How do I create a Draggable without using DragTarget in Flutter?

Question

I'm a newbie at Flutter. I'm trying to create a Draggable but I don't want to use a DragTarget. I want it to drag and drop wherever I want. When I did that after the drop operation object disappeared. I don't want it to disappear. How can I do that? I checked the resources and YouTube, however, I cannot find anything useful. Thanks in advance.

Answer 1

Following up to my comment, here is a code example. You have a Stack, with your Draggable element, you then rebuild it to the new position using a Positioned widget and an offset. You could also recreate a DragTarget following the same exemple, just repositioning it if you need its features.

You might need to adapt a bit the offset in order to make it react to your target element size.

import 'package:flutter/material.dart';

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);
  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool _started = false;
  Offset _position = Offset(20, 20);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Stack(
          children: <Widget>[
            Positioned(
              top: _position.dy - 30, // Size of widget to reposition correctly
              left: _position.dx,
              child: Draggable(
                child: Chip(label: Text('Element')),
                feedback: Material(
                    child: Chip(
                  label: Text('Element'),
                )),
                onDragEnd: (details) {
                  print(details.offset);
                  setState(() {
                    if (!_started) _started = true;
                    _position = details.offset;
                  });
                },
              ),
            ),
          ],
        ),
      ),
    );
  }
}