001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2013, 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 2001-2013, 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 * 03-Jul-2013 : Use ParamChecks (DG);
047 * 
048 */
049
050package org.jfree.data.time;
051
052import java.io.Serializable;
053import org.jfree.chart.util.ParamChecks;
054import org.jfree.util.ObjectUtilities;
055
056/**
057 * Represents one data item in a time series.
058 * <P>
059 * The time period can be any of the following:
060 * <ul>
061 * <li>{@link Year}</li>
062 * <li>{@link Quarter}</li>
063 * <li>{@link Month}</li>
064 * <li>{@link Week}</li>
065 * <li>{@link Day}</li>
066 * <li>{@link Hour}</li>
067 * <li>{@link Minute}</li>
068 * <li>{@link Second}</li>
069 * <li>{@link Millisecond}</li>
070 * <li>{@link FixedMillisecond}</li>
071 * </ul>
072 *
073 * The time period is an immutable property of the data item.  Data items will
074 * often be sorted within a list, and allowing the time period to be changed
075 * could destroy the sort order.
076 * <P>
077 * Implements the <code>Comparable</code> interface so that standard Java
078 * sorting can be used to keep the data items in order.
079 *
080 */
081public class TimeSeriesDataItem implements Cloneable, Comparable, Serializable {
082
083    /** For serialization. */
084    private static final long serialVersionUID = -2235346966016401302L;
085
086    /** The time period. */
087    private RegularTimePeriod period;
088
089    /** The value associated with the time period. */
090    private Number value;
091
092    /**
093     * Constructs a new data item that associates a value with a time period.
094     *
095     * @param period  the time period (<code>null</code> not permitted).
096     * @param value  the value (<code>null</code> permitted).
097     */
098    public TimeSeriesDataItem(RegularTimePeriod period, Number value) {
099        ParamChecks.nullNotPermitted(period, "period");
100        this.period = period;
101        this.value = value;
102    }
103
104    /**
105     * Constructs a new data item that associates a value with a time period.
106     *
107     * @param period  the time period (<code>null</code> not permitted).
108     * @param value  the value associated with the time period.
109     */
110    public TimeSeriesDataItem(RegularTimePeriod period, double value) {
111        this(period, new Double(value));
112    }
113
114    /**
115     * Returns the time period.
116     *
117     * @return The time period (never <code>null</code>).
118     */
119    public RegularTimePeriod getPeriod() {
120        return this.period;
121    }
122
123    /**
124     * Returns the value.
125     *
126     * @return The value (<code>null</code> possible).
127     *
128     * @see #setValue(java.lang.Number)
129     */
130    public Number getValue() {
131        return this.value;
132    }
133
134    /**
135     * Sets the value for this data item.
136     *
137     * @param value  the value (<code>null</code> permitted).
138     *
139     * @see #getValue()
140     */
141    public void setValue(Number value) {
142        this.value = value;
143    }
144
145    /**
146     * Tests this object for equality with an arbitrary object.
147     *
148     * @param obj  the other object (<code>null</code> permitted).
149     *
150     * @return A boolean.
151     */
152    @Override
153    public boolean equals(Object obj) {
154        if (this == obj) {
155            return true;
156        }
157        if (!(obj instanceof TimeSeriesDataItem)) {
158            return false;
159        }
160        TimeSeriesDataItem that = (TimeSeriesDataItem) obj;
161        if (!ObjectUtilities.equal(this.period, that.period)) {
162            return false;
163        }
164        if (!ObjectUtilities.equal(this.value, that.value)) {
165            return false;
166        }
167        return true;
168    }
169
170    /**
171     * Returns a hash code.
172     *
173     * @return A hash code.
174     */
175    @Override
176    public int hashCode() {
177        int result;
178        result = (this.period != null ? this.period.hashCode() : 0);
179        result = 29 * result + (this.value != null ? this.value.hashCode() : 0);
180        return result;
181    }
182
183    /**
184     * Returns an integer indicating the order of this data pair object
185     * relative to another object.
186     * <P>
187     * For the order we consider only the timing:
188     * negative == before, zero == same, positive == after.
189     *
190     * @param o1  The object being compared to.
191     *
192     * @return An integer indicating the order of the data item object
193     *         relative to another object.
194     */
195    @Override
196    public int compareTo(Object o1) {
197
198        int result;
199
200        // CASE 1 : Comparing to another TimeSeriesDataItem object
201        // -------------------------------------------------------
202        if (o1 instanceof TimeSeriesDataItem) {
203            TimeSeriesDataItem datapair = (TimeSeriesDataItem) o1;
204            result = getPeriod().compareTo(datapair.getPeriod());
205        }
206
207        // CASE 2 : Comparing to a general object
208        // ---------------------------------------------
209        else {
210            // consider time periods to be ordered after general objects
211            result = 1;
212        }
213
214        return result;
215
216    }
217
218    /**
219     * Clones the data item.  Note: there is no need to clone the period or
220     * value since they are immutable classes.
221     *
222     * @return A clone of the data item.
223     */
224    @Override
225    public Object clone() {
226        Object clone = null;
227        try {
228            clone = super.clone();
229        }
230        catch (CloneNotSupportedException e) { // won't get here...
231            e.printStackTrace();
232        }
233        return clone;
234    }
235
236}