qtextengine.cpp

奇趣公司比较新的qt/emd版本

                        eor = current; status.eor = QChar::DirL;
                    }
                default:
                    break;
                }
            status.lastStrong = QChar::DirL;
            break;
        case QChar::DirAL:
        case QChar::DirR:
            hasBidi = true;
            if(dir == QChar::DirON) dir = QChar::DirR;
            switch(status.last)
                {
                case QChar::DirL:
                case QChar::DirEN:
                case QChar::DirAN:
                    if (eor >= 0)
                        appendItems(engine, sor, eor, control, dir);
                    // fall through
                case QChar::DirR:
                case QChar::DirAL:
                    dir = QChar::DirR; eor = current; status.eor = QChar::DirR; 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(status.eor != QChar::DirR && status.eor != QChar::DirAL) {
                        //last stuff takes embedding dir
                        if(control.direction() == QChar::DirR
                           || status.lastStrong == QChar::DirR || status.lastStrong == QChar::DirAL) {
                            appendItems(engine, sor, eor, control, dir);
                            dir = QChar::DirR; status.eor = QChar::DirON;
                            eor = current;
                        } else {
                            eor = current - 1;
                            appendItems(engine, sor, eor, control, dir);
                            dir = QChar::DirR; status.eor = QChar::DirON;
                        }
                    } else {
                        eor = current; status.eor = QChar::DirR;
                    }
                default:
                    break;
                }
            status.lastStrong = dirCurrent;
            break;

            // weak types:

        case QChar::DirNSM:
            if (eor == current-1)
                eor = current;
            break;
        case QChar::DirEN:
            // if last strong was AL change EN to AN
            if(status.lastStrong != QChar::DirAL) {
                if(dir == QChar::DirON) {
                    if(status.lastStrong == QChar::DirL)
                        dir = QChar::DirL;
                    else
                        dir = QChar::DirEN;
                }
                switch(status.last)
                    {
                    case QChar::DirET:
                        if (status.lastStrong == QChar::DirR || status.lastStrong == QChar::DirAL) {
                            appendItems(engine, sor, eor, control, dir);
                            status.eor = QChar::DirON;
                            dir = QChar::DirAN;
                        }
                        // fall through
                    case QChar::DirEN:
                    case QChar::DirL:
                        eor = current;
                        status.eor = dirCurrent;
                        break;
                    case QChar::DirR:
                    case QChar::DirAL:
                    case QChar::DirAN:
                        if (eor >= 0)
                            appendItems(engine, sor, eor, control, dir);
                        else
                            eor = current;
                        status.eor = QChar::DirEN;
                        dir = QChar::DirAN; break;
                    case QChar::DirES:
                    case QChar::DirCS:
                        if(status.eor == QChar::DirEN || dir == QChar::DirAN) {
                            eor = current; break;
                        }
                    case QChar::DirBN:
                    case QChar::DirB:
                    case QChar::DirS:
                    case QChar::DirWS:
                    case QChar::DirON:
                        if(status.eor == QChar::DirR) {
                            // neutrals go to R
                            eor = current - 1;
                            appendItems(engine, sor, eor, control, dir);
                            dir = QChar::DirON; status.eor = QChar::DirEN;
                            dir = QChar::DirAN;
                        }
                        else if(status.eor == QChar::DirL ||
                                 (status.eor == QChar::DirEN && status.lastStrong == QChar::DirL)) {
                            eor = current; status.eor = dirCurrent;
                        } else {
                            // numbers on both sides, neutrals get right to left direction
                            if(dir != QChar::DirL) {
                                appendItems(engine, sor, eor, control, dir);
                                dir = QChar::DirON; status.eor = QChar::DirON;
                                eor = current - 1;
                                dir = QChar::DirR;
                                appendItems(engine, sor, eor, control, dir);
                                dir = QChar::DirON; status.eor = QChar::DirON;
                                dir = QChar::DirAN;
                            } else {
                                eor = current; status.eor = dirCurrent;
                            }
                        }
                    default:
                        break;
                    }
                break;
            }
        case QChar::DirAN:
            hasBidi = true;
            dirCurrent = QChar::DirAN;
            if(dir == QChar::DirON) dir = QChar::DirAN;
            switch(status.last)
                {
                case QChar::DirL:
                case QChar::DirAN:
                    eor = current; status.eor = QChar::DirAN; break;
                case QChar::DirR:
                case QChar::DirAL:
                case QChar::DirEN:
                    if (eor >= 0){
                        appendItems(engine, sor, eor, control, dir);
                    } else {
                        eor = current;
                    }
                    dir = QChar::DirON; status.eor = QChar::DirAN;
                    break;
                case QChar::DirCS:
                    if(status.eor == QChar::DirAN) {
                        eor = current; break;
                    }
                case QChar::DirES:
                case QChar::DirET:
                case QChar::DirBN:
                case QChar::DirB:
                case QChar::DirS:
                case QChar::DirWS:
                case QChar::DirON:
                    if(status.eor == QChar::DirR) {
                        // neutrals go to R
                        eor = current - 1;
                        appendItems(engine, sor, eor, control, dir);
                        status.eor = QChar::DirAN;
                        dir = QChar::DirAN;
                    } else if(status.eor == QChar::DirL ||
                               (status.eor == QChar::DirEN && status.lastStrong == QChar::DirL)) {
                        eor = current; status.eor = dirCurrent;
                    } else {
                        // numbers on both sides, neutrals get right to left direction
                        if(dir != QChar::DirL) {
                            appendItems(engine, sor, eor, control, dir);
                            status.eor = QChar::DirON;
                            eor = current - 1;
                            dir = QChar::DirR;
                            appendItems(engine, sor, eor, control, dir);
                            status.eor = QChar::DirAN;
                            dir = QChar::DirAN;
                        } else {
                            eor = current; status.eor = dirCurrent;
                        }
                    }
                default:
                    break;
                }
            break;
        case QChar::DirES:
        case QChar::DirCS:
            break;
        case QChar::DirET:
            if(status.last == QChar::DirEN) {
                dirCurrent = QChar::DirEN;
                eor = current; status.eor = dirCurrent;
            }
            break;

            // boundary neutrals should be ignored
        case QChar::DirBN:
            break;
            // neutrals
        case QChar::DirB:
            // ### what do we do with newline and paragraph separators that come to here?
            break;
        case QChar::DirS:
            // ### implement rule L1
            break;
        case QChar::DirWS:
        case QChar::DirON:
            break;
        default:
            break;
        }

        //cout << "     after: dir=" << //        dir << " current=" << dirCurrent << " last=" << status.last << " eor=" << status.eor << " lastStrong=" << status.lastStrong << " embedding=" << control.direction() << endl;

        if(current >= (int)length) break;

        // set status.last as needed.
        switch(dirCurrent) {
        case QChar::DirET:
        case QChar::DirES:
        case QChar::DirCS:
        case QChar::DirS:
        case QChar::DirWS:
        case QChar::DirON:
            switch(status.last)
            {
            case QChar::DirL:
            case QChar::DirR:
            case QChar::DirAL:
            case QChar::DirEN:
            case QChar::DirAN:
                status.last = dirCurrent;
                break;
            default:
                status.last = QChar::DirON;
            }
            break;
        case QChar::DirNSM:
        case QChar::DirBN:
            // ignore these
            break;
        case QChar::DirLRO:
        case QChar::DirLRE:
            status.last = QChar::DirL;
            break;
        case QChar::DirRLO:
        case QChar::DirRLE:
            status.last = QChar::DirR;
            break;
        case QChar::DirEN:
            if (status.last == QChar::DirL) {
                status.last = QChar::DirL;
                break;
            }
            // fall through
        default:
            status.last = dirCurrent;
        }

        ++current;
    }

#if (BIDI_DEBUG >= 1)
    cout << "reached end of line current=" << current << ", eor=" << eor << endl;
#endif
    eor = current - 1; // remove dummy char

    if (sor <= eor)
        appendItems(engine, sor, eor, control, dir);

    return hasBidi;
}

void QTextEngine::bidiReorder(int numItems, const quint8 *levels, int *visualOrder)
{

    // first find highest and lowest levels
    uchar levelLow = 128;
    uchar levelHigh = 0;
    int i = 0;
    while (i < numItems) {
        //printf("level = %d\n", r->level);
        if (levels[i] > levelHigh)
            levelHigh = levels[i];
        if (levels[i] < levelLow)
            levelLow = levels[i];
        i++;
    }

    // implements reordering of the line (L2 according to BiDi spec):
    // L2. From the highest level found in the text to the lowest odd level on each line,
    // reverse any contiguous sequence of characters that are at that level or higher.

    // reversing is only done up to the lowest odd level
    if(!(levelLow%2)) levelLow++;

#if (BIDI_DEBUG >= 1)
    cout << "reorderLine: lineLow = " << (uint)levelLow << ", lineHigh = " << (uint)levelHigh << endl;
#endif

    int count = numItems - 1;
    for (i = 0; i < numItems; i++)
        visualOrder[i] = i;

    while(levelHigh >= levelLow) {
        int i = 0;
        while (i < count) {
            while(i < count && levels[i] < levelHigh) i++;
            int start = i;
            while(i <= count && levels[i] >= levelHigh) i++;
            int end = i-1;

            if(start != end) {
                //cout << "reversing from " << start << " to " << end << endl;
                for(int j = 0; j < (end-start+1)/2; j++) {
                    int tmp = visualOrder[start+j];
                    visualOrder[start+j] = visualOrder[end-j];
                    visualOrder[end-j] = tmp;
                }
            }
            i++;
        }
        levelHigh--;
    }

#if (BIDI_DEBUG >= 1)
    cout << "visual order is:" << endl;
    for (i = 0; i < numItems; i++)
        cout << visualOrder[i] << endl;
#endif
}


// -----------------------------------------------------------------------------------------------------
//
// The line break algorithm. See http://www.unicode.org/reports/tr14/tr14-13.html
//
// -----------------------------------------------------------------------------------------------------

/* The Unicode algorithm does in our opinion allow line breaks at some
   places they shouldn't be allowed. The following changes were thus
   made in comparison to the Unicode reference:

   EX->AL from DB to IB
   SY->AL from DB to IB
   SY->PO from DB to IB
   SY->PR from DB to IB
   SY->OP from DB to IB
   AL->PR from DB to IB
   AL->PO from DB to IB
   PR->PR from DB to IB
   PO->PO from DB to IB
   PR->PO from DB to IB
   PO->PR from DB to IB
   HY->PO from DB to IB
   HY->PR from DB to IB
   HY->OP from DB to IB
   NU->EX from PB to IB
   EX->PO from DB to IB
*/