C++ SVGUseElement::title方法代码示例

String SVGStyledElement::title() const
{
    // According to spec, we should not return titles when hovering over root <svg> elements (those
    // <title> elements are the title of the document, not a tooltip) so we instantly return.
    if (isOutermostSVGSVGElement())
        return String();

    // Walk up the tree, to find out whether we're inside a <use> shadow tree, to find the right title.
    if (isInShadowTree()) {
        SVGUseElement* useElement = static_cast<SVGUseElement*>(treeScope()->rootNode()->shadowHost());
        ASSERT(useElement);

        // If the <use> title is not empty we found the title to use.
        String useTitle(useElement->title());
        if (!useTitle.isEmpty())
            return useTitle;
    }

    // If we aren't an instance in a <use> or the <use> title was not found, then find the first
    // <title> child of this element.
    Element* titleElement = firstElementChild();
    for (; titleElement; titleElement = titleElement->nextElementSibling()) {
        if (titleElement->hasTagName(SVGNames::titleTag) && titleElement->isSVGElement())
            break;
    }

    // If a title child was found, return the text contents.
    if (titleElement)
        return titleElement->innerText();
    
    // Otherwise return a null/empty string.
    return String();
}

String SVGStyledElement::title() const
{
    // According to spec, we should not return titles when hovering over root <svg> elements (those
    // <title> elements are the title of the document, not a tooltip) so we instantly return.
    if (hasTagName(SVGNames::svgTag)) {
        const SVGSVGElement* svg = static_cast<const SVGSVGElement*>(this);
        if (svg->isOutermostSVG())
            return String();
    }
    
    // Walk up the tree, to find out whether we're inside a <use> shadow tree, to find the right title.
    Node* parent = const_cast<SVGStyledElement*>(this);
    while (parent) {
        if (!parent->isSVGShadowRoot()) {
            parent = parent->parentNodeGuaranteedHostFree();
            continue;
        }
        
        // Get the <use> element.
        Element* shadowParent = parent->svgShadowHost();
        if (shadowParent && shadowParent->isSVGElement() && shadowParent->hasTagName(SVGNames::useTag)) {
            SVGUseElement* useElement = static_cast<SVGUseElement*>(shadowParent);
            // If the <use> title is not empty we found the title to use.
            String useTitle(useElement->title());
            if (useTitle.isEmpty())
                break;
            return useTitle;
        }
        parent = parent->parentNode();
    }
    
    // If we aren't an instance in a <use> or the <use> title was not found, then find the first
    // <title> child of this element.
    Element* titleElement = firstElementChild();
    for (; titleElement; titleElement = titleElement->nextElementSibling()) {
        if (titleElement->hasTagName(SVGNames::titleTag) && titleElement->isSVGElement())
            break;
    }

    // If a title child was found, return the text contents.
    if (titleElement)
        return titleElement->innerText();
    
    // Otherwise return a null/empty string.
    return String();
}

String SVGElement::title() const
{
    // According to spec, we should not return titles when hovering over root <svg> elements (those
    // <title> elements are the title of the document, not a tooltip) so we instantly return.
    if (isOutermostSVGSVGElement())
        return String();

    // Walk up the tree, to find out whether we're inside a <use> shadow tree, to find the right title.
    if (isInShadowTree()) {
        Element* shadowHostElement = toShadowRoot(treeScope().rootNode()).host();
        // At this time, SVG nodes are not allowed in non-<use> shadow trees, so any shadow root we do
        // have should be a use. The assert and following test is here to catch future shadow DOM changes
        // that do enable SVG in a shadow tree.
        ASSERT(!shadowHostElement || shadowHostElement->hasTagName(SVGNames::useTag));
        if (shadowHostElement && shadowHostElement->hasTagName(SVGNames::useTag)) {
            SVGUseElement* useElement = toSVGUseElement(shadowHostElement);

            // If the <use> title is not empty we found the title to use.
            String useTitle(useElement->title());
            if (!useTitle.isEmpty())
                return useTitle;
        }
    }

    // If we aren't an instance in a <use> or the <use> title was not found, then find the first
    // <title> child of this element.
    Element* titleElement = ElementTraversal::firstWithin(*this);
    for (; titleElement; titleElement = ElementTraversal::nextSkippingChildren(*titleElement, this)) {
        if (titleElement->hasTagName(SVGNames::titleTag) && titleElement->isSVGElement())
            break;
    }

    // If a title child was found, return the text contents.
    if (titleElement)
        return titleElement->innerText();

    // Otherwise return a null/empty string.
    return String();
}