| 1 | // Copyright 2014 The Flutter Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | import 'dart:math' show cos, sin; |
| 6 | import 'dart:typed_data'; |
| 7 | |
| 8 | import 'package:flutter/material.dart'; |
| 9 | |
| 10 | class RRectBlur extends StatefulWidget { |
| 11 | const RRectBlur({super.key}); |
| 12 | |
| 13 | @override |
| 14 | State<RRectBlur> createState() => _RRectBlurPageState(); |
| 15 | } |
| 16 | |
| 17 | class _RRectBlurPageState extends State<RRectBlur> with SingleTickerProviderStateMixin { |
| 18 | late final AnimationController controller; |
| 19 | double tick = 0.0; |
| 20 | |
| 21 | @override |
| 22 | void initState() { |
| 23 | super.initState(); |
| 24 | controller = AnimationController(vsync: this, duration: const Duration(hours: 1)); |
| 25 | controller.addListener(() { |
| 26 | setState(() { |
| 27 | tick += 1; |
| 28 | }); |
| 29 | }); |
| 30 | controller.forward(from: 0); |
| 31 | } |
| 32 | |
| 33 | @override |
| 34 | void dispose() { |
| 35 | controller.dispose(); |
| 36 | super.dispose(); |
| 37 | } |
| 38 | |
| 39 | @override |
| 40 | Widget build(BuildContext context) { |
| 41 | return CustomPaint( |
| 42 | size: const Size(500, 500), |
| 43 | painter: PointsPainter(tick), |
| 44 | child: Container(), |
| 45 | ); |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | class PointsPainter extends CustomPainter { |
| 50 | PointsPainter(this.tick); |
| 51 | |
| 52 | final double tick; |
| 53 | |
| 54 | final Float32List data = Float32List(8000); |
| 55 | |
| 56 | static const List<Color> kColors = <Color>[ |
| 57 | Colors.red, |
| 58 | Colors.blue, |
| 59 | Colors.green, |
| 60 | Colors.yellow, |
| 61 | Colors.orange, |
| 62 | Colors.purple, |
| 63 | Colors.pink, |
| 64 | Colors.deepPurple, |
| 65 | ]; |
| 66 | |
| 67 | @override |
| 68 | void paint(Canvas canvas, Size size) { |
| 69 | if (size.width == 0) { |
| 70 | return; |
| 71 | } |
| 72 | final double halfHeight = size.height / 2.0; |
| 73 | const double freq = 0.25; |
| 74 | const int circleCount = 40; |
| 75 | for (int i = 0; i < circleCount; ++i) { |
| 76 | final double radius = 25 * cos(i + (1.0 * 2.0 * 3.1415 * tick) / 60.0) + 25; |
| 77 | final Paint paint = |
| 78 | Paint() |
| 79 | ..style = PaintingStyle.fill |
| 80 | ..filterQuality = FilterQuality.low |
| 81 | ..maskFilter = MaskFilter.blur(BlurStyle.normal, radius); |
| 82 | final double yval = halfHeight * sin(i + (freq * 2.0 * 3.1415 * tick) / 60.0) + halfHeight; |
| 83 | final double xval = (i.toDouble() / circleCount) * size.width; |
| 84 | canvas.drawCircle(Offset(xval, yval), 50, paint..color = kColors[i % kColors.length]); |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | @override |
| 89 | bool shouldRepaint(covariant CustomPainter oldDelegate) { |
| 90 | return true; |
| 91 | } |
| 92 | } |
| 93 |