TypeAhead different widgets flutter - flutter

Question

I'm trying to create different widgets in TypeAhead suggestion depends on suggestion.subName.length
1. ListTile with a subTitle
2. ListTile without subTitle
TypeAhead(
...
itemBuilder: (context, suggestion) {
return ListTile(
dense: true,
title: AutoSizeText(
suggestion.primeName,
maxLines: 1,
overflow: TextOverflow.ellipsis,
minFontSize: 20,
),
subtitle: suggestion.subName.length == 0 ? null:AutoSizeText(
suggestion.subName.join(', '),
maxLines: 1,
overflow: TextOverflow.ellipsis,
minFontSize: 15,
),
);
},
...
But everything comes back with a subtitle.
What could cause that? Is it possible to make 2 different types of widgets in TypeAhead?

Answer 1

You can copy paste run full code below
I use the following example to simulate this case
You can return Container() not null
subtitle: suggestion.subName.length == 0 ? Container() : AutoSizeText(
or put condition in itemBuilder, for more complex condition you can use if
itemBuilder: (context, suggestion) {
return suggestion.subName.length == 0 ? ListTile(...) : ListTile(...);
working demo
full code
import 'package:flutter/material.dart';
import 'dart:math';
import 'package:flutter_typeahead/flutter_typeahead.dart';
class BackendService {
static Future<List> getSuggestions(String query) async {
await Future.delayed(Duration(seconds: 1));
return List.generate(3, (index) {
return {'name': query + index.toString(), 'price': Random().nextInt(100)};
});
}
}
class CitiesService {
static final List<String> cities = [
'Beirut',
'Damascus',
'San Fransisco',
'Rome',
'Los Angeles',
'Madrid',
'Bali',
'Barcelona',
'Paris',
'Bucharest',
'New York City',
'Philadelphia',
'Sydney',
];
static List<String> getSuggestions(String query) {
List<String> matches = List();
matches.addAll(cities);
matches.retainWhere((s) => s.toLowerCase().contains(query.toLowerCase()));
return matches;
}
}
class NavigationExample extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Padding(
padding: EdgeInsets.all(32.0),
child: Column(
children: <Widget>[
SizedBox(
height: 10.0,
),
TypeAheadField(
textFieldConfiguration: TextFieldConfiguration(
autofocus: true,
style: DefaultTextStyle.of(context)
.style
.copyWith(fontStyle: FontStyle.italic),
decoration: InputDecoration(
border: OutlineInputBorder(),
hintText: 'What are you looking for?'),
),
suggestionsCallback: (pattern) async {
return await BackendService.getSuggestions(pattern);
},
itemBuilder: (context, suggestion) {
return ListTile(
leading: Icon(Icons.shopping_cart),
title: Text(suggestion['name']),
subtitle: suggestion['price'] < 20
? Container()
: Text('\$${suggestion['price']}'),
);
},
onSuggestionSelected: (suggestion) {
Navigator.of(context).push(MaterialPageRoute(
builder: (context) => ProductPage(product: suggestion)));
},
),
],
),
);
}
}
class ProductPage extends StatelessWidget {
final Map<String, dynamic> product;
ProductPage({this.product});
#override
Widget build(BuildContext context) {
return Scaffold(
body: Padding(
padding: const EdgeInsets.all(50.0),
child: Column(
children: [
Text(
this.product['name'],
style: Theme.of(context).textTheme.headline,
),
Text(
this.product['price'].toString() + ' USD',
style: Theme.of(context).textTheme.subhead,
)
],
),
),
);
}
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#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 _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
NavigationExample(),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}