qtextengine.cpp

奇趣公司比较新的qt/emd版本

// The following line break classes are not treated by the table:
//  AI, BK, CB, CR, LF, NL, SA, SG, SP, XX

enum break_class {
    // the first 4 values have to agree with the enum in QCharAttributes
    ProhibitedBreak,            // PB in table
    DirectBreak,                // DB in table
    IndirectBreak,              // IB in table
    CombiningIndirectBreak,     // CI in table
    CombiningProhibitedBreak,   // CP in table
};
#define DB DirectBreak
#define IB IndirectBreak
#define CI CombiningIndirectBreak
#define CP CombiningProhibitedBreak
#define PB ProhibitedBreak

static const quint8 breakTable[QUnicodeTables::LineBreak_JT+1][QUnicodeTables::LineBreak_JT+1] =
{
/*          OP  CL  QU  GL  NS  EX  SY  IS  PR  PO  NU  AL  ID  IN  HY  BA  BB  B2  ZW  CM  WJ  H2  H3  JL  JV  JT */
/* OP */ { PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, CP, PB, PB, PB, PB, PB, PB },
/* CL */ { DB, PB, IB, IB, PB, PB, PB, PB, IB, IB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* QU */ { PB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
/* GL */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
/* NS */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* EX */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* SY */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* IS */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* PR */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, DB, IB, IB, DB, DB, PB, CI, PB, IB, IB, IB, IB, IB },
/* PO */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* NU */ { IB, PB, IB, IB, IB, IB, PB, PB, IB, IB, IB, IB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* AL */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* ID */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* IN */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* HY */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, DB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* BA */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* BB */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
/* B2 */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, DB, IB, IB, DB, PB, PB, CI, PB, DB, DB, DB, DB, DB },
/* ZW */ { DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, PB, DB, DB, DB, DB, DB, DB, DB },
/* CM */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, IB, IB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
/* WJ */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
/* H2 */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, IB, IB },
/* H3 */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, IB },
/* JL */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, IB, IB, IB, IB, DB },
/* JV */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, IB, IB },
/* JT */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, IB }
};
#undef DB
#undef IB
#undef CI
#undef CP
#undef PB


static void calcLineBreaks(const QString &string, QCharAttributes *charAttributes)
{
    int len = string.length();
    if (!len)
        return;

    const QChar *uc = string.unicode();
    // ##### can this fail if the first char is a surrogate?
    const QUnicodeTables::Properties *prop = QUnicodeTables::properties(uc->unicode());

    int cls = prop->line_break_class;
    // handle case where input starts with an LF
    if (cls == QUnicodeTables::LineBreak_LF)
        cls = QUnicodeTables::LineBreak_BK;

    charAttributes[0].whiteSpace = (cls == QUnicodeTables::LineBreak_SP || cls == QUnicodeTables::LineBreak_BK);
    charAttributes[0].charStop = true;

    int lcls = cls;
    for (int i = 1; i < len; ++i) {
        charAttributes[i].whiteSpace = false;
        charAttributes[i].charStop = true;

        prop = QUnicodeTables::properties(uc[i].unicode());

        int ncls = prop->line_break_class;
        // handle surrogates
        if (ncls == QUnicodeTables::LineBreak_SG) {
            if (uc[i].isHighSurrogate() && i < len - 1 && uc[i+1].isLowSurrogate()) {
                continue;
            } else if (uc[i].isLowSurrogate() && uc[i-1].isHighSurrogate()) {
                uint code = QChar::surrogateToUcs4(uc[i-1].unicode(), uc[i].unicode());
                prop = QUnicodeTables::properties(code);
                ncls = prop->line_break_class;
                charAttributes[i].charStop = false;
            } else {
                ncls = QUnicodeTables::LineBreak_AL;
            }
        }

        // set white space and char stop flag
        if (ncls >= QUnicodeTables::LineBreak_SP)
            charAttributes[i].whiteSpace = true;
        if (ncls == QUnicodeTables::LineBreak_CM)
            charAttributes[i].charStop = false;

        QCharAttributes::LineBreakType lineBreakType = QCharAttributes::NoBreak;
        if (cls >= QUnicodeTables::LineBreak_LF) {
            lineBreakType = QCharAttributes::ForcedBreak;
        } else if(cls == QUnicodeTables::LineBreak_CR) {
            lineBreakType = (ncls == QUnicodeTables::LineBreak_LF) ? QCharAttributes::NoBreak : QCharAttributes::ForcedBreak;
        }

        if (ncls == QUnicodeTables::LineBreak_SP)
            goto next_no_cls_update;
        if (ncls >= QUnicodeTables::LineBreak_CR)
            goto next;

        // two complex chars (thai or lao), thai_attributes might override, but here we do a best guess
	if (cls == QUnicodeTables::LineBreak_SA && ncls == QUnicodeTables::LineBreak_SA) {
            lineBreakType = QCharAttributes::Break;
            goto next;
        }

        {
            int tcls = ncls;
            if (tcls >= QUnicodeTables::LineBreak_SA)
                tcls = QUnicodeTables::LineBreak_ID;
            if (cls >= QUnicodeTables::LineBreak_SA)
                cls = QUnicodeTables::LineBreak_ID;

            int brk = breakTable[cls][tcls];
            switch (brk) {
            case DirectBreak:
                lineBreakType = QCharAttributes::Break;
                if (uc[i-1].unicode() == 0xad) // soft hyphen
                    lineBreakType = QCharAttributes::SoftHyphen;
                break;
            case IndirectBreak:
                lineBreakType = (lcls == QUnicodeTables::LineBreak_SP) ? QCharAttributes::Break : QCharAttributes::NoBreak;
                break;
            case CombiningIndirectBreak:
                lineBreakType = QCharAttributes::NoBreak;
                if (lcls == QUnicodeTables::LineBreak_SP){
                    if (i > 1)
                        charAttributes[i-2].lineBreakType = QCharAttributes::Break;
                } else {
                    goto next_no_cls_update;
                }
                break;
            case CombiningProhibitedBreak:
                lineBreakType = QCharAttributes::NoBreak;
                if (lcls != QUnicodeTables::LineBreak_SP)
                    goto next_no_cls_update;
            case ProhibitedBreak:
            default:
                break;
            }
        }
    next:
        cls = ncls;
    next_no_cls_update:
        lcls = ncls;
        charAttributes[i-1].lineBreakType = lineBreakType;
    }
    charAttributes[len-1].lineBreakType = QCharAttributes::ForcedBreak;
}

#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->forceJustification = false;

    e->layoutData = 0;

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

    e->underlinePositions = 0;
    e->specialData = 0;
    e->stackEngine = false;
}

QTextEngine::QTextEngine()
{
    init(this);
}

QTextEngine::QTextEngine(const QString &str, const QFont &f)
    : fnt(f)
{
    init(this);
    text = str;
}

QTextEngine::~QTextEngine()
{
    if (!stackEngine)
        delete layoutData;
    delete specialData;
}

const QCharAttributes *QTextEngine::attributes() const
{
    if (layoutData && layoutData->haveCharAttributes)
        return (QCharAttributes *) layoutData->memory;

    itemize();
    ensureSpace(layoutData->string.length());

    calcLineBreaks(layoutData->string, (QCharAttributes *) layoutData->memory);

    for (int i = 0; i < layoutData->items.size(); i++) {
        const QScriptItem &si = layoutData->items[i];
        int script = si.analysis.script;
#ifdef Q_WS_WIN
        if(hasUsp10) {
            script = QUnicodeTables::script(layoutData->string.at(si.position));
        }
#endif
        if (script == QUnicodeTables::Inherited)
            script = QUnicodeTables::Common;
        AttributeFunction attributes = qt_scriptEngines[script].charAttributes;
        if (!attributes)
            continue;
        int from = si.position;
        int len = length(i);
        attributes(script, layoutData->string, from, len, (QCharAttributes *) layoutData->memory);
    }

    layoutData->haveCharAttributes = true;
    return (QCharAttributes *) layoutData->memory;
}

void QTextEngine::shape(int item) const
{
    if (layoutData->items[item].isObject) {
        ensureSpace(1);
        if (block.docHandle()) {
            QTextFormat format = formats()->format(formatIndex(&layoutData->items[item]));
            docLayout()->resizeInlineObject(QTextInlineObject(item, const_cast<QTextEngine *>(this)),
                                            layoutData->items[item].position + block.position(), format);
        }
    } else {
        shapeText(item);
    }
}

void QTextEngine::invalidate()
{
    freeMemory();
    lines.clear();
    minWidth = 0;
    maxWidth = 0;
    if (specialData)
        specialData->resolvedFormatIndices.clear();
}

void QTextEngine::validate() const
{
    if (layoutData)
        return;
    layoutData = new LayoutData();
    if (block.docHandle())
        layoutData->string = block.text();
    else
        layoutData->string = text;
    if (specialData && specialData->preeditPosition != -1)
        layoutData->string.insert(specialData->preeditPosition, specialData->preeditText);
}


void QTextEngine::itemize() const
{
    validate();
    if (layoutData->items.size())
        return;

    if (layoutData->string.length() == 0)
        return;

    bool ignore = ignoreBidi;
    if (!ignore && option.textDirection() == Qt::LeftToRight) {
        ignore = true;
        const QChar *start = layoutData->string.unicode();
        const QChar * const end = start + layoutData->string.length();
        while (start < end) {
            if (start->unicode() >= 0x590) {
                ignore = false;
                break;
            }
            ++start;
        }
    }
    
    if (!ignore) {
        layoutData->hasBidi = bidiItemize(const_cast<QTextEngine *>(this), (option.textDirection() == Qt::RightToLeft));
    } else {
        QBidiControl control(false);
        int start = 0;
        int stop = layoutData->string.length() - 1;
        appendItems(const_cast<QTextEngine *>(this), start, stop, control, QChar::DirL);
        layoutData->hasBidi = false;
    }

    addRequiredBoundaries();
    resolveAdditionalFormats();
}

int QTextEngine::findItem(int strPos) const
{
    itemize();

    // ##### use binary search
    int item;
    for (item = layoutData->items.size()-1; item > 0; --item) {
        if (layoutData->items[item].position <= strPos)
            break;
    }
    return item;
}

QFixed QTextEngine::width(int from, int len) const
{
    itemize();

    QFixed w = 0;

//     qDebug("QTextEngine::width(from = %d, len = %d), numItems=%d, strleng=%d", from,  len, items.size(), string.length());
    for (int i = 0; i < layoutData->items.size(); i++) {
        const QScriptItem *si = layoutData->items.constData() + i;
        int pos = si->position;
        int ilen = length(i);
//          qDebug("item %d: from %d len %d", i, pos, ilen);
        if (pos >= from + len)
            break;
        if (pos + ilen > from) {
            if (!si->num_glyphs)
                shape(i);

            if (si->isObject) {
                w += si->width;
                continue;
            } else if (si->isTab) {
                w = nextTab(si, w);
                continue;
            }


            QGlyphLayout *glyphs = this->glyphs(si);
            unsigned short *logClusters = this->logClusters(si);

//             fprintf(stderr, "  logclusters:");
//             for (int k = 0; k < ilen; k++)