fix: lifecycle

lib/pages/bootloader_recovery_update_page.dart

@@ -66,15 +66,21 @@ class _BootloaderRecoveryUpdatePageState
     unawaited(_firmwareProgressSubscription?.cancel());
     unawaited(() async {
       await service?.dispose();
-      await _disconnectBootloaderIfStillConnected(bluetooth: bluetooth);
+      await _disconnectBootloaderIfStillConnected(
+        bluetooth: bluetooth,
+        allowRefRead: false,
+      );
     }());
     super.dispose();
   }
 
   Future<void> _disconnectBootloaderIfStillConnected({
     BluetoothController? bluetooth,
+    bool allowRefRead = true,
   }) async {
-    bluetooth ??= ref.read(bluetoothProvider).valueOrNull;
+    if (bluetooth == null && allowRefRead) {
+      bluetooth = ref.read(bluetoothProvider).valueOrNull;
+    }
     if (bluetooth == null) {
       return;
     }

lib/pages/device_details_page.dart

@@ -66,6 +66,7 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
   bool _isPairingCheckRunning = false;
   ProviderSubscription<AsyncValue<(ConnectionStatus, String?)>>?
       _connectionStatusSubscription;
+  BluetoothController? _bluetooth;
 
   ShifterService? _shifterService;
   StreamSubscription<CentralStatus>? _statusSubscription;
@@ -146,7 +147,10 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
       'Disposing device details page for ${widget.deviceAddress}; '
       'dfuState=${_dfuProgress.state}, isFirmwareUpdateBusy=$_isFirmwareUpdateBusy',
     );
-    unawaited(_disconnectOnClose());
+    final bluetooth = _bluetooth;
+    unawaited(
+      _disconnectOnClose(bluetooth: bluetooth, allowRefRead: false),
+    );
     _connectionStatusSubscription?.close();
     _statusSubscription?.cancel();
     _shifterService?.dispose();
@@ -155,7 +159,10 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
     super.dispose();
   }
 
-  Future<void> _disconnectOnClose() async {
+  Future<void> _disconnectOnClose({
+    BluetoothController? bluetooth,
+    bool allowRefRead = true,
+  }) async {
     if (_isFirmwareUpdateBusy) {
       _log.info('Skipping disconnect on close because firmware update is busy');
       return;
@@ -169,10 +176,16 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
     _hasRequestedDisconnect = true;
     _isExitingPage = true;
 
+    final bluetoothController = bluetooth ??
+        _bluetooth ??
+        (allowRefRead ? ref.read(bluetoothProvider).value : null);
+    if (bluetoothController != null) {
+      _bluetooth = bluetoothController;
+    }
+
     await _disposeFirmwareUpdateService();
 
-    final bluetooth = ref.read(bluetoothProvider).value;
-    await bluetooth?.disconnect();
+    await bluetoothController?.disconnect();
     await _stopStatusStreaming();
   }
 
@@ -211,6 +224,9 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
 
     if (_shifterService != null) {
       final bluetooth = ref.read(bluetoothProvider).value;
+      if (bluetooth != null) {
+        _bluetooth = bluetooth;
+      }
       if (bluetooth == null || !isCurrentDeviceConnected(bluetooth)) {
         return;
       }
@@ -239,6 +255,7 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
     } else {
       bluetooth = await ref.read(bluetoothProvider.future);
     }
+    _bluetooth = bluetooth;
     if (!isCurrentDeviceConnected(bluetooth)) {
       return;
     }
@@ -264,6 +281,9 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
       }
 
       final bluetooth = ref.read(bluetoothProvider).value;
+      if (bluetooth != null) {
+        _bluetooth = bluetooth;
+      }
       if (bluetooth == null || !isCurrentDeviceConnected(bluetooth)) {
         break;
       }
@@ -523,6 +543,7 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
     if (bluetooth == null) {
       return null;
     }
+    _bluetooth = bluetooth;
 
     final service = FirmwareUpdateService(
       transport: ShifterFirmwareUpdateTransport(
@@ -722,6 +743,7 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
 
     try {
       final bluetooth = await ref.read(bluetoothProvider.future);
+      _bluetooth = bluetooth;
       final result = await bluetooth.connectById(
         widget.deviceAddress,
         timeout: const Duration(seconds: 10),

lib/pages/devices_tab_page.dart

@@ -26,8 +26,10 @@ class _DevicesTabPageState extends ConsumerState<DevicesTabPage> {
   static const Duration _bootloaderScanTimeout = Duration(seconds: 10);
 
   StreamSubscription<List<DiscoveredDevice>>? _scanSubscription;
+  BluetoothController? _bluetooth;
   DiscoveredDevice? _dfuDevice;
   bool _isBootloaderScanStarting = false;
+  bool _isDisposed = false;
 
   @override
   void initState() {
@@ -37,8 +39,8 @@ class _DevicesTabPageState extends ConsumerState<DevicesTabPage> {
 
   @override
   void dispose() {
-    final bluetooth = ref.read(bluetoothProvider).valueOrNull;
-    unawaited(_scanSubscription?.cancel());
+    _isDisposed = true;
+    final bluetooth = _bluetooth;
     unawaited(_stopBootloaderScan(bluetooth));
     super.dispose();
   }
@@ -52,14 +54,19 @@ class _DevicesTabPageState extends ConsumerState<DevicesTabPage> {
 
     try {
       final bluetooth = await ref.read(bluetoothProvider.future);
-      if (!mounted) {
+      if (!mounted || _isDisposed) {
         return;
       }
+      _bluetooth = bluetooth;
 
       final scanResult = await bluetooth.startScan(
         timeout: _bootloaderScanTimeout,
         scanMode: ScanMode.lowLatency,
       );
+      if (!mounted || _isDisposed) {
+        await bluetooth.stopScan();
+        return;
+      }
       if (scanResult.isErr()) {
         return;
       }
@@ -74,20 +81,22 @@ class _DevicesTabPageState extends ConsumerState<DevicesTabPage> {
   }
 
   Future<void> _stopBootloaderScan([BluetoothController? bluetooth]) async {
-    await _scanSubscription?.cancel();
+    final subscription = _scanSubscription;
     _scanSubscription = null;
+    await subscription?.cancel();
 
     await bluetooth?.stopScan();
   }
 
   void _updateBootloaderDevice(List<DiscoveredDevice> devices) {
+    if (_isDisposed || !mounted) {
+      return;
+    }
+
     final dfuDevice = devices.cast<DiscoveredDevice?>().firstWhere(
           (device) => device != null && _isBootloaderAdvertisement(device),
           orElse: () => null,
         );
-    if (!mounted) {
-      return;
-    }
 
     if (dfuDevice == null) {
       _clearBootloaderDevice();
@@ -104,7 +113,7 @@ class _DevicesTabPageState extends ConsumerState<DevicesTabPage> {
   }
 
   void _clearBootloaderDevice() {
-    if (!mounted || _dfuDevice == null) {
+    if (_isDisposed || !mounted || _dfuDevice == null) {
       return;
     }
 
@@ -139,12 +148,12 @@ class _DevicesTabPageState extends ConsumerState<DevicesTabPage> {
         builder: (_) => _BootloaderRecoverySetupPage(device: device),
       ),
     );
-    if (!mounted || firmware == null) {
+    if (!mounted || _isDisposed || firmware == null) {
       return;
     }
 
     await _stopBootloaderScan();
-    if (!mounted) {
+    if (!mounted || _isDisposed) {
       return;
     }
     _clearBootloaderDevice();