001    // Copyright 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.listener;
016    
017    import org.apache.hivemind.util.Defense;
018    import org.apache.tapestry.IActionListener;
019    import org.apache.tapestry.IComponent;
020    import org.apache.tapestry.IRequestCycle;
021    
022    /**
023     * Adapter class that combines a target object (typically, a component) with a
024     * {@link org.apache.tapestry.listener.ListenerMethodInvoker}. This is the
025     * bridge from listener method names to listener method invocations.
026     * <p>
027     * TODO: It would really be nice if we could get the location of the listener
028     * binding into thrown exceptions. As implemented, as best, it will be the
029     * location of the &lt;page-specification&gt; (or &lt;component&gt;) of the page
030     * (or component) containing the listener method.
031     * 
032     * @author Howard M. Lewis Ship
033     * @since 4.0
034     */
035    public class SyntheticListener implements IActionListener
036    {
037        private final Object _target;
038    
039        private final ListenerMethodInvoker _invoker;
040    
041        public SyntheticListener(Object target, ListenerMethodInvoker invoker)
042        {
043            Defense.notNull(target, "target");
044            Defense.notNull(invoker, "invoker");
045    
046            _target = target;
047            _invoker = invoker;
048        }
049    
050        public void actionTriggered(IComponent component, IRequestCycle cycle)
051        {
052            _invoker.invokeListenerMethod(_target, cycle);
053        }
054        
055        public String getMethodName()
056        {
057            return _invoker.getMethodName();
058        }
059    
060        public String toString()
061        {
062            return "SyntheticListener[methodName = " + _invoker.getMethodName() + "]";
063        }
064    }