ContentView.swift

//
//  ContentView.swift
//  VisibleAfterFullTextReview
//
//  Created by Philipp on 28.05.22.
//
// Based on the question found in the HWS SwiftUI forum
// https://www.hackingwithswift.com/forums/swiftui/swiftui-webview-are-we-at-the-bottom-of-the-scrollview/14576
//

import SwiftUI

struct ContentView: View {

    @State private var readToEnd = false
    @State private var scrollViewHeight = CGFloat.infinity

    @Namespace private var scrollViewNameSpace

    var body: some View {

        NavigationView {
            VStack {
                ScrollView {
                    Text(eula)
                    Text("hidden tag")
                        .hidden()
                        .background(
                            GeometryReader { proxy in
                                Color.clear
                                    .onChange(of: proxy.frame(in: .named(scrollViewNameSpace))) { newFrame in
                                        if newFrame.minY < scrollViewHeight {
                                            readToEnd = true
                                        }
                                    }
                            }
                        )
                        .border(Color.red)
                }
                .background(
                    GeometryReader { proxy in
                        Color.clear
                            .onChange(of: proxy.size, perform: { newSize in
                                let _ = print("ScrollView: ", newSize)
                                scrollViewHeight = newSize.height
                            })
                    }
                )
                .coordinateSpace(name: scrollViewNameSpace)

                NavigationLink("Accept", destination: Text("Welcome and Thank you!"))
                    .opacity(readToEnd ? 1 : 0)
                    .animation(.default, value: readToEnd)
            }
            .padding(.horizontal)
            .navigationTitle("EULA")
        }
    }


    let eula = Array(repeating: """
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.


""", count: 10).joined(separator: "").trimmingCharacters(in: .whitespacesAndNewlines)
}