Offline-first launch: open on saved data, sync in the background

CHANGELOG.md

@@ -32,6 +32,11 @@ What changed in each version of the app, newest first. The format is
 - Exchange-rate estimates only use a rate from within a week of the expense's day, and the server keeps a full year of rates to draw on.
 - Two people editing the same expense at once no longer quietly lose one edit: whichever arrives second is set aside, with the newer version shown, to be applied again on top of it.
 - Saving something syncs that group alone, and all your groups are read in one request, so syncing uses far less data and battery.
+- OpenSplit opens straight onto what is saved on this device, behind one launch screen, with a thin bar while it checks for changes.
+- When you are offline, a cloud icon at the top of the screen says so.
+- Moving between Groups, Account and Settings fades from one to the next.
+- The Android launch screen shows the logo without a tile behind it.
+- Text on screen is no longer selectable, as in other apps. Invite links can still be copied.
 
 ### Fixed
 - Settling up with somebody and then removing them while offline no longer leaves the removal refused once you are back online.
@@ -52,6 +57,9 @@ What changed in each version of the app, newest first. The format is
 - Nobody can add a new expense that charges somebody who has left a group.
 - An expense split among 26 or more people now saves; before, the server refused it and the app kept retrying.
 - In Settle up, making the person being paid the payer now clears "Who is being paid" on screen too, not just behind it.
+- Swiping back with the date or time picker open closes the picker, not the screen behind it.
+- The Account page opens with your name and UPI ID already showing, instead of filling them in a moment later.
+- Syncing tries again as soon as you are back online, rather than waiting for its next turn.
 
 ## [2.0.0] - 2026-10-01
 ### Changed

android/app/src/main/res/values-night-v31/styles.xml

@@ -16,9 +16,7 @@
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
         <item name="android:windowSplashScreenBackground">#131318</item>
         <item name="android:windowSplashScreenAnimatedIcon">@drawable/android12splash</item>
-        <item name="android:windowSplashScreenIconBackgroundColor">#1F1F25</item>
     </style>
-
     <!-- Same as the pre-31 NormalTheme, and stated again because this file
          shadows it on Android 12 and up. The generator leaves
          ?android:colorBackground here, which is the platform's white and is

android/app/src/main/res/values-night/styles.xml

@@ -12,7 +12,6 @@
         <item name="android:windowDrawsSystemBarBackgrounds">false</item>
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
     </style>
-
     <!-- The window behind the Flutter UI once it is running. Visible during a
          rotation or a resize, so it is the app's surface rather than the
          platform's ?android:colorBackground, which is plain white. -->

android/app/src/main/res/values-v31/styles.xml

@@ -16,9 +16,7 @@
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
         <item name="android:windowSplashScreenBackground">#FCF8FF</item>
         <item name="android:windowSplashScreenAnimatedIcon">@drawable/android12splash</item>
-        <item name="android:windowSplashScreenIconBackgroundColor">#E3DFFF</item>
     </style>
-
     <!-- Same as the pre-31 NormalTheme, and stated again because this file
          shadows it on Android 12 and up. The generator leaves
          ?android:colorBackground here, which is the platform's white and is

android/app/src/main/res/values/styles.xml

@@ -12,7 +12,6 @@
         <item name="android:windowDrawsSystemBarBackgrounds">false</item>
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
     </style>
-
     <!-- The window behind the Flutter UI once it is running. Visible during a
          rotation or a resize, so it is the app's surface rather than the
          platform's ?android:colorBackground, which is plain white. -->

flutter_native_splash.yaml

@@ -1,8 +1,8 @@
 # Regenerate with: dart run flutter_native_splash:create
 #
 # Colours here are ColorScheme values written out as literals, because none of
-# this runs Dart — the same duplication the web loading skeleton has, and pinned
-# the same way, by a test.
+# this runs Dart — the same duplication the web splash has, and pinned the same
+# way, by a test.
 #
 # #FCF8FF is ColorScheme.surface in the light scheme, #131318 in the dark.
 # The brand kit quotes the light one as #FBF8FF; this is what
@@ -17,19 +17,21 @@ flutter_native_splash:
   # Android 12 replaced the full-bleed splash image with an icon in a masked
   # circle. splash-icon.png is 1152px with the mark at 640px specifically to
   # survive that crop.
+  #
+  # No icon_background_color: the mark sits directly on the surface, as it does
+  # below Android 12 and on the web. A background is drawn in the launcher's
+  # icon shape, which varies by manufacturer, and in a container colour too
+  # close to the surface to read as deliberate.
   android_12:
     image: assets/splash/splash-icon.png
     image_dark: assets/splash/splash-icon-dark.png
-    icon_background_color: "#E3DFFF"
-    icon_background_color_dark: "#1F1F25"
 
   android: true
   android_gravity: center
 
   # No iOS target in this repo.
   ios: false
 
-  # The web has its own loading state, written by hand in web/index.html: a
-  # skeleton of the screen that is about to appear, drawn in the theme's own
-  # colours. This generator would inject a centred logo above it and fight it.
+  # The web's splash is written by hand in web/index.html, as inline SVG so it
+  # paints on the first round trip and fades out on Flutter's first frame.
   web: false

lib/application/sync_coordinator.dart

@@ -4,6 +4,7 @@ import 'dart:math' as math;
 
 import 'package:flutter/foundation.dart';
 
+import '../data/sync/api_client.dart';
 import '../data/sync/sync_engine.dart';
 
 @immutable
@@ -25,6 +26,10 @@ class SyncStatus {
   final DateTime? retryAt;
 
   Object? get error => lastReport?.error;
+
+  /// Whether the last attempt failed because no server could be reached,
+  /// which is the ordinary state of an offline device rather than a fault.
+  bool get isOffline => isUnreachable(error);
 }
 
 /// Decides when to sync, runs one sync at a time, and reports status.
@@ -72,7 +77,14 @@ class SyncCoordinator extends ChangeNotifier {
     _subscriptions
       ..add(
         _online.listen((isOnline) {
-          if (isOnline) resumed();
+          if (!isOnline) return;
+          // A failed attempt is retried as soon as the network is back, not
+          // when its back-off ends or the usual gap has passed.
+          if (_status.error == null) {
+            resumed();
+          } else {
+            unawaited(syncAll());
+          }
         }),
       )
       ..add(_writes.listen((_) => _writeQueued()));

lib/data/sync/api_client.dart

@@ -28,7 +28,12 @@ api.OpensplitApi buildApiClient({
 
 /// A request the server refused, or that never got an answer.
 class ApiFailure implements Exception {
-  const ApiFailure(this.message, {required this.retry, this.code});
+  const ApiFailure(
+    this.message, {
+    required this.retry,
+    this.code,
+    this.unreachable = false,
+  });
 
   /// Reads the `{error: {code, message, retry}}` envelope off a failed request.
   factory ApiFailure.from(DioException error) {
@@ -54,6 +59,7 @@ class ApiFailure implements Exception {
       retry: status == null || status >= 500
           ? api.Retry.transient
           : api.Retry.permanent,
+      unreachable: _neverAnswered(error),
     );
   }
 
@@ -63,6 +69,10 @@ class ApiFailure implements Exception {
   /// Null when no server answered in the expected shape.
   final api.ErrorCode? code;
 
+  /// Whether the request never reached a server that answered: the device is
+  /// offline, or the server is out of reach from where it is.
+  final bool unreachable;
+
   static api.ErrorError? _decode(Map<String, dynamic> body) {
     try {
       return api.Error.fromJson(body).error;
@@ -99,3 +109,17 @@ Future<void> send(Future<Response<void>> request) async {
     throw ApiFailure.from(error);
   }
 }
+
+/// Whether [error] means no server answered at all, as opposed to a server
+/// that answered and refused.
+///
+/// Judged by the request itself rather than by the device's network
+/// interfaces, which report a captive portal or a dead Wi-Fi as connected.
+bool isUnreachable(Object? error) => switch (error) {
+  ApiFailure(:final unreachable) => unreachable,
+  DioException() => _neverAnswered(error),
+  _ => false,
+};
+
+bool _neverAnswered(DioException error) =>
+    error.response == null && error.type != DioExceptionType.cancel;

lib/data/web/launch_signal.dart

@@ -0,0 +1,5 @@
+/// Telling the page outside Flutter that the app is on screen.
+library;
+
+export 'launch_signal_stub.dart'
+    if (dart.library.js_interop) 'launch_signal_web.dart';

lib/data/web/launch_signal_stub.dart

@@ -0,0 +1,2 @@
+/// Android's splash is the platform's, and goes by itself on the first frame.
+void announceLaunchShown() {}

lib/data/web/launch_signal_web.dart

@@ -0,0 +1,13 @@
+import 'package:web/web.dart' as web;
+
+/// The event `web/index.html` waits for before fading out its splash.
+const _launchShown = 'opensplit-launch-shown';
+
+/// Tells `web/index.html` that the first real frame is on screen.
+///
+/// Flutter's own `flutter-first-frame` event fires after the first frame is
+/// built even while that frame is deferred, so it would take the splash down
+/// onto a blank page while the app is still reading saved data.
+void announceLaunchShown() {
+  web.window.dispatchEvent(web.Event(_launchShown));
+}

lib/main.dart

@@ -12,12 +12,18 @@ import 'package:shared_preferences/shared_preferences.dart';
 import 'application/backend_providers.dart';
 import 'application/preferences_providers.dart';
 import 'config.dart';
+import 'data/web/launch_signal.dart';
 import 'data/auth/session_store.dart';
 import 'presentation/app.dart';
+import 'presentation/launch_hold.dart';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
 
+  // The splash stays up while the first screen reads what is saved, so a launch
+  // is one wait that ends on real content.
+  LaunchHold.begin(onShown: announceLaunchShown);
+
   // google_fonts falls back to downloading a face it cannot find in the bundle.
   GoogleFonts.config.allowRuntimeFetching = false;
 

lib/presentation/app.dart

@@ -8,11 +8,11 @@ import 'package:in_app_update/in_app_update.dart';
 import '../application/local_providers.dart';
 import '../application/preferences_providers.dart';
 import '../application/push_providers.dart';
+import '../application/ledger_providers.dart';
 import '../application/router_provider.dart';
 import '../application/session_providers.dart';
 import '../application/sync_providers.dart';
 import '../data/platform/app_update_service.dart';
-import '../data/web/boot_hint.dart';
 import '../data/web/release_updates.dart';
 import '../domain/auth_service.dart';
 import '../l10n/app_localizations.dart';
@@ -66,11 +66,12 @@ class _OpenSplitAppState extends ConsumerState<OpenSplitApp> {
     // Built for each account, which starts its automatic sync.
     ref.listenManual(syncControllerProvider, (_, _) {}, fireImmediately: true);
 
-    ref.listenManual(signedInProvider, (_, signedIn) {
-      // Leaves a note for the next cold start, so the web loader draws the
-      // layout this session will actually land on.
-      recordSignedIn(signedIn);
-    }, fireImmediately: true);
+    // Your own profile is app state, so it is read at launch and kept current:
+    // the Account destination then has it on the frame it is first built,
+    // instead of drawing "no name yet" until it arrives. Building that branch
+    // early would not do it, because Riverpod pauses providers that only
+    // offstage widgets listen to.
+    ref.listenManual(myProfileProvider, (_, _) {});
 
     // A Google flow that left the page finishes here, on the one launch that is
     // a return from it.