import 'dart:ui';

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return const MaterialApp(home: MyHomePage());
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

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

class _MyHomePageState extends State<MyHomePage> {
  double y = 400;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          Center(
            child: ImageFiltered(
              imageFilter: ImageFilter.dilate(radiusX: 100, radiusY: 100),
              child: Container(
                height: 200,
                color: Colors.green,
                margin: const EdgeInsets.all(24),
              ),
            ),
          ),
          Positioned(
            left: 0,
            right: 0,
            top: y,
            height: 24,
            child: GestureDetector(
              onHorizontalDragUpdate: (details) {
                setState(() {
                  y = details.globalPosition.dy;
                });
              },
              child: Container(
                color: Colors.black,
              ),
            ),
          ),
        ],
      ),
    );
  }
}