1/*
2 *******************************************************************************
3 * Copyright (C) 2008-2012, Google, International Business Machines Corporation and
4 * others. All Rights Reserved.
5 *******************************************************************************
6 */
7
8#include "utypeinfo.h"  // for 'typeid' to work
9
10#include "unicode/tmunit.h"
11
12#if !UCONFIG_NO_FORMATTING
13
14U_NAMESPACE_BEGIN
15
16UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TimeUnit)
17
18
19/*
20 * There are only 7 time units.
21 * So, TimeUnit could be made as singleton
22 * (similar to uniset_props.cpp, or unorm.cpp,
23 * in which a static TimeUnit* array is created, and
24 * the creatInstance() returns a const TimeUnit*).
25 * But the constraint is TimeUnit is a data member of Measure.
26 * But Measure (which is an existing API) does not expect it's "unit" member
27 * as singleton. Meaure takes ownership of the "unit" member.
28 * In its constructor, it does not take a const "unit" pointer.
29 * Also, Measure can clone and destruct the "unit" pointer.
30 * In order to preserve the old behavior and let Measure handle singleton "unit",
31 * 1. a flag need to be added in Measure;
32 * 2. a new constructor which takes const "unit" as parameter need to be added,
33 *    and this new constructor will set the flag on.
34 * 3. clone and destructor need to check upon this flag to distinguish on how
35 *    to handle the "unit".
36 *
37 * Since TimeUnit is such a light weight object, comparing with the heavy weight
38 * format operation, we decided to avoid the above complication.
39 *
40 * So, both TimeUnit and CurrencyUnit (the 2 subclasses of MeasureUnit) are
41 * immutable and non-singleton.
42 *
43 * Currently, TimeUnitAmount and CurrencyAmount are immutable.
44 * If an application needs to create a long list of TimeUnitAmount on the same
45 * time unit but different number, for example,
46 * 1 hour, 2 hour, 3 hour, ................. 10,000 hour,
47 * there might be performance hit because 10,000 TimeUnit object,
48 * although all are the same time unit, will be created in heap and deleted.
49 *
50 * To address this performance issue, if there is any in the future,
51 * we should and need to change TimeUnitAmount and CurrencyAmount to be
52 * immutable by allowing a setter on the number.
53 * Or we need to add 2 parallel mutable classes in order to
54 * preserve the existing API.
55 * Or we can use freezable.
56 */
57TimeUnit* U_EXPORT2
58TimeUnit::createInstance(TimeUnit::UTimeUnitFields timeUnitField,
59                         UErrorCode& status) {
60    if (U_FAILURE(status)) {
61        return NULL;
62    }
63    if (timeUnitField < 0 || timeUnitField >= UTIMEUNIT_FIELD_COUNT) {
64        status = U_ILLEGAL_ARGUMENT_ERROR;
65        return NULL;
66    }
67    return new TimeUnit(timeUnitField);
68}
69
70
71TimeUnit::TimeUnit(TimeUnit::UTimeUnitFields timeUnitField) {
72    fTimeUnitField = timeUnitField;
73}
74
75
76TimeUnit::TimeUnit(const TimeUnit& other)
77:   MeasureUnit(other) {
78    *this = other;
79}
80
81
82UObject*
83TimeUnit::clone() const {
84    return new TimeUnit(*this);
85}
86
87
88TimeUnit&
89TimeUnit::operator=(const TimeUnit& other) {
90    if (this == &other) {
91        return *this;
92    }
93    fTimeUnitField = other.fTimeUnitField;
94    return *this;
95}
96
97
98UBool
99TimeUnit::operator==(const UObject& other) const {
100    return (typeid(*this) == typeid(other)
101            && fTimeUnitField == ((TimeUnit*)&other)->fTimeUnitField);
102}
103
104
105TimeUnit::UTimeUnitFields
106TimeUnit::getTimeUnitField() const {
107    return fTimeUnitField;
108}
109
110
111TimeUnit::~TimeUnit() {
112}
113
114
115U_NAMESPACE_END
116
117#endif
118