simple-drawing-board

simple-drawing-board.js

Just simple minimal canvas drawing lib.

• 0 dependencies
• Modern browser compatibility
• Under 500 lines of code

For v2.x users, See https://github.com/leader22/simple-drawing-board.js/tree/v2.1.1

For v1.x users, See https://github.com/leader22/simple-drawing-board.js/tree/v1.4.1

Install

npm i simple-drawing-board

or

<script src="./path/to/dist/simple-drawing-board.min.js"></script>

How to use

Prepare your canvas element.

<canvas id="canvas" width="500" height="300"></canvas>

Then create drawing board.

import { create } from "simple-drawing-board.js";

const sdb = create(document.getElementById("canvas"));

APIs

See also type definitions.

setLineSize()

sdb.setLineSize(10);
sdb.setLineSize(0);  // to be 1
sdb.setLineSize(-1); // to be 1

setLineColor()

sdb.setLineColor("#0094c8");
sdb.setLineColor("red");
sdb.setLineColor("#0f0");

fill()

sdb.fill("#000");
sdb.fill("orange");

clear()

sdb.clear();

toggleMode()

// switch DRAW <=> ERASE
sdb.mode; // "draw"
sdb.toggleMode();
sdb.mode; // "erase"

toDataURL()

sdb.toDataURL(); // "data:image/png;base64,xxxxxx...."
sdb.toDataURL({ type: "image/jpeg" }); // "data:image/jpeg;base64,xxxxxx...."
sdb.toDataURL({ type: "image/jpeg", quality: 0.3 }); // compression quality

fillImageByElement()

sdb.fillImageByElement(document.getElementById("img"));
sdb.fillImageByElement(document.getElementById("img"), { isOverlay: true });

async fillImageByDataURL()

await sdb.fillImageByDataURL("data:image/png;base64,xxxxxx....");
await sdb.fillImageByDataURL("data:image/png;base64,xxxxxx....", { isOverlay: true });

async undo()

await sdb.undo();

async redo()

await sdb.redo();

destroy()

Just detach from canvas element.

sdb.destroy();

Events

Events are available via observer property.

drawBegin

sdb.observer.on("drawBegin", (coords) => {
    console.log(coords.x, coords.y);
});

draw

sdb.observer.on("draw", (coords) => {
    console.log(coords.x, coords.y);
});

drawEnd

sdb.observer.on("drawEnd", (coords) => {
    console.log(coords.x, coords.y);
});

save

sdb.observer.on("save", (curImg) => {
    console.log(curImg); // "data:image/png;base64,xxxxxx...."
});

Alternatives

• Fabric.js: More and more functions and utils.
• drawingboard.js: With jQuery.

License

MIT