/*

 * 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