Consider supporting native screen headers in Form Sheets on Android

[SimpleCreations]

Hi!

Currently there's a divide between the Android and iOS formSheet implementation — native screen headers are only supported on iOS. This has been brought up before here: #2657

This divide is very unfortunate. My app has reusable hooks that set native header options to fit the design needs; they include background and shadow transitions, custom buttons, status bar color transitions, etc. I use these hooks throughout the codebase for stack screens and modals. Since iOS form sheets have native headers, these customizations can be applied to them as well, but not to Android form sheets. I know I can use a JS header implementation, but this would mean maintaining 2 separate versions of all this code just for the form sheets, which is terrible 😔

Maybe it's possible that native screen headers will be added on Android at some point in the future? I could explore preparing a PR for this but would appreciate some directions

[kkafar]

Hey!

Thanks for reaching out here. This is unsupported for few reasons, mostly related to layout.

Our current plans here is to support header component, but not really "native one". That is, currently on "modal" on iOS, when you pass presentation: 'modal', headerShown: true we render nested native stack inside of the modal and this is where the header comes from.

With the formsheet situation is a bit more complicated due to it's resizing capabilities & bugs in layout it introduces due to asynchronous nature of react-native layout system. We've done some initial research and it seemed that implementing this correctly was not really feasible. Things change, now, since [email protected] we have "almost synchronous" shadow state updates, but they're limited to iOS.

tldr; we plan to support non-native headers in formsheets (and all modals), but we still need to wait for some changes in core to land.

Also important thing atm. is that we're working on next major version, and we are in process of rewriting modals / formsheets implementation from the group up, therefore I won't be willing to do wide-scoped refactors / architectural changes in react-native-screes@4 implementation, as it will be slowly going into maintenance mode.