michael@0: /*
michael@0:  *******************************************************************************
michael@0:  * Copyright (C) 2008-2012, Google, International Business Machines Corporation and
michael@0:  * others. All Rights Reserved.
michael@0:  *******************************************************************************
michael@0:  */
michael@0: 
michael@0: #include "utypeinfo.h"  // for 'typeid' to work
michael@0: 
michael@0: #include "unicode/tmunit.h"
michael@0: 
michael@0: #if !UCONFIG_NO_FORMATTING
michael@0: 
michael@0: U_NAMESPACE_BEGIN
michael@0: 
michael@0: UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TimeUnit)
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * There are only 7 time units.
michael@0:  * So, TimeUnit could be made as singleton 
michael@0:  * (similar to uniset_props.cpp, or unorm.cpp,
michael@0:  * in which a static TimeUnit* array is created, and 
michael@0:  * the creatInstance() returns a const TimeUnit*).
michael@0:  * But the constraint is TimeUnit is a data member of Measure.
michael@0:  * But Measure (which is an existing API) does not expect it's "unit" member
michael@0:  * as singleton. Meaure takes ownership of the "unit" member.
michael@0:  * In its constructor, it does not take a const "unit" pointer.
michael@0:  * Also, Measure can clone and destruct the "unit" pointer.
michael@0:  * In order to preserve the old behavior and let Measure handle singleton "unit",  
michael@0:  * 1. a flag need to be added in Measure; 
michael@0:  * 2. a new constructor which takes const "unit" as parameter need to be added,
michael@0:  *    and this new constructor will set the flag on.
michael@0:  * 3. clone and destructor need to check upon this flag to distinguish on how
michael@0:  *    to handle the "unit". 
michael@0:  * 
michael@0:  * Since TimeUnit is such a light weight object, comparing with the heavy weight
michael@0:  * format operation, we decided to avoid the above complication.
michael@0:  * 
michael@0:  * So, both TimeUnit and CurrencyUnit (the 2 subclasses of MeasureUnit) are
michael@0:  * immutable and non-singleton.
michael@0:  *
michael@0:  * Currently, TimeUnitAmount and CurrencyAmount are immutable.
michael@0:  * If an application needs to create a long list of TimeUnitAmount on the same
michael@0:  * time unit but different number, for example,
michael@0:  * 1 hour, 2 hour, 3 hour, ................. 10,000 hour,
michael@0:  * there might be performance hit because 10,000 TimeUnit object, 
michael@0:  * although all are the same time unit, will be created in heap and deleted.
michael@0:  *
michael@0:  * To address this performance issue, if there is any in the future,
michael@0:  * we should and need to change TimeUnitAmount and CurrencyAmount to be 
michael@0:  * immutable by allowing a setter on the number.
michael@0:  * Or we need to add 2 parallel mutable classes in order to 
michael@0:  * preserve the existing API.
michael@0:  * Or we can use freezable.
michael@0:  */
michael@0: TimeUnit* U_EXPORT2 
michael@0: TimeUnit::createInstance(TimeUnit::UTimeUnitFields timeUnitField, 
michael@0:                          UErrorCode& status) {
michael@0:     if (U_FAILURE(status)) {
michael@0:         return NULL;
michael@0:     }
michael@0:     if (timeUnitField < 0 || timeUnitField >= UTIMEUNIT_FIELD_COUNT) {
michael@0:         status = U_ILLEGAL_ARGUMENT_ERROR;
michael@0:         return NULL;
michael@0:     }
michael@0:     return new TimeUnit(timeUnitField);
michael@0: }
michael@0: 
michael@0: 
michael@0: TimeUnit::TimeUnit(TimeUnit::UTimeUnitFields timeUnitField) {
michael@0:     fTimeUnitField = timeUnitField;
michael@0: }
michael@0: 
michael@0: 
michael@0: TimeUnit::TimeUnit(const TimeUnit& other) 
michael@0: :   MeasureUnit(other) {
michael@0:     *this = other;
michael@0: }
michael@0: 
michael@0: 
michael@0: UObject* 
michael@0: TimeUnit::clone() const {
michael@0:     return new TimeUnit(*this);
michael@0: }
michael@0: 
michael@0: 
michael@0: TimeUnit&
michael@0: TimeUnit::operator=(const TimeUnit& other) {
michael@0:     if (this == &other) {
michael@0:         return *this;
michael@0:     }
michael@0:     fTimeUnitField = other.fTimeUnitField;
michael@0:     return *this;
michael@0: }
michael@0: 
michael@0: 
michael@0: UBool 
michael@0: TimeUnit::operator==(const UObject& other) const {
michael@0:     return (typeid(*this) == typeid(other)
michael@0:             && fTimeUnitField == ((TimeUnit*)&other)->fTimeUnitField);
michael@0: }
michael@0: 
michael@0: 
michael@0: TimeUnit::UTimeUnitFields
michael@0: TimeUnit::getTimeUnitField() const {
michael@0:     return fTimeUnitField;
michael@0: }
michael@0: 
michael@0: 
michael@0: TimeUnit::~TimeUnit() {
michael@0: }
michael@0: 
michael@0: 
michael@0: U_NAMESPACE_END
michael@0: 
michael@0: #endif