    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 * XYDataItem.java
    029 * ---------------
    030 * (C) Copyright 2003-2009, by Object Refinery Limited.
    031 *
    032 * Original Author:  David Gilbert (for Object Refinery Limited);
    033 * Contributor(s):   -;
    034 *
    035 * Changes
    036 * -------
    037 * 05-Aug-2003 : Renamed XYDataPair --> XYDataItem (DG);
    038 * 03-Feb-2004 : Fixed bug in equals() method (DG);
    039 * 21-Feb-2005 : Added setY(double) method (DG);
    040 * ------------- JFREECHART 1.0.x ---------------------------------------------
    041 * 30-Nov-2007 : Implemented getXValue() and getYValue(), plus toString() for
    042 *               debugging use (DG);
    043 * 10-Jun-2009 : Reimplemented cloning (DG);
    044 *
    045 */
    046
    047package org.jfree.data.xy;
    048
    049import java.io.Serializable;
    050
    051import org.jfree.util.ObjectUtilities;
    052
    053/**
    054 * Represents one (x, y) data item for an {@link XYSeries}.  Note that
    055 * subclasses are REQUIRED to support cloning.
    056 */
    057public class XYDataItem implements Cloneable, Comparable, Serializable {
    058
    059    /** For serialization. */
    060    private static final long serialVersionUID = 2751513470325494890L;
    061
    062    /** The x-value (<code>null</code> not permitted). */
    063    private Number x;
    064
    065    /** The y-value. */
    066    private Number y;
    067
    068    /**
    069     * Constructs a new data item.
    070     *
    071     * @param x  the x-value (<code>null</code> NOT permitted).
    072     * @param y  the y-value (<code>null</code> permitted).
    073     */
    074    public XYDataItem(Number x, Number y) {
    075        if (x == null) {
    076            throw new IllegalArgumentException("Null 'x' argument.");
    077        }
    078        this.x = x;
    079        this.y = y;
    080    }
    081
    082    /**
    083     * Constructs a new data item.
    084     *
    085     * @param x  the x-value.
    086     * @param y  the y-value.
    087     */
    088    public XYDataItem(double x, double y) {
    089        this(new Double(x), new Double(y));
    090    }
    091
    092    /**
    093     * Returns the x-value.
    094     *
    095     * @return The x-value (never <code>null</code>).
    096     */
    097    public Number getX() {
    098        return this.x;
    099    }
    100
    101    /**
    102     * Returns the x-value as a double primitive.
    103     *
    104     * @return The x-value.
    105     *
    106     * @see #getX()
    107     * @see #getYValue()
    108     *
    109     * @since 1.0.9
    110     */
    111    public double getXValue() {
    112        // this.x is not allowed to be null...
    113        return this.x.doubleValue();
    114    }
    115
    116    /**
    117     * Returns the y-value.
    118     *
    119     * @return The y-value (possibly <code>null</code>).
    120     */
    121    public Number getY() {
    122        return this.y;
    123    }
    124
    125    /**
    126     * Returns the y-value as a double primitive.
    127     *
    128     * @return The y-value.
    129     *
    130     * @see #getY()
    131     * @see #getXValue()
    132     *
    133     * @since 1.0.9
    134     */
    135    public double getYValue() {
    136        double result = Double.NaN;
    137        if (this.y != null) {
    138            result = this.y.doubleValue();
    139        }
    140        return result;
    141    }
    142
    143    /**
    144     * Sets the y-value for this data item.  Note that there is no
    145     * corresponding method to change the x-value.
    146     *
    147     * @param y  the new y-value.
    148     */
    149    public void setY(double y) {
    150        setY(new Double(y));
    151    }
    152
    153    /**
    154     * Sets the y-value for this data item.  Note that there is no
    155     * corresponding method to change the x-value.
    156     *
    157     * @param y  the new y-value (<code>null</code> permitted).
    158     */
    159    public void setY(Number y) {
    160        this.y = y;
    161    }
    162
    163    /**
    164     * Returns an integer indicating the order of this object relative to
    165     * another object.
    166     * <P>
    167     * For the order we consider only the x-value:
    168     * negative == "less-than", zero == "equal", positive == "greater-than".
    169     *
    170     * @param o1  the object being compared to.
    171     *
    172     * @return An integer indicating the order of this data pair object
    173     *      relative to another object.
    174     */
    175    public int compareTo(Object o1) {
    176
    177        int result;
    178
    179        // CASE 1 : Comparing to another TimeSeriesDataPair object
    180        // -------------------------------------------------------
    181        if (o1 instanceof XYDataItem) {
    182            XYDataItem dataItem = (XYDataItem) o1;
    183            double compare = this.x.doubleValue()
    184                             - dataItem.getX().doubleValue();
    185            if (compare > 0.0) {
    186                result = 1;
    187            }
    188            else {
    189                if (compare < 0.0) {
    190                    result = -1;
    191                }
    192                else {
    193                    result = 0;
    194                }
    195            }
    196        }
    197
    198        // CASE 2 : Comparing to a general object
    199        // ---------------------------------------------
    200        else {
    201            // consider time periods to be ordered after general objects
    202            result = 1;
    203        }
    204
    205        return result;
    206
    207    }
    208
    209    /**
    210     * Returns a clone of this object.
    211     *
    212     * @return A clone.
    213     */
    214    public Object clone() {
    215        Object clone = null;
    216        try {
    217            clone = super.clone();
    218        }
    219        catch (CloneNotSupportedException e) { // won't get here...
    220            e.printStackTrace();
    221        }
    222        return clone;
    223    }
    224
    225    /**
    226     * Tests if this object is equal to another.
    227     *
    228     * @param obj  the object to test against for equality (<code>null</code>
    229     *             permitted).
    230     *
    231     * @return A boolean.
    232     */
    233    public boolean equals(Object obj) {
    234        if (obj == this) {
    235            return true;
    236        }
    237        if (!(obj instanceof XYDataItem)) {
    238            return false;
    239        }
    240        XYDataItem that = (XYDataItem) obj;
    241        if (!this.x.equals(that.x)) {
    242            return false;
    243        }
    244        if (!ObjectUtilities.equal(this.y, that.y)) {
    245            return false;
    246        }
    247        return true;
    248    }
    249
    250    /**
    251     * Returns a hash code.
    252     *
    253     * @return A hash code.
    254     */
    255    public int hashCode() {
    256        int result;
    257        result = this.x.hashCode();
    258        result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
    259        return result;
    260    }
    261
    262    /**
    263     * Returns a string representing this instance, primarily for debugging
    264     * use.
    265     *
    266     * @return A string.
    267     */
    268    public String toString() {
    269        return "[" + getXValue() + ", " + getYValue() + "]";
    270    }
    271
    272}