SwiftUI_page_transition.swift

import SwiftUI
import PlaygroundSupport

/*:
 # Example of SwiftUI Page Transition
 
 Run on Swift Playground (iPad)
 
 nest is too deep...
 */

struct ContentView: View {
    @State private var pushed: Bool = false
    var body: some View {
        VStack {
            if self.pushed {
                VStack {
                    SecondView().padding(10)
                    Button(action: { 
                        self.pushed = false
                    }) { 
                        Text("Back")
                    }
                }
            }
            else {
                VStack {
                    FirstView().padding(10)
                    Button(action: { 
                        self.pushed = true
                    }) {
                        Text("Change")
                    }
                }
            }
        }
    }
}

struct FirstView: View {
    var body: some View {
        Text("FIRST")
    }
}

struct SecondView: View {
    var body: some View {
        Text("SECOND")
    }
}

PlaygroundPage.current.liveView =
    UIHostingController(rootView: ContentView())