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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 "core/platform/text/TextBoundaries.h"
     29 
     30 #include "core/platform/text/TextBreakIterator.h"
     31 #include "wtf/text/StringImpl.h"
     32 #include "wtf/unicode/Unicode.h"
     33 
     34 using namespace WTF;
     35 using namespace Unicode;
     36 
     37 namespace WebCore {
     38 
     39 int endOfFirstWordBoundaryContext(const UChar* characters, int length)
     40 {
     41     for (int i = 0; i < length; ) {
     42         int first = i;
     43         UChar32 ch;
     44         U16_NEXT(characters, i, length, ch);
     45         if (!requiresContextForWordBoundary(ch))
     46             return first;
     47     }
     48     return length;
     49 }
     50 
     51 int startOfLastWordBoundaryContext(const UChar* characters, int length)
     52 {
     53     for (int i = length; i > 0; ) {
     54         int last = i;
     55         UChar32 ch;
     56         U16_PREV(characters, 0, i, ch);
     57         if (!requiresContextForWordBoundary(ch))
     58             return last;
     59     }
     60     return 0;
     61 }
     62 
     63 int findNextWordFromIndex(const UChar* chars, int len, int position, bool forward)
     64 {
     65     TextBreakIterator* it = wordBreakIterator(chars, len);
     66 
     67     if (forward) {
     68         position = textBreakFollowing(it, position);
     69         while (position != TextBreakDone) {
     70             // We stop searching when the character preceeding the break
     71             // is alphanumeric.
     72             if (position < len && isAlphanumeric(chars[position - 1]))
     73                 return position;
     74 
     75             position = textBreakFollowing(it, position);
     76         }
     77 
     78         return len;
     79     } else {
     80         position = textBreakPreceding(it, position);
     81         while (position != TextBreakDone) {
     82             // We stop searching when the character following the break
     83             // is alphanumeric.
     84             if (position > 0 && isAlphanumeric(chars[position]))
     85                 return position;
     86 
     87             position = textBreakPreceding(it, position);
     88         }
     89 
     90         return 0;
     91     }
     92 }
     93 
     94 void findWordBoundary(const UChar* chars, int len, int position, int* start, int* end)
     95 {
     96     TextBreakIterator* it = wordBreakIterator(chars, len);
     97     *end = textBreakFollowing(it, position);
     98     if (*end < 0)
     99         *end = textBreakLast(it);
    100     *start = textBreakPrevious(it);
    101 }
    102 
    103 
    104 } // namespace WebCore
    105