Heart Beat line for splash screen - flutter

Question

i want to add heart beat horizontal line for splash screen, it will start animating from one side and go all the way to other if the initial data is still not loaded it will continue animation
i tried below code but its only pulse kinda animation
import 'dart:math';
import 'package:flutter/material.dart';
class SpritePainter extends CustomPainter {
final Animation<double> _animation;
SpritePainter(this._animation) : super(repaint: _animation);
void circle(Canvas canvas, Rect rect, double value) {
double opacity = (1.0 - (value / 4.0)).clamp(0.0, 1.0);
Color color = Color.fromRGBO(0, 117, 194, opacity);
double size = rect.width / 2;
double area = size * size;
double radius = sqrt(area * value / 4);
final Paint paint = Paint()..color = color;
canvas.drawCircle(rect.center, radius, paint);
}
#override
void paint(Canvas canvas, Size size) {
Rect rect = Rect.fromLTRB(0.0, 0.0, size.width, size.height);
for (int wave = 3; wave >= 0; wave--) {
circle(canvas, rect, wave + _animation.value);
}
}
#override
bool shouldRepaint(SpritePainter oldDelegate) {
return true;
}
}
class SpriteDemo extends StatefulWidget {
#override
SpriteDemoState createState() => SpriteDemoState();
}
class SpriteDemoState extends State<SpriteDemo>
with SingleTickerProviderStateMixin {
late final AnimationController _controller;
#override
void initState() {
super.initState();
_controller = AnimationController(
vsync: this,
);
//_startAnimation();
}
#override
void dispose() {
_controller.dispose();
super.dispose();
}
void _startAnimation() {
_controller
..stop()
..reset()
..repeat(period: const Duration(seconds: 1));
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: const Text('Pulse')),
body: CustomPaint(
painter: SpritePainter(_controller),
child: SizedBox(
width: 200.0,
height: 200.0,
),
),
floatingActionButton: FloatingActionButton(
onPressed: _startAnimation,
child: new Icon(Icons.play_arrow),
),
);
}
}
void main() {
runApp(
MaterialApp(
home: SpriteDemo(),
),
);
}
I want it to start(animate) from center left and go all the way to right just like in image