Move RTL related functions from app/l10n_util to base/i18n/rtl...

base/i18n/rtl.cc

Index: base/i18n/rtl.cc
===================================================================
--- base/i18n/rtl.cc	(revision 0)
+++ base/i18n/rtl.cc	(revision 0)
@@ -0,0 +1,228 @@
+// 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/i18n/rtl.h"
+
+#include "base/file_path.h"
+#include "base/logging.h"
+#include "base/string_util.h"
+#include "base/utf_string_conversions.h"
+#include "base/sys_string_conversions.h"
+#include "unicode/coll.h"
+#include "unicode/locid.h"
+#include "unicode/uchar.h"
+#include "unicode/uscript.h"
+
+#if defined(TOOLKIT_GTK)
+#include <gtk/gtk.h>
+#endif
+
+namespace base {
+namespace i18n {
+
+// Represents the locale-specific ICU text direction.
+static TextDirection g_icu_text_direction = UNKNOWN_DIRECTION;
+
+void GetLanguageAndRegionFromOS(std::string* lang, std::string* region) {
+  // Later we may have to change this to be OS-dependent so that
+  // it's not affected by ICU's default locale. It's all right
+  // to do this way because SetICUDefaultLocale is internal
+  // to this file and we know that it's not yet called when this function
+  // is called.
+  icu::Locale locale = icu::Locale::getDefault();
+  const char* language = locale.getLanguage();
+  const char* country = locale.getCountry();
+  DCHECK(language);
+  *lang = language;
+  *region = country;
+}
+
+// Convert Chrome locale name to ICU locale name
+std::string ICULocaleName(const std::string& locale_string) {
+  // If not Spanish, just return it.
+  if (locale_string.substr(0, 2) != "es")
+    return locale_string;
+  // Expand es to es-ES.
+  if (LowerCaseEqualsASCII(locale_string, "es"))
+    return "es-ES";
+  // Map es-419 (Latin American Spanish) to es-FOO depending on the system
+  // locale.  If it's es-RR other than es-ES, map to es-RR. Otherwise, map
+  // to es-MX (the most populous in Spanish-speaking Latin America).
+  if (LowerCaseEqualsASCII(locale_string, "es-419")) {
+    std::string lang, region;
+    GetLanguageAndRegionFromOS(&lang, &region);
+    if (LowerCaseEqualsASCII(lang, "es") &&
+      !LowerCaseEqualsASCII(region, "es")) {
+        lang.append("-");
+        lang.append(region);
+        return lang;
+    }
+    return "es-MX";
+  }
+  // Currently, Chrome has only "es" and "es-419", but later we may have
+  // more specific "es-RR".
+  return locale_string;
+}
+
+void SetICUDefaultLocale(const std::string& locale_string) {
+  icu::Locale locale(ICULocaleName(locale_string).c_str());
+  UErrorCode error_code = U_ZERO_ERROR;
+  icu::Locale::setDefault(locale, error_code);
+  // This return value is actually bogus because Locale object is
+  // an ID and setDefault seems to always succeed (regardless of the
+  // presence of actual locale data). However,
+  // it does not hurt to have it as a sanity check.
+  DCHECK(U_SUCCESS(error_code));
+  g_icu_text_direction = UNKNOWN_DIRECTION;
+}
+
+TextDirection GetICUTextDirection() {
+  if (g_icu_text_direction == UNKNOWN_DIRECTION) {
+    const icu::Locale& locale = icu::Locale::getDefault();
+    g_icu_text_direction = GetTextDirectionForLocale(locale.getName());
+  }
+  return g_icu_text_direction;
+}
+
+TextDirection GetTextDirection() {
+#if defined(TOOLKIT_GTK)
+  GtkTextDirection gtk_dir = gtk_widget_get_default_direction();
+  return (gtk_dir == GTK_TEXT_DIR_LTR) ? LEFT_TO_RIGHT : RIGHT_TO_LEFT;
+#else
+  return GetICUTextDirection();
+#endif
+}
+
+bool IsRTL() {
+  return GetTextDirection() == RIGHT_TO_LEFT;
+}
+
+TextDirection GetTextDirectionForLocale(const char* locale_name) {
+  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 std::wstring& text) {
+#if defined(WCHAR_T_IS_UTF32)
+  string16 text_utf16 = WideToUTF16(text);
+  const UChar* string = text_utf16.c_str();
+#else
+  const UChar* string = text.c_str();
+#endif
+  size_t length = text.length();
+  size_t position = 0;
+  while (position < length) {
+    UChar32 character;
+    size_t next_position = position;
+    U16_NEXT(string, next_position, length, character);
+
+    // Now that we have the character, we use ICU in order to query for the
+    // appropriate Unicode BiDi character type.
+    int32_t property = u_getIntPropertyValue(character, UCHAR_BIDI_CLASS);
+    if ((property == U_RIGHT_TO_LEFT) ||
+        (property == U_RIGHT_TO_LEFT_ARABIC) ||
+        (property == U_RIGHT_TO_LEFT_EMBEDDING) ||
+        (property == U_RIGHT_TO_LEFT_OVERRIDE)) {
+      return RIGHT_TO_LEFT;
+    } else if ((property == U_LEFT_TO_RIGHT) ||
+               (property == U_LEFT_TO_RIGHT_EMBEDDING) ||
+               (property == U_LEFT_TO_RIGHT_OVERRIDE)) {
+      return LEFT_TO_RIGHT;
+    }
+
+    position = next_position;
+  }
+
+  return LEFT_TO_RIGHT;
+}
+
+bool AdjustStringForLocaleDirection(const std::wstring& text,
+                                    std::wstring* localized_text) {
+  if (GetTextDirection() == LEFT_TO_RIGHT || text.length() == 0)
+    return false;
+
+  // Marking the string as LTR if the locale is RTL and the string does not
+  // contain strong RTL characters. Otherwise, mark the string as RTL.
+  *localized_text = text;
+  bool has_rtl_chars = StringContainsStrongRTLChars(text);
+  if (!has_rtl_chars)
+    WrapStringWithLTRFormatting(localized_text);
+  else
+    WrapStringWithRTLFormatting(localized_text);
+
+  return true;
+}
+
+bool StringContainsStrongRTLChars(const std::wstring& text) {
+#if defined(WCHAR_T_IS_UTF32)
+  string16 text_utf16 = WideToUTF16(text);
+  const UChar* string = text_utf16.c_str();
+#else
+  const UChar* string = text.c_str();
+#endif
+  size_t length = text.length();
+  size_t position = 0;
+  while (position < length) {
+    UChar32 character;
+    size_t next_position = position;
+    U16_NEXT(string, next_position, length, character);
+
+    // Now that we have the character, we use ICU in order to query for the
+    // appropriate Unicode BiDi character type.
+    int32_t property = u_getIntPropertyValue(character, UCHAR_BIDI_CLASS);
+    if ((property == U_RIGHT_TO_LEFT) || (property == U_RIGHT_TO_LEFT_ARABIC))
+      return true;
+
+    position = next_position;
+  }
+
+  return false;
+}
+
+void WrapStringWithLTRFormatting(std::wstring* text) {
+  // Inserting an LRE (Left-To-Right Embedding) mark as the first character.
+  text->insert(0, 1, static_cast<wchar_t>(kLeftToRightEmbeddingMark));
+
+  // Inserting a PDF (Pop Directional Formatting) mark as the last character.
+  text->push_back(static_cast<wchar_t>(kPopDirectionalFormatting));
+}
+
+void WrapStringWithRTLFormatting(std::wstring* text) {
+  // Inserting an RLE (Right-To-Left Embedding) mark as the first character.
+  text->insert(0, 1, static_cast<wchar_t>(kRightToLeftEmbeddingMark));
+
+  // Inserting a PDF (Pop Directional Formatting) mark as the last character.
+  text->push_back(static_cast<wchar_t>(kPopDirectionalFormatting));
+}
+
+void WrapPathWithLTRFormatting(const FilePath& path,
+                               string16* rtl_safe_path) {
+  // Wrap the overall path with LRE-PDF pair which essentialy marks the
+  // string as a Left-To-Right string.
+  // Inserting an LRE (Left-To-Right Embedding) mark as the first character.
+  rtl_safe_path->push_back(kLeftToRightEmbeddingMark);
+#if defined(OS_MACOSX)
+    rtl_safe_path->append(UTF8ToUTF16(path.value()));
+#elif defined(OS_WIN)
+    rtl_safe_path->append(path.value());
+#else  // defined(OS_POSIX) && !defined(OS_MACOSX)
+    std::wstring wide_path = base::SysNativeMBToWide(path.value());
+    rtl_safe_path->append(WideToUTF16(wide_path));
+#endif
+  // Inserting a PDF (Pop Directional Formatting) mark as the last character.
+  rtl_safe_path->push_back(kPopDirectionalFormatting);
+}
+
+std::wstring GetDisplayStringInLTRDirectionality(std::wstring* text) {
+  if (GetTextDirection() == RIGHT_TO_LEFT)
+    WrapStringWithLTRFormatting(text);
+  return *text;
+}
+
+}  // namespace i18n
+}  // namespace base
+