Allow clients to fetch statuses made while they were offline (#6876)

app/javascript/mastodon/components/status_list.js

@@ -1,11 +1,31 @@
+import { debounce } from 'lodash';
 import React from 'react';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import PropTypes from 'prop-types';
 import StatusContainer from '../containers/status_container';
 import ImmutablePureComponent from 'react-immutable-pure-component';
+import LoadMore from './load_more';
 import ScrollableList from './scrollable_list';
 import { FormattedMessage } from 'react-intl';
 
+class LoadGap extends ImmutablePureComponent {
+
+  static propTypes = {
+    disabled: PropTypes.bool,
+    maxId: PropTypes.string,
+    onClick: PropTypes.func.isRequired,
+  };
+
+  handleClick = () => {
+    this.props.onClick(this.props.maxId);
+  }
+
+  render () {
+    return <LoadMore onClick={this.handleClick} disabled={this.props.disabled} />;
+  }
+
+}
+
 export default class StatusList extends ImmutablePureComponent {
 
   static propTypes = {
@@ -38,6 +58,10 @@ export default class StatusList extends ImmutablePureComponent {
     this._selectChild(elementIndex);
   }
 
+  handleLoadOlder = debounce(() => {
+    this.props.onLoadMore(this.props.statusIds.last());
+  }, 300, { leading: true })
+
   _selectChild (index) {
     const element = this.node.node.querySelector(`article:nth-of-type(${index + 1}) .focusable`);
 
@@ -51,7 +75,7 @@ export default class StatusList extends ImmutablePureComponent {
   }
 
   render () {
-    const { statusIds, featuredStatusIds, ...other }  = this.props;
+    const { statusIds, featuredStatusIds, onLoadMore, ...other }  = this.props;
     const { isLoading, isPartial } = other;
 
     if (isPartial) {
@@ -70,7 +94,14 @@ export default class StatusList extends ImmutablePureComponent {
     }
 
     let scrollableContent = (isLoading || statusIds.size > 0) ? (
-      statusIds.map(statusId => (
+      statusIds.map((statusId, index) => statusId === null ? (
+        <LoadGap
+          key={'gap:' + statusIds.get(index + 1)}
+          disabled={isLoading}
+          maxId={index > 0 ? statusIds.get(index - 1) : null}
+          onClick={onLoadMore}
+        />
+      ) : (
         <StatusContainer
           key={statusId}
           id={statusId}
@@ -93,7 +124,7 @@ export default class StatusList extends ImmutablePureComponent {
     }
 
     return (
-      <ScrollableList {...other} ref={this.setRef}>
+      <ScrollableList {...other} onLoadMore={onLoadMore && this.handleLoadOlder} ref={this.setRef}>
         {scrollableContent}
       </ScrollableList>
     );