    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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, 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
    041package org.jfree.chart.labels;
    042
    043import java.io.Serializable;
    044import java.text.MessageFormat;
    045import java.text.NumberFormat;
    046import org.jfree.chart.plot.Crosshair;
    047
    048/**
    049 * A default label generator.
    050 *
    051 * @since 1.0.13
    052 */
    053public 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}