    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 * ComparableObjectItem.java
    029 * -------------------------
    030 * (C) Copyright 2006-2008, by Object Refinery Limited.
    031 *
    032 * Original Author:  David Gilbert (for Object Refinery Limited);
    033 * Contributor(s):   -;
    034 *
    035 * Changes
    036 * -------
    037 * 19-Oct-2006 : New class, based on XYDataItem (DG);
    038 *
    039 */
    040
    041package org.jfree.data;
    042
    043import java.io.Serializable;
    044
    045import org.jfree.util.ObjectUtilities;
    046
    047/**
    048 * Represents one (Comparable, Object) data item for use in a
    049 * {@link ComparableObjectSeries}.
    050 *
    051 * @since 1.0.3
    052 */
    053public class ComparableObjectItem implements Cloneable, Comparable,
    054        Serializable {
    055
    056    /** For serialization. */
    057    private static final long serialVersionUID = 2751513470325494890L;
    058
    059    /** The x-value. */
    060    private Comparable x;
    061
    062    /** The y-value. */
    063    private Object obj;
    064
    065    /**
    066     * Constructs a new data item.
    067     *
    068     * @param x  the x-value (<code>null</code> NOT permitted).
    069     * @param y  the y-value (<code>null</code> permitted).
    070     */
    071    public ComparableObjectItem(Comparable x, Object y) {
    072        if (x == null) {
    073            throw new IllegalArgumentException("Null 'x' argument.");
    074        }
    075        this.x = x;
    076        this.obj = y;
    077    }
    078
    079    /**
    080     * Returns the x-value.
    081     *
    082     * @return The x-value (never <code>null</code>).
    083     */
    084    protected Comparable getComparable() {
    085        return this.x;
    086    }
    087
    088    /**
    089     * Returns the y-value.
    090     *
    091     * @return The y-value (possibly <code>null</code>).
    092     */
    093    protected Object getObject() {
    094        return this.obj;
    095    }
    096
    097    /**
    098     * Sets the y-value for this data item.  Note that there is no
    099     * corresponding method to change the x-value.
    100     *
    101     * @param y  the new y-value (<code>null</code> permitted).
    102     */
    103    protected void setObject(Object y) {
    104        this.obj = y;
    105    }
    106
    107    /**
    108     * Returns an integer indicating the order of this object relative to
    109     * another object.
    110     * <P>
    111     * For the order we consider only the x-value:
    112     * negative == "less-than", zero == "equal", positive == "greater-than".
    113     *
    114     * @param o1  the object being compared to.
    115     *
    116     * @return An integer indicating the order of this data pair object
    117     *      relative to another object.
    118     */
    119    public int compareTo(Object o1) {
    120
    121        int result;
    122
    123        // CASE 1 : Comparing to another ComparableObjectItem object
    124        // ---------------------------------------------------------
    125        if (o1 instanceof ComparableObjectItem) {
    126            ComparableObjectItem that = (ComparableObjectItem) o1;
    127            return this.x.compareTo(that.x);
    128        }
    129
    130        // CASE 2 : Comparing to a general object
    131        // ---------------------------------------------
    132        else {
    133            // consider these to be ordered after general objects
    134            result = 1;
    135        }
    136
    137        return result;
    138
    139    }
    140
    141    /**
    142     * Returns a clone of this object.
    143     *
    144     * @return A clone.
    145     *
    146     * @throws CloneNotSupportedException not thrown by this class, but
    147     *         subclasses may differ.
    148     */
    149    public Object clone() throws CloneNotSupportedException {
    150        return super.clone();
    151    }
    152
    153    /**
    154     * Tests if this object is equal to another.
    155     *
    156     * @param obj  the object to test against for equality (<code>null</code>
    157     *             permitted).
    158     *
    159     * @return A boolean.
    160     */
    161    public boolean equals(Object obj) {
    162        if (obj == this) {
    163            return true;
    164        }
    165        if (!(obj instanceof ComparableObjectItem)) {
    166            return false;
    167        }
    168        ComparableObjectItem that = (ComparableObjectItem) obj;
    169        if (!this.x.equals(that.x)) {
    170            return false;
    171        }
    172        if (!ObjectUtilities.equal(this.obj, that.obj)) {
    173            return false;
    174        }
    175        return true;
    176    }
    177
    178    /**
    179     * Returns a hash code.
    180     *
    181     * @return A hash code.
    182     */
    183    public int hashCode() {
    184        int result;
    185        result = this.x.hashCode();
    186        result = 29 * result + (this.obj != null ? this.obj.hashCode() : 0);
    187        return result;
    188    }
    189
    190}