bidi.cpp

将konqueror浏览器移植到ARM9 2410中

/**
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000 Lars Knoll ([e-mail])
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * $Id: bidi.cpp,v 1.105.2.1 2001/11/01 18:57:06 mueller Exp $
 */
#include "bidi.h"
#include "break_lines.h"
#include "render_flow.h"
#include "render_text.h"
using namespace khtml;

#include "kdebug.h"
#include "qdatetime.h"
#include "qfontmetrics.h"

#define BIDI_DEBUG 0
//#define DEBUG_LINEBREAKS

// ---------------------------------------------------------------------

/* a small helper class used internally to resolve Bidi embedding levels.
   Each line of text caches the embedding level at the start of the line for faster
   relayouting
*/
BidiContext::BidiContext(unsigned char l, QChar::Direction e, BidiContext *p, bool o)
    : level(l) , override(o), dir(e)
{
    parent = p;
    if(p) {
        p->ref();
        basicDir = p->basicDir;
    } else
        basicDir = e;
    count = 0;
}

BidiContext::~BidiContext()
{
    if(parent) parent->deref();
}

void BidiContext::ref() const
{
    count++;
}

void BidiContext::deref() const
{
    count--;
    if(count <= 0) delete this;
}

// ---------------------------------------------------------------------

BidiIterator::BidiIterator()
{
    par = 0;
    obj = 0;
    pos = 0;
}

BidiIterator::BidiIterator(RenderFlow *_par)
{
    par = _par;
    obj = par->first();
    pos = 0;
}

BidiIterator::BidiIterator(const BidiIterator &it)
{
    par = it.par;
    obj = it.obj;
    pos = it.pos;
}

BidiIterator::BidiIterator(RenderFlow *_par, RenderObject *_obj, int _pos)
{
    par = _par;
    obj = _obj;
    pos = _pos;
}

BidiIterator &BidiIterator::operator = (const BidiIterator &it)
{
    obj = it.obj;
    pos = it.pos;
    par = it.par;
    return *this;
}

inline void BidiIterator::operator ++ ()
{
    if(!obj) return;
    if(obj->isText()) {
        pos++;
        if(pos >= obj->length()) {
            obj = par->next(obj);
            pos = 0;
        }
    } else {
        obj = par->next(obj);
        pos = 0;
    }
}

inline bool BidiIterator::atEnd()
{
    if(!obj) return true;
    return false;
}

const QChar &BidiIterator::current()
{
    static const QChar nbsp = QChar(0xA0);
    if( !obj || !obj->isText()) return nbsp; // non breaking space
    return static_cast<RenderText *>(obj)->text()[pos];
}

QChar::Direction BidiIterator::direction()
{
    if(!obj || !obj->isText() || obj->length() <= 0) return QChar::DirON;
    RenderText *renderTxt = static_cast<RenderText *>( obj );
    if ( pos >= renderTxt->length() )
        return QChar::DirON;
    return renderTxt->text()[pos].direction();
}

inline bool operator==( const BidiIterator &it1, const BidiIterator &it2 )
{
    if(it1.pos != it2.pos) return false;
    if(it1.obj != it2.obj) return false;
    return true;
}

inline bool operator!=( const BidiIterator &it1, const BidiIterator &it2 )
{
    if(it1.pos != it2.pos) return true;
    if(it1.obj != it2.obj) return true;
    return false;
}

// -------------------------------------------------------------------------------------------------

void RenderFlow::appendRun(QList<BidiRun> &runs, BidiIterator &sor, BidiIterator &eor,
                           BidiContext *context, QChar::Direction dir)
{
#if BIDI_DEBUG > 1
    kdDebug(6041) << "appendRun: dir="<<(int)dir<<endl;
#endif

    int start = sor.pos;
    RenderObject *obj = sor.obj;
    while( obj && obj != eor.obj ) {
        if(!obj->isHidden()) {
            //kdDebug(6041) << "appendRun: "<< start << "/" << obj->length() <<endl;
            runs.append( new BidiRun(start, obj->length(), obj, context, dir) );
        }
        start = 0;
        obj = next(obj);
    }
    if( obj && !obj->isHidden()) {
        //kdDebug(6041) << "appendRun: "<< start << "/" << eor.pos <<endl;
        runs.append( new BidiRun(start, eor.pos + 1, obj, context, dir) );
    }
}


// collects one line of the paragraph and transforms it to visual order
BidiContext *RenderFlow::bidiReorderLine(BidiStatus &status, const BidiIterator &start, const BidiIterator &end, BidiContext *startEmbed)
{

    //kdDebug(6041) << "reordering Line from " << start.obj << "/" << start.pos << " to " << end.obj << "/" << end.pos << endl;

    QList<BidiRun> runs;
    runs.setAutoDelete(true);

    BidiContext *context = startEmbed;
    //    context->ref();

    QChar::Direction dir = QChar::DirON;

    BidiIterator sor = start;
    BidiIterator eor = start;

#ifndef QT_NO_UNICODETABLES
    BidiIterator current = start;
    BidiIterator last = current;
    while(current != end) {

        QChar::Direction dirCurrent;
        if(current.atEnd()) {
            //kdDebug(6041) << "atEnd" << endl;
            BidiContext *c = context;
            while ( c->parent )
                c = c->parent;
            dirCurrent = c->dir;
        } else
            dirCurrent = current.direction();


#if BIDI_DEBUG > 1
        kdDebug(6041) << "directions: dir=" << (int)dir << " current=" << (int)dirCurrent << " last=" << status.last << " eor=" << status.eor << " lastStrong=" << status.lastStrong << " embedding=" << (int)context->dir << " level =" << (int)context->level << endl;
#endif

        switch(dirCurrent) {

            // embedding and overrides (X1-X9 in the Bidi specs)
        case QChar::DirRLE:
            {
                unsigned char level = context->level;
                if(level%2) // we have an odd level
                    level += 2;
                else
                    level++;
                if(level < 61) {
                    appendRun(runs, sor, eor, context, dir);
                    ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                    context = new BidiContext(level, QChar::DirR, context);
                    context->ref();
                    status.last = QChar::DirR;
                    status.lastStrong = QChar::DirR;
                }
                break;
            }
        case QChar::DirLRE:
            {
                unsigned char level = context->level;
                if(level%2) // we have an odd level
                    level++;
                else
                    level += 2;
                if(level < 61) {
                    appendRun(runs, sor, eor, context, dir);
                    ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                    context = new BidiContext(level, QChar::DirL, context);
                    context->ref();
                    status.last = QChar::DirL;
                    status.lastStrong = QChar::DirL;
                }
                break;
            }
        case QChar::DirRLO:
            {
                unsigned char level = context->level;
                if(level%2) // we have an odd level
                    level += 2;
                else
                    level++;
                if(level < 61) {
                    appendRun(runs, sor, eor, context, dir);
                    ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                    context = new BidiContext(level, QChar::DirR, context, true);
                    context->ref();
                    dir = QChar::DirR;
                    status.last = QChar::DirR;
                    status.lastStrong = QChar::DirR;
                }
                break;
            }
        case QChar::DirLRO:
            {
                unsigned char level = context->level;
                if(level%2) // we have an odd level
                    level++;
                else
                    level += 2;
                if(level < 61) {
                    appendRun(runs, sor, eor, context, dir);
                    ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                    context = new BidiContext(level, QChar::DirL, context, true);
                    context->ref();
                    dir = QChar::DirL;
                    status.last = QChar::DirL;
                    status.lastStrong = QChar::DirL;
                }
                break;
            }
        case QChar::DirPDF:
            {
                BidiContext *c = context->parent;
                if(c) {
                    appendRun(runs, sor, eor, context, dir);
                    ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                    status.last = context->dir;
                    context->deref();
                    context = c;
                    if(context->override)
                        dir = context->dir;
                    else
                        dir = QChar::DirON;
                    status.lastStrong = context->dir;
                }
                break;
            }

            // strong types
        case QChar::DirL:
            if(dir == QChar::DirON)
                dir = QChar::DirL;
            switch(status.last)
                {
                case QChar::DirL:
                    eor = current; status.eor = QChar::DirL; break;
                case QChar::DirR:
                case QChar::DirAL:
                case QChar::DirEN:
                case QChar::DirAN:
                    appendRun(runs, sor, eor, context, dir);
                    ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                    break;
                case QChar::DirES:
                case QChar::DirET:
                case QChar::DirCS:
                case QChar::DirBN:
                case QChar::DirB:
                case QChar::DirS:
                case QChar::DirWS:
                case QChar::DirON:
                    if(dir != QChar::DirL) {
                        //last stuff takes embedding dir
                        if( context->dir == QChar::DirR ) {
                            if(status.eor != QChar::DirR) {
                                // AN or EN
                                appendRun(runs, sor, eor, context, dir);
                                ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                                dir = QChar::DirR;
                            }
                            else
                                eor = last;
                            appendRun(runs, sor, eor, context, dir);
                            ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                        } else {
                            if(status.eor == QChar::DirR) {
                                appendRun(runs, sor, eor, context, dir);
                                ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                                dir = QChar::DirL;
                            } else {
                                eor = current; status.eor = QChar::DirL; break;
                            }
                        }
                    } else {
                        eor = current; status.eor = QChar::DirL;
                    }
                default:
                    break;
                }
            status.lastStrong = QChar::DirL;
            break;
        case QChar::DirAL:
        case QChar::DirR:
            if(dir == QChar::DirON) dir = QChar::DirR;
            switch(status.last)
                {
                case QChar::DirR:
                case QChar::DirAL:
                    eor = current; status.eor = QChar::DirR; break;
                case QChar::DirL:
                case QChar::DirEN:
                case QChar::DirAN:
                    appendRun(runs, sor, eor, context, dir);
                    ++eor; sor = eor; dir = QChar::DirON; status.eor = QChar::DirON;
                    break;