Source for org.jfree.chart.axis.MonthDateFormat

   1: /* ===========================================================
   2:  * JFreeChart : a free chart 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/jfreechart/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:  * MonthDateFormat.java
  29:  * --------------------
  30:  * (C) Copyright 2005, by Object Refinery Limited and Contributors.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * $Id: MonthDateFormat.java,v 1.1.2.3 2005/10/25 20:37:34 mungady Exp $
  36:  *
  37:  * Changes:
  38:  * --------
  39:  * 10-May-2005 : Version 1 (DG);
  40:  *
  41:  */
  42: 
  43: package org.jfree.chart.axis;
  44: 
  45: import java.text.DateFormat;
  46: import java.text.DateFormatSymbols;
  47: import java.text.FieldPosition;
  48: import java.text.NumberFormat;
  49: import java.text.ParsePosition;
  50: import java.text.SimpleDateFormat;
  51: import java.util.Arrays;
  52: import java.util.Calendar;
  53: import java.util.Date;
  54: import java.util.GregorianCalendar;
  55: import java.util.Locale;
  56: import java.util.TimeZone;
  57: 
  58: import org.jfree.data.time.Month;
  59: 
  60: /**
  61:  * A formatter that formats dates to show the initial letter(s) of the month
  62:  * name and, as an option, the year for the first or last month of each year.
  63:  */
  64: public class MonthDateFormat extends DateFormat {
  65:     
  66:     /** The symbols used for the months. */
  67:     private String[] months;
  68:     
  69:     /** Flags that control which months will have the year appended. */
  70:     private boolean[] showYear;
  71:     
  72:     /** The year formatter. */
  73:     private DateFormat yearFormatter;
  74:     
  75:     /**
  76:      * Creates a new instance for the default time zone.
  77:      */
  78:     public MonthDateFormat() {
  79:         this(TimeZone.getDefault());  
  80:     }
  81:     
  82:     /**
  83:      * Creates a new instance for the specified time zone.
  84:      * 
  85:      * @param zone  the time zone (<code>null</code> not permitted).
  86:      */
  87:     public MonthDateFormat(TimeZone zone) {
  88:         this(zone, Locale.getDefault(), 1, true, false);
  89:     }
  90:     
  91:     /**
  92:      * Creates a new instance for the specified time zone.
  93:      * 
  94:      * @param locale  the locale used to obtain the month 
  95:      *                names (<code>null</code> not permitted).
  96:      */
  97:     public MonthDateFormat(Locale locale) {
  98:         this(TimeZone.getDefault(), locale, 1, true, false);
  99:     }
 100:     
 101:     /**
 102:      * Creates a new instance for the specified time zone.
 103:      * 
 104:      * @param zone  the time zone (<code>null</code> not permitted).
 105:      * @param chars  the maximum number of characters to use from the month
 106:      *               names (that are obtained from the date symbols of the
 107:      *               default locale).  If this value is <= 0, the entire 
 108:      *               month name is used in each case.
 109:      */
 110:     public MonthDateFormat(TimeZone zone, int chars) {
 111:         this(zone, Locale.getDefault(), chars, true, false);
 112:     }
 113:     
 114:     /**
 115:      * Creates a new instance for the specified time zone.
 116:      * 
 117:      * @param locale  the locale (<code>null</code> not permitted).
 118:      * @param chars  the maximum number of characters to use from the month
 119:      *               names (that are obtained from the date symbols of the
 120:      *               default locale).  If this value is <= 0, the entire 
 121:      *               month name is used in each case.
 122:      */
 123:     public MonthDateFormat(Locale locale, int chars) {
 124:         this(TimeZone.getDefault(), locale, chars, true, false);
 125:     }
 126: 
 127:     /**
 128:      * Creates a new formatter.
 129:      * 
 130:      * @param zone  the time zone used to extract the month and year from dates
 131:      *              passed to this formatter (<code>null</code> not permitted).
 132:      * @param locale  the locale used to determine the month names 
 133:      *                (<code>null</code> not permitted).
 134:      * @param chars  the maximum number of characters to use from the month 
 135:      *               names, or zero to indicate that the entire month name 
 136:      *               should be used.
 137:      * @param showYearForJan  a flag that controls whether or not the year is
 138:      *                        appended to the symbol for the first month of
 139:      *                        each year.
 140:      * @param showYearForDec  a flag that controls whether or not the year is
 141:      *                        appended to the symbol for the last month of
 142:      *                        each year.
 143:      */
 144:     public MonthDateFormat(TimeZone zone, Locale locale, int chars, 
 145:                            boolean showYearForJan, boolean showYearForDec) {
 146:         this(
 147:             zone, locale, chars, new boolean[] {showYearForJan, false, false, 
 148:             false, false, false, false, false, false, false, false, false,
 149:             showYearForDec}, new SimpleDateFormat("yy")
 150:         );       
 151:     }
 152:     
 153:     /**
 154:      * Creates a new formatter.
 155:      * 
 156:      * @param zone  the time zone used to extract the month and year from dates
 157:      *              passed to this formatter (<code>null</code> not permitted).
 158:      * @param locale  the locale used to determine the month names 
 159:      *                (<code>null</code> not permitted).
 160:      * @param chars  the maximum number of characters to use from the month 
 161:      *               names, or zero to indicate that the entire month name 
 162:      *               should be used.
 163:      * @param showYear  an array of flags that control whether or not the
 164:      *                  year is displayed for a particular month.
 165:      * @param yearFormatter  the year formatter.
 166:      */
 167:     public MonthDateFormat(TimeZone zone, Locale locale, int chars, 
 168:                            boolean[] showYear, DateFormat yearFormatter) {
 169:         if (locale == null) {
 170:             throw new IllegalArgumentException("Null 'locale' argument.");
 171:         }
 172:         DateFormatSymbols dfs = new DateFormatSymbols(locale);
 173:         String[] monthsFromLocale = dfs.getMonths();
 174:         this.months = new String[12];
 175:         for (int i = 0; i < 12; i++) {
 176:             if (chars > 0) {
 177:                 months[i] = monthsFromLocale[i].substring(
 178:                     0, Math.min(chars, monthsFromLocale[i].length())
 179:                 );
 180:             }
 181:             else {
 182:                 months[i] = monthsFromLocale[i];
 183:             }
 184:         }
 185:         this.calendar = new GregorianCalendar(zone);
 186:         this.showYear = showYear;
 187:         this.yearFormatter = yearFormatter; 
 188:         
 189:         // the following is never used, but it seems that DateFormat requires
 190:         // it to be non-null.  It isn't well covered in the spec, refer to 
 191:         // bug parade 5061189 for more info.
 192:         this.numberFormat = NumberFormat.getNumberInstance();
 193:     }
 194: 
 195:     /**
 196:      * Formats the given date.
 197:      * 
 198:      * @param date  the date.
 199:      * @param toAppendTo  the string buffer.
 200:      * @param fieldPosition  the field position.
 201:      * 
 202:      * @return The formatted date.
 203:      */
 204:     public StringBuffer format(Date date, StringBuffer toAppendTo,
 205:                                FieldPosition fieldPosition) {
 206:         this.calendar.setTime(date);
 207:         int month = this.calendar.get(Calendar.MONTH);
 208:         toAppendTo.append(this.months[month]);
 209:         if (this.showYear[month]) {
 210:             toAppendTo.append(this.yearFormatter.format(date));
 211:         }
 212:         return toAppendTo;   
 213:     }
 214: 
 215:     /**
 216:      * Parses the given string (not implemented).
 217:      * 
 218:      * @param source  the date string.
 219:      * @param pos  the parse position.
 220:      * 
 221:      * @return <code>null</code>, as this method has not been implemented.
 222:      */
 223:     public Date parse(String source, ParsePosition pos) {
 224:         return null;   
 225:     }
 226: 
 227:     /**
 228:      * Tests this formatter for equality with an arbitrary object.
 229:      * 
 230:      * @param obj  the object.
 231:      * 
 232:      * @return A boolean.
 233:      */
 234:     public boolean equals(Object obj) {
 235:         if (obj == this) {
 236:             return true;
 237:         }
 238:         if (!(obj instanceof MonthDateFormat)) {
 239:             return false;
 240:         }
 241:         if (!super.equals(obj)) {
 242:             return false;
 243:         }
 244:         MonthDateFormat that = (MonthDateFormat) obj;
 245:         if (!Arrays.equals(this.months, that.months)) {
 246:             return false;
 247:         }
 248:         if (!Arrays.equals(this.showYear, that.showYear)) {
 249:             return false;
 250:         }
 251:         if (!this.yearFormatter.equals(that.yearFormatter)) {
 252:             return false;
 253:         }
 254:         return true;
 255:     }
 256: 
 257:     /**
 258:      * Some test code.
 259:      * 
 260:      * @param args  ignored.
 261:      */
 262:     public static void main(String[] args) {
 263:         MonthDateFormat mdf = new MonthDateFormat(Locale.UK, 2);
 264:         System.out.println("UK:");
 265:         System.out.println(mdf.format(new Month(1, 2005).getStart()));       
 266:         System.out.println(mdf.format(new Month(2, 2005).getStart()));       
 267:         System.out.println(mdf.format(new Month(3, 2005).getStart()));       
 268:         System.out.println(mdf.format(new Month(4, 2005).getStart()));       
 269:         System.out.println(mdf.format(new Month(5, 2005).getStart()));       
 270:         System.out.println(mdf.format(new Month(6, 2005).getStart()));       
 271:         System.out.println(mdf.format(new Month(7, 2005).getStart()));       
 272:         System.out.println(mdf.format(new Month(8, 2005).getStart()));       
 273:         System.out.println(mdf.format(new Month(9, 2005).getStart()));       
 274:         System.out.println(mdf.format(new Month(10, 2005).getStart()));       
 275:         System.out.println(mdf.format(new Month(11, 2005).getStart()));       
 276:         System.out.println(mdf.format(new Month(12, 2005).getStart()));  
 277:         System.out.println();
 278: 
 279:         mdf = new MonthDateFormat(Locale.GERMANY, 2);
 280:         System.out.println("GERMANY:");
 281:         System.out.println(mdf.format(new Month(1, 2005).getStart()));       
 282:         System.out.println(mdf.format(new Month(2, 2005).getStart()));       
 283:         System.out.println(mdf.format(new Month(3, 2005).getStart()));       
 284:         System.out.println(mdf.format(new Month(4, 2005).getStart()));       
 285:         System.out.println(mdf.format(new Month(5, 2005).getStart()));       
 286:         System.out.println(mdf.format(new Month(6, 2005).getStart()));       
 287:         System.out.println(mdf.format(new Month(7, 2005).getStart()));       
 288:         System.out.println(mdf.format(new Month(8, 2005).getStart()));       
 289:         System.out.println(mdf.format(new Month(9, 2005).getStart()));       
 290:         System.out.println(mdf.format(new Month(10, 2005).getStart()));       
 291:         System.out.println(mdf.format(new Month(11, 2005).getStart()));       
 292:         System.out.println(mdf.format(new Month(12, 2005).getStart()));  
 293:         System.out.println();
 294:         
 295:         mdf = new MonthDateFormat(Locale.FRANCE, 2);
 296:         System.out.println("FRANCE:");
 297:         System.out.println(mdf.format(new Month(1, 2005).getStart()));       
 298:         System.out.println(mdf.format(new Month(2, 2005).getStart()));       
 299:         System.out.println(mdf.format(new Month(3, 2005).getStart()));       
 300:         System.out.println(mdf.format(new Month(4, 2005).getStart()));       
 301:         System.out.println(mdf.format(new Month(5, 2005).getStart()));       
 302:         System.out.println(mdf.format(new Month(6, 2005).getStart()));       
 303:         System.out.println(mdf.format(new Month(7, 2005).getStart()));       
 304:         System.out.println(mdf.format(new Month(8, 2005).getStart()));       
 305:         System.out.println(mdf.format(new Month(9, 2005).getStart()));       
 306:         System.out.println(mdf.format(new Month(10, 2005).getStart()));       
 307:         System.out.println(mdf.format(new Month(11, 2005).getStart()));       
 308:         System.out.println(mdf.format(new Month(12, 2005).getStart()));  
 309:         System.out.println();
 310:         
 311:         SimpleDateFormat sdf = new SimpleDateFormat("yyyy");
 312:         sdf.setNumberFormat(null);
 313:         System.out.println(sdf.equals("X"));
 314:     }
 315: }