Reorganize data-managing widgets to accommodate global data

lib/model/store.dart

@@ -13,6 +13,50 @@ import '../api/route/messages.dart';
 import '../credential_fixture.dart' as credentials;
 import 'message_list.dart';
 
+/// Store for the user's cross-account data.
+///
+/// This includes data that is independent of the account, like some settings.
+/// It also includes a small amount of data for each account: enough to
+/// authenticate as the active account, if there is one.
+class GlobalStore extends ChangeNotifier {
+  GlobalStore._({required Map<int, Account> accounts})
+      : _accounts = accounts;
+
+  // For convenience, a number we won't use as an ID in the database table.
+  static const fixtureAccountId = -1;
+
+  // We keep the API simple and synchronous for the bulk of the app's code
+  // by doing this loading up front before constructing a [GlobalStore].
+  static Future<GlobalStore> load() async {
+    const accounts = {fixtureAccountId: _fixtureAccount};
+    return GlobalStore._(accounts: accounts);
+  }
+
+  final Map<int, Account> _accounts;
+
+  // TODO settings (those that are per-device rather than per-account)
+  // TODO push token, and other data corresponding to GlobalSessionState
+
+  // Just an Iterable, not the actual Map, to avoid clients mutating the map.
+  // Mutations should go through the setters/mutators below.
+  Iterable<Account> get accounts => _accounts.values;
+
+  Account? getAccount(int id) => _accounts[id];
+
+  // TODO add setters/mutators; will want to write to database
+  // Future<void> insertAccount...
+  // Future<void> updateAccount...
+
+  // TODO add a registry of [PerAccountStore]s, like the latter's of [MessageListView]
+  //   That will allow us to have many [PerAccountRoot] widgets for a given
+  //   account, e.g. at the top of each page; and to access server data from
+  //   outside any [PerAccountRoot], e.g. for handling a notification.
+}
+
+/// Store for the user's data for a given Zulip account.
+///
+/// This should always have a consistent snapshot of the state on the server,
+/// as maintained by the Zulip event system.
 class PerAccountStore extends ChangeNotifier {
   PerAccountStore._({
     required this.account,
@@ -23,9 +67,10 @@ class PerAccountStore extends ChangeNotifier {
     required this.subscriptions,
   });
 
-  // Load the user's data from storage.  (Once we have such a thing.)
-  static Future<PerAccountStore> load() async {
-    const account = _fixtureAccount;
+  /// Load the user's data from the server, and start an event queue going.
+  ///
+  /// In the future this might load an old snapshot from local storage first.
+  static Future<PerAccountStore> load(Account account) async {
     final connection = ApiConnection(auth: account);
 
     final stopwatch = Stopwatch()..start();
@@ -124,6 +169,7 @@ const Account _fixtureAccount = Account(
   apiKey: credentials.api_key,
 );
 
+@immutable
 class Account implements Auth {
   const Account(
       {required this.realmUrl, required this.email, required this.apiKey});

lib/widgets/app.dart

@@ -1,69 +1,33 @@
 import 'package:flutter/material.dart';
 
+import '../model/store.dart';
 import 'compose_box.dart';
 import 'message_list.dart';
-import '../model/store.dart';
+import 'store.dart';
 
 class ZulipApp extends StatelessWidget {
   const ZulipApp({super.key});
 
   @override
   Widget build(BuildContext context) {
-    // Just one account for now.
-    return const PerAccountRoot();
-  }
-}
-
-class PerAccountRoot extends StatefulWidget {
-  const PerAccountRoot({super.key});
-
-  @override
-  State<PerAccountRoot> createState() => _PerAccountRootState();
-}
-
-class _PerAccountRootState extends State<PerAccountRoot> {
-  PerAccountStore? store;
-
-  @override
-  void initState() {
-    super.initState();
-    (() async {
-      final store = await PerAccountStore.load();
-      setState(() {
-        this.store = store;
-      });
-    })();
-  }
-
-  @override
-  void reassemble() {
-    // The [reassemble] method runs upon hot reload, in development.
-    // Here, we rerun parsing the messages.  This gives us the same
-    // highly productive workflow of Flutter hot reload when developing
-    // changes there as we have on changes to widgets.
-    store?.reassemble();
-    super.reassemble();
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    if (store == null) return const LoadingPage();
-    return PerAccountStoreWidget(
-        store: store!,
+    final theme = ThemeData(
+        // This applies Material 3's color system to produce a palette of
+        // appropriately matching and contrasting colors for use in a UI.
+        // The Zulip brand color is a starting point, but doesn't end up as
+        // one that's directly used.  (After all, we didn't design it for that
+        // purpose; we designed a logo.)  See docs:
+        //   https://api.flutter.dev/flutter/material/ColorScheme/ColorScheme.fromSeed.html
+        // Or try this tool to see the whole palette:
+        //   https://m3.material.io/theme-builder#/custom
+        colorScheme: ColorScheme.fromSeed(seedColor: kZulipBrandColor));
+    return DataRoot(
+      child: PerAccountRoot(
+        // Just one account for now.
+        accountId: GlobalStore.fixtureAccountId,
         child: MaterialApp(
           title: 'Zulip',
-          theme: ThemeData(
-              // This applies Material 3's color system to produce a palette of
-              // appropriately matching and contrasting colors for use in a UI.
-              // The Zulip brand color is a starting point, but doesn't end up as
-              // one that's directly used.  (After all, we didn't design it for that
-              // purpose; we designed a logo.)  See docs:
-              //   https://api.flutter.dev/flutter/material/ColorScheme/ColorScheme.fromSeed.html
-              // Or try this tool to see the whole palette:
-              //   https://m3.material.io/theme-builder#/custom
-              colorScheme: ColorScheme.fromSeed(seedColor: kZulipBrandColor)),
-          home: const HomePage(),
-        ));
+          theme: theme,
+          home: const HomePage())));
   }
 }
 
@@ -73,34 +37,6 @@ class _PerAccountRootState extends State<PerAccountRoot> {
 // As computed by Anders: https://github.com/zulip/zulip-mobile/pull/4467
 const kZulipBrandColor = Color.fromRGBO(0x64, 0x92, 0xfe, 1);
 
-class LoadingPage extends StatelessWidget {
-  const LoadingPage({super.key});
-
-  @override
-  Widget build(BuildContext context) {
-    return const Center(child: CircularProgressIndicator());
-  }
-}
-
-class PerAccountStoreWidget extends InheritedNotifier<PerAccountStore> {
-  const PerAccountStoreWidget(
-      {super.key, required PerAccountStore store, required super.child})
-      : super(notifier: store);
-
-  PerAccountStore get store => notifier!;
-
-  static PerAccountStore of(BuildContext context) {
-    final widget =
-        context.dependOnInheritedWidgetOfExactType<PerAccountStoreWidget>();
-    assert(widget != null, 'No PerAccountStoreWidget ancestor');
-    return widget!.store;
-  }
-
-  @override
-  bool updateShouldNotify(covariant PerAccountStoreWidget oldWidget) =>
-      store != oldWidget.store;
-}
-
 class HomePage extends StatelessWidget {
   const HomePage({super.key});
 

lib/widgets/compose_box.dart

@@ -1,8 +1,8 @@
 import 'package:flutter/material.dart';
 import 'dialog.dart';
 
-import 'app.dart';
 import '../api/route/messages.dart';
+import 'store.dart';
 
 const double _inputVerticalPadding = 8;
 const double _sendButtonSize = 36;

lib/widgets/content.dart

@@ -4,7 +4,7 @@ import 'package:html/dom.dart' as dom;
 import '../api/model/model.dart';
 import '../model/content.dart';
 import '../model/store.dart';
-import 'app.dart';
+import 'store.dart';
 
 /// The font size for message content in a plain unstyled paragraph.
 const double kBaseFontSize = 14;

lib/widgets/message_list.dart

@@ -7,9 +7,9 @@ import '../model/content.dart';
 import '../model/message_list.dart';
 import '../model/narrow.dart';
 import '../model/store.dart';
-import 'app.dart';
 import 'content.dart';
 import 'sticky_header.dart';
+import 'store.dart';
 
 class MessageList extends StatefulWidget {
   const MessageList({Key? key}) : super(key: key);

lib/widgets/store.dart

@@ -0,0 +1,137 @@
+import 'package:flutter/material.dart';
+
+import '../model/store.dart';
+
+class DataRoot extends StatefulWidget {
+  const DataRoot({super.key, required this.child});
+
+  final Widget child;
+
+  @override
+  State<DataRoot> createState() => _DataRootState();
+}
+
+class _DataRootState extends State<DataRoot> {
+  GlobalStore? store;
+
+  @override
+  void initState() {
+    super.initState();
+    (() async {
+      final store = await GlobalStore.load();
+      setState(() {
+        this.store = store;
+      });
+    })();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final store = this.store;
+    // TODO: factor out the use of LoadingPage to be configured by the widget, like [widget.child] is
+    if (store == null) return const LoadingPage();
+    return GlobalStoreWidget(store: store, child: widget.child);
+  }
+}
+
+class GlobalStoreWidget extends InheritedNotifier<GlobalStore> {
+  const GlobalStoreWidget(
+      {super.key, required GlobalStore store, required super.child})
+      : super(notifier: store);
+
+  GlobalStore get store => notifier!;
+
+  static GlobalStore of(BuildContext context) {
+    final widget =
+        context.dependOnInheritedWidgetOfExactType<GlobalStoreWidget>();
+    assert(widget != null, 'No GlobalStoreWidget ancestor');
+    return widget!.store;
+  }
+
+  @override
+  bool updateShouldNotify(covariant GlobalStoreWidget oldWidget) =>
+      store != oldWidget.store;
+}
+
+class PerAccountRoot extends StatefulWidget {
+  const PerAccountRoot(
+      {super.key, required this.accountId, required this.child});
+
+  final int accountId;
+  final Widget child;
+
+  @override
+  State<PerAccountRoot> createState() => _PerAccountRootState();
+}
+
+class _PerAccountRootState extends State<PerAccountRoot> {
+  PerAccountStore? store;
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final globalStore = GlobalStoreWidget.of(context);
+    final account = globalStore.getAccount(widget.accountId);
+    assert(account != null, 'Account not found on global store');
+    if (store != null) {
+      // The data we use to auth to the server should be unchanged;
+      // changing those should mean a new account ID in our database.
+      assert(account!.realmUrl == store!.account.realmUrl);
+      assert(account!.email == store!.account.email);
+      assert(account!.apiKey == store!.account.apiKey);
+      // TODO if Account has anything else change, update the PerAccountStore for that
+      return;
+    }
+    (() async {
+      final store = await PerAccountStore.load(account!);
+      setState(() {
+        this.store = store;
+      });
+    })();
+  }
+
+  @override
+  void reassemble() {
+    // The [reassemble] method runs upon hot reload, in development.
+    // Here, we rerun parsing the messages.  This gives us the same
+    // highly productive workflow of Flutter hot reload when developing
+    // changes there as we have on changes to widgets.
+    store?.reassemble();
+    super.reassemble();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    // TODO: factor out the use of LoadingPage to be configured by the widget, like [widget.child] is
+    if (store == null) return const LoadingPage();
+    return PerAccountStoreWidget(store: store!, child: widget.child);
+  }
+}
+
+class PerAccountStoreWidget extends InheritedNotifier<PerAccountStore> {
+  const PerAccountStoreWidget(
+      {super.key, required PerAccountStore store, required super.child})
+      : super(notifier: store);
+
+  PerAccountStore get store => notifier!;
+
+  static PerAccountStore of(BuildContext context) {
+    final widget =
+    context.dependOnInheritedWidgetOfExactType<PerAccountStoreWidget>();
+    assert(widget != null, 'No PerAccountStoreWidget ancestor');
+    return widget!.store;
+  }
+
+  @override
+  bool updateShouldNotify(covariant PerAccountStoreWidget oldWidget) =>
+      store != oldWidget.store;
+}
+
+class LoadingPage extends StatelessWidget {
+  const LoadingPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const Center(child: CircularProgressIndicator());
+  }
+}