signature

pub package

A Flutter plugin providing performance optimized signature canvas with ability to set custom style, boundaries and initial state. This is native flutter implementation, so it supports all platforms.

Why

In time of creation of this plugin, there was no available solution that had:

  • required performance on wide range of devices
  • ability to set canvas boundaries
  • ability to initialize using previously saved state

Usage

To use this plugin, add signature as a dependency in your pubspec.yaml file.

Example

// IMPORT PACKAGE
import 'package:signature/signature.dart';

// INITIALIZE. RESULT IS A WIDGET, SO IT CAN BE DIRECTLY USED IN BUILD METHOD 
var _signatureCanvas = Signature(
  width: 300,
  height: 300,
  backgroundColor: Colors.lightBlueAccent,
);

// CLEAR CANVAS
_signatureCanvas.clear();

// EXPORT BYTES (EXPORTING FORMAT IS PNG)
_signatureCanvas.exportBytes();

// EXPORT POINTS (2D POINTS ROUGHLY REPRESENTING WHAT IS VISIBLE ON CANVAS)
var exportedPoints = _signatureCanvas.exportPoints();

//EXPORTED POINTS CAN BE USED TO INITIALIZE PREVIOUS STATE VIA CONSTRUCTOR
var _signatureCanvas = Signature(
  points: exportedPoints,
  width: 300,
  height: 300,
  backgroundColor: Colors.lightBlueAccent,
);

Contribution and Support

  • Contributions are welcome!
  • If you want to contribute code please create a PR
  • If you find a bug or want a feature, please fill an issue

Libraries

i18n
signature

Dart

dart:ui
Built-in types and core primitives for a Flutter application. [...]

Core

dart:async
Support for asynchronous programming, with classes such as Future and Stream. [...]
dart:collection
Classes and utilities that supplement the collection support in dart:core. [...]
dart:convert
Encoders and decoders for converting between different data representations, including JSON and UTF-8. [...]
dart:core
Built-in types, collections, and other core functionality for every Dart program. [...]
dart:developer
Interact with developer tools such as the debugger and inspector. [...]
dart:math
Mathematical constants and functions, plus a random number generator. [...]
dart:typed_data
Lists that efficiently handle fixed sized data (for example, unsigned 8 byte integers) and SIMD numeric types. [...]

VM

dart:io
File, socket, HTTP, and other I/O support for non-web applications. [...]
dart:isolate
Concurrent programming using isolates: independent workers that are similar to threads but don't share memory, communicating only via messages. [...]