* The TimeZone class contains a static list containing a TimeZone object for every * combination of GMT offset and daylight-savings time rules currently in use in the * world, each with a unique ID. Each ID consists of a region (usually a continent or * ocean) and a city in that region, separated by a slash, (for example, Pacific * Standard Time is "America/Los_Angeles.") Because older versions of this class used * three- or four-letter abbreviations instead, there is also a table that maps the older * abbreviations to the newer ones (for example, "PST" maps to "America/LosAngeles"). * Anywhere the API requires an ID, you can use either form. *
* To create a new TimeZone, you call the factory function TimeZone::createTimeZone() * and pass it a time zone ID. You can use the createAvailableIDs() function to * obtain a list of all the time zone IDs recognized by createTimeZone(). *
* You can also use TimeZone::createDefault() to create a TimeZone. This function uses * platform-specific APIs to produce a TimeZone for the time zone corresponding to * the client's computer's physical location. For example, if you're in Japan (assuming * your machine is set up correctly), TimeZone::createDefault() will return a TimeZone * for Japanese Standard Time ("Asia/Tokyo"). */ #ifdef NLS_MAC #pragma export on #endif class T_FORMAT_API TimeZone { public: virtual ~TimeZone(); /** * Creates a new TimeZone for the given tmie zone ID. If the given ID is not * supported by TimeZone class, returns null. The result is a new TimeZone object * that the client owns and is responsible for deleting. * * @param ID A time zone ID. * @return A new TimeZone corresponding to the time zone with the given ID, * or NULL if there is no time zone with the given ID. */ static TimeZone* createTimeZone(const UnicodeString& ID); /** * Returns a list of time zone IDs, one for each time zone with a given GMT offset. * The return value is a list because there may be several times zones with the same * GMT offset that differ in the way they handle daylight savings time. For example, * the state of Arizona doesn't observe Daylight Savings time. So if you ask for * the time zone IDs corresponding to GMT-7:00, you'll get back two time zone IDs: * "America/Denver," which corresponds to Mountain Standard Time in the winter and * Mountain Daylight Time in the summer, and "America/Phoenix", which corresponds to * Mountain Standard Time year-round, even in the summer. *
* The caller owns the list that is returned, but does not own the strings contained * in that list. Delete the array, but DON'T delete the elements in the array. * * @param rawOffset An offset from GMT in milliseconds. * @param numIDs Receives the number of items in the array that is returned. * @return An array of UnicodeString pointers, where each UnicodeString is * a time zone ID for a time zone with the given GMT offset. If * there is no timezone that matches the GMT offset * specified, NULL is returned. */ static const UnicodeString** const createAvailableIDs(t_int32 rawOffset, long& numIDs); /** * Returns a list of all time zone IDs supported by the TimeZone class (i.e., all * IDs that it's legal to pass to createTimeZone()). The caller owns the list that * is returned, but does not own the strings contained in that list. Delete the array, * but DON'T delete the elements in the array. * * @param numIDs Receives the number of zone IDs returned. * @return An array of UnicodeString pointers, where each is a time zone ID * supported by the TimeZone class. */ static const UnicodeString** const createAvailableIDs(long& numIDs); /** * Creates a new copy of the default TimeZone for this host. Unless the default time * zone has already been set using adoptDefault() or serDefault(), the default is * determined by querying the system using methods in TPlatformUtilities. If the * system routines fail, or if they specify a TimeZone or TimeZone offset which is not * recognized, the TimeZone indicated by the ID kLastResortID is instantiated * and made the default. * * @return A default TimeZone. Clients are responsible for deleting the time zone * object returned. */ static TimeZone* createDefault(); /** * Sets the default time zone (i.e., what's returned by getDefault()) to be the * specified time zone. If NULL is specified for the time zone, the default time * zone is set to the default host time zone. This call adopts the TimeZone object * passed in; the clent is no longer responsible for deleting it. * * @param zone A pointer to the new TimeZone object to use as the default. */ static void adoptDefault(TimeZone* zone); /** * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted; * the caller remains responsible for deleting it. * * @param zone The given timezone. */ static void setDefault(const TimeZone& zone); /** * Returns true if the two TimeZones are equal. (The TimeZone version only compares * IDs, but subclasses are expected to also compare the fields they add.) * * @param that The TimeZone object to be compared with. * @return True if the given TimeZone is equal to this TimeZone; false * otherwise. */ virtual t_bool operator==(const TimeZone& that) const; /** * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns * false. * * @param that The TimeZone object to be compared with. * @return True if the given TimeZone is not equal to this TimeZone; false * otherwise. */ t_bool operator!=(const TimeZone& that) const {return !operator==(that);} /** * 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 = 0; /** * 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) = 0; /** * 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 = 0; /** * Fills in "ID" with the TimeZone's ID. * * @param ID Receives this TimeZone's ID. * @return "ID" */ UnicodeString& getID(UnicodeString& ID) const; /** * Sets the TimeZone's ID to the specified value. This doesn't affect any other * fields (for example, if you say< * blockquote>
* . TimeZone* foo = TimeZone::createTimeZone("America/New_York");
* . foo.setID("America/Los_Angeles");
*
* the time zone's GMT offset and daylight-savings rules don't change to those for
* Los Angeles. They're still those for New York. Only the ID has changed.)
*
* @param ID The new timezone ID.
*/
void setID(const UnicodeString& ID);
/**
* Queries if this TimeZone uses Daylight Savings Time.
*
* @return True if this TimeZone uses Daylight Savings Time; false otherwise.
*/
virtual t_bool useDaylightTime() const = 0;
/**
* 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 = 0;
/**
* 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 = 0;
/**
* Returns a unique class ID POLYMORPHICALLY. Pure virtual method. 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.
* * Concrete subclasses of TimeZone must implement getDynamicClassID() and also a * static method and data member: *
* . static ClassID getStaticClassID() { return (ClassID)&fgClassID; }
* . static char fgClassID;
*
* @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 = 0;
/**
* Netscape Extension for library termination
*/
static void terminateLibrary(void);
protected:
/**
* Default constructor. ID is initialized to the empty string.
*/
TimeZone();
/**
* Copy constructor.
*/
TimeZone(const TimeZone& source);
/**
* Default assignment operator.
*/
TimeZone& operator=(const TimeZone& right);
private:
/**
* Convert a non-localized string to an integer using a system function. Return a
* failing ErrorCode status if all characters are not parsed.
*/
// static t_int32 stringToInteger(const UnicodeString& string, ErrorCode& status);
/**
* Delete function for fgHashtable.
*/
static void deleteTimeZone(void*);
static Hashtable* fgHashtable; // hash table of objects in kSystemTimeZones,
// maps zone ID to TimeZone object (lazy evaluated)
static TimeZone* fgDefaultZone; // default time zone (lazy evaluated)
static UnicodeString* fgAvailableIDs; // array containing all the IDs in kSystemTimeZones
static t_int32 fgAvailableIDsCount; // number of IDs in fgAvailableIDs
static UnicodeString kLastResortID; // ID of time zone to use as default if we can't
// get a default from the system
/**
* Return a reference to the static Hashtable of registered TimeZone
* objects. Performs initialization if necessary.
* * This method is also responsible for initializing the array * fgAvailableIDs and fgAvailableIDsCount. */ static const Hashtable& getHashtable(); /** * Responsible for setting up fgDefaultZone. Uses routines in TPlatformUtilities * (i.e., platform-specific calls) to get the current system time zone. Failing * that, uses the platform-specific default time zone. Failing that, uses the time * zone specified by kLastResortID. */ static void initDefault(); static SimpleTimeZone kSystemTimeZones[]; // an array of TimeZone objects for // all possible time zones in // use around the world as of 1997. static const int kSystemTimeZonesCount; // number of TimeZones in kSystemTimeZones. static const t_int32 millisPerHour; // number of milliseconds in an hour static const char* compatibilityMap[]; // maps old-style 3-letter time zone IDs // to the new region/city form (e.g., maps // "PST" to "America/Los_Angeles") static const int compatibilityMapCount; // number of entries in compatibilityMap. UnicodeString fID; // this time zone's ID }; #ifdef NLS_MAC #pragma export off #endif // ------------------------------------- inline UnicodeString& TimeZone::getID(UnicodeString& ID) const { ID = fID; return ID; } // ------------------------------------- inline void TimeZone::setID(const UnicodeString& ID) { fID = ID; } #endif //_TIMEZONE //eof