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.tapestry.IActionListener;
018    import org.apache.tapestry.IComponent;
019    import org.apache.tapestry.IRequestCycle;
020    
021    /**
022     * Pipeline service interface for the tapestry.listener.ListenerInvoker pipeline service.
023     * 
024     * @author Howard M. Lewis Ship
025     * @since 4.0
026     * @see org.apache.tapestry.listener.ListenerInvokerFilter
027     */
028    public interface ListenerInvoker
029    {
030        /**
031         * Part of the pipeline for invoking the given listener object. This may be supplemented by
032         * various filters.
033         * 
034         * @param listener
035         *            to be invoked, may be null if no listener is found (a convienience for all the
036         *            places where listeners are optional)
037         * @param source
038         *            the component generating the listener "event", to be passed to the listener. Not
039         *            generally used, but may not be null.
040         * @param cycle
041         *            the current request cycle, to be passed to the listener.
042         */
043    
044        public void invokeListener(IActionListener listener, IComponent source, IRequestCycle cycle);
045    }