Check in the pristine copy of ICU 4.6...

icu46/source/i18n/unicode/basictz.h

+/*
+*******************************************************************************
+* Copyright (C) 2007-2008, International Business Machines Corporation and         *
+* others. All Rights Reserved.                                                *
+*******************************************************************************
+*/
+#ifndef BASICTZ_H
+#define BASICTZ_H
+
+/**
+ * \file 
+ * \brief C++ API: ICU TimeZone base class
+ */
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/timezone.h"
+#include "unicode/tzrule.h"
+#include "unicode/tztrans.h"
+
+U_NAMESPACE_BEGIN
+
+// forward declarations
+class UVector;
+
+/**
+ * <code>BasicTimeZone</code> is an abstract class extending <code>TimeZone</code>.
+ * This class provides some additional methods to access time zone transitions and rules.
+ * All ICU <code>TimeZone</code> concrete subclasses extend this class.
+ * @stable ICU 3.8
+ */
+class U_I18N_API BasicTimeZone: public TimeZone {
+public:
+    /**
+     * Destructor.
+     * @stable ICU 3.8
+     */
+    virtual ~BasicTimeZone();
+
+    /**
+     * Gets the first time zone transition after the base time.
+     * @param base      The base time.
+     * @param inclusive Whether the base time is inclusive or not.
+     * @param result    Receives the first transition after the base time.
+     * @return  TRUE if the transition is found.
+     * @stable ICU 3.8
+     */
+    virtual UBool getNextTransition(UDate base, UBool inclusive, TimeZoneTransition& result) /*const*/ = 0;
+
+    /**
+     * Gets the most recent time zone transition before the base time.
+     * @param base      The base time.
+     * @param inclusive Whether the base time is inclusive or not.
+     * @param result    Receives the most recent transition before the base time.
+     * @return  TRUE if the transition is found.
+     * @stable ICU 3.8
+     */
+    virtual UBool getPreviousTransition(UDate base, UBool inclusive, TimeZoneTransition& result) /*const*/ = 0;
+
+    /**
+     * Checks if the time zone has equivalent transitions in the time range.
+     * This method returns true when all of transition times, from/to standard
+     * offsets and DST savings used by this time zone match the other in the
+     * time range.
+     * @param tz    The <code>BasicTimeZone</code> object to be compared with.
+     * @param start The start time of the evaluated time range (inclusive)
+     * @param end   The end time of the evaluated time range (inclusive)
+     * @param ignoreDstAmount
+     *              When true, any transitions with only daylight saving amount
+     *              changes will be ignored, except either of them is zero.
+     *              For example, a transition from rawoffset 3:00/dstsavings 1:00
+     *              to rawoffset 2:00/dstsavings 2:00 is excluded from the comparison,
+     *              but a transtion from rawoffset 2:00/dstsavings 1:00 to
+     *              rawoffset 3:00/dstsavings 0:00 is included.
+     * @param ec    Output param to filled in with a success or an error.
+     * @return      true if the other time zone has the equivalent transitions in the
+     *              time range.
+     * @stable ICU 3.8
+     */
+    virtual UBool hasEquivalentTransitions(/*const*/ BasicTimeZone& tz, UDate start, UDate end,
+        UBool ignoreDstAmount, UErrorCode& ec) /*const*/;
+
+    /**
+     * Returns the number of <code>TimeZoneRule</code>s which represents time transitions,
+     * for this time zone, that is, all <code>TimeZoneRule</code>s for this time zone except
+     * <code>InitialTimeZoneRule</code>.  The return value range is 0 or any positive value.
+     * @param status    Receives error status code.
+     * @return The number of <code>TimeZoneRule</code>s representing time transitions.
+     * @stable ICU 3.8
+     */
+    virtual int32_t countTransitionRules(UErrorCode& status) /*const*/ = 0;
+
+    /**
+     * Gets the <code>InitialTimeZoneRule</code> and the set of <code>TimeZoneRule</code>
+     * which represent time transitions for this time zone.  On successful return,
+     * the argument initial points to non-NULL <code>InitialTimeZoneRule</code> and
+     * the array trsrules is filled with 0 or multiple <code>TimeZoneRule</code>
+     * instances up to the size specified by trscount.  The results are referencing the
+     * rule instance held by this time zone instance.  Therefore, after this time zone
+     * is destructed, they are no longer available.
+     * @param initial       Receives the initial timezone rule
+     * @param trsrules      Receives the timezone transition rules
+     * @param trscount      On input, specify the size of the array 'transitions' receiving
+     *                      the timezone transition rules.  On output, actual number of
+     *                      rules filled in the array will be set.
+     * @param status        Receives error status code.
+     * @stable ICU 3.8
+     */
+    virtual void getTimeZoneRules(const InitialTimeZoneRule*& initial,
+        const TimeZoneRule* trsrules[], int32_t& trscount, UErrorCode& status) /*const*/ = 0;
+
+    /**
+     * Gets the set of time zone rules valid at the specified time.  Some known external time zone
+     * implementations are not capable to handle historic time zone rule changes.  Also some
+     * implementations can only handle certain type of rule definitions.
+     * If this time zone does not use any daylight saving time within about 1 year from the specified
+     * time, only the <code>InitialTimeZone</code> is returned.  Otherwise, the rule for standard
+     * time and daylight saving time transitions are returned in addition to the
+     * <code>InitialTimeZoneRule</code>.  The standard and daylight saving time transition rules are
+     * represented by <code>AnnualTimeZoneRule</code> with <code>DateTimeRule::DOW</code> for its date
+     * rule and <code>DateTimeRule::WALL_TIME</code> for its time rule.  Because daylight saving time
+     * rule is changing time to time in many time zones and also mapping a transition time rule to
+     * different type is lossy transformation, the set of rules returned by this method may be valid
+     * for short period of time.
+     * The time zone rule objects returned by this method is owned by the caller, so the caller is
+     * responsible for deleting them after use.
+     * @param date      The date used for extracting time zone rules.
+     * @param initial   Receives the <code>InitialTimeZone</code>, always not NULL.
+     * @param std       Receives the <code>AnnualTimeZoneRule</code> for standard time transitions.
+     *                  When this time time zone does not observe daylight saving times around the
+     *                  specified date, NULL is set.
+     * @param dst       Receives the <code>AnnualTimeZoneRule</code> for daylight saving time
+     *                  transitions.  When this time zone does not observer daylight saving times
+     *                  around the specified date, NULL is set.
+     * @param status    Receives error status code.
+     * @stable ICU 3.8
+     */
+    virtual void getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
+        AnnualTimeZoneRule*& std, AnnualTimeZoneRule*& dst, UErrorCode& status) /*const*/;
+
+
+    /**
+     * The time type option bit flags used by getOffsetFromLocal
+     * @internal
+     */
+    enum {
+        kStandard = 0x01,
+        kDaylight = 0x03,
+        kFormer = 0x04,
+        kLatter = 0x0C
+    };
+
+    /**
+     * Get time zone offsets from local wall time.
+     * @internal
+     */
+    virtual void getOffsetFromLocal(UDate date, int32_t nonExistingTimeOpt, int32_t duplicatedTimeOpt,
+        int32_t& rawOffset, int32_t& dstOffset, UErrorCode& status) /*const*/;
+
+protected:
+
+    /**
+     * The time type option bit masks used by getOffsetFromLocal
+     * @internal
+     */
+    enum {
+        kStdDstMask = kDaylight,
+        kFormerLatterMask = kLatter
+    };
+
+    /**
+     * Default constructor.
+     * @stable ICU 3.8
+     */
+    BasicTimeZone();
+
+    /**
+     * Construct a timezone with a given ID.
+     * @param id a system time zone ID
+     * @stable ICU 3.8
+     */
+    BasicTimeZone(const UnicodeString &id);
+
+    /**
+     * Copy constructor.
+     * @param source the object to be copied.
+     * @stable ICU 3.8
+     */
+    BasicTimeZone(const BasicTimeZone& source);
+
+    /**
+     * Gets the set of TimeZoneRule instances applicable to the specified time and after.
+     * @param start     The start date used for extracting time zone rules
+     * @param initial   Receives the InitialTimeZone, always not NULL
+     * @param transitionRules   Receives the transition rules, could be NULL
+     * @param status    Receives error status code
+     */
+    void getTimeZoneRulesAfter(UDate start, InitialTimeZoneRule*& initial, UVector*& transitionRules,
+        UErrorCode& status) /*const*/;
+};
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_FORMATTING */
+
+#endif // BASICTZ_H
+
+//eof