Swift 4用にタイポグラフィの独自の変換を作成しましたいくつかの投稿を確認した後ました。これは、次のようなほとんどのケースをカバーしています。
プロジェクトのestructureと.plistファイル（同じ名前）にフォントを追加します。
<key>UIAppFonts</key>
<array>
<string>Typo-Light.ttf</string>
<string>Typo-Regular.ttf</string>
<string>Typo-Semibold.ttf</string>
<string>Typo-LightItalic.ttf</string>
</array>
その後
struct Resources {
struct Fonts {
//struct is extended in Fonts
}
}
extension Resources.Fonts {
enum Weight: String {
case light = "Typo-Light"
case regular = "Typo-Regular"
case semibold = "Typo-Semibold"
case italic = "Typo-LightItalic"
}
}
extension UIFontDescriptor.AttributeName {
static let nsctFontUIUsage = UIFontDescriptor.AttributeName(rawValue: "NSCTFontUIUsageAttribute")
}
extension UIFont {
@objc class func mySystemFont(ofSize: CGFloat, weight: UIFont.Weight) -> UIFont {
switch weight {
case .semibold, .bold, .heavy, .black:
return UIFont(name: Resources.Fonts.Weight.semibold.rawValue, size: ofSize)!
case .medium, .regular:
return UIFont(name: Resources.Fonts.Weight.regular.rawValue, size: ofSize)!
default:
return UIFont(name: Resources.Fonts.Weight.light.rawValue, size: ofSize)!
}
}
@objc class func mySystemFont(ofSize size: CGFloat) -> UIFont {
return UIFont(name: Resources.Fonts.Weight.light.rawValue, size: size)!
}
@objc class func myBoldSystemFont(ofSize size: CGFloat) -> UIFont {
return UIFont(name: Resources.Fonts.Weight.semibold.rawValue, size: size)!
}
@objc class func myItalicSystemFont(ofSize size: CGFloat) -> UIFont {
return UIFont(name: Resources.Fonts.Weight.italic.rawValue, size: size)!
}
@objc convenience init(myCoder aDecoder: NSCoder) {
guard
let fontDescriptor = aDecoder.decodeObject(forKey: "UIFontDescriptor") as? UIFontDescriptor,
let fontAttribute = fontDescriptor.fontAttributes[.nsctFontUIUsage] as? String else {
self.init(myCoder: aDecoder)
return
}
var fontName = ""
switch fontAttribute {
case "CTFontRegularUsage", "CTFontMediumUsage":
fontName = Resources.Fonts.Weight.regular.rawValue
case "CTFontEmphasizedUsage", "CTFontBoldUsage", "CTFontSemiboldUsage","CTFontHeavyUsage", "CTFontBlackUsage":
fontName = Resources.Fonts.Weight.semibold.rawValue
case "CTFontObliqueUsage":
fontName = Resources.Fonts.Weight.italic.rawValue
default:
fontName = Resources.Fonts.Weight.light.rawValue
}
self.init(name: fontName, size: fontDescriptor.pointSize)!
}
class func overrideDefaultTypography() {
guard self == UIFont.self else { return }
if let systemFontMethodWithWeight = class_getClassMethod(self, #selector(systemFont(ofSize: weight:))),
let mySystemFontMethodWithWeight = class_getClassMethod(self, #selector(mySystemFont(ofSize: weight:))) {
method_exchangeImplementations(systemFontMethodWithWeight, mySystemFontMethodWithWeight)
}
if let systemFontMethod = class_getClassMethod(self, #selector(systemFont(ofSize:))),
let mySystemFontMethod = class_getClassMethod(self, #selector(mySystemFont(ofSize:))) {
method_exchangeImplementations(systemFontMethod, mySystemFontMethod)
}
if let boldSystemFontMethod = class_getClassMethod(self, #selector(boldSystemFont(ofSize:))),
let myBoldSystemFontMethod = class_getClassMethod(self, #selector(myBoldSystemFont(ofSize:))) {
method_exchangeImplementations(boldSystemFontMethod, myBoldSystemFontMethod)
}
if let italicSystemFontMethod = class_getClassMethod(self, #selector(italicSystemFont(ofSize:))),
let myItalicSystemFontMethod = class_getClassMethod(self, #selector(myItalicSystemFont(ofSize:))) {
method_exchangeImplementations(italicSystemFontMethod, myItalicSystemFontMethod)
}
if let initCoderMethod = class_getInstanceMethod(self, #selector(UIFontDescriptor.init(coder:))),
let myInitCoderMethod = class_getInstanceMethod(self, #selector(UIFont.init(myCoder:))) {
method_exchangeImplementations(initCoderMethod, myInitCoderMethod)
}
}
}
最後にAppdelegate次のように作成されたメソッドを呼び出します：
class AppDelegate: UIResponder, UIApplicationDelegate {
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
UIFont.overrideDefaultTypography()
return true
}
}