diff options
Diffstat (limited to 'base/i18n/rtl.h')
-rw-r--r-- | base/i18n/rtl.h | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/base/i18n/rtl.h b/base/i18n/rtl.h new file mode 100644 index 0000000..05a5ff0 --- /dev/null +++ b/base/i18n/rtl.h @@ -0,0 +1,121 @@ +// 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. + +#ifndef BASE_I18N_RTL_H_ +#define BASE_I18N_RTL_H_ + +#include "base/string16.h" + +class FilePath; + +namespace base { +namespace i18n { + +const char16 kRightToLeftMark = 0x200f; +const char16 kLeftToRightMark = 0x200e; +const char16 kLeftToRightEmbeddingMark = 0x202A; +const char16 kRightToLeftEmbeddingMark = 0x202B; +const char16 kPopDirectionalFormatting = 0x202C; + +// Represents the text direction returned by the GetTextDirection() function. +enum TextDirection { + UNKNOWN_DIRECTION, + RIGHT_TO_LEFT, + LEFT_TO_RIGHT, +}; + +// Get language and region from the OS. +void GetLanguageAndRegionFromOS(std::string* lang, std::string* region); + +// Sets the default locale of ICU. +// Once the application locale of Chrome in GetApplicationLocale is determined, +// the default locale of ICU need to be changed to match the application locale +// so that ICU functions work correctly in a locale-dependent manner. +// This is handy in that we don't have to call GetApplicationLocale() +// everytime we call locale-dependent ICU APIs as long as we make sure +// that this is called before any locale-dependent API is called. +void SetICUDefaultLocale(const std::string& locale_string); + +// Returns the text direction for the default ICU locale. It is assumed +// that SetICUDefaultLocale has been called to set the default locale to +// the UI locale of Chrome. Its return is one of the following three: +// * LEFT_TO_RIGHT: Left-To-Right (e.g. English, Chinese, etc.); +// * RIGHT_TO_LEFT: Right-To-Left (e.g. Arabic, Hebrew, etc.), and; +// * UNKNOWN_DIRECTION: unknown (or error). +TextDirection GetICUTextDirection(); + +// Get the application text direction. (This is just the ICU direction, +// except on GTK.) +TextDirection GetTextDirection(); + +// Returns true if the application text direction is right-to-left. +bool IsRTL(); + +// Returns the text direction for |locale_name|. +TextDirection GetTextDirectionForLocale(const char* locale_name); + +// Given the string in |text|, returns the directionality of the first +// character with strong directionality in the string. If no character in the +// text has strong directionality, LEFT_TO_RIGHT is returned. The Bidi +// character types L, LRE, LRO, R, AL, RLE, and RLO are considered as strong +// directionality characters. Please refer to http://unicode.org/reports/tr9/ +// for more information. +TextDirection GetFirstStrongCharacterDirection(const std::wstring& text); + +// Given the string in |text|, this function creates a copy of the string with +// the appropriate Unicode formatting marks that mark the string direction +// (either left-to-right or right-to-left). The new string is returned in +// |localized_text|. The function checks both the current locale and the +// contents of the string in order to determine the direction of the returned +// string. The function returns true if the string in |text| was properly +// adjusted. +// +// Certain LTR strings are not rendered correctly when the context is RTL. For +// example, the string "Foo!" will appear as "!Foo" if it is rendered as is in +// an RTL context. Calling this function will make sure the returned localized +// string is always treated as a right-to-left string. This is done by +// inserting certain Unicode formatting marks into the returned string. +// +// TODO(idana) bug# 1206120: this function adjusts the string in question only +// if the current locale is right-to-left. The function does not take care of +// the opposite case (an RTL string displayed in an LTR context) since +// adjusting the string involves inserting Unicode formatting characters that +// Windows does not handle well unless right-to-left language support is +// installed. Since the English version of Windows doesn't have right-to-left +// language support installed by default, inserting the direction Unicode mark +// results in Windows displaying squares. +bool AdjustStringForLocaleDirection(const std::wstring& text, + std::wstring* localized_text); + +// Returns true if the string contains at least one character with strong right +// to left directionality; that is, a character with either R or AL Unicode +// BiDi character type. +bool StringContainsStrongRTLChars(const std::wstring& text); + +// Wraps a string with an LRE-PDF pair which essentialy marks the string as a +// Left-To-Right string. Doing this is useful in order to make sure LTR +// strings are rendered properly in an RTL context. +void WrapStringWithLTRFormatting(std::wstring* text); + +// Wraps a string with an RLE-PDF pair which essentialy marks the string as a +// Right-To-Left string. Doing this is useful in order to make sure RTL +// strings are rendered properly in an LTR context. +void WrapStringWithRTLFormatting(std::wstring* text); + +// Wraps file path to get it to display correctly in RTL UI. All filepaths +// should be passed through this function before display in UI for RTL locales. +void WrapPathWithLTRFormatting(const FilePath& path, + string16* rtl_safe_path); + +// Given the string in |text|, this function returns the adjusted string having +// LTR directionality for display purpose. Which means that in RTL locale the +// string is wrapped with LRE (Left-To-Right Embedding) and PDF (Pop +// Directional Formatting) marks and returned. In LTR locale, the string itself +// is returned. +std::wstring GetDisplayStringInLTRDirectionality(std::wstring* text); + +} // namespace i18n +} // namespace base + +#endif // BASE_I18N_RTL_H_ |