SHView.swift

//
//  TextLabelViewForSeanHeber.swift
//  NewWorld12
//
//  Created by Matthew on 8/1/20.
//

// https://twitter.com/BigZaphod/status/1289674767684046848

import SwiftUI

struct SHPreferenceKey: PreferenceKey {
    static let defaultValue: CGFloat = 0
    static func reduce(value: inout Value, nextValue: () -> Value) {
        value = max(value, nextValue())
    }
}

struct SHModifier: ViewModifier {
    func body(content: Content) -> some View {
        content
            .padding()
            .fixedSize()
            .background(
                GeometryReader {
                    Color.clear
                        .preference(key: SHPreferenceKey.self, value: $0.size.width)
                }
            )
    }
}

struct SHView<Title: View, Body: View>: View {
    let titleView: Title
    let bodyView: Body

    @State var viewWidth: CGFloat = 0

    init(@ViewBuilder titleView: () -> Title, @ViewBuilder bodyView: () -> Body) {
        self.titleView = titleView()
        self.bodyView = bodyView()
    }


    var body: some View {
        VStack(alignment: .leading) {
            titleView
                .modifier(SHModifier())
                // force the view width to expand to full width of parent
                .frame(maxWidth: .infinity, alignment: .leading)
                .background(Color.black)

            bodyView
                .modifier(SHModifier())
        }
        .onPreferenceChange(SHPreferenceKey.self) { viewWidth = $0 }
        .frame(width: viewWidth)
        .background(Color.red)
        .cornerRadius(15)
    }
}



struct TextLabelViewForSeanHeberDemo: View {
    var body: some View {
        VStack(alignment: .leading, spacing: 5) {
            SHView {
                Text("Title Here")
                    .foregroundColor(.white)
                    .font(.title)
            }
            bodyView: {
                Text("Text something with a long string.")
                    .bold()
            }

            SHView {
                Text("Something Else")
                    .foregroundColor(.white)
                    .font(.title)
            }
            bodyView: {
                Text("Lorem Ipsum, Lorem Ipsum")
                    .bold()
            }

            SHView {
                Text("The title is longer than body")
                    .foregroundColor(.white)
                    .font(.title)
            }
            bodyView: {
                Text("Lorem Ipsum, Lorem Ipsum")
                    .bold()
            }
        }
    }
}

struct TextLabelViewForSeanHeber_Previews: PreviewProvider {
    static var previews: some View {
        TextLabelViewForSeanHeberDemo()
    }
}