🐛 Fix focus track still exists after that track disappeared

lib/main.dart

@@ -19,6 +19,7 @@ import 'package:solian/providers/content/realm.dart';
 import 'package:solian/providers/friend.dart';
 import 'package:solian/providers/account_status.dart';
 import 'package:solian/router.dart';
+import 'package:solian/shells/system_shell.dart';
 import 'package:solian/theme.dart';
 import 'package:solian/translations.dart';
 
@@ -85,8 +86,10 @@ class SolianApp extends StatelessWidget {
       fallbackLocale: const Locale('en', 'US'),
       onInit: () => _initializeProviders(context),
       builder: (context, child) {
-        return ScaffoldMessenger(
-          child: child ?? const SizedBox(),
+        return SystemShell(
+          child: ScaffoldMessenger(
+            child: child ?? const SizedBox(),
+          ),
         );
       },
     );

lib/providers/content/call.dart

@@ -34,7 +34,7 @@ class ChatCallProvider extends GetxController {
   late Room room;
   late EventsListener<RoomEvent> listener;
 
-  RxList participantTracks = [].obs;
+  RxList<ParticipantTrack> participantTracks = RxList.empty(growable: true);
   Rx<ParticipantTrack?> focusTrack = Rx(null);
 
   Future<void> checkPermissions() async {
@@ -194,7 +194,7 @@ class ChatCallProvider extends GetxController {
       }
     }
 
-    final newTracks = List.empty(growable: true);
+    final newTracks = List<ParticipantTrack>.empty(growable: true);
 
     final mediaTrackList = mediaTracks.values.toList();
     mediaTrackList.sort((a, b) {
@@ -247,6 +247,15 @@ class ChatCallProvider extends GetxController {
     }
 
     participantTracks.value = newTracks;
+
+    if (focusTrack.value != null) {
+      final idx = participantTracks.indexWhere(
+          (x) => x.participant.sid == focusTrack.value!.participant.sid);
+      if (idx == -1) {
+        focusTrack.value = null;
+      }
+    }
+
     if (focusTrack.value == null) {
       focusTrack.value = participantTracks.firstOrNull;
     } else {

lib/shells/root_shell.dart

@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_animate/flutter_animate.dart';
 import 'package:go_router/go_router.dart';
-import 'package:solian/platform.dart';
 import 'package:solian/router.dart';
 import 'package:solian/theme.dart';
 import 'package:solian/widgets/navigation/app_navigation.dart';
@@ -32,49 +31,33 @@ class RootShell extends StatelessWidget {
         AppNavigation.destinationPages.contains(routeName);
 
     return Scaffold(
-      body: Column(
-        children: [
-          if (PlatformInfo.isMacOS)
-            Container(
-              height: 28,
-              color: Theme.of(context).colorScheme.surface,
-            ),
-          if (PlatformInfo.isMacOS)
-            const Divider(
-              thickness: 0.3,
-              height: 0.3,
-            ),
-          Expanded(
-            child: SolianTheme.isLargeScreen(context)
-                ? Row(
-                    children: [
-                      if (showNavigation) const AppNavigationRail(),
-                      if (showNavigation)
-                        const VerticalDivider(thickness: 0.3, width: 1),
-                      Expanded(child: child),
-                    ],
-                  )
-                : Stack(
-                    children: [
-                      child,
-                      Positioned(
-                        bottom: 0,
-                        left: 0,
-                        right: 0,
-                        child: const AppNavigationBottomBar()
-                            .animate(target: showBottom ? 0 : 1)
-                            .slideY(
-                              duration: 250.ms,
-                              begin: 0,
-                              end: 1,
-                              curve: Curves.easeInToLinear,
-                            ),
+      body: SolianTheme.isLargeScreen(context)
+          ? Row(
+              children: [
+                if (showNavigation) const AppNavigationRail(),
+                if (showNavigation)
+                  const VerticalDivider(thickness: 0.3, width: 1),
+                Expanded(child: child),
+              ],
+            )
+          : Stack(
+              children: [
+                child,
+                Positioned(
+                  bottom: 0,
+                  left: 0,
+                  right: 0,
+                  child: const AppNavigationBottomBar()
+                      .animate(target: showBottom ? 0 : 1)
+                      .slideY(
+                        duration: 250.ms,
+                        begin: 0,
+                        end: 1,
+                        curve: Curves.easeInToLinear,
                       ),
-                    ],
-                  ),
-          ),
-        ],
-      ),
+                ),
+              ],
+            ),
     );
   }
 }

lib/shells/system_shell.dart

@@ -0,0 +1,29 @@
+import 'package:flutter/material.dart';
+import 'package:solian/platform.dart';
+
+class SystemShell extends StatelessWidget {
+  final Widget child;
+
+  const SystemShell({super.key, required this.child});
+
+  @override
+  Widget build(BuildContext context) {
+    if (PlatformInfo.isMacOS) {
+      return Column(
+        children: [
+          Container(
+            height: 28,
+            color: Theme.of(context).colorScheme.surface,
+          ),
+          const Divider(
+            thickness: 0.3,
+            height: 0.3,
+          ),
+          Expanded(child: child),
+        ],
+      );
+    }
+
+    return child;
+  }
+}