Feat/faster qr codes

cold-wallet-app/lib/components/animated_ur_qr.dart

@@ -4,18 +4,19 @@ import 'package:flutter/material.dart';
 import 'package:qr_flutter/qr_flutter.dart';
 
 /// Renders a UR payload as a QR code. A multi-part UR is animated by cycling
-/// through its fragments with a [Timer] (no post-frame callbacks).
+/// through its fragments with a [Timer] (no post-frame callbacks). Reacts to
+/// [fps], [paused] and [parts] changes so the animation can be tuned live.
+///
+/// Every frame's QR is encoded once up front: encoding a dense QR takes long
+/// enough that doing it inside build caps the real frame rate well below the
+/// requested one. Painting a precomputed module matrix keeps ticks cheap.
 class AnimatedUrQr extends StatefulWidget {
   final List<String> parts;
-  final Duration interval;
+  final int fps;
+  final bool paused;
   final double size;
 
-  const AnimatedUrQr({
-    super.key,
-    required this.parts,
-    this.interval = const Duration(milliseconds: 200),
-    this.size = 280,
-  });
+  const AnimatedUrQr({super.key, required this.parts, required this.fps, this.paused = false, this.size = 280});
 
   @override
   State<AnimatedUrQr> createState() => _AnimatedUrQrState();
@@ -24,15 +25,46 @@ class AnimatedUrQr extends StatefulWidget {
 class _AnimatedUrQrState extends State<AnimatedUrQr> {
   Timer? _timer;
   int _index = 0;
+  late List<QrPainter> _painters;
 
   @override
   void initState() {
     super.initState();
-    if (widget.parts.length > 1) {
-      _timer = Timer.periodic(widget.interval, (_) {
-        setState(() => _index = (_index + 1) % widget.parts.length);
-      });
+    _painters = _buildPainters();
+    _restartTimer();
+  }
+
+  List<QrPainter> _buildPainters() => widget.parts
+      .map(
+        (part) => QrPainter.withQr(
+          qr: QrCode.fromData(data: part, errorCorrectLevel: QrErrorCorrectLevel.L),
+          gapless: true,
+          eyeStyle: const QrEyeStyle(eyeShape: QrEyeShape.square, color: Colors.black),
+          dataModuleStyle: const QrDataModuleStyle(dataModuleShape: QrDataModuleShape.square, color: Colors.black),
+        ),
+      )
+      .toList();
+
+  @override
+  void didUpdateWidget(AnimatedUrQr oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    final partsChanged = !identical(widget.parts, oldWidget.parts);
+    if (partsChanged) {
+      _painters = _buildPainters();
+      _index = 0;
     }
+    if (partsChanged || widget.fps != oldWidget.fps || widget.paused != oldWidget.paused) {
+      _restartTimer();
+    }
+  }
+
+  void _restartTimer() {
+    _timer?.cancel();
+    _timer = null;
+    if (widget.paused || widget.parts.length <= 1) return;
+    _timer = Timer.periodic(Duration(milliseconds: (1000 / widget.fps).round()), (_) {
+      setState(() => _index = (_index + 1) % widget.parts.length);
+    });
   }
 
   @override
@@ -48,14 +80,7 @@ class _AnimatedUrQrState extends State<AnimatedUrQr> {
       height: widget.size,
       padding: const EdgeInsets.all(16),
       decoration: BoxDecoration(color: Colors.white, borderRadius: BorderRadius.circular(16)),
-      child: QrImageView(
-        data: widget.parts[_index],
-        errorCorrectionLevel: QrErrorCorrectLevel.L,
-        version: QrVersions.auto,
-        backgroundColor: Colors.white,
-        eyeStyle: const QrEyeStyle(eyeShape: QrEyeShape.square, color: Colors.black),
-        dataModuleStyle: const QrDataModuleStyle(dataModuleShape: QrDataModuleShape.square, color: Colors.black),
-      ),
+      child: CustomPaint(painter: _painters[_index]),
     );
   }
 }

cold-wallet-app/lib/components/confirm_dialog.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/material.dart';
+import 'package:quantus_cold_wallet/theme/app_colors.dart';
+
+Future<bool> showConfirmDialog(
+  BuildContext context, {
+  required String title,
+  required String message,
+  required String confirmLabel,
+}) async {
+  final colors = context.colors;
+  final confirmed = await showDialog<bool>(
+    context: context,
+    builder: (ctx) => AlertDialog(
+      backgroundColor: colors.sheetBackground,
+      title: Text(title),
+      content: Text(message),
+      actions: [
+        TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('Cancel')),
+        TextButton(
+          onPressed: () => Navigator.pop(ctx, true),
+          child: Text(confirmLabel, style: TextStyle(color: colors.error)),
+        ),
+      ],
+    ),
+  );
+  return confirmed == true;
+}

cold-wallet-app/lib/components/qr_tuning_controls.dart

@@ -0,0 +1,91 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:quantus_cold_wallet/providers/settings_providers.dart';
+import 'package:quantus_cold_wallet/theme/app_colors.dart';
+import 'package:quantus_cold_wallet/theme/app_text_styles.dart';
+
+/// FPS and bytes-per-frame sliders bound to [coldSettingsProvider], shared by
+/// the settings screen and the signature view so tuning behaves identically.
+class QrTuningControls extends ConsumerWidget {
+  const QrTuningControls({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final settings = ref.watch(coldSettingsProvider);
+    final controller = ref.read(coldSettingsProvider.notifier);
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        _TuningSlider(
+          label: 'Frame rate',
+          valueText: '${settings.qrFps} FPS',
+          value: settings.qrFps.toDouble(),
+          min: ColdSettings.minQrFps.toDouble(),
+          max: ColdSettings.maxQrFps.toDouble(),
+          divisions: ColdSettings.maxQrFps - ColdSettings.minQrFps,
+          onChanged: (v) => controller.setQrFps(v.round()),
+        ),
+        const SizedBox(height: 8),
+        _TuningSlider(
+          label: 'Bytes per frame',
+          valueText: '${settings.qrBytes} bytes',
+          value: settings.qrBytes.toDouble(),
+          min: ColdSettings.minQrBytes.toDouble(),
+          max: ColdSettings.maxQrBytes.toDouble(),
+          divisions: (ColdSettings.maxQrBytes - ColdSettings.minQrBytes) ~/ 25,
+          onChanged: (v) => controller.setQrBytes(v.round()),
+        ),
+      ],
+    );
+  }
+}
+
+class _TuningSlider extends StatelessWidget {
+  final String label;
+  final String valueText;
+  final double value;
+  final double min;
+  final double max;
+  final int divisions;
+  final ValueChanged<double> onChanged;
+
+  const _TuningSlider({
+    required this.label,
+    required this.valueText,
+    required this.value,
+    required this.min,
+    required this.max,
+    required this.divisions,
+    required this.onChanged,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = context.colors;
+    final text = context.themeText;
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Row(
+          mainAxisAlignment: MainAxisAlignment.spaceBetween,
+          children: [
+            Text(label, style: text.detail?.copyWith(color: colors.textSecondary)),
+            Text(valueText, style: text.detail?.copyWith(color: colors.textPrimary)),
+          ],
+        ),
+        SliderTheme(
+          data: SliderTheme.of(context).copyWith(
+            activeTrackColor: colors.accentOrange,
+            inactiveTrackColor: colors.borderButton,
+            thumbColor: colors.accentOrange,
+            overlayColor: colors.accentOrange.withValues(alpha: 0.15),
+            trackHeight: 2,
+          ),
+          child: Slider(value: value, min: min, max: max, divisions: divisions, onChanged: onChanged),
+        ),
+      ],
+    );
+  }
+}

cold-wallet-app/lib/providers/settings_providers.dart

@@ -0,0 +1,85 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+@immutable
+class ColdSettings {
+  static const minQrFps = 5;
+  static const maxQrFps = 50;
+  static const defaultQrFps = 15;
+  static const minQrBytes = 300;
+
+  // 1400 payload bytes encode to ~2870 UR chars, under the 2953-char capacity
+  // of a version-40 byte-mode QR at error correction L; encodeUrForQr measures
+  // the final strings and shrinks fragments if they would still overflow.
+  static const maxQrBytes = 1400;
+  static const defaultQrBytes = 1100;
+
+  final bool wifiOverrideEnabled;
+  final int qrFps;
+  final int qrBytes;
+
+  const ColdSettings({this.wifiOverrideEnabled = false, this.qrFps = defaultQrFps, this.qrBytes = defaultQrBytes});
+
+  ColdSettings copyWith({bool? wifiOverrideEnabled, int? qrFps, int? qrBytes}) => ColdSettings(
+    wifiOverrideEnabled: wifiOverrideEnabled ?? this.wifiOverrideEnabled,
+    qrFps: qrFps ?? this.qrFps,
+    qrBytes: qrBytes ?? this.qrBytes,
+  );
+}
+
+class ColdSettingsController extends Notifier<ColdSettings> {
+  static const _wifiOverrideKey = 'wifi_lock_override';
+  static const _qrFpsKey = 'qr_fps';
+  static const _qrBytesKey = 'qr_bytes_per_frame';
+
+  @override
+  ColdSettings build() {
+    _load();
+    return const ColdSettings();
+  }
+
+  Future<void> _load() async {
+    final prefs = await SharedPreferences.getInstance();
+    state = ColdSettings(
+      wifiOverrideEnabled: prefs.getBool(_wifiOverrideKey) ?? false,
+      qrFps: (prefs.getInt(_qrFpsKey) ?? ColdSettings.defaultQrFps).clamp(ColdSettings.minQrFps, ColdSettings.maxQrFps),
+      qrBytes: (prefs.getInt(_qrBytesKey) ?? ColdSettings.defaultQrBytes).clamp(
+        ColdSettings.minQrBytes,
+        ColdSettings.maxQrBytes,
+      ),
+    );
+  }
+
+  Future<void> setWifiOverrideEnabled(bool enabled) async {
+    state = state.copyWith(wifiOverrideEnabled: enabled);
+    if (!enabled) ref.read(wifiLockOverriddenProvider.notifier).set(false);
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(_wifiOverrideKey, enabled);
+  }
+
+  Future<void> setQrFps(int fps) async {
+    state = state.copyWith(qrFps: fps);
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setInt(_qrFpsKey, fps);
+  }
+
+  Future<void> setQrBytes(int bytes) async {
+    state = state.copyWith(qrBytes: bytes);
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setInt(_qrBytesKey, bytes);
+  }
+}
+
+final coldSettingsProvider = NotifierProvider<ColdSettingsController, ColdSettings>(ColdSettingsController.new);
+
+/// Session-only: armed from the connectivity guard after the user confirms the
+/// override warning; disarmed when the persistent toggle is switched off.
+class WifiLockOverridden extends Notifier<bool> {
+  @override
+  bool build() => false;
+
+  void set(bool value) => state = value;
+}
+
+final wifiLockOverriddenProvider = NotifierProvider<WifiLockOverridden, bool>(WifiLockOverridden.new);

cold-wallet-app/lib/screens/home_screen.dart

@@ -4,35 +4,14 @@ import 'package:quantus_cold_wallet/components/scaffold_base.dart';
 import 'package:quantus_cold_wallet/components/v2_app_bar.dart';
 import 'package:quantus_cold_wallet/providers/wallet_providers.dart';
 import 'package:quantus_cold_wallet/screens/scan_transaction_screen.dart';
+import 'package:quantus_cold_wallet/screens/settings_screen.dart';
 import 'package:quantus_cold_wallet/screens/show_key_screen.dart';
 import 'package:quantus_cold_wallet/theme/app_colors.dart';
 import 'package:quantus_cold_wallet/theme/app_text_styles.dart';
 
 class HomeScreen extends ConsumerWidget {
   const HomeScreen({super.key});
 
-  Future<void> _confirmReset(BuildContext context, WidgetRef ref) async {
-    final colors = context.colors;
-    final confirmed = await showDialog<bool>(
-      context: context,
-      builder: (ctx) => AlertDialog(
-        backgroundColor: colors.sheetBackground,
-        title: const Text('Reset wallet?'),
-        content: const Text(
-          'This erases the encrypted key from this device. You can only restore it with your recovery phrase.',
-        ),
-        actions: [
-          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('Cancel')),
-          TextButton(
-            onPressed: () => Navigator.pop(ctx, true),
-            child: Text('Reset', style: TextStyle(color: colors.error)),
-          ),
-        ],
-      ),
-    );
-    if (confirmed == true) await ref.read(walletControllerProvider.notifier).wipe();
-  }
-
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final colors = context.colors;
@@ -46,8 +25,8 @@ class HomeScreen extends ConsumerWidget {
           child: Icon(Icons.lock_outline, color: colors.textPrimary, size: 22),
         ),
         trailing: GestureDetector(
-          onTap: () => _confirmReset(context, ref),
-          child: Icon(Icons.more_horiz, color: colors.textPrimary, size: 22),
+          onTap: () => Navigator.push(context, MaterialPageRoute(builder: (_) => const SettingsScreen())),
+          child: Icon(Icons.settings_outlined, color: colors.textPrimary, size: 22),
         ),
       ),
       mainContent: Column(

cold-wallet-app/lib/screens/scan_transaction_screen.dart

@@ -18,7 +18,13 @@ class ScanTransactionScreen extends StatefulWidget {
 }
 
 class _ScanTransactionScreenState extends State<ScanTransactionScreen> {
-  final MobileScannerController _controller = MobileScannerController();
+  // Unrestricted: the default DetectionSpeed.normal enforces a 250ms timeout
+  // between detections, capping an animated QR at ~4 frames/second. Duplicate
+  // deliveries are cheap — parts dedupe through the set below.
+  final MobileScannerController _controller = MobileScannerController(
+    detectionSpeed: DetectionSpeed.unrestricted,
+    formats: const [BarcodeFormat.qrCode],
+  );
   final Set<String> _parts = {};
   final Set<int> _seenSeq = {};
   final RegExp _seqPattern = RegExp(r'/(\d+)-(\d+)/');