I am trying to create a uniform drawer that is accessible across all pages in my app. How do I make it persist throughout all these pages without having to recreate my custom Drawer widget in every single dart file?
There are a few different options for this. The most basic is hopefully something you've already done, but I'll list it anyways:
1: Create a class for your drawer
Your widget should be its own stateful or stateless widget. This way, you just have to instantiate it each time.
class MyDrawer extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Drawer(...);
}
}
And then when using it in each page:
Scaffold(
drawer: MyDrawer(...),
...
)
I hope you're already doing this; if not you should be. A class's build function shouldn't be too large or it can lead to poor performance and harder to maintain code; splitting things into logical units will help you in the long run.
2: Create a class for your scaffold
If having to include the same drawer in a scaffold for each page is still too much code, you can instead use a class that encapsulates your scaffold. It would essentially take inputs for each of the scaffold inputs you actually use.
class MyScaffold extends StatelessWidget {
final Widget body;
MyScaffold({this.body});
@override
Widget build(BuildContext context) {
return Scaffold(
body: body,
drawer: MyDrawer(...),
);
}
}
And then instead of using Scaffold in your code, use MyScaffold (but please name it something better =D).
3: Multi level scaffold
I'm only including this way of doing it to be complete, and I don't recommend it. That being said, there are certain things you can't get to work within flutter's normal workflow that you could do by doing this - for example if you want a custom animation for when the user taps on different items in the drawer.
Basically, what you'd do in this case is to have a Scaffold outside of your MaterialApp or Navigator (which I believe would also mean you'd have to have another Navigator outside that, but I'm not 100% sure). You would have the scaffold that's outside your navigation show the drawer while the other one (on each page within the navigation) would do whatever else you need it to do. There's a few caveats - you'd have to make sure you get the right scaffold (i.e. Scaffold.of(context)
by itself wouldn't cut it - you'd have to get the context of the first scaffold and use it to find the higher-level one), and you'd probably need to pass a GlobalKey (of the lower-level scaffold) to the Drawer so that it could actually change pages within it.
As I said, I don't recommend this approach, so I'm not going to go into any more detail than that but rather leave it as an exercise for the reader if they want to go down that rabbit hole!
context.rootAncestorStateOfType
. This removes the need of using a GlobalKey
in most situations –
Exsert rmtmckenzie is very correct.
Although if you are curious about the multi scaffold solution, this can be more elegant than you think.
To share a drawer between all pages we could add a builder
in our MaterialApp
instance.
This will instantiate a Scaffold
under Navigator
but above all routes.
MaterialApp(
title: 'Flutter Demo',
builder: (context, child) {
return Scaffold(
drawer: MyDrawer(),
body: child,
);
},
home: MyHome()
)
Inside your page, you can instantiate another Scaffold
without restriction as you'd usually do.
You can then show the shared drawer by doing the following in any widget under MaterialApp
:
final ScaffoldState scaffoldState = context.rootAncestorStateOfType(TypeMatcher<ScaffoldState>());
scaffoldState.openDrawer();
Code which you can extract into a nice helper :
class RootScaffold {
static openDrawer(BuildContext context) {
final ScaffoldState scaffoldState =
context.rootAncestorStateOfType(TypeMatcher<ScaffoldState>());
scaffoldState.openDrawer();
}
}
Then reuse using RootScaffold.openDrawer(context)
In Addition to @Rémi Rousselet Answer
MaterialApp(
title: 'Flutter Demo',
builder: (context, child) {
return Scaffold(
drawer: MyDrawer(),
body: child,
);
},
home: MyHome()
)
For Navigation in root drawer if you use Navigator.of(context) // push or pop
that will throw error and for that you must use child widget to navigate to different pages
Like that
(child.key as GlobalKey<NavigatorState>).currentState // push or pop
In Addition to @Rémi Rousselet Answer, the code has slightly changed (2022) - due to null safety amends. Replace this:
class RootScaffold {
static openDrawer(BuildContext context) {
final ScaffoldState scaffoldState =
context.rootAncestorStateOfType(TypeMatcher<ScaffoldState>());
scaffoldState.openDrawer();
}
}
...with...
class RootScaffold {
static openDrawer(BuildContext context) {
final ScaffoldState? scaffoldState = context.findRootAncestorStateOfType<ScaffoldState>();
scaffoldState?.openDrawer();
}
}
if somebody looking for fancy stuff while navigating look here. What I use as a drawer for my project is flutter_inner_drawer package.
I created a stateful class named CustomDrawer.
class CustomDrawer extends StatefulWidget {
final Widget scaffold;
final GlobalKey<InnerDrawerState> innerDrawerKey;
CustomDrawer({
Key key,
this.scaffold,
this.innerDrawerKey,
}) : super(key: key);
@override
_CustomDrawerState createState() => _CustomDrawerState();
}
class _CustomDrawerState extends State<CustomDrawer> {
MainPageIcons assets = MainPageIcons();//From my actual code dont care it
final vars = GlobalVars.shared; //From my actual code dont care it
@override
Widget build(BuildContext context) {
return InnerDrawer(
key: widget.innerDrawerKey,
onTapClose: true, // default false
tapScaffoldEnabled: true,
swipe: true, // default true
colorTransition: Colors.teal, // default Color.black54
//innerDrawerCallback: (a) => print(a ),// return bool
leftOffset: 0.2, // default 0.4
leftScale: 1,// default 1
boxShadow: [
BoxShadow(color: Colors.teal,blurRadius: 20.0, // has the effect of softening the shadow
spreadRadius: 10.0, // has the effect of extending the shadow
offset: Offset(
10.0, // horizontal, move right 10
10.0, // vertical, move down 10
),)],
borderRadius: 20, // default 0
leftAnimationType: InnerDrawerAnimation.quadratic, // default static
//when a pointer that is in contact with the screen and moves to the right or left
onDragUpdate: (double val, InnerDrawerDirection direction) =>
setState(() => _dragUpdate = val),
//innerDrawerCallback: (a) => print(a),
// innerDrawerCallback: (a) => print(a), // return true (open) or false (close)
leftChild: menus(), // required if rightChild is not set
scaffold:widget.scaffold
);
}
double _dragUpdate = 0;
Widget menus(){
return
Material(
child: Stack(
children: <Widget>[
Container(
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topRight,
end: Alignment.bottomLeft,
colors: [
ColorTween(
begin: Colors.blueAccent,
end: Colors.blueGrey[400].withRed(100),
).lerp(_dragUpdate),
ColorTween(
begin: Colors.green,
end: Colors.blueGrey[800].withGreen(80),
).lerp(_dragUpdate),
],
),
),
child: Stack(
children: <Widget>[
Padding(
padding: EdgeInsets.only(left: 30),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Column(
children: <Widget>[
Container(
margin: EdgeInsets.only(left: 10, bottom: 15),
width: 80,
child: ClipRRect(
child: Image.network(
"https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSrWfWLnxIT5TnuE-JViLzLuro9IID2d7QEc2sRPTRoGWpgJV75",
),
borderRadius: BorderRadius.circular(60),
),
),
Text(
"User",
style: TextStyle(color: Colors.white, fontSize: 18),
)
],
//mainAxisAlignment: MainAxisAlignment.center,
),
Padding(
padding: EdgeInsets.all(10),
),
ListTile(
onTap: ()=>navigate(Profile.tag),
title: Text(
"Profile",
style: TextStyle(color: Colors.white, fontSize: 14),
),
leading: Icon(
Icons.dashboard,
color: Colors.white,
size: 22,
),
),
ListTile(
title: Text(
"Camera",
style: TextStyle(fontSize: 14,color:Colors.white),
),
leading: Icon(
Icons.camera,
size: 22,
color: Colors.white,
),
onTap: ()=>navigate(Camera.tag)
),
ListTile(
title: Text(
"Pharmacies",
style: TextStyle(fontSize: 14,color:Colors.white),
),
leading: Icon(
Icons.add_to_photos,
size: 22,
color: Colors.white,
),
onTap: ()=>navigate(Pharmacies.tag)
),
],
),
),
Positioned(
bottom: 20,
child: Container(
alignment: Alignment.bottomLeft,
margin: EdgeInsets.only(top: 50),
padding: EdgeInsets.symmetric(vertical: 15, horizontal: 25),
width: double.maxFinite,
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Icon(
Icons.all_out,
size: 18,
color: Colors.grey,
),
Text(
" LogOut",
style: TextStyle(
fontSize: 16,
color: Colors.grey,
),
),
],
),
),
)
],
),
),
_dragUpdate < 1
? BackdropFilter(
filter: ImageFilter.blur(
sigmaX: (10 - _dragUpdate * 10),
sigmaY: (10 - _dragUpdate * 10)),
child: Container(
decoration: BoxDecoration(
color: Colors.black.withOpacity(0),
),
),
)
: null,
].where((a) => a != null).toList(),
));
}
navigate(String route) async{
await navigatorKey.currentState.pushNamed(route).then((_){
Timer(Duration(milliseconds: 500),()=>widget.innerDrawerKey.currentState.toggle() );
});
}
}
I copied example from package and didnt touch original much. only aded a function to toggle after turn back.
navigate(String route) async{
await navigatorKey.currentState.pushNamed(route).then((_){
Timer(Duration(milliseconds: 500),()=>widget.innerDrawerKey.currentState.toggle() );
});
}
to navigate from all over pages aded GlobalKey globally so that reachable from every class
final GlobalKey<NavigatorState> navigatorKey = GlobalKey(debugLabel: "Main Navigator");
inner_drawer also needs a globalkey for state to toogle but if you create only one when navigate between pages it gives duplicate global key error. to avoid I created a global variable named innerKeys
Map<String,GlobalKey<InnerDrawerState>>innerKeys={
'main':GlobalKey<InnerDrawerState>(),
'profile':GlobalKey<InnerDrawerState>(),
'pharmacies':GlobalKey<InnerDrawerState>(),
};
finally I added this CustomDrawer to every pages
@override
Widget build(BuildContext context) {
return CustomDrawer(
innerDrawerKey: vars.innerKeys['profile'],
scaffold:Scaffold(
appBar: CustomAppBar(
title: 'Profile',
actions: <Widget>[
],),
body: Stack(
children: <Widget>[
Background(),
])));
}
I hope it will helps to someone.
NOTE: please check original flutter pack if anything updated. Be avare that this example is not perfect and needs to taken care that if many navigation over this drawer then widget tree will have many pages and performance will be impacted. any tuning suggestion will be appriciated.
My Solution Navigation Drawer with Multiple Fragments using bloc package
First, add below dependencies
in your pubspec.yaml
file
flutter_bloc: ^4.0.0
Now create below files
drawer_event.dart
import 'nav_drawer_state.dart';
abstract class NavDrawerEvent {
const NavDrawerEvent();
}
class NavigateTo extends NavDrawerEvent {
final NavItem destination;
const NavigateTo(this.destination);
}
nav_drawer_bloc.dart
import 'package:bloc/bloc.dart';
import 'drawer_event.dart';
import 'nav_drawer_state.dart';
class NavDrawerBloc extends Bloc<NavDrawerEvent, NavDrawerState> {
@override
NavDrawerState get initialState => NavDrawerState(NavItem.homePage);
@override
Stream<NavDrawerState> mapEventToState(NavDrawerEvent event) async* {
if (event is NavigateTo) {
if (event.destination != state.selectedItem) {
yield NavDrawerState(event.destination);
}
}
}
}
nav_drawer_state.dart
class NavDrawerState {
final NavItem selectedItem;
const NavDrawerState(this.selectedItem);
}
enum NavItem {
homePage,
profilePage,
orderPage,
myCart,
}
drawer_widget.dart
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutterdrawerwithbloc/bloc/drawer_event.dart';
import 'package:flutterdrawerwithbloc/bloc/nav_drawer_bloc.dart';
import 'package:flutterdrawerwithbloc/bloc/nav_drawer_state.dart';
class NavDrawerWidget extends StatelessWidget {
final String accountName;
final String accountEmail;
final List<_NavigationItem> _listItems = [
_NavigationItem(true, null, null, null),
_NavigationItem(false, NavItem.homePage, "Home", Icons.home),
_NavigationItem(false, NavItem.profilePage, "Profile Page", Icons.person),
_NavigationItem(false, NavItem.orderPage, "My Orders", Icons.list),
_NavigationItem(false, NavItem.myCart, "My Cart", Icons.shopping_cart),
];
NavDrawerWidget(this.accountName, this.accountEmail);
@override
Widget build(BuildContext context) => Drawer(
child: Container(
child: ListView.builder(
padding: EdgeInsets.zero,
itemCount: _listItems.length,
itemBuilder: (BuildContext context, int index) =>
BlocBuilder<NavDrawerBloc, NavDrawerState>(
builder: (BuildContext context, NavDrawerState state) =>
_buildItem(_listItems[index], state),
)),
));
Widget _buildItem(_NavigationItem data, NavDrawerState state) =>
data.header ? _makeHeaderItem() : _makeListItem(data, state);
Widget _makeHeaderItem() => UserAccountsDrawerHeader(
accountName: Text(accountName, style: TextStyle(color: Colors.white)),
accountEmail: Text(accountEmail, style: TextStyle(color: Colors.white)),
decoration: BoxDecoration(color: Colors.indigo),
currentAccountPicture: CircleAvatar(
backgroundColor: Colors.white,
foregroundColor: Colors.amber,
child: Icon(
Icons.person,
size: 54,
),
),
);
Widget _makeListItem(_NavigationItem data, NavDrawerState state) => Card(
shape: ContinuousRectangleBorder(borderRadius: BorderRadius.zero),
borderOnForeground: true,
elevation: 0,
margin: EdgeInsets.zero,
child: Builder(
builder: (BuildContext context) => ListTile(
title: Text(
data.title,
style: TextStyle(
color: data.item == state.selectedItem ? Colors.green : Colors.blueGrey,
),
),
leading: Icon(
data.icon,
color: data.item == state.selectedItem ? Colors.green : Colors.blueGrey,
),
onTap: () => _handleItemClick(context, data.item),
),
),
);
void _handleItemClick(BuildContext context, NavItem item) {
BlocProvider.of<NavDrawerBloc>(context).add(NavigateTo(item));
Navigator.pop(context);
}
}
class _NavigationItem {
final bool header;
final NavItem item;
final String title;
final IconData icon;
_NavigationItem(this.header, this.item, this.title, this.icon);
}
main.dart
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutterdrawerwithbloc/bloc/nav_drawer_bloc.dart';
import 'package:flutterdrawerwithbloc/bloc/nav_drawer_state.dart';
import 'package:flutterdrawerwithbloc/drawer_widget.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Navigation Drawer Demo',
theme: ThemeData(primarySwatch: Colors.blue, scaffoldBackgroundColor: Colors.white),
home: MyHomePage(),
);
;
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
NavDrawerBloc _bloc;
Widget _content;
@override
void initState() {
super.initState();
_bloc = NavDrawerBloc();
_content = _getContentForState(_bloc.state.selectedItem);
}
@override
void dispose() {
super.dispose();
}
@override
Widget build(BuildContext context) => BlocProvider<NavDrawerBloc>(
create: (BuildContext context) => _bloc,
child: BlocListener<NavDrawerBloc, NavDrawerState>(
listener: (BuildContext context, NavDrawerState state) {
setState(() {
_content = _getContentForState(state.selectedItem);
});
},
child: BlocBuilder<NavDrawerBloc, NavDrawerState>(
builder: (BuildContext context, NavDrawerState state) => Scaffold(
drawer: NavDrawerWidget("AskNilesh", "[email protected]"),
appBar: AppBar(
title: Text(_getAppbarTitle(state.selectedItem)),
centerTitle: false,
brightness: Brightness.light,
backgroundColor: Colors.indigo,
),
body: AnimatedSwitcher(
switchInCurve: Curves.easeInExpo,
switchOutCurve: Curves.easeOutExpo,
duration: Duration(milliseconds: 300),
child: _content,
),
),
),
));
_getAppbarTitle(NavItem state) {
switch (state) {
case NavItem.homePage:
return 'Home';
case NavItem.profilePage:
return 'Profile Page';
case NavItem.orderPage:
return 'My Orders';
case NavItem.myCart:
return 'My Cart';
default:
return '';
}
}
_getContentForState(NavItem state) {
switch (state) {
case NavItem.homePage:
return Center(
child: Text(
'Home Page',
style: TextStyle(fontWeight: FontWeight.bold),
),
);
case NavItem.profilePage:
return Center(
child: Text(
'Profile Page',
style: TextStyle(fontWeight: FontWeight.bold),
),
);
case NavItem.orderPage:
return Center(
child: Text(
'My Orders',
style: TextStyle(fontWeight: FontWeight.bold),
),
);
case NavItem.myCart:
return Center(
child: Text(
'My Cart',
style: TextStyle(fontWeight: FontWeight.bold),
),
);
default:
return Center(
child: Text(
'Home Page',
style: TextStyle(fontWeight: FontWeight.bold),
),
);
}
}
}
You can find complete project here Navigation Drawer with Multiple Fragments using bloc
You can create the ScaffoldCustom
when you ensure that all pages have only the body
differently.
But I feel that this approach is too restrictive.
So, I am using this.
For the AppBar
:
class AppBarPattern1 extends StatelessWidget implements PreferredSizeWidget {
const AppBarPattern1({Key? key}) : super(key: key);
@override
// TODO: implement preferredSize
Size get preferredSize => const Size.fromHeight(kToolbarHeight); // You can change it.
/*
/// The height of the toolbar component of the [AppBar].
const double kToolbarHeight = 56.0;
*/
@override
Widget build(BuildContext context) {
return AppBar();
}
}
For the Drawer
:
class DrawerPattern1 extends StatelessWidget {
const DrawerPattern1({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return const Drawer();
}
}
Using like this:
class ExamplePage extends StatelessWidget {
const ExamplePage({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: const AppBarPattern1(),
endDrawer: const DrawerPattern1(),
body: SafeArea(child: Container()),
);
}
}
As you see these custom widgets can be const
.
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