[VeggieSeasons] added restore defaults feature (#639)

experimental/veggieseasons/lib/data/preferences.dart

@@ -50,6 +50,12 @@ class Preferences extends ChangeNotifier {
     notifyListeners();
   }
 
+  Future<void> restoreDefaults() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.clear();
+    load();
+  }
+
   void load() {
     _loading = _loadFromSharedPrefs();
   }

experimental/veggieseasons/lib/screens/settings.dart

@@ -213,6 +213,44 @@ class SettingsScreen extends StatelessWidget {
     );
   }
 
+  SettingsItem _buildRestoreDefaultsItem(
+      BuildContext context, Preferences prefs) {
+    return SettingsItem(
+      label: 'Restore Defaults',
+      icon: SettingsIcon(
+        backgroundColor: CupertinoColors.systemRed,
+        icon: Styles.resetIcon,
+      ),
+      content: SettingsNavigationIndicator(),
+      onPress: () {
+        showCupertinoDialog<void>(
+          context: context,
+          builder: (context) => CupertinoAlertDialog(
+            title: Text('Are you sure?'),
+            content: Text(
+              'Are you sure you want to reset the current settings?',
+            ),
+            actions: <Widget>[
+              CupertinoDialogAction(
+                isDestructiveAction: true,
+                child: Text('Yes'),
+                onPressed: () async {
+                  await prefs.restoreDefaults();
+                  Navigator.pop(context);
+                },
+              ),
+              CupertinoDialogAction(
+                isDefaultAction: true,
+                child: Text('No'),
+                onPressed: () => Navigator.pop(context),
+              )
+            ],
+          ),
+        );
+      },
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     final prefs = Provider.of<Preferences>(context);
@@ -238,6 +276,7 @@ class SettingsScreen extends StatelessWidget {
                         items: [
                           _buildCaloriesItem(context, prefs),
                           _buildCategoriesItem(context, prefs),
+                          _buildRestoreDefaultsItem(context, prefs),
                         ],
                       ),
                     ],

experimental/veggieseasons/lib/styles.dart

@@ -198,7 +198,7 @@ abstract class Styles {
           : CupertinoColors.darkBackgroundGray;
 
   static Color settingsLineation(Brightness brightness) =>
-      brightness == Brightness.light ? Color(0xffbcbbc1) : Color(0xFF4C4B4B);
+      brightness == Brightness.light ? Color(0xffbcbbc1) : Color(0xff4c4b4b);
 
   static const Color settingsBackground = Color(0xffefeff4);
 
@@ -214,6 +214,12 @@ abstract class Styles {
     fontPackage: CupertinoIcons.iconFontPackage,
   );
 
+  static const resetIcon = IconData(
+    0xf4c4,
+    fontFamily: CupertinoIcons.iconFont,
+    fontPackage: CupertinoIcons.iconFontPackage,
+  );
+
   static const calorieIcon = IconData(
     0xf3bb,
     fontFamily: CupertinoIcons.iconFont,
@@ -230,5 +236,5 @@ abstract class Styles {
 
   static const ColorFilter desaturatedColorFilter =
       // 222222 is a random color that has low color saturation.
-      ColorFilter.mode(Color(0xFF222222), BlendMode.saturation);
+      ColorFilter.mode(Color(0xff222222), BlendMode.saturation);
 }