containernode.cpp

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

/*
 * Copyright (C) 1999 Lars Knoll ([e-mail])
 *           (C) 1999 Antti Koivisto ([e-mail])
 *           (C) 2001 Dirk Mueller ([e-mail])
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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 "ContainerNodeAlgorithms.h"
#include "DeleteButtonController.h"
#include "EventNames.h"
#include "ExceptionCode.h"
#include "FloatRect.h"
#include "Frame.h"
#include "FrameView.h"
#include "InlineTextBox.h"
#include "MutationEvent.h"
#include "Page.h"
#include "RenderTheme.h"
#include "RootInlineBox.h"
#include <wtf/CurrentTime.h>

namespace WebCore {

static void dispatchChildInsertionEvents(Node*, ExceptionCode&);
static void dispatchChildRemovalEvents(Node*, ExceptionCode&);

typedef Vector<std::pair<NodeCallback, RefPtr<Node> > > NodeCallbackQueue;
static NodeCallbackQueue* s_postAttachCallbackQueue;

static size_t s_attachDepth;
static bool s_shouldReEnableMemoryCacheCallsAfterAttach;

void ContainerNode::removeAllChildren()
{
    removeAllChildrenInContainer<Node, ContainerNode>(this);
}

ContainerNode::~ContainerNode()
{
    removeAllChildren();
}

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

    ec = 0;

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

    // Make sure adding the new child is OK.
    checkAddChild(newChild.get(), ec);
    if (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;
    }

    bool isFragment = newChild->nodeType() == DOCUMENT_FRAGMENT_NODE;

    // If newChild is a DocumentFragment with no children; there's nothing to do.
    // Just return true
    if (isFragment && !newChild->firstChild())
        return true;

    // Now actually add the child(ren)
    if (refChild->previousSibling() == newChild || refChild == newChild) // nothing to do
        return true;

    RefPtr<Node> next = refChild;
    RefPtr<Node> prev = refChild->previousSibling();

    int childCountDelta = 0;
    RefPtr<Node> child = isFragment ? newChild->firstChild() : newChild;
    while (child) {
        RefPtr<Node> nextChild = isFragment ? child->nextSibling() : 0;

        // If child is already present in the tree, first remove it from the old location.
        if (Node* oldParent = child->parentNode())
            oldParent->removeChild(child.get(), ec);
        if (ec)
            return 0;

        // FIXME: After sending the mutation events, "this" could be destroyed.
        // We can prevent that by doing a "ref", but first we have to make sure
        // that no callers call with ref count == 0 and parent = 0 (as of this
        // writing, there are definitely callers who call that way).

        // 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;

        ASSERT(!child->nextSibling());
        ASSERT(!child->previousSibling());

        childCountDelta++;

        // Add child before "next".
        forbidEventDispatch();
        Node* prev = next->previousSibling();
        ASSERT(m_lastChild != prev);
        next->setPreviousSibling(child.get());
        if (prev) {
            ASSERT(m_firstChild != next);
            ASSERT(prev->nextSibling() == next);
            prev->setNextSibling(child.get());
        } else {
            ASSERT(m_firstChild == next);
            m_firstChild = child.get();
        }
        child->setParent(this);
        child->setPreviousSibling(prev);
        child->setNextSibling(next.get());
        allowEventDispatch();

        // Dispatch the mutation events.
        dispatchChildInsertionEvents(child.get(), ec);
                
        // Add child to the rendering tree.
        if (attached() && !child->attached() && child->parent() == this) {
            if (shouldLazyAttach)
                child->lazyAttach();
            else
                child->attach();
        }

        child = nextChild.release();
    }

    document()->setDocumentChanged(true);
    if (childCountDelta)
        childrenChanged(false, prev.get(), next.get(), childCountDelta);
    dispatchSubtreeModifiedEvent();
    return true;
}

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

    ec = 0;

    if (oldChild == newChild) // nothing to do
        return true;
    
    // Make sure replacing the old child with the new is ok
    checkReplaceChild(newChild.get(), oldChild, ec);
    if (ec)
        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> prev = oldChild->previousSibling();
    RefPtr<Node> next = oldChild->nextSibling();

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

    // FIXME: After sending the mutation events, "this" could be destroyed.
    // We can prevent that by doing a "ref", but first we have to make sure
    // that no callers call with ref count == 0 and parent = 0 (as of this
    // writing, there are definitely callers who call that way).

    bool isFragment = newChild->nodeType() == DOCUMENT_FRAGMENT_NODE;

    // Add the new child(ren)
    int childCountDelta = 0;
    RefPtr<Node> child = isFragment ? newChild->firstChild() : newChild;
    while (child) {
        // If the new child is already in the right place, we're done.
        if (prev && (prev == child || prev == child->previousSibling()))
            break;

        // For a fragment we have more children to do.
        RefPtr<Node> nextChild = isFragment ? child->nextSibling() : 0;

        // Remove child from its old position.
        if (Node* oldParent = child->parentNode())
            oldParent->removeChild(child.get(), ec);
        if (ec)
            return false;

        // Due to arbitrary code running in response to a DOM mutation event it's
        // possible that "prev" 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 (prev && prev->parentNode() != this)
            break;
        if (child->parentNode())
            break;

        childCountDelta++;

        ASSERT(!child->nextSibling());
        ASSERT(!child->previousSibling());

        // Add child after "prev".
        forbidEventDispatch();
        Node* next;
        if (prev) {
            next = prev->nextSibling();
            ASSERT(m_firstChild != next);
            prev->setNextSibling(child.get());
        } else {
            next = m_firstChild;
            m_firstChild = child.get();
        }
        if (next) {
            ASSERT(m_lastChild != prev);
            ASSERT(next->previousSibling() == prev);
            next->setPreviousSibling(child.get());
        } else {
            ASSERT(m_lastChild == prev);
            m_lastChild = child.get();
        }
        child->setParent(this);
        child->setPreviousSibling(prev.get());
        child->setNextSibling(next);
        allowEventDispatch();

        // Dispatch the mutation events
        dispatchChildInsertionEvents(child.get(), ec);
                
        // Add child to the rendering tree
        if (attached() && !child->attached() && child->parent() == this) {
            if (shouldLazyAttach)
                child->lazyAttach();
            else
                child->attach();
        }

        prev = child;
        child = nextChild.release();
    }

    document()->setDocumentChanged(true);
    if (childCountDelta)
        childrenChanged(false, prev.get(), next.get(), childCountDelta);
    dispatchSubtreeModifiedEvent();
    return true;
}

void ContainerNode::willRemove()
{
    for (Node *n = m_firstChild; n != 0; n = n->nextSibling())
        n->willRemove();
    Node::willRemove();
}

static ExceptionCode willRemoveChild(Node *child)
{
    ExceptionCode ec = 0;

    // fire removed from document mutation events.
    dispatchChildRemovalEvents(child, ec);
    if (ec)
        return ec;

    if (child->attached())
        child->willRemove();
    
    return 0;
}

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() || parent());

    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;

    ec = willRemoveChild(child.get());
    if (ec)
        return false;

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

    document()->removeFocusedNodeOfSubtree(child.get());
    
    // FIXME: After sending the mutation events, "this" could be destroyed.
    // We can prevent that by doing a "ref", but first we have to make sure
    // that no callers call with ref count == 0 and parent = 0 (as of this
    // writing, there are definitely callers who call that way).

    forbidEventDispatch();

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

    // Remove the child
    Node *prev, *next;
    prev = child->previousSibling();
    next = child->nextSibling();

    if (next)
        next->setPreviousSibling(prev);
    if (prev)
        prev->setNextSibling(next);
    if (m_firstChild == child)
        m_firstChild = next;
    if (m_lastChild == child)
        m_lastChild = prev;

    child->setPreviousSibling(0);
    child->setNextSibling(0);
    child->setParent(0);

    allowEventDispatch();

    document()->setDocumentChanged(true);

    // Dispatch post-removal mutation events
    childrenChanged(false, prev, next, -1);
    dispatchSubtreeModifiedEvent();

    if (child->inDocument())
        child->removedFromDocument();
    else
        child->removedFromTree(true);

    return child;
}

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

    // The container node can be removed from event handlers.
    RefPtr<Node> protect(this);
    
    // Do any prep work needed before actually starting to detach
    // and remove... e.g. stop loading frames, fire unload events.
    // FIXME: Adding new children from event handlers can cause an infinite loop here.
    for (RefPtr<Node> n = m_firstChild; n; n = n->nextSibling())
        willRemoveChild(n.get());
    
    // exclude this node when looking for removed focusedNode since only children will be removed
    document()->removeFocusedNodeOfSubtree(this, true);

    forbidEventDispatch();
    int childCountDelta = 0;
    while (RefPtr<Node> n = m_firstChild) {
        childCountDelta--;

        Node* next = n->nextSibling();
        
        // Remove the node from the tree before calling detach or removedFromDocument (4427024, 4129744)
        n->setPreviousSibling(0);
        n->setNextSibling(0);
        n->setParent(0);
        
        m_firstChild = next;
        if (n == m_lastChild)
            m_lastChild = 0;

        if (n->attached())
            n->detach();
        
        if (n->inDocument())
            n->removedFromDocument();
    }
    allowEventDispatch();

    // Dispatch a single post-removal mutation event denoting a modified subtree.
    childrenChanged(false, 0, 0, childCountDelta);
    dispatchSubtreeModifiedEvent();

    return true;
}

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

    ec = 0;

    // Make sure adding the new child is ok
    checkAddChild(newChild.get(), ec);
    if (ec)
        return 0;
    
    if (newChild == m_lastChild) // nothing to do
        return newChild;

    bool isFragment = newChild->nodeType() == DOCUMENT_FRAGMENT_NODE;

    // If newChild is a DocumentFragment with no children.... there's nothing to do.
    // Just return the document fragment
    if (isFragment && !newChild->firstChild())
        return true;

    // Now actually add the child(ren)
    int childCountDelta = 0;
    RefPtr<Node> prev = lastChild();
    RefPtr<Node> child = isFragment ? newChild->firstChild() : newChild;
    while (child) {
        // For a fragment we have more children to do.
        RefPtr<Node> nextChild = isFragment ? child->nextSibling() : 0;

        // If child is already present in the tree, first remove it
        if (Node* oldParent = child->parentNode()) {
            oldParent->removeChild(child.get(), ec);
            if (ec)
                return 0;