A SwiftUI extension that scales a frame using a specified dynamic type style

View+ScaledFrame.swift

struct ScalingFrameModifier: ViewModifier {
	@ScaledMetric var width: CGFloat
	@ScaledMetric var height: CGFloat
	var hasWidthSpecified: Bool
	var hasHeightSpecified: Bool
	var alignment: Alignment = .center
	
	init(
		width: CGFloat? = nil,
		height: CGFloat? = nil,
		relativeTo style: Font.TextStyle,
		alignment: Alignment = .center
	) {
		self._width = ScaledMetric(wrappedValue: width ?? 0, relativeTo: style)
		self.hasWidthSpecified = width != nil
		self._height = ScaledMetric(wrappedValue: height ?? 0, relativeTo: style)
		self.hasHeightSpecified = height != nil
		self.alignment = alignment
	}
	
	func body(content: Content) -> some View {
		content.frame(
			width: hasWidthSpecified ? width : nil,
			height: hasHeightSpecified ? height : nil,
			alignment: alignment
		)
	}
}

extension View {
	func frame(
		width: CGFloat? = nil,
		height: CGFloat? = nil,
		relativeTo style: Font.TextStyle,
		alignment: Alignment = .center
	) -> some View {
		self.modifier(ScalingFrameModifier(width: width, height: height, relativeTo: style, alignment: alignment))
	}
	
	func frame(
		dimension: CGFloat?,
		relativeTo style: Font.TextStyle,
		alignment: Alignment = .center
	) -> some View {
		self.modifier(ScalingFrameModifier(width: dimension, height: dimension, relativeTo: style, alignment: alignment))
	}
}