SwiftUI - How to add toolbars to TabView tabs inside a NavigationView? - swiftui

Question

I'm trying to add different toolbars to each of my tabs but they are not displayed. The app will mostly be used on a landscape iPad and I can add the toolbars to the TabView itself and they display but then I don't know how to pass the button press down the navigation stack to the individual views/view-models to be handled locally.
I've tried adding new NavigationViews (including .stack navigationViewStyles) but this still just adds another column to the view.
This is some barebones, working code:
import SwiftUI
#main
struct NavTabTestApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
struct ContentView: View {
var body: some View {
MasterView()
}
}
struct MasterView: View {
var body: some View {
NavigationView {
List {
ForEach(0..<20) { index in
NavigationLink(
destination: DetailView(index: index)
.navigationTitle("Row \(index)")
) {
Text("\(index) th row")
}.tag(index)
}
}.navigationTitle(Text("Ratty"))
}
}
}
struct DetailView: View {
var index: Int
#State var selectedTab = 1
var body: some View {
TabView(selection: $selectedTab) {
Tab1(index: index).tabItem { Label("Tab1", systemImage: "list.dash") }
Tab2(index: index).tabItem { Label("Tab2", systemImage: "aqi.medium") }
Tab3(index: index).tabItem { Label("Tab3", systemImage: "move.3d") }
}
}
}
struct Tab1: View {
var index: Int
var body: some View {
Text("This is \(index) in tab 1")
.toolbar {
ToolbarItem(placement: .primaryAction) {
Button("Bingo") { print("Bingo") }
}
}
}
}
struct Tab2: View {
var index: Int
var body: some View {
Text("This is \(index) in tab 2")
.toolbar {
ToolbarItem(placement: .primaryAction) {
Button("Bongo") { print("Bongo") }
}
}
}
}
struct Tab3: View {
var index: Int
var body: some View {
Text("This is \(index) in tab 3")
.toolbar {
ToolbarItem(placement: .primaryAction) {
Button("Banjo") { print("Banjo") }
}
}
}
}
I'm starting to wonder if this is even possible and whether it would be better to just implement my own view with buttons at the top of each tab.
EDIT:

Answer 1

Not sure if this will help but it does go over some interesting concepts with the toolbar in the nav view.
link: Stewart Lynch

Answer 2

You need to use only one level NavigationView. In other words, you should not nest NavigationViews. Have a look at this answer.
Only Back Button Visible on Custom Navigation Bar SwiftUI
Use a NavgationView for the MasterView as you have used.
Use a NavigationView for each of the Tab# veiws.
Switch between MasterView and DetailsView.
Use Button instead of NavigationLink in MasterView (You can customise it to look like a NavigationLink)
Use a custom back button in each of the Tab# veiws.
This controls which one of MasterView and DetailsView should be shown.
class BaseViewModel: ObservableObject {
#Published var userFlow: UserFlow = .masterView
init(){
userFlow = .masterView
}
enum UserFlow {
case masterView, detailsView
}
}
This view to be used either in ContentView or instead of it. When you are in MasterView and click on one of the list row, set appState.userFlow = .detailView. When you click the back buttons, set appState.userFlow = .masterView.
Doing so, you switch between the two views and one NavigationView is shown at a time.
As of now, it does not have animation. Use if you wish so
https://developer.apple.com/tutorials/swiftui/animating-views-and-transitions
struct BaseView: View {
#EnvironmentObject var appState: BaseViewModel
#State var index: Int = 0
var body: some View {
Group {
switch appState.userFlow {
case .masterView:
MasterView(index: $index)
default:
DetailView(index: index)
}
}
.edgesIgnoringSafeArea(.bottom)
}
}
Complete code
struct ContentView: View {
var body: some View {
BaseView().environmentObject(BaseViewModel())
}
}
class BaseViewModel: ObservableObject {
#Published var userFlow: UserFlow = .masterView
init(){
userFlow = .masterView
}
enum UserFlow {
case masterView, detailsView
}
}
struct BaseView: View {
#EnvironmentObject var appState: BaseViewModel
#State var index: Int = 0
var body: some View {
Group {
switch appState.userFlow {
case .masterView:
MasterView(index: $index)
default:
DetailView(index: index)
}
}
.edgesIgnoringSafeArea(.bottom)
}
}
struct MasterView: View {
#EnvironmentObject var appState: BaseViewModel
#Binding var index: Int
var body: some View {
NavigationView {
List {
ForEach(0..<20) { index in
Button(action: {
appState.userFlow = .detailsView
$index.wrappedValue = index
}, label: {
HStack {
Text("\(index) th row")
Spacer()
Image(systemName: "greaterthan")
}
})
.tag(index)
}
}.navigationTitle(Text("Ratty"))
}
}
}
struct DetailView: View {
var index: Int
#State var selectedTab = 1
var body: some View {
TabView(selection: $selectedTab) {
Tab1(index: index).tabItem { Label("Tab1", systemImage: "list.dash") }
Tab2(index: index).tabItem { Label("Tab2", systemImage: "aqi.medium") }
Tab3(index: index).tabItem { Label("Tab3", systemImage: "move.3d") }
}
}
}
struct Tab1: View {
#EnvironmentObject var appState: BaseViewModel
var index: Int
var body: some View {
NavigationView {
Text("This is \(index) in tab 1")
.toolbar {
ToolbarItem(placement: .navigationBarLeading) {
Button("back") { appState.userFlow = .masterView }
}
ToolbarItem(placement: .navigationBarTrailing) {
Button("Bingo") { print("Bingo") }
}
}
}
}
}
struct Tab2: View {
#EnvironmentObject var appState: BaseViewModel
var index: Int
var body: some View {
NavigationView {
Text("This is \(index) in tab 2")
.toolbar {
ToolbarItem(placement: .navigationBarLeading) {
Button("back") { appState.userFlow = .masterView }
}
ToolbarItem(placement: .primaryAction) {
Button("Bongo") { print("Bongo") }
}
}
}
}
}
struct Tab3: View {
#EnvironmentObject var appState: BaseViewModel
var index: Int
var body: some View {
NavigationView {
Text("This is \(index) in tab 3")
.toolbar {
ToolbarItem(placement: .navigationBarLeading) {
Button("back") { appState.userFlow = .masterView }
}
ToolbarItem(placement: .primaryAction) {
Button("Banjo") { print("Banjo") }
}
}
}
}
}
I have customised xtwistedx 's solution.