utils/sync_settings_ui
Krzysztof kuhy Rudnicki db3d8f827f Let a host explain an absent Google button instead of hiding it
lyricanki's Linux desktop cannot use google_sign_in (no Linux
implementation) and its loopback replacement is dark until a Desktop OAuth
client exists. Hiding the button there makes the screen silently offer less
on one platform, which reads as a bug.

googleUnavailableReason renders a *disabled* button plus the reason. That is
not the "control that can never succeed" trap: the trap is a live-looking
button that reports a fake cancellation, and a null onPressed cannot be
tapped at all. Null stays the default, so every existing host is unchanged.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CFSGeWxHPY5rHUGrPqhcmG
2026-08-22 19:03:24 +02:00
..
lib Let a host explain an absent Google button instead of hiding it 2026-08-22 19:03:24 +02:00
scripts Add sync_settings_ui: shared Firebase-only sync settings screen 2026-08-12 23:10:17 +02:00
test Let a host explain an absent Google button instead of hiding it 2026-08-22 19:03:24 +02:00
.gitignore Add sync_settings_ui: shared Firebase-only sync settings screen 2026-08-12 23:10:17 +02:00
.pre-commit-config.yaml Fix the cap hook in CI, and the re-exports its --all-files run exposed 2026-08-22 15:52:59 +02:00
analysis_options.yaml sync_settings_ui: split sync_settings_screen.dart 382 -> 192 2026-08-22 15:38:58 +02:00
pubspec.yaml Let a host explain an absent Google button instead of hiding it 2026-08-22 19:03:24 +02:00
README.md Extract the Flutter sync glue into crdt_sync_flutter, and document it 2026-08-22 17:26:34 +02:00

sync_settings_ui

The shared Sync settings screen: Firebase sign-in (email/password or Google one-tap), Disconnect, a live status line, and an optional Backup section. Reused across every one of kuhy's Flutter apps that syncs, so the screen behaves identically everywhere and is fixed in one place.

Generalized from the near-identical _connectFirebase / _connectGoogle / _disconnectFirebase / _load logic that had been duplicated into every app's settings screen.

Install

dependencies:
  sync_settings_ui:
    git:
      url: https://github.com/kuhyx/utils
      ref: sync_settings_ui-v0.1.0
      path: sync_settings_ui

Usage

This package never touches flutter_secure_storage or google_sign_in itself — every keystore read/write and every platform sign-in arrives as an already-built closure. crdt_sync_flutter provides all of them, so the two fit together directly:

import 'package:crdt_sync_flutter/crdt_sync_flutter.dart';
import 'package:sync_settings_ui/sync_settings_ui.dart';

SyncSettingsScreen(
  accountLoader: () => loadAccount(),
  accountSaver: saveAccount,
  accountClearer: clearAccount,
  sessionProbe: () => isSyncConfigured(kApp),
  firebaseFactory: () => openSync(kApp),
  googleFirebaseFactory: () => signInWithGoogle(
    kApp,
    tokenFetcher: googleIdToken, // the app's own google_sign_in call
  ),
  googleAvailable: googleSignInSupported,
  backup: BackupSlot(label: 'notes', export: _export, import: _import),
)

Pass backup: null to omit the Backup section entirely.

What it gets right, so you don't re-derive it

"Connected" means the session probe says so — never that a factory returned a non-null client. FirebaseSyncController returns a FirebaseConnectResult carrying a six-case outcome:

Outcome Meaning
connected Signed in, and the probe confirms a live session.
rejected The credentials were refused.
cancelled The user dismissed the picker.
signedInButNotPersisted Sign-in worked; nothing durable was stored.
wrongAccount Authenticated as a uid the rules do not allow.
failed Anything else.

signedInButNotPersisted and wrongAccount exist because both looked identical to success from the call site and both produced a device that appeared connected and synced nothing.

The Google button is double-gated on supportsGoogle && googleAvailable, so a button that cannot possibly succeed is never rendered — a visible control that always reports "cancelled" is worse than no control.

Development

flutter pub get
flutter analyze
flutter test