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