53db386731
MSC: https://github.com/matrix-org/matrix-doc/pull/2448 While the image loads, we can show a blurred version of it (calculated at upload time) so we don't have a blank space in the timeline.
56 lines
1.6 KiB
TypeScript
56 lines
1.6 KiB
TypeScript
/*
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Copyright 2020 The Matrix.org Foundation C.I.C.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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import React from 'react';
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import {decode} from "blurhash";
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interface IProps {
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blurhash: string;
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width: number;
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height: number;
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}
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export default class BlurhashPlaceholder extends React.PureComponent<IProps> {
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private canvas: React.RefObject<HTMLCanvasElement> = React.createRef();
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public componentDidMount() {
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this.draw();
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}
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public componentDidUpdate() {
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this.draw();
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}
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private draw() {
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if (!this.canvas.current) return;
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try {
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const {width, height} = this.props;
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const pixels = decode(this.props.blurhash, Math.ceil(width), Math.ceil(height));
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const ctx = this.canvas.current.getContext("2d");
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const imgData = ctx.createImageData(width, height);
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imgData.data.set(pixels);
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ctx.putImageData(imgData, 0, 0);
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} catch (e) {
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console.error("Error rendering blurhash: ", e);
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}
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}
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public render() {
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return <canvas height={this.props.height} width={this.props.width} ref={this.canvas} />;
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}
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}
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