1/*
2 * Copyright (C) Research In Motion Limited 2011. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB.  If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#ifndef SurrogatePairAwareTextIterator_h
22#define SurrogatePairAwareTextIterator_h
23
24#include "platform/PlatformExport.h"
25#include "wtf/text/WTFString.h"
26#include "wtf/unicode/CharacterNames.h"
27
28namespace blink {
29
30class PLATFORM_EXPORT SurrogatePairAwareTextIterator {
31public:
32    // The passed in UChar pointer starts at 'currentCharacter'. The iterator operatoes on the range [currentCharacter, lastCharacter].
33    // 'endCharacter' denotes the maximum length of the UChar array, which might exceed 'lastCharacter'.
34    SurrogatePairAwareTextIterator(const UChar*, int currentCharacter, int lastCharacter, int endCharacter);
35
36    inline bool consume(UChar32& character, unsigned& clusterLength)
37    {
38        if (m_currentCharacter >= m_lastCharacter)
39            return false;
40
41        character = *m_characters;
42        clusterLength = 1;
43
44        if (character < HiraganaLetterSmallA)
45            return true;
46
47        return consumeSlowCase(character, clusterLength);
48    }
49
50    void advance(unsigned advanceLength)
51    {
52        m_characters += advanceLength;
53        m_currentCharacter += advanceLength;
54    }
55
56    int currentCharacter() const { return m_currentCharacter; }
57    const UChar* characters() const { return m_characters; }
58
59private:
60    bool consumeSlowCase(UChar32&, unsigned&);
61    UChar32 normalizeVoicingMarks();
62
63    const UChar* m_characters;
64    int m_currentCharacter;
65    int m_lastCharacter;
66    int m_endCharacter;
67};
68
69}
70
71#endif
72