//: A UIKit based Playground for presenting user interface import SwiftUI import UIKit import PlaygroundSupport class Model: ObservableObject { @Published var on: Bool = false } class Thing: NSObject { @ObservedObject var model = Model() } var thing = Thing() struct MyView: View { @Binding var on: Bool var body: some View { Rectangle() .foregroundColor(on ? .blue : .red) .frame(width: 100.0, height: 100.0, alignment: .center) .onTapGesture { self.on.toggle() print(self.on) } } } // Present the view controller in the Live View window PlaygroundPage.current.liveView = UIHostingController(rootView: MyView(on: thing.$model.on))