qtextengine.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

                        eor = current;
                        status.eor = dirCurrent;
                        break;
                    case QChar::DirR:
                    case QChar::DirAL:
                    case QChar::DirAN:
                        if (!first)
                            appendItems(engine, sor, eor, control, dir);
                        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 (!first)
                        appendItems(engine, sor, eor, control, dir);
                    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;
        }

        first = false;
        ++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:

   CL->AL from Dbk to Ibk
   CL->PR from Dbk to Ibk
   EX->AL from Dbk to Ibk
   IS->AL from Dbk to Ibk
   PO->AL from Dbk to Ibk
   SY->AL from Dbk to Ibk
   SY->PO from Dbk to Ibk
   SY->PR from Dbk to Ibk
   SY->OP from Dbk to Ibk
   Al->OP from Dbk to Ibk
   AL->HY from Dbk to Ibk
   AL->PR from Dbk to Ibk
   AL->PO from Dbk to Ibk
   PR->PR from Dbk to Ibk
   PO->PO from Dbk to Ibk
   PR->PO from Dbk to Ibk
   PO->PR from Dbk to Ibk
   HY->PO from Dbk to Ibk
   HY->PR from Dbk to Ibk
   HY->OP from Dbk to Ibk
   PO->OP from Dbk to Ibk
   NU->EX from Dbk to Ibk
   NU->PR from Dbk to Ibk
   PO->NU from Dbk to Ibk
   EX->PO from Dbk to Ibk
*/

enum break_action {
    Dbk, // Direct break
    Ibk, // Indirect break; only allowed if space between the two chars
    Pbk // Prohibited break; no break allowed even if space between chars
};

// The following line break classes are not treated by the table:
// SA, BK, CR, LF, SG, CB, SP
static const quint8 breakTable[QUnicodeTables::LineBreak_CM+1][QUnicodeTables::LineBreak_CM+1] =
{
    // OP,  CL,  QU,  GL, NS,  EX,  SY,  IS,  PR,  PO,  NU,  AL,  ID,  IN,  HY,  BA,  BB,  B2,  ZW,  CM
    { Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk, Pbk }, // OP
    { Dbk, Pbk, Ibk, Pbk, Pbk, Pbk, Pbk, Pbk, Ibk, Ibk, Dbk, Ibk, Dbk, Dbk, Ibk, Ibk, Pbk, Pbk, Pbk, Pbk }, // CL
    { Pbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Pbk, Pbk }, // QU
    { Ibk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Pbk, Pbk }, // GL
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // NS
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Ibk, Ibk, Ibk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // EX
    { Ibk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // SY
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // IS
    { Ibk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Ibk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Pbk }, // PR
    { Ibk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // PO
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Dbk, Ibk, Ibk, Ibk, Dbk, Dbk, Pbk, Pbk }, // NU
    { Ibk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Dbk, Ibk, Ibk, Ibk, Dbk, Dbk, Pbk, Pbk }, // AL
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Ibk, Dbk, Dbk, Dbk, Ibk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // ID
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Dbk, Dbk, Dbk, Dbk, Ibk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // IN
    { Ibk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // HY
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Ibk, Ibk, Dbk, Dbk, Pbk, Ibk }, // BA
    { Ibk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Ibk, Pbk, Ibk }, // BB
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Ibk, Ibk, Dbk, Pbk, Pbk, Ibk }, // B2
    { Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Dbk, Pbk, Ibk }, // ZW
    { Dbk, Pbk, Ibk, Pbk, Ibk, Pbk, Pbk, Pbk, Dbk, Ibk, Dbk, Dbk, Dbk, Ibk, Ibk, Ibk, Dbk, Dbk, Pbk, Pbk }  // CM
};

// set the soft break flag at every possible line breaking point. This needs correct clustering information.
static void calcLineBreaks(const QString &str, QCharAttributes *charAttributes)
{
    int len = str.length();
    if (!len)
        return;

    const QChar *uc = str.unicode();
    const QUnicodeTables::Properties *prop = QUnicodeTables::properties(uc->unicode());
    int cls = prop->line_break_class;
    if (cls >= QUnicodeTables::LineBreak_CM)
        cls = QUnicodeTables::LineBreak_ID;

    charAttributes[0].softBreak = false;
    charAttributes[0].whiteSpace = (cls == QUnicodeTables::LineBreak_SP || cls == QUnicodeTables::LineBreak_BK);
    charAttributes[0].charStop = true;
    charAttributes[0].category = prop->category;

    for (int i = 1; i < len; ++i) {
        prop = QUnicodeTables::properties(uc[i].unicode());
        int ncls = prop->line_break_class;
        int category = prop->category;
        if (category == QChar::Mark_NonSpacing)
            goto nsm;
        
        if (category == QChar::Other_Surrogate) {
            // char stop only on first pair
            if (uc[i].unicode() >= 0xd800 && uc[i].unicode() < 0xdc00 && i < len-1
                && uc[i+1].unicode() >= 0xdc00 && uc[i+1].unicode() < 0xe000)
                goto nsm;
            // ### correctly handle second surrogate
        }

        if (ncls == QUnicodeTables::LineBreak_SP || ncls == QUnicodeTables::LineBreak_BK) {
            charAttributes[i].softBreak = false;
            charAttributes[i].whiteSpace = true;
            charAttributes[i].charStop = true;
            charAttributes[i].category = QChar::Separator_Space;
            cls = ncls;
            continue;
        }


	if (cls == QUnicodeTables::LineBreak_SA && ncls == QUnicodeTables::LineBreak_SA) {
            // two complex chars (thai or lao), thai_attributes might override, but here
            // we do a best guess
            charAttributes[i].softBreak = true;
            charAttributes[i].whiteSpace = false;
            charAttributes[i].charStop = true;
            charAttributes[i].category = QChar::Separator_Space;
            cls = ncls;
            continue;
        }
        {
	    int tcls = ncls;
	    if (tcls >= QUnicodeTables::LineBreak_SA)
		tcls = QUnicodeTables::LineBreak_ID;
	    if (cls >= QUnicodeTables::LineBreak_SA)
		cls = QUnicodeTables::LineBreak_ID;

	    bool softBreak;
	    int brk = breakTable[cls][tcls];
	    if (brk == Ibk)
		softBreak = (cls == QUnicodeTables::LineBreak_SP);
	    else
		softBreak = (brk == Dbk);
//        qDebug("char = %c %04x, cls=%d, ncls=%d, brk=%d soft=%d", uc[i].cell(), uc[i].unicode(), cls, ncls, brk, charAttributes[i].softBreak);
	    charAttributes[i].softBreak = softBreak;
	    charAttributes[i].whiteSpace = false;
	    charAttributes[i].charStop = true;
	    charAttributes[i].category = category;
	    cls = ncls;
	}
        continue;
    nsm:
        charAttributes[i].softBreak = false;
        charAttributes[i].whiteSpace = false;
        charAttributes[i].charStop = false;
        charAttributes[i].category = QChar::Mark_NonSpacing;
    }
}

#if defined(Q_WS_X11) || defined (Q_WS_QWS)
# include "qtextengine_unix.cpp"
#elif defined(Q_WS_WIN)
# include "qtextengine_win.cpp"
#elif defined(Q_WS_MAC)
# include "qtextengine_mac.cpp"
#endif

static void init(QTextEngine *e)
{
#ifdef Q_WS_WIN
    if(!resolvedUsp10)
        resolveUsp10();
#endif
    e->ignoreBidi = false;
    e->cacheGlyphs = false;

    e->layoutData = 0;

    e->minWidth = 0;
    e->maxWidth = 0;

    e->underlinePositions = 0;