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Java > Open Source Codes > groovy > model > ValueHolder


1 /*
2  $Id: ValueHolder.java,v 1.1 2003/10/24 12:47:15 jstrachan Exp $
3
4  Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5
6  Redistribution and use of this software and associated documentation
7  ("Software"), with or without modification, are permitted provided
8  that the following conditions are met:
9
10  1. Redistributions of source code must retain copyright
11     statements and notices. Redistributions must also contain a
12     copy of this document.
13
14  2. Redistributions in binary form must reproduce the
15     above copyright notice, this list of conditions and the
16     following disclaimer in the documentation and/or other
17     materials provided with the distribution.
18
19  3. The name "groovy" must not be used to endorse or promote
20     products derived from this Software without prior written
21     permission of The Codehaus. For written permission,
22     please contact info@codehaus.org.
23
24  4. Products derived from this Software may not be called "groovy"
25     nor may "groovy" appear in their names without prior written
26     permission of The Codehaus. "groovy" is a registered
27     trademark of The Codehaus.
28
29  5. Due credit should be given to The Codehaus -
30     http://groovy.codehaus.org/
31
32  THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
33  ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
34  NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
35  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
36  THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
39  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43  OF THE POSSIBILITY OF SUCH DAMAGE.
44
45  */
46 package groovy.model;
47
48 import java.beans.PropertyChangeListener JavaDoc;
49 import java.beans.PropertyChangeSupport JavaDoc;
50
51 /**
52  * A simple ValueModle implementation which is a holder of an object value.
53  * Used to share local variables with closures
54  *
55  * @author <a HREF="mailto:james@coredevelopers.net">James Strachan</a>
56  * @version $Revision: 1.1 $
57  */
58 public class ValueHolder implements ValueModel {
59     private Object JavaDoc value;
60     private Class JavaDoc type;
61     private PropertyChangeSupport JavaDoc propertyChangeSupport;
62     private boolean editable = true;
63
64     public ValueHolder() {
65         this(Object JavaDoc.class);
66     }
67     
68     public ValueHolder(Class JavaDoc type) {
69         this.type = type;
70     }
71     
72     public ValueHolder(Object JavaDoc value) {
73         this.value = value;
74         this.type = (value != null) ? value.getClass() : Object JavaDoc.class;
75     }
76     
77     /**
78      * Add a PropertyChangeListener to the listener list.
79      * @param l The listener to add.
80      */
81     public void addPropertyChangeListener(PropertyChangeListener JavaDoc listener) {
82         if ( propertyChangeSupport == null ) {
83             propertyChangeSupport = new PropertyChangeSupport JavaDoc(this);
84         }
85         propertyChangeSupport.addPropertyChangeListener(listener);
86     }
87     
88     /**
89      * Removes a PropertyChangeListener from the listener list.
90      * @param l The listener to remove.
91      */
92     public void removePropertyChangeListener(PropertyChangeListener JavaDoc listener) {
93         if ( propertyChangeSupport != null ) {
94             propertyChangeSupport.removePropertyChangeListener(listener);
95         }
96     }
97     
98
99     public Object JavaDoc getValue() {
100         return value;
101     }
102
103     public void setValue(Object JavaDoc value) {
104         Object JavaDoc oldValue = this.value;
105         this.value = value;
106         if ( propertyChangeSupport != null ) {
107             propertyChangeSupport.firePropertyChange("value", oldValue, value);
108         }
109     }
110
111     public Class JavaDoc getType() {
112         return type;
113     }
114
115     public boolean isEditable() {
116         return editable;
117     }
118     
119     public void setEditable(boolean editable) {
120         this.editable = editable;
121     }
122
123 }
124
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