001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ------------------------------------
028 * StandardCrosshairLabelGenerator.java
029 * ------------------------------------
030 * (C) Copyright 2009-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart.labels;
038
039import java.io.Serializable;
040import java.text.MessageFormat;
041import java.text.NumberFormat;
042import org.jfree.chart.plot.Crosshair;
043
044/**
045 * A default label generator.
046 */
047public class StandardCrosshairLabelGenerator implements CrosshairLabelGenerator,
048        Serializable {
049
050    /** The label format string. */
051    private String labelTemplate;
052
053    /** A number formatter for the value. */
054    private NumberFormat numberFormat;
055
056    /**
057     * Creates a new instance with default attributes.
058     */
059    public StandardCrosshairLabelGenerator() {
060        this("{0}", NumberFormat.getNumberInstance());
061    }
062
063    /**
064     * Creates a new instance with the specified attributes.
065     *
066     * @param labelTemplate  the label template ({@code null} not
067     *     permitted).
068     * @param numberFormat  the number formatter ({@code null} not
069     *     permitted).
070     */
071    public StandardCrosshairLabelGenerator(String labelTemplate,
072            NumberFormat numberFormat) {
073        super();
074        if (labelTemplate == null) {
075            throw new IllegalArgumentException(
076                    "Null 'labelTemplate' argument.");
077        }
078        if (numberFormat == null) {
079            throw new IllegalArgumentException(
080                    "Null 'numberFormat' argument.");
081        }
082        this.labelTemplate = labelTemplate;
083        this.numberFormat = numberFormat;
084    }
085
086    /**
087     * Returns the label template string.
088     *
089     * @return The label template string (never {@code null}).
090     */
091    public String getLabelTemplate() {
092        return this.labelTemplate;
093    }
094
095    /**
096     * Returns the number formatter.
097     *
098     * @return The formatter (never {@code null}).
099     */
100    public NumberFormat getNumberFormat() {
101        return this.numberFormat;
102    }
103
104    /**
105     * Returns a string that can be used as the label for a crosshair.
106     *
107     * @param crosshair  the crosshair ({@code null} not permitted).
108     *
109     * @return The label (possibly {@code null}).
110     */
111    @Override
112    public String generateLabel(Crosshair crosshair) {
113        Object[] v = new Object[] {this.numberFormat.format(
114                crosshair.getValue())};
115        String result = MessageFormat.format(this.labelTemplate, v);
116        return result;
117    }
118
119    /**
120     * Tests this generator for equality with an arbitrary object.
121     * 
122     * @param obj  the object ({@code null} permitted).
123     * 
124     * @return A boolean.
125     */
126    @Override
127    public boolean equals(Object obj) {
128        if (obj == this) {
129            return true;
130        }
131        if (!(obj instanceof StandardCrosshairLabelGenerator)) {
132            return false;
133        }
134        StandardCrosshairLabelGenerator that
135                = (StandardCrosshairLabelGenerator) obj;
136        if (!this.labelTemplate.equals(that.labelTemplate)) {
137            return false;
138        }
139        if (!this.numberFormat.equals(that.numberFormat)) {
140            return false;
141        }
142        return true;
143    }
144
145    /**
146     * Returns a hash code for this instance.
147     *
148     * @return A hash code for this instance.
149     */
150    @Override
151    public int hashCode() {
152        return this.labelTemplate.hashCode();
153    }
154
155}