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/*
* Copyright (C) 2005, 2007, 2010 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "break_lines.h"
#include "CharacterNames.h"
#include "TextBreakIterator.h"
#if PLATFORM(MAC)
#include <CoreServices/CoreServices.h>
#endif
namespace WebCore {
static inline bool isBreakableSpace(UChar ch, bool treatNoBreakSpaceAsBreak)
{
switch (ch) {
case ' ':
case '\n':
case '\t':
return true;
case noBreakSpace:
return treatNoBreakSpaceAsBreak;
default:
return false;
}
}
// This differs from the Unicode algorithm only in that Unicode does not break
// between a question mark and a vertical line (U+007C).
static const unsigned char internetExplorerLineBreaksAfterQuestionMarkTable[0x80] = {
1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, // \t
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, // ! " ' ) , . /
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, // : ; ?
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, // ]
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1 // }
};
static const size_t internetExplorerLineBreaksAfterQuestionMarkTableSize = sizeof(internetExplorerLineBreaksAfterQuestionMarkTable) / sizeof(*internetExplorerLineBreaksAfterQuestionMarkTable);
static inline bool shouldBreakAfter(UChar ch, UChar nextCh)
{
switch (ch) {
// For a question mark preceding a non-ASCII characters, defer to the Unicode algorithm by returning false.
// For ASCII characters, use a lookup table for enhanced speed and for compatibility with Internet Explorer.
case '?':
return nextCh < internetExplorerLineBreaksAfterQuestionMarkTableSize && internetExplorerLineBreaksAfterQuestionMarkTable[nextCh];
// Internet Explorer always allows breaking after a hyphen.
case '-':
case softHyphen:
// FIXME: cases for ideographicComma and ideographicFullStop are a workaround for an issue in Unicode 5.0
// which is likely to be resolved in Unicode 5.1 <http://bugs.webkit.org/show_bug.cgi?id=17411>.
// We may want to remove or conditionalize this workaround at some point.
case ideographicComma:
case ideographicFullStop:
return true;
default:
return false;
}
}
static inline bool needsLineBreakIterator(UChar ch)
{
return ch > 0x7F && ch != noBreakSpace;
}
#if PLATFORM(MAC) && defined(BUILDING_ON_TIGER)
static inline TextBreakLocatorRef lineBreakLocator()
{
TextBreakLocatorRef locator = 0;
UCCreateTextBreakLocator(0, 0, kUCTextBreakLineMask, &locator);
return locator;
}
#endif
int nextBreakablePosition(const UChar* str, int pos, int len, bool treatNoBreakSpaceAsBreak)
{
#if !PLATFORM(MAC) || !defined(BUILDING_ON_TIGER)
TextBreakIterator* breakIterator = 0;
#endif
int nextBreak = -1;
UChar lastCh = pos > 0 ? str[pos - 1] : 0;
for (int i = pos; i < len; i++) {
UChar ch = str[i];
if (isBreakableSpace(ch, treatNoBreakSpaceAsBreak) || shouldBreakAfter(lastCh, ch))
return i;
if (needsLineBreakIterator(ch) || needsLineBreakIterator(lastCh)) {
if (nextBreak < i && i) {
#if !PLATFORM(MAC) || !defined(BUILDING_ON_TIGER)
if (!breakIterator)
breakIterator = lineBreakIterator(str, len);
if (breakIterator)
nextBreak = textBreakFollowing(breakIterator, i - 1);
#else
static TextBreakLocatorRef breakLocator = lineBreakLocator();
if (breakLocator) {
UniCharArrayOffset nextUCBreak;
if (UCFindTextBreak(breakLocator, kUCTextBreakLineMask, 0, str, len, i, &nextUCBreak) == 0)
nextBreak = nextUCBreak;
}
#endif
}
if (i == nextBreak && !isBreakableSpace(lastCh, treatNoBreakSpaceAsBreak))
return i;
}
lastCh = ch;
}
return len;
}
} // namespace WebCore
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