look ahead

lib/screens/main_shell.dart

@@ -1,9 +1,11 @@
-/// Host scaffold: Home + Overview. Settings lives in the app-bar gear.
+/// Host scaffold: Home, Overview, Look ahead. Settings lives in the app-bar gear.
 library;
 
 import 'package:flutter/material.dart';
 
+import '../widgets/shell_tab_scope.dart';
 import 'home_screen.dart';
+import 'look_ahead_screen.dart';
 import 'overview_screen.dart';
 
 class MainShell extends StatefulWidget {
@@ -19,31 +21,40 @@ class _MainShellState extends State<MainShell> {
   static const _pages = [
     HomeScreen(),
     OverviewScreen(),
+    LookAheadScreen(),
   ];
 
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      body: IndexedStack(
-        index: _index,
-        children: _pages,
-      ),
-      bottomNavigationBar: NavigationBar(
-        selectedIndex: _index,
-        onDestinationSelected: (index) => setState(() => _index = index),
-        labelBehavior: NavigationDestinationLabelBehavior.alwaysShow,
-        destinations: const [
-          NavigationDestination(
-            icon: Icon(Icons.home_outlined),
-            selectedIcon: Icon(Icons.home),
-            label: 'Home',
-          ),
-          NavigationDestination(
-            icon: Icon(Icons.insights_outlined),
-            selectedIcon: Icon(Icons.insights),
-            label: 'Overview',
-          ),
-        ],
+    return ShellTabScope(
+      index: _index,
+      child: Scaffold(
+        body: IndexedStack(
+          index: _index,
+          children: _pages,
+        ),
+        bottomNavigationBar: NavigationBar(
+          selectedIndex: _index,
+          onDestinationSelected: (index) => setState(() => _index = index),
+          labelBehavior: NavigationDestinationLabelBehavior.alwaysShow,
+          destinations: const [
+            NavigationDestination(
+              icon: Icon(Icons.home_outlined),
+              selectedIcon: Icon(Icons.home),
+              label: 'Home',
+            ),
+            NavigationDestination(
+              icon: Icon(Icons.insights_outlined),
+              selectedIcon: Icon(Icons.insights),
+              label: 'Overview',
+            ),
+            NavigationDestination(
+              icon: Icon(Icons.event_repeat_outlined),
+              selectedIcon: Icon(Icons.event_repeat),
+              label: 'Look ahead',
+            ),
+          ],
+        ),
       ),
     );
   }