painter2

A simple flutter widget to paint with your fingers.

Features

The widget supports:

  • Changing fore- and background color
  • Setting an image as background
  • Changing the thickness of lines you draw
  • Exporting your painting as png
  • Undo/Redo drawing a line
  • Clear the whole drawing

Installation

In your pubspec.yaml file within your Flutter Project:

dependencies:
  painter2: any

Then import it:

import 'package:painter2/painter2.dart';

Use it

In order to use this plugin, first create a controller:

PainterController controller = PainterController();
controller.thickness = 5.0; // Set thickness of your brush. Defaults to 1.0
controller.backgroundColor = Colors.green; // Background color is ignores if you set a background image
controller.backgroundImage = Image.network(...); // Sets a background image. You can load images as you would normally do: From an asset, from the network, from memory...

That controller will handle all properties of your drawing space.

Then, to display the painting area, create an inline Painter object and give it a reference to your previously created controller:

Painter(controller)

By exporting the painting as PNG, you will get an Uint8List object which represents the bytes of the png final file:

await controller.exportAsPNGBytes();

The library does not handle saving the final image anywhere.

Example

For a full example take a look at the example project. Here is a short recording showing it. Note that the color picker is an external dependency which is only required for the example.

demo!

Libraries

painter

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. [...]