redesigned / search by submit / fixes

lib/localizations.dart

@@ -0,0 +1,46 @@
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+class AppLocalizations {
+  static final AppLocalizations _singleton = new AppLocalizations._internal();
+  AppLocalizations._internal();
+  static AppLocalizations get instance => _singleton;
+
+  Map<dynamic, dynamic> _localisedValues;
+  Locale _currentLocale;
+
+  Future<AppLocalizations> load(Locale locale) async {
+    String jsonContent = await rootBundle
+        .loadString("locale/locale_${locale.languageCode}.json");
+    _localisedValues = json.decode(jsonContent);
+    _currentLocale = locale;
+    return this;
+  }
+
+  String getLocale() {
+    return _currentLocale.languageCode;
+  }
+
+  String text(String key) {
+    return _localisedValues[key] ?? "$key not found";
+  }
+}
+
+class AppLocalizationsDelegate extends LocalizationsDelegate<AppLocalizations> {
+  const AppLocalizationsDelegate();
+
+  @override
+  bool isSupported(Locale locale) =>
+      ['en', 'pl', 'de'].contains(locale.languageCode);
+
+  @override
+  Future<AppLocalizations> load(Locale locale) {
+    return AppLocalizations.instance.load(locale);
+  }
+
+  @override
+  bool shouldReload(AppLocalizationsDelegate old) => true;
+}