Interactive Arc

import SwiftUI

struct InteractiveArc: View {
    @State private var startAngle = Angle.degrees(0)
    @State private var endAngle = Angle.degrees(120)

    let center = CGPoint(x: 150, y: 150)
    let radius: CGFloat = 100

    var body: some View {
        ZStack {
            // Background Circle
            Circle()
                .stroke(style: StrokeStyle(lineWidth: 1, dash: [5]))
                .foregroundColor(.gray.opacity(0.7))
                .frame(width: radius * 2, height: radius * 2)
                .position(center)

            // Arc
            Path { path in
                path.addArc(center: center,
                            radius: radius,
                            startAngle: startAngle,
                            endAngle: endAngle,
                            clockwise: false)
            }
            .stroke(Color.blue, lineWidth: 6)

            // Start Handle
            Circle()
                .fill(Color.green)
                .frame(width: 20, height: 20)
                .position(position(for: startAngle))
                .gesture(
                    DragGesture().onChanged { value in
                        updateAngle(&startAngle, from: value.location)
                    }
                )

            // End Handle
            Circle()
                .fill(Color.red)
                .frame(width: 20, height: 20)
                .position(position(for: endAngle))
                .gesture(
                    DragGesture().onChanged { value in
                        updateAngle(&endAngle, from: value.location)
                    }
                )
        }
        .frame(width: 300, height: 300)
    }

    // Convert angle to CGPoint on the circle
    func position(for angle: Angle) -> CGPoint {
        let radians = angle.radians
        let x = center.x + cos(radians) * radius
        let y = center.y + sin(radians) * radius
        return CGPoint(x: x, y: y)
    }

    // Convert drag position to angle relative to center
    func updateAngle(_ angle: inout Angle, from location: CGPoint) {
        let dx = location.x - center.x
        let dy = location.y - center.y
        let radians = atan2(dy, dx)
        angle = Angle(radians: radians)
    }
}


#Preview {
    ArcsDemo()
}