bottom nav bar init

lib/navigation.dart

@@ -0,0 +1,46 @@
+import 'dart:ffi';
+
+import 'package:flutter/material.dart';
+
+class Navigation extends StatefulWidget {
+  const Navigation({super.key});
+
+  @override
+  State<Navigation> createState() => _NavigationState();
+}
+
+class _NavigationState extends State<Navigation> {
+
+  int _selectedIndex = 1;
+  static const List<Widget> _widgetOptions = <Widget>[
+    Text("Calendar"),
+    Text("Inbox"),
+    Text("Notes"),
+  ];
+
+  void _onItemTapped(int index) {
+    setState(() {
+      _selectedIndex = index;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("BottomNavBar"),
+      ),
+      body: Center(child: _widgetOptions.elementAt(_selectedIndex)),
+      bottomNavigationBar: BottomNavigationBar(
+        items: const <BottomNavigationBarItem>[
+          BottomNavigationBarItem(
+              icon: Icon(Icons.calendar_today), label: "today"),
+          BottomNavigationBarItem(icon: Icon(Icons.inbox), label: "Inbox"),
+          BottomNavigationBarItem(icon: Icon(Icons.note), label: "Notes"),
+        ],
+        currentIndex: _selectedIndex,
+        onTap: _onItemTapped,
+      ),
+    );
+  }
+}