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// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
extension LengthFormatter {
public enum Unit: Int, Sendable {
case millimeter = 8
case centimeter = 9
case meter = 11
case kilometer = 14
case inch = 1281
case foot = 1282
case yard = 1283
case mile = 1284
}
}
@available(*, unavailable)
extension LengthFormatter : @unchecked Sendable { }
open class LengthFormatter : Formatter {
public override init() {
numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .decimal
unitStyle = .medium
isForPersonHeightUse = false
super.init()
}
public required init?(coder: NSCoder) {
numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .decimal
unitStyle = .medium
isForPersonHeightUse = false
super.init(coder:coder)
}
/*@NSCopying*/ open var numberFormatter: NumberFormatter! // default is NumberFormatter with NumberFormatter.Style.decimal
open var unitStyle: UnitStyle // default is NSFormattingUnitStyleMedium
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
// Format a combination of a number and an unit to a localized string.
open func string(fromValue value: Double, unit: LengthFormatter.Unit) -> String {
guard let formattedValue = numberFormatter.string(from:NSNumber(value: value)) else {
fatalError("Cannot format \(value) as string")
}
let separator = unitStyle == .short ? "" : " "
return "\(formattedValue)\(separator)\(unitString(fromValue: value, unit: unit))"
}
// 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).
open func string(fromMeters numberInMeters: Double) -> String {
let unitLength: [Unit:UnitLength] = [.millimeter:.millimeters,
.centimeter:.centimeters,
.meter:.meters,
.kilometer:.kilometers,
.inch:.inches,
.foot:.feet,
.yard:.yards,
.mile:.miles]
//Convert to the locale-appropriate unit
let unitFromMeters = unit(fromMeters: numberInMeters)
//Map the unit to UnitLength type for conversion later
let unitLengthFromMeters = unitLength[unitFromMeters]!
//Create a measurement object based on the value in meters
let meterMeasurement = Measurement<UnitLength>(value:numberInMeters, unit: .meters)
//Convert the object to the locale-appropriate unit determined above
let unitMeasurement = meterMeasurement.converted(to: unitLengthFromMeters)
//Extract the number from the measurement
let numberInUnit = unitMeasurement.value
if isForPersonHeightUse && !numberFormatter.locale.usesMetricSystem {
let feet = numberInUnit.rounded(.towardZero)
let feetString = string(fromValue: feet, unit: .foot)
let inches = abs(numberInUnit.truncatingRemainder(dividingBy: 1.0)) * 12
let inchesString = string(fromValue: inches, unit: .inch)
return ("\(feetString), \(inchesString)")
}
return string(fromValue: numberInUnit, unit: unitFromMeters)
}
// Return a localized string of the given unit, and if the unit is singular or plural is based on the given number.
open func unitString(fromValue value: Double, unit: Unit) -> String {
if unitStyle == .short {
return LengthFormatter.shortSymbol[unit]!
} else if unitStyle == .medium {
return LengthFormatter.mediumSymbol[unit]!
} else if value == 1.0 {
return LengthFormatter.largeSingularSymbol[unit]!
} else {
return LengthFormatter.largePluralSymbol[unit]!
}
}
// Return the locale-appropriate unit, the same unit used by -stringFromMeters:.
open func unitString(fromMeters numberInMeters: Double, usedUnit unitp: UnsafeMutablePointer<Unit>?) -> String {
let unitLength: [Unit:UnitLength] = [.millimeter:.millimeters,
.centimeter:.centimeters,
.meter:.meters,
.kilometer:.kilometers,
.inch:.inches,
.foot:.feet,
.yard:.yards,
.mile:.miles]
//Convert to the locale-appropriate unit
let unitFromMeters = unit(fromMeters: numberInMeters)
unitp?.pointee = unitFromMeters
//Map the unit to UnitLength type for conversion later
let unitLengthFromMeters = unitLength[unitFromMeters]!
//Create a measurement object based on the value in meters
let meterMeasurement = Measurement<UnitLength>(value:numberInMeters, unit: .meters)
//Convert the object to the locale-appropriate unit determined above
let unitMeasurement = meterMeasurement.converted(to: unitLengthFromMeters)
//Extract the number from the measurement
let numberInUnit = unitMeasurement.value
//Return the appropriate representation of the unit based on the selected unit style
return unitString(fromValue: numberInUnit, unit: unitFromMeters)
}
/// This method selects the appropriate unit based on the formatter’s locale,
/// the magnitude of the value, and isForPersonHeightUse property.
///
/// - Parameter numberInMeters: the magnitude in terms of meters
/// - Returns: Returns the appropriate unit
private func unit(fromMeters numberInMeters: Double) -> Unit {
if numberFormatter.locale.usesMetricSystem {
//Person height is always returned in cm for metric system
if isForPersonHeightUse { return .centimeter }
if numberInMeters > 1000 || numberInMeters < 0.0 {
return .kilometer
} else if numberInMeters > 1.0 {
return .meter
} else if numberInMeters > 0.01 {
return .centimeter
} else { return .millimeter }
} else {
//Person height is always returned in ft for U.S. system
if isForPersonHeightUse { return .foot }
let metricMeasurement = Measurement<UnitLength>(value:numberInMeters, unit: .meters)
let usMeasurement = metricMeasurement.converted(to: .feet)
let numberInFeet = usMeasurement.value
if numberInFeet < 0.0 || numberInFeet > 5280 {
return .mile
} else if numberInFeet > 3 || numberInFeet == 0.0 {
return .yard
} else if numberInFeet >= 1.0 {
return .foot
} else { return .inch }
}
}
/// Maps a unit to its short symbol. Reuses strings from UnitLength wherever possible.
private static let shortSymbol: [Unit: String] = [.millimeter:UnitLength.millimeters.symbol,
.centimeter:UnitLength.centimeters.symbol,
.meter:UnitLength.meters.symbol,
.kilometer:UnitLength.kilometers.symbol,
.inch:"″",
.foot:"′",
.yard:UnitLength.yards.symbol,
.mile:UnitLength.miles.symbol]
/// Maps a unit to its medium symbol. Reuses strings from UnitLength.
private static let mediumSymbol: [Unit: String] = [.millimeter:UnitLength.millimeters.symbol,
.centimeter:UnitLength.centimeters.symbol,
.meter:UnitLength.meters.symbol,
.kilometer:UnitLength.kilometers.symbol,
.inch:UnitLength.inches.symbol,
.foot:UnitLength.feet.symbol,
.yard:UnitLength.yards.symbol,
.mile:UnitLength.miles.symbol]
/// Maps a unit to its large, singular symbol.
private static let largeSingularSymbol: [Unit: String] = [.millimeter:"millimeter",
.centimeter:"centimeter",
.meter:"meter",
.kilometer:"kilometer",
.inch:"inch",
.foot:"foot",
.yard:"yard",
.mile:"mile"]
/// Maps a unit to its large, plural symbol.
private static let largePluralSymbol: [Unit: String] = [.millimeter:"millimeters",
.centimeter:"centimeters",
.meter:"meters",
.kilometer:"kilometers",
.inch:"inches",
.foot:"feet",
.yard:"yards",
.mile:"miles"]
}
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