1 // Copyright 2014 PDFium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com 6 7 #include "core/include/fxcrt/fx_basic.h" 8 9 void CFX_UTF8Decoder::Clear() { 10 m_Buffer.Clear(); 11 m_PendingBytes = 0; 12 } 13 void CFX_UTF8Decoder::AppendChar(FX_DWORD ch) { 14 m_Buffer.AppendChar((FX_WCHAR)ch); 15 } 16 void CFX_UTF8Decoder::Input(uint8_t byte) { 17 if (byte < 0x80) { 18 m_PendingBytes = 0; 19 m_Buffer.AppendChar(byte); 20 } else if (byte < 0xc0) { 21 if (m_PendingBytes == 0) { 22 return; 23 } 24 m_PendingBytes--; 25 m_PendingChar |= (byte & 0x3f) << (m_PendingBytes * 6); 26 if (m_PendingBytes == 0) { 27 AppendChar(m_PendingChar); 28 } 29 } else if (byte < 0xe0) { 30 m_PendingBytes = 1; 31 m_PendingChar = (byte & 0x1f) << 6; 32 } else if (byte < 0xf0) { 33 m_PendingBytes = 2; 34 m_PendingChar = (byte & 0x0f) << 12; 35 } else if (byte < 0xf8) { 36 m_PendingBytes = 3; 37 m_PendingChar = (byte & 0x07) << 18; 38 } else if (byte < 0xfc) { 39 m_PendingBytes = 4; 40 m_PendingChar = (byte & 0x03) << 24; 41 } else if (byte < 0xfe) { 42 m_PendingBytes = 5; 43 m_PendingChar = (byte & 0x01) << 30; 44 } 45 } 46 void CFX_UTF8Encoder::Input(FX_WCHAR unicode) { 47 if ((FX_DWORD)unicode < 0x80) { 48 m_Buffer.AppendChar(unicode); 49 } else { 50 if ((FX_DWORD)unicode >= 0x80000000) { 51 return; 52 } 53 int nbytes = 0; 54 if ((FX_DWORD)unicode < 0x800) { 55 nbytes = 2; 56 } else if ((FX_DWORD)unicode < 0x10000) { 57 nbytes = 3; 58 } else if ((FX_DWORD)unicode < 0x200000) { 59 nbytes = 4; 60 } else if ((FX_DWORD)unicode < 0x4000000) { 61 nbytes = 5; 62 } else { 63 nbytes = 6; 64 } 65 static uint8_t prefix[] = {0xc0, 0xe0, 0xf0, 0xf8, 0xfc}; 66 int order = 1 << ((nbytes - 1) * 6); 67 int code = unicode; 68 m_Buffer.AppendChar(prefix[nbytes - 2] | (code / order)); 69 for (int i = 0; i < nbytes - 1; i++) { 70 code = code % order; 71 order >>= 6; 72 m_Buffer.AppendChar(0x80 | (code / order)); 73 } 74 } 75 } 76 CFX_ByteString FX_UTF8Encode(const FX_WCHAR* pwsStr, FX_STRSIZE len) { 77 FXSYS_assert(pwsStr); 78 if (len < 0) { 79 len = FXSYS_wcslen(pwsStr); 80 } 81 CFX_UTF8Encoder encoder; 82 while (len-- > 0) { 83 encoder.Input(*pwsStr++); 84 } 85 return encoder.GetResult(); 86 } 87