126 lines
3.3 KiB
Dart
126 lines
3.3 KiB
Dart
import 'dart:ui' as ui;
|
|
import 'package:flutter/material.dart';
|
|
import '../components/coordinate.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 StatelessWidget {
|
|
const Paper({super.key});
|
|
|
|
@override
|
|
Widget build(BuildContext context) {
|
|
return Container(
|
|
color: Colors.white,
|
|
child: CustomPaint(
|
|
// 使用CustomPaint
|
|
painter: PaperPainter(),
|
|
),
|
|
);
|
|
}
|
|
}
|
|
|
|
class PaperPainter extends CustomPainter {
|
|
final Coordinate coordinate = Coordinate(step: 25);
|
|
|
|
late Paint _paint;
|
|
|
|
final double strokeWidth = 0.5;
|
|
final Color color = Colors.blue;
|
|
|
|
PaperPainter() {
|
|
_paint = Paint()
|
|
..style = PaintingStyle.fill
|
|
..strokeWidth = strokeWidth
|
|
..color = color;
|
|
}
|
|
|
|
@override
|
|
void paint(Canvas canvas, Size size) {
|
|
coordinate.paint(canvas, size);
|
|
canvas.translate(size.width / 2, size.height / 2);
|
|
|
|
_drawTextLeft(canvas);
|
|
_drawTextTextAlignRight(canvas);
|
|
_drawTextPaint(canvas, "100", offset: Offset(0, 0));
|
|
}
|
|
|
|
void _drawTextLeft(Canvas canvas) {
|
|
var builder = ui.ParagraphBuilder(ui.ParagraphStyle(
|
|
textAlign: TextAlign.left,
|
|
fontSize: 40,
|
|
textDirection: TextDirection.ltr,
|
|
maxLines: 1,
|
|
))
|
|
..pushStyle(
|
|
ui.TextStyle(
|
|
color: Colors.black87, textBaseline: ui.TextBaseline.alphabetic),
|
|
)
|
|
..addText("Flutter Unit");
|
|
|
|
canvas.drawParagraph(
|
|
builder.build()..layout(ui.ParagraphConstraints(width: 300)),
|
|
Offset(0, -100));
|
|
canvas.drawRect(Rect.fromLTRB(0, 0 - 100.0, 300, 40 - 100.0),
|
|
_paint..color = Colors.blue.withAlpha(33));
|
|
}
|
|
|
|
void _drawTextCenter(Canvas canvas,String str) {
|
|
var builder = ui.ParagraphBuilder(ui.ParagraphStyle(
|
|
textAlign: TextAlign.center,
|
|
fontSize: 12,
|
|
textDirection: TextDirection.ltr,
|
|
maxLines: 1,
|
|
))
|
|
..pushStyle(
|
|
ui.TextStyle(
|
|
color: Colors.black87, textBaseline: ui.TextBaseline.alphabetic),
|
|
)
|
|
..addText(str);
|
|
|
|
canvas.drawParagraph(
|
|
builder.build()..layout(ui.ParagraphConstraints(width: 12.0*str.length)),
|
|
Offset(0, 0));
|
|
|
|
}
|
|
|
|
void _drawTextTextAlignRight(Canvas canvas) {
|
|
var builder = ui.ParagraphBuilder(ui.ParagraphStyle(
|
|
textAlign: TextAlign.right,
|
|
fontSize: 40,
|
|
textDirection: TextDirection.ltr,
|
|
maxLines: 1,
|
|
))
|
|
..pushStyle(
|
|
ui.TextStyle(
|
|
color: Colors.black87, textBaseline: ui.TextBaseline.alphabetic),
|
|
)
|
|
..addText("Flutter Unit");
|
|
|
|
canvas.drawParagraph(
|
|
builder.build()..layout(ui.ParagraphConstraints(width: 300)),
|
|
Offset(0, 100));
|
|
|
|
canvas.drawRect(Rect.fromLTRB(0, 0 + 100.0, 300, 40 + 100.0),
|
|
_paint..color = Colors.blue.withAlpha(33));
|
|
}
|
|
|
|
void _drawTextPaint(Canvas canvas, String text,
|
|
{Offset offset = Offset.zero}) {
|
|
TextPainter(
|
|
text: TextSpan(
|
|
text: text, style: TextStyle(fontSize: 12, color: Colors.black)),
|
|
textAlign: TextAlign.left,
|
|
textDirection: TextDirection.ltr)
|
|
..layout(maxWidth: 300)
|
|
..paint(canvas, offset);
|
|
|
|
canvas.drawRect(Rect.fromLTRB(0, 0, 300, 40),
|
|
_paint..color = Colors.blue.withAlpha(33));
|
|
}
|
|
|
|
@override
|
|
bool shouldRepaint(PaperPainter oldDelegate) => false;
|
|
}
|