scuffed-code/icu4c/source/i18n/unicode/simpletz.h
2001-09-28 19:13:03 +00:00

616 lines
28 KiB
C++

/*
* Copyright (C) {1997-1999}, International Business Machines Corporation and others. All Rights Reserved.
* *
********************************************************************************
*
* File SIMPLETZ.H
*
* Modification History:
*
* Date Name Description
* 04/21/97 aliu Overhauled header.
* 08/10/98 stephen JDK 1.2 sync
* Added setStartRule() / setEndRule() overloads
* Added hasSameRules()
* 09/02/98 stephen Added getOffset(monthLen)
* Changed getOffset() to take UErrorCode
* 07/09/99 stephen Removed millisPerHour (unused, for HP compiler)
* 12/02/99 aliu Added TimeMode and constructor and setStart/EndRule
* methods that take TimeMode. Added to docs.
********************************************************************************
*/
#ifndef SIMPLETZ_H
#define SIMPLETZ_H
#include "unicode/timezone.h"
struct StandardZone;
struct DSTZone;
class TimeZone;
/**
* <code>SimpleTimeZone</code> is a concrete subclass of <code>TimeZone</code>
* that represents a time zone for use with a Gregorian calendar. This
* class does not handle historical changes.
* <P>
* When specifying daylight-savings-time begin and end dates, use a negative value for
* <code>dayOfWeekInMonth</code> to indicate that <code>SimpleTimeZone</code> should
* count from the end of the month backwards. For example, in the U.S., Daylight Savings
* Time ends at the last (dayOfWeekInMonth = -1) Sunday in October, at 2 AM in standard
* time.
*
* @see Calendar
* @see GregorianCalendar
* @see TimeZone
* @author David Goldsmith, Mark Davis, Chen-Lieh Huang, Alan Liu
*/
class U_I18N_API SimpleTimeZone: public TimeZone {
public:
/**
* TimeMode is used, together with a millisecond offset after
* midnight, to specify a rule transition time. Most rules
* transition at a local wall time, that is, according to the
* current time in effect, either standard, or DST. However, some
* rules transition at local standard time, and some at a specific
* UTC time. Although it might seem that all times could be
* converted to wall time, thus eliminating the need for this
* parameter, this is not the case.
*/
enum TimeMode {
WALL_TIME = 0,
STANDARD_TIME,
UTC_TIME
};
/**
* Copy constructor
* @stable
*/
SimpleTimeZone(const SimpleTimeZone& source);
/**
* Default assignment operator
* @stable
*/
SimpleTimeZone& operator=(const SimpleTimeZone& right);
/**
* Destructor
* @stable
*/
virtual ~SimpleTimeZone();
/**
* Returns true if the two TimeZone objects are equal; that is, they have
* the same ID, raw GMT offset, and DST rules.
*
* @param that The SimpleTimeZone object to be compared with.
* @return True if the given time zone is equal to this time zone; false
* otherwise.
* @stable
*/
virtual UBool operator==(const TimeZone& that) const;
/**
* Constructs a SimpleTimeZone with the given raw GMT offset and time zone ID,
* and which doesn't observe daylight savings time. Normally you should use
* TimeZone::createInstance() to create a TimeZone instead of creating a
* SimpleTimeZone directly with this constructor.
*
* @param rawOffsetGMT The given base time zone offset to GMT.
* @param ID The timezone ID which is obtained from
* TimeZone.getAvailableIDs.
* @stable
*/
SimpleTimeZone(int32_t rawOffsetGMT, const UnicodeString& ID);
/**
* Construct a SimpleTimeZone with the given raw GMT offset, time zone ID,
* and times to start and end daylight savings time. To create a TimeZone that
* doesn't observe daylight savings time, don't use this constructor; use
* SimpleTimeZone(rawOffset, ID) instead. Normally, you should use
* TimeZone.createInstance() to create a TimeZone instead of creating a
* SimpleTimeZone directly with this constructor.
* <P>
* Various types of daylight-savings time rules can be specfied by using different
* values for startDay and startDayOfWeek and endDay and endDayOfWeek. For a
* complete explanation of how these parameters work, see the documentation for
* setStartRule().
*
* @param rawOffsetGMT The new SimpleTimeZone's raw GMT offset
* @param ID The new SimpleTimeZone's time zone ID.
* @param savingsStartMonth The daylight savings starting month. Month is
* 0-based. eg, 0 for January.
* @param savingsStartDay The daylight savings starting
* day-of-week-in-month. See setStartRule() for a
* complete explanation.
* @param savingsStartDayOfWeek The daylight savings starting day-of-week.
* See setStartRule() for a complete explanation.
* @param savingsStartTime The daylight savings starting time, expressed as the
* number of milliseconds after midnight.
* @param savingsStartTimeMode Whether the start time is local wall time, local
* standard time, or UTC time. Default is local wall time.
* @param savingsEndMonth The daylight savings ending month. Month is
* 0-based. eg, 0 for January.
* @param savingsEndDay The daylight savings ending day-of-week-in-month.
* See setStartRule() for a complete explanation.
* @param savingsEndDayOfWeek The daylight savings ending day-of-week.
* See setStartRule() for a complete explanation.
* @param savingsEndTime The daylight savings ending time, expressed as the
* number of milliseconds after midnight.
* @param savingsEndTimeMode Whether the end time is local wall time, local
* standard time, or UTC time. Default is local wall time.
* @param savingsDST The number of milliseconds added to standard time
* to get DST time. Default is one hour.
* @param status An UErrorCode to receive the status.
* @stable
*/
SimpleTimeZone(int32_t rawOffsetGMT, const UnicodeString& ID,
int8_t savingsStartMonth, int8_t savingsStartDayOfWeekInMonth,
int8_t savingsStartDayOfWeek, int32_t savingsStartTime,
int8_t savingsEndMonth, int8_t savingsEndDayOfWeekInMonth,
int8_t savingsEndDayOfWeek, int32_t savingsEndTime,
UErrorCode& status);
SimpleTimeZone(int32_t rawOffsetGMT, const UnicodeString& ID,
int8_t savingsStartMonth, int8_t savingsStartDayOfWeekInMonth,
int8_t savingsStartDayOfWeek, int32_t savingsStartTime,
int8_t savingsEndMonth, int8_t savingsEndDayOfWeekInMonth,
int8_t savingsEndDayOfWeek, int32_t savingsEndTime,
int32_t savingsDST, UErrorCode& status);
SimpleTimeZone(int32_t rawOffsetGMT, const UnicodeString& ID,
int8_t savingsStartMonth, int8_t savingsStartDayOfWeekInMonth,
int8_t savingsStartDayOfWeek, int32_t savingsStartTime,
TimeMode savingsStartTimeMode,
int8_t savingsEndMonth, int8_t savingsEndDayOfWeekInMonth,
int8_t savingsEndDayOfWeek, int32_t savingsEndTime, TimeMode savingsEndTimeMode,
int32_t savingsDST, UErrorCode& status);
/**
* Sets the daylight savings starting year, that is, the year this time zone began
* observing its specified daylight savings time rules. The time zone is considered
* not to observe daylight savings time prior to that year; SimpleTimeZone doesn't
* support historical daylight-savings-time rules.
* @param year the daylight savings starting year.
* @stable
*/
void setStartYear(int32_t year);
/**
* Sets the daylight savings starting rule. For example, in the U.S., Daylight Savings
* Time starts at the first Sunday in April, at 2 AM in standard time.
* Therefore, you can set the start rule by calling:
* setStartRule(TimeFields.APRIL, 1, TimeFields.SUNDAY, 2*60*60*1000);
* The dayOfWeekInMonth and dayOfWeek parameters together specify how to calculate
* the exact starting date. Their exact meaning depend on their respective signs,
* allowing various types of rules to be constructed, as follows:<ul>
* <li>If both dayOfWeekInMonth and dayOfWeek are positive, they specify the
* day of week in the month (e.g., (2, WEDNESDAY) is the second Wednesday
* of the month).
* <li>If dayOfWeek is positive and dayOfWeekInMonth is negative, they specify
* the day of week in the month counting backward from the end of the month.
* (e.g., (-1, MONDAY) is the last Monday in the month)
* <li>If dayOfWeek is zero and dayOfWeekInMonth is positive, dayOfWeekInMonth
* specifies the day of the month, regardless of what day of the week it is.
* (e.g., (10, 0) is the tenth day of the month)
* <li>If dayOfWeek is zero and dayOfWeekInMonth is negative, dayOfWeekInMonth
* specifies the day of the month counting backward from the end of the
* month, regardless of what day of the week it is (e.g., (-2, 0) is the
* next-to-last day of the month).
* <li>If dayOfWeek is negative and dayOfWeekInMonth is positive, they specify the
* first specified day of the week on or after the specfied day of the month.
* (e.g., (15, -SUNDAY) is the first Sunday after the 15th of the month
* [or the 15th itself if the 15th is a Sunday].)
* <li>If dayOfWeek and DayOfWeekInMonth are both negative, they specify the
* last specified day of the week on or before the specified day of the month.
* (e.g., (-20, -TUESDAY) is the last Tuesday before the 20th of the month
* [or the 20th itself if the 20th is a Tuesday].)</ul>
* @param month the daylight savings starting month. Month is 0-based.
* eg, 0 for January.
* @param dayOfWeekInMonth the daylight savings starting
* day-of-week-in-month. Please see the member description for an example.
* @param dayOfWeek the daylight savings starting day-of-week. Please see
* the member description for an example.
* @param time the daylight savings starting time. Please see the member
* description for an example.
* @param mode whether the time is local wall time, local standard time,
* or UTC time. Default is local wall time.
* @param status An UErrorCode
* @stable
*/
void setStartRule(int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek,
int32_t time, UErrorCode& status);
void setStartRule(int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek,
int32_t time, TimeMode mode, UErrorCode& status);
/**
* Sets the DST start rule to a fixed date within a month.
*
* @param month The month in which this rule occurs (0-based).
* @param dayOfMonth The date in that month (1-based).
* @param time The time of that day (number of millis after midnight)
* when DST takes effect in local wall time, which is
* standard time in this case.
* @param mode whether the time is local wall time, local standard time,
* or UTC time. Default is local wall time.
* @param status An UErrorCode
* @stable
*/
void setStartRule(int32_t month, int32_t dayOfMonth, int32_t time,
UErrorCode& status);
void setStartRule(int32_t month, int32_t dayOfMonth, int32_t time,
TimeMode mode, UErrorCode& status);
/**
* Sets the DST start rule to a weekday before or after a give date within
* a month, e.g., the first Monday on or after the 8th.
*
* @param month The month in which this rule occurs (0-based).
* @param dayOfMonth A date within that month (1-based).
* @param dayOfWeek The day of the week on which this rule occurs.
* @param time The time of that day (number of millis after midnight)
* when DST takes effect in local wall time, which is
* standard time in this case.
* @param mode whether the time is local wall time, local standard time,
* or UTC time. Default is local wall time.
* @param after If true, this rule selects the first dayOfWeek on
* or after dayOfMonth. If false, this rule selects
* the last dayOfWeek on or before dayOfMonth.
* @param status An UErrorCode
* @stable
*/
void setStartRule(int32_t month, int32_t dayOfMonth, int32_t dayOfWeek,
int32_t time, UBool after, UErrorCode& status);
void setStartRule(int32_t month, int32_t dayOfMonth, int32_t dayOfWeek,
int32_t time, TimeMode mode, UBool after, UErrorCode& status);
/**
* Sets the daylight savings ending rule. For example, in the U.S., Daylight
* Savings Time ends at the last (-1) Sunday in October, at 2 AM in standard time.
* Therefore, you can set the end rule by calling:
* <pre>
* . setEndRule(TimeFields.OCTOBER, -1, TimeFields.SUNDAY, 2*60*60*1000);
* </pre>
* Various other types of rules can be specified by manipulating the dayOfWeek
* and dayOfWeekInMonth parameters. For complete details, see the documentation
* for setStartRule().
*
* @param month the daylight savings ending month. Month is 0-based.
* eg, 0 for January.
* @param dayOfWeekInMonth the daylight savings ending
* day-of-week-in-month. See setStartRule() for a complete explanation.
* @param dayOfWeek the daylight savings ending day-of-week. See setStartRule()
* for a complete explanation.
* @param time the daylight savings ending time. Please see the member
* description for an example.
* @param mode whether the time is local wall time, local standard time,
* or UTC time. Default is local wall time.
* @param status An UErrorCode
* @stable
*/
void setEndRule(int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek,
int32_t time, UErrorCode& status);
void setEndRule(int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek,
int32_t time, TimeMode mode, UErrorCode& status);
/**
* Sets the DST end rule to a fixed date within a month.
*
* @param month The month in which this rule occurs (0-based).
* @param dayOfMonth The date in that month (1-based).
* @param time The time of that day (number of millis after midnight)
* when DST ends in local wall time, which is daylight
* time in this case.
* @param mode whether the time is local wall time, local standard time,
* or UTC time. Default is local wall time.
* @param status An UErrorCode
* @stable
*/
void setEndRule(int32_t month, int32_t dayOfMonth, int32_t time, UErrorCode& status);
void setEndRule(int32_t month, int32_t dayOfMonth, int32_t time,
TimeMode mode, UErrorCode& status);
/**
* Sets the DST end rule to a weekday before or after a give date within
* a month, e.g., the first Monday on or after the 8th.
*
* @param month The month in which this rule occurs (0-based).
* @param dayOfMonth A date within that month (1-based).
* @param dayOfWeek The day of the week on which this rule occurs.
* @param time The time of that day (number of millis after midnight)
* when DST ends in local wall time, which is daylight
* time in this case.
* @param mode whether the time is local wall time, local standard time,
* or UTC time. Default is local wall time.
* @param after If true, this rule selects the first dayOfWeek on
* or after dayOfMonth. If false, this rule selects
* the last dayOfWeek on or before dayOfMonth.
* @param status An UErrorCode
* @stable
*/
void setEndRule(int32_t month, int32_t dayOfMonth, int32_t dayOfWeek,
int32_t time, UBool after, UErrorCode& status);
void setEndRule(int32_t month, int32_t dayOfMonth, int32_t dayOfWeek,
int32_t time, TimeMode mode, UBool after, UErrorCode& status);
/**
* Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add
* to GMT to get local time in this time zone, taking daylight savings time into
* account) as of a particular reference date. The reference date is used to determine
* whether daylight savings time is in effect and needs to be figured into the offset
* that is returned (in other words, what is the adjusted GMT offset in this time zone
* at this particular date and time?). For the time zones produced by createTimeZone(),
* the reference data is specified according to the Gregorian calendar, and the date
* and time fields are in GMT, NOT local time.
*
* @param era The reference date's era
* @param year The reference date's year
* @param month The reference date's month (0-based; 0 is January)
* @param day The reference date's day-in-month (1-based)
* @param dayOfWeek The reference date's day-of-week (1-based; 1 is Sunday)
* @param millis The reference date's milliseconds in day, UTT (NOT local time).
* @return The offset in milliseconds to add to GMT to get local time.
* @stable
*/
virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const;
virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
uint8_t dayOfWeek, int32_t millis) const;
/**
* Gets the time zone offset, for current date, modified in case of
* daylight savings. This is the offset to add *to* UTC to get local time.
* @param era the era of the given date.
* @param year the year in the given date.
* @param month the month in the given date.
* Month is 0-based. e.g., 0 for January.
* @param day the day-in-month of the given date.
* @param dayOfWeek the day-of-week of the given date.
* @param milliseconds the millis in day in <em>standard</em> local time.
* @param monthLength the length of the given month in days.
* @param prevMonthLength length of the previous month in days.
* @return the offset to add *to* GMT to get local time.
* @stable
*/
virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
uint8_t dayOfWeek, int32_t milliseconds,
int32_t monthLength, UErrorCode& status) const;
virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
uint8_t dayOfWeek, int32_t milliseconds,
int32_t monthLength, int32_t prevMonthLength,
UErrorCode& status) const;
/**
* Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add
* to GMT to get local time, before taking daylight savings time into account).
*
* @return The TimeZone's raw GMT offset.
* @stable
*/
virtual int32_t getRawOffset(void) const;
/**
* Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add
* to GMT to get local time, before taking daylight savings time into account).
*
* @param offsetMillis The new raw GMT offset for this time zone.
* @stable
*/
virtual void setRawOffset(int32_t offsetMillis);
/**
* Sets the amount of time in ms that the clock is advanced during DST.
* @param millisSavedDuringDST the number of milliseconds the time is
* advanced with respect to standard time when the daylight savings rules
* are in effect. A positive number, typically one hour (3600000).
* @stable
*/
void setDSTSavings(int32_t millisSavedDuringDST, UErrorCode& status);
/**
* @deprecated This will be removed after 2000-Dec-31. Use the other setDSTSavings().
*/
void setDSTSavings(int32_t millisSavedDuringDST);
/**
* Returns the amount of time in ms that the clock is advanced during DST.
* @return the number of milliseconds the time is
* advanced with respect to standard time when the daylight savings rules
* are in effect. A positive number, typically one hour (3600000).
*/
int32_t getDSTSavings(void) const;
/**
* Queries if this TimeZone uses Daylight Savings Time.
*
* @return True if this TimeZone uses Daylight Savings Time; false otherwise.
* @stable
*/
virtual UBool useDaylightTime(void) const;
/**
* Returns true if the given date is within the period when daylight savings time
* is in effect; false otherwise. If the TimeZone doesn't observe daylight savings
* time, this functions always returns false.
* @param date The date to test.
* @return true if the given date is in Daylight Savings Time;
* false otherwise.
* @stable
*/
virtual UBool inDaylightTime(UDate date, UErrorCode& status) const;
/**
* Return true if this zone has the same rules and offset as another zone.
* @param other the TimeZone object to be compared with
* @return true if the given zone has the same rules and offset as this one
* @stable
*/
UBool hasSameRules(const TimeZone& other) const;
/**
* Clones TimeZone objects polymorphically. Clients are responsible for deleting
* the TimeZone object cloned.
*
* @return A new copy of this TimeZone object.
* @stable
*/
virtual TimeZone* clone(void) const;
public:
/**
* Override TimeZone 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.
* @stable
*/
virtual UClassID getDynamicClassID(void) const { return (UClassID)&fgClassID; }
/**
* Return the class ID for this class. This is useful only for comparing to a return
* value from getDynamicClassID(). For example:
* <pre>
* . Base* polymorphic_pointer = createPolymorphicObject();
* . if (polymorphic_pointer->getDynamicClassID() ==
* . Derived::getStaticClassID()) ...
* </pre>
* @return The class ID for all objects of this class.
* @stable
*/
static UClassID getStaticClassID(void) { return (UClassID)&fgClassID; }
private:
/**
* Constants specifying values of startMode and endMode.
*/
enum EMode
{
DOM_MODE = 1,
DOW_IN_MONTH_MODE,
DOW_GE_DOM_MODE,
DOW_LE_DOM_MODE
};
friend class TimeZone; // for access to these 2 constructors:
/**
* Construct from memory-mapped data.
*/
SimpleTimeZone(const StandardZone& stdZone, const UnicodeString& id);
SimpleTimeZone(const DSTZone& dstZone, const UnicodeString& id);
/**
* Internal construction method.
*/
void construct(int32_t rawOffsetGMT,
int8_t startMonth, int8_t startDay, int8_t startDayOfWeek,
int32_t startTime, TimeMode startTimeMode,
int8_t endMonth, int8_t endDay, int8_t endDayOfWeek,
int32_t endTime, TimeMode endTimeMode,
int32_t dstSavings, UErrorCode& status);
/**
* Compare a given date in the year to a rule. Return 1, 0, or -1, depending
* on whether the date is after, equal to, or before the rule date. The
* millis are compared directly against the ruleMillis, so any
* standard-daylight adjustments must be handled by the caller.
*
* @return 1 if the date is after the rule date, -1 if the date is before
* the rule date, or 0 if the date is equal to the rule date.
*/
static int32_t compareToRule(int8_t month, int8_t monthLen, int8_t prevMonthLen,
int8_t dayOfMonth,
int8_t dayOfWeek, int32_t millis, int32_t millisDelta,
EMode ruleMode, int8_t ruleMonth, int8_t ruleDayOfWeek,
int8_t ruleDay, int32_t ruleMillis);
/**
* Given a set of encoded rules in startDay and startDayOfMonth, decode
* them and set the startMode appropriately. Do the same for endDay and
* endDayOfMonth.
* <P>
* Upon entry, the day of week variables may be zero or
* negative, in order to indicate special modes. The day of month
* variables may also be negative.
* <P>
* Upon exit, the mode variables will be
* set, and the day of week and day of month variables will be positive.
* <P>
* This method also recognizes a startDay or endDay of zero as indicating
* no DST.
*/
void decodeRules(UErrorCode& status);
void decodeStartRule(UErrorCode& status);
void decodeEndRule(UErrorCode& status);
static const char fgClassID;
int8_t startMonth, startDay, startDayOfWeek; // the month, day, DOW, and time DST starts
int32_t startTime;
TimeMode startTimeMode, endTimeMode; // Mode for startTime, endTime; see TimeMode
int8_t endMonth, endDay, endDayOfWeek; // the month, day, DOW, and time DST ends
int32_t endTime;
int32_t startYear; // the year these DST rules took effect
int32_t rawOffset; // the TimeZone's raw GMT offset
UBool useDaylight; // flag indicating whether this TimeZone uses DST
static const int8_t staticMonthLength[12]; // lengths of the months
EMode startMode, endMode; // flags indicating what kind of rules the DST rules are
/**
* A positive value indicating the amount of time saved during DST in ms.
* Typically one hour; sometimes 30 minutes.
*/
int32_t dstSavings;
};
inline void SimpleTimeZone::setStartRule(int32_t month, int32_t dayOfWeekInMonth,
int32_t dayOfWeek,
int32_t time, UErrorCode& status) {
setStartRule(month, dayOfWeekInMonth, dayOfWeek, time, WALL_TIME, status);
}
inline void SimpleTimeZone::setStartRule(int32_t month, int32_t dayOfMonth,
int32_t time,
UErrorCode& status) {
setStartRule(month, dayOfMonth, time, WALL_TIME, status);
}
inline void SimpleTimeZone::setStartRule(int32_t month, int32_t dayOfMonth,
int32_t dayOfWeek,
int32_t time, UBool after, UErrorCode& status) {
setStartRule(month, dayOfMonth, dayOfWeek, time, WALL_TIME, after, status);
}
inline void SimpleTimeZone::setEndRule(int32_t month, int32_t dayOfWeekInMonth,
int32_t dayOfWeek,
int32_t time, UErrorCode& status) {
setEndRule(month, dayOfWeekInMonth, dayOfWeek, time, WALL_TIME, status);
}
inline void SimpleTimeZone::setEndRule(int32_t month, int32_t dayOfMonth,
int32_t time, UErrorCode& status) {
setEndRule(month, dayOfMonth, time, WALL_TIME, status);
}
inline void SimpleTimeZone::setEndRule(int32_t month, int32_t dayOfMonth, int32_t dayOfWeek,
int32_t time, UBool after, UErrorCode& status) {
setEndRule(month, dayOfMonth, dayOfWeek, time, WALL_TIME, after, status);
}
#endif // _SIMPLETZ