SwiftUI Change color theme programmatically - swiftui

I have .light and .dark theme.
In preview (MyContainer_Previews) I can change them by:
ForEach([.light,.dark], id: \.self) { theme in
Group {
...
}
.environment(\.colorScheme, theme) //This line
}
...
How can I change app theme on the fly (f.e. button action).
I tri to change it in SceneDelegate:
let contentView = ContentView()
contentView.environment(\.colorScheme, .dark) //Not work

Reactive:
return NavigationView {
VStack(alignment: .trailing, spacing: 0) {
...
}
}
.environment(\.colorScheme, appState.options.theme == .light ? .light : .dark)

Some one told me if you put you code in NavagationView, you can use your enviorment to change the scheme.
var body: some View {
NavigationView{
//Your view here
}}
let contentView = ContentView()
contentView.environment(\.colorScheme, .dark) //works now
UIHostingController(rootView: ContentView().environment(\.colorScheme, .light)
struct ContentView: View {
var body: some View {
NavigationView{
Text("!")
}}}

Related

How hide navigation bar always back from any view directly using NavigationView?

I am using xcode-14.2 & minimum target version 14. I have three views ContentView, Welcome & `FundTransfer. Here is my case.
ContentView - Load first view & navigationBarHidden is working. When Welcome page button click it goes to Welcome page
Welcome view - When Fund Transfer button is clicked, it goes to FundTransfer view
FundTransfer - when Log out button is clicked, it goes to ContentView
It goeslike: ContentView-> FundTransfer-> ContentView
Problem: When it goes from FundTransfer view to ContentView it shows navigationBar. That means when back from FundTransfer view to ContentView shows navigationBar which was hidden at the first.
How do I hide navigation bar always back from any view directly to ContentView?
Here is my code:
ContentView:
struct ContentView: View {
#State private var showWelcome = false
#State var isNavigationBarHidden: Bool = true
var body: some View {
NavigationView {
VStack {
ScrollView {
VStack(alignment: .customCenter,spacing: 0){
VStack {
SubmitButton(action: {
self.showWelcome = true
}) {
Text("Welcome page")
}
}
NavigationLink(destination: Welcome(), isActive: $showWelcome) { EmptyView() }
}
}
}
.navigationBarTitle("") //this must be empty
.navigationBarHidden(true)
.navigationBarBackButtonHidden(true)
}
}
}
Welcome View:
struct Welcome: View {
#State private var showFundTransfer = false
#Environment(\.presentationMode) var presentationMode
var body: some View {
VStack {
ScrollView {
VStack(alignment: .customCenter,spacing: 0){
VStack {
SubmitButton(action: {
showFundTransfer = true
}) {
Text("Fund Transfer")
}
}
NavigationLink(destination: FundTransfer(), isActive: $showFundTransfer) { EmptyView() }
}
}
.navigationBarHidden(true)
}
}
}
FundTransfer View:
struct FundTransfer: View {
#State var isNavigationBarHidden: Bool = true
#State private var logon = false
var body: some View {
VStack {
ScrollView {
VStack(alignment: .customCenter,spacing: 0){
SubmitButton(action: {
self.logon = true
}) {
Text("Log out")
}
}
}
NavigationLink(destination: ApplicationSwitcher(), isActive: $logon) { EmptyView() }.opacity(0)
}
.navigationBarHidden(true)
}
}
Please help me..
Add .navigationBarHidden(true) in NavigationLink also for eg:
NavigationLink(destination: ApplicationSwitcher()
.navigationBarHidden(true), isActive: $logon) { EmptyView() }.opacity(0)
In ContentView add "navigationBarHidden(true)" after the closure of NavigationView instead of VStack as mentioned below:
NavigationView {
...
}.navigationBarTitle("")
.navigationBarHidden(true)
.navigationBarBackButtonHidden(true)

SwiftUI: Logout and switch screens from a popover

In my app, I have a View which is set to either a login View or a home TabView, depending on if the user is logged in. From the TabView, the user can go to a profile popover and logout. I want to switch back to the login View from this popover.
I tried dismissing the popover and immediately logging the user out, but when I test on a real device, what happens is the popover stays on the screen and also no longer responds to user input. It can't be dismissed. I'm not sure why, and what should I do instead?
Starting View:
struct StartView: View {
#EnvironmentObject var authService:AuthService
var body: some View {
ZStack {
if(!authService.signedIn) {
LoginView()
} else {
HomeView()
}
}
}
}
Home TabView:
import SwiftUI
struct HomeView: View {
#State private var showingProfilePopover:Bool = false
var body: some View {
TabView {
NavigationView {
VStack(alignment: .leading) {
Text("Tab 1")
.padding(.leading, 30)
}
.toolbar {
ToolbarItem {
Button(action: {
showingProfilePopover = true
}, label: {
Image(systemName: "person.crop.circle").imageScale(.large)
}
)
}
}
}.popover(isPresented: $showingProfilePopover) {
ProfileView(isPresented: $showingProfilePopover)
}
.tabItem {
Image(systemName: "list.bullet")
.font(.system(size: 26))
Text("Tab 1")
}
NavigationView {
VStack(alignment: .leading) {
Text("Tab 2")
}
}.tabItem {
Image(systemName: "books.vertical")
.font(.system(size: 26))
Text("Tab 2")
}
}
}
}
Popover:
struct ProfileView: View {
#EnvironmentObject var authService:AuthService
#Binding var isPresented: Bool
var body: some View {
Button("Logout") {
// Close the popup and switch to LoginView
print("Tapped logout")
isPresented = false
authService.signOut()
}
.font(Font.custom("OpenSans-Regular", size: 18))
.padding(20)
}
}
LoginView:
import SwiftUI
struct LoginView: View {
#EnvironmentObject var authService:AuthService
var body: some View {
VStack {
Button("Login") {
self.authService.signIn()
}.buttonStyle(.borderedProminent)
}
}
}
AuthService:
import SwiftUI
class AuthService: ObservableObject {
#Published var signedIn:Bool
init(signedIn:Bool) {
self.signedIn = signedIn
}
func signIn() {
self.signedIn = true
}
func signOut(){
self.signedIn = false
}
}
Seems like an issue connected to .popover. I can reproduce the issue, but it works just fine using .sheet instead.
Consider attaching the .popover on the TabView or the Button itself then it seems to work just fine.
I realized the issue only happens on the older versions of iOS. it works fine on iOS 15, but not on iOS 14 and below iOS 14.
#main
struct LoginApp: App {
let authService: AuthService
init() {
authService = AuthService(signedIn: false)
}
var body: some Scene {
WindowGroup {
StartView().environmentObject(authService)
}
}
}
This is iPhone 8, iOS 14

SwiftUI changing navigation bar background color for inline navigationBarTitleDisplayMode

I just started coding in SwiftUI and came across a problem. I need to give different colors to the background of the navigation bar (NavigationView). The colors will change as I go from one view to the next. I need to have this working for navigationBarTitleDisplayMode being "inline".
I tried the solutions presented in:
SwiftUI update navigation bar title color
but none of these solutions work fully for what I need.
The solution in this reply to that post works for inline:
Using UIViewControllerRepresentable. Nevertheless, when we first open the view it will show the color of the previous view for one second, before changing to the new color. I would like to avoid this and have the color displayed as soon as everything appears on screen. Is there a way to do this?
This other solution will not work either: Changing UINavigation's appearance in init(), because when I set the background in init(), it will change the background of all the views in the app. Again, I need the views to have different background colors.
I tried something similar to this solution: Modifying Toolbar, but it does not allow me to change the color of the navigation bar.
The other solution I tried was this: Creating navigationBarColor function, which is based on: NAVIGATIONVIEW DYNAMIC BACKGROUND COLOR IN SWIFTUI. This solution works for navigationBarTitleDisplayMode "large", but when setting navigationBarTitleDisplayMode to "inline", it will show the background color of the navigation bar in a different color, as if it was covered by a gray/transparent layer. For example, the color it shows in "large" mode is:
Red color in large mode
But instead, it shows this color:
Red color in inline mode
Finally, I tried this solution: Subclassing UIViewController and configuring viewDidLayoutSubviews(), but it did not work for what I want it either.
The closest solutions for what I need are 1. and 4., but they still do not work 100%.
Would anybody know how to make any of these solutions work for navigationBarTitleDisplayMode inline, being able to change the background color of the navigation bar in different layouts, and showing the new color once the view is shown (without delays)?
Thank you!
By the way, I am using XCode 12.5.
Here is the sample code that I am using, taking example 4. as a model:
FirstView.swift
import SwiftUI
struct FirstView: View {
#State private var selection: String? = nil
var body: some View {
NavigationView {
GeometryReader { metrics in
VStack {
Text("This is the first view")
NavigationLink(destination: SecondView(), tag: "SecondView", selection: $selection) {
EmptyView()
}
Button(action: {
self.selection = "SecondView"
print("Go to second view")
}) {
Text("Go to second view")
}
}
}
}.navigationViewStyle(StackNavigationViewStyle())
}
}
struct FirstView_Previews: PreviewProvider {
static var previews: some View {
FirstView()
}
}
SecondView.swift
On this screen, if I use
.navigationBarTitleDisplayMode(.large)
the color will be displayed properly: Navigation bar with red color
But using
.navigationBarTitleDisplayMode(.inline)
there is a blur on it: Navigation bar with some sort of blur over red color
import SwiftUI
struct SecondView: View {
#State private var selection: String? = nil
var body: some View {
GeometryReader { metrics in
VStack {
Text("This is the second view")
NavigationLink(destination: ThirdView(), tag: "ThirdView", selection: $selection) {
EmptyView()
}
Button(action: {
self.selection = "ThirdView"
print("Go to third view")
}) {
Text("Go to third view")
}
}
}
.navigationBarColor(backgroundColor: Color.red, titleColor: .black)
.navigationBarTitleDisplayMode(.inline)
}
}
struct SecondView_Previews: PreviewProvider {
static var previews: some View {
SecondView()
}
}
ThirdView.swift
This view displays the color properly as it is using
.navigationBarTitleDisplayMode(.large)
But if changed to
.navigationBarTitleDisplayMode(.inline)
it will show the blur on top of the color as well.
import SwiftUI
struct ThirdView: View {
var body: some View {
GeometryReader { metrics in
Text("This is the third view")
}
.navigationBarColor(backgroundColor: Color.blue, titleColor: .black)
.navigationBarTitleDisplayMode(.large)
}
}
struct ThirdView_Previews: PreviewProvider {
static var previews: some View {
ThirdView()
}
}
NavigationBarModifierView.swift
import SwiftUI
struct NavigationBarModifier: ViewModifier {
var backgroundColor: UIColor?
var titleColor: UIColor?
init(backgroundColor: Color, titleColor: UIColor?) {
self.backgroundColor = UIColor(backgroundColor)
let coloredAppearance = UINavigationBarAppearance()
coloredAppearance.configureWithTransparentBackground()
coloredAppearance.backgroundColor = UIColor(backgroundColor)
coloredAppearance.titleTextAttributes = [.foregroundColor: titleColor ?? .white]
coloredAppearance.largeTitleTextAttributes = [.foregroundColor: titleColor ?? .white]
coloredAppearance.shadowColor = .clear
UINavigationBar.appearance().standardAppearance = coloredAppearance
UINavigationBar.appearance().compactAppearance = coloredAppearance
UINavigationBar.appearance().scrollEdgeAppearance = coloredAppearance
UINavigationBar.appearance().tintColor = titleColor
}
func body(content: Content) -> some View {
ZStack{
content
VStack {
GeometryReader { geometry in
Color(self.backgroundColor ?? .clear)
.frame(height: geometry.safeAreaInsets.top)
.edgesIgnoringSafeArea(.top)
Spacer()
}
}
}
}
}
extension View {
func navigationBarColor(backgroundColor: Color, titleColor: UIColor?) -> some View {
self.modifier(NavigationBarModifier(backgroundColor: backgroundColor, titleColor: titleColor))
}
}
NOTE TO THE MODERATORS: Please, do not delete this post. I know similar questions were asked before, but I need an answer to this in particular which was not addressed. Please read before deleting indiscriminately, I need this for work. Also, I cannot ask questions inline in each of those solutions because I do not have the minimum 50 points in stackoverflow required to write there.
I think I have what you want. It is VERY touchy... It is a hack, and not terribly robust, so take as is...
I got it to work by having your modifier return a clear NavBar, and then the solution from this answer works for you. I even added a ScrollView to ThirdView() to make sure that scrolling under didn't affect in. Also note, you lose all of the other built in effects of the bar like translucency, etc.
Edit: I went over the code. The .navigationViewStyle was in the wrong spot. It likes to be outside of the NavigaionView(), where everything else needs to be inside. Also, I removed the part of the code setting the bar color in FirstView() as it was redundant and ugly. I hadn't meant to leave that in there.
struct NavigationBarModifier: ViewModifier {
var backgroundColor: UIColor?
var titleColor: UIColor?
init(backgroundColor: Color, titleColor: UIColor?) {
self.backgroundColor = UIColor(backgroundColor)
let coloredAppearance = UINavigationBarAppearance()
coloredAppearance.configureWithTransparentBackground()
coloredAppearance.backgroundColor = .clear // The key is here. Change the actual bar to clear.
coloredAppearance.titleTextAttributes = [.foregroundColor: titleColor ?? .white]
coloredAppearance.largeTitleTextAttributes = [.foregroundColor: titleColor ?? .white]
coloredAppearance.shadowColor = .clear
UINavigationBar.appearance().standardAppearance = coloredAppearance
UINavigationBar.appearance().compactAppearance = coloredAppearance
UINavigationBar.appearance().scrollEdgeAppearance = coloredAppearance
UINavigationBar.appearance().tintColor = titleColor
}
func body(content: Content) -> some View {
ZStack{
content
VStack {
GeometryReader { geometry in
Color(self.backgroundColor ?? .clear)
.frame(height: geometry.safeAreaInsets.top)
.edgesIgnoringSafeArea(.top)
Spacer()
}
}
}
}
}
extension View {
func navigationBarColor(backgroundColor: Color, titleColor: UIColor?) -> some View {
self.modifier(NavigationBarModifier(backgroundColor: backgroundColor, titleColor: titleColor))
}
}
struct FirstView: View {
#State private var selection: String? = nil
var body: some View {
NavigationView {
GeometryReader { _ in
VStack {
Text("This is the first view")
NavigationLink(destination: SecondView(), tag: "SecondView", selection: $selection) {
EmptyView()
}
Button(action: {
self.selection = "SecondView"
print("Go to second view")
}) {
Text("Go to second view")
}
}
.navigationTitle("First")
.navigationBarTitleDisplayMode(.inline)
.navigationBarColor(backgroundColor: .red, titleColor: .black)
}
}
.navigationViewStyle(StackNavigationViewStyle())
}
}
struct SecondView: View {
#State private var selection: String? = nil
var body: some View {
VStack {
Text("This is the second view")
NavigationLink(destination: ThirdView(), tag: "ThirdView", selection: $selection) {
EmptyView()
}
Button(action: {
self.selection = "ThirdView"
print("Go to third view")
}) {
Text("Go to third view")
}
}
.navigationTitle("Second")
.navigationBarTitleDisplayMode(.inline)
.navigationBarColor(backgroundColor: .blue, titleColor: .black)
}
}
struct ThirdView: View {
var body: some View {
ScrollView {
ForEach(0..<50) { _ in
Text("This is the third view")
}
}
.navigationTitle("Third")
.navigationBarTitleDisplayMode(.inline)
.navigationBarColor(backgroundColor: .green, titleColor: .black)
}
}
iOS 16
Since this version of SwiftUI, there is a dedicated modifier for setting any toolbar background color (including the navigation bar):
Xcode 14 beta 5 (Not working 🤦🏻‍♂️, waiting for beta 6...)
.toolbarBackground(.red, for: .navigationBar)
Xcode 14 beta 1,2,3,4
.toolbarBackground(.red, in: .navigationBar)
It works perfectly in in inline mode and also animates between modes.
For my custom view the following code worked well.
struct HomeView: View {
init() {
//Use this if NavigationBarTitle is with Large Font
UINavigationBar.appearance().largeTitleTextAttributes = [.foregroundColor: UIColor.systemIndigo]
//Use this if NavigationBarTitle is with displayMode = .inline
UINavigationBar.appearance().titleTextAttributes = [.foregroundColor: UIColor.systemIndigo]
UINavigationBar.appearance().backgroundColor = UIColor.clear
UINavigationBar.appearance().barTintColor = UIColor(Color(red: 32 / 255, green: 72 / 255, blue: 63 / 255))
}
var body: some View {
NavigationView {
ZStack {
...
...
...
}
.padding(.zero)
.navigationTitle("Feedbacks")
}
}
}
and result is like that:
Here is a bit hacky solution, but it works for me (as of iOS 15) both for .large and .inline display modes.
import SwiftUI
enum Kind: String, CaseIterable {
case checking
case savings
case investment
}
struct PaddedList: View {
#Binding var name: String
#Binding var kind: Kind
var body: some View {
NavigationView {
List {
TextField("Account name", text: $name)
Picker("Kind", selection: $kind) {
ForEach(Kind.allCases, id: \.self) { kind in
Text(kind.rawValue).tag(kind)
}
}
.listRowSeparatorTint(.red)
Spacer()
}
.padding(.top, 1) // note top 1 padding!
.background(.green) // the color "bleeds" through
.navigationBarTitle("Navigation Bar")
}
}
}
struct PaddedList_Previews: PreviewProvider {
static var previews: some View {
PaddedList(name: .constant(""), kind: .constant(.checking))
}
}

SwiftUI View appear differently in device and preview compare to view hierarchy capture

I have a problem with SwiftUI
There was a issue
yello view don't appear at first launch view
move to home that makes app into background mode
move to app (foreground)
then yellow view appears
I captured view hierarchy in step 1.
(left is view hierarchy capture, right is simulator)
view hierarchy capture shows the yellow square but simulator didn't show yellow square
I checked the view breadscrum but both was same so I have no clue.
I'm sure this is not a networking problem.
There is two way to appear yellow square
background -> foreground
present alert -> dismiss alert
I'm not sure this is a framework bug or else.
Also, is there any API that I can print the swiftUI rendering request succeed or fail?
Thank you in advance and merry christmas!
(left is before yello square appear on simulator/ right is after yello square appear on simulator)
edit - add sample code
contentView
import SwiftUI
struct ContentView: View {
#ObservedObject var viewModel : viewModel
#ObservedObject var params : otherViewModel
var body: some View {
HorizontalScrollView(viewModel: viewModel, someParmas: params)
.padding(.leading, 24)
.frame(width: UIScreen.main.bounds.width, height:400)
.background(Color.red)
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView(viewModel: viewModel(homeAPI: HomeAPI()), params: otherViewModel())
}
}
import SwiftUI
struct HorizontalScrollView: View {
#ObservedObject var viewModel: viewModel
#ObservedObject var holder : otherViewModel
private var homeHightlightRange: Range<Int> {
return 0..<(viewModel.something?.somethingList?.count ?? 0)
}
init(viewModel: viewModel, someParmas: otherViewModel) {
self.viewModel = viewModel
self.holder = someParmas
}
var body: some View {
VStack(spacing: 20) {
HStack(spacing: 0) {
Text("Merry christmas")
.font(.system(size: 24))
.foregroundColor(.white)
.bold()
.onTapGesture {
viewModel.getHighlight()
}
Spacer()
}
ScrollView(.horizontal, showsIndicators: false, content: {
HStack(alignment:.bottom, spacing: 14) {
ForEach(homeHightlightRange, id: \.self) { index in
Color.yellow.frame(width:200, height:300)
}
}
})
}
.frame(height: 339)
}
}
struct HighlightView_Previews: PreviewProvider {
static var previews: some View {
HorizontalScrollView(viewModel: viewModel(homeAPI: HomeAPI()),someParmas: otherViewModel())
.previewLayout(.sizeThatFits)
}
}
homeHightlightRange is got from server via viewModel
I suppose that the solution is to add ScrollView conditionally on API results appear, like (not tested - typed here, so typos might be present)
if viewModel.something?.somethingList?.count != 0 {
ScrollView(.horizontal, showsIndicators: false, content: {
HStack(alignment:.bottom, spacing: 14) {
ForEach(homeHightlightRange, id: \.self) { index in
Color.yellow.frame(width:200, height:300)
}
}
})
}

Show a new View from Button press Swift UI

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