I see page-based navigation is supported for WatchOS, but is there a way to access this functionality with SwiftUI?
If you are using the new SwiftUI App Lifecycle and can't access Storyboards (or just need a solution for App Delegate Cycle without using Storyboards), you can use the new Page View style in SwiftUI 2:
WindowGroup {
TabView {
Page1View()
Page2View()
}
.tabViewStyle(PageTabViewStyle())
}
Yes, this is possible. First, define hosting controllers for each of your pages like so
class Page1HostingController: WKHostingController<Page1View> {
override var body: Page1View {
self.setTitle("page1")
return Page1View()
}
}
class Page2HostingController: WKHostingController<Page2View> {
override var body: Page2View {
self.setTitle("page2")
return Page2View()
}
}
where Page1View and Page2View are your SwiftUI implementations.
Then, add new view controllers to your Interface.storyboard, set their implementation classes to your new controller classes and connect them via a "next page" segue.
There is NavigationLink button which triggers a navigation presentation when pressed.
var body: some View {
VStack() {
NavigationLink(destination: Text("Destination view"), label: {
Text("Title of the NavigationLink button")
})
}
}
Related
I am developing an app which uses UIKit. I have integrated a UIKit UIViewController inside SwiftUI and everything works as expected. I am still wondering if there is a way to 'know' when a SwiftUI View is completely gone.
My understanding is that a #StateObject knows this information. I now have some code in the deinit block of the corresponding class of the StateObject. There is some code running which unsubscribes the user of that screen.
The problem is that it is a fragile solution. In some scenario's the deinit block isn't called.
Is there any recommended way to know if the user pressed the back button in a SwiftUI View (or swiped the view away)? I don't want to get notified with the .onDisppear modifier because that is also called when the user taps somewhere on the screen which adds another view to the navigation stack. I want to run some code once when the screen is completely gone.
Is there any recommended way to know if the user pressed the back button in a SwiftUI View (or swiped the view away)?
This implies you're using a NavigationView and presenting your view with a NavigationLink.
You can be notified when the user goes “back” from your view by using one of the NavigationLink initializers that takes a Binding. Create a custom binding and in its set function, check whether the old value is true (meaning the child view was presented) and the new value is false (meaning the child view is now being popped from the stack). Example:
struct ContentView: View {
#State var childIsPresented = false
#State var childPopCount = 0
var body: some View {
NavigationView {
VStack {
Text("Child has been popped \(childPopCount) times")
NavigationLink(
"Push Child",
isActive: Binding(
get: { childIsPresented },
set: {
if childIsPresented && !$0 {
childPopCount += 1
}
childIsPresented = $0
}
)
) {
ChildView()
}
}
}
}
}
struct ChildView: View {
var body: some View {
VStack {
Text("Sweet child o' mine")
NavigationLink("Push Grandchild") {
GrandchildView()
}
}
}
}
struct GrandchildView: View {
var body: some View {
VStack {
Text("👶")
.font(.system(size: 100))
}
}
}
Note that these initializers, and NavigationView, are deprecated if your deployment target is iOS 16. In that case, you'll want to use a NavigationStack and give it a custom Binding that performs the pop-detection.
I need to navigate my page and open it like this
I was doing this in my previous app by performSegue like this
self.performSegue(withIdentifier: "goToResult", sender: self)
But now i am using SwiftUI so i need to know how can i achieve this
I am calling my page simple like this
NavigationLink(destination: LoginScreenView()) {
Text("Go To Next Step")
}
And the other page is
struct LoginScreenView: View {
var body: some View {
NavigationView {
Text("Hello, World!")
}
}
}
struct LoginScreenView_Previews: PreviewProvider {
static var previews: some View {
LoginScreenView()
.previewDevice("iPhone 11")
.previewInterfaceOrientation(.portrait)
}
}
I was learning some couse on udemy that use UIView but I am now using SwiftUI and stuck on this navigation how can I achieve this type of model navigation on this(Simple Navigation is wokring fine)
Use .sheet
// for example
NavigationView{}.sheet(isPresented: $showingSheet) {
LoginScreenView()
}
Here showingSheet is a state:
#State private var showingSheet = false
Set this state to true, to open a new page.
I have a TabView with two tabs in a SwiftUI lifecycle app, one of them has complex view structure: NavigationView with a lot of sub-views inside, i.e.: NavigationLinks and their DestinationViews are spread on multiple levels down the view tree, each sub-view on its own is another view hierarchy with sheets and / or other DestinationViews. At some point inside this hierarchy, I want to reset the TabView to its original state which is displaying the first most view, so the user can restart their journey right at that state, as they were to open the app for the first time, so it's kinda impossible to track down something like isActive & isPresented bindings to pop-off or dismiss the views and sheets.
I thought of wrapping the TabView inside another view: RootView in an attempt to find an easy way to recreate that TabView from scratch or something like refreshing / resetting the TabView, but couldn't find a clew on how to do it.
Here's my code snippet:
#main
struct TestApp: App {
var body: some Scene {
WindowGroup {
RootView()
}
}
}
struct RootView: View {
var body: some View {
ContentView()
}
}
struct ContentView: View {
var body: some View {
TabView { // <-- I need to reset it to its original state
View1() // <---- this view has complex view hierarchy
.tabItem {
Text("Home")
}.tag(0)
View2()
.tabItem {
Text("Settings")
}.tag(1)
}
}
}
p.s. I'm not looking for "popping off the view to root view", because this can't be done when there are many active NavigationLink destinations where the user might open one of the sheets and start a new navigation journey inside the sheet.
****** UPDATE ******
I've created a new Environment value to hold a boolean that should indicate whether the TabView should reset or not, and I've tracked every isPresented and isActive state variables in every view and reset them once that environment value is set to true like this:
struct ResetTabView: EnvironmentKey {
static var defaultValue: Binding<ResetTabObservable> = .constant(ResetTabObservable())
}
extension EnvironmentValues {
var resetTabView: Binding<ResetTabObservable> {
get { self[ResetTabView.self] }
set { self[ResetTabView.self] = newValue }
}
}
class ResetTabObservable: ObservableObject {
#Published var newValue = false
}
in every view that will present a sheet or push a new view I added something like this:
struct View3: View {
#State var showSheet = false
#Environment(\.resetTabView) var reset
var body: some View {
Text("This is view 3")
Button(action: {
showSheet = true
}, label: {
Text("show view 4")
})
.sheet(isPresented: $showSheet) {
View4()
}
.onReceive(reset.$newValue.wrappedValue, perform: { val in
if val == true {
showSheet = false
}
})
}
}
and in the last view (which will reset the TabView) I toggle the Environment value like this:
struct View5: View {
#Environment(\.resetTabView) var reset
var body: some View {
VStack {
Text("This is view 5")
Button(action: {
reset.newValue.wrappedValue = true
}, label: {
Text("reset tab view")
})
}
}
}
This resulted in awkward dismissal for views:
What i do for this is i make all my presentation bindings be stored using #SceneStorage("key") (instead of #State) this way they not only respect state restoration ! but you can also access them throughout your app easily by using the same key. This post gives a good example of how this enables the switching from Tab to Sidebar view on iPad.
I used this in my apps so if i have a button or something that needs to unwind many presentations it can read on all of these values and reset them back to wanted value without needing to pass around a load of bindings.
I don't know how to navigate between views with buttons.
The only thing I've found online is detail view, but I don't want a back button in the top left corner. I want two independent views connected via two buttons one on the first and one on the second.
In addition, if I were to delete the button on the second view, I should be stuck there, with the only option to going back to the first view being crashing the app.
In storyboard I would just create a button with the action TouchUpInSide() and point to the preferred view controller.
Also do you think getting into SwiftUI is worth it when you are used to storyboard?
One of the solutions is to have a #Statevariable in the main view. This view will display one of the child views depending on the value of the #Statevariable:
struct ContentView: View {
#State var showView1 = false
var body: some View {
VStack {
if showView1 {
SomeView(showView: $showView1)
.background(Color.red)
} else {
SomeView(showView: $showView1)
.background(Color.green)
}
}
}
}
And you pass this variable to its child views where you can modify it:
struct SomeView: View {
#Binding var showView: Bool
var body: some View {
Button(action: {
self.showView.toggle()
}) {
Text("Switch View")
}
}
}
If you want to have more than two views you can make #State var showView1 to be an enum instead of a Bool.
My app has simple navigation needs
List View (parent objects)
List View (child objects)
Detail View (child object)
I have this setup and working on iPhone, but when I run the app on iPad in portrait mode the master list is always hidden.
I'm using .isDetailLink(false) on the navigation link from the first list to the second, so both lists always stay in the master column. In iPad landscape everything works as expected but in portrait the detail view fills the screen. I can swipe in from the left side of the screen to show the list but I'd like to provide more clarity to the user.
I'd like to show or add the back button to show the master/list side (sort of like the Apple Notes app). On the iPhone I get the back button by default but on iPad in portrait mode there is nothing in its place.
This is what I see on iPhone
But this is what I see on iPad
Parent list
struct ParentList: View {
let firstList = ["Sample data 01", "Sample data 02", "Sample data 03", "Sample data 04", "Sample data 05"]
var body: some View {
NavigationView {
List{
ForEach(firstList, id: \.self) { item in
NavigationLink(destination: ChildList()){
Text(item)
}
.isDetailLink(false)
}
}
}
}
}
Child list
struct ChildList: View {
let secondList = ["More Sample data 01", "More Sample data 02", "More Sample data 03", "More Sample data 04", "More Sample data 05"]
var body: some View {
List{
ForEach(secondList, id: \.self) { item in
NavigationLink(destination: ChildDetail()){
Text(item)
}
}
}
}
}
Child detail
struct ChildDetail: View {
var body: some View {
Text("Child detail view")
}
}
Update: As of Oct 17, 2019 I have not found a way to get this to work. I decided to use .navigationViewStyle(StackNavigationViewStyle()) for the time being. Interestingly, this needs to go outside of the navigation view like a normal modifier, not inside it with the navigation title.
In portrait the default split view does not work. This may be fixed in future but it appears the current options are:
(a) change the navigation view style of your first list to .navigationViewStyle(StackNavigationViewStyle()) so the navigation will work like on iPhone and push each view.
(b) leave the style to default and only support landscape for iPad
(c) implement a UIKit split view controller
There also is a quite hacky workaround (see https://stackoverflow.com/a/57215664/3187762)
By adding .padding() to the NavigationView it seems to achieve the behaviour of always display the Master.
NavigationView {
MyMasterView()
DetailsView()
}.navigationViewStyle(DoubleColumnNavigationViewStyle())
.padding()
Not sure if it is intended though. Might break in the future (works using Xcode 11.0, in simulator on iOS 13.0 and device with 13.1.2).
You should not rely on it. This comment seems to be the better answer: https://stackoverflow.com/a/57919024/3187762
in iOS 13.4, a "back to master view" button has been added to the iPad layout. From the release notes:
When using a NavigationView with multiple columns, the navigation bar now shows a control to toggle the columns. (49074511)
For example:
struct MyNavView: View {
var body: some View {
NavigationView {
NavigationLink(
destination: Text("navigated"),
label: {Text("Go somwhere")}
)
.navigationBarTitle("Pick Item")
}
}
}
Has the following result:
Look this solution here
I hope this help
For my project I'm using this extension.
They will always use StackNavigationViewStyle for iPhone, iPad in a vertical orientation, and if you provide forceStackedStyle: true.
Otherwise DoubleColumnNavigationViewStyle will be used.
var body: some View {
NavigationView {
Text("Hello world")
}
.resolveNavigationViewStyle(forceStackedStyle: false)
}
extension View {
func resolveNavigationViewStyle(forceStackedStyle: Bool) -> some View {
if forceStackedStyle || UIDevice.current.userInterfaceIdiom == .phone {
return self.navigationViewStyle(StackNavigationViewStyle())
.eraseToAnyView()
} else {
return GeometryReader { p in
if p.size.height > p.size.width { self.navigationViewStyle(StackNavigationViewStyle())
} else {
self.navigationViewStyle(DoubleColumnNavigationViewStyle())
}
}
.eraseToAnyView()
}
}
}