GeometryReader size as subview - swiftui

Question

At an early stage of SwiftUI, it was easy to frame a view relative to its parent. That's gone, and we're left with GeometryReader.
I'll start with GeometryReader as the parent: It position its subview in the top left and that's fine.
As a subview, its size is unclear. The idea is to avoid giving 'hardcoded' height. Here's an image, wrapped in a GeometryReader, where I attempt to set a Text view under the image:
struct ContentView1: View {
var body: some View {
VStack {
GeometryReader { proxy in
Image("image")
.resizable()
.aspectRatio(contentMode: .fit)
.frame(width: proxy.size.width * 0.8)
}
.background(Color.green)
Text("Text under image")
Spacer() // I'm being ignored
}
}
}
The GeometryReader has taking higher priority than the Spacer. At this point I can only give GeometryReader a hardcoded hight.
Let's try scaledToFit():
VStack {
GeometryReader { proxy in
Image("image")
.resizable()
.aspectRatio(contentMode: .fit)
.frame(width: proxy.size.width * 0.8)
}
.background(Color.green)
.scaledToFit() // Scaled to fit 'something', who knows
Text("Text under image")
Spacer()
}
Unless GeometryReader is the top 'view':
struct ContentViewSuper: View {
var body: some View {
GeometryReader { proxy in
VStack {
Image("image")
.resizable()
.aspectRatio(contentMode: .fit)
.frame(width: proxy.size.width * 0.8)
Text("Text under image")
Spacer()
}
}
.background(Color.green)
}
}
What's the right way to size GeometryReader? Use hardcode height? Use as the parent view of the screen? Is there another way to create a subview with GeometryReader that is more predictable in size?

Answer 1

Until a better answer comes along, this is what I have:
GeometryReader is meant best used as either the superview (not a subview), or a background view layout. Otherwise, a specific size (height) needs to be used.
GeometryReader will use flexible preferred size, it will not wrap its content. The size will behave differently than other views (higher tolerance to Spacer for example).
Used as a superview, the geometry, similar to UIKit, will place the (0,0) origin at the top left.