Migrate 104-complete to NNBD.

mdc_100_series/analysis_options.yaml

@@ -0,0 +1,3 @@
+analyzer:
+  enable-experiment:
+    - non-nullable

mdc_100_series/lib/app.dart

@@ -58,7 +58,7 @@ class _ShrineAppState extends State<ShrineApp> {
   }
 }
 
-Route<dynamic> _getRoute(RouteSettings settings) {
+Route<dynamic>? _getRoute(RouteSettings settings) {
   if (settings.name != '/login') {
     return null;
   }
@@ -107,17 +107,17 @@ ThemeData _buildShrineTheme() {
 
 TextTheme _buildShrineTextTheme(TextTheme base) {
   return base.copyWith(
-    headline5: base.headline5.copyWith(
+    headline5: base.headline5!.copyWith(
       fontWeight: FontWeight.w500,
     ),
-    headline6: base.headline6.copyWith(
+    headline6: base.headline6!.copyWith(
         fontSize: 18.0
     ),
-    caption: base.caption.copyWith(
+    caption: base.caption!.copyWith(
       fontWeight: FontWeight.w400,
       fontSize: 14.0,
     ),
-    bodyText1: base.bodyText1.copyWith(
+    bodyText1: base.bodyText1!.copyWith(
       fontWeight: FontWeight.w500,
       fontSize: 16.0,
     ),

mdc_100_series/lib/backdrop.dart

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 import 'package:flutter/material.dart';
-import 'package:meta/meta.dart';
 
 import 'model/product.dart';
 import 'login.dart';
@@ -22,12 +21,12 @@ const double _kFlingVelocity = 2.0;
 
 class _FrontLayer extends StatelessWidget {
   const _FrontLayer({
-    Key key,
+    Key? key,
     this.onTap,
-    this.child,
+    required this.child,
   }) : super(key: key);
 
-  final VoidCallback onTap;
+  final VoidCallback? onTap;
   final Widget child;
 
   @override
@@ -58,26 +57,27 @@ class _FrontLayer extends StatelessWidget {
 }
 
 class _BackdropTitle extends AnimatedWidget {
-  final Function onPress;
+  final void Function() onPress;
   final Widget frontTitle;
   final Widget backTitle;
 
   const _BackdropTitle({
-    Key key,
-    Listenable listenable,
-    this.onPress,
-    @required this.frontTitle,
-    @required this.backTitle,
-  })  : assert(frontTitle != null),
-        assert(backTitle != null),
+    Key? key,
+    required Animation<double> listenable,
+    required this.onPress,
+    required this.frontTitle,
+    required this.backTitle,
+  })  : _listenable = listenable,
         super(key: key, listenable: listenable);
 
+  final Animation<double> _listenable;
+
   @override
   Widget build(BuildContext context) {
-    final Animation<double> animation = this.listenable;
+    final Animation<double> animation = _listenable;
 
     return DefaultTextStyle(
-      style: Theme.of(context).primaryTextTheme.headline6,
+      style: Theme.of(context)!.primaryTextTheme.headline6!,
       softWrap: false,
       overflow: TextOverflow.ellipsis,
       child: Row(children: <Widget>[
@@ -158,16 +158,12 @@ class Backdrop extends StatefulWidget {
   final Widget backTitle;
 
   const Backdrop({
-    @required this.currentCategory,
-    @required this.frontLayer,
-    @required this.backLayer,
-    @required this.frontTitle,
-    @required this.backTitle,
-  })  : assert(currentCategory != null),
-        assert(frontLayer != null),
-        assert(backLayer != null),
-        assert(frontTitle != null),
-        assert(backTitle != null);
+    required this.currentCategory,
+    required this.frontLayer,
+    required this.backLayer,
+    required this.frontTitle,
+    required this.backTitle,
+  });
 
   @override
   _BackdropState createState() => _BackdropState();
@@ -176,7 +172,7 @@ class Backdrop extends StatefulWidget {
 class _BackdropState extends State<Backdrop>
     with SingleTickerProviderStateMixin {
   final GlobalKey _backdropKey = GlobalKey(debugLabel: 'Backdrop');
-  AnimationController _controller;
+  late AnimationController _controller;
 
   @override
   void initState() {

mdc_100_series/lib/category_menu_page.dart

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 import 'package:flutter/material.dart';
-import 'package:meta/meta.dart';
 
 import 'colors.dart';
 import 'model/product.dart';
@@ -24,16 +23,15 @@ class CategoryMenuPage extends StatelessWidget {
   final List<Category> _categories = Category.values;
 
   const CategoryMenuPage({
-    Key key,
-    @required this.currentCategory,
-    @required this.onCategoryTap,
-  })  : assert(currentCategory != null),
-        assert(onCategoryTap != null);
+    Key? key,
+    required this.currentCategory,
+    required this.onCategoryTap,
+  });
 
   Widget _buildCategory(Category category, BuildContext context) {
     final categoryString =
         category.toString().replaceAll('Category.', '').toUpperCase();
-    final ThemeData theme = Theme.of(context);
+    final ThemeData theme = Theme.of(context)!;
     return GestureDetector(
       onTap: () => onCategoryTap(category),
       child: category == currentCategory
@@ -57,7 +55,7 @@ class CategoryMenuPage extends StatelessWidget {
         padding: EdgeInsets.symmetric(vertical: 16.0),
         child: Text(
           categoryString,
-          style: theme.textTheme.bodyText1.copyWith(
+          style: theme.textTheme.bodyText1!.copyWith(
               color: kShrineBrown900.withAlpha(153)
             ),
           textAlign: TextAlign.center,

mdc_100_series/lib/login.dart

@@ -39,7 +39,7 @@ class _LoginPageState extends State<LoginPage> {
                 SizedBox(height: 16.0),
                 Text(
                   'SHRINE',
-                  style: Theme.of(context).textTheme.headline5,
+                  style: Theme.of(context)!.textTheme.headline5,
                 ),
               ],
             ),
@@ -96,7 +96,7 @@ class _LoginPageState extends State<LoginPage> {
 }
 
 class AccentColorOverride extends StatelessWidget {
-  const AccentColorOverride({Key key, this.color, this.child})
+  const AccentColorOverride({Key? key, required this.color, required this.child})
       : super(key: key);
 
   final Color color;
@@ -106,7 +106,7 @@ class AccentColorOverride extends StatelessWidget {
   Widget build(BuildContext context) {
     return Theme(
       child: child,
-      data: Theme.of(context).copyWith(
+      data: Theme.of(context)!.copyWith(
         accentColor: color,
         brightness: Brightness.dark,
       ),

mdc_100_series/lib/model/product.dart

@@ -12,22 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import 'package:flutter/foundation.dart';
-
 enum Category { all, accessories, clothing, home, }
 
 class Product {
   const Product({
-    @required this.category,
-    @required this.id,
-    @required this.isFeatured,
-    @required this.name,
-    @required this.price,
-  })  : assert(category != null),
-        assert(id != null),
-        assert(isFeatured != null),
-        assert(name != null),
-        assert(price != null);
+    required this.category,
+    required this.id,
+    required this.isFeatured,
+    required this.name,
+    required this.price,
+  });
 
   final Category category;
   final int id;

mdc_100_series/lib/supplemental/asymmetric_view.dart

@@ -20,10 +20,10 @@ import 'product_columns.dart';
 class AsymmetricView extends StatelessWidget {
   final List<Product> products;
 
-  AsymmetricView({Key key, this.products});
+  AsymmetricView({Key? key, required this.products});
 
   List<Container> _buildColumns(BuildContext context) {
-    if (products == null || products.isEmpty) {
+    if (products.isEmpty) {
       return <Container>[];
     }
 
@@ -36,7 +36,7 @@ class AsymmetricView extends StatelessWidget {
     /// helpers for creating the index of the product list that will correspond
     /// to the index of the list of columns.
     return List.generate(_listItemCount(products.length), (int index) {
-      double width = .59 * MediaQuery.of(context).size.width;
+      double width = .59 * MediaQuery.of(context)!.size.width;
       Widget column;
       if (index % 2 == 0) {
         /// Even cases

mdc_100_series/lib/supplemental/cut_corners_border.dart

@@ -19,21 +19,21 @@ import 'package:flutter/widgets.dart';
 
 class CutCornersBorder extends OutlineInputBorder {
   const CutCornersBorder({
-    BorderSide borderSide: const BorderSide(),
-    BorderRadius borderRadius: const BorderRadius.all(Radius.circular(2.0)),
-    this.cut: 7.0,
-    double gapPadding: 2.0,
+    BorderSide borderSide = const BorderSide(),
+    BorderRadius borderRadius = const BorderRadius.all(Radius.circular(2.0)),
+    this.cut = 7.0,
+    double gapPadding = 2.0,
   }) : super(
             borderSide: borderSide,
             borderRadius: borderRadius,
             gapPadding: gapPadding);
 
   @override
   CutCornersBorder copyWith({
-    BorderSide borderSide,
-    BorderRadius borderRadius,
-    double gapPadding,
-    double cut,
+    BorderSide? borderSide,
+    BorderRadius? borderRadius,
+    double? gapPadding,
+    double? cut,
   }) {
     return CutCornersBorder(
       borderRadius: borderRadius ?? this.borderRadius,
@@ -46,11 +46,11 @@ class CutCornersBorder extends OutlineInputBorder {
   final double cut;
 
   @override
-  ShapeBorder lerpFrom(ShapeBorder a, double t) {
+  ShapeBorder? lerpFrom(ShapeBorder? a, double t) {
     if (a is CutCornersBorder) {
       final CutCornersBorder outline = a;
       return CutCornersBorder(
-        borderRadius: BorderRadius.lerp(outline.borderRadius, borderRadius, t),
+        borderRadius: BorderRadius.lerp(outline.borderRadius, borderRadius, t)!,
         borderSide: BorderSide.lerp(outline.borderSide, borderSide, t),
         cut: cut,
         gapPadding: outline.gapPadding,
@@ -60,11 +60,11 @@ class CutCornersBorder extends OutlineInputBorder {
   }
 
   @override
-  ShapeBorder lerpTo(ShapeBorder b, double t) {
+  ShapeBorder? lerpTo(ShapeBorder? b, double t) {
     if (b is CutCornersBorder) {
       final CutCornersBorder outline = b;
       return CutCornersBorder(
-        borderRadius: BorderRadius.lerp(borderRadius, outline.borderRadius, t),
+        borderRadius: BorderRadius.lerp(borderRadius, outline.borderRadius, t)!,
         borderSide: BorderSide.lerp(borderSide, outline.borderSide, t),
         cut: cut,
         gapPadding: outline.gapPadding,
@@ -103,12 +103,11 @@ class CutCornersBorder extends OutlineInputBorder {
   void paint(
     Canvas canvas,
     Rect rect, {
-    double gapStart,
+    double? gapStart,
     double gapExtent: 0.0,
     double gapPercentage: 0.0,
-    TextDirection textDirection,
+    TextDirection? textDirection,
   }) {
-    assert(gapExtent != null);
     assert(gapPercentage >= 0.0 && gapPercentage <= 1.0);
 
     final Paint paint = borderSide.toPaint();
@@ -117,8 +116,8 @@ class CutCornersBorder extends OutlineInputBorder {
       canvas.drawPath(_notchedCornerPath(outer.middleRect), paint);
     } else {
       final double extent =
-          lerpDouble(0.0, gapExtent + gapPadding * 2.0, gapPercentage);
-      switch (textDirection) {
+          lerpDouble(0.0, gapExtent + gapPadding * 2.0, gapPercentage)!;
+      switch (textDirection!) {
         case TextDirection.rtl:
           {
             final Path path = _notchedCornerPath(

mdc_100_series/lib/supplemental/product_card.dart

@@ -18,8 +18,8 @@ import 'package:intl/intl.dart';
 import '../model/product.dart';
 
 class ProductCard extends StatelessWidget {
-  ProductCard({this.imageAspectRatio: 33 / 49, this.product})
-      : assert(imageAspectRatio == null || imageAspectRatio > 0);
+  ProductCard({this.imageAspectRatio = 33 / 49, required this.product})
+      : assert(imageAspectRatio > 0);
 
   final double imageAspectRatio;
   final Product product;
@@ -30,7 +30,7 @@ class ProductCard extends StatelessWidget {
   Widget build(BuildContext context) {
     final NumberFormat formatter = NumberFormat.simpleCurrency(
         decimalDigits: 0, locale: Localizations.localeOf(context).toString());
-    final ThemeData theme = Theme.of(context);
+    final ThemeData theme = Theme.of(context)!;
 
     final imageWidget = Image.asset(
       product.assetName,
@@ -47,22 +47,22 @@ class ProductCard extends StatelessWidget {
           child: imageWidget,
         ),
         SizedBox(
-          height: kTextBoxHeight * MediaQuery.of(context).textScaleFactor,
+          height: kTextBoxHeight * MediaQuery.of(context)!.textScaleFactor,
           width: 121.0,
           child: Column(
             mainAxisAlignment: MainAxisAlignment.end,
             crossAxisAlignment: CrossAxisAlignment.center,
             children: <Widget>[
               Text(
-                product == null ? '' : product.name,
+                product.name,
                 style: theme.textTheme.headline6,
                 softWrap: false,
                 overflow: TextOverflow.ellipsis,
                 maxLines: 1,
               ),
               SizedBox(height: 4.0),
               Text(
-                product == null ? '' : formatter.format(product.price),
+                formatter.format(product.price),
                 style: theme.textTheme.subtitle2,
               ),
             ],