| // Copyright 2014 PDFium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com |
| |
| #include <vector> |
| |
| #include "core/fxcrt/fx_string.h" |
| |
| namespace { |
| |
| class CFX_UTF8Encoder { |
| public: |
| CFX_UTF8Encoder() {} |
| ~CFX_UTF8Encoder() {} |
| |
| void Input(wchar_t unicodeAsWchar) { |
| uint32_t unicode = static_cast<uint32_t>(unicodeAsWchar); |
| if (unicode < 0x80) { |
| m_Buffer.push_back(unicode); |
| } else { |
| if (unicode >= 0x80000000) |
| return; |
| |
| int nbytes = 0; |
| if (unicode < 0x800) |
| nbytes = 2; |
| else if (unicode < 0x10000) |
| nbytes = 3; |
| else if (unicode < 0x200000) |
| nbytes = 4; |
| else if (unicode < 0x4000000) |
| nbytes = 5; |
| else |
| nbytes = 6; |
| |
| static uint8_t prefix[] = {0xc0, 0xe0, 0xf0, 0xf8, 0xfc}; |
| int order = 1 << ((nbytes - 1) * 6); |
| int code = unicodeAsWchar; |
| m_Buffer.push_back(prefix[nbytes - 2] | (code / order)); |
| for (int i = 0; i < nbytes - 1; i++) { |
| code = code % order; |
| order >>= 6; |
| m_Buffer.push_back(0x80 | (code / order)); |
| } |
| } |
| } |
| |
| // The data returned by GetResult() is invalidated when this is modified by |
| // appending any data. |
| CFX_ByteStringC GetResult() const { |
| return CFX_ByteStringC(m_Buffer.data(), m_Buffer.size()); |
| } |
| |
| private: |
| std::vector<uint8_t> m_Buffer; |
| }; |
| |
| } // namespace |
| |
| CFX_ByteString FX_UTF8Encode(const CFX_WideStringC& wsStr) { |
| FX_STRSIZE len = wsStr.GetLength(); |
| const wchar_t* pStr = wsStr.unterminated_c_str(); |
| CFX_UTF8Encoder encoder; |
| while (len-- > 0) |
| encoder.Input(*pStr++); |
| |
| return CFX_ByteString(encoder.GetResult()); |
| } |