node.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

                return elem->namespaceURI();
            
            if (elem->hasAttributes()) {
                NamedAttrMap *attrs = elem->attributes();
                
                for (unsigned i = 0; i < attrs->length(); i++) {
                    Attribute *attr = attrs->attributeItem(i);
                    
                    if (attr->prefix() == "xmlns" && attr->localName() == prefix) {
                        if (!attr->value().isEmpty())
                            return attr->value();
                        
                        return String();
                    } else if (attr->localName() == "xmlns" && prefix.isNull()) {
                        if (!attr->value().isEmpty())
                            return attr->value();
                        
                        return String();
                    }
                }
            }
            if (Element* ancestor = ancestorElement())
                return ancestor->lookupNamespaceURI(prefix);
            return String();
        }
        case DOCUMENT_NODE:
            if (Element* de = static_cast<const Document*>(this)->documentElement())
                return de->lookupNamespaceURI(prefix);
            return String();
        case ENTITY_NODE:
        case NOTATION_NODE:
        case DOCUMENT_TYPE_NODE:
        case DOCUMENT_FRAGMENT_NODE:
            return String();
        case ATTRIBUTE_NODE: {
            const Attr *attr = static_cast<const Attr *>(this);
            
            if (attr->ownerElement())
                return attr->ownerElement()->lookupNamespaceURI(prefix);
            else
                return String();
        }
        default:
            if (Element* ancestor = ancestorElement())
                return ancestor->lookupNamespaceURI(prefix);
            return String();
    }
}

String Node::lookupNamespacePrefix(const AtomicString &_namespaceURI, const Element *originalElement) const
{
    if (_namespaceURI.isNull())
        return String();
            
    if (originalElement->lookupNamespaceURI(prefix()) == _namespaceURI)
        return prefix();
    
    if (hasAttributes()) {
        NamedAttrMap *attrs = attributes();
        
        for (unsigned i = 0; i < attrs->length(); i++) {
            Attribute *attr = attrs->attributeItem(i);
            
            if (attr->prefix() == "xmlns" &&
                attr->value() == _namespaceURI &&
                originalElement->lookupNamespaceURI(attr->localName()) == _namespaceURI)
                return attr->localName();
        }
    }
    
    if (Element* ancestor = ancestorElement())
        return ancestor->lookupNamespacePrefix(_namespaceURI, originalElement);
    return String();
}

void Node::appendTextContent(bool convertBRsToNewlines, StringBuilder& content) const
{
    switch (nodeType()) {
        case TEXT_NODE:
        case CDATA_SECTION_NODE:
        case COMMENT_NODE:
            content.append(static_cast<const CharacterData*>(this)->CharacterData::nodeValue());
            break;

        case PROCESSING_INSTRUCTION_NODE:
            content.append(static_cast<const ProcessingInstruction*>(this)->ProcessingInstruction::nodeValue());
            break;
        
        case ELEMENT_NODE:
            if (hasTagName(brTag) && convertBRsToNewlines) {
                content.append('\n');
                break;
        }
        // Fall through.
        case ATTRIBUTE_NODE:
        case ENTITY_NODE:
        case ENTITY_REFERENCE_NODE:
        case DOCUMENT_FRAGMENT_NODE:
            content.setNonNull();

            for (Node *child = firstChild(); child; child = child->nextSibling()) {
                if (child->nodeType() == COMMENT_NODE || child->nodeType() == PROCESSING_INSTRUCTION_NODE)
                    continue;
            
                child->appendTextContent(convertBRsToNewlines, content);
            }
            break;

        case DOCUMENT_NODE:
        case DOCUMENT_TYPE_NODE:
        case NOTATION_NODE:
        case XPATH_NAMESPACE_NODE:
            break;
    }
}

String Node::textContent(bool convertBRsToNewlines) const
{
    StringBuilder content;
    appendTextContent(convertBRsToNewlines, content);
    return content.toString();
}

void Node::setTextContent(const String &text, ExceptionCode& ec)
{           
    switch (nodeType()) {
        case TEXT_NODE:
        case CDATA_SECTION_NODE:
        case COMMENT_NODE:
        case PROCESSING_INSTRUCTION_NODE:
            setNodeValue(text, ec);
            break;
        case ELEMENT_NODE:
        case ATTRIBUTE_NODE:
        case ENTITY_NODE:
        case ENTITY_REFERENCE_NODE:
        case DOCUMENT_FRAGMENT_NODE: {
            ContainerNode *container = static_cast<ContainerNode *>(this);
            
            container->removeChildren();
            
            if (!text.isEmpty())
                appendChild(document()->createTextNode(text), ec);
            break;
        }
        case DOCUMENT_NODE:
        case DOCUMENT_TYPE_NODE:
        case NOTATION_NODE:
        default:
            // Do nothing
            break;
    }
}

Element* Node::ancestorElement() const
{
    // In theory, there can be EntityReference nodes between elements, but this is currently not supported.
    for (Node* n = parentNode(); n; n = n->parentNode()) {
        if (n->isElementNode())
            return static_cast<Element*>(n);
    }
    return 0;
}

bool Node::offsetInCharacters() const
{
    return false;
}

unsigned short Node::compareDocumentPosition(Node* otherNode)
{
    // It is not clear what should be done if |otherNode| is 0.
    if (!otherNode)
        return DOCUMENT_POSITION_DISCONNECTED;

    if (otherNode == this)
        return DOCUMENT_POSITION_EQUIVALENT;
    
    Attr* attr1 = nodeType() == ATTRIBUTE_NODE ? static_cast<Attr*>(this) : 0;
    Attr* attr2 = otherNode->nodeType() == ATTRIBUTE_NODE ? static_cast<Attr*>(otherNode) : 0;
    
    Node* start1 = attr1 ? attr1->ownerElement() : this;
    Node* start2 = attr2 ? attr2->ownerElement() : otherNode;
    
    // If either of start1 or start2 is null, then we are disconnected, since one of the nodes is
    // an orphaned attribute node.
    if (!start1 || !start2)
        return DOCUMENT_POSITION_DISCONNECTED | DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;

    Vector<Node*, 16> chain1;
    Vector<Node*, 16> chain2;
    if (attr1)
        chain1.append(attr1);
    if (attr2)
        chain2.append(attr2);
    
    if (attr1 && attr2 && start1 == start2 && start1) {
        // We are comparing two attributes on the same node.  Crawl our attribute map
        // and see which one we hit first.
        NamedAttrMap* map = attr1->ownerElement()->attributes(true);
        unsigned length = map->length();
        for (unsigned i = 0; i < length; ++i) {
            // If neither of the two determining nodes is a child node and nodeType is the same for both determining nodes, then an 
            // implementation-dependent order between the determining nodes is returned. This order is stable as long as no nodes of
            // the same nodeType are inserted into or removed from the direct container. This would be the case, for example, 
            // when comparing two attributes of the same element, and inserting or removing additional attributes might change 
            // the order between existing attributes.
            Attribute* attr = map->attributeItem(i);
            if (attr1->attr() == attr)
                return DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC | DOCUMENT_POSITION_FOLLOWING;
            if (attr2->attr() == attr)
                return DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC | DOCUMENT_POSITION_PRECEDING;
        }
        
        ASSERT_NOT_REACHED();
        return DOCUMENT_POSITION_DISCONNECTED;
    }

    // If one node is in the document and the other is not, we must be disconnected.
    // If the nodes have different owning documents, they must be disconnected.  Note that we avoid
    // comparing Attr nodes here, since they return false from inDocument() all the time (which seems like a bug).
    if (start1->inDocument() != start2->inDocument() ||
        start1->document() != start2->document())
        return DOCUMENT_POSITION_DISCONNECTED | DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;

    // We need to find a common ancestor container, and then compare the indices of the two immediate children.
    Node* current;
    for (current = start1; current; current = current->parentNode())
        chain1.append(current);
    for (current = start2; current; current = current->parentNode())
        chain2.append(current);
   
    // Walk the two chains backwards and look for the first difference.
    unsigned index1 = chain1.size();
    unsigned index2 = chain2.size();
    for (unsigned i = min(index1, index2); i; --i) {
        Node* child1 = chain1[--index1];
        Node* child2 = chain2[--index2];
        if (child1 != child2) {
            // If one of the children is an attribute, it wins.
            if (child1->nodeType() == ATTRIBUTE_NODE)
                return DOCUMENT_POSITION_FOLLOWING;
            if (child2->nodeType() == ATTRIBUTE_NODE)
                return DOCUMENT_POSITION_PRECEDING;
            
            if (!child2->nextSibling())
                return DOCUMENT_POSITION_FOLLOWING;
            if (!child1->nextSibling())
                return DOCUMENT_POSITION_PRECEDING;

            // Otherwise we need to see which node occurs first.  Crawl backwards from child2 looking for child1.
            for (Node* child = child2->previousSibling(); child; child = child->previousSibling()) {
                if (child == child1)
                    return DOCUMENT_POSITION_FOLLOWING;
            }
            return DOCUMENT_POSITION_PRECEDING;
        }
    }
    
    // There was no difference between the two parent chains, i.e., one was a subset of the other.  The shorter
    // chain is the ancestor.
    return index1 < index2 ? 
               DOCUMENT_POSITION_FOLLOWING | DOCUMENT_POSITION_CONTAINED_BY :
               DOCUMENT_POSITION_PRECEDING | DOCUMENT_POSITION_CONTAINS;
}

FloatPoint Node::convertToPage(const FloatPoint& p) const
{
    // If there is a renderer, just ask it to do the conversion
    if (renderer())
        return renderer()->localToAbsolute(p, false, true);
    
    // Otherwise go up the tree looking for a renderer
    Element *parent = ancestorElement();
    if (parent)
        return parent->convertToPage(p);

    // No parent - no conversion needed
    return p;
}

FloatPoint Node::convertFromPage(const FloatPoint& p) const
{
    // If there is a renderer, just ask it to do the conversion
    if (renderer())
        return renderer()->absoluteToLocal(p, false, true);

    // Otherwise go up the tree looking for a renderer
    Element *parent = ancestorElement();
    if (parent)
        return parent->convertFromPage(p);

    // No parent - no conversion needed
    return p;
}

#ifndef NDEBUG

static void appendAttributeDesc(const Node* node, String& string, const QualifiedName& name, const char* attrDesc)
{
    if (node->isElementNode()) {
        String attr = static_cast<const Element*>(node)->getAttribute(name);
        if (!attr.isEmpty()) {
            string += attrDesc;
            string += attr;
        }
    }
}

void Node::showNode(const char* prefix) const
{
    if (!prefix)
        prefix = "";
    if (isTextNode()) {
        String value = nodeValue();
        value.replace('\\', "\\\\");
        value.replace('\n', "\\n");
        fprintf(stderr, "%s%s\t%p \"%s\"\n", prefix, nodeName().utf8().data(), this, value.utf8().data());
    } else {
        String attrs = "";
        appendAttributeDesc(this, attrs, classAttr, " CLASS=");
        appendAttributeDesc(this, attrs, styleAttr, " STYLE=");
        fprintf(stderr, "%s%s\t%p%s\n", prefix, nodeName().utf8().data(), this, attrs.utf8().data());
    }
}

void Node::showTreeForThis() const
{
    showTreeAndMark(this, "*");
}

void Node::showTreeAndMark(const Node* markedNode1, const char* markedLabel1, const Node* markedNode2, const char * markedLabel2) const
{
    const Node* rootNode;
    const Node* node = this;
    while (node->parentNode() && !node->hasTagName(bodyTag))
        node = node->parentNode();
    rootNode = node;
        
    for (node = rootNode; node; node = node->traverseNextNode()) {
        if (node == markedNode1)
            fprintf(stderr, "%s", markedLabel1);
        if (node == markedNode2)
            fprintf(stderr, "%s", markedLabel2);
                        
        for (const Node* tmpNode = node; tmpNode && tmpNode != rootNode; tmpNode = tmpNode->parentNode())
            fprintf(stderr, "\t");
        node->showNode();
    }
}

void Node::formatForDebugger(char* buffer, unsigned length) const
{
    String result;
    String s;
    
    s = nodeName();
    if (s.length() == 0)
        result += "<none>";
    else
        result += s;
          
    strncpy(buffer, result.utf8().data(), length - 1);
}

#endif

// --------

void NodeListsNodeData::invalidateCaches()
{
    m_childNodeListCaches.reset();
    TagCacheMap::const_iterator tagCachesEnd = m_tagNodeListCaches.end();
    for (TagCacheMap::const_iterator it = m_tagNodeListCaches.begin(); it != tagCachesEnd; ++it)
        it->second->reset();
    invalidateCachesThatDependOnAttributes();
}

void NodeListsNodeData::invalidateCachesThatDependOnAttributes()
{
    CacheMap::iterator classCachesEnd = m_classNodeListCaches.end();
    for (CacheMap::iterator it = m_classNodeListCaches.begin(); it != classCachesEnd; ++it)
        it->second->reset();

    CacheMap::iterator nameCachesEnd = m_nameNodeListCaches.end();
    for (CacheMap::iterator it = m_nameNodeListCaches.begin(); it != nameCachesEnd; ++it)
        it->second->reset();
}

bool NodeListsNodeData::isEmpty() const
{
    if (!m_listsWithCaches.isEmpty())
        return false;

    if (m_childNodeListCaches.refCount)
        return false;
    
    TagCacheMap::const_iterator tagCachesEnd = m_tagNodeListCaches.end();
    for (TagCacheMap::const_iterator it = m_tagNodeListCaches.begin(); it != tagCachesEnd; ++it) {
        if (it->second->refCount)
            return false;
    }

    CacheMap::const_iterator classCachesEnd = m_classNodeListCaches.end();
    for (CacheMap::const_iterator it = m_classNodeListCaches.begin(); it != classCachesEnd; ++it) {
        if (it->second->refCount)
            return false;
    }

    CacheMap::const_iterator nameCachesEnd = m_nameNodeListCaches.end();
    for (CacheMap::const_iterator it = m_nameNodeListCaches.begin(); it != nameCachesEnd; ++it) {
        if (it->second->refCount)
            return false;
    }

    return true;
}

void Node::getSubresourceURLs(ListHashSet<KURL>& urls) const
{
    addSubresourceAttributeURLs(urls);
}

ContainerNode* Node::eventParentNode()
{
    Node* parent = parentNode();
    ASSERT(!parent || parent->isContainerNode());
    return static_cast<ContainerNode*>(parent);
}

// --------

ScriptExecutionContext* Node::scri