code: /*
   * 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
   *
   * 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.
   */
  /*
   * $Id$
   */
  package org.apache.xpath.axes;
  
  import org.apache.xml.dtm.Axis;
  import org.apache.xml.dtm.DTM;
  import org.apache.xml.dtm.DTMAxisTraverser;
  import org.apache.xml.dtm.DTMIterator;
  import org.apache.xpath.compiler.Compiler;
  
  /**
   * This class implements an optimized iterator for
   * children patterns that have a node test, and possibly a predicate.
   * @see org.apache.xpath.axes.BasicTestIterator
   * @xsl.usage advanced
   */
  public class ChildTestIterator extends BasicTestIterator
  {
      static final long serialVersionUID = -7936835957960705722L;
    /** The traverser to use to navigate over the descendants. */
    transient protected DTMAxisTraverser m_traverser;
    
    /** The extended type ID, not set until setRoot. */
  //  protected int m_extendedTypeID;
  
  
    /**
     * Create a ChildTestIterator object.
     *
     * @param compiler A reference to the Compiler that contains the op map.
     * @param opPos The position within the op map, which contains the
     * location path expression for this itterator.
     *
     * @throws javax.xml.transform.TransformerException
     */
    ChildTestIterator(Compiler compiler, int opPos, int analysis)
            throws javax.xml.transform.TransformerException
    {
      super(compiler, opPos, analysis);
    }
    
    /**
     * Create a ChildTestIterator object.
     *
     * @param traverser Traverser that tells how the KeyIterator is to be handled.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public ChildTestIterator(DTMAxisTraverser traverser)
    {
  
      super(null);
  
      m_traverser = traverser;
    }
  
    /**
     * Get the next node via getNextXXX.  Bottlenecked for derived class override.
     * @return The next node on the axis, or DTM.NULL.
     */
    protected int getNextNode()
    {                     
      if(true /* 0 == m_extendedTypeID */)
      {
        m_lastFetched = (DTM.NULL == m_lastFetched)
                     ? m_traverser.first(m_context)
                     : m_traverser.next(m_context, m_lastFetched);
      }
  //    else
  //    {
  //      m_lastFetched = (DTM.NULL == m_lastFetched)
  //                   ? m_traverser.first(m_context, m_extendedTypeID)
  //                   : m_traverser.next(m_context, m_lastFetched, 
  //                                      m_extendedTypeID);
  //    }
  
      return m_lastFetched;
    }
  
    
    /**
     *  Get a cloned Iterator that is reset to the beginning
     *  of the query.
     * 
     *  @return A cloned NodeIterator set of the start of the query.
     * 
     *  @throws CloneNotSupportedException
     */
    public DTMIterator cloneWithReset() throws CloneNotSupportedException
    {
  
      ChildTestIterator clone = (ChildTestIterator) super.cloneWithReset();
      clone.m_traverser = m_traverser;
  
      return clone;
    }
    
  
    /**
     * Initialize the context values for this expression
     * after it is cloned.
     *
     * @param context The XPath runtime context for this
     * transformation.
     */
    public void setRoot(int context, Object environment)
    {
      super.setRoot(context, environment);
      m_traverser = m_cdtm.getAxisTraverser(Axis.CHILD);
      
  //    String localName = getLocalName();
  //    String namespace = getNamespace();
  //    int what = m_whatToShow;
  //    // System.out.println("what: ");
  //    // NodeTest.debugWhatToShow(what);
  //    if(DTMFilter.SHOW_ALL == what ||
  //       ((DTMFilter.SHOW_ELEMENT & what) == 0)
  //       || localName == NodeTest.WILD
  //       || namespace == NodeTest.WILD)
  //    {
  //      m_extendedTypeID = 0;
  //    }
  //    else
  //    {
  //      int type = getNodeTypeTest(what);
  //      m_extendedTypeID = m_cdtm.getExpandedTypeID(namespace, localName, type);
  //    }
      
    }
    
    /**
     * Returns the axis being iterated, if it is known.
     * 
     * @return Axis.CHILD, etc., or -1 if the axis is not known or is of multiple 
     * types.
     */
    public int getAxis()
    {
      return org.apache.xml.dtm.Axis.CHILD;
    }
  
    /**
     *  Detaches the iterator from the set which it iterated over, releasing
     * any computational resources and placing the iterator in the INVALID
     * state. After<code>detach</code> has been invoked, calls to
     * <code>nextNode</code> or<code>previousNode</code> will raise the
     * exception INVALID_STATE_ERR.
     */
    public void detach()
    {   
      if(m_allowDetach)
      {
        m_traverser = null;
        
        // Always call the superclass detach last!
        super.detach();
      }
    }
  
  }
  