| /* |
| * 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" |
| #include <wtf/IsoMallocInlines.h> |
| |
| namespace WebCore { |
| |
| WTF_MAKE_ISO_ALLOCATED_IMPL(NodeIterator); |
| |
| 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 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 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 |
