95 lines
2.4 KiB
Dart
95 lines
2.4 KiB
Dart
import 'dart:math';
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import 'package:flutter/material.dart';
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/// create by 张风捷特烈 on 2020/11/2
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/// contact me by email 1981462002@qq.com
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/// 说明:
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///
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class Paper extends StatefulWidget {
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final Color color;
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const Paper({Key? key, this.color = Colors.lightBlue}) : super(key: key);
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@override
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_PaperState createState() => _PaperState();
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}
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class _PaperState extends State<Paper> with SingleTickerProviderStateMixin {
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late AnimationController _controller;
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late Animation<Color?> _colorCtrl;
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late Animation<double> _angleCtrl;
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@override
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void initState() {
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super.initState();
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_controller = AnimationController(
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duration: const Duration(seconds: 1),
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vsync: this,
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);
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_angleCtrl = _controller.drive(Tween(begin: 10, end: 40));
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_colorCtrl =
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ColorTween(begin: Colors.blue, end: Colors.red).animate(_controller);
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_controller.repeat(reverse: true);
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}
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@override
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void dispose() {
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_controller.dispose();
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super.dispose();
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}
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@override
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Widget build(BuildContext context) {
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return Center(
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child: CustomPaint(
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size: Size(100, 100),
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painter: PicManPainter(
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color: _colorCtrl, angle: _angleCtrl, repaint: _controller),
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),
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);
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}
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}
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class PicManPainter extends CustomPainter {
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final Animation<double> repaint;
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final Animation<double> angle;
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final Animation<Color?> color;
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Paint _paint = Paint();
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PicManPainter({ required this.repaint,required this.color,required this.angle})
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: super(repaint: repaint);
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@override
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void paint(Canvas canvas, Size size) {
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canvas.clipRect(Offset.zero & size); //剪切画布
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final double radius = size.width / 2;
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canvas.translate(radius, size.height / 2);
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_drawHead(canvas, size);
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_drawEye(canvas, radius);
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}
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//绘制头
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void _drawHead(Canvas canvas, Size size) {
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var rect = Rect.fromCenter(
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center: Offset(0, 0), height: size.width, width: size.height);
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var a = angle.value / 180 * pi;
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canvas.drawArc(
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rect, a, 2 * pi - a.abs() * 2, true, _paint..color = color.value??Colors.black);
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}
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//绘制眼睛
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void _drawEye(Canvas canvas, double radius) {
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canvas.drawCircle(Offset(radius * 0.15, -radius * 0.6), radius * 0.12,
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_paint..color = Colors.white);
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}
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@override
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bool shouldRepaint(covariant PicManPainter oldDelegate)=> oldDelegate.repaint != repaint;
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}
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