I am having issues presenting one sheet on top of another.
Looking into the Mail app presents a long navigation stack. List of email accounts (1) > list of messages (2) > single message view (3) > text field and suggestions list (4)
1 and 2 use new main & detail navigation with nice circular back button. You can select any message (2), and then you can hit Reply in the bottom right corner. I assume this shows a sheet (3). From the sheet select any option, like Reply. That shows another sheet with a text field and suggestions depicted below. (4)
It looks like the whole navigation stack is preserved because dismissing the top sheet, shows the previous one. When I try to do the same in my app I see this nice warning message.
Currently, only presenting a single sheet is supported.
The next sheet will be presented when the currently presented sheet gets dismissed.
UIKit speaking, in watchOS you can only present views, except, main & detail navigation introduced in watchOS 10, you can't push views. It seems like the Mail app somehow does it. I am wondering if is it a private API.
I will explore 2 NavigationSplitView presented on top of each other and will report back.
Quick update, will post full details later. I realised that I was using SwiftUI in the wrong way. My problem is that I had a view with multiple .sheet modifiers. If you present a second view, add the .sheet modifier to the second view. Essentially this should allow an unlimited navigation stack.