Source for org.jfree.date.RelativeDayOfWeekRule

   1: /* ========================================================================
   2:  * JCommon : a free general purpose class library for the Java(tm) platform
   3:  * ========================================================================
   4:  *
   5:  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   6:  * 
   7:  * Project Info:  http://www.jfree.org/jcommon/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * --------------------------
  28:  * RelativeDayOfWeekRule.java
  29:  * --------------------------
  30:  * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * $Id: RelativeDayOfWeekRule.java,v 1.6 2005/11/16 15:58:40 taqua Exp $
  36:  *
  37:  * Changes (from 26-Oct-2001)
  38:  * --------------------------
  39:  * 26-Oct-2001 : Changed package to com.jrefinery.date.*;
  40:  * 03-Oct-2002 : Fixed errors reported by Checkstyle (DG);
  41:  *
  42:  */
  43: 
  44: package org.jfree.date;
  45: 
  46: /**
  47:  * An annual date rule that returns a date for each year based on (a) a
  48:  * reference rule; (b) a day of the week; and (c) a selection parameter
  49:  * (SerialDate.PRECEDING, SerialDate.NEAREST, SerialDate.FOLLOWING).
  50:  * <P>
  51:  * For example, Good Friday can be specified as 'the Friday PRECEDING Easter 
  52:  * Sunday'.
  53:  *
  54:  * @author David Gilbert
  55:  */
  56: public class RelativeDayOfWeekRule extends AnnualDateRule {
  57: 
  58:     /** A reference to the annual date rule on which this rule is based. */
  59:     private AnnualDateRule subrule;
  60: 
  61:     /** 
  62:      * The day of the week (SerialDate.MONDAY, SerialDate.TUESDAY, and so on). 
  63:      */
  64:     private int dayOfWeek;
  65: 
  66:     /** Specifies which day of the week (PRECEDING, NEAREST or FOLLOWING). */
  67:     private int relative;
  68: 
  69:     /**
  70:      * Default constructor - builds a rule for the Monday following 1 January.
  71:      */
  72:     public RelativeDayOfWeekRule() {
  73:         this(new DayAndMonthRule(), SerialDate.MONDAY, SerialDate.FOLLOWING);
  74:     }
  75: 
  76:     /**
  77:      * Standard constructor - builds rule based on the supplied sub-rule.
  78:      *
  79:      * @param subrule  the rule that determines the reference date.
  80:      * @param dayOfWeek  the day-of-the-week relative to the reference date.
  81:      * @param relative  indicates *which* day-of-the-week (preceding, nearest 
  82:      *                  or following).
  83:      */
  84:     public RelativeDayOfWeekRule(final AnnualDateRule subrule, 
  85:             final int dayOfWeek, final int relative) {
  86:         this.subrule = subrule;
  87:         this.dayOfWeek = dayOfWeek;
  88:         this.relative = relative;
  89:     }
  90: 
  91:     /**
  92:      * Returns the sub-rule (also called the reference rule).
  93:      *
  94:      * @return The annual date rule that determines the reference date for this 
  95:      *         rule.
  96:      */
  97:     public AnnualDateRule getSubrule() {
  98:         return this.subrule;
  99:     }
 100: 
 101:     /**
 102:      * Sets the sub-rule.
 103:      *
 104:      * @param subrule  the annual date rule that determines the reference date 
 105:      *                 for this rule.
 106:      */
 107:     public void setSubrule(final AnnualDateRule subrule) {
 108:         this.subrule = subrule;
 109:     }
 110: 
 111:     /**
 112:      * Returns the day-of-the-week for this rule.
 113:      *
 114:      * @return the day-of-the-week for this rule.
 115:      */
 116:     public int getDayOfWeek() {
 117:         return this.dayOfWeek;
 118:     }
 119: 
 120:     /**
 121:      * Sets the day-of-the-week for this rule.
 122:      *
 123:      * @param dayOfWeek  the day-of-the-week (SerialDate.MONDAY, 
 124:      *                   SerialDate.TUESDAY, and so on).
 125:      */
 126:     public void setDayOfWeek(final int dayOfWeek) {
 127:         this.dayOfWeek = dayOfWeek;
 128:     }
 129: 
 130:     /**
 131:      * Returns the 'relative' attribute, that determines *which* 
 132:      * day-of-the-week we are interested in (SerialDate.PRECEDING, 
 133:      * SerialDate.NEAREST or SerialDate.FOLLOWING).
 134:      *
 135:      * @return The 'relative' attribute.
 136:      */
 137:     public int getRelative() {
 138:         return this.relative;
 139:     }
 140: 
 141:     /**
 142:      * Sets the 'relative' attribute (SerialDate.PRECEDING, SerialDate.NEAREST,
 143:      * SerialDate.FOLLOWING).
 144:      *
 145:      * @param relative  determines *which* day-of-the-week is selected by this 
 146:      *                  rule.
 147:      */
 148:     public void setRelative(final int relative) {
 149:         this.relative = relative;
 150:     }
 151: 
 152:     /**
 153:      * Creates a clone of this rule.
 154:      *
 155:      * @return a clone of this rule.
 156:      *
 157:      * @throws CloneNotSupportedException this should never happen.
 158:      */
 159:     public Object clone() throws CloneNotSupportedException {
 160:         final RelativeDayOfWeekRule duplicate 
 161:             = (RelativeDayOfWeekRule) super.clone();
 162:         duplicate.subrule = (AnnualDateRule) duplicate.getSubrule().clone();
 163:         return duplicate;
 164:     }
 165: 
 166:     /**
 167:      * Returns the date generated by this rule, for the specified year.
 168:      *
 169:      * @param year  the year (1900 &lt;= year &lt;= 9999).
 170:      *
 171:      * @return The date generated by the rule for the given year (possibly 
 172:      *         <code>null</code>).
 173:      */
 174:     public SerialDate getDate(final int year) {
 175: 
 176:         // check argument...
 177:         if ((year < SerialDate.MINIMUM_YEAR_SUPPORTED)
 178:             || (year > SerialDate.MAXIMUM_YEAR_SUPPORTED)) {
 179:             throw new IllegalArgumentException(
 180:                 "RelativeDayOfWeekRule.getDate(): year outside valid range.");
 181:         }
 182: 
 183:         // calculate the date...
 184:         SerialDate result = null;
 185:         final SerialDate base = this.subrule.getDate(year);
 186: 
 187:         if (base != null) {
 188:             switch (this.relative) {
 189:                 case(SerialDate.PRECEDING):
 190:                     result = SerialDate.getPreviousDayOfWeek(this.dayOfWeek, 
 191:                             base);
 192:                     break;
 193:                 case(SerialDate.NEAREST):
 194:                     result = SerialDate.getNearestDayOfWeek(this.dayOfWeek, 
 195:                             base);
 196:                     break;
 197:                 case(SerialDate.FOLLOWING):
 198:                     result = SerialDate.getFollowingDayOfWeek(this.dayOfWeek, 
 199:                             base);
 200:                     break;
 201:                 default:
 202:                     break;
 203:             }
 204:         }
 205:         return result;
 206: 
 207:     }
 208: 
 209: }