001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2006, 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 2004-2006, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: StandardXYSeriesLabelGenerator.java,v 1.5.2.2 2006/11/24 16:36:33 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 16-Nov-2004 : Version 1 (DG);
040     * ------------- JFREECHART 1.0.x ---------------------------------------------
041     * 24-Nov-2006 : Fixed equals() method and updated API docs (DG);
042     *
043     */
044    
045    package org.jfree.chart.labels;
046    
047    import java.io.Serializable;
048    import java.text.MessageFormat;
049    
050    import org.jfree.data.xy.XYDataset;
051    import org.jfree.util.PublicCloneable;
052    
053    /**
054     * A standard series label generator for plots that use data from 
055     * an {@link org.jfree.data.xy.XYDataset}.
056     * <br><br>
057     * This class implements <code>PublicCloneable</code> by mistake but we retain
058     * this for the sake of backward compatibility.
059     */
060    public class StandardXYSeriesLabelGenerator implements XYSeriesLabelGenerator, 
061                                                           Cloneable, 
062                                                           PublicCloneable,
063                                                           Serializable {
064    
065        /** For serialization. */
066        private static final long serialVersionUID = 1916017081848400024L;
067        
068        /** The default item label format. */
069        public static final String DEFAULT_LABEL_FORMAT = "{0}";
070        
071        /** The format pattern. */
072        private String formatPattern;
073    
074        /**
075         * Creates a default series label generator (uses 
076         * {@link #DEFAULT_LABEL_FORMAT}).
077         */
078        public StandardXYSeriesLabelGenerator() {
079            this(DEFAULT_LABEL_FORMAT);
080        }
081        
082        /**
083         * Creates a new series label generator.
084         * 
085         * @param format  the format pattern (<code>null</code> not permitted).
086         */
087        public StandardXYSeriesLabelGenerator(String format) {
088            if (format == null) {
089                throw new IllegalArgumentException("Null 'format' argument.");
090            }
091            this.formatPattern = format;
092        }
093    
094        /**
095         * Generates a label for the specified series.  This label will be
096         * used for the chart legend.
097         * 
098         * @param dataset  the dataset (<code>null</code> not permitted).
099         * @param series  the series.
100         * 
101         * @return A series label.
102         */
103        public String generateLabel(XYDataset dataset, int series) {
104            if (dataset == null) {
105                throw new IllegalArgumentException("Null 'dataset' argument.");
106            }
107            String label = MessageFormat.format(
108                this.formatPattern, createItemArray(dataset, series)
109            );
110            return label;
111        }
112    
113        /**
114         * Creates the array of items that can be passed to the 
115         * {@link MessageFormat} class for creating labels.
116         *
117         * @param dataset  the dataset (<code>null</code> not permitted).
118         * @param series  the series (zero-based index).
119         *
120         * @return The items (never <code>null</code>).
121         */
122        protected Object[] createItemArray(XYDataset dataset, int series) {
123            Object[] result = new Object[1];
124            result[0] = dataset.getSeriesKey(series).toString();
125            return result;
126        }
127    
128        /**
129         * Returns an independent copy of the generator.  This is unnecessary, 
130         * because instances are immutable anyway, but we retain this 
131         * behaviour for backwards compatibility.
132         * 
133         * @return A clone.
134         * 
135         * @throws CloneNotSupportedException if cloning is not supported.
136         */
137        public Object clone() throws CloneNotSupportedException { 
138            return super.clone();
139        }
140        
141        /**
142         * Tests this object for equality with an arbitrary object.
143         *
144         * @param obj  the other object (<code>null</code> permitted).
145         *
146         * @return A boolean.
147         */
148        public boolean equals(Object obj) {
149            if (obj == this) {
150                return true;
151            }
152            if (!(obj instanceof StandardXYSeriesLabelGenerator)) {
153                return false;
154            }
155            StandardXYSeriesLabelGenerator that 
156                    = (StandardXYSeriesLabelGenerator) obj;
157            if (!this.formatPattern.equals(that.formatPattern)) {
158                return false;
159            }
160            return true;
161        }
162    
163    }