114 lines
2.5 KiB
Dart
114 lines
2.5 KiB
Dart
import 'dart:math';
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import 'dart:ui';
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import 'package:flutter/material.dart';
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import 'package:flutter_first_station/paper/conform_dialog.dart';
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import 'model.dart';
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import 'paper_app_bar.dart';
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class Paper extends StatefulWidget {
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const Paper({Key? key}) : super(key: key);
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@override
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State<Paper> createState() => _PaperState();
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}
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class _PaperState extends State<Paper> {
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List<Line> _lines = []; // 线列表
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int _activeColorIndex = 0; // 颜色激活索引
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int _activeStorkWidthIndex = 0; // 线宽激活索引
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// 支持的颜色
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final List<Color> supportColors = [
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Colors.black, Colors.red, Colors.orange,
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Colors.yellow, Colors.green, Colors.blue,
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Colors.indigo, Colors.purple,
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];
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// 支持的线粗
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final List<double> supportStorkWidths = [1,2, 4, 6, 8, 10];
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@override
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Widget build(BuildContext context) {
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return Scaffold(
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appBar: PaperAppBar(
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onClear: _showClearDialog,
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),
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body: GestureDetector(
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onPanStart: _onPanStart,
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onPanUpdate: _onPanUpdate,
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child: CustomPaint(
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painter: PaperPainter(
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lines: _lines
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),
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child: ConstrainedBox(constraints: const BoxConstraints.expand()),
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),
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),
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);
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}
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void _showClearDialog() {
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String msg = "您的当前操作会清空绘制内容，是否确定删除!";
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showDialog(
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context: context,
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builder: (ctx) => ConformDialog(
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title: '清空提示',
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conformText: '确定',
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msg: msg,
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onConform: _clear,
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));
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}
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void _clear(){
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_lines.clear();
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Navigator.of(context).pop();
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setState(() {
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});
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}
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void _onPanStart(DragStartDetails details) {
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_lines.add(Line(points: [details.localPosition],));
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}
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void _onPanUpdate(DragUpdateDetails details) {
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_lines.last.points.add(details.localPosition);
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setState(() {
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});
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}
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}
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class PaperPainter extends CustomPainter {
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PaperPainter({
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required this.lines,
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}) {
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_paint = Paint()
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..style = PaintingStyle.stroke
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..strokeCap = StrokeCap.round;
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}
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late Paint _paint;
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final List<Line> lines;
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@override
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void paint(Canvas canvas, Size size) {
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for (int i = 0; i < lines.length; i++) {
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drawLine(canvas, lines[i]);
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}
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}
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///根据点位绘制线
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void drawLine(Canvas canvas, Line line) {
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_paint.color = line.color;
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_paint.strokeWidth = line.strokeWidth;
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canvas.drawPoints(PointMode.polygon, line.points, _paint);
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}
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@override
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bool shouldRepaint(CustomPainter oldDelegate) => true;
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}
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