How to pop multiple views off a navigation stack? - swiftui

Looking for some guidance on a simple way to pop multiple views off a navigation stack in SwiftUI.
I have 4 views chained together using NavigationLink. At the last view I would like to jump back to the initial ContentView, popping all the other views off the stack. I don't want to use the "Back" button on the NavigationBar of each view to achieve this.
Thanks in advance.
Bob.
'''
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: BView()) {
Text("This is View A, now go to View B.")
}
}
}
}
}
struct BView: View {
var body: some View {
NavigationLink(destination: CView()) {
Text("This is View B, now go to View C.")
}
}
}
struct CView: View {
var body: some View {
NavigationLink(destination: DView()) {
Text("This is View C, now go to View D.")
}
}
}
struct DView: View {
var body: some View {
// The following line adds ContentView onto the existing navigation stack. Instead, I want to pop the previous views off the stack, leaving me back at ContentView.
NavigationLink(destination: ContentView()) {
Text("This is View D, now jump back to View A.")
}
}
}
'''

It's not really "popping" views off of the stack, but your SceneDelegate can set the rootViewController to any View you want (see line 28 of default SceneDelegate.swift). In your case you want it to be ContentView again.
For example in your SceneDelegate add something like:
func toContentView() {
let contentView = ContentView()
window?.rootViewController = UIHostingController(rootView: contentView)
}
Then in DView, change the NavigationLink to a Button that just does:
(UIApplication.shared.connectedScenes.first?.delegate as? SceneDelegate)?.toContentView()
If you have multiple scenes, you'll need a bit more.

Making Cenk Bilgen's answer more generic.
struct RootView {
static func change(to view: AnyView) {
guard let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene,
let sceneDelegate = windowScene.delegate as? SceneDelegate else {
return
}
let contentView = view
sceneDelegate.window?.rootViewController = UIHostingController(rootView: contentView)
}
}
Usage:
RootView.change(to: AnyView(DashboardView()))

Related

Navigation + Tabview + Sheet broken in iOS 15

It looks like Navigation + TabView + Sheet is broken in iOS 15.
When I do this:
ContentView -> DetailView -> Bottom Sheet
When the bottom sheet comes up, the Detail view is automatically popped off the stack:
https://www.youtube.com/watch?v=gguLptAx0l4
I expect the Detail view to stay there even when the bottom sheet appears. Does anyone have any idea on why this happens and how to fix it?
Here is my sample code:
import Combine
import SwiftUI
import RealmSwift
struct ContentView: View {
var body: some View {
NavigationView {
TabView {
TabItemView(num: 1)
.tabItem {
Text("One")
}
TabItemView(num: 2)
.tabItem {
Text("Two")
}
}
}
}
}
struct TabItemView: View {
private let num: Int
init(num: Int) {
self.num = num
}
var body: some View {
NavigationLink(destination: DetailView(text: "Detail View \(num)")) {
Text("Go to Detail View")
}
}
}
struct DetailView: View {
#State private var showingSheet = false
private let text: String
init(text: String) {
self.text = text
}
var body: some View {
Button("Open Sheet") {
showingSheet.toggle()
}.sheet(isPresented: $showingSheet) {
Text("Sheet Text")
}
}
}
This works on iOS 14 btw
UPDATE 1:
Tried #Sebastian's suggestion of putting NavigationView inside of TabView. While this fixed the nav bug, it fundamentally changed the behavior (I don't want to show the tabs in DetailView).
Also tried his suggestion of using Introspect to set navigationController.hidesBottomBarWhenPushed = true on the NavigationLink destination, but that didn't do anything:
struct ContentView: View {
var body: some View {
TabView {
NavigationView {
TabItemView(num: 1)
}.tabItem {
Text("One")
}
NavigationView {
TabItemView(num: 2)
}.tabItem {
Text("Two")
}
}
}
}
struct TabItemView: View {
private let num: Int
init(num: Int) {
self.num = num
}
var body: some View {
NavigationLink(destination: DetailView(text: "Detail View \(num)").introspectNavigationController { navigationController in
navigationController.hidesBottomBarWhenPushed = true
}) {
Text("Go to Detail View")
}
}
}
struct DetailView: View {
#State private var showingSheet = false
private let text: String
init(text: String) {
self.text = text
}
var body: some View {
Button("Open Sheet") {
showingSheet.toggle()
}.sheet(isPresented: $showingSheet) {
Text("Sheet Text")
}
}
}
You need to flip how you nest TabView & NavigationView. Instead of nesting several TabView views inside a NavigationView, use the TabView as the parent component, with a NavigationView for each tab.
This is how the updated ContentView would look like:
struct ContentView: View {
var body: some View {
TabView {
NavigationView {
TabItemView(num: 1)
}
.tabItem {
Text("One")
}
NavigationView {
TabItemView(num: 2)
}
.tabItem {
Text("Two")
}
}
}
}
This makes sense and is more correct: The tabs should always be visible, but you want to show a different navigation stack with different content in each tab.
That it worked previously doesn't make it more correct - SwiftUI probably just changed its mind on dealing with unexpected situations. That, and the lack of error messages in these situations, is the downside of using a framework that tries to render anything you throw at it!
If the goal is specifically to hide the tabs when pushing a new view on a NavigationView (e.g., when tapping on a conversation in a messaging app), you have to use a different solution. Apple added the UIViewController.hidesBottomBarWhenPushed property to UIKit to support this specific use case.
This property is set on the UIViewController that, when presented, should not show a toolbar. In other words: Not the UINavigationController or the UITabBarController, but the child UIViewController that you push onto the UINavigationController.
This property is not supported in SwiftUI natively. You could set it using SwiftUI-Introspect, or simply write the navigation structure of your application using UIKit and write the views inside in SwiftUI, linking them using UIHostingViewController.

SwiftUI - Navigating back to home without nesting?

In the code below, if I use the links to go back and forth between views A and B, I will end up with nested views as shown in the image. The only way I've found to avoid nesting is to never link to a view where a NavigationView is declared - as it is in ViewA below. My question...is there any way to go back to ViewA without the views nesting?
struct ViewA: View {
var body: some View {
NavigationView{
NavigationLink(destination: ViewB()) {
Text("ViewB")
}
}
.navigationBarTitle("ViewA")
}
}
struct ViewB: View {
var body: some View {
NavigationLink(destination: ViewA()) {
Text("ViewA")
}
.navigationBarTitle("ViewB")
}
}
You should not create NavigationLink(destination: ViewA()) because it is not back it creates a new ViewA. Once you navigate to ViewB, the back button will be create for you automatically.
struct ViewA: View {
var body: some View {
NavigationView{
NavigationLink(destination: ViewB()) {
Text("ViewB")
}
}
.navigationBarTitle("ViewA")
}
}
struct ViewB: View {
var body: some View {
Text("ViewB Pure Content")
.navigationBarTitle("ViewB")
}
}
You are nesting views because every time you click ViewA/ViewB it creates a new view object. You can add
#Environment(\.presentationMode) var presentationMode
and call
presentationMode.wrappedValue.dismiss()
when the view button gets pressed you dismiss it.

PresentationMode.dismiss weird behaviour when using multiple NavigationLinks inside ForEach

My app has 4 views (let's call them View_A[root] -> View_B -> View_C -> View_D). The navigation between them was made using NavigationView/NavigationLink.
When I call self.presentationMode.wrappedValue.dismiss() from the last view(View_D) I expect it to dismiss the current view (D) only, but for some reason it dismissed ALL the views and stops at view A (root view).
That's weird.
I spent a couple of hours trying to figure out what's going on there and I found that
- if I remove "ForEach" from "View_A" it works correctly and only the last view is dismissed. Even though ForEach gets just 1 static object in this example.
The second weird thing is that
- if I don't change "self.thisSession.stats" to false it also works correctly dismissing only the last view.
This is super weird as View_A (as far as I understand) is not dependent on thisSession environment variable.
Any ideas on how to prevent View_C and View_B from being dismissed in this case? I wanna end up at View_C after clicking the link, not at View_A.
Any help is appreciated, it took me a while to find out where it comes from but I'm not smart enough to proceed any further ;)
import SwiftUI
struct A_View: View {
#EnvironmentObject var thisSession: CurrentSession
var body: some View {
NavigationView {
VStack {
Text("View A")
ForEach([TestObject()], id: \.id) { _ in
NavigationLink(destination: View_B() ) {
Text("Move to View B")
}
}
}
}
}
}
struct View_B: View {
var body: some View {
NavigationView {
NavigationLink(destination: View_C()
) {
Text("GO TO VIEW C")
}
}
}
}
struct View_C: View {
var body: some View {
ZStack {
NavigationView {
NavigationLink(destination: View_D()) {
Text("GO TO VIEW D")
}
}
}
}
}
struct View_D: View {
#EnvironmentObject var thisSession: CurrentSession
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
ZStack {
VStack {
Button(action: {
self.thisSession.stats = false
self.presentationMode.wrappedValue.dismiss()
}) {
Text("Return!")
}
}
}
}
}
class CurrentSession: ObservableObject {
#Published var stats: Bool = false
#Published var user: String = "user"
}
struct TestObject: Identifiable, Codable {
let id = UUID()
}
Your issue is with:
NavigationView
There is only supposed to be one NavigationView in an entire view stack. Try removing the NavigationView from views B and C

Disable swipe-back for a NavigationLink SwiftUI

How can I disable the swipe-back gesture in SwiftUI? The child view should only be dismissed with a back-button.
By hiding the back-button in the navigation bar, the swipe-back gesture is disabled. You can set a custom back-button with .navigationBarItems()
struct ContentView: View {
var body: some View {
NavigationView{
List{
NavigationLink(destination: Text("You can swipe back")){
Text("Child 1")
}
NavigationLink(destination: ChildView()){
Text("Child 2")
}
}
}
}
}
struct ChildView: View{
#Environment(\.presentationMode) var presentationMode
var body:some View{
Text("You cannot swipe back")
.navigationBarBackButtonHidden(true)
.navigationBarItems(leading: Button("Back"){self.presentationMode.wrappedValue.dismiss()})
}
}
I use Introspect library then I just do:
import SwiftUI
import Introspect
struct ContentView: View {
var body: some View {
Text("A view that cannot be swiped back")
.introspectNavigationController { navigationController in
navigationController.interactivePopGestureRecognizer?.isEnabled = false
}
}
}
Only complete removal of the gesture recognizer worked for me.
I wrapped it up into a single modifier (to be added to the detail view).
struct ContentView: View {
var body: some View {
VStack {
...
)
.disableSwipeBack()
}
}
DisableSwipeBack.swift
import Foundation
import SwiftUI
extension View {
func disableSwipeBack() -> some View {
self.background(
DisableSwipeBackView()
)
}
}
struct DisableSwipeBackView: UIViewControllerRepresentable {
typealias UIViewControllerType = DisableSwipeBackViewController
func makeUIViewController(context: Context) -> UIViewControllerType {
UIViewControllerType()
}
func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
}
}
class DisableSwipeBackViewController: UIViewController {
override func didMove(toParent parent: UIViewController?) {
super.didMove(toParent: parent)
if let parent = parent?.parent,
let navigationController = parent.navigationController,
let interactivePopGestureRecognizer = navigationController.interactivePopGestureRecognizer {
navigationController.view.removeGestureRecognizer(interactivePopGestureRecognizer)
}
}
}
You can resolve the navigation controller without third party by using a UIViewControllerRepresentable in the SwiftUI hierarchy, then access the parent of its parent.
Adding this extension worked for me (disables swipe back everywhere, and another way of disabling the gesture recognizer):
extension UINavigationController: UIGestureRecognizerDelegate {
override open func viewDidLoad() {
super.viewDidLoad()
interactivePopGestureRecognizer?.delegate = self
}
public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return false
}
}
This answer shows how to configure your navigation controller in SwiftUI (In short, use UIViewControllerRepresentable to gain access to the UINavigationController). And this answer shows how to disable the swipe gesture. Combining them, we can do something like:
Text("Hello")
.background(NavigationConfigurator { nc in
nc.interactivePopGestureRecognizer?.isEnabled = false
})
This way you can continue to use the built in back button functionality.
Setting navigationBarBackButtonHidden to true will lose the beautiful animation when you have set the navigationTitle.
So I tried another answer
navigationController.interactivePopGestureRecognizer?.isEnabled = false
But It's not working for me.
After trying the following code works fine
NavigationLink(destination: CustomView()).introspectNavigationController {navController in
navController.view.gestureRecognizers = []
}
preview
The following more replicates the existing iOS chevron image.
For the accepted answer.
That is replace the "back" with image chevron.
.navigationBarItems(leading: Button("Back"){self.presentationMode.wrappedValue.dismiss()})
With
Button(action: {self.presentationMode.wrappedValue.dismiss()}){Image(systemName: "chevron.left").foregroundColor(Color.blue).font(Font.system(size:23, design: .serif)).padding(.leading,-6)}

SwiftUI Navigation Multiple back button

When I push more than one view, multiple back buttons are visible in the navigation bar.
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLink(destination:SecView()) {
Text("Primo")
}
}
}
}
struct SecView: View {
var body: some View {
NavigationView {
NavigationLink(destination:TerView()) {
Text("Secondo")
}
}
}
}
struct TerView: View {
var body: some View {
Text("Hello World!")
}
}
I would like to have only one back button per view.
Here is a screenshot of the problem.
There should only be a single NavigationView at the root of your navigation stack.
Remove the NavigationView block from SecView and you will then have a single navigation bar owned by ContentView.
as Gene said, there should only be a single NavigationView at the root of you navigation stack. This means that the next time you need to navigate to a page in a different View, you will add a NavigationLink but not wrap it in a NavigationView. So in the code that you initially posted, you need to remove the NavigationView from your SecView View but still keep the NavigationLink. See the code below:
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLink(destination:SecView()) {
Text("Primo")
}
}
}
}
struct SecView: View {
var body: some View {
NavigationLink(destination:TerView()) {
Text("Secondo")
}
}
}
struct TerView: View {
var body: some View {
Text("Hello World!")
}
}