I am a beginner with flutter and dart. I have been trying to implement a navigationBar on three different pages in my app. The toggling works well for an individual page but I have problems persisting the active and inactive tabs state on all the pages. It seems like when it navigates to another page, I lose the active state too the tabs. This is my code.
AppFooter.dart
import 'package:flutter/material.dart';
class AppFooter extends StatefulWidget {
#override
_AppFooterState createState() => _AppFooterState();
}
class _AppFooterState extends State<AppFooter> {
int index = 0;
#override
Widget build(BuildContext context) {
return new Theme(
data: Theme.of(context).copyWith(
// sets the background color of the `BottomNavigationBar`
canvasColor: Colors.white,
// sets the active color of the `BottomNavigationBar` if `Brightness` is light
primaryColor: Colors.green,
textTheme: Theme.of(context)
.textTheme
.copyWith(caption: new TextStyle(color: Colors.grey))),
child: new BottomNavigationBar(
type: BottomNavigationBarType.fixed,
currentIndex: index,
onTap: (int index) {
setState(() {
this.index = index;
});
switch (index){
case 0: Navigator.of(context).pushNamed('/dashboard');
break;
case 1: Navigator.of(context).pushNamed('/medical centre');
break;
case 2: Navigator.of(context).pushNamed('/history');
break;
}
},
items: [
new BottomNavigationBarItem(
backgroundColor: Colors.white,
icon: index==0?new Image.asset('assets/images/dashboard_active.png'):new Image.asset('assets/images/dashboard_inactive.png'),
title: new Text('Dashboard', style: new TextStyle(fontSize: 12.0))),
new BottomNavigationBarItem(
backgroundColor: Colors.white,
icon: index==1?new Image.asset('assets/images/medical_sevice_active.png'):new Image.asset('assets/images/medical_sevice_inactive.png'),
title: new Text('Health Services', style: new TextStyle(fontSize: 12.0))),
new BottomNavigationBarItem(
icon: InkWell(
child: Icon(
Icons.format_align_left,
// color: green,
size: 20.0,
),
),
title: new Text('History', style: new TextStyle(fontSize: 12.0))),
]),
);
}
}
If I understand your question correctly, you need the bottom navigation bar persisted on all three pages. There is a well-written article on how to achieve it. You can find the details here.
https://medium.com/coding-with-flutter/flutter-case-study-multiple-navigators-with-bottomnavigationbar-90eb6caa6dbf
https://github.com/bizz84/nested-navigation-demo-flutter
All credits go to the original author.
Use PageView and bottomNavigationBar:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
/// This Widget is the main application widget.
class MyApp extends StatelessWidget {
static const String _title = 'Flutter App';
#override
Widget build(BuildContext context) {
return MaterialApp(
title: _title,
home: App(),
);
}
}
class App extends StatefulWidget {
App({Key key}) : super(key: key);
_AppState createState() => _AppState();
}
class _AppState extends State<App> {
PageController _myPage;
var selectedPage;
#override
void initState() {
super.initState();
_myPage = PageController(initialPage: 1);
selectedPage = 1;
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: PageView(
physics: NeverScrollableScrollPhysics(),
controller: _myPage,
children: <Widget>[
Center(
child: Text("Another Page"),
),
Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text("Page 1"),
RaisedButton(
onPressed: () {
_myPage.jumpToPage(0);
setState(() {
selectedPage = 0;
});
},
child: Text("Go to another page"),
)
],
)),
Center(child: Text("Page 2")),
Center(child: Text("Page 3")),
],
),
bottomNavigationBar: BottomAppBar(
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
IconButton(
icon: Icon(Icons.home),
color: selectedPage == 1 ? Colors.blue : Colors.grey,
onPressed: () {
_myPage.jumpToPage(1);
setState(() {
selectedPage = 1;
});
},
),
IconButton(
icon: Icon(Icons.star),
color: selectedPage == 2 ? Colors.blue : Colors.grey,
onPressed: () {
_myPage.jumpToPage(2);
setState(() {
selectedPage = 2;
});
},
),
IconButton(
icon: Icon(
Icons.settings,
),
color: selectedPage == 3 ? Colors.blue : Colors.grey,
onPressed: () {
_myPage.jumpToPage(3);
setState(() {
selectedPage = 3;
});
},
),
],
),
));
}
}
In addition, if you want preserve the state between pages such that going to another page won't cause the previous page to lose its state, use AutomaticKeepAliveClientMixin
Also, to lazily load the pages, PageView.builder is another solution.
Hope it helps.
Another great solution is the persistent_bottom_nav_bar package provided by Bilal Shahid.
It is easy to use and offers you a bunch of features:
Highly customizable persistent 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. Click here for more information.
Handles hardware/software Android back button.
Before I found this package I followed the solution from the article #Abin mentioned in his answer. But I ran into the problem, that all screens from the navbar beeing loaded on first load of the navbar which is not that perfomant. I did not mangaed to solve this, but luckily Bilal Shahid provide a good solution with his package.
All credits to him.
Just copy & past :)
main.dart:
void main() async{
runApp(MyGrillApp());
}
class MyGrillApp extends StatelessWidget {
const MyGrillApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
routes: {
'/mainlayout': (context) => MainLayout(),
'/page1': (context) => Page1(),
'/page2': (context) => Page2(),
'/page3': (context) => Page3(),
'/page4': (context) => Page4(),
},
initialRoute: '/mainlayout',
);
}
}
main_layout.dart:
class MainLayout extends StatefulWidget {
#override
_MainLayoutState createState() => _MainLayoutState();
}
class _MainLayoutState extends State<MainLayout> {
int _currentIndex = 0;
final _page1 = GlobalKey<NavigatorState>();
final _page2 = GlobalKey<NavigatorState>();
final _page3 = GlobalKey<NavigatorState>();
final _page4 = GlobalKey<NavigatorState>();
#override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButtonLocation: FloatingActionButtonLocation.miniCenterDocked,
floatingActionButton: Padding(
padding: const EdgeInsets.all(6.0),
child: FloatingActionButton(
backgroundColor: Colors.redAccent,
child: const Icon(Icons.add, color: Colors.white),
onPressed: () {
// ToDo...
},
),
),
body: IndexedStack(
index: _currentIndex,
children: <Widget>[
Navigator(
key: _page1,
onGenerateRoute: (route) => MaterialPageRoute(
settings: route,
builder: (context) => Page1(),
),
),
Navigator(
key: _page2,
onGenerateRoute: (route) => MaterialPageRoute(
settings: route,
builder: (context) => Page2(),
),
),
Navigator(
key: _page3,
onGenerateRoute: (route) => MaterialPageRoute(
settings: route,
builder: (context) => Page3(),
),
),
Navigator(
key: _page4,
onGenerateRoute: (route) => MaterialPageRoute(
settings: route,
builder: (context) => Page4(),
),
),
],
),
bottomNavigationBar: BottomAppBar(
shape: const CircularNotchedRectangle(),
clipBehavior: Clip.antiAlias,
child: BottomNavigationBar(
backgroundColor: Colors.white,
currentIndex: _currentIndex,
onTap: (index) {
setState(() {
_currentIndex = index;
});
},
type: BottomNavigationBarType.fixed,
selectedItemColor: Colors.redAccent,
unselectedItemColor: Colors.grey,
showSelectedLabels: false,
showUnselectedLabels: false,
items: const <BottomNavigationBarItem>[
BottomNavigationBarItem(icon: Icon(Icons.home), label: 'Home'),
BottomNavigationBarItem(icon: Icon(Icons.date_range), label: 'Statistics'),
BottomNavigationBarItem(icon: Icon(Icons.wallet_giftcard), label: 'Wallet'),
BottomNavigationBarItem(icon: Icon(Icons.person), label: 'Profile'),
],
),
),
);
}
}
Details screen:
class ItemDetailsPage extends StatefulWidget {
const ItemDetailsPage({Key? key}) : super(key: key);
#override
_ItemDetailsPageState createState() => _ItemDetailsPageState();
}
class _ItemDetailsPageState extends State<ItemDetailsPage> with AutomaticKeepAliveClientMixin{
#override
Widget build(BuildContext context) {
super.build(context);
return Scaffold(
appBar: AppBar(
backgroundColor: themeColorPrimary,
title: Text('Item details',),
),
body : Container(child: Text('Hello from details'),));
}
#override
bool get wantKeepAlive => true;
}
A note about routing in my solution:
If you encounter trouble when you routing by:
Navigator.pushNamed(context, '/page3');
or by:
Navigator.of(context).pushNamed(Page3());
You can fix it using MaterialPageRoute:
Navigator.pushReplacement(
context,
MaterialPageRoute(
builder: (context) => Page3(),
),
);
You can use IndexedStack to persist State when you touch/change the page
Scaffold(
body: SafeArea(
top: false,
child: IndexedStack(
//Permet de garder le state des vues même quand on change de vue
index: _currentIndex,
children: _children,
),
),
bottomNavigationBar: BottomNavigationBar( items: [ ] ),
);
I highly recommend using stack. This gives you pretty much total control over how and when you would like to show bottom app bar.
Make list of all pages you want to show using your botttomAppBar. Let's say has three icons.
final List<Widget> pages=[FirstScreen(),SecondScreen(),ThirdScreen()];
In the Build Method
Scaffold(
child: Stack(
children: <Widget>[
Navigator(
key: _navigatorKey,
onGenerateRoute: (RouteSettings settings) {
return MaterialPageRoute(
builder: (BuildContext context) => pages[cur_ind],
);
},
),
],
bottomNavigationBar: BottomNavigationBar(
onTap: (int index){
setState(() {
cur_ind=index;
});
},
currentIndex: cur_ind,
fixedColor: Colors.green, //let's say
items: [
BottomNavigationBarItem(
icon: Icon(Icons.home),
title: Text('Home'),
),
BottomNavigationBarItem(
icon: Icon(Icons.mail),
title: Text('Messages'),
),
BottomNavigationBarItem(
icon: Icon(Icons.person), title: Text('Profile'))
],
),
),
),
where cur_ind is the variable used to control which page to show. And since the body is stacked, the Bottom Navigation Bar will be persistent always.
I created a small, super easy to use package that let you do that effect CustomNavigator.
And wrote a tutorial about it on Medium you can find it here.
So it goes like this
// Here's the custom scaffold widget
// It takes a normal scaffold with mandatory bottom navigation bar
// and children who are your pages
CustomScaffold(
scaffold: Scaffold(
bottomNavigationBar: BottomNavigationBar(
items: _items,
),
),
// Children are the pages that will be shown by every click
// They should placed in order such as
// `page 0` will be presented when `item 0` in the [BottomNavigationBar] clicked.
children: <Widget>[
Page('0'),
Page('1'),
Page('2'),
],
// Called when one of the [items] is tapped.
onItemTap: (index) {},
);
The cool thing about this library that it works efficiently. It creates a nested navigator (which is very unpleasant to do) and uses it for navigation in your widget tree.
And of course you can always use the default navigator from MaterialApp
If you are looking for a solution that performs well (that doesn't build the tabs/pages unnecessarily) even using IndexedStack take a look at my answer here
For anyone looking for this in the future auto_route handle this pretty much well with very little boilerplate using AutoTabsScaffold.
Widget build(context) {
return AutoTabsScaffold(
routes: const [
BooksRouter(),
AccountRouter(),
],
bottomNavigationBuilder: (_, tabsRouter) {
return BottomNavigationBar(
currentIndex: tabsRouter.activeIndex,
onTap: tabsRouter.setActiveIndex,
items: [
BottomNavigationBarItem(
icon: Icon(Icons.book),
label: 'Books',
),
BottomNavigationBarItem(
icon: Icon(Icons.account_box),
label: 'Account',
),
],
);
},
);
}
I am working on a beta version of an express_app plugin, which achieve the required result.
Two days ago, I implemented an addition where you can set an ExpressHome and it can be any part of your tree, in addition to setting your routes of course. When changing the routes, everything under ExpressHome will change only and the rest will stay the same (i.e. you can have a permanent bar easily.
I will publish a more-recent version this evening, and if you would like a specific demo about your use case, let me know.
i had this issue too...after days of research i came across this package
persistent_bottom_nav_bar: ^4.0.0
it quite easy to implement.
You can use a scaffold widget to contain the whole screen then put IndexedStack widget as a Body option then use at the bottom navigation option in the scaffold widget you favorite implementation of the bottom navigation bar
Scaffold(
// here is the IndexedStack as body
body: IndexedStack(
index: this._bottomNavIndex,
children: [MangaGridView(), FavoriteManga()]),
backgroundColor: Colors.black,
bottomNavigationBar: AnimatedBottomNavigationBar(
icons: [
Icons.home_outlined,
Icons.favorite_border,
Icons.settings,
],
inactiveColor: Colors.black,
activeIndex: this._bottomNavIndex,
gapLocation: GapLocation.none,
activeColor: Theme.of(context).primaryColor,
notchSmoothness: NotchSmoothness.verySmoothEdge,
leftCornerRadius: 32,
rightCornerRadius: 32,
onTap: (index) => setState(() => this._bottomNavIndex = index),
height: 70,
splashColor: Theme.of(context).primaryColor,
splashRadius: 40.0,
splashSpeedInMilliseconds: 400,
iconSize: 34,
),
);
Navigator.of(context).pushNamed(); is for Navigation with page transition. So, in this situation, the method is not match.
You can use BottomNavigationBar with Scaffold.
example code:
class AppFooter extends StatefulWidget {
#override
_AppFooterState createState() => _AppFooterState();
}
class _AppFooterState extends State<AppFooter> {
int _currentIndex = 0;
List<Widget> _pages = [
Text("page1"),
Text("page2"),
Text("page3"),
];
#override
Widget build(BuildContext context) {
return Scaffold(
body: _pages[_currentIndex],
bottomNavigationBar: BottomNavigationBar(
type: BottomNavigationBarType.fixed,
currentIndex: _currentIndex,
onTap: (int index) {
setState(() {
_currentIndex = index;
});
},
items: [
new BottomNavigationBarItem(
backgroundColor: Colors.white,
icon: _currentIndex == 0
? new Image.asset('assets/images/dashboard_active.png')
: new Image.asset('assets/images/dashboard_inactive.png'),
title:
new Text('Dashboard', style: new TextStyle(fontSize: 12.0))),
new BottomNavigationBarItem(
backgroundColor: Colors.white,
icon: _currentIndex == 1
? new Image.asset('assets/images/medical_sevice_active.png')
: new Image.asset(
'assets/images/medical_sevice_inactive.png'),
title: new Text('Health Services',
style: new TextStyle(fontSize: 12.0))),
new BottomNavigationBarItem(
icon: InkWell(
child: Icon(
Icons.format_align_left,
// color: green,
size: 20.0,
),
),
title: new Text('History', style: new TextStyle(fontSize: 12.0))),
],
),
);
}
}
Just make your index variable static
like:
static int index = 0;
i want to open profile page from home page without press 'profile' button inside bottomnavigation item.
Thanks for help.
this is a main class of my project. i put all page here and i already import all page here.
MainClass
int _currentIndex = 0;
final List<Widget> _children = [
HomePage(),
MessagePage(),
ProfilePage()
];
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('My Flutter App'),
),
body: _children[_currentIndex],
bottomNavigationBar: BottomNavigationBar(
currentIndex: _currentIndex,
onTap: onTabTapped,
items: [
BottomNavigationBarItem(
icon: new Icon(Icons.home),
title: new Text('Home'),
),
BottomNavigationBarItem(
icon: new Icon(Icons.mail),
title: new Text('Messages'),
),
BottomNavigationBarItem(
icon: Icon(Icons.person),
title: Text('Profile')
)
],
),
);
}
and this my home page. this page same as profile and message page. i need to open profile page from home page without pressing profile menu in bottom. i just wanna press profile button inside home page.
HomePage
import 'package:flutter/material.dart';
import 'package:navigation/profile_page.dart';
class HomePage extends StatefulWidget {
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Column(
children: <Widget>[
Text("Home Page"),
RaisedButton(
child: Text("GO TO PROFILE PAGE"),
onPressed: (){
);
},
)
],
),
),
);
}
}
This can be done by directly calling the class name.
For example consider Profile() be the class extending statefull class.
Home class
....
int _index = 1;
final options = [
Text('Home'),
Text('Message'),
Profile() //directly call the class to load
];
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("My flutter app"),
),
body: Center(
child: options.elementAt(_index),
),
bottomNavigationBar: BottomNavigationBar(
items: [
new BottomNavigationBarItem(
icon: Icon(Icons.home),
title: Text('Home'),
),
new BottomNavigationBarItem(
icon: Icon(Icons.message),
title: Text('message'),
),
new BottomNavigationBarItem(
icon: Icon(Icons.person),
title: Text('profile')
)
],
currentIndex: _index,
onTap: _onTapped,
),
);
}
void _onTapped(int index) {
setState(() {
_index = index;
});
}
Similarly you can load other classes too.
hope it helped:)
I am trying to show a menu when a navigation bar item is clicked. This was my attempt:
#override
Widget build(BuildContext context) {
return DefaultTabController(
length: 3,
child: Scaffold(
appBar: MyAppBar(
title: "Home",
context: context,
),
bottomNavigationBar: BottomNavigationBar(
items: [
BottomNavigationBarItem(
icon: new Icon(Icons.home), title: Text('Home')),
BottomNavigationBarItem(
icon: new Icon(Icons.book), title: Text('Second')),
BottomNavigationBarItem(
icon: new PopupMenuButton(
icon: Icon(Icons.add),
itemBuilder: (_) => <PopupMenuItem<String>>[
new PopupMenuItem<String>(
child: const Text('test1'), value: 'test1'),
new PopupMenuItem<String>(
child: const Text('test2'), value: 'test2'),
],
),
title: Text('more')),
],
currentIndex: 0,
),
body: new Container()));
}
I encountered two problems. First one is the display of the NavigationBarItem. There is a padding between the icon the title that I could not remove (even by adding padding: EdgeInsets.all(0.0)) (as the picture below shows). And the second is that I need to click exactly on the icon for the menu to appear.
I tried calling showMenu directly (the method that PopupMenuButton calls) when a BottomNavigationBarItem of index=2 (for example) is clicked. But it was tricky how to determine the location of origin where the menu should appear from.
Here's an attempt that uses the showMenu directly and calling the function buttonMenuPosition to get the position for the menu. It's fairly fragile, but you can change the location of the button to the middle for example with bar.size.center instead of bar.size.bottomRight. With some MATH and by manually manipulating Offset objects (if/when you have more than 3 items), you can change the location to have the menu on one that isn't the center or at the end).
RelativeRect buttonMenuPosition(BuildContext c) {
final RenderBox bar = c.findRenderObject();
final RenderBox overlay = Overlay.of(c).context.findRenderObject();
final RelativeRect position = RelativeRect.fromRect(
Rect.fromPoints(
bar.localToGlobal(bar.size.bottomRight(Offset.zero), ancestor: overlay),
bar.localToGlobal(bar.size.bottomRight(Offset.zero), ancestor: overlay),
),
Offset.zero & overlay.size,
);
return position;
}
#override
Widget build(BuildContext context) {
final key = GlobalKey<State<BottomNavigationBar>>();
return DefaultTabController(
length: 3,
child: Scaffold(
appBar: AppBar(
title: Text("Home"),
),
bottomNavigationBar: BottomNavigationBar(
key: key,
items: [
const BottomNavigationBarItem(
icon: Icon(Icons.home), title: Text('Home')),
const BottomNavigationBarItem(
icon: Icon(Icons.book), title: Text('Second')),
const BottomNavigationBarItem(
icon: Icon(Icons.add), title: Text('more')),
],
currentIndex: 0,
onTap: (index) async {
final position = buttonMenuPosition(key.currentContext);
if (index == 2) {
final result = await showMenu(
context: context,
position: position,
items: <PopupMenuItem<String>>[
const PopupMenuItem<String>(
child: Text('test1'), value: 'test1'),
const PopupMenuItem<String>(
child: Text('test2'), value: 'test2'),
],
);
}
},
),
body: Container()));
}
Here's my attempt at it:
#override
Widget build(BuildContext context) {
return Material(
child: DefaultTabController(
length: 3,
child: Scaffold(
appBar: AppBar(
title: Text("Home"),
),
bottomNavigationBar: BottomNavigationBar(
items: [
BottomNavigationBarItem(
icon: new Icon(Icons.home), title: Text('Home')),
BottomNavigationBarItem(
icon: new Icon(Icons.book), title: Text('Second')),
BottomNavigationBarItem(
icon: new Icon(Icons.add),
title: Text('More')),
],
currentIndex: 0,
onTap: (int index) async {
if(index == 2){
await showMenu<String>(
context: context,
position: RelativeRect.fromLTRB(1000.0, 1000.0, 0.0, 0.0),
items: <PopupMenuItem<String>>[
new PopupMenuItem<String>(
child: const Text('test1'), value: 'test1'),
new PopupMenuItem<String>(
child: const Text('test2'), value: 'test2'),
],
elevation: 8.0,
);
}
},
),
body: new Container())));
}
Basically using the showMenu method as you said except I've put the values for the RelativeRect as 1000.0 so that it'll be in the bottom right of any device. You could mess around with these values to get a position more right above the icon but I think having it like this works well: