From 593396279dbe2e6f3135effc29b9201a6410598e Mon Sep 17 00:00:00 2001
From: Katerina Koukiou <kkoukiou@redhat.com>
Date: Wed, 16 Nov 2022 18:22:56 +0100
Subject: [PATCH] fix(VncConsole): prevent running initialization code more
 than once (#8373)

The functions that were on the dependency list of the useEffect hook
got redefined each time the component got updated, resulting
in the component's initialization code, from within the useEffect hook,
to be running more than once.
That was unwanted behavior and the useCallback wrappers should prevent
it.
---
 .../src/components/VncConsole/VncConsole.tsx  | 76 ++++++++++---------
 1 file changed, 42 insertions(+), 34 deletions(-)

diff --git a/packages/react-console/src/components/VncConsole/VncConsole.tsx b/packages/react-console/src/components/VncConsole/VncConsole.tsx
index c8ac73999e2..d65a5fa9f11 100644
--- a/packages/react-console/src/components/VncConsole/VncConsole.tsx
+++ b/packages/react-console/src/components/VncConsole/VncConsole.tsx
@@ -92,28 +92,47 @@ export const VncConsole: React.FunctionComponent<VncConsoleProps> = ({
   textCtrlAltDel
 }) => {
   const rfb = React.useRef<any>();
-  let novncStaticComponent: React.ReactNode;
-  let novncElem: HTMLDivElement;
 
+  const novncElem = React.useRef<HTMLDivElement>(null);
   const [status, setStatus] = React.useState(CONNECTING);
 
-  const addEventListeners = () => {
+  const onConnected = () => {
+    setStatus(CONNECTED);
+  };
+
+  const _onDisconnected = React.useCallback((e: any) => {
+    setStatus(DISCONNECTED);
+    onDisconnected(e);
+  }, []);
+
+  const _onSecurityFailure = React.useCallback((e: any) => {
+    setStatus(DISCONNECTED);
+    onSecurityFailure(e);
+  }, []);
+
+  const onCtrlAltDel = () => {
+    if (rfb.current) {
+      rfb?.current?.sendCtrlAltDel();
+    }
+  };
+
+  const addEventListeners = React.useCallback(() => {
     if (rfb.current) {
       rfb.current?.addEventListener('connect', onConnected);
       rfb.current?.addEventListener('disconnect', _onDisconnected);
       rfb.current?.addEventListener('securityfailure', _onSecurityFailure);
     }
-  };
+  }, [rfb, _onDisconnected, _onSecurityFailure]);
 
-  const removeEventListeners = () => {
+  const removeEventListeners = React.useCallback(() => {
     if (rfb.current) {
       rfb.current.removeEventListener('connect', onConnected);
       rfb.current.removeEventListener('disconnect', _onDisconnected);
       rfb.current.removeEventListener('securityfailure', _onSecurityFailure);
     }
-  };
+  }, [rfb, _onDisconnected, _onSecurityFailure]);
 
-  const connect = () => {
+  const connect = React.useCallback(() => {
     const protocol = encrypt ? 'wss' : 'ws';
     const url = `${protocol}://${host}:${port}/${path}`;
 
@@ -122,12 +141,25 @@ export const VncConsole: React.FunctionComponent<VncConsoleProps> = ({
       shared,
       credentials
     };
-    rfb.current = new RFB(novncElem, url, options);
+    rfb.current = new RFB(novncElem.current, url, options);
     addEventListeners();
     rfb.current.viewOnly = viewOnly;
     rfb.current.scaleViewport = scaleViewport;
     rfb.current.resizeSession = resizeSession;
-  };
+  }, [
+    addEventListeners,
+    host,
+    path,
+    port,
+    resizeSession,
+    scaleViewport,
+    viewOnly,
+    encrypt,
+    rfb,
+    repeaterID,
+    shared,
+    credentials
+  ]);
 
   React.useEffect(() => {
     initLogging(vncLogging);
@@ -152,26 +184,6 @@ export const VncConsole: React.FunctionComponent<VncConsoleProps> = ({
     rfb.current.disconnect();
   };
 
-  const onConnected = () => {
-    setStatus(CONNECTED);
-  };
-
-  const _onDisconnected = (e: any) => {
-    setStatus(DISCONNECTED);
-    onDisconnected(e);
-  };
-
-  const _onSecurityFailure = (e: any) => {
-    setStatus(DISCONNECTED);
-    onSecurityFailure(e);
-  };
-
-  const onCtrlAltDel = () => {
-    if (rfb.current) {
-      rfb?.current?.sendCtrlAltDel();
-    }
-  };
-
   let rightContent;
   let emptyState;
   switch (status) {
@@ -207,10 +219,6 @@ export const VncConsole: React.FunctionComponent<VncConsoleProps> = ({
       );
   }
 
-  if (!novncStaticComponent) {
-    novncStaticComponent = <div id={consoleContainerId} ref={e => (novncElem = e)} />;
-  }
-
   return (
     <>
       {rightContent}
@@ -219,7 +227,7 @@ export const VncConsole: React.FunctionComponent<VncConsoleProps> = ({
         <React.Fragment>
           <div>
             {emptyState}
-            {novncStaticComponent}
+            <div id={consoleContainerId} ref={novncElem} />;
           </div>
         </React.Fragment>
       </div>