Esempio n. 1
0
static void measureTextRenderer(RenderSVGInlineText* text, MeasureTextData* data, bool processRenderer)
{
    ASSERT(text);

    SVGTextLayoutAttributes* attributes = text->layoutAttributes();
    Vector<SVGTextMetrics>* textMetricsValues = &attributes->textMetricsValues();
    if (processRenderer) {
        if (data->allCharactersMap)
            attributes->clear();
        else
            textMetricsValues->clear();
    }

    SVGTextMetricsCalculator calculator(text);
    bool preserveWhiteSpace = text->style()->whiteSpace() == PRE;
    unsigned surrogatePairCharacters = 0;
    unsigned skippedCharacters = 0;
    unsigned textPosition = 0;
    unsigned textLength = calculator.textLength();

    SVGTextMetrics currentMetrics;
    for (; textPosition < textLength; textPosition += currentMetrics.length()) {
        currentMetrics = calculator.computeMetricsForCharacter(textPosition);
        if (!currentMetrics.length())
            break;

        bool characterIsWhiteSpace = calculator.characterIsWhiteSpace(textPosition);
        if (characterIsWhiteSpace && !preserveWhiteSpace && data->lastCharacterWasWhiteSpace) {
            if (processRenderer)
                textMetricsValues->append(SVGTextMetrics(SVGTextMetrics::SkippedSpaceMetrics));
            if (data->allCharactersMap)
                skippedCharacters += currentMetrics.length();
            continue;
        }

        if (processRenderer) {
            if (data->allCharactersMap) {
                const SVGCharacterDataMap::const_iterator it = data->allCharactersMap->find(data->valueListPosition + textPosition - skippedCharacters - surrogatePairCharacters + 1);
                if (it != data->allCharactersMap->end())
                    attributes->characterDataMap().set(textPosition + 1, it->value);
            }
            textMetricsValues->append(currentMetrics);
        }

        if (data->allCharactersMap && calculator.characterStartsSurrogatePair(textPosition))
            surrogatePairCharacters++;

        data->lastCharacterWasWhiteSpace = characterIsWhiteSpace;
    }

    if (!data->allCharactersMap)
        return;

    data->valueListPosition += textPosition - skippedCharacters;
}
SVGTextMetrics SVGTextMetricsCalculator::computeMetricsForCharacter(unsigned textPosition)
{
    if (m_bidiRun) {
        if (textPosition >= static_cast<unsigned>(m_bidiRun->stop())) {
            m_bidiRun = m_bidiRun->next();
            // New BiDi run means new reference position for measurements, so reset |m_totalWidth|.
            m_totalWidth = 0;
        }
        ASSERT(m_bidiRun);
        ASSERT(static_cast<int>(textPosition) < m_bidiRun->stop());
        m_textDirection = m_bidiRun->direction();
    }

    unsigned metricsLength = characterStartsSurrogatePair(textPosition) ? 2 : 1;
    SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(m_text, textPosition, metricsLength, m_textDirection);
    ASSERT(metrics.length() == metricsLength);

    unsigned startPosition = m_bidiRun ? m_bidiRun->start() : 0;
    ASSERT(startPosition <= textPosition);
    SVGTextMetrics complexStartToCurrentMetrics = SVGTextMetrics::measureCharacterRange(m_text, startPosition, textPosition - startPosition + metricsLength, m_textDirection);
    // Frequent case for Arabic text: when measuring a single character the arabic isolated form is taken
    // when laying out the glyph "in context" (with it's surrounding characters) it changes due to shaping.
    // So whenever currentWidth != currentMetrics.width(), we are processing a text run whose length is
    // not equal to the sum of the individual lengths of the glyphs, when measuring them isolated.
    float currentWidth = complexStartToCurrentMetrics.width() - m_totalWidth;
    if (currentWidth != metrics.width())
        metrics.setWidth(currentWidth);

    m_totalWidth = complexStartToCurrentMetrics.width();
    return metrics;
}
Esempio n. 3
0
void SVGTextLayoutAttributesBuilder::propagateLayoutAttributes(RenderObject* start, unsigned& atCharacter, UChar& lastCharacter) const
{
    for (RenderObject* child = start->firstChild(); child; child = child->nextSibling()) { 
        if (child->isSVGInlineText()) {
            RenderSVGInlineText* text = toRenderSVGInlineText(child);
            const UChar* characters = text->characters();
            unsigned textLength = text->textLength();
            bool preserveWhiteSpace = shouldPreserveAllWhiteSpace(text->style());

            SVGTextLayoutAttributes attributes;
            attributes.reserveCapacity(textLength);
    
            unsigned valueListPosition = atCharacter;
            unsigned metricsLength = 1;
            for (unsigned textPosition = 0; textPosition < textLength; textPosition += metricsLength) {
                const UChar& currentCharacter = characters[textPosition];

                SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(text, textPosition, 1);
                metricsLength = metrics.length();

                if (!preserveWhiteSpace && characterIsSpace(currentCharacter) && characterIsSpaceOrNull(lastCharacter)) {
                    assignEmptyLayoutAttributesForCharacter(attributes);
                    attributes.textMetricsValues().append(SVGTextMetrics::emptyMetrics());
                    continue;
                }

                assignLayoutAttributesForCharacter(attributes, metrics, valueListPosition);

                if (metricsLength > 1) {
                    for (unsigned i = 0; i < metricsLength - 1; ++i)
                        assignEmptyLayoutAttributesForCharacter(attributes);
                }

                lastCharacter = currentCharacter;
                valueListPosition += metricsLength;
            }

#if DUMP_TEXT_LAYOUT_ATTRIBUTES > 0
            fprintf(stderr, "\nDumping layout attributes for RenderSVGInlineText, renderer=%p, node=%p (atCharacter: %i)\n", text, text->node(), atCharacter);
            attributes.dump();
#endif

            text->storeLayoutAttributes(attributes);
            atCharacter = valueListPosition;
            continue;
        }

        if (!child->isSVGInline())
            continue;

        propagateLayoutAttributes(child, atCharacter, lastCharacter);
    }
}
Esempio n. 4
0
SVGTextMetrics SVGTextMetricsCalculator::computeMetricsForCharacterComplex(unsigned textPosition)
{
    unsigned metricsLength = characterStartsSurrogatePair(textPosition) ? 2 : 1;
    SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(m_text, textPosition, metricsLength, m_textDirection);
    ASSERT(metrics.length() == metricsLength);

    unsigned startPosition = m_bidiRun ? m_bidiRun->start() : 0;
    ASSERT(startPosition <= textPosition);
    SVGTextMetrics complexStartToCurrentMetrics = SVGTextMetrics::measureCharacterRange(m_text, startPosition, textPosition - startPosition + metricsLength, m_textDirection);
    // Frequent case for Arabic text: when measuring a single character the arabic isolated form is taken
    // when rendering the glyph "in context" (with it's surrounding characters) it changes due to shaping.
    // So whenever currentWidth != currentMetrics.width(), we are processing a text run whose length is
    // not equal to the sum of the individual lengths of the glyphs, when measuring them isolated.
    float currentWidth = complexStartToCurrentMetrics.width() - m_totalWidth;
    if (currentWidth != metrics.width())
        metrics.setWidth(currentWidth);

    m_totalWidth = complexStartToCurrentMetrics.width();
    return metrics;
}
Esempio n. 5
0
void SVGTextLayoutEngine::advanceToNextLogicalCharacter(const SVGTextMetrics& logicalMetrics)
{
    ++m_logicalMetricsListOffset;
    m_logicalCharacterOffset += logicalMetrics.length();
}
void SVGTextLayoutEngine::advanceToNextVisualCharacter(const SVGTextMetrics& visualMetrics)
{
    ++m_visualMetricsListOffset;
    m_visualCharacterOffset += visualMetrics.length();
}
Esempio n. 7
0
void SVGTextLayoutAttributesBuilder::propagateLayoutAttributes(RenderObject* start, Vector<SVGTextLayoutAttributes>& allAttributes, unsigned& atCharacter, UChar& lastCharacter) const
{
    for (RenderObject* child = start->firstChild(); child; child = child->nextSibling()) { 
        if (child->isSVGInlineText()) {
            RenderSVGInlineText* text = toRenderSVGInlineText(child);
            const UChar* characters = text->characters();
            unsigned textLength = text->textLength();
            bool preserveWhiteSpace = shouldPreserveAllWhiteSpace(text->style());

            SVGTextLayoutAttributes attributes(text);
            attributes.reserveCapacity(textLength);
    
            unsigned valueListPosition = atCharacter;
            unsigned metricsLength = 1;
            SVGTextMetrics lastMetrics(SVGTextMetrics::SkippedSpaceMetrics);

            for (unsigned textPosition = 0; textPosition < textLength; textPosition += metricsLength) {
                const UChar& currentCharacter = characters[textPosition];

                SVGTextMetrics startToCurrentMetrics;
                SVGTextMetrics currentMetrics;
                unsigned valueListAdvance = 0;

                if (U16_IS_LEAD(currentCharacter) && (textPosition + 1) < textLength && U16_IS_TRAIL(characters[textPosition + 1])) {
                    // Handle surrogate pairs.
                    startToCurrentMetrics = SVGTextMetrics::measureCharacterRange(text, 0, textPosition + 2);
                    currentMetrics = SVGTextMetrics::measureCharacterRange(text, textPosition, 2);
                    metricsLength = currentMetrics.length();
                    valueListAdvance = 1;
                } else {
                    // Handle BMP characters.
                    startToCurrentMetrics = SVGTextMetrics::measureCharacterRange(text, 0, textPosition + 1);
                    currentMetrics = SVGTextMetrics::measureCharacterRange(text, textPosition, 1);
                    metricsLength = currentMetrics.length();
                    valueListAdvance = metricsLength;
                }

                if (!metricsLength)
                    break;
                
                // Frequent case for Arabic text: when measuring a single character the arabic isolated form is taken
                // when rendering the glyph "in context" (with it's surrounding characters) it changes due to shaping.
                // So whenever runWidthAdvance != currentMetrics.width(), we are processing a text run whose length is
                // not equal to the sum of the individual lengths of the glyphs, when measuring them isolated.
                float runWidthAdvance = startToCurrentMetrics.width() - lastMetrics.width();
                if (runWidthAdvance != currentMetrics.width())
                    currentMetrics.setWidth(runWidthAdvance);

                lastMetrics = startToCurrentMetrics;

                if (!preserveWhiteSpace && characterIsSpace(currentCharacter) && characterIsSpaceOrNull(lastCharacter)) {
                    attributes.positioningLists().appendEmptyValues();
                    attributes.textMetricsValues().append(SVGTextMetrics(SVGTextMetrics::SkippedSpaceMetrics));
                    continue;
                }

                SVGTextLayoutAttributes::PositioningLists& positioningLists = attributes.positioningLists();
                positioningLists.appendValuesFromPosition(m_positioningLists, valueListPosition);
                attributes.textMetricsValues().append(currentMetrics);

                // Pad x/y/dx/dy/rotate value lists with empty values, if the metrics span more than one character.
                if (metricsLength > 1) {
                    for (unsigned i = 0; i < metricsLength - 1; ++i)
                        positioningLists.appendEmptyValues();
                }

                lastCharacter = currentCharacter;
                valueListPosition += valueListAdvance;
            }

#if DUMP_TEXT_LAYOUT_ATTRIBUTES > 0
            fprintf(stderr, "\nDumping layout attributes for RenderSVGInlineText, renderer=%p, node=%p (atCharacter: %i)\n", text, text->node(), atCharacter);
            fprintf(stderr, "BiDi properties: unicode-bidi=%i, block direction=%i\n", text->style()->unicodeBidi(), text->style()->direction());
            attributes.dump();
#endif

            text->storeLayoutAttributes(attributes);
            allAttributes.append(attributes);
            atCharacter = valueListPosition;
            continue;
        }

        if (!child->isSVGInline())
            continue;

        propagateLayoutAttributes(child, allAttributes, atCharacter, lastCharacter);
    }
}