Выпадающее меню с тремя кнопками

lib/screens/purchase_success.dart

@@ -0,0 +1,67 @@
+import 'package:flutter/material.dart';
+
+import 'package:checker/common.dart';
+import 'package:checker/consts.dart';
+import 'package:checker/strings.dart';
+import 'package:checker/base_state.dart';
+
+/// Экран проведения покупки.
+class PurchaseSuccessScreen extends StatefulWidget {
+
+  PurchaseSuccessScreen(this.val, this.name);
+  final String val;
+  final String name;
+
+  @override State createState() => new PurchaseSuccessScreenState(val, name);
+}
+
+class PurchaseSuccessScreenState<T> extends BaseState<PurchaseSuccessScreen> {
+
+  PurchaseSuccessScreenState(this.sum, this.username);
+
+  String sum;
+  String username;
+
+  @override getMenuButtons() {
+    return <Widget>[getFaqButton(), getLogoutButton()];
+  }
+
+  @override String getTitle() {
+    return StringsLocalization.carryingPurchase();
+  }
+
+  @override String getHint() {
+    return null;
+  }
+
+  @override Widget getScreenContent() {
+    return new Column(children: <Widget>[
+      getValueWithDescription(StringsLocalization.buyer(), username),
+      getSuccessMessage(),
+      new Expanded(child: new Center()),
+      wrapButton(getScreenMargins(74.0), getScanButton())
+    ]);
+  }
+
+  getScreenMargins(double bottom) {
+    double side = 42.0;
+    return new EdgeInsets.only(bottom: bottom, left: side, right: side);
+  }
+
+  getScanButton() {
+    String title = StringsLocalization.scan();
+    return buildRaisedButton(title, () => startScanner(context, app, helper));
+  }
+
+  getSuccessMessage() {
+  	return new Row(children: <Widget>[new Expanded(child: new Container(margin: new EdgeInsets.only(top: 20.0), height: 64.0,
+      decoration: new BoxDecoration(color: greenBackground),
+      child: new Center(child: new Text(getMessageTitle(), textAlign: TextAlign.center,
+        style: new TextStyle(fontWeight: FontWeight.bold, color: tokenActiveTextColor)))))]);
+  }
+
+  getMessageTitle() {
+    return StringsLocalization.purchaseCompleted(sum);
+  }
+
+}