1/*
2 * (C) 1999 Lars Knoll (knoll@kde.org)
3 * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
4 * Copyright (C) 2007-2009 Torch Mobile, Inc.
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#include "config.h"
23#include "PlatformString.h"
24
25#include "SharedBuffer.h"
26#include "TextBreakIterator.h"
27#include <wtf/unicode/UTF8.h>
28#include <wtf/unicode/Unicode.h>
29
30using namespace WTF;
31using namespace WTF::Unicode;
32
33namespace WebCore {
34
35PassRefPtr<SharedBuffer> utf8Buffer(const String& string)
36{
37    // Allocate a buffer big enough to hold all the characters.
38    const int length = string.length();
39    Vector<char> buffer(length * 3);
40
41    // Convert to runs of 8-bit characters.
42    char* p = buffer.data();
43    const UChar* d = string.characters();
44    ConversionResult result = convertUTF16ToUTF8(&d, d + length, &p, p + buffer.size(), true);
45    if (result != conversionOK)
46        return 0;
47
48    buffer.shrink(p - buffer.data());
49    return SharedBuffer::adoptVector(buffer);
50}
51
52unsigned numGraphemeClusters(const String& s)
53{
54    TextBreakIterator* it = characterBreakIterator(s.characters(), s.length());
55    if (!it)
56        return s.length();
57
58    unsigned num = 0;
59    while (textBreakNext(it) != TextBreakDone)
60        ++num;
61    return num;
62}
63
64unsigned numCharactersInGraphemeClusters(const String& s, unsigned numGraphemeClusters)
65{
66    TextBreakIterator* it = characterBreakIterator(s.characters(), s.length());
67    if (!it)
68        return min(s.length(), numGraphemeClusters);
69
70    for (unsigned i = 0; i < numGraphemeClusters; ++i) {
71        if (textBreakNext(it) == TextBreakDone)
72            return s.length();
73    }
74    return textBreakCurrent(it);
75}
76
77} // namespace WebCore
78