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      1 /*
      2  * Copyright (C) 2006, 2007 Apple Inc.  All rights reserved.
      3  * Copyright (C) 2009 Dominik Rttsches <dominik.roettsches (at) access-company.com>
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include "config.h"
     28 #include "platform/text/TextBoundaries.h"
     29 
     30 #include "platform/text/TextBreakIterator.h"
     31 #include "wtf/text/StringImpl.h"
     32 
     33 using namespace WTF;
     34 using namespace Unicode;
     35 
     36 namespace WebCore {
     37 
     38 int endOfFirstWordBoundaryContext(const UChar* characters, int length)
     39 {
     40     for (int i = 0; i < length; ) {
     41         int first = i;
     42         UChar32 ch;
     43         U16_NEXT(characters, i, length, ch);
     44         if (!requiresContextForWordBoundary(ch))
     45             return first;
     46     }
     47     return length;
     48 }
     49 
     50 int startOfLastWordBoundaryContext(const UChar* characters, int length)
     51 {
     52     for (int i = length; i > 0; ) {
     53         int last = i;
     54         UChar32 ch;
     55         U16_PREV(characters, 0, i, ch);
     56         if (!requiresContextForWordBoundary(ch))
     57             return last;
     58     }
     59     return 0;
     60 }
     61 
     62 int findNextWordFromIndex(const UChar* chars, int len, int position, bool forward)
     63 {
     64     TextBreakIterator* it = wordBreakIterator(chars, len);
     65 
     66     if (forward) {
     67         position = it->following(position);
     68         while (position != TextBreakDone) {
     69             // We stop searching when the character preceeding the break
     70             // is alphanumeric.
     71             if (position < len && isAlphanumeric(chars[position - 1]))
     72                 return position;
     73 
     74             position = it->following(position);
     75         }
     76 
     77         return len;
     78     } else {
     79         position = it->preceding(position);
     80         while (position != TextBreakDone) {
     81             // We stop searching when the character following the break
     82             // is alphanumeric.
     83             if (position > 0 && isAlphanumeric(chars[position]))
     84                 return position;
     85 
     86             position = it->preceding(position);
     87         }
     88 
     89         return 0;
     90     }
     91 }
     92 
     93 void findWordBoundary(const UChar* chars, int len, int position, int* start, int* end)
     94 {
     95     TextBreakIterator* it = wordBreakIterator(chars, len);
     96     *end = it->following(position);
     97     if (*end < 0)
     98         *end = it->last();
     99     *start = it->previous();
    100 }
    101 
    102 
    103 } // namespace WebCore
    104