Animation Ripple

 import "package:flutter/material.dart";

void main() {
  runApp(const RiDemo(),);
}
class RiDemo extends StatelessWidget {
  const RiDemo({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "Ripple Animation in Flutter",
      theme: ThemeData(
        primarySwatch: Colors.purple,
      ),
      home: const RippleDemo(),
    );
  }
}
class RippleDemo extends StatefulWidget {
  const RippleDemo({super.key});

  @override
  State<RippleDemo> createState() {
    return RippleState();
  }
}
class RippleState extends State<RippleDemo> with SingleTickerProviderStateMixin {
  late Animation _animation;
  late AnimationController _animationController;

  var listRadius = [150.0, 200.0, 250.0, 300.0, 350.0, 400.0, 450.0];

  @override
  void initState() {
    super.initState();

    _animationController = AnimationController(vsync: this, duration: Duration(seconds: 3,), lowerBound: 0.5,);
    // _animation = Tween(begin: 0.0, end: 1.0).animate(_animationController);

    _animationController.addListener(() {
      setState(() {},);
    },);

    _animationController.forward();

  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Ripple Animation"),
      ),
      body: Center(
        child: Stack(
          alignment: Alignment.center,
          children: listRadius.map((radius) {
            return Container(
              width: radius * _animationController.value,
              height: radius * _animationController.value,
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                color: Colors.blue.withOpacity(1.0 - _animationController.value),
              ),
            );
          }).toList(),
        ),
      ),
    );
  }
}