001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.contrib.table.components;
016    
017    import java.io.Serializable;
018    
019    import org.apache.tapestry.contrib.table.model.ITableModel;
020    import org.apache.tapestry.contrib.table.model.ITableSessionStateManager;
021    import org.apache.tapestry.contrib.table.model.simple.SimpleTableState;
022    
023    /**
024     *  Acts like {@link org.apache.tapestry.contrib.table.model.common.FullTableSessionStateManager} 
025     *  if the model is provided via the tableModel parameter; 
026     *  saves only the model state otherwise. 
027     * 
028     *  @author mindbridge
029     */
030    public class TableViewSessionStateManager implements ITableSessionStateManager
031    {
032        private TableView m_objView;
033    
034        public TableViewSessionStateManager(TableView objView)
035        {
036            m_objView = objView;
037        }
038        
039        /**
040         * @see org.apache.tapestry.contrib.table.model.ITableSessionStateManager#getSessionState(org.apache.tapestry.contrib.table.model.ITableModel)
041         */
042        public Serializable getSessionState(ITableModel objModel)
043        {
044            // if the model is provided using the 'tableModel' parameter, 
045            // emulate FullTableSessionStateManager and save everything
046            // (backward compatibility)
047            if (m_objView.getCachedTableModelValue() != null)
048                return (Serializable) objModel;
049                
050            // otherwise save only the state
051            return new SimpleTableState(objModel.getPagingState(), objModel.getSortingState());
052        }
053    
054        /**
055         * @see org.apache.tapestry.contrib.table.model.ITableSessionStateManager#recreateTableModel(java.io.Serializable)
056         */
057        public ITableModel recreateTableModel(Serializable objState)
058        {
059            // if the state implements ITableModel, return itself
060            // (backward compatibility)
061            if (objState instanceof ITableModel)
062                return (ITableModel) objState;
063                
064            // otherwise have the component re-generate the model using the provided state
065            return m_objView.generateTableModel((SimpleTableState) objState);
066        }
067    
068    }