The UI language rather than the locale is now used to pick Chrome's language ...

base/win/i18n.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/win/i18n.h"
+
+#include <windows.h>
+
+#include "base/logging.h"
+
+namespace {
+
+// Keep this enum in sync with kLanguageFunctionNames.
+enum LanguageFunction {
+  SYSTEM_LANGUAGES,
+  USER_LANGUAGES,
+  PROCESS_LANGUAGES,
+  THREAD_LANGUAGES,
+  NUM_FUNCTIONS
+};
+
+const char kSystemLanguagesFunctionName[] = "GetSystemPreferredUILanguages";
+const char kUserLanguagesFunctionName[] = "GetUserPreferredUILanguages";
+const char kProcessLanguagesFunctionName[] = "GetProcessPreferredUILanguages";
+const char kThreadLanguagesFunctionName[] = "GetThreadPreferredUILanguages";
+
+// Keep this array in sync with enum LanguageFunction.
+const char *const kLanguageFunctionNames[] = {
+  &kSystemLanguagesFunctionName[0],
+  &kUserLanguagesFunctionName[0],
+  &kProcessLanguagesFunctionName[0],
+  &kThreadLanguagesFunctionName[0]
+};
+
+COMPILE_ASSERT(NUM_FUNCTIONS == arraysize(kLanguageFunctionNames),
+               language_function_enum_and_names_out_of_sync);
+
+// Calls one of the MUI Get*PreferredUILanguages functions, placing the result
+// in |languages|.  |function| identifies the function to call and |flags| is
+// the function-specific flags (callers must not specify MUI_LANGUAGE_ID or
+// MUI_LANGUAGE_NAME).  Returns true if at least one language is placed in
+// |languages|.
+bool GetMUIPreferredUILanguageList(LanguageFunction function, ULONG flags,
+                                   std::vector<wchar_t>* languages) {
+  DCHECK(0 <= function && NUM_FUNCTIONS > function);
+  DCHECK_EQ(0U, (flags & (MUI_LANGUAGE_ID | MUI_LANGUAGE_NAME)));
+  DCHECK(languages);
+
+  HMODULE kernel32 = GetModuleHandle(L"kernel32.dll");
+  if (NULL != kernel32) {
+    typedef BOOL (WINAPI* GetPreferredUILanguages_Fn)(
+        DWORD, PULONG, PZZWSTR, PULONG);
+    GetPreferredUILanguages_Fn get_preferred_ui_languages =
+        reinterpret_cast<GetPreferredUILanguages_Fn>(
+            GetProcAddress(kernel32, kLanguageFunctionNames[function]));
+    if (NULL != get_preferred_ui_languages) {
+      const ULONG call_flags = flags | MUI_LANGUAGE_NAME;
+      ULONG language_count = 0;
+      ULONG buffer_length = 0;
+      if (get_preferred_ui_languages(call_flags, &language_count, NULL,
+                                     &buffer_length) &&
+          0 != buffer_length) {
+        languages->resize(buffer_length);
+        if (get_preferred_ui_languages(call_flags, &language_count,
+                                       &(*languages)[0], &buffer_length) &&
+            0 != language_count) {
+          DCHECK(languages->size() == buffer_length);
+          return true;
+        } else {
+          DPCHECK(0 == language_count)
+              << "Failed getting preferred UI languages.";
+        }
+      } else {
+        DPCHECK(0 == buffer_length)
+            << "Failed getting size of preferred UI languages.";
+      }
+    } else {
+      VLOG(2) << "MUI not available.";
+    }
+  } else {
+    NOTREACHED() << "kernel32.dll not found.";
+  }
+
+  return false;
+}
+
+bool GetUserDefaultUILanguage(std::wstring* language, std::wstring* region) {
+  DCHECK(language);
+
+  LANGID lang_id = ::GetUserDefaultUILanguage();
+  if (LOCALE_CUSTOM_UI_DEFAULT != lang_id) {
+    const LCID locale_id = MAKELCID(lang_id, SORT_DEFAULT);
+    // max size for LOCALE_SISO639LANGNAME and LOCALE_SISO3166CTRYNAME is 9
+    wchar_t result_buffer[9];
+    int result_length =
+        GetLocaleInfo(locale_id, LOCALE_SISO639LANGNAME, &result_buffer[0],
+                      arraysize(result_buffer));
+    DPCHECK(0 != result_length) << "Failed getting language id";
+    if (1 < result_length) {
+      language->assign(&result_buffer[0], result_length - 1);
+      region->clear();
+      if (SUBLANG_NEUTRAL != SUBLANGID(lang_id)) {
+        result_length =
+            GetLocaleInfo(locale_id, LOCALE_SISO3166CTRYNAME, &result_buffer[0],
+                          arraysize(result_buffer));
+        DPCHECK(0 != result_length) << "Failed getting region id";
+        if (1 < result_length)
+          region->assign(&result_buffer[0], result_length - 1);
+      }
+      return true;
+    }
+  } else {
+    // This is entirely unexpected on pre-Vista, which is the only time we
+    // should try GetUserDefaultUILanguage anyway.
+    NOTREACHED() << "Cannot determine language for a supplemental locale.";
+  }
+  return false;
+}
+
+bool GetPreferredUILanguageList(LanguageFunction function, ULONG flags,
+                                std::vector<std::wstring>* languages) {
+  std::vector<wchar_t> buffer;
+  std::wstring language;
+  std::wstring region;
+
+  if (GetMUIPreferredUILanguageList(function, flags, &buffer)) {
+    std::vector<wchar_t>::const_iterator scan = buffer.begin();
+    language.assign(&*scan);
+    while (!language.empty()) {
+      languages->push_back(language);
+      scan += language.size() + 1;
+      language.assign(&*scan);
+    }
+  } else if (GetUserDefaultUILanguage(&language, &region)) {
+    // Mimic the MUI behavior of putting the neutral version of the lang after
+    // the regional one (e.g., "fr-CA, fr").
+    if (!region.empty())
+      languages->push_back(std::wstring(language)
+                               .append(1, L'-')
+                               .append(region));
+    languages->push_back(language);
+  } else {
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace
+
+namespace base {
+namespace win {
+namespace i18n {
+
+bool GetUserPreferredUILanguageList(std::vector<std::wstring>* languages) {
+  DCHECK(languages);
+  return GetPreferredUILanguageList(USER_LANGUAGES, 0, languages);
+}
+
+bool GetThreadPreferredUILanguageList(std::vector<std::wstring>* languages) {
+  DCHECK(languages);
+  return GetPreferredUILanguageList(
+      THREAD_LANGUAGES, MUI_MERGE_SYSTEM_FALLBACK | MUI_MERGE_USER_FALLBACK,
+      languages);
+}
+
+}  // namespace i18n
+}  // namespace win
+}  // namespace base