001    /*
002     $Id: ClosureModel.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 groovy.lang.Closure;
049    
050    /**
051     * Represents a value model using a closure to extract
052     * the value from some source model and an optional write closure
053     * for updating the value.
054     * 
055     * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
056     * @version $Revision: 1.1 $
057     */
058    public class ClosureModel implements ValueModel, NestedValueModel {
059    
060        private ValueModel sourceModel;
061        private Closure readClosure;
062        private Closure writeClosure;
063        private Class type;
064    
065        public ClosureModel(ValueModel sourceModel, Closure readClosure) {
066            this(sourceModel, readClosure, null);
067        }
068    
069        public ClosureModel(ValueModel sourceModel, Closure readClosure, Closure writeClosure) {
070            this(sourceModel, readClosure, writeClosure, Object.class);
071        }
072    
073        public ClosureModel(ValueModel sourceModel, Closure readClosure, Closure writeClosure, Class type) {
074            this.sourceModel = sourceModel;
075            this.readClosure = readClosure;
076            this.writeClosure = writeClosure;
077            this.type = type;
078        }
079    
080        public ValueModel getSourceModel() {
081            return sourceModel;
082        }
083    
084        public Object getValue() {
085            Object source = sourceModel.getValue();
086            if (source != null) {
087                return readClosure.call(source);
088            }
089            return null;
090        }
091    
092        public void setValue(Object value) {
093            if (writeClosure != null) {
094                Object source = sourceModel.getValue();
095                if (source != null) {
096                    writeClosure.call(new Object[] { source, value });
097                }
098            }
099        }
100    
101        public Class getType() {
102            return type;
103        }
104    
105        public boolean isEditable() {
106            return writeClosure != null;
107        }
108    }