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// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
import UIKit
public protocol DynamicFontHelper {
/// Returns a font that will dynamically scale with dynamic text
/// - Parameters:
/// - textStyle: The desired textStyle for the font
/// - size: The size of the font
/// - Returns: The UIFont with the specified font size and style
static func preferredFont(withTextStyle textStyle: UIFont.TextStyle,
size: CGFloat,
weight: UIFont.Weight?,
symbolicTraits: UIFontDescriptor.SymbolicTraits?
) -> UIFont
/// Return a bold font that will dynamically scale up to a certain size
/// - Parameters:
/// - textStyle: The desired textStyle for the font
/// - size: The size of the font
/// - Returns: The UIFont with the specified font size, style and bold weight
static func preferredBoldFont(withTextStyle textStyle: UIFont.TextStyle,
size: CGFloat
) -> UIFont
}
public extension DynamicFontHelper {
static func preferredFont(withTextStyle textStyle: UIFont.TextStyle,
size: CGFloat,
weight: UIFont.Weight? = nil,
symbolicTraits: UIFontDescriptor.SymbolicTraits? = nil
) -> UIFont {
preferredFont(withTextStyle: textStyle, size: size, weight: weight, symbolicTraits: symbolicTraits)
}
}
public struct DefaultDynamicFontHelper: DynamicFontHelper {
public static func preferredFont(withTextStyle textStyle: UIFont.TextStyle,
size: CGFloat,
weight: UIFont.Weight? = nil,
symbolicTraits: UIFontDescriptor.SymbolicTraits? = nil) -> UIFont {
let fontMetrics = UIFontMetrics(forTextStyle: textStyle)
var fontDescriptor = UIFontDescriptor.preferredFontDescriptor(withTextStyle: textStyle)
if let symbolicTraits = symbolicTraits, let descriptor = fontDescriptor.withSymbolicTraits(symbolicTraits) {
fontDescriptor = descriptor
}
var font: UIFont
if let weight = weight {
font = UIFont.systemFont(ofSize: size, weight: weight)
} else {
font = UIFont(descriptor: fontDescriptor, size: size)
}
return fontMetrics.scaledFont(for: font)
}
public static func preferredBoldFont(withTextStyle textStyle: UIFont.TextStyle, size: CGFloat) -> UIFont {
return preferredFont(withTextStyle: textStyle, size: size, weight: .bold)
}
}