C++ TextRun::activePaintServer方法代码示例

void Font::drawTextUsingSVGFont(GraphicsContext* context, const TextRun& run, 
                                const FloatPoint& point, int from, int to) const
{
    SVGFontElement* fontElement = 0;
    SVGFontFaceElement* fontFaceElement = 0;

    if (const SVGFontData* fontData = svgFontAndFontFaceElementForFontData(primaryFont(), fontFaceElement, fontElement)) {
        if (!fontElement)
            return;

        SVGTextRunWalkerDrawTextData data;
        FloatPoint currentPoint = point;
        float scale = convertEmUnitToPixel(size(), fontFaceElement->unitsPerEm(), 1.0f);

        SVGPaintServer* activePaintServer = run.activePaintServer();

        // If renderObject is not set, we're dealing for HTML text rendered using SVG Fonts.
        if (!run.referencingRenderObject()) {
            ASSERT(!activePaintServer);

            // TODO: We're only supporting simple filled HTML text so far.
            SVGPaintServerSolid* solidPaintServer = SVGPaintServer::sharedSolidPaintServer();
            solidPaintServer->setColor(context->fillColor());

            activePaintServer = solidPaintServer;
        }

        ASSERT(activePaintServer);

        int charsConsumed;
        String glyphName;
        bool isVerticalText = false;
        float xStartOffset = floatWidthOfSubStringUsingSVGFont(this, run, 0, run.rtl() ? to : 0, run.rtl() ? run.length() : from, charsConsumed, glyphName);
        FloatPoint glyphOrigin;

        String language;

        // TODO: language matching & svg glyphs should be possible for HTML text, too.
        if (run.referencingRenderObject()) {
            isVerticalText = isVerticalWritingMode(run.referencingRenderObject()->style()->svgStyle());    

            if (SVGElement* element = static_cast<SVGElement*>(run.referencingRenderObject()->element()))
                language = element->getAttribute(XMLNames::langAttr);
        }

        if (!isVerticalText) {
            glyphOrigin.setX(fontData->horizontalOriginX() * scale);
            glyphOrigin.setY(fontData->horizontalOriginY() * scale);
        }

        data.extraCharsAvailable = 0;
        data.charsConsumed = 0;

        SVGTextRunWalker<SVGTextRunWalkerDrawTextData> runWalker(fontData, fontElement, data, drawTextUsingSVGFontCallback, drawTextMissingGlyphCallback);
        runWalker.walk(run, isVerticalText, language, from, to);

        SVGPaintTargetType targetType = context->textDrawingMode() == cTextStroke ? ApplyToStrokeTargetType : ApplyToFillTargetType;

        unsigned numGlyphs = data.glyphIdentifiers.size();
        unsigned fallbackCharacterIndex = 0;
        for (unsigned i = 0; i < numGlyphs; ++i) {
            const SVGGlyphIdentifier& identifier = data.glyphIdentifiers[run.rtl() ? numGlyphs - i - 1 : i];
            if (identifier.isValid) {
                // FIXME: Support arbitary SVG content as glyph (currently limited to <glyph d="..."> situations).
                if (!identifier.pathData.isEmpty()) {
                    context->save();

                    if (isVerticalText) {
                        glyphOrigin.setX(identifier.verticalOriginX * scale);
                        glyphOrigin.setY(identifier.verticalOriginY * scale);
                    }

                    context->translate(xStartOffset + currentPoint.x() + glyphOrigin.x(), currentPoint.y() + glyphOrigin.y());
                    context->scale(FloatSize(scale, -scale));

                    context->beginPath();
                    context->addPath(identifier.pathData);

                    if (activePaintServer->setup(context, run.referencingRenderObject(), targetType)) {
                        // Spec: Any properties specified on a text elements which represents a length, such as the
                        // 'stroke-width' property, might produce surprising results since the length value will be
                        // processed in the coordinate system of the glyph. (TODO: What other lengths? miter-limit? dash-offset?)
                        if (targetType == ApplyToStrokeTargetType && scale != 0.0f)
                            context->setStrokeThickness(context->strokeThickness() / scale);

                        activePaintServer->renderPath(context, run.referencingRenderObject(), targetType);
                        activePaintServer->teardown(context, run.referencingRenderObject(), targetType);
                    }

                    context->restore();
                }

                if (isVerticalText)
                    currentPoint.move(0.0f, identifier.verticalAdvanceY * scale);
                else
                    currentPoint.move(identifier.horizontalAdvanceX * scale, 0.0f);
            } else {
                // Handle system font fallback
                FontDescription fontDescription(context->font().fontDescription());
                fontDescription.setFamily(FontFamily());
//.........这里部分代码省略.........