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/*
* Copyright (C) 2003, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
* Copyright (C) 2008 Holger Hans Peter Freyther
* Copyright (C) Research In Motion Limited 2011. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "SurrogatePairAwareTextIterator.h"
#if USE(ICU_UNICODE)
#include <unicode/unorm.h>
#endif
using namespace WTF;
using namespace Unicode;
namespace WebCore {
SurrogatePairAwareTextIterator::SurrogatePairAwareTextIterator(const UChar* characters, int currentCharacter, int lastCharacter, int endCharacter)
: m_characters(characters)
, m_currentCharacter(currentCharacter)
, m_lastCharacter(lastCharacter)
, m_endCharacter(endCharacter)
{
}
bool SurrogatePairAwareTextIterator::consumeSlowCase(UChar32& character, unsigned& clusterLength)
{
if (character <= 0x30FE) {
// Deal with Hiragana and Katakana voiced and semi-voiced syllables.
// Normalize into composed form, and then look for glyph with base + combined mark.
// Check above for character range to minimize performance impact.
if (UChar32 normalized = normalizeVoicingMarks()) {
character = normalized;
clusterLength = 2;
}
return true;
}
if (!U16_IS_SURROGATE(character))
return true;
// If we have a surrogate pair, make sure it starts with the high part.
if (!U16_IS_SURROGATE_LEAD(character))
return false;
// Do we have a surrogate pair? If so, determine the full Unicode (32 bit) code point before glyph lookup.
// Make sure we have another character and it's a low surrogate.
if (m_currentCharacter + 1 >= m_endCharacter)
return false;
UChar low = m_characters[1];
if (!U16_IS_TRAIL(low))
return false;
character = U16_GET_SUPPLEMENTARY(character, low);
clusterLength = 2;
return true;
}
UChar32 SurrogatePairAwareTextIterator::normalizeVoicingMarks()
{
// According to http://www.unicode.org/Public/UNIDATA/UCD.html#Canonical_Combining_Class_Values
static const uint8_t hiraganaKatakanaVoicingMarksCombiningClass = 8;
if (m_currentCharacter + 1 >= m_endCharacter)
return 0;
if (combiningClass(m_characters[1]) == hiraganaKatakanaVoicingMarksCombiningClass) {
#if USE(ICU_UNICODE)
// Normalize into composed form using 3.2 rules.
UChar normalizedCharacters[2] = { 0, 0 };
UErrorCode uStatus = U_ZERO_ERROR;
int32_t resultLength = unorm_normalize(m_characters, 2, UNORM_NFC, UNORM_UNICODE_3_2, &normalizedCharacters[0], 2, &uStatus);
if (resultLength == 1 && !uStatus)
return normalizedCharacters[0];
#endif
}
return 0;
}
}
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