001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2007, 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     * FixedMillisecond.java
029     * ---------------------
030     * (C) Copyright 2002-2007 by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * Changes
036     * -------
037     * 19-Mar-2002 : Version 1, based on original Millisecond implementation (DG);
038     * 24-Jun-2002 : Removed unnecessary imports (DG);
039     * 10-Sep-2002 : Added getSerialIndex() method (DG);
040     * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
041     * 13-Mar-2003 : Moved to com.jrefinery.data.time package and implemented 
042     *               Serializable (DG);
043     * 21-Oct-2003 : Added hashCode() method (DG);
044     * ------------- JFREECHART 1.0.x ---------------------------------------------
045     * 06-Oct-2006 : Added peg() method (DG);
046     *
047     */
048    
049    package org.jfree.data.time;
050    
051    import java.io.Serializable;
052    import java.util.Calendar;
053    import java.util.Date;
054    
055    /**
056     * Wrapper for a <code>java.util.Date</code> object that allows it to be used 
057     * as a {@link RegularTimePeriod}.  This class is immutable, which is a 
058     * requirement for all {@link RegularTimePeriod} subclasses.
059     */
060    public class FixedMillisecond extends RegularTimePeriod 
061                                  implements Serializable {
062    
063        /** For serialization. */
064        private static final long serialVersionUID = 7867521484545646931L;
065        
066        /** The millisecond. */
067        private Date time;
068    
069        /**
070         * Constructs a millisecond based on the current system time.
071         */
072        public FixedMillisecond() {
073            this(new Date());
074        }
075    
076        /**
077         * Constructs a millisecond.
078         *
079         * @param millisecond  the millisecond (same encoding as java.util.Date).
080         */
081        public FixedMillisecond(long millisecond) {
082            this(new Date(millisecond));
083        }
084    
085        /**
086         * Constructs a millisecond.
087         *
088         * @param time  the time.
089         */
090        public FixedMillisecond(Date time) {
091            this.time = time;
092        }
093    
094        /**
095         * Returns the date/time.
096         *
097         * @return The date/time.
098         */
099        public Date getTime() {
100            return this.time;
101        }
102    
103        /**
104         * This method is overridden to do nothing.
105         * 
106         * @param calendar  ignored
107         * 
108         * @since 1.0.3
109         */
110        public void peg(Calendar calendar) {
111            // nothing to do        
112        }
113    
114        /**
115         * Returns the millisecond preceding this one.
116         *
117         * @return The millisecond preceding this one.
118         */
119        public RegularTimePeriod previous() {
120            RegularTimePeriod result = null;
121            long t = this.time.getTime();
122            if (t != Long.MIN_VALUE) {
123                result = new FixedMillisecond(t - 1);
124            }
125            return result;
126        }
127    
128        /**
129         * Returns the millisecond following this one.
130         *
131         * @return The millisecond following this one.
132         */
133        public RegularTimePeriod next() {
134            RegularTimePeriod result = null;
135            long t = this.time.getTime();
136            if (t != Long.MAX_VALUE) {
137                result = new FixedMillisecond(t + 1);
138            }
139            return result;
140        }
141    
142        /**
143         * Tests the equality of this object against an arbitrary Object.
144         *
145         * @param object  the object to compare
146         *
147         * @return A boolean.
148         */
149        public boolean equals(Object object) {
150            if (object instanceof FixedMillisecond) {
151                FixedMillisecond m = (FixedMillisecond) object;
152                return this.time.equals(m.getTime());
153            }
154            else {
155                return false;
156            }
157    
158        }
159    
160        /**
161         * Returns a hash code for this object instance.
162         * 
163         * @return A hash code.
164         */
165        public int hashCode() {
166            return this.time.hashCode();
167        }
168    
169        /**
170         * Returns an integer indicating the order of this Millisecond object
171         * relative to the specified
172         * object: negative == before, zero == same, positive == after.
173         *
174         * @param o1    the object to compare.
175         *
176         * @return negative == before, zero == same, positive == after.
177         */
178        public int compareTo(Object o1) {
179    
180            int result;
181            long difference;
182    
183            // CASE 1 : Comparing to another Second object
184            // -------------------------------------------
185            if (o1 instanceof FixedMillisecond) {
186                FixedMillisecond t1 = (FixedMillisecond) o1;
187                difference = this.time.getTime() - t1.time.getTime();
188                if (difference > 0) {
189                    result = 1;
190                }
191                else {
192                    if (difference < 0) {
193                       result = -1;
194                    }
195                    else {
196                        result = 0;
197                    }
198                }
199            }
200    
201            // CASE 2 : Comparing to another TimePeriod object
202            // -----------------------------------------------
203            else if (o1 instanceof RegularTimePeriod) {
204                // more difficult case - evaluate later...
205                result = 0;
206            }
207    
208            // CASE 3 : Comparing to a non-TimePeriod object
209            // ---------------------------------------------
210            else {
211                // consider time periods to be ordered after general objects
212                result = 1;
213            }
214    
215            return result;
216    
217        }
218    
219        /**
220         * Returns the first millisecond of the time period.
221         *
222         * @return The first millisecond of the time period.
223         */
224        public long getFirstMillisecond() {
225            return this.time.getTime();
226        }
227    
228    
229        /**
230         * Returns the first millisecond of the time period.
231         *
232         * @param calendar  the calendar.
233         *
234         * @return The first millisecond of the time period.
235         */
236        public long getFirstMillisecond(Calendar calendar) {
237            return this.time.getTime();
238        }
239    
240        /**
241         * Returns the last millisecond of the time period.
242         *
243         * @return The last millisecond of the time period.
244         */
245        public long getLastMillisecond() {
246            return this.time.getTime();
247        }
248    
249        /**
250         * Returns the last millisecond of the time period.
251         *
252         * @param calendar  the calendar.
253         *
254         * @return The last millisecond of the time period.
255         */
256        public long getLastMillisecond(Calendar calendar) {
257            return this.time.getTime();
258        }
259    
260        /**
261         * Returns the millisecond closest to the middle of the time period.
262         *
263         * @return The millisecond closest to the middle of the time period.
264         */
265        public long getMiddleMillisecond() {
266            return this.time.getTime();
267        }
268    
269        /**
270         * Returns the millisecond closest to the middle of the time period.
271         *
272         * @param calendar  the calendar.
273         *
274         * @return The millisecond closest to the middle of the time period.
275         */
276        public long getMiddleMillisecond(Calendar calendar) {
277            return this.time.getTime();
278        }
279    
280        /**
281         * Returns a serial index number for the millisecond.
282         *
283         * @return The serial index number.
284         */
285        public long getSerialIndex() {
286            return this.time.getTime();
287        }
288    
289    }