SwiftUI: Tap target for Navigation Bar Button misaligned after dismissing a sheet

Question

I am noticing a rather strange, possibly buggy behavior in SwiftUI using iOS 13.3.1 and earlier. To demonstrate, this very simple scenario:

Full sample code:

import SwiftUI

struct ContentView: View {
    @State var showingSheet: Bool = false
    var body: some View {
        NavigationView {
            Text("ParentView")
                .navigationBarItems(trailing: Button(action: { self.showingSheet = true }) { Text("Show") })
        }.sheet(isPresented: $showingSheet) { SheetView() }
    }
}

struct SheetView: View {
    @Environment(\.presentationMode) var presentationMode
    var body: some View {
        VStack {
            Text("Sheet content")
            Button(action: { self.presentationMode.wrappedValue.dismiss() }) { Text("Hide") }
        }
    }
}

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To reproduce:

1. Launch the app on iOS 13.4.1
2. Tap the "Show" button
3. (The sheet shows, as expected)
4. Dismiss the sheet using the "Hide" button
5. (The sheet is dismissed, as expected)
6. Try to show the sheet again, using the "Show" button

Expected result: The sheet shows again.

Actual result: The tap target of the "Show" button is shifted some pixels to the bottom, resulting in the action not triggering. This can also be observed in the View Hierarchy Debugger:

Other observations:

• This does not happen when dismissing the sheet by dragging it to the bottom of the screen
• This occurs only if large navigation item titles are activated for the hosting view, it's fine when using an inline title

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So now I'm here wondering: Am I making a mistake, or is this an actual SwiftUI bug? If so, is there an easy workaround? I searched SO for similar issues, but didn't come across any that were identical.

Edit: I filed this with Apple as Radar Feedback FB7560960 in the meantime.

Edit 2: Still happening in 13.4.1.

Answer 1

I don't know why, but adding @Environment(\.presentationMode) var presentationMode to contentView seems to fix it.