001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 * StandardXYSeriesLabelGenerator.java
029 * -----------------------------------
030 * (C) Copyright 2004-2007, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes
036 * -------
037 * 16-Nov-2004 : Version 1 (DG);
038 * ------------- JFREECHART 1.0.x ---------------------------------------------
039 * 24-Nov-2006 : Fixed equals() method and updated API docs (DG);
040 *
041 */
042
043package org.jfree.chart.labels;
044
045import java.io.Serializable;
046import java.text.MessageFormat;
047
048import org.jfree.data.xy.XYDataset;
049import org.jfree.util.PublicCloneable;
050
051/**
052 * A standard series label generator for plots that use data from 
053 * an {@link org.jfree.data.xy.XYDataset}.
054 * <br><br>
055 * This class implements <code>PublicCloneable</code> by mistake but we retain
056 * this for the sake of backward compatibility.
057 */
058public class StandardXYSeriesLabelGenerator implements XYSeriesLabelGenerator, 
059                                                       Cloneable, 
060                                                       PublicCloneable,
061                                                       Serializable {
062
063    /** For serialization. */
064    private static final long serialVersionUID = 1916017081848400024L;
065    
066    /** The default item label format. */
067    public static final String DEFAULT_LABEL_FORMAT = "{0}";
068    
069    /** The format pattern. */
070    private String formatPattern;
071
072    /**
073     * Creates a default series label generator (uses 
074     * {@link #DEFAULT_LABEL_FORMAT}).
075     */
076    public StandardXYSeriesLabelGenerator() {
077        this(DEFAULT_LABEL_FORMAT);
078    }
079    
080    /**
081     * Creates a new series label generator.
082     * 
083     * @param format  the format pattern (<code>null</code> not permitted).
084     */
085    public StandardXYSeriesLabelGenerator(String format) {
086        if (format == null) {
087            throw new IllegalArgumentException("Null 'format' argument.");
088        }
089        this.formatPattern = format;
090    }
091
092    /**
093     * Generates a label for the specified series.  This label will be
094     * used for the chart legend.
095     * 
096     * @param dataset  the dataset (<code>null</code> not permitted).
097     * @param series  the series.
098     * 
099     * @return A series label.
100     */
101    public String generateLabel(XYDataset dataset, int series) {
102        if (dataset == null) {
103            throw new IllegalArgumentException("Null 'dataset' argument.");
104        }
105        String label = MessageFormat.format(
106            this.formatPattern, createItemArray(dataset, series)
107        );
108        return label;
109    }
110
111    /**
112     * Creates the array of items that can be passed to the 
113     * {@link MessageFormat} class for creating labels.
114     *
115     * @param dataset  the dataset (<code>null</code> not permitted).
116     * @param series  the series (zero-based index).
117     *
118     * @return The items (never <code>null</code>).
119     */
120    protected Object[] createItemArray(XYDataset dataset, int series) {
121        Object[] result = new Object[1];
122        result[0] = dataset.getSeriesKey(series).toString();
123        return result;
124    }
125
126    /**
127     * Returns an independent copy of the generator.  This is unnecessary, 
128     * because instances are immutable anyway, but we retain this 
129     * behaviour for backwards compatibility.
130     * 
131     * @return A clone.
132     * 
133     * @throws CloneNotSupportedException if cloning is not supported.
134     */
135    public Object clone() throws CloneNotSupportedException { 
136        return super.clone();
137    }
138    
139    /**
140     * Tests this object for equality with an arbitrary object.
141     *
142     * @param obj  the other object (<code>null</code> permitted).
143     *
144     * @return A boolean.
145     */
146    public boolean equals(Object obj) {
147        if (obj == this) {
148            return true;
149        }
150        if (!(obj instanceof StandardXYSeriesLabelGenerator)) {
151            return false;
152        }
153        StandardXYSeriesLabelGenerator that 
154                = (StandardXYSeriesLabelGenerator) obj;
155        if (!this.formatPattern.equals(that.formatPattern)) {
156            return false;
157        }
158        return true;
159    }
160
161}