/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * -----------------------
 * XYToolTipGenerator.java
 * -----------------------
 * (C) Copyright 2001-2004, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: XYToolTipGenerator.java,v 1.2.2.1 2005/10/25 20:49:02 mungady Exp $
 *
 * Changes
 * -------
 * 15-Apr-2004 : Extracted the generateToolTip() method from the 
 *               XYItemLabelGenerator interface and put it into this new 
 *               interface (DG);
 *
 */

package org.jfree.chart.labels;

import org.jfree.data.xy.XYDataset;

/**
 * Interface for a tooltip generator for plots that use data from an 
 * {@link XYDataset}.
 */
public interface XYToolTipGenerator {

    /**
     * Generates the tooltip text for the specified item.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param series  the series index (zero-based).
     * @param item  the item index (zero-based).
     *
     * @return The tooltip text (possibly <code>null</code>).
     */
    public String generateToolTip(XYDataset dataset, int series, int item);

}