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.pattern;
  
  import org.jaxen.Context;
  import org.jaxen.JaxenException;
  
  /** <p><code>Pattern</code> defines the behaviour for pattern in
    * the XSLT processing model.</p>
    *
    * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
    * @version $Revision$
    */
  public abstract class Pattern {
  
      // These node numbers are compatible with both DOM and dom4j's node types
      /** Matches Element nodes */
      public static final short ELEMENT_NODE = 1;
      /** Matches attribute nodes */
      public static final short ATTRIBUTE_NODE = 2;
      /** Matches text nodes */
      public static final short TEXT_NODE = 3;
      /** Matches CDATA section nodes */
      public static final short CDATA_SECTION_NODE = 4;
      /** Matches entity reference nodes */
      public static final short ENTITY_REFERENCE_NODE = 5;
      /** Matches entity nodes */
      //public static final short ENTITY_NODE = 6;
      /** Matches ProcessingInstruction */
      public static final short PROCESSING_INSTRUCTION_NODE = 7;
      /** Matches comment nodes */
      public static final short COMMENT_NODE = 8;
      /** Matches document nodes */
      public static final short DOCUMENT_NODE = 9;
      /** Matches DocumentType nodes */
      public static final short DOCUMENT_TYPE_NODE = 10;
      //public static final short DOCUMENT_FRAGMENT_NODE = 11;
      //public static final short NOTATION_NODE = 12;
      
      /** Matches a Namespace Node */
      // This has the same value as the DOM Level 3 XPathNamespace type
      public static final short NAMESPACE_NODE = 13;
      
      /** Does not match any valid node */
      public static final short UNKNOWN_NODE = 14;
      
      /** The maximum number of node types for sizing purposes */
      public static final short MAX_NODE_TYPE = 14;
  
      /** Matches any node */
      public static final short ANY_NODE = 0;
      
      /** Matches no nodes */
      public static final short NO_NODE = 14;
      
      
      /** 
       * 
       * @param node ????
       * @param context ????
       * @return true if the pattern matches the given node
       * @throws JaxenException  if ????
        */
      public abstract boolean matches( Object node, Context context ) throws JaxenException;
      
      /** Returns the default resolution policy of the pattern according to the
        * <a href="http://www.w3.org/TR/xslt#conflict">
        * XSLT conflict resolution rules</a>.
        *  
       * @return 0.5; the default priority defined in XSLT
       * 
       * @see <a href="http://www.w3.org/TR/xslt#conflict" target="_top">Section 5.5 of the XSLT specification</a>
        * 
        */
      public double getPriority() 
      {
          return 0.5;
      }
      
      /** If this pattern is a union pattern then this
        * method should return an array of patterns which
        * describe the union pattern, which should contain more than one pattern.
        * Otherwise this method should return null.
        *
        * @return an array of the patterns which make up this union pattern
        * or null if this pattern is not a union pattern
        */
      public Pattern[] getUnionPatterns() 
      {
          return null;
      }
  
      
      /** 
       * Returns the type of node the pattern matches.
       * 
       * @return <code>ANY_NODE</code> unless overridden
        */
      public short getMatchType() 
      {
          return ANY_NODE;
      }
  
  
      /** For patterns which only match an ATTRIBUTE_NODE or an 
        * ELEMENT_NODE then this pattern may return the name of the
        * element or attribute it matches. This allows a more efficient
        * rule matching algorithm to be performed, rather than a brute 
        * force approach of evaluating every pattern for a given Node.
        *
        * @return the name of the element or attribute this pattern matches
        * or null if this pattern matches any or more than one name
        */
      public String getMatchesNodeName() 
      {
          return null;
      }
      
      
      public Pattern simplify() 
      {
          return this;
      }
      
      /** Returns a textual representation of this pattern
       * 
       * @return the usual string form of this XSLT pattern
       */
      public abstract String getText();
  
  }
  