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.Collections;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  
  import org.jaxen.Context;
  import org.jaxen.ContextSupport;
  import org.jaxen.JaxenException;
  
  abstract class DefaultLocationPath extends DefaultExpr implements LocationPath
  {
      private List steps;
      
      /**
       * Create a new empty location path.
       */
      DefaultLocationPath()
      {
          this.steps = new LinkedList();
      }
  
      public void addStep(Step step)
      {
          getSteps().add(step);
      }
  
      public List getSteps()
      {
          return this.steps;
      }
  
      public Expr simplify()
      {
          Iterator stepIter = getSteps().iterator();
          Step eachStep = null;
          while (stepIter.hasNext())
          {
              eachStep = (Step) stepIter.next();
              eachStep.simplify();
          }
          return this;
      }
  
      public String getText()
      {
          StringBuffer buf = new StringBuffer();
          Iterator stepIter = getSteps().iterator();
          while (stepIter.hasNext())
          {
              buf.append(((Step) stepIter.next()).getText());
              if (stepIter.hasNext())
              {
                  buf.append("/");
              }
          }
          return buf.toString();
      }
  
      public String toString()
      {
          StringBuffer buf = new StringBuffer();
          Iterator stepIter = getSteps().iterator();
          while (stepIter.hasNext())
          {
              buf.append(stepIter.next().toString());
              if (stepIter.hasNext())
              {
                  buf.append("/");
              }
          }
          return buf.toString();
      }
  
      public boolean isAbsolute()
      {
          return false;
      }
  
      public Object evaluate(Context context) throws JaxenException
      {
          List nodeSet = context.getNodeSet();
          List contextNodeSet = new ArrayList(nodeSet);
          ContextSupport support = context.getContextSupport();
          Context stepContext = new Context(support);
          Iterator stepIter = getSteps().iterator();
          while ( stepIter.hasNext() )
          {
              Step eachStep = (Step) stepIter.next();
              stepContext.setNodeSet(contextNodeSet);
              contextNodeSet = eachStep.evaluate(stepContext);
              // now we need to reverse the list if this is a reverse axis
              if (isReverseAxis(eachStep)) {
                  Collections.reverse(contextNodeSet);
              }
          }
          
          if (getSteps().size() > 1 || nodeSet.size() > 1) {
              Collections.sort(contextNodeSet, new NodeComparator(support.getNavigator()));
          }
          
          return contextNodeSet;
      }
  
      private boolean isReverseAxis(Step step) {
  
          int axis = step.getAxis();
          return axis == org.jaxen.saxpath.Axis.PRECEDING
            || axis == org.jaxen.saxpath.Axis.PRECEDING_SIBLING
            || axis == org.jaxen.saxpath.Axis.ANCESTOR
            || axis == org.jaxen.saxpath.Axis.ANCESTOR_OR_SELF;
      }
  
  }
  
  