flutter_drawing_board 0.4.0+1 flutter_drawing_board: ^0.4.0+1 copied to clipboard
A Flutter package of drawing board, provides basic drawing tools, canvas operations, and image data acquisition.
import 'dart:convert';
import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_drawing_board/flutter_drawing_board.dart';
import 'package:flutter_drawing_board/paint_extension.dart';
const Map<String, dynamic> _testLine1 = <String, dynamic>{
'type': 'StraightLine',
'startPoint': <String, dynamic>{
'dx': 68.94337550070736,
'dy': 62.05980083656557
},
'endPoint': <String, dynamic>{
'dx': 277.1373386828114,
'dy': 277.32029957032194
},
'paint': <String, dynamic>{
'blendMode': 3,
'color': 4294198070,
'filterQuality': 3,
'invertColors': false,
'isAntiAlias': false,
'strokeCap': 1,
'strokeJoin': 1,
'strokeWidth': 4.0,
'style': 1
}
};
const Map<String, dynamic> _testLine2 = <String, dynamic>{
'type': 'StraightLine',
'startPoint': <String, dynamic>{
'dx': 106.35164817830423,
'dy': 255.9575653134524
},
'endPoint': <String, dynamic>{
'dx': 292.76034659254094,
'dy': 92.125586665872
},
'paint': <String, dynamic>{
'blendMode': 3,
'color': 4294198070,
'filterQuality': 3,
'invertColors': false,
'isAntiAlias': false,
'strokeCap': 1,
'strokeJoin': 1,
'strokeWidth': 4.0,
'style': 1
}
};
/// 自定义绘制三角形
class Triangle extends PaintContent {
Triangle();
Triangle.data({
required this.startPoint,
required this.A,
required this.B,
required this.C,
required Paint paint,
}) : super.paint(paint);
factory Triangle.fromJson(Map<String, dynamic> data) {
return Triangle.data(
startPoint: jsonToOffset(data['startPoint'] as Map<String, dynamic>),
A: jsonToOffset(data['A'] as Map<String, dynamic>),
B: jsonToOffset(data['B'] as Map<String, dynamic>),
C: jsonToOffset(data['C'] as Map<String, dynamic>),
paint: jsonToPaint(data['paint'] as Map<String, dynamic>),
);
}
Offset startPoint = Offset.zero;
Offset A = Offset.zero;
Offset B = Offset.zero;
Offset C = Offset.zero;
@override
void startDraw(Offset startPoint) => this.startPoint = startPoint;
@override
void drawing(Offset nowPoint) {
A = Offset(
startPoint.dx + (nowPoint.dx - startPoint.dx) / 2, startPoint.dy);
B = Offset(startPoint.dx, nowPoint.dy);
C = nowPoint;
}
@override
void draw(Canvas canvas, Size size, bool deeper) {
final Path path = Path()
..moveTo(A.dx, A.dy)
..lineTo(B.dx, B.dy)
..lineTo(C.dx, C.dy)
..close();
canvas.drawPath(path, paint);
}
@override
Triangle copy() => Triangle();
@override
Map<String, dynamic> toJson() {
return <String, dynamic>{
'startPoint': startPoint.toJson(),
'A': A.toJson(),
'B': B.toJson(),
'C': C.toJson(),
'paint': paint.toJson(),
};
}
}
void main() {
FlutterError.onError = (FlutterErrorDetails details) {
FlutterError.dumpErrorToConsole(details);
if (kReleaseMode) {
exit(1);
}
};
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Drawing Test',
theme: ThemeData(primarySwatch: Colors.blue),
home: const MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
/// 绘制控制器
final DrawingController _drawingController = DrawingController();
@override
void dispose() {
_drawingController.dispose();
super.dispose();
}
/// 获取画板数据 `getImageData()`
Future<void> _getImageData() async {
final Uint8List? data =
(await _drawingController.getImageData())?.buffer.asUint8List();
if (data == null) {
print('获取图片数据失败');
return;
}
showDialog<void>(
context: context,
builder: (BuildContext c) {
return Material(
color: Colors.transparent,
child:
InkWell(onTap: () => Navigator.pop(c), child: Image.memory(data)),
);
},
);
}
/// 获取画板内容 Json `getJsonList()`
Future<void> _getJson() async {
showDialog<void>(
context: context,
builder: (BuildContext c) {
return Center(
child: Material(
color: Colors.white,
child: InkWell(
onTap: () => Navigator.pop(c),
child: Container(
constraints:
const BoxConstraints(maxWidth: 500, maxHeight: 800),
padding: const EdgeInsets.all(20.0),
child: SelectableText(
const JsonEncoder.withIndent(' ')
.convert(_drawingController.getJsonList()),
),
),
),
),
);
},
);
}
/// 添加Json测试内容
void _addTestLine() {
_drawingController.addContent(StraightLine.fromJson(_testLine1));
_drawingController
.addContents(<PaintContent>[StraightLine.fromJson(_testLine2)]);
}
@override
Widget build(BuildContext context) {
return Scaffold(
resizeToAvoidBottomInset: false,
backgroundColor: Colors.grey,
appBar: AppBar(
title: const Text('Drawing Test'),
systemOverlayStyle: SystemUiOverlayStyle.light,
actions: <Widget>[
IconButton(
icon: const Icon(Icons.line_axis), onPressed: _addTestLine),
IconButton(
icon: const Icon(Icons.javascript_outlined), onPressed: _getJson),
IconButton(icon: const Icon(Icons.check), onPressed: _getImageData),
const SizedBox(width: 40),
],
),
body: Column(
children: <Widget>[
Expanded(
child: DrawingBoard(
controller: _drawingController,
background:
Container(width: 400, height: 400, color: Colors.white),
showDefaultActions: true,
showDefaultTools: true,
defaultToolsBuilder: (Type t, _) {
return DrawingBoard.defaultTools(t, _drawingController)
..insert(
1,
DefToolItem(
icon: Icons.change_history_rounded,
isActive: t == Triangle,
onTap: () =>
_drawingController.setPaintContent = Triangle(),
),
);
},
),
),
const Padding(
padding: EdgeInsets.all(8.0),
child: SelectableText(
'https://github.com/xSILENCEx/flutter_drawing_board',
style: TextStyle(fontSize: 10, color: Colors.white),
),
),
],
),
);
}
}