import'dart:async';import'dart:ui';import'package:flutter/material.dart';voidmain()=>runApp(MyApp());classMyAppextendsStatelessWidget {@overrideWidgetbuild(BuildContext context) {returnMaterialApp(      title:'Flutter Custom Painter',      theme:ThemeData(        primarySwatch:Colors.pink,      ),      home:MyPainter(),    );  }}classMyPainterextendsStatefulWidget {@override_MyPainterStatecreateState()=>_MyPainterState();}class_MyPainterStateextendsState<MyPainter> {_MyPainterState() {    timer=Timer.periodic(constDuration(milliseconds:10), execute);  }Timer timer;ValueNotifier<int> repaintNotifier;finalPaint paint=Paint()    ..color=Colors.red    ..style=PaintingStyle.fill;@overridevoidinitState() {    repaintNotifier=ValueNotifier<int>(0);super.initState();  }@overridevoiddispose() {    repaintNotifier.dispose();super.dispose();  }@overrideWidgetbuild(BuildContext context) {returnScaffold(      appBar:AppBar(        title:Text('Polygons'),      ),      body:CustomPaint(        size:Size.infinite,//2        painter:ProfileCardPainter(Colors.red, repaintNotifier, paint),//3      ),    );  }voidexecute(Timer timer) {setState(() {      repaintNotifier.value++;    });  }}classProfileCardPainterextendsCustomPainter {ProfileCardPainter(this.color,this.repaintNotifier,this.paints);Color color;ValueNotifier<int> repaintNotifier;Paint paints;@overridevoidpaint(Canvas canvas,Size size) {    repaintNotifier.value.isOdd? canvas.drawRect(Rect.fromLTWH(size.width/2, size.height/2, size.width/2,                size.height/2),            paints): canvas.drawRect(Rect.fromLTWH(size.width/4, size.height/4, size.width/4,                size.height/4),            paints);    repaintNotifier.value++;  }@overrideboolshouldRepaint(covariantCustomPainter oldDelegate)=>true;}