content: package org.jaxen.util;
  
  /*
   * $Header$
   * $Revision$
   * $Date$
   *
   * ====================================================================
   *
   * 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/>.
   *
   * $Id$
  */
  
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  import org.jaxen.Navigator;
  import org.jaxen.UnsupportedAxisException;
  import org.jaxen.JaxenRuntimeException;
  
  /**
   * <p>
   * Represents the XPath <code>ancestor-or-self</code> axis. 
   * The "<code>ancestor-or-self</code> axis contains the context node and 
   * the ancestors of the context node; thus, the ancestor axis will 
   * always include the root node."
   * </p>
   * 
   * @version 1.2b12
   */
  public class AncestorOrSelfAxisIterator implements Iterator
  {
      
      private Object    contextNode;
      private Navigator navigator;
  
      /**
       * Create a new <code>ancestor-or-self</code> axis iterator.
       * 
       * @param contextNode the node to start from
       * @param navigator the object model specific navigator
       */
      public AncestorOrSelfAxisIterator(Object contextNode,
                                        Navigator navigator)
      {
          // XXX should we throw a NullPointerException here if contextNode is null?
          this.contextNode = contextNode;
          this.navigator = navigator;
      }
  
      /**
       * Returns true if there are any nodes remaining 
       * on the ancestor-or-self axis; false otherwise.
       * 
       * @return true if any ancestors or self remain
       * 
       * @see java.util.Iterator#hasNext()
       */
      public boolean hasNext()
      {
          return contextNode != null;
      }
  
      /**
       * Returns the next ancestor-or-self node.
       * 
       * @return the next ancestor-or-self node
       * 
       * @throws NoSuchElementException if no ancestors remain
       * 
       * @see java.util.Iterator#next()
       */
      public Object next()
      {
          try
          {
              if (hasNext()) {
                  Object result = contextNode;
                  contextNode = navigator.getParentNode(contextNode);
                  return result;
              }
              throw new NoSuchElementException("Exhausted ancestor-or-self axis");
          }
          catch (UnsupportedAxisException e)
          {
              throw new JaxenRuntimeException(e);
          }
      }
  
      /**
       * This operation is not supported.
       * 
       * @throws UnsupportedOperationException always
       */
      public void remove()
      {
          throw new UnsupportedOperationException();
      }
      
  }
  