113 lines
2.9 KiB
Dart
113 lines
2.9 KiB
Dart
import 'dart:async';
|
|
import 'dart:ui' as ui;
|
|
import 'package:flutter/material.dart';
|
|
import 'package:flutter/services.dart';
|
|
|
|
import '../components/coordinate_pro.dart';
|
|
|
|
/// create by 张风捷特烈 on 2020-03-19
|
|
/// contact me by email 1981462002@qq.com
|
|
/// 说明: 纸
|
|
|
|
class Paper extends StatefulWidget {
|
|
const Paper({super.key});
|
|
|
|
@override
|
|
_PaperState createState() => _PaperState();
|
|
}
|
|
|
|
class _PaperState extends State<Paper> {
|
|
ui.Image? _image;
|
|
|
|
@override
|
|
void initState() {
|
|
super.initState();
|
|
_loadImage();
|
|
}
|
|
|
|
void _loadImage() async {
|
|
_image =
|
|
await loadImageFromAssets('assets/images/icon_head.png');
|
|
setState(() {});
|
|
}
|
|
|
|
//读取 assets 中的图片
|
|
Future<ui.Image>? loadImageFromAssets(String path) async {
|
|
ByteData data = await rootBundle.load(path);
|
|
return decodeImageFromList(data.buffer.asUint8List());
|
|
}
|
|
|
|
@override
|
|
Widget build(BuildContext context) {
|
|
return Container(
|
|
color: Colors.white, child: CustomPaint(painter: PaperPainter(_image)));
|
|
}
|
|
|
|
|
|
}
|
|
|
|
class PaperPainter extends CustomPainter {
|
|
|
|
final ui.Image? image;
|
|
|
|
|
|
PaperPainter(this.image);
|
|
|
|
static const double step = 20; // 方格变长
|
|
final Coordinate coordinate = Coordinate(step: step);
|
|
|
|
// 颜色列表 256 个元素
|
|
final List<Color> colors =
|
|
List<Color>.generate(256, (i) => Color.fromARGB(255 - i, 255, 0, 0));
|
|
|
|
@override
|
|
void paint(Canvas canvas, Size size) {
|
|
if(image ==null) return;
|
|
|
|
Paint srcPaint = Paint();
|
|
canvas.translate(size.width / 2, size.height / 2);
|
|
canvas.translate(-step * 17, -step * 7);
|
|
Paint dstPaint = Paint();
|
|
BlendMode.values.asMap().forEach((i, value) {
|
|
int line = i ~/ 10;
|
|
int row = i % 10;
|
|
canvas.save();
|
|
|
|
canvas.translate(3.7 * step * row, 5.5 * step * line);
|
|
canvas.drawImageRect(image!, Rect.fromPoints(Offset.zero, Offset(image!.width*1.0,image!.height*1.0)),
|
|
Rect.fromCenter(center:Offset.zero, width: 25*2.0,height: 25*2.0), dstPaint);
|
|
|
|
srcPaint
|
|
..color = Color(0xffff0000)
|
|
..blendMode = value;
|
|
canvas.drawRect(
|
|
Rect.fromPoints(Offset.zero, Offset(20 * 2.0, 20 * 2.0)), srcPaint);
|
|
|
|
_simpleDrawText(canvas,value.toString().split(".")[1],offset: Offset(-10, 50));
|
|
canvas.restore();
|
|
});
|
|
}
|
|
|
|
@override
|
|
bool shouldRepaint(CustomPainter oldDelegate) => true;
|
|
|
|
void _simpleDrawText(Canvas canvas, String str,
|
|
{Offset offset = Offset.zero, Color color = Colors.black}) {
|
|
var builder = ui.ParagraphBuilder(ui.ParagraphStyle(
|
|
textAlign: TextAlign.left,
|
|
fontSize: 11,
|
|
textDirection: TextDirection.ltr,
|
|
maxLines: 1,
|
|
))
|
|
..pushStyle(
|
|
ui.TextStyle(color: color, textBaseline: ui.TextBaseline.alphabetic),
|
|
)
|
|
..addText(str);
|
|
|
|
canvas.drawParagraph(
|
|
builder.build()
|
|
..layout(ui.ParagraphConstraints(width: 11.0 * str.length)),
|
|
offset);
|
|
}
|
|
}
|