feat: add rows count (broken), fix: bug with low stock items

lib/app/app_bootstrap.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
+import 'package:flutter/services.dart';
 
 import '../database/app_database.dart';
 import '../services/default_product_seeder.dart';
@@ -31,6 +32,9 @@ class _AppBootstrapState extends State<AppBootstrap> {
       context.read<BarScreenViewModel>().ensureLoaded();
 
       DefaultExportService(database: database).uploadToServer();
+
+
+      SystemChrome.setEnabledSystemUIMode(SystemUiMode.immersiveSticky);
     });
   }
 

lib/database/app_database.dart

@@ -2,7 +2,6 @@ import 'package:drift/drift.dart';
 import 'package:drift_flutter/drift_flutter.dart';
 import 'package:path_provider/path_provider.dart';
 
-
 part 'app_database.g.dart';
 
 @DataClassName('ProductRow')
@@ -111,6 +110,8 @@ class AppSettingsTable extends Table {
 
   TextColumn get language => text().withDefault(const Constant('system'))();
 
+  IntColumn get barGridRows => integer().withDefault(const Constant(3))();
+
   @override
   Set<Column> get primaryKey => {id};
 }
@@ -131,7 +132,7 @@ class AppDatabase extends _$AppDatabase {
   AppDatabase([QueryExecutor? executor]) : super(executor ?? _openConnection());
 
   @override
-  int get schemaVersion => 7;
+  int get schemaVersion => 8;
 
   @override
   MigrationStrategy get migration {
@@ -140,6 +141,14 @@ class AppDatabase extends _$AppDatabase {
         await migrator.createAll();
       },
       onUpgrade: (migrator, from, to) async {
+        Future<bool> hasSettingsColumn(String columnName) async {
+          final columns = await migrator.database
+              .customSelect('PRAGMA table_info(app_settings)')
+              .get();
+
+          return columns.any((column) => column.data['name'] == columnName);
+        }
+
         if (from < 2) {
           await migrator.createTable(barTabs);
           await migrator.createTable(tabItems);
@@ -162,9 +171,16 @@ class AppDatabase extends _$AppDatabase {
           await migrator.addColumn(closedTabs, closedTabs.paymentMethod);
         }
 
-        if (from < 7) {
+        if (from < 7 && !await hasSettingsColumn('language')) {
           await migrator.addColumn(appSettingsTable, appSettingsTable.language);
         }
+
+        if (from < 8 && !await hasSettingsColumn('bar_grid_rows')) {
+          await migrator.addColumn(
+            appSettingsTable,
+            appSettingsTable.barGridRows,
+          );
+        }
       },
     );
   }

lib/database/app_database.g.dart

@@ -2231,8 +2231,26 @@ class $AppSettingsTableTable extends AppSettingsTable
     requiredDuringInsert: false,
     defaultValue: const Constant('system'),
   );
+  static const VerificationMeta _barGridRowsMeta = const VerificationMeta(
+    'barGridRows',
+  );
   @override
-  List<GeneratedColumn> get $columns => [id, pinRequired, themeMode, language];
+  late final GeneratedColumn<int> barGridRows = GeneratedColumn<int>(
+    'bar_grid_rows',
+    aliasedName,
+    false,
+    type: DriftSqlType.int,
+    requiredDuringInsert: false,
+    defaultValue: const Constant(3),
+  );
+  @override
+  List<GeneratedColumn> get $columns => [
+    id,
+    pinRequired,
+    themeMode,
+    language,
+    barGridRows,
+  ];
   @override
   String get aliasedName => _alias ?? actualTableName;
   @override
@@ -2271,6 +2289,15 @@ class $AppSettingsTableTable extends AppSettingsTable
         language.isAcceptableOrUnknown(data['language']!, _languageMeta),
       );
     }
+    if (data.containsKey('bar_grid_rows')) {
+      context.handle(
+        _barGridRowsMeta,
+        barGridRows.isAcceptableOrUnknown(
+          data['bar_grid_rows']!,
+          _barGridRowsMeta,
+        ),
+      );
+    }
     return context;
   }
 
@@ -2296,6 +2323,10 @@ class $AppSettingsTableTable extends AppSettingsTable
         DriftSqlType.string,
         data['${effectivePrefix}language'],
       )!,
+      barGridRows: attachedDatabase.typeMapping.read(
+        DriftSqlType.int,
+        data['${effectivePrefix}bar_grid_rows'],
+      )!,
     );
   }
 
@@ -2310,11 +2341,13 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
   final bool pinRequired;
   final String themeMode;
   final String language;
+  final int barGridRows;
   const AppSettingsRow({
     required this.id,
     required this.pinRequired,
     required this.themeMode,
     required this.language,
+    required this.barGridRows,
   });
   @override
   Map<String, Expression> toColumns(bool nullToAbsent) {
@@ -2323,6 +2356,7 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
     map['pin_required'] = Variable<bool>(pinRequired);
     map['theme_mode'] = Variable<String>(themeMode);
     map['language'] = Variable<String>(language);
+    map['bar_grid_rows'] = Variable<int>(barGridRows);
     return map;
   }
 
@@ -2332,6 +2366,7 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
       pinRequired: Value(pinRequired),
       themeMode: Value(themeMode),
       language: Value(language),
+      barGridRows: Value(barGridRows),
     );
   }
 
@@ -2345,6 +2380,7 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
       pinRequired: serializer.fromJson<bool>(json['pinRequired']),
       themeMode: serializer.fromJson<String>(json['themeMode']),
       language: serializer.fromJson<String>(json['language']),
+      barGridRows: serializer.fromJson<int>(json['barGridRows']),
     );
   }
   @override
@@ -2355,6 +2391,7 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
       'pinRequired': serializer.toJson<bool>(pinRequired),
       'themeMode': serializer.toJson<String>(themeMode),
       'language': serializer.toJson<String>(language),
+      'barGridRows': serializer.toJson<int>(barGridRows),
     };
   }
 
@@ -2363,11 +2400,13 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
     bool? pinRequired,
     String? themeMode,
     String? language,
+    int? barGridRows,
   }) => AppSettingsRow(
     id: id ?? this.id,
     pinRequired: pinRequired ?? this.pinRequired,
     themeMode: themeMode ?? this.themeMode,
     language: language ?? this.language,
+    barGridRows: barGridRows ?? this.barGridRows,
   );
   AppSettingsRow copyWithCompanion(AppSettingsTableCompanion data) {
     return AppSettingsRow(
@@ -2377,6 +2416,9 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
           : this.pinRequired,
       themeMode: data.themeMode.present ? data.themeMode.value : this.themeMode,
       language: data.language.present ? data.language.value : this.language,
+      barGridRows: data.barGridRows.present
+          ? data.barGridRows.value
+          : this.barGridRows,
     );
   }
 
@@ -2386,13 +2428,15 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
           ..write('id: $id, ')
           ..write('pinRequired: $pinRequired, ')
           ..write('themeMode: $themeMode, ')
-          ..write('language: $language')
+          ..write('language: $language, ')
+          ..write('barGridRows: $barGridRows')
           ..write(')'))
         .toString();
   }
 
   @override
-  int get hashCode => Object.hash(id, pinRequired, themeMode, language);
+  int get hashCode =>
+      Object.hash(id, pinRequired, themeMode, language, barGridRows);
   @override
   bool operator ==(Object other) =>
       identical(this, other) ||
@@ -2400,7 +2444,8 @@ class AppSettingsRow extends DataClass implements Insertable<AppSettingsRow> {
           other.id == this.id &&
           other.pinRequired == this.pinRequired &&
           other.themeMode == this.themeMode &&
-          other.language == this.language);
+          other.language == this.language &&
+          other.barGridRows == this.barGridRows);
 }
 
 class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
@@ -2408,12 +2453,14 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
   final Value<bool> pinRequired;
   final Value<String> themeMode;
   final Value<String> language;
+  final Value<int> barGridRows;
   final Value<int> rowid;
   const AppSettingsTableCompanion({
     this.id = const Value.absent(),
     this.pinRequired = const Value.absent(),
     this.themeMode = const Value.absent(),
     this.language = const Value.absent(),
+    this.barGridRows = const Value.absent(),
     this.rowid = const Value.absent(),
   });
   AppSettingsTableCompanion.insert({
@@ -2421,6 +2468,7 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
     this.pinRequired = const Value.absent(),
     this.themeMode = const Value.absent(),
     this.language = const Value.absent(),
+    this.barGridRows = const Value.absent(),
     this.rowid = const Value.absent(),
   }) : id = Value(id);
   static Insertable<AppSettingsRow> custom({
@@ -2428,6 +2476,7 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
     Expression<bool>? pinRequired,
     Expression<String>? themeMode,
     Expression<String>? language,
+    Expression<int>? barGridRows,
     Expression<int>? rowid,
   }) {
     return RawValuesInsertable({
@@ -2435,6 +2484,7 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
       if (pinRequired != null) 'pin_required': pinRequired,
       if (themeMode != null) 'theme_mode': themeMode,
       if (language != null) 'language': language,
+      if (barGridRows != null) 'bar_grid_rows': barGridRows,
       if (rowid != null) 'rowid': rowid,
     });
   }
@@ -2444,6 +2494,7 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
     Value<bool>? pinRequired,
     Value<String>? themeMode,
     Value<String>? language,
+    Value<int>? barGridRows,
     Value<int>? rowid,
   }) {
     return AppSettingsTableCompanion(
@@ -2451,6 +2502,7 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
       pinRequired: pinRequired ?? this.pinRequired,
       themeMode: themeMode ?? this.themeMode,
       language: language ?? this.language,
+      barGridRows: barGridRows ?? this.barGridRows,
       rowid: rowid ?? this.rowid,
     );
   }
@@ -2470,6 +2522,9 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
     if (language.present) {
       map['language'] = Variable<String>(language.value);
     }
+    if (barGridRows.present) {
+      map['bar_grid_rows'] = Variable<int>(barGridRows.value);
+    }
     if (rowid.present) {
       map['rowid'] = Variable<int>(rowid.value);
     }
@@ -2483,6 +2538,7 @@ class AppSettingsTableCompanion extends UpdateCompanion<AppSettingsRow> {
           ..write('pinRequired: $pinRequired, ')
           ..write('themeMode: $themeMode, ')
           ..write('language: $language, ')
+          ..write('barGridRows: $barGridRows, ')
           ..write('rowid: $rowid')
           ..write(')'))
         .toString();
@@ -4071,6 +4127,7 @@ typedef $$AppSettingsTableTableCreateCompanionBuilder =
       Value<bool> pinRequired,
       Value<String> themeMode,
       Value<String> language,
+      Value<int> barGridRows,
       Value<int> rowid,
     });
 typedef $$AppSettingsTableTableUpdateCompanionBuilder =
@@ -4079,6 +4136,7 @@ typedef $$AppSettingsTableTableUpdateCompanionBuilder =
       Value<bool> pinRequired,
       Value<String> themeMode,
       Value<String> language,
+      Value<int> barGridRows,
       Value<int> rowid,
     });
 
@@ -4110,6 +4168,11 @@ class $$AppSettingsTableTableFilterComposer
     column: $table.language,
     builder: (column) => ColumnFilters(column),
   );
+
+  ColumnFilters<int> get barGridRows => $composableBuilder(
+    column: $table.barGridRows,
+    builder: (column) => ColumnFilters(column),
+  );
 }
 
 class $$AppSettingsTableTableOrderingComposer
@@ -4140,6 +4203,11 @@ class $$AppSettingsTableTableOrderingComposer
     column: $table.language,
     builder: (column) => ColumnOrderings(column),
   );
+
+  ColumnOrderings<int> get barGridRows => $composableBuilder(
+    column: $table.barGridRows,
+    builder: (column) => ColumnOrderings(column),
+  );
 }
 
 class $$AppSettingsTableTableAnnotationComposer
@@ -4164,6 +4232,11 @@ class $$AppSettingsTableTableAnnotationComposer
 
   GeneratedColumn<String> get language =>
       $composableBuilder(column: $table.language, builder: (column) => column);
+
+  GeneratedColumn<int> get barGridRows => $composableBuilder(
+    column: $table.barGridRows,
+    builder: (column) => column,
+  );
 }
 
 class $$AppSettingsTableTableTableManager
@@ -4207,12 +4280,14 @@ class $$AppSettingsTableTableTableManager
                 Value<bool> pinRequired = const Value.absent(),
                 Value<String> themeMode = const Value.absent(),
                 Value<String> language = const Value.absent(),
+                Value<int> barGridRows = const Value.absent(),
                 Value<int> rowid = const Value.absent(),
               }) => AppSettingsTableCompanion(
                 id: id,
                 pinRequired: pinRequired,
                 themeMode: themeMode,
                 language: language,
+                barGridRows: barGridRows,
                 rowid: rowid,
               ),
           createCompanionCallback:
@@ -4221,12 +4296,14 @@ class $$AppSettingsTableTableTableManager
                 Value<bool> pinRequired = const Value.absent(),
                 Value<String> themeMode = const Value.absent(),
                 Value<String> language = const Value.absent(),
+                Value<int> barGridRows = const Value.absent(),
                 Value<int> rowid = const Value.absent(),
               }) => AppSettingsTableCompanion.insert(
                 id: id,
                 pinRequired: pinRequired,
                 themeMode: themeMode,
                 language: language,
+                barGridRows: barGridRows,
                 rowid: rowid,
               ),
           withReferenceMapper: (p0) => p0

lib/l10n/app_en.arb

@@ -31,6 +31,9 @@
   "languageSystem": "System default",
   "languageEnglish": "English",
   "languageDutch": "Dutch",
+  "productGridRows": "Product grid rows",
+  "rowsCount": "{count} rows",
+  "@rowsCount": {"placeholders": {"count": {"type": "int"}}},
   "theme": "Theme",
   "system": "System",
   "light": "Light",

lib/l10n/app_localizations.dart

@@ -278,6 +278,18 @@ abstract class AppLocalizations {
   /// **'Dutch'**
   String get languageDutch;
 
+  /// No description provided for @productGridRows.
+  ///
+  /// In en, this message translates to:
+  /// **'Product grid rows'**
+  String get productGridRows;
+
+  /// No description provided for @rowsCount.
+  ///
+  /// In en, this message translates to:
+  /// **'{count} rows'**
+  String rowsCount(int count);
+
   /// No description provided for @theme.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_en.dart

@@ -100,6 +100,14 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get languageDutch => 'Dutch';
 
+  @override
+  String get productGridRows => 'Product grid rows';
+
+  @override
+  String rowsCount(int count) {
+    return '$count rows';
+  }
+
   @override
   String get theme => 'Theme';
 

lib/l10n/app_localizations_nl.dart

@@ -100,6 +100,14 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get languageDutch => 'Nederlands';
 
+  @override
+  String get productGridRows => 'Rijen in productraster';
+
+  @override
+  String rowsCount(int count) {
+    return '$count rijen';
+  }
+
   @override
   String get theme => 'Thema';
 

lib/l10n/app_nl.arb

@@ -31,6 +31,9 @@
   "languageSystem": "Systeemstandaard",
   "languageEnglish": "Engels",
   "languageDutch": "Nederlands",
+  "productGridRows": "Rijen in productraster",
+  "rowsCount": "{count} rijen",
+  "@rowsCount": {"placeholders": {"count": {"type": "int"}}},
   "theme": "Thema",
   "system": "Systeem",
   "light": "Licht",

lib/models/settings.dart

@@ -1,26 +1,31 @@
 enum AppThemeMode { system, light, dark, ugly }
+
 enum AppLanguage { system, english, dutch }
 
 class AppSettings {
   final bool pinRequired;
   final AppThemeMode themeMode;
   final AppLanguage language;
+  final int barGridRows;
 
   const AppSettings({
     required this.pinRequired,
     required this.themeMode,
     this.language = AppLanguage.system,
+    this.barGridRows = 3,
   });
 
   AppSettings copyWith({
     bool? pinRequired,
     AppThemeMode? themeMode,
     AppLanguage? language,
+    int? barGridRows,
   }) {
     return AppSettings(
       pinRequired: pinRequired ?? this.pinRequired,
       themeMode: themeMode ?? this.themeMode,
       language: language ?? this.language,
+      barGridRows: barGridRows ?? this.barGridRows,
     );
   }
 
@@ -35,8 +40,10 @@ class AppSettings {
       other is AppSettings &&
           pinRequired == other.pinRequired &&
           themeMode == other.themeMode &&
-          language == other.language;
+          language == other.language &&
+          barGridRows == other.barGridRows;
 
   @override
-  int get hashCode => Object.hash(pinRequired, themeMode, language);
+  int get hashCode =>
+      Object.hash(pinRequired, themeMode, language, barGridRows);
 }

lib/services/product_service.dart

@@ -4,6 +4,13 @@ import 'package:uuid/uuid.dart';
 import '../database/app_database.dart';
 import '../models/product.dart';
 
+class InsufficientStockException implements Exception {
+  const InsufficientStockException();
+
+  @override
+  String toString() => 'Not enough stock';
+}
+
 abstract class ProductService {
   Future<List<Product>> getProducts();
 
@@ -130,7 +137,7 @@ class DriftProductService implements ProductService {
     }
 
     if (product.stockQuantity < amount) {
-      throw Exception('Not enough stock');
+      throw const InsufficientStockException();
     }
 
     await updateProduct(

lib/services/settings_service.dart

@@ -26,6 +26,7 @@ class DriftSettingsService implements SettingsService {
         (language) => language.name == row.language,
         orElse: () => AppLanguage.system,
       ),
+      barGridRows: row.barGridRows.clamp(2, 6).toInt(),
     );
   }
 
@@ -51,6 +52,7 @@ class DriftSettingsService implements SettingsService {
             pinRequired: Value(settings.pinRequired),
             themeMode: Value(settings.themeMode.name),
             language: Value(settings.language.name),
+            barGridRows: Value(settings.barGridRows),
           ),
         );
   }

lib/viewmodels/bar_screen_view_model.dart

@@ -6,6 +6,7 @@ import '../models/bar_tab.dart';
 import '../models/product.dart';
 import '../models/tab_item.dart';
 import '../services/bar_tab_service.dart';
+import '../services/product_service.dart';
 import 'inventory_view_model.dart';
 
 class BarScreenViewModel extends ChangeNotifier {
@@ -95,9 +96,7 @@ class BarScreenViewModel extends ChangeNotifier {
     if (tab == null) return;
 
     if (product.stockQuantity <= 0) {
-      _errorMessage = 'Product is out of stock.';
+      throw const InsufficientStockException();
-      notifyListeners();
-      return;
     }
 
     try {
@@ -109,6 +108,8 @@ class BarScreenViewModel extends ChangeNotifier {
 
       await _reloadTabs();
     } catch (e, stack) {
+      if (e is InsufficientStockException) rethrow;
+
       debugPrint('BarScreenViewModel: addProductToSelectedTab error: $e');
       _errorMessage = 'Could not add product to tab.';
       notifyListeners();
@@ -120,6 +121,20 @@ class BarScreenViewModel extends ChangeNotifier {
   Future<void> changeItemQuantity(TabItem item, int quantity) async {
     final difference = quantity - item.quantity;
 
+    if (difference > 0) {
+      Product? product;
+      for (final candidate in inventory.products) {
+        if (candidate.id == item.productId) {
+          product = candidate;
+          break;
+        }
+      }
+
+      if (product != null && product.stockQuantity < difference) {
+        throw const InsufficientStockException();
+      }
+    }
+
     try {
       await barTabService.updateTabItemQuantity(
         tabItemId: item.id,
@@ -135,6 +150,8 @@ class BarScreenViewModel extends ChangeNotifier {
 
       await _reloadTabs();
     } catch (e, stack) {
+      if (e is InsufficientStockException) rethrow;
+
       debugPrint('BarScreenViewModel: changeItemQuantity error: $e');
       _errorMessage = 'Could not update item quantity.';
       notifyListeners();

lib/viewmodels/inventory_view_model.dart

@@ -38,6 +38,8 @@ class InventoryViewModel extends ChangeNotifier {
 
       notifyListeners();
     } catch (e, stack) {
+      if (e is InsufficientStockException) rethrow;
+
       debugPrint('InventoryViewModel: decreaseStock error: $e');
       Sentry.captureException(e, stackTrace: stack);
       rethrow;

lib/viewmodels/settings_view_model.dart

@@ -114,6 +114,9 @@ class SettingsViewModel extends ChangeNotifier {
   Future<void> updateLanguage(AppLanguage language) =>
       _save(_settings.copyWith(language: language));
 
+  Future<void> updateBarGridRows(int rows) =>
+      _save(_settings.copyWith(barGridRows: rows.clamp(2, 6).toInt()));
+
   Future<void> _save(AppSettings updated) async {
     final previous = _settings;
     _settings = updated;

lib/views/bar_screen_view.dart

@@ -12,8 +12,10 @@ import 'package:flutter_slidable/flutter_slidable.dart';
 import '../models/bar_tab.dart';
 import '../models/product.dart';
 import '../models/tab_item.dart';
+import '../services/product_service.dart';
 import '../utils/app_updater.dart';
 import '../viewmodels/bar_screen_view_model.dart';
+import '../viewmodels/settings_view_model.dart';
 import '../l10n/app_localizations.dart';
 import '../l10n/app_localizations_helpers.dart';
 
@@ -38,6 +40,11 @@ class _BarScreenViewState extends State<BarScreenView> {
     final l10n = AppLocalizations.of(context);
     final viewModel = context.watch<BarScreenViewModel>();
     final productsViewModel = context.watch<ProductListViewModel>();
+    final settings = context.watch<SettingsViewModel>().settings;
+    final stockByProductId = {
+      for (final product in productsViewModel.products)
+        product.id: product.stockQuantity,
+    };
 
     return Scaffold(
       appBar: AppBar(
@@ -118,6 +125,7 @@ class _BarScreenViewState extends State<BarScreenView> {
                 flex: 2,
                 child: _ProductGrid(
                   products: productsViewModel.products,
+                  rows: settings.barGridRows,
                   hasSelectedTab: viewModel.selectedTab != null,
                   onProductTap: (product) async {
                     if (viewModel.selectedTab == null) {
@@ -130,10 +138,18 @@ class _BarScreenViewState extends State<BarScreenView> {
                     try {
                       await viewModel.addProductToSelectedTab(product);
                     } catch (e, stack) {
-                      Sentry.captureException(e, stackTrace: stack);
+                      if (e is! InsufficientStockException) {
+                        Sentry.captureException(e, stackTrace: stack);
+                      }
                       if (!context.mounted) return;
                       ScaffoldMessenger.of(context).showSnackBar(
-                        SnackBar(content: Text(l10n.couldNotAddProductToTab)),
+                        SnackBar(
+                          content: Text(
+                            e is InsufficientStockException
+                                ? l10n.productOutOfStock
+                                : l10n.couldNotAddProductToTab,
+                          ),
+                        ),
                       );
                     }
                   },
@@ -146,6 +162,7 @@ class _BarScreenViewState extends State<BarScreenView> {
                   tabs: viewModel.tabs,
                   selectedTab: viewModel.selectedTab,
                   selectedTabId: viewModel.selectedTabId,
+                  stockByProductId: stockByProductId,
                   onNewTabPressed: () => showNewTabDialog(context),
                   onTabSelected: viewModel.selectTab,
                   onItemQuantityChanged: viewModel.changeItemQuantity,
@@ -166,11 +183,13 @@ class _BarScreenViewState extends State<BarScreenView> {
 // ---------------------------------------------------------------------------
 class _ProductGrid extends StatelessWidget {
   final List<Product> products;
+  final int rows;
   final bool hasSelectedTab;
   final ValueChanged<Product> onProductTap;
 
   const _ProductGrid({
     required this.products,
+    required this.rows,
     required this.hasSelectedTab,
     required this.onProductTap,
   });
@@ -267,11 +286,26 @@ class _ProductGrid extends StatelessWidget {
         Expanded(
           child: LayoutBuilder(
             builder: (context, constraints) {
-              final columns = ((constraints.maxWidth / 170).floor())
+              const horizontalPadding = 32.0;
-                  .clamp(3, 5)
+              const verticalPadding = 28.0;
-                  .toInt();
+              const spacing = 12.0;
+              final rowCount = rows.clamp(2, 6).toInt();
+              final rowHeight =
+                  ((constraints.maxHeight -
+                              verticalPadding -
+                              (rowCount - 1) * spacing) /
+                          rowCount)
+                      .clamp(96.0, 320.0)
+                      .toDouble();
+              final columns =
+                  (((constraints.maxWidth - horizontalPadding + spacing) /
+                              (rowHeight + spacing))
+                          .ceil())
+                      .clamp(2, 8)
+                      .toInt();
 
               return GridView.builder(
+                key: ValueKey('product-grid-$rows'),
                 padding: const EdgeInsets.fromLTRB(16, 12, 16, 16),
                 itemCount: products.length,
                 gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
@@ -306,6 +340,7 @@ class _TabPanel extends StatefulWidget {
   final List<BarTab> tabs;
   final BarTab? selectedTab;
   final String? selectedTabId;
+  final Map<String, int> stockByProductId;
   final VoidCallback onNewTabPressed;
   final ValueChanged<String> onTabSelected;
   final Future<void> Function(TabItem item, int quantity) onItemQuantityChanged;
@@ -316,6 +351,7 @@ class _TabPanel extends StatefulWidget {
     required this.tabs,
     required this.selectedTab,
     required this.selectedTabId,
+    required this.stockByProductId,
     required this.onNewTabPressed,
     required this.onTabSelected,
     required this.onItemQuantityChanged,
@@ -452,6 +488,7 @@ class _TabPanelState extends State<_TabPanel> {
                     )
                   : _SelectedTabDetails(
                       tab: widget.selectedTab!,
+                      stockByProductId: widget.stockByProductId,
                       onItemQuantityChanged: widget.onItemQuantityChanged,
                       onCloseTabPressed: widget.onCloseTabPressed,
                     ),
@@ -596,11 +633,13 @@ class _OpenTabsList extends StatelessWidget {
 
 class _SelectedTabDetails extends StatelessWidget {
   final BarTab tab;
+  final Map<String, int> stockByProductId;
   final Future<void> Function(TabItem item, int quantity) onItemQuantityChanged;
   final VoidCallback onCloseTabPressed;
 
   const _SelectedTabDetails({
     required this.tab,
+    required this.stockByProductId,
     required this.onItemQuantityChanged,
     required this.onCloseTabPressed,
   });
@@ -654,6 +693,7 @@ class _SelectedTabDetails extends StatelessWidget {
 
                     return _TabItemRow(
                       item: item,
+                      stockByProductId: stockByProductId,
                       onQuantityChanged: onItemQuantityChanged,
                     );
                   },
@@ -706,14 +746,21 @@ class _SelectedTabDetails extends StatelessWidget {
 
 class _TabItemRow extends StatelessWidget {
   final TabItem item;
+  final Map<String, int> stockByProductId;
   final Future<void> Function(TabItem item, int quantity) onQuantityChanged;
 
-  const _TabItemRow({required this.item, required this.onQuantityChanged});
+  const _TabItemRow({
+    required this.item,
+    required this.stockByProductId,
+    required this.onQuantityChanged,
+  });
 
   @override
   Widget build(BuildContext context) {
     final scheme = Theme.of(context).colorScheme;
     final l10n = AppLocalizations.of(context);
+    final availableStock = stockByProductId[item.productId];
+    final canIncrease = availableStock == null || availableStock > 0;
 
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: 10),
@@ -771,18 +818,28 @@ class _TabItemRow extends StatelessWidget {
                 ),
                 IconButton(
                   visualDensity: VisualDensity.compact,
-                  onPressed: () async {
+                  onPressed: canIncrease
-                    try {
+                      ? () async {
-                      await onQuantityChanged(item, item.quantity + 1);
+                          try {
-                    } catch (e, stack) {
+                            await onQuantityChanged(item, item.quantity + 1);
-                      Sentry.captureException(e, stackTrace: stack);
+                          } catch (e, stack) {
-                      if (context.mounted) {
+                            if (e is! InsufficientStockException) {
-                        ScaffoldMessenger.of(context).showSnackBar(
+                              Sentry.captureException(e, stackTrace: stack);
-                          SnackBar(content: Text(l10n.couldNotUpdateQuantity)),
+                            }
-                        );
+                            if (context.mounted) {
-                      }
+                              ScaffoldMessenger.of(context).showSnackBar(
-                    }
+                                SnackBar(
-                  },
+                                  content: Text(
+                                    e is InsufficientStockException
+                                        ? l10n.productOutOfStock
+                                        : l10n.couldNotUpdateQuantity,
+                                  ),
+                                ),
+                              );
+                            }
+                          }
+                        }
+                      : null,
                   icon: const Icon(Icons.add_rounded, size: 18),
                 ),
               ],

lib/views/settings_view.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:io';
 
 import 'package:flutter/material.dart';
@@ -22,7 +23,7 @@ class SettingsScreenView extends StatefulWidget {
 
 class _SettingsScreenViewState extends State<SettingsScreenView> {
   String _appVersion = '';
-  int _versionTaps = 0;
+  Timer? _versionHoldTimer;
 
   @override
   void initState() {
@@ -41,13 +42,23 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
     return info.version;
   }
 
-  void _onVersionTap() {
+  void _startVersionHold() {
-    _versionTaps++;
+    _versionHoldTimer?.cancel();
+    _versionHoldTimer = Timer(const Duration(seconds: 3), () {
+      _versionHoldTimer = null;
+      if (mounted) context.push('/dev');
+    });
+  }
 
-    if (_versionTaps >= 7) {
+  void _cancelVersionHold() {
-      _versionTaps = 0;
+    _versionHoldTimer?.cancel();
-      context.push('/dev');
+    _versionHoldTimer = null;
-    }
+  }
+
+  @override
+  void dispose() {
+    _cancelVersionHold();
+    super.dispose();
   }
 
   Future<void> _loadVersion() async {
@@ -277,6 +288,35 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
                       }
                     },
                   ),
+                  _SettingsTile(
+                    icon: Icons.grid_view_rounded,
+                    title: l10n.productGridRows,
+                    subtitle: l10n.rowsCount(settings.barGridRows),
+                    onTap: () async {
+                      final selected = await showModalBottomSheet<int>(
+                        context: context,
+                        builder: (context) => SafeArea(
+                          child: Column(
+                            mainAxisSize: MainAxisSize.min,
+                            children: [
+                              for (final rows in [2, 3, 4, 5, 6])
+                                RadioListTile<int>(
+                                  value: rows,
+                                  groupValue: settings.barGridRows,
+                                  title: Text(l10n.rowsCount(rows)),
+                                  onChanged: (value) =>
+                                      Navigator.pop(context, value),
+                                ),
+                            ],
+                          ),
+                        ),
+                      );
+
+                      if (selected != null) {
+                        await settingsViewModel.updateBarGridRows(selected);
+                      }
+                    },
+                  ),
                   _SettingsTile(
                     icon: Icons.brightness_6_rounded,
                     title: l10n.theme,
@@ -334,7 +374,9 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
                 ),
               const SizedBox(height: 40),
               GestureDetector(
-                onTap: _onVersionTap,
+                onTapDown: (_) => _startVersionHold(),
+                onTapUp: (_) => _cancelVersionHold(),
+                onTapCancel: _cancelVersionHold,
                 child: Center(
                   child: Text(
                     l10n.version(_appVersion),

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.7+1
+version: 1.0.9+1
 
 environment:
   sdk: ^3.12.2

test/bar_screen_view_model_test.dart

@@ -0,0 +1,64 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:kooltab2/models/product.dart';
+import 'package:kooltab2/models/tab_item.dart';
+import 'package:kooltab2/services/bar_tab_service.dart';
+import 'package:kooltab2/services/product_service.dart';
+import 'package:kooltab2/viewmodels/bar_screen_view_model.dart';
+import 'package:kooltab2/viewmodels/inventory_view_model.dart';
+import 'package:mocktail/mocktail.dart';
+
+class MockBarTabService extends Mock implements BarTabService {}
+
+class MockProductService extends Mock implements ProductService {}
+
+void main() {
+  late MockBarTabService barTabService;
+  late MockProductService productService;
+  late InventoryViewModel inventory;
+  late BarScreenViewModel viewModel;
+
+  setUp(() {
+    barTabService = MockBarTabService();
+    productService = MockProductService();
+    inventory = InventoryViewModel(productService: productService);
+    viewModel = BarScreenViewModel(
+      barTabService: barTabService,
+      inventory: inventory,
+    );
+  });
+
+  test(
+    'does not increase a tab item when its product is out of stock',
+    () async {
+      const product = Product(
+        id: 'prod-1',
+        name: 'Chips',
+        category: 'Snacks',
+        stockQuantity: 0,
+        lowStockThreshold: 5,
+        priceInCents: 150,
+      );
+      const item = TabItem(
+        id: 'item-1',
+        tabId: 'tab-1',
+        productId: 'prod-1',
+        productName: 'Chips',
+        quantity: 20,
+        unitPriceInCents: 150,
+      );
+
+      when(
+        () => productService.getProducts(),
+      ).thenAnswer((_) async => [product]);
+      await inventory.load();
+
+      await expectLater(
+        viewModel.changeItemQuantity(item, 21),
+        throwsA(isA<InsufficientStockException>()),
+      );
+
+      expect(viewModel.errorMessage, isNull);
+      verifyNoMoreInteractions(barTabService);
+    },
+  );
+}

test/product_service_test.dart

@@ -218,7 +218,7 @@ void main() {
 
         expect(
           () => service.decreaseStock('low-stock', 5),
-          throwsA(isA<Exception>()),
+          throwsA(isA<InsufficientStockException>()),
         );
       });
     });