1/*
2*******************************************************************************
3* Copyright (C) 2007-2013, 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
23U_NAMESPACE_BEGIN
24
25// forward declarations
26class 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 */
34class U_I18N_API BasicTimeZone: public TimeZone {
35public:
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
164protected:
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
208U_NAMESPACE_END
209
210#endif /* #if !UCONFIG_NO_FORMATTING */
211
212#endif // BASICTZ_H
213
214//eof
215