msglist [nfc]: Make narrow mutable for _MessageListPageState.

This allows us to switch narrow when a move happens.

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

integration_test/unreadmarker_test.dart

@@ -40,7 +40,7 @@ void main() {
           child: PerAccountStoreWidget(
             accountId: eg.selfAccount.id,
             placeholder: const LoadingPlaceholderPage(),
-            child: const MessageListPage(narrow: CombinedFeedNarrow())))));
+            child: const MessageListPage(initNarrow: CombinedFeedNarrow())))));
     await tester.pumpAndSettle();
     return messages;
   }

lib/notifications/display.dart

@@ -273,7 +273,7 @@ class NotificationDisplayManager {
     // TODO(nav): Better interact with existing nav stack on notif open
     navigator.push(MaterialAccountWidgetRoute<void>(accountId: account.id,
       // TODO(#82): Open at specific message, not just conversation
-      page: MessageListPage(narrow: narrow)));
+      page: MessageListPage(initNarrow: narrow)));
     return;
   }
 

lib/widgets/message_list.dart

@@ -37,12 +37,12 @@ abstract class MessageListPageState {
 }
 
 class MessageListPage extends StatefulWidget {
-  const MessageListPage({super.key, required this.narrow});
+  const MessageListPage({super.key, required this.initNarrow});
 
   static Route<void> buildRoute({int? accountId, BuildContext? context,
       required Narrow narrow}) {
     return MaterialAccountWidgetRoute(accountId: accountId, context: context,
-      page: MessageListPage(narrow: narrow));
+      page: MessageListPage(initNarrow: narrow));
   }
 
   /// The [MessageListPageState] above this context in the tree.
@@ -57,7 +57,7 @@ class MessageListPage extends StatefulWidget {
     return state!;
   }
 
-  final Narrow narrow;
+  final Narrow initNarrow;
 
   @override
   State<MessageListPage> createState() => _MessageListPageState();
@@ -68,20 +68,26 @@ const _kUnsubscribedStreamRecipientHeaderColor = Color(0xfff5f5f5);
 
 class _MessageListPageState extends State<MessageListPage> implements MessageListPageState {
   @override
-  Narrow get narrow => widget.narrow;
+  late Narrow narrow;
 
   @override
   ComposeBoxController? get composeBoxController => _composeBoxKey.currentState;
 
   final GlobalKey<ComposeBoxController> _composeBoxKey = GlobalKey();
 
+  @override
+  void initState() {
+    narrow = widget.initNarrow;
+    super.initState();
+  }
+
   @override
   Widget build(BuildContext context) {
     final store = PerAccountStoreWidget.of(context);
 
     final Color? appBarBackgroundColor;
     bool removeAppBarBottomBorder = false;
-    switch(widget.narrow) {
+    switch(narrow) {
       case CombinedFeedNarrow():
         appBarBackgroundColor = null; // i.e., inherit
 
@@ -103,7 +109,7 @@ class _MessageListPageState extends State<MessageListPage> implements MessageLis
     }
 
     return Scaffold(
-      appBar: AppBar(title: MessageListAppBarTitle(narrow: widget.narrow),
+      appBar: AppBar(title: MessageListAppBarTitle(narrow: narrow),
         backgroundColor: appBarBackgroundColor,
         shape: removeAppBarBottomBorder
           ? const Border()
@@ -129,11 +135,11 @@ class _MessageListPageState extends State<MessageListPage> implements MessageLis
               //   if those details get complicated, refactor to avoid copying.
               // TODO(#311) If we have a bottom nav, it will pad the bottom
               //   inset, and this should always be true.
-              removeBottom: widget.narrow is! CombinedFeedNarrow,
+              removeBottom: narrow is! CombinedFeedNarrow,
 
               child: Expanded(
-                child: MessageList(narrow: widget.narrow))),
-            ComposeBox(controllerKey: _composeBoxKey, narrow: widget.narrow),
+                child: MessageList(narrow: narrow))),
+            ComposeBox(controllerKey: _composeBoxKey, narrow: narrow),
           ]))));
   }
 }

test/notifications/display_test.dart

@@ -362,7 +362,7 @@ void main() {
       route.isA<MaterialAccountWidgetRoute>()
         ..accountId.equals(account.id)
         ..page.isA<MessageListPage>()
-          .narrow.equals(SendableNarrow.ofMessage(message,
+          .initNarrow.equals(SendableNarrow.ofMessage(message,
             selfUserId: account.userId));
     }
 

test/widgets/action_sheet_test.dart

@@ -68,7 +68,7 @@ Future<void> setupToMessageActionSheet(WidgetTester tester, {
       home: GlobalStoreWidget(
         child: PerAccountStoreWidget(
           accountId: eg.selfAccount.id,
-          child: MessageListPage(narrow: narrow))))));
+          child: MessageListPage(initNarrow: narrow))))));
 
   // global store, per-account store, and message list get loaded
   await tester.pumpAndSettle();

test/widgets/autocomplete_test.dart

@@ -58,7 +58,7 @@ Future<Finder> setupToComposeInput(WidgetTester tester, {
         child: PerAccountStoreWidget(
           accountId: eg.selfAccount.id,
           child: MessageListPage(
-            narrow: DmNarrow(
+            initNarrow: DmNarrow(
               allRecipientIds: [eg.selfUser.userId, eg.otherUser.userId],
               selfUserId: eg.selfUser.userId,
             )))))));

test/widgets/content_test.dart

@@ -820,7 +820,7 @@ void main() {
       await tapText(tester, find.text('stream'));
       check(testBinding.takeLaunchUrlCalls()).isEmpty();
       check(pushedRoutes).single.isA<WidgetRoute>()
-        .page.isA<MessageListPage>().narrow.equals(const StreamNarrow(1));
+        .page.isA<MessageListPage>().initNarrow.equals(const StreamNarrow(1));
     });
 
     testWidgets('invalid internal links are opened in browser', (tester) async {

test/widgets/message_list_checks.dart

@@ -3,5 +3,5 @@ import 'package:zulip/model/narrow.dart';
 import 'package:zulip/widgets/message_list.dart';
 
 extension MessageListPageChecks on Subject<MessageListPage> {
-  Subject<Narrow> get narrow => has((x) => x.narrow, 'narrow');
+  Subject<Narrow> get initNarrow => has((x) => x.initNarrow, 'initNarrow');
 }

test/widgets/message_list_test.dart

@@ -76,7 +76,7 @@ void main() {
         home: GlobalStoreWidget(
           child: PerAccountStoreWidget(
             accountId: eg.selfAccount.id,
-            child: MessageListPage(narrow: narrow))))));
+            child: MessageListPage(initNarrow: narrow))))));
 
     // global store, per-account store, and message list get loaded
     await tester.pumpAndSettle();

test/widgets/profile_test.dart

@@ -259,7 +259,7 @@ void main() {
       await tester.tap(targetWidget);
       check(pushedRoutes).last.isA<WidgetRoute>().page
         .isA<MessageListPage>()
-        .narrow.equals(DmNarrow.withUser(1, selfUserId: eg.selfUser.userId));
+        .initNarrow.equals(DmNarrow.withUser(1, selfUserId: eg.selfUser.userId));
     });
 
     testWidgets('page builds; user links render multiple avatars', (WidgetTester tester) async {

test/widgets/recent_dm_conversations_test.dart

@@ -328,7 +328,7 @@ void main() {
 
         check(pushedRoutes).last.isA<WidgetRoute>().page
           .isA<MessageListPage>()
-          .narrow.equals(expectedNarrow);
+          .initNarrow.equals(expectedNarrow);
       }
 
       testWidgets('1:1', (WidgetTester tester) async {