How to create a vertical scrolling menu effect in Flutter - flutter

Question

this question is an improvement for this question. In this case, I would like to reproduce the vertical menu the you can see on the left side of this we base. If you click the link relative to the example on the left you see a number of menu. For instance, clicking on Base you are going to see a vertical menu appearing and disappearing. I would like to know how to reproduce it as well. An example code would be really appreciated.
Thanks all

Answer 1

You can achieve this by simply using a StatefulWidget & managing the hide/show functionality using a boolean value.
Here is the updated code:
import 'package:flutter/material.dart';
final Color darkBlue = Color.fromARGB(255, 18, 32, 47);
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
debugShowCheckedModeBanner: false,
home: Scaffold(
body: Center(
child: MyWidget(),
),
),
);
}
}
class MyWidget extends StatefulWidget {
#override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget>
with SingleTickerProviderStateMixin {
final colors = <Color>[Colors.indigo, Colors.blue, Colors.orange, Colors.red];
double _size = 250.0;
bool _large = true;
void _updateSize() {
setState(() {
_size = _large ? 250.0 : 0.0;
_large = !_large;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: Row(
children: [
AnimatedSize(
curve: Curves.easeIn,
vsync: this,
duration: Duration(seconds: 1),
child: LeftDrawer(size: _size)),
Expanded(
flex: 4,
child: Container(
child: Column(
children: [
Container(
color: Colors.white,
padding: const EdgeInsets.all(8),
child: Row(
children: [
IconButton(
icon: Icon(Icons.menu, color: Colors.black87),
onPressed: () {
_updateSize();
},
),
FlatButton(
child: Text(
'Dashboard',
style: const TextStyle(color: Colors.black87),
),
onPressed: () {},
),
FlatButton(
child: Text(
'User',
style: const TextStyle(color: Colors.black87),
),
onPressed: () {},
),
FlatButton(
child: Text(
'Settings',
style: const TextStyle(color: Colors.black87),
),
onPressed: () {},
),
const Spacer(),
IconButton(
icon: Icon(Icons.brightness_3, color: Colors.black87),
onPressed: () {},
),
IconButton(
icon: Icon(Icons.notification_important,
color: Colors.black87),
onPressed: () {},
),
CircleAvatar(),
],
),
),
Container(
height: 1,
color: Colors.black12,
),
Card(
margin: EdgeInsets.zero,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(0),
),
child: Container(
color: Colors.white,
padding: const EdgeInsets.all(20),
child: Row(
children: [
Text(
'Home / Admin / Dashboard',
style: const TextStyle(color: Colors.black),
),
],
),
),
),
Expanded(
child: ListView(
children: [
Row(
children: [
_container(0),
_container(1),
_container(2),
_container(3),
],
),
Container(
height: 400,
color: Color(0xFFE7E7E7),
padding: const EdgeInsets.all(16),
child: Card(
color: Colors.white,
child: Container(
padding: const EdgeInsets.all(16),
child: Text(
'Traffic',
style: const TextStyle(color: Colors.black87),
),
),
),
),
],
),
),
],
),
),
),
],
),
);
}
Widget _container(int index) {
return Expanded(
child: Container(
padding: const EdgeInsets.all(20),
color: Color(0xFFE7E7E7),
child: Card(
color: Color(0xFFE7E7E7),
child: Container(
color: colors[index],
width: 250,
height: 140,
padding: const EdgeInsets.all(20),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Row(
children: [
Expanded(
child: Text(
'9.823',
style: TextStyle(fontSize: 24),
)),
Icon(Icons.more_vert),
],
),
Text('Members online')
],
),
),
),
),
);
}
}
class LeftDrawer extends StatefulWidget {
LeftDrawer({
Key key,
this.size,
}) : super(key: key);
final double size;
#override
_LeftDrawerState createState() => _LeftDrawerState();
}
class _LeftDrawerState extends State<LeftDrawer> {
bool dropdownVisible = false;
#override
Widget build(BuildContext context) {
return Expanded(
flex: 1,
child: Container(
width: widget.size,
color: const Color(0xFF2C3C56),
child: ListView(
children: [
Container(
alignment: Alignment.center,
padding: const EdgeInsets.all(16),
color: Color(0xFF223047),
child: Text('CORE UI'),
),
_tile('Dashboard'),
Container(
padding: const EdgeInsets.only(left: 10),
margin: const EdgeInsets.only(top: 30),
child: Text('THEME',
style: TextStyle(
color: Colors.white54,
))),
_tile('Colors'),
_tile('Typography'),
_tileDropdown('Base'),
_tile('Buttons'),
],
),
),
);
}
Widget _tile(String label) {
return ListTile(
title: Text(label),
onTap: () {},
);
}
Widget _option(String label) {
return ListTile(
tileColor: Color(0xFF223047),
contentPadding: const EdgeInsets.only(left: 40),
title: Text(label),
onTap: () {},
);
}
Widget _tileDropdown(String label) {
return Column(
mainAxisSize: MainAxisSize.min,
children: [
ListTile(
title: Text(label),
onTap: () {
setState(() {
dropdownVisible = !dropdownVisible;
});
},
trailing: dropdownVisible
? Icon(Icons.arrow_drop_up)
: Icon(Icons.chevron_left),
),
Visibility(
visible: dropdownVisible,
child: _option('Breadcrumbs'),
),
Visibility(
visible: dropdownVisible,
child: _option('Cloud'),
),
Visibility(
visible: dropdownVisible,
child: _option('Carousel'),
),
Visibility(
visible: dropdownVisible,
child: _option('Collapse'),
),
],
);
}
}