001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, 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 2004-2008, 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 * 31-Mar-2008 : Added hashCode() method to appease FindBugs (DG);
041 *
042 */
043
044 package org.jfree.chart.labels;
045
046 import java.io.Serializable;
047 import java.text.MessageFormat;
048
049 import org.jfree.chart.HashUtilities;
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, PublicCloneable, 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 /**
162 * Returns a hash code for this instance.
163 *
164 * @return A hash code.
165 */
166 public int hashCode() {
167 int result = 127;
168 result = HashUtilities.hashCode(result, this.formatPattern);
169 return result;
170 }
171
172 }