001// Copyright 2006, 2007, 2008, 2011 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 015package org.apache.tapestry5.internal.event; 016 017import org.apache.tapestry5.ioc.internal.util.CollectionFactory; 018import org.apache.tapestry5.services.InvalidationEventHub; 019import org.apache.tapestry5.services.InvalidationListener; 020 021import java.util.List; 022 023/** 024 * Base implementation class for classes (especially services) that need to manage a list of 025 * {@link org.apache.tapestry5.services.InvalidationListener}s. 026 */ 027public class InvalidationEventHubImpl implements InvalidationEventHub 028{ 029 private final List<InvalidationListener> listeners; 030 031 protected InvalidationEventHubImpl(boolean productionMode) 032 { 033 if (productionMode) 034 { 035 listeners = null; 036 } else 037 { 038 listeners = CollectionFactory.newThreadSafeList(); 039 } 040 } 041 042 /** 043 * Notifies all {@link InvalidationListener listener}s. 044 */ 045 protected final void fireInvalidationEvent() 046 { 047 if (listeners == null) 048 { 049 return; 050 } 051 052 for (InvalidationListener listener : listeners) 053 { 054 listener.objectWasInvalidated(); 055 } 056 } 057 058 public final void addInvalidationListener(InvalidationListener listener) 059 { 060 if (listeners != null) 061 { 062 listeners.add(listener); 063 } 064 } 065}