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      1 /*
      2 *******************************************************************************
      3 * Copyright (C) 2007-2011, International Business Machines Corporation and
      4 * others. All Rights Reserved.
      5 *******************************************************************************
      6 */
      7 #ifndef BASICTZ_H
      8 #define BASICTZ_H
      9 
     10 /**
     11  * \file
     12  * \brief C++ API: ICU TimeZone base class
     13  */
     14 
     15 #include "unicode/utypes.h"
     16 
     17 #if !UCONFIG_NO_FORMATTING
     18 
     19 #include "unicode/timezone.h"
     20 #include "unicode/tzrule.h"
     21 #include "unicode/tztrans.h"
     22 
     23 U_NAMESPACE_BEGIN
     24 
     25 // forward declarations
     26 class UVector;
     27 
     28 /**
     29  * <code>BasicTimeZone</code> is an abstract class extending <code>TimeZone</code>.
     30  * This class provides some additional methods to access time zone transitions and rules.
     31  * All ICU <code>TimeZone</code> concrete subclasses extend this class.
     32  * @stable ICU 3.8
     33  */
     34 class U_I18N_API BasicTimeZone: public TimeZone {
     35 public:
     36     /**
     37      * Destructor.
     38      * @stable ICU 3.8
     39      */
     40     virtual ~BasicTimeZone();
     41 
     42     /**
     43      * Gets the first time zone transition after the base time.
     44      * @param base      The base time.
     45      * @param inclusive Whether the base time is inclusive or not.
     46      * @param result    Receives the first transition after the base time.
     47      * @return  TRUE if the transition is found.
     48      * @stable ICU 3.8
     49      */
     50     virtual UBool getNextTransition(UDate base, UBool inclusive, TimeZoneTransition& result) /*const*/ = 0;
     51 
     52     /**
     53      * Gets the most recent time zone transition before the base time.
     54      * @param base      The base time.
     55      * @param inclusive Whether the base time is inclusive or not.
     56      * @param result    Receives the most recent transition before the base time.
     57      * @return  TRUE if the transition is found.
     58      * @stable ICU 3.8
     59      */
     60     virtual UBool getPreviousTransition(UDate base, UBool inclusive, TimeZoneTransition& result) /*const*/ = 0;
     61 
     62     /**
     63      * Checks if the time zone has equivalent transitions in the time range.
     64      * This method returns true when all of transition times, from/to standard
     65      * offsets and DST savings used by this time zone match the other in the
     66      * time range.
     67      * @param tz    The <code>BasicTimeZone</code> object to be compared with.
     68      * @param start The start time of the evaluated time range (inclusive)
     69      * @param end   The end time of the evaluated time range (inclusive)
     70      * @param ignoreDstAmount
     71      *              When true, any transitions with only daylight saving amount
     72      *              changes will be ignored, except either of them is zero.
     73      *              For example, a transition from rawoffset 3:00/dstsavings 1:00
     74      *              to rawoffset 2:00/dstsavings 2:00 is excluded from the comparison,
     75      *              but a transtion from rawoffset 2:00/dstsavings 1:00 to
     76      *              rawoffset 3:00/dstsavings 0:00 is included.
     77      * @param ec    Output param to filled in with a success or an error.
     78      * @return      true if the other time zone has the equivalent transitions in the
     79      *              time range.
     80      * @stable ICU 3.8
     81      */
     82     virtual UBool hasEquivalentTransitions(/*const*/ BasicTimeZone& tz, UDate start, UDate end,
     83         UBool ignoreDstAmount, UErrorCode& ec) /*const*/;
     84 
     85     /**
     86      * Returns the number of <code>TimeZoneRule</code>s which represents time transitions,
     87      * for this time zone, that is, all <code>TimeZoneRule</code>s for this time zone except
     88      * <code>InitialTimeZoneRule</code>.  The return value range is 0 or any positive value.
     89      * @param status    Receives error status code.
     90      * @return The number of <code>TimeZoneRule</code>s representing time transitions.
     91      * @stable ICU 3.8
     92      */
     93     virtual int32_t countTransitionRules(UErrorCode& status) /*const*/ = 0;
     94 
     95     /**
     96      * Gets the <code>InitialTimeZoneRule</code> and the set of <code>TimeZoneRule</code>
     97      * which represent time transitions for this time zone.  On successful return,
     98      * the argument initial points to non-NULL <code>InitialTimeZoneRule</code> and
     99      * the array trsrules is filled with 0 or multiple <code>TimeZoneRule</code>
    100      * instances up to the size specified by trscount.  The results are referencing the
    101      * rule instance held by this time zone instance.  Therefore, after this time zone
    102      * is destructed, they are no longer available.
    103      * @param initial       Receives the initial timezone rule
    104      * @param trsrules      Receives the timezone transition rules
    105      * @param trscount      On input, specify the size of the array 'transitions' receiving
    106      *                      the timezone transition rules.  On output, actual number of
    107      *                      rules filled in the array will be set.
    108      * @param status        Receives error status code.
    109      * @stable ICU 3.8
    110      */
    111     virtual void getTimeZoneRules(const InitialTimeZoneRule*& initial,
    112         const TimeZoneRule* trsrules[], int32_t& trscount, UErrorCode& status) /*const*/ = 0;
    113 
    114     /**
    115      * Gets the set of time zone rules valid at the specified time.  Some known external time zone
    116      * implementations are not capable to handle historic time zone rule changes.  Also some
    117      * implementations can only handle certain type of rule definitions.
    118      * If this time zone does not use any daylight saving time within about 1 year from the specified
    119      * time, only the <code>InitialTimeZone</code> is returned.  Otherwise, the rule for standard
    120      * time and daylight saving time transitions are returned in addition to the
    121      * <code>InitialTimeZoneRule</code>.  The standard and daylight saving time transition rules are
    122      * represented by <code>AnnualTimeZoneRule</code> with <code>DateTimeRule::DOW</code> for its date
    123      * rule and <code>DateTimeRule::WALL_TIME</code> for its time rule.  Because daylight saving time
    124      * rule is changing time to time in many time zones and also mapping a transition time rule to
    125      * different type is lossy transformation, the set of rules returned by this method may be valid
    126      * for short period of time.
    127      * The time zone rule objects returned by this method is owned by the caller, so the caller is
    128      * responsible for deleting them after use.
    129      * @param date      The date used for extracting time zone rules.
    130      * @param initial   Receives the <code>InitialTimeZone</code>, always not NULL.
    131      * @param std       Receives the <code>AnnualTimeZoneRule</code> for standard time transitions.
    132      *                  When this time time zone does not observe daylight saving times around the
    133      *                  specified date, NULL is set.
    134      * @param dst       Receives the <code>AnnualTimeZoneRule</code> for daylight saving time
    135      *                  transitions.  When this time zone does not observer daylight saving times
    136      *                  around the specified date, NULL is set.
    137      * @param status    Receives error status code.
    138      * @stable ICU 3.8
    139      */
    140     virtual void getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
    141         AnnualTimeZoneRule*& std, AnnualTimeZoneRule*& dst, UErrorCode& status) /*const*/;
    142 
    143 
    144 #ifndef U_HIDE_INTERNAL_API
    145     /**
    146      * The time type option bit flags used by getOffsetFromLocal
    147      * @internal
    148      */
    149     enum {
    150         kStandard = 0x01,
    151         kDaylight = 0x03,
    152         kFormer = 0x04,
    153         kLatter = 0x0C
    154     };
    155 #endif  /* U_HIDE_INTERNAL_API */
    156 
    157     /**
    158      * Get time zone offsets from local wall time.
    159      * @internal
    160      */
    161     virtual void getOffsetFromLocal(UDate date, int32_t nonExistingTimeOpt, int32_t duplicatedTimeOpt,
    162         int32_t& rawOffset, int32_t& dstOffset, UErrorCode& status) /*const*/;
    163 
    164 protected:
    165 
    166 #ifndef U_HIDE_INTERNAL_API
    167     /**
    168      * The time type option bit masks used by getOffsetFromLocal
    169      * @internal
    170      */
    171     enum {
    172         kStdDstMask = kDaylight,
    173         kFormerLatterMask = kLatter
    174     };
    175 #endif  /* U_HIDE_INTERNAL_API */
    176 
    177     /**
    178      * Default constructor.
    179      * @stable ICU 3.8
    180      */
    181     BasicTimeZone();
    182 
    183     /**
    184      * Construct a timezone with a given ID.
    185      * @param id a system time zone ID
    186      * @stable ICU 3.8
    187      */
    188     BasicTimeZone(const UnicodeString &id);
    189 
    190     /**
    191      * Copy constructor.
    192      * @param source the object to be copied.
    193      * @stable ICU 3.8
    194      */
    195     BasicTimeZone(const BasicTimeZone& source);
    196 
    197     /**
    198      * Gets the set of TimeZoneRule instances applicable to the specified time and after.
    199      * @param start     The start date used for extracting time zone rules
    200      * @param initial   Receives the InitialTimeZone, always not NULL
    201      * @param transitionRules   Receives the transition rules, could be NULL
    202      * @param status    Receives error status code
    203      */
    204     void getTimeZoneRulesAfter(UDate start, InitialTimeZoneRule*& initial, UVector*& transitionRules,
    205         UErrorCode& status) /*const*/;
    206 };
    207 
    208 U_NAMESPACE_END
    209 
    210 #endif /* #if !UCONFIG_NO_FORMATTING */
    211 
    212 #endif // BASICTZ_H
    213 
    214 //eof
    215