001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2022, 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 2009-2022, 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.internal.Args;
043import org.jfree.chart.plot.Crosshair;
044
045/**
046 * A default label generator.
047 */
048public class StandardCrosshairLabelGenerator implements CrosshairLabelGenerator,
049        Serializable {
050
051    /** The label format string. */
052    private final String labelTemplate;
053
054    /** A number formatter for the value. */
055    private final NumberFormat numberFormat;
056
057    /**
058     * Creates a new instance with default attributes.
059     */
060    public StandardCrosshairLabelGenerator() {
061        this("{0}", NumberFormat.getNumberInstance());
062    }
063
064    /**
065     * Creates a new instance with the specified attributes.
066     *
067     * @param labelTemplate  the label template ({@code null} not
068     *     permitted).
069     * @param numberFormat  the number formatter ({@code null} not
070     *     permitted).
071     */
072    public StandardCrosshairLabelGenerator(String labelTemplate,
073            NumberFormat numberFormat) {
074        super();
075        Args.nullNotPermitted(labelTemplate, "labelTemplate");
076        Args.nullNotPermitted(numberFormat, "numberFormat");
077        this.labelTemplate = labelTemplate;
078        this.numberFormat = numberFormat;
079    }
080
081    /**
082     * Returns the label template string.
083     *
084     * @return The label template string (never {@code null}).
085     */
086    public String getLabelTemplate() {
087        return this.labelTemplate;
088    }
089
090    /**
091     * Returns the number formatter.
092     *
093     * @return The formatter (never {@code null}).
094     */
095    public NumberFormat getNumberFormat() {
096        return this.numberFormat;
097    }
098
099    /**
100     * Returns a string that can be used as the label for a crosshair.
101     *
102     * @param crosshair  the crosshair ({@code null} not permitted).
103     *
104     * @return The label (possibly {@code null}).
105     */
106    @Override
107    public String generateLabel(Crosshair crosshair) {
108        Object[] v = new Object[] {this.numberFormat.format(
109                crosshair.getValue())};
110        String result = MessageFormat.format(this.labelTemplate, v);
111        return result;
112    }
113
114    /**
115     * Tests this generator for equality with an arbitrary object.
116     * 
117     * @param obj  the object ({@code null} permitted).
118     * 
119     * @return A boolean.
120     */
121    @Override
122    public boolean equals(Object obj) {
123        if (obj == this) {
124            return true;
125        }
126        if (!(obj instanceof StandardCrosshairLabelGenerator)) {
127            return false;
128        }
129        StandardCrosshairLabelGenerator that
130                = (StandardCrosshairLabelGenerator) obj;
131        if (!this.labelTemplate.equals(that.labelTemplate)) {
132            return false;
133        }
134        if (!this.numberFormat.equals(that.numberFormat)) {
135            return false;
136        }
137        return true;
138    }
139
140    /**
141     * Returns a hash code for this instance.
142     *
143     * @return A hash code for this instance.
144     */
145    @Override
146    public int hashCode() {
147        return this.labelTemplate.hashCode();
148    }
149
150}