From 2e3f56c0d472b10825e20217c9cb63e1fab9ea45 Mon Sep 17 00:00:00 2001
From: Alf Eaton <alf.eaton@overleaf.com>
Date: Mon, 29 Nov 2021 11:59:34 +0000
Subject: [PATCH] Check for the presence of window.ResizeObserver (#5924)

GitOrigin-RevId: d072c9313967b52370a870fc2d30b50c498d8d1d
---
 .../js/features/pdf-preview/components/pdf-js-viewer.js  | 2 +-
 .../js/features/pdf-preview/hooks/use-resize-observer.js | 2 +-
 .../features/pdf-preview/hooks/use-toolbar-breakpoint.js | 9 +++++----
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/services/web/frontend/js/features/pdf-preview/components/pdf-js-viewer.js b/services/web/frontend/js/features/pdf-preview/components/pdf-js-viewer.js
index e8e153f1af..d3c1aae8ac 100644
--- a/services/web/frontend/js/features/pdf-preview/components/pdf-js-viewer.js
+++ b/services/web/frontend/js/features/pdf-preview/components/pdf-js-viewer.js
@@ -220,7 +220,7 @@ function PdfJsViewer({ url }) {
 
   // adjust the scale when the container is resized
   useEffect(() => {
-    if (pdfJsWrapper) {
+    if (pdfJsWrapper && 'ResizeObserver' in window) {
       const resizeListener = () => {
         pdfJsWrapper.updateOnResize()
       }
diff --git a/services/web/frontend/js/features/pdf-preview/hooks/use-resize-observer.js b/services/web/frontend/js/features/pdf-preview/hooks/use-resize-observer.js
index b14a4af141..56003230ab 100644
--- a/services/web/frontend/js/features/pdf-preview/hooks/use-resize-observer.js
+++ b/services/web/frontend/js/features/pdf-preview/hooks/use-resize-observer.js
@@ -5,7 +5,7 @@ export const useResizeObserver = handleResize => {
 
   const elementRef = useCallback(
     element => {
-      if (element) {
+      if (element && 'ResizeObserver' in window) {
         if (resizeRef.current) {
           resizeRef.current.observer.unobserve(resizeRef.current.element)
         }
diff --git a/services/web/frontend/js/features/pdf-preview/hooks/use-toolbar-breakpoint.js b/services/web/frontend/js/features/pdf-preview/hooks/use-toolbar-breakpoint.js
index 252d929d0e..8fa1704f70 100644
--- a/services/web/frontend/js/features/pdf-preview/hooks/use-toolbar-breakpoint.js
+++ b/services/web/frontend/js/features/pdf-preview/hooks/use-toolbar-breakpoint.js
@@ -11,13 +11,14 @@ export default function useToolbarBreakpoint(element) {
   const [breakpoint, setBreakpoint] = useState(2)
   const [recalculate, setRecalculate] = useState(true)
 
-  const [resizeObserver] = useState(
-    () =>
-      new ResizeObserver(() => {
+  const [resizeObserver] = useState(() => {
+    if ('ResizeObserver' in window) {
+      return new ResizeObserver(() => {
         setBreakpoint(2)
         setRecalculate(true)
       })
-  )
+    }
+  })
 
   const [mutationObserver] = useState(
     () =>