/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
// Class header file.
#include "TreeWalker.hpp"


#include <cassert>


#include <xalanc/XalanDOM/XalanNode.hpp>


XALAN_CPP_NAMESPACE_BEGIN


TreeWalker::TreeWalker()
{
}


TreeWalker::~TreeWalker()
{
}


const XalanNode*
TreeWalker::traverse(const XalanNode*	pos)
{
	assert(pos != 0);

	const XalanNode*	thePos = pos;

	bool	fStop = false;

	while(0 != thePos && fStop == false)
	{
		fStop = startNode(thePos);

		const XalanNode*	nextNode = thePos->getFirstChild();

		while(0 == nextNode)
		{
			if (fStop == false)
			{
				fStop = endNode(thePos);
			}
			else
			{
				endNode(thePos);
			}

			nextNode = thePos->getNextSibling();

			if(0 == nextNode)
			{
				thePos = thePos->getParentNode();

				if(0 == thePos)
				{
					nextNode = thePos;

					break;
				}
			}
		}

		thePos = nextNode;
	}

	return thePos;
}


XalanNode*
TreeWalker::traverse(XalanNode*		pos)
{
	assert(pos != 0);

	XalanNode*	thePos = pos;

	bool	fStop = false;

	while(0 != thePos && fStop == false)
	{
		fStop = startNode(thePos);

		XalanNode*	nextNode = thePos->getFirstChild();

		while(0 == nextNode)
		{
			if (fStop == false)
			{
				fStop = endNode(thePos);
			}
			else
			{
				endNode(thePos);
			}

			nextNode = thePos->getNextSibling();

			if(0 == nextNode)
			{
				thePos = thePos->getParentNode();

				if(0 == thePos)
				{
					nextNode = thePos;

					break;
				}
			}
		}

		thePos = nextNode;
	}

	return thePos;
}


const XalanNode*
TreeWalker::traverse(
			const XalanNode*	pos,
			const XalanNode*	parent)
{
	assert(pos != 0);
	assert(parent != 0);

	const XalanNode*	thePos = pos;

	bool	fStop = false;

	while(parent != thePos && fStop == false)
	{	  
		fStop = startNode(thePos);
	  
		const XalanNode*	nextNode = thePos->getFirstChild();

		while(0 == nextNode)
		{
			if (fStop == false)
			{
				fStop = endNode(thePos);
			}
			else
			{
				endNode(thePos);
			}

			nextNode = thePos->getNextSibling();

			if(0 == nextNode)
			{
				thePos = thePos->getParentNode();
				assert(thePos != 0);

				if(parent == thePos)
				{
					nextNode = thePos;

					break;
				}
			}
		}

		thePos = nextNode;
	}

	return thePos;
}


XalanNode*
TreeWalker::traverse(
			XalanNode*	pos,
			XalanNode*	parent)
{
	assert(pos != 0);
	assert(parent != 0);

	XalanNode*	thePos = pos;

	bool	fStop = false;

	while(parent != thePos && fStop == false)
	{	  
		fStop = startNode(thePos);
	  
		XalanNode*	nextNode = thePos->getFirstChild();

		while(0 == nextNode)
		{
			if (fStop == false)
			{
				fStop = endNode(thePos);
			}
			else
			{
				endNode(thePos);
			}

			nextNode = thePos->getNextSibling();

			if(0 == nextNode)
			{
				thePos = thePos->getParentNode();
				assert(thePos != 0);

				if(parent == thePos)
				{
					nextNode = thePos;

					break;
				}
			}
		}

		thePos = nextNode;
	}

	return thePos;
}


void
TreeWalker::traverseSubtree(const XalanNode*	pos)
{
	if (pos != 0)
	{
		startNode(pos);

		const XalanNode* const	theFirstChild = pos->getFirstChild();

		if (theFirstChild != 0)
		{
			traverse(theFirstChild, pos);
		}

		endNode(pos);
	}
}


void
TreeWalker::traverseSubtree(XalanNode*	pos)
{
	if (pos != 0)
	{
		startNode(pos);

		XalanNode* const	theFirstChild = pos->getFirstChild();

		if (theFirstChild != 0)
		{
			traverse(theFirstChild, pos);
		}

		endNode(pos);
	}
}


XALAN_CPP_NAMESPACE_END