bool SVGLinearGradientElement::collectGradientAttributes(LinearGradientAttributes& attributes)
{
    if (!renderer())
        return false;

    HashSet<SVGGradientElement*> processedGradients;
    SVGGradientElement* current = this;

    setGradientAttributes(current, attributes);
    processedGradients.add(current);

    while (true) {
        // Respect xlink:href, take attributes from referenced element
        Node* refNode = SVGURIReference::targetElementFromIRIString(current->href()->currentValue()->value(), treeScope());
        if (refNode && isSVGGradientElement(*refNode)) {
            current = toSVGGradientElement(refNode);

            // Cycle detection
            if (processedGradients.contains(current))
                return true;

            if (!current->renderer())
                return false;

            setGradientAttributes(current, attributes, isSVGLinearGradientElement(*current));
            processedGradients.add(current);
        } else {
            return true;
        }
    }

    ASSERT_NOT_REACHED();
    return false;
}
bool SVGLinearGradientElement::collectGradientAttributes(LinearGradientAttributes& attributes)
{
    if (!renderer())
        return false;

    HashSet<SVGGradientElement*> processedGradients;
    SVGGradientElement* current = this;

    setGradientAttributes(*current, attributes);
    processedGradients.add(current);

    while (true) {
        // Respect xlink:href, take attributes from referenced element
        Node* refNode = SVGURIReference::targetElementFromIRIString(current->href(), document());
        if (is<SVGGradientElement>(refNode)) {
            current = downcast<SVGGradientElement>(refNode);

            // Cycle detection
            if (processedGradients.contains(current))
                return true;

            if (!current->renderer())
                return false;

            setGradientAttributes(*current, attributes, current->hasTagName(SVGNames::linearGradientTag));
            processedGradients.add(current);
        } else
            return true;
    }

    ASSERT_NOT_REACHED();
    return false;
}
LinearGradientAttributes SVGLinearGradientElement::collectGradientProperties()
{
    LinearGradientAttributes attributes;
    HashSet<SVGGradientElement*> processedGradients;

    bool isLinear = true;
    SVGGradientElement* current = this;

    while (current) {
        if (!attributes.hasSpreadMethod() && current->hasAttribute(SVGNames::spreadMethodAttr))
            attributes.setSpreadMethod((GradientSpreadMethod) current->spreadMethod());

        if (!attributes.hasBoundingBoxMode() && current->hasAttribute(SVGNames::gradientUnitsAttr))
            attributes.setBoundingBoxMode(current->gradientUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX);

        if (!attributes.hasGradientTransform() && current->hasAttribute(SVGNames::gradientTransformAttr))
            attributes.setGradientTransform(current->gradientTransform()->consolidate().matrix());

        if (!attributes.hasStops()) {
            const Vector<Gradient::ColorStop>& stops(current->buildStops());
            if (!stops.isEmpty())
                attributes.setStops(stops);
        }

        if (isLinear) {
            SVGLinearGradientElement* linear = static_cast<SVGLinearGradientElement*>(current);

            if (!attributes.hasX1() && current->hasAttribute(SVGNames::x1Attr))
                attributes.setX1(linear->x1());

            if (!attributes.hasY1() && current->hasAttribute(SVGNames::y1Attr))
                attributes.setY1(linear->y1());

            if (!attributes.hasX2() && current->hasAttribute(SVGNames::x2Attr))
                attributes.setX2(linear->x2());

            if (!attributes.hasY2() && current->hasAttribute(SVGNames::y2Attr))
                attributes.setY2(linear->y2());
        }

        processedGradients.add(current);

        // Respect xlink:href, take attributes from referenced element
        Node* refNode = ownerDocument()->getElementById(SVGURIReference::getTarget(current->href()));
        if (refNode && (refNode->hasTagName(SVGNames::linearGradientTag) || refNode->hasTagName(SVGNames::radialGradientTag))) {
            current = static_cast<SVGGradientElement*>(refNode);

            // Cycle detection
            if (processedGradients.contains(current))
                return LinearGradientAttributes();

            isLinear = current->hasTagName(SVGNames::linearGradientTag);
        } else
            current = 0;
    }

    return attributes;
}
bool SVGRadialGradientElement::collectGradientAttributes(RadialGradientAttributes& attributes)
{
    if (!renderer())
        return false;

    WillBeHeapHashSet<RawPtrWillBeMember<SVGGradientElement> > processedGradients;
    SVGGradientElement* current = this;

    setGradientAttributes(current, attributes);
    processedGradients.add(current);

    while (true) {
        // Respect xlink:href, take attributes from referenced element
        Node* refNode = SVGURIReference::targetElementFromIRIString(current->href()->currentValue()->value(), treeScope());
        if (refNode && isSVGGradientElement(*refNode)) {
            current = toSVGGradientElement(refNode);

            // Cycle detection
            if (processedGradients.contains(current))
                break;

            if (!current->renderer())
                return false;

            setGradientAttributes(current, attributes, isSVGRadialGradientElement(*current));
            processedGradients.add(current);
        } else {
            break;
        }
    }

    // Handle default values for fx/fy
    if (!attributes.hasFx())
        attributes.setFx(attributes.cx());

    if (!attributes.hasFy())
        attributes.setFy(attributes.cy());

    return true;
}
bool SVGRadialGradientElement::collectGradientAttributes(RadialGradientAttributes& attributes)
{
    if (!renderer())
        return false;

    HashSet<SVGGradientElement*> processedGradients;
    SVGGradientElement* current = this;

    setGradientAttributes(*current, attributes);
    processedGradients.add(current);

    while (true) {
        // Respect xlink:href, take attributes from referenced element
        Node* refNode = SVGURIReference::targetElementFromIRIString(current->href(), document());
        if (is<SVGGradientElement>(refNode)) {
            current = downcast<SVGGradientElement>(refNode);

            // Cycle detection
            if (processedGradients.contains(current))
                break;

            if (!current->renderer())
                return false;

            setGradientAttributes(*current, attributes, current->hasTagName(SVGNames::radialGradientTag));
            processedGradients.add(current);
        } else
            break;
    }

    // Handle default values for fx/fy
    if (!attributes.hasFx())
        attributes.setFx(attributes.cx());

    if (!attributes.hasFy())
        attributes.setFy(attributes.cy());

    return true;
}