62 lines
1.6 KiB
JavaScript
62 lines
1.6 KiB
JavaScript
|
// @ts-check
|
||
|
|
|
||
|
|
import { decode } from 'blurhash';
|
||
|
|
import React, { useRef, useEffect } from 'react';
|
||
|
|
import PropTypes from 'prop-types';
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @typedef BlurhashPropsBase
|
||
|
|
* @property {string} hash Hash to render
|
||
|
|
* @property {number} width
|
||
|
|
* Width of the blurred region in pixels. Defaults to 32
|
||
|
|
* @property {number} [height]
|
||
|
|
* Height of the blurred region in pixels. Defaults to width
|
||
|
|
* @property {boolean} [dummy]
|
||
|
|
* Whether dummy mode is enabled. If enabled, nothing is rendered
|
||
|
|
* and canvas left untouched
|
||
|
|
*/
|
||
|
|
|
||
|
|
/** @typedef {JSX.IntrinsicElements['canvas'] & BlurhashPropsBase} BlurhashProps */
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Component that is used to render blurred of blurhash string
|
||
|
|
*
|
||
|
|
* @param {BlurhashProps} param1 Props of the component
|
||
|
|
* @returns Canvas which will render blurred region element to embed
|
||
|
|
*/
|
||
|
|
function Blurhash({
|
||
|
|
hash,
|
||
|
|
width = 32,
|
||
|
|
height = width,
|
||
|
|
dummy = false,
|
||
|
|
...canvasProps
|
||
|
|
}) {
|
||
|
|
const canvasRef = /** @type {import('react').MutableRefObject<HTMLCanvasElement>} */ (useRef());
|
||
|
|
|
||
|
|
useEffect(() => {
|
||
|
|
const { current: canvas } = canvasRef;
|
||
|
|
canvas.width = canvas.width; // resets canvas
|
||
|
|
|
||
|
|
if (dummy) return;
|
||
|
|
|
||
|
|
const pixels = decode(hash, width, height);
|
||
|
|
const ctx = canvas.getContext('2d');
|
||
|
|
const imageData = new ImageData(pixels, width, height);
|
||
|
|
|
||
|
|
ctx.putImageData(imageData, 0, 0);
|
||
|
|
}, [dummy, hash, width, height]);
|
||
|
|
|
||
|
|
return (
|
||
|
|
<canvas {...canvasProps} ref={canvasRef} width={width} height={height} />
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
Blurhash.propTypes = {
|
||
|
|
hash: PropTypes.string.isRequired,
|
||
|
|
width: PropTypes.number,
|
||
|
|
height: PropTypes.number,
|
||
|
|
dummy: PropTypes.bool,
|
||
|
|
};
|
||
|
|
|
||
|
|
export default React.memo(Blurhash);
|