Show "read more" link on overly long in-stream statuses (#8205)

Show "read more" link on overly long in-stream statuses

app/javascript/mastodon/components/status.js

@@ -285,7 +285,7 @@ class Status extends ImmutablePureComponent {
               </a>
             </div>
 
-            <StatusContent status={status} onClick={this.handleClick} expanded={!status.get('hidden')} onExpandedToggle={this.handleExpandedToggle} />
+            <StatusContent status={status} onClick={this.handleClick} expanded={!status.get('hidden')} onExpandedToggle={this.handleExpandedToggle} collapsable />
 
             {media}
 

app/javascript/mastodon/components/status_content.js

@@ -6,6 +6,8 @@ import { FormattedMessage } from 'react-intl';
 import Permalink from './permalink';
 import classnames from 'classnames';
 
+const MAX_HEIGHT = 322; // 20px * 16 (+ 2px padding at the top)
+
 export default class StatusContent extends React.PureComponent {
 
   static contextTypes = {
@@ -17,10 +19,12 @@ export default class StatusContent extends React.PureComponent {
     expanded: PropTypes.bool,
     onExpandedToggle: PropTypes.func,
     onClick: PropTypes.func,
+    collapsable: PropTypes.bool,
   };
 
   state = {
     hidden: true,
+    collapsed: null, //  `collapsed: null` indicates that an element doesn't need collapsing, while `true` or `false` indicates that it does (and is/isn't).
   };
 
   _updateStatusLinks () {
@@ -53,6 +57,16 @@ export default class StatusContent extends React.PureComponent {
       link.setAttribute('target', '_blank');
       link.setAttribute('rel', 'noopener');
     }
+
+    if (
+      this.props.collapsable
+      && this.props.onClick
+      && this.state.collapsed === null
+      && node.clientHeight > MAX_HEIGHT
+      && this.props.status.get('spoiler_text').length === 0
+    ) {
+      this.setState({ collapsed: true });
+    }
   }
 
   componentDidMount () {
@@ -113,6 +127,11 @@ export default class StatusContent extends React.PureComponent {
     }
   }
 
+  handleCollapsedClick = (e) => {
+    e.preventDefault();
+    this.setState({ collapsed: !this.state.collapsed });
+  }
+
   setRef = (c) => {
     this.node = c;
   }
@@ -132,12 +151,19 @@ export default class StatusContent extends React.PureComponent {
     const classNames = classnames('status__content', {
       'status__content--with-action': this.props.onClick && this.context.router,
       'status__content--with-spoiler': status.get('spoiler_text').length > 0,
+      'status__content--collapsed': this.state.collapsed === true,
     });
 
     if (isRtl(status.get('search_index'))) {
       directionStyle.direction = 'rtl';
     }
 
+    const readMoreButton = (
+      <button className='status__content__read-more-button' onClick={this.props.onClick}>
+        <FormattedMessage id='status.read_more' defaultMessage='Read more' /><i className='fa fa-fw fa-angle-right' />
+      </button>
+    );
+
     if (status.get('spoiler_text').length > 0) {
       let mentionsPlaceholder = '';
 
@@ -167,17 +193,23 @@ export default class StatusContent extends React.PureComponent {
         </div>
       );
     } else if (this.props.onClick) {
-      return (
+      const output = [
         <div
           ref={this.setRef}
           tabIndex='0'
           className={classNames}
           style={directionStyle}
+          dangerouslySetInnerHTML={content}
           onMouseDown={this.handleMouseDown}
           onMouseUp={this.handleMouseUp}
-          dangerouslySetInnerHTML={content}
+        />,
-        />
+      ];
-      );
+
+      if (this.state.collapsed) {
+        output.push(readMoreButton);
+      }
+
+      return output;
     } else {
       return (
         <div

app/javascript/styles/mastodon/components.scss

@@ -631,11 +631,13 @@
 
 .status__content,
 .reply-indicator__content {
+  position: relative;
   font-size: 15px;
   line-height: 20px;
   word-wrap: break-word;
   font-weight: 400;
   overflow: hidden;
+  text-overflow: ellipsis;
   white-space: pre-wrap;
   padding-top: 2px;
   color: $primary-text-color;
@@ -721,6 +723,26 @@
   }
 }
 
+.status__content.status__content--collapsed {
+  max-height: 20px * 15; // 15 lines is roughly above 500 characters
+}
+
+.status__content__read-more-button {
+  display: block;
+  font-size: 15px;
+  line-height: 20px;
+  color: lighten($ui-highlight-color, 8%);
+  border: 0;
+  background: transparent;
+  padding: 0;
+  padding-top: 8px;
+
+  &:hover,
+  &:active {
+    text-decoration: underline;
+  }
+}
+
 .status__content__spoiler-link {
   display: inline-block;
   border-radius: 2px;