/*

  * 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.el;

 import java.io.Externalizable;

 import java.io.IOException;

 import java.io.ObjectInput;

 import java.io.ObjectOutput;

 import javax.el.ELContext;

 import javax.el.ValueExpression;

 import javax.faces.FacesWrapper;

 import javax.faces.context.FacesContext;

 import javax.faces.view.Location;

 /**

  * A ValueExpression that contains the original ValueExpression and

  * the Location of the facelet file from which the ValueExpression was

  * created. This is needed when the current composite component (cc) 

  * has to be resolved by the ValueExpression, because #{cc} refers to the

  * composite component which is implemented in the file the ValueExpression

  * comes from and not the one currently on top of the composite component stack.

  * 

  * This ValueExpression implementation passes through all methods to the delegate

  * ValueExpression, but saves the related composite component in a FacesContext attribute 

  * before the invocation of the method on the delegate and removes it afterwards. 

  * 

  * @author Jakob Korherr (latest modification by $Author$)

  * @version $Revision$ $Date$

  */

 public class LocationValueExpression extends ValueExpression

     implements FacesWrapper<ValueExpression>, Externalizable

 {

     private static final long serialVersionUID = -5636849184764526288L;

     // location and delegate need to be available in LocationValueExpressionUEL

     Location location;

     ValueExpression delegate;

     int ccLevel;

     public LocationValueExpression()

     {

         super();

     }

     public LocationValueExpression(Location location, ValueExpression delegate)

     {

         this.location = location;

         this.delegate = delegate;

         this.ccLevel = 0;

     }

     public LocationValueExpression(Location location, ValueExpression delegate, int ccLevel)

     {

         this.location = location;

         this.delegate = delegate;

         this.ccLevel = ccLevel;

     }

     public Location getLocation()

     {

         return location;

     }

     public int getCCLevel()

     {

         return ccLevel;

     }

     public LocationValueExpression apply(int newCCLevel)

     {

         if(this.ccLevel == newCCLevel)

         {

             return this;

         }

         else

         {

             return new LocationValueExpression(this.location, this.delegate, newCCLevel);

         }

     }

     public LocationValueExpression apply(int newCCLevel, Location newLocation)

     {

         if(this.ccLevel == newCCLevel && this.location.getPath().equals(newLocation.getPath()))

         {

             return this;

         }

         else

         {

             return new LocationValueExpression(newLocation, this.delegate, newCCLevel);

         }

     }

     @Override

     public Class<?> getExpectedType()

     {

         return delegate.getExpectedType();

     }

     @Override

     public Class<?> getType(ELContext context)

     {

         FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);

         CompositeComponentELUtils.saveCompositeComponentForResolver(facesContext, location, ccLevel);

         try

         {

             return delegate.getType(context);

         }

         finally

         {

             CompositeComponentELUtils.removeCompositeComponentForResolver(facesContext);

         }

     }

     @Override

     public Object getValue(ELContext context)

     {

         FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);

         CompositeComponentELUtils.saveCompositeComponentForResolver(facesContext, location, ccLevel);

         try

         {

             return delegate.getValue(context);

         }

         finally

         {

             CompositeComponentELUtils.removeCompositeComponentForResolver(facesContext);

         }

     }

     @Override

     public boolean isReadOnly(ELContext context)

     {

         FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);

         CompositeComponentELUtils.saveCompositeComponentForResolver(facesContext, location, ccLevel);

         try

         {

             return delegate.isReadOnly(context);

         }

         finally

         {

             CompositeComponentELUtils.removeCompositeComponentForResolver(facesContext);

         }

     }

     @Override

     public void setValue(ELContext context, Object value)

     {

         FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);

         CompositeComponentELUtils.saveCompositeComponentForResolver(facesContext, location, ccLevel);

         try

         {

             delegate.setValue(context, value);

         }

         finally

         {

             CompositeComponentELUtils.removeCompositeComponentForResolver(facesContext);

         }

     }

     @Override

     public boolean equals(Object obj)

     {

         return delegate.equals(obj);

     }

     @Override

     public String getExpressionString()

     {

         return delegate.getExpressionString();

     }

     @Override

     public int hashCode()

     {

         return delegate.hashCode();

     }

     @Override

     public boolean isLiteralText()

     {

         return delegate.isLiteralText();

     }

     public ValueExpression getWrapped()

     {

         return delegate;

     }

     public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException

     {

         this.delegate = (ValueExpression) in.readObject();

         this.location = (Location) in.readObject();

         this.ccLevel = in.readInt();

     }

     public void writeExternal(ObjectOutput out) throws IOException

     {

         out.writeObject(this.delegate);

         out.writeObject(this.location);

         out.writeInt(this.ccLevel);

     }

 }