Adding favorites screen to veggieseasons. (#16)

veggieseasons/lib/screens/favorites.dart

@@ -4,18 +4,55 @@
 
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/widgets.dart';
+import 'package:scoped_model/scoped_model.dart';
+import 'package:veggieseasons/data/model.dart';
+import 'package:veggieseasons/data/veggie.dart';
 import 'package:veggieseasons/styles.dart';
+import 'package:veggieseasons/widgets/veggie_headline.dart';
 
 class FavoritesScreen extends StatelessWidget {
+  /// Builds the "content" of the favorites screen: either a list of favorite
+  /// veggies or a note that says the user hasn't favorited any yet.
+  Widget _buildScaffoldBody(BuildContext context) {
+    final model = ScopedModel.of<AppState>(context, rebuildOnChange: true);
+
+    if (model.favoriteVeggies.length == 0) {
+      return Padding(
+        padding: const EdgeInsets.symmetric(horizontal: 24.0),
+        child: Text(
+          'You haven\'t added any favorite veggies to your garden yet.',
+          style: Styles.headlineDescription,
+        ),
+      );
+    }
+
+    final rows = <Widget>[
+      SizedBox(height: 24.0),
+    ];
+
+    for (Veggie veggie in model.favoriteVeggies) {
+      rows.add(
+        Padding(
+          padding: EdgeInsets.only(left: 16.0, right: 16.0, bottom: 24.0),
+          child: VeggieHeadline(veggie),
+        ),
+      );
+    }
+
+    return ListView(
+      children: rows,
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return CupertinoPageScaffold(
       navigationBar: CupertinoNavigationBar(
-        middle: Text('My Garden'),
+        middle: Text('Your Garden'),
       ),
       backgroundColor: Styles.scaffoldBackground,
       child: Center(
-        child: Text('Not yet implemented.'),
+        child: _buildScaffoldBody(context),
       ),
     );
   }