Исправлены баги

lib/screens/faq.dart

@@ -1,5 +1,7 @@
 import 'dart:async';
 
+import 'package:checker/base/base_screen.dart';
+import 'package:checker/db.dart';
 import 'package:checker/resources.dart';
 import 'package:checker/strings.dart';
 import 'package:flutter/material.dart';
@@ -62,17 +64,22 @@ class EntryItem extends StatelessWidget {
   }
 }
 
-class FAQScreen extends StatefulWidget {
+class FAQScreen extends BaseScreen {
 
-  FAQScreen(this.b);
-  final bool b;
+  FAQScreen(SqliteHelper helper, String app,
+      this.returnToScanner) : super(helper, app);
 
-  @override State createState() => new FAQScreenState<FAQScreen>(b);
+  final bool returnToScanner;
+
+  @override State createState() => new FAQScreenState<FAQScreen>(returnToScanner, helper, app);
 }
 
 class FAQScreenState<T> extends BaseState<FAQScreen> {
 
-  FAQScreenState(this.returnToScanner);
+  FAQScreenState(this.returnToScanner, SqliteHelper helper, String app) {
+    this.helper = helper;
+    this.app = app;
+  }
 
   bool returnToScanner;
 
@@ -87,7 +94,7 @@ class FAQScreenState<T> extends BaseState<FAQScreen> {
   }
 
   @override Widget build(BuildContext context) {
-    if (app == null) {
+    if (data == null) {
       platform.invokeMethod('getFlavor').then((flavor) {
         initPhoneAndUrl().then((_) {
           setState(() {

lib/screens/purchase.dart

@@ -1,3 +1,4 @@
+import 'package:checker/base/base_screen.dart';
 import 'package:checker/db.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -13,14 +14,15 @@ import 'package:checker/base/base_state.dart';
 import 'package:checker/screens/purchase_success.dart';
 
 /// Экран проведения покупки.
-class PurchaseScreen extends StatefulWidget {
-  PurchaseScreen(this.user, this.card);
+class PurchaseScreen extends BaseScreen {
+
+  PurchaseScreen(helper, app, this.user, this.card) : super(helper, app);
 
   final String user;
   final String card;
 
   @override
-  State createState() => new PurchaseScreenState<PurchaseScreen>(user, card);
+  State createState() => new PurchaseScreenState<PurchaseScreen>(helper, app, user, card);
 }
 
 class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
@@ -29,9 +31,11 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
   /// (удаляет запрещенные символы до их отображаения).
   TextEditingController controller = new TextEditingController();
 
-  PurchaseScreenState(String userString, String card) {
+  PurchaseScreenState(SqliteHelper helper, String app, String userString, String card) {
     this.user = JSON.decode(userString);
     this.card = card;
+    this.helper = helper;
+    this.app = app;
   }
 
   @override
@@ -62,18 +66,18 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
     return new Column(children: <Widget>[
       new Expanded(
           child: new ListView(children: <Widget>[
-        getValueWithDescription(StringsLocalization.buyer(),
-            user['first_name'] == null ? '' : user['first_name']),
-        getValueWithDescription(StringsLocalization.card(), card),
-        getValueWithDescription(StringsLocalization.reward(), loyalty),
-        getHintLabel(),
-        getInputField(),
-        wrapButton(getScreenMargins(36.0), getCompleteButton()),
-        wrapButton(
-            getScreenMargins(24.0),
-            getScanButton(context, StringsLocalization.scan(),
-                Resources.getPrimaryColor(app)))
-      ]))
+            getValueWithDescription(StringsLocalization.buyer(),
+                user['first_name'] == null ? '' : user['first_name']),
+            getValueWithDescription(StringsLocalization.card(), card),
+            getValueWithDescription(StringsLocalization.reward(), loyalty),
+            getHintLabel(),
+            getInputField(),
+            wrapButton(getScreenMargins(36.0), getCompleteButton()),
+            wrapButton(
+                getScreenMargins(24.0),
+                getScanButton(context, StringsLocalization.scan(),
+                    Resources.getPrimaryColor(app)))
+          ]))
     ]);
   }
 
@@ -185,7 +189,7 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
           child: new AlertDialog(
               title: new Text(StringsLocalization.confirmation()),
               content:
-                  new Text(StringsLocalization.confirmPurchase(val, currency)),
+              new Text(StringsLocalization.confirmPurchase(val, currency)),
               actions: <Widget>[
                 new FlatButton(
                   child: new Text(StringsLocalization.no()),
@@ -254,7 +258,7 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
       this.loyalty = '${user['discount']}%';
     } else {
       double loyaltyVal = (double.parse(bonuses['amount_to_bonus'][1]) /
-              bonuses['amount_to_bonus'][0]) * 100;
+          bonuses['amount_to_bonus'][0]) * 100;
       this.loyalty = '${loyaltyVal.toStringAsFixed(0)}%';
     }
   }

lib/screens/settings.dart

@@ -28,7 +28,10 @@ class MenuItem {
 
 class SettingsState extends BaseState<SettingsScreen> {
 
-  List<MenuItem> menuItems;
+  List<MenuItem> menuItems = [
+    new MenuItem('', ''),
+    new MenuItem('', '')
+  ];
 
   bool returnToScanner;
 
@@ -39,22 +42,14 @@ class SettingsState extends BaseState<SettingsScreen> {
   }
 
   @override Widget build(BuildContext ctx) {
-    if (menuItems == null) {
-      menuItems = [
-        new MenuItem('', ''),
-        new MenuItem('', '')
-      ];
-      helper.getSettings().then((info) {
-        setState(() {
-          menuItems[0].title = StringsLocalization.currency();
-          menuItems[1].title = StringsLocalization.locale();
-          menuItems[0].selectedValue = info['currency'].toString();
-          menuItems[1].selectedValue =
-          info['locale'] == null ? Intl.defaultLocale : info['locale']
-              .toString();
-        });
+    helper.getSettings().then((info) {
+      setState(() {
+        menuItems[0].title = StringsLocalization.currency();
+        menuItems[1].title = StringsLocalization.locale();
+        menuItems[0].selectedValue = info['currency'].toString();
+        menuItems[1].selectedValue = info['locale'] == null ? Intl.defaultLocale : info['locale'].toString();
       });
-    }
+    });
     return new WillPopScope(onWillPop: onWillPop, child: getMainWidget());
   }
 
@@ -77,16 +72,11 @@ class SettingsState extends BaseState<SettingsScreen> {
 
   List<Widget> getSettings() {
     List<Widget> widgets = new List();
-    if (menuItems != null) {
-      for (int i = 0; i < menuItems.length; i++) {
-        if (menuItems[i].selectedValue != '') {
-          widgets.add(
-              getSettingsItem(() => onPressed(menuItems.indexOf(menuItems[i])),
-                  menuItems[i].title,
-                  i == 0 ? getCurrencyTitle(
-                      int.parse(menuItems[i].selectedValue)) : getLocaleTitle(
-                      menuItems[i].selectedValue)));
-        }
+    for (int i = 0; i < menuItems.length; i++) {
+      if (menuItems[i].selectedValue != '') {
+        widgets.add(getSettingsItem(() => onPressed(menuItems.indexOf(menuItems[i])),
+            menuItems[i].title,
+            i == 0 ? getCurrencyTitle(int.parse(menuItems[i].selectedValue)) : getLocaleTitle(menuItems[i].selectedValue)));
       }
     }
     return widgets;
@@ -115,10 +105,8 @@ class SettingsState extends BaseState<SettingsScreen> {
   void onPressed(int position) {
     switch (position) {
       case 0 :
-        menuItems = null;
         return pushRoute(context, new CurrenciesScreen(helper, app));
       case 1 :
-        menuItems = null;
         return pushRoute(context, new LanguagesScreen(helper, app));
     }
   }