How to create interactive flowchart in flutter - flutter

Question

I want to create a flutter UI where there are some shapes like square, rectangle, circle, arrow. And I must be able to drag and drop them at the centre and add text to it and connect them. I have just started with flutter so I am not sure how to do this. Can anyone please help me?

Answer 1

Use Draggable class
Example:
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
static const String _title = 'Flutter Code Sample';
#override
Widget build(BuildContext context) {
return MaterialApp(
title: _title,
home: Scaffold(
appBar: AppBar(title: const Text(_title)),
body: const MyStatefulWidget(),
),
);
}
}
class MyStatefulWidget extends StatefulWidget {
const MyStatefulWidget({Key? key}) : super(key: key);
#override
State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
int acceptedData = 0;
#override
Widget build(BuildContext context) {
return Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Draggable<int>(
// Data is the value this Draggable stores.
data: 10,
feedback: Container(
color: Colors.deepOrange,
height: 100,
width: 100,
child: const Icon(Icons.directions_run),
),
childWhenDragging: Container(
height: 100.0,
width: 100.0,
color: Colors.pinkAccent,
child: const Center(
child: Text('Child When Dragging'),
),
),
child: Container(
height: 100.0,
width: 100.0,
color: Colors.lightGreenAccent,
child: const Center(
child: Text('Draggable'),
),
),
),
DragTarget<int>(
builder: (
BuildContext context,
List<dynamic> accepted,
List<dynamic> rejected,
) {
return Container(
height: 100.0,
width: 100.0,
color: Colors.cyan,
child: Center(
child: Text('Value is updated to: $acceptedData'),
),
);
},
onAccept: (int data) {
setState(() {
acceptedData += data;
});
},
),
],
);
}
}