Source for org.jfree.chart.labels.StandardXYSeriesLabelGenerator

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2006, by Object Refinery Limited and Contributors.
   6:  *
   7:  * Project Info:  http://www.jfree.org/jfreechart/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * -----------------------------------
  28:  * StandardXYSeriesLabelGenerator.java
  29:  * -----------------------------------
  30:  * (C) Copyright 2004-2006, by Object Refinery Limited.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * $Id: StandardXYSeriesLabelGenerator.java,v 1.5.2.2 2006/11/24 16:36:33 mungady Exp $
  36:  *
  37:  * Changes
  38:  * -------
  39:  * 16-Nov-2004 : Version 1 (DG);
  40:  * ------------- JFREECHART 1.0.x ---------------------------------------------
  41:  * 24-Nov-2006 : Fixed equals() method and updated API docs (DG);
  42:  *
  43:  */
  44: 
  45: package org.jfree.chart.labels;
  46: 
  47: import java.io.Serializable;
  48: import java.text.MessageFormat;
  49: 
  50: import org.jfree.data.xy.XYDataset;
  51: import org.jfree.util.PublicCloneable;
  52: 
  53: /**
  54:  * A standard series label generator for plots that use data from 
  55:  * an {@link org.jfree.data.xy.XYDataset}.
  56:  * <br><br>
  57:  * This class implements <code>PublicCloneable</code> by mistake but we retain
  58:  * this for the sake of backward compatibility.
  59:  */
  60: public class StandardXYSeriesLabelGenerator implements XYSeriesLabelGenerator, 
  61:                                                        Cloneable, 
  62:                                                        PublicCloneable,
  63:                                                        Serializable {
  64: 
  65:     /** For serialization. */
  66:     private static final long serialVersionUID = 1916017081848400024L;
  67:     
  68:     /** The default item label format. */
  69:     public static final String DEFAULT_LABEL_FORMAT = "{0}";
  70:     
  71:     /** The format pattern. */
  72:     private String formatPattern;
  73: 
  74:     /**
  75:      * Creates a default series label generator (uses 
  76:      * {@link #DEFAULT_LABEL_FORMAT}).
  77:      */
  78:     public StandardXYSeriesLabelGenerator() {
  79:         this(DEFAULT_LABEL_FORMAT);
  80:     }
  81:     
  82:     /**
  83:      * Creates a new series label generator.
  84:      * 
  85:      * @param format  the format pattern (<code>null</code> not permitted).
  86:      */
  87:     public StandardXYSeriesLabelGenerator(String format) {
  88:         if (format == null) {
  89:             throw new IllegalArgumentException("Null 'format' argument.");
  90:         }
  91:         this.formatPattern = format;
  92:     }
  93: 
  94:     /**
  95:      * Generates a label for the specified series.  This label will be
  96:      * used for the chart legend.
  97:      * 
  98:      * @param dataset  the dataset (<code>null</code> not permitted).
  99:      * @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: }