Overlay Entry

Overlay entry.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final focusNode = FocusNode();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Padding(
              padding: const EdgeInsets.all(8.0),
              child: TextFormField(
                focusNode: focusNode,
                onTap: onTap,
              ),
            ),
          ],
        ),
      ),
    );
  }

  OverlayEntry? entry;
  void onTap() {
    entry = OverlayEntry(
      builder: (context) => Positioned(
        left: 8,
        top: focusNode.offset.dy - (128 + 24),
        right: 8,
        child: GestureDetector(
          onTap: () => entry!.remove(),
          child: Material(
            borderRadius: BorderRadius.circular(8),
            elevation: 10,
            child: Container(
              width: MediaQuery.of(context).size.width,
              height: 128,
              margin: const EdgeInsets.all(4.0),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(8),
                color: Colors.white,
              ),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: List.generate(
                3,
                (index) => Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: List.generate(
                    8,
                    (index) => Text('${index + 1}'),
                  ),
                ),
              )),
            ),
          ),
        ),
      ),
    );

    Overlay.of(context).insert(entry!);
  }
}