SwiftUI_Bounce-BasedOnSize.swift

import SwiftUI

struct ContentView: View {
    @State var maxNumber: Int = 50
    var body: some View {
        Text(verbatim: "Bounce-BasedOnSize")
        Slider(value: Binding(
            get: { Double(maxNumber) },
            set: { maxNumber = Int($0) }
        ), in: 1...50, step: 1)
        .padding()
        Divider()
        ScrollView{
            VStack {
                ForEach(1...maxNumber, id: \.self) { number in
                    Text("\(number)")
                }
            }
            .id(String(maxNumber))
            .frame(maxWidth: .infinity)
        }
        .viewExtractor{ view in
            guard let scrollView = view as? UIScrollView else { return }
            scrollView.alwaysBounceVertical = false
        }
    }
}


extension View {
    @ViewBuilder
    func viewExtractor(result: @escaping (UIView) -> ()) -> some View {
        self
            .background(UIKitHelper(result: result))
            .compositingGroup()
    }
}

fileprivate struct UIKitHelper: UIViewRepresentable {
    var result: (UIView) -> ()
    func makeUIView(context: Context) -> UIView {
        let view = UIView(frame: .zero)
        view.backgroundColor = .clear
        view.isUserInteractionEnabled = false
        DispatchQueue.main.async {
            if let uiKitView = view.superview?.superview?.subviews.last?.subviews.first {
                result(uiKitView)
            }
        }
        return view
    }
    func updateUIView(_ uiView: UIView, context: Context) {}
}