Xcode RealityKit / Failed to produce diagnostic for expression - xcode

Im trying to make Augmented Reality app with RealityKit but ContentView.swift I have some problems
What is missing here ?` You can see errors on picture which I shared. I followed some tutorial so Im new on Xcode and Realitykit.
Failed to produce diagnostic for expression; please file a bug report
Cannot find 'PlacementButtonsView' in scope
import SwiftUI
import RealityKit
struct ContentView : View {
var models: [String] = {
let filemanager = FileManager.default
guard let path = Bundle.main.resourcePath, let files = try?
filemanager.contentsOfDirectory(atPath:path) else
{ return[]
}
var avaliableModels: [String] = []
for filename in files where filename.hasSuffix("usdz") {
let modelName = filename.replacingOccurrences(of: ".usdz", with: "")
avaliableModels.append(modelName)
}
return avaliableModels
}()
var body: some View {
ZStack(alignment: .bottom) {
ARViewContainer()
ModelPickerView(models: self.models)
PlacementButtonsView()
}
}
}
struct ARViewContainer: UIViewRepresentable {
func makeUIView(context: Context) -> ARView {
let arView = ARView(frame: .zero)
return arView
}
func updateUIView(_ uiView: ARView, context: Context) {}
}
struct ModelPickerView: View {
var models: [String]
var body: some View {
ScrollView(.horizontal, showsIndicators: false) {
HStack(spacing: 20) {
ForEach(0 ..<
self.models.count) { index in
Button(action: {
print("DEBUG: selected model with name: \(self.models[index])")
}) {
Image(uiImage: UIImage(named: self.models[index])!)
.resizable()
.frame(height: 60)
.aspectRatio(1/1,contentMode: .fit)
.background(Color.white)
.cornerRadius(12)
}
.buttonStyle (PlainButtonStyle())
}
}
}
.padding(15)
.background(Color.black.opacity(0.5))
}
struct PlacementButtonsView: View {
var body: some View {
HStack {
//Cancel Button
Button(action: {
print("DEBUG: model placement canceled.")
}) {
Image(systemName: "xmark")
.frame(width: 60, height: 60)
.font(.title)
.background(Color.white.opacity(0.75))
.cornerRadius(30)
.padding(20)
}
//Confirm Button
Button(action: {
print("DEBUG: model placement confirmed.")
}) {
Image(systemName: "checkmark")
.frame(width: 60, height: 60)
.font(.title)
.background(Color.white.opacity(0.65))
.cornerRadius(30)
.padding(20)
}
}
}
}
#if DEBUG
struct ContentView_Previews : PreviewProvider {
static var previews: some View {
ContentView()
}
}
#endif
}

Check your braces. The PlacementButtonsView struct is actually nested within the ModelPickerView struct, and not globally available, hence why it is not available from your ContentView.
By the way, in Xcode, you can find this out by option clicking on the declaration of PlacementButtonsView:
ModelPickerView.PlacementButtonsView shows you what went wrong here; PlacementButtonsView is nested within ModelPickerView. This is why you seem to have a strange closing brace on the final line of your code sample - the same issue occurs with the preview, as it is also nested in ModelPickerView.
To make this issue more visible, and see similar issues like this in the future more easily, you can also have Xcode indent your code for you by selecting all (Cmd + A) and then pressing Control + I. You'll see the PlacementButtonsView struct indent, making it more clear that it is not globally available.

Related

SwiftUI: Animation problem - fading instead of moving

Iโ€™m trying to build a custom sidebar menu that animates out when a button in it is tapped. For debugging purposes the animation is deliberately slow at 2.0 seconds. As you can see the animation does not work properly:
I suspect there are two parts to this problem:
The background of the newly selected button is moving out faster than the menu. I think this is rooted in the default system animation of Button.
When I replace Button with Text and use an .onTapGesture, there is still the fading animation, so I assume there is something structurally wrong in the way Iโ€™m setting selected in FeatureButton.
Sorry the example code is a bit long, tried to simplify my app architecture as much as possible. The reason for using MenuState as an EnvironmentObject is to be able to the change its properties from various places throughout the app.
Hereโ€™s the code:
class MenuState: ObservableObject {
#Published var currentFeature: Feature = .featureA
#Published var menuOffset: CGFloat = 0
}
enum Feature: String, CaseIterable {
case featureA = "Feature A"
case featureB = "Feature B"
case featureC = "Feature C"
}
extension Feature: Identifiable {
var id: RawValue { rawValue }
}
struct ContentView: View {
#StateObject var menuState = MenuState()
var body: some View {
ZStack(alignment: .leading) {
content
menu
}
.environmentObject(menuState)
.animation(.easeOut(duration: 2.0), value: menuState.menuOffset)
}
var menu: some View {
VStack {
ForEach(Feature.allCases) { feature in
FeatureButton(feature: feature)
}
}
.frame(maxHeight: .infinity)
.frame(width: 200)
.background(.thinMaterial)
.offset(x: menuState.menuOffset)
}
var content: some View {
VStack {
Button("Show Menu") {
menuState.menuOffset = 0
}
Text(menuState.currentFeature.rawValue)
.frame(maxWidth: .infinity, maxHeight: .infinity)
}
}
}
struct FeatureButton: View {
#EnvironmentObject var menuState: MenuState
let feature: Feature
var selected: Bool {
return menuState.currentFeature == feature
}
var body: some View {
Button(feature.rawValue) {
menuState.currentFeature = feature
menuState.menuOffset = -200
}
.buttonStyle(FeatureButtonStyle(selected: selected))
}
}
struct FeatureButtonStyle: ButtonStyle {
#EnvironmentObject var menuState: MenuState
var selected: Bool
public func makeBody(configuration: Configuration) -> some View {
configuration.label
.frame(maxWidth: .infinity, minHeight: 44)
.foregroundColor(selected ? .blue : .primary)
.background(Color.gray.opacity(selected ? 0.4 : 0))
.contentShape(Rectangle())
}
}
EDIT:
For some reason making the animation explicit solves the issue, see answer below.
The problem can be solved by making the animation explicit instead of using the .animation modifier:
Button(feature.rawValue) {
menuState.currentFeature = feature
withAnimation(.easeOut) {
menuState.menuOffset = -200
}
}
.buttonStyle(FeatureButtonStyle(selected: selected))
I don't understand why it only works like this though.

View Modifier messing with animations

I've been looking to add a loading indicator to my project, and found a really cool animation here. To make it easier to use, I wanted to incorporate it into a view modifier to put it on top of the current view. However, when I do so, it doesn't animate when I first press the button. I have played around with it a little, and my hypothesis is that the View Modifier doesn't pass the initial isAnimating = false, so only passes it isAnimating = true when the button is pressed. Because the ArcsAnimationView doesn't get the false value initially, it doesn't actually animate anything and just shows the static arcs. However, if I press the button a second time afterwards, it seems to be initialized and the view properly animates as desired.
Is there a better way to structure my code to avoid this issue? Am I missing something key? Any help is greatly appreciated.
Below is the complete code:
import SwiftUI
struct ArcsAnimationView: View {
#Binding var isAnimating: Bool
let count: UInt = 4
let width: CGFloat = 5
let spacing: CGFloat = 2
init(isAnimating: Binding<Bool>) {
self._isAnimating = isAnimating
}
var body: some View {
GeometryReader { geometry in
ForEach(0..<Int(count)) { index in
item(forIndex: index, in: geometry.size)
// the rotation below is what is animated ...
// I think the problem is that it just starts at .degrees(360), instead of
// .degrees(0) as expected, where it is then animated to .degrees(360)
.rotationEffect(isAnimating ? .degrees(360) : .degrees(0))
.animation(
Animation.default
.speed(Double.random(in: 0.05...0.25))
.repeatCount(isAnimating ? .max : 1, autoreverses: false)
, value: isAnimating
)
.foregroundColor(Color(hex: AppColors.darkBlue1.rawValue))
}
}
.aspectRatio(contentMode: .fit)
}
private func item(forIndex index: Int, in geometrySize: CGSize) -> some View {
Group { () -> Path in
var p = Path()
p.addArc(center: CGPoint(x: geometrySize.width/2, y: geometrySize.height/2),
radius: geometrySize.width/2 - width/2 - CGFloat(index) * (width + spacing),
startAngle: .degrees(0),
endAngle: .degrees(Double(Int.random(in: 120...300))),
clockwise: true)
return p.strokedPath(.init(lineWidth: width))
}
.frame(width: geometrySize.width, height: geometrySize.height)
}
}
struct ArcsAnimationModifier: ViewModifier {
#Binding var isAnimating: Bool
func body(content: Content) -> some View {
ZStack {
if isAnimating {
ArcsAnimationView(isAnimating: _isAnimating)
.frame(width: 150)
}
content
.disabled(isAnimating)
}
}
}
extension View {
func loadingAnimation(isAnimating: Binding<Bool>) -> some View {
self.modifier(ArcsAnimationModifier(isAnimating: isAnimating))
}
}
Here is where I actually call the function:
struct AnimationView: View {
#State var isAnimating = false
var body: some View {
VStack {
Button(action: {
self.isAnimating = true
DispatchQueue.main.asyncAfter(deadline: .now() + 4) {
self.isAnimating = false
}
}, label: {
Text("show animation")
})
}
.loadingAnimation(isAnimating: $isAnimating)
}
}
Note: I am fairly certain the issue is with View Modifier since if I call ArcsAnimationView as a regular view in AnimationView, it works as expected.
I get there to see some implementation, but I think others would prefer a simple base to start from.
here my 2 cents to show how to write an AnimatableModifier that can be used on multiple objects cleaning up ".animation" in code.
struct ContentView: View {
#State private var hideWhilelUpdating = false
var body: some View {
Image(systemName: "tshirt.fill")
.modifier(SmoothHideAndShow(hide: hideWhilelUpdating))
Text("Some contents to show...")
.modifier(SmoothHideAndShow(hide: hideWhilelUpdating))
Button( "hide and show smootly") {
hideWhilelUpdating.toggle()
}
.padding(60)
}
}
struct SmoothHideAndShow: AnimatableModifier {
var hide: Bool
var animatableData: CGFloat {
get { CGFloat(hide ? 0 : 1) }
set { hide = newValue == 0 }
}
func body(content: Content) -> some View {
content
.opacity(hide ? 0.2 : 1)
.animation(.easeIn(duration: 1), value: hide)
}
}
when pressing button, our bool will trigger animation that fades in and out our text.
I use it during network calls (omitted for clarity... and replaced with button) to hide values under remote update. When network returns, I toggle boolean.

How to link child View state to menus using FocusedValues

SwiftUI newbie here. ๐Ÿ‘‹ I'm struggling to understand how #FocusedBinding and FocusedValues work when building menus for a MacOS app. I'm trying to build the Apple HIG UI pattern with buttons in the window toolbar for changing the list view, and matching menu items in the View menu. Much like Finder windows have the four different view modes.
I have gone through the Apple's Landmarks tutorial, the Frameworks Engineer's example code in Apple dev forum, and Majid's tutorial.
The Apple documentation says FocusedValues is "a collection of state exported by the focused view and its ancestors." I assume the collection is global and I can set a focusedValue in any child View, and read or bind to any of the FocusedValues from anywhere in my code.
Therefore I don't understand why my first example below works, but the second one doesn't?
This works:
import SwiftUI
#main
struct TestiApp: App {
var body: some Scene {
WindowGroup {
ContentView()
.frame(minWidth: 200, minHeight: 300)
.onAppear {
NSWindow.allowsAutomaticWindowTabbing = false
}
}
.windowStyle(HiddenTitleBarWindowStyle())
.commands {
MenuCommands()
}
}
}
struct ContentView: View {
// In the working version of the code selectedView is defined here
// in the ContentView, which is a direct child of the WindowGroup
// that has the .commands modifier.
#State private var selectedView: Int = 0
// For demonstration purposes I have simplified the authorization
// code to a hardcoded boolean.
private var isAuthorized: Bool = true
var body: some View {
switch isAuthorized {
case true:
// focusedValue is set here to the selectedView binding.
// I don't really understand why do it here, but it works.
AuthorizedView(selectedView: $selectedView)
.focusedValue(\.selectedViewBinding, $selectedView)
default:
NotYetAuthorizedView()
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct AuthorizedView: View {
// selectedView is passed to this view as an argument and
// bound from ContentView.
#Binding var selectedView: Int
var body: some View {
List {
Text("Something here")
Text("Something more")
Text("Even more")
}
.toolbar {
// The Picker element sets and gets the bound selectedView value
Picker("View", selection: $selectedView) {
Text("View 1").tag(0)
Text("View 2").tag(1)
}
.pickerStyle(SegmentedPickerStyle())
}
}
}
struct NotYetAuthorizedView: View {
var body: some View {
VStack {
Text("You need permission to access this ๐Ÿ˜ญ")
.padding()
}
}
}
struct MenuCommands: Commands {
private struct MenuContent: View {
// Command menu binds the selectedView value through focusedValues.
// MenuContent is a View, because otherwise the binding doesn't
// work (I read there's a bug in SwiftUI...).
#FocusedBinding(\.selectedViewBinding) var selectedView: Int?
var body: some View {
Button("View 1") {
selectedView = 0
}
.keyboardShortcut("1")
Button("View 2") {
selectedView = 1
}
.keyboardShortcut("2")
}
}
var body: some Commands {
CommandGroup(before: .toolbar) {
MenuContent()
}
}
}
struct SelectedViewBinding: FocusedValueKey {
typealias Value = Binding<Int>
}
extension FocusedValues {
var selectedViewBinding: SelectedViewBinding.Value? {
get { self[SelectedViewBinding.self] }
set { self[SelectedViewBinding.self] = newValue }
}
}
But if I make the following changes to ContentView and AuthorizedView, the project compiles fine but the binding between selectedView and the command menus no longer works:
struct ContentView: View {
// selectedView definition has been removed from ContentView
// and moved to AuthorizedView.
private var isAuthorized: Bool = true
var body: some View {
switch isAuthorized {
case true:
AuthorizedView()
// Also setting the focusedValue here has been removed
default:
NotYetAuthorizedView()
}
}
}
struct AuthorizedView: View {
// Moved selectedView definition here
#State private var selectedView: Int = 0
var body: some View {
List {
Text("Something here")
Text("Something more")
Text("Even more")
}
.toolbar {
Picker("View", selection: $selectedView) {
Text("View 1").tag(0)
Text("View 2").tag(1)
}
.pickerStyle(SegmentedPickerStyle())
.focusedValue(\.selectedViewBinding, $selectedView)
// I am now setting the focusedValue here, which seems
// more logical to me...
}
}
}
I like the second example better, because the selectedView state is encapsulated in the AuthorizedView where it belongs.

Animations triggered by events in SwiftUI

SwiftUI animations are typically driven by state, which is great, but sometimes you really want to trigger a temporary (often reversible) animation in response to some event. For example, I want to temporarily increase the size of a button when a it is tapped (both the increase and decrease in size should happen as a single animation when the button is released), but I haven't been able to figure this out.
It can sort of be hacked together with transitions I think, but not very nicely. Also, if I make an animation that uses autoreverse, it will increase the size, decrease it and then jump back to the increased state.
That is something I have been into as well.
So far my solution depends on applying GeometryEffect modifier and misusing the fact that its method effectValue is called continuously during some animation. So the desired effect is actually a transformation of interpolated values from 0..1 that has the main effect in 0.5 and no effect at 0 or 1
It works great, it is applicable to all views not just buttons, no need to depend on touch events or button styles, but still sort of seems to me as a hack.
Example with random rotation and scale effect:
Code sample:
struct ButtonEffect: GeometryEffect {
var offset: Double // 0...1
var animatableData: Double {
get { offset }
set { offset = newValue }
}
func effectValue(size: CGSize) -> ProjectionTransform {
let effectValue = abs(sin(offset*Double.pi))
let scaleFactor = 1+0.2*effectValue
let affineTransform = CGAffineTransform(rotationAngle: CGFloat(effectValue)).translatedBy(x: -size.width/2, y: -size.height/2).scaledBy(x: CGFloat(scaleFactor), y: CGFloat(scaleFactor))
return ProjectionTransform(affineTransform)
}
}
struct ButtonActionView: View {
#State var animOffset: Double = 0
var body: some View {
Button(action:{
withAnimation(.spring()) {
self.animOffset += 1
}
})
{
Text("Press ME")
.padding()
}
.background(Color.yellow)
.modifier(ButtonEffect(offset: animOffset))
}
}
You can use a #State variable tied to a longPressAction():
Code updated for Beta 5:
struct ContentView: View {
var body: some View {
HStack {
Spacer()
MyButton(label: "Button 1")
Spacer()
MyButton(label: "Button 2")
Spacer()
MyButton(label: "Button 3")
Spacer()
}
}
}
struct MyButton: View {
let label: String
#State private var pressed = false
var body: some View {
return Text(label)
.font(.title)
.foregroundColor(.white)
.padding(10)
.background(RoundedRectangle(cornerRadius: 10).foregroundColor(.green))
.scaleEffect(self.pressed ? 1.2 : 1.0)
.onLongPressGesture(minimumDuration: .infinity, maximumDistance: .infinity, pressing: { pressing in
withAnimation(.easeInOut(duration: 0.2)) {
self.pressed = pressing
}
}, perform: { })
}
}
I believe this is what you're after. (this is how I solved this problem)
Based on dfd's link in i came up with this, which is not dependent on any #State variable. You simply just implement your own button style.
No need for Timers, #Binding, #State or other complex workarounds.
import SwiftUI
struct MyCustomPressButton: ButtonStyle {
func makeBody(configuration: Self.Configuration) -> some View {
configuration.label
.padding(10)
.cornerRadius(10)
.scaleEffect(configuration.isPressed ? 0.8 : 1.0)
}
}
struct Play: View {
var body: some View {
Button("Tap") {
}.buttonStyle(MyCustomPressButton())
.animation(.easeIn(duration: 0.2))
}
}
struct Play_Previews: PreviewProvider {
static var previews: some View {
Play()
}
}
There is no getting around the need to update via state in SwiftUI. You need to have some property that is only true for a short time that then toggles back.
The following animates from small to large and back.
struct ViewPlayground: View {
#State var enlargeIt = false
var body: some View {
Button("Event!") {
withAnimation {
self.enlargeIt = true
}
}
.background(Momentary(doIt: self.$enlargeIt))
.scaleEffect(self.enlargeIt ? 2.0 : 1.0)
}
}
struct Momentary: View {
#Binding var doIt: Bool
var delay: TimeInterval = 0.35
var body: some View {
Group {
if self.doIt {
ZStack { Spacer() }
.onAppear {
DispatchQueue.main.asyncAfter(deadline: .now() + self.delay) {
withAnimation {
self.doIt = false
}
}
}
}
}
}
}
Unfortunately delay was necessary to get the animation to occur when setting self.enlargeIt = true. Without that it only animates back down. Not sure if that's a bug in Beta 4 or not.

Is there any way to make a paged ScrollView in SwiftUI?

I've been looking through the docs with each beta but haven't seen a way to make a traditional paged ScrollView. I'm not familiar with AppKit so I am wondering if this doesn't exist in SwiftUI because it's primarily a UIKit construct. Anyway, does anyone have an example of this, or can anyone tell me it's definitely impossible so I can stop looking and roll my own?
You can now use a TabView and set the .tabViewStyle to PageTabViewStyle()
TabView {
View1()
View2()
View3()
}
.tabViewStyle(PageTabViewStyle())
As of Beta 3 there is no native SwiftUI API for paging. I've filed feedback and recommend you do the same. They changed the ScrollView API from Beta 2 to Beta 3 and I wouldn't be surprised to see a further update.
It is possible to wrap a UIScrollView in order to provide this functionality now. Unfortunately, you must wrap the UIScrollView in a UIViewController, which is further wrapped in UIViewControllerRepresentable in order to support SwiftUI content.
Gist here
class UIScrollViewViewController: UIViewController {
lazy var scrollView: UIScrollView = {
let v = UIScrollView()
v.isPagingEnabled = true
return v
}()
var hostingController: UIHostingController<AnyView> = UIHostingController(rootView: AnyView(EmptyView()))
override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(self.scrollView)
self.pinEdges(of: self.scrollView, to: self.view)
self.hostingController.willMove(toParent: self)
self.scrollView.addSubview(self.hostingController.view)
self.pinEdges(of: self.hostingController.view, to: self.scrollView)
self.hostingController.didMove(toParent: self)
}
func pinEdges(of viewA: UIView, to viewB: UIView) {
viewA.translatesAutoresizingMaskIntoConstraints = false
viewB.addConstraints([
viewA.leadingAnchor.constraint(equalTo: viewB.leadingAnchor),
viewA.trailingAnchor.constraint(equalTo: viewB.trailingAnchor),
viewA.topAnchor.constraint(equalTo: viewB.topAnchor),
viewA.bottomAnchor.constraint(equalTo: viewB.bottomAnchor),
])
}
}
struct UIScrollViewWrapper<Content: View>: UIViewControllerRepresentable {
var content: () -> Content
init(#ViewBuilder content: #escaping () -> Content) {
self.content = content
}
func makeUIViewController(context: Context) -> UIScrollViewViewController {
let vc = UIScrollViewViewController()
vc.hostingController.rootView = AnyView(self.content())
return vc
}
func updateUIViewController(_ viewController: UIScrollViewViewController, context: Context) {
viewController.hostingController.rootView = AnyView(self.content())
}
}
And then to use it:
var body: some View {
GeometryReader { proxy in
UIScrollViewWrapper {
VStack {
ForEach(0..<1000) { _ in
Text("Hello world")
}
}
.frame(width: proxy.size.width) // This ensures the content uses the available width, otherwise it will be pinned to the left
}
}
}
Apple's official tutorial covers this as an example. I find it easy to follow and suitable for my case. I really recommend you check this out and try to understand how to interface with UIKit. Since SwiftUI is so young, not every feature in UIKit would be covered at this moment. Interfacing with UIKit should address most if not all needs.
https://developer.apple.com/tutorials/swiftui/interfacing-with-uikit
Not sure if this helps your question but for the time being while Apple is working on adding a Paging View in SwiftUI I've written a utility library that gives you a SwiftUI feel while using a UIPageViewController under the hood tucked away.
You can use it like this:
Pages {
Text("Page 1")
Text("Page 2")
Text("Page 3")
Text("Page 4")
}
Or if you have a list of models in your application you can use it like this:
struct Car {
var model: String
}
let cars = [Car(model: "Ford"), Car(model: "Ferrari")]
ModelPages(cars) { index, car in
Text("The \(index) car is a \(car.model)")
.padding(50)
.foregroundColor(.white)
.background(Color.blue)
.cornerRadius(10)
}
You can simply track state using .onAppear() to load your next page.
struct YourListView : View {
#ObservedObject var viewModel = YourViewModel()
let numPerPage = 50
var body: some View {
NavigationView {
List(viewModel.items) { item in
NavigationLink(destination: DetailView(item: item)) {
ItemRow(item: item)
.onAppear {
if self.shouldLoadNextPage(currentItem: item) {
self.viewModel.fetchItems(limitPerPage: self.numPerPage)
}
}
}
}
.navigationBarTitle(Text("Items"))
.onAppear {
guard self.viewModel.items.isEmpty else { return }
self.viewModel.fetchItems(limitPerPage: self.numPerPage)
}
}
}
private func shouldLoadNextPage(currentItem item: Item) -> Bool {
let currentIndex = self.viewModel.items.firstIndex(where: { $0.id == item.id } )
let lastIndex = self.viewModel.items.count - 1
let offset = 5 //Load next page when 5 from bottom, adjust to meet needs
return currentIndex == lastIndex - offset
}
}
class YourViewModel: ObservableObject {
#Published private(set) items = [Item]()
// add whatever tracking you need for your paged API like next/previous and count
private(set) var fetching = false
private(set) var next: String?
private(set) var count = 0
func fetchItems(limitPerPage: Int = 30, completion: (([Item]?) -> Void)? = nil) {
// Do your stuff here based on the API rules for paging like determining the URL etc...
if items.count == 0 || items.count < count {
let urlString = next ?? "https://somePagedAPI?limit=/(limitPerPage)"
fetchNextItems(url: urlString, completion: completion)
} else {
completion?(pokemon)
}
}
private func fetchNextItems(url: String, completion: (([Item]?) -> Void)?) {
guard !fetching else { return }
fetching = true
Networking.fetchItems(url: url) { [weak self] (result) in
DispatchQueue.main.async { [weak self] in
self?.fetching = false
switch result {
case .success(let response):
if let count = response.count {
self?.count = count
}
if let newItems = response.results {
self?.items += newItems
}
self?.next = response.next
case .failure(let error):
// Error state tracking not implemented but would go here...
os_log("Error fetching data: %#", error.localizedDescription)
}
}
}
}
}
Modify to fit whatever API you are calling and handle errors based on your app architecture.
Checkout SwiftUIPager. It's a pager built on top of SwiftUI native components:
If you would like to exploit the new PageTabViewStyle of TabView, but you need a vertical paged scroll view, you can make use of effect modifiers like .rotationEffect().
Using this method I wrote a library called VerticalTabView ๐Ÿ” that turns a TabView vertical just by changing your existing TabView to VTabView.
You can use such custom modifier:
struct ScrollViewPagingModifier: ViewModifier {
func body(content: Content) -> some View {
content
.onAppear {
UIScrollView.appearance().isPagingEnabled = true
}
.onDisappear {
UIScrollView.appearance().isPagingEnabled = false
}
}
}
extension ScrollView {
func isPagingEnabled() -> some View {
modifier(ScrollViewPagingModifier())
}
}
To simplify Lorenzos answer, you can basically add UIScrollView.appearance().isPagingEnabled = true to your scrollview as below:
VStack{
ScrollView(showsIndicators: false){
VStack(spacing: 0){ // to remove spacing between rows
ForEach(1..<10){ i in
ZStack{
Text(String(i))
Circle()
} .frame(width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height)
}
}
}.onAppear {
UIScrollView.appearance().isPagingEnabled = true
}
.onDisappear {
UIScrollView.appearance().isPagingEnabled = false
}
}

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