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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_I18N_RTL_H_
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#define BASE_I18N_RTL_H_
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#include "base/compiler_specific.h"
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#include "base/i18n/base_i18n_export.h"
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#include "base/strings/string16.h"
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#include "build/build_config.h"
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const char16 kRightToLeftMark = 0x200F;
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const char16 kLeftToRightMark = 0x200E;
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const char16 kLeftToRightEmbeddingMark = 0x202A;
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const char16 kRightToLeftEmbeddingMark = 0x202B;
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const char16 kPopDirectionalFormatting = 0x202C;
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const char16 kLeftToRightOverride = 0x202D;
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const char16 kRightToLeftOverride = 0x202E;
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// Locale.java mirrored this enum TextDirection. Please keep in sync.
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UNKNOWN_DIRECTION = 0,
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TEXT_DIRECTION_NUM_DIRECTIONS = 3,
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// Get the locale that the currently running process has been configured to use.
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// The return value is of the form language[-country] (e.g., en-US) where the
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// language is the 2 or 3 letter code from ISO-639.
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BASE_I18N_EXPORT std::string GetConfiguredLocale();
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// Canonicalize a string (eg. a POSIX locale string) to a Chrome locale name.
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BASE_I18N_EXPORT std::string GetCanonicalLocale(const char* locale);
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// Sets the default locale of ICU.
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// Once the application locale of Chrome in GetApplicationLocale is determined,
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// the default locale of ICU need to be changed to match the application locale
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// so that ICU functions work correctly in a locale-dependent manner.
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// This is handy in that we don't have to call GetApplicationLocale()
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// everytime we call locale-dependent ICU APIs as long as we make sure
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// that this is called before any locale-dependent API is called.
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BASE_I18N_EXPORT void SetICUDefaultLocale(const std::string& locale_string);
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// Returns true if the application text direction is right-to-left.
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BASE_I18N_EXPORT bool IsRTL();
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// Returns whether the text direction for the default ICU locale is RTL. This
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// assumes that SetICUDefaultLocale has been called to set the default locale to
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// the UI locale of Chrome.
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// NOTE: Generally, you should call IsRTL() instead of this.
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BASE_I18N_EXPORT bool ICUIsRTL();
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// Returns the text direction for |locale_name|.
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BASE_I18N_EXPORT TextDirection GetTextDirectionForLocale(
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const char* locale_name);
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// Given the string in |text|, returns the directionality of the first or last
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// character with strong directionality in the string. If no character in the
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// text has strong directionality, LEFT_TO_RIGHT is returned. The Bidi
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// character types L, LRE, LRO, R, AL, RLE, and RLO are considered as strong
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// directionality characters. Please refer to http://unicode.org/reports/tr9/
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// for more information.
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BASE_I18N_EXPORT TextDirection GetFirstStrongCharacterDirection(
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const string16& text);
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BASE_I18N_EXPORT TextDirection GetLastStrongCharacterDirection(
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const string16& text);
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// Given the string in |text|, returns LEFT_TO_RIGHT or RIGHT_TO_LEFT if all the
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// strong directionality characters in the string are of the same
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// directionality. It returns UNKNOWN_DIRECTION if the string contains a mix of
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// LTR and RTL strong directionality characters. Defaults to LEFT_TO_RIGHT if
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// the string does not contain directionality characters. Please refer to
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// http://unicode.org/reports/tr9/ for more information.
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BASE_I18N_EXPORT TextDirection GetStringDirection(const string16& text);
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// Given the string in |text|, this function modifies the string in place with
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// the appropriate Unicode formatting marks that mark the string direction
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// (either left-to-right or right-to-left). The function checks both the current
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// locale and the contents of the string in order to determine the direction of
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// the returned string. The function returns true if the string in |text| was
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// Certain LTR strings are not rendered correctly when the context is RTL. For
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// example, the string "Foo!" will appear as "!Foo" if it is rendered as is in
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// an RTL context. Calling this function will make sure the returned localized
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// string is always treated as a right-to-left string. This is done by
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// inserting certain Unicode formatting marks into the returned string.
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// ** Notes about the Windows version of this function:
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// TODO(idana) bug 6806: this function adjusts the string in question only
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// if the current locale is right-to-left. The function does not take care of
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// the opposite case (an RTL string displayed in an LTR context) since
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// adjusting the string involves inserting Unicode formatting characters that
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// Windows does not handle well unless right-to-left language support is
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// installed. Since the English version of Windows doesn't have right-to-left
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// language support installed by default, inserting the direction Unicode mark
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// results in Windows displaying squares.
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BASE_I18N_EXPORT bool AdjustStringForLocaleDirection(string16* text);
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// Undoes the actions of the above function (AdjustStringForLocaleDirection).
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BASE_I18N_EXPORT bool UnadjustStringForLocaleDirection(string16* text);
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// Returns true if the string contains at least one character with strong right
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// to left directionality; that is, a character with either R or AL Unicode
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// BiDi character type.
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BASE_I18N_EXPORT bool StringContainsStrongRTLChars(const string16& text);
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// Wraps a string with an LRE-PDF pair which essentialy marks the string as a
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// Left-To-Right string. Doing this is useful in order to make sure LTR
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// strings are rendered properly in an RTL context.
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BASE_I18N_EXPORT void WrapStringWithLTRFormatting(string16* text);
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// Wraps a string with an RLE-PDF pair which essentialy marks the string as a
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// Right-To-Left string. Doing this is useful in order to make sure RTL
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// strings are rendered properly in an LTR context.
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BASE_I18N_EXPORT void WrapStringWithRTLFormatting(string16* text);
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// Wraps file path to get it to display correctly in RTL UI. All filepaths
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// should be passed through this function before display in UI for RTL locales.
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BASE_I18N_EXPORT void WrapPathWithLTRFormatting(const FilePath& path,
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string16* rtl_safe_path);
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// Return the string in |text| wrapped with LRE (Left-To-Right Embedding) and
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// PDF (Pop Directional Formatting) marks, if needed for UI display purposes.
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BASE_I18N_EXPORT string16 GetDisplayStringInLTRDirectionality(
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const string16& text) WARN_UNUSED_RESULT;
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// Strip the beginning (U+202A..U+202B, U+202D..U+202E) and/or ending (U+202C)
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// explicit bidi control characters from |text|, if there are any. Otherwise,
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// return the text itself. Explicit bidi control characters display and have
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// semantic effect. They can be deleted so they might not always appear in a
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BASE_I18N_EXPORT string16 StripWrappingBidiControlCharacters(
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const string16& text) WARN_UNUSED_RESULT;
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#endif // BASE_I18N_RTL_H_