rand dart fix

deprecated/responsive_scaffold/example/lib/examples/layout.dart

@@ -74,7 +74,7 @@ class LayoutExample extends StatelessWidget {
       ),
       floatingActionButton: FloatingActionButton(
         child: Icon(Icons.add),
-        backgroundColor: Theme.of(context).accentColor,
+        backgroundColor: Theme.of(context).colorScheme.secondary,
         onPressed: () {},
       ),
     );

deprecated/responsive_scaffold/example/lib/examples/list.dart

@@ -53,7 +53,7 @@ class _ListExampleState extends State<ListExample> {
           title: Text("App Bar"),
         ),
       ],
-      itemCount: _items?.length ?? 0,
+      itemCount: _items.length ?? 0,
       itemBuilder: (BuildContext context, int index) {
         final i = _items[index];
         return ListTile(

deprecated/responsive_scaffold/example/lib/main.dart

@@ -22,16 +22,14 @@ void _setTargetPlatformForDesktop() {
   } else if (Platform.isLinux || Platform.isWindows) {
     targetPlatform = TargetPlatform.android;
   }
-  if (targetPlatform != null) {
-    debugDefaultTargetPlatformOverride = targetPlatform;
-  }
+  debugDefaultTargetPlatformOverride = targetPlatform;
 }
 
 class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      theme: ThemeData.light().copyWith(accentColor: Colors.red),
+      theme: ThemeData.light().copyWith(colorScheme: ColorScheme.fromSwatch().copyWith(secondary: Colors.red)),
       debugShowCheckedModeBanner: false,
       home: HomePage(),
     );