/*

  * 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.view.facelets.tag.jsf;

 import javax.el.MethodExpression;

 import javax.faces.component.PartialStateHolder;

 import javax.faces.context.FacesContext;

 import javax.faces.event.MethodExpressionValueChangeListener;

 public class PartialMethodExpressionValueChangeListener extends MethodExpressionValueChangeListener

     implements PartialStateHolder

 {

     private boolean _initialStateMarked;

     public PartialMethodExpressionValueChangeListener()

     {

         super();

     }

     public PartialMethodExpressionValueChangeListener(MethodExpression methodExpression1,

             MethodExpression methodExpression2)

     {

         super(methodExpression1, methodExpression2);

     }

     public PartialMethodExpressionValueChangeListener(MethodExpression methodExpression)

     {

         super(methodExpression);

     }

     public void clearInitialState()

     {

         _initialStateMarked = false;

     }

     public boolean initialStateMarked()

     {

         return _initialStateMarked;

     }

     public void markInitialState()

     {

         _initialStateMarked = true;

     }

     public void restoreState(FacesContext context, Object state)

     {

         if (state == null)

         {

             return;

         }

         super.restoreState(context, state);

     }

     public Object saveState(FacesContext context)

     {

         if (initialStateMarked())

         {

             return null;

         }

         return super.saveState(context);

     }

 }