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    
047    package org.jfree.data.xy;
048    
049    import java.io.Serializable;
050    
051    import 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     */
057    public 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    }