import 'dart:ui';

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      checkerboardOffscreenLayers: true,
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
  AnimationController animation;

  @override
  void initState() {
    super.initState();
    animation = AnimationController(vsync: this, duration: Duration(seconds: 1));
    _startAnimation();
  }

  Future _startAnimation() async {
    try {
      await animation
          .repeat()
          .orCancel;
    } on TickerCanceled {}
  }

  @override
  Widget build(BuildContext context) {
    Widget text() {
      return ClipRect(
        child: BackdropFilter(
            filter: ImageFilter.blur(sigmaX: 5, sigmaY: 5),
            child: Column(
              children: <Widget>[
                Container(padding: EdgeInsets.all(5), child: Text("txt")),
              ],
            )),
      );
    }

    Widget col() {
      return Column(children: List.generate(17, (i) => text()));
    }

    return Scaffold(
      backgroundColor: Colors.grey,
      body: Container(
        child: Column(
          children: [
            Expanded(
              child: RepaintBoundary(
                  child: Center(
                child: AnimatedBuilder(
                    animation: animation,
                    builder: (c, w) {
                      final val = (animation.value * 255).round();
                      return Container(
                        width: 50,
                        height: 50,
                        color: Color.fromARGB(255, val, val, val));
                    }),
              )),
            ),
            SizedBox(height: 50),
            RepaintBoundary(
              child: Row(mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: List.generate(5, (i) => col())),
            ),
            SizedBox(height: 50),
          ],
        ),
      ),
    );
  }
}