C++ SVGUseElement::hasAttribute方法代码示例

void RenderSVGViewportContainer::calcViewport()
{
    SVGSVGElement& svg = svgSVGElement();
    FloatRect oldViewport = m_viewport;

    SVGLengthContext lengthContext(&svg);
    m_viewport = FloatRect(svg.x().value(lengthContext), svg.y().value(lengthContext), svg.width().value(lengthContext), svg.height().value(lengthContext));

    SVGElement* correspondingElement = svg.correspondingElement();
    if (correspondingElement && svg.isInShadowTree()) {
        const HashSet<SVGElementInstance*>& instances = correspondingElement->instancesForElement();
        ASSERT(!instances.isEmpty());

        SVGUseElement* useElement = 0;
        const HashSet<SVGElementInstance*>::const_iterator end = instances.end();
        for (HashSet<SVGElementInstance*>::const_iterator it = instances.begin(); it != end; ++it) {
            const SVGElementInstance* instance = (*it);
            ASSERT(instance->correspondingElement()->hasTagName(SVGNames::svgTag) || instance->correspondingElement()->hasTagName(SVGNames::symbolTag));
            if (instance->shadowTreeElement() == &svg) {
                ASSERT(correspondingElement == instance->correspondingElement());
                useElement = instance->directUseElement();
                if (!useElement)
                    useElement = instance->correspondingUseElement();
                break;
            }
        }

        ASSERT(useElement);
        bool isSymbolElement = correspondingElement->hasTagName(SVGNames::symbolTag);

        // Spec (<use> on <symbol>): This generated 'svg' will always have explicit values for attributes width and height.
        // If attributes width and/or height are provided on the 'use' element, then these attributes
        // will be transferred to the generated 'svg'. If attributes width and/or height are not specified,
        // the generated 'svg' element will use values of 100% for these attributes.

        // Spec (<use> on <svg>): If attributes width and/or height are provided on the 'use' element, then these
        // values will override the corresponding attributes on the 'svg' in the generated tree.

        SVGLengthContext lengthContext(&svg);
        if (useElement->hasAttribute(SVGNames::widthAttr))
            m_viewport.setWidth(useElement->width().value(lengthContext));
        else if (isSymbolElement && svg.hasAttribute(SVGNames::widthAttr)) {
            SVGLength containerWidth(LengthModeWidth, "100%");
            m_viewport.setWidth(containerWidth.value(lengthContext));
        }

        if (useElement->hasAttribute(SVGNames::heightAttr))
            m_viewport.setHeight(useElement->height().value(lengthContext));
        else if (isSymbolElement && svg.hasAttribute(SVGNames::heightAttr)) {
            SVGLength containerHeight(LengthModeHeight, "100%");
            m_viewport.setHeight(containerHeight.value(lengthContext));
        }
    }

    if (oldViewport != m_viewport) {
        setNeedsBoundariesUpdate();
        setNeedsTransformUpdate();
    }
}

PassRefPtr<DisplayList> RenderSVGResourceClipper::asDisplayList(GraphicsContext* context,
    const AffineTransform& contentTransformation)
{
    ASSERT(context);
    ASSERT(frame());

    context->beginRecording(repaintRectInLocalCoordinates());

    // Switch to a paint behavior where all children of this <clipPath> will be rendered using special constraints:
    // - fill-opacity/stroke-opacity/opacity set to 1
    // - masker/filter not applied when rendering the children
    // - fill is set to the initial fill paint server (solid, black)
    // - stroke is set to the initial stroke paint server (none)
    PaintBehavior oldBehavior = frame()->view()->paintBehavior();
    frame()->view()->setPaintBehavior(oldBehavior | PaintBehaviorRenderingSVGMask);

    for (Node* childNode = element()->firstChild(); childNode; childNode = childNode->nextSibling()) {
        RenderObject* renderer = childNode->renderer();
        if (!childNode->isSVGElement() || !renderer)
            continue;

        RenderStyle* style = renderer->style();
        if (!style || style->display() == NONE || style->visibility() != VISIBLE)
            continue;

        WindRule newClipRule = style->svgStyle()->clipRule();
        bool isUseElement = childNode->hasTagName(SVGNames::useTag);
        if (isUseElement) {
            SVGUseElement* useElement = toSVGUseElement(childNode);
            renderer = useElement->rendererClipChild();
            if (!renderer)
                continue;
            if (!useElement->hasAttribute(SVGNames::clip_ruleAttr))
                newClipRule = renderer->style()->svgStyle()->clipRule();
        }

        // Only shapes, paths and texts are allowed for clipping.
        if (!renderer->isSVGShape() && !renderer->isSVGText())
            continue;

        context->setFillRule(newClipRule);

        if (isUseElement)
            renderer = childNode->renderer();

        SVGRenderingContext::renderSubtree(context, renderer, contentTransformation);
    }

    frame()->view()->setPaintBehavior(oldBehavior);

    return context->endRecording();
}

bool RenderSVGResourceClipper::drawContentIntoMaskImage(ClipperData* clipperData, const FloatRect& objectBoundingBox)
{
    ASSERT(clipperData);
    ASSERT(clipperData->clipMaskImage);

    GraphicsContext* maskContext = clipperData->clipMaskImage->context();
    ASSERT(maskContext);

    AffineTransform maskContentTransformation;
    SVGClipPathElement* clipPath = static_cast<SVGClipPathElement*>(node());
    if (clipPath->clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
        maskContentTransformation.translate(objectBoundingBox.x(), objectBoundingBox.y());
        maskContentTransformation.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
        maskContext->concatCTM(maskContentTransformation);
    }

    // Draw all clipPath children into a global mask.
    for (Node* childNode = node()->firstChild(); childNode; childNode = childNode->nextSibling()) {
        RenderObject* renderer = childNode->renderer();
        if (!childNode->isSVGElement() || !static_cast<SVGElement*>(childNode)->isStyled() || !renderer)
            continue;
        RenderStyle* style = renderer->style();
        if (!style || style->display() == NONE || style->visibility() != VISIBLE)
            continue;

        WindRule newClipRule = style->svgStyle()->clipRule();
        bool isUseElement = renderer->isSVGShadowTreeRootContainer();
        if (isUseElement) {
            SVGUseElement* useElement = static_cast<SVGUseElement*>(childNode);
            renderer = useElement->rendererClipChild();
            if (!renderer)
                continue;
            if (!useElement->hasAttribute(SVGNames::clip_ruleAttr))
                newClipRule = renderer->style()->svgStyle()->clipRule();
        }

        // Only shapes, paths and texts are allowed for clipping.
        if (!renderer->isSVGPath() && !renderer->isSVGText())
            continue;

        // Save the old RenderStyle of the current object for restoring after drawing
        // it to the MaskImage. The new intermediate RenderStyle needs to inherit from
        // the old one.
        RefPtr<RenderStyle> oldRenderStyle = renderer->style();
        RefPtr<RenderStyle> newRenderStyle = RenderStyle::clone(oldRenderStyle.get());
        SVGRenderStyle* svgStyle = newRenderStyle.get()->accessSVGStyle();
        svgStyle->setFillPaint(SVGPaint::defaultFill());
        svgStyle->setStrokePaint(SVGPaint::defaultStroke());
        svgStyle->setFillRule(newClipRule);
        newRenderStyle.get()->setOpacity(1.0f);
        svgStyle->setFillOpacity(1.0f);
        svgStyle->setStrokeOpacity(1.0f);
        svgStyle->setFilterResource(String());
        svgStyle->setMaskerResource(String());

        // The setStyle() call results in a styleDidChange() call, which in turn invalidations the resources.
        // As we're mutating the resource on purpose, block updates until we've resetted the style again.
        m_invalidationBlocked = true;
        renderer->setStyle(newRenderStyle.release());

        // In the case of a <use> element, we obtained its renderere above, to retrieve its clipRule.
        // We have to pass the <use> renderer itself to renderSubtreeToImageBuffer() to apply it's x/y/transform/etc. values when rendering.
        // So if isUseElement is true, refetch the childNode->renderer(), as renderer got overriden above.
        SVGImageBufferTools::renderSubtreeToImageBuffer(clipperData->clipMaskImage.get(), isUseElement ? childNode->renderer() : renderer, maskContentTransformation);

        renderer->setStyle(oldRenderStyle.release());
        m_invalidationBlocked = false;
    }

    return true;
}