ContainerNode.cpp   [plain text]

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
 *
 * 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 "ContainerNode.h"

#include "AXObjectCache.h"
#include "ChildListMutationScope.h"
#include "Chrome.h"
#include "ChromeClient.h"
#include "ContainerNodeAlgorithms.h"
#include "Editor.h"
#include "EventNames.h"
#include "ExceptionCode.h"
#include "FloatRect.h"
#include "Frame.h"
#include "FrameView.h"
#include "HTMLNames.h"
#include "InlineTextBox.h"
#include "InsertionPoint.h"
#include "InspectorInstrumentation.h"
#include "JSNode.h"
#include "LoaderStrategy.h"
#include "MemoryCache.h"
#include "MutationEvent.h"
#include "NodeRenderStyle.h"
#include "NodeTraversal.h"
#include "Page.h"
#include "PlatformStrategies.h"
#include "RenderBox.h"
#include "RenderTheme.h"
#include "RenderWidget.h"
#include "ResourceLoadScheduler.h"
#include "RootInlineBox.h"
#include "TemplateContentDocumentFragment.h"
#include <wtf/CurrentTime.h>
#include <wtf/Vector.h>

#if ENABLE(DELETION_UI)
#include "DeleteButtonController.h"
#endif

using namespace std;

namespace WebCore {

static void dispatchChildInsertionEvents(Node*);
static void dispatchChildRemovalEvents(Node*);
static void updateTreeAfterInsertion(ContainerNode*, Node*, AttachBehavior);

typedef pair<RefPtr<Node>, unsigned> CallbackParameters;
typedef pair<NodeCallback, CallbackParameters> CallbackInfo;
typedef Vector<CallbackInfo> NodeCallbackQueue;

static NodeCallbackQueue* s_postAttachCallbackQueue;

static size_t s_attachDepth;
static bool s_shouldReEnableMemoryCacheCallsAfterAttach;

ChildNodesLazySnapshot* ChildNodesLazySnapshot::latestSnapshot = 0;

#ifndef NDEBUG
unsigned NoEventDispatchAssertion::s_count = 0;
#endif

static void collectChildrenAndRemoveFromOldParent(Node* node, NodeVector& nodes, ExceptionCode& ec)
{
    if (node->nodeType() != Node::DOCUMENT_FRAGMENT_NODE) {
        nodes.append(node);
        if (ContainerNode* oldParent = node->parentNode())
            oldParent->removeChild(node, ec);
        return;
    }
    getChildNodes(node, nodes);
    toContainerNode(node)->removeChildren();
}

void ContainerNode::removeDetachedChildren()
{
    if (connectedSubframeCount()) {
        for (Node* child = firstChild(); child; child = child->nextSibling())
            child->updateAncestorConnectedSubframeCountForRemoval();
    }
    // FIXME: We should be able to ASSERT(!attached()) here: https://bugs.webkit.org/show_bug.cgi?id=107801
    removeDetachedChildrenInContainer<Node, ContainerNode>(this);
}

void ContainerNode::takeAllChildrenFrom(ContainerNode* oldParent)
{
    NodeVector children;
    getChildNodes(oldParent, children);

    if (oldParent->document()->hasMutationObserversOfType(MutationObserver::ChildList)) {
        ChildListMutationScope mutation(oldParent);
        for (unsigned i = 0; i < children.size(); ++i)
            mutation.willRemoveChild(children[i].get());
    }

    // FIXME: We need to do notifyMutationObserversNodeWillDetach() for each child,
    // probably inside removeDetachedChildrenInContainer.

    oldParent->removeDetachedChildren();

    for (unsigned i = 0; i < children.size(); ++i) {
        if (children[i]->attached())
            children[i]->detach();
        // FIXME: We need a no mutation event version of adoptNode.
        RefPtr<Node> child = document()->adoptNode(children[i].release(), ASSERT_NO_EXCEPTION);
        parserAppendChild(child.get());
        // FIXME: Together with adoptNode above, the tree scope might get updated recursively twice
        // (if the document changed or oldParent was in a shadow tree, AND *this is in a shadow tree).
        // Can we do better?
        treeScope()->adoptIfNeeded(child.get());
        if (attached() && !child->attached())
            child->attach();
    }
}

ContainerNode::~ContainerNode()
{
    if (Document* document = documentInternal())
        willBeDeletedFrom(document);
    removeDetachedChildren();
}

static inline bool isChildTypeAllowed(ContainerNode* newParent, Node* child)
{
    if (!child->isDocumentFragment())
        return newParent->childTypeAllowed(child->nodeType());

    for (Node* node = child->firstChild(); node; node = node->nextSibling()) {
        if (!newParent->childTypeAllowed(node->nodeType()))
            return false;
    }
    return true;
}

static inline bool isInTemplateContent(const Node* node)
{
#if ENABLE(TEMPLATE_ELEMENT)
    Document* document = node->document();
    return document && document == document->templateDocument();
#else
    UNUSED_PARAM(node);
    return false;
#endif
}

static inline bool containsConsideringHostElements(const Node* newChild, const Node* newParent)
{
    return (newParent->isInShadowTree() || isInTemplateContent(newParent))
        ? newChild->containsIncludingHostElements(newParent)
        : newChild->contains(newParent);
}

static inline ExceptionCode checkAcceptChild(ContainerNode* newParent, Node* newChild, Node* oldChild)
{
    // Not mentioned in spec: throw NOT_FOUND_ERR if newChild is null
    if (!newChild)
        return NOT_FOUND_ERR;

    // Use common case fast path if possible.
    if ((newChild->isElementNode() || newChild->isTextNode()) && newParent->isElementNode()) {
        ASSERT(!newParent->isReadOnlyNode());
        ASSERT(!newParent->isDocumentTypeNode());
        ASSERT(isChildTypeAllowed(newParent, newChild));
        if (containsConsideringHostElements(newChild, newParent))
            return HIERARCHY_REQUEST_ERR;
        return 0;
    }

    // This should never happen, but also protect release builds from tree corruption.
    ASSERT(!newChild->isPseudoElement());
    if (newChild->isPseudoElement())
        return HIERARCHY_REQUEST_ERR;

    if (newParent->isReadOnlyNode())
        return NO_MODIFICATION_ALLOWED_ERR;
    if (newChild->inDocument() && newChild->isDocumentTypeNode())
        return HIERARCHY_REQUEST_ERR;
    if (containsConsideringHostElements(newChild, newParent))
        return HIERARCHY_REQUEST_ERR;

    if (oldChild && newParent->isDocumentNode()) {
        if (!toDocument(newParent)->canReplaceChild(newChild, oldChild))
            return HIERARCHY_REQUEST_ERR;
    } else if (!isChildTypeAllowed(newParent, newChild))
        return HIERARCHY_REQUEST_ERR;

    return 0;
}

static inline bool checkAcceptChildGuaranteedNodeTypes(ContainerNode* newParent, Node* newChild, ExceptionCode& ec)
{
    ASSERT(!newParent->isReadOnlyNode());
    ASSERT(!newParent->isDocumentTypeNode());
    ASSERT(isChildTypeAllowed(newParent, newChild));
    if (newChild->contains(newParent)) {
        ec = HIERARCHY_REQUEST_ERR;
        return false;
    }

    return true;
}

static inline bool checkAddChild(ContainerNode* newParent, Node* newChild, ExceptionCode& ec)
{
    ec = checkAcceptChild(newParent, newChild, 0);
    if (ec)
        return false;

    return true;
}

static inline bool checkReplaceChild(ContainerNode* newParent, Node* newChild, Node* oldChild, ExceptionCode& ec)
{
    ec = checkAcceptChild(newParent, newChild, oldChild);
    if (ec)
        return false;

    return true;
}

bool ContainerNode::insertBefore(PassRefPtr<Node> newChild, Node* refChild, ExceptionCode& ec, AttachBehavior attachBehavior)
{
    // Check that this node is not "floating".
    // If it is, it can be deleted as a side effect of sending mutation events.
    ASSERT(refCount() || parentOrShadowHostNode());

    RefPtr<Node> protect(this);

    ec = 0;

    // insertBefore(node, 0) is equivalent to appendChild(node)
    if (!refChild)
        return appendChild(newChild, ec, attachBehavior);

    // Make sure adding the new child is OK.
    if (!checkAddChild(this, newChild.get(), ec))
        return false;

    // NOT_FOUND_ERR: Raised if refChild is not a child of this node
    if (refChild->parentNode() != this) {
        ec = NOT_FOUND_ERR;
        return false;
    }

    if (refChild->previousSibling() == newChild || refChild == newChild) // nothing to do
        return true;

    RefPtr<Node> next = refChild;

    NodeVector targets;
    collectChildrenAndRemoveFromOldParent(newChild.get(), targets, ec);
    if (ec)
        return false;
    if (targets.isEmpty())
        return true;

    // We need this extra check because collectChildrenAndRemoveFromOldParent() can fire mutation events.
    if (!checkAcceptChildGuaranteedNodeTypes(this, newChild.get(), ec))
        return false;

    InspectorInstrumentation::willInsertDOMNode(document(), this);

    ChildListMutationScope mutation(this);
    for (NodeVector::const_iterator it = targets.begin(); it != targets.end(); ++it) {
        Node* child = it->get();

        // Due to arbitrary code running in response to a DOM mutation event it's
        // possible that "next" is no longer a child of "this".
        // It's also possible that "child" has been inserted elsewhere.
        // In either of those cases, we'll just stop.
        if (next->parentNode() != this)
            break;
        if (child->parentNode())
            break;

        treeScope()->adoptIfNeeded(child);

        insertBeforeCommon(next.get(), child);

        updateTreeAfterInsertion(this, child, attachBehavior);
    }

    dispatchSubtreeModifiedEvent();
    return true;
}

void ContainerNode::insertBeforeCommon(Node* nextChild, Node* newChild)
{
    NoEventDispatchAssertion assertNoEventDispatch;

    ASSERT(newChild);
    ASSERT(!newChild->parentNode()); // Use insertBefore if you need to handle reparenting (and want DOM mutation events).
    ASSERT(!newChild->nextSibling());
    ASSERT(!newChild->previousSibling());
    ASSERT(!newChild->isShadowRoot());

    Node* prev = nextChild->previousSibling();
    ASSERT(m_lastChild != prev);
    nextChild->setPreviousSibling(newChild);
    if (prev) {
        ASSERT(m_firstChild != nextChild);
        ASSERT(prev->nextSibling() == nextChild);
        prev->setNextSibling(newChild);
    } else {
        ASSERT(m_firstChild == nextChild);
        m_firstChild = newChild;
    }
    newChild->setParentOrShadowHostNode(this);
    newChild->setPreviousSibling(prev);
    newChild->setNextSibling(nextChild);
}

void ContainerNode::parserInsertBefore(PassRefPtr<Node> newChild, Node* nextChild)
{
    ASSERT(newChild);
    ASSERT(nextChild);
    ASSERT(nextChild->parentNode() == this);
    ASSERT(!newChild->isDocumentFragment());
#if ENABLE(TEMPLATE_ELEMENT)
    ASSERT(!hasTagName(HTMLNames::templateTag));
#endif

    if (nextChild->previousSibling() == newChild || nextChild == newChild) // nothing to do
        return;

    if (document() != newChild->document())
        document()->adoptNode(newChild.get(), ASSERT_NO_EXCEPTION);

    insertBeforeCommon(nextChild, newChild.get());

    newChild->updateAncestorConnectedSubframeCountForInsertion();

    ChildListMutationScope(this).childAdded(newChild.get());

    childrenChanged(true, newChild->previousSibling(), nextChild, 1);
    ChildNodeInsertionNotifier(this).notify(newChild.get());
}

bool ContainerNode::replaceChild(PassRefPtr<Node> newChild, Node* oldChild, ExceptionCode& ec, AttachBehavior attachBehavior)
{
    // Check that this node is not "floating".
    // If it is, it can be deleted as a side effect of sending mutation events.
    ASSERT(refCount() || parentOrShadowHostNode());

    RefPtr<Node> protect(this);

    ec = 0;

    if (oldChild == newChild) // nothing to do
        return true;

    if (!oldChild) {
        ec = NOT_FOUND_ERR;
        return false;
    }

    // Make sure replacing the old child with the new is ok
    if (!checkReplaceChild(this, newChild.get(), oldChild, ec))
        return false;

    // NOT_FOUND_ERR: Raised if oldChild is not a child of this node.
    if (oldChild->parentNode() != this) {
        ec = NOT_FOUND_ERR;
        return false;
    }

    ChildListMutationScope mutation(this);

    RefPtr<Node> next = oldChild->nextSibling();

    // Remove the node we're replacing
    RefPtr<Node> removedChild = oldChild;
    removeChild(oldChild, ec);
    if (ec)
        return false;

    if (next && (next->previousSibling() == newChild || next == newChild)) // nothing to do
        return true;

    // Does this one more time because removeChild() fires a MutationEvent.
    if (!checkReplaceChild(this, newChild.get(), oldChild, ec))
        return false;

    NodeVector targets;
    collectChildrenAndRemoveFromOldParent(newChild.get(), targets, ec);
    if (ec)
        return false;

    // Does this yet another check because collectChildrenAndRemoveFromOldParent() fires a MutationEvent.
    if (!checkReplaceChild(this, newChild.get(), oldChild, ec))
        return false;

    InspectorInstrumentation::willInsertDOMNode(document(), this);

    // Add the new child(ren)
    for (NodeVector::const_iterator it = targets.begin(); it != targets.end(); ++it) {
        Node* child = it->get();

        // Due to arbitrary code running in response to a DOM mutation event it's
        // possible that "next" is no longer a child of "this".
        // It's also possible that "child" has been inserted elsewhere.
        // In either of those cases, we'll just stop.
        if (next && next->parentNode() != this)
            break;
        if (child->parentNode())
            break;

        treeScope()->adoptIfNeeded(child);

        // Add child before "next".
        {
            NoEventDispatchAssertion assertNoEventDispatch;
            if (next)
                insertBeforeCommon(next.get(), child);
            else
                appendChildToContainer(child, this);
        }

        updateTreeAfterInsertion(this, child, attachBehavior);
    }

    dispatchSubtreeModifiedEvent();
    return true;
}

static void willRemoveChild(Node* child)
{
    ASSERT(child->parentNode());
    ChildListMutationScope(child->parentNode()).willRemoveChild(child);
    child->notifyMutationObserversNodeWillDetach();
    dispatchChildRemovalEvents(child);
    child->document()->nodeWillBeRemoved(child); // e.g. mutation event listener can create a new range.
    ChildFrameDisconnector(child).disconnect();
}

static void willRemoveChildren(ContainerNode* container)
{
    NodeVector children;
    getChildNodes(container, children);

    container->document()->nodeChildrenWillBeRemoved(container);

    ChildListMutationScope mutation(container);
    for (NodeVector::const_iterator it = children.begin(); it != children.end(); ++it) {
        Node* child = it->get();
        mutation.willRemoveChild(child);
        child->notifyMutationObserversNodeWillDetach();

        // fire removed from document mutation events.
        dispatchChildRemovalEvents(child);
    }

    ChildFrameDisconnector(container).disconnect(ChildFrameDisconnector::DescendantsOnly);
}

void ContainerNode::disconnectDescendantFrames()
{
    ChildFrameDisconnector(this).disconnect();
}

bool ContainerNode::removeChild(Node* oldChild, ExceptionCode& ec)
{
    // Check that this node is not "floating".
    // If it is, it can be deleted as a side effect of sending mutation events.
    ASSERT(refCount() || parentOrShadowHostNode());

    RefPtr<Node> protect(this);

    ec = 0;

    // NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
    if (isReadOnlyNode()) {
        ec = NO_MODIFICATION_ALLOWED_ERR;
        return false;
    }

    // NOT_FOUND_ERR: Raised if oldChild is not a child of this node.
    if (!oldChild || oldChild->parentNode() != this) {
        ec = NOT_FOUND_ERR;
        return false;
    }

    RefPtr<Node> child = oldChild;

    document()->removeFocusedNodeOfSubtree(child.get());

#if ENABLE(FULLSCREEN_API)
    document()->removeFullScreenElementOfSubtree(child.get());
#endif

    // Events fired when blurring currently focused node might have moved this
    // child into a different parent.
    if (child->parentNode() != this) {
        ec = NOT_FOUND_ERR;
        return false;
    }

    willRemoveChild(child.get());

    // Mutation events might have moved this child into a different parent.
    if (child->parentNode() != this) {
        ec = NOT_FOUND_ERR;
        return false;
    }

    {
        WidgetHierarchyUpdatesSuspensionScope suspendWidgetHierarchyUpdates;

        Node* prev = child->previousSibling();
        Node* next = child->nextSibling();
        removeBetween(prev, next, child.get());
        childrenChanged(false, prev, next, -1);
        ChildNodeRemovalNotifier(this).notify(child.get());
    }
    dispatchSubtreeModifiedEvent();

    return child;
}

void ContainerNode::removeBetween(Node* previousChild, Node* nextChild, Node* oldChild)
{
    NoEventDispatchAssertion assertNoEventDispatch;

    ASSERT(oldChild);
    ASSERT(oldChild->parentNode() == this);

    // Remove from rendering tree
    if (oldChild->attached())
        oldChild->detach();

    if (nextChild)
        nextChild->setPreviousSibling(previousChild);
    if (previousChild)
        previousChild->setNextSibling(nextChild);
    if (m_firstChild == oldChild)
        m_firstChild = nextChild;
    if (m_lastChild == oldChild)
        m_lastChild = previousChild;

    oldChild->setPreviousSibling(0);
    oldChild->setNextSibling(0);
    oldChild->setParentOrShadowHostNode(0);

    document()->adoptIfNeeded(oldChild);
}

void ContainerNode::parserRemoveChild(Node* oldChild)
{
    ASSERT(oldChild);
    ASSERT(oldChild->parentNode() == this);
    ASSERT(!oldChild->isDocumentFragment());

    Node* prev = oldChild->previousSibling();
    Node* next = oldChild->nextSibling();

    oldChild->updateAncestorConnectedSubframeCountForRemoval();

    ChildListMutationScope(this).willRemoveChild(oldChild);
    oldChild->notifyMutationObserversNodeWillDetach();

    removeBetween(prev, next, oldChild);

    childrenChanged(true, prev, next, -1);
    ChildNodeRemovalNotifier(this).notify(oldChild);
}

// this differs from other remove functions because it forcibly removes all the children,
// regardless of read-only status or event exceptions, e.g.
void ContainerNode::removeChildren()
{
    if (!m_firstChild)
        return;

    // The container node can be removed from event handlers.
    RefPtr<ContainerNode> protect(this);

    // exclude this node when looking for removed focusedNode since only children will be removed
    document()->removeFocusedNodeOfSubtree(this, true);

#if ENABLE(FULLSCREEN_API)
    document()->removeFullScreenElementOfSubtree(this, true);
#endif

    // Do any prep work needed before actually starting to detach
    // and remove... e.g. stop loading frames, fire unload events.
    willRemoveChildren(protect.get());

    NodeVector removedChildren;
    {
        WidgetHierarchyUpdatesSuspensionScope suspendWidgetHierarchyUpdates;
        {
            NoEventDispatchAssertion assertNoEventDispatch;
            removedChildren.reserveInitialCapacity(childNodeCount());
            while (RefPtr<Node> n = m_firstChild) {
                removedChildren.append(m_firstChild);
                removeBetween(0, m_firstChild->nextSibling(), m_firstChild);
            }
        }

        childrenChanged(false, 0, 0, -static_cast<int>(removedChildren.size()));
        
        for (size_t i = 0; i < removedChildren.size(); ++i)
            ChildNodeRemovalNotifier(this).notify(removedChildren[i].get());
    }

    dispatchSubtreeModifiedEvent();
}

bool ContainerNode::appendChild(PassRefPtr<Node> newChild, ExceptionCode& ec, AttachBehavior attachBehavior)
{
    RefPtr<ContainerNode> protect(this);

    // Check that this node is not "floating".
    // If it is, it can be deleted as a side effect of sending mutation events.
    ASSERT(refCount() || parentOrShadowHostNode());

    ec = 0;

    // Make sure adding the new child is ok
    if (!checkAddChild(this, newChild.get(), ec))
        return false;

    if (newChild == m_lastChild) // nothing to do
        return newChild;

    NodeVector targets;
    collectChildrenAndRemoveFromOldParent(newChild.get(), targets, ec);
    if (ec)
        return false;

    if (targets.isEmpty())
        return true;

    // We need this extra check because collectChildrenAndRemoveFromOldParent() can fire mutation events.
    if (!checkAcceptChildGuaranteedNodeTypes(this, newChild.get(), ec))
        return false;

    InspectorInstrumentation::willInsertDOMNode(document(), this);

    // Now actually add the child(ren)
    ChildListMutationScope mutation(this);
    for (NodeVector::const_iterator it = targets.begin(); it != targets.end(); ++it) {
        Node* child = it->get();

        // If the child has a parent again, just stop what we're doing, because
        // that means someone is doing something with DOM mutation -- can't re-parent
        // a child that already has a parent.
        if (child->parentNode())
            break;

        treeScope()->adoptIfNeeded(child);

        // Append child to the end of the list
        {
            NoEventDispatchAssertion assertNoEventDispatch;
            appendChildToContainer(child, this);
        }

        updateTreeAfterInsertion(this, child, attachBehavior);
    }

    dispatchSubtreeModifiedEvent();
    return true;
}

void ContainerNode::parserAppendChild(PassRefPtr<Node> newChild)
{
    ASSERT(newChild);
    ASSERT(!newChild->parentNode()); // Use appendChild if you need to handle reparenting (and want DOM mutation events).
    ASSERT(!newChild->isDocumentFragment());
#if ENABLE(TEMPLATE_ELEMENT)
    ASSERT(!hasTagName(HTMLNames::templateTag));
#endif

    if (document() != newChild->document())
        document()->adoptNode(newChild.get(), ASSERT_NO_EXCEPTION);

    Node* last = m_lastChild;
    {
        NoEventDispatchAssertion assertNoEventDispatch;
        // FIXME: This method should take a PassRefPtr.
        appendChildToContainer(newChild.get(), this);
        treeScope()->adoptIfNeeded(newChild.get());
    }

    newChild->updateAncestorConnectedSubframeCountForInsertion();

    ChildListMutationScope(this).childAdded(newChild.get());

    childrenChanged(true, last, 0, 1);
    ChildNodeInsertionNotifier(this).notify(newChild.get());
}

void ContainerNode::suspendPostAttachCallbacks()
{
    if (!s_attachDepth) {
        ASSERT(!s_shouldReEnableMemoryCacheCallsAfterAttach);
        if (Page* page = document()->page()) {
            // FIXME: How can this call be specific to one Page, while the
            // s_attachDepth is a global? Doesn't make sense.
            if (page->areMemoryCacheClientCallsEnabled()) {
                page->setMemoryCacheClientCallsEnabled(false);
                s_shouldReEnableMemoryCacheCallsAfterAttach = true;
            }
        }
        platformStrategies()->loaderStrategy()->resourceLoadScheduler()->suspendPendingRequests();
    }
    ++s_attachDepth;
}

void ContainerNode::resumePostAttachCallbacks()
{
    if (s_attachDepth == 1) {
        RefPtr<ContainerNode> protect(this);

        if (s_postAttachCallbackQueue)
            dispatchPostAttachCallbacks();
        if (s_shouldReEnableMemoryCacheCallsAfterAttach) {
            s_shouldReEnableMemoryCacheCallsAfterAttach = false;
            if (Page* page = document()->page())
                page->setMemoryCacheClientCallsEnabled(true);
        }
        platformStrategies()->loaderStrategy()->resourceLoadScheduler()->resumePendingRequests();
    }
    --s_attachDepth;
}

void ContainerNode::queuePostAttachCallback(NodeCallback callback, Node* node, unsigned callbackData)
{
    if (!s_postAttachCallbackQueue)
        s_postAttachCallbackQueue = new NodeCallbackQueue;
    
    s_postAttachCallbackQueue->append(CallbackInfo(callback, CallbackParameters(node, callbackData)));
}

bool ContainerNode::postAttachCallbacksAreSuspended()
{
    return s_attachDepth;
}

void ContainerNode::dispatchPostAttachCallbacks()
{
    // We recalculate size() each time through the loop because a callback
    // can add more callbacks to the end of the queue.
    for (size_t i = 0; i < s_postAttachCallbackQueue->size(); ++i) {
        const CallbackInfo& info = (*s_postAttachCallbackQueue)[i];
        NodeCallback callback = info.first;
        CallbackParameters params = info.second;

        callback(params.first.get(), params.second);
    }
    s_postAttachCallbackQueue->clear();
}

static void needsStyleRecalcCallback(Node* node, unsigned data)
{
    node->setNeedsStyleRecalc(static_cast<StyleChangeType>(data));
}

void ContainerNode::scheduleSetNeedsStyleRecalc(StyleChangeType changeType)
{
    if (postAttachCallbacksAreSuspended())
        queuePostAttachCallback(needsStyleRecalcCallback, this, static_cast<unsigned>(changeType));
    else
        setNeedsStyleRecalc(changeType);
}

void ContainerNode::attach(const AttachContext& context)
{
    attachChildren();
    Node::attach(context);
}

void ContainerNode::detach(const AttachContext& context)
{
    detachChildren();
    clearChildNeedsStyleRecalc();
    Node::detach(context);
}

void ContainerNode::childrenChanged(bool changedByParser, Node*, Node*, int childCountDelta)
{
    document()->incDOMTreeVersion();
    if (!changedByParser && childCountDelta)
        document()->updateRangesAfterChildrenChanged(this);
    invalidateNodeListCachesInAncestors();
}

inline static void cloneChildNodesAvoidingDeleteButton(ContainerNode* parent, ContainerNode* clonedParent, HTMLElement* deleteButtonContainerElement)
{
    ExceptionCode ec = 0;
    for (Node* child = parent->firstChild(); child && !ec; child = child->nextSibling()) {

#if ENABLE(DELETION_UI)
        if (child == deleteButtonContainerElement)
            continue;
#else
        UNUSED_PARAM(deleteButtonContainerElement);
#endif

        RefPtr<Node> clonedChild = child->cloneNode(false);
        clonedParent->appendChild(clonedChild, ec);

        if (!ec && child->isContainerNode())
            cloneChildNodesAvoidingDeleteButton(toContainerNode(child), toContainerNode(clonedChild.get()), deleteButtonContainerElement);
    }
}

void ContainerNode::cloneChildNodes(ContainerNode *clone)
{
#if ENABLE(DELETION_UI)
    HTMLElement* deleteButtonContainerElement = 0;
    if (Frame* frame = document()->frame())
        deleteButtonContainerElement = frame->editor().deleteButtonController()->containerElement();
    cloneChildNodesAvoidingDeleteButton(this, clone, deleteButtonContainerElement);
#else
    cloneChildNodesAvoidingDeleteButton(this, clone, 0);
#endif
}

bool ContainerNode::getUpperLeftCorner(FloatPoint& point) const
{
    if (!renderer())
        return false;
    // What is this code really trying to do?
    RenderObject* o = renderer();
    RenderObject* p = o;

    if (!o->isInline() || o->isReplaced()) {
        point = o->localToAbsolute(FloatPoint(), UseTransforms);
        return true;
    }

    // find the next text/image child, to get a position
    while (o) {
        p = o;
        if (o->firstChild())
            o = o->firstChild();
        else if (o->nextSibling())
            o = o->nextSibling();
        else {
            RenderObject* next = 0;
            while (!next && o->parent()) {
                o = o->parent();
                next = o->nextSibling();
            }
            o = next;

            if (!o)
                break;
        }
        ASSERT(o);

        if (!o->isInline() || o->isReplaced()) {
            point = o->localToAbsolute(FloatPoint(), UseTransforms);
            return true;
        }

        if (p->node() && p->node() == this && o->isText() && !o->isBR() && !toRenderText(o)->firstTextBox()) {
            // do nothing - skip unrendered whitespace that is a child or next sibling of the anchor
        } else if ((o->isText() && !o->isBR()) || o->isReplaced()) {
            point = FloatPoint();
            if (o->isText() && toRenderText(o)->firstTextBox()) {
                point.move(toRenderText(o)->linesBoundingBox().x(), toRenderText(o)->firstTextBox()->root()->lineTop());
            } else if (o->isBox()) {
                RenderBox* box = toRenderBox(o);
                point.moveBy(box->location());
            }
            point = o->container()->localToAbsolute(point, UseTransforms);
            return true;
        }
    }
    
    // If the target doesn't have any children or siblings that could be used to calculate the scroll position, we must be
    // at the end of the document. Scroll to the bottom. FIXME: who said anything about scrolling?
    if (!o && document()->view()) {
        point = FloatPoint(0, document()->view()->contentsHeight());
        return true;
    }
    return false;
}

bool ContainerNode::getLowerRightCorner(FloatPoint& point) const
{
    if (!renderer())
        return false;

    RenderObject* o = renderer();
    if (!o->isInline() || o->isReplaced()) {
        RenderBox* box = toRenderBox(o);
        point = o->localToAbsolute(LayoutPoint(box->size()), UseTransforms);
        return true;
    }

    // find the last text/image child, to get a position
    while (o) {
        if (o->lastChild())
            o = o->lastChild();
        else if (o->previousSibling())
            o = o->previousSibling();
        else {
            RenderObject* prev = 0;
            while (!prev) {
                o = o->parent();
                if (!o)
                    return false;
                prev = o->previousSibling();
            }
            o = prev;
        }
        ASSERT(o);
        if (o->isText() || o->isReplaced()) {
            point = FloatPoint();
            if (o->isText()) {
                RenderText* text = toRenderText(o);
                IntRect linesBox = text->linesBoundingBox();
                if (!linesBox.maxX() && !linesBox.maxY())
                    continue;
                point.moveBy(linesBox.maxXMaxYCorner());
            } else {
                RenderBox* box = toRenderBox(o);
                point.moveBy(box->frameRect().maxXMaxYCorner());
            }
            point = o->container()->localToAbsolute(point, UseTransforms);
            return true;
        }
    }
    return true;
}

LayoutRect ContainerNode::boundingBox() const
{
    FloatPoint upperLeft, lowerRight;
    bool foundUpperLeft = getUpperLeftCorner(upperLeft);
    bool foundLowerRight = getLowerRightCorner(lowerRight);
    
    // If we've found one corner, but not the other,
    // then we should just return a point at the corner that we did find.
    if (foundUpperLeft != foundLowerRight) {
        if (foundUpperLeft)
            lowerRight = upperLeft;
        else
            upperLeft = lowerRight;
    } 

    return enclosingLayoutRect(FloatRect(upperLeft, lowerRight.expandedTo(upperLeft) - upperLeft));
}

unsigned ContainerNode::childNodeCount() const
{
    unsigned count = 0;
    Node *n;
    for (n = firstChild(); n; n = n->nextSibling())
        count++;
    return count;
}

Node *ContainerNode::childNode(unsigned index) const
{
    unsigned i;
    Node *n = firstChild();
    for (i = 0; n != 0 && i < index; i++)
        n = n->nextSibling();
    return n;
}

static void dispatchChildInsertionEvents(Node* child)
{
    if (child->isInShadowTree())
        return;

    ASSERT(!NoEventDispatchAssertion::isEventDispatchForbidden());

    RefPtr<Node> c = child;
    RefPtr<Document> document = child->document();

    if (c->parentNode() && document->hasListenerType(Document::DOMNODEINSERTED_LISTENER))
        c->dispatchScopedEvent(MutationEvent::create(eventNames().DOMNodeInsertedEvent, true, c->parentNode()));

    // dispatch the DOMNodeInsertedIntoDocument event to all descendants
    if (c->inDocument() && document->hasListenerType(Document::DOMNODEINSERTEDINTODOCUMENT_LISTENER)) {
        for (; c; c = NodeTraversal::next(c.get(), child))
            c->dispatchScopedEvent(MutationEvent::create(eventNames().DOMNodeInsertedIntoDocumentEvent, false));
    }
}

static void dispatchChildRemovalEvents(Node* child)
{
    if (child->isInShadowTree()) {
        InspectorInstrumentation::willRemoveDOMNode(child->document(), child);
        return;
    }

    ASSERT(!NoEventDispatchAssertion::isEventDispatchForbidden());

    willCreatePossiblyOrphanedTreeByRemoval(child);
    InspectorInstrumentation::willRemoveDOMNode(child->document(), child);

    RefPtr<Node> c = child;
    RefPtr<Document> document = child->document();

    // dispatch pre-removal mutation events
    if (c->parentNode() && document->hasListenerType(Document::DOMNODEREMOVED_LISTENER))
        c->dispatchScopedEvent(MutationEvent::create(eventNames().DOMNodeRemovedEvent, true, c->parentNode()));

    // dispatch the DOMNodeRemovedFromDocument event to all descendants
    if (c->inDocument() && document->hasListenerType(Document::DOMNODEREMOVEDFROMDOCUMENT_LISTENER)) {
        for (; c; c = NodeTraversal::next(c.get(), child))
            c->dispatchScopedEvent(MutationEvent::create(eventNames().DOMNodeRemovedFromDocumentEvent, false));
    }
}

static void updateTreeAfterInsertion(ContainerNode* parent, Node* child, AttachBehavior attachBehavior)
{
    ASSERT(parent->refCount());
    ASSERT(child->refCount());

    ChildListMutationScope(parent).childAdded(child);

    parent->childrenChanged(false, child->previousSibling(), child->nextSibling(), 1);

    ChildNodeInsertionNotifier(parent).notify(child);

    // FIXME: Attachment should be the first operation in this function, but some code
    // (for example, HTMLFormControlElement's autofocus support) requires this ordering.
    if (parent->attached() && !child->attached() && child->parentNode() == parent) {
        if (attachBehavior == AttachLazily)
            child->lazyAttach();
        else
            child->attach();
    }

    dispatchChildInsertionEvents(child);
}

#ifndef NDEBUG
bool childAttachedAllowedWhenAttachingChildren(ContainerNode* node)
{
    if (node->isShadowRoot())
        return true;

    if (node->isInsertionPoint())
        return true;

    if (node->isElementNode() && toElement(node)->shadow())
        return true;

    return false;
}
#endif

} // namespace WebCore