WebCore/dom/Element.cpp
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/dom/Element.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,1590 @@
+/*
+ * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
+ *           (C) 1999 Antti Koivisto (koivisto@kde.org)
+ *           (C) 2001 Peter Kelly (pmk@post.com)
+ *           (C) 2001 Dirk Mueller (mueller@kde.org)
+ *           (C) 2007 David Smith (catfish.man@gmail.com)
+ * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
+ *           (C) 2007 Eric Seidel (eric@webkit.org)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "config.h"
+#include "Element.h"
+
+#include "AXObjectCache.h"
+#include "Attr.h"
+#include "CSSParser.h"
+#include "CSSSelectorList.h"
+#include "CSSStyleSelector.h"
+#include "ClientRect.h"
+#include "ClientRectList.h"
+#include "DatasetDOMStringMap.h"
+#include "Document.h"
+#include "DocumentFragment.h"
+#include "ElementRareData.h"
+#include "ExceptionCode.h"
+#include "FocusController.h"
+#include "Frame.h"
+#include "FrameView.h"
+#include "HTMLElement.h"
+#include "HTMLNames.h"
+#include "InspectorController.h"
+#include "NodeList.h"
+#include "NodeRenderStyle.h"
+#include "Page.h"
+#include "RenderLayer.h"
+#include "RenderView.h"
+#include "RenderWidget.h"
+#include "TextIterator.h"
+#include "XMLNames.h"
+#include <wtf/text/CString.h>
+
+#if ENABLE(SVG)
+#include "SVGNames.h"
+#endif
+
+namespace WebCore {
+
+using namespace HTMLNames;
+using namespace XMLNames;
+    
+PassRefPtr<Element> Element::create(const QualifiedName& tagName, Document* document)
+{
+    return adoptRef(new Element(tagName, document, CreateElement));
+}
+
+Element::~Element()
+{
+    if (m_attributeMap)
+        m_attributeMap->detachFromElement();
+}
+
+inline ElementRareData* Element::rareData() const
+{
+    ASSERT(hasRareData());
+    return static_cast<ElementRareData*>(NodeRareData::rareDataFromMap(this));
+}
+    
+inline ElementRareData* Element::ensureRareData()
+{
+    return static_cast<ElementRareData*>(Node::ensureRareData());
+}
+    
+NodeRareData* Element::createRareData()
+{
+    return new ElementRareData;
+}
+
+PassRefPtr<DocumentFragment> Element::createContextualFragment(const String& markup, FragmentScriptingPermission scriptingPermission)
+{
+    RefPtr<DocumentFragment> fragment = document()->createDocumentFragment();
+
+    if (document()->isHTMLDocument())
+        fragment->parseHTML(markup, scriptingPermission);
+    else {
+        if (!fragment->parseXML(markup, this, scriptingPermission))
+            // FIXME: We should propagate a syntax error exception out here.
+            return 0;
+    }
+    
+    // Exceptions are ignored because none ought to happen here.
+    ExceptionCode ignoredExceptionCode;
+    
+    // We need to pop <html> and <body> elements and remove <head> to
+    // accommodate folks passing complete HTML documents to make the
+    // child of an element.
+    
+    RefPtr<Node> nextNode;
+    for (RefPtr<Node> node = fragment->firstChild(); node; node = nextNode) {
+        nextNode = node->nextSibling();
+        if (node->hasTagName(htmlTag) || node->hasTagName(bodyTag)) {
+            Node* firstChild = node->firstChild();
+            if (firstChild)
+                nextNode = firstChild;
+            RefPtr<Node> nextChild;
+            for (RefPtr<Node> child = firstChild; child; child = nextChild) {
+                nextChild = child->nextSibling();
+                node->removeChild(child.get(), ignoredExceptionCode);
+                ASSERT(!ignoredExceptionCode);
+                fragment->insertBefore(child, node.get(), ignoredExceptionCode);
+                ASSERT(!ignoredExceptionCode);
+            }
+            fragment->removeChild(node.get(), ignoredExceptionCode);
+            ASSERT(!ignoredExceptionCode);
+        } else if (node->hasTagName(headTag)) {
+            fragment->removeChild(node.get(), ignoredExceptionCode);
+            ASSERT(!ignoredExceptionCode);
+        }
+    }
+    
+    return fragment.release();
+}
+    
+PassRefPtr<Node> Element::cloneNode(bool deep)
+{
+    return deep ? cloneElementWithChildren() : cloneElementWithoutChildren();
+}
+
+PassRefPtr<Element> Element::cloneElementWithChildren()
+{
+    RefPtr<Element> clone = cloneElementWithoutChildren();
+    cloneChildNodes(clone.get());
+    return clone.release();
+}
+
+PassRefPtr<Element> Element::cloneElementWithoutChildren()
+{
+    RefPtr<Element> clone = document()->createElement(tagQName(), false);
+    // This will catch HTML elements in the wrong namespace that are not correctly copied.
+    // This is a sanity check as HTML overloads some of the DOM methods.
+    ASSERT(isHTMLElement() == clone->isHTMLElement());
+
+    // Call attributes(true) to force attribute synchronization to occur for SVG and style attributes.
+    if (NamedNodeMap* attributeMap = attributes(true))
+        clone->attributes()->setAttributes(*attributeMap);
+
+    clone->copyNonAttributeProperties(this);
+
+    return clone.release();
+}
+
+void Element::removeAttribute(const QualifiedName& name, ExceptionCode& ec)
+{
+    if (m_attributeMap) {
+        ec = 0;
+        m_attributeMap->removeNamedItem(name, ec);
+        if (ec == NOT_FOUND_ERR)
+            ec = 0;
+    }
+}
+
+void Element::setAttribute(const QualifiedName& name, const AtomicString& value)
+{
+    ExceptionCode ec;
+    setAttribute(name, value, ec);
+}
+    
+void Element::setCStringAttribute(const QualifiedName& name, const char* cStringValue)
+{
+    ExceptionCode ec;
+    setAttribute(name, AtomicString(cStringValue), ec);
+}
+
+void Element::setBooleanAttribute(const QualifiedName& name, bool b)
+{
+    if (b)
+        setAttribute(name, emptyAtom);
+    else {
+        ExceptionCode ex;
+        removeAttribute(name, ex);
+    }
+}
+
+Node::NodeType Element::nodeType() const
+{
+    return ELEMENT_NODE;
+}
+
+bool Element::hasAttribute(const QualifiedName& name) const
+{
+    return hasAttributeNS(name.namespaceURI(), name.localName());
+}
+
+const AtomicString& Element::getAttribute(const QualifiedName& name) const
+{
+    if (UNLIKELY(name == styleAttr) && !isStyleAttributeValid())
+        updateStyleAttribute();
+
+#if ENABLE(SVG)
+    if (UNLIKELY(!areSVGAttributesValid()))
+        updateAnimatedSVGAttribute(name);
+#endif
+
+    return fastGetAttribute(name);
+}
+
+void Element::scrollIntoView(bool alignToTop) 
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    IntRect bounds = getRect();    
+    if (renderer()) {
+        // Align to the top / bottom and to the closest edge.
+        if (alignToTop)
+            renderer()->enclosingLayer()->scrollRectToVisible(bounds, false, ScrollAlignment::alignToEdgeIfNeeded, ScrollAlignment::alignTopAlways);
+        else
+            renderer()->enclosingLayer()->scrollRectToVisible(bounds, false, ScrollAlignment::alignToEdgeIfNeeded, ScrollAlignment::alignBottomAlways);
+    }
+}
+
+void Element::scrollIntoViewIfNeeded(bool centerIfNeeded)
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    IntRect bounds = getRect();    
+    if (renderer()) {
+        if (centerIfNeeded)
+            renderer()->enclosingLayer()->scrollRectToVisible(bounds, false, ScrollAlignment::alignCenterIfNeeded, ScrollAlignment::alignCenterIfNeeded);
+        else
+            renderer()->enclosingLayer()->scrollRectToVisible(bounds, false, ScrollAlignment::alignToEdgeIfNeeded, ScrollAlignment::alignToEdgeIfNeeded);
+    }
+}
+
+void Element::scrollByUnits(int units, ScrollGranularity granularity)
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderObject *rend = renderer()) {
+        if (rend->hasOverflowClip()) {
+            ScrollDirection direction = ScrollDown;
+            if (units < 0) {
+                direction = ScrollUp;
+                units = -units;
+            }
+            toRenderBox(rend)->layer()->scroll(direction, granularity, units);
+        }
+    }
+}
+
+void Element::scrollByLines(int lines)
+{
+    scrollByUnits(lines, ScrollByLine);
+}
+
+void Element::scrollByPages(int pages)
+{
+    scrollByUnits(pages, ScrollByPage);
+}
+
+static float localZoomForRenderer(RenderObject* renderer)
+{
+    // FIXME: This does the wrong thing if two opposing zooms are in effect and canceled each
+    // other out, but the alternative is that we'd have to crawl up the whole render tree every
+    // time (or store an additional bit in the RenderStyle to indicate that a zoom was specified).
+    float zoomFactor = 1.0f;
+    if (renderer->style()->effectiveZoom() != 1.0f) {
+        // Need to find the nearest enclosing RenderObject that set up
+        // a differing zoom, and then we divide our result by it to eliminate the zoom.
+        RenderObject* prev = renderer;
+        for (RenderObject* curr = prev->parent(); curr; curr = curr->parent()) {
+            if (curr->style()->effectiveZoom() != prev->style()->effectiveZoom()) {
+                zoomFactor = prev->style()->zoom();
+                break;
+            }
+            prev = curr;
+        }
+        if (prev->isRenderView())
+            zoomFactor = prev->style()->zoom();
+    }
+    return zoomFactor;
+}
+
+static int adjustForLocalZoom(int value, RenderObject* renderer)
+{
+    float zoomFactor = localZoomForRenderer(renderer);
+    if (zoomFactor == 1)
+        return value;
+    // Needed because computeLengthInt truncates (rather than rounds) when scaling up.
+    if (zoomFactor > 1)
+        value++;
+    return static_cast<int>(value / zoomFactor);
+}
+
+int Element::offsetLeft()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBoxModelObject* rend = renderBoxModelObject())
+        return adjustForLocalZoom(rend->offsetLeft(), rend);
+    return 0;
+}
+
+int Element::offsetTop()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBoxModelObject* rend = renderBoxModelObject())
+        return adjustForLocalZoom(rend->offsetTop(), rend);
+    return 0;
+}
+
+int Element::offsetWidth()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBoxModelObject* rend = renderBoxModelObject())
+        return adjustForAbsoluteZoom(rend->offsetWidth(), rend);
+    return 0;
+}
+
+int Element::offsetHeight()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBoxModelObject* rend = renderBoxModelObject())
+        return adjustForAbsoluteZoom(rend->offsetHeight(), rend);
+    return 0;
+}
+
+Element* Element::offsetParent()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderObject* rend = renderer())
+        if (RenderObject* offsetParent = rend->offsetParent())
+            return static_cast<Element*>(offsetParent->node());
+    return 0;
+}
+
+int Element::clientLeft()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->clientLeft(), rend);
+    return 0;
+}
+
+int Element::clientTop()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->clientTop(), rend);
+    return 0;
+}
+
+int Element::clientWidth()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+
+    // When in strict mode, clientWidth for the document element should return the width of the containing frame.
+    // When in quirks mode, clientWidth for the body element should return the width of the containing frame.
+    bool inCompatMode = document()->inCompatMode();
+    if ((!inCompatMode && document()->documentElement() == this) ||
+        (inCompatMode && isHTMLElement() && document()->body() == this)) {
+        if (FrameView* view = document()->view()) {
+            if (RenderView* renderView = document()->renderView())
+                return adjustForAbsoluteZoom(view->layoutWidth(), renderView);
+        }
+    }
+    
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->clientWidth(), rend);
+    return 0;
+}
+
+int Element::clientHeight()
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+
+    // When in strict mode, clientHeight for the document element should return the height of the containing frame.
+    // When in quirks mode, clientHeight for the body element should return the height of the containing frame.
+    bool inCompatMode = document()->inCompatMode();     
+
+    if ((!inCompatMode && document()->documentElement() == this) ||
+        (inCompatMode && isHTMLElement() && document()->body() == this)) {
+        if (FrameView* view = document()->view()) {
+            if (RenderView* renderView = document()->renderView())
+                return adjustForAbsoluteZoom(view->layoutHeight(), renderView);
+        }
+    }
+    
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->clientHeight(), rend);
+    return 0;
+}
+
+int Element::scrollLeft() const
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->scrollLeft(), rend);
+    return 0;
+}
+
+int Element::scrollTop() const
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->scrollTop(), rend);
+    return 0;
+}
+
+void Element::setScrollLeft(int newLeft)
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBox* rend = renderBox())
+        rend->setScrollLeft(static_cast<int>(newLeft * rend->style()->effectiveZoom()));
+}
+
+void Element::setScrollTop(int newTop)
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBox* rend = renderBox())
+        rend->setScrollTop(static_cast<int>(newTop * rend->style()->effectiveZoom()));
+}
+
+int Element::scrollWidth() const
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->scrollWidth(), rend);
+    return 0;
+}
+
+int Element::scrollHeight() const
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    if (RenderBox* rend = renderBox())
+        return adjustForAbsoluteZoom(rend->scrollHeight(), rend);
+    return 0;
+}
+
+PassRefPtr<ClientRectList> Element::getClientRects() const
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+
+    RenderBoxModelObject* renderBoxModelObject = this->renderBoxModelObject();
+    if (!renderBoxModelObject)
+        return ClientRectList::create();
+
+    // FIXME: Handle SVG elements.
+    // FIXME: Handle table/inline-table with a caption.
+
+    Vector<FloatQuad> quads;
+    renderBoxModelObject->absoluteQuads(quads);
+
+    if (FrameView* view = document()->view()) {
+        IntRect visibleContentRect = view->visibleContentRect();
+        for (size_t i = 0; i < quads.size(); ++i) {
+            quads[i].move(-visibleContentRect.x(), -visibleContentRect.y());
+            adjustFloatQuadForAbsoluteZoom(quads[i], renderBoxModelObject);
+        }
+    }
+
+    return ClientRectList::create(quads);
+}
+
+PassRefPtr<ClientRect> Element::getBoundingClientRect() const
+{
+    document()->updateLayoutIgnorePendingStylesheets();
+    RenderBoxModelObject* renderBoxModelObject = this->renderBoxModelObject();
+    if (!renderBoxModelObject)
+        return ClientRect::create();
+
+    Vector<FloatQuad> quads;
+    renderBoxModelObject->absoluteQuads(quads);
+
+    if (quads.isEmpty())
+        return ClientRect::create();
+
+    IntRect result = quads[0].enclosingBoundingBox();
+    for (size_t i = 1; i < quads.size(); ++i)
+        result.unite(quads[i].enclosingBoundingBox());
+
+    if (FrameView* view = document()->view()) {
+        IntRect visibleContentRect = view->visibleContentRect();
+        result.move(-visibleContentRect.x(), -visibleContentRect.y());
+    }
+
+    adjustIntRectForAbsoluteZoom(result, renderBoxModelObject);
+
+    return ClientRect::create(result);
+}
+
+static inline bool shouldIgnoreAttributeCase(const Element* e)
+{
+    return e && e->document()->isHTMLDocument() && e->isHTMLElement();
+}
+
+const AtomicString& Element::getAttribute(const String& name) const
+{
+    bool ignoreCase = shouldIgnoreAttributeCase(this);
+    
+    // Update the 'style' attribute if it's invalid and being requested:
+    if (!isStyleAttributeValid() && equalPossiblyIgnoringCase(name, styleAttr.localName(), ignoreCase))
+        updateStyleAttribute();
+
+#if ENABLE(SVG)
+    if (!areSVGAttributesValid()) {
+        // We're not passing a namespace argument on purpose. SVGNames::*Attr are defined w/o namespaces as well.
+        updateAnimatedSVGAttribute(QualifiedName(nullAtom, name, nullAtom));
+    }
+#endif
+
+    if (m_attributeMap) {
+        if (Attribute* attribute = m_attributeMap->getAttributeItem(name, ignoreCase))
+            return attribute->value();
+    }
+
+    return nullAtom;
+}
+
+const AtomicString& Element::getAttributeNS(const String& namespaceURI, const String& localName) const
+{
+    return getAttribute(QualifiedName(nullAtom, localName, namespaceURI));
+}
+
+void Element::setAttribute(const AtomicString& name, const AtomicString& value, ExceptionCode& ec)
+{
+    if (!Document::isValidName(name)) {
+        ec = INVALID_CHARACTER_ERR;
+        return;
+    }
+
+#if COMPILER(RVCT)
+    const AtomicString localName = shouldIgnoreAttributeCase(this) ? name.lower() : name;
+#else
+    const AtomicString& localName = shouldIgnoreAttributeCase(this) ? name.lower() : name;
+#endif
+
+    // Allocate attribute map if necessary.
+    Attribute* old = attributes(false)->getAttributeItem(localName, false);
+
+    document()->incDOMTreeVersion();
+
+    // FIXME: This check is probably not correct for the case where the document has an id attribute
+    // with a non-null namespace, because it will return true if the local name happens to match
+    // but the namespace does not.
+    if (localName == document()->idAttributeName().localName())
+        updateId(old ? old->value() : nullAtom, value);
+
+    if (old && value.isNull())
+        m_attributeMap->removeAttribute(old->name());
+    else if (!old && !value.isNull())
+        m_attributeMap->addAttribute(createAttribute(QualifiedName(nullAtom, localName, nullAtom), value));
+    else if (old && !value.isNull()) {
+        old->setValue(value);
+        attributeChanged(old);
+    }
+
+#if ENABLE(INSPECTOR)
+    if (Page* page = document()->page()) {
+        if (InspectorController* inspectorController = page->inspectorController()) {
+            if (!isSynchronizingStyleAttribute())
+                inspectorController->didModifyDOMAttr(this);
+        }
+    }
+#endif
+}
+
+void Element::setAttribute(const QualifiedName& name, const AtomicString& value, ExceptionCode&)
+{
+    document()->incDOMTreeVersion();
+
+    // Allocate attribute map if necessary.
+    Attribute* old = attributes(false)->getAttributeItem(name);
+
+    if (isIdAttributeName(name))
+        updateId(old ? old->value() : nullAtom, value);
+
+    if (old && value.isNull())
+        m_attributeMap->removeAttribute(name);
+    else if (!old && !value.isNull())
+        m_attributeMap->addAttribute(createAttribute(name, value));
+    else if (old) {
+        old->setValue(value);
+        attributeChanged(old);
+    }
+
+#if ENABLE(INSPECTOR)
+    if (Page* page = document()->page()) {
+        if (InspectorController* inspectorController = page->inspectorController()) {
+            if (!isSynchronizingStyleAttribute())
+                inspectorController->didModifyDOMAttr(this);
+        }
+    }
+#endif
+}
+
+PassRefPtr<Attribute> Element::createAttribute(const QualifiedName& name, const AtomicString& value)
+{
+    return Attribute::create(name, value);
+}
+
+void Element::attributeChanged(Attribute* attr, bool)
+{
+    recalcStyleIfNeededAfterAttributeChanged(attr);
+    updateAfterAttributeChanged(attr);
+}
+
+void Element::updateAfterAttributeChanged(Attribute* attr)
+{
+    if (!AXObjectCache::accessibilityEnabled())
+        return;
+
+    const QualifiedName& attrName = attr->name();
+    if (attrName == aria_activedescendantAttr) {
+        // any change to aria-activedescendant attribute triggers accessibility focus change, but document focus remains intact
+        document()->axObjectCache()->handleActiveDescendantChanged(renderer());
+    } else if (attrName == roleAttr) {
+        // the role attribute can change at any time, and the AccessibilityObject must pick up these changes
+        document()->axObjectCache()->handleAriaRoleChanged(renderer());
+    } else if (attrName == aria_valuenowAttr) {
+        // If the valuenow attribute changes, AX clients need to be notified.
+        document()->axObjectCache()->postNotification(renderer(), AXObjectCache::AXValueChanged, true);
+    } else if (attrName == aria_labelAttr || attrName == aria_labeledbyAttr || attrName == altAttr || attrName == titleAttr) {
+        // If the content of an element changes due to an attribute change, notify accessibility.
+        document()->axObjectCache()->contentChanged(renderer());
+    } else if (attrName == aria_selectedAttr)
+        document()->axObjectCache()->selectedChildrenChanged(renderer());
+    else if (attrName == aria_expandedAttr)
+        document()->axObjectCache()->handleAriaExpandedChange(renderer());
+}
+    
+void Element::recalcStyleIfNeededAfterAttributeChanged(Attribute* attr)
+{
+    if (document()->attached() && document()->styleSelector()->hasSelectorForAttribute(attr->name().localName()))
+        setNeedsStyleRecalc();
+}
+
+// Returns true is the given attribute is an event handler.
+// We consider an event handler any attribute that begins with "on".
+// It is a simple solution that has the advantage of not requiring any
+// code or configuration change if a new event handler is defined.
+
+static bool isEventHandlerAttribute(const QualifiedName& name)
+{
+    return name.namespaceURI().isNull() && name.localName().startsWith("on");
+}
+
+static bool isAttributeToRemove(const QualifiedName& name, const AtomicString& value)
+{    
+    return (name.localName().endsWith(hrefAttr.localName()) || name == srcAttr || name == actionAttr) && protocolIsJavaScript(deprecatedParseURL(value));       
+}
+
+void Element::setAttributeMap(PassRefPtr<NamedNodeMap> list, FragmentScriptingPermission scriptingPermission)
+{
+    document()->incDOMTreeVersion();
+
+    // If setting the whole map changes the id attribute, we need to call updateId.
+
+    const QualifiedName& idName = document()->idAttributeName();
+    Attribute* oldId = m_attributeMap ? m_attributeMap->getAttributeItem(idName) : 0;
+    Attribute* newId = list ? list->getAttributeItem(idName) : 0;
+
+    if (oldId || newId)
+        updateId(oldId ? oldId->value() : nullAtom, newId ? newId->value() : nullAtom);
+
+    if (m_attributeMap)
+        m_attributeMap->m_element = 0;
+
+    m_attributeMap = list;
+
+    if (m_attributeMap) {
+        m_attributeMap->m_element = this;
+        // If the element is created as result of a paste or drag-n-drop operation
+        // we want to remove all the script and event handlers.
+        if (scriptingPermission == FragmentScriptingNotAllowed) {
+            unsigned i = 0;
+            while (i < m_attributeMap->length()) {
+                const QualifiedName& attributeName = m_attributeMap->m_attributes[i]->name();
+                if (isEventHandlerAttribute(attributeName)) {
+                    m_attributeMap->m_attributes.remove(i);
+                    continue;
+                }
+
+                if (isAttributeToRemove(attributeName, m_attributeMap->m_attributes[i]->value()))
+                    m_attributeMap->m_attributes[i]->setValue(nullAtom);
+                i++;
+            }
+        }
+        unsigned len = m_attributeMap->length();
+        for (unsigned i = 0; i < len; i++)
+            attributeChanged(m_attributeMap->m_attributes[i].get());
+        // FIXME: What about attributes that were in the old map that are not in the new map?
+    }
+}
+
+bool Element::hasAttributes() const
+{
+    if (!isStyleAttributeValid())
+        updateStyleAttribute();
+
+#if ENABLE(SVG)
+    if (!areSVGAttributesValid())
+        updateAnimatedSVGAttribute(anyQName());
+#endif
+
+    return m_attributeMap && m_attributeMap->length();
+}
+
+String Element::nodeName() const
+{
+    return m_tagName.toString();
+}
+
+String Element::nodeNamePreservingCase() const
+{
+    return m_tagName.toString();
+}
+
+void Element::setPrefix(const AtomicString& prefix, ExceptionCode& ec)
+{
+    ec = 0;
+    checkSetPrefix(prefix, ec);
+    if (ec)
+        return;
+
+    m_tagName.setPrefix(prefix.isEmpty() ? AtomicString() : prefix);
+}
+
+KURL Element::baseURI() const
+{
+    const AtomicString& baseAttribute = getAttribute(baseAttr);
+    KURL base(KURL(), baseAttribute);
+    if (!base.protocol().isEmpty())
+        return base;
+
+    Node* parent = parentNode();
+    if (!parent)
+        return base;
+
+    const KURL& parentBase = parent->baseURI();
+    if (parentBase.isNull())
+        return base;
+
+    return KURL(parentBase, baseAttribute);
+}
+
+void Element::createAttributeMap() const
+{
+    m_attributeMap = NamedNodeMap::create(const_cast<Element*>(this));
+}
+
+bool Element::isURLAttribute(Attribute*) const
+{
+    return false;
+}
+
+const QualifiedName& Element::imageSourceAttributeName() const
+{
+    return srcAttr;
+}
+
+RenderObject* Element::createRenderer(RenderArena* arena, RenderStyle* style)
+{
+    if (document()->documentElement() == this && style->display() == NONE) {
+        // Ignore display: none on root elements.  Force a display of block in that case.
+        RenderBlock* result = new (arena) RenderBlock(this);
+        if (result)
+            result->setAnimatableStyle(style);
+        return result;
+    }
+    return RenderObject::createObject(this, style);
+}
+
+
+void Element::insertedIntoDocument()
+{
+    // need to do superclass processing first so inDocument() is true
+    // by the time we reach updateId
+    ContainerNode::insertedIntoDocument();
+
+    if (hasID()) {
+        if (m_attributeMap) {
+            Attribute* idItem = m_attributeMap->getAttributeItem(document()->idAttributeName());
+            if (idItem && !idItem->isNull())
+                updateId(nullAtom, idItem->value());
+        }
+    }
+}
+
+void Element::removedFromDocument()
+{
+    if (hasID()) {
+        if (m_attributeMap) {
+            Attribute* idItem = m_attributeMap->getAttributeItem(document()->idAttributeName());
+            if (idItem && !idItem->isNull())
+                updateId(idItem->value(), nullAtom);
+        }
+    }
+
+    ContainerNode::removedFromDocument();
+}
+
+void Element::attach()
+{
+    suspendPostAttachCallbacks();
+    RenderWidget::suspendWidgetHierarchyUpdates();
+
+    createRendererIfNeeded();
+    ContainerNode::attach();
+    if (hasRareData()) {   
+        ElementRareData* data = rareData();
+        if (data->needsFocusAppearanceUpdateSoonAfterAttach()) {
+            if (isFocusable() && document()->focusedNode() == this)
+                document()->updateFocusAppearanceSoon(false /* don't restore selection */);
+            data->setNeedsFocusAppearanceUpdateSoonAfterAttach(false);
+        }
+    }
+
+    RenderWidget::resumeWidgetHierarchyUpdates();
+    resumePostAttachCallbacks();
+}
+
+void Element::detach()
+{
+    RenderWidget::suspendWidgetHierarchyUpdates();
+
+    cancelFocusAppearanceUpdate();
+    if (hasRareData())
+        rareData()->resetComputedStyle();
+    ContainerNode::detach();
+
+    RenderWidget::resumeWidgetHierarchyUpdates();
+}
+
+bool Element::pseudoStyleCacheIsInvalid(const RenderStyle* currentStyle, RenderStyle* newStyle)
+{
+    ASSERT(currentStyle == renderStyle());
+
+    if (!renderer() || !currentStyle)
+        return false;
+
+    const PseudoStyleCache* pseudoStyleCache = currentStyle->cachedPseudoStyles();
+    if (!pseudoStyleCache)
+        return false;
+
+    size_t cacheSize = pseudoStyleCache->size();
+    for (size_t i = 0; i < cacheSize; ++i) {
+        RefPtr<RenderStyle> newPseudoStyle;
+        PseudoId pseudoId = pseudoStyleCache->at(i)->styleType();
+        if (pseudoId == VISITED_LINK) {
+            newPseudoStyle =  newStyle->getCachedPseudoStyle(VISITED_LINK); // This pseudo-style was aggressively computed already when we first called styleForElement on the new style.
+            if (!newPseudoStyle || *newPseudoStyle != *pseudoStyleCache->at(i))
+                return true;
+        } else if (pseudoId == FIRST_LINE || pseudoId == FIRST_LINE_INHERITED)
+            newPseudoStyle = renderer()->uncachedFirstLineStyle(newStyle);
+        else
+            newPseudoStyle = renderer()->getUncachedPseudoStyle(pseudoId, newStyle, newStyle);
+        if (!newPseudoStyle)
+            return true;
+        if (*newPseudoStyle != *pseudoStyleCache->at(i)) {
+            if (pseudoId < FIRST_INTERNAL_PSEUDOID)
+                newStyle->setHasPseudoStyle(pseudoId);
+            newStyle->addCachedPseudoStyle(newPseudoStyle);
+            if (pseudoId == FIRST_LINE || pseudoId == FIRST_LINE_INHERITED) {
+                // FIXME: We should do an actual diff to determine whether a repaint vs. layout
+                // is needed, but for now just assume a layout will be required.  The diff code
+                // in RenderObject::setStyle would need to be factored out so that it could be reused.
+                renderer()->setNeedsLayoutAndPrefWidthsRecalc();
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
+void Element::recalcStyle(StyleChange change)
+{
+    // Ref currentStyle in case it would otherwise be deleted when setRenderStyle() is called.
+    RefPtr<RenderStyle> currentStyle(renderStyle());
+    bool hasParentStyle = parentNode() ? parentNode()->renderStyle() : false;
+    bool hasPositionalRules = needsStyleRecalc() && currentStyle && currentStyle->childrenAffectedByPositionalRules();
+    bool hasDirectAdjacentRules = currentStyle && currentStyle->childrenAffectedByDirectAdjacentRules();
+
+#if ENABLE(SVG)
+    if (!hasParentStyle && isShadowNode() && isSVGElement())
+        hasParentStyle = true;
+#endif
+
+    if ((change > NoChange || needsStyleRecalc())) {
+        if (hasRareData())
+            rareData()->resetComputedStyle();
+    }
+    if (hasParentStyle && (change >= Inherit || needsStyleRecalc())) {
+        RefPtr<RenderStyle> newStyle = document()->styleSelector()->styleForElement(this);
+        StyleChange ch = diff(currentStyle.get(), newStyle.get());
+        if (ch == Detach || !currentStyle) {
+            if (attached())
+                detach();
+            attach(); // FIXME: The style gets computed twice by calling attach. We could do better if we passed the style along.
+            // attach recalulates the style for all children. No need to do it twice.
+            setNeedsStyleRecalc(NoStyleChange);
+            clearChildNeedsStyleRecalc();
+            return;
+        }
+
+        if (currentStyle) {
+            // Preserve "affected by" bits that were propagated to us from descendants in the case where we didn't do a full
+            // style change (e.g., only inline style changed).
+            if (currentStyle->affectedByHoverRules())
+                newStyle->setAffectedByHoverRules(true);
+            if (currentStyle->affectedByActiveRules())
+                newStyle->setAffectedByActiveRules(true);
+            if (currentStyle->affectedByDragRules())
+                newStyle->setAffectedByDragRules(true);
+            if (currentStyle->childrenAffectedByForwardPositionalRules())
+                newStyle->setChildrenAffectedByForwardPositionalRules();
+            if (currentStyle->childrenAffectedByBackwardPositionalRules())
+                newStyle->setChildrenAffectedByBackwardPositionalRules();
+            if (currentStyle->childrenAffectedByFirstChildRules())
+                newStyle->setChildrenAffectedByFirstChildRules();
+            if (currentStyle->childrenAffectedByLastChildRules())
+                newStyle->setChildrenAffectedByLastChildRules();
+            if (currentStyle->childrenAffectedByDirectAdjacentRules())
+                newStyle->setChildrenAffectedByDirectAdjacentRules();
+        }
+
+        if (ch != NoChange || pseudoStyleCacheIsInvalid(currentStyle.get(), newStyle.get()) || (change == Force && renderer() && renderer()->requiresForcedStyleRecalcPropagation())) {
+            setRenderStyle(newStyle);
+        } else if (needsStyleRecalc() && (styleChangeType() != SyntheticStyleChange) && (document()->usesSiblingRules() || document()->usesDescendantRules())) {
+            // Although no change occurred, we use the new style so that the cousin style sharing code won't get
+            // fooled into believing this style is the same.  This is only necessary if the document actually uses
+            // sibling/descendant rules, since otherwise it isn't possible for ancestor styles to affect sharing of
+            // descendants.
+            if (renderer())
+                renderer()->setStyleInternal(newStyle.get());
+            else
+                setRenderStyle(newStyle);
+        } else if (styleChangeType() == SyntheticStyleChange)
+             setRenderStyle(newStyle);
+
+        if (change != Force) {
+            // If "rem" units are used anywhere in the document, and if the document element's font size changes, then go ahead and force font updating
+            // all the way down the tree.  This is simpler than having to maintain a cache of objects (and such font size changes should be rare anyway).
+            if (document()->usesRemUnits() && ch != NoChange && currentStyle && newStyle && currentStyle->fontSize() != newStyle->fontSize() && document()->documentElement() == this)
+                change = Force;
+            else if ((document()->usesDescendantRules() || hasPositionalRules) && styleChangeType() >= FullStyleChange)
+                change = Force;
+            else
+                change = ch;
+        }
+    }
+
+    // FIXME: This check is good enough for :hover + foo, but it is not good enough for :hover + foo + bar.
+    // For now we will just worry about the common case, since it's a lot trickier to get the second case right
+    // without doing way too much re-resolution.
+    bool forceCheckOfNextElementSibling = false;
+    for (Node *n = firstChild(); n; n = n->nextSibling()) {
+        bool childRulesChanged = n->needsStyleRecalc() && n->styleChangeType() == FullStyleChange;
+        if (forceCheckOfNextElementSibling && n->isElementNode())
+            n->setNeedsStyleRecalc();
+        if (change >= Inherit || n->isTextNode() || n->childNeedsStyleRecalc() || n->needsStyleRecalc())
+            n->recalcStyle(change);
+        if (n->isElementNode())
+            forceCheckOfNextElementSibling = childRulesChanged && hasDirectAdjacentRules;
+    }
+
+    setNeedsStyleRecalc(NoStyleChange);
+    clearChildNeedsStyleRecalc();
+}
+
+bool Element::childTypeAllowed(NodeType type)
+{
+    switch (type) {
+        case ELEMENT_NODE:
+        case TEXT_NODE:
+        case COMMENT_NODE:
+        case PROCESSING_INSTRUCTION_NODE:
+        case CDATA_SECTION_NODE:
+        case ENTITY_REFERENCE_NODE:
+            return true;
+            break;
+        default:
+            return false;
+    }
+}
+
+static void checkForSiblingStyleChanges(Element* e, RenderStyle* style, bool finishedParsingCallback,
+                                        Node* beforeChange, Node* afterChange, int childCountDelta)
+{
+    if (!style || (e->needsStyleRecalc() && style->childrenAffectedByPositionalRules()))
+        return;
+
+    // :first-child.  In the parser callback case, we don't have to check anything, since we were right the first time.
+    // In the DOM case, we only need to do something if |afterChange| is not 0.
+    // |afterChange| is 0 in the parser case, so it works out that we'll skip this block.
+    if (style->childrenAffectedByFirstChildRules() && afterChange) {
+        // Find our new first child.
+        Node* newFirstChild = 0;
+        for (newFirstChild = e->firstChild(); newFirstChild && !newFirstChild->isElementNode(); newFirstChild = newFirstChild->nextSibling()) {};
+        
+        // Find the first element node following |afterChange|
+        Node* firstElementAfterInsertion = 0;
+        for (firstElementAfterInsertion = afterChange;
+             firstElementAfterInsertion && !firstElementAfterInsertion->isElementNode();
+             firstElementAfterInsertion = firstElementAfterInsertion->nextSibling()) {};
+        
+        // This is the insert/append case.
+        if (newFirstChild != firstElementAfterInsertion && firstElementAfterInsertion && firstElementAfterInsertion->attached() &&
+            firstElementAfterInsertion->renderStyle() && firstElementAfterInsertion->renderStyle()->firstChildState())
+            firstElementAfterInsertion->setNeedsStyleRecalc();
+            
+        // We also have to handle node removal.
+        if (childCountDelta < 0 && newFirstChild == firstElementAfterInsertion && newFirstChild && newFirstChild->renderStyle() && !newFirstChild->renderStyle()->firstChildState())
+            newFirstChild->setNeedsStyleRecalc();
+    }
+
+    // :last-child.  In the parser callback case, we don't have to check anything, since we were right the first time.
+    // In the DOM case, we only need to do something if |afterChange| is not 0.
+    if (style->childrenAffectedByLastChildRules() && beforeChange) {
+        // Find our new last child.
+        Node* newLastChild = 0;
+        for (newLastChild = e->lastChild(); newLastChild && !newLastChild->isElementNode(); newLastChild = newLastChild->previousSibling()) {};
+        
+        // Find the last element node going backwards from |beforeChange|
+        Node* lastElementBeforeInsertion = 0;
+        for (lastElementBeforeInsertion = beforeChange;
+             lastElementBeforeInsertion && !lastElementBeforeInsertion->isElementNode();
+             lastElementBeforeInsertion = lastElementBeforeInsertion->previousSibling()) {};
+        
+        if (newLastChild != lastElementBeforeInsertion && lastElementBeforeInsertion && lastElementBeforeInsertion->attached() &&
+            lastElementBeforeInsertion->renderStyle() && lastElementBeforeInsertion->renderStyle()->lastChildState())
+            lastElementBeforeInsertion->setNeedsStyleRecalc();
+            
+        // We also have to handle node removal.  The parser callback case is similar to node removal as well in that we need to change the last child
+        // to match now.
+        if ((childCountDelta < 0 || finishedParsingCallback) && newLastChild == lastElementBeforeInsertion && newLastChild && newLastChild->renderStyle() && !newLastChild->renderStyle()->lastChildState())
+            newLastChild->setNeedsStyleRecalc();
+    }
+
+    // The + selector.  We need to invalidate the first element following the insertion point.  It is the only possible element
+    // that could be affected by this DOM change.
+    if (style->childrenAffectedByDirectAdjacentRules() && afterChange) {
+        Node* firstElementAfterInsertion = 0;
+        for (firstElementAfterInsertion = afterChange;
+             firstElementAfterInsertion && !firstElementAfterInsertion->isElementNode();
+             firstElementAfterInsertion = firstElementAfterInsertion->nextSibling()) {};
+        if (firstElementAfterInsertion && firstElementAfterInsertion->attached())
+            firstElementAfterInsertion->setNeedsStyleRecalc();
+    }
+
+    // Forward positional selectors include the ~ selector, nth-child, nth-of-type, first-of-type and only-of-type.
+    // Backward positional selectors include nth-last-child, nth-last-of-type, last-of-type and only-of-type.
+    // We have to invalidate everything following the insertion point in the forward case, and everything before the insertion point in the
+    // backward case.
+    // |afterChange| is 0 in the parser callback case, so we won't do any work for the forward case if we don't have to.
+    // For performance reasons we just mark the parent node as changed, since we don't want to make childrenChanged O(n^2) by crawling all our kids
+    // here.  recalcStyle will then force a walk of the children when it sees that this has happened.
+    if ((style->childrenAffectedByForwardPositionalRules() && afterChange) ||
+        (style->childrenAffectedByBackwardPositionalRules() && beforeChange))
+        e->setNeedsStyleRecalc();
+    
+    // :empty selector.
+    if (style->affectedByEmpty() && (!style->emptyState() || e->hasChildNodes()))
+        e->setNeedsStyleRecalc();
+}
+
+void Element::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
+{
+    ContainerNode::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
+    if (!changedByParser)
+        checkForSiblingStyleChanges(this, renderStyle(), false, beforeChange, afterChange, childCountDelta);
+}
+
+void Element::finishParsingChildren()
+{
+    ContainerNode::finishParsingChildren();
+    setIsParsingChildrenFinished();
+    checkForSiblingStyleChanges(this, renderStyle(), true, lastChild(), 0, 0);
+}
+
+void Element::dispatchAttrRemovalEvent(Attribute*)
+{
+    ASSERT(!eventDispatchForbidden());
+
+#if 0
+    if (!document()->hasListenerType(Document::DOMATTRMODIFIED_LISTENER))
+        return;
+    ExceptionCode ec = 0;
+    dispatchEvent(MutationEvent::create(DOMAttrModifiedEvent, true, attr, attr->value(),
+        attr->value(), document()->attrName(attr->id()), MutationEvent::REMOVAL), ec);
+#endif
+}
+
+void Element::dispatchAttrAdditionEvent(Attribute*)
+{
+    ASSERT(!eventDispatchForbidden());
+
+#if 0
+    if (!document()->hasListenerType(Document::DOMATTRMODIFIED_LISTENER))
+        return;
+    ExceptionCode ec = 0;
+    dispatchEvent(MutationEvent::create(DOMAttrModifiedEvent, true, attr, attr->value(),
+        attr->value(), document()->attrName(attr->id()), MutationEvent::ADDITION), ec);
+#endif
+}
+
+String Element::openTagStartToString() const
+{
+    String result = "<" + nodeName();
+
+    NamedNodeMap* attrMap = attributes(true);
+
+    if (attrMap) {
+        unsigned numAttrs = attrMap->length();
+        for (unsigned i = 0; i < numAttrs; i++) {
+            result += " ";
+
+            Attribute *attribute = attrMap->attributeItem(i);
+            result += attribute->name().toString();
+            if (!attribute->value().isNull()) {
+                result += "=\"";
+                // FIXME: substitute entities for any instances of " or '
+                result += attribute->value();
+                result += "\"";
+            }
+        }
+    }
+
+    return result;
+}
+
+#ifndef NDEBUG
+void Element::formatForDebugger(char* buffer, unsigned length) const
+{
+    String result;
+    String s;
+    
+    s = nodeName();
+    if (s.length() > 0) {
+        result += s;
+    }
+          
+    s = getIdAttribute();
+    if (s.length() > 0) {
+        if (result.length() > 0)
+            result += "; ";
+        result += "id=";
+        result += s;
+    }
+          
+    s = getAttribute(classAttr);
+    if (s.length() > 0) {
+        if (result.length() > 0)
+            result += "; ";
+        result += "class=";
+        result += s;
+    }
+          
+    strncpy(buffer, result.utf8().data(), length - 1);
+}
+#endif
+
+PassRefPtr<Attr> Element::setAttributeNode(Attr* attr, ExceptionCode& ec)
+{
+    if (!attr) {
+        ec = TYPE_MISMATCH_ERR;
+        return 0;
+    }
+    return static_pointer_cast<Attr>(attributes(false)->setNamedItem(attr, ec));
+}
+
+PassRefPtr<Attr> Element::setAttributeNodeNS(Attr* attr, ExceptionCode& ec)
+{
+    if (!attr) {
+        ec = TYPE_MISMATCH_ERR;
+        return 0;
+    }
+    return static_pointer_cast<Attr>(attributes(false)->setNamedItem(attr, ec));
+}
+
+PassRefPtr<Attr> Element::removeAttributeNode(Attr* attr, ExceptionCode& ec)
+{
+    if (!attr) {
+        ec = TYPE_MISMATCH_ERR;
+        return 0;
+    }
+    if (attr->ownerElement() != this) {
+        ec = NOT_FOUND_ERR;
+        return 0;
+    }
+    if (document() != attr->document()) {
+        ec = WRONG_DOCUMENT_ERR;
+        return 0;
+    }
+
+    NamedNodeMap* attrs = attributes(true);
+    if (!attrs)
+        return 0;
+
+    return static_pointer_cast<Attr>(attrs->removeNamedItem(attr->qualifiedName(), ec));
+}
+
+void Element::setAttributeNS(const AtomicString& namespaceURI, const AtomicString& qualifiedName, const AtomicString& value, ExceptionCode& ec, FragmentScriptingPermission scriptingPermission)
+{
+    String prefix, localName;
+    if (!Document::parseQualifiedName(qualifiedName, prefix, localName, ec))
+        return;
+
+    QualifiedName qName(prefix, localName, namespaceURI);
+
+    if (scriptingPermission == FragmentScriptingNotAllowed && (isEventHandlerAttribute(qName) || isAttributeToRemove(qName, value)))
+        return;
+
+    setAttribute(qName, value, ec);
+}
+
+void Element::removeAttribute(const String& name, ExceptionCode& ec)
+{
+    String localName = shouldIgnoreAttributeCase(this) ? name.lower() : name;
+
+    if (m_attributeMap) {
+        m_attributeMap->removeNamedItem(localName, ec);
+        if (ec == NOT_FOUND_ERR)
+            ec = 0;
+    }
+    
+#if ENABLE(INSPECTOR)
+    if (Page* page = document()->page()) {
+        if (InspectorController* inspectorController = page->inspectorController())
+            inspectorController->didModifyDOMAttr(this);
+    }
+#endif
+    
+}
+
+void Element::removeAttributeNS(const String& namespaceURI, const String& localName, ExceptionCode& ec)
+{
+    removeAttribute(QualifiedName(nullAtom, localName, namespaceURI), ec);
+}
+
+PassRefPtr<Attr> Element::getAttributeNode(const String& name)
+{
+    NamedNodeMap* attrs = attributes(true);
+    if (!attrs)
+        return 0;
+    String localName = shouldIgnoreAttributeCase(this) ? name.lower() : name;
+    return static_pointer_cast<Attr>(attrs->getNamedItem(localName));
+}
+
+PassRefPtr<Attr> Element::getAttributeNodeNS(const String& namespaceURI, const String& localName)
+{
+    NamedNodeMap* attrs = attributes(true);
+    if (!attrs)
+        return 0;
+    return static_pointer_cast<Attr>(attrs->getNamedItem(QualifiedName(nullAtom, localName, namespaceURI)));
+}
+
+bool Element::hasAttribute(const String& name) const
+{
+    NamedNodeMap* attrs = attributes(true);
+    if (!attrs)
+        return false;
+
+    // This call to String::lower() seems to be required but
+    // there may be a way to remove it.
+    String localName = shouldIgnoreAttributeCase(this) ? name.lower() : name;
+    return attrs->getAttributeItem(localName, false);
+}
+
+bool Element::hasAttributeNS(const String& namespaceURI, const String& localName) const
+{
+    NamedNodeMap* attrs = attributes(true);
+    if (!attrs)
+        return false;
+    return attrs->getAttributeItem(QualifiedName(nullAtom, localName, namespaceURI));
+}
+
+CSSStyleDeclaration *Element::style()
+{
+    return 0;
+}
+
+void Element::focus(bool restorePreviousSelection)
+{
+    Document* doc = document();
+    if (doc->focusedNode() == this)
+        return;
+
+    if (!supportsFocus())
+        return;
+
+    // If the stylesheets have already been loaded we can reliably check isFocusable.
+    // If not, we continue and set the focused node on the focus controller below so
+    // that it can be updated soon after attach. 
+    if (doc->haveStylesheetsLoaded()) {
+        doc->updateLayoutIgnorePendingStylesheets();
+        if (!isFocusable())
+            return;
+    }
+
+    RefPtr<Node> protect;
+    if (Page* page = doc->page()) {
+        // Focus and change event handlers can cause us to lose our last ref.
+        protect = this;
+        page->focusController()->setFocusedNode(this, doc->frame());
+    }
+
+    // Setting the focused node above might have invalidated the layout due to scripts.
+    doc->updateLayoutIgnorePendingStylesheets();
+
+    if (!isFocusable()) {
+        ensureRareData()->setNeedsFocusAppearanceUpdateSoonAfterAttach(true);
+        return;
+    }
+        
+    cancelFocusAppearanceUpdate();
+    updateFocusAppearance(restorePreviousSelection);
+}
+
+void Element::updateFocusAppearance(bool /*restorePreviousSelection*/)
+{
+    if (this == rootEditableElement()) { 
+        Frame* frame = document()->frame();
+        if (!frame)
+            return;
+
+        // FIXME: We should restore the previous selection if there is one.
+        VisibleSelection newSelection = hasTagName(htmlTag) || hasTagName(bodyTag) ? VisibleSelection(Position(this, 0), DOWNSTREAM) : VisibleSelection::selectionFromContentsOfNode(this);
+        
+        if (frame->shouldChangeSelection(newSelection)) {
+            frame->selection()->setSelection(newSelection);
+            frame->revealSelection();
+        }
+    } else if (renderer() && !renderer()->isWidget())
+        renderer()->enclosingLayer()->scrollRectToVisible(getRect());
+}
+
+void Element::blur()
+{
+    cancelFocusAppearanceUpdate();
+    Document* doc = document();
+    if (doc->focusedNode() == this) {
+        if (doc->frame())
+            doc->frame()->page()->focusController()->setFocusedNode(0, doc->frame());
+        else
+            doc->setFocusedNode(0);
+    }
+}
+
+String Element::innerText() const
+{
+    // We need to update layout, since plainText uses line boxes in the render tree.
+    document()->updateLayoutIgnorePendingStylesheets();
+
+    if (!renderer())
+        return textContent(true);
+
+    return plainText(rangeOfContents(const_cast<Element*>(this)).get());
+}
+
+String Element::outerText() const
+{
+    // Getting outerText is the same as getting innerText, only
+    // setting is different. You would think this should get the plain
+    // text for the outer range, but this is wrong, <br> for instance
+    // would return different values for inner and outer text by such
+    // a rule, but it doesn't in WinIE, and we want to match that.
+    return innerText();
+}
+
+String Element::title() const
+{
+    return String();
+}
+
+IntSize Element::minimumSizeForResizing() const
+{
+    return hasRareData() ? rareData()->m_minimumSizeForResizing : defaultMinimumSizeForResizing();
+}
+
+void Element::setMinimumSizeForResizing(const IntSize& size)
+{
+    if (size == defaultMinimumSizeForResizing() && !hasRareData())
+        return;
+    ensureRareData()->m_minimumSizeForResizing = size;
+}
+
+RenderStyle* Element::computedStyle(PseudoId pseudoElementSpecifier)
+{
+    // FIXME: Find and use the renderer from the pseudo element instead of the actual element so that the 'length'
+    // properties, which are only known by the renderer because it did the layout, will be correct and so that the
+    // values returned for the ":selection" pseudo-element will be correct.
+    if (RenderStyle* usedStyle = renderStyle())
+        return pseudoElementSpecifier ? usedStyle->getCachedPseudoStyle(pseudoElementSpecifier) : usedStyle;
+
+    if (!attached())
+        // FIXME: Try to do better than this. Ensure that styleForElement() works for elements that are not in the
+        // document tree and figure out when to destroy the computed style for such elements.
+        return 0;
+
+    ElementRareData* data = ensureRareData();
+    if (!data->m_computedStyle)
+        data->m_computedStyle = document()->styleForElementIgnoringPendingStylesheets(this);
+    return pseudoElementSpecifier ? data->m_computedStyle->getCachedPseudoStyle(pseudoElementSpecifier) : data->m_computedStyle.get();
+}
+
+void Element::cancelFocusAppearanceUpdate()
+{
+    if (hasRareData())
+        rareData()->setNeedsFocusAppearanceUpdateSoonAfterAttach(false);
+    if (document()->focusedNode() == this)
+        document()->cancelFocusAppearanceUpdate();
+}
+
+void Element::normalizeAttributes()
+{
+    // Normalize attributes.
+    NamedNodeMap* attrs = attributes(true);
+    if (!attrs)
+        return;
+
+    if (attrs->isEmpty())
+        return;
+
+    Vector<RefPtr<Attribute> > attributeVector;
+    attrs->copyAttributesToVector(attributeVector);
+    size_t numAttrs = attributeVector.size();
+    for (size_t i = 0; i < numAttrs; ++i) {
+        if (Attr* attr = attributeVector[i]->attr())
+            attr->normalize();
+    }
+}
+
+// ElementTraversal API
+Element* Element::firstElementChild() const
+{
+    Node* n = firstChild();
+    while (n && !n->isElementNode())
+        n = n->nextSibling();
+    return static_cast<Element*>(n);
+}
+
+Element* Element::lastElementChild() const
+{
+    Node* n = lastChild();
+    while (n && !n->isElementNode())
+        n = n->previousSibling();
+    return static_cast<Element*>(n);
+}
+
+Element* Element::previousElementSibling() const
+{
+    Node* n = previousSibling();
+    while (n && !n->isElementNode())
+        n = n->previousSibling();
+    return static_cast<Element*>(n);
+}
+
+Element* Element::nextElementSibling() const
+{
+    Node* n = nextSibling();
+    while (n && !n->isElementNode())
+        n = n->nextSibling();
+    return static_cast<Element*>(n);
+}
+
+unsigned Element::childElementCount() const
+{
+    unsigned count = 0;
+    Node* n = firstChild();
+    while (n) {
+        count += n->isElementNode();
+        n = n->nextSibling();
+    }
+    return count;
+}
+
+bool Element::webkitMatchesSelector(const String& selector, ExceptionCode& ec)
+{
+    if (selector.isEmpty()) {
+        ec = SYNTAX_ERR;
+        return false;
+    }
+
+    bool strictParsing = !document()->inCompatMode();
+    CSSParser p(strictParsing);
+
+    CSSSelectorList selectorList;
+    p.parseSelector(selector, document(), selectorList);
+
+    if (!selectorList.first()) {
+        ec = SYNTAX_ERR;
+        return false;
+    }
+
+    // Throw a NAMESPACE_ERR if the selector includes any namespace prefixes.
+    if (selectorList.selectorsNeedNamespaceResolution()) {
+        ec = NAMESPACE_ERR;
+        return false;
+    }
+
+    CSSStyleSelector::SelectorChecker selectorChecker(document(), strictParsing);
+    for (CSSSelector* selector = selectorList.first(); selector; selector = CSSSelectorList::next(selector)) {
+        if (selectorChecker.checkSelector(selector, this))
+            return true;
+    }
+
+    return false;
+}
+
+DOMStringMap* Element::dataset()
+{
+    ElementRareData* data = ensureRareData();
+    if (!data->m_datasetDOMStringMap)
+        data->m_datasetDOMStringMap = DatasetDOMStringMap::create(this);
+    return data->m_datasetDOMStringMap.get();
+}
+
+KURL Element::getURLAttribute(const QualifiedName& name) const
+{
+#if !ASSERT_DISABLED
+    if (m_attributeMap) {
+        if (Attribute* attribute = m_attributeMap->getAttributeItem(name))
+            ASSERT(isURLAttribute(attribute));
+    }
+#endif
+    return document()->completeURL(deprecatedParseURL(getAttribute(name)));
+}
+
+KURL Element::getNonEmptyURLAttribute(const QualifiedName& name) const
+{
+#if !ASSERT_DISABLED
+    if (m_attributeMap) {
+        if (Attribute* attribute = m_attributeMap->getAttributeItem(name))
+            ASSERT(isURLAttribute(attribute));
+    }
+#endif
+    String value = deprecatedParseURL(getAttribute(name));
+    if (value.isEmpty())
+        return KURL();
+    return document()->completeURL(value);
+}
+
+int Element::getIntegralAttribute(const QualifiedName& attributeName) const
+{
+    return getAttribute(attributeName).string().toInt();
+}
+
+void Element::setIntegralAttribute(const QualifiedName& attributeName, int value)
+{
+    // FIXME: Need an AtomicString version of String::number.
+    ExceptionCode ec;
+    setAttribute(attributeName, String::number(value), ec);
+}
+
+unsigned Element::getUnsignedIntegralAttribute(const QualifiedName& attributeName) const
+{
+    return getAttribute(attributeName).string().toUInt();
+}
+
+void Element::setUnsignedIntegralAttribute(const QualifiedName& attributeName, unsigned value)
+{
+    // FIXME: Need an AtomicString version of String::number.
+    ExceptionCode ec;
+    setAttribute(attributeName, String::number(value), ec);
+}
+
+#if ENABLE(SVG)
+bool Element::childShouldCreateRenderer(Node* child) const
+{
+    // Only create renderers for SVG elements whose parents are SVG elements, or for proper <svg xmlns="svgNS"> subdocuments.
+    if (child->isSVGElement())
+        return child->hasTagName(SVGNames::svgTag) || isSVGElement();
+
+    return Node::childShouldCreateRenderer(child);
+}
+#endif
+
+} // namespace WebCore