001// Copyright 2007, 2008 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
015package org.apache.tapestry5.internal.grid;
016
017import org.apache.tapestry5.grid.GridDataSource;
018import org.apache.tapestry5.grid.SortConstraint;
019
020import java.util.List;
021
022/**
023 * An implementation of {@link org.apache.tapestry5.grid.GridDataSource} used when the value null is provided as the
024 * source.
025 */
026public class NullDataSource implements GridDataSource
027{
028    public int getAvailableRows()
029    {
030        return 0;
031    }
032
033    public Class getRowType()
034    {
035        return null;
036    }
037
038    public void prepare(int startIndex, int endIndex, List<SortConstraint> sortConstraints)
039    {
040    }
041
042    public Object getRowValue(int index)
043    {
044        return null;
045    }
046
047}