[Gallery] Fix directory structure (#312)

gallery/lib/studies/crane/app.dart

@@ -0,0 +1,67 @@
+// Copyright 2019 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:gallery/data/gallery_options.dart';
+import 'package:gallery/l10n/gallery_localizations.dart';
+import 'package:gallery/studies/crane/backdrop.dart';
+import 'package:gallery/studies/crane/eat_form.dart';
+import 'package:gallery/studies/crane/fly_form.dart';
+import 'package:gallery/studies/crane/sleep_form.dart';
+import 'package:gallery/studies/crane/theme.dart';
+
+class CraneApp extends StatefulWidget {
+  const CraneApp({Key key, this.navigatorKey}) : super(key: key);
+
+  final GlobalKey<NavigatorState> navigatorKey;
+
+  @override
+  _CraneAppState createState() => _CraneAppState();
+}
+
+class _CraneAppState extends State<CraneApp> {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      navigatorKey: widget.navigatorKey,
+      title: 'Crane',
+      debugShowCheckedModeBanner: false,
+      localizationsDelegates: GalleryLocalizations.localizationsDelegates,
+      supportedLocales: GalleryLocalizations.supportedLocales,
+      locale: GalleryOptions.of(context).locale,
+      initialRoute: '/',
+      onGenerateRoute: _getRoute,
+      theme: craneTheme.copyWith(
+        platform: GalleryOptions.of(context).platform,
+      ),
+      darkTheme: craneTheme.copyWith(
+        platform: GalleryOptions.of(context).platform,
+      ),
+      home: ApplyTextOptions(
+        child: Backdrop(
+          frontLayer: Container(),
+          backLayerItems: [
+            FlyForm(index: 0),
+            SleepForm(index: 1),
+            EatForm(index: 2),
+          ],
+          frontTitle: Text('CRANE'),
+          backTitle: Text('MENU'),
+        ),
+      ),
+    );
+  }
+}
+
+Route<dynamic> _getRoute(RouteSettings settings) {
+  if (settings.name != '/') {
+    return null;
+  }
+
+  return MaterialPageRoute<void>(
+    settings: settings,
+    builder: (context) => CraneApp(),
+    fullscreenDialog: true,
+  );
+}