joakin/elm-canvas

This library exposes a low level API that mirrors most of the DOM canvas API to be used with Elm in a declarative way.

Live examples (sources)

WARNING: This library is in development and right now it only exposes a low-level API that mirrors the DOM API, providing a bit of extra type safety where it makes sense. The DOM API is highly stateful and side-effectful, so be careful. To understand how to use this library for now, please familiarize yourself with the MDN Canvas Tutorial. We will be iterating on the design of the library to make it nicer and provide better defaults as time goes by, and make specific tutorials with Elm.

Usage

To use it, remember to include the elm-canvas custom element script in your page before you initialize your Elm application.

• http://unpkg.com/elm-canvas/elm-canvas.js
  • CDN link. Visit it and copy the redirected URL with the version number into your HTML.
• http://npmjs.com/package/elm-canvas
  • See docs for version compatibility, in general, latest npm package should work fine with the latest elm package.

Then, you can add your HTML element like this:

module Main exposing (main)

import Html exposing (Html)
import Canvas

view : Html msg
view =
    let
        width = 500
        height = 300
    in
        Canvas.element
            width
            height
            [ style [ ( "border", "1px solid black" ) ] ]
            ( Canvas.empty
                |> Canvas.clearRect 0 0 width height
                |> renderSquare
            )

renderSquare cmds =
    cmds
        |> Canvas.fillStyle (Color.rgba 0 0 0 1)
        |> Canvas.fillRect 0 0 100 50

main = view

Examples

You can see many examples in the examples/ folder, and experience them live.