blob: 65f6a534d35bed6b0fd543b69e843511c60e9d39 [file] [log] [blame]
// 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/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 {
// 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 =
(language != NULL && *language != '\0') ? language : "und";
if (country != NULL && *country != '\0') {
result += '-';
result += country;
}
if (variant != NULL && *variant != '\0') {
std::string variant_str(variant);
StringToLowerASCII(&variant_str);
result += '@' + variant_str;
}
return result;
}
} // namespace
namespace base {
namespace i18n {
// Represents the locale-specific ICU text direction.
static TextDirection g_icu_text_direction = UNKNOWN_DIRECTION;
// Convert the ICU default locale to a string.
std::string GetConfiguredLocale() {
return GetLocaleString(icu::Locale::getDefault());
}
// Convert the ICU canonicalized locale to a string.
std::string GetCanonicalLocale(const char* locale) {
return GetLocaleString(icu::Locale::createCanonical(locale));
}
// 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")) {
const icu::Locale& locale = icu::Locale::getDefault();
std::string language = locale.getLanguage();
const char* country = locale.getCountry();
if (LowerCaseEqualsASCII(language, "es") &&
!LowerCaseEqualsASCII(country, "es")) {
language += '-';
language += country;
return language;
}
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;
}
bool IsRTL() {
#if defined(TOOLKIT_GTK)
GtkTextDirection gtk_dir = gtk_widget_get_default_direction();
return gtk_dir == GTK_TEXT_DIR_RTL;
#else
return ICUIsRTL();
#endif
}
bool ICUIsRTL() {
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 == RIGHT_TO_LEFT;
}
TextDirection GetTextDirectionForLocale(const char* locale_name) {
#if defined(__LB_SHELL__) || defined(OS_STARBOARD)
// lbshell does not have the icu tables needed to determine RTL-ness.
// Rather than beef up our icu tables, hard-code the list of RTL languages
// that Chrome supports. RTL layout is implemented by other components,
// so this does not affect our ability to do RTL layout nor RTL text.
return (!strncmp(locale_name, "he", 2) ||
!strncmp(locale_name, "ar", 2) ||
!strncmp(locale_name, "iw", 2) ||
!strncmp(locale_name, "fa", 2) ||
!strncmp(locale_name, "ur", 2))
? RIGHT_TO_LEFT : LEFT_TO_RIGHT;
#else
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;
#endif
}
TextDirection GetFirstStrongCharacterDirection(const string16& text) {
const UChar* string = text.c_str();
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;
}
#if defined(OS_WIN)
bool AdjustStringForLocaleDirection(string16* text) {
if (!IsRTL() || text->empty())
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.
bool has_rtl_chars = StringContainsStrongRTLChars(*text);
if (!has_rtl_chars)
WrapStringWithLTRFormatting(text);
else
WrapStringWithRTLFormatting(text);
return true;
}
bool UnadjustStringForLocaleDirection(string16* text) {
if (!IsRTL() || text->empty())
return false;
*text = StripWrappingBidiControlCharacters(*text);
return true;
}
#else
bool AdjustStringForLocaleDirection(string16* text) {
// On OS X & GTK the directionality of a label is determined by the first
// strongly directional character.
// However, we want to make sure that in an LTR-language-UI all strings are
// left aligned and vice versa.
// A problem can arise if we display a string which starts with user input.
// User input may be of the opposite directionality to the UI. So the whole
// string will be displayed in the opposite directionality, e.g. if we want to
// display in an LTR UI [such as US English]:
//
// EMAN_NOISNETXE is now installed.
//
// Since EXTENSION_NAME begins with a strong RTL char, the label's
// directionality will be set to RTL and the string will be displayed visually
// as:
//
// .is now installed EMAN_NOISNETXE
//
// In order to solve this issue, we prepend an LRM to the string. An LRM is a
// strongly directional LTR char.
// We also append an LRM at the end, which ensures that we're in an LTR
// context.
// Unlike Windows, Linux and OS X can correctly display RTL glyphs out of the
// box so there is no issue with displaying zero-width bidi control characters
// on any system. Thus no need for the !IsRTL() check here.
if (text->empty())
return false;
bool ui_direction_is_rtl = IsRTL();
bool has_rtl_chars = StringContainsStrongRTLChars(*text);
if (!ui_direction_is_rtl && has_rtl_chars) {
WrapStringWithRTLFormatting(text);
text->insert(0U, 1U, kLeftToRightMark);
text->push_back(kLeftToRightMark);
} else if (ui_direction_is_rtl && has_rtl_chars) {
WrapStringWithRTLFormatting(text);
text->insert(0U, 1U, kRightToLeftMark);
text->push_back(kRightToLeftMark);
} else if (ui_direction_is_rtl) {
WrapStringWithLTRFormatting(text);
text->insert(0U, 1U, kRightToLeftMark);
text->push_back(kRightToLeftMark);
} else {
return false;
}
return true;
}
bool UnadjustStringForLocaleDirection(string16* text) {
if (text->empty())
return false;
size_t begin_index = 0;
char16 begin = text->at(begin_index);
if (begin == kLeftToRightMark ||
begin == kRightToLeftMark) {
++begin_index;
}
size_t end_index = text->length() - 1;
char16 end = text->at(end_index);
if (end == kLeftToRightMark ||
end == kRightToLeftMark) {
--end_index;
}
string16 unmarked_text =
text->substr(begin_index, end_index - begin_index + 1);
*text = StripWrappingBidiControlCharacters(unmarked_text);
return true;
}
#endif // !OS_WIN
bool StringContainsStrongRTLChars(const string16& text) {
const UChar* string = text.c_str();
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(string16* text) {
if (text->empty())
return;
// Inserting an LRE (Left-To-Right Embedding) mark as the first character.
text->insert(0U, 1U, kLeftToRightEmbeddingMark);
// Inserting a PDF (Pop Directional Formatting) mark as the last character.
text->push_back(kPopDirectionalFormatting);
}
void WrapStringWithRTLFormatting(string16* text) {
if (text->empty())
return;
// Inserting an RLE (Right-To-Left Embedding) mark as the first character.
text->insert(0U, 1U, kRightToLeftEmbeddingMark);
// Inserting a PDF (Pop Directional Formatting) mark as the last character.
text->push_back(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);
}
string16 GetDisplayStringInLTRDirectionality(const string16& text) {
// Always wrap the string in RTL UI (it may be appended to RTL string).
// Also wrap strings with an RTL first strong character direction in LTR UI.
if (IsRTL() || GetFirstStrongCharacterDirection(text) == RIGHT_TO_LEFT) {
string16 text_mutable(text);
WrapStringWithLTRFormatting(&text_mutable);
return text_mutable;
}
return text;
}
string16 StripWrappingBidiControlCharacters(const string16& text) {
if (text.empty())
return text;
size_t begin_index = 0;
char16 begin = text[begin_index];
if (begin == kLeftToRightEmbeddingMark ||
begin == kRightToLeftEmbeddingMark ||
begin == kLeftToRightOverride ||
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