content: /*
   * $Header$
   * $Revision$
   * $Date$
   *
   * ====================================================================
   *
   * Copyright 2000-2002 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/>.
   * 
   * $Id$
   */
  package org.jaxen.expr;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import org.jaxen.Context;
  import org.jaxen.ContextSupport;
  import org.jaxen.JaxenException;
  import org.jaxen.UnsupportedAxisException;
  import org.jaxen.expr.iter.IterableAxis;
  import org.jaxen.saxpath.Axis;
  
  /**
   * @deprecated this class will become non-public in the future;
   *     use the interface instead
   */
  public abstract class DefaultStep implements Step
  {
      private IterableAxis axis;
      private PredicateSet predicates;
  
      public DefaultStep(IterableAxis axis, PredicateSet predicates)
      {
          this.axis = axis;
          this.predicates = predicates;
      }
  
      public void addPredicate(Predicate predicate)
      {
          this.predicates.addPredicate(predicate);
      }
  
      public List getPredicates()
      {
          return this.predicates.getPredicates();
      }
  
      public PredicateSet getPredicateSet()
      {
          return this.predicates;
      }
  
      public int getAxis()
      {
          return this.axis.value();
      }
  
      public IterableAxis getIterableAxis()
      {
          return this.axis;
      }
  
      public String getAxisName()
      {
          return Axis.lookup(getAxis());
      }
  
      public String getText()
      {
          return this.predicates.getText();
      }
  
      public String toString()
      {
          return getIterableAxis() + " " + super.toString();
      }
  
      public void simplify()
      {
          this.predicates.simplify();
      }
  
      public Iterator axisIterator(Object contextNode, ContextSupport support)
          throws UnsupportedAxisException
      {
          return getIterableAxis().iterator(contextNode, support);
      }
  
      public List evaluate(final Context context) throws JaxenException
      {
          final List contextNodeSet  = context.getNodeSet();
          final IdentitySet unique = new IdentitySet();
          final int contextSize = contextNodeSet.size();
  
          // ???? try linked lists instead?
          // ???? initial size for these?
          final ArrayList interimSet = new ArrayList();
          final ArrayList newNodeSet = new ArrayList();
          final ContextSupport support = context.getContextSupport();
              
          // ???? use iterator instead
          for ( int i = 0 ; i < contextSize ; ++i )
          {
              Object eachContextNode = contextNodeSet.get( i );
  
  
                  /* See jaxen-106. Might be able to optimize this by doing
                   * specific matching for individual axes. For instance on namespace axis
                   * we should only get namespace nodes and on attribute axes we only get 
                   * attribute nodes. Self and parent axes have single members.
                   * Children, descendant, ancestor, and sibling axes never 
                   * see any attributes or namespaces
                   */
              Iterator axisNodeIter = axis.iterator(eachContextNode, support);
              while ( axisNodeIter.hasNext() )
              {
                  Object eachAxisNode = axisNodeIter.next();
                  if ( ! unique.contains( eachAxisNode ) )
                  {
                      if ( matches( eachAxisNode, support ) )
                      {
                          unique.add( eachAxisNode );
                          interimSet.add( eachAxisNode );
                      }
                  }
              }
              newNodeSet.addAll(getPredicateSet().evaluatePredicates(
                                interimSet, support ));
              interimSet.clear();
          }
          return newNodeSet;
      }
  
  }
  