Support XCode's "Right to Left Pseudolanguage" on iOS.

base/i18n/rtl.cc

 // Copyright (c) 2011 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/i18n/rtl.h"
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "third_party/icu/source/common/unicode/locid.h"
 #include "third_party/icu/source/common/unicode/uchar.h"
 #include "third_party/icu/source/common/unicode/uscript.h"
 #include "third_party/icu/source/i18n/unicode/coll.h"
 
+#if defined(OS_IOS)
+#include "base/ios/ios_util.h"
+#endif
+
 namespace {
 
 // Extract language, country and variant, but ignore keywords.  For example,
 // en-US, ca@valencia, ca-ES@valencia.
 std::string GetLocaleString(const icu::Locale& locale) {
   const char* language = locale.getLanguage();
   const char* country = locale.getCountry();
   const char* variant = locale.getVariant();
 
   std::string result =
@@ skipping 106 matching lines @@
 TextDirection GetTextDirectionForLocale(const char* locale_name) {
   const std::string group_name =
       FieldTrialList::FindFullName("LightSpeed");
   // StartsWith allows flexibility for this experiment to apply to multiple
   // group names. To start, this will apply to AvoidMMapOnStartup.
   if (StartsWith(group_name, "AvoidMMap", CompareCase::SENSITIVE)) {
     static const char kEnglishLocale[] = "en_";
     if (StartsWith(locale_name, kEnglishLocale, CompareCase::SENSITIVE))
       return LEFT_TO_RIGHT;
   }
+
+  // On iOS, check for RTL forcing.
+#if defined(OS_IOS)
+  if (ios::IsInForcedRTL())
+    return RIGHT_TO_LEFT;
+#endif
+
   UErrorCode status = U_ZERO_ERROR;
   ULayoutType layout_dir = uloc_getCharacterOrientation(locale_name, &status);
   DCHECK(U_SUCCESS(status));
   // Treat anything other than RTL as LTR.
   return (layout_dir != ULOC_LAYOUT_RTL) ? LEFT_TO_RIGHT : RIGHT_TO_LEFT;
 }
 
 TextDirection GetFirstStrongCharacterDirection(const string16& text) {
   const UChar* string = text.c_str();
   size_t length = text.length();
@@ skipping 241 matching lines @@
       begin == kRightToLeftOverride)
     ++begin_index;
   size_t end_index = text.length() - 1;
   if (text[end_index] == kPopDirectionalFormatting)
     --end_index;
   return text.substr(begin_index, end_index - begin_index + 1);
 }
 
 }  // namespace i18n
 }  // namespace base