package org.jaxen.util;
/*
* $Header$
* $Revision: 1255 $
* $Date: 2006-11-09 10:20:12 -0800 (Thu, 09 Nov 2006) $
*
* ====================================================================
*
* Copyright 2000-2005 bob mcwhirter & James Strachan.
* All rights reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of the Jaxen Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ====================================================================
* This software consists of voluntary contributions made by many
* individuals on behalf of the Jaxen Project and was originally
* created by bob mcwhirter <bob@werken.com> and
* James Strachan <jstrachan@apache.org>. For more information on the
* Jaxen Project, please see <http://www.jaxen.org/>.
*
* $Id: DescendantAxisIterator.java 1255 2006-11-09 18:20:12Z elharo $
*/
import org.jaxen.Navigator;
import org.jaxen.UnsupportedAxisException;
import org.jaxen.JaxenRuntimeException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.ArrayList;
/**
* Represents the XPath <code>descendant</code> axis.
* The "<code>descendant</code> axis contains the descendants of the context node;
* a descendant is a child or a child of a child and so on; thus
* the descendant axis never contains attribute or namespace nodes."
*
* @version 1.2b12
*/
public class DescendantAxisIterator implements Iterator
{
private ArrayList stack = new ArrayList();
private Iterator children;
private Navigator navigator;
/**
* Create a new <code>descendant</code> axis iterator.
*
* @param contextNode the node to start from
* @param navigator the object model specific navigator
*/
public DescendantAxisIterator(Object contextNode,
Navigator navigator) throws UnsupportedAxisException
{
this(navigator, navigator.getChildAxisIterator(contextNode));
}
public DescendantAxisIterator(Navigator navigator,
Iterator iterator)
{
this.navigator = navigator;
this.children = iterator;
}
/**
* Returns true if there are any descendants remaining; false otherwise.
*
* @return true if any descendants remain; false otherwise
*
* @see java.util.Iterator#hasNext()
*/ public boolean hasNext()
{
while (!children.hasNext())
{
if (stack.isEmpty())
{
return false;
}
children = (Iterator) stack.remove(stack.size()-1);
}
return true;
}
/**
* Returns the next descendant node.
*
* @return the next descendant node
*
* @throws NoSuchElementException if no descendants remain
*
* @see java.util.Iterator#next()
*/
public Object next()
{
try
{
if (hasNext())
{
Object node = children.next();
stack.add(children);
children = navigator.getChildAxisIterator(node);
return node;
}
throw new NoSuchElementException();
}
catch (UnsupportedAxisException e)
{
throw new JaxenRuntimeException(e);
}
}
/**
* This operation is not supported.
*
* @throws UnsupportedOperationException always
*/
public void remove()
{
throw new UnsupportedOperationException();
}
}