blob: 09989f7c695dfee4942100e8a16c438162798195 [file] [log] [blame]
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:typed_data';
import 'dart:ui';
import 'package:flutter/material.dart';
class DrawPointsPage extends StatefulWidget {
const DrawPointsPage({super.key});
@override
State<DrawPointsPage> createState() => _DrawPointsPageState();
}
class _DrawPointsPageState extends State<DrawPointsPage> with SingleTickerProviderStateMixin {
late final AnimationController controller;
double tick = 0.0;
@override
void initState() {
super.initState();
controller = AnimationController(vsync: this, duration: const Duration(hours: 1));
controller.addListener(() {
setState(() {
tick += 1;
});
});
controller.forward(from: 0);
}
@override
void dispose() {
controller.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return CustomPaint(
size: const Size(500, 500),
painter: PointsPainter(tick),
child: Container(),
);
}
}
class PointsPainter extends CustomPainter {
PointsPainter(this.tick);
final double tick;
final Float32List data = Float32List(8000);
static const List<Color> kColors = <Color>[
Colors.red,
Colors.blue,
Colors.green,
Colors.yellow,
Colors.orange,
Colors.purple,
Colors.pink,
Colors.deepPurple,
];
@override
void paint(Canvas canvas, Size size) {
if (size.width == 0) {
return;
}
canvas.drawPaint(Paint()..color = Colors.white);
for (int i = 0; i < 8; i++) {
final double x = ((size.width / (i + 1)) + tick) % size.width;
for (int j = 0; j < data.length; j += 2) {
data[j] = x;
data[j + 1] = (size.height / (j + 1)) + 200;
}
final Paint paint = Paint()
..color = kColors[i]
..strokeWidth = 5
..strokeCap = StrokeCap.round
..style = PaintingStyle.stroke;
canvas.drawRawPoints(PointMode.points, data, paint);
}
}
@override
bool shouldRepaint(covariant CustomPainter oldDelegate) {
return true;
}
}