rtl.h revision 5821806d5e7f356e8fa4b058a389a808ea183019
1e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Copyright (c) 2011 The Chromium Authors. All rights reserved. 2e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Use of this source code is governed by a BSD-style license that can be 3e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// found in the LICENSE file. 4e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 5e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith#ifndef BASE_I18N_RTL_H_ 6e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith#define BASE_I18N_RTL_H_ 7e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 8e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith#include <string> 9e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 10e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith#include "base/compiler_specific.h" 11e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith#include "base/i18n/base_i18n_export.h" 12e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith#include "base/string16.h" 134874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko#include "build/build_config.h" 14e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 15e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithclass FilePath; 16e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 17e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithnamespace base { 18e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithnamespace i18n { 19e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 20e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithconst char16 kRightToLeftMark = 0x200F; 21e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithconst char16 kLeftToRightMark = 0x200E; 22e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithconst char16 kLeftToRightEmbeddingMark = 0x202A; 23e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithconst char16 kRightToLeftEmbeddingMark = 0x202B; 24e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithconst char16 kPopDirectionalFormatting = 0x202C; 25e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithconst char16 kLeftToRightOverride = 0x202D; 26e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithconst char16 kRightToLeftOverride = 0x202E; 27e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 28e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smithenum TextDirection { 29e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith UNKNOWN_DIRECTION, 30e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith RIGHT_TO_LEFT, 31e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith LEFT_TO_RIGHT, 32e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith}; 33e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 34e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Get the locale that the currently running process has been configured to use. 35e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// The return value is of the form language[-country] (e.g., en-US) where the 36a189d8976f1193b788508a1a29b2e9d0aca06acaAlexander Kornienko// language is the 2 or 3 letter code from ISO-639. 37e992ed1a065d857947b3969e6b779c41cc35c234Alexander KornienkoBASE_I18N_EXPORT std::string GetConfiguredLocale(); 38e992ed1a065d857947b3969e6b779c41cc35c234Alexander Kornienko 39a189d8976f1193b788508a1a29b2e9d0aca06acaAlexander Kornienko// Canonicalize a string (eg. a POSIX locale string) to a Chrome locale name. 40e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT std::string GetCanonicalLocale(const char* locale); 41c6dcea93b499b504da22f9921fc198423ad0b13bAlexander Kornienko 424874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko// Sets the default locale of ICU. 434874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko// Once the application locale of Chrome in GetApplicationLocale is determined, 44c6dcea93b499b504da22f9921fc198423ad0b13bAlexander Kornienko// the default locale of ICU need to be changed to match the application locale 454874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko// so that ICU functions work correctly in a locale-dependent manner. 464874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko// This is handy in that we don't have to call GetApplicationLocale() 47c6dcea93b499b504da22f9921fc198423ad0b13bAlexander Kornienko// everytime we call locale-dependent ICU APIs as long as we make sure 484874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko// that this is called before any locale-dependent API is called. 49c6dcea93b499b504da22f9921fc198423ad0b13bAlexander KornienkoBASE_I18N_EXPORT void SetICUDefaultLocale(const std::string& locale_string); 50c6dcea93b499b504da22f9921fc198423ad0b13bAlexander Kornienko 51c6dcea93b499b504da22f9921fc198423ad0b13bAlexander Kornienko// Returns true if the application text direction is right-to-left. 52e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT bool IsRTL(); 53e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 54e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Returns whether the text direction for the default ICU locale is RTL. This 55e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// assumes that SetICUDefaultLocale has been called to set the default locale to 56e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// the UI locale of Chrome. 57e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// NOTE: Generally, you should call IsRTL() instead of this. 58e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT bool ICUIsRTL(); 59e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 60e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Returns the text direction for |locale_name|. 61e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT TextDirection GetTextDirectionForLocale( 62e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith const char* locale_name); 63e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 64e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Given the string in |text|, returns the directionality of the first 65e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// character with strong directionality in the string. If no character in the 66e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// text has strong directionality, LEFT_TO_RIGHT is returned. The Bidi 67e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// character types L, LRE, LRO, R, AL, RLE, and RLO are considered as strong 68e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// directionality characters. Please refer to http://unicode.org/reports/tr9/ 69e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// for more information. 70e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT TextDirection GetFirstStrongCharacterDirection( 71e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith const string16& text); 72e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 73e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Given the string in |text|, this function modifies the string in place with 74e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// the appropriate Unicode formatting marks that mark the string direction 75e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// (either left-to-right or right-to-left). The function checks both the current 76e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// locale and the contents of the string in order to determine the direction of 77e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// the returned string. The function returns true if the string in |text| was 78e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// properly adjusted. 79e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// 80e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Certain LTR strings are not rendered correctly when the context is RTL. For 81e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// example, the string "Foo!" will appear as "!Foo" if it is rendered as is in 82e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// an RTL context. Calling this function will make sure the returned localized 83e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// string is always treated as a right-to-left string. This is done by 84e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// inserting certain Unicode formatting marks into the returned string. 85e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// 86e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// ** Notes about the Windows version of this function: 87e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// TODO(idana) bug 6806: this function adjusts the string in question only 88e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// if the current locale is right-to-left. The function does not take care of 89e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// the opposite case (an RTL string displayed in an LTR context) since 90e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// adjusting the string involves inserting Unicode formatting characters that 91e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Windows does not handle well unless right-to-left language support is 92e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// installed. Since the English version of Windows doesn't have right-to-left 93e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// language support installed by default, inserting the direction Unicode mark 94e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// results in Windows displaying squares. 95e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT bool AdjustStringForLocaleDirection(string16* text); 96e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 97e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Undoes the actions of the above function (AdjustStringForLocaleDirection). 98e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT bool UnadjustStringForLocaleDirection(string16* text); 99e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 100e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Returns true if the string contains at least one character with strong right 101e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// to left directionality; that is, a character with either R or AL Unicode 102e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// BiDi character type. 103e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT bool StringContainsStrongRTLChars(const string16& text); 104e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 105e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Wraps a string with an LRE-PDF pair which essentialy marks the string as a 106e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Left-To-Right string. Doing this is useful in order to make sure LTR 107e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// strings are rendered properly in an RTL context. 108e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT void WrapStringWithLTRFormatting(string16* text); 109e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 110e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Wraps a string with an RLE-PDF pair which essentialy marks the string as a 111e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Right-To-Left string. Doing this is useful in order to make sure RTL 112e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// strings are rendered properly in an LTR context. 113e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT void WrapStringWithRTLFormatting(string16* text); 114e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 115e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Wraps file path to get it to display correctly in RTL UI. All filepaths 116e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// should be passed through this function before display in UI for RTL locales. 117e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT void WrapPathWithLTRFormatting(const FilePath& path, 118e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith string16* rtl_safe_path); 119e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 120e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Return the string in |text| wrapped with LRE (Left-To-Right Embedding) and 121e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// PDF (Pop Directional Formatting) marks, if needed for UI display purposes. 122e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT string16 GetDisplayStringInLTRDirectionality( 123e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith const string16& text) WARN_UNUSED_RESULT; 124e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith 125e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// Strip the beginning (U+202A..U+202B, U+202D..U+202E) and/or ending (U+202C) 126e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// explicit bidi control characters from |text|, if there are any. Otherwise, 127e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// return the text itself. Explicit bidi control characters display and have 128e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// semantic effect. They can be deleted so they might not always appear in a 129e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith// pair. 130e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard SmithBASE_I18N_EXPORT string16 StripWrappingBidiControlCharacters( 131e0d3b4cd2b66f1cef26cacbed5820ab7c22ad5b3Richard Smith const string16& text) WARN_UNUSED_RESULT; 1324874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko 1334874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko} // namespace i18n 1344874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko} // namespace base 1354874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko 1364874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko#endif // BASE_I18N_RTL_H_ 1374874a8143dc3032205f97527ff619730db3d1f57Alexander Kornienko