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 * reserved comment block

 * DO NOT REMOVE OR ALTER!

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/*

 * 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.

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package com.sun.org.apache.xpath.internal.axes;

import com.sun.org.apache.xml.internal.dtm.DTM;

import com.sun.org.apache.xml.internal.dtm.DTMFilter;

import com.sun.org.apache.xpath.internal.Expression;

import com.sun.org.apache.xpath.internal.compiler.Compiler;

import com.sun.org.apache.xpath.internal.compiler.OpMap;

/**

 * This class implements a general iterator for

 * those LocationSteps with only one step, and perhaps a predicate,

 * that only go forward (i.e. it can not be used with ancestors,

 * preceding, etc.)

 * @see com.sun.org.apache.xpath.internal.axes#ChildTestIterator

 * @xsl.usage advanced

 */

public class OneStepIteratorForward extends ChildTestIterator

{

    static final long serialVersionUID = -1576936606178190566L;

  /** The traversal axis from where the nodes will be filtered. */

  protected int m_axis = -1;

  /**

   * Create a OneStepIterator 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

   */

  OneStepIteratorForward(Compiler compiler, int opPos, int analysis)

          throws javax.xml.transform.TransformerException

  {

    super(compiler, opPos, analysis);

    int firstStepPos = OpMap.getFirstChildPos(opPos);

    m_axis = WalkerFactory.getAxisFromStep(compiler, firstStepPos);

  }

  /**

   * Create a OneStepIterator object that will just traverse the self axes.

   *

   * @param axis One of the com.sun.org.apache.xml.internal.dtm.Axis integers.

   *

   * @throws javax.xml.transform.TransformerException

   */

  public OneStepIteratorForward(int axis)

  {

    super(null);

    m_axis = axis;

    int whatToShow = DTMFilter.SHOW_ALL;

    initNodeTest(whatToShow);

  }

  /**

   * 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(m_axis);

  }

//  /**

//   * Return the first node out of the nodeset, if this expression is

//   * a nodeset expression.  This is the default implementation for

//   * nodesets.

//   * <p>WARNING: Do not mutate this class from this function!</p>

//   * @param xctxt The XPath runtime context.

//   * @return the first node out of the nodeset, or DTM.NULL.

//   */

//  public int asNode(XPathContext xctxt)

//    throws javax.xml.transform.TransformerException

//  {

//    if(getPredicateCount() > 0)

//      return super.asNode(xctxt);

//

//    int current = xctxt.getCurrentNode();

//

//    DTM dtm = xctxt.getDTM(current);

//    DTMAxisTraverser traverser = dtm.getAxisTraverser(m_axis);

//

//    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)

//    {

//      return traverser.first(current);

//    }

//    else

//    {

//      int type = getNodeTypeTest(what);

//      int extendedType = dtm.getExpandedTypeID(namespace, localName, type);

//      return traverser.first(current, extendedType);

//    }

//  }

  /**

   * Get the next node via getFirstAttribute && getNextAttribute.

   */

  protected int getNextNode()

  {

    m_lastFetched = (DTM.NULL == m_lastFetched)

                     ? m_traverser.first(m_context)

                     : m_traverser.next(m_context, m_lastFetched);

    return m_lastFetched;

  }

  /**

   * 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 m_axis;

  }

  /**

   * @see Expression#deepEquals(Expression)

   */

  public boolean deepEquals(Expression expr)

  {

        if(!super.deepEquals(expr))

                return false;

        if(m_axis != ((OneStepIteratorForward)expr).m_axis)

                return false;

        return true;

  }

}