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}