1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/intl/icu/source/i18n/islamcal.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,429 @@
1.4 +/*
1.5 + ********************************************************************************
1.6 + * Copyright (C) 2003-2013, International Business Machines Corporation
1.7 + * and others. All Rights Reserved.
1.8 + ******************************************************************************
1.9 + *
1.10 + * File ISLAMCAL.H
1.11 + *
1.12 + * Modification History:
1.13 + *
1.14 + * Date Name Description
1.15 + * 10/14/2003 srl ported from java IslamicCalendar
1.16 + *****************************************************************************
1.17 + */
1.18 +
1.19 +#ifndef ISLAMCAL_H
1.20 +#define ISLAMCAL_H
1.21 +
1.22 +#include "unicode/utypes.h"
1.23 +
1.24 +#if !UCONFIG_NO_FORMATTING
1.25 +
1.26 +#include "unicode/calendar.h"
1.27 +
1.28 +U_NAMESPACE_BEGIN
1.29 +
1.30 +/**
1.31 + * <code>IslamicCalendar</code> is a subclass of <code>Calendar</code>
1.32 + * that implements the Islamic civil and religious calendars. It
1.33 + * is used as the civil calendar in most of the Arab world and the
1.34 + * liturgical calendar of the Islamic faith worldwide. This calendar
1.35 + * is also known as the "Hijri" calendar, since it starts at the time
1.36 + * of Mohammed's emigration (or "hijra") to Medinah on Thursday,
1.37 + * July 15, 622 AD (Julian).
1.38 + * <p>
1.39 + * The Islamic calendar is strictly lunar, and thus an Islamic year of twelve
1.40 + * lunar months does not correspond to the solar year used by most other
1.41 + * calendar systems, including the Gregorian. An Islamic year is, on average,
1.42 + * about 354 days long, so each successive Islamic year starts about 11 days
1.43 + * earlier in the corresponding Gregorian year.
1.44 + * <p>
1.45 + * Each month of the calendar starts when the new moon's crescent is visible
1.46 + * at sunset. However, in order to keep the time fields in this class
1.47 + * synchronized with those of the other calendars and with local clock time,
1.48 + * we treat days and months as beginning at midnight,
1.49 + * roughly 6 hours after the corresponding sunset.
1.50 + * <p>
1.51 + * There are two main variants of the Islamic calendar in existence. The first
1.52 + * is the <em>civil</em> calendar, which uses a fixed cycle of alternating 29-
1.53 + * and 30-day months, with a leap day added to the last month of 11 out of
1.54 + * every 30 years. This calendar is easily calculated and thus predictable in
1.55 + * advance, so it is used as the civil calendar in a number of Arab countries.
1.56 + * This is the default behavior of a newly-created <code>IslamicCalendar</code>
1.57 + * object.
1.58 + * <p>
1.59 + * The Islamic <em>religious</em> calendar, however, is based on the <em>observation</em>
1.60 + * of the crescent moon. It is thus affected by the position at which the
1.61 + * observations are made, seasonal variations in the time of sunset, the
1.62 + * eccentricities of the moon's orbit, and even the weather at the observation
1.63 + * site. This makes it impossible to calculate in advance, and it causes the
1.64 + * start of a month in the religious calendar to differ from the civil calendar
1.65 + * by up to three days.
1.66 + * <p>
1.67 + * Using astronomical calculations for the position of the sun and moon, the
1.68 + * moon's illumination, and other factors, it is possible to determine the start
1.69 + * of a lunar month with a fairly high degree of certainty. However, these
1.70 + * calculations are extremely complicated and thus slow, so most algorithms,
1.71 + * including the one used here, are only approximations of the true astronical
1.72 + * calculations. At present, the approximations used in this class are fairly
1.73 + * simplistic; they will be improved in later versions of the code.
1.74 + * <p>
1.75 + * The {@link #setCivil setCivil} method determines
1.76 + * which approach is used to determine the start of a month. By default, the
1.77 + * fixed-cycle civil calendar is used. However, if <code>setCivil(false)</code>
1.78 + * is called, an approximation of the true lunar calendar will be used.
1.79 + *
1.80 + * @see GregorianCalendar
1.81 + *
1.82 + * @author Laura Werner
1.83 + * @author Alan Liu
1.84 + * @author Steven R. Loomis
1.85 + * @internal
1.86 + */
1.87 +class U_I18N_API IslamicCalendar : public Calendar {
1.88 + public:
1.89 + //-------------------------------------------------------------------------
1.90 + // Constants...
1.91 + //-------------------------------------------------------------------------
1.92 +
1.93 + /**
1.94 + * Calendar type - civil or religious or um alqura
1.95 + * @internal
1.96 + */
1.97 + enum ECalculationType {
1.98 + ASTRONOMICAL,
1.99 + CIVIL,
1.100 + UMALQURA,
1.101 + TBLA
1.102 + };
1.103 +
1.104 + /**
1.105 + * Constants for the months
1.106 + * @internal
1.107 + */
1.108 + enum EMonths {
1.109 + /**
1.110 + * Constant for Muharram, the 1st month of the Islamic year.
1.111 + * @internal
1.112 + */
1.113 + MUHARRAM = 0,
1.114 +
1.115 + /**
1.116 + * Constant for Safar, the 2nd month of the Islamic year.
1.117 + * @internal
1.118 + */
1.119 + SAFAR = 1,
1.120 +
1.121 + /**
1.122 + * Constant for Rabi' al-awwal (or Rabi' I), the 3rd month of the Islamic year.
1.123 + * @internal
1.124 + */
1.125 + RABI_1 = 2,
1.126 +
1.127 + /**
1.128 + * Constant for Rabi' al-thani or (Rabi' II), the 4th month of the Islamic year.
1.129 + * @internal
1.130 + */
1.131 + RABI_2 = 3,
1.132 +
1.133 + /**
1.134 + * Constant for Jumada al-awwal or (Jumada I), the 5th month of the Islamic year.
1.135 + * @internal
1.136 + */
1.137 + JUMADA_1 = 4,
1.138 +
1.139 + /**
1.140 + * Constant for Jumada al-thani or (Jumada II), the 6th month of the Islamic year.
1.141 + * @internal
1.142 + */
1.143 + JUMADA_2 = 5,
1.144 +
1.145 + /**
1.146 + * Constant for Rajab, the 7th month of the Islamic year.
1.147 + * @internal
1.148 + */
1.149 + RAJAB = 6,
1.150 +
1.151 + /**
1.152 + * Constant for Sha'ban, the 8th month of the Islamic year.
1.153 + * @internal
1.154 + */
1.155 + SHABAN = 7,
1.156 +
1.157 + /**
1.158 + * Constant for Ramadan, the 9th month of the Islamic year.
1.159 + * @internal
1.160 + */
1.161 + RAMADAN = 8,
1.162 +
1.163 + /**
1.164 + * Constant for Shawwal, the 10th month of the Islamic year.
1.165 + * @internal
1.166 + */
1.167 + SHAWWAL = 9,
1.168 +
1.169 + /**
1.170 + * Constant for Dhu al-Qi'dah, the 11th month of the Islamic year.
1.171 + * @internal
1.172 + */
1.173 + DHU_AL_QIDAH = 10,
1.174 +
1.175 + /**
1.176 + * Constant for Dhu al-Hijjah, the 12th month of the Islamic year.
1.177 + * @internal
1.178 + */
1.179 + DHU_AL_HIJJAH = 11,
1.180 +
1.181 + ISLAMIC_MONTH_MAX
1.182 + };
1.183 +
1.184 +
1.185 + //-------------------------------------------------------------------------
1.186 + // Constructors...
1.187 + //-------------------------------------------------------------------------
1.188 +
1.189 + /**
1.190 + * Constructs an IslamicCalendar based on the current time in the default time zone
1.191 + * with the given locale.
1.192 + *
1.193 + * @param aLocale The given locale.
1.194 + * @param success Indicates the status of IslamicCalendar object construction.
1.195 + * Returns U_ZERO_ERROR if constructed successfully.
1.196 + * @param type The Islamic calendar calculation type. The default value is CIVIL.
1.197 + * @internal
1.198 + */
1.199 + IslamicCalendar(const Locale& aLocale, UErrorCode &success, ECalculationType type = CIVIL);
1.200 +
1.201 + /**
1.202 + * Copy Constructor
1.203 + * @internal
1.204 + */
1.205 + IslamicCalendar(const IslamicCalendar& other);
1.206 +
1.207 + /**
1.208 + * Destructor.
1.209 + * @internal
1.210 + */
1.211 + virtual ~IslamicCalendar();
1.212 +
1.213 + /**
1.214 + * Sets Islamic calendar calculation type used by this instance.
1.215 + *
1.216 + * @param type The calendar calculation type, <code>CIVIL</code> to use the civil
1.217 + * calendar, <code>ASTRONOMICAL</code> to use the astronomical calendar.
1.218 + * @internal
1.219 + */
1.220 + void setCalculationType(ECalculationType type, UErrorCode &status);
1.221 +
1.222 + /**
1.223 + * Returns <code>true</code> if this object is using the fixed-cycle civil
1.224 + * calendar, or <code>false</code> if using the religious, astronomical
1.225 + * calendar.
1.226 + * @internal
1.227 + */
1.228 + UBool isCivil();
1.229 +
1.230 +
1.231 + // TODO: copy c'tor, etc
1.232 +
1.233 + // clone
1.234 + virtual Calendar* clone() const;
1.235 +
1.236 + private:
1.237 + /**
1.238 + * Determine whether a year is a leap year in the Islamic civil calendar
1.239 + */
1.240 + static UBool civilLeapYear(int32_t year);
1.241 +
1.242 + /**
1.243 + * Return the day # on which the given year starts. Days are counted
1.244 + * from the Hijri epoch, origin 0.
1.245 + */
1.246 + int32_t yearStart(int32_t year) const;
1.247 +
1.248 + /**
1.249 + * Return the day # on which the given month starts. Days are counted
1.250 + * from the Hijri epoch, origin 0.
1.251 + *
1.252 + * @param year The hijri year
1.253 + * @param year The hijri month, 0-based
1.254 + */
1.255 + int32_t monthStart(int32_t year, int32_t month) const;
1.256 +
1.257 + /**
1.258 + * Find the day number on which a particular month of the true/lunar
1.259 + * Islamic calendar starts.
1.260 + *
1.261 + * @param month The month in question, origin 0 from the Hijri epoch
1.262 + *
1.263 + * @return The day number on which the given month starts.
1.264 + */
1.265 + int32_t trueMonthStart(int32_t month) const;
1.266 +
1.267 + /**
1.268 + * Return the "age" of the moon at the given time; this is the difference
1.269 + * in ecliptic latitude between the moon and the sun. This method simply
1.270 + * calls CalendarAstronomer.moonAge, converts to degrees,
1.271 + * and adjusts the resultto be in the range [-180, 180].
1.272 + *
1.273 + * @param time The time at which the moon's age is desired,
1.274 + * in millis since 1/1/1970.
1.275 + */
1.276 + static double moonAge(UDate time, UErrorCode &status);
1.277 +
1.278 + //-------------------------------------------------------------------------
1.279 + // Internal data....
1.280 + //
1.281 +
1.282 + /**
1.283 + * <code>CIVIL</code> if this object uses the fixed-cycle Islamic civil calendar,
1.284 + * and <code>ASTRONOMICAL</code> if it approximates the true religious calendar using
1.285 + * astronomical calculations for the time of the new moon.
1.286 + */
1.287 + ECalculationType cType;
1.288 +
1.289 + //----------------------------------------------------------------------
1.290 + // Calendar framework
1.291 + //----------------------------------------------------------------------
1.292 + protected:
1.293 + /**
1.294 + * @internal
1.295 + */
1.296 + virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const;
1.297 +
1.298 + /**
1.299 + * Return the length (in days) of the given month.
1.300 + *
1.301 + * @param year The hijri year
1.302 + * @param year The hijri month, 0-based
1.303 + * @internal
1.304 + */
1.305 + virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const;
1.306 +
1.307 + /**
1.308 + * Return the number of days in the given Islamic year
1.309 + * @internal
1.310 + */
1.311 + virtual int32_t handleGetYearLength(int32_t extendedYear) const;
1.312 +
1.313 + //-------------------------------------------------------------------------
1.314 + // Functions for converting from field values to milliseconds....
1.315 + //-------------------------------------------------------------------------
1.316 +
1.317 + // Return JD of start of given month/year
1.318 + /**
1.319 + * @internal
1.320 + */
1.321 + virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const;
1.322 +
1.323 + //-------------------------------------------------------------------------
1.324 + // Functions for converting from milliseconds to field values
1.325 + //-------------------------------------------------------------------------
1.326 +
1.327 + /**
1.328 + * @internal
1.329 + */
1.330 + virtual int32_t handleGetExtendedYear();
1.331 +
1.332 + /**
1.333 + * Override Calendar to compute several fields specific to the Islamic
1.334 + * calendar system. These are:
1.335 + *
1.336 + * <ul><li>ERA
1.337 + * <li>YEAR
1.338 + * <li>MONTH
1.339 + * <li>DAY_OF_MONTH
1.340 + * <li>DAY_OF_YEAR
1.341 + * <li>EXTENDED_YEAR</ul>
1.342 + *
1.343 + * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
1.344 + * method is called. The getGregorianXxx() methods return Gregorian
1.345 + * calendar equivalents for the given Julian day.
1.346 + * @internal
1.347 + */
1.348 + virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
1.349 +
1.350 + // UObject stuff
1.351 + public:
1.352 + /**
1.353 + * @return The class ID for this object. All objects of a given class have the
1.354 + * same class ID. Objects of other classes have different class IDs.
1.355 + * @internal
1.356 + */
1.357 + virtual UClassID getDynamicClassID(void) const;
1.358 +
1.359 + /**
1.360 + * Return the class ID for this class. This is useful only for comparing to a return
1.361 + * value from getDynamicClassID(). For example:
1.362 + *
1.363 + * Base* polymorphic_pointer = createPolymorphicObject();
1.364 + * if (polymorphic_pointer->getDynamicClassID() ==
1.365 + * Derived::getStaticClassID()) ...
1.366 + *
1.367 + * @return The class ID for all objects of this class.
1.368 + * @internal
1.369 + */
1.370 + /*U_I18N_API*/ static UClassID U_EXPORT2 getStaticClassID(void);
1.371 +
1.372 + /**
1.373 + * return the calendar type, "buddhist".
1.374 + *
1.375 + * @return calendar type
1.376 + * @internal
1.377 + */
1.378 + virtual const char * getType() const;
1.379 +
1.380 + private:
1.381 + IslamicCalendar(); // default constructor not implemented
1.382 +
1.383 + // Default century.
1.384 + protected:
1.385 +
1.386 + /**
1.387 + * (Overrides Calendar) Return true if the current date for this Calendar is in
1.388 + * Daylight Savings Time. Recognizes DST_OFFSET, if it is set.
1.389 + *
1.390 + * @param status Fill-in parameter which receives the status of this operation.
1.391 + * @return True if the current date for this Calendar is in Daylight Savings Time,
1.392 + * false, otherwise.
1.393 + * @internal
1.394 + */
1.395 + virtual UBool inDaylightTime(UErrorCode& status) const;
1.396 +
1.397 +
1.398 + /**
1.399 + * Returns TRUE because the Islamic Calendar does have a default century
1.400 + * @internal
1.401 + */
1.402 + virtual UBool haveDefaultCentury() const;
1.403 +
1.404 + /**
1.405 + * Returns the date of the start of the default century
1.406 + * @return start of century - in milliseconds since epoch, 1970
1.407 + * @internal
1.408 + */
1.409 + virtual UDate defaultCenturyStart() const;
1.410 +
1.411 + /**
1.412 + * Returns the year in which the default century begins
1.413 + * @internal
1.414 + */
1.415 + virtual int32_t defaultCenturyStartYear() const;
1.416 +
1.417 + private:
1.418 + /**
1.419 + * Initializes the 100-year window that dates with 2-digit years
1.420 + * are considered to fall within so that its start date is 80 years
1.421 + * before the current time.
1.422 + */
1.423 + static void initializeSystemDefaultCentury(void);
1.424 +};
1.425 +
1.426 +U_NAMESPACE_END
1.427 +
1.428 +#endif
1.429 +#endif
1.430 +
1.431 +
1.432 +
