import 'dart:math';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'dart:ui' as ui;

/// create by 张风捷特烈 on 2020-03-19
/// contact me by email 1981462002@qq.com
/// 说明: 纸

class Paper extends StatelessWidget{
  const Paper({super.key});

  @override
  Widget build(BuildContext context) {
   return CustomPaint(
      painter: PaperPainter(),
    );
  }

}

class PaperPainter extends CustomPainter {

  @override
  void paint(Canvas canvas, Size size) {
    drawShaderSweep(canvas);
  }

  void drawShaderSweep(Canvas canvas) {
    var colors = [
      Color(0xFFF60C0C),
      Color(0xFFF3B913),
      Color(0xFFE7F716),
      Color(0xFF3DF30B),
      Color(0xFF0DF6EF),
      Color(0xFF0829FB),
      Color(0xFFB709F4),
    ];

    var pos = [1.0 / 7, 2.0 / 7, 3.0 / 7, 4.0 / 7, 5.0 / 7, 6.0 / 7, 1.0];
    Paint paint =  Paint();
    paint
      ..style = PaintingStyle.fill
      ..color = Colors.blue;

    paint.shader = ui.Gradient.sweep(
        Offset(80 + 150.0 * 0, 80), colors, pos, TileMode.clamp, pi / 2, pi);
    canvas.drawCircle(
      Offset(80 + 150.0 * 0, 80),
      50,
      paint,
    );
    paint.shader = ui.Gradient.sweep(
        Offset(80 + 150.0 * 1, 80), colors, pos, TileMode.repeated, pi / 2, pi);
    canvas.drawCircle(
      Offset(80 + 150.0 * 1, 80),
      50,
      paint,
    );
    paint.shader = ui.Gradient.sweep(
        Offset(80 + 150.0 * 2, 80), colors, pos, TileMode.mirror, pi / 2, pi);
    canvas.drawCircle(
      Offset(80 + 150.0 * 2, 80),
      50,
      paint,
    );

    paint.shader = ui.Gradient.sweep(
        Offset(80 + 150.0 * 3, 80), colors, pos, TileMode.clamp);
    canvas.drawCircle(
      Offset(80 + 150.0 * 3, 80),
      50,
      paint,
    );
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => true;
}