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 * Terminator implementation for the tapestry.listener.InvokeListener pipeline; 024 * this is what finally turns around and invokes 025 * {@link org.apache.tapestry.IActionListener#actionTriggered(IComponent, IRequestCycle)}. 026 * 027 * @author Howard M. Lewis Ship 028 * @since 4.0 029 */ 030 public class ListenerInvokerTerminator implements ListenerInvoker 031 { 032 033 /** 034 * @param listener 035 * to be invoked, may be null if no listener is found (a 036 * convienience for all the places where listeners are optional) 037 * @param source 038 * the component generating the listener "event", to be passed to 039 * the listener. Not generally used, but may not be null. 040 * @param cycle 041 * the current request cycle, to be passed to the listener. 042 */ 043 public void invokeListener(IActionListener listener, IComponent source, 044 IRequestCycle cycle) 045 { 046 Defense.notNull(source, "source"); 047 Defense.notNull(cycle, "cycle"); 048 049 if (listener != null) 050 listener.actionTriggered(source, cycle); 051 } 052 053 }