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Java > Open Source Codes > org > netbeans > lib > jmi > query > AlterQuery


1 /*
2  * The contents of this file are subject to the terms of the Common Development
3  * and Distribution License (the License). You may not use this file except in
4  * compliance with the License.
5  *
6  * You can obtain a copy of the License at http://www.netbeans.org/cddl.html
7  * or http://www.netbeans.org/cddl.txt.
8  *
9  * When distributing Covered Code, include this CDDL Header Notice in each file
10  * and include the License file at http://www.netbeans.org/cddl.txt.
11  * If applicable, add the following below the CDDL Header, with the fields
12  * enclosed by brackets [] replaced by your own identifying information:
13  * "Portions Copyrighted [year] [name of copyright owner]"
14  *
15  * The Original Software is NetBeans. The Initial Developer of the Original
16  * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
17  * Microsystems, Inc. All Rights Reserved.
18  */
19 package org.netbeans.lib.jmi.query;
20
21 import java.util.Iterator JavaDoc;
22 import java.util.NoSuchElementException JavaDoc;
23
24 /** Alters the objects in the query to other objects.
25  *
26  * @author Petr Hrebejk
27  */
28 public abstract class AlterQuery implements Query {
29
30     private final Query QUERY;
31     private final Alternator ALTERNATOR;
32
33     AlterQuery(Query query) {
34         this.QUERY = query;
35         this.ALTERNATOR = null;
36     }
37
38     AlterQuery(Query query, Alternator alternator ) {
39         this.QUERY = query;
40         this.ALTERNATOR = alternator;
41     }
42
43     public Iterator JavaDoc iterator() {
44         return new AlterIterator();
45     }
46     
47     public boolean contains( Object JavaDoc object ) {
48         return QUERY.contains( alterBack( object ) );
49     }
50     
51     protected Object JavaDoc alter( Object JavaDoc object ) {
52         if ( ALTERNATOR == null ) {
53             return object;
54         }
55         else {
56             return ALTERNATOR.alter( object );
57         }
58     }
59     
60     protected Object JavaDoc alterBack( Object JavaDoc object ) {
61         if ( ALTERNATOR == null ) {
62             return object;
63         }
64         else {
65             return ALTERNATOR.alterBack( object );
66         }
67     }
68     
69     // Inner classes -----------------------------------------------------------
70
71     public interface Alternator {
72         
73         public Object JavaDoc alter( Object JavaDoc object );
74         
75         public Object JavaDoc alterBack( Object JavaDoc object );
76     }
77     
78     private class AlterIterator extends QueryIterator.Delegate {
79         
80         /** The object which will be returned as next */
81         private Object JavaDoc next = null;
82         
83         AlterIterator() {
84             super ( QUERY.iterator() );
85         }
86         
87         public boolean hasNext() {
88             return ITERATOR.hasNext();
89         }
90         
91         public Object JavaDoc next() {
92             
93             Object JavaDoc next = ITERATOR.next();
94             return alter( next );
95         }
96     }
97     
98 }
99
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