[Gallery] Fix directory structure (#312)

gallery/lib/demos/material/bottom_app_bar_demo.dart

@@ -0,0 +1,169 @@
+// 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/l10n/gallery_localizations.dart';
+
+// BEGIN bottomAppBarDemo
+
+class BottomAppBarDemo extends StatefulWidget {
+  @override
+  State createState() => _BottomAppBarDemoState();
+}
+
+class _BottomAppBarDemoState extends State<BottomAppBarDemo> {
+  var _showFab = true;
+  var _showNotch = true;
+  var _fabLocation = FloatingActionButtonLocation.endDocked;
+
+  void _onShowNotchChanged(bool value) {
+    setState(() {
+      _showNotch = value;
+    });
+  }
+
+  void _onShowFabChanged(bool value) {
+    setState(() {
+      _showFab = value;
+    });
+  }
+
+  void _onFabLocationChanged(FloatingActionButtonLocation value) {
+    setState(() {
+      _fabLocation = value;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        automaticallyImplyLeading: false,
+        title: Text(GalleryLocalizations.of(context).demoBottomAppBarTitle),
+      ),
+      body: ListView(
+        padding: const EdgeInsets.only(bottom: 88),
+        children: [
+          SwitchListTile(
+            title: Text(
+              GalleryLocalizations.of(context).demoFloatingButtonTitle,
+            ),
+            value: _showFab,
+            onChanged: _onShowFabChanged,
+          ),
+          SwitchListTile(
+            title: Text(GalleryLocalizations.of(context).bottomAppBarNotch),
+            value: _showNotch,
+            onChanged: _onShowNotchChanged,
+          ),
+          Padding(
+            padding: const EdgeInsets.all(16),
+            child: Text(GalleryLocalizations.of(context).bottomAppBarPosition),
+          ),
+          RadioListTile<FloatingActionButtonLocation>(
+            title: Text(
+              GalleryLocalizations.of(context).bottomAppBarPositionDockedEnd,
+            ),
+            value: FloatingActionButtonLocation.endDocked,
+            groupValue: _fabLocation,
+            onChanged: _onFabLocationChanged,
+          ),
+          RadioListTile<FloatingActionButtonLocation>(
+            title: Text(
+              GalleryLocalizations.of(context).bottomAppBarPositionDockedCenter,
+            ),
+            value: FloatingActionButtonLocation.centerDocked,
+            groupValue: _fabLocation,
+            onChanged: _onFabLocationChanged,
+          ),
+          RadioListTile<FloatingActionButtonLocation>(
+            title: Text(
+              GalleryLocalizations.of(context).bottomAppBarPositionFloatingEnd,
+            ),
+            value: FloatingActionButtonLocation.endFloat,
+            groupValue: _fabLocation,
+            onChanged: _onFabLocationChanged,
+          ),
+          RadioListTile<FloatingActionButtonLocation>(
+            title: Text(
+              GalleryLocalizations.of(context)
+                  .bottomAppBarPositionFloatingCenter,
+            ),
+            value: FloatingActionButtonLocation.centerFloat,
+            groupValue: _fabLocation,
+            onChanged: _onFabLocationChanged,
+          ),
+        ],
+      ),
+      floatingActionButton: _showFab
+          ? FloatingActionButton(
+              onPressed: () {
+                print('Floating action button pressed');
+              },
+              child: Icon(Icons.add),
+              tooltip: GalleryLocalizations.of(context).buttonTextCreate,
+            )
+          : null,
+      floatingActionButtonLocation: _fabLocation,
+      bottomNavigationBar: _DemoBottomAppBar(
+        fabLocation: _fabLocation,
+        shape: _showNotch ? CircularNotchedRectangle() : null,
+      ),
+    );
+  }
+}
+
+class _DemoBottomAppBar extends StatelessWidget {
+  const _DemoBottomAppBar({
+    this.fabLocation,
+    this.shape,
+  });
+
+  final FloatingActionButtonLocation fabLocation;
+  final NotchedShape shape;
+
+  static final centerLocations = <FloatingActionButtonLocation>[
+    FloatingActionButtonLocation.centerDocked,
+    FloatingActionButtonLocation.centerFloat,
+  ];
+
+  @override
+  Widget build(BuildContext context) {
+    return BottomAppBar(
+      shape: shape,
+      child: IconTheme(
+        data: IconThemeData(color: Theme.of(context).colorScheme.onPrimary),
+        child: Row(
+          children: [
+            IconButton(
+              tooltip: MaterialLocalizations.of(context).openAppDrawerTooltip,
+              icon: const Icon(Icons.menu),
+              onPressed: () {
+                print('Menu button pressed');
+              },
+            ),
+            if (centerLocations.contains(fabLocation)) const Spacer(),
+            IconButton(
+              tooltip: GalleryLocalizations.of(context).starterAppTooltipSearch,
+              icon: const Icon(Icons.search),
+              onPressed: () {
+                print('Search button pressed');
+              },
+            ),
+            IconButton(
+              tooltip:
+                  GalleryLocalizations.of(context).starterAppTooltipFavorite,
+              icon: const Icon(Icons.favorite),
+              onPressed: () {
+                print('Favorite button pressed');
+              },
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+// END