/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.myfaces.webapp.filter.portlet;
  
  import org.apache.myfaces.shared_tomahawk.util.NullEnumeration;
  
  import java.util.Enumeration;
  import java.util.Map;
  import javax.portlet.PortletRequest;
  import javax.portlet.PortletSession;
  import org.apache.myfaces.webapp.filter.servlet.AbstractAttributeMap;
  
  /**
   * Portlet scope PortletSession attibutes as Map.
   * <p>
   * NOTE: This class was copied from myfaces impl 
   * org.apache.myfaces.context.portlet and it is
   * used by TomahawkFacesContextWrapper. By that reason, it could change
   * in the future.
   * </p>
   * 
   * @since 1.1.7
   * @author  Stan Silvert (latest modification by $Author: lu4242 $)
   * @version $Revision: 691871 $ $Date: 2008-09-03 23:32:08 -0500 (Wed, 03 Sep 2008) $
   */
  public class SessionMap extends AbstractAttributeMap
  {
      private final PortletRequest _portletRequest;
  
      SessionMap(PortletRequest portletRequest)
      {
          _portletRequest = portletRequest;
      }
  
      protected Object getAttribute(String key)
      {
          PortletSession portletSession = getSession();
          return (portletSession == null)
                 ? null : portletSession.getAttribute(key.toString(), PortletSession.PORTLET_SCOPE);
      }
  
      protected void setAttribute(String key, Object value)
      {
          _portletRequest.getPortletSession(true).setAttribute(key, value, PortletSession.PORTLET_SCOPE);
      }
  
      protected void removeAttribute(String key)
      {
          PortletSession portletSession = getSession();
          if (portletSession != null)
          {
              portletSession.removeAttribute(key, PortletSession.PORTLET_SCOPE);
          }
      }
  
      protected Enumeration getAttributeNames()
      {
          PortletSession portletSession = getSession();
          return (portletSession == null)
                 ? NullEnumeration.instance()
                 : portletSession.getAttributeNames(PortletSession.PORTLET_SCOPE);
      }
  
      private PortletSession getSession()
      {
          return _portletRequest.getPortletSession(false);
      }
  
      public void putAll(Map t)
      {
          throw new UnsupportedOperationException();
      }
  
  
      public void clear()
      {
          throw new UnsupportedOperationException();
      }
  }