| // 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. |
| |
| #ifndef BASE_STRINGS_UTF_STRING_CONVERSION_UTILS_H_ |
| #define BASE_STRINGS_UTF_STRING_CONVERSION_UTILS_H_ |
| |
| #include <string> |
| |
| // This should only be used by the various UTF string conversion files. |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include "base/base_export.h" |
| |
| namespace base { |
| |
| inline bool IsValidCodepoint(uint32_t code_point) { |
| // Excludes the surrogate code points ([0xD800, 0xDFFF]) and |
| // codepoints larger than 0x10FFFF (the highest codepoint allowed). |
| // Non-characters and unassigned codepoints are allowed. |
| return code_point < 0xD800u || |
| (code_point >= 0xE000u && code_point <= 0x10FFFFu); |
| } |
| |
| inline bool IsValidCharacter(uint32_t code_point) { |
| // Excludes non-characters (U+FDD0..U+FDEF, and all codepoints ending in |
| // 0xFFFE or 0xFFFF) from the set of valid code points. |
| return code_point < 0xD800u || (code_point >= 0xE000u && |
| code_point < 0xFDD0u) || (code_point > 0xFDEFu && |
| code_point <= 0x10FFFFu && (code_point & 0xFFFEu) != 0xFFFEu); |
| } |
| |
| // ReadUnicodeCharacter -------------------------------------------------------- |
| |
| // Reads a UTF-8 stream, placing the next code point into the given output |
| // |*code_point|. |src| represents the entire string to read, and |*char_index| |
| // is the character offset within the string to start reading at. |*char_index| |
| // will be updated to index the last character read, such that incrementing it |
| // (as in a for loop) will take the reader to the next character. |
| // |
| // Returns true on success. On false, |*code_point| will be invalid. |
| bool ReadUnicodeCharacter(const char* src, |
| int32_t src_len, |
| int32_t* char_index, |
| uint32_t* code_point_out); |
| |
| #if defined(WCHAR_T_IS_UTF32) |
| // Reads UTF-32 character. The usage is the same as the 8-bit version above. |
| bool ReadUnicodeCharacter(const wchar_t* src, |
| int32_t src_len, |
| int32_t* char_index, |
| uint32_t* code_point); |
| #endif // defined(WCHAR_T_IS_UTF32) |
| |
| // WriteUnicodeCharacter ------------------------------------------------------- |
| |
| // Appends a UTF-8 character to the given 8-bit string. Returns the number of |
| // bytes written. |
| // TODO(brettw) Bug 79631: This function should not be exposed. |
| size_t WriteUnicodeCharacter(uint32_t code_point, std::string* output); |
| |
| #if defined(WCHAR_T_IS_UTF32) |
| // Appends the given UTF-32 character to the given 32-bit string. Returns the |
| // number of 32-bit values written. |
| inline size_t WriteUnicodeCharacter(uint32_t code_point, std::wstring* output) { |
| // This is the easy case, just append the character. |
| output->push_back(code_point); |
| return 1; |
| } |
| #endif // defined(WCHAR_T_IS_UTF32) |
| |
| // Generalized Unicode converter ----------------------------------------------- |
| |
| // Guesses the length of the output in UTF-8 in bytes, clears that output |
| // string, and reserves that amount of space. We assume that the input |
| // character types are unsigned, which will be true for UTF-16 and -32 on our |
| // systems. |
| template<typename CHAR> |
| void PrepareForUTF8Output(const CHAR* src, size_t src_len, std::string* output); |
| |
| // Prepares an output buffer (containing either UTF-16 or -32 data) given some |
| // UTF-8 input that will be converted to it. See PrepareForUTF8Output(). |
| template<typename STRING> |
| void PrepareForUTF16Or32Output(const char* src, size_t src_len, STRING* output); |
| |
| } // namespace base |
| |
| #endif // BASE_STRINGS_UTF_STRING_CONVERSION_UTILS_H_ |