BasicTimeZone is an abstract class extending TimeZone. More...

#include <basictz.h>

Inheritance diagram for icu::BasicTimeZone:

Public Types
enum	{ kStandard = 0x01, kDaylight = 0x03, kFormer = 0x04, kLatter = 0x0C }
	The time type option bit flags used by getOffsetFromLocal. More...
Public Member Functions
virtual	~BasicTimeZone ()
	Destructor.
virtual BasicTimeZone *	clone () const override=0
	Clones this object polymorphically.
virtual UBool	getNextTransition (UDate base, UBool inclusive, TimeZoneTransition &result) const =0
	Gets the first time zone transition after the base time.
virtual UBool	getPreviousTransition (UDate base, UBool inclusive, TimeZoneTransition &result) const =0
	Gets the most recent time zone transition before the base time.
virtual UBool	hasEquivalentTransitions (const BasicTimeZone &tz, UDate start, UDate end, UBool ignoreDstAmount, UErrorCode &ec) const
	Checks if the time zone has equivalent transitions in the time range.
virtual int32_t	countTransitionRules (UErrorCode &status) const =0
	Returns the number of `TimeZoneRule`s which represents time transitions, for this time zone, that is, all `TimeZoneRule`s for this time zone except `InitialTimeZoneRule`.
virtual void	getTimeZoneRules (const InitialTimeZoneRule &initial, const TimeZoneRule trsrules[], int32_t &trscount, UErrorCode &status) const =0
	Gets the `InitialTimeZoneRule` and the set of `TimeZoneRule` which represent time transitions for this time zone.
virtual void	getSimpleRulesNear (UDate date, InitialTimeZoneRule &initial, AnnualTimeZoneRule &std, AnnualTimeZoneRule *&dst, UErrorCode &status) const
	Gets the set of time zone rules valid at the specified time.
virtual void	getOffsetFromLocal (UDate date, UTimeZoneLocalOption nonExistingTimeOpt, UTimeZoneLocalOption duplicatedTimeOpt, int32_t &rawOffset, int32_t &dstOffset, UErrorCode &status) const
	Get time zone offsets from local wall time.
void	getOffsetFromLocal (UDate date, int32_t nonExistingTimeOpt, int32_t duplicatedTimeOpt, int32_t &rawOffset, int32_t &dstOffset, UErrorCode &status) const
	Get time zone offsets from local wall time.
Protected Member Functions
	BasicTimeZone ()
	Default constructor.
	BasicTimeZone (const UnicodeString &id)
	Construct a timezone with a given ID.
	BasicTimeZone (const BasicTimeZone &source)
	Copy constructor.
BasicTimeZone &	operator= (const BasicTimeZone &)
	Copy assignment.
void	getTimeZoneRulesAfter (UDate start, InitialTimeZoneRule &initial, UVector &transitionRules, UErrorCode &status) const
	Gets the set of TimeZoneRule instances applicable to the specified time and after.
Static Protected Attributes
static constexpr int32_t	kStdDstMask = kDaylight
	A time type option bit mask used by getOffsetFromLocal.
static constexpr int32_t	kFormerLatterMask = kLatter
	A time type option bit mask used by getOffsetFromLocal.

Detailed Description

BasicTimeZone is an abstract class extending TimeZone.

This class provides some additional methods to access time zone transitions and rules. All ICU TimeZone concrete subclasses extend this class.

Stable:: ICU 3.8

Definition at line 38 of file basictz.h.

Member Enumeration Documentation

anonymous enum

The time type option bit flags used by getOffsetFromLocal.

Internal:: Do not use.

This API is for internal use only.

Definition at line 170 of file basictz.h.

Constructor & Destructor Documentation

virtual icu::BasicTimeZone::~BasicTimeZone ( ) [virtual]

Destructor.

Stable:: ICU 3.8

icu::BasicTimeZone::BasicTimeZone ( ) [protected]

Default constructor.

Stable:: ICU 3.8

icu::BasicTimeZone::BasicTimeZone ( const UnicodeString & id ) [protected]

Construct a timezone with a given ID.

Parameters:

id	a system time zone ID

Stable:: ICU 3.8

icu::BasicTimeZone::BasicTimeZone ( const BasicTimeZone & source ) [protected]

Copy constructor.

Parameters:

source the object to be copied.

Stable:: ICU 3.8

Member Function Documentation

virtual BasicTimeZone* icu::BasicTimeZone::clone ( ) const [override, pure virtual]

Clones this object polymorphically.

The caller owns the result and should delete it when done.

Returns:: clone, or nullptr if an error occurred

Stable:: ICU 3.8

Implements icu::TimeZone.

Implemented in icu::SimpleTimeZone, icu::VTimeZone, and icu::RuleBasedTimeZone.

virtual int32_t icu::BasicTimeZone::countTransitionRules ( UErrorCode & status ) const [pure virtual]

Returns the number of TimeZoneRules which represents time transitions, for this time zone, that is, all TimeZoneRules for this time zone except InitialTimeZoneRule.

The return value range is 0 or any positive value.

Parameters:

status Receives error status code.

Returns:: The number of TimeZoneRules representing time transitions.

Stable:: ICU 3.8

Implemented in icu::SimpleTimeZone, icu::VTimeZone, and icu::RuleBasedTimeZone.

virtual UBool icu::BasicTimeZone::getNextTransition	(	UDate	base,
		UBool	inclusive,
		TimeZoneTransition &	result
	)		const `[pure virtual]`

Gets the first time zone transition after the base time.

Parameters:

base	The base time.
inclusive	Whether the base time is inclusive or not.
result	Receives the first transition after the base time.

Returns:: true if the transition is found.

Stable:: ICU 3.8

Implemented in icu::SimpleTimeZone, icu::VTimeZone, and icu::RuleBasedTimeZone.

virtual void icu::BasicTimeZone::getOffsetFromLocal	(	UDate	date,
		UTimeZoneLocalOption	nonExistingTimeOpt,
		UTimeZoneLocalOption	duplicatedTimeOpt,
		int32_t &	rawOffset,
		int32_t &	dstOffset,
		UErrorCode &	status
	)		const `[virtual]`

Get time zone offsets from local wall time.

Stable:: ICU 69

Reimplemented in icu::SimpleTimeZone, icu::RuleBasedTimeZone, and icu::VTimeZone.

void icu::BasicTimeZone::getOffsetFromLocal	(	UDate	date,
		int32_t	nonExistingTimeOpt,
		int32_t	duplicatedTimeOpt,
		int32_t &	rawOffset,
		int32_t &	dstOffset,
		UErrorCode &	status
	)		const

Get time zone offsets from local wall time.

Internal:: Do not use. This API is for internal use only.

virtual UBool icu::BasicTimeZone::getPreviousTransition	(	UDate	base,
		UBool	inclusive,
		TimeZoneTransition &	result
	)		const `[pure virtual]`

Gets the most recent time zone transition before the base time.

Parameters:

base	The base time.
inclusive	Whether the base time is inclusive or not.
result	Receives the most recent transition before the base time.

Returns:: true if the transition is found.

Stable:: ICU 3.8

Implemented in icu::SimpleTimeZone, icu::VTimeZone, and icu::RuleBasedTimeZone.

virtual void icu::BasicTimeZone::getSimpleRulesNear	(	UDate	date,
		InitialTimeZoneRule *&	initial,
		AnnualTimeZoneRule *&	std,
		AnnualTimeZoneRule *&	dst,
		UErrorCode &	status
	)		const `[virtual]`

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 InitialTimeZone is returned. Otherwise, the rule for standard time and daylight saving time transitions are returned in addition to the InitialTimeZoneRule. The standard and daylight saving time transition rules are represented by AnnualTimeZoneRule with DateTimeRule::DOW for its date rule and DateTimeRule::WALL_TIME 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.

Parameters:

date	The date used for extracting time zone rules.
initial	Receives the `InitialTimeZone`, always not nullptr.
std	Receives the `AnnualTimeZoneRule` for standard time transitions. When this time time zone does not observe daylight saving times around the specified date, nullptr is set.
dst	Receives the `AnnualTimeZoneRule` for daylight saving time transitions. When this time zone does not observer daylight saving times around the specified date, nullptr is set.
status	Receives error status code.

Stable:: ICU 3.8

virtual void icu::BasicTimeZone::getTimeZoneRules	(	const InitialTimeZoneRule *&	initial,
		const TimeZoneRule *	trsrules[],
		int32_t &	trscount,
		UErrorCode &	status
	)		const `[pure virtual]`

Gets the InitialTimeZoneRule and the set of TimeZoneRule which represent time transitions for this time zone.

On successful return, the argument initial points to non-nullptr InitialTimeZoneRule and the array trsrules is filled with 0 or multiple TimeZoneRule 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.

Parameters:

initial	Receives the initial timezone rule
trsrules	Receives the timezone transition rules
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.
status	Receives error status code.

Stable:: ICU 3.8

Implemented in icu::SimpleTimeZone, icu::VTimeZone, and icu::RuleBasedTimeZone.

void icu::BasicTimeZone::getTimeZoneRulesAfter	(	UDate	start,
		InitialTimeZoneRule *&	initial,
		UVector *&	transitionRules,
		UErrorCode &	status
	)		const `[protected]`

Gets the set of TimeZoneRule instances applicable to the specified time and after.

Parameters:

start	The start date used for extracting time zone rules
initial	Output parameter, receives the InitialTimeZone. Always not nullptr (except in case of error)
transitionRules	Output parameter, a UVector of transition rules. May be nullptr, if there are no transition rules. The caller owns the returned vector; the UVector owns the rules.
status	Receives error status code

virtual UBool icu::BasicTimeZone::hasEquivalentTransitions	(	const BasicTimeZone &	tz,
		UDate	start,
		UDate	end,
		UBool	ignoreDstAmount,
		UErrorCode &	ec
	)		const `[virtual]`

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.

Parameters:

tz	The `BasicTimeZone` object to be compared with.
start	The start time of the evaluated time range (inclusive)
end	The end time of the evaluated time range (inclusive)
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 transition from rawoffset 2:00/dstsavings 1:00 to rawoffset 3:00/dstsavings 0:00 is included.
ec	Output param to filled in with a success or an error.

Returns:: true if the other time zone has the equivalent transitions in the time range.

Stable:: ICU 3.8

BasicTimeZone& icu::BasicTimeZone::operator= ( const BasicTimeZone & ) [protected]

Copy assignment.

Stable:: ICU 3.8

Field Documentation

constexpr int32_t icu::BasicTimeZone::kFormerLatterMask = kLatter [static, protected]

A time type option bit mask used by getOffsetFromLocal.

Internal:: Do not use. This API is for internal use only.

Definition at line 197 of file basictz.h.

constexpr int32_t icu::BasicTimeZone::kStdDstMask = kDaylight [static, protected]

A time type option bit mask used by getOffsetFromLocal.

Internal:: Do not use. This API is for internal use only.

Definition at line 192 of file basictz.h.

The documentation for this class was generated from the following file:

basictz.h

Public Types

Public Member Functions

Protected Member Functions

Static Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation