blob: 45d860ba86f490366198bfe8464f1c26512e9b79 [file] [log] [blame]
/*
* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
* Copyright (C) 2000 Frederik Holljen (frederik.holljen@hig.no)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
* Copyright (C) 2004, 2008 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 "NodeIterator.h"
#include "Document.h"
#include "NodeTraversal.h"
namespace WebCore {
inline NodeIterator::NodePointer::NodePointer(Node& node, bool isPointerBeforeNode)
: node(&node)
, isPointerBeforeNode(isPointerBeforeNode)
{
}
inline void NodeIterator::NodePointer::clear()
{
node = nullptr;
}
inline bool NodeIterator::NodePointer::moveToNext(Node& root)
{
if (!node)
return false;
if (isPointerBeforeNode) {
isPointerBeforeNode = false;
return true;
}
node = NodeTraversal::next(*node, &root);
return node;
}
inline bool NodeIterator::NodePointer::moveToPrevious(Node& root)
{
if (!node)
return false;
if (!isPointerBeforeNode) {
isPointerBeforeNode = true;
return true;
}
if (node == &root) {
node = nullptr;
return false;
}
node = NodeTraversal::previous(*node);
return node;
}
inline NodeIterator::NodeIterator(Node& rootNode, unsigned whatToShow, RefPtr<NodeFilter>&& filter)
: NodeIteratorBase(rootNode, whatToShow, WTFMove(filter))
, m_referenceNode(rootNode, true)
{
root().document().attachNodeIterator(this);
}
Ref<NodeIterator> NodeIterator::create(Node& rootNode, unsigned whatToShow, RefPtr<NodeFilter>&& filter)
{
return adoptRef(*new NodeIterator(rootNode, whatToShow, WTFMove(filter)));
}
NodeIterator::~NodeIterator()
{
root().document().detachNodeIterator(this);
}
ExceptionOr<RefPtr<Node>> NodeIterator::nextNode()
{
RefPtr<Node> result;
m_candidateNode = m_referenceNode;
while (m_candidateNode.moveToNext(root())) {
// NodeIterators treat the DOM tree as a flat list of nodes.
// In other words, FILTER_REJECT does not pass over descendants
// of the rejected node. Hence, FILTER_REJECT is the same as FILTER_SKIP.
RefPtr<Node> provisionalResult = m_candidateNode.node;
auto filterResult = acceptNode(*provisionalResult);
if (filterResult.hasException()) {
m_candidateNode.clear();
return filterResult.releaseException();
}
bool nodeWasAccepted = filterResult.returnValue() == NodeFilter::FILTER_ACCEPT;
if (nodeWasAccepted) {
m_referenceNode = m_candidateNode;
result = WTFMove(provisionalResult);
break;
}
}
m_candidateNode.clear();
return WTFMove(result);
}
ExceptionOr<RefPtr<Node>> NodeIterator::previousNode()
{
RefPtr<Node> result;
m_candidateNode = m_referenceNode;
while (m_candidateNode.moveToPrevious(root())) {
// NodeIterators treat the DOM tree as a flat list of nodes.
// In other words, FILTER_REJECT does not pass over descendants
// of the rejected node. Hence, FILTER_REJECT is the same as FILTER_SKIP.
RefPtr<Node> provisionalResult = m_candidateNode.node;
auto filterResult = acceptNode(*provisionalResult);
if (filterResult.hasException()) {
m_candidateNode.clear();
return filterResult.releaseException();
}
bool nodeWasAccepted = filterResult.returnValue() == NodeFilter::FILTER_ACCEPT;
if (nodeWasAccepted) {
m_referenceNode = m_candidateNode;
result = WTFMove(provisionalResult);
break;
}
}
m_candidateNode.clear();
return WTFMove(result);
}
void NodeIterator::nodeWillBeRemoved(Node& removedNode)
{
updateForNodeRemoval(removedNode, m_candidateNode);
updateForNodeRemoval(removedNode, m_referenceNode);
}
void NodeIterator::updateForNodeRemoval(Node& removedNode, NodePointer& referenceNode) const
{
ASSERT(&root().document() == &removedNode.document());
// Iterator is not affected if the removed node is the reference node and is the root.
// or if removed node is not the reference node, or the ancestor of the reference node.
if (!removedNode.isDescendantOf(root()))
return;
bool willRemoveReferenceNode = &removedNode == referenceNode.node;
bool willRemoveReferenceNodeAncestor = referenceNode.node && referenceNode.node->isDescendantOf(removedNode);
if (!willRemoveReferenceNode && !willRemoveReferenceNodeAncestor)
return;
if (referenceNode.isPointerBeforeNode) {
Node* node = NodeTraversal::next(removedNode, &root());
if (node) {
// Move out from under the node being removed if the new reference
// node is a descendant of the node being removed.
while (node && node->isDescendantOf(removedNode))
node = NodeTraversal::next(*node, &root());
if (node)
referenceNode.node = node;
} else {
node = NodeTraversal::previous(removedNode);
if (node) {
// Move out from under the node being removed if the reference node is
// a descendant of the node being removed.
if (willRemoveReferenceNodeAncestor) {
while (node && node->isDescendantOf(&removedNode))
node = NodeTraversal::previous(*node);
}
if (node) {
// Removing last node.
// Need to move the pointer after the node preceding the
// new reference node.
referenceNode.node = node;
referenceNode.isPointerBeforeNode = false;
}
}
}
} else {
Node* node = NodeTraversal::previous(removedNode);
if (node) {
// Move out from under the node being removed if the reference node is
// a descendant of the node being removed.
if (willRemoveReferenceNodeAncestor) {
while (node && node->isDescendantOf(removedNode))
node = NodeTraversal::previous(*node);
}
if (node)
referenceNode.node = node;
} else {
// FIXME: This branch doesn't appear to have any LayoutTests.
node = NodeTraversal::next(removedNode, &root());
// Move out from under the node being removed if the reference node is
// a descendant of the node being removed.
if (willRemoveReferenceNodeAncestor) {
while (node && node->isDescendantOf(removedNode))
node = NodeTraversal::previous(*node);
}
if (node)
referenceNode.node = node;
}
}
}
} // namespace WebCore