/**

 * This file is part of the DOM implementation for KDE.

 *

 * 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 Apple Computer, Inc.

 *

 * 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 "TreeWalker.h"

#include "ExceptionCode.h"

#include "Node.h"

#include "NodeFilter.h"

#include <wtf/PassRefPtr.h>

namespace WebCore {

TreeWalker::TreeWalker(Node* rootNode, unsigned whatToShow, PassRefPtr<NodeFilter> filter, bool expandEntityReferences)

    : Traversal(rootNode, whatToShow, filter, expandEntityReferences)

    , m_current(rootNode)

{

}

void TreeWalker::setCurrentNode(Node* node, ExceptionCode& ec)

{

    if (!node) {

        ec = NOT_SUPPORTED_ERR;

        return;

    }

    m_current = node;

}

void TreeWalker::setCurrentNode(Node* node)

{

    ASSERT(node);

    int dummy;

    setCurrentNode(node, dummy);

}

Node* TreeWalker::parentNode()

{

    Node* result = 0;

    for (Node* node = currentNode()->parentNode(); node && node != root(); node = node->parentNode()) {

        if (acceptNode(node) == NodeFilter::FILTER_ACCEPT) {

            setCurrentNode(node);

            result = node;

            break;

        }

    }

    return result;

}

Node* TreeWalker::firstChild()

{

    Node* result = 0;

    for (Node* node = currentNode()->firstChild(); node; node = node->nextSibling()) {

        if (acceptNode(node) == NodeFilter::FILTER_ACCEPT) {

            setCurrentNode(node);

            result = node;

            break;

        }

    }

    return result;

}

Node* TreeWalker::lastChild()

{

    Node* result = 0;

    for (Node* node = currentNode()->lastChild(); node; node = node->previousSibling()) {

        if (acceptNode(node) == NodeFilter::FILTER_ACCEPT) {

            setCurrentNode(node);

            result = node;

            break;

        }

    }

    return result;

}

Node* TreeWalker::previousSibling()

{

    Node* result = 0;

    for (Node* node = currentNode()->previousSibling(); node; node = node->previousSibling()) {

        if (acceptNode(node) == NodeFilter::FILTER_ACCEPT) {

            setCurrentNode(node);

            result = node;

            break;

        }

    }

    return result;

}

Node* TreeWalker::nextSibling()

{

    Node* result = 0;

    for (Node* node = currentNode()->nextSibling(); node; node = node->nextSibling()) {

        if (acceptNode(node) == NodeFilter::FILTER_ACCEPT) {

            setCurrentNode(node);

            result = node;

            break;

        }

    }

    return result;

}

Node* TreeWalker::previousNode()

{

    Node* result = 0;

    for (Node* node = currentNode()->traversePreviousNode(root()); node; node = node->traversePreviousNode(root())) {

        if (acceptNode(node) == NodeFilter::FILTER_ACCEPT && !ancestorRejected(node)) {

            setCurrentNode(node);

            result = node;

            break;

        }

    }

    return result;

}

Node* TreeWalker::nextNode()

{

    Node* result = 0;

    for (Node* node = currentNode()->traverseNextNode(root()); node; node = node->traverseNextNode(root())) {

        if (acceptNode(node) == NodeFilter::FILTER_ACCEPT && !ancestorRejected(node)) {

            setCurrentNode(node);

            result = node;

            break;

        }

    }

    return result;

}

bool TreeWalker::ancestorRejected(const Node* node) const

{

    for (Node* a = node->parentNode(); a && a != root(); a = a->parentNode()) {

        if (acceptNode(a) == NodeFilter::FILTER_REJECT)

            return true;

    }

    return false;

}

} // namespace WebCore