    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2008, 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     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025     * in the United States and other countries.]
    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
    041    package org.jfree.data;
    042
    043    import java.io.Serializable;
    044
    045    import 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     */
    053    public 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    }