Inspecting The View Tree - Compatible with Xcode 11, Beta 5

Inspecting-View-Tree-1a.swift

// The SwiftUI Lab: https://swiftui-lab.com
// Article: Inspecting the View Tree – Part 1
// https://swiftui-lab.com/communicating-with-the-view-tree-part-1/

import SwiftUI

struct EasyExample : View {
    @State private var activeIdx: Int = 0
    
    var body: some View {
        VStack {
            Spacer()
            
            HStack {
                MonthView(activeMonth: $activeIdx, label: "January", idx: 0)
                MonthView(activeMonth: $activeIdx, label: "February", idx: 1)
                MonthView(activeMonth: $activeIdx, label: "March", idx: 2)
                MonthView(activeMonth: $activeIdx, label: "April", idx: 3)
            }
            
            Spacer()
            
            HStack {
                MonthView(activeMonth: $activeIdx, label: "May", idx: 4)
                MonthView(activeMonth: $activeIdx, label: "June", idx: 5)
                MonthView(activeMonth: $activeIdx, label: "July", idx: 6)
                MonthView(activeMonth: $activeIdx, label: "August", idx: 7)
            }
            
            Spacer()
            
            HStack {
                MonthView(activeMonth: $activeIdx, label: "September", idx: 8)
                MonthView(activeMonth: $activeIdx, label: "October", idx: 9)
                MonthView(activeMonth: $activeIdx, label: "November", idx: 10)
                MonthView(activeMonth: $activeIdx, label: "December", idx: 11)
            }
            
            Spacer()
        }
    }
}

struct MonthView: View {
    @Binding var activeMonth: Int
    let label: String
    let idx: Int
    
    var body: some View {
        Text(label)
            .padding(10)
            .onTapGesture { self.activeMonth = self.idx }
            .background(MonthBorder(show: activeMonth == idx))
    }
}

struct MonthBorder: View {
    let show: Bool
    
    var body: some View {
        RoundedRectangle(cornerRadius: 15)
            .stroke(lineWidth: 3.0).foregroundColor(show ? Color.red : Color.clear)
            .animation(.easeInOut(duration: 0.6))
    }
}