Add ability to specify alternative text for media attachments (#5123)

* Fix #117 - Add ability to specify alternative text for media attachments

- POST /api/v1/media accepts `description` straight away
- PUT /api/v1/media/:id to update `description` (only for unattached ones)
- Serialized as `name` of Document object in ActivityPub
- Uploads form adjusted for better performance and description input

* Add tests

* Change undo button blend mode to difference

3 files changed, 12 insertions, 209 deletions

diff --git a/app/javascript/mastodon/components/extended_video_player.js b/app/javascript/mastodon/components/extended_video_player.js
index 5ab5e9e58..f8bd067e8 100644
--- a/app/javascript/mastodon/components/extended_video_player.js
+++ b/app/javascript/mastodon/components/extended_video_player.js
@@ -5,6 +5,7 @@ export default class ExtendedVideoPlayer extends React.PureComponent {
 
   static propTypes = {
     src: PropTypes.string.isRequired,
+    alt: PropTypes.string,
     width: PropTypes.number,
     height: PropTypes.number,
     time: PropTypes.number,
@@ -31,15 +32,20 @@ export default class ExtendedVideoPlayer extends React.PureComponent {
   }
 
   render () {
+    const { src, muted, controls, alt } = this.props;
+
     return (
       <div className='extended-video-player'>
         <video
           ref={this.setRef}
-          src={this.props.src}
+          src={src}
           autoPlay
-          muted={this.props.muted}
-          controls={this.props.controls}
-          loop={!this.props.controls}
+          role='button'
+          tabIndex='0'
+          aria-label={alt}
+          muted={muted}
+          controls={controls}
+          loop={!controls}
         />
       </div>
     );
diff --git a/app/javascript/mastodon/components/media_gallery.js b/app/javascript/mastodon/components/media_gallery.js
index a81409871..38b26b1fc 100644
--- a/app/javascript/mastodon/components/media_gallery.js
+++ b/app/javascript/mastodon/components/media_gallery.js
@@ -136,7 +136,7 @@ class Item extends React.PureComponent {
           onClick={this.handleClick}
           target='_blank'
         >
-          <img src={previewUrl} srcSet={srcSet} sizes={sizes} alt='' />
+          <img src={previewUrl} srcSet={srcSet} sizes={sizes} alt={attachment.get('description')} />
         </a>
       );
     } else if (attachment.get('type') === 'gifv') {
@@ -146,6 +146,7 @@ class Item extends React.PureComponent {
         <div className={classNames('media-gallery__gifv', { autoplay: autoPlay })}>
           <video
             className='media-gallery__item-gifv-thumbnail'
+            aria-label={attachment.get('description')}
             role='application'
             src={attachment.get('url')}
             onClick={this.handleClick}
diff --git a/app/javascript/mastodon/components/video_player.js b/app/javascript/mastodon/components/video_player.js
deleted file mode 100644
index 2a2d91c33..000000000
--- a/app/javascript/mastodon/components/video_player.js
+++ /dev/null
@@ -1,204 +0,0 @@
-import React from 'react';
-import ImmutablePropTypes from 'react-immutable-proptypes';
-import PropTypes from 'prop-types';
-import IconButton from './icon_button';
-import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
-import { isIOS } from '../is_mobile';
-
-const messages = defineMessages({
-  toggle_sound: { id: 'video_player.toggle_sound', defaultMessage: 'Toggle sound' },
-  toggle_visible: { id: 'video_player.toggle_visible', defaultMessage: 'Toggle visibility' },
-  expand_video: { id: 'video_player.expand', defaultMessage: 'Expand video' },
-});
-
-@injectIntl
-export default class VideoPlayer extends React.PureComponent {
-
-  static contextTypes = {
-    router: PropTypes.object,
-  };
-
-  static propTypes = {
-    media: ImmutablePropTypes.map.isRequired,
-    width: PropTypes.number,
-    height: PropTypes.number,
-    sensitive: PropTypes.bool,
-    intl: PropTypes.object.isRequired,
-    autoplay: PropTypes.bool,
-    onOpenVideo: PropTypes.func.isRequired,
-  };
-
-  static defaultProps = {
-    width: 239,
-    height: 110,
-  };
-
-  state = {
-    visible: !this.props.sensitive,
-    preview: true,
-    muted: true,
-    hasAudio: true,
-    videoError: false,
-  };
-
-  handleClick = () => {
-    this.setState({ muted: !this.state.muted });
-  }
-
-  handleVideoClick = (e) => {
-    e.stopPropagation();
-
-    const node = this.video;
-
-    if (node.paused) {
-      node.play();
-    } else {
-      node.pause();
-    }
-  }
-
-  handleOpen = () => {
-    this.setState({ preview: !this.state.preview });
-  }
-
-  handleVisibility = () => {
-    this.setState({
-      visible: !this.state.visible,
-      preview: true,
-    });
-  }
-
-  handleExpand = () => {
-    this.video.pause();
-    this.props.onOpenVideo(this.props.media, this.video.currentTime);
-  }
-
-  setRef = (c) => {
-    this.video = c;
-  }
-
-  handleLoadedData = () => {
-    if (('WebkitAppearance' in document.documentElement.style && this.video.audioTracks.length === 0) || this.video.mozHasAudio === false) {
-      this.setState({ hasAudio: false });
-    }
-  }
-
-  handleVideoError = () => {
-    this.setState({ videoError: true });
-  }
-
-  componentDidMount () {
-    if (!this.video) {
-      return;
-    }
-
-    this.video.addEventListener('loadeddata', this.handleLoadedData);
-    this.video.addEventListener('error', this.handleVideoError);
-  }
-
-  componentDidUpdate () {
-    if (!this.video) {
-      return;
-    }
-
-    this.video.addEventListener('loadeddata', this.handleLoadedData);
-    this.video.addEventListener('error', this.handleVideoError);
-  }
-
-  componentWillUnmount () {
-    if (!this.video) {
-      return;
-    }
-
-    this.video.removeEventListener('loadeddata', this.handleLoadedData);
-    this.video.removeEventListener('error', this.handleVideoError);
-  }
-
-  render () {
-    const { media, intl, width, height, sensitive, autoplay } = this.props;
-
-    let spoilerButton = (
-      <div className={`status__video-player-spoiler ${this.state.visible ? 'status__video-player-spoiler--visible' : ''}`}>
-        <IconButton overlay title={intl.formatMessage(messages.toggle_visible)} icon={this.state.visible ? 'eye' : 'eye-slash'} onClick={this.handleVisibility} />
-      </div>
-    );
-
-    let expandButton = '';
-
-    if (this.context.router) {
-      expandButton = (
-        <div className='status__video-player-expand'>
-          <IconButton overlay title={intl.formatMessage(messages.expand_video)} icon='expand' onClick={this.handleExpand} />
-        </div>
-      );
-    }
-
-    let muteButton = '';
-
-    if (this.state.hasAudio) {
-      muteButton = (
-        <div className='status__video-player-mute'>
-          <IconButton overlay title={intl.formatMessage(messages.toggle_sound)} icon={this.state.muted ? 'volume-off' : 'volume-up'} onClick={this.handleClick} />
-        </div>
-      );
-    }
-
-    if (!this.state.visible) {
-      if (sensitive) {
-        return (
-          <button style={{ width: `${width}px`, height: `${height}px`, marginTop: '8px' }} className='media-spoiler' onClick={this.handleVisibility}>
-            {spoilerButton}
-            <span className='media-spoiler__warning'><FormattedMessage id='status.sensitive_warning' defaultMessage='Sensitive content' /></span>
-            <span className='media-spoiler__trigger'><FormattedMessage id='status.sensitive_toggle' defaultMessage='Click to view' /></span>
-          </button>
-        );
-      } else {
-        return (
-          <button style={{ width: `${width}px`, height: `${height}px`, marginTop: '8px' }} className='media-spoiler' onClick={this.handleVisibility}>
-            {spoilerButton}
-            <span className='media-spoiler__warning'><FormattedMessage id='status.media_hidden' defaultMessage='Media hidden' /></span>
-            <span className='media-spoiler__trigger'><FormattedMessage id='status.sensitive_toggle' defaultMessage='Click to view' /></span>
-          </button>
-        );
-      }
-    }
-
-    if (this.state.preview && !autoplay) {
-      return (
-        <button className='media-spoiler-video' style={{ width: `${width}px`, height: `${height}px`, backgroundImage: `url(${media.get('preview_url')})` }} onClick={this.handleOpen}>
-          {spoilerButton}
-          <div className='media-spoiler-video-play-icon'><i className='fa fa-play' /></div>
-        </button>
-      );
-    }
-
-    if (this.state.videoError) {
-      return (
-        <div style={{ width: `${width}px`, height: `${height}px` }} className='video-error-cover' >
-          <span className='media-spoiler__warning'><FormattedMessage id='video_player.video_error' defaultMessage='Video could not be played' /></span>
-        </div>
-      );
-    }
-
-    return (
-      <div className='status__video-player' style={{ width: `${width}px`, height: `${height}px` }}>
-        {spoilerButton}
-        {muteButton}
-        {expandButton}
-
-        <video
-          className='status__video-player-video'
-          role='button'
-          tabIndex='0'
-          ref={this.setRef}
-          src={media.get('url')}
-          autoPlay={!isIOS()}
-          loop
-          muted={this.state.muted}
-          onClick={this.handleVideoClick}
-        />
-      </div>
-    );
-  }
-
-}