    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 * TimeSeriesDataItem.java
    029 * -----------------------
    030 * (C) Copyright 2001-2009, by Object Refinery Limited.
    031 *
    032 * Original Author:  David Gilbert (for Object Refinery Limited);
    033 * Contributor(s):   -;
    034 *
    035 * Changes
    036 * -------
    037 * 11-Oct-2001 : Version 1 (DG);
    038 * 15-Nov-2001 : Updated Javadoc comments (DG);
    039 * 29-Nov-2001 : Added cloning (DG);
    040 * 24-Jun-2002 : Removed unnecessary import (DG);
    041 * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
    042 * 13-Mar-2003 : Renamed TimeSeriesDataPair --> TimeSeriesDataItem, moved to
    043 *               com.jrefinery.data.time package, implemented Serializable (DG)
    044 * ------------- JFREECHART 1.0.x ---------------------------------------------
    045 * 09-Jun-2009 : Tidied up equals() (DG);
    046 */
    047
    048package org.jfree.data.time;
    049
    050import java.io.Serializable;
    051import org.jfree.util.ObjectUtilities;
    052
    053/**
    054 * Represents one data item in a time series.
    055 * <P>
    056 * The time period can be any of the following:
    057 * <ul>
    058 * <li>{@link Year}</li>
    059 * <li>{@link Quarter}</li>
    060 * <li>{@link Month}</li>
    061 * <li>{@link Week}</li>
    062 * <li>{@link Day}</li>
    063 * <li>{@link Hour}</li>
    064 * <li>{@link Minute}</li>
    065 * <li>{@link Second}</li>
    066 * <li>{@link Millisecond}</li>
    067 * <li>{@link FixedMillisecond}</li>
    068 * </ul>
    069 *
    070 * The time period is an immutable property of the data item.  Data items will
    071 * often be sorted within a list, and allowing the time period to be changed
    072 * could destroy the sort order.
    073 * <P>
    074 * Implements the <code>Comparable</code> interface so that standard Java
    075 * sorting can be used to keep the data items in order.
    076 *
    077 */
    078public class TimeSeriesDataItem implements Cloneable, Comparable, Serializable {
    079
    080    /** For serialization. */
    081    private static final long serialVersionUID = -2235346966016401302L;
    082
    083    /** The time period. */
    084    private RegularTimePeriod period;
    085
    086    /** The value associated with the time period. */
    087    private Number value;
    088
    089    /**
    090     * Constructs a new data item that associates a value with a time period.
    091     *
    092     * @param period  the time period (<code>null</code> not permitted).
    093     * @param value  the value (<code>null</code> permitted).
    094     */
    095    public TimeSeriesDataItem(RegularTimePeriod period, Number value) {
    096        if (period == null) {
    097            throw new IllegalArgumentException("Null 'period' argument.");
    098        }
    099        this.period = period;
    100        this.value = value;
    101    }
    102
    103    /**
    104     * Constructs a new data item that associates a value with a time period.
    105     *
    106     * @param period  the time period (<code>null</code> not permitted).
    107     * @param value  the value associated with the time period.
    108     */
    109    public TimeSeriesDataItem(RegularTimePeriod period, double value) {
    110        this(period, new Double(value));
    111    }
    112
    113    /**
    114     * Returns the time period.
    115     *
    116     * @return The time period (never <code>null</code>).
    117     */
    118    public RegularTimePeriod getPeriod() {
    119        return this.period;
    120    }
    121
    122    /**
    123     * Returns the value.
    124     *
    125     * @return The value (<code>null</code> possible).
    126     *
    127     * @see #setValue(java.lang.Number)
    128     */
    129    public Number getValue() {
    130        return this.value;
    131    }
    132
    133    /**
    134     * Sets the value for this data item.
    135     *
    136     * @param value  the value (<code>null</code> permitted).
    137     *
    138     * @see #getValue()
    139     */
    140    public void setValue(Number value) {
    141        this.value = value;
    142    }
    143
    144    /**
    145     * Tests this object for equality with an arbitrary object.
    146     *
    147     * @param obj  the other object (<code>null</code> permitted).
    148     *
    149     * @return A boolean.
    150     */
    151    public boolean equals(Object obj) {
    152        if (this == obj) {
    153            return true;
    154        }
    155        if (!(obj instanceof TimeSeriesDataItem)) {
    156            return false;
    157        }
    158        TimeSeriesDataItem that = (TimeSeriesDataItem) obj;
    159        if (!ObjectUtilities.equal(this.period, that.period)) {
    160            return false;
    161        }
    162        if (!ObjectUtilities.equal(this.value, that.value)) {
    163            return false;
    164        }
    165        return true;
    166    }
    167
    168    /**
    169     * Returns a hash code.
    170     *
    171     * @return A hash code.
    172     */
    173    public int hashCode() {
    174        int result;
    175        result = (this.period != null ? this.period.hashCode() : 0);
    176        result = 29 * result + (this.value != null ? this.value.hashCode() : 0);
    177        return result;
    178    }
    179
    180    /**
    181     * Returns an integer indicating the order of this data pair object
    182     * relative to another object.
    183     * <P>
    184     * For the order we consider only the timing:
    185     * negative == before, zero == same, positive == after.
    186     *
    187     * @param o1  The object being compared to.
    188     *
    189     * @return An integer indicating the order of the data item object
    190     *         relative to another object.
    191     */
    192    public int compareTo(Object o1) {
    193
    194        int result;
    195
    196        // CASE 1 : Comparing to another TimeSeriesDataItem object
    197        // -------------------------------------------------------
    198        if (o1 instanceof TimeSeriesDataItem) {
    199            TimeSeriesDataItem datapair = (TimeSeriesDataItem) o1;
    200            result = getPeriod().compareTo(datapair.getPeriod());
    201        }
    202
    203        // CASE 2 : Comparing to a general object
    204        // ---------------------------------------------
    205        else {
    206            // consider time periods to be ordered after general objects
    207            result = 1;
    208        }
    209
    210        return result;
    211
    212    }
    213
    214    /**
    215     * Clones the data item.  Note: there is no need to clone the period or
    216     * value since they are immutable classes.
    217     *
    218     * @return A clone of the data item.
    219     */
    220    public Object clone() {
    221        Object clone = null;
    222        try {
    223            clone = super.clone();
    224        }
    225        catch (CloneNotSupportedException e) { // won't get here...
    226            e.printStackTrace();
    227        }
    228        return clone;
    229    }
    230
    231}