flutter_drawing_board 0.3.0 flutter_drawing_board: ^0.3.0 copied to clipboard
A Flutter package of drawing board, provides basic drawing tools, canvas operations, and image data acquisition.
import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_drawing_board/flutter_drawing_board.dart';
/// 自定义绘制三角形
class Triangle extends PaintContent {
Triangle();
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();
}
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)),
);
},
);
}
@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.check), onPressed: _getImageData)
],
),
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),
),
),
],
),
);
}
}