lib/main.dart

@@ -1,6 +1,8 @@
 import 'package:calorimeter/food_entry/food_entry_bloc.dart';
 import 'package:calorimeter/perdate/perdate_pageview.dart';
+import 'package:calorimeter/perdate/perdate_pageview_controller.dart';
 import 'package:calorimeter/storage/storage.dart';
+import 'package:calorimeter/utils/date_time_helper.dart';
 import 'package:calorimeter/utils/settings_bloc.dart';
 import 'package:calorimeter/utils/theme_bloc.dart';
 import 'package:flutter/material.dart';
@@ -87,14 +89,8 @@ class MainApp extends StatelessWidget {
                   GoRoute(
                     path: '/',
                     builder: (context, state) {
-                      return PerDatePageview(
-                        initalDate: DateTime.now().copyWith(
-                          hour: 0,
-                          minute: 0,
-                          second: 0,
-                          millisecond: 0,
-                          microsecond: 0,
-                        ),
+                      return PerDatePageViewController(
+                        initialDate: DateTimeHelper.now(),
                       );
                     },
                   ),

lib/perdate/perdate_pageview.dart

@@ -1,76 +1,46 @@
+import 'dart:developer';
+
+import 'package:calorimeter/perdate/perdate_pageview_controller.dart';
 import 'package:calorimeter/perdate/perdate_widget.dart';
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
 
-class PerDatePageview extends StatefulWidget {
+class PerDatePageView extends StatelessWidget {
   // this is the date for which the PerDate widget will be shown on screen
   // left of it will be yesterday's PerDate widget
   // right of it will be tomorrow's PerDate widget
-  final DateTime initalDate;
-  const PerDatePageview({required this.initalDate, super.key});
+  final DateTime initialDate;
+  final PageController pageController;
 
-  @override
-  State<PerDatePageview> createState() => _PerDatePageviewState();
-}
-
-class _PerDatePageviewState extends State<PerDatePageview> {
-  late PageController pageController;
-  late DateTime displayedDate;
-  late List<int> visitedIndexes = [];
-  final int initialOffset = 36500000;
-
-  //TODO: that is just ugly
-  bool backButtonWasPressed = false;
-
-  @override
-  void initState() {
-    super.initState();
-    pageController = PageController(initialPage: initialOffset);
-    displayedDate = widget.initalDate;
-    visitedIndexes.add(initialOffset);
-  }
+  const PerDatePageView({
+    required this.initialDate,
+    required this.pageController,
+    super.key,
+  });
 
   @override
   Widget build(BuildContext context) {
-    return BackButtonListener(
-      onBackButtonPressed: () async {
-        if (visitedIndexes.length == 1) {
-          return false;
-        }
-
-        visitedIndexes.removeLast();
-
-        backButtonWasPressed = true;
-        pageController.jumpToPage(visitedIndexes.last);
-
-        return true;
-      },
-      child: PageView.builder(
+    log("PerDatePageView's build()");
+    return PageView.builder(
         reverse: true,
         controller: pageController,
         onPageChanged: (value) {
-            if (backButtonWasPressed) {
-              backButtonWasPressed = false;
-              return;
-            }
+          log("onPageChanged() with value $value");
 
-            visitedIndexes.add(value);
+          var diff = value - pageController.initialPage;
+          var newDate = initialDate.subtract(Duration(days: diff));
+          log("newDate = $newDate");
+          context.read<PageViewStateProvider>().setDisplayedDate(newDate);
         },
         itemBuilder: (context, index) {
-            var dateToBuildWidgetFor =
-                displayedDate.subtract(Duration(days: index - initialOffset));
+          log("itemBuilder() called with index $index");
+          var dateToBuildWidgetFor = initialDate
+              .subtract(Duration(days: index - pageController.initialPage));
 
           return PerDateWidget(
             key: ValueKey(dateToBuildWidgetFor.toString()),
-                date: dateToBuildWidgetFor.copyWith(isUtc: true),
-                onDateSelected: (dateSelected) {
-                  if (dateSelected == null) return;
-
-                  var diff = dateSelected.difference(dateToBuildWidgetFor);
-                  var newIndex = index - diff.inDays;
-
-                  pageController.jumpToPage(newIndex);
-                });
-          }),
+            date: dateToBuildWidgetFor,
           );
+        });
   }
 }

lib/perdate/perdate_pageview_controller.dart

@@ -0,0 +1,126 @@
+import 'dart:developer';
+
+import 'package:barcode_scan2/barcode_scan2.dart';
+import 'package:calorimeter/food_entry/food_entry_bloc.dart';
+import 'package:calorimeter/perdate/perdate_pageview.dart';
+import 'package:calorimeter/utils/app_drawer.dart';
+import 'package:calorimeter/utils/calendar_floating_button.dart';
+import 'package:calorimeter/utils/date_time_helper.dart';
+import 'package:calorimeter/utils/rectangular_notch_shape.dart';
+import 'package:calorimeter/utils/scan_food_floating_button.dart';
+import 'package:calorimeter/utils/sum_widget.dart';
+import 'package:calorimeter/utils/theme_switcher_button.dart';
+import 'package:flutter/material.dart';
+import 'package:intl/intl.dart';
+import 'package:provider/provider.dart';
+
+class PerDatePageViewController extends StatelessWidget {
+  // this is the date for which the PerDate widget will be shown on screen
+  // left of it will be yesterday's PerDate widget
+  // right of it will be tomorrow's PerDate widget
+  final DateTime initialDate;
+  final PageController pageController;
+  static final int initialOffset = 36500000;
+
+  const PerDatePageViewController._(
+      {required this.initialDate, required this.pageController});
+
+  factory PerDatePageViewController({required initialDate}) {
+    return PerDatePageViewController._(
+        initialDate: initialDate,
+        pageController: PageController(initialPage: initialOffset));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return BackButtonListener(
+      onBackButtonPressed: () async {
+        var visitedIndexes =
+            context.read<PageViewStateProvider>().visitedIndexes;
+        if (visitedIndexes.length == 1) {
+          return false;
+        }
+
+        visitedIndexes.removeLast();
+
+        pageController.jumpToPage(visitedIndexes.last);
+
+        return true;
+      },
+      child: ChangeNotifierProvider(
+        create: (context) => PageViewStateProvider(
+          initialDate: initialDate,
+          initialOffset: initialOffset,
+        ),
+        child: Builder(builder: (context) {
+          return Scaffold(
+            appBar: AppBar(
+              title: Builder(builder: (context) {
+                return Text(DateFormat.yMMMMd('de').format(
+                    context.watch<PageViewStateProvider>().displayedDate));
+              }),
+              actions: const [ThemeSwitcherButton()],
+            ),
+            bottomNavigationBar: BottomAppBar(
+                shape: const RectangularNotchShape(),
+                color: Theme.of(context).colorScheme.secondary,
+                child: SumWidget(foodEntries: [])),
+            drawer: const AppDrawer(),
+            floatingActionButton: OverflowBar(children: [
+              ScanFoodFAB(
+                onPressed: () {
+                  var result = BarcodeScanner.scan();
+                  context
+                      .read<FoodEntryBloc>()
+                      .add(BarcodeScanned(scanResultFuture: result));
+                },
+              ),
+              const SizedBox(width: 8),
+              CalendarFAB(
+                startFromDate: DateTimeHelper.now(),
+                onDateSelected: (dateSelected) {
+                  if (dateSelected == null) return;
+
+                  var dateDiff = dateSelected.difference(initialDate).inDays;
+
+                  log("dateDiff = $dateDiff");
+                  pageController.jumpToPage(initialOffset - dateDiff);
+                },
+              ),
+            ]),
+            floatingActionButtonLocation:
+                FloatingActionButtonLocation.endDocked,
+            body: PerDatePageView(
+              pageController: pageController,
+              initialDate: initialDate,
+            ),
+          );
+        }),
+      ),
+    );
+  }
+}
+
+class PageViewStateProvider with ChangeNotifier {
+  DateTime _displayedDate;
+  List<int> visitedIndexes = [];
+  bool _backButtonWasPressed = false;
+
+  PageViewStateProvider({required DateTime initialDate, int initialOffset = 0})
+      : _displayedDate = initialDate {
+    visitedIndexes.add(initialOffset);
+  }
+
+  set backButtonWasPressed(val) => _backButtonWasPressed = val;
+  get backButtonWasPressed => _backButtonWasPressed;
+
+  get displayedDate => _displayedDate;
+  void setDisplayedDate(date) {
+    _displayedDate = date;
+    notifyListeners();
+  }
+
+  void addVisitedindex(int index) {
+    visitedIndexes.add(index);
+  }
+}

lib/perdate/perdate_widget.dart

@@ -1,22 +1,13 @@
-import 'package:barcode_scan2/barcode_scan2.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';
 import 'package:calorimeter/perdate/entry_list.dart';
 import 'package:calorimeter/storage/storage.dart';
-import 'package:calorimeter/utils/calendar_floating_button.dart';
-import 'package:calorimeter/utils/rectangular_notch_shape.dart';
-import 'package:calorimeter/utils/sum_widget.dart';
-import 'package:calorimeter/utils/theme_switcher_button.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
-import 'package:intl/intl.dart';
+import 'package:provider/provider.dart';
 
 class PerDateWidget extends StatefulWidget {
   final DateTime date;
-  final Function(DateTime?) onDateSelected;
-  const PerDateWidget(
-      {super.key, required this.date, required this.onDateSelected});
+  const PerDateWidget({super.key, required this.date});
 
   @override
   State<PerDateWidget> createState() => _PerDateWidgetState();
@@ -25,13 +16,16 @@ class PerDateWidget extends StatefulWidget {
 class _PerDateWidgetState extends State<PerDateWidget>
     with AutomaticKeepAliveClientMixin<PerDateWidget> {
   late FoodStorage storage;
+  late Future<List<FoodEntryState>> entriesFuture;
   List<FoodEntryState> entries = [];
 
   @override
   void initState() {
-    context
-        .read<FoodEntryBloc>()
-        .add(PageBeingInitialized(forDate: widget.date));
+    storage = FoodStorage.getInstance();
+    entriesFuture = storage.getEntriesForDate(widget.date);
+    entriesFuture.then((val) {
+      entries = val;
+    });
     super.initState();
   }
 
@@ -44,51 +38,29 @@ class _PerDateWidgetState extends State<PerDateWidget>
   Widget build(BuildContext context) {
     super.build(context);
 
-    return BlocConsumer<FoodEntryBloc, GlobalEntryState>(
+    return FutureBuilder(
+        future: entriesFuture,
+        builder: (context, snapshot) {
+          return snapshot.connectionState != ConnectionState.done
+              ? const Center(child: CircularProgressIndicator())
+              : BlocProvider(
+                  create: (context) => FoodEntryBloc(
+                    initialState: PageState(foodEntries: entries),
+                    storage: storage,
+                    forDate: widget.date,
+                  ),
+                  child: BlocConsumer<FoodEntryBloc, PageState>(
                     listener: (context, pageState) {
                       if (pageState.errorString != null) {
                         showNewSnackbarWith(context, pageState.errorString!);
                       }
                     },
-      builder: (context, globalState) {
-        return Scaffold(
-            appBar: AppBar(
-              title: Text(DateFormat.yMMMMd('de').format(widget.date)),
-              actions: const [ThemeSwitcherButton()],
-            ),
-            body: FoodEntryList(
-                entries: globalState.foodEntries[widget.date] ?? [],
-                date: widget.date),
-            bottomNavigationBar: BottomAppBar(
-                shape: const RectangularNotchShape(),
-                color: Theme.of(context).colorScheme.secondary,
-                child: SumWidget(
-                    foodEntries: globalState.foodEntries[widget.date] ?? [])),
-            drawer: const AppDrawer(),
-            floatingActionButton: OverflowBar(children: [
-              ScanFoodFloatingButton(
-                onPressed: () {
-                  var result = BarcodeScanner.scan();
-                  context.read<FoodEntryBloc>().add(
-                        BarcodeScanned(
-                          scanResultFuture: result,
-                          forDate: widget.date,
+                    builder: (context, pageState) {
+                      return FoodEntryList(entries: pageState.foodEntries);
+                    },
                   ),
                 );
-                },
-              ),
-              const SizedBox(width: 8),
-              CalendarFloatingButton(
-                startFromDate: widget.date,
-                onDateSelected: (dateSelected) {
-                  widget.onDateSelected(dateSelected);
-                },
-              ),
-            ]),
-            floatingActionButtonLocation:
-                FloatingActionButtonLocation.endDocked);
-      },
-    );
+        });
   }
 
   void showNewSnackbarWith(BuildContext context, String text) {

lib/storage/storage.dart

@@ -1,6 +1,7 @@
 import 'dart:io';
 
 import 'package:calorimeter/food_entry/food_entry_bloc.dart';
+import 'package:calorimeter/utils/date_time_helper.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:universal_platform/universal_platform.dart';
 
@@ -157,7 +158,7 @@ class FoodStorage {
     // get a list of dates of the last 365 days
     var dates = List<DateTime>.generate(365, (idx) {
       var durationToPast = Duration(days: idx);
-      return DateTime.now().subtract(durationToPast);
+      return DateTimeHelper.now().subtract(durationToPast);
     });
 
     for (var date in dates.reversed) {

lib/utils/calendar_floating_button.dart

@@ -1,10 +1,11 @@
+import 'package:calorimeter/utils/date_time_helper.dart';
 import 'package:flutter/material.dart';
 
-class CalendarFloatingButton extends StatelessWidget {
+class CalendarFAB extends StatelessWidget {
   final DateTime startFromDate;
   final Function(DateTime?) onDateSelected;
 
-  const CalendarFloatingButton(
+  const CalendarFAB(
       {super.key, required this.startFromDate, required this.onDateSelected});
 
   @override
@@ -15,17 +16,18 @@ class CalendarFloatingButton extends StatelessWidget {
           locale: const Locale('de'),
           context: context,
           initialDate: startFromDate,
-          currentDate: DateTime.now(),
-          firstDate: DateTime.now().subtract(const Duration(days: 365 * 10)),
-          lastDate: DateTime.now().add(const Duration(days: 365 * 10)),
+          currentDate: DateTimeHelper.now(),
+          firstDate:
+              DateTimeHelper.now().subtract(const Duration(days: 365 * 10)),
+          lastDate: DateTimeHelper.now().add(const Duration(days: 365 * 10)),
         );
 
         if (!context.mounted) return;
 
-        onDateSelected(datePicked);
+        onDateSelected(datePicked?.copyWith(isUtc: true));
       },
       heroTag: "calendarFAB",
-      child: const Icon(Icons.today),
+      child: const Icon(Icons.date_range),
     );
   }
 }

lib/utils/date_time_helper.dart

@@ -0,0 +1,12 @@
+class DateTimeHelper {
+  static DateTime now() {
+    return DateTime.now().copyWith(
+      isUtc: true,
+      hour: 0,
+      minute: 0,
+      second: 0,
+      millisecond: 0,
+      microsecond: 0,
+    );
+  }
+}

lib/utils/scan_food_floating_button.dart

@@ -1,8 +1,8 @@
 import 'package:flutter/material.dart';
 
-class ScanFoodFloatingButton extends StatelessWidget {
+class ScanFoodFAB extends StatelessWidget {
   final Function() onPressed;
-  const ScanFoodFloatingButton({super.key, required this.onPressed});
+  const ScanFoodFAB({super.key, required this.onPressed});
 
   @override
   Widget build(BuildContext context) {

lib/utils/scan_food_notifier.dart

@@ -0,0 +1,48 @@
+import 'package:barcode_scan2/barcode_scan2.dart';
+import 'package:calorimeter/food_entry/food_entry_bloc.dart';
+import 'package:calorimeter/food_scan/food_fact_lookup.dart';
+import 'package:flutter/material.dart';
+
+class ScanFoodNotifier with ChangeNotifier {
+  void handleBarcodeScannedEvent(BarcodeScanned barcode) async {
+    var client = FoodFactLookupClient();
+    var scanResult = await barcode.scanResultFuture;
+
+    if (scanResult.type == ResultType.Cancelled) {
+      return;
+    }
+    if (scanResult.type == ResultType.Error) {
+      return;
+    }
+    var responseFuture = client.retrieveFoodInfo(scanResult.rawContent);
+
+    var newEntryWaiting = FoodEntryState(
+      kcalPer100: 0,
+      name: "",
+      mass: 0,
+      waitingForNetwork: true,
+      isSelected: false,
+    );
+
+    await responseFuture.then((response) async {
+      if (response.status ==
+          FoodFactResponseStatus.foodFactServerNotReachable) {
+        return;
+      }
+
+      var newEntryFinishedWaiting = FoodEntryState(
+        name: response.food?.name ?? "",
+        mass: response.food?.mass ?? 0,
+        kcalPer100: response.food?.kcalPer100g ?? 0,
+        waitingForNetwork: false,
+        isSelected: false,
+      );
+    });
+  }
+}
+
+class BarcodeScanned {
+  final Future<ScanResult> scanResultFuture;
+
+  BarcodeScanned({required this.scanResultFuture});
+}