gh-XcodesOrg-XcodesApp/Xcodes/AppStoreButtonStyle.swift

import SwiftUI

struct AppStoreButtonStyle: ButtonStyle {
    var installed: Bool
    var highlighted: Bool
    
    var textColor: Color {
        if installed {
            if highlighted {
                return Color.white
            }
            else {
                return Color.secondary
            }
        }
        else {
            if highlighted {
                return Color.accentColor
            }
            else {
                return Color.white
            }
        }
    }
    
    func background(isPressed: Bool) -> some View {
        Group {
            if installed {
                EmptyView()
            } else {
                Capsule()
                    .fill(
                        highlighted ?
                            Color.white :
                            Color.accentColor
                    )
                    .brightness(isPressed ? -0.25 : 0)
            }
        }
    }
    
    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .font(Font.caption.weight(.medium))
            .foregroundColor(textColor)
            .padding(EdgeInsets(top: 2, leading: 8, bottom: 2, trailing: 8))
            .frame(minWidth: 80)
            .background(background(isPressed: configuration.isPressed))
            .padding(1)
    }
}

struct AppStoreButtonStyle_Previews: PreviewProvider {
    static var previews: some View {
        Group {
            Button("INSTALL", action: {})
                .buttonStyle(AppStoreButtonStyle(installed: true, highlighted: false))
                .padding()
            Button("UNINSTALLED", action: {})
                .buttonStyle(AppStoreButtonStyle(installed: false, highlighted: false))
                .padding()
        }
    }
}