Deprecated Apis

Retiring Deprecated Android APIs

Never introduce these deprecated APIs in new code, and replace them when you touch code that uses them — a Java→Kotlin conversion is the right moment, since the IDE converter leaves them untouched. Each replacement below is behaviour-preserving. Examples are real conversions from the nextcloud/android client (PRs #16878, #16792), not from this repository.

startActivityForResult / onActivityResult → Activity Result API

The request-code + onActivityResult protocol is deprecated. Register a launcher at construction time and receive the result in its callback.

// BEFORE
startActivityForResult(action, SELECT_LOCATION_REQUEST_CODE)
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    if (requestCode == SELECT_LOCATION_REQUEST_CODE && data != null) { handle(data) }
}

// AFTER
private val folderPickerLauncher = registerForActivityResult(
    ActivityResultContracts.StartActivityForResult()
) { result ->
    if (result.resultCode == Activity.RESULT_OK) {
        handle(result.data)
    }
}

// launch it:
folderPickerLauncher.launch(intent)

Type-safe, no manual request-code bookkeeping, and it survives process death because registration is declarative. Register during initialization (a field initializer or onCreate/onViewCreated) — never inside a click handler, or the registration is lost.

onCreateOptionsMenu / onOptionsItemSelected → MenuProvider

setHasOptionsMenu(true) plus the two menu overrides are deprecated on Fragment. Add a MenuProvider bound to the view lifecycle instead.

// AFTER
val menuHost: MenuHost = requireActivity()
menuHost.addMenuProvider(object : MenuProvider {
    override fun onCreateMenu(menu: Menu, inflater: MenuInflater) =
        inflater.inflate(R.menu.gallery_menu, menu)

    override fun onMenuItemSelected(item: MenuItem): Boolean = when (item.itemId) {
        R.id.action_select_all -> { selectAll(); true }
        else -> false
    }
}, viewLifecycleOwner, Lifecycle.State.RESUMED)

Passing viewLifecycleOwner + Lifecycle.State.RESUMED auto-adds and removes the menu as the view's lifecycle changes — no leak, no manual setHasOptionsMenu. (PR #16878)

java.util.Observable — Keep or Migrate?

java.util.Observable / Observer are deprecated (Java 9+). But a conversion is behaviour-locked, so do not silently swap the notification mechanism — existing Java observers rely on setChanged() / notifyObservers(). PR #16792 deliberately KEPT it:

class UploadsStorageManager(...) : Observable() {
    fun notifyObserversNow() {
        Handler(Looper.getMainLooper()).post {
            setChanged()
            notifyObservers()
        }
    }
}

Migrating to StateFlow / SharedFlow changes the observation contract and every call site — that is a separate, opt-in refactor, not part of a 1:1 conversion. Note the deprecation, propose the flow migration as a follow-up, and keep the current mechanism unless the developer scopes the larger change.