Check in the pristine copy of ICU 4.6...

icu46/source/i18n/hebrwcal.h

+/*
+******************************************************************************
+* Copyright (C) 2003-2009, International Business Machines Corporation
+* and others. All Rights Reserved.
+******************************************************************************
+*
+* File HEBRWCAL.H
+*
+* Modification History:
+*
+*   Date        Name        Description
+*   05/13/2003  srl          copied from gregocal.h
+*   11/26/2003  srl          copied from buddhcal.h
+******************************************************************************
+*/
+
+#ifndef HEBRWCAL_H
+#define HEBRWCAL_H
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/calendar.h"
+#include "unicode/gregocal.h"
+
+U_NAMESPACE_BEGIN
+
+/**
+ * <code>HebrewCalendar</code> is a subclass of <code>Calendar</code>
+ * that that implements the traditional Hebrew calendar.
+ * This is the civil calendar in Israel and the liturgical calendar
+ * of the Jewish faith worldwide.
+ * <p>
+ * The Hebrew calendar is lunisolar and thus has a number of interesting
+ * properties that distinguish it from the Gregorian.  Months start
+ * on the day of (an arithmetic approximation of) each new moon.  Since the
+ * solar year (approximately 365.24 days) is not an even multiple of
+ * the lunar month (approximately 29.53 days) an extra "leap month" is
+ * inserted in 7 out of every 19 years.  To make matters even more
+ * interesting, the start of a year can be delayed by up to three days
+ * in order to prevent certain holidays from falling on the Sabbath and
+ * to prevent certain illegal year lengths.  Finally, the lengths of certain
+ * months can vary depending on the number of days in the year.
+ * <p>
+ * The leap month is known as "Adar 1" and is inserted between the
+ * months of Shevat and Adar in leap years.  Since the leap month does
+ * not come at the end of the year, calculations involving
+ * month numbers are particularly complex.  Users of this class should
+ * make sure to use the {@link #roll roll} and {@link #add add} methods
+ * rather than attempting to perform date arithmetic by manipulating
+ * the fields directly.
+ * <p>
+ * <b>Note:</b> In the traditional Hebrew calendar, days start 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>
+ * If you are interested in more information on the rules behind the Hebrew
+ * calendar, see one of the following references:
+ * <ul>
+ * <li>"<a href="http://www.amazon.com/exec/obidos/ASIN/0521564743">Calendrical Calculations</a>",
+ *      by Nachum Dershowitz & Edward Reingold, Cambridge University Press, 1997, pages 85-91.
+ *
+ * <li>Hebrew Calendar Science and Myths,
+ *      <a href="http://www.geocities.com/Athens/1584/">
+ *      http://www.geocities.com/Athens/1584/</a>
+ *
+ * <li>The Calendar FAQ,
+ *      <a href="http://www.faqs.org/faqs/calendars/faq/">
+ *      http://www.faqs.org/faqs/calendars/faq/</a>
+ * </ul>
+ * <p>
+ * @see com.ibm.icu.util.GregorianCalendar
+ *
+ * @author Laura Werner
+ * @author Alan Liu
+ * @author Steven R. Loomis
+ * <p>
+ * @internal
+ */
+class U_I18N_API HebrewCalendar : public Calendar {
+public:
+  /**
+   * Useful constants for HebrewCalendar.
+   * @internal
+   */
+  enum EEras {
+    /** 
+     * Constant for Tishri, the 1st month of the Hebrew year. 
+     */
+      TISHRI,
+      /**
+     * Constant for Heshvan, the 2nd month of the Hebrew year. 
+     */
+      HESHVAN,
+      /**
+     * Constant for Kislev, the 3rd month of the Hebrew year. 
+     */
+      KISLEV,
+
+    /**
+     * Constant for Tevet, the 4th month of the Hebrew year. 
+     */
+      TEVET,
+
+    /**
+     * Constant for Shevat, the 5th month of the Hebrew year. 
+     */
+      SHEVAT,
+
+    /**
+     * Constant for Adar I, the 6th month of the Hebrew year
+     * (present in leap years only). In non-leap years, the calendar
+     * jumps from Shevat (5th month) to Adar (7th month).
+     */
+      ADAR_1,
+
+    /** 
+     * Constant for the Adar, the 7th month of the Hebrew year. 
+     */
+      ADAR,
+
+    /**
+     * Constant for Nisan, the 8th month of the Hebrew year. 
+     */
+      NISAN,
+
+    /**
+     * Constant for Iyar, the 9th month of the Hebrew year. 
+     */
+      IYAR,
+
+    /**
+     * Constant for Sivan, the 10th month of the Hebrew year. 
+     */
+      SIVAN,
+
+    /**
+     * Constant for Tammuz, the 11th month of the Hebrew year. 
+     */
+      TAMUZ,
+
+    /**
+     * Constant for Av, the 12th month of the Hebrew year. 
+     */
+      AV,
+
+    /**
+     * Constant for Elul, the 13th month of the Hebrew year. 
+     */
+      ELUL
+    };
+
+    /**
+     * Constructs a HebrewCalendar 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 HebrewCalendar object construction.
+     *                 Returns U_ZERO_ERROR if constructed successfully.
+     * @internal
+     */
+    HebrewCalendar(const Locale& aLocale, UErrorCode& success);
+
+
+    /**
+     * Destructor
+     * @internal
+     */
+    virtual ~HebrewCalendar();
+
+    /**
+     * Copy constructor
+     * @param source    the object to be copied.
+     * @internal
+     */
+    HebrewCalendar(const HebrewCalendar& source);
+
+    /**
+     * Default assignment operator
+     * @param right    the object to be copied.
+     * @internal
+     */
+    HebrewCalendar& operator=(const HebrewCalendar& right);
+
+    /**
+     * Create and return a polymorphic copy of this calendar.
+     * @return    return a polymorphic copy of this calendar.
+     * @internal
+     */
+    virtual Calendar* clone(void) const;
+    
+public:
+    /**
+     * Override Calendar Returns a unique class ID POLYMORPHICALLY. Pure virtual
+     * override. This method is to implement a simple version of RTTI, since not all C++
+     * compilers support genuine RTTI. Polymorphic operator==() and clone() methods call
+     * this method.
+     *
+     * @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
+     */
+    static UClassID U_EXPORT2 getStaticClassID(void);
+
+    /**
+     * return the calendar type, "hebrew".
+     *
+     * @return calendar type
+     * @internal
+     */
+    virtual const char * getType() const;
+
+
+    // Calendar API
+ public:
+    /**
+     * (Overrides Calendar) UDate Arithmetic function. Adds the specified (signed) amount
+     * of time to the given time field, based on the calendar's rules.  For more
+     * information, see the documentation for Calendar::add().
+     *
+     * @param field   The time field.
+     * @param amount  The amount of date or time to be added to the field.
+     * @param status  Output param set to success/failure code on exit. If any value
+     *                previously set in the time field is invalid, this will be set to
+     *                an error status.
+     */
+    virtual void add(UCalendarDateFields field, int32_t amount, UErrorCode& status);
+    /**
+     * @deprecated ICU 2.6 use UCalendarDateFields instead of EDateFields
+     */
+    virtual void add(EDateFields field, int32_t amount, UErrorCode& status);
+
+
+    /**
+     * (Overrides Calendar) Rolls up or down by the given amount in the specified field.
+     * For more information, see the documentation for Calendar::roll().
+     *
+     * @param field   The time field.
+     * @param amount  Indicates amount to roll.
+     * @param status  Output param set to success/failure code on exit. If any value
+     *                previously set in the time field is invalid, this will be set to
+     *                an error status.
+     * @internal
+     */
+    virtual void roll(UCalendarDateFields field, int32_t amount, UErrorCode& status);
+
+    /**
+     * (Overrides Calendar) Rolls up or down by the given amount in the specified field.
+     * For more information, see the documentation for Calendar::roll().
+     *
+     * @param field   The time field.
+     * @param amount  Indicates amount to roll.
+     * @param status  Output param set to success/failure code on exit. If any value
+     *                previously set in the time field is invalid, this will be set to
+     *                an error status.
+     * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead.
+`     */
+    virtual void roll(EDateFields field, int32_t amount, UErrorCode& status);
+
+    /**
+     * @internal 
+     */
+    static UBool isLeapYear(int32_t year) ;
+
+ protected:
+
+    /**
+     * Subclass API for defining limits of different types.
+     * Subclasses must implement this method to return limits for the
+     * following fields:
+     *
+     * <pre>UCAL_ERA
+     * UCAL_YEAR
+     * UCAL_MONTH
+     * UCAL_WEEK_OF_YEAR
+     * UCAL_WEEK_OF_MONTH
+     * UCAL_DATE (DAY_OF_MONTH on Java)
+     * UCAL_DAY_OF_YEAR
+     * UCAL_DAY_OF_WEEK_IN_MONTH
+     * UCAL_YEAR_WOY
+     * UCAL_EXTENDED_YEAR</pre>
+     *
+     * @param field one of the above field numbers
+     * @param limitType one of <code>MINIMUM</code>, <code>GREATEST_MINIMUM</code>,
+     * <code>LEAST_MAXIMUM</code>, or <code>MAXIMUM</code>
+     * @internal
+     */
+    virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const;
+
+    /**
+     * Return the number of days in the given month of the given extended
+     * year of this calendar system.  Subclasses should override this
+     * method if they can provide a more correct or more efficient
+     * implementation than the default implementation in Calendar.
+     * @internal
+     */
+    virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const;
+
+    /**
+     * Return the number of days in the given extended year of this
+     * calendar system.  Subclasses should override this method if they can
+     * provide a more correct or more efficient implementation than the
+     * default implementation in Calendar.
+     * @stable ICU 2.0
+     */
+    virtual int32_t handleGetYearLength(int32_t eyear) const;
+    /**
+     * Subclasses may override this method to compute several fields
+     * specific to each calendar system.  These are:
+     *
+     * <ul><li>ERA
+     * <li>YEAR
+     * <li>MONTH
+     * <li>DAY_OF_MONTH
+     * <li>DAY_OF_YEAR
+     * <li>EXTENDED_YEAR</ul>
+     *
+     * <p>The GregorianCalendar implementation implements
+     * a calendar with the specified Julian/Gregorian cutover date.
+     * @internal
+     */
+    virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
+    /**
+     * Return the extended year defined by the current fields.  This will
+     * use the UCAL_EXTENDED_YEAR field or the UCAL_YEAR and supra-year fields (such
+     * as UCAL_ERA) specific to the calendar system, depending on which set of
+     * fields is newer.
+     * @return the extended year
+     * @internal
+     */
+    virtual int32_t handleGetExtendedYear();
+    /**
+     * Return the Julian day number of day before the first day of the
+     * given month in the given extended year.  Subclasses should override
+     * this method to implement their calendar system.
+     * @param eyear the extended year
+     * @param month the zero-based month, or 0 if useMonth is false
+     * @param useMonth if false, compute the day before the first day of
+     * the given year, otherwise, compute the day before the first day of
+     * the given month
+     * @param return the Julian day number of the day before the first
+     * day of the given month and year
+     * @internal
+     */
+    virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month,
+                                                   UBool useMonth) const;
+
+
+
+ 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 Hebrew 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: // default century stuff.
+    /**
+     * The system maintains a static default century start date.  This is initialized
+     * the first time it is used.  Before then, it is set to SYSTEM_DEFAULT_CENTURY to
+     * indicate an uninitialized state.  Once the system default century date and year
+     * are set, they do not change.
+     */
+    static UDate         fgSystemDefaultCenturyStart;
+
+    /**
+     * See documentation for systemDefaultCenturyStart.
+     */
+    static int32_t          fgSystemDefaultCenturyStartYear;
+
+    /**
+     * Default value that indicates the defaultCenturyStartYear is unitialized
+     */
+    static const int32_t    fgSystemDefaultCenturyYear;
+
+    /**
+     * start of default century, as a date
+     */
+    static const UDate        fgSystemDefaultCentury;
+
+    /**
+     * Returns the beginning date of the 100-year window that dates 
+     * with 2-digit years are considered to fall within.
+     */
+    UDate         internalGetDefaultCenturyStart(void) const;
+
+    /**
+     * Returns the first year of the 100-year window that dates with 
+     * 2-digit years are considered to fall within.
+     */
+    int32_t          internalGetDefaultCenturyStartYear(void) const;
+
+    /**
+     * 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);
+
+ private: // Calendar-specific implementation
+    /**
+     * Finds the day # of the first day in the given Hebrew year.
+     * To do this, we want to calculate the time of the Tishri 1 new moon
+     * in that year.
+     * <p>
+     * The algorithm here is similar to ones described in a number of
+     * references, including:
+     * <ul>
+     * <li>"Calendrical Calculations", by Nachum Dershowitz & Edward Reingold,
+     *     Cambridge University Press, 1997, pages 85-91.
+     *
+     * <li>Hebrew Calendar Science and Myths,
+     *     <a href="http://www.geocities.com/Athens/1584/">
+     *     http://www.geocities.com/Athens/1584/</a>
+     *
+     * <li>The Calendar FAQ,
+     *      <a href="http://www.faqs.org/faqs/calendars/faq/">
+     *      http://www.faqs.org/faqs/calendars/faq/</a>
+     * </ul>
+     * @param year extended year
+     * @return day number (JD)
+     * @internal
+     */
+    static int32_t startOfYear(int32_t year, UErrorCode& status);
+
+    static int32_t absoluteDayToDayOfWeek(int32_t day) ;
+    
+    /**
+     * @internal 
+     */
+    int32_t yearType(int32_t year) const;
+
+    /**
+     * @internal 
+     */
+    static int32_t monthsInYear(int32_t year) ;
+};
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_FORMATTING */
+
+#endif 
+//eof
+