[Shrine] New Shrine with expanding cart bottom sheet from experimenal (#18)

shrine/lib/home.dart

@@ -15,21 +15,45 @@
 import 'package:flutter/material.dart';
 import 'package:scoped_model/scoped_model.dart';
 
+import 'backdrop.dart';
+import 'expanding_bottom_sheet.dart';
 import 'model/app_state_model.dart';
 import 'model/product.dart';
 import 'supplemental/asymmetric_view.dart';
 
-class HomePage extends StatelessWidget {
+class ProductPage extends StatelessWidget {
   final Category category;
 
-  const HomePage({this.category: Category.all});
+  const ProductPage({this.category: Category.all});
 
   @override
   Widget build(BuildContext context) {
     return ScopedModelDescendant<AppStateModel>(
-      builder: (context, child, model) => AsymmetricView(
-            products: model.getProducts(),
-          ),
+        builder: (BuildContext context, Widget child, AppStateModel model) {
+      return AsymmetricView(
+        products: model.getProducts(),
+      );
+    });
+  }
+}
+
+class HomePage extends StatelessWidget {
+  final ExpandingBottomSheet expandingBottomSheet;
+  final Backdrop backdrop;
+
+  const HomePage({
+    Key key,
+    this.expandingBottomSheet,
+    this.backdrop
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Stack(
+      children: <Widget>[
+        backdrop,
+        Align(child: expandingBottomSheet, alignment: Alignment.bottomRight)
+      ],
     );
   }
 }