001/*
002 *  Copyright 2012 Anyware Services
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.ametys.runtime.request;
017
018import java.util.ArrayList;
019import java.util.Collection;
020
021import org.apache.avalon.framework.activity.Initializable;
022import org.apache.avalon.framework.component.Component;
023import org.apache.avalon.framework.context.ContextException;
024import org.apache.avalon.framework.context.Contextualizable;
025import org.apache.avalon.framework.thread.ThreadSafe;
026import org.apache.cocoon.Constants;
027import org.apache.cocoon.environment.Context;
028
029/**
030 * Avalon component responsible for registering <code>RequestListener</code>s
031 */
032public class RequestListenerManager implements Contextualizable, ThreadSafe, Initializable, Component
033{
034    /** Avalon Role */
035    public static final String ROLE = RequestListenerManager.class.getName();
036    
037    /** ServletContext attribute id containing an ArrayList&lt;RequestListener&gt; */
038    public static final String CONTEXT_ATTRIBUTE_REQUEST_LISTENERS = "runtime:requestListeners";
039
040    private Context _context;
041
042    public void contextualize(org.apache.avalon.framework.context.Context context) throws ContextException
043    {
044        _context = (Context) context.get(Constants.CONTEXT_ENVIRONMENT_CONTEXT);
045    }
046    
047    public void initialize() throws Exception
048    {
049        _context.setAttribute(org.ametys.runtime.request.RequestListenerManager.CONTEXT_ATTRIBUTE_REQUEST_LISTENERS, new ArrayList<RequestListener>());
050    }
051    
052    /**
053     * Registers a RequestListener
054     * @param listener the listener being registered
055     */
056    @SuppressWarnings("unchecked")
057    public void registerListener(RequestListener listener)
058    {
059        Collection<RequestListener> listeners = (Collection) _context.getAttribute(org.ametys.runtime.request.RequestListenerManager.CONTEXT_ATTRIBUTE_REQUEST_LISTENERS);
060        listeners.add(listener);
061    }
062    
063    /**
064     * Unregisters a RequestListener
065     * @param listener the listener being unregistered
066     */
067    @SuppressWarnings("unchecked")
068    public void unregisterListener(RequestListener listener)
069    {
070        Collection<RequestListener> listeners = (Collection) _context.getAttribute(org.ametys.runtime.request.RequestListenerManager.CONTEXT_ATTRIBUTE_REQUEST_LISTENERS);
071        listeners.remove(listener);
072    }
073}