expandable_tree_menu 0.1.0-dev.5 expandable_tree_menu: ^0.1.0-dev.5 copied to clipboard
Tree of menu-nodes that can be expanded/collapsed to review more menu nodes, built from a recursive list of nodes.
import 'package:expandable_tree_menu/expandable_tree_menu.dart';
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: 'Getting Started',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key? key}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final nodes = <TreeNode>[];
void _addData(data) {
setState(() {
nodes.addAll(data);
});
}
Future<List<TreeNode>> fetchData() async {
// Load the data from somewhere;
return await _dataLoad();
}
@override
void initState() {
super.initState();
fetchData().then(_addData);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Menu demo'),
),
body: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Flexible(
child: SingleChildScrollView(
child: ExpandableTree(
nodes: nodes,
nodeBuilder: _nodeBuilder,
onSelect: (node) => _nodeSelected(context, node),
),
),
),
],
),
);
}
/// Handle the onTap event on a Node Widget
void _nodeSelected(context, nodeValue) {
final route =
MaterialPageRoute(builder: (context) => DetailPage(value: nodeValue));
Navigator.of(context).push(route);
}
/// Build the Node widget at a specific node in the tree
Widget _nodeBuilder(context, nodeValue) {
return Card(
margin: EdgeInsets.symmetric(vertical: 1),
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(nodeValue.toString()),
));
}
}
// A less contrived example would use a DataModel as type for the value
class DetailPage extends StatelessWidget {
final value;
const DetailPage({Key? key, this.value}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(value.toString()),
),
body: Center(
child: Text(value.toString()),
),
);
}
}
Future<List<TreeNode>> _dataLoad() async {
// Fetch the data here
// Then generate the TreeNode tree structure
return [
TreeNode<String>('Some String'),
TreeNode<String>('Node with sub-items', subNodes: [
TreeNode<String>('First sub node'),
TreeNode<String>('Second sub node'),
])
];
}