| // Copyright 2006, 2007, 2010 The Apache Software Foundation |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package org.apache.tapestry5.ioc.internal.services; |
| |
| import java.lang.ref.WeakReference; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.tapestry5.ioc.annotations.PreventServiceDecoration; |
| import org.apache.tapestry5.ioc.internal.util.CollectionFactory; |
| import org.apache.tapestry5.services.UpdateListener; |
| import org.apache.tapestry5.services.UpdateListenerHub; |
| |
| @PreventServiceDecoration |
| public class UpdateListenerHubImpl implements UpdateListenerHub |
| { |
| private final List<WeakReference<UpdateListener>> listeners = CollectionFactory.newThreadSafeList(); |
| |
| public void addUpdateListener(UpdateListener listener) |
| { |
| assert listener != null; |
| listeners.add(new WeakReference<UpdateListener>(listener)); |
| } |
| |
| /** |
| * Notifies all {@link UpdateListener}s. |
| */ |
| public void fireCheckForUpdates() |
| { |
| List<WeakReference<UpdateListener>> deadReferences = CollectionFactory.newList(); |
| |
| Iterator<WeakReference<UpdateListener>> i = listeners.iterator(); |
| |
| while (i.hasNext()) |
| { |
| WeakReference<UpdateListener> reference = i.next(); |
| |
| UpdateListener listener = reference.get(); |
| |
| if (listener == null) |
| deadReferences.add(reference); |
| else |
| listener.checkForUpdates(); |
| } |
| |
| if (!deadReferences.isEmpty()) |
| listeners.removeAll(deadReferences); |
| } |
| } |