How to navigate with a custom button without changing styling? - swift

If I don't use .disabled(true) then the button does not navigate. If I used .disabled(true) then the style changes to make the foreground a grayed version of the foreground color. I want to navigate without changing the style of my custom button. I used a non-custom button in the example to save space.
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLink(
destination: ContentView2(),
label: {
Button(action: {}, label: {
Text("Button")
}).disabled(true)
})
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct ContentView2: View {
var body: some View {
Text("wdfokjokjokjokjwdofjk")
.padding()
}
}

Instead of making your own Button, just use Text. When you are doing .disabled(true) to make a button active, something is definitely wrong...
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLink(destination: ContentView2()) {
Text("Button")
}
}
}
}

You can use an isActive parameter for the NavigationLink and set it as an invisible background or overlay:
struct ContentView: View {
#State private var navLinkActive = false
var body: some View {
NavigationView {
Button(action: {
navLinkActive = true
}, label: {
Text("Button")
})
.buttonStyle(CustomButtonStyle())
.background(NavigationLink(
destination: ContentView2(),
isActive: $navLinkActive,
label: {
EmptyView()
}))
}
}
}
struct CustomButtonStyle : ButtonStyle {
func makeBody(configuration: Configuration) -> some View {
configuration.label
.background(configuration.isPressed ? Color.red : Color.green)
}
}

Related

Binding a button leads to "Missing argument for parameter in call" error

I'm trying to create a Binding in two views so I can change something on one side and have it reflected on the other.
I basically have:
a circle on both views
a button to change the other view's circle color
and one to go to the other view
It all works fine if I only have a Binding in the "ColorChange2"
view, but when I add a Binding in "ColorChange1" I get into trouble.
It tells me: Missing argument for parameter 'isOn2'.
But when I add isOn2 into ColorChange1() it wants a binding, but if I do ColorChange1(isOn2: $isOn2) it says it can't find '$isOn2' in scope.
I found one solution suggesting to add .constant(true)) into the preview but since it's a constant, it wont change the view like I wanted since it's a constant.
What can I do to make it work?
Code:
struct ColorChange1: View {
#State private var isOn = false
#Binding var isOn2 : Bool
var body: some View {
NavigationView {
VStack {
Circle()
.fill(isOn ? .green : .red)
.frame(width: 100)
Button(action: {
isOn2.toggle()
}, label: {
Text("Change button view 2")
.padding()
})
NavigationLink(destination: {
ColorChange2(isOn: $isOn)
}, label: {
Text("Go to view 2")
})
}
}
}
}
struct ColorChange2: View {
#Binding var isOn : Bool
#State private var isOn2 = false
#Environment(\.dismiss) var dismiss
var body: some View {
VStack {
Circle()
.fill(isOn2 ? .green : .red)
.frame(width: 100)
Button(action: {
isOn.toggle()
}, label: {
Text("Change button view 1")
.padding()
})
Button(action: {
dismiss.callAsFunction()
}, label: {
Text("Go to view 1")
})
}
.navigationBarBackButtonHidden(true)
}
}
struct ColorChange_Previews: PreviewProvider {
static var previews: some View {
// ColorChange(isOn2: .constant(true))
ColorChange1()
}
} ```
You don't need both #Binding value in both screen to connect between screen like that.
#Binding means that get the value in #State of the first view and make a connection in the second view. In this scenero, when you go back from second view, it was dismissed.
For your problem, make an ObservableObject to store value. 1 for present in first view and 1 for second view. Then add it to second view when ever you need to display.
Code will be like this
class ColorModel : ObservableObject {
#Published var isOnFirstView = false
#Published var isOnSecondView = false
func didTapChangeColor(atFirstView: Bool) {
if atFirstView {
isOnSecondView = !isOnSecondView
} else {
isOnFirstView = !isOnFirstView
}
}
}
struct ColorChange2: View {
// binding model
#ObservedObject var colorModel : ColorModel
#Environment(\.dismiss) var dismiss
var body: some View {
VStack {
Circle()
.fill(colorModel.isOnSecondView ? .green : .red)
.frame(width: 100)
Button(action: {
colorModel.didTapChangeColor(atFirstView: false)
}, label: {
Text("Change button view 1")
.padding()
})
Button(action: {
dismiss.callAsFunction()
}, label: {
Text("Go to view 1")
})
}
.navigationBarBackButtonHidden(true)
}
}
struct ColorChange1: View {
#StateObject private var colorModel = ColorModel()
var body: some View {
NavigationView {
VStack {
Circle()
.fill(colorModel.isOnFirstView ? .green : .red)
.frame(width: 100)
Button(action: {
colorModel.didTapChangeColor(atFirstView: true)
}, label: {
Text("Change button view 2")
.padding()
})
NavigationLink(destination: {
ColorChange2(colorModel: colorModel)
}, label: {
Text("Go to view 2")
})
}
}
}
}
struct ColorChange_Previews: PreviewProvider {
static var previews: some View {
ColorChange1()
}
}

SwiftUI Hidden ".navigationBarHidden" appearance bug

I have 3 windows that are connected by a NavigationLink and the NavigationBar is hidden, but I need the ability to swipe to go back, for this I use this code:
import SwiftUI
extension UINavigationController: UIGestureRecognizerDelegate {
override open func viewDidLoad() {
super.viewDidLoad()
interactivePopGestureRecognizer?.delegate = self
}
public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return viewControllers.count > 1
}
}
#main
struct testSheetApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
struct ContentView: View {
var body: some View {
NavigationView{
ZStack{
VStack{
NavigationLink(destination: {
ContentView2()
}, label: {
Text("new")
})
}
} .navigationBarHidden(true)
}
}
}
struct ContentView2: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
ZStack{
VStack{
Button(action: {
presentationMode.wrappedValue.dismiss()
}, label: {
Text("back")
})
NavigationLink(destination: {
ContentView3()
}, label: {
Text("next")
})
}
} .navigationBarHidden(true)
}
}
struct ContentView3: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
VStack{
Button(action: {
presentationMode.wrappedValue.dismiss()
}, label: {
Text("back")
})
}
.navigationBarHidden(true)
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Everything works fine with the second form, you can return with a swipe, but on the 3rd form, when you cancel the swipe, when the screen remains on the same form, a NavigationBar appears
Bug NavigationBar
I found a solution to this problem, you need to add to the NavigationLink, ".isDetailLink (false)"
code snippet:
NavigationLink(destination: {
ContentView3()
}, label: {
Text("next")
}).isDetailLink(false)

SwiftUI - OnExitCommand inside TabView

I have lately been trying to make a tvOS app, but have run into the following rather annoying problem. I can't use navigation inside a TabView and still have the menu button on the remove take me back to the previous state.
struct TestView: View {
#State var selection : Int = 0
var body: some View {
TabView(selection: self.$selection) {
ExpView()
.tabItem {
HStack {
Image(systemName: "magnifyingglass")
Text("Explore")
}
}
.tag(0)
}
}
}
struct ExpView: View {
var body: some View {
NavigationView {
NavigationLink(destination: DetailView(title: "Hey")) {
Text("Detail")
}
}
}
}
struct DetailView: View {
var title : String
var body: some View {
VStack {
Text(title)
}
}
}
My question is: Is there any way to enable the menu button to go back to the previous view in the hierachy without dismissing the app completely?
You don't need to call dismiss on Menu it is called automatically for NavigationLink (so calling one more dismiss quits to main menu)
Here are fixed views. Tested with Xcode 11.4
struct ExploreView: View {
var body: some View {
NavigationView {
NavigationLink(destination: DetailView(title: "Hey")) {
Text("Detail")
}
}
}
}
struct DetailView: View {
var title : String
var body: some View {
VStack {
Text(title)
}
}
}
So I found a workaround for the issue.
If you place the navigationView outside the TabView and then use the following code it works:
struct TestView: View {
#State var selection : Int = 0
#State var hideNavigationBar : Bool
var body: some View {
NavigationView {
TabView(selection: self.$selection) {
ExpView(hideNavigationBar: self.$hideNavigationBar)
.tabItem {
HStack {
Image(systemName: "magnifyingglass")
Text("Explore")
}
}
.tag(0)
}
}
}
}
struct ExpView: View {
#Binding var hideNavigationBar : Bool
var body: some View {
NavigationLink(destination: DetailView(title: "Hey")) {
Text("Detail")
}.navigationBarTitle("")
.navigationBarHidden(self.hideNavigationBar)
.onAppear {
self.hideNavigationBar = true
}
}
}
struct DetailView: View {
var title : String
var body: some View {
VStack {
Text(title)
}
}
}

How to navigate to a new view from navigationBar button click in SwiftUI

Learning to SwiftUI. Trying to navigate to a new view from navigation bar buttton clicked.
The sample code below:
var body: some View {
NavigationView {
List(0...< 5) { item in
NavigationLink(destination: EventDetails()){
EventView()
}
}
.navigationBarTitle("Events")
.navigationBarItems(trailing:
NavigationLink(destination: CreateEvent()){
Text("Create Event")
}
)
}
}
Three steps got this working for me : first add an #State Bool to track the showing of the new view :
#State var showNewView = false
Add the navigationBarItem, with an action that sets the above property :
.navigationBarItems(trailing:
Button(action: {
self.showNewView = true
}) {
Text("Go To Destination")
}
)
Finally add a navigation link somewhere in your view code (this relies on also having a NavigationView somewhere in the view stack)
NavigationLink(
destination: MyDestinationView(),
isActive: $showNewView
) {
EmptyView()
}.isDetailLink(false)
Put the NavigationLink into the label of a button.
.navigationBarItems(
trailing: Button(action: {}, label: {
NavigationLink(destination: NewView()) {
Text("")
}
}))
This works for me:
.navigationBarItems(trailing: HStack { AddButton(destination: EntityAddView()) ; EditButton() } )
Where:
struct AddButton<Destination : View>: View {
var destination: Destination
var body: some View {
NavigationLink(destination: self.destination) { Image(systemName: "plus") }
}
}
It is an iOS13 bug at the moment: https://forums.developer.apple.com/thread/124757
The "sort-of" workaround can be found here: https://stackoverflow.com/a/57837007/4514671
Here is my solution:
MasterView -
import SwiftUI
struct MasterView: View {
#State private var navigationSelectionTag: Int? = 0
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DestinationView(), tag: 1, selection: self.$navigationSelectionTag) {
EmptyView()
}
Spacer()
}
.navigationBarTitle("Master")
.navigationBarItems(trailing: Button(action: {
self.navigationSelectionTag = 1
}, label: {
Image(systemName: "person.fill")
}))
}
}
}
struct MasterView_Previews: PreviewProvider {
static var previews: some View {
MasterView()
}
}
And the DetailsView -
import SwiftUI
struct DetailsView: View {
var body: some View {
Text("Hello, Details!")
}
}
struct DetailsView_Previews: PreviewProvider {
static var previews: some View {
DetailsView()
}
}

Custom back button for NavigationView's navigation bar in SwiftUI

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")
}
}
}