Source code for CodeSlicing quick tips episode on applying effects to views

AddingEffectsToViewsDemo.swift

//
//  AddingEffectsToViewsDemo.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.
//
//  Copyright © 2021 Adam Fordyce. All rights reserved.
//

import SwiftUI
import PureSwiftUI

struct AddingEffectsToViewsDemo: View {
    var body: some View {
        LikeButton()
            .frame(200)
            .compositingGroup()
            .shadowColor(.white(0.3), 5)
    }
}

private struct LikeButton: View {
    
    @State private var isLiked = false
    
    var body: some View {
        GeometryReader { (geo: GeometryProxy) in
            let minDimension = geo.minDimension
            Button {
                isLiked.toggle()
            } label: {
                ZStack {
                    Circle()
                        .fill(.blue)
                        .background(Circle().fill(.white).frame(minDimension * 1.1))
                    SFSymbol(isLiked ? .hand_thumbsup_fill : .hand_thumbsup)
                        .resizedToFit(minDimension * 0.5)
                        .yOffset(-minDimension * 0.02)
                        .foregroundColor(.white)
                }
            }
        }
    }
}

struct AddingEffectsToViewsDemo_Previews: PreviewProvider {
    struct AddingEffectsToViewsDemo_Harness: View {

        var body: some View {
            AddingEffectsToViewsDemo()
                .greedyFrame()
                .ignoresSafeArea()
        }
    }

    static var previews: some View {
        AddingEffectsToViewsDemo_Harness()
            .previewDevice(.iPhone_13_Pro_Max)
    }
}