Get the position of a child View by wrapping it in a UIView

UIViewWrapper.swift

//
//  UIViewWrapper.swift
//  lingq-5
//
//  Created by Timothy Costa on 2019/06/14.
//  Copyright © 2019 timothycosta.com. All rights reserved.
//

import SwiftUI
import UIKit

struct UIViewWrapper<V: UIView> : UIViewRepresentable {
	var update: ((V, Context) -> Void)? = nil
	var make: () -> V

	func makeCoordinator() -> NSObject {
		return NSObject()
	}

	func makeUIView(context: Context) -> V {
		self.make()
	}

	func updateUIView(_ view: V, context: Context) {
		self.update?(view, context)
	}
}

struct PositionFinder<Content: View>: View {

	var alignment: Alignment = .center
	var fixedWidth = true
	var fixedHeight = true
	@Binding var view: UIView?

	let builder: () -> Content

	var body: some View {
		ZStack(alignment: self.alignment) {
			UIViewWrapper(update: { (view, _) in
				print(view.convert(view.bounds, to: nil))
			}) { () -> UIView in
				let v = UIView()
				v.backgroundColor = .red //.clear
				DispatchQueue.main.asyncAfter(deadline: .now()) {
					self.view = v
				}
				return v
			}
			self.builder()
		}.fixedSize(horizontal: self.fixedWidth, vertical: self.fixedHeight)
	}

}

struct FinderTester: View {

	@State var position: CGPoint = .zero
	@State var view: UIView?

	var dragGesture: some Gesture {
		DragGesture().onChanged { (value) in
			self.position = value.location
			}.onEnded { _ in
		}
	}

	var text: String {
		guard let v = self.view else { return "" }
		return "frame: \(v.convert(v.bounds, to: nil))"
	}

	var body: some View {
		VStack {
			Text(self.text)
			PositionFinder(view: self.$view) {
				Image(systemName: "xmark")
					.resizable()
					.frame(width: 44.0, height: 44.0)
			}
			.position(self.position)
			.gesture(self.dragGesture)
		}
	}
}

#if DEBUG

struct UIViewWrapper_Previews : PreviewProvider {

	static var previews: some View {
		VStack {
			HStack {
				UIViewWrapper {
					let label = UILabel()
					label.text = "Hello world"
					label.setContentHuggingPriority(.defaultHigh, for: .vertical)
					return label
				}
				UIViewWrapper {
					return UISwitch()
				}
			}
			VStack {
				FinderTester()
			}
		}
	}
}
#endif