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1   /*
2    * $Header$
3    * $Revision: 1128 $
4    * $Date: 2006-02-05 13:49:04 -0800 (Sun, 05 Feb 2006) $
5    *
6    * ====================================================================
7    *
8    * Copyright 2000-2002 bob mcwhirter & James Strachan.
9    * All rights reserved.
10   *
11   * Redistribution and use in source and binary forms, with or without
12   * modification, are permitted provided that the following conditions are
13   * met:
14   * 
15   *   * Redistributions of source code must retain the above copyright
16   *     notice, this list of conditions and the following disclaimer.
17   * 
18   *   * Redistributions in binary form must reproduce the above copyright
19   *     notice, this list of conditions and the following disclaimer in the
20   *     documentation and/or other materials provided with the distribution.
21   * 
22   *   * Neither the name of the Jaxen Project nor the names of its
23   *     contributors may be used to endorse or promote products derived 
24   *     from this software without specific prior written permission.
25   * 
26   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27   * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29   * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30   * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37   *
38   * ====================================================================
39   * This software consists of voluntary contributions made by many 
40   * individuals on behalf of the Jaxen Project and was originally 
41   * created by bob mcwhirter <bob@werken.com> and 
42   * James Strachan <jstrachan@apache.org>.  For more information on the 
43   * Jaxen Project, please see <http://www.jaxen.org/>.
44   * 
45   * $Id: UnionPattern.java 1128 2006-02-05 21:49:04Z elharo $
46   */
47  
48  package org.jaxen.pattern;
49  
50  import org.jaxen.Context;
51  import org.jaxen.JaxenException;
52  
53  /** <p><code>UnionPattern</code> represents a union pattern.</p>
54    *
55    * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
56    * @version $Revision: 1128 $
57    */
58  public class UnionPattern extends Pattern {
59  
60      private Pattern lhs;
61      private Pattern rhs;
62      private short nodeType = ANY_NODE;
63      private String matchesNodeName = null;
64      
65      
66      public UnionPattern() 
67      {
68      }
69      
70      public UnionPattern(Pattern lhs, Pattern rhs) 
71      {
72          this.lhs = lhs;
73          this.rhs = rhs;
74          init();
75      }
76      
77      
78      public Pattern getLHS() 
79      {
80          return lhs;
81      }
82      
83      public void setLHS(Pattern lhs) 
84      {
85          this.lhs = lhs;
86          init();
87      }
88      
89      public Pattern getRHS() 
90      {
91          return rhs;
92      }
93      
94      public void setRHS(Pattern rhs) 
95      {
96          this.rhs = rhs;
97          init();
98      }
99      
100     
101     // Pattern interface
102     //-------------------------------------------------------------------------    
103     
104     /** @return true if the pattern matches the given node
105       */
106     public boolean matches( Object node, Context context ) throws JaxenException
107     {
108         return lhs.matches( node, context ) || rhs.matches( node, context );
109     }
110     
111     public Pattern[] getUnionPatterns() 
112     {
113         return new Pattern[] { lhs, rhs };
114     }
115 
116     
117     public short getMatchType() 
118     {
119         return nodeType;
120     }
121 
122 
123     public String getMatchesNodeName() 
124     {
125         return matchesNodeName;
126     }
127     
128     
129     public Pattern simplify() 
130     {
131         this.lhs = lhs.simplify();
132         this.rhs = rhs.simplify();
133         init();
134         return this;
135     }
136     
137     public String getText() 
138     {
139         return lhs.getText() + " | " + rhs.getText();
140     }
141         
142     public String toString()
143     {
144         return super.toString() + "[ lhs: " + lhs + " rhs: " + rhs + " ]";
145     }
146     
147     // Implementation methods
148     //-------------------------------------------------------------------------    
149     private void init() 
150     {
151         short type1 = lhs.getMatchType();
152         short type2 = rhs.getMatchType();
153         this.nodeType = ( type1 == type2 ) ? type1 : ANY_NODE;
154         
155         String name1 = lhs.getMatchesNodeName();
156         String name2 = rhs.getMatchesNodeName();
157         
158         this.matchesNodeName = null;
159         if ( name1 != null && name2 != null && name1.equals( name2 ) ) 
160         {
161             this.matchesNodeName = name1;
162         }
163     }    
164 }