001 /*
002 $Id: ValueHolder.java,v 1.1 2003/10/24 12:47:15 jstrachan Exp $
003
004 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005
006 Redistribution and use of this software and associated documentation
007 ("Software"), with or without modification, are permitted provided
008 that the following conditions are met:
009
010 1. Redistributions of source code must retain copyright
011 statements and notices. Redistributions must also contain a
012 copy of this document.
013
014 2. Redistributions in binary form must reproduce the
015 above copyright notice, this list of conditions and the
016 following disclaimer in the documentation and/or other
017 materials provided with the distribution.
018
019 3. The name "groovy" must not be used to endorse or promote
020 products derived from this Software without prior written
021 permission of The Codehaus. For written permission,
022 please contact info@codehaus.org.
023
024 4. Products derived from this Software may not be called "groovy"
025 nor may "groovy" appear in their names without prior written
026 permission of The Codehaus. "groovy" is a registered
027 trademark of The Codehaus.
028
029 5. Due credit should be given to The Codehaus -
030 http://groovy.codehaus.org/
031
032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043 OF THE POSSIBILITY OF SUCH DAMAGE.
044
045 */
046 package groovy.model;
047
048 import java.beans.PropertyChangeListener;
049 import java.beans.PropertyChangeSupport;
050
051 /**
052 * A simple ValueModle implementation which is a holder of an object value.
053 * Used to share local variables with closures
054 *
055 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
056 * @version $Revision: 1.1 $
057 */
058 public class ValueHolder implements ValueModel {
059 private Object value;
060 private Class type;
061 private PropertyChangeSupport propertyChangeSupport;
062 private boolean editable = true;
063
064 public ValueHolder() {
065 this(Object.class);
066 }
067
068 public ValueHolder(Class type) {
069 this.type = type;
070 }
071
072 public ValueHolder(Object value) {
073 this.value = value;
074 this.type = (value != null) ? value.getClass() : Object.class;
075 }
076
077 /**
078 * Add a PropertyChangeListener to the listener list.
079 * @param l The listener to add.
080 */
081 public void addPropertyChangeListener(PropertyChangeListener listener) {
082 if ( propertyChangeSupport == null ) {
083 propertyChangeSupport = new PropertyChangeSupport(this);
084 }
085 propertyChangeSupport.addPropertyChangeListener(listener);
086 }
087
088 /**
089 * Removes a PropertyChangeListener from the listener list.
090 * @param l The listener to remove.
091 */
092 public void removePropertyChangeListener(PropertyChangeListener listener) {
093 if ( propertyChangeSupport != null ) {
094 propertyChangeSupport.removePropertyChangeListener(listener);
095 }
096 }
097
098
099 public Object getValue() {
100 return value;
101 }
102
103 public void setValue(Object value) {
104 Object oldValue = this.value;
105 this.value = value;
106 if ( propertyChangeSupport != null ) {
107 propertyChangeSupport.firePropertyChange("value", oldValue, value);
108 }
109 }
110
111 public Class 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 }