[Glitch] Responsively enforce 16:9 ratio on video thumbnails in web UI

Port the video-player part of 036dd98abb to
glitch-soc. MediaGallery part ignored since it has diverged quite a bit.

This fixes #423

app/javascript/flavours/glitch/components/status.js

@@ -326,6 +326,7 @@ export default class Status extends ImmutablePureComponent {
             {Component => (<Component
               preview={video.get('preview_url')}
               src={video.get('url')}
+              inline
               sensitive={status.get('sensitive')}
               letterbox={settings.getIn(['media', 'letterbox'])}
               fullwidth={settings.getIn(['media', 'fullwidth'])}

app/javascript/flavours/glitch/features/status/components/detailed_status.js

@@ -58,6 +58,7 @@ export default class DetailedStatus extends ImmutablePureComponent {
           <Video
             preview={video.get('preview_url')}
             src={video.get('url')}
+            inline
             sensitive={status.get('sensitive')}
             letterbox={settings.getIn(['media', 'letterbox'])}
             fullwidth={settings.getIn(['media', 'fullwidth'])}

app/javascript/flavours/glitch/features/video/index.js

@@ -98,6 +98,7 @@ export default class Video extends React.PureComponent {
     letterbox: PropTypes.bool,
     fullwidth: PropTypes.bool,
     detailed: PropTypes.bool,
+    inline: PropTypes.bool,
     intl: PropTypes.object.isRequired,
   };
 
@@ -106,6 +107,7 @@ export default class Video extends React.PureComponent {
     duration: 0,
     paused: true,
     dragging: false,
+    containerWidth: false,
     fullscreen: false,
     hovered: false,
     muted: false,
@@ -114,6 +116,12 @@ export default class Video extends React.PureComponent {
 
   setPlayerRef = c => {
     this.player = c;
+
+    if (c) {
+      this.setState({
+        containerWidth: c.offsetWidth,
+      });
+    }
   }
 
   setVideoRef = c => {
@@ -247,12 +255,23 @@ export default class Video extends React.PureComponent {
   }
 
   render () {
-    const { preview, src, width, height, startTime, onOpenVideo, onCloseVideo, intl, alt, letterbox, fullwidth, detailed } = this.props;
-    const { currentTime, duration, buffer, dragging, paused, fullscreen, hovered, muted, revealed } = this.state;
+    const { preview, src, inline, startTime, onOpenVideo, onCloseVideo, intl, alt, letterbox, fullwidth, detailed } = this.props;
+    const { containerWidth, currentTime, duration, buffer, dragging, paused, fullscreen, hovered, muted, revealed } = this.state;
     const progress = (currentTime / duration) * 100;
+    const playerStyle = {};
+
+    let { width, height } = this.props;
+
+    if (inline && containerWidth) {
+      width  = containerWidth;
+      height = containerWidth / (16/9);
+
+      playerStyle.width  = width;
+      playerStyle.height = height;
+    }
 
     return (
-      <div className={classNames('video-player', { inactive: !revealed, detailed, inline: width && height && !fullscreen, fullscreen, letterbox, 'full-width': fullwidth })} style={{ width, height }} ref={this.setPlayerRef} onMouseEnter={this.handleMouseEnter} onMouseLeave={this.handleMouseLeave}>
+      <div className={classNames('video-player', { inactive: !revealed, detailed, inline: width && height && !fullscreen, fullscreen, letterbox, 'full-width': fullwidth })} style={playerStyle} ref={this.setPlayerRef} onMouseEnter={this.handleMouseEnter} onMouseLeave={this.handleMouseLeave}>
         <video
           ref={this.setVideoRef}
           src={src}

app/javascript/flavours/glitch/styles/components/media.scss

@@ -307,7 +307,7 @@
 
   &.inline {
     video {
-      object-fit: cover;
+      object-fit: contain;
       position: relative;
       top: 50%;
       transform: translateY(-50%);