/*
- ******************************************************************************
- * Copyright (C) 1996-2003, International Business Machines Corporation and *
- * others. All Rights Reserved. *
- ******************************************************************************
+ *****************************************************************************
+ * Copyright (C) 2007-2008, International Business Machines Corporation
+ * and others. All Rights Reserved.
+ *****************************************************************************
*
+ * File CHNSECAL.H
*
- **************************************************************************
+ * Modification History:
+ *
+ * Date Name Description
+ * 9/18/2007 ajmacher ported from java ChineseCalendar
+ *****************************************************************************
+ */
+
+#ifndef CHNSECAL_H
+#define CHNSECAL_H
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/calendar.h"
+
+U_NAMESPACE_BEGIN
+
+/**
+ * <code>ChineseCalendar</code> is a concrete subclass of {@link Calendar}
+ * that implements a traditional Chinese calendar. The traditional Chinese
+ * calendar is a lunisolar calendar: Each month starts on a new moon, and
+ * the months are numbered according to solar events, specifically, to
+ * guarantee that month 11 always contains the winter solstice. In order
+ * to accomplish this, leap months are inserted in certain years. Leap
+ * months are numbered the same as the month they follow. The decision of
+ * which month is a leap month depends on the relative movements of the sun
+ * and moon.
+ *
+ * <p>This class defines one addition field beyond those defined by
+ * <code>Calendar</code>: The <code>IS_LEAP_MONTH</code> field takes the
+ * value of 0 for normal months, or 1 for leap months.
+ *
+ * <p>All astronomical computations are performed with respect to a time
+ * zone of GMT+8:00 and a longitude of 120 degrees east. Although some
+ * calendars implement a historically more accurate convention of using
+ * Beijing's local longitude (116 degrees 25 minutes east) and time zone
+ * (GMT+7:45:40) for dates before 1929, we do not implement this here.
+ *
+ * <p>Years are counted in two different ways in the Chinese calendar. The
+ * first method is by sequential numbering from the 61st year of the reign
+ * of Huang Di, 2637 BCE, which is designated year 1 on the Chinese
+ * calendar. The second method uses 60-year cycles from the same starting
+ * point, which is designated year 1 of cycle 1. In this class, the
+ * <code>EXTENDED_YEAR</code> field contains the sequential year count.
+ * The <code>ERA</code> field contains the cycle number, and the
+ * <code>YEAR</code> field contains the year of the cycle, a value between
+ * 1 and 60.
+ *
+ * <p>There is some variation in what is considered the starting point of
+ * the calendar, with some sources starting in the first year of the reign
+ * of Huang Di, rather than the 61st. This gives continuous year numbers
+ * 60 years greater and cycle numbers one greater than what this class
+ * implements.
+ *
+ * <p>Because <code>ChineseCalendar</code> defines an additional field and
+ * redefines the way the <code>ERA</code> field is used, it requires a new
+ * format class, <code>ChineseDateFormat</code>. As always, use the
+ * methods <code>DateFormat.getXxxInstance(Calendar cal,...)</code> to
+ * obtain a formatter for this calendar.
+ *
+ * <p>References:<ul>
+ *
+ * <li>Dershowitz and Reingold, <i>Calendrical Calculations</i>,
+ * Cambridge University Press, 1997</li>
+ *
+ * <li>Helmer Aslaksen's
+ * <a href="http://www.math.nus.edu.sg/aslaksen/calendar/chinese.shtml">
+ * Chinese Calendar page</a></li>
+ *
+ * <li>The <a href="http://www.tondering.dk/claus/calendar.html">
+ * Calendar FAQ</a></li>
+ *
+ * </ul>
+ *
+ * <p>
+ * This class should not be subclassed.</p>
+ * <p>
+ * ChineseCalendar usually should be instantiated using
+ * {@link com.ibm.icu.util.Calendar#getInstance(ULocale)} passing in a <code>ULocale</code>
+ * with the tag <code>"@calendar=chinese"</code>.</p>
+ *
+ * @see com.ibm.icu.text.ChineseDateFormat
+ * @see com.ibm.icu.util.Calendar
+ * @author Alan Liu
+ * @stable ICU 2.8
*/
+class ChineseCalendar : public Calendar {
+ public:
+ //-------------------------------------------------------------------------
+ // Constructors...
+ //-------------------------------------------------------------------------
+
+ /**
+ * Constructs an ChineseCalendar 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 ChineseCalendar object construction.
+ * Returns U_ZERO_ERROR if constructed successfully.
+ * @internal
+ */
+ ChineseCalendar(const Locale& aLocale, UErrorCode &success);
+
+ /**
+ * Copy Constructor
+ * @internal
+ */
+ ChineseCalendar(const ChineseCalendar& other);
+
+ /**
+ * Destructor.
+ * @internal
+ */
+ virtual ~ChineseCalendar();
+
+ // clone
+ virtual Calendar* clone() const;
+
+ private:
+
+ //-------------------------------------------------------------------------
+ // Internal data....
+ //-------------------------------------------------------------------------
+
+ UBool isLeapYear;
+
+ //----------------------------------------------------------------------
+ // Calendar framework
+ //----------------------------------------------------------------------
+
+ protected:
+ virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const;
+ virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const;
+ virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const;
+ virtual int32_t handleGetExtendedYear();
+ virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
+ virtual const UFieldResolutionTable* getFieldResolutionTable() const;
+
+
+
+public:
+ virtual void add(UCalendarDateFields field, int32_t amount, UErrorCode &status);
+ virtual void add(EDateFields field, int32_t amount, UErrorCode &status);
+ virtual void roll(UCalendarDateFields field, int32_t amount, UErrorCode &status);
+ virtual void roll(EDateFields field, int32_t amount, UErrorCode &status);
+
+
+ //----------------------------------------------------------------------
+ // Internal methods & astronomical calculations
+ //----------------------------------------------------------------------
+
+private:
+
+ static const UFieldResolutionTable CHINESE_DATE_PRECEDENCE[];
+
+ static double daysToMillis(double days);
+ static double millisToDays(double millis);
+ virtual int32_t winterSolstice(int32_t gyear) const;
+ virtual int32_t newMoonNear(double days, UBool after) const;
+ virtual int32_t synodicMonthsBetween(int32_t day1, int32_t day2) const;
+ virtual int32_t majorSolarTerm(int32_t days) const;
+ virtual UBool hasNoMajorSolarTerm(int32_t newMoon) const;
+ virtual UBool isLeapMonthBetween(int32_t newMoon1, int32_t newMoon2) const;
+ virtual void computeChineseFields(int32_t days, int32_t gyear,
+ int32_t gmonth, UBool setAllFields);
+ virtual int32_t newYear(int32_t gyear) const;
+ virtual void offsetMonth(int32_t newMoon, int32_t dom, int32_t delta);
+
+
+ // 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, "chinese".
+ *
+ * @return calendar type
+ * @internal
+ */
+ virtual const char * getType() 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 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: // 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);
+
+ ChineseCalendar(); // default constructor not implemented
+};
+
+U_NAMESPACE_END
+
+#endif
+#endif
+
+
-// placeholder
projects / apple / icu.git / blobdiff