track last open book

lib/main.dart

@@ -3,23 +3,41 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 import 'screens/home_screen.dart';
+import 'services/last_location.dart';
 import 'services/tracker_storage.dart';
 import 'widgets/theme.dart';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
   final SharedPreferences prefs = await SharedPreferences.getInstance();
+  // Load the last location synchronously before the root navigator can fire
+  // its initial didPush and clear the saved value.
+  final LastLocation? pending = LastLocationService(prefs).load();
   runApp(
     ProviderScope(
-      overrides: <Override>[sharedPreferencesProvider.overrideWithValue(prefs)],
+      overrides: <Override>[
+        sharedPreferencesProvider.overrideWithValue(prefs),
+        pendingRestoreProvider.overrideWithValue(pending),
+      ],
       child: const BibleTrackerApp(),
     ),
   );
 }
 
-class BibleTrackerApp extends StatelessWidget {
+class BibleTrackerApp extends ConsumerStatefulWidget {
   const BibleTrackerApp({super.key});
 
+  @override
+  ConsumerState<BibleTrackerApp> createState() => _BibleTrackerAppState();
+}
+
+class _BibleTrackerAppState extends ConsumerState<BibleTrackerApp> {
+  late final LastLocationObserver _observer = LastLocationObserver((
+    LastLocation? location,
+  ) async {
+    await ref.read(lastLocationServiceProvider).save(location);
+  });
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -29,6 +47,7 @@ class BibleTrackerApp extends StatelessWidget {
       darkTheme: AppTheme.dark(),
       themeMode: ThemeMode.system,
       home: const HomeScreen(),
+      navigatorObservers: <NavigatorObserver>[_observer],
     );
   }
 }

lib/screens/home_screen.dart

@@ -1,33 +1,77 @@
+import 'package:collection/collection.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import '../data/bible.dart';
 import '../models/tracker.dart';
+import '../services/last_location.dart';
 import '../services/tracker_service.dart';
 import '../widgets/theme.dart';
 import '../widgets/tracker_tile.dart';
+import 'book_screen.dart';
 import 'create_tracker_screen.dart';
 import 'tracker_screen.dart';
 
-class HomeScreen extends ConsumerWidget {
+class HomeScreen extends ConsumerStatefulWidget {
   const HomeScreen({super.key});
 
   @override
-  Widget build(BuildContext context, WidgetRef ref) {
+  ConsumerState<HomeScreen> createState() => _HomeScreenState();
-    final AsyncValue<List<Tracker>> state = ref.watch(trackerServiceProvider);
+}
+
+class _HomeScreenState extends ConsumerState<HomeScreen> {
+  bool _restoreAttempted = false;
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) => _maybeRestore());
+  }
+
+  void _maybeRestore() {
+    if (_restoreAttempted || !mounted) return;
+    _restoreAttempted = true;
+
+    final LastLocation? pending = ref.read(pendingRestoreProvider);
+    if (pending == null) return;
+    final List<Tracker> trackers = ref.read(trackerServiceProvider);
+    final Tracker? tracker = trackers.firstWhereOrNull(
+      (Tracker t) => t.id == pending.trackerId,
+    );
+    if (tracker == null) return;
+
+    final NavigatorState navigator = Navigator.of(context);
+    navigator.push<void>(
+      MaterialPageRoute<void>(
+        settings: RouteSettings(name: '/tracker/${tracker.id}'),
+        builder: (_) => TrackerScreen(trackerId: tracker.id),
+      ),
+    );
+    final int? bookIndex = pending.bookIndex;
+    if (bookIndex != null && bookIndex >= 0 && bookIndex < Bible.books.length) {
+      navigator.push<void>(
+        MaterialPageRoute<void>(
+          settings: RouteSettings(
+            name: '/tracker/${tracker.id}/book/$bookIndex',
+          ),
+          builder: (_) =>
+              BookScreen(trackerId: tracker.id, bookIndex: bookIndex),
+        ),
+      );
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final List<Tracker> trackers = ref.watch(trackerServiceProvider);
     return Scaffold(
       appBar: AppBar(title: const Text('My Bible Tracker')),
-      body: state.when(
+      body: trackers.isEmpty
-        loading: () => const Center(child: CircularProgressIndicator()),
+          ? const _EmptyState()
-        error: (Object error, StackTrace stack) =>
+          : ListView.separated(
-            Center(child: Text('Something went wrong:\n$error')),
-        data: (List<Tracker> trackers) {
-          if (trackers.isEmpty) {
-            return const _EmptyState();
-          }
-          return ListView.separated(
               padding: const EdgeInsets.all(AppTokens.spaceL),
               itemCount: trackers.length,
-            separatorBuilder: (_, __) =>
+              separatorBuilder: (_, _) =>
                   const SizedBox(height: AppTokens.spaceM),
               itemBuilder: (BuildContext context, int index) {
                 final Tracker tracker = trackers[index];
@@ -35,14 +79,13 @@ class HomeScreen extends ConsumerWidget {
                   tracker: tracker,
                   onTap: () => Navigator.of(context).push<void>(
                     MaterialPageRoute<void>(
+                      settings: RouteSettings(name: '/tracker/${tracker.id}'),
                       builder: (_) => TrackerScreen(trackerId: tracker.id),
                     ),
                   ),
                   onLongPress: () => _showTrackerMenu(context, ref, tracker),
                 );
               },
-          );
-        },
             ),
       floatingActionButton: FloatingActionButton.extended(
         onPressed: () => Navigator.of(context).push<void>(

lib/screens/tracker_screen.dart

@@ -248,6 +248,9 @@ class _BooksSliver extends ConsumerWidget {
           accent: accent,
           onTap: () => Navigator.of(context).push<void>(
             MaterialPageRoute<void>(
+              settings: RouteSettings(
+                name: '/tracker/${tracker.id}/book/${book.index}',
+              ),
               builder: (_) =>
                   BookScreen(trackerId: tracker.id, bookIndex: book.index),
             ),

lib/services/last_location.dart

@@ -0,0 +1,135 @@
+import 'dart:convert';
+
+import 'package:flutter/widgets.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import 'tracker_storage.dart';
+
+part 'last_location.freezed.dart';
+part 'last_location.g.dart';
+
+/// The deepest route the user was viewing when the app was last active.
+///
+/// Encoded via [toRouteName] into [Route.settings.name] so a single
+/// [NavigatorObserver] can track it without every screen needing to know
+/// about persistence.
+@freezed
+class LastLocation with _$LastLocation {
+  const LastLocation._();
+
+  const factory LastLocation({required String trackerId, int? bookIndex}) =
+      _LastLocation;
+
+  factory LastLocation.fromJson(Map<String, dynamic> json) =>
+      _$LastLocationFromJson(json);
+
+  static const String _trackerPrefix = '/tracker/';
+
+  String toRouteName() => bookIndex == null
+      ? '$_trackerPrefix$trackerId'
+      : '$_trackerPrefix$trackerId/book/$bookIndex';
+
+  /// Parses a route name such as `/tracker/<id>` or
+  /// `/tracker/<id>/book/<bookIndex>` back into a [LastLocation].
+  ///
+  /// Returns null for the root `/` route, unnamed routes (modals, dialogs),
+  /// and malformed names.
+  static LastLocation? tryParseRoute(String? name) {
+    if (name == null) return null;
+    final List<String> parts = name
+        .split('/')
+        .where((String s) => s.isNotEmpty)
+        .toList(growable: false);
+    if (parts.isEmpty || parts.first != 'tracker') return null;
+    if (parts.length == 2) return LastLocation(trackerId: parts[1]);
+    if (parts.length == 4 && parts[2] == 'book') {
+      final int? idx = int.tryParse(parts[3]);
+      if (idx != null) {
+        return LastLocation(trackerId: parts[1], bookIndex: idx);
+      }
+    }
+    return null;
+  }
+}
+
+/// Reads and writes the most recent [LastLocation] to [SharedPreferences].
+class LastLocationService {
+  LastLocationService(this._prefs);
+
+  static const String _key = 'bible_tracker.last_location.v1';
+
+  final SharedPreferences _prefs;
+
+  LastLocation? load() {
+    final String? raw = _prefs.getString(_key);
+    if (raw == null || raw.isEmpty) return null;
+    try {
+      return LastLocation.fromJson(jsonDecode(raw) as Map<String, dynamic>);
+    } catch (_) {
+      return null;
+    }
+  }
+
+  Future<void> save(LastLocation? location) async {
+    if (location == null) {
+      await _prefs.remove(_key);
+      return;
+    }
+    await _prefs.setString(_key, jsonEncode(location.toJson()));
+  }
+}
+
+final Provider<LastLocationService> lastLocationServiceProvider =
+    Provider<LastLocationService>(
+      (Ref ref) => LastLocationService(ref.read(sharedPreferencesProvider)),
+    );
+
+/// Populated at startup in `main.dart` with the location that was persisted
+/// during the previous session. Reading it once avoids a race where the root
+/// navigator's initial `didPush` clears the saved value before the UI has
+/// had a chance to restore it.
+final Provider<LastLocation?> pendingRestoreProvider = Provider<LastLocation?>(
+  (Ref ref) => null,
+);
+
+/// Writes the top-most named route to [_onChange] whenever navigation
+/// changes. Unnamed routes (bottom sheets, dialogs, the create-tracker page)
+/// are ignored so they don't clobber the underlying tracker/book location.
+class LastLocationObserver extends NavigatorObserver {
+  LastLocationObserver(this._onChange);
+
+  final void Function(LastLocation? location) _onChange;
+
+  @override
+  void didPush(Route<dynamic> route, Route<dynamic>? previousRoute) {
+    _notify(route);
+  }
+
+  @override
+  void didPop(Route<dynamic> route, Route<dynamic>? previousRoute) {
+    _notify(previousRoute);
+  }
+
+  @override
+  void didReplace({Route<dynamic>? newRoute, Route<dynamic>? oldRoute}) {
+    _notify(newRoute);
+  }
+
+  @override
+  void didRemove(Route<dynamic> route, Route<dynamic>? previousRoute) {
+    _notify(previousRoute);
+  }
+
+  void _notify(Route<dynamic>? route) {
+    final String? name = route?.settings.name;
+    if (name == null) return;
+    if (name == '/') {
+      _onChange(null);
+      return;
+    }
+    final LastLocation? parsed = LastLocation.tryParseRoute(name);
+    if (parsed != null) _onChange(parsed);
+  }
+}

lib/services/last_location.freezed.dart

@@ -0,0 +1,188 @@
+// coverage:ignore-file
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'last_location.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+T _$identity<T>(T value) => value;
+
+final _privateConstructorUsedError = UnsupportedError(
+  'It seems like you constructed your class using `MyClass._()`. This constructor is only meant to be used by freezed and you are not supposed to need it nor use it.\nPlease check the documentation here for more information: https://github.com/rrousselGit/freezed#adding-getters-and-methods-to-our-models',
+);
+
+LastLocation _$LastLocationFromJson(Map<String, dynamic> json) {
+  return _LastLocation.fromJson(json);
+}
+
+/// @nodoc
+mixin _$LastLocation {
+  String get trackerId => throw _privateConstructorUsedError;
+  int? get bookIndex => throw _privateConstructorUsedError;
+
+  /// Serializes this LastLocation to a JSON map.
+  Map<String, dynamic> toJson() => throw _privateConstructorUsedError;
+
+  /// Create a copy of LastLocation
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  $LastLocationCopyWith<LastLocation> get copyWith =>
+      throw _privateConstructorUsedError;
+}
+
+/// @nodoc
+abstract class $LastLocationCopyWith<$Res> {
+  factory $LastLocationCopyWith(
+    LastLocation value,
+    $Res Function(LastLocation) then,
+  ) = _$LastLocationCopyWithImpl<$Res, LastLocation>;
+  @useResult
+  $Res call({String trackerId, int? bookIndex});
+}
+
+/// @nodoc
+class _$LastLocationCopyWithImpl<$Res, $Val extends LastLocation>
+    implements $LastLocationCopyWith<$Res> {
+  _$LastLocationCopyWithImpl(this._value, this._then);
+
+  // ignore: unused_field
+  final $Val _value;
+  // ignore: unused_field
+  final $Res Function($Val) _then;
+
+  /// Create a copy of LastLocation
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({Object? trackerId = null, Object? bookIndex = freezed}) {
+    return _then(
+      _value.copyWith(
+            trackerId: null == trackerId
+                ? _value.trackerId
+                : trackerId // ignore: cast_nullable_to_non_nullable
+                      as String,
+            bookIndex: freezed == bookIndex
+                ? _value.bookIndex
+                : bookIndex // ignore: cast_nullable_to_non_nullable
+                      as int?,
+          )
+          as $Val,
+    );
+  }
+}
+
+/// @nodoc
+abstract class _$$LastLocationImplCopyWith<$Res>
+    implements $LastLocationCopyWith<$Res> {
+  factory _$$LastLocationImplCopyWith(
+    _$LastLocationImpl value,
+    $Res Function(_$LastLocationImpl) then,
+  ) = __$$LastLocationImplCopyWithImpl<$Res>;
+  @override
+  @useResult
+  $Res call({String trackerId, int? bookIndex});
+}
+
+/// @nodoc
+class __$$LastLocationImplCopyWithImpl<$Res>
+    extends _$LastLocationCopyWithImpl<$Res, _$LastLocationImpl>
+    implements _$$LastLocationImplCopyWith<$Res> {
+  __$$LastLocationImplCopyWithImpl(
+    _$LastLocationImpl _value,
+    $Res Function(_$LastLocationImpl) _then,
+  ) : super(_value, _then);
+
+  /// Create a copy of LastLocation
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({Object? trackerId = null, Object? bookIndex = freezed}) {
+    return _then(
+      _$LastLocationImpl(
+        trackerId: null == trackerId
+            ? _value.trackerId
+            : trackerId // ignore: cast_nullable_to_non_nullable
+                  as String,
+        bookIndex: freezed == bookIndex
+            ? _value.bookIndex
+            : bookIndex // ignore: cast_nullable_to_non_nullable
+                  as int?,
+      ),
+    );
+  }
+}
+
+/// @nodoc
+@JsonSerializable()
+class _$LastLocationImpl extends _LastLocation {
+  const _$LastLocationImpl({required this.trackerId, this.bookIndex})
+    : super._();
+
+  factory _$LastLocationImpl.fromJson(Map<String, dynamic> json) =>
+      _$$LastLocationImplFromJson(json);
+
+  @override
+  final String trackerId;
+  @override
+  final int? bookIndex;
+
+  @override
+  String toString() {
+    return 'LastLocation(trackerId: $trackerId, bookIndex: $bookIndex)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        (other.runtimeType == runtimeType &&
+            other is _$LastLocationImpl &&
+            (identical(other.trackerId, trackerId) ||
+                other.trackerId == trackerId) &&
+            (identical(other.bookIndex, bookIndex) ||
+                other.bookIndex == bookIndex));
+  }
+
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  int get hashCode => Object.hash(runtimeType, trackerId, bookIndex);
+
+  /// Create a copy of LastLocation
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  @pragma('vm:prefer-inline')
+  _$$LastLocationImplCopyWith<_$LastLocationImpl> get copyWith =>
+      __$$LastLocationImplCopyWithImpl<_$LastLocationImpl>(this, _$identity);
+
+  @override
+  Map<String, dynamic> toJson() {
+    return _$$LastLocationImplToJson(this);
+  }
+}
+
+abstract class _LastLocation extends LastLocation {
+  const factory _LastLocation({
+    required final String trackerId,
+    final int? bookIndex,
+  }) = _$LastLocationImpl;
+  const _LastLocation._() : super._();
+
+  factory _LastLocation.fromJson(Map<String, dynamic> json) =
+      _$LastLocationImpl.fromJson;
+
+  @override
+  String get trackerId;
+  @override
+  int? get bookIndex;
+
+  /// Create a copy of LastLocation
+  /// with the given fields replaced by the non-null parameter values.
+  @override
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  _$$LastLocationImplCopyWith<_$LastLocationImpl> get copyWith =>
+      throw _privateConstructorUsedError;
+}

lib/services/last_location.g.dart

@@ -0,0 +1,19 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'last_location.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+_$LastLocationImpl _$$LastLocationImplFromJson(Map<String, dynamic> json) =>
+    _$LastLocationImpl(
+      trackerId: json['trackerId'] as String,
+      bookIndex: (json['bookIndex'] as num?)?.toInt(),
+    );
+
+Map<String, dynamic> _$$LastLocationImplToJson(_$LastLocationImpl instance) =>
+    <String, dynamic>{
+      'trackerId': instance.trackerId,
+      'bookIndex': instance.bookIndex,
+    };

lib/services/tracker_service.dart

@@ -8,32 +8,18 @@ import 'tracker_storage.dart';
 
 /// Manages the list of [Tracker]s and exposes them as state to the UI.
 ///
-/// Kept as a plain service (no repository) because storage access is
+/// Initial state is loaded synchronously from [TrackerStorage] so the first
-/// simple read/write-all and there are no complex queries or caches.
+/// frame already has the full list. Mutations persist asynchronously.
-class TrackerService extends StateNotifier<AsyncValue<List<Tracker>>> {
+class TrackerService extends StateNotifier<List<Tracker>> {
   TrackerService(this._storage, {Uuid? uuid})
     : _uuid = uuid ?? const Uuid(),
-      super(const AsyncValue<List<Tracker>>.loading()) {
+      super(_storage.loadAll());
-    unawaitedLoad();
-  }
 
   final TrackerStorage _storage;
   final Uuid _uuid;
 
-  @visibleForTesting
-  Future<void> unawaitedLoad() => _load();
-
-  Future<void> _load() async {
-    try {
-      final List<Tracker> trackers = await _storage.loadAll();
-      state = AsyncValue<List<Tracker>>.data(trackers);
-    } catch (error, stack) {
-      state = AsyncValue<List<Tracker>>.error(error, stack);
-    }
-  }
-
   Future<void> _persist(List<Tracker> trackers) async {
-    state = AsyncValue<List<Tracker>>.data(trackers);
+    state = trackers;
     await _storage.saveAll(trackers);
   }
 
@@ -41,27 +27,21 @@ class TrackerService extends StateNotifier<AsyncValue<List<Tracker>>> {
     final Tracker tracker = Tracker(
       id: _uuid.v4(),
       name: name,
-      // ignore: deprecated_member_use
+      colorValue: color.toARGB32(),
-      colorValue: color.value,
       startDate: DateTime.now(),
     );
-    final List<Tracker> next = <Tracker>[
+    final List<Tracker> next = <Tracker>[...state, tracker];
-      ...state.value ?? const <Tracker>[],
-      tracker,
-    ];
     await _persist(next);
     return tracker;
   }
 
   Future<void> updateMeta(String id, {String? name, Color? color}) async {
-    final List<Tracker> current = state.value ?? const <Tracker>[];
+    final List<Tracker> next = state
-    final List<Tracker> next = current
         .map(
           (Tracker tracker) => tracker.id == id
               ? tracker.copyWith(
                   name: name ?? tracker.name,
-                  // ignore: deprecated_member_use
+                  colorValue: color?.toARGB32() ?? tracker.colorValue,
-                  colorValue: color?.value ?? tracker.colorValue,
                 )
               : tracker,
         )
@@ -70,8 +50,7 @@ class TrackerService extends StateNotifier<AsyncValue<List<Tracker>>> {
   }
 
   Future<void> delete(String id) async {
-    final List<Tracker> current = state.value ?? const <Tracker>[];
+    final List<Tracker> next = state
-    final List<Tracker> next = current
         .where((Tracker tracker) => tracker.id != id)
         .toList(growable: false);
     await _persist(next);
@@ -79,8 +58,7 @@ class TrackerService extends StateNotifier<AsyncValue<List<Tracker>>> {
 
   Future<void> toggleChapter(String id, int bookIndex, int chapter) async {
     final String key = Bible.chapterKey(bookIndex, chapter);
-    final List<Tracker> current = state.value ?? const <Tracker>[];
+    final List<Tracker> next = state
-    final List<Tracker> next = current
         .map((Tracker tracker) {
           if (tracker.id != id) return tracker;
           final Set<String> updated = <String>{...tracker.readChapters};
@@ -99,8 +77,7 @@ class TrackerService extends StateNotifier<AsyncValue<List<Tracker>>> {
     required bool read,
   }) async {
     final Book book = Bible.books[bookIndex];
-    final List<Tracker> current = state.value ?? const <Tracker>[];
+    final List<Tracker> next = state
-    final List<Tracker> next = current
         .map((Tracker tracker) {
           if (tracker.id != id) return tracker;
           final Set<String> updated = <String>{...tracker.readChapters};
@@ -119,8 +96,7 @@ class TrackerService extends StateNotifier<AsyncValue<List<Tracker>>> {
   }
 
   Future<void> reset(String id) async {
-    final List<Tracker> current = state.value ?? const <Tracker>[];
+    final List<Tracker> next = state
-    final List<Tracker> next = current
         .map(
           (Tracker tracker) => tracker.id == id
               ? tracker.copyWith(readChapters: const <String>{})
@@ -131,18 +107,17 @@ class TrackerService extends StateNotifier<AsyncValue<List<Tracker>>> {
   }
 }
 
-final StateNotifierProvider<TrackerService, AsyncValue<List<Tracker>>>
+final StateNotifierProvider<TrackerService, List<Tracker>>
-trackerServiceProvider =
+trackerServiceProvider = StateNotifierProvider<TrackerService, List<Tracker>>(
-    StateNotifierProvider<TrackerService, AsyncValue<List<Tracker>>>(
   (Ref ref) => TrackerService(ref.read(trackerStorageProvider)),
 );
 
 /// Convenience selector for a single tracker by id.
 final ProviderFamily<Tracker?, String> trackerByIdProvider =
     Provider.family<Tracker?, String>((Ref ref, String id) {
-      final AsyncValue<List<Tracker>> state = ref.watch(trackerServiceProvider);
+      final List<Tracker> trackers = ref.watch(trackerServiceProvider);
-      return state.value?.cast<Tracker?>().firstWhere(
+      for (final Tracker tracker in trackers) {
-        (Tracker? t) => t?.id == id,
+        if (tracker.id == id) return tracker;
-        orElse: () => null,
+      }
-      );
+      return null;
     });

lib/services/tracker_storage.dart

@@ -17,7 +17,10 @@ class TrackerStorage {
 
   final SharedPreferences _prefs;
 
-  Future<List<Tracker>> loadAll() async {
+  /// Synchronous because the underlying [SharedPreferences] getter already
+  /// works against an in-memory cache. Keeping this sync lets the service
+  /// start up with real data on the first frame, with no async-load race.
+  List<Tracker> loadAll() {
     final String? raw = _prefs.getString(_storageKey);
     if (raw == null || raw.isEmpty) {
       return <Tracker>[];

test/screens/home_screen_test.dart

@@ -1,4 +1,11 @@
+import 'dart:convert';
+
+import 'package:bible_tracker/data/bible.dart';
+import 'package:bible_tracker/models/tracker.dart';
+import 'package:bible_tracker/screens/book_screen.dart';
 import 'package:bible_tracker/screens/home_screen.dart';
+import 'package:bible_tracker/screens/tracker_screen.dart';
+import 'package:bible_tracker/services/last_location.dart';
 import 'package:bible_tracker/services/tracker_service.dart';
 import 'package:bible_tracker/services/tracker_storage.dart';
 import 'package:bible_tracker/widgets/theme.dart';
@@ -7,32 +14,44 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
-Future<Widget> _wrapped() async {
+Future<Widget> _pumpApp({
-  SharedPreferences.setMockInitialValues(<String, Object>{});
+  Map<String, Object>? initialPrefs,
+  LastLocation? pending,
+}) async {
+  SharedPreferences.setMockInitialValues(initialPrefs ?? <String, Object>{});
   final prefs = await SharedPreferences.getInstance();
   return ProviderScope(
-    overrides: <Override>[sharedPreferencesProvider.overrideWithValue(prefs)],
+    overrides: <Override>[
-    child: MaterialApp(theme: AppTheme.light(), home: const HomeScreen()),
+      sharedPreferencesProvider.overrideWithValue(prefs),
+      pendingRestoreProvider.overrideWithValue(pending),
+    ],
+    child: MaterialApp(
+      theme: AppTheme.light(),
+      home: const HomeScreen(),
+      navigatorObservers: <NavigatorObserver>[
+        LastLocationObserver(
+          (LastLocation? loc) => LastLocationService(prefs).save(loc),
+        ),
+      ],
+    ),
   );
 }
 
+String _seedTrackerJson(Tracker tracker) =>
+    jsonEncode(<Map<String, dynamic>>[tracker.toJson()]);
+
 void main() {
   testWidgets('shows empty state when no trackers exist', (tester) async {
-    await tester.pumpWidget(await _wrapped());
+    await tester.pumpWidget(await _pumpApp());
     await tester.pumpAndSettle();
     expect(find.text('Start your first tracker'), findsOneWidget);
     expect(find.text('New Tracker'), findsOneWidget);
   });
 
   testWidgets('creating a tracker shows it on the list', (tester) async {
-    await tester.pumpWidget(await _wrapped());
+    await tester.pumpWidget(await _pumpApp());
     await tester.pumpAndSettle();
 
-    final ProviderScope scope = tester.widget<ProviderScope>(
-      find.byType(ProviderScope),
-    );
-    expect(scope, isNotNull);
-
     final BuildContext context = tester.element(find.byType(HomeScreen));
     final ProviderContainer container = ProviderScope.containerOf(context);
     await container
@@ -43,4 +62,138 @@ void main() {
     expect(find.text('My Plan'), findsOneWidget);
     expect(find.text('0%'), findsOneWidget);
   });
+
+  testWidgets(
+    'restores tracker + book on launch when pending location matches',
+    (tester) async {
+      final tracker = Tracker(
+        id: 'seed-1',
+        name: 'Persisted',
+        colorValue: 0xFF3F51B5,
+        startDate: DateTime(2024),
+      );
+      const int bookIndex = 42; // John
+
+      await tester.pumpWidget(
+        await _pumpApp(
+          initialPrefs: <String, Object>{
+            'bible_tracker.trackers.v1': _seedTrackerJson(tracker),
+          },
+          pending: LastLocation(trackerId: tracker.id, bookIndex: bookIndex),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      // TrackerScreen sits underneath BookScreen and is offstage.
+      expect(
+        find.byType(TrackerScreen, skipOffstage: false),
+        findsOneWidget,
+      );
+      expect(find.byType(BookScreen), findsOneWidget);
+      expect(find.text(Bible.books[bookIndex].name), findsWidgets);
+    },
+  );
+
+  testWidgets('restores tracker only when no book index is saved', (
+    tester,
+  ) async {
+    final tracker = Tracker(
+      id: 'seed-2',
+      name: 'Resumed',
+      colorValue: 0xFF3F51B5,
+      startDate: DateTime(2024),
+    );
+    await tester.pumpWidget(
+      await _pumpApp(
+        initialPrefs: <String, Object>{
+          'bible_tracker.trackers.v1': _seedTrackerJson(tracker),
+        },
+        pending: LastLocation(trackerId: tracker.id),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    expect(find.byType(TrackerScreen), findsOneWidget);
+    expect(find.byType(BookScreen), findsNothing);
+    expect(find.text('Resumed'), findsWidgets);
+  });
+
+  testWidgets('skips restore when the saved tracker no longer exists', (
+    tester,
+  ) async {
+    await tester.pumpWidget(
+      await _pumpApp(pending: const LastLocation(trackerId: 'missing')),
+    );
+    await tester.pumpAndSettle();
+
+    expect(find.byType(TrackerScreen), findsNothing);
+    expect(find.byType(BookScreen), findsNothing);
+    expect(find.text('Start your first tracker'), findsOneWidget);
+  });
+
+  testWidgets('navigating into a book persists the location via the observer', (
+    tester,
+  ) async {
+    SharedPreferences.setMockInitialValues(<String, Object>{});
+    final prefs = await SharedPreferences.getInstance();
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: <Override>[
+          sharedPreferencesProvider.overrideWithValue(prefs),
+        ],
+        child: MaterialApp(
+          theme: AppTheme.light(),
+          home: const HomeScreen(),
+          navigatorObservers: <NavigatorObserver>[
+            LastLocationObserver(
+              (LastLocation? loc) => LastLocationService(prefs).save(loc),
+            ),
+          ],
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    final BuildContext context = tester.element(find.byType(HomeScreen));
+    final ProviderContainer container = ProviderScope.containerOf(context);
+    final tracker = await container
+        .read(trackerServiceProvider.notifier)
+        .create(name: 'Plan', color: const Color(0xFF3F51B5));
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.text('Plan'));
+    await tester.pumpAndSettle();
+
+    expect(
+      LastLocationService(prefs).load(),
+      LastLocation(trackerId: tracker.id),
+    );
+
+    await tester.tap(find.text('Genesis'));
+    await tester.pumpAndSettle();
+
+    expect(
+      LastLocationService(prefs).load(),
+      LastLocation(trackerId: tracker.id, bookIndex: 0),
+    );
+
+    // Pop back to the tracker screen — the persisted location should
+    // shrink back to "tracker only".
+    final NavigatorState navigator = tester.state<NavigatorState>(
+      find.byType(Navigator).first,
+    );
+    navigator.pop();
+    await tester.pumpAndSettle();
+
+    expect(
+      LastLocationService(prefs).load(),
+      LastLocation(trackerId: tracker.id),
+    );
+
+    // Pop all the way to home — location should clear.
+    navigator.pop();
+    await tester.pumpAndSettle();
+
+    expect(LastLocationService(prefs).load(), isNull);
+  });
 }

test/services/last_location_test.dart

@@ -0,0 +1,68 @@
+import 'package:bible_tracker/services/last_location.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  group('LastLocation.tryParseRoute', () {
+    test('parses tracker-only route', () {
+      final parsed = LastLocation.tryParseRoute('/tracker/abc');
+      expect(parsed, const LastLocation(trackerId: 'abc'));
+    });
+
+    test('parses tracker + book route', () {
+      final parsed = LastLocation.tryParseRoute('/tracker/abc/book/12');
+      expect(parsed, const LastLocation(trackerId: 'abc', bookIndex: 12));
+    });
+
+    test('returns null for unrelated routes', () {
+      expect(LastLocation.tryParseRoute(null), isNull);
+      expect(LastLocation.tryParseRoute('/'), isNull);
+      expect(LastLocation.tryParseRoute('/settings'), isNull);
+      expect(LastLocation.tryParseRoute('/tracker'), isNull);
+      expect(
+        LastLocation.tryParseRoute('/tracker/abc/book/not-a-number'),
+        isNull,
+      );
+    });
+
+    test('toRouteName round-trips', () {
+      const a = LastLocation(trackerId: 'abc');
+      const b = LastLocation(trackerId: 'abc', bookIndex: 0);
+      expect(LastLocation.tryParseRoute(a.toRouteName()), a);
+      expect(LastLocation.tryParseRoute(b.toRouteName()), b);
+    });
+  });
+
+  group('LastLocationService', () {
+    test('returns null when nothing is persisted', () async {
+      SharedPreferences.setMockInitialValues(<String, Object>{});
+      final prefs = await SharedPreferences.getInstance();
+      final service = LastLocationService(prefs);
+      expect(service.load(), isNull);
+    });
+
+    test('round-trips a location through SharedPreferences', () async {
+      SharedPreferences.setMockInitialValues(<String, Object>{});
+      final prefs = await SharedPreferences.getInstance();
+      final service = LastLocationService(prefs);
+
+      const location = LastLocation(trackerId: 't1', bookIndex: 7);
+      await service.save(location);
+      expect(service.load(), location);
+
+      await service.save(null);
+      expect(service.load(), isNull);
+    });
+
+    test('load returns null when stored JSON is corrupt', () async {
+      SharedPreferences.setMockInitialValues(<String, Object>{
+        'bible_tracker.last_location.v1': 'not-json',
+      });
+      final prefs = await SharedPreferences.getInstance();
+      final service = LastLocationService(prefs);
+      expect(service.load(), isNull);
+    });
+  });
+}

test/services/tracker_service_test.dart

@@ -15,30 +15,18 @@ Future<ProviderContainer> _container() async {
   );
 }
 
-Future<List<Tracker>> _waitForData(ProviderContainer container) async {
-  while (true) {
-    final AsyncValue<List<Tracker>> state = container.read(
-      trackerServiceProvider,
-    );
-    if (state.hasValue) return state.value!;
-    await Future<void>.delayed(const Duration(milliseconds: 5));
-  }
-}
-
 void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
 
-  test('starts empty after initial load', () async {
+  test('starts empty when nothing is persisted', () async {
     final container = await _container();
     addTearDown(container.dispose);
-    final List<Tracker> data = await _waitForData(container);
+    expect(container.read(trackerServiceProvider), isEmpty);
-    expect(data, isEmpty);
   });
 
   test('create adds a tracker with the given name and color', () async {
     final container = await _container();
     addTearDown(container.dispose);
-    await _waitForData(container);
 
     final tracker = await container
         .read(trackerServiceProvider.notifier)
@@ -46,14 +34,12 @@ void main() {
 
     expect(tracker.name, 'My Plan');
     expect(tracker.colorValue, const Color(0xFF123456).toARGB32());
-    expect(container.read(trackerServiceProvider).value, <Tracker>[tracker]);
+    expect(container.read(trackerServiceProvider), <Tracker>[tracker]);
   });
 
   test('toggleChapter adds and then removes chapter', () async {
     final container = await _container();
     addTearDown(container.dispose);
-    await _waitForData(container);
-
     final service = container.read(trackerServiceProvider.notifier);
     final tracker = await service.create(
       name: 'Plan',
@@ -61,18 +47,17 @@ void main() {
     );
 
     await service.toggleChapter(tracker.id, 0, 1);
-    Tracker current = container.read(trackerServiceProvider).value!.single;
+    Tracker current = container.read(trackerServiceProvider).single;
     expect(current.readChapters, <String>{Bible.chapterKey(0, 1)});
 
     await service.toggleChapter(tracker.id, 0, 1);
-    current = container.read(trackerServiceProvider).value!.single;
+    current = container.read(trackerServiceProvider).single;
     expect(current.readChapters, isEmpty);
   });
 
   test('setBookRead marks all chapters of the book', () async {
     final container = await _container();
     addTearDown(container.dispose);
-    await _waitForData(container);
     final service = container.read(trackerServiceProvider.notifier);
     final tracker = await service.create(
       name: 'Plan',
@@ -80,10 +65,7 @@ void main() {
     );
 
     await service.setBookRead(tracker.id, 0, read: true);
-    final Tracker current = container
+    final Tracker current = container.read(trackerServiceProvider).single;
-        .read(trackerServiceProvider)
-        .value!
-        .single;
     final Book genesis = Bible.books[0];
     expect(current.readChapters.length, genesis.chapterCount);
     for (int chapter = 1; chapter <= genesis.chapterCount; chapter++) {
@@ -94,7 +76,6 @@ void main() {
   test('reset clears only the target tracker', () async {
     final container = await _container();
     addTearDown(container.dispose);
-    await _waitForData(container);
     final service = container.read(trackerServiceProvider.notifier);
     final a = await service.create(name: 'A', color: const Color(0xFF111111));
     final b = await service.create(name: 'B', color: const Color(0xFF222222));
@@ -103,7 +84,7 @@ void main() {
 
     await service.reset(a.id);
 
-    final List<Tracker> current = container.read(trackerServiceProvider).value!;
+    final List<Tracker> current = container.read(trackerServiceProvider);
     expect(
       current.firstWhere((Tracker t) => t.id == a.id).readChapters,
       isEmpty,
@@ -117,13 +98,12 @@ void main() {
   test('delete removes the tracker', () async {
     final container = await _container();
     addTearDown(container.dispose);
-    await _waitForData(container);
     final service = container.read(trackerServiceProvider.notifier);
     final a = await service.create(name: 'A', color: const Color(0xFF111111));
     await service.create(name: 'B', color: const Color(0xFF222222));
 
     await service.delete(a.id);
-    final List<Tracker> current = container.read(trackerServiceProvider).value!;
+    final List<Tracker> current = container.read(trackerServiceProvider);
     expect(current.length, 1);
     expect(current.single.name, 'B');
   });
@@ -135,7 +115,6 @@ void main() {
     final first = ProviderContainer(
       overrides: <Override>[sharedPreferencesProvider.overrideWithValue(prefs)],
     );
-    await _waitForData(first);
     final created = await first
         .read(trackerServiceProvider.notifier)
         .create(name: 'Persisted', color: const Color(0xFFAABBCC));
@@ -148,7 +127,7 @@ void main() {
       overrides: <Override>[sharedPreferencesProvider.overrideWithValue(prefs)],
     );
     addTearDown(second.dispose);
-    final List<Tracker> loaded = await _waitForData(second);
+    final List<Tracker> loaded = second.read(trackerServiceProvider);
 
     expect(loaded.length, 1);
     expect(loaded.single.name, 'Persisted');
@@ -158,7 +137,6 @@ void main() {
   test('updateMeta changes name and color', () async {
     final container = await _container();
     addTearDown(container.dispose);
-    await _waitForData(container);
     final service = container.read(trackerServiceProvider.notifier);
     final tracker = await service.create(
       name: 'Old',
@@ -170,10 +148,7 @@ void main() {
       name: 'New',
       color: const Color(0xFF222222),
     );
-    final Tracker current = container
+    final Tracker current = container.read(trackerServiceProvider).single;
-        .read(trackerServiceProvider)
-        .value!
-        .single;
     expect(current.name, 'New');
     expect(current.colorValue, const Color(0xFF222222).toARGB32());
   });