MinimumBottomPadding.swift

//
//  ContentView.swift
//  SafeArea
//
//  Created by Kyle Bashour on 5/24/23.
//

import SwiftUI

struct ContentView: View {
    var body: some View {
        VStack {
            Image(systemName: "globe")
                .imageScale(.large)
                .foregroundColor(.accentColor)
            Text("Hello, world!")
        }
        .padding()
        .frame(maxHeight: .infinity)
        .bottom(minimumPadding: 20) {
            Text("Hello")
        }
    }
}

struct MinimumBottomPadding<BottomContent: View>: ViewModifier {
    @State private var bottomSafeAreaInset: CGFloat = 0

    var bottomContent: BottomContent
    var minimumPadding: CGFloat

    init(minimumPadding: CGFloat, @ViewBuilder bottomContent: () -> BottomContent) {
        self.minimumPadding = minimumPadding
        self.bottomContent = bottomContent()
    }

    func body(content: Content) -> some View {
        content.safeAreaInset(edge: .bottom) {
            bottomContent
                .padding(.bottom, max(minimumPadding - bottomSafeAreaInset, 0))
                .background {
                    GeometryReader { geometry in
                        Color.clear.onAppear {
                            self.bottomSafeAreaInset = geometry.safeAreaInsets.bottom
                        }
                    }
                }
        }
    }
}

extension View {
    func bottom(minimumPadding: CGFloat, @ViewBuilder content: () -> some View) -> some View {
        modifier(MinimumBottomPadding(minimumPadding: minimumPadding, bottomContent: content))
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
        ContentView()
            .previewDevice("iPhone SE (3rd generation)")
    }
}