/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   Licensed to the Apache Software Foundation (ASF) under one or more

 *   contributor license agreements. See the NOTICE file distributed

 *   with this work for additional information regarding copyright

 *   ownership. The ASF licenses this file to you under the Apache

 *   License, Version 2.0 (the "License"); you may not use this file

 *   except in compliance with the License. You may obtain a copy of

 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .

 */

#ifndef INCLUDED_SVX_SOURCE_INC_TREEVISITOR_HXX

#define INCLUDED_SVX_SOURCE_INC_TREEVISITOR_HXX

#include <stack>

template< class ELEMENT, class NODEINFO, class PROCESSOR >

class TreeVisitor

{

public:

    TreeVisitor( NODEINFO _nodeInfo )

        :m_visitedRoot( false )

        ,m_root()

        ,m_current()

        ,m_nodeInfo( _nodeInfo )

    {

    }

    void    process( const ELEMENT& _root, PROCESSOR& _processor )

    {

        m_root = _root;

        m_visitedRoot = false;

        while ( do_step() )

            _processor.process( m_current );

    }

private:

    bool    do_step();

private:

    bool            m_visitedRoot;

    ELEMENT         m_root;

    ELEMENT         m_current;

    const NODEINFO  m_nodeInfo;

    ::std::stack< size_t >  m_pathToCurrent;

    ::std::stack< ELEMENT > m_currentAncestors;

};

template< class ELEMENT, class NODEINFO, class PROCESSOR >

bool TreeVisitor< ELEMENT, NODEINFO, PROCESSOR >::do_step()

{

    if ( !m_visitedRoot )

    {

        m_current = m_root;

        m_visitedRoot = true;

        return true;

    }

    // can we step down from the current node?

    size_t childCount = m_nodeInfo.childCount( m_current );

    if ( childCount )

    {

        m_currentAncestors.push( m_current );

        m_current = m_nodeInfo.getChild( m_current, 0 );

        m_pathToCurrent.push( 0 );

        return true;

    }

    // is there a right sibling of the current node?

    while ( !m_pathToCurrent.empty() )

    {

        const ELEMENT& currentParent = m_currentAncestors.top();

        childCount = m_nodeInfo.childCount( currentParent );

        size_t currentChildPos = m_pathToCurrent.top();

        if ( ++currentChildPos < childCount )

        {

            // yes there is

            m_pathToCurrent.top() = currentChildPos;

            m_current = m_nodeInfo.getChild( currentParent, currentChildPos );

            return true;

        }

        // no there isn't => step up

        m_currentAncestors.pop();

        m_pathToCurrent.pop();

    }

    return false;

}

#endif // INCLUDED_SVX_SOURCE_INC_TREEVISITOR_HXX

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