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      1 /*
      2  * Copyright 2008, The Android Open Source Project
      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  *  * Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  *  * 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 THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #define LOG_TAG "webviewglue"
     27 
     28 #include "config.h"
     29 
     30 #include "BidiResolver.h"
     31 #include "BidiRunList.h"
     32 #include "GLExtras.h"
     33 #include "LayerAndroid.h"
     34 #include "SelectText.h"
     35 #include "SkBitmap.h"
     36 #include "SkBounder.h"
     37 #include "SkCanvas.h"
     38 #include "SkPicture.h"
     39 #include "SkPoint.h"
     40 #include "SkRect.h"
     41 #include "SkRegion.h"
     42 #include "TextRun.h"
     43 
     44 #ifdef DEBUG_NAV_UI
     45 #include <wtf/text/CString.h>
     46 #endif
     47 
     48 #define VERBOSE_LOGGING 0
     49 // #define EXTRA_NOISY_LOGGING 1
     50 #define DEBUG_TOUCH_HANDLES 0
     51 #if DEBUG_TOUCH_HANDLES
     52 #define DBG_HANDLE_LOG(format, ...) ALOGD("%s " format, __FUNCTION__, __VA_ARGS__)
     53 #else
     54 #define DBG_HANDLE_LOG(...)
     55 #endif
     56 
     57 // TextRunIterator has been copied verbatim from GraphicsContext.cpp
     58 namespace WebCore {
     59 
     60 class TextRunIterator {
     61 public:
     62     TextRunIterator()
     63         : m_textRun(0)
     64         , m_offset(0)
     65     {
     66     }
     67 
     68     TextRunIterator(const TextRun* textRun, unsigned offset)
     69         : m_textRun(textRun)
     70         , m_offset(offset)
     71     {
     72     }
     73 
     74     TextRunIterator(const TextRunIterator& other)
     75         : m_textRun(other.m_textRun)
     76         , m_offset(other.m_offset)
     77     {
     78     }
     79 
     80     unsigned offset() const { return m_offset; }
     81     void increment() { m_offset++; }
     82     bool atEnd() const { return !m_textRun || m_offset >= m_textRun->length(); }
     83     UChar current() const { return (*m_textRun)[m_offset]; }
     84     WTF::Unicode::Direction direction() const { return atEnd() ? WTF::Unicode::OtherNeutral : WTF::Unicode::direction(current()); }
     85 
     86     bool operator==(const TextRunIterator& other)
     87     {
     88         return m_offset == other.m_offset && m_textRun == other.m_textRun;
     89     }
     90 
     91     bool operator!=(const TextRunIterator& other) { return !operator==(other); }
     92 
     93 private:
     94     const TextRun* m_textRun;
     95     int m_offset;
     96 };
     97 
     98 // ReverseBidi is a trimmed-down version of GraphicsContext::drawBidiText()
     99 void ReverseBidi(UChar* chars, int len) {
    100     using namespace WTF::Unicode;
    101     WTF::Vector<UChar> result;
    102     result.reserveCapacity(len);
    103     TextRun run(chars, len);
    104     BidiResolver<TextRunIterator, BidiCharacterRun> bidiResolver;
    105     BidiRunList<BidiCharacterRun>& bidiRuns = bidiResolver.runs();
    106     bidiResolver.setStatus(BidiStatus(LeftToRight, LeftToRight, LeftToRight,
    107         BidiContext::create(0, LeftToRight, false)));
    108     bidiResolver.setPosition(TextRunIterator(&run, 0));
    109     bidiResolver.createBidiRunsForLine(TextRunIterator(&run, len));
    110     if (!bidiRuns.runCount())
    111         return;
    112     BidiCharacterRun* bidiRun = bidiRuns.firstRun();
    113     while (bidiRun) {
    114         int bidiStart = bidiRun->start();
    115         int bidiStop = bidiRun->stop();
    116         int size = result.size();
    117         int bidiCount = bidiStop - bidiStart;
    118         result.append(chars + bidiStart, bidiCount);
    119         if (bidiRun->level() % 2) {
    120             UChar* start = &result[size];
    121             UChar* end = start + bidiCount;
    122             // reverse the order of any RTL substrings
    123             while (start < end) {
    124                 UChar temp = *start;
    125                 *start++ = *--end;
    126                 *end = temp;
    127             }
    128             start = &result[size];
    129             end = start + bidiCount - 1;
    130             // if the RTL substring had a surrogate pair, restore its order
    131             while (start < end) {
    132                 UChar trail = *start++;
    133                 if (!U16_IS_SURROGATE(trail))
    134                     continue;
    135                 start[-1] = *start; // lead
    136                 *start++ = trail;
    137             }
    138         }
    139         bidiRun = bidiRun->next();
    140     }
    141     bidiRuns.deleteRuns();
    142     memcpy(chars, &result[0], len * sizeof(UChar));
    143 }
    144 
    145 }
    146 
    147