/*
 * 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: ChildTestIterator.java 468655 2006-10-28 07:12:06Z minchau $
 */
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 Also:
BasicTestIterator
@xsl.usage
advanced/**
 * 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. /** 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.
Params:
compiler – A reference to the Compiler that contains the op map.
opPos – The position within the op map, which contains the
location path expression for this itterator.
Throws:
TransformerException – /**
   * 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.
Params:
traverser – Traverser that tells how the KeyIterator is to be handled.
Throws:
TransformerException – /**
   * 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.
Returns:
The next node on the axis, or DTM.NULL./**
   * 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
/**
   *  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.
Params:
context – The XPath runtime context for this
transformation./**
   * 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.
Returns:
Axis.CHILD, etc., or -1 if the axis is not known or is of multiple 
types./**
   * 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. Afterdetach has been invoked, calls to
nextNode orpreviousNode will raise the
exception INVALID_STATE_ERR.
/**
   *  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();
    }
  }

}