001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2020, 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 * [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 2009-2020, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
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 *
047 * @since 1.0.13
048 */
049public class StandardCrosshairLabelGenerator implements CrosshairLabelGenerator,
050        Serializable {
051
052    /** The label format string. */
053    private String labelTemplate;
054
055    /** A number formatter for the value. */
056    private NumberFormat numberFormat;
057
058    /**
059     * Creates a new instance with default attributes.
060     */
061    public StandardCrosshairLabelGenerator() {
062        this("{0}", NumberFormat.getNumberInstance());
063    }
064
065    /**
066     * Creates a new instance with the specified attributes.
067     *
068     * @param labelTemplate  the label template ({@code null} not
069     *     permitted).
070     * @param numberFormat  the number formatter ({@code null} not
071     *     permitted).
072     */
073    public StandardCrosshairLabelGenerator(String labelTemplate,
074            NumberFormat numberFormat) {
075        super();
076        if (labelTemplate == null) {
077            throw new IllegalArgumentException(
078                    "Null 'labelTemplate' argument.");
079        }
080        if (numberFormat == null) {
081            throw new IllegalArgumentException(
082                    "Null 'numberFormat' argument.");
083        }
084        this.labelTemplate = labelTemplate;
085        this.numberFormat = numberFormat;
086    }
087
088    /**
089     * Returns the label template string.
090     *
091     * @return The label template string (never {@code null}).
092     */
093    public String getLabelTemplate() {
094        return this.labelTemplate;
095    }
096
097    /**
098     * Returns the number formatter.
099     *
100     * @return The formatter (never {@code null}).
101     */
102    public NumberFormat getNumberFormat() {
103        return this.numberFormat;
104    }
105
106    /**
107     * Returns a string that can be used as the label for a crosshair.
108     *
109     * @param crosshair  the crosshair ({@code null} not permitted).
110     *
111     * @return The label (possibly {@code null}).
112     */
113    @Override
114    public String generateLabel(Crosshair crosshair) {
115        Object[] v = new Object[] {this.numberFormat.format(
116                crosshair.getValue())};
117        String result = MessageFormat.format(this.labelTemplate, v);
118        return result;
119    }
120
121    /**
122     * Tests this generator for equality with an arbitrary object.
123     * 
124     * @param obj  the object ({@code null} permitted).
125     * 
126     * @return A boolean.
127     */
128    @Override
129    public boolean equals(Object obj) {
130        if (obj == this) {
131            return true;
132        }
133        if (!(obj instanceof StandardCrosshairLabelGenerator)) {
134            return false;
135        }
136        StandardCrosshairLabelGenerator that
137                = (StandardCrosshairLabelGenerator) obj;
138        if (!this.labelTemplate.equals(that.labelTemplate)) {
139            return false;
140        }
141        if (!this.numberFormat.equals(that.numberFormat)) {
142            return false;
143        }
144        return true;
145    }
146
147    /**
148     * Returns a hash code for this instance.
149     *
150     * @return A hash code for this instance.
151     */
152    @Override
153    public int hashCode() {
154        return this.labelTemplate.hashCode();
155    }
156
157}