Merge pull request #13720 from overleaf/td-review-panel-entry-pos

React review panel entry positioning

GitOrigin-RevId: c22617b1d3243b7d54b093426358aeb291421b9e

services/web/frontend/js/features/source-editor/components/review-panel/current-file-container.tsx

@@ -1,4 +1,4 @@
-import { useMemo } from 'react'
+import { useCallback, useMemo } from 'react'
 import Container from './container'
 import Toolbar from './toolbar/toolbar'
 import Nav from './nav'
@@ -8,13 +8,21 @@ import AggregateChangeEntry from './entries/aggregate-change-entry'
 import CommentEntry from './entries/comment-entry'
 import AddCommentEntry from './entries/add-comment-entry'
 import BulkActionsEntry from './entries/bulk-actions-entry/bulk-actions-entry'
+import PositionedEntries from './positioned-entries'
 import {
   useReviewPanelUpdaterFnsContext,
   useReviewPanelValueContext,
 } from '../../context/review-panel/review-panel-context'
 import useCodeMirrorContentHeight from '../../hooks/use-codemirror-content-height'
 import { ReviewPanelEntry } from '../../../../../../types/review-panel/entry'
-import { ThreadId } from '../../../../../../types/review-panel/review-panel'
+import {
+  ReviewPanelDocEntries,
+  ThreadId,
+} from '../../../../../../types/review-panel/review-panel'
+
+const isEntryAThreadId = (
+  entry: keyof ReviewPanelDocEntries
+): entry is ThreadId => entry !== 'add-comment' && entry !== 'bulk-actions'
 
 function CurrentFileContainer() {
   const {
@@ -36,10 +44,18 @@ function CurrentFileContainer() {
 
   const objectEntries = useMemo(() => {
     return Object.entries(currentDocEntries || {}) as Array<
-      [ThreadId, ReviewPanelEntry]
+      [keyof ReviewPanelDocEntries, ReviewPanelEntry]
     >
   }, [currentDocEntries])
 
+  const onMouseEnter = useCallback(() => {
+    setEntryHover(true)
+  }, [setEntryHover])
+
+  const onMouseLeave = useCallback(() => {
+    setEntryHover(false)
+  }, [setEntryHover])
+
   return (
     <Container classNames={{ 'rp-collapsed-displaying-entry': entryHover }}>
       <div className="review-panel-tools">
@@ -53,9 +69,9 @@ function CurrentFileContainer() {
         tabIndex={0}
         aria-labelledby="review-panel-tab-current-file"
       >
-        <div
-          className="rp-entry-list-inner"
-          style={{ height: `${contentHeight}px` }}
+        <PositionedEntries
+          entries={objectEntries}
+          contentHeight={contentHeight}
         >
           {openDocId &&
             objectEntries.map(([id, entry]) => {
@@ -63,37 +79,46 @@ function CurrentFileContainer() {
                 return null
               }
 
-              if (entry.type === 'insert' || entry.type === 'delete') {
+              if (
+                isEntryAThreadId(id) &&
+                (entry.type === 'insert' || entry.type === 'delete')
+              ) {
                 return (
                   <ChangeEntry
                     key={id}
                     docId={openDocId}
                     entry={entry}
+                    entryId={id}
                     permissions={permissions}
                     user={users[entry.metadata.user_id]}
-                    onMouseEnter={setEntryHover.bind(null, true)}
-                    onMouseLeave={setEntryHover.bind(null, false)}
+                    onMouseEnter={onMouseEnter}
+                    onMouseLeave={onMouseLeave}
                     onIndicatorClick={toggleReviewPanel}
                   />
                 )
               }
 
-              if (entry.type === 'aggregate-change') {
+              if (isEntryAThreadId(id) && entry.type === 'aggregate-change') {
                 return (
                   <AggregateChangeEntry
                     key={id}
                     docId={openDocId}
                     entry={entry}
+                    entryId={id}
                     permissions={permissions}
                     user={users[entry.metadata.user_id]}
-                    onMouseEnter={setEntryHover.bind(null, true)}
-                    onMouseLeave={setEntryHover.bind(null, false)}
+                    onMouseEnter={onMouseEnter}
+                    onMouseLeave={onMouseLeave}
                     onIndicatorClick={toggleReviewPanel}
                   />
                 )
               }
 
-              if (entry.type === 'comment' && !loadingThreads) {
+              if (
+                isEntryAThreadId(id) &&
+                entry.type === 'comment' &&
+                !loadingThreads
+              ) {
                 return (
                   <CommentEntry
                     key={id}
@@ -102,15 +127,15 @@ function CurrentFileContainer() {
                     entryId={id}
                     permissions={permissions}
                     threads={commentThreads}
-                    onMouseEnter={setEntryHover.bind(null, true)}
-                    onMouseLeave={setEntryHover.bind(null, false)}
+                    onMouseEnter={onMouseEnter}
+                    onMouseLeave={onMouseLeave}
                     onIndicatorClick={toggleReviewPanel}
                   />
                 )
               }
 
               if (entry.type === 'add-comment' && permissions.comment) {
-                return <AddCommentEntry key={id} entry={entry} />
+                return <AddCommentEntry key={id} entryId={entry.type} />
               }
 
               if (entry.type === 'bulk-actions') {
@@ -118,6 +143,7 @@ function CurrentFileContainer() {
                   <BulkActionsEntry
                     key={id}
                     entry={entry}
+                    entryId={entry.type}
                     nChanges={nChanges}
                   />
                 )
@@ -125,7 +151,7 @@ function CurrentFileContainer() {
 
               return null
             })}
-        </div>
+        </PositionedEntries>
       </div>
     </Container>
   )

services/web/frontend/js/features/source-editor/components/review-panel/editor-widgets/editor-widgets.tsx

@@ -12,8 +12,6 @@ import { useCodeMirrorViewContext } from '../../codemirror-editor'
 import Modal, { useBulkActionsModal } from '../entries/bulk-actions-entry/modal'
 import getMeta from '../../../../../utils/meta'
 import useScopeValue from '../../../../../shared/hooks/use-scope-value'
-import { MergeAndOverride } from '../../../../../../../types/utils'
-import { ReviewPanelBulkActionsEntry } from '../../../../../../../types/review-panel/entry'
 
 function EditorWidgets() {
   const { t } = useTranslation()
@@ -32,30 +30,13 @@ function EditorWidgets() {
     )
   const view = useCodeMirrorViewContext()
 
-  type UseReviewPanelValueContextReturnType = ReturnType<
-    typeof useReviewPanelValueContext
-  >
   const {
     entries,
     openDocId,
     nVisibleSelectedChanges: nChanges,
     wantTrackChanges,
     permissions,
-    // Remapping entries as they may contain `add-comment` and `bulk-actions` props along with DocIds
-    // Ideally the `add-comment` and `bulk-actions` objects should not be within the entries object
-    // as the doc data, but this is what currently angular returns.
-  } = useReviewPanelValueContext() as MergeAndOverride<
-    UseReviewPanelValueContextReturnType,
-    {
-      entries: {
-        // eslint-disable-next-line no-use-before-define
-        [Entry in UseReviewPanelValueContextReturnType['entries'] as keyof Entry]: Entry & {
-          'add-comment': ReviewPanelBulkActionsEntry
-          'bulk-actions': ReviewPanelBulkActionsEntry
-        }
-      }
-    }
-  >
+  } = useReviewPanelValueContext()
 
   const hasTrackChangesFeature = getMeta('ol-hasTrackChangesFeature')
 

services/web/frontend/js/features/source-editor/components/review-panel/entries/add-comment-entry.tsx

@@ -1,5 +1,5 @@
 import { useTranslation } from 'react-i18next'
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 import EntryContainer from './entry-container'
 import EntryCallout from './entry-callout'
 import EntryActions from './entry-actions'
@@ -14,34 +14,41 @@ import classnames from 'classnames'
 import { ReviewPanelAddCommentEntry } from '../../../../../../../types/review-panel/entry'
 
 type AddCommentEntryProps = {
-  entry: ReviewPanelAddCommentEntry
+  entryId: ReviewPanelAddCommentEntry['type']
 }
 
-function AddCommentEntry({ entry }: AddCommentEntryProps) {
+function AddCommentEntry({ entryId }: AddCommentEntryProps) {
   const { t } = useTranslation()
-  const { isAddingComment, submitNewComment, handleLayoutChange } =
-    useReviewPanelValueContext()
-  const { setIsAddingComment } = useReviewPanelUpdaterFnsContext()
+  const { isAddingComment, submitNewComment } = useReviewPanelValueContext()
+  const { setIsAddingComment, handleLayoutChange } =
+    useReviewPanelUpdaterFnsContext()
 
   const [content, setContent] = useState('')
 
   const handleStartNewComment = () => {
     setIsAddingComment(true)
-    handleLayoutChange()
+    window.setTimeout(handleLayoutChange, 0)
   }
 
   const handleSubmitNewComment = () => {
     submitNewComment(content)
     setIsAddingComment(false)
     setContent('')
+    window.setTimeout(handleLayoutChange, 0)
   }
 
   const handleCancelNewComment = () => {
     setIsAddingComment(false)
     setContent('')
-    handleLayoutChange()
+    window.setTimeout(handleLayoutChange, 0)
   }
 
+  useEffect(() => {
+    return () => {
+      setIsAddingComment(false)
+    }
+  }, [setIsAddingComment])
+
   const handleCommentKeyPress = (
     e: React.KeyboardEvent<HTMLTextAreaElement>
   ) => {
@@ -62,16 +69,12 @@ function AddCommentEntry({ entry }: AddCommentEntryProps) {
   }
 
   return (
-    <EntryContainer>
+    <EntryContainer id={entryId}>
       <EntryCallout className="rp-entry-callout-add-comment" />
       <div
         className={classnames('rp-entry', 'rp-entry-add-comment', {
           'rp-entry-adding-comment': isAddingComment,
         })}
-        style={{
-          top: entry.screenPos.y + 'px',
-          visibility: entry.visible ? 'visible' : 'hidden',
-        }}
       >
         {isAddingComment ? (
           <>

services/web/frontend/js/features/source-editor/components/review-panel/entries/aggregate-change-entry.tsx

@@ -4,19 +4,24 @@ import EntryContainer from './entry-container'
 import EntryCallout from './entry-callout'
 import EntryActions from './entry-actions'
 import Icon from '../../../../../shared/components/icon'
-import { useReviewPanelValueContext } from '../../../context/review-panel/review-panel-context'
+import {
+  useReviewPanelUpdaterFnsContext,
+  useReviewPanelValueContext,
+} from '../../../context/review-panel/review-panel-context'
 import { formatTime } from '../../../../utils/format-date'
 import classnames from 'classnames'
 import { ReviewPanelAggregateChangeEntry } from '../../../../../../../types/review-panel/entry'
 import {
   ReviewPanelPermissions,
   ReviewPanelUser,
+  ThreadId,
 } from '../../../../../../../types/review-panel/review-panel'
 import { DocId } from '../../../../../../../types/project-settings'
 
 type AggregateChangeEntryProps = {
   docId: DocId
   entry: ReviewPanelAggregateChangeEntry
+  entryId: ThreadId
   permissions: ReviewPanelPermissions
   user: ReviewPanelUser | undefined
   contentLimit?: number
@@ -28,6 +33,7 @@ type AggregateChangeEntryProps = {
 function AggregateChangeEntry({
   docId,
   entry,
+  entryId,
   permissions,
   user,
   contentLimit = 17,
@@ -36,8 +42,9 @@ function AggregateChangeEntry({
   onIndicatorClick,
 }: AggregateChangeEntryProps) {
   const { t } = useTranslation()
-  const { acceptChanges, rejectChanges, handleLayoutChange, gotoEntry } =
+  const { acceptChanges, rejectChanges, gotoEntry } =
     useReviewPanelValueContext()
+  const { handleLayoutChange } = useReviewPanelUpdaterFnsContext()
   const [isDeletionCollapsed, setIsDeletionCollapsed] = useState(true)
   const [isInsertionCollapsed, setIsInsertionCollapsed] = useState(true)
 
@@ -82,26 +89,17 @@ function AggregateChangeEntry({
 
   return (
     <EntryContainer
+      id={entryId}
       onClick={handleEntryClick}
       onMouseEnter={onMouseEnter}
       onMouseLeave={onMouseLeave}
     >
-      <EntryCallout
-        className="rp-entry-callout-aggregate"
-        style={{
-          top: entry.screenPos
-            ? entry.screenPos.y + entry.screenPos.height - 1 + 'px'
-            : undefined,
-        }}
-      />
+      <EntryCallout className="rp-entry-callout-aggregate" />
       {/* eslint-disable-next-line jsx-a11y/click-events-have-key-events,jsx-a11y/no-static-element-interactions */}
       <div
         className={classnames('rp-entry-indicator', {
           'rp-entry-indicator-focused': entry.focused,
         })}
-        style={{
-          top: entry.screenPos ? entry.screenPos.y + 'px' : undefined,
-        }}
         onClick={onIndicatorClick}
       >
         <Icon type="pencil" />
@@ -110,10 +108,6 @@ function AggregateChangeEntry({
         className={classnames('rp-entry', 'rp-entry-aggregate', {
           'rp-entry-focused': entry.focused,
         })}
-        style={{
-          top: entry.screenPos ? entry.screenPos.y + 'px' : undefined,
-          visibility: entry.visible ? 'visible' : 'hidden',
-        }}
       >
         <div className="rp-entry-body">
           <div className="rp-entry-action-icon">

services/web/frontend/js/features/source-editor/components/review-panel/entries/bulk-actions-entry/bulk-actions-entry.tsx

@@ -8,10 +8,11 @@ import { ReviewPanelBulkActionsEntry } from '../../../../../../../../types/revie
 
 type BulkActionsEntryProps = {
   entry: ReviewPanelBulkActionsEntry
+  entryId: ReviewPanelBulkActionsEntry['type']
   nChanges: number
 }
 
-function BulkActionsEntry({ entry, nChanges }: BulkActionsEntryProps) {
+function BulkActionsEntry({ entry, entryId, nChanges }: BulkActionsEntryProps) {
   const { t } = useTranslation()
   const {
     show,
@@ -24,7 +25,7 @@ function BulkActionsEntry({ entry, nChanges }: BulkActionsEntryProps) {
 
   return (
     <>
-      <EntryContainer>
+      <EntryContainer id={entryId}>
         {nChanges > 1 && (
           <>
             <EntryCallout

services/web/frontend/js/features/source-editor/components/review-panel/entries/change-entry.tsx

@@ -4,7 +4,10 @@ import EntryContainer from './entry-container'
 import EntryCallout from './entry-callout'
 import EntryActions from './entry-actions'
 import Icon from '../../../../../shared/components/icon'
-import { useReviewPanelValueContext } from '../../../context/review-panel/review-panel-context'
+import {
+  useReviewPanelUpdaterFnsContext,
+  useReviewPanelValueContext,
+} from '../../../context/review-panel/review-panel-context'
 import { formatTime } from '../../../../utils/format-date'
 import classnames from 'classnames'
 import {
@@ -14,12 +17,14 @@ import {
 import {
   ReviewPanelPermissions,
   ReviewPanelUser,
+  ThreadId,
 } from '../../../../../../../types/review-panel/review-panel'
 import { DocId } from '../../../../../../../types/project-settings'
 
 type ChangeEntryProps = {
   docId: DocId
   entry: ReviewPanelInsertEntry | ReviewPanelDeleteEntry
+  entryId: ThreadId
   permissions: ReviewPanelPermissions
   user: ReviewPanelUser | undefined
   contentLimit?: number
@@ -31,6 +36,7 @@ type ChangeEntryProps = {
 function ChangeEntry({
   docId,
   entry,
+  entryId,
   permissions,
   user,
   contentLimit = 40,
@@ -39,8 +45,9 @@ function ChangeEntry({
   onIndicatorClick,
 }: ChangeEntryProps) {
   const { t } = useTranslation()
-  const { acceptChanges, rejectChanges, handleLayoutChange, gotoEntry } =
+  const { acceptChanges, rejectChanges, gotoEntry } =
     useReviewPanelValueContext()
+  const { handleLayoutChange } = useReviewPanelUpdaterFnsContext()
   const [isCollapsed, setIsCollapsed] = useState(true)
 
   const content = isCollapsed
@@ -75,23 +82,14 @@ function ChangeEntry({
       onClick={handleEntryClick}
       onMouseEnter={onMouseEnter}
       onMouseLeave={onMouseLeave}
+      id={entryId}
     >
-      <EntryCallout
-        className={`rp-entry-callout-${entry.type}`}
-        style={{
-          top: entry.screenPos
-            ? entry.screenPos.y + entry.screenPos.height - 1 + 'px'
-            : undefined,
-        }}
-      />
+      <EntryCallout className={`rp-entry-callout-${entry.type}`} />
       {/* eslint-disable-next-line jsx-a11y/click-events-have-key-events, jsx-a11y/no-static-element-interactions */}
       <div
         className={classnames('rp-entry-indicator', {
           'rp-entry-indicator-focused': entry.focused,
         })}
-        style={{
-          top: entry.screenPos ? entry.screenPos.y + 'px' : undefined,
-        }}
         onClick={onIndicatorClick}
       >
         {entry.type === 'insert' ? (
@@ -104,10 +102,6 @@ function ChangeEntry({
         className={classnames('rp-entry', `rp-entry-${entry.type}`, {
           'rp-entry-focused': entry.focused,
         })}
-        style={{
-          top: entry.screenPos ? entry.screenPos.y + 'px' : undefined,
-          visibility: entry.visible ? 'visible' : 'hidden',
-        }}
       >
         <div className="rp-entry-body">
           <div className="rp-entry-action-icon">

services/web/frontend/js/features/source-editor/components/review-panel/entries/comment-entry.tsx

@@ -1,4 +1,4 @@
-import { useState, useRef } from 'react'
+import { useState, useRef, useEffect } from 'react'
 import { useTranslation } from 'react-i18next'
 import EntryContainer from './entry-container'
 import EntryCallout from './entry-callout'
@@ -8,7 +8,10 @@ import AutoExpandingTextArea, {
   resetHeight,
 } from '../../../../../shared/components/auto-expanding-text-area'
 import Icon from '../../../../../shared/components/icon'
-import { useReviewPanelValueContext } from '../../../context/review-panel/review-panel-context'
+import {
+  useReviewPanelUpdaterFnsContext,
+  useReviewPanelValueContext,
+} from '../../../context/review-panel/review-panel-context'
 import classnames from 'classnames'
 import { ReviewPanelCommentEntry } from '../../../../../../../types/review-panel/entry'
 import {
@@ -40,8 +43,9 @@ function CommentEntry({
   onIndicatorClick,
 }: CommentEntryProps) {
   const { t } = useTranslation()
-  const { gotoEntry, resolveComment, submitReply, handleLayoutChange } =
+  const { gotoEntry, resolveComment, submitReply } =
     useReviewPanelValueContext()
+  const { handleLayoutChange } = useReviewPanelUpdaterFnsContext()
   const [replyContent, setReplyContent] = useState('')
   const [animating, setAnimating] = useState(false)
   const [resolved, setResolved] = useState(false)
@@ -103,12 +107,24 @@ function CommentEntry({
     }
   }
 
+  const submitting = Boolean(thread?.submitting)
+
+  // Update the layout when loading finishes
+  useEffect(() => {
+    if (!submitting) {
+      // Ensure everything is rendered in the DOM before updating the layout.
+      // Having to use a timeout seems less than ideal.
+      window.setTimeout(handleLayoutChange, 0)
+    }
+  }, [submitting, handleLayoutChange])
+
   if (!thread || resolved) {
     return null
   }
 
   return (
     <EntryContainer
+      id={entryId}
       onClick={handleEntryClick}
       onMouseEnter={onMouseEnter}
       onMouseLeave={onMouseLeave}
@@ -119,22 +135,12 @@ function CommentEntry({
           'rp-comment-wrapper-resolving': animating,
         })}
       >
-        <EntryCallout
-          className="rp-entry-callout-comment"
-          style={{
-            top: entry.screenPos
-              ? entry.screenPos.y + entry.screenPos.height - 1 + 'px'
-              : undefined,
-          }}
-        />
+        <EntryCallout className="rp-entry-callout-comment" />
         {/* eslint-disable-next-line jsx-a11y/click-events-have-key-events, jsx-a11y/no-static-element-interactions */}
         <div
           className={classnames('rp-entry-indicator', {
             'rp-entry-indicator-focused': entry.focused,
           })}
-          style={{
-            top: entry.screenPos ? `${entry.screenPos.y}px` : undefined,
-          }}
           onClick={onIndicatorClick}
         >
           <Icon type="comment" />
@@ -144,13 +150,9 @@ function CommentEntry({
             'rp-entry-focused': entry.focused,
             'rp-entry-comment-resolving': animating,
           })}
-          style={{
-            top: entry.screenPos ? `${entry.screenPos.y}px` : undefined,
-            visibility: entry.visible ? 'visible' : 'hidden',
-          }}
           ref={entryDivRef}
         >
-          {!thread.submitting && (!thread || thread.messages.length === 0) && (
+          {!submitting && (!thread || thread.messages.length === 0) && (
             <div className="rp-loading">{t('no_comments')}</div>
           )}
           <div className="rp-comment-loaded">
@@ -163,7 +165,7 @@ function CommentEntry({
               />
             ))}
           </div>
-          {thread.submitting && (
+          {submitting && (
             <div className="rp-loading">
               <Icon type="spinner" spin />
             </div>

services/web/frontend/js/features/source-editor/components/review-panel/entries/comment.tsx

@@ -2,7 +2,10 @@ import { useTranslation } from 'react-i18next'
 import { useState } from 'react'
 import AutoExpandingTextArea from '../../../../../shared/components/auto-expanding-text-area'
 import { formatTime } from '../../../../utils/format-date'
-import { useReviewPanelValueContext } from '../../../context/review-panel/review-panel-context'
+import {
+  useReviewPanelUpdaterFnsContext,
+  useReviewPanelValueContext,
+} from '../../../context/review-panel/review-panel-context'
 import { ReviewPanelCommentThread } from '../../../../../../../types/review-panel/comment-thread'
 import {
   ReviewPanelCommentThreadMessage,
@@ -17,8 +20,8 @@ type CommentProps = {
 
 function Comment({ thread, threadId, comment }: CommentProps) {
   const { t } = useTranslation()
-  const { deleteComment, handleLayoutChange, saveEdit } =
-    useReviewPanelValueContext()
+  const { deleteComment, saveEdit } = useReviewPanelValueContext()
+  const { handleLayoutChange } = useReviewPanelUpdaterFnsContext()
   const [deleting, setDeleting] = useState(false)
   const [editing, setEditing] = useState(false)
 

services/web/frontend/js/features/source-editor/components/review-panel/entries/entry-container.tsx

@@ -1,7 +1,17 @@
 import classnames from 'classnames'
 
-function EntryContainer({ className, ...rest }: React.ComponentProps<'div'>) {
-  return <div className={classnames('rp-entry-wrapper', className)} {...rest} />
+function EntryContainer({
+  id,
+  className,
+  ...rest
+}: React.ComponentProps<'div'>) {
+  return (
+    <div
+      className={classnames('rp-entry-wrapper', className)}
+      data-entry-id={id}
+      {...rest}
+    />
+  )
 }
 
 export default EntryContainer

services/web/frontend/js/features/source-editor/components/review-panel/nav.tsx

@@ -6,14 +6,28 @@ import {
   useReviewPanelUpdaterFnsContext,
 } from '../../context/review-panel/review-panel-context'
 import { isCurrentFileView, isOverviewView } from '../../utils/sub-view'
+import { useCallback } from 'react'
+import { useResizeObserver } from '../../../../shared/hooks/use-resize-observer'
 
 function Nav() {
   const { t } = useTranslation()
   const { subView } = useReviewPanelValueContext()
-  const { handleSetSubview } = useReviewPanelUpdaterFnsContext()
+  const { handleSetSubview, setNavHeight } = useReviewPanelUpdaterFnsContext()
+  const handleResize = useCallback(
+    el => {
+      // Use requestAnimationFrame to prevent errors like "ResizeObserver loop
+      // completed with undelivered notifications" that occur if onResize does
+      // something complicated. The cost of this is that onResize lags one frame
+      // behind, but it's unlikely to matter.
+      const height = el.offsetHeight
+      window.requestAnimationFrame(() => setNavHeight(height))
+    },
+    [setNavHeight]
+  )
+  const resizeRef = useResizeObserver(handleResize)
 
   return (
-    <div className="rp-nav" role="tablist">
+    <div ref={resizeRef} className="rp-nav" role="tablist">
       <button
         type="button"
         id="review-panel-tab-current-file"

services/web/frontend/js/features/source-editor/components/review-panel/overview-file.tsx

@@ -82,6 +82,7 @@ function OverviewFile({ docId, docPath }: OverviewFileProps) {
                 key={id}
                 docId={docId}
                 entry={entry}
+                entryId={id}
                 permissions={permissions}
                 user={users[entry.metadata.user_id]}
               />
@@ -94,6 +95,7 @@ function OverviewFile({ docId, docPath }: OverviewFileProps) {
                 key={id}
                 docId={docId}
                 entry={entry}
+                entryId={id}
                 permissions={permissions}
                 user={users[entry.metadata.user_id]}
               />

services/web/frontend/js/features/source-editor/components/review-panel/positioned-entries.tsx

@@ -0,0 +1,409 @@
+import { useEffect, useRef } from 'react'
+import { useLayoutContext } from '../../../../shared/context/layout-context'
+import {
+  ReviewPanelEntry,
+  ReviewPanelEntryScreenPos,
+} from '../../../../../../types/review-panel/entry'
+import useScopeValue from '../../../../shared/hooks/use-scope-value'
+import { debugConsole } from '../../../../utils/debugging'
+import { useReviewPanelValueContext } from '../../context/review-panel/review-panel-context'
+import useEventListener from '../../../../shared/hooks/use-event-listener'
+import { ReviewPanelDocEntries } from '../../../../../../types/review-panel/review-panel'
+import { dispatchReviewPanelLayout } from '../../extensions/changes/change-manager'
+
+type EntryView = {
+  wrapper: HTMLElement
+  indicator: HTMLElement | null
+  box: HTMLElement
+  callout: HTMLElement
+  layout: HTMLElement
+  height: number
+  previousEntryTop: number | null
+  previousCalloutTop: number | null
+  entry: ReviewPanelEntry
+  visible: boolean
+  positions?: {
+    entryTop: number
+    callout: { top: number; height: number; inverted: boolean }
+  }
+}
+
+function css(el: HTMLElement, props: React.CSSProperties) {
+  Object.assign(el.style, props)
+}
+
+function applyEntryVisibility(entryView: EntryView) {
+  const visible = !!entryView.entry.screenPos
+  entryView.wrapper.classList.toggle('rp-entry-hidden', !visible)
+  return visible
+}
+
+function calculateCalloutPosition(
+  screenPos: ReviewPanelEntryScreenPos,
+  entryTop: number,
+  lineHeight: number
+) {
+  const height = screenPos.height ?? lineHeight
+  const originalTop = screenPos.y
+  const inverted = entryTop <= originalTop
+  return {
+    top: inverted ? entryTop + height : originalTop + height - 1,
+    height: Math.abs(entryTop - originalTop),
+    inverted,
+  }
+}
+
+const calculateEntryViewPositions = (
+  entryViews: EntryView[],
+  lineHeight: number,
+  calculateTop: (originalTop: number, height: number) => number
+) => {
+  for (const entryView of entryViews) {
+    const entryVisible = applyEntryVisibility(entryView)
+    if (entryVisible) {
+      const entryTop = calculateTop(
+        entryView.entry.screenPos.y,
+        entryView.height
+      )
+      const callout = calculateCalloutPosition(
+        entryView.entry.screenPos,
+        entryTop,
+        lineHeight
+      )
+      entryView.positions = {
+        entryTop,
+        callout,
+      }
+    }
+    debugConsole.log('ENTRY', { entry: entryView.entry, top })
+  }
+}
+
+type PositionedEntriesProps = {
+  entries: Array<[keyof ReviewPanelDocEntries, ReviewPanelEntry]>
+  contentHeight: number
+  children: React.ReactNode
+}
+
+function PositionedEntries({
+  entries,
+  contentHeight,
+  children,
+}: PositionedEntriesProps) {
+  const { navHeight, toolbarHeight } = useReviewPanelValueContext()
+  const containerRef = useRef<HTMLDivElement | null>(null)
+  const { reviewPanelOpen } = useLayoutContext()
+  const [lineHeight] = useScopeValue<number>(
+    'reviewPanel.rendererData.lineHeight'
+  )
+  const animationTimerRef = useRef<number | null>(null)
+  const previousFocusedEntryIndexRef = useRef(0)
+
+  const layout = () => {
+    const container = containerRef.current
+    if (!container) {
+      return
+    }
+
+    const padding = reviewPanelOpen ? 8 : 4
+    const toolbarPaddedHeight = reviewPanelOpen ? toolbarHeight + 6 : 0
+    const navPaddedHeight = reviewPanelOpen ? navHeight + 4 : 0
+
+    // Create a list of entry views, typing together DOM elements and model.
+    // No measuring or style change is done at this point.
+    const entryViews: EntryView[] = []
+
+    // TODO: Look into tying the entry to the DOM element without going via a DOM data attribute
+    for (const wrapper of container.querySelectorAll<HTMLElement>(
+      '.rp-entry-wrapper'
+    )) {
+      const entryId = wrapper.dataset.entryId
+      if (!entryId) {
+        throw new Error('Could not find an entry ID')
+      }
+
+      const entry = entries.find(value => value[0] === entryId)?.[1]
+      if (!entry) {
+        throw new Error(`Could not find an entry for ID ${entryId}`)
+      }
+
+      const indicator = wrapper.querySelector<HTMLElement>(
+        '.rp-entry-indicator'
+      )
+      const box = wrapper.querySelector<HTMLElement>('.rp-entry')
+      const callout = wrapper.querySelector<HTMLElement>('.rp-entry-callout')
+      const layoutElement = reviewPanelOpen ? box : indicator
+
+      if (box && callout && layoutElement) {
+        const previousEntryTopData = box.dataset.previousEntryTop
+        const previousCalloutTopData = callout.dataset.previousEntryTop
+        entryViews.push({
+          wrapper,
+          indicator,
+          box,
+          callout,
+          layout: layoutElement,
+          visible: !!entry.screenPos,
+          height: 0,
+          previousEntryTop:
+            previousEntryTopData !== undefined
+              ? parseInt(previousEntryTopData)
+              : null,
+          previousCalloutTop:
+            previousCalloutTopData !== undefined
+              ? parseInt(previousCalloutTopData)
+              : null,
+          entry,
+        })
+      } else {
+        debugConsole.log(
+          'Entry wrapper is missing indicator, box or callout, so ignoring',
+          wrapper
+        )
+      }
+    }
+
+    if (entryViews.length === 0) {
+      return
+    }
+
+    entryViews.sort((a, b) => a.entry.offset - b.entry.offset)
+
+    // Do the DOM interaction in three phases:
+    //
+    // - Apply the `display` property to all elements whose visibility has
+    //   changed. This needs to happen first in order to measure heights.
+    // - Measure the height of each entry
+    // - Move each entry without animation to their original position
+    //   relative to the editor content
+    // - In the next animation frame, re-enable animation and position each
+    //   entry
+    //
+    // The idea is to batch DOM reads and writes to avoid layout thrashing. In
+    // this case, the best we can do is a write phase, a read phase then a
+    // final write phase.
+    // See https://web.dev/avoid-large-complex-layouts-and-layout-thrashing/
+
+    // First, update visibility for each entry that needs it
+    for (const entryView of entryViews) {
+      entryView.wrapper.classList.toggle('rp-entry-hidden', !entryView.visible)
+    }
+
+    // Next, measure the height of each entry
+    for (const entryView of entryViews) {
+      if (entryView.visible) {
+        entryView.height = entryView.layout.offsetHeight
+      }
+    }
+
+    // Calculate positions for all visible entries
+    let focusedEntryIndex = entryViews.findIndex(view => view.entry.focused)
+    if (focusedEntryIndex === -1) {
+      focusedEntryIndex = Math.min(
+        previousFocusedEntryIndexRef.current,
+        entryViews.length - 1
+      )
+    }
+    previousFocusedEntryIndexRef.current = focusedEntryIndex
+
+    const focusedEntryView = entryViews[focusedEntryIndex]
+    if (!focusedEntryView.entry.screenPos) {
+      return
+    }
+
+    // If the focused entry has no screenPos, we can't position other
+    // entryViews relative to it, so we position all other entryViews as
+    // though the focused entry is at the top and the rest follow it
+    const entryViewsAfter = focusedEntryView.visible
+      ? entryViews.slice(focusedEntryIndex + 1)
+      : [...entryViews]
+    const entryViewsBefore = focusedEntryView.visible
+      ? entryViews.slice(0, focusedEntryIndex).reverse() // Work through backwards, starting with the one just above
+      : []
+
+    debugConsole.log('focusedEntryIndex', focusedEntryIndex)
+
+    let lastEntryBottom = 0
+    let firstEntryTop = 0
+
+    // Put the focused entry as close to where it wants to be as possible
+    if (focusedEntryView.visible) {
+      const focusedEntryScreenPos = focusedEntryView.entry.screenPos
+      const entryTop = Math.max(focusedEntryScreenPos.y, toolbarPaddedHeight)
+      const callout = calculateCalloutPosition(
+        focusedEntryScreenPos,
+        entryTop,
+        lineHeight
+      )
+      focusedEntryView.positions = {
+        entryTop,
+        callout,
+      }
+      lastEntryBottom = entryTop + focusedEntryView.height
+      firstEntryTop = entryTop
+    }
+
+    // Calculate positions for entries that are below the focused entry
+    calculateEntryViewPositions(
+      entryViewsAfter,
+      lineHeight,
+      (originalTop: number, height: number) => {
+        const top = Math.max(originalTop, lastEntryBottom + padding)
+        lastEntryBottom = top + height
+        return top
+      }
+    )
+
+    // Calculate positions for entries that are above the focused entry
+    calculateEntryViewPositions(
+      entryViewsBefore,
+      lineHeight,
+      (originalTop: number, height: number) => {
+        const originalBottom = originalTop + height
+        const bottom = Math.min(originalBottom, firstEntryTop - padding)
+        const top = bottom - height
+        firstEntryTop = top
+        return top
+      }
+    )
+
+    // Calculate the new top overflow
+    const overflowTop = Math.max(0, toolbarPaddedHeight - firstEntryTop)
+
+    // Position everything where it was before, taking into account the new top
+    // overflow
+    const moveEntriesToInitialPosition = () => {
+      // Prevent CSS animation of position for this phase
+      container.classList.add('no-animate')
+      for (const entryView of entryViews) {
+        const { callout: calloutEl, positions } = entryView
+        if (positions) {
+          const { entryTop, callout } = positions
+
+          // Position the main wrapper in its original position, if it had
+          // one, or its new position otherwise
+          const entryTopInitial =
+            entryView.previousEntryTop === null
+              ? entryTop
+              : entryView.previousEntryTop
+
+          css(entryView.box, {
+            top: entryTopInitial + overflowTop + 'px',
+            // The entry element is invisible by default, to avoid flickering
+            // when positioning for the first time. Here we make sure it becomes
+            // visible after having a "top" value.
+            visibility: 'visible',
+          })
+
+          if (entryView.indicator) {
+            entryView.indicator.style.top = entryTopInitial + overflowTop + 'px'
+          }
+
+          entryView.box.dataset.previousEntryTop = entryTopInitial + ''
+
+          // Position the callout element in its original position, if it had
+          // one, or its new position otherwise
+          calloutEl.classList.toggle(
+            'rp-entry-callout-inverted',
+            callout.inverted
+          )
+          const calloutTopInitial =
+            entryView.previousCalloutTop === null
+              ? callout.top
+              : entryView.previousCalloutTop
+
+          css(calloutEl, {
+            top: calloutTopInitial + overflowTop + 'px',
+            height: callout.height + 'px',
+          })
+
+          entryView.box.dataset.previousCalloutTop = calloutTopInitial + ''
+        }
+      }
+    }
+
+    const moveToFinalPositions = () => {
+      // Re-enable CSS animation of position for this phase
+      container.classList.remove('no-animate')
+
+      for (const entryView of entryViews) {
+        const { callout: calloutEl, positions } = entryView
+        if (positions) {
+          const { entryTop, callout } = positions
+
+          // Position the main wrapper, if it's moved
+          if (entryView.previousEntryTop !== entryTop) {
+            entryView.box.style.top = entryTop + overflowTop + 'px'
+          }
+          entryView.box.dataset.previousEntryTop = entryTop + ''
+
+          if (entryView.indicator) {
+            entryView.indicator.style.top = entryTop + overflowTop + 'px'
+          }
+
+          // Position the callout element
+          if (entryView.previousCalloutTop !== callout.top) {
+            calloutEl.style.top = callout.top + overflowTop + 'px'
+            entryView.callout.dataset.previousCalloutTop = callout.top + ''
+          }
+        }
+      }
+
+      animationTimerRef.current = null
+    }
+
+    moveEntriesToInitialPosition()
+
+    // Inform the editor of the new top overflow
+    window.dispatchEvent(
+      new CustomEvent('review-panel:event', {
+        detail: {
+          type: 'sizes',
+          payload: {
+            overflowTop,
+            height: lastEntryBottom + navPaddedHeight,
+          },
+        },
+      })
+    )
+
+    // Schedule the final, animated move
+    animationTimerRef.current = window.setTimeout(moveToFinalPositions, 60)
+  }
+
+  useEventListener('review-panel:layout', () => {
+    if (animationTimerRef.current) {
+      window.clearTimeout(animationTimerRef.current)
+      animationTimerRef.current = null
+    }
+    layout()
+  })
+
+  // Cancel scheduled move on unmount
+  useEffect(() => {
+    return () => {
+      if (animationTimerRef.current) {
+        window.clearTimeout(animationTimerRef.current)
+        animationTimerRef.current = null
+      }
+    }
+  }, [])
+
+  // Layout on first render. This is necessary to ensure layout happens when
+  // switching from overview to current file view
+  useEffect(() => {
+    dispatchReviewPanelLayout()
+  }, [])
+
+  return (
+    <div
+      ref={containerRef}
+      className="rp-entry-list-react"
+      style={{ height: `${contentHeight}px` }}
+    >
+      {children}
+    </div>
+  )
+}
+
+export default PositionedEntries

services/web/frontend/js/features/source-editor/components/review-panel/toolbar/resolved-comments-dropdown.tsx

@@ -11,12 +11,13 @@ import {
 } from '../../../../../../../types/review-panel/review-panel'
 import { ReviewPanelResolvedCommentThread } from '../../../../../../../types/review-panel/comment-thread'
 import { DocId } from '../../../../../../../types/project-settings'
+import { ReviewPanelEntry } from '../../../../../../../types/review-panel/entry'
 
 export interface FilteredResolvedComments
   extends ReviewPanelResolvedCommentThread {
   content: string
   threadId: ThreadId
-  entryId: string
+  entryId: ThreadId
   docId: DocId
   docName: string | null
 }
@@ -56,7 +57,9 @@ function ResolvedCommentsDropdown() {
     for (const [docId, docEntries] of Object.entries(resolvedComments) as Array<
       [DocId, ReviewPanelDocEntries]
     >) {
-      for (const [entryId, entry] of Object.entries(docEntries)) {
+      for (const [entryId, entry] of Object.entries(docEntries) as Array<
+        [ThreadId, ReviewPanelEntry]
+      >) {
         if (entry.type === 'comment') {
           const threadId = entry.thread_id
           const thread =

services/web/frontend/js/features/source-editor/components/review-panel/toolbar/toolbar.tsx

@@ -1,9 +1,26 @@
 import ResolvedCommentsDropdown from './resolved-comments-dropdown'
 import ToggleMenu from './toggle-menu'
+import { useReviewPanelUpdaterFnsContext } from '../../../context/review-panel/review-panel-context'
+import { useCallback } from 'react'
+import { useResizeObserver } from '../../../../../shared/hooks/use-resize-observer'
 
 function Toolbar() {
+  const { setToolbarHeight } = useReviewPanelUpdaterFnsContext()
+  const handleResize = useCallback(
+    el => {
+      // Use requestAnimationFrame to prevent errors like "ResizeObserver loop
+      // completed with undelivered notifications" that occur if onResize does
+      // something complicated. The cost of this is that onResize lags one frame
+      // behind, but it's unlikely to matter.
+      const height = el.offsetHeight
+      window.requestAnimationFrame(() => setToolbarHeight(height))
+    },
+    [setToolbarHeight]
+  )
+  const resizeRef = useResizeObserver(handleResize)
+
   return (
-    <div className="review-panel-toolbar">
+    <div ref={resizeRef} className="review-panel-toolbar">
       <ResolvedCommentsDropdown />
       <ToggleMenu />
     </div>

services/web/frontend/js/features/source-editor/context/review-panel/hooks/use-angular-review-panel-state.ts

@@ -1,15 +1,13 @@
 import { useState, useMemo, useCallback } from 'react'
 import useScopeValue from '../../../../../shared/hooks/use-scope-value'
-import useScopeEventEmitter from '../../../../../shared/hooks/use-scope-event-emitter'
 import { sendMB } from '../../../../../infrastructure/event-tracking'
 import { ReviewPanelState } from '../types/review-panel-state'
 import * as ReviewPanel from '../types/review-panel-state'
 import { SubView } from '../../../../../../../types/review-panel/review-panel'
 import { ReviewPanelCommentEntry } from '../../../../../../../types/review-panel/entry'
+import { dispatchReviewPanelLayout as handleLayoutChange } from '../../../extensions/changes/change-manager'
 
 function useAngularReviewPanelState(): ReviewPanelState {
-  const emitLayoutChange = useScopeEventEmitter('review-panel:layout', false)
-
   const [subView, setSubView] = useScopeValue<ReviewPanel.Value<'subView'>>(
     'reviewPanel.subView'
   )
@@ -113,12 +111,6 @@ function useAngularReviewPanelState(): ReviewPanelState {
     [setSubView]
   )
 
-  const handleLayoutChange = useCallback(() => {
-    window.requestAnimationFrame(() => {
-      emitLayoutChange()
-    })
-  }, [emitLayoutChange])
-
   const submitReply = useCallback(
     (entry: ReviewPanelCommentEntry, replyContent: string) => {
       submitReplyAngular({ ...entry, replyContent })
@@ -128,6 +120,8 @@ function useAngularReviewPanelState(): ReviewPanelState {
 
   const [entryHover, setEntryHover] = useState(false)
   const [isAddingComment, setIsAddingComment] = useState(false)
+  const [navHeight, setNavHeight] = useState(0)
+  const [toolbarHeight, setToolbarHeight] = useState(0)
 
   const values = useMemo<ReviewPanelState['values']>(
     () => ({
@@ -139,7 +133,6 @@ function useAngularReviewPanelState(): ReviewPanelState {
       entryHover,
       isAddingComment,
       gotoEntry,
-      handleLayoutChange,
       loadingThreads,
       nVisibleSelectedChanges,
       permissions,
@@ -148,6 +141,8 @@ function useAngularReviewPanelState(): ReviewPanelState {
       resolvedComments,
       saveEdit,
       shouldCollapse,
+      navHeight,
+      toolbarHeight,
       submitReply,
       subView,
       wantTrackChanges,
@@ -180,7 +175,6 @@ function useAngularReviewPanelState(): ReviewPanelState {
       entryHover,
       isAddingComment,
       gotoEntry,
-      handleLayoutChange,
       loadingThreads,
       nVisibleSelectedChanges,
       permissions,
@@ -189,6 +183,8 @@ function useAngularReviewPanelState(): ReviewPanelState {
       resolvedComments,
       saveEdit,
       shouldCollapse,
+      navHeight,
+      toolbarHeight,
       submitReply,
       subView,
       wantTrackChanges,
@@ -217,10 +213,13 @@ function useAngularReviewPanelState(): ReviewPanelState {
   const updaterFns = useMemo<ReviewPanelState['updaterFns']>(
     () => ({
       handleSetSubview,
+      handleLayoutChange,
       setEntryHover,
       setCollapsed,
       setShouldCollapse,
       setIsAddingComment,
+      setNavHeight,
+      setToolbarHeight,
     }),
     [
       handleSetSubview,
@@ -228,6 +227,8 @@ function useAngularReviewPanelState(): ReviewPanelState {
       setEntryHover,
       setShouldCollapse,
       setIsAddingComment,
+      setNavHeight,
+      setToolbarHeight,
     ]
   )
 

services/web/frontend/js/features/source-editor/context/review-panel/types/review-panel-state.ts

@@ -24,7 +24,6 @@ export interface ReviewPanelState {
     entryHover: boolean
     isAddingComment: boolean
     gotoEntry: (docId: DocId, entryOffset: number) => void
-    handleLayoutChange: () => void
     loadingThreads: boolean
     nVisibleSelectedChanges: number
     permissions: ReviewPanelPermissions
@@ -37,6 +36,8 @@ export interface ReviewPanelState {
       content: string
     ) => void
     shouldCollapse: boolean
+    navHeight: number
+    toolbarHeight: number
     submitReply: (entry: ReviewPanelCommentEntry, replyContent: string) => void
     subView: SubView
     wantTrackChanges: boolean
@@ -68,6 +69,7 @@ export interface ReviewPanelState {
   }
   updaterFns: {
     handleSetSubview: (subView: SubView) => void
+    handleLayoutChange: () => void
     setEntryHover: React.Dispatch<React.SetStateAction<Value<'entryHover'>>>
     setIsAddingComment: React.Dispatch<
       React.SetStateAction<Value<'isAddingComment'>>
@@ -76,6 +78,10 @@ export interface ReviewPanelState {
     setShouldCollapse: React.Dispatch<
       React.SetStateAction<Value<'shouldCollapse'>>
     >
+    setNavHeight: React.Dispatch<React.SetStateAction<Value<'navHeight'>>>
+    setToolbarHeight: React.Dispatch<
+      React.SetStateAction<Value<'toolbarHeight'>>
+    >
   }
 }
 /* eslint-enable no-use-before-define */

services/web/frontend/js/features/source-editor/extensions/changes/change-manager.ts

@@ -25,6 +25,15 @@ export const dispatchEditorEvent = (type: string, payload?: unknown) => {
   }, 0)
 }
 
+export const dispatchReviewPanelLayout = () => {
+  window.dispatchEvent(new CustomEvent('review-panel:layout'))
+}
+
+const scheduleDispatchReviewPanelLayout = debounce(
+  dispatchReviewPanelLayout,
+  50
+)
+
 export type ChangeManager = {
   initialize: () => void
   handleUpdate: (update: ViewUpdate) => void
@@ -66,6 +75,10 @@ export const createChangeManager = (
         const y = Math.round(coords.top - contentRect.top - editorPaddingTop)
         const height = Math.round(coords.bottom - coords.top)
 
+        if (!entry.screenPos) {
+          visibilityChanged = true
+        }
+
         entry.screenPos = { y, height, editorPaddingTop }
       }
 
@@ -284,6 +297,12 @@ export const createChangeManager = (
         if (changed) {
           dispatchEditorEvent('track-changes:visibility_changed')
         }
+        dispatchReviewPanelLayout()
+        // Ensure the layout is updated again once the review panel entries
+        // have updated in the React review panel. The use of a timeout is bad
+        // but the timings are a bit of a mess and will be improved when the
+        // review panel state is migrated away from Angular
+        scheduleDispatchReviewPanelLayout()
         break
       }
 
@@ -348,7 +367,6 @@ export const createChangeManager = (
             })
           )
         }
-
         break
       }
     }

services/web/frontend/js/ide/review-panel/controllers/ReviewPanelController.js

@@ -128,17 +128,17 @@ export default App.controller(
     })
 
     $scope.$on('layout:pdf:linked', (event, state) =>
-      $scope.$broadcast('review-panel:layout')
+      ide.$scope.$broadcast('review-panel:layout')
     )
 
     $scope.$on('layout:pdf:resize', (event, state) => {
       ide.$scope.reviewPanel.layoutToLeft =
         state.east?.size < 220 || state.east?.initClosed
-      $scope.$broadcast('review-panel:layout', false)
+      ide.$scope.$broadcast('review-panel:layout', false)
     })
 
     $scope.$on('expandable-text-area:resize', event =>
-      $timeout(() => $scope.$broadcast('review-panel:layout'))
+      $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
     )
 
     $scope.$on('review-panel:sizes', (e, sizes) => {
@@ -206,7 +206,7 @@ export default App.controller(
       delete thread.submitting
       thread.messages.push(formatComment(comment))
       $scope.$apply()
-      return $timeout(() => $scope.$broadcast('review-panel:layout'))
+      return $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
     })
 
     ide.socket.on('accept-changes', function (doc_id, change_ids) {
@@ -321,7 +321,7 @@ export default App.controller(
       }
       return $timeout(function () {
         $scope.$broadcast('review-panel:toggle')
-        return $scope.$broadcast('review-panel:layout', false)
+        return ide.$scope.$broadcast('review-panel:layout', false)
       })
     })
 
@@ -559,12 +559,12 @@ export default App.controller(
         $scope.$broadcast('review-panel:recalculate-screen-positions')
         dispatchReviewPanelEvent('recalculate-screen-positions', entries)
 
-        return $scope.$broadcast('review-panel:layout')
+        return ide.$scope.$broadcast('review-panel:layout')
       }
     })
 
     $scope.$on('editor:track-changes:visibility_changed', () =>
-      $timeout(() => $scope.$broadcast('review-panel:layout', false))
+      $timeout(() => ide.$scope.$broadcast('review-panel:layout', false))
     )
 
     $scope.$on(
@@ -576,20 +576,41 @@ export default App.controller(
         ide.$scope.reviewPanel.selectedEntryIds = []
         // Count of user-visible changes, i.e. an aggregated change will count as one.
         ide.$scope.reviewPanel.nVisibleSelectedChanges = 0
-        delete entries['add-comment']
-        delete entries['bulk-actions']
 
+        const offset = selection_offset_start
+        const length = selection_offset_end - selection_offset_start
+
+        // Recreate the add comment and bulk actions entries only when
+        // necessary. This is to avoid the UI thinking that these entries have
+        // changed and getting into an infinite loop.
         if (selection) {
-          entries['add-comment'] = {
-            type: 'add-comment',
-            offset: selection_offset_start,
-            length: selection_offset_end - selection_offset_start,
+          const existingAddComment = entries['add-comment']
+          if (
+            !existingAddComment ||
+            existingAddComment.offset !== offset ||
+            existingAddComment.length !== length
+          ) {
+            entries['add-comment'] = {
+              type: 'add-comment',
+              offset,
+              length,
+            }
           }
-          entries['bulk-actions'] = {
-            type: 'bulk-actions',
-            offset: selection_offset_start,
-            length: selection_offset_end - selection_offset_start,
+          const existingBulkActions = entries['bulk-actions']
+          if (
+            !existingBulkActions ||
+            existingBulkActions.offset !== offset ||
+            existingBulkActions.length !== length
+          ) {
+            entries['bulk-actions'] = {
+              type: 'bulk-actions',
+              offset,
+              length,
+            }
           }
+        } else {
+          delete entries['add-comment']
+          delete entries['bulk-actions']
         }
 
         for (const id in entries) {
@@ -640,7 +661,11 @@ export default App.controller(
 
         dispatchReviewPanelEvent('recalculate-screen-positions', entries)
 
-        return $scope.$broadcast('review-panel:layout')
+        // Ensure that watchers, such as the React-based review panel component,
+        // are informed of the changes to entries
+        ide.$scope.$apply()
+
+        return ide.$scope.$broadcast('review-panel:layout')
       }
     )
 
@@ -757,7 +782,7 @@ export default App.controller(
         $scope.toggleReviewPanel()
       }
       return $timeout(function () {
-        $scope.$broadcast('review-panel:layout')
+        ide.$scope.$broadcast('review-panel:layout')
         return $scope.$broadcast('comment:start_adding')
       })
     }
@@ -765,7 +790,7 @@ export default App.controller(
     $scope.startNewComment = function () {
       $scope.$broadcast('comment:select_line')
       dispatchReviewPanelEvent('comment:select_line')
-      return $timeout(() => $scope.$broadcast('review-panel:layout'))
+      return $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
     }
 
     ide.$scope.submitNewComment = function (content) {
@@ -800,16 +825,16 @@ export default App.controller(
         )
       // TODO: unused?
       $scope.$broadcast('editor:clearSelection')
-      $timeout(() => $scope.$broadcast('review-panel:layout'))
+      $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
       eventTracking.sendMB('rp-new-comment', { size: content.length })
     }
 
     $scope.cancelNewComment = entry =>
-      $timeout(() => $scope.$broadcast('review-panel:layout'))
+      $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
 
     $scope.startReply = function (entry) {
       entry.replying = true
-      return $timeout(() => $scope.$broadcast('review-panel:layout'))
+      return $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
     }
 
     ide.$scope.submitReply = function (entry, entry_id) {
@@ -839,14 +864,14 @@ export default App.controller(
       thread.submitting = true
       entry.replyContent = ''
       entry.replying = false
-      $timeout(() => $scope.$broadcast('review-panel:layout'))
+      $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
       eventTracking.sendMB('rp-comment-reply', trackingMetadata)
     }
 
     $scope.cancelReply = function (entry) {
       entry.replying = false
       entry.replyContent = ''
-      return $scope.$broadcast('review-panel:layout')
+      return ide.$scope.$broadcast('review-panel:layout')
     }
 
     ide.$scope.resolveComment = function (doc_id, entry_id) {
@@ -947,7 +972,7 @@ export default App.controller(
           _csrf: window.csrfToken,
         }
       )
-      return $timeout(() => $scope.$broadcast('review-panel:layout'))
+      return $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
     }
 
     ide.$scope.deleteComment = function (thread_id, comment_id) {
@@ -959,7 +984,7 @@ export default App.controller(
           'X-CSRF-Token': window.csrfToken,
         },
       })
-      return $timeout(() => $scope.$broadcast('review-panel:layout'))
+      return $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
     }
 
     $scope.setSubView = function (subView) {
@@ -1244,7 +1269,7 @@ export default App.controller(
           }
           ide.$scope.reviewPanel.commentThreads = threads
           dispatchReviewPanelEvent('loaded_threads')
-          return $timeout(() => $scope.$broadcast('review-panel:layout'))
+          return $timeout(() => ide.$scope.$broadcast('review-panel:layout'))
         })
     }
 
@@ -1310,7 +1335,7 @@ export default App.controller(
       switch (type) {
         case 'line-height': {
           ide.$scope.reviewPanel.rendererData.lineHeight = payload
-          $scope.$broadcast('review-panel:layout')
+          ide.$scope.$broadcast('review-panel:layout')
           break
         }
 

services/web/frontend/js/shared/components/auto-expanding-text-area.tsx

@@ -50,7 +50,11 @@ function AutoExpandingTextArea({
       if (isFirstResize) {
         isFirstResize = false
       } else {
-        onResize()
+        // Prevent errors like "ResizeObserver loop completed with undelivered
+        // notifications" that occur if onResize does something complicated.
+        // The cost of this is that onResize lags one frame behind, but it's
+        // unlikely to matter.
+        window.requestAnimationFrame(onResize)
       }
     })
 

services/web/frontend/js/utils/debugging.ts

@@ -0,0 +1,7 @@
+type DebugConsole = { log(...data: any[]): void }
+
+export const debugging =
+  new URLSearchParams(window.location.search).get('debug') === 'true'
+export const debugConsole: DebugConsole = debugging
+  ? console
+  : { log: () => {} }

services/web/frontend/stylesheets/app/editor/review-panel.less

@@ -27,6 +27,8 @@
 @rp-toolbar-height: 32px;
 
 @rp-entry-animation-speed: 0.3s;
+// Move a little faster in React to compensate for the delay before moving the vertical position
+@rp-entry-animation-speed-react: 0.2s;
 
 .rp-button() {
   display: block; // IE doesn't do flex with inline items.
@@ -65,6 +67,8 @@
 }
 
 #review-panel {
+  --rp-animation-speed: @rp-entry-animation-speed;
+
   display: block;
 
   .rp-size-expanded & {
@@ -248,10 +252,10 @@
   border-radius: 3px;
   color: #fff;
   cursor: pointer;
-  transition: top @rp-entry-animation-speed, left 0.1s, right 0.1s;
+  transition: top var(--rp-animation-speed), left 0.1s, right 0.1s;
 
   .no-animate & {
-    transition: none;
+    transition: left 0.1s, right 0.1s;
   }
 
   &-focused {
@@ -372,10 +376,10 @@
   border-left: solid @rp-entry-ribbon-width transparent;
   border-radius: 3px;
   background-color: #fff;
-  transition: top @rp-entry-animation-speed, left 0.1s, right 0.1s;
+  transition: top var(--rp-animation-speed), left 0.1s, right 0.1s;
 
   .no-animate & {
-    transition: none;
+    transition: left 0.1s, right 0.1s;
   }
 
   &-insert,
@@ -640,7 +644,7 @@
 }
 
 .rp-entry-callout {
-  transition: top @rp-entry-animation-speed, height @rp-entry-animation-speed;
+  transition: top var(--rp-animation-speed), height var(--rp-animation-speed);
 
   .rp-state-current-file & {
     position: absolute;
@@ -1193,6 +1197,8 @@ button when (@is-overleaf-light = true) {
 
 // CM6-specific review panel rules
 .ol-cm-review-panel {
+  --rp-animation-speed: @rp-entry-animation-speed-react;
+
   position: relative;
   z-index: 6;
   display: block;
@@ -1254,6 +1260,17 @@ button when (@is-overleaf-light = true) {
     bottom: 0;
   }
 
+  .rp-entry-list-react {
+    position: relative;
+
+    .rp-entry-list-react-inner {
+      position: absolute;
+      top: 0;
+      left: 0;
+      right: 0;
+    }
+  }
+
   .rp-state-current-file & {
     .review-panel-tools {
       display: flex;

services/web/types/review-panel/entry.ts

@@ -1,6 +1,6 @@
 import { ThreadId, UserId } from './review-panel'
 
-interface ReviewPanelEntryScreenPos {
+export interface ReviewPanelEntryScreenPos {
   y: number
   height: number
   editorPaddingTop: number

services/web/types/review-panel/review-panel.ts

@@ -1,6 +1,10 @@
 import { Brand } from '../helpers/brand'
 import { DocId } from '../project-settings'
-import { ReviewPanelEntry } from './entry'
+import {
+  ReviewPanelAddCommentEntry,
+  ReviewPanelBulkActionsEntry,
+  ReviewPanelEntry,
+} from './entry'
 import { ReviewPanelCommentThread } from './comment-thread'
 
 export type SubView = 'cur_file' | 'overview'
@@ -13,7 +17,15 @@ export interface ReviewPanelPermissions {
 }
 
 export type ThreadId = Brand<string, 'ThreadId'>
-export type ReviewPanelDocEntries = Record<ThreadId, ReviewPanelEntry>
+// Entries may contain `add-comment` and `bulk-actions` props along with DocIds
+// Ideally the `add-comment` and `bulk-actions` objects should not be within the entries object
+// as the doc data, but this is what currently angular returns.
+export type ReviewPanelDocEntries = Record<
+  | ThreadId
+  | ReviewPanelAddCommentEntry['type']
+  | ReviewPanelBulkActionsEntry['type'],
+  ReviewPanelEntry
+>
 
 export type ReviewPanelEntries = Record<DocId, ReviewPanelDocEntries>
 
@@ -27,6 +39,7 @@ export interface ReviewPanelUser {
   isSelf: boolean
   name: string
 }
+
 export type ReviewPanelUsers = Record<UserId, ReviewPanelUser>
 
 export type CommentId = Brand<string, 'CommentId'>