userfront 연동이력 맞춤

userfront/lib/features/auth/presentation/qr_scan_screen.dart

@@ -16,6 +16,7 @@ class _QRScanScreenState extends State<QRScanScreen> {
   final _log = Logger('QRScanScreen');
   final MobileScannerController controller = MobileScannerController(
     detectionSpeed: DetectionSpeed.noDuplicates,
+    autoStart: false,
   );
   bool _isScanned = false;
   bool _isCheckingSession = false;
@@ -28,6 +29,9 @@ class _QRScanScreenState extends State<QRScanScreen> {
   void initState() {
     super.initState();
     _bootstrapCookieSession();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _startScannerIfNeeded();
+    });
   }
 
   Future<bool> _bootstrapCookieSession() async {
@@ -52,6 +56,28 @@ class _QRScanScreenState extends State<QRScanScreen> {
     }
   }
 
+  Future<void> _startScannerIfNeeded() async {
+    if (controller.value.isRunning || controller.value.isStarting) {
+      return;
+    }
+    try {
+      await controller.start();
+    } catch (e) {
+      _log.warning('Scanner start failed: $e');
+    }
+  }
+
+  Future<void> _stopScannerIfRunning() async {
+    if (!controller.value.isRunning && !controller.value.isStarting) {
+      return;
+    }
+    try {
+      await controller.stop();
+    } catch (e) {
+      _log.warning('Scanner stop failed: $e');
+    }
+  }
+
   @override
   void dispose() {
     controller.dispose();
@@ -65,6 +91,7 @@ class _QRScanScreenState extends State<QRScanScreen> {
     for (final barcode in barcodes) {
       if (barcode.rawValue != null) {
         _isScanned = true;
+        await _stopScannerIfRunning();
         if (mounted) {
           setState(() => _isProcessing = true);
         }
@@ -142,14 +169,14 @@ class _QRScanScreenState extends State<QRScanScreen> {
       _isSuccess = null;
       _resultMessage = null;
     });
-    controller.start();
+    _startScannerIfNeeded();
   }
 
   Future<void> _requestCameraPermission() async {
     if (_isRequestingCamera) return;
     setState(() => _isRequestingCamera = true);
     try {
-      await controller.start();
+      await _startScannerIfNeeded();
     } catch (e) {
       _log.warning('Camera permission request failed: $e');
       if (mounted) {