react-sketch-canvas-sf-2

Freehand vector drawing component for React using SVG as canvas 🖌

Overview

$3

- Supports Desktop and Mobile.
- Accepts input from Mouse, touch, and graphic tablets.

$3

- Requires React >= 16.4

$3

- Try here

Installation

If you use npm

``sh
npm i react-sketch-canvas
`

or with yarn

`sh
yarn add react-sketch-canvas
`

Example

Common usage example

`javascript
import * as React from 'react';
import { ReactSketchCanvas } from 'react-sketch-canvas';

const styles = {
border: '0.0625rem solid #9c9c9c',
borderRadius: '0.25rem',
};

const Canvas = () => {
return (
style={styles}
width="600"
height="400"
strokeWidth={4}
strokeColor="red"
/>
);
};
`

To export Data URL of your sketch use ref

`javascript
import * as React from "react";
import { ReactSketchCanvas } from "react-sketch-canvas";

const styles = {
border: "0.0625rem solid #9c9c9c",
borderRadius: "0.25rem"
};

const Canvas = class extends React.Component {
constructor(props) {
super(props);

this.canvas = React.createRef();
}

render() {
return (



);
}
};
`

List of Props

| Props | Expected datatype | Default value | Description |
| ---------------------------------- | ----------------- | --------------------- | --------------------------------------------------------------------------------------------------- |
| width | PropTypes.string | 100% | canvas width (em/rem/px) |
| height | PropTypes.string | 100% | canvas width (em/rem/px) |
| id | PropTypes.string | "react-sketch-canvas" | ID field to uniquely identify a SVG canvas (Supports multiple canvases in a single page) |
| className | PropTypes.string | "" | Class for using with CSS selectors |
| strokeColor | PropTypes.string | black | Pen color |
| canvasColor | PropTypes.string | white | canvas color (HTML colors) |
| backgroundImage | PropTypes.string | '' | Set SVG background with image URL |
| exportWithBackgroundImage | PropTypes.bool | false | Keep background image on image/SVG export (on false, canvasColor will be set as background) |
| preserveBackgroundImageAspectRatio | PropTypes.string | none | Set aspect ratio of the background image. For possible values check [MDN docs][preserveaspectratio] |
| strokeWidth | PropTypes.number | 4 | Pen stroke size |
| eraserWidth | PropTypes.number | 8 | Erase size |
| allowOnlyPointerType | PropTypes.string | all | allow pointer type ("all"/"mouse"/"pen"/"touch") |
| onChange | PropTypes.func | | Returns the current sketch path in CanvasPath type on every path change |
| onStroke | PropTypes.func | | Returns the the last stroke path and whether it is an eraser stroke on every pointer up event |
| style | PropTypes.object | false | Add CSS styling as CSS-in-JS object |
| svgStyle | PropTypes.object | {} | Add CSS styling as CSS-in-JS object for the SVG |
| withTimestamp | PropTypes.bool | false | Add timestamp to individual strokes for measuring sketching time |

Set SVG background using CSS [background][css-bg] value

You can specify width and height values in em or rem. It fills the parent element space if width and height are not set




Methods

You can export the sketch as an image or as a svg

_Use ref to access the element and call the following functions to export image_

| Props | Expected datatype |
| ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| eraseMode(boolean) | Switch to eraser mode by passing true. You can switch back to pen mode by passing false |
| clearCanvas() | Clears the canvas. |
| resetCanvas() | Resets the canvas and clears the undo/redo stack along with it. |
| undo() | Undo the last action. |
| redo() | Redo the previous action. |
| exportImage(imageTypeString) | Accepts an image type as argument (ExportImageType) and returns a Promise which resolves to base64 data url of the sketch. |
| exportSvg() | returns a Promise which resolves to an inline SVG element. |
| exportPaths() | returns a Promise which resolves to an instance of CanvasPath. |
| loadPaths(CanvasPath) | Accepts an CanvasPath exported from exportPaths() and loads it on the canvas. |
| getSketchingTime() | returns a Promise which resolves the time that user sketched in the canvas (considers only when the user made the strokes or erased the strokes) |

Types

`ts
type ExportImageType = 'jpeg' | 'png';

interface Point {
x: number;
y: number;
}

interface CanvasPath {
paths: Point[];
strokeWidth: number;
strokeColor: string;
drawMode: boolean;
startTimestamp?: number;
endTimestamp?: number;
}
``

---

Thanks to

- Philipp Spiess' [tutorial][based-on]
- Draws smooth curves, thanks to François Romain's [tutorial][smooth-curve-tutorial]

---

[based-on]: https://pspdfkit.com/blog/2017/how-to-build-free-hand-drawing-using-react/
[smooth-curve-tutorial]: https://medium.com/@francoisromain/smooth-a-svg-path-with-cubic-bezier-curves-e37b49d46c74
[css-bg]: https://developer.mozilla.org/en-US/docs/Web/CSS/background
[preserveaspectratio]: https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/preserveAspectRatio