SwiftUI: Sheet with fullscreen on MacOS - xcode

Question

Goal:fullscreen sheet on MacOS
Problem: .fullScreenCover() modifier is not available on MacOS
Tried:
This allows you to resize the view to full screen, but does not open default full screen
.frame(maxWidth: .infinity, maxHeight: .infinity)
This crashes
.frame(minWidth: 200, idealWidth: .infinity, maxWidth: .infinity, minHeight: 400, idealHeight: .infinity, maxHeight: .infinity)
Question: how can I make a view that opens by default at full screen on MacOS?

Answer 1

If you can, there's the option of going for a simple ZStack, them showing/hiding the first item accordingly. But, if you want to go further than that, you could try using overlay(). Here's a simple popup that covers the entire view it is called for. If you call it from the first view of your scene, it would take the entire window.
extension View {
func popup<T: View>(isPresented: Bool, #ViewBuilder content: () -> T) -> some View {
modifier(Popup(isPresented: isPresented, content: content))
}
}
struct Popup<T: View>: ViewModifier {
let popup: T
let isPresented: Bool
init(isPresented: Bool, #ViewBuilder content: () -> T) {
self.isPresented = isPresented
popup = content()
}
func body(content: Content) -> some View {
content
.overlay(popupContent())
}
#ViewBuilder private func popupContent() -> some View {
GeometryReader { geometry in
if isPresented {
popup
.frame(width: geometry.size.width, height: geometry.size.height)
}
}
}
}
This example comes from here, which also shows some more personalization for this method. One think to note: As this code was initially written for iPhones, it does not consider things like the window title bar, popup backgrounds and similar features that you could want to have to make it feel more native, but it is a good starting point for what you wanted to do.