feat: 5594 - multi product scan mode as a dev mode option for price r…

…eceipt input (openfoodfacts#6008)

Impacted files:
* `price_add_product_card.dart`: now calling the scan card with the bool multi product scan mode parameter, and manages a _list_ of scanned barcodes
* `price_scan_page.dart`: now manages a multi product scan mode, with floating action button and snackbar
* `user_preferences_dev_mode.dart`: new flag for "multi product scan in price receipt"

packages/smooth_app/lib/pages/preferences/user_preferences_dev_mode.dart

@@ -55,6 +55,8 @@ class UserPreferencesDevMode extends AbstractUserPreferences {
   static const String userPreferencesFlagAccessibilityEmoji =
       '__accessibilityEmoji';
   static const String userPreferencesFlagUserOrderedKP = '__userOrderedKP';
+  static const String userPreferencesFlagPricesReceiptMultiSelection =
+      '__pricesReceiptMultiSelection';
   static const String userPreferencesFlagSpellCheckerOnOcr =
       '__spellcheckerOcr';
   static const String userPreferencesCustomNewsJSONURI = '__newsJsonURI';
@@ -431,6 +433,19 @@ class UserPreferencesDevMode extends AbstractUserPreferences {
         UserPreferencesItemSection(
           label: appLocalizations.dev_mode_section_experimental_features,
         ),
+        UserPreferencesItemSwitch(
+          title: 'Multi-products selection for prices',
+          value: userPreferences
+                  .getFlag(userPreferencesFlagPricesReceiptMultiSelection) ??
+              false,
+          onChanged: (bool value) async {
+            await userPreferences.setFlag(
+              userPreferencesFlagPricesReceiptMultiSelection,
+              value,
+            );
+            _showSuccessMessage();
+          },
+        ),
         UserPreferencesItemSwitch(
           title: 'User ordered knowledge panels',
           value: userPreferences.getFlag(userPreferencesFlagUserOrderedKP) ??

packages/smooth_app/lib/pages/prices/price_add_product_card.dart

@@ -1,11 +1,13 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:provider/provider.dart';
+import 'package:smooth_app/data_models/preferences/user_preferences.dart';
 import 'package:smooth_app/database/local_database.dart';
 import 'package:smooth_app/generic_lib/buttons/smooth_large_button_with_icon.dart';
 import 'package:smooth_app/generic_lib/dialogs/smooth_alert_dialog.dart';
 import 'package:smooth_app/generic_lib/widgets/smooth_card.dart';
 import 'package:smooth_app/generic_lib/widgets/smooth_text_form_field.dart';
+import 'package:smooth_app/pages/preferences/user_preferences_dev_mode.dart';
 import 'package:smooth_app/pages/prices/price_amount_model.dart';
 import 'package:smooth_app/pages/prices/price_meta_product.dart';
 import 'package:smooth_app/pages/prices/price_model.dart';
@@ -50,21 +52,29 @@ class _PriceAddProductCardState extends State<PriceAddProductCard> {
             text: appLocalizations.prices_barcode_reader_action,
             icon: Icons.barcode_reader,
             onPressed: () async {
-              final String? barcode = await Navigator.of(context).push<String>(
-                MaterialPageRoute<String>(
+              final UserPreferences userPreferences =
+                  context.read<UserPreferences>();
+              final List<String>? barcodes =
+                  await Navigator.of(context).push<List<String>>(
+                MaterialPageRoute<List<String>>(
                   builder: (BuildContext context) => PriceScanPage(
                     latestScannedBarcode: _latestScannedBarcode,
+                    isMultiProducts: userPreferences.getFlag(
+                          UserPreferencesDevMode
+                              .userPreferencesFlagPricesReceiptMultiSelection,
+                        ) ??
+                        false,
                   ),
                 ),
               );
-              if (barcode == null) {
+              if (barcodes == null || barcodes.isEmpty) {
                 return;
               }
-              _latestScannedBarcode = barcode;
+              _latestScannedBarcode = barcodes.last;
               if (!context.mounted) {
                 return;
               }
-              await _addToList(barcode, context);
+              await _addBarcodesToList(barcodes, context);
             },
           ),
           SmoothLargeButtonWithIcon(
@@ -75,19 +85,20 @@ class _PriceAddProductCardState extends State<PriceAddProductCard> {
               if (barcode == null) {
                 return;
               }
+              _latestScannedBarcode = null;
               if (!context.mounted) {
                 return;
               }
-              await _addToList(barcode, context);
+              await _addBarcodesToList(<String>[barcode], context);
             },
           ),
         ],
       ),
     );
   }
 
-  Future<void> _addToList(
-    final String barcode,
+  Future<void> _addBarcodesToList(
+    final List<String> barcodes,
     final BuildContext context,
   ) async {
     final AppLocalizations appLocalizations = AppLocalizations.of(context);
@@ -96,39 +107,71 @@ class _PriceAddProductCardState extends State<PriceAddProductCard> {
       context,
       listen: false,
     );
-    for (int i = 0; i < priceModel.length; i++) {
-      final PriceAmountModel model = priceModel.elementAt(i);
-      if (model.product.barcode == barcode) {
-        await showDialog<void>(
-          context: context,
-          builder: (final BuildContext context) => SmoothAlertDialog(
-            body: Text(appLocalizations.prices_barcode_already(barcode)),
-            positiveAction: SmoothActionButton(
-              text: appLocalizations.okay,
-              onPressed: () => Navigator.of(context).pop(),
-            ),
+
+    bool barcodeAlreadyThere(final String barcode) {
+      for (int i = 0; i < priceModel.length; i++) {
+        final PriceAmountModel model = priceModel.elementAt(i);
+        if (model.product.barcode == barcode) {
+          return true;
+        }
+      }
+      return false;
+    }
+
+    final List<String> alreadyThere = <String>[];
+    final List<String> notThere = <String>[];
+    for (final String barcode in barcodes) {
+      if (barcodeAlreadyThere(barcode)) {
+        alreadyThere.add(barcode);
+      } else {
+        notThere.add(barcode);
+      }
+    }
+
+    if (notThere.isNotEmpty) {
+      for (final String barcode in notThere) {
+        _addProductToList(
+          priceModel,
+          PriceMetaProduct.unknown(
+            barcode,
+            localDatabase,
+            priceModel,
           ),
+          context,
         );
-        return;
       }
+      priceModel.notifyListeners();
     }
-    priceModel.add(
-      PriceAmountModel(
-        product: PriceMetaProduct.unknown(
-          barcode,
-          localDatabase,
-          priceModel,
+
+    for (final String barcode in alreadyThere) {
+      if (!context.mounted) {
+        return;
+      }
+      await showDialog<void>(
+        context: context,
+        builder: (final BuildContext context) => SmoothAlertDialog(
+          body: Text(appLocalizations.prices_barcode_already(barcode)),
+          positiveAction: SmoothActionButton(
+            text: appLocalizations.okay,
+            onPressed: () => Navigator.of(context).pop(),
+          ),
         ),
-      ),
-    );
+      );
+    }
+  }
+
+  void _addProductToList(
+    final PriceModel priceModel,
+    final PriceMetaProduct product,
+    final BuildContext context,
+  ) {
+    priceModel.add(PriceAmountModel(product: product));
 
     // unfocus from the previous price amount text field.
     // looks like the most efficient way to unfocus: focus somewhere in space...
     final FocusNode focusNode = FocusNode();
     _dummyFocusNodes.add(focusNode);
     FocusScope.of(context).requestFocus(focusNode);
-
-    priceModel.notifyListeners();
   }
 
   Future<String?> _textInput(final BuildContext context) async {

packages/smooth_app/lib/pages/prices/price_scan_page.dart

@@ -1,19 +1,27 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:matomo_tracker/matomo_tracker.dart';
+import 'package:smooth_app/generic_lib/duration_constants.dart';
 import 'package:smooth_app/helpers/analytics_helper.dart';
 import 'package:smooth_app/helpers/camera_helper.dart';
 import 'package:smooth_app/helpers/global_vars.dart';
 import 'package:smooth_app/helpers/haptic_feedback_helper.dart';
 import 'package:smooth_app/pages/scan/camera_scan_page.dart';
 import 'package:smooth_app/widgets/smooth_app_bar.dart';
+import 'package:smooth_app/widgets/smooth_floating_message.dart';
 import 'package:smooth_app/widgets/smooth_scaffold.dart';
 
 /// Page showing the camera feed and decoding the first barcode, for Prices.
 class PriceScanPage extends StatefulWidget {
-  const PriceScanPage({required this.latestScannedBarcode});
+  const PriceScanPage({
+    required this.latestScannedBarcode,
+    required this.isMultiProducts,
+  });
 
   final String? latestScannedBarcode;
+  final bool isMultiProducts;
 
   @override
   State<PriceScanPage> createState() => _PriceScanPageState();
@@ -26,29 +34,67 @@ class _PriceScanPageState extends State<PriceScanPage>
   // `Failed assertion: line 5277 pos 12: '!_debugLocked': is not true.`
   bool _mutex = false;
 
+  final List<String> _barcodes = <String>[];
+  late String? _latestScannedBarcode;
+
   @override
   String get actionName =>
       'Opened ${GlobalVars.barcodeScanner.getType()}_page for price';
 
+  @override
+  void initState() {
+    super.initState();
+    _latestScannedBarcode = widget.latestScannedBarcode;
+  }
+
   @override
   Widget build(BuildContext context) {
     final AppLocalizations appLocalizations = AppLocalizations.of(context);
     return SmoothScaffold(
       appBar: SmoothAppBar(
         title: Text(appLocalizations.prices_add_an_item),
       ),
+      floatingActionButton: !widget.isMultiProducts
+          ? null
+          : _barcodes.isEmpty
+              ? null
+              : FloatingActionButton.extended(
+                  onPressed: () => _pop(context),
+                  label:
+                      Text(appLocalizations.user_list_length(_barcodes.length)),
+                  icon: const Icon(Icons.add),
+                ),
       body: GlobalVars.barcodeScanner.getScanner(
         onScan: (final String barcode) async {
           // for some reason, the scanner sometimes returns immediately the
           // previously scanned barcode.
-          if (widget.latestScannedBarcode == barcode) {
+          if (_latestScannedBarcode == barcode) {
             return false;
           }
-          if (_mutex) {
+          _latestScannedBarcode = barcode;
+          if (_barcodes.contains(barcode)) {
             return false;
           }
-          _mutex = true;
-          Navigator.of(context).pop(barcode);
+          if (!widget.isMultiProducts) {
+            if (_mutex) {
+              return false;
+            }
+            _mutex = true;
+          }
+          _barcodes.add(barcode);
+          if (!widget.isMultiProducts) {
+            _pop(context);
+            return true;
+          }
+          SmoothFloatingMessage(
+            message: appLocalizations.scan_announce_new_barcode(barcode),
+          ).show(
+            context,
+            duration: SnackBarDuration.medium,
+            alignment: const Alignment(0.0, -0.75),
+          );
+          unawaited(SmoothHapticFeedback.click());
+          setState(() {});
           return true;
         },
         hapticFeedback: () => SmoothHapticFeedback.click(),
@@ -61,4 +107,8 @@ class _PriceScanPageState extends State<PriceScanPage>
       ),
     );
   }
+
+  void _pop(final BuildContext context) {
+    Navigator.of(context).pop(_barcodes);
+  }
 }