Make SwiftUI TabView wrap its content - swiftui

Question

Is it possible to make paged TabView that wraps its content? I don't know the height of the content (it is an Image resized to fit the width of the screen) so I can't use frame modifier.
My code looks like this:
ZStack(alignment: .topTrailing) {
TabView {
ForEach(data) { entry in
VStack {
entry.image
.resizable()
.scaledToFit()
.frame(maxWidth: .infinity)
Text(entry.description)
}
}
}
.tabViewStyle(.page(indexDisplayMode: .never))
Color.red
.frame(width: 20, height: 20)
}
The problem is that the TabView is as big as the screen and PageIndicator is placed in the top right corner of the screen instead of top right corner of the image. Tanks for any suggestions.
EDIT:
I've added code that is reproducible. PageIndicator was replaced by red rectangle.
struct Test: View {
struct Entry: Identifiable {
let image: Image
let description: String
var id: String { description }
}
let data = [
Entry(image: Image(systemName: "scribble"), description: "image 1"),
Entry(image: Image(systemName: "trash"), description: "image 2")
]
var body: some View {
ZStack(alignment: .topTrailing) {
TabView {
ForEach(data) { entry in
VStack {
entry.image
.resizable()
.scaledToFit()
.frame(maxWidth: .infinity)
Text(entry.description)
}
}
}
.tabViewStyle(.page(indexDisplayMode: .never))
Color.red
.frame(width: 20, height: 20)
}
}
}

Answer 1

Your PageIndicator is not placed on the image, because you didn't place it there. You are placing it in a layer on top of a VStack that happens to contain text and an image that can be shorter than the screen. If you want the PageIndicator on the image, then you need to do that specifically. You didn't provide a Minimal, Reproducible Example, but does something like this work:
TabView {
ForEach(data) { entry in
VStack {
entry.image
.resizable()
.scaledToFit()
.overlay(
PageIndicator()
)
.frame(maxWidth: .infinity)
.overlay(
PageIndicator()
)
Text(entry.description)
}
}
}
.tabViewStyle(.page(indexDisplayMode: .never))
The .overlay() needs to go before the .frame() so it stays on the image, instead of overlaying the .frame().
Edit:
Based off of the MRE and the comment, here is alternate solution that aligns the PageIndicator to the top of the image, but does not scroll with the image. Please note that this is not a perfect MRE as the image heights are different, but this solution actually accounts for that as well. Lastly, I added a yellow background on the image to show that things are aligned properly.
struct Test: View {
struct Entry: Identifiable {
let image: Image
let description: String
var id: String { description }
}
let data = [
Entry(image: Image(systemName: "scribble"), description: "image 1"),
Entry(image: Image(systemName: "trash"), description: "image 2")
]
#State private var imageTop: CGFloat = 50
var body: some View {
ZStack(alignment: .topTrailing) {
TabView {
ForEach(data) { entry in
VStack {
entry.image
.resizable()
.scaledToFit()
.frame(maxWidth: .infinity)
.background(Color.yellow)
.background(
GeometryReader { imageProxy in
Color.clear.preference(
key: ImageTopInGlobal.self,
// This returns the top of the image relative to the TabView()
value: imageProxy.frame(in: .named("TabView")).minY)
}
)
Text(entry.description)
}
}
}
// This gives a reference to another container for comparison
.coordinateSpace(name: "TabView")
.tabViewStyle(.page(indexDisplayMode: .never))
VStack {
Spacer()
.frame(height: imageTop)
Color.red
.frame(width: 20, height: 20)
}
}
// You either have to ignore the safe area or account for it with regard to the TabView(). This was simpler.
.edgesIgnoringSafeArea(.top)
.onPreferenceChange(ImageTopInGlobal.self) {
imageTop = $0
}
}
}
private extension Test {
struct ImageTopInGlobal: PreferenceKey {
static let defaultValue: CGFloat = 0
static func reduce(value: inout CGFloat,
nextValue: () -> CGFloat) {
value = nextValue()
}
}
}
Final edit:
In response to the last comment, my answer is a qualified no. I don't think there is any way to make a TabView hug its contents. (I take the original question using the term wrap to mean hug, as the TabView always "wraps" its contents.) If you try to use a preference key, the TabView collapses. There would have to be a minHeight or height set to prevent this which defeats the purpose of the hugging attempt.