/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * ---------------------

 * XYLabelGenerator.java

 * ---------------------

 * (C) Copyright 2001-2004, by Object Refinery Limited.

 *

 * Original Author:  David Gilbert (for Object Refinery Limited);

 * Contributor(s):   -;

 *

 * $Id: XYLabelGenerator.java,v 1.1 2004/08/31 14:36:24 mungady Exp $

 *

 * Changes

 * -------

 * 13-Dec-2001 : Version 1 (DG);

 * 16-Jan-2002 : Completed Javadocs (DG);

 * 13-Jun-2002 : Correction to Javadoc comments (DG);

 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);

 * 25-Feb-2004 : Renamed XYToolTipGenerator --> XYItemLabelGenerator (DG);

 * 15-Apr-2004 : Moved the generateToolTip() method to a separate interface (DG);

 * 11-May-2004 : Renamed XYItemLabelGenerator --> XYLabelGenerator (DG);

 *

 */



package org.jfree.chart.labels;



import org.jfree.data.xy.XYDataset;



/**

 * Interface for a label generator for plots that use data from an {@link XYDataset}.

 */

public interface XYLabelGenerator {



    /**

     * Generates a label for the specified item. The label is typically a formatted version of 

     * the data value, but any text can be used.

     *

     * @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 label (possibly <code>null</code>).

     */

    public String generateLabel(XYDataset dataset, int series, int item);



}

