SwiftUI Navigation Controller stuttering with two Navigationlinks per List row - swiftui

I am trying to create two NavigationLinks in a repeating List. Each has a separate destination. The code all works fine until I imbed the call to the root view in a List/ForEach loop. At which point the navigation becomes very strange.
Try to click on either link and then click the back indicator at the top. It will go to one NavigationLink, and then the other. Sometimes in a different order, and sometimes it will auto-return from one of the links, and othertimes it won't open the second detail view until you return from the first detail view. It does this both in Preview, as well as if you build and run the application.
I have distilled down the code to the most basic below. If you comment the 2 lines as indicated in ContentView, you will then see correct behavior.
I am running Catalina 10.15.5, xCode 11.6, with the application target of IOS 13.6.
How can I modify the code, so that it will work with the List/ForEach loop?
import SwiftUI
struct DetailView1: View {
var body: some View {
HStack {
Text("Here is Detail View 1." )}
.foregroundColor(.green)
}
}
struct DetailView2: View {
var body: some View {
HStack {
Text( "Here is Detail View 2.") }
.foregroundColor(.red)
}
}
struct RootView: View {
var body: some View {
HStack {
VStack {
NavigationLink(destination: DetailView1())
{ VStack { Image(systemName: "ant.circle").resizable()
.frame(width:75, height:75)
.scaledToFit()
}.buttonStyle(PlainButtonStyle())
Text("Tap for Detail 1.")
.foregroundColor(.green)
}
}
NavigationLink(destination: DetailView2())
{ Text("Tap for Detail 2.")
.foregroundColor(.red)
}
}
}
}
struct ContentView: View {
var body: some View {
NavigationView {
// Comment the following line for correct behavior
List { ForEach(0..<3) {_ in
RootView()
// Comment the following line for correct behavior
} }
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
NavigationView {
ContentView()
.navigationBarTitle("Strange Behavior")
}
}
}

In your case both navigation links are activated at once user tap a row, to avoid this below is possible approach
Tested with Xcode 12 / iOS 14
The idea is to have one link which is activated programmatically and destination is selected dynamically depending on which button is clicked
struct RootView: View {
#State private var isFirst = false
#State private var isActive = false
var body: some View {
HStack {
VStack {
Button(action: {
self.isFirst = true
self.isActive = true
})
{ VStack { Image(systemName: "ant.circle").resizable()
.frame(width:75, height:75)
.scaledToFit()
}
Text("Tap for Detail 1.")
.foregroundColor(.green)
}
}
Button(action: {
self.isFirst = false
self.isActive = true
})
{ Text("Tap for Detail 2.")
.foregroundColor(.red)
}
.background(
NavigationLink(destination: self.destination(), isActive: $isActive) { EmptyView() }
)
}
.buttonStyle(PlainButtonStyle())
}
#ViewBuilder
private func destination() -> some View {
if isFirst {
DetailView1()
} else {
DetailView2()
}
}
}

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)

How can I use multiple fullScreenCover in IOS14

I want to present the two destinations view in full screen mode from a single view.
Below is a sample of my code. Seem that the function only works for single presentation, if I have a second fullScreenCover defined, the first fullScreenCover didn't work properly.Is that any workaround at this moment?
import SwiftUI
struct TesFullScreen: View {
init(game : Int){
print(game)
}
var body: some View {
Text("Full Screen")
}
}
ContentView
import SwiftUI
struct ContentView: View {
#State var showFullScreen1 : Bool = false
#State var showFullScreen2 : Bool = false
var body: some View {
NavigationView {
VStack {
Spacer()
Button(action: { self.showFullScreen1 = true }) {
Text("Show Full Screen 1")
}
Button(action: { self.showFullScreen2 = true }) {
Text("Show Full Screen 2")
}
Spacer()
}
.navigationBarTitle("TextBugs", displayMode: .inline)
}
.fullScreenCover(isPresented: self.$showFullScreen1){
TesFullScreen(game: 1)
}
.fullScreenCover(isPresented: self.$showFullScreen2){
TesFullScreen(game: 2)
}
}
}
Not always the accepted answer works (for example if you have a ScrollView with subviews (cells in former days) which holds the buttons, that set the navigational flags).
But I found out, that you also can add the fullScreen-modifier onto an EmptyView. This code worked for me:
// IMPORTANT: Has to be within a container (e.g. VStack, HStack, ZStack, ...)
if myNavigation.flag1 || myNavigation.flag2 {
EmptyView().fullScreenCover(isPresented: $myNavigation.flag1)
{ MailComposer() }
EmptyView().fullScreenCover(isPresented: $myNavigation.flag2)
{ RatingStore() }
}
Usually some same modifier added one after another is ignored. So the simplest fix is to attach them to different views, like
struct FullSContentView: View {
#State var showFullScreen1 : Bool = false
#State var showFullScreen2 : Bool = false
var body: some View {
NavigationView {
VStack {
Spacer()
Button(action: { self.showFullScreen1 = true }) {
Text("Show Full Screen 1")
}
.fullScreenCover(isPresented: self.$showFullScreen1){
Text("TesFullScreen(game: 1)")
}
Button(action: { self.showFullScreen2 = true }) {
Text("Show Full Screen 2")
}
.fullScreenCover(isPresented: self.$showFullScreen2){
Text("TesFullScreen(game: 2)")
}
Spacer()
}
.navigationBarTitle("TextBugs", displayMode: .inline)
}
}
}
Alternate is to have one .fullScreenCover(item:... modifier and show inside different views depending on input item.
The only thing that worked for me was the answer in this link:
https://forums.swift.org/t/multiple-sheet-view-modifiers-on-the-same-view/35267
Using the EmptyView method or other solutions always broke a transition animation on one of the two presentations. Either transitioning to or from that view and depending on what order I chose them.
Using the approach by Lantua in the link which is using the item argument instead of isPresented worked in all cases:
enum SheetChoice: Hashable, Identifiable {
case a, b
var id: SheetChoice { self }
}
struct ContentView: View {
#State var sheetState: SheetChoice?
var body: some View {
VStack {
...
}
.sheet(item: $sheetState) { item in
if item == .a {
Text("A")
} else {
Text("B")
}
}
}
}
The sheetState needs to be optional for it to work.

SwiftUI ContextMenu navigation to another view

I am trying to get a context menu to navigate to another view using the following code
var body: some View
{
VStack
{
Text(self.event.name).font(.body)
...
Spacer()
NavigationLink(destination: EditView(event: self.event))
{
Image(systemName: "pencil")
}
}
.navigationBarTitle(Text(appName))
.contextMenu
{
NavigationLink(destination: EditView(event: self.event))
{
Image(systemName: "pencil")
}
}
}
The NavigationLink within the VStack works as expected and navigates to the edit view but I want to use a contextMenu. Although the context menu displays the image, when I tap on it it doesn't navigate to the edit view, instead it just cancels the context menu.
I am doing this within a watch app but don't think that should make a difference, is there anything special I have to do with context menu navigation?
I would use the isActive variant of NavigationLink that you can trigger by setting a state variable. Apple documents this here
This variant of NavigationLink is well fit for dynamic/programatic navigation.
Your .contextMenu sets the state variable to true and that activates the NavigationLink. Because you don't want the link to be visible, set the label view to EmptyView
Here's an example, not identical to your post but hopefully makes it clear.
struct ContentView: View {
#State private var showEditView = false
var body: some View {
NavigationView {
VStack {
Text("Long Press Me")
.contextMenu {
Button(action: {
self.showEditView = true
}, label: {
HStack {
Text("Edit")
Image(systemName: "pencil")
}
})
}
NavigationLink(destination: Text("Edit Mode View Here"), isActive: $showEditView) {
EmptyView()
}
}
.navigationBarTitle("Context Menu")
}
}
}
In Xcode 11.4 it's now possible to do this with sensible NavigationLink buttons. Yay! 🎉
.contextMenu {
NavigationLink(destination: VisitEditView(visit: visit)) {
Text("Edit visit")
Image(systemName: "square.and.pencil")
}
NavigationLink(destination: SegmentsEditView(timelineItem: visit)) {
Text("Edit individual segments")
Image(systemName: "ellipsis")
}
}
This works on Xcode 11.6
struct ContentView: View {
#State var isActiveFromContextMenu = false
var body: some View {
NavigationView{
VStack{
NavigationLink(destination : detailTwo(), isActive: $isActiveFromContextMenu ){
EmptyView()
}
List{
NavigationLink(destination: detail() ){
row(isActiveFromContextMenu: $isActiveFromContextMenu)
}
NavigationLink(destination: detail() ){
row(isActiveFromContextMenu: $isActiveFromContextMenu)
}
NavigationLink(destination: detail() ){
row(isActiveFromContextMenu: $isActiveFromContextMenu)
}
}
}
}
}
}
struct detail: View {
var body: some View{
Text("Detail view")
}
}
struct detailTwo: View {
var body: some View{
Text("DetailTwo view")
}
}
struct row: View {
#Binding var isActiveFromContextMenu : Bool
var body: some View {
HStack{
Text("item")
}.contextMenu{
Button(action: {
self.isActiveFromContextMenu = true
})
{
Text("navigate to")
}
}
}
}
I found success in masking the NavigationLink in the background and switching the context with a Button as the shortest yet simplest alternative.
struct ContentView: View {
#State private var isShowing = false
var body: some View {
NavigationView {
Text("Hello")
.background(NavigationLink("", destination: Text("World!"), isActive: $isShowing))
.contextMenu {
Button {
isShowing = true
} label: {
Label("Switch to New View", systemImage: "chevron.forward")
}
}
}
}
}

How can you have other selectable areas within a List row with NavigationLink?

I can't get a row to be selectable for something other than navigating, if there's also a NavigationLink in the row view. This is no problem with UIKit. Is it impossible because of lack of implementation at present, just a bug, or is it in fact presently possible?
This is probably the simplest snippet that can illustrate the problem.
struct ContentView: View {
var body: some View {
NavigationView {
List {
HStack {
Button("How can I tap over here without transitioning?") { }
NavigationLink( destination: ContentView() ) {
Spacer()
}
}
}
}
}
}
Your button should be not default style.
Here is a simple demo of possible approach. Prepared & tested with Xcode 11.7 / iOS 13.7
struct ContentView: View {
#State private var selected = false
var body: some View {
NavigationView {
List {
HStack {
Button(action: { self.selected.toggle() }) {
Image(systemName: selected ? "checkmark.circle" : "circle")
}.buttonStyle(PlainButtonStyle())
.padding(.horizontal)
NavigationLink( destination: Text("Details") ) {
Text("Link")
.frame(maxWidth: .infinity, alignment: .leading)
}
}
}
}
}
}

SwiftUI NavigationButton without the disclosure indicator?

When making a List with a row that pushes to a new view, SwiftUI adds a disclosure indicator ">" automatically? How do I remove it if I don't want it?
NavigationView {
List {
NavigationButton(destination: DetailView()) {
ListItem()
}
}
.navigationBarTitle(Text("Some title"))
}
On a UITableViewCell you set Accessory to None but how do I do that in SwiftUI?
Setting the NavigationLink width and hiding it did the trick for me
List {
ForEach(pages) { page in
HStack(spacing: 0) {
Text("Something")
NavigationLink(destination: Text("Somewhere")) {
EmptyView()
}
.frame(width: 0)
.opacity(0)
}
}
}
Swift 5, Xcode 11. ZStack works perfect.
var body: some View {
NavigationView {
List {
ForEach(viewModel.currenciesViewModel) { cellViewModel in
ZStack {
cellViewModel.makeView()
NavigationLink(destination: ChooseCurrencyListView()) {
EmptyView()
}
.buttonStyle(PlainButtonStyle())
}
}
}
.navigationBarHidden(true)
.navigationBarTitle("", displayMode: .inline)
}
}
The easiest one. The content for each item in the list.
ZStack {
NavigationLink(destination: DetailView()) {
EmptyView()
}.hidden()
RowView()
}
As workaround I can suggest to add .padding modifier like this:
NavigationView {
List {
NavigationButton(destination: DetailView()) {
ListItem()
}
}
.navigationBarTitle(Text("Some title"))
}
.padding(.trailing, -32.0)
So you will get rows without visible disclosure:
You can also put it in the .background modifier:
List {
Text("Go to...")
.background(NavigationLink("", destination: Text("Detail View")))
}
If you already have the background modifier on the Text, you can wrap the Text in a HStack and apply background to the HStack.
What you can do, if you are using list, is setting the navigationlink to hidden and its frame width to zero.
HStack{
Button(action: {self.statusShow = 1}, label: {
Image(systemName: "info.circle")
})
NavigationLink(destination: StimulatorSettingView(),
tag: 1,
selection: self.$statusShow){
EmptyView()
}.hidden().frame(width: 0)
}
This worked for me.
As of beta 6, this works well:
struct SwiftUIView: View {
var body: some View {
NavigationView {
List {
HStack {
Text("My Cell Content")
NavigationLink(destination: Text("destination"), label: {
EmptyView()
})
}
}
}
}
}
You don't have to use NavigationLink to wrap your Label directly. It will work as long as the link is anywhere in your view hierarchy.
Here I've wrapped it in a button, which allows you to trigger an action prior to pushing the view. Since the NavigationLink has an EmptyView for the label the disclosure indicator is not visible. You can also style this with ButtonStyle.
struct NavigationButton<Destination: View, Label: View>: View {
var action: () -> Void = { }
var destination: () -> Destination
var label: () -> Label
#State private var isActive: Bool = false
var body: some View {
Button(action: {
self.action()
self.isActive.toggle()
}) {
self.label()
.background(NavigationLink(destination: self.destination(), isActive: self.$isActive) {
EmptyView()
})
}
}
}
And to use it:
NavigationButton(
action: { print("tapped!") },
destination: { Text("Pushed View") },
label: { Text("Tap me") }
)
NavigationLink is what we should define in a scope enclosed inside a NavigationView.
But when we use NavigationLink it is attached to the enclosing view, so to reuse the same NavigationLink with other views, we use tag which differentiates between different Destinations.
struct SwiftUIView: View {
#State private var viewState: Int? = 0
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: Text("View 1"), tag: 1, selection: $viewState) {
EmptyView()
}
NavigationLink(destination: Text("View 2"), tag: 2, selection: $viewState) {
EmptyView()
}
Text("First View")
.onTapGesture {
self.viewState = 1
}
Text("Second View")
.onTapGesture {
self.viewState = 2
}
}
}
}
}
Here we bind a Hashable property with all the NavigationLinks present in our VStack so that when a particular View is tapped we can notify which Destination should be opened by setting the value of Bindable property.
If we don't notify the correct Destination by setting the value of tag, always the View defined inside the Closure of NavigationLink will be clickable and nothing else.
Using this approach you don't need to wrap all your clickable views inside NavigationView, any action on any view can use any NavigationLink just by setting the tag.
Thanks, hope this helps.
Works well for me!
import SwiftUI
struct LandmarkList: View {
var body: some View {
NavigationView {
List(landmarkData) { landmark in
LandmarkRow(landmark: landmark)
NavigationLink(destination: LandmarkDetail(landmark: landmark)) {
EmptyView()
}
}
.navigationBarTitle(Text("Landmarks"))
}
}
}
struct LandmarkList_Previews: PreviewProvider {
static var previews: some View {
ForEach(["iPhone SE", "iPhone 11 Pro Max"], id: \.self) { deviceName in
LandmarkList()
.previewDevice(PreviewDevice(rawValue: deviceName))
.previewDisplayName(deviceName)
}
}
}
Use .frame(width: 0).opacity(0.0):
NavigationView {
List {
ForEach(options) {
option in
ZStack {
YourView(option: option)
NavigationLink(destination: ProductListView(),
label: {
EmptyView()
}).frame(width: 0).opacity(0.0)
}.listRowInsets(EdgeInsets())
}
}.navigationBarHidden(true)
}
My version of this solution is to make a view modifier. I think it's the cleanest way, as it doesn't use AnyView.
Note that this solution runs the init() for the destination when it draws the element the .navigationLink() is attached to.
Usage
Text("Link")
.navigationLink({
// put your destination here
})
How To
import SwiftUI
extension View {
func navigationLink<Destination: View>(_ destination: #escaping () -> Destination) -> some View {
modifier(NavigationLinkModifier(destination: destination))
}
}
fileprivate struct NavigationLinkModifier<Destination: View>: ViewModifier {
#ViewBuilder var destination: () -> Destination
func body(content: Content) -> some View {
content
.background(
NavigationLink(destination: self.destination) { EmptyView() }.opacity(0)
)
}
}
This helps to push and pass the model to the next navigation view controller.
struct ContentView : View {
#State var model = PostListViewModel()
var body: some View {
NavigationView {
List(model.post) { post in
ListCell(listData: post)
}.navigationBarTitle(Text("My Post"))
}
}
}
struct ListCell: View {
var listData: Post
var body: some View {
return NavigationButton(destination: DetailContentView(post: listData)) {
HStack {
ImageRow(model: listData) // Get image
VStack(alignment: .leading) {
Text(listData.login).font(.headline).lineLimit(nil)
Text(listData.url).font(.subheadline).lineLimit(nil)
}.padding(.leading, 10)
}.padding(.init(top: 5, leading: 0, bottom: 5, trailing: 0))
}
}
}
Here's a reusable "plain" navigation link view (i.e. without the chevron disclosure indicator) that can be a drop-in replacement for NavigationLink:
struct PlainNavigationLink<Label, Destination>: View where Label: View, Destination: View {
#ViewBuilder var destination: () -> Destination
#ViewBuilder var label: () -> Label
var body: some View {
label()
.background(
NavigationLink(destination: destination, label: {})
.opacity(0)
)
}
}
To use it, simply replace NavigationLink with PlainNavigationLink:
NavigationView { // or NavigationStack in iOS 16
List {
ForEach(1...30, id: \.self) { _ in
PlainNavigationLink {
Text("Hello, world!")
} label: {
Text("Hello, world!")
}
}
}
}
We can also extend it with convenience initializers for LocalizedStringKey and String, just like NavigationLink does.
just came here looking for the answer to this question, but none of the proposed solutions worked for me (can't have an empty view, because i want to put something in the list row; i'm already messing with the padding (and increasing trailing padding didn't seem to work) ... i was about to give up, and then something occurred to me: what if you crank up the z-index of the list row itself? seemed somewhat unlikely, but i gave it a try and, i'll be damned, it worked! i was so pleasantly surprised, i felt like sharing ...
e.g.:
// in body of your list row view
HStack(alignment: .top, spacing: 0.0) {
// stuff ...
}
.zIndex(9999999999)
If you need children behaviour for List and NavigationLink, without additional discloser in the same time, I want to promote this tricky solution, main point at HStack
var body: some View {
NavigationView {
List(items, children: \.items) { item in
ZStack {
NavigationLink(destination: DetailsView()) {
EmptyView()
}.hidden()
HStack {
RowView(item: item)
Spacer()
}
}
}
}
}
Once you put your button in a scrollview, the disclosure button will be hidden. Just make sure to disable your scroll indicator.
there is no documentation yet, so you can use ScrollView for now
NavigationView {
ScrollView {
ForEach(0...100){ x in
NavigationButton(destination: Text("ss")) {
HStack {
Text(String(x))
Spacer()
}
.padding()
.background(Color.white)
.shadow(radius:1,y:1)
}
}
.frame(width: UIScreen.main.bounds.width - 32)
.padding()
}
}
Removing List and just using ForEach works fine with navigation link. You just have to create your own list row. This works for me
NavigationView {
ForEach(pages) {
page in
NavigationLink(destination: DetailView()) {
ListItem()
}
}
}