Flutter Create Animated Bottom Navigation Bar

Last updated Oct 28, 2021

When it comes to Mobile Applications, the Bottom Navigation Bar plays an Important role so, In this tutorial, we will learn how you can get Animated Bottom Navigation Bar in Flutter.

Let's start by creating a new application in Flutter Once you created a new application follow these steps:

Step 1: Add required packages in pubspec.yaml file and run flutter pub add

dependencies:
  ...
  bottom_navy_bar: ^5.6.0

Step 2: Inside your MaterialApp add a Stateful Widget in your home and declare a page controller and an int variable for your current index/state.

Example

int currentIndex = 0;

PageController _pageController;

Step 3: Inside your body declare Page View Widget and give page controller to it and add children as pages to your app for example if you want three bottom navigation buttons then add three children inside Page View.

body: SizedBox.expand(   
   child: PageView(
   controller: _pageController,
   onPageChanged: (index){
   setState(() {
   currentState = index;
   });
   },
   children: [
   Container(
   color: Colors.blue,
   child: Center(
   child: Text('Welcome',style: textStyle,),
   ),
   ),
   Container(
   color: Colors.red,
   child: Center(
   child: Text('To',style: textStyle,),
   ),
   ),Container(
   color: Colors.green,
   child: Center(
   child: Text('The',style: textStyle,),
   ),
   ),
   Container(
   color: Colors.pink,
   child: Center(
   child: Text('Jungle',style: textStyle,),
   ),
   ),
   ],
   ),
   ),

Step 4: Declare BottomNavyBar in Bottom Navigation Bar below your body and you can find various properties.

BottomNavyBar

iconSize - the item icon's size
items - navigation items, required more than one item and less than six
selectedIndex - the current item index. Use this to change the selected item. Default to zero
onItemSelected - required to listen when a item is tapped it provide the selected item's index
backgroundColor - the navigation bar's background color
showElevation - if false the appBar's elevation will be removed
mainAxisAlignment - use this property to change the horizontal alignment of the items. It is mostly used when you have ony two items and you want to center the items
curve - param to customize the item change's animation
containerHeight - changes the Navigation Bar's height

BottomNavyBarItem

icon - the icon of this item
title - the text that will appear next to the icon when this item is selected
activeColor - the active item's background and text color
inactiveColor - the inactive item's icon color
textAlign - property to change the alignment of the item title.

Using these properties you can customize your beautiful animated bottom navigation bar.

bottomNavigationBar: BottomNavyBar(      
   curve: Curves.easeIn,
   showElevation: true,
   selectedIndex: currentState,
   onItemSelected:(index){
   setState(() {
   currentState = index;
   });
   _pageController.jumpToPage(index);
   },
   items: [
   BottomNavyBarItem(icon: Icon(Icons.home),
   title: Text('Home'),
   inactiveColor: Colors.grey,
   activeColor: Colors.redAccent,
   textAlign: TextAlign.center
   ),
   BottomNavyBarItem(
   icon: Icon(Icons.message),
   title: Text('Message'),
   inactiveColor: Colors.grey,
   activeColor: Colors.indigoAccent,
   textAlign: TextAlign.center
   ),
   BottomNavyBarItem(
   icon: Icon(Icons.notifications),
   title: Text('Notification'),
   inactiveColor: Colors.grey,
   activeColor: Colors.green,
   textAlign: TextAlign.center
   ),
   BottomNavyBarItem(
   icon: Icon(Icons.settings),
   title: Text('Settings'),
   inactiveColor: Colors.grey,
   activeColor: Colors.blue,
   textAlign: TextAlign.center
   ),
   ],
   ),

Video Tutorial + Source Code

Completed Example code for Flutter Animated Bottom Navigation Bar:

import 'package:bottom_navy_bar/bottom_navy_bar.dart';
   import 'package:flutter/material.dart';
    
   void main()=> runApp(MyApp());
    
   class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
   return MaterialApp(
   debugShowCheckedModeBanner: false,
   home: BottomBarDemo(),
   );
   }
   }
    
   class BottomBarDemo extends StatefulWidget {
   @override
   _BottomBarDemoState createState() => _BottomBarDemoState();
   }
    
   class _BottomBarDemoState extends State<BottomBarDemo> {
    
   int currentState = 0;
   PageController _pageController;
   TextStyle textStyle = TextStyle(fontSize: 30,fontStyle: FontStyle.italic);
    
   @override
   void initState() {
   // TODO: implement initState
   super.initState();
   _pageController = PageController();
   }
    
   @override
   void dispose() {
   // TODO: implement dispose
   super.dispose();
   _pageController.dispose();
   }
    
   @override
   Widget build(BuildContext context) {
   return Scaffold(
   appBar: AppBar(title: Text('Demo'),),
   body: SizedBox.expand(
   child: PageView(
   controller: _pageController,
   onPageChanged: (index){
   setState(() {
   currentState = index;
   });
   },
   children: [
   Container(
   color: Colors.blue,
   child: Center(
   child: Text('Welcome',style: textStyle,),
   ),
   ),
   Container(
   color: Colors.red,
   child: Center(
   child: Text('To',style: textStyle,),
   ),
   ),Container(
   color: Colors.green,
   child: Center(
   child: Text('The',style: textStyle,),
   ),
   ),
   Container(
   color: Colors.pink,
   child: Center(
   child: Text('Jungle',style: textStyle,),
   ),
   ),
   ],
   ),
   ),
   bottomNavigationBar: BottomNavyBar(
   curve: Curves.easeIn,
   showElevation: true,
   selectedIndex: currentState,
   onItemSelected:(index){
   setState(() {
   currentState = index;
   });
   _pageController.jumpToPage(index);
   },
   items: [
   BottomNavyBarItem(icon: Icon(Icons.home),
   title: Text('Home'),
   inactiveColor: Colors.grey,
   activeColor: Colors.redAccent,
   textAlign: TextAlign.center
   ),
   BottomNavyBarItem(
   icon: Icon(Icons.message),
   title: Text('Message'),
   inactiveColor: Colors.grey,
   activeColor: Colors.indigoAccent,
   textAlign: TextAlign.center
   ),
   BottomNavyBarItem(
   icon: Icon(Icons.notifications),
   title: Text('Notification'),
   inactiveColor: Colors.grey,
   activeColor: Colors.green,
   textAlign: TextAlign.center
   ),
   BottomNavyBarItem(
   icon: Icon(Icons.settings),
   title: Text('Settings'),
   inactiveColor: Colors.grey,
   activeColor: Colors.blue,
   textAlign: TextAlign.center
   ),
   ],
   ),
   );
   }
   }

Conclusion: In this tutorial, we learned how you can create a beautiful animated Bottom Navigation Bar in Flutter.

Article Contributed By :

854 Views

Projects By category