content: import 'package:flutter/material.dart';
  import 'dart:math';
  
  class ColorLoader2 extends StatefulWidget {
    final Color color1;
    final Color color2;
    final Color color3;
  
    ColorLoader2(
        {this.color1 = Colors.deepOrangeAccent,
        this.color2 = Colors.yellow,
        this.color3 = Colors.lightGreen});
  
    @override
    _ColorLoader2State createState() => _ColorLoader2State();
  }
  
  class _ColorLoader2State extends State<ColorLoader2>
      with TickerProviderStateMixin {
    late Animation<double> animation1;
    late Animation<double> animation2;
    late Animation<double> animation3;
    late AnimationController controller1;
    late AnimationController controller2;
    late AnimationController controller3;
  
    @override
    void initState() {
      super.initState();
  
      controller1 = AnimationController(
          duration: const Duration(milliseconds: 1200), vsync: this);
  
      controller2 = AnimationController(
          duration: const Duration(milliseconds: 900), vsync: this);
  
      controller3 = AnimationController(
          duration: const Duration(milliseconds: 2000), vsync: this);
  
      animation1 = Tween<double>(begin: 0.0, end: 1.0).animate(CurvedAnimation(
          parent: controller1, curve: Interval(0.0, 1.0, curve: Curves.linear)));
  
      animation2 = Tween<double>(begin: -1.0, end: 0.0).animate(CurvedAnimation(
          parent: controller2, curve: Interval(0.0, 1.0, curve: Curves.easeIn)));
  
      animation3 = Tween<double>(begin: 0.0, end: 1.0).animate(CurvedAnimation(
          parent: controller3,
          curve: Interval(0.0, 1.0, curve: Curves.decelerate)));
  
      controller1.repeat();
      controller2.repeat();
      controller3.repeat();
    }
  
    @override
    Widget build(BuildContext context) {
      return Center(
        child: Container(
          child: Stack(
            children: <Widget>[
              new RotationTransition(
                turns: animation1,
                child: CustomPaint(
                  painter: Arc1Painter(widget.color1),
                  child: Container(
                    width: 50.0,
                    height: 50.0,
                  ),
                ),
              ),
              new RotationTransition(
                turns: animation2,
                child: CustomPaint(
                  painter: Arc2Painter(widget.color2),
                  child: Container(
                    width: 50.0,
                    height: 50.0,
                  ),
                ),
              ),
              new RotationTransition(
                turns: animation3,
                child: CustomPaint(
                  painter: Arc3Painter(widget.color3),
                  child: Container(
                    width: 50.0,
                    height: 50.0,
                  ),
                ),
              )
            ],
          ),
        ),
      );
    }
  
    @override
    void dispose() {
      controller1.dispose();
      controller2.dispose();
      controller3.dispose();
      super.dispose();
    }
  }
  
  class Arc1Painter extends CustomPainter {
    final Color color;
  
    Arc1Painter(this.color);
  
    @override
    void paint(Canvas canvas, Size size) {
      Paint p1 = new Paint()
        ..color = color
        ..strokeWidth = 2.0
        ..strokeCap = StrokeCap.round
        ..style = PaintingStyle.stroke;
  
      Rect rect1 = new Rect.fromLTWH(0.0, 0.0, size.width, size.height);
  
      canvas.drawArc(rect1, 0.0, 0.5 * pi, false, p1);
      canvas.drawArc(rect1, 0.6 * pi, 0.8 * pi, false, p1);
      canvas.drawArc(rect1, 1.5 * pi, 0.4 * pi, false, p1);
    }
  
    @override
    bool shouldRepaint(CustomPainter oldDelegate) {
      return true;
    }
  }
  
  class Arc2Painter extends CustomPainter {
    final Color color;
  
    Arc2Painter(this.color);
  
    @override
    void paint(Canvas canvas, Size size) {
      Paint p2 = new Paint()
        ..color = color
        ..strokeWidth = 2.0
        ..strokeCap = StrokeCap.round
        ..style = PaintingStyle.stroke;
  
      Rect rect2 = new Rect.fromLTWH(
          0.0 + (0.2 * size.width) / 2,
          0.0 + (0.2 * size.height) / 2,
          size.width - 0.2 * size.width,
          size.height - 0.2 * size.height);
  
      canvas.drawArc(rect2, 0.0, 0.5 * pi, false, p2);
      canvas.drawArc(rect2, 0.8 * pi, 0.6 * pi, false, p2);
      canvas.drawArc(rect2, 1.6 * pi, 0.2 * pi, false, p2);
    }
  
    @override
    bool shouldRepaint(CustomPainter oldDelegate) {
      return true;
    }
  }
  
  class Arc3Painter extends CustomPainter {
    final Color color;
  
    Arc3Painter(this.color);
  
    @override
    void paint(Canvas canvas, Size size) {
      Paint p3 = new Paint()
        ..color = color
        ..strokeWidth = 1.5
        ..strokeCap = StrokeCap.round
        ..style = PaintingStyle.stroke;
  
      Rect rect3 = new Rect.fromLTWH(
          0.0 + (0.4 * size.width) / 2,
          0.0 + (0.4 * size.height) / 2,
          size.width - 0.4 * size.width,
          size.height - 0.4 * size.height);
  
      canvas.drawArc(rect3, 0.0, 0.9 * pi, false, p3);
      canvas.drawArc(rect3, 1.1 * pi, 0.8 * pi, false, p3);
    }
  
    @override
    bool shouldRepaint(CustomPainter oldDelegate) {
      return true;
    }
  }
  