Custom back button for NavigationView's navigation bar in SwiftUI - swift

I want to add a custom navigation button that will look somewhat like this:
Now, I've written a custom BackButton view for this. When applying that view as leading navigation bar item, by doing:
.navigationBarItems(leading: BackButton())
...the navigation view looks like this:
I've played around with modifiers like:
.navigationBarItem(title: Text(""), titleDisplayMode: .automatic, hidesBackButton: true)
without any luck.
Question
How can I...
set a view used as custom back button in the navigation bar? OR:
programmatically pop the view back to its parent?
When going for this approach, I could hide the navigation bar altogether using .navigationBarHidden(true)

TL;DR
Use this to transition to your view:
NavigationLink(destination: SampleDetails()) {}
Add this to the view itself:
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
Then, in a button action or something, dismiss the view:
presentationMode.wrappedValue.dismiss()
Full code
From a parent, navigate using NavigationLink
NavigationLink(destination: SampleDetails()) {}
In DetailsView hide navigationBarBackButton and set custom back button to leading navigationBarItem,
struct SampleDetails: View {
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var btnBack : some View { Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
HStack {
Image("ic_back") // set image here
.aspectRatio(contentMode: .fit)
.foregroundColor(.white)
Text("Go back")
}
}
}
var body: some View {
List {
Text("sample code")
}
.navigationBarBackButtonHidden(true)
.navigationBarItems(leading: btnBack)
}
}

SwiftUI 1.0
It looks like you can now combine the navigationBarBackButtonHidden and .navigationBarItems to get the effect you're trying to achieve.
Code
struct Navigation_CustomBackButton_Detail: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
ZStack {
Color("Theme3BackgroundColor")
VStack(spacing: 25) {
Image(systemName: "globe").font(.largeTitle)
Text("NavigationView").font(.largeTitle)
Text("Custom Back Button").foregroundColor(.gray)
HStack {
Image("NavBarBackButtonHidden")
Image(systemName: "plus")
Image("NavBarItems")
}
Text("Hide the system back button and then use the navigation bar items modifier to add your own.")
.frame(maxWidth: .infinity)
.padding()
.background(Color("Theme3ForegroundColor"))
.foregroundColor(Color("Theme3BackgroundColor"))
Spacer()
}
.font(.title)
.padding(.top, 50)
}
.navigationBarTitle(Text("Detail View"), displayMode: .inline)
.edgesIgnoringSafeArea(.bottom)
// Hide the system back button
.navigationBarBackButtonHidden(true)
// Add your custom back button here
.navigationBarItems(leading:
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
HStack {
Image(systemName: "arrow.left.circle")
Text("Go Back")
}
})
}
}
Example
Here is what it looks like (excerpt from the "SwiftUI Views" book):

Based on other answers here, this is a simplified answer for Option 2 working for me in XCode 11.0:
struct DetailView: View {
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
Image(systemName: "gobackward").padding()
}
.navigationBarHidden(true)
}
}
Note: To get the NavigationBar to be hidden, I also needed to set and then hide the NavigationBar in ContentView.
struct ContentView: View {
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView()) {
Text("Link").padding()
}
} // Main VStack
.navigationBarTitle("Home")
.navigationBarHidden(true)
} //NavigationView
}
}

Here's a more condensed version using principles shown in the other comments to change only the text of the button. The chevron.left icon can also be easily replaced with another icon.
Create your own button, then assign it using .navigationBarItems(). I found the following format most nearly approximated the default back button.
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var backButton : some View {
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
HStack(spacing: 0) {
Image(systemName: "chevron.left")
.font(.title2)
Text("Cancel")
}
}
}
Make sure you use .navigationBarBackButtonHidden(true) to hide the default button and replace it with your own!
List(series, id:\.self, selection: $selection) { series in
Text(series.SeriesLabel)
}
.navigationBarBackButtonHidden(true)
.navigationBarItems(leading: backButton)

iOS 15+
presentationMode.wrappedValue.dismiss() is now deprecated.
It's replaced by DismissAction
private struct SheetContents: View {
#Environment(\.dismiss) private var dismiss
var body: some View {
Button("Done") {
dismiss()
}
}
}
You can create a custom back button that will use this dismiss action
struct NavBackButton: View {
let dismiss: DismissAction
var body: some View {
Button {
dismiss()
} label: {
Image("...custom back button here")
}
}
}
then attach it to your view.
.navigationBarBackButtonHidden(true) // Hide default button
.navigationBarItems(leading: NavBackButton(dismiss: self.dismiss)) // Attach custom button

I expect you want to use custom back button in all navigable screens,
so I wrote custom wrapper based on #Ashish answer.
struct NavigationItemContainer<Content>: View where Content: View {
private let content: () -> Content
#Environment(\.presentationMode) var presentationMode
private var btnBack : some View { Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
HStack {
Image("back_icon") // set image here
.aspectRatio(contentMode: .fit)
.foregroundColor(.black)
Text("Go back")
}
}
}
var body: some View {
content()
.navigationBarBackButtonHidden(true)
.navigationBarItems(leading: btnBack)
}
init(#ViewBuilder content: #escaping () -> Content) {
self.content = content
}
}
Wrap screen content in NavigationItemContainer:
Usage:
struct CreateAccountScreenView: View {
var body: some View {
NavigationItemContainer {
VStack(spacing: 21) {
AppLogoView()
//...
}
}
}
}

Swiping is not disabled this way.
Works for me. XCode 11.3.1
Put this in your root View
init() {
UINavigationBar.appearance().isUserInteractionEnabled = false
UINavigationBar.appearance().backgroundColor = .clear
UINavigationBar.appearance().barTintColor = .clear
UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .default)
UINavigationBar.appearance().shadowImage = UIImage()
UINavigationBar.appearance().tintColor = .clear
}
And this in your child View
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
Button(action: {self.presentationMode.wrappedValue.dismiss()}) {
Image(systemName: "gobackward")
}

You can use UIAppearance for this:
if let image = UIImage(named: "back-button") {
UINavigationBar.appearance().backIndicatorImage = image
UINavigationBar.appearance().backIndicatorTransitionMaskImage = image
}
This should be added early on in your app like App.init. This also preserves the native swipe back functionality.

All of the solutions I see here seem to disable swipe to go back functionality to navigate to the previous page, so sharing a solution I found that maintains that functionality. You can make an extension of your root view and override your navigation style and call the function in the view initializer.
Sample View
struct SampleRootView: View {
init() {
overrideNavigationAppearance()
}
var body: some View {
Text("Hello, World!")
}
}
Extension
extension SampleRootView {
func overrideNavigationAppearance() {
let navigationBarAppearance = UINavigationBarAppearance()
let barAppearace = UINavigationBar.appearance()
barAppearace.tintColor = *desired UIColor for icon*
barAppearace.barTintColor = *desired UIColor for icon*
navigationBarAppearance.setBackIndicatorImage(*desired UIImage for custom icon*, transitionMaskImage: *desired UIImage for custom icon*)
UINavigationBar.appearance().standardAppearance = navigationBarAppearance
UINavigationBar.appearance().compactAppearance = navigationBarAppearance
UINavigationBar.appearance().scrollEdgeAppearance = navigationBarAppearance
}
}
The only downfall to this approach is I haven't found a way to remove/change the text associated with the custom back button.

Really simple method. Only two lines code 🔥
#Environment(\.presentationMode) var presentationMode
self.presentationMode.wrappedValue.dismiss()
Example:
import SwiftUI
struct FirstView: View {
#State var showSecondView = false
var body: some View {
NavigationLink(destination: SecondView(),isActive : self.$showSecondView){
Text("Push to Second View")
}
}
}
struct SecondView : View{
#Environment(\.presentationMode) var presentationMode
var body : some View {
Button(action:{ self.presentationMode.wrappedValue.dismiss() }){
Text("Go Back")
}
}
}

This solution works for iPhone. However, for iPad it won't work because of the splitView.
import SwiftUI
struct NavigationBackButton: View {
var title: Text?
#Environment(\.presentationMode) private var presentationMode: Binding<PresentationMode>
var body: some View {
ZStack {
VStack {
ZStack {
HStack {
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
Image(systemName: "chevron.left")
.font(.title)
.frame(width: 44, height: 44)
title
}
Spacer()
}
}
Spacer()
}
}
.zIndex(1)
.navigationBarTitle("")
.navigationBarHidden(true)
}
}
struct NavigationBackButton_Previews: PreviewProvider {
static var previews: some View {
NavigationBackButton()
}
}

I found this: https://ryanashcraft.me/swiftui-programmatic-navigation/
It does work, and it may lay the foundation for a state machine to control what is showing, but it is not a simple as it was before.
import Combine
import SwiftUI
struct DetailView: View {
var onDismiss: () -> Void
var body: some View {
Button(
"Here are details. Tap to go back.",
action: self.onDismiss
)
}
}
struct RootView: View {
var link: NavigationDestinationLink<DetailView>
var publisher: AnyPublisher<Void, Never>
init() {
let publisher = PassthroughSubject<Void, Never>()
self.link = NavigationDestinationLink(
DetailView(onDismiss: { publisher.send() }),
isDetail: false
)
self.publisher = publisher.eraseToAnyPublisher()
}
var body: some View {
VStack {
Button("I am root. Tap for more details.", action: {
self.link.presented?.value = true
})
}
.onReceive(publisher, perform: { _ in
self.link.presented?.value = false
})
}
}
struct ContentView: View {
var body: some View {
NavigationView {
RootView()
}
}
}
If you want to hide the button then you can replace the DetailView with this:
struct LocalDetailView: View {
var onDismiss: () -> Void
var body: some View {
Button(
"Here are details. Tap to go back.",
action: self.onDismiss
)
.navigationBarItems(leading: Text(""))
}
}

Just write this:
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
}.onAppear() {
UINavigationBar.appearance().tintColor = .clear
UINavigationBar.appearance().backIndicatorImage = UIImage(named: "back")?.withRenderingMode(.alwaysOriginal)
UINavigationBar.appearance().backIndicatorTransitionMaskImage = UIImage(named: "back")?.withRenderingMode(.alwaysOriginal)
}
}
}

On iOS 14+ it's actually very easy using presentationMode variable
In this example NewItemView will get dismissed on addItem completion:
struct NewItemView: View {
#State private var itemDescription:String = ""
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
VStack {
TextEditor(text: $itemDescription)
}.onTapGesture {
hideKeyboard()
}.toolbar {
ToolbarItem {
Button(action: addItem){
Text("Save")
}
}
}.navigationTitle("Add Question")
}
private func addItem() {
// Add save logic
// ...
// Dismiss on complete
presentationMode.wrappedValue.dismiss()
}
private func hideKeyboard() {
UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
}
}
struct NewItemView_Previews: PreviewProvider {
static var previews: some View {
NewItemView()
}
}
In case you need the parent (Main) view:
struct SampleMainView: View {
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(
sortDescriptors: [NSSortDescriptor(keyPath: \DbQuestion.timestamp, ascending: true)],
animation: .default)
private var items: FetchedResults<Item>
var body: some View {
NavigationView {
List {
ForEach(items) { item in
NavigationLink {
Text("This is item detail page")
} label: {
Text("Item at \(item.id)")
}
}
}
.toolbar {
ToolbarItem {
// Creates a button on toolbar
NavigationLink {
// New Item Page
NewItemView()
} label: {
Text("Add item")
}
}
ToolbarItem(placement: .navigationBarTrailing) {
EditButton()
}
}.navigationTitle("Main Screen")
}
}
}

Related

SwiftUI: How can I change the Color of Alert Button and NavigationLink back button?

How can I change the Color from the Button in a Alert and the back Button from NavigationLink? To set .accentColor(.init("someColor")) after the Text from the Alert Button doesn't work. To set .accentColor(.init("someColor")) after navigationLink does not work too. What can I do?
The Alert Button:
The Back Button from NavigationLink:
struct ContentView: View {
#State var showSheet = false
#State var alertShouldBeShown = !UserDefaults.standard.bool(forKey: "£Start")
var body: some View {
Button(action: {
self.showSheet.toggle()
}) {
Text("click me")
//.accentColor(colorScheme == .dark ? Image("") : Image("Info-Icon"))
}.sheet(isPresented: $showSheet) {
SheetView(showSheet: self.$showSheet)
}
.alert(isPresented: $alertShouldBeShown, content: {
Alert(title: Text("Headline"),
message: Text("Text"),
dismissButton: Alert.Button.default(
Text("Ok"), action: {
UserDefaults.standard.set(true, forKey: "Start")
}
)
)
})
}
}
struct SheetView: View {
#Binding var showSheet: Bool
var body: some View {
NavigationView {
DetailView()
.navigationBarTitle(Text("Headline"), displayMode: .inline)
.navigationBarItems(trailing: Button(action: {
self.showSheet = false
}) {
Text("Done")
.bold()
})
}.navigationViewStyle(StackNavigationViewStyle())
}
}
struct DetailView: View {
var body: some View {
List {
HStack {
NavigationLink(destination: DetailViewOne()) {
Text("View 1")
}
}
HStack {
NavigationLink(destination: DetailViewTwo()) {
Text("View 2")
}
}
}
}
}
struct DetailViewOne: View {
var body: some View {
Text("1")
}
}
struct DetailViewTwo: View {
var body: some View {
Text("2")
}
}
You can change the NavigationBar accent color by using accentColor but you need to apply it to the SheetView (the root view of a given environment):
SheetView(showSheet: self.$showSheet)
.accentColor(.red)
Unfortunately SwiftUI doesn't allow much of Alert customisation so far.
However, as Alert is built on top of UIKit components (UIAlertController) this also means you can change the appearance of UIView when contained in UIAlertController.
You can put this code in your #main App init or in the SceneDelegate:
UIView.appearance(whenContainedInInstancesOf: [UIAlertController.self]).tintColor = .red

Button, how to open a new View in swiftUI embedded in navigation bar

I embedded a button on on the NavigationBar.
I'm try to make button to open a new View called DetailView
I try to use NavigationLink but it does't work inside a button.
import SwiftUI
struct ContentView: View {
#ObservedObject var dm: DataManager
#State var isAddPresented = false
var body: some View {
NavigationView {
HStack {
List () {
ForEach (dm.storage) { data in
StileCella(dm2: data)
}
}
.navigationBarTitle("Lista Rubrica")
.navigationBarItems(trailing: Button(action: {
self.isAddPresented = true
// Load here the DetailView??? How??
DetailView()
}) {
Text("Button")
})
}
}
}
}
struct DetailView: View {
var body: some View {
VStack(alignment: .center) {
Text("CIAO").bold()
Spacer()
Image(systemName: "star")
.resizable()
}
}
}
You just need to add a sheet modifier to your view, which presents your view depending on the value of isAddPresented, just like this:
struct ContentView: View {
#State var isAddPresented = false
var body: some View {
NavigationView {
List(dm.storage){ data in
StileCella(dm2: data)
}
.navigationBarTitle("Lista Rubrica")
.navigationBarItems(trailing: Button("Button") {
self.isAddPresented = true
})
} .sheet(isPresented: $isAddPresented,
onDismiss: { self.isAddPresented = false }) {
DetailView()
}
}
}
The important bit is to remember to set isAddPresented back to false in on dismiss to prevent it form presenting again.
If you want to open a new view just like we used to open through storyboard other than sheet, you can update the code in the following way:
import SwiftUI
struct ContentView: View {
#ObservedObject var dm: DataManager
#State var isAddPresented = false
var body: some View {
NavigationView {
HStack {
List () {
ForEach (dm.storage) { data in
StileCella(dm2: data)
}
}
.navigationBarTitle("Lista Rubrica")
.navigationBarItems(leading:
NavigationLink(destination: DetailView()) {
Text("Button")
})
}
}
}
}
struct DetailView: View {
var body: some View {
VStack(alignment: .center) {
Text("CIAO").bold()
Spacer()
Image(systemName: "star")
.resizable()
}
}
}
Instead of button, simply add NavigationLink inside navigationBarItems. This would do the trick! I wrote the complete for guidance but main change point is, I used
.navigationBarItems(leading:
NavigationLink(destination: DetailView()) {
Text("Button")
})
instead of:
.navigationBarItems(trailing: Button(action: {
self.isAddPresented = true
// Load here the DetailView??? How??
DetailView()
}) {
Text("Button")
})

How to resolve "Use of unresolved identifier 'PresentationLink'" error in swiftUI? [duplicate]

I am attempting to dismiss a modal view presented via a .sheet in SwiftUI - called by a Button which is within a NavigationViews navigationBarItems, as per below:
struct ModalView : View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
Button(action: {
self.presentationMode.value.dismiss()
}, label: { Text("Save")})
}
}
struct ContentView : View {
#State var showModal: Bool = false
var body: some View {
NavigationView {
Text("test")
.navigationBarTitle(Text("Navigation Title Text"))
.navigationBarItems(trailing:
Button(action: {
self.showModal = true
}, label: { Text("Add") })
.sheet(isPresented: $showModal, content: { ModalView() })
)
}
}
}
The modal does not dismiss when the Save button is tapped, it just remains on screen. The only way to get rid of it is swiping down on the modal.
Printing the value of self.presentationMode.value always shows false so it seems to think that it hasn't been presented.
This only happens when it is presented from the NavigationView. Take that out and it works fine.
Am I missing something here, or is this a beta issue?
You need to move the .sheet outside the Button.
NavigationView {
Text("test")
.navigationBarTitle(Text("Navigation Title Text"))
.navigationBarItems(trailing:
Button("Add") {
self.showModal = true
}
)
.sheet(isPresented: $showModal, content: { ModalView() })
}
You can even move it outside the NavigationView closure.
NavigationView {
Text("test")
.navigationBarTitle(Text("Navigation Title Text"))
.navigationBarItems(trailing:
Button("Add") { self.showModal = true }
)
}
.sheet(isPresented: $showModal, content: { ModalView() })
Notice you can also simplify the Button call if you have a simple text button.
The solution is not readily apparent in the documentation and most tutorials opt for simple solutions. But I really wanted a button in the NavigationBar of the sheet that would dismiss the sheet. Here is the solution in six steps:
Set the DetailView to not show.
Add a button to set the DetailView to show.
Call the .sheet(isPresented modifier to display the sheet.
Wrap the view that will appear in the sheet in a NavigationView because we want to display a .navigationBarItem button.
PresentationMode is required to dismiss the sheet view.
Add a button to the NavBar and call the dismiss method.
import SwiftUI
struct ContentView: View {
// 1
#State private var showingDetail = false
var body: some View {
VStack {
Text("Hello, world!")
.padding()
Button("Show Detail") {
showingDetail = true // 2
}
// 3
.sheet(isPresented: $showingDetail) {
// 4
NavigationView {
DetailView()
}
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct DetailView: View {
// 5
#Environment(\.presentationMode) var presentationMode
var body: some View {
Text("Detail View!")
// 6
.navigationBarItems(leading: Button(action: {
presentationMode.wrappedValue.dismiss()
}) {
Image(systemName: "x.circle")
.font(.headline)
.foregroundColor(.accentColor)
})
}
}

SwiftUI: Global Overlay That Can Be Triggered From Any View

I'm quite new to the SwiftUI framework and I haven't wrapped my head around all of it yet so please bear with me.
Is there a way to trigger an "overlay view" from inside "another view" when its binding changes? See illustration below:
I figure this "overlay view" would wrap all my views. I'm not sure how to do this yet - maybe using ZIndex. I also guess I'd need some sort of callback when the binding changes, but I'm also not sure how to do that either.
This is what I've got so far:
ContentView
struct ContentView : View {
#State private var liked: Bool = false
var body: some View {
VStack {
LikeButton(liked: $liked)
}
}
}
LikeButton
struct LikeButton : View {
#Binding var liked: Bool
var body: some View {
Button(action: { self.toggleLiked() }) {
Image(systemName: liked ? "heart" : "heart.fill")
}
}
private func toggleLiked() {
self.liked = !self.liked
// NEED SOME SORT OF TOAST CALLBACK HERE
}
}
I feel like I need some sort of callback inside my LikeButton, but I'm not sure how this all works in Swift.
Any help with this would be appreciated. Thanks in advance!
It's quite easy - and entertaining - to build a "toast" in SwiftUI!
Let's do it!
struct Toast<Presenting>: View where Presenting: View {
/// The binding that decides the appropriate drawing in the body.
#Binding var isShowing: Bool
/// The view that will be "presenting" this toast
let presenting: () -> Presenting
/// The text to show
let text: Text
var body: some View {
GeometryReader { geometry in
ZStack(alignment: .center) {
self.presenting()
.blur(radius: self.isShowing ? 1 : 0)
VStack {
self.text
}
.frame(width: geometry.size.width / 2,
height: geometry.size.height / 5)
.background(Color.secondary.colorInvert())
.foregroundColor(Color.primary)
.cornerRadius(20)
.transition(.slide)
.opacity(self.isShowing ? 1 : 0)
}
}
}
}
Explanation of the body:
GeometryReader gives us the preferred size of the superview , thus allowing the perfect sizing for our Toast.
ZStack stacks views on top of each other.
The logic is trivial: if the toast is not supposed to be seen (isShowing == false), then we render the presenting view. If the toast has to be presented (isShowing == true), then we render the presenting view with a little bit of blur - because we can - and we create our toast next.
The toast is just a VStack with a Text, with custom frame sizing, some design bells and whistles (colors and corner radius), and a default slide transition.
I added this method on View to make the Toast creation easier:
extension View {
func toast(isShowing: Binding<Bool>, text: Text) -> some View {
Toast(isShowing: isShowing,
presenting: { self },
text: text)
}
}
And a little demo on how to use it:
struct ContentView: View {
#State var showToast: Bool = false
var body: some View {
NavigationView {
List(0..<100) { item in
Text("\(item)")
}
.navigationBarTitle(Text("A List"), displayMode: .large)
.navigationBarItems(trailing: Button(action: {
withAnimation {
self.showToast.toggle()
}
}){
Text("Toggle toast")
})
}
.toast(isShowing: $showToast, text: Text("Hello toast!"))
}
}
I used a NavigationView to make sure the view fills the entire screen, so the Toast is sized and positioned correctly.
The withAnimation block ensures the Toast transition is applied.
How it looks:
It's easy to extend the Toast with the power of SwiftUI DSL.
The Text property can easily become a #ViewBuilder closure to accomodate the most extravagant of the layouts.
To add it to your content view:
struct ContentView : View {
#State private var liked: Bool = false
var body: some View {
VStack {
LikeButton(liked: $liked)
}
// make it bigger by using "frame" or wrapping it in "NavigationView"
.toast(isShowing: $liked, text: Text("Hello toast!"))
}
}
How to hide the toast afte 2 seconds (as requested):
Append this code after .transition(.slide) in the toast VStack.
.onAppear {
DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
withAnimation {
self.isShowing = false
}
}
}
Tested on Xcode 11.1
I modified Matteo Pacini's great answer, above, incorporating comments to have the Toast fade in and fade out after a delay. I also modified the View extension to be a bit more generic, and to accept a trailing closure similar to the way .sheet works.
ContentView.swift:
struct ContentView: View {
#State private var lightsOn: Bool = false
#State private var showToast: Bool = false
var body: some View {
VStack {
Button(action: {
if (!self.showToast) {
self.lightsOn.toggle()
withAnimation {
self.showToast = true
}
}
}){
Text("switch")
} //Button
.padding(.top)
Image(systemName: self.lightsOn ? "lightbulb" : "lightbulb.fill")
.resizable()
.aspectRatio(contentMode: .fit)
.padding(.all)
.toast(isPresented: self.$showToast) {
HStack {
Text("Lights: \(self.lightsOn ? "ON" : "OFF")")
Image(systemName: self.lightsOn ? "lightbulb" : "lightbulb.fill")
} //HStack
} //toast
} //VStack
} //body
} //ContentView
View+Toast.swift:
extension View {
func toast<Content>(isPresented: Binding<Bool>, content: #escaping () -> Content) -> some View where Content: View {
Toast(
isPresented: isPresented,
presenter: { self },
content: content
)
}
}
Toast.swift:
struct Toast<Presenting, Content>: View where Presenting: View, Content: View {
#Binding var isPresented: Bool
let presenter: () -> Presenting
let content: () -> Content
let delay: TimeInterval = 2
var body: some View {
if self.isPresented {
DispatchQueue.main.asyncAfter(deadline: .now() + self.delay) {
withAnimation {
self.isPresented = false
}
}
}
return GeometryReader { geometry in
ZStack(alignment: .bottom) {
self.presenter()
ZStack {
Capsule()
.fill(Color.gray)
self.content()
} //ZStack (inner)
.frame(width: geometry.size.width / 1.25, height: geometry.size.height / 10)
.opacity(self.isPresented ? 1 : 0)
} //ZStack (outer)
.padding(.bottom)
} //GeometryReader
} //body
} //Toast
With this you could toast Text, or an Image (or both, as shown below), or any other View.
here is the how to overlay on all of your views including NavigationView!
create a class model to store your views!
class ParentView:ObservableObject {
#Published var view:AnyView = AnyView(EmptyView())
}
create the model in your parrent view and call it in your view hierarchy
pass this class to your environment object of your parent view
struct Example: View {
#StateObject var parentView = ParentView()
var body: some View {
ZStack{
NavigationView{
ChildView()
.environmentObject(parentView)
.navigationTitle("dynamic parent view")
}
parentView.view
}
}
}
from now on you can call parentview in your child view by
#EnvironmentObject var parentView:ParentView
then for example in your tap gesture, you can change the parent view and show a pop up that covers everything including your navigationviews
#StateObject var parentView = ParentView()
here is the full solution copy and play with it in your preview!
import SwiftUI
class ParentView:ObservableObject {
#Published var view:AnyView = AnyView(EmptyView())
}
struct example: View {
#StateObject var parentView = ParentView()
var body: some View {
ZStack{
NavigationView{
ChildView()
.environmentObject(parentView)
.navigationTitle("dynamic parent view")
}
parentView.view
}
}
}
struct ChildView: View {
#EnvironmentObject var parentView:ParentView
var body: some View {
ZStack{
Text("hello")
.onTapGesture {
parentView.view = AnyView(Color.red.opacity(0.4).ignoresSafeArea())
}
}
}
}
struct example_Previews: PreviewProvider {
static var previews: some View {
example()
}
}
also you can improve this dramatically like this...!
struct ParentViewModifire:ViewModifier {
#EnvironmentObject var parentView:ParentView
#Binding var presented:Bool
let anyView:AnyView
func body(content: Content) -> some View {
content
.onChange(of: presented, perform: { value in
if value {
parentView.view = anyView
}
})
}
}
extension View {
func overlayAll<Overlay>(_ overlay: Overlay, presented: Binding<Bool>) -> some View where Overlay : View {
self
.modifier(ParentViewModifire(presented: presented, anyView: AnyView(overlay)))
}
}
now in your child view you can call this modifier on your view
struct ChildView: View {
#State var newItemPopUp:Bool = false
var body: some View {
ZStack{
Text("hello")
.overlayAll(newCardPopup, presented: $newItemPopUp)
}
}
}
App-wide View
If you want it to be app-wide, put in somewhere app-wide! For example, you can add it to the MyProjectApp.swift (or in sceneDelegate for UIKit/AppDelegate projects) file like this:
Note that the button and the State are just for more explanation and you may consider changing them in the way you like
#main
struct SwiftUIAppPlaygroundApp: App { // <- Note that where we are!
#State var showToast = false
var body: some Scene {
WindowGroup {
Button("App-Wide Button") { showToast.toggle() }
ZStack {
ContentView() // <- The app flow
if showToast {
MyCustomToastView().ignoresSafeArea(.all, edges: .all) // <- App-wide overlays
}
}
}
}
}
See? now you can add any sort of view on anywhere of the screen, without blocking animations. Just convert that #State to some sort of AppState like Observables or Environments and boom! 💥 you did it!
Note that it is a demo, you should use an environment variable or smt to be able for changing it from outside of this view's body
Apple does not currently provide any APIs that allow you to make global views similar to their own alert pop-ups.
In fact these views are actually still using UIKit under the hood.
If you want your own global pop-ups you can sort of hack your own (note this isn't tested, but something very similar should work for global presentation of toasts):
import SwiftUI
import Foundation
/// Global class that will manage toasts
class ToastPresenter: ObservableObject {
// This static property probably isn't even needed as you can inject via #EnvironmentObject
static let shared: ToastPresenter = ToastPresenter()
private init() {}
#Published private(set) var isPresented: Bool = false
private(set) var text: String?
private var timer: Timer?
/// Call this function to present toasts
func presentToast(text: String, duration: TimeInterval = 5) {
// reset the toast if one is currently being presented.
isPresented = false
self.text = nil
timer?.invalidate()
self.text = text
isPresented = true
timer = Timer(timeInterval: duration, repeats: false) { [weak self] _ in
self?.isPresented = false
}
}
}
/// The UI for a toast
struct Toast: View {
var text: String
var body: some View {
Text(text)
.padding()
.background(Capsule().fill(Color.gray))
.shadow(radius: 6)
.transition(AnyTransition.opacity.animation(.default))
}
}
extension View {
/// ViewModifier that will present a toast when its binding changes
#ViewBuilder func toast(presented: Binding<Bool>, text: String) -> some View {
ZStack {
self
if presented.wrappedValue {
Toast(text: text)
}
}
.ignoresSafeArea(.all, edges: .all)
}
}
/// The first view in your app's view hierarchy
struct RootView: View {
#StateObject var toastPresenter = ToastPresenter.shared
var body: some View {
MyAppMainView()
.toast(presented: $toastPresenter.isPresented, text: toastPresenter.text)
// Inject the toast presenter into the view hierarchy
.environmentObject(toastPresenter)
}
}
/// Some view later on in the app
struct SomeViewDeepInTheHierarchy: View {
#EnvironmentObject var toastPresenter: ToastPresenter
var body: some View {
Button {
toastPresenter.presentToast(text: "Hello World")
} label: {
Text("Show Toast")
}
}
}
Use .presentation() to show an alert when the button is tapped.
In LikeButton:
#Binding var liked: Bool
var body: some View {
Button(action: {self.liked = !self.liked}, label: {
Image(systemName: liked ? "heart.fill" : "heart")
}).presentation($liked) { () -> Alert in
Alert.init(title: Text("Thanks for liking!"))
}
}
You can also use .presentation() to present other Modal views, like a Popover or ActionSheet. See here and the "See Also" section on that page in Apple's SwiftUI documentation for info on the different .presentation() options.
Edit: Example of what you want with a custom view using Popover:
#State var liked = false
let popover = Popover(content: Text("Thanks for liking!").frame(width: 200, height: 100).background(Color.white), dismissHandler: {})
var body: some View {
Button(action: {self.liked = !self.liked}, label: {
Image(systemName: liked ? "heart.fill" : "heart")
}).presentation(liked ? popover : nil)
}
I am using this open source: https://github.com/huynguyencong/ToastSwiftUI . It is very simple to use.
struct ContentView: View {
#State private var isShowingToast = false
var body: some View {
VStack(spacing: 20) {
Button("Show toast") {
self.isShowingToast = true
}
Spacer()
}
.padding()
// Just add a modifier to show a toast, with binding variable to control
.toast(isPresenting: $isShowingToast, dismissType: .after(3)) {
ToastView(message: "Hello world!", icon: .info)
}
}
}

SwiftUI - Is there a popViewController equivalent in SwiftUI?

I was playing around with SwiftUI and want to be able to come back to the previous view when tapping a button, the same we use popViewController inside a UINavigationController.
Is there a provided way to do it so far ?
I've also tried to use NavigationDestinationLink to do so without success.
struct AView: View {
var body: some View {
NavigationView {
NavigationButton(destination: BView()) {
Text("Go to B")
}
}
}
}
struct BView: View {
var body: some View {
Button(action: {
// Trying to go back to the previous view
// previously: navigationController.popViewController(animated: true)
}) {
Text("Come back to A")
}
}
}
Modify your BView struct as follows. The button will perform just as popViewController did in UIKit.
struct BView: View {
#Environment(\.presentationMode) var mode: Binding<PresentationMode>
var body: some View {
Button(action: { self.mode.wrappedValue.dismiss() })
{ Text("Come back to A") }
}
}
Use #Environment(\.presentationMode) var presentationMode to go back previous view. Check below code for more understanding.
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
ZStack {
Color.gray.opacity(0.2)
NavigationLink(destination: NextView(), label: {Text("Go to Next View").font(.largeTitle)})
}.navigationBarTitle(Text("This is Navigation"), displayMode: .large)
.edgesIgnoringSafeArea(.bottom)
}
}
}
struct NextView: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
ZStack {
Color.gray.opacity(0.2)
}.navigationBarBackButtonHidden(true)
.navigationBarItems(leading: Button(action: {
self.presentationMode.wrappedValue.dismiss()
}, label: { Image(systemName: "arrow.left") }))
.navigationBarTitle("", displayMode: .inline)
}
}
struct NameRow: View {
var name: String
var body: some View {
HStack {
Image(systemName: "circle.fill").foregroundColor(Color.green)
Text(name)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
With State Variables. Try that.
struct ContentViewRoot: View {
#State var pushed: Bool = false
var body: some View {
NavigationView{
VStack{
NavigationLink(destination:ContentViewFirst(pushed: self.$pushed), isActive: self.$pushed) { EmptyView() }
.navigationBarTitle("Root")
Button("push"){
self.pushed = true
}
}
}
.navigationViewStyle(StackNavigationViewStyle())
}
}
struct ContentViewFirst: View {
#Binding var pushed: Bool
#State var secondPushed: Bool = false
var body: some View {
VStack{
NavigationLink(destination: ContentViewSecond(pushed: self.$pushed, secondPushed: self.$secondPushed), isActive: self.$secondPushed) { EmptyView() }
.navigationBarTitle("1st")
Button("push"){
self.secondPushed = true;
}
}
}
}
struct ContentViewSecond: View {
#Binding var pushed: Bool
#Binding var secondPushed: Bool
var body: some View {
VStack{
Spacer()
Button("PopToRoot"){
self.pushed = false
} .navigationBarTitle("2st")
Spacer()
Button("Pop"){
self.secondPushed = false
} .navigationBarTitle("1st")
Spacer()
}
}
}
This seems to work for me on watchOS (haven't tried on iOS):
#Environment(\.presentationMode) var presentationMode
And then when you need to pop
self.presentationMode.wrappedValue.dismiss()
There is now a way to programmatically pop in a NavigationView, if you would like. This is in beta 5.
Notice that you don't need the back button. You could programmatically trigger the showSelf property in the DetailView any way you like. And you don't have to display the "Push" text in the master. That could be an EmptyView(), thereby creating an invisible segue.
(The new NavigationLink functionality takes over the deprecated NavigationDestinationLink)
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
MasterView()
}
}
}
struct MasterView: View {
#State var showDetail = false
var body: some View {
VStack {
NavigationLink(destination: DetailView(showSelf: $showDetail), isActive: $showDetail) {
Text("Push")
}
}
}
}
struct DetailView: View {
#Binding var showSelf: Bool
var body: some View {
Button(action: {
self.showSelf = false
}) {
Text("Pop")
}
}
}
#if DEBUG
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
#endif
It seems that a ton of basic navigation functionality is super buggy, which is disappointing and may be worth walking away from for now to save hours of frustration. For me, PresentationButton is the only one that works. TabbedView tabs don't work properly, and NavigationButton doesn't work for me at all. Sounds like YMMV if NavigationButton works for you.
I'm hoping that they fix it at the same time they fix autocomplete, which would give us much better insight as to what is available to us. In the meantime, I'm reluctantly coding around it and keeping notes for when fixes come out. It sucks to have to figure out if we're doing something wrong or if it just doesn't work, but that's beta for you!
Update: the NavigationDestinationLink API in this solution has been deprecated as of iOS 13 Beta 5. It is now recommended to use NavigationLink with an isActive binding.
I figured out a solution for programmatic pushing/popping of views in a NavigationView using NavigationDestinationLink.
Here's a simple example:
import Combine
import SwiftUI
struct DetailView: View {
var onDismiss: () -> Void
var body: some View {
Button(
"Here are details. Tap to go back.",
action: self.onDismiss
)
}
}
struct MainView: View {
var link: NavigationDestinationLink<DetailView>
var publisher: AnyPublisher<Void, Never>
init() {
let publisher = PassthroughSubject<Void, Never>()
self.link = NavigationDestinationLink(
DetailView(onDismiss: { publisher.send() }),
isDetail: false
)
self.publisher = publisher.eraseToAnyPublisher()
}
var body: some View {
VStack {
Button("I am root. Tap for more details.", action: {
self.link.presented?.value = true
})
}
.onReceive(publisher, perform: { _ in
self.link.presented?.value = false
})
}
}
struct RootView: View {
var body: some View {
NavigationView {
MainView()
}
}
}
I wrote about this in a blog post here.
You can also do it with .sheet
.navigationBarItems(trailing: Button(action: {
self.presentingEditView.toggle()
}) {
Image(systemName: "square.and.pencil")
}.sheet(isPresented: $presentingEditView) {
EditItemView()
})
In my case I use it from a right navigation bar item, then you have to create the view (EditItemView() in my case) that you are going to display in that modal view.
https://developer.apple.com/documentation/swiftui/view/sheet(ispresented:ondismiss:content:)
EDIT: This answer over here is better than mine, but both work: SwiftUI dismiss modal
What you really want (or should want) is a modal presentation, which several people have mentioned here. If you go that path, you definitely will need to be able to programmatically dismiss the modal, and Erica Sadun has a great example of how to do that here: https://ericasadun.com/2019/06/16/swiftui-modal-presentation/
Given the difference between declarative coding and imperative coding, the solution there may be non-obvious (toggling a bool to false to dismiss the modal, for example), but it makes sense if your model state is the source of truth, rather than the state of the UI itself.
Here's my quick take on Erica's example, using a binding passed into the TestModal so that it can dismiss itself without having to be a member of the ContentView itself (as Erica's is, for simplicity).
struct TestModal: View {
#State var isPresented: Binding<Bool>
var body: some View {
Button(action: { self.isPresented.value = false }, label: { Text("Done") })
}
}
struct ContentView : View {
#State var modalPresented = false
var body: some View {
NavigationView {
Text("Hello World")
.navigationBarTitle(Text("View"))
.navigationBarItems(trailing:
Button(action: { self.modalPresented = true }) { Text("Show Modal") })
}
.presentation(self.modalPresented ? Modal(TestModal(isPresented: $modalPresented)) {
self.modalPresented.toggle()
} : nil)
}
}
Below works for me in XCode11 GM
self.myPresentationMode.wrappedValue.dismiss()
instead of NavigationButton use Navigation DestinationLink
but You should import Combine
struct AView: View {
var link: NavigationDestinationLink<BView>
var publisher: AnyPublisher<Void, Never>
init() {
let publisher = PassthroughSubject<Void, Never>()
self.link = NavigationDestinationLink(
BView(onDismiss: { publisher.send() }),
isDetail: false
)
self.publisher = publisher.eraseToAnyPublisher()
}
var body: some View {
NavigationView {
Button(action:{
self.link.presented?.value = true
}) {
Text("Go to B")
}.onReceive(publisher, perform: { _ in
self.link.presented?.value = false
})
}
}
}
struct BView: View {
var onDismiss: () -> Void
var body: some View {
Button(action: self.onDismiss) {
Text("Come back to A")
}
}
}
In the destination pass the view you want to redirect, and inside block pass data you to pass in another view.
NavigationLink(destination: "Pass the particuter View") {
Text("Push")
}