tabs.swift

//
//  ContentView.swift
//  TabBar
//
//  Created by Chris Eidhof on 13.07.20.
//

import SwiftUI

struct ContentView: View {
    let tabs: [Text] = [
        Text("World Clock"),
        Text("Alarm"),
        Text("Bedtime")
    ]
    
    @State var selectedTabIndex = 0
    @Namespace var ns
    
    var body: some View {
        HStack(alignment: .top) {
            ForEach(tabs.indices) { tabIndex in
                VStack {
                    Button(action: {
                        withAnimation(.default) {
                        	self.selectedTabIndex = tabIndex
                        }
                    }, label: { self.tabs[tabIndex] }).padding(.bottom, 4)
                    .overlay(Group {
                        if selectedTabIndex == tabIndex {
                            VStack {
                                Spacer()
                                Rectangle()
                                    .fill(Color.accentColor)
                                    .matchedGeometryEffect(id: "indicator", in: ns)
                                    .frame(height: 2, alignment: .bottom)
                            }

                        }
                    })
                }
            }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}