Native Source code for CodeSlicing episode on demystifying property wrappers part 1

StateAndBindingDemoNative.swift

//
//  StateAndBindingDemoNative.swift
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
//  of the Software, and to permit persons to whom the Software is furnished to do so,
//  subject to the following conditions:
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
//  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
//  PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
//  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
//  AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
//  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//  Created by Adam Fordyce on 27/03/2021.
//  Copyright © 2020 Adam Fordyce. All rights reserved.
//

import SwiftUI

struct StateAndBindingDemoNative: View {
    
    private let _counter = State(initialValue: 0)
    
    private var counter: Int {
        _counter.wrappedValue
    }
    
    private var _$counter: Binding<Int> {
        _counter.projectedValue
    }
    
    var body: some View {
        VStack(spacing: 50) {
            Text("Current count: \(counter)")
                .font(.title)
            CounterUpdatingButton(counter: _$counter)
        }
    }
}

private struct CounterUpdatingButton: View {
    
    
    let counter: Binding<Int>
    
    var body: some View {
        VStack {
            Button {
                counter.wrappedValue += 1
            } label: {
                Text("Increment")
                    .font(.title)
                    .shadow(radius: 2)
                    .padding()
                    .background(LinearGradient(
                                    gradient: Gradient(colors: [.red, .orange]),
                                    startPoint: .topLeading,
                                    endPoint: .bottomTrailing))
                    .clipShape(Capsule())
                    .overlay(Capsule().stroke(Color.white, lineWidth: 1))
                    .contentShape(Capsule())
            }
        }
    }
}

struct BindingDemo_Previews: PreviewProvider {
    struct BindingDemo_Harness: View {

        var body: some View {
            StateAndBindingDemoNative()
                .frame(maxWidth: .infinity, maxHeight: .infinity)
                .foregroundColor(.white)
                .background(Color(white: 0.1))
                .ignoresSafeArea()
        }
    }

    static var previews: some View {
        BindingDemo_Harness()
            
            .previewDevice("iPhone 8")
            .previewDisplayName("iPhone 8")
    }
}