Hi I am pretty new to using SwiftUI. I have been having trouble with adding a tap gesture to my welcome page that will allow the user to move on to another view with drop down question boxes. I currently have this:
import SwiftUI
struct ContentView: View {
var body: some View {
VStack {
Image(systemName: "Globe")
.imageScale(.large)
.foregroundColor(.accentColor)
Text("Welcome to WOD planner!")
.font(.title)
.multilineTextAlignment(.center)
.onTapGesture{ action:{
//go to question page
}
}
}
.padding()
}
}
I made another view labeled QuestionPage. Im just confused how to code this gesture to make it change and isolate the two different views.
Thanks!
I solve this by having a State variable that will track the View that I want to show. Within the WindowGroup in my App, I now present the View that the viewState refers to.
This sample code should do the trick, it will change Views if you tap on the text in the middle of the screen. I personally would rather use a button, but it can be done with onTapGesture:
enum ViewState {
case welcomeView
case questionView
}
#main
struct MyApp: App {
#State var currentView: ViewState = .welcomeView
var body: some Scene {
WindowGroup {
switch (currentView) {
case .welcomeView:
WelcomeView(viewState: $currentView)
case .questionView:
QuestionView(viewState: $currentView)
}
}
}
}
struct WelcomeView: View {
#Binding var viewState: ViewState
var body: some View {
// your view here
Text("Welcome")
.onTapGesture { viewState = .questionView }
}
}
struct QuestionView: View {
#Binding var viewState: ViewState
var body: some View {
// your view here
Text("Some questions")
.onTapGesture { viewState = .welcomeView }
}
}
Related
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.
I'm having trouble with what I think may be a bug, but most likely me doing something wrong.
I have a slightly complex navigation state variable in my model that I'm using for tracking/setting state between tab and sidebar presentations when multitasking on iPad. That all works fine except in tab mode, once I use a navigation link once I can't seem to use one again, whether the binding is on my tab view or navigation links in a list.
Would really appreciate any thoughts on this,
Cheers!
Example
NavigationItem.swift
enum SubNavigationItem: Hashable {
case overview, user, hobby
}
enum NavigationItem: Hashable {
case home(SubNavigationItem)
case settings
}
Model.swift
final class Model: ObservableObject {
#Published var selectedTab: NavigationItem = .home(.overview)
}
SwiftUIApp.swift
#main
struct SwiftUIApp: App {
#StateObject var model = Model()
var body: some Scene {
WindowGroup {
ContentView()
.environmentObject(model)
}
}
}
ContentView.swift
struct ContentView: View {
var body: some View {
AppTabNavigation()
}
}
AppTabNavigation.swift
struct AppTabNavigation: View {
#EnvironmentObject private var model: Model
var body: some View {
TabView(selection: $model.selectedTab) {
NavigationView {
HomeView()
}
.tabItem {
Label("Home", systemImage: "house")
}
.tag(NavigationItem.home(.overview))
NavigationView {
Text("Settings View")
}
.tabItem {
Label("Settings", systemImage: "gear")
}
.tag(NavigationItem.settings)
}
}
}
HomeView.swift
I created a binding here because selection required an optional <NavigationItem?> not
struct HomeView: View {
#EnvironmentObject private var model: Model
var body: some View {
let binding = Binding<NavigationItem?>(
get: {
model.selectedTab
},
set: {
guard let item = $0 else { return }
model.selectedTab = item
}
)
List {
NavigationLink(
destination: Text("Users"),
tag: .home(.user),
selection: binding
) {
Text("Users")
}
NavigationLink(
destination: Text("Hobbies"),
tag: .home(.hobby),
selection: binding
) {
Text("Hobbies")
}
}
.navigationTitle("Home")
}
}
Second Attempt
I tried making the selectedTab property optional as #Lorem Ipsum suggested. Which means I can remove the binding there. But then the TabView doesn't work with the property. So I create a binding for that and have the same issue but with the tab bar!
Make the selected tab optional
#Published var selectedTab: NavigationItem? = .home(.overview)
And get rid of that makeshift binding variable. Just use the variable
$model.selectedTab
If the variable can never be nil then something is always selected IAW with that makeshift variable it will just keep the last value.
I've created a SwiftUI "multiplatform" (iOS and macOS) app from the Xcode 12 beta 6 (12A8189n) app template.
My issue is that one of my views, AnotherView, is displaying incorrectly. Here's a gif showing the problem. Notice that AnotherView displays with the navigation stack already pushed to a non-existent view. Tapping the back button reveals the expected screen, however it is displayed only partially filling the expected area.
Here's the code:
TestNavigationApp.swift
import SwiftUI
#main
struct TestNavigationApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
ContentView.swift
import SwiftUI
struct ContentView: View {
#State private var presentingFirstView = false
var body: some View {
Button(action: { self.presentingFirstView = true }) {
Text("Present First View")
}
.sheet(isPresented: $presentingFirstView) {
FirstView(isPresented: $presentingFirstView)
}
}
}
FirstView.swift
import SwiftUI
struct FirstView: View {
#Binding var isPresented: Bool
var body: some View {
NavigationView {
EmbeddedView()
.navigationBarTitle("First View", displayMode: .large)
}
}
}
EmbeddedView.swift
import SwiftUI
struct EmbeddedView: View {
#State private var presentingAnotherView = false
var body: some View {
VStack {
Text("Embedded View")
Button(action: { self.presentingAnotherView = true }) {
Text("Present Another View")
}
}
.sheet(isPresented: $presentingAnotherView) {
AnotherView(isPresented: $presentingAnotherView)
}
}
}
AnotherView.swift
import SwiftUI
struct AnotherView: View {
#Binding var isPresented: Bool
var body: some View {
NavigationView {
Text("Another View")
.navigationBarTitle("Another View", displayMode: .large)
}
}
}
Anyway, not really sure what's happening here. Any suggestions appreciated.
Try to use navigation view style explicitly
var body: some View {
NavigationView {
Text("Another View")
.navigationBarTitle("Another View", displayMode: .large)
}.navigationViewStyle(StackNavigationViewStyle())
}
I am trying to change a view without having something over it like when you used segue in swift. But the only solution I came up with is to have a navigation bar navigationBar or a popover.
struct view1: View {
var body: some View{
Button(action: {
// go to view2``
}) {
Text("press")
}
}
}
struct view2: View {
var body: some View{
Text("yeay")
}
}
If you just want to hide the navigation bar it's easy:
import SwiftUI
struct View2: View {
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
VStack {
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
Text("POP")
}
}
.navigationBarTitle("")
.navigationBarBackButtonHidden(true)
.navigationBarHidden(true)
}
}
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLink(destination: View2()) {
Text("PUSH")
.navigationBarTitle("")
.navigationBarHidden(true)
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
If you, instead, want to get rid of the NavigationView and NavigationLink views you have to implement your own custom navigation. It's a little more complicated. The following is just a simple example of a push/pop transition between two views.
import SwiftUI
struct View2: View {
#Binding var push: Bool
var body: some View {
ZStack {
Color.yellow
Button(action: {
withAnimation(.easeOut(duration: 0.3)) {
self.push.toggle()
}
}) {
Text("POP")
}
}
.edgesIgnoringSafeArea(.all)
}
}
struct View1: View {
#Binding var push: Bool
var body: some View {
ZStack {
Color.green
Button(action: {
withAnimation(.easeOut(duration: 0.3)) {
self.push.toggle()
}
}) {
Text("PUSH")
}
}
.edgesIgnoringSafeArea(.all)
}
}
struct ContentView: View {
#State private var push = false
var body: some View {
ZStack {
if !push {
View1(push: $push)
.transition(.asymmetric(insertion: .move(edge: .leading), removal: .move(edge: .leading)))
}
if push {
View2(push: $push)
.transition(.asymmetric(insertion: .move(edge: .trailing), removal: .move(edge: .trailing)))
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Anyone coming to this later might find this to be of interest; in short, shove a hunk of data into #environment, tickle that with a button push in whatever view you want, and since it's at the very top of the overall application stack, it forces a redraw, which acts like a full view navigation, without the potential lost memory and orphaned or lost objects of the whole push/pop navigation view silliness.
It's still a little more "single page app"-ey than I'd like, but since SwiftUI is so crippled in its navigation thoroughness, it'll do nicely.
Not my site, not my link, not my tutorial, and it's buried way down in the list of hits when searching, which is a shame; this is the closest to what many are looking for. IMO, this should be baked into SwiftUI as a first class operation, and made less workaround-ey.
https://blckbirds.com/post/how-to-navigate-between-views-in-swiftui-by-using-an-environmentobject/
You can also do this completely without NavigationView. Take a look at the following example:
struct MainView: View
{
#State private var showView = "LoginView"
var body: some View
{
switch showView
{
case "LoginView":
Text("Please login.")
Button("Login")
{
showView = "NormalView"
}
case "NormalView":
Text("This is youre NormalView!")
Button("Next view")
{
showView = "NextView"
}
case "NextView":
Text("This is the NextView")
Button("Back")
{
showView = "NormalView"
}
default:
Text("Default") // you should never reach this
}
}
}
Perhaps not the best code practice, but it solves your problem.
I think this not best way but it's easy
struct ContentView: View {
#State var gotoDetail3:Bool = false
var body: some View {
NavigationView{
ZStack{
VStack {
// Normal NavigationLink
NavigationLink {
Text("Detail......")
} label: {
Text("goto..")
}
//use for change state
Button {
gotoDetail3.toggle()
} label: {
Text("goto33333")
}
}// End VStack
// Hide Navigation Link
NavigationLink(
LocalizedStringKey("123"), destination: Text("Subsequent View"),
isActive: $gotoDetail3)
.hidden()
}
}
}
}
I would like to be able to show a new view when a button is pressed on one of my views.
From the tutorials I have looked at and other answered questions here it seems like everyone is using navigation button within a navigation view, unless im mistaken navigation view is the one that gives me a menu bar right arrows the top of my app so I don't want that. when I put the navigation button in my view that wasn't a child of NavigationView it was just disabled on the UI and I couldn't click it, so I guess I cant use that.
The other examples I have seen seem to use presentation links / buttons which seem to show a sort of pop over view.
Im just looking for how to click a regular button and show another a view full screen just like performing a segue used to in the old way of doing things.
Possible solutions
1.if you want to present on top of current view(ex: presentation style in UIKit)
struct ContentView: View {
#State var showingDetail = false
var body: some View {
Button(action: {
self.showingDetail.toggle()
}) {
Text("Show Detail")
}.sheet(isPresented: $showingDetail) {
DetailView()
}
}
}
2.if you want to reset current window scene stack(ex:after login show home screen)
Button(action: goHome) {
HStack(alignment: .center) {
Spacer()
Text("Login").foregroundColor(Color.white).bold()
Spacer()
}
}
func goHome() {
if let window = UIApplication.shared.windows.first {
window.rootViewController = UIHostingController(rootView: HomeScreen())
window.makeKeyAndVisible()
}
}
3.push new view (ex: list->detail, navigation controller of UIKit)
struct ContentView: View {
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView()) {
Text("Show Detail View")
}.navigationBarTitle("Navigation")
}
}
}
}
4.update the current view based on #state property, (ex:show error message on login failure)
struct ContentView: View {
#State var error = true
var body: some View {
...
... //login email
.. //login password
if error {
Text("Failed to login")
}
}
}
For simple example you can use something like below
import SwiftUI
struct ExampleFlag : View {
#State var flag = true
var body: some View {
ZStack {
if flag {
ExampleView().tapAction {
self.flag.toggle()
}
} else {
OtherExampleView().tapAction {
self.flag.toggle()
}
}
}
}
}
struct ExampleView: View {
var body: some View {
Text("some text")
}
}
struct OtherExampleView: View {
var body: some View {
Text("other text")
}
}
but if you want to present more view this way looks nasty
You can use stack to control view state without NavigationView
For Example:
class NavigationStack: BindableObject {
let didChange = PassthroughSubject<Void, Never>()
var list: [AuthState] = []
public func push(state: AuthState) {
list.append(state)
didChange.send()
}
public func pop() {
list.removeLast()
didChange.send()
}
}
enum AuthState {
case mainScreenState
case userNameScreen
case logginScreen
case emailScreen
case passwordScreen
}
struct NavigationRoot : View {
#EnvironmentObject var state: NavigationStack
#State private var aligment = Alignment.leading
fileprivate func CurrentView() -> some View {
switch state.list.last {
case .mainScreenState:
return AnyView(GalleryState())
case .none:
return AnyView(LoginScreen().environmentObject(state))
default:
return AnyView(AuthenticationView().environmentObject(state))
}
}
var body: some View {
GeometryReader { geometry in
self.CurrentView()
.background(Image("background")
.animation(.fluidSpring())
.edgesIgnoringSafeArea(.all)
.frame(width: geometry.size.width, height: geometry.size.height,
alignment: self.aligment))
.edgesIgnoringSafeArea(.all)
.onAppear {
withAnimation() {
switch self.state.list.last {
case .none:
self.aligment = Alignment.leading
case .passwordScreen:
self.aligment = Alignment.trailing
default:
self.aligment = Alignment.center
}
}
}
}
.background(Color.black)
}
}
struct ExampleOfAddingNewView: View {
#EnvironmentObject var state: NavigationStack
var body: some View {
VStack {
Button(action:{ self.state.push(state: .emailScreen) }){
Text("Tap me")
}
}
}
}
struct ExampleOfRemovingView: View {
#EnvironmentObject var state: NavigationStack
var body: some View {
VStack {
Button(action:{ self.state.pop() }){
Text("Tap me")
}
}
}
}
In my opinion this bad way, but navigation in SwiftUI much worse