/*

  * 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.shared.view;

 import java.io.IOException;

 import java.io.PrintWriter;

 import javax.servlet.ServletOutputStream;

 import javax.servlet.ServletResponse;

 import javax.servlet.http.HttpServletResponse;

 import javax.servlet.http.HttpServletResponseWrapper;

 /**

  * Implementation of a switching response wrapper to turn 

  * output on and off according to the JSF spec 2.0.

  * <p/>

  * Implemented as HttpServletResponseWrapper,

  * so that the switching does not interfere with methods that

  * expect a HttpServletResponse when invoking ExternalContext.getResponse().

  */

 public class HttpServletResponseSwitch extends HttpServletResponseWrapper implements ResponseSwitch

 {

     private PrintWriter _switchableWriter;

     private SwitchableOutputStream _switchableOutputStream;

     private boolean _enabled = true;

     public HttpServletResponseSwitch(HttpServletResponse response)

     {

         super(response);

     }

     /**

      * Enables or disables the Response's Writer and OutputStream.

      * @param enabled

      */

     public void setEnabled(boolean enabled)

     {

         _enabled = enabled;

     }

     /**

      * Are the Response's Writer and OutputStream currently enabled?

      * @return

      */

     public boolean isEnabled()

     {

         return _enabled;

     }

     @Override

     public int getBufferSize()

     {

         if (isEnabled())

         {

             return super.getBufferSize();

         }

         return 0;

     }

     @Override

     public boolean isCommitted()

     {

         if (isEnabled())

         {

             return super.isCommitted();

         }

         return false;

     }

     @Override

     public void reset()

     {

         if (isEnabled())

         {

             super.reset();

         }

     }

     @Override

     public void resetBuffer()

     {

         if (isEnabled())

         {

             super.resetBuffer();

         }

     }

     @Override

     public void flushBuffer() throws IOException

     {

         if (isEnabled())

         {

             super.flushBuffer();

         }

     }

     @Override

     public void setResponse(ServletResponse response)

     {

         // only change the response if it is not the same object

         if (response instanceof HttpServletResponse && response != getResponse())

         {

             // our OutputStream and our Writer are not valid for the new response

             _switchableOutputStream = null;

             _switchableWriter = null;

             // set the new response

             super.setResponse(response);

         }

     }

     @Override

     public ServletOutputStream getOutputStream() throws IOException

     {

         if (_switchableOutputStream == null)

         {

             _switchableOutputStream = new SwitchableOutputStream(super.getOutputStream(), this);

         }

         return _switchableOutputStream;

     }

     @Override

     public PrintWriter getWriter() throws IOException

     {

         if (_switchableWriter == null)

         {

             _switchableWriter = new PrintWriter(new SwitchableWriter(super.getWriter(), this));

         }

         return _switchableWriter;

     }

 }