icuSources/i18n/indiancal.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4  *****************************************************************************
   5  * Copyright (C) 2003-2008, International Business Machines Corporation
   6  * and others. All Rights Reserved.
   7  *****************************************************************************
   8  *
   9  * File INDIANCAL.H
  10  *****************************************************************************
  11  */
  12
  13 #ifndef INDIANCAL_H
  14 #define INDIANCAL_H
  15
  16 #include "unicode/utypes.h"
  17
  18 #if !UCONFIG_NO_FORMATTING
  19
  20 #include "unicode/calendar.h"
  21
  22 U_NAMESPACE_BEGIN
  23
  24 /**
  25  * Concrete class which provides the Indian calendar.
  26  * <P>
  27  * <code>IndianCalendar</code> is a subclass of <code>Calendar</code>
  28  * that numbers years since the begining of SAKA ERA.  This is the civil calendar
  29  * which is accepted by government of India as Indian National Calendar.
  30  * The two calendars most widely used in India today are the Vikrama calendar
  31  * followed in North India and the Shalivahana or Saka calendar which is followed
  32  * in South India and Maharashtra.
  33
  34  * A variant of the Shalivahana Calendar was reformed and standardized as the
  35  * Indian National calendar in 1957.
  36  * <p>
  37  * Some details of Indian National Calendar (to be implemented) :
  38  * The Months
  39  * Month          Length      Start date (Gregorian)
  40  * =================================================
  41  * 1 Chaitra      30/31          March 22*
  42  * 2 Vaisakha     31             April 21
  43  * 3 Jyaistha     31             May 22
  44  * 4 Asadha       31             June 22
  45  * 5 Sravana      31             July 23
  46  * 6 Bhadra       31             August 23
  47  * 7 Asvina       30             September 23
  48  * 8 Kartika      30             October 23
  49  * 9 Agrahayana   30             November 22
  50  * 10 Pausa       30             December 22
  51  * 11 Magha       30             January 21
  52  * 12 Phalguna    30             February 20
  53
  54  * In leap years, Chaitra has 31 days and starts on March 21 instead.
  55  * The leap years of Gregorian calendar and Indian National Calendar are in synchornization.
  56  * So When its a leap year in Gregorian calendar then Chaitra has 31 days.
  57  *
  58  * The Years
  59  * Years are counted in the Saka Era, which starts its year 0 in 78AD (by gregorian calendar).
  60  * So for eg. 9th June 2006 by Gregorian Calendar, is same as 19th of Jyaistha in 1928 of Saka
  61  * era by Indian National Calendar.
  62  * <p>
  63  * The Indian Calendar has only one allowable era: <code>Saka Era</code>.  If the
  64  * calendar is not in lenient mode (see <code>setLenient</code>), dates before
  65  * 1/1/1 Saka Era are rejected with an <code>IllegalArgumentException</code>.
  66  * <p>
  67  * @internal
  68  */
  69
  70
  71 class U_I18N_API IndianCalendar : public Calendar {
  72 public:
  73   /**
  74    * Useful constants for IndianCalendar.
  75    * @internal
  76    */
  77   enum EEras {
  78     /**
  79      * Constant for Chaitra, the 1st month of the Indian year.
  80      */
  81       CHAITRA,
  82
  83       /**
  84      * Constant for Vaisakha, the 2nd month of the Indian year.
  85      */
  86       VAISAKHA,
  87
  88       /**
  89      * Constant for Jyaistha, the 3rd month of the Indian year.
  90      */
  91       JYAISTHA,
  92
  93     /**
  94      * Constant for Asadha, the 4th month of the Indian year.
  95      */
  96       ASADHA,
  97
  98     /**
  99      * Constant for Sravana, the 5th month of the Indian year.
 100      */
 101       SRAVANA,
 102
 103     /**
 104      * Constant for Bhadra the 6th month of the Indian year
 105      */
 106       BHADRA,
 107
 108     /**
 109      * Constant for the Asvina, the 7th month of the Indian year.
 110      */
 111       ASVINA,
 112
 113     /**
 114      * Constant for Kartika, the 8th month of the Indian year.
 115      */
 116       KARTIKA,
 117
 118     /**
 119      * Constant for Agrahayana, the 9th month of the Indian year.
 120      */
 121       AGRAHAYANA,
 122
 123     /**
 124      * Constant for Pausa, the 10th month of the Indian year.
 125      */
 126       PAUSA,
 127
 128     /**
 129      * Constant for Magha, the 11th month of the Indian year.
 130      */
 131       MAGHA,
 132
 133     /**
 134      * Constant for Phalguna, the 12th month of the Indian year.
 135      */
 136       PHALGUNA
 137     };
 138
 139   //-------------------------------------------------------------------------
 140   // Constructors...
 141   //-------------------------------------------------------------------------
 142
 143   /**
 144    * Constructs an IndianCalendar based on the current time in the default time zone
 145    * with the given locale.
 146    *
 147    * @param aLocale  The given locale.
 148    * @param success  Indicates the status of IndianCalendar object construction.
 149    *                 Returns U_ZERO_ERROR if constructed successfully.
 150    * @param beCivil  Whether the calendar should be civil (default-TRUE) or religious (FALSE)
 151    * @internal
 152    */
 153   IndianCalendar(const Locale& aLocale, UErrorCode &success);
 154
 155   /**
 156    * Copy Constructor
 157    * @internal
 158    */
 159   IndianCalendar(const IndianCalendar& other);
 160
 161   /**
 162    * Destructor.
 163    * @internal
 164    */
 165   virtual ~IndianCalendar();
 166
 167   /**
 168    * Determines whether this object uses the fixed-cycle Indian civil calendar
 169    * or an approximation of the religious, astronomical calendar.
 170    *
 171    * @param beCivil   <code>CIVIL</code> to use the civil calendar,
 172    *                  <code>ASTRONOMICAL</code> to use the astronomical calendar.
 173    * @internal
 174    */
 175   //void setCivil(ECivil beCivil, UErrorCode &status);
 176
 177   /**
 178    * Returns <code>true</code> if this object is using the fixed-cycle civil
 179    * calendar, or <code>false</code> if using the religious, astronomical
 180    * calendar.
 181    * @internal
 182    */
 183   //UBool isCivil();
 184
 185
 186   // TODO: copy c'tor, etc
 187
 188   // clone
 189   virtual Calendar* clone() const;
 190
 191  private:
 192   /**
 193    * Determine whether a year is the gregorian year a leap year
 194    */
 195   //static UBool isGregorianLeap(int32_t year);
 196   //----------------------------------------------------------------------
 197   // Calendar framework
 198   //----------------------------------------------------------------------
 199  protected:
 200   /**
 201    * @internal
 202    */
 203   virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const;
 204
 205   /**
 206    * Return the length (in days) of the given month.
 207    *
 208    * @param year  The year in Saka era
 209    * @param year  The month(0-based) in Indian year
 210    * @internal
 211    */
 212   virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const;
 213
 214   /**
 215    * Return the number of days in the given Indian year
 216    * @internal
 217    */
 218   virtual int32_t handleGetYearLength(int32_t extendedYear) const;
 219
 220   //-------------------------------------------------------------------------
 221   // Functions for converting from field values to milliseconds....
 222   //-------------------------------------------------------------------------
 223
 224   // Return JD of start of given month/year
 225   /**
 226    * @internal
 227    */
 228   virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const;
 229
 230   //-------------------------------------------------------------------------
 231   // Functions for converting from milliseconds to field values
 232   //-------------------------------------------------------------------------
 233
 234   /**
 235    * @internal
 236    */
 237   virtual int32_t handleGetExtendedYear();
 238
 239   /**
 240    * Override Calendar to compute several fields specific to the Indian
 241    * calendar system.  These are:
 242    *
 243    * <ul><li>ERA
 244    * <li>YEAR
 245    * <li>MONTH
 246    * <li>DAY_OF_MONTH
 247    * <li>DAY_OF_YEAR
 248    * <li>EXTENDED_YEAR</ul>
 249    *
 250    * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
 251    * method is called. The getGregorianXxx() methods return Gregorian
 252    * calendar equivalents for the given Julian day.
 253    * @internal
 254    */
 255   virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
 256
 257   // UObject stuff
 258  public:
 259   /**
 260    * @return   The class ID for this object. All objects of a given class have the
 261    *           same class ID. Objects of other classes have different class IDs.
 262    * @internal
 263    */
 264   virtual UClassID getDynamicClassID(void) const;
 265
 266   /**
 267    * Return the class ID for this class. This is useful only for comparing to a return
 268    * value from getDynamicClassID(). For example:
 269    *
 270    *      Base* polymorphic_pointer = createPolymorphicObject();
 271    *      if (polymorphic_pointer->getDynamicClassID() ==
 272    *          Derived::getStaticClassID()) ...
 273    *
 274    * @return   The class ID for all objects of this class.
 275    * @internal
 276    */
 277   static UClassID U_EXPORT2 getStaticClassID(void);
 278
 279   /**
 280    * return the calendar type, "indian".
 281    *
 282    * @return calendar type
 283    * @internal
 284    */
 285   virtual const char * getType() const;
 286
 287 private:
 288   IndianCalendar(); // default constructor not implemented
 289
 290   // Default century.
 291 protected:
 292
 293   /**
 294    * (Overrides Calendar) Return true if the current date for this Calendar is in
 295    * Daylight Savings Time. Recognizes DST_OFFSET, if it is set.
 296    *
 297    * @param status Fill-in parameter which receives the status of this operation.
 298    * @return   True if the current date for this Calendar is in Daylight Savings Time,
 299    *           false, otherwise.
 300    * @internal
 301    */
 302   virtual UBool inDaylightTime(UErrorCode& status) const;
 303
 304
 305   /**
 306    * Returns TRUE because the Indian Calendar does have a default century
 307    * @internal
 308    */
 309   virtual UBool haveDefaultCentury() const;
 310
 311   /**
 312    * Returns the date of the start of the default century
 313    * @return start of century - in milliseconds since epoch, 1970
 314    * @internal
 315    */
 316   virtual UDate defaultCenturyStart() const;
 317
 318   /**
 319    * Returns the year in which the default century begins
 320    * @internal
 321    */
 322   virtual int32_t defaultCenturyStartYear() const;
 323 };
 324
 325 U_NAMESPACE_END
 326
 327 #endif
 328 #endif
 329
 330
 331