001    /**
002     * ========================================
003     * JFreeReport : a free Java report library
004     * ========================================
005     *
006     * Project Info:  http://reporting.pentaho.org/
007     *
008     * (C) Copyright 2000-2007, by Object Refinery Limited, Pentaho Corporation and Contributors.
009     *
010     * This library is free software; you can redistribute it and/or modify it under the terms
011     * of the GNU Lesser General Public License as published by the Free Software Foundation;
012     * either version 2.1 of the License, or (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015     * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016     * See the GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public License along with this
019     * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020     * Boston, MA 02111-1307, USA.
021     *
022     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023     * in the United States and other countries.]
024     *
025     * ------------
026     * $Id: ColumnAggregationExpression.java 3525 2007-10-16 11:43:48Z tmorgner $
027     * ------------
028     * (C) Copyright 2000-2005, by Object Refinery Limited.
029     * (C) Copyright 2005-2007, by Pentaho Corporation.
030     */
031    package org.jfree.report.expressions;
032    
033    import org.jfree.report.DataSourceException;
034    
035    /**
036     * Creation-Date: 04.01.2006, 17:23:01
037     *
038     * @author Thomas Morgner
039     */
040    public abstract class ColumnAggregationExpression extends AbstractExpression
041    {
042      protected ColumnAggregationExpression()
043      {
044      }
045    
046      protected abstract int getFieldListParameterPosition();
047    
048      protected Object[] getFieldValues() throws DataSourceException
049      {
050        return getFieldValues(Object.class);
051      }
052    
053      protected Object[] getFieldValues(final Class type) throws DataSourceException
054      {
055        return null; // todo
056      }
057    
058    }