Bottom Navigation Bar in Flutter
The bottom navigation bar in flutter is a beautiful bottom navigation bar for flutter. It is highly customizable. You can easily implement this library in a flutter.
Available Styles
More styles available here
Features
- Highly customizable bottom navigation bar.
- Ability to push new screens with or without bottom navigation bar.
- 20 styles for the bottom navigation bar.
- Includes functions for pushing screen with or without the bottom navigation bar i.e. pushNewScreen() and pushNewScreenWithRouteSettings().
- Based on flutter’s Cupertino(iOS) bottom navigation bar.
- Can be
translucent
for a particular tab. - Custom styling for the navigation bar.
- Handles hardware/software Android back button.
Getting Started
In your flutter project add the dependency:
dependencies: persistent_bottom_nav_bar: any
Import the package:
import 'package:persistent_bottom_nav_bar/persistent-tab-view.dart';
Persistent bottom navigation bar uses PersistentTabController
as its controller. Here is how to declare it:
PersistentTabController _controller; _controller = PersistentTabController(initialIndex: 0);
The main widget then to be declared is PersistentTabView
. NOTE: This widget includes SCAFFOLD (based on CupertinoTabScaffold
), so no need to declare it. Following is an example for demonstration purposes:
class MyApp extends StatelessWidget { const MyApp({Key key}) : super(key: key); @override Widget build(BuildContext context) { return PersistentTabView( context, controller: _controller, screens: _buildScreens(), items: _navBarsItems(), confineInSafeArea: true, backgroundColor: Colors.white, // Default is Colors.white. handleAndroidBackButtonPress: true, // Default is true. resizeToAvoidBottomInset: true, // This needs to be true if you want to move up the screen when keyboard appears. Default is true. stateManagement: true, // Default is true. hideNavigationBarWhenKeyboardShows: true, // Recommended to set 'resizeToAvoidBottomInset' as true while using this argument. Default is true. decoration: NavBarDecoration( borderRadius: BorderRadius.circular(10.0), colorBehindNavBar: Colors.white, ), popAllScreensOnTapOfSelectedTab: true, popActionScreens: PopActionScreensType.all, itemAnimationProperties: ItemAnimationProperties( // Navigation Bar's items animation properties. duration: Duration(milliseconds: 200), curve: Curves.ease, ), screenTransitionAnimation: ScreenTransitionAnimation( // Screen transition animation on change of selected tab. animateTabTransition: true, curve: Curves.ease, duration: Duration(milliseconds: 200), ), navBarStyle: NavBarStyle.style1, // Choose the nav bar style with this property. ); } }
List<Widget> _buildScreens() { return [ MainScreen(), SettingsScreen() ]; }
List<PersistentBottomNavBarItem> _navBarsItems() { return [ PersistentBottomNavBarItem( icon: Icon(CupertinoIcons.home), title: ("Home"), activeColorPrimary: CupertinoColors.activeBlue, inactiveColorPrimary: CupertinoColors.systemGrey, ), PersistentBottomNavBarItem( icon: Icon(CupertinoIcons.settings), title: ("Settings"), activeColorPrimary: CupertinoColors.activeBlue, inactiveColorPrimary: CupertinoColors.systemGrey, ), ]; }
Navigator Functions
Note: You still can use regular Navigator functions like ‘pushNamed’ but be sure to check the argument routeAndNavigatorSettings
your PersistentBottomNavBarItem
for route settings and some other navigator related properties To push a new screen, use the following functions to control the visibility
of bottom navigation bar on a particular screen. You can use your own logic to implement platform-specific
behavior. One of the solutions could be to use the property withNavBar
and toggle it according to the Platform.
In platform-specific
behavior, while pushing a new screen, on Android
it will push the screen WITHOUT the bottom navigation bar but on iOS
it will persist the bottom navigation bar. This is the default behavior specified by each platform.
pushNewScreen( context, screen: MainScreen(), withNavBar: true, // OPTIONAL VALUE. True by default. pageTransitionAnimation: PageTransitionAnimation.cupertino, );
pushNewScreenWithRouteSettings( context, settings: RouteSettings(name: MainScreen.routeName), screen: MainScreen(), withNavBar: true, pageTransitionAnimation: PageTransitionAnimation.cupertino, );
If you are pushing a new modal
screen, use the following function:
pushDynamicScreen( context, screen: HomeModalScreen(), withNavBar: true, );
Some Useful Tips
Pop to any screen in the navigation graph for a given tab:
Navigator.of(context).popUntil((route) { return route.settings.name == "ScreenToPopBackTo"; });
Pop back to first screen in the navigation graph for a given tab:
Navigator.of(context).popUntil(ModalRoute.withName("/"));
Navigator.of(context).pushAndRemoveUntil( CupertinoPageRoute( builder: (BuildContext context) { return FirstScreen(); }, ), (_) => false, );
To push bottom sheet on top of the Navigation Bar, use showModalBottomScreen and set it’s property useRootNavigator
to true. See example project for an illustration.
Custom Navigation Bar Styling
If you want to have your own style for the navigation bar, follow these steps:
- Declare your custom widget. Please keep in mind that you will have to handle the function
onSelectedItem
and the integerselectedIndex
yourself to maintain full functionality. Also please note that you can define your own model for the navigation bar item instead of the providedPersistentBottomNavBarItem
. See this example below for better understanding:
class CustomNavBarWidget extends StatelessWidget { final int selectedIndex; final List<PersistentBottomNavBarItem> items; // NOTE: You CAN declare your own model here instead of `PersistentBottomNavBarItem`. final ValueChanged<int> onItemSelected; CustomNavBarWidget( {Key key, this.selectedIndex, @required this.items, this.onItemSelected,}); Widget _buildItem( PersistentBottomNavBarItem item, bool isSelected) { return Container( alignment: Alignment.center, height: 60.0, child: Column( mainAxisAlignment: MainAxisAlignment.center, crossAxisAlignment: CrossAxisAlignment.center, mainAxisSize: MainAxisSize.min, children: <Widget>[ Flexible( child: IconTheme( data: IconThemeData( size: 26.0, color: isSelected ? (item.activeColorSecondary == null ? item.activeColorPrimary : item.activeColorSecondary) : item.inactiveColorPrimary == null ? item.activeColorPrimary : item.inactiveColorPrimary), child: item.icon, ), ), Padding( padding: const EdgeInsets.only(top: 5.0), child: Material( type: MaterialType.transparency, child: FittedBox( child: Text( item.title, style: TextStyle( color: isSelected ? (item.activeColorSecondary == null ? item.activeColorPrimary : item.activeColorSecondary) : item.inactiveColorPrimary, fontWeight: FontWeight.w400, fontSize: 12.0), )), ), ) ], ), ); } @override Widget build(BuildContext context) { return Container( color: Colors.white, child: Container( width: double.infinity, height: 60.0, child: Row( mainAxisAlignment: MainAxisAlignment.spaceAround, children: items.map((item) { int index = items.indexOf(item); return Flexible( child: GestureDetector( onTap: () { this.onItemSelected(index); }, child: _buildItem( item, selectedIndex == index), ), ); }).toList(), ), ), ); } }
In the main PersistentTabView
widget, set the navBarStyle
property as NavBarStyle.custom
and pass on the custom widget you just created in the customWidget
property like this:
class MyApp extends StatelessWidget { const MyApp({Key key}) : super(key: key); @override Widget build(BuildContext context) { return PersistentTabView.custom( context, controller: _controller, itemCount: items.length, // This is required in case of custom style! Pass the number of items for the nav bar. screens: _buildScreens(), confineInSafeArea: true, handleAndroidBackButtonPress: true, onItemSelected: (int) { setState(() {}); // This is required to update the nav bar if Android back button is pressed }, customWidget: CustomNavBarWidget( // Your custom widget goes here items: _navBarsItems(), selectedIndex: _controller.index, onItemSelected: (index) { setState(() { _controller.index = index; // NOTE: THIS IS CRITICAL!! Don't miss it! }); }, ), ); } }
NOTE: In the 'onSelected' function of the customWidget, don't forgot to change the index of the controller
- Done! As we can see, some of the other properties like
iconSize
,items
are not required here so you can skip those properties. To control the bottom padding of the screen, usebottomScreenPadding
. If you give too muchbottomScreenPadding
but less height in the custom widget or vice versa, layout issues might appear.
For better understanding, refer to the example project in the official git repo.
Credits:
This is developed by BilalShahid13.
Download this project from the below link.
https://github.com/wiltonribeiro/gooey_tabbar_flutter/archive/master.zip
You can visit original source page from the below link:
https://github.com/wiltonribeiro/gooey_tabbar_flutter