Add DM conversations mode similar to upstream

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

@@ -0,0 +1,104 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import { autoPlayGif } from 'flavours/glitch/util/initial_state';
+
+export default class AvatarComposite extends React.PureComponent {
+
+  static propTypes = {
+    accounts: ImmutablePropTypes.list.isRequired,
+    animate: PropTypes.bool,
+    size: PropTypes.number.isRequired,
+  };
+
+  static defaultProps = {
+    animate: autoPlayGif,
+  };
+
+  renderItem (account, size, index) {
+    const { animate } = this.props;
+
+    let width  = 50;
+    let height = 100;
+    let top    = 'auto';
+    let left   = 'auto';
+    let bottom = 'auto';
+    let right  = 'auto';
+
+    if (size === 1) {
+      width = 100;
+    }
+
+    if (size === 4 || (size === 3 && index > 0)) {
+      height = 50;
+    }
+
+    if (size === 2) {
+      if (index === 0) {
+        right = '2px';
+      } else {
+        left = '2px';
+      }
+    } else if (size === 3) {
+      if (index === 0) {
+        right = '2px';
+      } else if (index > 0) {
+        left = '2px';
+      }
+
+      if (index === 1) {
+        bottom = '2px';
+      } else if (index > 1) {
+        top = '2px';
+      }
+    } else if (size === 4) {
+      if (index === 0 || index === 2) {
+        right = '2px';
+      }
+
+      if (index === 1 || index === 3) {
+        left = '2px';
+      }
+
+      if (index < 2) {
+        bottom = '2px';
+      } else {
+        top = '2px';
+      }
+    }
+
+    const style = {
+      left: left,
+      top: top,
+      right: right,
+      bottom: bottom,
+      width: `${width}%`,
+      height: `${height}%`,
+      backgroundSize: 'cover',
+      backgroundImage: `url(${account.get(animate ? 'avatar' : 'avatar_static')})`,
+    };
+
+    return (
+      <a
+        href={account.get('url')}
+        target='_blank'
+        onClick={(e) => this.props.onAccountClick(account.get('id'), e)}
+        title={`@${account.get('acct')}`}
+        key={account.get('id')}
+      >
+        <div style={style} data-avatar-of={`@${account.get('acct')}`} />
+      </a>
+    );
+  }
+
+  render() {
+    const { accounts, size } = this.props;
+
+    return (
+      <div className='account__avatar-composite' style={{ width: `${size}px`, height: `${size}px` }}>
+        {accounts.take(4).map((account, i) => this.renderItem(account, accounts.size, i))}
+      </div>
+    );
+  }
+
+}