flutter overlay

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('Overlay Example')),
        body: OverlayExample(),
      ),
    );
  }
}

class OverlayExample extends StatefulWidget {
  @override
  _OverlayExampleState createState() => _OverlayExampleState();
}

class _OverlayExampleState extends State<OverlayExample> {
  OverlayEntry? _overlayEntry;

  void _showOverlay() {
    _overlayEntry = OverlayEntry(
      builder: (context) => Positioned(
        top: 100,
        left: 100,
        child: Container(
          width: 100,
          height: 100,
          color: Colors.red,
          child: Center(child: Text('Overlay')),
        ),
      ),
    );
    Overlay.of(context)!.insert(_overlayEntry!);
  }

  void _removeOverlay() {
    _overlayEntry?.remove();
  }

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          ElevatedButton(onPressed: _showOverlay, child: Text('Show Overlay')),
          SizedBox(height: 20),
          ElevatedButton(onPressed: _removeOverlay, child: Text('Remove Overlay')),
        ],
      ),
    );
  }
}