1/*
2 * Copyright (C) 2005, 2007, 2010 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "break_lines.h"
28
29#include "TextBreakIterator.h"
30#include <wtf/StdLibExtras.h>
31#include <wtf/unicode/CharacterNames.h>
32
33#if PLATFORM(MAC)
34#include <CoreServices/CoreServices.h>
35#endif
36
37namespace WebCore {
38
39static inline bool isBreakableSpace(UChar ch, bool treatNoBreakSpaceAsBreak)
40{
41    switch (ch) {
42    case ' ':
43    case '\n':
44    case '\t':
45        return true;
46    case noBreakSpace:
47        return treatNoBreakSpaceAsBreak;
48    default:
49        return false;
50    }
51}
52
53static const UChar asciiLineBreakTableFirstChar = '!';
54static const UChar asciiLineBreakTableLastChar = 127;
55
56// Pack 8 bits into one byte
57#define B(a, b, c, d, e, f, g, h) \
58    ((a) | ((b) << 1) | ((c) << 2) | ((d) << 3) | ((e) << 4) | ((f) << 5) | ((g) << 6) | ((h) << 7))
59
60// Line breaking table row for each digit (0-9)
61#define DI { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
62
63// Line breaking table row for ascii letters (a-z A-Z)
64#define AL { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
65
66#define F 0xFF
67
68// Line breaking table for printable ASCII characters. Line breaking opportunities in this table are as below:
69// - before openning punctuations such as '(', '<', '[', '{' after certain characters (compatible with Firefox 3.6);
70// - after '-' and '?' (backward-compatible, and compatible with Internet Explorer).
71// Please refer to <https://bugs.webkit.org/show_bug.cgi?id=37698> for line breaking matrixes of different browsers
72// and the ICU standard.
73static const unsigned char asciiLineBreakTable[][(asciiLineBreakTableLastChar - asciiLineBreakTableFirstChar) / 8 + 1] = {
74    //  !  "  #  $  %  &  '  (     )  *  +  ,  -  .  /  0  1-8   9  :  ;  <  =  >  ?  @     A-X      Y  Z  [  \  ]  ^  _  `     a-x      y  z  {  |  }  ~  DEL
75    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // !
76    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // "
77    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // #
78    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // $
79    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // %
80    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // &
81    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // '
82    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // (
83    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // )
84    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // *
85    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // +
86    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // ,
87    { B(1, 1, 1, 1, 1, 1, 1, 1), B(1, 1, 1, 1, 1, 1, 1, 1), F, B(1, 1, 1, 1, 1, 1, 1, 1), F, F, F, B(1, 1, 1, 1, 1, 1, 1, 1), F, F, F, B(1, 1, 1, 1, 1, 1, 1, 1) }, // -
88    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // .
89    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // /
90    DI,  DI,  DI,  DI,  DI,  DI,  DI,  DI,  DI,  DI, // 0-9
91    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // :
92    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // ;
93    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // <
94    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // =
95    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // >
96    { B(0, 0, 1, 1, 1, 1, 0, 1), B(0, 1, 1, 0, 1, 0, 0, 1), F, B(1, 0, 0, 1, 1, 1, 0, 1), F, F, F, B(1, 1, 1, 1, 0, 1, 1, 1), F, F, F, B(1, 1, 1, 1, 0, 1, 1, 0) }, // ?
97    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // @
98    AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL, // A-Z
99    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // [
100    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // '\'
101    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // ]
102    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // ^
103    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // _
104    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // `
105    AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL,  AL, // a-z
106    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // {
107    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // |
108    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // }
109    { B(0, 0, 0, 0, 0, 0, 0, 1), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 1, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 1, 0, 0, 0, 0, 0) }, // ~
110    { B(0, 0, 0, 0, 0, 0, 0, 0), B(0, 0, 0, 0, 0, 0, 0, 0), 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0), 0, 0, 0, B(0, 0, 0, 0, 0, 0, 0, 0) }, // DEL
111};
112
113#undef B
114#undef F
115#undef DI
116#undef AL
117
118COMPILE_ASSERT(WTF_ARRAY_LENGTH(asciiLineBreakTable) == asciiLineBreakTableLastChar - asciiLineBreakTableFirstChar + 1, TestLineBreakTableConsistency);
119
120static inline bool shouldBreakAfter(UChar ch, UChar nextCh)
121{
122#ifdef ANDROID_LAYOUT
123    if (ch == '/')  // as '/' is used in uri which is always long, we would like to break it
124        return true;
125#endif
126
127    // If both ch and nextCh are ASCII characters, use a lookup table for enhanced speed and for compatibility
128    // with other browsers (see comments for asciiLineBreakTable for details).
129    if (ch >= asciiLineBreakTableFirstChar && ch <= asciiLineBreakTableLastChar
130        && nextCh >= asciiLineBreakTableFirstChar && nextCh <= asciiLineBreakTableLastChar) {
131        const unsigned char* tableRow = asciiLineBreakTable[ch - asciiLineBreakTableFirstChar];
132        int nextChIndex = nextCh - asciiLineBreakTableFirstChar;
133        return tableRow[nextChIndex / 8] & (1 << (nextChIndex % 8));
134    }
135    // Otherwise defer to the Unicode algorithm by returning false.
136    return false;
137}
138
139static inline bool needsLineBreakIterator(UChar ch)
140{
141    return ch > asciiLineBreakTableLastChar && ch != noBreakSpace;
142}
143
144#if PLATFORM(MAC) && defined(BUILDING_ON_TIGER)
145static inline TextBreakLocatorRef lineBreakLocator()
146{
147    TextBreakLocatorRef locator = 0;
148    UCCreateTextBreakLocator(0, 0, kUCTextBreakLineMask, &locator);
149    return locator;
150}
151#endif
152
153int nextBreakablePosition(LazyLineBreakIterator& lazyBreakIterator, int pos, bool treatNoBreakSpaceAsBreak)
154{
155    const UChar* str = lazyBreakIterator.string();
156    int len = lazyBreakIterator.length();
157    int nextBreak = -1;
158
159    UChar lastCh = pos > 0 ? str[pos - 1] : 0;
160    for (int i = pos; i < len; i++) {
161        UChar ch = str[i];
162
163        if (isBreakableSpace(ch, treatNoBreakSpaceAsBreak) || shouldBreakAfter(lastCh, ch))
164            return i;
165
166        if (needsLineBreakIterator(ch) || needsLineBreakIterator(lastCh)) {
167            if (nextBreak < i && i) {
168#if !PLATFORM(MAC) || !defined(BUILDING_ON_TIGER)
169                TextBreakIterator* breakIterator = lazyBreakIterator.get();
170                if (breakIterator)
171                    nextBreak = textBreakFollowing(breakIterator, i - 1);
172#else
173                static TextBreakLocatorRef breakLocator = lineBreakLocator();
174                if (breakLocator) {
175                    UniCharArrayOffset nextUCBreak;
176                    if (UCFindTextBreak(breakLocator, kUCTextBreakLineMask, 0, str, len, i, &nextUCBreak) == 0)
177                        nextBreak = nextUCBreak;
178                }
179#endif
180            }
181            if (i == nextBreak && !isBreakableSpace(lastCh, treatNoBreakSpaceAsBreak))
182                return i;
183        }
184
185        lastCh = ch;
186    }
187
188    return len;
189}
190
191} // namespace WebCore
192