Libraries/LibWebView/ViewImplementation.cpp

@@ -169,6 +169,11 @@ void ViewImplementation::set_preferred_motion(Web::CSS::PreferredMotion motion)
     client().async_set_preferred_motion(page_id(), motion);
 }
 
+void ViewImplementation::set_preferred_languages(Vector<String> preferred_languages)
+{
+    client().async_set_preferred_languages(page_id(), move(preferred_languages));
+}
+
 void ViewImplementation::set_enable_do_not_track(bool enable)
 {
     client().async_set_enable_do_not_track(page_id(), enable);

Userland/Libraries/LibWebView/ViewImplementation.h

@@ -66,6 +66,8 @@ public:
     void set_preferred_contrast(Web::CSS::PreferredContrast);
     void set_preferred_motion(Web::CSS::PreferredMotion);
 
+    void set_preferred_languages(Vector<String>);
+
     void set_enable_do_not_track(bool);
 
     ByteString selected_text();

Userland/Services/WebContent/ConnectionFromClient.cpp

@@ -946,6 +946,15 @@ void ConnectionFromClient::set_preferred_motion(u64 page_id, Web::CSS::Preferred
         page->set_preferred_motion(motion);
 }
 
+void ConnectionFromClient::set_preferred_languages(u64, Vector<String> const& preferred_languages)
+{
+    // FIXME: Whenever the user agent needs to make the navigator.languages attribute of a Window or WorkerGlobalScope
+    // object global return a new set of language tags, the user agent must queue a global task on the DOM manipulation
+    // task source given global to fire an event named languagechange at global, and wait until that task begins to be
+    // executed before actually returning a new value.
+    Web::ResourceLoader::the().set_preferred_languages(preferred_languages);
+}
+
 void ConnectionFromClient::set_enable_do_not_track(u64, bool enable)
 {
     Web::ResourceLoader::the().set_enable_do_not_track(enable);

Userland/Services/WebContent/ConnectionFromClient.h

@@ -95,6 +95,7 @@ private:
     virtual void set_preferred_color_scheme(u64 page_id, Web::CSS::PreferredColorScheme const&) override;
     virtual void set_preferred_contrast(u64 page_id, Web::CSS::PreferredContrast const&) override;
     virtual void set_preferred_motion(u64 page_id, Web::CSS::PreferredMotion const&) override;
+    virtual void set_preferred_languages(u64 page_id, Vector<String> const&) override;
     virtual void set_enable_do_not_track(u64 page_id, bool) override;
     virtual void set_has_focus(u64 page_id, bool) override;
     virtual void set_is_scripting_enabled(u64 page_id, bool) override;

Userland/Services/WebContent/WebContentServer.ipc

@@ -81,6 +81,7 @@ endpoint WebContentServer
     set_preferred_color_scheme(u64 page_id, Web::CSS::PreferredColorScheme color_scheme) =|
     set_preferred_contrast(u64 page_id, Web::CSS::PreferredContrast contrast) =|
     set_preferred_motion(u64 page_id, Web::CSS::PreferredMotion motion) =|
+    set_preferred_languages(u64 page_id, Vector<String> preferred_languages) =|
     set_enable_do_not_track(u64 page_id, bool enable) =|
     set_has_focus(u64 page_id, bool has_focus) =|
     set_is_scripting_enabled(u64 page_id, bool is_scripting_enabled) =|