Method resolveHref

src/svg/node/SVGPattern.cpp:84–129

https://www.w3.org/TR/SVG11/pservers.html#PatternElementHrefAttribute * * Any attributes which are defined on the referenced element which are not defined on this element * are inherited by this element. If this element has no children, and the referenced element does * (possibly due to its own ‘xlink:href’ attribute), then this element inherits the children from * the referenced element. Inh

 * the current element can inherit those attributes or children.
 */
const SVGPattern* SVGPattern::resolveHref(const SVGRenderContext& context,
                                          PatternAttributes* attrs) const {
  const SVGPattern* currentNode = this;
  const SVGPattern* contentNode = this;

  do {
    // Bitwise OR to avoid short-circuiting.
    const bool didInherit =
        inherit_if_needed(currentNode->X, attrs->x) | inherit_if_needed(currentNode->Y, attrs->y) |
        inherit_if_needed(currentNode->Width, attrs->width) |
        inherit_if_needed(currentNode->Height, attrs->height) |
        inherit_if_needed(currentNode->PatternTransform, attrs->patternTransform);

    if (!contentNode->hasChildren()) {
      contentNode = currentNode;
    }

    if (contentNode->hasChildren() && !didInherit) {
      // All attributes have been resolved, and a valid content node has been found.
      // We can terminate the href chain early.
      break;
    }

    currentNode = currentNode->hrefTarget(context);
  } while (currentNode);

  // To unify with Chrome and macOS preview, the width and height attributes here need to be
  // converted to percentages, direct numbers are not supported.
  if (PatternUnits.type() == SVGObjectBoundingBoxUnits::Type::UserSpaceOnUse) {
    if (attrs->width.has_value() && attrs->width->unit() == SVGLength::Unit::Percentage) {
      attrs->width = SVGLength(attrs->width->value() / 100.f, SVGLength::Unit::Number);
    }
    if (attrs->height.has_value() && attrs->height->unit() == SVGLength::Unit::Percentage) {
      attrs->height = SVGLength(attrs->height->value() / 100.f, SVGLength::Unit::Number);
    }
  } else if (PatternUnits.type() == SVGObjectBoundingBoxUnits::Type::ObjectBoundingBox) {
    if (attrs->width.has_value() && attrs->width->unit() == SVGLength::Unit::Number) {
      attrs->width = SVGLength(attrs->width->value() * 100.f, SVGLength::Unit::Percentage);
    }
    if (attrs->height.has_value() && attrs->height->unit() == SVGLength::Unit::Number) {
      attrs->height = SVGLength(attrs->height->value() * 100.f, SVGLength::Unit::Percentage);
    }
  }

  return contentNode;
}

bool SVGPattern::onAsPaint(const SVGRenderContext& context, Paint* paint) const {
  PatternAttributes attrs;