diff --git a/frontend/src/components/markdown-view/comments-list.js b/frontend/src/components/markdown-view/comments-list.js
deleted file mode 100644
index 0531ea6d7e..0000000000
--- a/frontend/src/components/markdown-view/comments-list.js
+++ /dev/null
@@ -1,305 +0,0 @@
-import React from 'react';
-import PropTypes from 'prop-types';
-import { processor } from '@seafile/seafile-editor/dist/utils/seafile-markdown2html';
-import { Button, Dropdown, DropdownToggle, DropdownMenu, DropdownItem } from 'reactstrap';
-import Loading from '../loading';
-import { gettext } from '../../utils/constants';
-import moment from 'moment';
-import '../../css/markdown-viewer/comments-list.css';
-
-const propTypes = {
-  editorUtilities: PropTypes.object.isRequired,
-  scrollToQuote: PropTypes.func.isRequired,
-  getCommentsNumber: PropTypes.func.isRequired,
-  commentsNumber: PropTypes.number.isRequired,
-};
-
-class CommentsList extends React.Component {
-
-  constructor(props) {
-    super(props);
-    this.state = {
-      commentsList: [],
-      showResolvedComment: true,
-    };
-  }
-
-  listComments = () => {
-    this.props.editorUtilities.listComments().then((response) => {
-      this.setState({
-        commentsList: response.data.comments
-      });
-    });
-  }
-
-  handleCommentChange = (event) => {
-    this.setState({
-      comment: event.target.value,
-    });
-  }
-
-  submitComment = () => {
-    let comment = this.refs.commentTextarea.value;
-    if (comment.trim().length > 0) {
-      this.props.editorUtilities.postComment(comment.trim()).then((response) => {
-        this.listComments();
-        this.props.getCommentsNumber();
-      });
-    }
-    this.refs.commentTextarea.value = '';
-  }
-
-  resolveComment = (event) => {
-    this.props.editorUtilities.updateComment(event.target.id, 'true').then((response) => {
-      this.listComments();
-    });
-  }
-
-  deleteComment = (event) => {
-    this.props.editorUtilities.deleteComment(event.target.id).then((response) => {
-      this.props.getCommentsNumber();
-      this.listComments();
-    });
-  }
-
-  editComment = (commentID, newComment) => {
-    this.props.editorUtilities.updateComment(commentID, null, null, newComment).then((res) => {
-      this.props.getCommentsNumber();
-      this.listComments();
-    });
-  }
-
-  setQuoteText = (text) => {
-    if (text.length > 0) {
-      this.refs.commentTextarea.value = '> ' + text;
-    }
-  }
-
-  scrollToQuote = (detail) => {
-    this.props.scrollToQuote(detail);
-    this.refs.commentTextarea.value = '';
-  }
-
-  toggleResolvedComment = () => {
-    this.setState({
-      showResolvedComment: !this.state.showResolvedComment
-    });
-  }
-
-  componentWillMount() {
-    this.listComments();
-  }
-
-  componentWillReceiveProps(nextProps) {
-    if (this.props.commentsNumber !== nextProps.commentsNumber) {
-      this.listComments();
-    }
-  }
-
-  render() {
-    return (
-      <div className="seafile-comment">
-        <div className="seafile-comment-title">
-          <div className="seafile-comment-text">{gettext('Show resolved comments')}</div>
-          <div className="d-flex">
-            <label className="custom-switch" id="toggle-resolved-comments">
-              <input type="checkbox" name="option" className="custom-switch-input"
-                onChange={this.toggleResolvedComment}
-                checked={this.state.showResolvedComment && 'checked'}
-              />
-              <span className="custom-switch-indicator"></span>
-            </label>
-          </div>
-        </div>
-        <ul className={'seafile-comment-list'}>
-          { (this.state.commentsList.length > 0 && this.props.commentsNumber > 0) &&
-            this.state.commentsList.map((item, index = 0, arr) => {
-              let oldTime = (new Date(item.created_at)).getTime();
-              let time = moment(oldTime).format('YYYY-MM-DD HH:mm');
-              return (
-                <CommentItem
-                  item={item} time={time} key={index}
-                  editorUtilities={this.props.editorUtilities}
-                  editComment={this.editComment}
-                  showResolvedComment={this.state.showResolvedComment}
-                  deleteComment={this.deleteComment} resolveComment={this.resolveComment}
-                  commentsList={this.state.commentsList} scrollToQuote={this.scrollToQuote}
-                />
-              );
-            })
-          }
-          {(this.state.commentsList.length == 0 && this.props.commentsNumber > 0) && <Loading/>}
-          { this.props.commentsNumber == 0 &&
-            <li className="comment-vacant">{gettext('No comment yet.')}</li>
-          }
-        </ul>
-        <div className="seafile-comment-footer">
-          <div className="seafile-add-comment">
-            <textarea className="add-comment-input" ref="commentTextarea"
-              placeholder={gettext('Add a comment')}
-              clos="100" rows="3" warp="virtual"></textarea>
-            <Button className="submit-comment" color="success"
-              size="sm" onClick={this.submitComment} >
-              {gettext('Submit')}</Button>
-          </div>
-        </div>
-      </div>
-    );
-  }
-}
-
-CommentsList.propTypes = propTypes;
-
-const CommentItempropTypes = {
-  editorUtilities: PropTypes.object.isRequired,
-  item: PropTypes.object,
-  time: PropTypes.string,
-  editComment: PropTypes.func,
-  showResolvedComment: PropTypes.bool,
-  deleteComment: PropTypes.func,
-  resolveComment: PropTypes.func,
-  commentsList: PropTypes.array,
-  scrollToQuote: PropTypes.func.isRequired,
-};
-
-class CommentItem extends React.Component {
-
-  constructor(props) {
-    super(props);
-    this.state = {
-      dropdownOpen: false,
-      html: '',
-      quote: '',
-      newComment: this.props.item.comment,
-      editable: false,
-    };
-  }
-
-  toggleDropDownMenu = () => {
-    this.setState({
-      dropdownOpen: !this.state.dropdownOpen,
-    });
-  }
-
-  convertComment = (item) => {
-    processor.process(item.comment).then(
-      (result) => {
-        let comment = String(result);
-        this.setState({
-          comment: comment
-        });
-      }
-    );
-    if (item.detail) {
-      const quote = JSON.parse(item.detail).quote;
-      processor.process(quote).then(
-        (result) => {
-          let quote = String(result);
-          this.setState({
-            quote: quote
-          });
-        }
-      );
-    }
-  }
-
-  toggleEditComment = () => {
-    this.setState({
-      editable: !this.state.editable
-    });
-  }
-
-  updateComment = (event) => {
-    const newComment = this.state.newComment;
-    if (this.props.item.comment !== newComment) {
-      this.props.editComment(event.target.id, newComment);
-    }
-    this.toggleEditComment();
-  }
-
-  handleCommentChange = (event) => {
-    this.setState({
-      newComment: event.target.value,
-    });
-  }
-
-  scrollToQuote = () => {
-    const position = JSON.parse(this.props.item.detail).position;
-    this.props.scrollToQuote(position);
-  }
-
-  componentWillMount() {
-    this.convertComment(this.props.item);
-  }
-
-  componentWillReceiveProps(nextProps) {
-    this.convertComment(nextProps.item);
-  }
-
-  render() {
-    const item = this.props.item;
-    const { id, user_email, avatar_url, user_name, resolved } = item;
-    if (item.resolved && !this.props.showResolvedComment) {
-      return null;
-    }
-    if (this.state.editable) {
-      return(
-        <li className="seafile-comment-item" id={item.id}>
-          <div className="seafile-comment-info">
-            <img className="avatar" src={avatar_url} alt=""/>
-            <div className="reviewer-info">
-              <div className="reviewer-name">{user_name}</div>
-              <div className="review-time">{this.props.time}</div>
-            </div>
-          </div>
-          <div className="seafile-edit-comment">
-            <textarea className="edit-comment-input" value={this.state.newComment} onChange={this.handleCommentChange} clos="100" rows="3" warp="virtual"></textarea>
-            <Button className="comment-btn" color="success" size="sm" onClick={this.updateComment} id={item.id}>{gettext('Update')}</Button>{' '}
-            <Button className="comment-btn" color="secondary" size="sm" onClick={this.toggleEditComment}>{gettext('Cancle')}</Button>
-          </div>
-        </li>
-      );
-    }
-    return (
-      <li className={resolved ? 'seafile-comment-item seafile-comment-item-resolved' : 'seafile-comment-item'} id={id}>
-        <div className="seafile-comment-info">
-          <img className="avatar" src={avatar_url} alt=""/>
-          <div className="reviewer-info">
-            <div className="reviewer-name">{user_name}</div>
-            <div className="review-time">{this.props.time}</div>
-          </div>          
-          <Dropdown isOpen={this.state.dropdownOpen} size="sm"
-            className="seafile-comment-dropdown" toggle={this.toggleDropDownMenu}>
-            <DropdownToggle className="seafile-comment-dropdown-btn">
-              <i className="fas fa-ellipsis-v"></i>
-            </DropdownToggle>
-            <DropdownMenu>
-              {(user_email === this.props.editorUtilities.userName) &&
-                <DropdownItem onClick={this.props.deleteComment}
-                  className="delete-comment" id={item.id}>{gettext('Delete')}</DropdownItem>
-                }
-              {(user_email === this.props.editorUtilities.userName) &&
-                <DropdownItem onClick={this.toggleEditComment}
-                  className="edit-comment" id={item.id}>{gettext('Edit')}</DropdownItem>
-              }
-              {!resolved &&
-                <DropdownItem onClick={this.props.resolveComment} className="seafile-comment-resolved"
-                  id={item.id}>{gettext('Mark as resolved')}</DropdownItem>
-              }
-            </DropdownMenu>
-          </Dropdown>
-        </div>       
-        {item.detail &&
-          <blockquote className="seafile-comment-content">
-            <div onClick={this.scrollToQuote} dangerouslySetInnerHTML={{ __html: this.state.quote }}></div>
-          </blockquote>
-        }
-        <div className="seafile-comment-content" dangerouslySetInnerHTML={{ __html: this.state.comment }}></div>
-      </li>
-    );
-  }
-}
-
-CommentItem.propTypes = CommentItempropTypes;
-
-export default CommentsList;
diff --git a/frontend/src/components/markdown-view/history-list.js b/frontend/src/components/markdown-view/history-list.js
index a38a7ffbf4..36066cfb46 100644
--- a/frontend/src/components/markdown-view/history-list.js
+++ b/frontend/src/components/markdown-view/history-list.js
@@ -4,6 +4,7 @@ import PropTypes from 'prop-types';
 import axios from 'axios';
 import Loading from '../loading';
 import moment from 'moment';
+import { gettext } from '../../utils/constants';
 import '../../css/markdown-viewer/history-viewer.css';
 
 const propTypes = {
@@ -97,6 +98,12 @@ class HistoryList extends React.Component {
   render() {
     return (
       <div className="seafile-history-side-panel">
+        <div className="seafile-history-title">
+          <div onClick={this.props.toggleHistoryPanel} className={'seafile-history-title-close'}>
+            <i className={'fa fa-times-circle'}/>
+          </div>
+          <div className={'seafile-history-title-text'}>{gettext('History Versions')}</div>
+        </div>
         <ul onScroll={this.onScroll} className={'history-list-container'}>
           {this.state.historyList ?
             this.state.historyList.map((item, index = 0, arr) => {
diff --git a/frontend/src/components/markdown-view/markdown-viewer-side-panel.js b/frontend/src/components/markdown-view/markdown-viewer-side-panel.js
deleted file mode 100644
index 03c24fde29..0000000000
--- a/frontend/src/components/markdown-view/markdown-viewer-side-panel.js
+++ /dev/null
@@ -1,164 +0,0 @@
-import React from 'react';
-import PropTypes from 'prop-types';
-import classnames from 'classnames';
-import { Nav, NavItem, NavLink, TabContent, TabPane } from 'reactstrap';
-import HistoryList from './history-list';
-import CommentsList from './comments-list';
-import OutlineView from './outline';
-
-const URL = require('url-parse');
-
-const propTypes = {
-  editorUtilities: PropTypes.object.isRequired,
-  markdownContent: PropTypes.string.isRequired,
-  commentsNumber: PropTypes.number.isRequired,
-  viewer: PropTypes.object.isRequired,
-  value: PropTypes.object.isRequired,
-  activeTab: PropTypes.string.isRequired,
-  showDiffViewer: PropTypes.func.isRequired,
-  setDiffViewerContent: PropTypes.func.isRequired,
-  reloadDiffContent: PropTypes.func.isRequired,
-  tabItemClick: PropTypes.func.isRequired,
-  getCommentsNumber: PropTypes.func.isRequired,
-};
-
-class MarkdownViewerSidePanel extends React.Component {
-
-  constructor(props) {
-    super(props);
-  }
-
-  tabItemClick = (tab) => {
-    this.props.tabItemClick(tab);
-  }
-
-  showNavItem = (showTab) => {
-    switch(showTab) {
-      case 'outline':
-        return (
-          <NavLink className={classnames({ active: this.props.activeTab === 'outline' })}
-            onClick={() => { this.tabItemClick('outline');}} ><i className="fa fa-list"></i>
-          </NavLink>
-        );
-      case 'comments':
-        return (
-          <NavLink className={classnames({ active: this.props.activeTab === 'comments' })}
-            onClick={() => {this.tabItemClick('comments');}}><i className="fa fa-comments"></i>
-            {this.props.commentsNumber > 0 && <div className='comments-number'>{this.props.commentsNumber}</div>}
-          </NavLink>
-        );
-      case 'history':
-        return (
-          <NavLink className={classnames({ active: this.props.activeTab === 'history' })}
-            onClick={() => { this.tabItemClick('history');}}><i className="fas fa-history"></i>
-          </NavLink>
-        );
-    }
-  } 
-
-  renderNavItems = () => {
-    return (
-      <Nav tabs className="md-side-panel-nav">
-        <NavItem className="nav-item">{this.showNavItem('outline')}</NavItem>
-        <NavItem className="nav-item">{this.showNavItem('comments')}</NavItem>
-        <NavItem className="nav-item">{this.showNavItem('history')}</NavItem>
-      </Nav>
-    );
-  }
-
-  scrollToNode = (node) => {
-    let url = new URL(window.location.href);
-    url.set('hash', 'user-content-' + node.text);
-    window.location.href = url.toString();
-  }
-
-  findScrollContainer = (el, window) => {
-    let parent = el.parentNode;
-    const OVERFLOWS = ['auto', 'overlay', 'scroll'];
-    let scroller;
-    while (!scroller) {
-      if (!parent.parentNode) break;
-      const style = window.getComputedStyle(parent);
-      const { overflowY } = style;
-      if (OVERFLOWS.includes(overflowY)) {
-        scroller = parent;
-        break;
-      }
-      parent = parent.parentNode;
-    }
-    if (!scroller) {
-      return window.document.body;
-    }
-    return scroller;
-  }
-
-  scrollToQuote = (path) => {
-    if (!path) return;
-    const win = window;
-    if (path.length > 2) {
-      // deal with code block or chart
-      path[0] = path[0] > 1 ? path[0] - 1 : path[0] + 1;
-      path = path.slice(0, 1);
-    }
-    let node = this.props.value.document.getNode(path);
-    if (!node) {
-      path = path.slice(0, 1);
-      node = this.props.value.document.getNode(path);
-    }
-    if (node) {
-      let element = win.document.querySelector(`[data-key="${node.key}"]`);
-      while (element.tagName === 'CODE') {
-        element = element.parentNode;
-      }
-      const scroller = this.findScrollContainer(element, win);
-      const isWindow = scroller == win.document.body || scroller == win.document.documentElement;
-      if (isWindow) {
-        win.scrollTo(0, element.offsetTop);
-      } else {
-        scroller.scrollTop = element.offsetTop;
-      }
-    }
-  }
-
-  componentDidMount() {
-    this.tabItemClick('outline');
-  }
-
-  render() {
-    return (
-      <div className="seafile-md-viewer-side-panel">
-        {this.renderNavItems()}
-        <TabContent activeTab={this.props.activeTab}>
-          <TabPane tabId="outline" className="outline">
-            <OutlineView
-              isViewer={true}
-              document={this.props.value.document}
-              editor={this.props.viewer}
-              scrollToNode={this.scrollToNode}
-            />
-          </TabPane>
-          <TabPane tabId="comments" className="comments">
-            <CommentsList
-              editorUtilities={this.props.editorUtilities}
-              scrollToQuote={this.scrollToQuote}
-              getCommentsNumber={this.props.getCommentsNumber}
-              commentsNumber={this.props.commentsNumber}
-            />
-          </TabPane>
-          <TabPane tabId="history" className="history">
-            <HistoryList
-              editorUtilities={this.props.editorUtilities}
-              showDiffViewer={this.props.showDiffViewer}
-              setDiffViewerContent={this.props.setDiffViewerContent}
-              reloadDiffContent={this.props.reloadDiffContent}
-            />
-          </TabPane>
-        </TabContent>
-      </div>
-    );
-  }
-}
-
-MarkdownViewerSidePanel.propTypes = propTypes;
-
-export default MarkdownViewerSidePanel;
diff --git a/frontend/src/components/markdown-view/outline.js b/frontend/src/components/markdown-view/outline.js
index f3a5b1aa81..c246742fbb 100644
--- a/frontend/src/components/markdown-view/outline.js
+++ b/frontend/src/components/markdown-view/outline.js
@@ -2,7 +2,6 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import { gettext } from '../../utils/constants';
 
-
 const OutlineItempropTypes = {
   scrollToNode: PropTypes.func.isRequired,
   node: PropTypes.object.isRequired,
@@ -41,7 +40,6 @@ const propTypes = {
   scrollToNode: PropTypes.func.isRequired,
   isViewer: PropTypes.bool.isRequired,
   document: PropTypes.object.isRequired,
-  editor: PropTypes.object.isRequired,
   activeTitleIndex: PropTypes.number,
   value: PropTypes.object,
 };
@@ -56,13 +54,13 @@ class OutlineView extends React.PureComponent {
 
     return (
       <div className="seafile-editor-outline">
+        <div className="seafile-editor-outline-heading">{gettext('Contents')}</div>
         {headerList.size > 0 ?
           headerList.map((node, index) => {
             let active = (index === this.props.activeTitleIndex) ? ' active' : ''; 
             return (
               <OutlineItem
                 key={node.key}
-                editor={this.props.editor}
                 value={this.props.value}
                 node={node}
                 active={active}
diff --git a/frontend/src/components/toolbar/markdown-viewer-toolbar.js b/frontend/src/components/toolbar/markdown-viewer-toolbar.js
index f8567734cb..2b71ea374c 100644
--- a/frontend/src/components/toolbar/markdown-viewer-toolbar.js
+++ b/frontend/src/components/toolbar/markdown-viewer-toolbar.js
@@ -18,6 +18,10 @@ const propTypes = {
   toggleStar: PropTypes.func.isRequired,
   backToParentDirectory: PropTypes.func.isRequired,
   openDialogs: PropTypes.func.isRequired,
+  showFileHistory: PropTypes.bool.isRequired,
+  toggleHistory: PropTypes.func.isRequired,
+  commentsNumber: PropTypes.number.isRequired,
+  toggleCommentList: PropTypes.func.isRequired,
 };
 
 class MarkdownViewerToolbar extends React.Component {
@@ -47,12 +51,25 @@ class MarkdownViewerToolbar extends React.Component {
           <ButtonGroup>
             <IconButton id={'shareBtn'} text={gettext('Share')} icon={'fa fa-share-alt'}
               onMouseDown={this.props.toggleShareLinkDialog}/>
+            {
+              this.props.commentsNumber > 0 ?
+                <button className="btn btn-icon btn-secondary btn-active" id="commentsNumber" type="button"
+                  data-active="false" onMouseDown={this.props.toggleCommentList}>
+                  <i className="fa fa-comments"></i>{' '}<span>{this.props.commentsNumber}</span>
+                </button>
+                :
+                <IconButton id={'commentsNumber'} text={gettext('Comments')} icon={'fa fa-comments'} onMouseDown={this.props.toggleCommentList}/>
+            }
             <IconButton text={gettext('Back to parent directory')} id={'parentDirectory'}
               icon={'fa fa-folder-open'} onMouseDown={this.props.backToParentDirectory}/>
             {
               (!this.props.hasDraft && this.props.fileInfo.permission === 'rw')? <IconButton text={gettext('Edit')}
                 id={'editButton'} icon={'fa fa-edit'} onMouseDown={this.props.onEdit}/>: null
             }
+            {
+              this.props.showFileHistory && <IconButton id={'historyButton'}
+                text={gettext('File history')} onMouseDown={this.props.toggleHistory} icon={'fa fa-history'}/>
+            }
           </ButtonGroup>
         </div>
       </div>
diff --git a/frontend/src/css/comments-list.css b/frontend/src/css/comments-list.css
index b39d026f76..b5e90761c2 100644
--- a/frontend/src/css/comments-list.css
+++ b/frontend/src/css/comments-list.css
@@ -4,7 +4,8 @@
   flex-direction: column;
   width: 29%;
 }
-.seafile-comment-title {
+.seafile-comment-title,
+.seafile-history-title {
   border-bottom: 1px solid #e5e5e5;
   min-height: 3em;
   line-height: 3em;
@@ -12,15 +13,18 @@
   display: flex;
   background-color: #fafaf9;
 }
-.seafile-comment-title .seafile-comment-title-text {
+.seafile-comment-title .seafile-comment-title-text,
+.seafile-history-title .seafile-history-title-text {
   width: 100%;
   text-align: center;
   font-weight: 700;
 }
-.seafile-comment-title .seafile-comment-title-close {
+.seafile-comment-title .seafile-comment-title-close,
+.seafile-history-title .seafile-history-title-close {
   color: #b9b9b9;
 }
-.seafile-comment-title .seafile-comment-title-close:hover {
+.seafile-comment-title .seafile-comment-title-close:hover,
+.seafile-history-title .seafile-history-title-close:hover {
   color: #888;
 }
 .seafile-comment-toggle-resolved {
diff --git a/frontend/src/css/markdown-viewer/comments-list.css b/frontend/src/css/markdown-viewer/comments-list.css
deleted file mode 100644
index ef4843a3d3..0000000000
--- a/frontend/src/css/markdown-viewer/comments-list.css
+++ /dev/null
@@ -1,138 +0,0 @@
-.seafile-comment {
-  background-color: #fff;
-  display: flex;
-  flex-direction: column;
-  flex: 0 0 auto;
-  min-height: 18.5em;
-  z-index: 3;
-  width: 380px;
-}
-.seafile-comment-title {
-  border-bottom: 1px solid #e5e5e5;
-  min-height: 2em;
-  line-height: 2em;
-  padding: 2px 1em;
-  display: flex;
-  flex-direction: row;
-  justify-content: space-between;
-  background-color: #fafaf9;
-  position: absolute;
-  z-index: 1;
-  width: 30%;
-}
-.seafile-comment-title .seafile-comment-title-close {
-  color: #b9b9b9;
-}
-.seafile-comment-title .seafile-comment-title-close:hover {
-  color: #888;
-}
-.seafile-comment-list {
-  height: calc(100% - 40px);
-  overflow-y: auto;
-  margin: 30px 0 120px;
-}
-.seafile-comment::-webkit-scrollbar {
-  display: none;
-}
-.seafile-comment-list .comment-vacant {
-  padding: 1em;
-  text-align: center;
-}
-.seafile-comment-item {
-  padding: 15px 10px;
-  margin-bottom: 0;
-}
-.seafile-comment-item .seafile-comment-info {
-  padding-bottom: 0.5em;
-  height: 3em;
-  display: flex;
-  justify-content: flex-start;
-}
-.seafile-comment-item .seafile-comment-info .reviewer-info {
-  padding-left: 10px;
-}
-.seafile-comment-item .seafile-comment-info .review-time {
-  font-size: 10px;
-  color: #777;
-}
-.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown {
-  margin-left: auto;
-}
-.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown button {
-  border: none;
-  box-shadow: none;
-  background-color: #fff;
-}
-.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown .seafile-comment-dropdown-btn {
-  color: #999;
-  background-color: transparent;
-}
-.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown:hover .seafile-comment-dropdown-btn {
-  color: #555;
-  background-color: transparent;
-}
-.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown button:hover,
-.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown button:focus {
-  border: none;
-  box-shadow: none;
-  background-color: #eee;
-}
-.seafile-comment-item .seafile-comment-content {
-  margin-left: 42px;
-}
-.seafile-comment-item .seafile-comment-content ol,
-.seafile-comment-item .seafile-comment-content ul,
-.seafile-comment-item .seafile-comment-content li {
-  margin-left: 10px;
-}
-.seafile-comment-item .seafile-comment-content table,
-.seafile-comment-item .seafile-comment-content th,
-.seafile-comment-item .seafile-comment-content td {
-  border: 1px solid #333;
-}
-.seafile-comment-item blockquote {
-  cursor: pointer;
-}
-.seafile-comment-footer {
-  background-color: #fafaf9;
-  border-top: 1px solid #e5e5e5;
-  min-height: 120px;
-  position: absolute;
-  bottom: 0;
-  padding: 0;
-  width: 30%;
-}
-.seafile-comment-footer .seafile-add-comment {
-  margin: 10px 20px 5px 15px;
-  height: 100%;
-  width: 100%;
-}
-.seafile-add-comment .add-comment-input,
-.seafile-edit-comment .edit-comment-input {
-  background-color: #fff;
-  border: 1px solid #e6e6dd;
-  padding: 5px;
-  min-height: 70px;
-  border-radius: 5px;
-  width: 100%;
-}
-.seafile-add-comment .add-comment-input {
-  height: calc(100% - 50px);
-  width: 92%;
-  max-height: 300px;
-}
-.seafile-comment-footer .seafile-add-comment .submit-comment {
-  margin-top: 5px;
-  width: 60px;
-  height: 28px;
-}
-.seafile-comment-item-resolved {
-  background-color: #e6ffed;
-}
-.seafile-comment-footer .seafile-add-comment .comment-btn,
-.seafile-edit-comment .comment-btn {
-  height: 28px;
-}
-.seafile-edit-comment {
-  margin-top: 10px;
-}
diff --git a/frontend/src/css/markdown-viewer/markdown-editor.css b/frontend/src/css/markdown-viewer/markdown-editor.css
index 1774e8beeb..788c235907 100644
--- a/frontend/src/css/markdown-viewer/markdown-editor.css
+++ b/frontend/src/css/markdown-viewer/markdown-editor.css
@@ -13,29 +13,52 @@
   align-items: center;
 }
 .seafile-md-viewer-container {
-  width: 70%;
+  width: 100%;
   background-color: #fafaf9;
-  overflow: hidden;
   height: 100%;
-}
-.seafile-md-viewer-container:hover {
+  position: relative;
   overflow: auto;
 }
+.seafile-md-viewer-container.side-panel-on {
+  width: 70%;
+}
 .seafile-md-viewer-slate {
   flex: auto;
   position: relative;
   margin: 20px 40px;
+  margin-right: 30%;
 }
 .seafile-md-viewer-main {
-  flex:auto;
-  overflow:auto;
+  flex: auto;
+  overflow: auto;
   background:#fafaf9;
   width: 70%;
 }
-.seafile-editor-outline .active {
+.seafile-md-viewer-slate.side-panel-on {
+  margin-right: 40px;
+}
+/* outline */
+.seafile-md-viewer .seafile-editor-outline {
+  background-color: #fafaf9;
+  margin: 40px;
+  border-left: 0;
+  width: 20%;
+  position: fixed;
+  top: 68px;
+  overflow-y: auto;
+  right: 5%;
+  z-index: 1;
+  height: 80%;
+}
+.seafile-md-viewer .seafile-editor-outline .active {
   color: #eb8205;
   border-left: 1px solid #eb8205;
 }
+.seafile-md-viewer .seafile-editor-outline-heading {
+  padding: 7px 0;
+  border-bottom: 1px solid #eee;
+  color: #a0a0a0;
+}
 .seafile-editor-outline .outline-h2, .seafile-editor-outline .outline-h3 {
   height: 30px;
   margin-left: 0;
@@ -52,71 +75,26 @@
 }
 /* side-panel */
 .seafile-md-viewer-side-panel {
-  height: 100%;
-  overflow:hidden;
-  user-select: none;
-  width: 30%;
-}
-.seafile-md-viewer-side-panel .seafile-editor-outline {
-  border-left: 0;
-}
-.seafile-md-viewer-side-panel:hover {
-  overflow: auto;
-}
-.seafile-md-viewer-side-panel-heading {
-  padding:7px 0;
-  border-bottom: 1px solid #eee;
-  color: #a0a0a0;
-}
-.seafile-md-viewer-side-panel-content {
-  padding:8px 0;
-  font-size: 0.875rem;
-}
-
-.seafile-md-viewer-side-panel {
-  border-left: 1px solid #e6e6dd;
-  background-color: #fff;
   height: 100%;
   overflow: hidden;
+  width: 30%;
+  position: fixed;
+  right: 0;
+  top: 87px;
 }
-.seafile-md-viewer-side-panel .tab-content {
-  height: calc(100% - 39px);
-  overflow-y: auto;
-  overflow-x: hidden;
+.seafile-md-viewer-side-panel .seafile-comment,
+.seafile-md-viewer-side-panel .seafile-history-side-panel {
+  width: 100%;
+  height: 100%;
 }
-.seafile-md-viewer-side-panel .tab-content .outline {
-  padding: 20px;
+.seafile-md-viewer-side-panel .seafile-comment .add-comment-input,
+.seafile-md-viewer-side-panel .seafile-comment .edit-comment-input {
+  background-color: #fff;
+  width: 100%;
 }
-.seafile-md-viewer-side-panel .md-side-panel-nav {
-  margin: 0;
+.seafile-md-viewer-side-panel .seafile-history-side-panel {
+  border-left: 1px solid #e6e6dd;
 }
-.md-side-panel-nav .nav-item {
-  width: 33.3%;
-  padding-top: 4px;
-}
-.md-side-panel-nav .nav-item .nav-link {
-  margin: 0 auto;
-}
-.md-side-panel-nav .nav-item i {
-  padding: 0 8px;
-  font-size: 1rem;
-  width: 1rem;
-}
-.comments-number {
-  font-size: 12px;
-  width: 16px;
-  height: 16px;
-  border-radius: 8px;
-  text-align: center;
-  line-height: 16px;
-  font-weight: 600;
-  background-color: #fd9644;
-  position: absolute;
-  top: 10%;
-  right: 30%;
-  color: #fff;
-}
-
 .seafile-viewer-comment-btn {
   position: absolute;
   top: 0;
@@ -131,11 +109,13 @@
   cursor: pointer;
   background-color: #eee;
 }
-
+.seafile-md-viewer .seafile-comment .seafile-comment-footer {
+  min-height: 230px;
+}
+.seafile-md-viewer .seafile-comment-toggle-resolved {
+  width: 100%;
+}
 @media (max-width:991.8px) {
-  .seafile-md-viewer-side-panel {
-    display:none;
-  }
   .seafile-editor-outline {
     display: none;
   }
@@ -143,9 +123,4 @@
     width: calc(100% - 80px);
     margin: 20px 40px;
   }
-}
-@media (min-width:992px) {
-  .seafile-md-viewer-side-panel {
-    width: 30%;
-  }
 }
\ No newline at end of file
diff --git a/frontend/src/markdown-editor.js b/frontend/src/markdown-editor.js
index ec304bb465..d057de4150 100644
--- a/frontend/src/markdown-editor.js
+++ b/frontend/src/markdown-editor.js
@@ -18,13 +18,16 @@ import { serialize, deserialize } from '@seafile/seafile-editor/dist/utils/slate
 import LocalDraftDialog from '@seafile/seafile-editor/dist/components/local-draft-dialog';
 import DiffViewer from '@seafile/seafile-editor/dist/viewer/diff-viewer';
 import MarkdownViewerToolbar from './components/toolbar/markdown-viewer-toolbar';
-import MarkdownViewerSidePanel from './components/markdown-view/markdown-viewer-side-panel';
+import HistoryList from './components/markdown-view/history-list';
+import CommentPanel from './components/file-view/comment-panel';
+import OutlineView from './components/markdown-view/outline';
 import Loading from './components/loading';
 import { findRange } from '@seafile/slate-react';
 
 import './css/markdown-viewer/markdown-editor.css';
 
 const CryptoJS = require('crypto-js');
+const URL = require('url-parse');
 const { repoID, repoName, filePath, fileName, mode, draftID, isDraft, hasDraft } = window.app.pageOptions;
 const { siteRoot, serviceUrl, seafileCollabServer } = window.app.config;
 const userInfo = window.app.userInfo;
@@ -300,9 +303,11 @@ class MarkdownEditor extends React.Component {
       collabUsers: userInfo ?
         [{user: userInfo, is_editing: false}] : [],
       commentsNumber: null,
-      activeTab: 'outline',
       loadingDiff: false,
       value: null,
+      isShowComments: false,
+      isShowHistory: false,
+      isShowOutline: true,
     };
 
     if (this.state.collabServer) {
@@ -721,17 +726,8 @@ class MarkdownEditor extends React.Component {
     });
   }
 
-  tabItemClick = (tab) => {
-    if (this.state.activeTab !== tab) {
-      this.setState({
-        activeTab: tab
-      });
-    }
-  }
-
   setBtnPosition = (e) => {
-    let isShowComments = this.state.activeTab === 'comments' ? true : false;
-    if (!isShowComments) return;
+    if (!this.state.isShowComments) return;
     const nativeSelection = window.getSelection();
     if (!nativeSelection.rangeCount) {
       this.range = null;
@@ -855,9 +851,95 @@ class MarkdownEditor extends React.Component {
     return newNodes;
   }
 
+  scrollToNode = (node) => {
+    let url = new URL(window.location.href);
+    url.set('hash', 'user-content-' + node.text);
+    window.location.href = url.toString();
+  }
+
+  findScrollContainer = (el, window) => {
+    let parent = el.parentNode;
+    const OVERFLOWS = ['auto', 'overlay', 'scroll'];
+    let scroller;
+    while (!scroller) {
+      if (!parent.parentNode) break;
+      const style = window.getComputedStyle(parent);
+      const { overflowY } = style;
+      if (OVERFLOWS.includes(overflowY)) {
+        scroller = parent;
+        break;
+      }
+      parent = parent.parentNode;
+    }
+    if (!scroller) {
+      return window.document.body;
+    }
+    return scroller;
+  }
+
+  scrollToQuote = (path) => {
+    if (!path) return;
+    const win = window;
+    if (path.length > 2) {
+      // deal with code block or chart
+      path[0] = path[0] > 1 ? path[0] - 1 : path[0] + 1;
+      path = path.slice(0, 1);
+    }
+    let node = this.state.value.document.getNode(path);
+    if (!node) {
+      path = path.slice(0, 1);
+      node = this.state.value.document.getNode(path);
+    }
+    if (node) {
+      let element = win.document.querySelector(`[data-key="${node.key}"]`);
+      while (element.tagName === 'CODE') {
+        element = element.parentNode;
+      }
+      const scroller = this.findScrollContainer(element, win);
+      const isWindow = scroller == win.document.body || scroller == win.document.documentElement;
+      if (isWindow) {
+        win.scrollTo(0, element.offsetTop);
+      } else {
+        scroller.scrollTop = element.offsetTop;
+      }
+    }
+  }
+
+  toggleHistory = () => {
+    if (this.state.isShowHistory) {
+      this.setState({
+        isShowHistory: false,
+        isShowOutline: true,
+        isShowComments: false,
+      });
+    } else {
+      this.setState({
+        isShowHistory: true,
+        isShowOutline: false,
+        isShowComments: false,
+      });
+    }
+  }
+
+  toggleCommentList = () => {
+    if (this.state.isShowComments) {
+      this.setState({
+        isShowHistory: false,
+        isShowOutline: true,
+        isShowComments: false,
+      });
+    } else {
+      this.setState({
+        isShowHistory: false,
+        isShowOutline: false,
+        isShowComments: true,
+      });
+    }
+  }
+
   render() {
     let component;
-    let isShowComments = this.state.activeTab === 'comments' ? true : false;
+    let sidePanel = (this.state.isShowHistory || this.state.isShowComments) ? true : false;
     if (this.state.loading) {
       return (
         <div className="empty-loading-page">
@@ -882,11 +964,15 @@ class MarkdownEditor extends React.Component {
               toggleShareLinkDialog={this.toggleShareLinkDialog}
               onEdit={this.onEdit}
               toggleNewDraft={editorUtilities.createDraftFile}
+              commentsNumber={this.state.commentsNumber}
+              toggleCommentList={this.toggleCommentList}
+              showFileHistory={true}
+              toggleHistory={this.toggleHistory}
             />
             <div className="seafile-md-viewer d-flex">
-              <div className="seafile-md-viewer-container" ref="markdownContainer">
+              <div className={sidePanel ? "seafile-md-viewer-container side-panel-on":"seafile-md-viewer-container"} ref="markdownContainer">
                 {
-                  this.state.activeTab === 'history' ?
+                  this.state.isShowHistory ?
                     <div className="diff-container">
                       <div className="diff-wrapper article">
                         { this.state.loadingDiff ?
@@ -899,30 +985,38 @@ class MarkdownEditor extends React.Component {
                       </div>
                     </div>
                     :
-                    <div className='seafile-md-viewer-slate'>
+                    <div className={sidePanel ? "seafile-md-viewer-slate side-panel-on" : "seafile-md-viewer-slate"}>
                       <MarkdownViewerSlate
                         relatedFiles={this.state.relatedFiles}
                         siteRoot={siteRoot}
                         value={this.state.value}
                       />
-                    {isShowComments &&
+                    {this.state.isShowComments &&
                       <i className="fa fa-plus-square seafile-viewer-comment-btn" ref="commentbtn" onMouseDown={this.addComment}></i>}
                     </div>
                 }
+                {
+                  this.state.isShowOutline &&
+                  <OutlineView
+                    isViewer={true}
+                    document={this.state.value.document}
+                    scrollToNode={this.scrollToNode}
+                  />
+                }
+              </div>
+              <div className="seafile-md-viewer-side-panel">
+                {this.state.isShowComments && <CommentPanel toggleCommentPanel={this.toggleCommentList}/>}
+                {
+                  this.state.isShowHistory &&
+                  <HistoryList
+                    editorUtilities={editorUtilities}
+                    showDiffViewer={this.showDiffViewer}
+                    setDiffViewerContent={this.setDiffViewerContent}
+                    reloadDiffContent={this.reloadDiffContent}
+                    toggleHistoryPanel={this.toggleHistory}
+                  />
+                }
               </div>
-              <MarkdownViewerSidePanel
-                viewer={this}
-                value={this.state.value}
-                markdownContent={this.state.markdownContent}
-                editorUtilities={editorUtilities}
-                commentsNumber={this.state.commentsNumber}
-                getCommentsNumber={this.getCommentsNumber}
-                showDiffViewer={this.showDiffViewer}
-                setDiffViewerContent={this.setDiffViewerContent}
-                reloadDiffContent={this.reloadDiffContent}
-                activeTab={this.state.activeTab}
-                tabItemClick={this.tabItemClick}
-              />
             </div>
           </div>
         );
@@ -952,7 +1046,7 @@ class MarkdownEditor extends React.Component {
           fileTagList={this.state.fileTagList}
           deleteDraft={this.deleteDraft}
           showDraftSaved={this.state.showDraftSaved}
-        />;
+        />
       }
 
       return (