The Tor Browser: intl/icu/source/i18n/islamcal.h@6474c204b198 (annotated)

intl/icu/source/i18n/islamcal.h@6474c204b198 (annotated)

intl/icu/source/i18n/islamcal.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  ********************************************************************************
  * Copyright (C) 2003-2013, International Business Machines Corporation
  * and others. All Rights Reserved.
  ******************************************************************************
  *
  * File ISLAMCAL.H
  *
  * Modification History:
  *
  *   Date        Name        Description
  *   10/14/2003  srl         ported from java IslamicCalendar
  *****************************************************************************
  */
 #ifndef ISLAMCAL_H
 #define ISLAMCAL_H
 #include "unicode/utypes.h"
 #if !UCONFIG_NO_FORMATTING
 #include "unicode/calendar.h"
 U_NAMESPACE_BEGIN
 /**
  * <code>IslamicCalendar</code> is a subclass of <code>Calendar</code>
  * that implements the Islamic civil and religious calendars.  It
  * is used as the civil calendar in most of the Arab world and the
  * liturgical calendar of the Islamic faith worldwide.  This calendar
  * is also known as the "Hijri" calendar, since it starts at the time
  * of Mohammed's emigration (or "hijra") to Medinah on Thursday,
  * July 15, 622 AD (Julian).
  * <p>
  * The Islamic calendar is strictly lunar, and thus an Islamic year of twelve
  * lunar months does not correspond to the solar year used by most other
  * calendar systems, including the Gregorian.  An Islamic year is, on average,
  * about 354 days long, so each successive Islamic year starts about 11 days
  * earlier in the corresponding Gregorian year.
  * <p>
  * Each month of the calendar starts when the new moon's crescent is visible
  * at sunset.  However, in order to keep the time fields in this class
  * synchronized with those of the other calendars and with local clock time,
  * we treat days and months as beginning at midnight,
  * roughly 6 hours after the corresponding sunset.
  * <p>
  * There are two main variants of the Islamic calendar in existence.  The first
  * is the <em>civil</em> calendar, which uses a fixed cycle of alternating 29-
  * and 30-day months, with a leap day added to the last month of 11 out of
  * every 30 years.  This calendar is easily calculated and thus predictable in
  * advance, so it is used as the civil calendar in a number of Arab countries.
  * This is the default behavior of a newly-created <code>IslamicCalendar</code>
  * object.
  * <p>
  * The Islamic <em>religious</em> calendar, however, is based on the <em>observation</em>
  * of the crescent moon.  It is thus affected by the position at which the
  * observations are made, seasonal variations in the time of sunset, the
  * eccentricities of the moon's orbit, and even the weather at the observation
  * site.  This makes it impossible to calculate in advance, and it causes the
  * start of a month in the religious calendar to differ from the civil calendar
  * by up to three days.
  * <p>
  * Using astronomical calculations for the position of the sun and moon, the
  * moon's illumination, and other factors, it is possible to determine the start
  * of a lunar month with a fairly high degree of certainty.  However, these
  * calculations are extremely complicated and thus slow, so most algorithms,
  * including the one used here, are only approximations of the true astronical
  * calculations.  At present, the approximations used in this class are fairly
  * simplistic; they will be improved in later versions of the code.
  * <p>
  * The {@link #setCivil setCivil} method determines
  * which approach is used to determine the start of a month.  By default, the
  * fixed-cycle civil calendar is used.  However, if <code>setCivil(false)</code>
  * is called, an approximation of the true lunar calendar will be used.
  *
  * @see GregorianCalendar
  *
  * @author Laura Werner
  * @author Alan Liu
  * @author Steven R. Loomis
  * @internal
  */
 class U_I18N_API IslamicCalendar : public Calendar {
  public:
   //-------------------------------------------------------------------------
   // Constants...
   //-------------------------------------------------------------------------
   /**
    * Calendar type - civil or religious or um alqura
    * @internal
    */
   enum ECalculationType {
     ASTRONOMICAL,
     CIVIL,
     UMALQURA,
     TBLA
   };
   /**
    * Constants for the months
    * @internal
    */
   enum EMonths {
     /**
      * Constant for Muharram, the 1st month of the Islamic year.
      * @internal
      */
     MUHARRAM = 0,
     /**
      * Constant for Safar, the 2nd month of the Islamic year.
      * @internal
      */
     SAFAR = 1,
     /**
      * Constant for Rabi' al-awwal (or Rabi' I), the 3rd month of the Islamic year.
      * @internal
      */
     RABI_1 = 2,
     /**
      * Constant for Rabi' al-thani or (Rabi' II), the 4th month of the Islamic year.
      * @internal
      */
     RABI_2 = 3,
     /**
      * Constant for Jumada al-awwal or (Jumada I), the 5th month of the Islamic year.
      * @internal
      */
     JUMADA_1 = 4,
     /**
      * Constant for Jumada al-thani or (Jumada II), the 6th month of the Islamic year.
      * @internal
      */
     JUMADA_2 = 5,
     /**
      * Constant for Rajab, the 7th month of the Islamic year.
      * @internal
      */
     RAJAB = 6,
     /**
      * Constant for Sha'ban, the 8th month of the Islamic year.
      * @internal
      */
     SHABAN = 7,
     /**
      * Constant for Ramadan, the 9th month of the Islamic year.
      * @internal
      */
     RAMADAN = 8,
     /**
      * Constant for Shawwal, the 10th month of the Islamic year.
      * @internal
      */
     SHAWWAL = 9,
     /**
      * Constant for Dhu al-Qi'dah, the 11th month of the Islamic year.
      * @internal
      */
     DHU_AL_QIDAH = 10,
     /**
      * Constant for Dhu al-Hijjah, the 12th month of the Islamic year.
      * @internal
      */
     DHU_AL_HIJJAH = 11,
     ISLAMIC_MONTH_MAX
   };
   //-------------------------------------------------------------------------
   // Constructors...
   //-------------------------------------------------------------------------
   /**
    * Constructs an IslamicCalendar based on the current time in the default time zone
    * with the given locale.
    *
    * @param aLocale  The given locale.
    * @param success  Indicates the status of IslamicCalendar object construction.
    *                 Returns U_ZERO_ERROR if constructed successfully.
    * @param type     The Islamic calendar calculation type. The default value is CIVIL.
    * @internal
    */
   IslamicCalendar(const Locale& aLocale, UErrorCode &success, ECalculationType type = CIVIL);
   /**
    * Copy Constructor
    * @internal
    */
   IslamicCalendar(const IslamicCalendar& other);
   /**
    * Destructor.
    * @internal
    */
   virtual ~IslamicCalendar();
   /**
    * Sets Islamic calendar calculation type used by this instance.
    *
    * @param type    The calendar calculation type, <code>CIVIL</code> to use the civil
    *                calendar, <code>ASTRONOMICAL</code> to use the astronomical calendar.
    * @internal
    */
   void setCalculationType(ECalculationType type, UErrorCode &status);
   /**
    * Returns <code>true</code> if this object is using the fixed-cycle civil
    * calendar, or <code>false</code> if using the religious, astronomical
    * calendar.
    * @internal
    */
   UBool isCivil();
   // TODO: copy c'tor, etc
   // clone
   virtual Calendar* clone() const;
  private:
   /**
    * Determine whether a year is a leap year in the Islamic civil calendar
    */
   static UBool civilLeapYear(int32_t year);
   /**
    * Return the day # on which the given year starts.  Days are counted
    * from the Hijri epoch, origin 0.
    */
   int32_t yearStart(int32_t year) const;
   /**
    * Return the day # on which the given month starts.  Days are counted
    * from the Hijri epoch, origin 0.
    *
    * @param year  The hijri year
    * @param year  The hijri month, 0-based
    */
   int32_t monthStart(int32_t year, int32_t month) const;
   /**
    * Find the day number on which a particular month of the true/lunar
    * Islamic calendar starts.
    *
    * @param month The month in question, origin 0 from the Hijri epoch
    *
    * @return The day number on which the given month starts.
    */
   int32_t trueMonthStart(int32_t month) const;
   /**
    * Return the "age" of the moon at the given time; this is the difference
    * in ecliptic latitude between the moon and the sun.  This method simply
    * calls CalendarAstronomer.moonAge, converts to degrees,
    * and adjusts the resultto be in the range [-180, 180].
    *
    * @param time  The time at which the moon's age is desired,
    *              in millis since 1/1/1970.
    */
   static double moonAge(UDate time, UErrorCode &status);
   //-------------------------------------------------------------------------
   // Internal data....
   //
   /**
    * <code>CIVIL</code> if this object uses the fixed-cycle Islamic civil calendar,
    * and <code>ASTRONOMICAL</code> if it approximates the true religious calendar using
    * astronomical calculations for the time of the new moon.
    */
   ECalculationType cType;
   //----------------------------------------------------------------------
   // Calendar framework
   //----------------------------------------------------------------------
  protected:
   /**
    * @internal
    */
   virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const;
   /**
    * Return the length (in days) of the given month.
    *
    * @param year  The hijri year
    * @param year  The hijri month, 0-based
    * @internal
    */
   virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const;
   /**
    * Return the number of days in the given Islamic year
    * @internal
    */
   virtual int32_t handleGetYearLength(int32_t extendedYear) const;
   //-------------------------------------------------------------------------
   // Functions for converting from field values to milliseconds....
   //-------------------------------------------------------------------------
   // Return JD of start of given month/year
   /**
    * @internal
    */
   virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const;
   //-------------------------------------------------------------------------
   // Functions for converting from milliseconds to field values
   //-------------------------------------------------------------------------
   /**
    * @internal
    */
   virtual int32_t handleGetExtendedYear();
   /**
    * Override Calendar to compute several fields specific to the Islamic
    * calendar system.  These are:
    *
    * <ul><li>ERA
    * <li>YEAR
    * <li>MONTH
    * <li>DAY_OF_MONTH
    * <li>DAY_OF_YEAR
    * <li>EXTENDED_YEAR</ul>
    *
    * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
    * method is called. The getGregorianXxx() methods return Gregorian
    * calendar equivalents for the given Julian day.
    * @internal
    */
   virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
   // UObject stuff
  public:
   /**
    * @return   The class ID for this object. All objects of a given class have the
    *           same class ID. Objects of other classes have different class IDs.
    * @internal
    */
   virtual UClassID getDynamicClassID(void) const;
   /**
    * Return the class ID for this class. This is useful only for comparing to a return
    * value from getDynamicClassID(). For example:
    *
    *      Base* polymorphic_pointer = createPolymorphicObject();
    *      if (polymorphic_pointer->getDynamicClassID() ==
    *          Derived::getStaticClassID()) ...
    *
    * @return   The class ID for all objects of this class.
    * @internal
    */
   /*U_I18N_API*/ static UClassID U_EXPORT2 getStaticClassID(void);
   /**
    * return the calendar type, "buddhist".
    *
    * @return calendar type
    * @internal
    */
   virtual const char * getType() const;
  private:
   IslamicCalendar(); // default constructor not implemented
   // Default century.
  protected:
   /**
    * (Overrides Calendar) Return true if the current date for this Calendar is in
    * Daylight Savings Time. Recognizes DST_OFFSET, if it is set.
    *
    * @param status Fill-in parameter which receives the status of this operation.
    * @return   True if the current date for this Calendar is in Daylight Savings Time,
    *           false, otherwise.
    * @internal
    */
   virtual UBool inDaylightTime(UErrorCode& status) const;
   /**
    * Returns TRUE because the Islamic Calendar does have a default century
    * @internal
    */
   virtual UBool haveDefaultCentury() const;
   /**
    * Returns the date of the start of the default century
    * @return start of century - in milliseconds since epoch, 1970
    * @internal
    */
   virtual UDate defaultCenturyStart() const;
   /**
    * Returns the year in which the default century begins
    * @internal
    */
   virtual int32_t defaultCenturyStartYear() const;
  private:
   /**
    * Initializes the 100-year window that dates with 2-digit years
    * are considered to fall within so that its start date is 80 years
    * before the current time.
    */
   static void  initializeSystemDefaultCentury(void);
 };
 U_NAMESPACE_END
 #endif
 #endif

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intl/icu/source/i18n/islamcal.h@6474c204b198 (annotated)

intl/icu/source/i18n/islamcal.h