/*

  * Created on Feb 27, 2005

  *

  * Copyright 2004 Chris Nelson

  * 

  * Licensed 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.trails.callback;

 import org.apache.hivemind.ApplicationRuntimeException;

 import org.apache.hivemind.util.Defense;

 import org.apache.tapestry.IRequestCycle;

 import org.apache.tapestry.callback.ICallback;

 import org.trails.page.EditPage;

 /**

  * @author Chris Nelson

  *         <p/>

  *         Returns control to an EditPage

  */

 public class EditCallback extends TrailsCallback

 {

         protected Object model;

         private boolean modelNew;

         /**

          *

          */

         public EditCallback(String pageName, Object model)

         {

                 super(pageName);

                 this.model = model;

         }

         public EditCallback(String pageName, Object model, boolean modelNew)

         {

                 this(pageName, model);

                 this.modelNew = modelNew;

         }

         /* (non-Javadoc)

                  * @see org.apache.tapestry.callback.ICallback#performCallback(org.apache.tapestry.IRequestCycle)

                  */

         public void performCallback(IRequestCycle cycle)

         {

                 Defense.notNull(cycle, "cycle");

                 try

                 {

                         EditPage editPage = (EditPage) cycle.getPage(getPageName());

                         editPage.setModel(model);

                         cycle.activate(editPage);

                 }

                 catch (ClassCastException ex)

                 {

                         throw new ApplicationRuntimeException(ex);

                 }

         }

         public Object getModel()

         {

                 return model;

         }

         public void setModel(Object model)

         {

                 this.model = model;

         }

         public boolean isModelNew()

         {

                 return modelNew;

         }

         public void setModelNew(boolean modelNew)

         {

                 this.modelNew = modelNew;

         }

         /**

          * We should always replace this callback if its model is new.

          * This works to make sure that after a model is saved for the first

          * time its call back is replaced and we can go back to the right one.

          */

         @Override

         public boolean shouldReplace(ICallback callback)

         {

                 if (callback instanceof EditCallback)

                 {

                         EditCallback editCallback = (EditCallback) callback;

                         if (editCallback.isModelNew())

                         {

                                 return true;

                         } else

                         {

                                 return this.equals(editCallback);

                         }

                 } else

                 {

                         return false;

                 }

         }

 }