UIActivityIndicatorView in SwiftUI

Spinner.swift

import SwiftUI
import UIKit

struct Spinner: UIViewRepresentable {
  let style: UIActivityIndicatorView.Style
  @State var animating: Bool = true

  func makeUIView(context: Context) -> UIActivityIndicatorView {
    UIActivityIndicatorView(style: style)
  }

  func updateUIView(_ uiView: UIActivityIndicatorView, context: Context) {
    if animating {
      uiView.startAnimating()
    } else {
      uiView.stopAnimating()
    }
  }
}

struct Spinner_Previews: PreviewProvider {
  static var previews: some View {
    Group {
      Spinner(style: .medium)
        .previewLayout(.sizeThatFits)
      Spinner(style: .large)
        .previewLayout(.sizeThatFits)
    }
  }
}

struct Spinner_Library: LibraryContentProvider {
  @LibraryContentBuilder
  var views: [LibraryItem] {
    LibraryItem(Spinner(style: .medium), title: "Spinner medium", category: .control)
    LibraryItem(Spinner(style: .large), title: "Spinner large", category: .control)
  }
}