SimpleTimeZone is a concrete subclass of TimeZone
* that represents a time zone for use with a Gregorian calendar. This
* class does not handle historical changes.
*
* When specifying daylight-savings-time begin and end dates, use a negative value for
* dayOfWeekInMonth to indicate that SimpleTimeZone 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
* @version 1.24 10/30/97
* @author David Goldsmith, Mark Davis, Chen-Lieh Huang, Alan Liu
*/
#ifdef NLS_MAC
#pragma export on
#endif
class T_FORMAT_API SimpleTimeZone: public TimeZone {
public:
/**
* Need default constructor for some UNIX platforms
*/
SimpleTimeZone(void);
/**
* Copy constructor
*/
SimpleTimeZone(const SimpleTimeZone& source);
/**
* Default assignment operator
*/
SimpleTimeZone& operator=(const SimpleTimeZone& right);
/**
* Destructor
*/
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.
*/
virtual t_bool 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 rawOffset The given base time zone offset to GMT.
* @param ID The timezone ID which is obtained from
* TimeZone.getAvailableIDs.
*/
SimpleTimeZone(t_int32 rawOffset, 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.
*
* 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 rawOffset The new SimpleTimeZone's raw GMT offset * @param ID The new SimpleTimeZone's time zone ID. * @param startMonth The daylight savings starting month. Month is * 0-based. eg, 0 for January. * @param startDay The daylight savings starting * day-of-week-in-month. See setStartRule() for a * complete explanation. * @param startDayOfWeek The daylight savings starting day-of-week. See setStartRule() * for a complete explanation. * @param startTime The daylight savings starting time, expressed as the * number of milliseconds after midnight. * @param endMonth The daylight savings ending month. Month is * 0-based. eg, 0 for January. * @param endDay The daylight savings ending day-of-week-in-month. * See setStartRule() for a complete explanation. * @param endDayOfWeek The daylight savings ending day-of-week. See setStartRule() * for a complete explanation. * @param endTime The daylight savings ending time, expressed as the * number of milliseconds after midnight. * @param dstSavings The number of milliseconds to add to the raw GMT offset * when daylight savings time is in effect. (e.g., in the * U.S. daylight savings time shifts the time forward one * hour.) Defaults to plus one hour. */ SimpleTimeZone(t_int32 rawOffset, const UnicodeString& ID, t_int8 startMonth, t_int8 startDayOfWeekInMonth, t_int8 startDayOfWeek, t_int32 startTime, t_int8 endMonth, t_int8 endDayOfWeekInMonth, t_int8 endDayOfWeek, t_int32 endTime, t_int32 dstSavings = kMillisPerHour); /** * 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. */ void setStartYear(t_int32 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:
* . setEndRule(TimeFields.OCTOBER, -1, TimeFields.SUNDAY, 2*60*60*1000);
*
* 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.
*/
void setEndRule(int month, int dayOfWeekInMonth, int dayOfWeek,
t_int32 time);
/**
* 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. */ virtual t_int32 getOffset(t_uint8 era, t_int32 year, t_int32 month, t_int32 day, t_uint8 dayOfWeek, t_int32 millis) 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. */ virtual t_int32 getRawOffset() 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. */ virtual void setRawOffset(t_int32 offsetMillis); /** * Queries if this TimeZone uses Daylight Savings Time. * * @return True if this TimeZone uses Daylight Savings Time; false otherwise. */ virtual t_bool useDaylightTime() 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. */ virtual t_bool inDaylightTime(Date date, ErrorCode& status) const; /** * Clones TimeZone objects polymorphically. Clients are responsible for deleting * the TimeZone object cloned. * * @return A new copy of this TimeZone object. */ virtual TimeZone* clone() 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. */ virtual ClassID getDynamicClassID() const { return (ClassID)&fgClassID; } /** * 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.
*/
static ClassID getStaticClassID() { return (ClassID)&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
};
/**
* 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. Assume that
* no rule references the end of February (e.g., last Sunday in February).
*
* @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 int compareToRule(int month, int dayOfMonth, int dayOfWeek, t_int32 millis,
EMode ruleMode, int ruleMonth, int ruleDayOfWeek,
int ruleDay, t_int32 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.
* * 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. *
* Upon exit, the mode variables will be * set, and the day of week and day of month variables will be positive. *
* This method also recognizes a startDay or endDay of zero as indicating * no DST. */ void decodeRules(); static char fgClassID; int startMonth, startDay, startDayOfWeek; // the month, day, DOW, and time DST starts t_int32 startTime; int endMonth, endDay, endDayOfWeek; // the month, day, DOW, and time DST ends t_int32 endTime; int startYear; // the year these DST rules took effect t_int32 rawOffset; // the TimeZone's raw GMT offset t_bool useDaylight; // flag indicating whether this TimeZone uses DST static t_int32 millisPerHour; // number of millis in an hour static const t_uint8 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. */ t_int32 dstSavings; }; #ifdef NLS_MAC #pragma export off #endif #endif // _SIMPLETZ