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 * ValueMarker.java
029 * ----------------
030 * (C) Copyright 2004-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   Tracy Hiltbrand (equals/hashCode comply with EqualsVerifier);
034 *
035 */
036
037package org.jfree.chart.plot;
038
039import java.awt.Paint;
040import java.awt.Stroke;
041
042import org.jfree.chart.event.MarkerChangeEvent;
043
044/**
045 * A marker that represents a single value.  Markers can be added to plots to
046 * highlight specific values.
047 */
048public class ValueMarker extends Marker {
049
050    /** The value. */
051    private double value;
052
053    /**
054     * Creates a new marker.
055     *
056     * @param value  the value.
057     */
058    public ValueMarker(double value) {
059        super();
060        this.value = value;
061    }
062
063    /**
064     * Creates a new marker.
065     *
066     * @param value  the value.
067     * @param paint  the paint ({@code null} not permitted).
068     * @param stroke  the stroke ({@code null} not permitted).
069     */
070    public ValueMarker(double value, Paint paint, Stroke stroke) {
071        this(value, paint, stroke, paint, stroke, 1.0f);
072    }
073
074    /**
075     * Creates a new value marker.
076     *
077     * @param value  the value.
078     * @param paint  the paint ({@code null} not permitted).
079     * @param stroke  the stroke ({@code null} not permitted).
080     * @param outlinePaint  the outline paint ({@code null} permitted).
081     * @param outlineStroke  the outline stroke ({@code null} permitted).
082     * @param alpha  the alpha transparency (in the range 0.0f to 1.0f).
083     */
084    public ValueMarker(double value, Paint paint, Stroke stroke,
085                       Paint outlinePaint, Stroke outlineStroke, float alpha) {
086        super(paint, stroke, outlinePaint, outlineStroke, alpha);
087        this.value = value;
088    }
089
090    /**
091     * Returns the value.
092     *
093     * @return The value.
094     *
095     * @see #setValue(double)
096     */
097    public double getValue() {
098        return this.value;
099    }
100
101    /**
102     * Sets the value for the marker and sends a {@link MarkerChangeEvent} to
103     * all registered listeners.
104     *
105     * @param value  the value.
106     *
107     * @see #getValue()
108     */
109    public void setValue(double value) {
110        this.value = value;
111        notifyListeners(new MarkerChangeEvent(this));
112    }
113
114    /**
115     * Tests this marker for equality with an arbitrary object.  This method
116     * returns {@code true} if:
117     *
118     * <ul>
119     * <li>{@code obj} is not {@code null};</li>
120     * <li>{@code obj} is an instance of {@code ValueMarker};</li>
121     * <li>{@code obj} has the same value as this marker;</li>
122     * <li>{@code super.equals(obj)} returns {@code true}.</li>
123     * </ul>
124     *
125     * @param obj  the object ({@code null} permitted).
126     *
127     * @return A boolean.
128     */
129    @Override
130    public boolean equals(Object obj) {
131        if (obj == this) {
132            return true;
133        }
134        if (!(obj instanceof ValueMarker)) {
135            return false;
136        }
137        ValueMarker that = (ValueMarker) obj;
138        if (!that.canEqual(this)) {
139            return false;
140        }
141        if (Double.doubleToLongBits(this.value) !=
142            Double.doubleToLongBits(that.value)) {
143            return false;
144        }
145        return super.equals(obj);
146    }
147
148    /**
149     * Ensures symmetry between super/subclass implementations of equals. For
150     * more detail, see http://jqno.nl/equalsverifier/manual/inheritance.
151     *
152     * @param other Object
153     * 
154     * @return true ONLY if the parameter is THIS class type
155     */
156    @Override
157    public boolean canEqual(Object other)
158    {
159        // Solves Problem: equals not symmetric
160        return (other instanceof ValueMarker);
161    }
162
163    @Override
164    public int hashCode() {
165        int hash = super.hashCode(); // equals calls superclass, hashCode must also
166        hash = 47 * hash +
167               (int) (Double.doubleToLongBits(this.value) ^
168                      (Double.doubleToLongBits(this.value) >>> 32));
169        return hash;
170    }
171}