1 /* 2 * Copyright (C) 2003, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved. 3 * Copyright (C) 2008 Holger Hans Peter Freyther 4 * Copyright (C) Research In Motion Limited 2011. All rights reserved. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Library General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Library General Public License for more details. 15 * 16 * You should have received a copy of the GNU Library General Public License 17 * along with this library; see the file COPYING.LIB. If not, write to 18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA. 20 * 21 */ 22 23 #include "config.h" 24 #include "platform/text/SurrogatePairAwareTextIterator.h" 25 26 #include <unicode/unorm.h> 27 28 using namespace WTF; 29 using namespace Unicode; 30 31 namespace blink { 32 33 SurrogatePairAwareTextIterator::SurrogatePairAwareTextIterator(const UChar* characters, int currentCharacter, int lastCharacter, int endCharacter) 34 : m_characters(characters) 35 , m_currentCharacter(currentCharacter) 36 , m_lastCharacter(lastCharacter) 37 , m_endCharacter(endCharacter) 38 { 39 } 40 41 bool SurrogatePairAwareTextIterator::consumeSlowCase(UChar32& character, unsigned& clusterLength) 42 { 43 if (character <= 0x30FE) { 44 // Deal with Hiragana and Katakana voiced and semi-voiced syllables. 45 // Normalize into composed form, and then look for glyph with base + combined mark. 46 // Check above for character range to minimize performance impact. 47 if (UChar32 normalized = normalizeVoicingMarks()) { 48 character = normalized; 49 clusterLength = 2; 50 } 51 return true; 52 } 53 54 if (!U16_IS_SURROGATE(character)) 55 return true; 56 57 // If we have a surrogate pair, make sure it starts with the high part. 58 if (!U16_IS_SURROGATE_LEAD(character)) 59 return false; 60 61 // Do we have a surrogate pair? If so, determine the full Unicode (32 bit) code point before glyph lookup. 62 // Make sure we have another character and it's a low surrogate. 63 if (m_currentCharacter + 1 >= m_endCharacter) 64 return false; 65 66 UChar low = m_characters[1]; 67 if (!U16_IS_TRAIL(low)) 68 return false; 69 70 character = U16_GET_SUPPLEMENTARY(character, low); 71 clusterLength = 2; 72 return true; 73 } 74 75 UChar32 SurrogatePairAwareTextIterator::normalizeVoicingMarks() 76 { 77 // According to http://www.unicode.org/Public/UNIDATA/UCD.html#Canonical_Combining_Class_Values 78 static const uint8_t hiraganaKatakanaVoicingMarksCombiningClass = 8; 79 80 if (m_currentCharacter + 1 >= m_endCharacter) 81 return 0; 82 83 if (combiningClass(m_characters[1]) == hiraganaKatakanaVoicingMarksCombiningClass) { 84 // Normalize into composed form using 3.2 rules. 85 UChar normalizedCharacters[2] = { 0, 0 }; 86 UErrorCode uStatus = U_ZERO_ERROR; 87 int32_t resultLength = unorm_normalize(m_characters, 2, UNORM_NFC, UNORM_UNICODE_3_2, &normalizedCharacters[0], 2, &uStatus); 88 if (resultLength == 1 && !uStatus) 89 return normalizedCharacters[0]; 90 } 91 92 return 0; 93 } 94 95 } 96
