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 * DefaultCrosshairLabelGenerator.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 java.io.Serializable;
044 import java.text.MessageFormat;
045 import java.text.NumberFormat;
046 import org.jfree.chart.plot.Crosshair;
047
048 /**
049 * A default label generator.
050 *
051 * @since 1.0.13
052 */
053 public class StandardCrosshairLabelGenerator implements CrosshairLabelGenerator,
054 Serializable {
055
056 /** The label format string. */
057 private String labelTemplate;
058
059 /** A number formatter for the value. */
060 private NumberFormat numberFormat;
061
062 /**
063 * Creates a new instance with default attributes.
064 */
065 public StandardCrosshairLabelGenerator() {
066 this("{0}", NumberFormat.getNumberInstance());
067 }
068
069 /**
070 * Creates a new instance with the specified attributes.
071 *
072 * @param labelTemplate the label template (<code>null</code> not
073 * permitted).
074 * @param numberFormat the number formatter (<code>null</code> not
075 * permitted).
076 */
077 public StandardCrosshairLabelGenerator(String labelTemplate,
078 NumberFormat numberFormat) {
079 super();
080 if (labelTemplate == null) {
081 throw new IllegalArgumentException(
082 "Null 'labelTemplate' argument.");
083 }
084 if (numberFormat == null) {
085 throw new IllegalArgumentException(
086 "Null 'numberFormat' argument.");
087 }
088 this.labelTemplate = labelTemplate;
089 this.numberFormat = numberFormat;
090 }
091
092 /**
093 * Returns the label template string.
094 *
095 * @return The label template string (never <code>null</code>).
096 */
097 public String getLabelTemplate() {
098 return this.labelTemplate;
099 }
100
101 /**
102 * Returns the number formatter.
103 *
104 * @return The formatter (never <code>null</code>).
105 */
106 public NumberFormat getNumberFormat() {
107 return this.numberFormat;
108 }
109
110 /**
111 * Returns a string that can be used as the label for a crosshair.
112 *
113 * @param crosshair the crosshair (<code>null</code> not permitted).
114 *
115 * @return The label (possibly <code>null</code>).
116 */
117 public String generateLabel(Crosshair crosshair) {
118 Object[] v = new Object[] { this.numberFormat.format(
119 crosshair.getValue()) };
120 String result = MessageFormat.format(this.labelTemplate, v);
121 return result;
122 }
123
124 /**
125 * Tests this generator for equality with an arbitrary object.
126 *
127 * @param obj the object (<code>null</code> permitted).
128 *
129 * @return A boolean.
130 */
131 public boolean equals(Object obj) {
132 if (obj == this) {
133 return true;
134 }
135 if (!(obj instanceof StandardCrosshairLabelGenerator)) {
136 return false;
137 }
138 StandardCrosshairLabelGenerator that
139 = (StandardCrosshairLabelGenerator) obj;
140 if (!this.labelTemplate.equals(that.labelTemplate)) {
141 return false;
142 }
143 if (!this.numberFormat.equals(that.numberFormat)) {
144 return false;
145 }
146 return true;
147 }
148
149 /**
150 * Returns a hash code for this instance.
151 *
152 * @return A hash code for this instance.
153 */
154 public int hashCode() {
155 return this.labelTemplate.hashCode();
156 }
157
158 }