Replace repetitive blurhash code with component

https://github.com/tootsuite/mastodon/pull/14267
https://github.com/tootsuite/mastodon/pull/14278

app/soapbox/components/blurhash.js

@@ -0,0 +1,65 @@
+// @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 || !hash) return;
+
+    try {
+      const pixels = decode(hash, width, height);
+      const ctx = canvas.getContext('2d');
+      const imageData = new ImageData(pixels, width, height);
+
+      ctx.putImageData(imageData, 0, 0);
+    } catch (err) {
+      console.error('Blurhash decoding failure', { err, hash });
+    }
+  }, [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);

app/soapbox/components/media_gallery.js

@@ -8,12 +8,12 @@ import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
 import { isIOS } from '../is_mobile';
 import { truncateFilename } from 'soapbox/utils/media';
 import classNames from 'classnames';
-import { decode } from 'blurhash';
 import { isPanoramic, isPortrait, isNonConformingRatio, minimumAspectRatio, maximumAspectRatio } from '../utils/media_aspect_ratio';
 import { Map as ImmutableMap } from 'immutable';
 import { getSettings } from 'soapbox/actions/settings';
 import Icon from 'soapbox/components/icon';
 import StillImage from 'soapbox/components/still_image';
+import Blurhash from 'soapbox/components/blurhash';
 
 const ATTACHMENT_LIMIT = 4;
 const MAX_FILENAME_LENGTH = 45;
@@ -102,34 +102,6 @@ class Item extends React.PureComponent {
     e.stopPropagation();
   }
 
-  componentDidMount() {
-    if (this.props.attachment.get('blurhash')) {
-      this._decode();
-    }
-  }
-
-  componentDidUpdate(prevProps) {
-    if (prevProps.attachment.get('blurhash') !== this.props.attachment.get('blurhash') && this.props.attachment.get('blurhash')) {
-      this._decode();
-    }
-  }
-
-  _decode() {
-    const hash   = this.props.attachment.get('blurhash');
-    const pixels = decode(hash, 32, 32);
-
-    if (pixels) {
-      const ctx       = this.canvas.getContext('2d');
-      const imageData = new ImageData(pixels, 32, 32);
-
-      ctx.putImageData(imageData, 0, 0);
-    }
-  }
-
-  setCanvasRef = c => {
-    this.canvas = c;
-  }
-
   handleImageLoad = () => {
     this.setState({ loaded: true });
   }
@@ -174,7 +146,7 @@ class Item extends React.PureComponent {
       return (
         <div className={classNames('media-gallery__item', { standalone })} key={attachment.get('id')} style={{ position, float, left, top, right, bottom, height, width: `${width}%` }}>
           <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url')} target='_blank' style={{ cursor: 'pointer' }}>
-            <canvas width={32} height={32} ref={this.setCanvasRef} className='media-gallery__preview' />
+            <Blurhash hash={attachment.get('blurhash')} className='media-gallery__preview' />
             <span className='media-gallery__item__icons'><Icon id='file' /></span>
             <span className='media-gallery__filename__label'>{filename}</span>
           </a>
@@ -273,7 +245,12 @@ class Item extends React.PureComponent {
             +{total - ATTACHMENT_LIMIT + 1}
           </div>
         )}
-        <canvas width={32} height={32} ref={this.setCanvasRef} className={classNames('media-gallery__preview', { 'media-gallery__preview--hidden': visible && this.state.loaded })} />
+        <Blurhash
+          hash={attachment.get('blurhash')}
+          className={classNames('media-gallery__preview', {
+            'media-gallery__preview--hidden': visible && this.state.loaded,
+          })}
+        />
         {visible && thumbnail}
       </div>
     );

app/soapbox/features/account_gallery/components/media_item.js

@@ -5,7 +5,7 @@ import ImmutablePropTypes from 'react-immutable-proptypes';
 import ImmutablePureComponent from 'react-immutable-pure-component';
 import Icon from 'soapbox/components/icon';
 import classNames from 'classnames';
-import { decode } from 'blurhash';
+import Blurhash from 'soapbox/components/blurhash';
 import { isIOS } from 'soapbox/is_mobile';
 import { getSettings } from 'soapbox/actions/settings';
 import StillImage from 'soapbox/components/still_image';
@@ -31,34 +31,6 @@ class MediaItem extends ImmutablePureComponent {
     loaded: false,
   };
 
-  componentDidMount() {
-    if (this.props.attachment.get('blurhash')) {
-      this._decode();
-    }
-  }
-
-  componentDidUpdate(prevProps) {
-    if (prevProps.attachment.get('blurhash') !== this.props.attachment.get('blurhash') && this.props.attachment.get('blurhash')) {
-      this._decode();
-    }
-  }
-
-  _decode() {
-    const hash   = this.props.attachment.get('blurhash');
-    const pixels = decode(hash, 32, 32);
-
-    if (pixels) {
-      const ctx       = this.canvas.getContext('2d');
-      const imageData = new ImageData(pixels, 32, 32);
-
-      ctx.putImageData(imageData, 0, 0);
-    }
-  }
-
-  setCanvasRef = c => {
-    this.canvas = c;
-  }
-
   handleImageLoad = () => {
     this.setState({ loaded: true });
   }
@@ -169,7 +141,12 @@ class MediaItem extends ImmutablePureComponent {
     return (
       <div className='account-gallery__item' style={{ width, height }}>
         <a className='media-gallery__item-thumbnail' href={status.get('url')} target='_blank' onClick={this.handleClick} title={title}>
-          <canvas width={32} height={32} ref={this.setCanvasRef} className={classNames('media-gallery__preview', { 'media-gallery__preview--hidden': visible && loaded })} />
+          <Blurhash
+            hash={attachment.get('blurhash')}
+            className={classNames('media-gallery__preview', {
+              'media-gallery__preview--hidden': visible && loaded,
+            })}
+          />
           {visible && thumbnail}
           {!visible && icon}
         </a>

app/soapbox/features/video/index.js

@@ -7,7 +7,7 @@ import { throttle } from 'lodash';
 import classNames from 'classnames';
 import { isFullscreen, requestFullscreen, exitFullscreen } from '../ui/util/fullscreen';
 import Icon from 'soapbox/components/icon';
-import { decode } from 'blurhash';
+import Blurhash from 'soapbox/components/blurhash';
 import { isPanoramic, isPortrait, minimumAspectRatio, maximumAspectRatio } from '../../utils/media_aspect_ratio';
 import { getSettings } from 'soapbox/actions/settings';
 
@@ -167,10 +167,6 @@ class Video extends React.PureComponent {
     this.volume = c;
   }
 
-  setCanvasRef = c => {
-    this.canvas = c;
-  }
-
   handleClickRoot = e => e.stopPropagation();
 
   handlePlay = () => {
@@ -278,10 +274,6 @@ class Video extends React.PureComponent {
     document.addEventListener('webkitfullscreenchange', this.handleFullscreenChange, true);
     document.addEventListener('mozfullscreenchange', this.handleFullscreenChange, true);
     document.addEventListener('MSFullscreenChange', this.handleFullscreenChange, true);
-
-    if (this.props.blurhash) {
-      this._decode();
-    }
   }
 
   componentWillUnmount() {
@@ -292,7 +284,7 @@ class Video extends React.PureComponent {
   }
 
   componentDidUpdate(prevProps, prevState) {
-    const { visible, blurhash } = this.props;
+    const { visible } = this.props;
 
     if (!is(visible, prevProps.visible) && visible !== undefined) {
       this.setState({ revealed: visible });
@@ -301,22 +293,6 @@ class Video extends React.PureComponent {
     if (prevState.revealed && !this.state.revealed && this.video) {
       this.video.pause();
     }
-
-    if (prevProps.blurhash !== blurhash && blurhash) {
-      this._decode();
-    }
-  }
-
-  _decode() {
-    const hash   = this.props.blurhash;
-    const pixels = decode(hash, 32, 32);
-
-    if (pixels) {
-      const ctx       = this.canvas.getContext('2d');
-      const imageData = new ImageData(pixels, 32, 32);
-
-      ctx.putImageData(imageData, 0, 0);
-    }
   }
 
   handleFullscreenChange = () => {
@@ -396,7 +372,7 @@ class Video extends React.PureComponent {
   }
 
   render() {
-    const { src, inline, onOpenVideo, onCloseVideo, intl, alt, detailed, sensitive, link, aspectRatio } = this.props;
+    const { src, inline, onOpenVideo, onCloseVideo, intl, alt, detailed, sensitive, link, aspectRatio, blurhash } = this.props;
     const { containerWidth, currentTime, duration, volume, buffer, dragging, paused, fullscreen, hovered, muted, revealed } = this.state;
     const progress = (currentTime / duration) * 100;
     const playerStyle = {};
@@ -437,7 +413,12 @@ class Video extends React.PureComponent {
         onClick={this.handleClickRoot}
         tabIndex={0}
       >
-        <canvas width={32} height={32} ref={this.setCanvasRef} className={classNames('media-gallery__preview', { 'media-gallery__preview--hidden': revealed })} />
+        <Blurhash
+          hash={blurhash}
+          className={classNames('media-gallery__preview', {
+            'media-gallery__preview--hidden': revealed,
+          })}
+        />
 
         {revealed && <video
           ref={this.setVideoRef}