77// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
88//
99
10-
1110extension LengthFormatter {
12- public enum Unit : Int {
13-
14- case millimeter
15- case centimeter
16- case meter
17- case kilometer
18- case inch
19- case foot
20- case yard
21- case mile
11+ public enum Unit : Int {
12+ case millimeter = 8
13+ case centimeter = 9
14+ case meter = 11
15+ case kilometer = 14
16+ case inch = 1281
17+ case foot = 1282
18+ case yard = 1283
19+ case mile = 1284
2220 }
2321}
2422
2523open class LengthFormatter : Formatter {
2624
25+ public override init ( ) {
26+ numberFormatter = NumberFormatter ( )
27+ numberFormatter. numberStyle = . decimal
28+ unitStyle = . medium
29+ isForPersonHeightUse = false
30+ super. init ( )
31+ }
32+
2733 public required init ? ( coder: NSCoder ) {
28- NSUnimplemented ( )
34+ numberFormatter = NumberFormatter ( )
35+ numberFormatter. numberStyle = . decimal
36+ unitStyle = . medium
37+ isForPersonHeightUse = false
38+ super. init ( coder: coder)
2939 }
3040
3141 /*@NSCopying*/ open var numberFormatter : NumberFormatter ! // default is NSNumberFormatter with NSNumberFormatterDecimalStyle
@@ -34,20 +44,183 @@ open class LengthFormatter : Formatter {
3444 open var isForPersonHeightUse : Bool // default is NO; if it is set to YES, the number argument for -stringFromMeters: and -unitStringFromMeters: is considered as a person's height
3545
3646 // Format a combination of a number and an unit to a localized string.
37- open func string( fromValue value: Double , unit: LengthFormatter . Unit ) -> String { NSUnimplemented ( ) }
47+ open func string( fromValue value: Double , unit: LengthFormatter . Unit ) -> String {
48+ guard let formattedValue = numberFormatter. string ( from: NSNumber ( value: value) ) else {
49+ fatalError ( " Cannot format \( value) as string " )
50+ }
51+ let separator = unitStyle == LengthFormatter . UnitStyle. short ? " " : " "
52+ return " \( formattedValue) \( separator) \( unitString ( fromValue: value, unit: unit) ) "
53+ }
3854
3955 // Format a number in meters to a localized string with the locale-appropriate unit and an appropriate scale (e.g. 4.3m = 14.1ft in the US locale).
40- open func string( fromMeters numberInMeters: Double ) -> String { NSUnimplemented ( ) }
56+ open func string( fromMeters numberInMeters: Double ) -> String {
57+ //Convert to the locale-appropriate unit
58+ let unitFromMeters = unit ( fromMeters: numberInMeters)
59+
60+ //Map the unit to UnitLength type for conversion later
61+ let unitLengthFromMeters = LengthFormatter . unitLength [ unitFromMeters] !
62+
63+ //Create a measurement object based on the value in meters
64+ let meterMeasurement = Measurement < UnitLength > ( value: numberInMeters, unit: . meters)
65+
66+ //Convert the object to the locale-appropriate unit determined above
67+ let unitMeasurement = meterMeasurement. converted ( to: unitLengthFromMeters)
68+
69+ //Extract the number from the measurement
70+ let numberInUnit = unitMeasurement. value
71+
72+ if isForPersonHeightUse && !LengthFormatter. isMetricSystemLocale ( numberFormatter. locale) {
73+ let feet = numberInUnit. rounded ( . towardZero)
74+ let feetString = string ( fromValue: feet, unit: . foot)
75+
76+ let inches = abs ( numberInUnit. truncatingRemainder ( dividingBy: 1.0 ) ) * 12
77+ let inchesString = string ( fromValue: inches, unit: . inch)
78+
79+ return ( " \( feetString) , \( inchesString) " )
80+ }
81+ return string ( fromValue: numberInUnit, unit: unitFromMeters)
82+ }
4183
4284 // Return a localized string of the given unit, and if the unit is singular or plural is based on the given number.
43- open func unitString( fromValue value: Double , unit: Unit ) -> String { NSUnimplemented ( ) }
85+ open func unitString( fromValue value: Double , unit: Unit ) -> String {
86+ if unitStyle == . short {
87+ return LengthFormatter . shortSymbol [ unit] !
88+ } else if unitStyle == . medium {
89+ return LengthFormatter . mediumSymbol [ unit] !
90+ } else if value == 1.0 {
91+ return LengthFormatter . largeSingularSymbol [ unit] !
92+ } else {
93+ return LengthFormatter . largePluralSymbol [ unit] !
94+ }
95+ }
4496
4597 // Return the locale-appropriate unit, the same unit used by -stringFromMeters:.
46- open func unitString( fromMeters numberInMeters: Double , usedUnit unitp: UnsafeMutablePointer < Unit > ? ) -> String { NSUnimplemented ( ) }
98+ open func unitString( fromMeters numberInMeters: Double , usedUnit unitp: UnsafeMutablePointer < Unit > ? ) -> String {
99+
100+ //Convert to the locale-appropriate unit
101+ let unitFromMeters = unit ( fromMeters: numberInMeters)
102+ unitp? . pointee = unitFromMeters
103+
104+ //Map the unit to UnitLength type for conversion later
105+ let unitLengthFromMeters = LengthFormatter . unitLength [ unitFromMeters] !
106+
107+ //Create a measurement object based on the value in meters
108+ let meterMeasurement = Measurement < UnitLength > ( value: numberInMeters, unit: . meters)
109+
110+ //Convert the object to the locale-appropriate unit determined above
111+ let unitMeasurement = meterMeasurement. converted ( to: unitLengthFromMeters)
112+
113+ //Extract the number from the measurement
114+ let numberInUnit = unitMeasurement. value
115+
116+ //Return the appropriate representation of the unit based on the selected unit style
117+ return unitString ( fromValue: numberInUnit, unit: unitFromMeters)
118+ }
119+
120+ /// This method selects the appropriate unit based on the formatter’s locale,
121+ /// the magnitude of the value, and isForPersonHeightUse property.
122+ ///
123+ /// - Parameter numberInMeters: the magnitude in terms of meters
124+ /// - Returns: Returns the appropriate unit
125+ private func unit( fromMeters numberInMeters: Double ) -> Unit {
126+ if LengthFormatter . isMetricSystemLocale ( numberFormatter. locale) {
127+ //Person height is always returned in cm for metric system
128+ if isForPersonHeightUse { return . centimeter }
129+
130+ if numberInMeters > 1000 || numberInMeters < 0.0 {
131+ return . kilometer
132+ } else if numberInMeters > 1.0 {
133+ return . meter
134+ } else if numberInMeters > 0.01 {
135+ return . centimeter
136+ } else { return . millimeter }
137+ } else {
138+ //Person height is always returned in ft for U.S. system
139+ if isForPersonHeightUse { return . foot }
140+
141+ let metricMeasurement = Measurement < UnitLength > ( value: numberInMeters, unit: . meters)
142+ let usMeasurement = metricMeasurement. converted ( to: . feet)
143+ let numberInFeet = usMeasurement. value
144+
145+ if numberInFeet < 0.0 || numberInFeet > 5280 {
146+ return . mile
147+ } else if numberInFeet > 3 || numberInFeet == 0.0 {
148+ return . yard
149+ } else if numberInFeet >= 1.0 {
150+ return . foot
151+ } else { return . inch }
152+ }
153+ }
154+
155+ /// TODO: Replace calls to the below function to use Locale.usesMetricSystem
156+ /// Temporary workaround due to unpopulated Locale attributes
157+ /// See https://bugs.swift.org/browse/SR-3202
158+ private static func isMetricSystemLocale( _ locale: Locale ) -> Bool {
159+ switch locale. identifier {
160+ case " en_US " : return false
161+ case " en_US_POSIX " : return false
162+ case " haw_US " : return false
163+ case " es_US " : return false
164+ case " chr_US " : return false
165+ case " my_MM " : return false
166+ case " en_LR " : return false
167+ case " vai_LR " : return false
168+ default : return true
169+ }
170+ }
47171
48172 /// - Experiment: This is a draft API currently under consideration for official import into Foundation as a suitable alternative
49173 /// - Note: Since this API is under consideration it may be either removed or revised in the near future
50174 open override func objectValue( _ string: String ) throws -> Any ? { return nil }
51- }
52-
175+
176+
177+ /// Maps NSLengthFormatter.Unit enum to UnitLength class. Used for measurement conversion.
178+ private static let unitLength : [ Unit : UnitLength ] = [ . millimeter: . millimeters,
179+ . centimeter: . centimeters,
180+ . meter: . meters,
181+ . kilometer: . kilometers,
182+ . inch: . inches,
183+ . foot: . feet,
184+ . yard: . yards,
185+ . mile: . miles]
53186
187+ /// Maps a unit to its short symbol. Reuses strings from UnitLength wherever possible.
188+ private static let shortSymbol : [ Unit : String ] = [ . millimeter: UnitLength . millimeters. symbol,
189+ . centimeter: UnitLength . centimeters. symbol,
190+ . meter: UnitLength . meters. symbol,
191+ . kilometer: UnitLength . kilometers. symbol,
192+ . inch: " \" " ,
193+ . foot: " ′ " ,
194+ . yard: UnitLength . yards. symbol,
195+ . mile: UnitLength . miles. symbol]
196+
197+ /// Maps a unit to its medium symbol. Reuses strings from UnitLength.
198+ private static let mediumSymbol : [ Unit : String ] = [ . millimeter: UnitLength . millimeters. symbol,
199+ . centimeter: UnitLength . centimeters. symbol,
200+ . meter: UnitLength . meters. symbol,
201+ . kilometer: UnitLength . kilometers. symbol,
202+ . inch: UnitLength . inches. symbol,
203+ . foot: UnitLength . feet. symbol,
204+ . yard: UnitLength . yards. symbol,
205+ . mile: UnitLength . miles. symbol]
206+
207+ /// Maps a unit to its large, singular symbol.
208+ private static let largeSingularSymbol : [ Unit : String ] = [ . millimeter: " millimeter " ,
209+ . centimeter: " centimeter " ,
210+ . meter: " meter " ,
211+ . kilometer: " kilometer " ,
212+ . inch: " inch " ,
213+ . foot: " foot " ,
214+ . yard: " yard " ,
215+ . mile: " mile " ]
216+
217+ /// Maps a unit to its large, plural symbol.
218+ private static let largePluralSymbol : [ Unit : String ] = [ . millimeter: " millimeters " ,
219+ . centimeter: " centimeters " ,
220+ . meter: " meters " ,
221+ . kilometer: " kilometers " ,
222+ . inch: " inches " ,
223+ . foot: " feet " ,
224+ . yard: " yards " ,
225+ . mile: " miles " ]
226+ }
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