Add blurhash (#10630)

* Add blurhash

* Use fallback color for spoiler when blurhash missing

* Federate the blurhash and accept it as long as it's at most 5x5

* Display unknown media attachments as blurhash placeholders

* Improve style of embed actions and spoiler button

* Change blurhash resolution from 3x3 to 4x4

* Improve dependency definitions

* Fix code style issues

8 files changed, 177 insertions, 50 deletions

diff --git a/app/javascript/mastodon/components/media_gallery.js b/app/javascript/mastodon/components/media_gallery.js
index a2bc95255..f548296d0 100644
--- a/app/javascript/mastodon/components/media_gallery.js
+++ b/app/javascript/mastodon/components/media_gallery.js
@@ -7,6 +7,7 @@ import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
 import { isIOS } from '../is_mobile';
 import classNames from 'classnames';
 import { autoPlayGif, displayMedia } from '../initial_state';
+import { decode } from 'blurhash';
 
 const messages = defineMessages({
   toggle_visible: { id: 'media_gallery.toggle_visible', defaultMessage: 'Toggle visibility' },
@@ -21,6 +22,7 @@ class Item extends React.PureComponent {
     size: PropTypes.number.isRequired,
     onClick: PropTypes.func.isRequired,
     displayWidth: PropTypes.number,
+    visible: PropTypes.bool.isRequired,
   };
 
   static defaultProps = {
@@ -29,6 +31,10 @@ class Item extends React.PureComponent {
     size: 1,
   };
 
+  state = {
+    loaded: false,
+  };
+
   handleMouseEnter = (e) => {
     if (this.hoverToPlay()) {
       e.target.play();
@@ -62,8 +68,40 @@ 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 });
+  }
+
   render () {
-    const { attachment, index, size, standalone, displayWidth } = this.props;
+    const { attachment, index, size, standalone, displayWidth, visible } = this.props;
 
     let width  = 50;
     let height = 100;
@@ -116,12 +154,20 @@ class Item extends React.PureComponent {
 
     let thumbnail = '';
 
-    if (attachment.get('type') === 'image') {
+    if (attachment.get('type') === 'unknown') {
+      return (
+        <div className={classNames('media-gallery__item', { standalone })} key={attachment.get('id')} style={{ left: left, top: top, right: right, bottom: bottom, width: `${width}%`, height: `${height}%` }}>
+          <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' />
+          </a>
+        </div>
+      );
+    } else if (attachment.get('type') === 'image') {
       const previewUrl   = attachment.get('preview_url');
       const previewWidth = attachment.getIn(['meta', 'small', 'width']);
 
-      const originalUrl    = attachment.get('url');
-      const originalWidth  = attachment.getIn(['meta', 'original', 'width']);
+      const originalUrl   = attachment.get('url');
+      const originalWidth = attachment.getIn(['meta', 'original', 'width']);
 
       const hasSize = typeof originalWidth === 'number' && typeof previewWidth === 'number';
 
@@ -147,6 +193,7 @@ class Item extends React.PureComponent {
             alt={attachment.get('description')}
             title={attachment.get('description')}
             style={{ objectPosition: `${x}% ${y}%` }}
+            onLoad={this.handleImageLoad}
           />
         </a>
       );
@@ -176,7 +223,8 @@ class Item extends React.PureComponent {
 
     return (
       <div className={classNames('media-gallery__item', { standalone })} key={attachment.get('id')} style={{ left: left, top: top, right: right, bottom: bottom, width: `${width}%`, height: `${height}%` }}>
-        {thumbnail}
+        <canvas width={32} height={32} ref={this.setCanvasRef} className={classNames('media-gallery__preview', { 'media-gallery__preview--hidden': visible && this.state.loaded })} />
+        {visible && thumbnail}
       </div>
     );
   }
@@ -225,6 +273,7 @@ class MediaGallery extends React.PureComponent {
     if (node /*&& this.isStandaloneEligible()*/) {
       // offsetWidth triggers a layout, so only calculate when we need to
       if (this.props.cacheWidth) this.props.cacheWidth(node.offsetWidth);
+
       this.setState({
         width: node.offsetWidth,
       });
@@ -242,7 +291,7 @@ class MediaGallery extends React.PureComponent {
 
     const width = this.state.width || defaultWidth;
 
-    let children;
+    let children, spoilerButton;
 
     const style = {};
 
@@ -256,35 +305,28 @@ class MediaGallery extends React.PureComponent {
       style.height = height;
     }
 
-    if (!visible) {
-      let warning;
+    const size = media.take(4).size;
 
-      if (sensitive) {
-        warning = <FormattedMessage id='status.sensitive_warning' defaultMessage='Sensitive content' />;
-      } else {
-        warning = <FormattedMessage id='status.media_hidden' defaultMessage='Media hidden' />;
-      }
+    if (this.isStandaloneEligible()) {
+      children = <Item standalone onClick={this.handleClick} attachment={media.get(0)} displayWidth={width} visible={visible} />;
+    } else {
+      children = media.take(4).map((attachment, i) => <Item key={attachment.get('id')} onClick={this.handleClick} attachment={attachment} index={i} size={size} displayWidth={width} visible={visible} />);
+    }
 
-      children = (
-        <button type='button' className='media-spoiler' onClick={this.handleOpen} style={style} ref={this.handleRef}>
-          <span className='media-spoiler__warning'>{warning}</span>
-          <span className='media-spoiler__trigger'><FormattedMessage id='status.sensitive_toggle' defaultMessage='Click to view' /></span>
+    if (visible) {
+      spoilerButton = <IconButton title={intl.formatMessage(messages.toggle_visible)} icon={visible ? 'eye' : 'eye-slash'} overlay onClick={this.handleOpen} />;
+    } else {
+      spoilerButton = (
+        <button type='button' onClick={this.handleOpen} className='spoiler-button__overlay'>
+          <span className='spoiler-button__overlay__label'>{sensitive ? <FormattedMessage id='status.sensitive_warning' defaultMessage='Sensitive content' /> : <FormattedMessage id='status.media_hidden' defaultMessage='Media hidden' />}</span>
         </button>
       );
-    } else {
-      const size = media.take(4).size;
-
-      if (this.isStandaloneEligible()) {
-        children = <Item standalone onClick={this.handleClick} attachment={media.get(0)} displayWidth={width} />;
-      } else {
-        children = media.take(4).map((attachment, i) => <Item key={attachment.get('id')} onClick={this.handleClick} attachment={attachment} index={i} size={size} displayWidth={width} />);
-      }
     }
 
     return (
       <div className='media-gallery' style={style} ref={this.handleRef}>
-        <div className={classNames('spoiler-button', { 'spoiler-button--visible': visible })}>
-          <IconButton title={intl.formatMessage(messages.toggle_visible)} icon={visible ? 'eye' : 'eye-slash'} overlay onClick={this.handleOpen} />
+        <div className={classNames('spoiler-button', { 'spoiler-button--minified': visible })}>
+          {spoilerButton}
         </div>
 
         {children}
diff --git a/app/javascript/mastodon/components/status.js b/app/javascript/mastodon/components/status.js
index cea9a0c2e..95ca4a548 100644
--- a/app/javascript/mastodon/components/status.js
+++ b/app/javascript/mastodon/components/status.js
@@ -274,7 +274,7 @@ class Status extends ImmutablePureComponent {
     if (status.get('poll')) {
       media = <PollContainer pollId={status.get('poll')} />;
     } else if (status.get('media_attachments').size > 0) {
-      if (this.props.muted || status.get('media_attachments').some(item => item.get('type') === 'unknown')) {
+      if (this.props.muted) {
         media = (
           <AttachmentList
             compact
@@ -289,6 +289,7 @@ class Status extends ImmutablePureComponent {
             {Component => (
               <Component
                 preview={video.get('preview_url')}
+                blurhash={video.get('blurhash')}
                 src={video.get('url')}
                 alt={video.get('description')}
                 width={this.props.cachedMediaWidth}
diff --git a/app/javascript/mastodon/features/report/components/status_check_box.js b/app/javascript/mastodon/features/report/components/status_check_box.js
index 2552d94d8..c29e517da 100644
--- a/app/javascript/mastodon/features/report/components/status_check_box.js
+++ b/app/javascript/mastodon/features/report/components/status_check_box.js
@@ -35,6 +35,7 @@ export default class StatusCheckBox extends React.PureComponent {
             {Component => (
               <Component
                 preview={video.get('preview_url')}
+                blurhash={video.get('blurhash')}
                 src={video.get('url')}
                 alt={video.get('description')}
                 width={239}
diff --git a/app/javascript/mastodon/features/status/components/detailed_status.js b/app/javascript/mastodon/features/status/components/detailed_status.js
index 5c79f9f19..84471f9a3 100644
--- a/app/javascript/mastodon/features/status/components/detailed_status.js
+++ b/app/javascript/mastodon/features/status/components/detailed_status.js
@@ -5,7 +5,6 @@ import Avatar from '../../../components/avatar';
 import DisplayName from '../../../components/display_name';
 import StatusContent from '../../../components/status_content';
 import MediaGallery from '../../../components/media_gallery';
-import AttachmentList from '../../../components/attachment_list';
 import { Link } from 'react-router-dom';
 import { FormattedDate, FormattedNumber } from 'react-intl';
 import Card from './card';
@@ -109,14 +108,13 @@ export default class DetailedStatus extends ImmutablePureComponent {
     if (status.get('poll')) {
       media = <PollContainer pollId={status.get('poll')} />;
     } else if (status.get('media_attachments').size > 0) {
-      if (status.get('media_attachments').some(item => item.get('type') === 'unknown')) {
-        media = <AttachmentList media={status.get('media_attachments')} />;
-      } else if (status.getIn(['media_attachments', 0, 'type']) === 'video') {
+      if (status.getIn(['media_attachments', 0, 'type']) === 'video') {
         const video = status.getIn(['media_attachments', 0]);
 
         media = (
           <Video
             preview={video.get('preview_url')}
+            blurhash={video.get('blurhash')}
             src={video.get('url')}
             alt={video.get('description')}
             width={300}
diff --git a/app/javascript/mastodon/features/ui/components/media_modal.js b/app/javascript/mastodon/features/ui/components/media_modal.js
index 2120746da..848cb20b3 100644
--- a/app/javascript/mastodon/features/ui/components/media_modal.js
+++ b/app/javascript/mastodon/features/ui/components/media_modal.js
@@ -144,6 +144,7 @@ class MediaModal extends ImmutablePureComponent {
         return (
           <Video
             preview={image.get('preview_url')}
+            blurhash={image.get('blurhash')}
             src={image.get('url')}
             width={image.get('width')}
             height={image.get('height')}
diff --git a/app/javascript/mastodon/features/ui/components/video_modal.js b/app/javascript/mastodon/features/ui/components/video_modal.js
index 7cf3eb4d4..52457a630 100644
--- a/app/javascript/mastodon/features/ui/components/video_modal.js
+++ b/app/javascript/mastodon/features/ui/components/video_modal.js
@@ -20,6 +20,7 @@ export default class VideoModal extends ImmutablePureComponent {
         <div>
           <Video
             preview={media.get('preview_url')}
+            blurhash={media.get('blurhash')}
             src={media.get('url')}
             startTime={time}
             onCloseVideo={onClose}
diff --git a/app/javascript/mastodon/features/video/index.js b/app/javascript/mastodon/features/video/index.js
index 55dd249e1..7b6113e6a 100644
--- a/app/javascript/mastodon/features/video/index.js
+++ b/app/javascript/mastodon/features/video/index.js
@@ -7,6 +7,7 @@ import classNames from 'classnames';
 import { isFullscreen, requestFullscreen, exitFullscreen } from '../ui/util/fullscreen';
 import { displayMedia } from '../../initial_state';
 import Icon from 'mastodon/components/icon';
+import { decode } from 'blurhash';
 
 const messages = defineMessages({
   play: { id: 'video.play', defaultMessage: 'Play' },
@@ -102,6 +103,7 @@ class Video extends React.PureComponent {
     inline: PropTypes.bool,
     cacheWidth: PropTypes.func,
     intl: PropTypes.object.isRequired,
+    blurhash: PropTypes.string,
   };
 
   state = {
@@ -139,6 +141,7 @@ class Video extends React.PureComponent {
 
   setVideoRef = c => {
     this.video = c;
+
     if (this.video) {
       this.setState({ volume: this.video.volume, muted: this.video.muted });
     }
@@ -152,6 +155,10 @@ class Video extends React.PureComponent {
     this.volume = c;
   }
 
+  setCanvasRef = c => {
+    this.canvas = c;
+  }
+
   handleClickRoot = e => e.stopPropagation();
 
   handlePlay = () => {
@@ -170,7 +177,6 @@ class Video extends React.PureComponent {
   }
 
   handleVolumeMouseDown = e => {
-
     document.addEventListener('mousemove', this.handleMouseVolSlide, true);
     document.addEventListener('mouseup', this.handleVolumeMouseUp, true);
     document.addEventListener('touchmove', this.handleMouseVolSlide, true);
@@ -190,7 +196,6 @@ class Video extends React.PureComponent {
   }
 
   handleMouseVolSlide = throttle(e => {
-
     const rect = this.volume.getBoundingClientRect();
     const x = (e.clientX - rect.left) / this.volWidth; //x position within the element.
 
@@ -261,6 +266,10 @@ 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 () {
@@ -270,6 +279,24 @@ class Video extends React.PureComponent {
     document.removeEventListener('MSFullscreenChange', this.handleFullscreenChange, true);
   }
 
+  componentDidUpdate (prevProps) {
+    if (prevProps.blurhash !== this.props.blurhash && this.props.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 = () => {
     this.setState({ fullscreen: isFullscreen() });
   }
@@ -314,6 +341,7 @@ class Video extends React.PureComponent {
 
   handleOpenVideo = () => {
     const { src, preview, width, height, alt } = this.props;
+
     const media = fromJS({
       type: 'video',
       url: src,
@@ -351,6 +379,7 @@ class Video extends React.PureComponent {
     }
 
     let preload;
+
     if (startTime || fullscreen || dragging) {
       preload = 'auto';
     } else if (detailed) {
@@ -360,6 +389,7 @@ class Video extends React.PureComponent {
     }
 
     let warning;
+
     if (sensitive) {
       warning = <FormattedMessage id='status.sensitive_warning' defaultMessage='Sensitive content' />;
     } else {
@@ -377,7 +407,9 @@ class Video extends React.PureComponent {
         onClick={this.handleClickRoot}
         tabIndex={0}
       >
-        <video
+        <canvas width={32} height={32} ref={this.setCanvasRef} className={classNames('media-gallery__preview', { 'media-gallery__preview--hidden': revealed })} />
+
+        {revealed && <video
           ref={this.setVideoRef}
           src={src}
           poster={preview}
@@ -397,12 +429,13 @@ class Video extends React.PureComponent {
           onLoadedData={this.handleLoadedData}
           onProgress={this.handleProgress}
           onVolumeChange={this.handleVolumeChange}
-        />
+        />}
 
-        <button type='button' className={classNames('video-player__spoiler', { active: !revealed })} onClick={this.toggleReveal}>
-          <span className='video-player__spoiler__title'>{warning}</span>
-          <span className='video-player__spoiler__subtitle'><FormattedMessage id='status.sensitive_toggle' defaultMessage='Click to view' /></span>
-        </button>
+        <div className={classNames('spoiler-button', { 'spoiler-button--hidden': revealed })}>
+          <button type='button' className='spoiler-button__overlay' onClick={this.toggleReveal}>
+            <span className='spoiler-button__overlay__label'>{warning}</span>
+          </button>
+        </div>
 
         <div className={classNames('video-player__controls', { active: paused || hovered })}>
           <div className='video-player__seek' onMouseDown={this.handleMouseDown} ref={this.setSeekRef}>
diff --git a/app/javascript/styles/mastodon/components.scss b/app/javascript/styles/mastodon/components.scss
index 0b1fd3652..48970f8bd 100644
--- a/app/javascript/styles/mastodon/components.scss
+++ b/app/javascript/styles/mastodon/components.scss
@@ -2412,7 +2412,7 @@ a.account__display-name {
 
     & > div {
       background: rgba($base-shadow-color, 0.6);
-      border-radius: 4px;
+      border-radius: 8px;
       padding: 12px 9px;
       flex: 0 0 auto;
       display: flex;
@@ -2423,19 +2423,18 @@ a.account__display-name {
     button,
     a {
       display: inline;
-      color: $primary-text-color;
+      color: $secondary-text-color;
       background: transparent;
       border: 0;
-      padding: 0 5px;
+      padding: 0 8px;
       text-decoration: none;
-      opacity: 0.6;
       font-size: 18px;
       line-height: 18px;
 
       &:hover,
       &:active,
       &:focus {
-        opacity: 1;
+        color: $primary-text-color;
       }
     }
 
@@ -2932,15 +2931,49 @@ a.status-card.compact:hover {
 }
 
 .spoiler-button {
-  display: none;
-  left: 4px;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
   position: absolute;
-  text-shadow: 0 1px 1px $base-shadow-color, 1px 0 1px $base-shadow-color;
-  top: 4px;
   z-index: 100;
 
-  &.spoiler-button--visible {
+  &--minified {
     display: block;
+    left: 4px;
+    top: 4px;
+    width: auto;
+    height: auto;
+  }
+
+  &--hidden {
+    display: none;
+  }
+
+  &__overlay {
+    display: block;
+    background: transparent;
+    width: 100%;
+    height: 100%;
+    border: 0;
+
+    &__label {
+      display: inline-block;
+      background: rgba($base-overlay-background, 0.5);
+      border-radius: 8px;
+      padding: 8px 12px;
+      color: $primary-text-color;
+      font-weight: 500;
+      font-size: 14px;
+    }
+
+    &:hover,
+    &:focus,
+    &:active {
+      .spoiler-button__overlay__label {
+        background: rgba($base-overlay-background, 0.8);
+      }
+    }
   }
 }
 
@@ -4313,6 +4346,8 @@ a.status-card.compact:hover {
   text-decoration: none;
   color: $secondary-text-color;
   line-height: 0;
+  position: relative;
+  z-index: 1;
 
   &,
   img {
@@ -4325,6 +4360,21 @@ a.status-card.compact:hover {
   }
 }
 
+.media-gallery__preview {
+  width: 100%;
+  height: 100%;
+  object-fit: cover;
+  position: absolute;
+  top: 0;
+  left: 0;
+  z-index: 0;
+  background: $base-overlay-background;
+
+  &--hidden {
+    display: none;
+  }
+}
+
 .media-gallery__gifv {
   height: 100%;
   overflow: hidden;