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 * ComparableObjectItem.java
029 * -------------------------
030 * (C) Copyright 2006-2020, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data;
038
039import java.io.Serializable;
040import org.jfree.chart.util.ObjectUtils;
041import org.jfree.chart.util.Args;
042
043/**
044 * Represents one (Comparable, Object) data item for use in a
045 * {@link ComparableObjectSeries}.
046 *
047 * @since 1.0.3
048 */
049public class ComparableObjectItem implements Cloneable, Comparable,
050        Serializable {
051
052    /** For serialization. */
053    private static final long serialVersionUID = 2751513470325494890L;
054
055    /** The x-value. */
056    private Comparable x;
057
058    /** The y-value. */
059    private Object obj;
060
061    /**
062     * Constructs a new data item.
063     *
064     * @param x  the x-value ({@code null} NOT permitted).
065     * @param y  the y-value ({@code null} permitted).
066     */
067    public ComparableObjectItem(Comparable x, Object y) {
068        Args.nullNotPermitted(x, "x");
069        this.x = x;
070        this.obj = y;
071    }
072
073    /**
074     * Returns the x-value.
075     *
076     * @return The x-value (never {@code null}).
077     */
078    protected Comparable getComparable() {
079        return this.x;
080    }
081
082    /**
083     * Returns the y-value.
084     *
085     * @return The y-value (possibly {@code null}).
086     */
087    protected Object getObject() {
088        return this.obj;
089    }
090
091    /**
092     * Sets the y-value for this data item.  Note that there is no
093     * corresponding method to change the x-value.
094     *
095     * @param y  the new y-value ({@code null} permitted).
096     */
097    protected void setObject(Object y) {
098        this.obj = y;
099    }
100
101    /**
102     * Returns an integer indicating the order of this object relative to
103     * another object.
104     * <P>
105     * For the order we consider only the x-value:
106     * negative == "less-than", zero == "equal", positive == "greater-than".
107     *
108     * @param o1  the object being compared to.
109     *
110     * @return An integer indicating the order of this data pair object
111     *      relative to another object.
112     */
113    @Override
114    public int compareTo(Object o1) {
115
116        int result;
117
118        // CASE 1 : Comparing to another ComparableObjectItem object
119        // ---------------------------------------------------------
120        if (o1 instanceof ComparableObjectItem) {
121            ComparableObjectItem that = (ComparableObjectItem) o1;
122            return this.x.compareTo(that.x);
123        }
124
125        // CASE 2 : Comparing to a general object
126        // ---------------------------------------------
127        else {
128            // consider these to be ordered after general objects
129            result = 1;
130        }
131
132        return result;
133
134    }
135
136    /**
137     * Returns a clone of this object.
138     *
139     * @return A clone.
140     *
141     * @throws CloneNotSupportedException not thrown by this class, but
142     *         subclasses may differ.
143     */
144    @Override
145    public Object clone() throws CloneNotSupportedException {
146        return super.clone();
147    }
148
149    /**
150     * Tests if this object is equal to another.
151     *
152     * @param obj  the object to test against for equality ({@code null}
153     *             permitted).
154     *
155     * @return A boolean.
156     */
157    @Override
158    public boolean equals(Object obj) {
159        if (obj == this) {
160            return true;
161        }
162        if (!(obj instanceof ComparableObjectItem)) {
163            return false;
164        }
165        ComparableObjectItem that = (ComparableObjectItem) obj;
166        if (!this.x.equals(that.x)) {
167            return false;
168        }
169        if (!ObjectUtils.equal(this.obj, that.obj)) {
170            return false;
171        }
172        return true;
173    }
174
175    /**
176     * Returns a hash code.
177     *
178     * @return A hash code.
179     */
180    @Override
181    public int hashCode() {
182        int result;
183        result = this.x.hashCode();
184        result = 29 * result + (this.obj != null ? this.obj.hashCode() : 0);
185        return result;
186    }
187
188}