Merge pull request 'Handle errors when scanning a barcode and show a snackbar in case' (#2) from error-handling into master

Reviewed-on: #2

lib/food_entry/enter_food_widget.dart

@@ -1,4 +1,4 @@
-import 'package:calorimeter/perdate/perdate_widget.dart';
+import 'package:calorimeter/utils/enter_food_controller.dart';
 import 'package:calorimeter/storage/storage.dart';
 import 'package:flutter/material.dart';
 import 'package:calorimeter/food_entry/food_entry_bloc.dart';

lib/food_scan/food_fact_lookup.dart

@@ -1,22 +1,44 @@
 import 'dart:convert';
+import 'dart:developer';
 import 'dart:io';
 
 class FoodFactLookupClient {
   FoodFactLookupClient();
 
-  static const String host = "world.openfoodfacts.org";
   static const String url = "https://world.openfoodfacts.org/api/v3/product/";
 
   String getProductUrl(String ean) {
     return "$url$ean.json";
   }
 
-  Future<FoodFactModel> retrieveFoodInfo(String ean) async {
+  Future<FoodFactResponse> retrieveFoodInfo(String ean) async {
     HttpClient client = HttpClient();
+    String asString = "";
+
+    try {
       var request = await client.getUrl(Uri.parse(getProductUrl(ean)));
+
       var response = await request.close();
-    var asString = await response.transform(utf8.decoder).join();
+
-    return FoodFactModel.fromJson(jsonDecode(asString));
+      if (response.statusCode != HttpStatus.ok) {
+        return FoodFactResponse(
+            food: null, status: FoodFactResponseStatus.barcodeNotFound);
+      }
+
+      asString = await response.transform(utf8.decoder).join();
+    } on SocketException {
+      return FoodFactResponse(
+          food: null,
+          status: FoodFactResponseStatus.foodFactServerNotReachable);
+    } catch (e) {
+      log(e.toString());
+    } finally {
+      client.close();
+    }
+
+    return FoodFactResponse(
+        food: FoodFactModel.fromJson(jsonDecode(asString)),
+        status: FoodFactResponseStatus.ok);
   }
 }
 
@@ -32,3 +54,16 @@ class FoodFactModel {
         kcalPer100g: json['product']['nutriments']['energy-kcal_100g']);
   }
 }
+
+enum FoodFactResponseStatus {
+  foodFactServerNotReachable,
+  barcodeNotFound,
+  ok,
+}
+
+class FoodFactResponse {
+  final FoodFactModel? food;
+  final FoodFactResponseStatus status;
+
+  FoodFactResponse({required this.food, required this.status});
+}

lib/perdate/perdate_widget.dart

@@ -1,5 +1,6 @@
-import 'dart:developer';
+import 'package:barcode_scan2/barcode_scan2.dart';
-
+import 'package:calorimeter/food_scan/food_fact_lookup.dart';
+import 'package:calorimeter/utils/enter_food_controller.dart';
 import 'package:calorimeter/utils/scan_food_floating_button.dart';
 import 'package:calorimeter/utils/app_drawer.dart';
 import 'package:calorimeter/food_entry/food_entry_bloc.dart';
@@ -29,7 +30,6 @@ class _PerDateWidgetState extends State<PerDateWidget> {
 
   @override
   void initState() {
-    log("PerDateWidgetState's initState()");
     storage = FoodStorage.getInstance();
     entriesFuture = storage.getEntriesForDate(widget.date);
     entriesFuture.then((val) {
@@ -40,20 +40,23 @@ class _PerDateWidgetState extends State<PerDateWidget> {
 
   @override
   Widget build(BuildContext context) {
-    log("PerDateWidgetState's build()");
     return FutureBuilder(
         future: entriesFuture,
         builder: (context, snapshot) {
-          if (snapshot.connectionState != ConnectionState.done) {
+          return snapshot.connectionState != ConnectionState.done
-            return const Center(child: CircularProgressIndicator());
+              ? const Center(child: CircularProgressIndicator())
-          } else {
+              : MultiProvider(
-            return ChangeNotifierProvider(
+                  providers: [
-              create: (context) => EnterFoodController(),
+                    ChangeNotifierProvider(
-              child: BlocProvider(
+                        create: (context) => EnterFoodController()),
+                    BlocProvider(
                       create: (context) => FoodEntryBloc(
                         initialState: FoodEntryState(foodEntries: entries),
                         storage: storage,
-                    forDate: widget.date),
+                        forDate: widget.date,
+                      ),
+                    )
+                  ],
                   child: BlocBuilder<FoodEntryBloc, FoodEntryState>(
                       builder: (context, state) {
                     return Scaffold(
@@ -69,7 +72,48 @@ class _PerDateWidgetState extends State<PerDateWidget> {
                             child: SumWidget(foodEntries: state.foodEntries)),
                         drawer: const AppDrawer(),
                         floatingActionButton: OverflowBar(children: [
-                        const ScanFoodFloatingButton(),
+                          ScanFoodFloatingButton(
+                            onPressed: () async {
+                              var client = FoodFactLookupClient();
+
+                              var scanResult = await BarcodeScanner.scan();
+
+                              if (scanResult.type == ResultType.Cancelled) {
+                                return;
+                              }
+
+                              if (!context.mounted) return;
+
+                              if (scanResult.type == ResultType.Error) {
+                                showNewSnackbarWith(context,
+                                    "Fehler beim Scannen des Barcodes.");
+                              }
+                              var response = await client
+                                  .retrieveFoodInfo(scanResult.rawContent);
+
+                              if (!context.mounted) return;
+
+                              if (response.status ==
+                                  FoodFactResponseStatus.barcodeNotFound) {
+                                showNewSnackbarWith(context,
+                                    "Barcode konnte nicht gefunden werden.");
+                                return;
+                              }
+
+                              if (response.status ==
+                                  FoodFactResponseStatus
+                                      .foodFactServerNotReachable) {
+                                showNewSnackbarWith(context,
+                                    "OpenFoodFacts-Server konnte nicht erreicht werden.");
+                                return;
+                              }
+
+                              context.read<EnterFoodController>().set(
+                                    response.food!.name,
+                                    response.food!.kcalPer100g.toString(),
+                                  );
+                            },
+                          ),
                           const SizedBox(width: 8),
                           CalendarFloatingButton(
                             startFromDate: widget.date,
@@ -87,20 +131,27 @@ class _PerDateWidgetState extends State<PerDateWidget> {
                         floatingActionButtonLocation:
                             FloatingActionButtonLocation.endDocked);
                   }),
-              ),
                 );
-          }
         });
   }
-}
 
-class EnterFoodController extends ChangeNotifier {
+  void showNewSnackbarWith(BuildContext context, String text) {
-  String name = "";
+    var snackbar =
-  String kcalPer100g = "";
+        ErrorSnackbar(colorScheme: Theme.of(context).colorScheme, text: text);
 
-  void set(String newName, String newKcal) {
+    ScaffoldMessenger.of(context).clearSnackBars();
-    name = newName;
+    ScaffoldMessenger.of(context).showSnackBar(snackbar);
-    kcalPer100g = newKcal;
-    notifyListeners();
   }
 }
+
+class ErrorSnackbar extends SnackBar {
+  final String text;
+  final ColorScheme colorScheme;
+  ErrorSnackbar({
+    required this.text,
+    required this.colorScheme,
+    super.key,
+  }) : super(
+            content: Text(text, style: TextStyle(color: colorScheme.onError)),
+            backgroundColor: colorScheme.error);
+}

lib/utils/enter_food_controller.dart

@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+
+class EnterFoodController extends ChangeNotifier {
+  String name = "";
+  String kcalPer100g = "";
+
+  void set(String newName, String newKcal) {
+    name = newName;
+    kcalPer100g = newKcal;
+    notifyListeners();
+  }
+}

lib/utils/scan_food_floating_button.dart

@@ -1,30 +1,16 @@
-import 'package:barcode_scan2/barcode_scan2.dart';
-import 'package:calorimeter/food_scan/food_fact_lookup.dart';
-import 'package:calorimeter/perdate/perdate_widget.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_bloc/flutter_bloc.dart';
 
 class ScanFoodFloatingButton extends StatelessWidget {
-  const ScanFoodFloatingButton({
+  final Function() onPressed;
-    super.key,
+  const ScanFoodFloatingButton({super.key, required this.onPressed});
-  });
 
   @override
   Widget build(BuildContext context) {
     return FloatingActionButton(
       heroTag: "scanFoodFAB",
       child: const Icon(Icons.barcode_reader),
-      onPressed: () async {
+      onPressed: () {
-        var client = FoodFactLookupClient();
+        onPressed();
-
-        var scanResult = await BarcodeScanner.scan();
-        var food = await client.retrieveFoodInfo(scanResult.rawContent);
-
-        if (!context.mounted) return;
-
-        context
-            .read<EnterFoodController>()
-            .set(food.name, food.kcalPer100g.toString());
       },
     );
   }

lib/utils/sum_widget.dart

@@ -2,37 +2,53 @@ import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:calorimeter/food_entry/food_entry_bloc.dart';
 import 'package:calorimeter/utils/settings_bloc.dart';
-import 'package:calorimeter/utils/row_with_spacers_widget.dart';
 
-class SumWidget extends StatefulWidget {
+class SumWidget extends StatelessWidget {
   final List<FoodEntry> foodEntries;
   const SumWidget({required this.foodEntries, super.key});
 
-  @override
-  State<SumWidget> createState() => _SumWidgetState();
-}
-
-class _SumWidgetState extends State<SumWidget> {
   @override
   Widget build(BuildContext context) {
     return BlocBuilder<SettingsDataBloc, SettingsState>(
       builder: (context, state) {
         var sum = 0.0;
-        for (var entry in widget.foodEntries) {
+        for (var entry in foodEntries) {
           sum += entry.kcalPerMass / 100 * entry.mass;
         }
+        var diff = state.kcalLimit - sum;
+        var diffLimit = state.kcalLimit ~/ 4;
 
-        return RowWidget(
+        var textColor = Theme.of(context).colorScheme.onSecondary;
-          Text(
+        var newTextColor = textColor;
+        var brightness = Theme.of(context).brightness;
+
+        switch (brightness) {
+          case Brightness.dark:
+            if (diff < 0) {
+              newTextColor = Colors.red[900]!;
+            } else if (diff < diffLimit) {
+              newTextColor = Colors.orange[900]!;
+            }
+            break;
+
+          case Brightness.light:
+            if (diff < 0) {
+              newTextColor = Colors.redAccent;
+            } else if (diff < diffLimit) {
+              newTextColor = Colors.orangeAccent;
+            }
+            break;
+        }
+
+        return Align(
+          alignment: Alignment.centerLeft,
+          child: Text(
             'kcal heute: ${sum.ceil().toString()}/${state.kcalLimit.ceil()}',
             style: Theme.of(context)
                 .textTheme
-                .bodyMedium!
+                .bodyLarge!
-                .copyWith(color: Theme.of(context).colorScheme.onPrimary),
+                .copyWith(color: newTextColor),
           ),
-          null,
-          null,
-          null,
         );
       },
     );