Add locations and save them, remove locations and delete them

lib/components/locations/manage_single_location.dart

@@ -15,7 +15,9 @@ class ManageSingleLocation extends StatelessWidget {
             child: Row(children: [
               Text(name, style: Theme.of(context).textTheme.headline5),
               const Spacer(),
-              const Icon(Icons.delete_sharp)
+              GestureDetector(
+                  onTap: () => delete(name),
+                  child: const Icon(Icons.delete_sharp))
             ])));
   }
 }

lib/components/main_menu.dart

@@ -28,8 +28,10 @@ class NavBar extends StatelessWidget {
             leading: const Icon(Icons.public),
             title: const Text("Locations"),
             onTap: (() {
-              Navigator.push(context,
-                  MaterialPageRoute(builder: (context) => const Locations()));
+              Navigator.push(
+                context,
+                MaterialPageRoute(builder: (context) => const Locations()),
+              );
             }),
           )
         ],

lib/main.dart

@@ -17,41 +17,52 @@ class MyApp extends StatefulWidget {
 }
 
 class _MyAppState extends State<MyApp> {
+  List<String> _locations = [];
+
   @override
-  Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Wetter',
-      theme: ThemeData(
-        primarySwatch: Colors.blue,
-        textTheme: const TextTheme(
-          headline1: TextStyle(fontSize: 72.0, fontWeight: FontWeight.bold),
-          headline6: TextStyle(fontSize: 36.0, fontStyle: FontStyle.italic),
-          bodyText2: TextStyle(fontSize: 14.0, fontFamily: 'Hind'),
-        ),
-      ),
-      home: DefaultTabController(
-        length: 3,
-        child: Scaffold(
-          appBar: AppBar(
-            title: const Text('Wetter'),
-            bottom: const TabBar(
-              tabs: [
-                Tab(icon: Text("Hamburg")),
-                Tab(icon: Text("Frankfurt")),
-                Tab(icon: Text("Freiburg")),
-              ],
-            ),
-          ),
-          drawer: const NavBar(),
-          body: const TabBarView(
-            children: [
-              MainWeatherView(53.46, 9.98),
-              MainWeatherView(50.15, 8.70),
-              MainWeatherView(47.99, 7.85)
-            ],
-          ),
+  void initState() {
+    _locations = UserPreferences.getSavedLocations();
+    super.initState();
+  }
+
+  Widget buildContent() {
+    return DefaultTabController(
+      length: _locations.length,
+      child: Scaffold(
+        appBar: AppBar(
+          title: const Text('Wetter'),
+          bottom: (_locations.isEmpty)
+              ? null
+              : TabBar(
+                  tabs: [for (String name in _locations) Tab(icon: Text(name))],
+                ),
         ),
+        drawer: const NavBar(),
+        body: (_locations.isEmpty)
+            ? const Text("No locations")
+            : TabBarView(
+                children: [
+                  for (String name in _locations)
+                    MainWeatherView(UserPreferences.getLat(name),
+                        UserPreferences.getLon(name))
+                ],
+              ),
       ),
     );
   }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+        title: 'Wetter',
+        theme: ThemeData(
+          primarySwatch: Colors.blue,
+          textTheme: const TextTheme(
+            headline1: TextStyle(fontSize: 72.0, fontWeight: FontWeight.bold),
+            headline6: TextStyle(fontSize: 36.0, fontStyle: FontStyle.italic),
+            bodyText2: TextStyle(fontSize: 14.0, fontFamily: 'Hind'),
+          ),
+        ),
+        home: buildContent());
+  }
 }

lib/screens/locations.dart

@@ -24,7 +24,11 @@ class _LocationsState extends State<Locations> {
     });
   }
 
-  void deleteLocation(String name) {}
+  void deleteLocation(String name) {
+    setState(() {
+      locations = UserPreferences.deleteLocation(name);
+    });
+  }
 
   @override
   Widget build(BuildContext context) {

lib/screens/main_weather_view.dart

@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
-import 'package:shared_preferences/shared_preferences.dart';
+import 'package:wetter/services/user_preferences.dart';
 
 import '../components/compact_weather_data.dart';
 import '../models/daily_weather_model.dart';
@@ -17,8 +17,7 @@ class MainWeatherView extends StatefulWidget {
 
 class _MainWeatherViewState extends State<MainWeatherView>
     with AutomaticKeepAliveClientMixin<MainWeatherView> {
-  SharedPreferences? prefs;
-  int _daysToLoad = 7;
+  int _daysToLoad = UserPreferences.preferences!.getInt("daysToLoad") ?? 7;
   late Future<List<DailyWeatherModel>> dailyWeather;
 
   @override
@@ -27,18 +26,10 @@ class _MainWeatherViewState extends State<MainWeatherView>
   @override
   void initState() {
     super.initState();
-    initializePreferences();
     dailyWeather = BrightSkyAPI.fetchForecastForTimeRange(
         DateTime.now(), _daysToLoad, widget.lat, widget.lon);
   }
 
-  Future<void> initializePreferences() async {
-    prefs = await SharedPreferences.getInstance();
-    setState(() {
-      _daysToLoad = prefs!.getInt("daysToLoad") ?? 7;
-    });
-  }
-
   @override
   Widget build(BuildContext context) {
     super.build(context);
@@ -46,7 +37,8 @@ class _MainWeatherViewState extends State<MainWeatherView>
         onRefresh: () {
           return Future(() {
             setState(() {
-              _daysToLoad = prefs?.getInt("daysToLoad") ?? 7;
+              _daysToLoad =
+                  UserPreferences.preferences!.getInt("daysToLoad") ?? 7;
               dailyWeather = BrightSkyAPI.fetchForecastForTimeRange(
                   DateTime.now(), _daysToLoad, widget.lat, widget.lon);
             });

lib/services/user_preferences.dart

@@ -19,4 +19,20 @@ class UserPreferences {
     preferences!.setDouble("$name-lon", lon);
     return getSavedLocations();
   }
+
+  static List<String> deleteLocation(String name) {
+    preferences!.remove("$name-lat");
+    preferences!.remove("$name-lon");
+    _savedLocations.remove(name);
+    preferences!.remove(name);
+    return getSavedLocations();
+  }
+
+  static getLat(String name) {
+    return preferences!.getDouble("$name-lat");
+  }
+
+  static getLon(String name) {
+    return preferences!.getDouble("$name-lon");
+  }
 }