Custom shape registers taps outside drawn path - swiftui

Question

I created a custom Arc shape in SwiftUI, but when I add an onTapGesture modifier to it, it registers taps outside the area I drew for the Arc (it registers taps anywhere within the rect used to draw the Arc). How can I make sure the taps only register within the drawn path of the Arc, not the entire rect?
Here's the Arc shape I drew:
struct Arc: Shape {
let angle: Angle
let thickness: CGFloat
let clockwise: Bool
func path(in rect: CGRect) -> Path {
var path = Path()
let innerArcEndPoint = CGPoint(x: rect.maxX - thickness, y: 0)
let innerArcStartPoint = CGPoint(
x: innerArcEndPoint.x * cos(CGFloat(angle.radians)),
y: innerArcEndPoint.x * sin(CGFloat(angle.radians)))
path.move(to: innerArcStartPoint)
path.addArc(center: rect.origin, radius: innerArcEndPoint.x, startAngle: angle, endAngle: Angle.zero, clockwise: !clockwise)
path.addLine(to: CGPoint(x: rect.maxX, y: 0))
path.addArc(center: rect.origin, radius: rect.maxX, startAngle: Angle.zero, endAngle: angle, clockwise: clockwise)
path.closeSubpath()
return path
}
}
Here's me using the Arc with an onTapGesture modifier:
struct TestTappingArc: View {
var body: some View {
Arc(angle: Angle(degrees: 45), thickness: 20, clockwise: false)
.foregroundColor(.blue) // The only area I want to be tappable
.background(Color.orange) // The area I DON'T want to be tappable (but currently is tappable)
.frame(width: 100, height: 100)
.onTapGesture {
print("hello")
}
}
}
And here's what it looks like on screen:

Answer 1

You need to use contentShape with same shape to restrict hit-testing area (because view is always rectangular), like
Arc(angle: Angle(degrees: 45), thickness: 20, clockwise: false)
.foregroundColor(.blue)
.contentShape(Arc(angle: Angle(degrees: 45), thickness: 20, clockwise: false))
.onTapGesture { // << here !!
print("hello")
}
.background(Color.orange)
.frame(width: 100, height: 100)

Answer 2

Thanks Asperi for that answer--that does fix the problem. However, I realized an even simpler solution is just to move the background to after the onTapGesture modifier, like this:
Arc(angle: Angle(degrees: 45), thickness: 20, clockwise: false)
.foregroundColor(.blue)
.frame(width: 100, height: 100)
.onTapGesture {
print("hello")
}
.background(Color.orange)