001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2009, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it
010     * under the terms of the GNU Lesser General Public License as published by
011     * the Free Software Foundation; either version 2.1 of the License, or
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022     * USA.
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025     * in the United States and other countries.]
026     *
027     * ----------------------------
028     * CrosshairLabelGenerator.java
029     * ----------------------------
030     * (C) Copyright 2009, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * Changes:
036     * --------
037     * 13-Feb-2009 : Version 1 (DG);
038     *
039     */
040    
041    package org.jfree.chart.labels;
042    
043    import org.jfree.chart.plot.Crosshair;
044    
045    /**
046     * A label generator for crosshairs.
047     *
048     * @since 1.0.13
049     */
050    public interface CrosshairLabelGenerator {
051    
052        /**
053         * Returns a string that can be used as the label for a crosshair.
054         * 
055         * @param crosshair  the crosshair (<code>null</code> not permitted).
056         * 
057         * @return The label (possibly <code>null</code>).
058         */
059        public String generateLabel(Crosshair crosshair);
060    
061    }