Работает функционал переключения валют, остались правки по ui

lib/screens/currencies.dart

@@ -1,8 +1,7 @@
 import 'package:checker/base/settings_base_state.dart';
 import 'package:flutter/material.dart';
-import 'package:checker/consts.dart';
 import 'package:checker/strings.dart';
-import 'package:checker/base/base_state.dart';
+import 'package:checker/common.dart';
 
 class CurrenciesScreen extends StatefulWidget {
   @override State createState() => new _CurrenciesState();
@@ -10,6 +9,8 @@ class CurrenciesScreen extends StatefulWidget {
 
 class _CurrenciesState extends SettingsBaseState<CurrenciesScreen> {
 
+  List<int> currencies = const [643, 840, 980];
+
   @override
   List<String> getOptions() {
 
@@ -20,8 +21,22 @@ class _CurrenciesState extends SettingsBaseState<CurrenciesScreen> {
     return [ruble, dollar, hryvna];
   }
 
+  @override
+  void getSelectedValue() {
+    helper.getCurrency().then((currency) {
+      setState(() {
+        selectedItem = currencies.indexOf(currency);
+      });
+    });
+  }
+
   @override
   String getTitle() {
     return StringsLocalization.settings();
   }
+
+  @override
+  saveOption() async {
+    await helper.saveCurrency(currencies[selectedItem]);
+  }
 }