feat: add chat scroll debug and use alternative ways of forcing scroll in DOM!

src/optionsGuiScheme.tsx

@@ -605,6 +605,10 @@ export const guiOptionsScheme: {
       debugResponseTimeIndicator: {
         text: 'Debug Input Lag',
       },
+    },
+    {
+      debugChatScroll: {
+      },
     }
   ],
   'export-import': [

src/optionsStorage.ts

@@ -72,6 +72,7 @@ const defaultOptions = {
   preventBackgroundTimeoutKick: false,
   preventSleep: false,
   debugContro: false,
+  debugChatScroll: false,
   chatVanillaRestrictions: true,
   debugResponseTimeIndicator: false,
   // antiAliasing: false,

src/react/Chat.tsx

@@ -41,6 +41,7 @@ type Props = {
   inputDisabled?: string
   placeholder?: string
   chatVanillaRestrictions?: boolean
+  debugChatScroll?: boolean
 }
 
 export const chatInputValueGlobal = proxy({
@@ -69,7 +70,8 @@ export default ({
   allowSelection,
   inputDisabled,
   placeholder,
-  chatVanillaRestrictions
+  chatVanillaRestrictions,
+  debugChatScroll
 }: Props) => {
   const sendHistoryRef = useRef(JSON.parse(window.sessionStorage.chatHistory || '[]'))
   const [isInputFocused, setIsInputFocused] = useState(false)
@@ -86,7 +88,16 @@ export default ({
   const chatHistoryPos = useRef(sendHistoryRef.current.length)
   const inputCurrentlyEnteredValue = useRef('')
 
-  const { scrollToBottom } = useScrollBehavior(chatMessages, { messages, opened })
+  const { scrollToBottom, isAtBottom, wasAtBottom, currentlyAtBottom } = useScrollBehavior(chatMessages, { messages, opened })
+  const [rightNowAtBottom, setRightNowAtBottom] = useState(false)
+
+  useEffect(() => {
+    if (!debugChatScroll) return
+    const interval = setInterval(() => {
+      setRightNowAtBottom(isAtBottom())
+    }, 50)
+    return () => clearInterval(interval)
+  }, [debugChatScroll])
 
   const setSendHistory = (newHistory: string[]) => {
     sendHistoryRef.current = newHistory
@@ -252,6 +263,55 @@ export default ({
         }}
       >
         {opacity && <div ref={chatMessages} className={`chat ${opened ? 'opened' : ''}`} id="chat-messages" style={{ opacity }}>
+          {debugChatScroll && (
+            <div
+              style={{
+                position: 'absolute',
+                top: 5,
+                left: 5,
+                display: 'flex',
+                gap: 4,
+                zIndex: 100,
+              }}
+            >
+              <div
+                title="Right now is at bottom (updated every 50ms)"
+                style={{
+                  width: 12,
+                  height: 12,
+                  backgroundColor: rightNowAtBottom ? '#00ff00' : '#ff0000',
+                  border: '1px solid #fff',
+                }}
+              />
+              <div
+                title="Currently at bottom"
+                style={{
+                  width: 12,
+                  height: 12,
+                  backgroundColor: currentlyAtBottom ? '#00ff00' : '#ff0000',
+                  border: '1px solid #fff',
+                }}
+              />
+              <div
+                title="Was at bottom"
+                style={{
+                  width: 12,
+                  height: 12,
+                  backgroundColor: wasAtBottom() ? '#00ff00' : '#ff0000',
+                  border: '1px solid #fff',
+                }}
+              />
+              <div
+                title="Chat opened"
+                style={{
+                  width: 12,
+                  height: 12,
+                  backgroundColor: opened ? '#00ff00' : '#ff0000',
+                  border: '1px solid #fff',
+                }}
+              />
+            </div>
+          )}
           {messages.map((m) => (
             <MessageLine key={reactKeyForMessage(m)} message={m} />
           ))}

src/react/ChatProvider.tsx

@@ -17,7 +17,7 @@ export default () => {
   const isChatActive = useIsModalActive('chat')
   const lastMessageId = useRef(0)
   const usingTouch = useSnapshot(miscUiState).currentTouch
-  const { chatSelect, messagesLimit, chatOpacity, chatOpacityOpened, chatVanillaRestrictions } = useSnapshot(options)
+  const { chatSelect, messagesLimit, chatOpacity, chatOpacityOpened, chatVanillaRestrictions, debugChatScroll } = useSnapshot(options)
   const isUsingMicrosoftAuth = useMemo(() => !!lastConnectOptions.value?.authenticatedAccount, [])
   const { forwardChat } = useSnapshot(viewerVersionState)
   const { viewerConnection } = useSnapshot(gameAdditionalState)
@@ -48,6 +48,7 @@ export default () => {
 
   return <Chat
     chatVanillaRestrictions={chatVanillaRestrictions}
+    debugChatScroll={debugChatScroll}
     allowSelection={chatSelect}
     usingTouch={!!usingTouch}
     opacity={(isChatActive ? chatOpacityOpened : chatOpacity) / 100}

src/react/hooks/useScrollBehavior.ts

@@ -1,4 +1,4 @@
-import { RefObject, useEffect, useLayoutEffect, useRef } from 'react'
+import { RefObject, useEffect, useLayoutEffect, useRef, useState } from 'react'
 import { pixelartIcons } from '../PixelartIcon'
 
 export const useScrollBehavior = (
@@ -12,6 +12,8 @@ export const useScrollBehavior = (
   }
 ) => {
   const openedWasAtBottom = useRef(true) // before new messages
+  const [currentlyAtBottom, setCurrentlyAtBottom] = useState(true)
+  const scrollTimeoutRef = useRef<NodeJS.Timeout | null>(null)
 
   const isAtBottom = () => {
     if (!elementRef.current) return true
@@ -20,17 +22,30 @@ export const useScrollBehavior = (
     return distanceFromBottom < 1
   }
 
-  const scrollToBottom = () => {
-    if (elementRef.current) {
-      elementRef.current.scrollTop = elementRef.current.scrollHeight
-      setTimeout(() => {
-        if (!elementRef.current) return
-        elementRef.current.scrollTo({
-          top: elementRef.current.scrollHeight,
-          behavior: 'instant'
-        })
-      }, 0)
+  const scrollToBottom = (behavior: ScrollBehavior = 'instant') => {
+    if (!elementRef.current) return
+
+    // Clear any existing scroll timeout
+    if (scrollTimeoutRef.current) {
+      clearTimeout(scrollTimeoutRef.current)
     }
+
+    const el = elementRef.current
+
+    // Immediate scroll
+    el.scrollTop = el.scrollHeight
+
+    // Double-check after a short delay to ensure we're really at the bottom
+    scrollTimeoutRef.current = setTimeout(() => {
+      if (!elementRef.current) return
+      const el = elementRef.current
+      el.scrollTo({
+        top: el.scrollHeight,
+        behavior
+      })
+      setCurrentlyAtBottom(true)
+      openedWasAtBottom.current = true
+    }, 5)
   }
 
   // Handle scroll position tracking
@@ -39,18 +54,28 @@ export const useScrollBehavior = (
     if (!element) return
 
     const handleScroll = () => {
-      openedWasAtBottom.current = isAtBottom()
+      const atBottom = isAtBottom()
+      openedWasAtBottom.current = atBottom
+      setCurrentlyAtBottom(atBottom)
     }
 
     element.addEventListener('scroll', handleScroll)
-    return () => element.removeEventListener('scroll', handleScroll)
+    return () => {
+      element.removeEventListener('scroll', handleScroll)
+      if (scrollTimeoutRef.current) {
+        clearTimeout(scrollTimeoutRef.current)
+      }
+    }
   }, [])
 
   // Handle opened state changes
   useLayoutEffect(() => {
     if (opened) {
-      openedWasAtBottom.current = true
-    } else {
+      // Wait a frame before scrolling to ensure DOM has updated
+      requestAnimationFrame(() => {
+        scrollToBottom()
+      })
+    } else if (elementRef.current) {
       scrollToBottom()
     }
   }, [opened])
@@ -64,6 +89,8 @@ export const useScrollBehavior = (
 
   return {
     scrollToBottom,
-    isAtBottom
+    isAtBottom,
+    wasAtBottom: () => openedWasAtBottom.current,
+    currentlyAtBottom
   }
 }