How to use itemBuilder to select the last tapped ListTile widget? - flutter

Question

I am trying to change the selected property of the last tapped ListTile widget to true inside a Drawer (and then obviously the selected property of other ListTiles to false), but I do not understand how can I use itemBuilder (which is mentioned in the official flutter docs) for this.
I tried putting my ListTiles into an AnimatedListItemBuilder widget, but that was not working for me.
Widget _buildDrawer() {
return ListView(
// Important: Remove any padding from the ListView.
padding: EdgeInsets.zero,
children: <Widget>[
DrawerHeader(
child:
Wrap(
alignment: WrapAlignment.center,
direction: Axis.vertical,
children: <Widget>[
Text(
_currentUser.displayName,
style: TextStyle(
fontSize: 20,
color: Colors.white
),
),
Wrap(
direction: Axis.vertical,
children: <Widget>[
Text(
"Iskolai kategória: A",
style: TextStyle(
fontSize: 18,
color: Colors.white70
),
),
Text(
"Kollégiumi kategória: A",
style: TextStyle(
fontSize: 18,
color: Colors.white70
),
),
],
)
],
),
decoration: BoxDecoration(
color: Colors.blue,
),
),
ListTile(
selected: true,
leading: Icon(Icons.date_range_rounded),
title: Text('Stúdium jelentkezés'),
onTap: () {
// Update the state of the app.
// ...
// Then close the drawer.
Navigator.pop(context);
},
),
ListTile(
leading: Icon(Icons.article_rounded),
title: Text('Koleszhírek'),
onTap: () {
// Update the state of the app.
// ...
Navigator.pop(context);
},
),
ListTile(
leading: Icon(Icons.account_box_rounded),
title: Text('Profil'),
onTap: () {
// Update the state of the app.
// ...
Navigator.pop(context);
},
),
ListTile(
leading: Icon(Icons.logout),
title: Text('Kijelentkezés'),
onTap: () => {
_googleSignIn.disconnect(),
Navigator.pop(context)
},
),
],
);
}

Answer 1

You have to save the 'selected index' in a variable and check if the current index equals selected index to highlight the ListView. I've updated your code to make it work.
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _selectedIndex = 0;
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
drawer: _buildDrawer(context),
body: Center(
child: Text("DrawerHeader Demo"),
),
);
}
Widget _buildDrawer(BuildContext context) {
List<Widget> leading = [
Icon(Icons.date_range_rounded),
Icon(Icons.article_rounded),
Icon(Icons.account_box_rounded),
Icon(Icons.logout),
];
List<Widget> title = [
Text('Stúdium jelentkezés'),
Text('Koleszhírek'),
Text('Profil'),
Text('Kijelentkezés'),
];
return Container(
color: Colors.white,
child: ListView(
padding: EdgeInsets.zero,
children: <Widget>[
DrawerHeader(
child: Wrap(
alignment: WrapAlignment.center,
direction: Axis.vertical,
children: <Widget>[
Text(
"A",
style: TextStyle(fontSize: 20, color: Colors.white),
),
Wrap(
direction: Axis.vertical,
children: <Widget>[
Text(
"Iskolai kategória: A",
style: TextStyle(fontSize: 18, color: Colors.white70),
),
Text(
"Kollégiumi kategória: A",
style: TextStyle(fontSize: 18, color: Colors.white70),
),
],
)
],
),
decoration: BoxDecoration(
color: Colors.blue,
),
),
ListView.builder(
itemCount: 4,
shrinkWrap: true,
itemBuilder: (BuildContext context, int index) {
return ListTile(
title: title[index],
leading: leading[index],
selected: index == _selectedIndex,
onTap: () {
setState(() {
_selectedIndex = index;
Navigator.pop(context);
});
},
);
},
),
],
),
);
}
}