import 'dart:math';

import 'package:flutter/material.dart';

///
/// desc:
///
class WaterRipple extends StatefulWidget {
  final Color color;
  final Duration duration;
  final Curve curve;
  final int count;

  const WaterRipple(
      {Key? key,
      this.color = Colors.white,
      this.count = 3,
      this.duration = const Duration(milliseconds: 800),
      this.curve = Curves.linear})
      : super(key: key);

  @override
  _WaterRippleState createState() => _WaterRippleState();
}

class _WaterRippleState extends State<WaterRipple>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation _animation;

  @override
  void initState() {
    _controller = AnimationController(vsync: this, duration: widget.duration)
      ..repeat();
    _animation = CurveTween(curve: widget.curve).animate(_controller);

    super.initState();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _controller,
      builder: (context, child) {
        return CustomPaint(
          painter: WaterRipplePainter(_animation.value,
              count: widget.count, color: widget.color),
        );
      },
    );
  }
}

class WaterRipplePainter extends CustomPainter {
  final double progress;
  final int count;
  final Color color;

  Paint _paint = Paint()..style = PaintingStyle.fill;

  WaterRipplePainter(this.progress,
      {this.count = 3, this.color = const Color(0xFF0080ff)});

  @override
  void paint(Canvas canvas, Size size) {
    double radius = min(size.width / 2, size.height / 2);

    for (int i = count; i >= 0; i--) {
      final double opacity = (1.0 - ((i + progress) / (count + 1)));
      final Color _color = color.withOpacity(opacity);
      _paint..color = _color;

      double _radius = radius * ((i + progress) / (count + 1));

      canvas.drawCircle(
          Offset(size.width / 2, size.height / 2), _radius, _paint);
    }
  }

  @override
  bool shouldRepaint(covariant WaterRipplePainter old) {
    return progress != old.progress || color != old.color || count != old.count;
  }
}