/* * Copyright © {1997-1999}, International Business Machines Corporation and others. All Rights Reserved. ******************************************************************************** * * File TIMEZONE.H * * Modification History: * * Date Name Description * 04/21/97 aliu Overhauled header. * 07/09/97 helena Changed createInstance to createDefault. * 08/06/97 aliu Removed dependency on internal header for Hashtable. * 08/10/98 stephen Changed getDisplayName() API conventions to match * 08/19/98 stephen Changed createTimeZone() to never return 0 * 09/02/98 stephen Sync to JDK 1.2 8/31 * - Added getOffset(... monthlen ...) * - Added hasSameRules() * 09/15/98 stephen Added getStaticClassID * 12/03/99 aliu Moved data out of static table into icudata.dll. * Hashtable replaced by new static data structures. * 12/14/99 aliu Made GMT public. ******************************************************************************** */ #ifndef TIMEZONE_H #define TIMEZONE_H #include "unicode/unistr.h" #include "unicode/locid.h" #include "unicode/udata.h" class SimpleTimeZone; struct TZHeader; struct OffsetIndex; /** * TimeZone represents a time zone offset, and also figures out daylight * savings. * *

* Typically, you get a TimeZone using createDefault * which creates a TimeZone based on the time zone where the program * is running. For example, for a program running in Japan, createDefault * creates a TimeZone object based on Japanese Standard Time. * *

* You can also get a TimeZone using createTimeZone along * with a time zone ID. For instance, the time zone ID for the Pacific * Standard Time zone is "PST". So, you can get a PST TimeZone object * with: *

*
 * TimeZone *tz = TimeZone::createTimeZone("PST");
 * 
*
* You can use getAvailableIDs method to iterate through * all the supported time zone IDs. You can then choose a * supported ID to get a TimeZone. * If the time zone you want is not represented by one of the * supported IDs, then you can create a custom time zone ID with * the following syntax: * *
*
 * GMT[+|-]hh[[:]mm]
 * 
*
* * For example, you might specify GMT+14:00 as a custom * time zone ID. The TimeZone that is returned * when you specify a custom time zone ID does not include * daylight savings time. * * TimeZone is an abstract class representing a time zone. A TimeZone is needed for * Calendar to produce local time for a particular time zone. A TimeZone comprises * three basic pieces of information: * * (Only the ID is actually implemented in TimeZone; subclasses of TimeZone may handle * daylight savings time and GMT offset in different ways. Currently we only have one * TimeZone subclass: SimpleTimeZone.) *

* 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"). */ class U_I18N_API TimeZone { public: /** * @stable */ virtual ~TimeZone(); /** * The GMT zone has a raw offset of zero and does not use daylight * savings time. */ static const TimeZone* GMT; /** * Creates a TimeZone for the given ID. * @param ID the ID for a TimeZone, either an abbreviation such as * "PST", a full name such as "America/Los_Angeles", or a custom ID * such as "GMT-8:00". * @return the specified TimeZone, or the GMT zone if the given ID * cannot be understood. Return result guaranteed to be non-null. If you * require that the specific zone asked for be returned, check the ID of the * return result. * @stable */ 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. * @stable */ static const UnicodeString** const createAvailableIDs(int32_t rawOffset, int32_t& 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. * @stable */ static const UnicodeString** const createAvailableIDs(int32_t& numIDs); /** * Creates a new copy of the default TimeZone for this host. Unless the default time * zone has already been set using adoptDefault() or setDefault(), 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. * @stable */ static TimeZone* createDefault(void); /** * 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. * @stable */ 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. * @system */ 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. * @stable */ virtual UBool 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. * @stable */ UBool 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. * @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 = 0; /** * @deprecated */ virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, uint8_t dayOfWeek, int32_t millis) const = 0; /** * 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 standard local time. * @param monthLength the length of the given 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 = 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. * @stable */ virtual void setRawOffset(int32_t 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. * @stable */ virtual int32_t getRawOffset(void) const = 0; /** * Fills in "ID" with the TimeZone's ID. * * @param ID Receives this TimeZone's ID. * @return "ID" * @stable */ 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. * @stable */ void setID(const UnicodeString& ID); /** * Enum for use with getDisplayName */ enum EDisplayType { SHORT = 1, LONG }; /** * Returns a name of this time zone suitable for presentation to the user * in the default locale. * This method returns the long name, not including daylight savings. * If the display name is not available for the locale, * then this method returns a string in the format * GMT[+-]hh:mm. * @return the human-readable name of this time zone in the default locale. * @stable */ UnicodeString& getDisplayName(UnicodeString& result) const; /** * Returns a name of this time zone suitable for presentation to the user * in the specified locale. * This method returns the long name, not including daylight savings. * If the display name is not available for the locale, * then this method returns a string in the format * GMT[+-]hh:mm. * @param locale the locale in which to supply the display name. * @return the human-readable name of this time zone in the given locale * or in the default locale if the given locale is not recognized. * @stable */ UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const; /** * Returns a name of this time zone suitable for presentation to the user * in the default locale. * If the display name is not available for the locale, * then this method returns a string in the format * GMT[+-]hh:mm. * @param daylight if true, return the daylight savings name. * @param style either LONG or SHORT * @return the human-readable name of this time zone in the default locale. * @stable */ UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const; /** * Returns a name of this time zone suitable for presentation to the user * in the specified locale. * If the display name is not available for the locale, * then this method returns a string in the format * GMT[+-]hh:mm. * @param daylight if true, return the daylight savings name. * @param style either LONG or SHORT * @param locale the locale in which to supply the display name. * @return the human-readable name of this time zone in the given locale * or in the default locale if the given locale is not recognized. * @stable */ UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const; /** * Queries if this time zone uses daylight savings time. * @return true if this time zone uses daylight savings time, * false, otherwise. * @stable */ virtual UBool useDaylightTime(void) const = 0; /** * Queries if the given date is in daylight savings time in * this time zone. * @param date the given UDate. * @return true if the given date is in daylight savings time, * false, otherwise. * @deprecated */ virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0; /** * Returns true if this zone has the same rule and offset as another zone. * That is, if this zone differs only in ID, if at all. * @param other the TimeZone object to be compared with * @return true if the given zone is the same as this one, * with the possible exception of the ID * @stable */ virtual 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 = 0; /** * 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. * @stable */ static UClassID getStaticClassID(void) { return (UClassID)&fgClassID; } /** * 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 UClassID getStaticClassID() { return (UClassID)&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. * @stable */ virtual UClassID getDynamicClassID(void) const = 0; protected: /** * Default constructor. ID is initialized to the empty string. * @stable */ TimeZone(); /** * Copy constructor. * @stable */ TimeZone(const TimeZone& source); /** * Default assignment operator. * @stable */ TimeZone& operator=(const TimeZone& right); private: static char fgClassID; static TimeZone* createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string. static TimeZone* fgDefaultZone; // default time zone (lazy evaluated) static const UnicodeString GMT_ID; static const int32_t GMT_ID_LENGTH; static const UnicodeString CUSTOM_ID; //////////////////////////////////////////////////////////////// // Pointers into memory-mapped icudata. Writing to this memory // will segfault! See tzdat.h for more details. //////////////////////////////////////////////////////////////// /** * DATA is the start of the memory-mapped zone data, and * specifically points to the header object located there. * May be zero if loading failed for some reason. */ static const TZHeader * DATA; /** * INDEX_BY_ID is an index table in lexicographic order of ID. * Each entry is an offset from DATA to the zone object, which * will either be a StandardZone or a DSTZone object. */ static const uint32_t* INDEX_BY_ID; /** * INDEX_BY_OFFSET is an OffsetIndex table. This table can only * be walked through sequentially because the entries are of * variable size. */ static const OffsetIndex* INDEX_BY_OFFSET; //////////////////////////////////////////////////////////////// // Other system zone data structures //////////////////////////////////////////////////////////////// /** * ZONE_IDS is an array of all the system zone ID strings, in * lexicographic order. The createAvailableIDs() methods return * arrays of pointers into this array. */ static UnicodeString* ZONE_IDS; /** * If DATA_LOADED is true, then an attempt has already been made * to load the system zone data, and further attempts will not be * made. If DATA_LOADED is true, DATA itself will be zero if * loading failed, or non-zero if it succeeded. */ static UBool DATA_LOADED; static UDataMemory* UDATA_POINTER; /** * The mutex object used to control write access to DATA, * INDEX_BY_ID, INDEX_BY_OFFSET, and ZONE_IDS. Also used to * control read/write access to fgDefaultZone. */ static UMTX LOCK; /** * 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 GMT. */ static void initDefault(void); // See source file for documentation static void loadZoneData(void); // See source file for documentation static UBool U_CALLCONV isDataAcceptable(void *context, const char *type, const char *name, const UDataInfo *pInfo); // See source file for documentation static TimeZone* createSystemTimeZone(const UnicodeString& name); UnicodeString fID; // this time zone's ID }; // ------------------------------------- inline UnicodeString& TimeZone::getID(UnicodeString& ID) const { ID = fID; return ID; } // ------------------------------------- inline void TimeZone::setID(const UnicodeString& ID) { fID = ID; } #endif //_TIMEZONE //eof