    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}