Pageview Indicator Has Worm Animation Using Flutter App

dependencies:
  flutter:
    sdk: flutter
  worm_indicator: ^0.2.4

flutter pub get

import 'package:worm_indicator/shape.dart';
import 'package:worm_indicator/worm_indicator.dart';

import 'package:flutter/material.dart';
import 'package:worm_indicator/shape.dart';
import 'package:worm_indicator/worm_indicator.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Worm Indicator Example',
      home: Scaffold(
        appBar: AppBar(
          backgroundColor: Colors.lightGreen,
          title: Text('Worm Indicator'),
        ),
        body: Example(),
      ),
    );
  }
}

class Example extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _ExampleState();
}

class _ExampleState extends State<Example> {
  PageController _controller;

  @override
  void initState() {
    super.initState();
    _controller = PageController();
  }

  Widget buildPageView() {
    return PageView.builder(
      physics: AlwaysScrollableScrollPhysics(),
      controller: _controller,
      itemBuilder: (BuildContext context, int pos) {
        return Container(
          margin: EdgeInsets.all(20),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text(
                "Worm Indicator - Page $pos",
                style: TextStyle(
                  fontSize: 25,
                  color: Colors.black,
                ),
              )
            ],
          ),
        );
      },
      itemCount: 4,
    );
  }

  Widget buildExampleIndicatorWithShapeAndBottomPos(
      Shape shape, double bottomPos) {
    return Positioned(
      bottom: bottomPos,
      left: 0,
      right: 0,
      child: WormIndicator(
        length: 3,
        controller: _controller,
        shape: shape,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final circleShape = Shape(
      size: 16,
      shape: DotShape.Circle,
      spacing: 8,
    );
    final squareShape = Shape(
      size: 16,
      shape: DotShape.Square,
      spacing: 8,
    );
    return Scaffold(
      body: Stack(
        children: <Widget>[
          buildPageView(),
          buildExampleIndicatorWithShapeAndBottomPos(circleShape, 20),
          buildExampleIndicatorWithShapeAndBottomPos(squareShape, 56),
        ],
      ),
    );
  }
}