Scroll fixes - Improve scroll to bottom handling for reasoning, bash and task tools (#288)

Fixes #286 and more

packages/ui/src/components/message-block.tsx

@@ -1,4 +1,4 @@
-import { For, Match, Show, Suspense, Switch, createEffect, createMemo, createSignal, lazy, onCleanup, untrack } from "solid-js"
+import { For, Index, Match, Show, Suspense, Switch, createEffect, createMemo, createSignal, lazy, onCleanup, untrack, type Accessor } from "solid-js"
 import { ChevronsDownUp, ChevronsUpDown, ExternalLink, FoldVertical, ListStart, Trash } from "lucide-solid"
 import MessageItem from "./message-item"
 import type { InstanceMessageStore } from "../stores/message-v2/instance-store"
@@ -16,6 +16,7 @@ import { useI18n } from "../lib/i18n"
 import type { DeleteHoverState } from "../types/delete-hover"
 import { useSpeech } from "../lib/hooks/use-speech"
 import SpeechActionButton from "./speech-action-button"
+import { createFollowScroll } from "../lib/follow-scroll"
 
 function DeleteUpToIcon() {
   return (
@@ -29,6 +30,7 @@ const TOOL_ICON = "🔧"
 const USER_BORDER_COLOR = "var(--message-user-border)"
 const ASSISTANT_BORDER_COLOR = "var(--message-assistant-border)"
 const TOOL_BORDER_COLOR = "var(--message-tool-border)"
+const REASONING_SCROLL_SENTINEL_MARGIN_PX = 48
 
 const LazyToolCall = lazy(() => import("./tool-call"))
 
@@ -803,19 +805,19 @@ export default function MessageBlock(props: MessageBlockProps) {
           data-message-id={resolvedBlock().record.id}
           data-delete-message-hover={isDeleteMessageHovered() ? "true" : undefined}
         >
-          <For each={resolvedBlock().items}>
+          <Index each={resolvedBlock().items}>
             {(item, index) => (
               <Switch>
-                <Match when={item.type === "content"}>
+                <Match when={item().type === "content"}>
                   <MessageContentItem
                     instanceId={props.instanceId}
                     sessionId={props.sessionId}
                     store={props.store}
-                    messageId={(item as ContentDisplayItem).messageId}
-                    startPartId={(item as ContentDisplayItem).startPartId}
+                    messageId={(item() as ContentDisplayItem).messageId}
+                    startPartId={(item() as ContentDisplayItem).startPartId}
                     messageIndex={props.messageIndex}
                     lastAssistantIndex={props.lastAssistantIndex}
-                    showDeleteMessage={index() === 0}
+                    showDeleteMessage={index === 0}
                     onDeleteHoverChange={props.onDeleteHoverChange}
                     onRevert={props.onRevert}
                     onDeleteMessagesUpTo={props.onDeleteMessagesUpTo}
@@ -825,18 +827,18 @@ export default function MessageBlock(props: MessageBlockProps) {
                     onContentRendered={props.onContentRendered}
                   />
                 </Match>
-                <Match when={item.type === "tool"}>
+                <Match when={item().type === "tool"}>
                   {(() => {
-                    const toolItem = item as ToolDisplayItem
+                    const toolItem = item() as ToolDisplayItem
                     return (
                       <div class="tool-call-message" data-key={toolItem.key}>
-                        <ToolCallItem
-                          instanceId={props.instanceId}
-                          sessionId={props.sessionId}
-                          store={props.store}
-                          messageId={toolItem.messageId}
-                          partId={toolItem.partId}
-                          showDeleteMessage={index() === 0}
+                          <ToolCallItem
+                            instanceId={props.instanceId}
+                            sessionId={props.sessionId}
+                            store={props.store}
+                            messageId={toolItem.messageId}
+                            partId={toolItem.partId}
+                            showDeleteMessage={index === 0}
                           deleteHover={props.deleteHover}
                           onDeleteHoverChange={props.onDeleteHoverChange}
                           onDeleteMessagesUpTo={props.onDeleteMessagesUpTo}
@@ -849,13 +851,13 @@ export default function MessageBlock(props: MessageBlockProps) {
                     )
                   })()}
                 </Match>
-                <Match when={item.type === "step-start"}>
+                <Match when={item().type === "step-start"}>
                   <StepCard
                     kind="start"
-                    part={(item as StepDisplayItem).part}
-                    messageInfo={(item as StepDisplayItem).messageInfo}
+                    part={(item() as StepDisplayItem).part}
+                    messageInfo={(item() as StepDisplayItem).messageInfo}
                     showAgentMeta
-                    showDeleteMessage={index() === 0}
+                    showDeleteMessage={index === 0}
                     instanceId={props.instanceId}
                     sessionId={props.sessionId}
                     messageId={props.messageId}
@@ -865,14 +867,14 @@ export default function MessageBlock(props: MessageBlockProps) {
                     onToggleSelectedMessage={props.onToggleSelectedMessage}
                   />
                 </Match>
-                <Match when={item.type === "step-finish"}>
+                <Match when={item().type === "step-finish"}>
                   <StepCard
                     kind="finish"
-                    part={(item as StepDisplayItem).part}
-                    messageInfo={(item as StepDisplayItem).messageInfo}
+                    part={(item() as StepDisplayItem).part}
+                    messageInfo={(item() as StepDisplayItem).messageInfo}
                     showUsage={props.showUsageMetrics()}
-                    borderColor={(item as StepDisplayItem).accentColor}
-                    showDeleteMessage={index() === 0}
+                    borderColor={(item() as StepDisplayItem).accentColor}
+                    showDeleteMessage={index === 0}
                     instanceId={props.instanceId}
                     sessionId={props.sessionId}
                     messageId={props.messageId}
@@ -882,31 +884,31 @@ export default function MessageBlock(props: MessageBlockProps) {
                     onToggleSelectedMessage={props.onToggleSelectedMessage}
                   />
                 </Match>
-                <Match when={item.type === "compaction"}>
+                <Match when={item().type === "compaction"}>
                   <CompactionCard
-                    part={(item as CompactionDisplayItem).part}
-                    messageInfo={(item as CompactionDisplayItem).messageInfo}
-                    borderColor={(item as CompactionDisplayItem).accentColor}
+                    part={(item() as CompactionDisplayItem).part}
+                    messageInfo={(item() as CompactionDisplayItem).messageInfo}
+                    borderColor={(item() as CompactionDisplayItem).accentColor}
                     instanceId={props.instanceId}
                     sessionId={props.sessionId}
-                    messageId={(item as CompactionDisplayItem).messageId}
-                    showDeleteMessage={index() === 0}
+                    messageId={(item() as CompactionDisplayItem).messageId}
+                    showDeleteMessage={index === 0}
                     onDeleteHoverChange={props.onDeleteHoverChange}
                     onDeleteMessagesUpTo={props.onDeleteMessagesUpTo}
                     selectedMessageIds={props.selectedMessageIds}
                     onToggleSelectedMessage={props.onToggleSelectedMessage}
                   />
                 </Match>
-                <Match when={item.type === "reasoning"}>
+                <Match when={item().type === "reasoning"}>
                   <ReasoningCard
-                    part={(item as ReasoningDisplayItem).part}
-                    messageInfo={(item as ReasoningDisplayItem).messageInfo}
+                    part={(item() as ReasoningDisplayItem).part}
+                    messageInfo={(item() as ReasoningDisplayItem).messageInfo}
                     instanceId={props.instanceId}
                     sessionId={props.sessionId}
-                    messageId={(item as ReasoningDisplayItem).messageId}
-                    showAgentMeta={(item as ReasoningDisplayItem).showAgentMeta}
-                    defaultExpanded={(item as ReasoningDisplayItem).defaultExpanded}
-                    showDeleteMessage={index() === 0}
+                    messageId={(item() as ReasoningDisplayItem).messageId}
+                    showAgentMeta={(item() as ReasoningDisplayItem).showAgentMeta}
+                    defaultExpanded={(item() as ReasoningDisplayItem).defaultExpanded}
+                    showDeleteMessage={index === 0}
                     onDeleteHoverChange={props.onDeleteHoverChange}
                     onDeleteMessagesUpTo={props.onDeleteMessagesUpTo}
                     selectedMessageIds={props.selectedMessageIds}
@@ -916,7 +918,7 @@ export default function MessageBlock(props: MessageBlockProps) {
                 </Match>
               </Switch>
             )}
-          </For>
+          </Index>
         </div>
       )}
     </Show>
@@ -1293,14 +1295,23 @@ interface ReasoningCardProps {
   onContentRendered?: () => void
 }
 
-function ReasoningCard(props: ReasoningCardProps) {
-  const { t } = useI18n()
-  const [expanded, setExpanded] = createSignal(Boolean(props.defaultExpanded))
-  const [deletingMessage, setDeletingMessage] = createSignal(false)
-  const [deletingUpTo, setDeletingUpTo] = createSignal(false)
-  const isSelectedForDeletion = () => Boolean(props.selectedMessageIds?.().has(props.messageId))
+function ReasoningStreamOutput(props: {
+  text: Accessor<string>
+  scrollTopSnapshot: Accessor<number>
+  setScrollTopSnapshot: (next: number) => void
+  onContentRendered?: () => void
+  ariaLabel: string
+}) {
+  let preRef: HTMLPreElement | undefined
   let pendingRenderNotificationFrame: number | null = null
 
+  const followScroll = createFollowScroll({
+    getScrollTopSnapshot: props.scrollTopSnapshot,
+    setScrollTopSnapshot: props.setScrollTopSnapshot,
+    sentinelMarginPx: REASONING_SCROLL_SENTINEL_MARGIN_PX,
+    sentinelClassName: "reasoning-scroll-sentinel",
+  })
+
   const notifyContentRendered = () => {
     if (!props.onContentRendered || typeof requestAnimationFrame !== "function") return
     if (pendingRenderNotificationFrame !== null) {
@@ -1312,6 +1323,17 @@ function ReasoningCard(props: ReasoningCardProps) {
     })
   }
 
+  createEffect(() => {
+    const nextText = props.text()
+    if (preRef && preRef.textContent !== nextText) {
+      preRef.textContent = nextText
+    }
+    if (followScroll.autoScroll()) {
+      followScroll.restoreAfterRender({ forceBottom: true })
+    }
+    notifyContentRendered()
+  })
+
   onCleanup(() => {
     if (pendingRenderNotificationFrame !== null) {
       cancelAnimationFrame(pendingRenderNotificationFrame)
@@ -1319,6 +1341,37 @@ function ReasoningCard(props: ReasoningCardProps) {
     }
   })
 
+  return (
+    <div
+      ref={followScroll.registerContainer}
+      class="message-reasoning-output"
+      role="region"
+      aria-label={props.ariaLabel}
+      onScroll={followScroll.handleScroll}
+    >
+      <pre
+        ref={(element) => {
+          preRef = element || undefined
+          if (preRef) {
+            preRef.textContent = props.text() || ""
+          }
+        }}
+        class="message-reasoning-text"
+        dir="auto"
+      />
+      {followScroll.renderSentinel()}
+    </div>
+  )
+}
+
+function ReasoningCard(props: ReasoningCardProps) {
+  const { t } = useI18n()
+  const [expanded, setExpanded] = createSignal(Boolean(props.defaultExpanded))
+  const [deletingMessage, setDeletingMessage] = createSignal(false)
+  const [deletingUpTo, setDeletingUpTo] = createSignal(false)
+  const [scrollTopSnapshot, setScrollTopSnapshot] = createSignal(0)
+  const isSelectedForDeletion = () => Boolean(props.selectedMessageIds?.().has(props.messageId))
+
   createEffect(() => {
     setExpanded(Boolean(props.defaultExpanded))
   })
@@ -1393,12 +1446,6 @@ function ReasoningCard(props: ReasoningCardProps) {
 
   const canSpeakReasoning = () => reasoningText().trim().length > 0 && speech.canUseSpeech()
 
-  createEffect(() => {
-    if (!expanded()) return
-    reasoningText()
-    notifyContentRendered()
-  })
-
   const canDeleteMessage = () => Boolean(props.showDeleteMessage) && !deletingMessage()
 
   const handleDeleteMessage = async (event: MouseEvent) => {
@@ -1553,9 +1600,13 @@ function ReasoningCard(props: ReasoningCardProps) {
       <Show when={expanded()}>
         <div class="message-reasoning-expanded">
           <div class="message-reasoning-body">
-            <div class="message-reasoning-output" role="region" aria-label={t("messageBlock.reasoning.detailsAriaLabel")}>
-              <pre class="message-reasoning-text" dir="auto">{reasoningText() || ""}</pre>
-            </div>
+            <ReasoningStreamOutput
+              text={reasoningText}
+              scrollTopSnapshot={scrollTopSnapshot}
+              setScrollTopSnapshot={setScrollTopSnapshot}
+              onContentRendered={props.onContentRendered}
+              ariaLabel={t("messageBlock.reasoning.detailsAriaLabel")}
+            />
           </div>
         </div>
       </Show>

packages/ui/src/components/tool-call.tsx

@@ -1,4 +1,4 @@
-import { createSignal, Show, createEffect, createMemo, onCleanup } from "solid-js"
+import { createSignal, Show, createEffect, createMemo, onCleanup, type Accessor } from "solid-js"
 import { ArrowRightSquare, Check, Copy, Hourglass, Loader2, XCircle } from "lucide-solid"
 import { stringify as stringifyYaml } from "yaml"
 import { messageStoreBus } from "../stores/message-v2/bus"
@@ -44,6 +44,7 @@ import { resolveTitleForTool } from "./tool-call/tool-title"
 import { getLogger } from "../lib/logger"
 import { useSpeech } from "../lib/hooks/use-speech"
 import SpeechActionButton from "./speech-action-button"
+import { createFollowScroll } from "../lib/follow-scroll"
 
 const log = getLogger("session")
 
@@ -51,8 +52,6 @@ type ToolState = import("@opencode-ai/sdk/v2").ToolState
 
 const TOOL_CALL_CACHE_SCOPE = "tool-call"
 const TOOL_SCROLL_SENTINEL_MARGIN_PX = 48
-const TOOL_SCROLL_INTENT_WINDOW_MS = 600
-const TOOL_SCROLL_INTENT_KEYS = new Set(["ArrowUp", "ArrowDown", "PageUp", "PageDown", "Home", "End", " ", "Spacebar"])
 
 function makeRenderCacheKey(
   toolCallId?: string | null,
@@ -82,6 +81,27 @@ interface ToolCallProps {
   forceCollapsed?: boolean
  }
 
+function ToolStatusIndicator(props: { status: Accessor<string> }) {
+  const isVisible = (value: string) => props.status() === value
+
+  return (
+    <span class="tool-call-header-status" aria-hidden="true" data-status={props.status() || "pending"}>
+      <span style={{ display: isVisible("pending") ? "inline-flex" : "none" }}>
+        <Hourglass class="w-4 h-4" />
+      </span>
+      <span style={{ display: isVisible("running") ? "inline-flex" : "none" }}>
+        <Loader2 class="w-4 h-4 animate-spin" />
+      </span>
+      <span style={{ display: isVisible("completed") ? "inline-flex" : "none" }}>
+        <Check class="w-4 h-4" />
+      </span>
+      <span style={{ display: isVisible("error") ? "inline-flex" : "none" }}>
+        <XCircle class="w-4 h-4" />
+      </span>
+    </span>
+  )
+}
+
 function ToolCallDetails(props: {
   toolCallMemo: () => ToolCallPart
   toolState: () => ToolState | undefined
@@ -166,179 +186,25 @@ function ToolCallDetails(props: {
   const [permissionSubmitting, setPermissionSubmitting] = createSignal(false)
   const [permissionError, setPermissionError] = createSignal<string | null>(null)
 
-  const [scrollContainer, setScrollContainer] = createSignal<HTMLDivElement | undefined>()
-  const [bottomSentinel, setBottomSentinel] = createSignal<HTMLDivElement | null>(null)
-  const [autoScroll, setAutoScroll] = createSignal(true)
-  const [bottomSentinelVisible, setBottomSentinelVisible] = createSignal(true)
-
-  let scrollContainerRef: HTMLDivElement | undefined
-  let detachScrollIntentListeners: (() => void) | undefined
-
-  let pendingScrollFrame: number | null = null
-  let pendingAnchorScroll: number | null = null
-  let userScrollIntentUntil = 0
-  let lastKnownScrollTop = props.scrollTopSnapshot()
-
-  function restoreScrollPosition(forceBottom = false) {
-    const container = scrollContainerRef
-    if (!container) return
-    if (forceBottom) {
-      container.scrollTop = container.scrollHeight
-      lastKnownScrollTop = container.scrollTop
-      props.setScrollTopSnapshot(lastKnownScrollTop)
-    } else {
-      container.scrollTop = lastKnownScrollTop
-    }
-  }
-
-  const persistScrollSnapshot = (element?: HTMLElement | null) => {
-    if (!element) return
-    lastKnownScrollTop = element.scrollTop
-    props.setScrollTopSnapshot(lastKnownScrollTop)
-  }
-
-  function markUserScrollIntent() {
-    const now = typeof performance !== "undefined" ? performance.now() : Date.now()
-    userScrollIntentUntil = now + TOOL_SCROLL_INTENT_WINDOW_MS
-  }
-
-  function hasUserScrollIntent() {
-    const now = typeof performance !== "undefined" ? performance.now() : Date.now()
-    return now <= userScrollIntentUntil
-  }
-
-  function attachScrollIntentListeners(element: HTMLDivElement) {
-    if (detachScrollIntentListeners) {
-      detachScrollIntentListeners()
-      detachScrollIntentListeners = undefined
-    }
-    const handlePointerIntent = () => markUserScrollIntent()
-    const handleKeyIntent = (event: KeyboardEvent) => {
-      if (TOOL_SCROLL_INTENT_KEYS.has(event.key)) {
-        markUserScrollIntent()
-      }
-    }
-    element.addEventListener("wheel", handlePointerIntent, { passive: true })
-    element.addEventListener("pointerdown", handlePointerIntent)
-    element.addEventListener("touchstart", handlePointerIntent, { passive: true })
-    element.addEventListener("keydown", handleKeyIntent)
-    detachScrollIntentListeners = () => {
-      element.removeEventListener("wheel", handlePointerIntent)
-      element.removeEventListener("pointerdown", handlePointerIntent)
-      element.removeEventListener("touchstart", handlePointerIntent)
-      element.removeEventListener("keydown", handleKeyIntent)
-    }
-  }
-
-  function scheduleAnchorScroll(immediate = false) {
-    if (!autoScroll()) return
-    const sentinel = bottomSentinel()
-    const container = scrollContainerRef
-    if (!sentinel || !container) return
-    if (pendingAnchorScroll !== null) {
-      cancelAnimationFrame(pendingAnchorScroll)
-      pendingAnchorScroll = null
-    }
-    pendingAnchorScroll = requestAnimationFrame(() => {
-      pendingAnchorScroll = null
-      const containerRect = container.getBoundingClientRect()
-      const sentinelRect = sentinel.getBoundingClientRect()
-      const delta = sentinelRect.bottom - containerRect.bottom + TOOL_SCROLL_SENTINEL_MARGIN_PX
-      if (Math.abs(delta) > 1) {
-        container.scrollBy({ top: delta, behavior: immediate ? "auto" : "smooth" })
-      }
-      lastKnownScrollTop = container.scrollTop
-      props.setScrollTopSnapshot(lastKnownScrollTop)
-    })
-  }
-
-  function handleScroll() {
-    const container = scrollContainer()
-    if (!container) return
-    if (pendingScrollFrame !== null) {
-      cancelAnimationFrame(pendingScrollFrame)
-    }
-    const isUserScroll = hasUserScrollIntent()
-    pendingScrollFrame = requestAnimationFrame(() => {
-      pendingScrollFrame = null
-      const atBottom = bottomSentinelVisible()
-      if (isUserScroll) {
-        if (atBottom) {
-          if (!autoScroll()) setAutoScroll(true)
-        } else if (autoScroll()) {
-          setAutoScroll(false)
-        }
-      }
-    })
-  }
-
-  const handleScrollEvent = (event: Event & { currentTarget: HTMLDivElement }) => {
-    handleScroll()
-    persistScrollSnapshot(event.currentTarget)
-  }
-
-  const handleScrollRendered = () => {
-    requestAnimationFrame(() => {
-      restoreScrollPosition(autoScroll())
-      scheduleAnchorScroll(true)
-    })
-  }
-
-  const initializeScrollContainer = (element: HTMLDivElement | null | undefined) => {
-    const next = element || undefined
-    if (next === scrollContainerRef) {
-      return
-    }
-    scrollContainerRef = next
-    setScrollContainer(scrollContainerRef)
-    if (scrollContainerRef) {
-      // Refresh our snapshot on mount (e.g. when remounting after collapse)
-      lastKnownScrollTop = props.scrollTopSnapshot()
-      restoreScrollPosition(autoScroll())
-    }
-  }
+  const followScroll = createFollowScroll({
+    getScrollTopSnapshot: props.scrollTopSnapshot,
+    setScrollTopSnapshot: props.setScrollTopSnapshot,
+    sentinelMarginPx: TOOL_SCROLL_SENTINEL_MARGIN_PX,
+    sentinelClassName: "tool-call-scroll-sentinel",
+  })
 
   const scrollHelpers: ToolScrollHelpers = {
     registerContainer: (element, options) => {
-      if (options?.disableTracking) return
-      initializeScrollContainer(element)
-    },
-    handleScroll: handleScrollEvent,
-    renderSentinel: (options) => {
-      if (options?.disableTracking) return null
-      return <div ref={setBottomSentinel} aria-hidden="true" class="tool-call-scroll-sentinel" style={{ height: "1px" }} />
+      followScroll.registerContainer(element, options)
     },
+    handleScroll: followScroll.handleScroll,
+    renderSentinel: followScroll.renderSentinel,
+    restoreAfterRender: followScroll.restoreAfterRender,
   }
 
-  createEffect(() => {
-    const container = scrollContainer()
-    if (!container) return
-    attachScrollIntentListeners(container)
-    onCleanup(() => {
-      if (detachScrollIntentListeners) {
-        detachScrollIntentListeners()
-        detachScrollIntentListeners = undefined
-      }
-    })
-  })
-
-  createEffect(() => {
-    const container = scrollContainer()
-    const sentinel = bottomSentinel()
-    if (!container || !sentinel) return
-    const observer = new IntersectionObserver(
-      (entries) => {
-        entries.forEach((entry) => {
-          if (entry.target === sentinel) {
-            setBottomSentinelVisible(entry.isIntersecting)
-          }
-        })
-      },
-      { root: container, threshold: 0, rootMargin: `0px 0px ${TOOL_SCROLL_SENTINEL_MARGIN_PX}px 0px` },
-    )
-    observer.observe(sentinel)
-    onCleanup(() => observer.disconnect())
-  })
+  const handleScrollRendered = () => {
+    scrollHelpers.restoreAfterRender()
+  }
 
   createEffect(() => {
     const permission = permissionDetails()
@@ -564,11 +430,13 @@ function ToolCallDetails(props: {
           partVersion={options.partVersion}
           instanceId={props.instanceId}
           sessionId={options.sessionId}
+          onContentRendered={props.onContentRendered}
           forceCollapsed={options.forceCollapsed}
         />
       )
     },
     scrollHelpers,
+    onContentRendered: props.onContentRendered,
   }
 
   let previousPartVersion: number | undefined
@@ -581,12 +449,12 @@ function ToolCallDetails(props: {
       return
     }
     previousPartVersion = version
-    scheduleAnchorScroll(true)
+    scrollHelpers.restoreAfterRender()
   })
 
   createEffect(() => {
-    if (autoScroll()) {
-      scheduleAnchorScroll(true)
+    if (followScroll.autoScroll()) {
+      scrollHelpers.restoreAfterRender({ forceBottom: true })
     }
   })
 
@@ -634,21 +502,6 @@ function ToolCallDetails(props: {
     />
   )
 
-  onCleanup(() => {
-    if (pendingScrollFrame !== null) {
-      cancelAnimationFrame(pendingScrollFrame)
-      pendingScrollFrame = null
-    }
-    if (pendingAnchorScroll !== null) {
-      cancelAnimationFrame(pendingAnchorScroll)
-      pendingAnchorScroll = null
-    }
-    if (detachScrollIntentListeners) {
-      detachScrollIntentListeners()
-      detachScrollIntentListeners = undefined
-    }
-  })
-
   return (
     <div class="tool-call-details">
       <Show
@@ -850,24 +703,6 @@ export default function ToolCall(props: ToolCallProps) {
       return !current
     })
   }
-
-
-  const statusIcon = () => {
-    const status = toolState()?.status || ""
-    switch (status) {
-      case "pending":
-        return <Hourglass class="w-4 h-4" />
-      case "running":
-        return <Loader2 class="w-4 h-4 animate-spin" />
-      case "completed":
-        return <Check class="w-4 h-4" />
-      case "error":
-        return <XCircle class="w-4 h-4" />
-      default:
-        return ""
-    }
-  }
-
   const statusClass = () => {
     const status = toolState()?.status || "pending"
     return `tool-call-status-${status}`
@@ -1051,9 +886,7 @@ export default function ToolCall(props: ToolCallProps) {
           />
         </Show>
 
-        <span class="tool-call-header-status" aria-hidden="true">
-          {statusIcon()}
-        </span>
+        <ToolStatusIndicator status={status} />
       </div>
 
       <Show when={expanded()}>

packages/ui/src/components/tool-call/ansi-render.tsx

@@ -1,4 +1,4 @@
-import type { Accessor, JSXElement } from "solid-js"
+import { createEffect, onCleanup, type Accessor, type JSXElement } from "solid-js"
 import type { RenderCache } from "../../types/message"
 import { ansiToHtml, createAnsiStreamRenderer, hasAnsi } from "../../lib/ansi"
 import { escapeHtml } from "../../lib/text-render-utils"
@@ -11,6 +11,97 @@ type CacheHandle = {
   set(value: unknown): void
 }
 
+export interface StableAnsiStreamUpdater {
+  update: (element: HTMLElement, content: string) => void
+  reset: () => void
+}
+
+export function createStableAnsiStreamUpdater(): StableAnsiStreamUpdater {
+  const renderer = createAnsiStreamRenderer()
+  let previousContent = ""
+  let ansiActive = false
+
+  return {
+    update(element: HTMLElement, content: string) {
+      const resetStreaming = !previousContent || !content.startsWith(previousContent)
+
+      if (resetStreaming) {
+        ansiActive = hasAnsi(content)
+        renderer.reset()
+        element.innerHTML = ansiActive ? renderer.render(content) : escapeHtml(content)
+        previousContent = content
+        return
+      }
+
+      const delta = content.slice(previousContent.length)
+      if (delta.length === 0) {
+        return
+      }
+
+      if (!ansiActive && hasAnsi(delta)) {
+        ansiActive = true
+        renderer.reset()
+        element.innerHTML = renderer.render(content)
+        previousContent = content
+        return
+      }
+
+      if (ansiActive) {
+        const htmlChunk = renderer.render(delta)
+        if (htmlChunk.length > 0) {
+          element.insertAdjacentHTML("beforeend", htmlChunk)
+        }
+      } else {
+        const escapedDelta = escapeHtml(delta)
+        if (escapedDelta.length > 0) {
+          element.insertAdjacentHTML("beforeend", escapedDelta)
+        }
+      }
+
+      previousContent = content
+    },
+    reset() {
+      previousContent = ""
+      ansiActive = false
+      renderer.reset()
+    },
+  }
+}
+
+function StreamingAnsiContent(props: {
+  html: string
+  htmlChunk?: string
+  updateMode: "replace" | "append" | "noop"
+}) {
+  let preRef: HTMLPreElement | undefined
+
+  createEffect(() => {
+    const element = preRef
+    if (!element) return
+    if (props.updateMode === "noop") return
+    if (props.updateMode === "append") {
+      if (element.innerHTML.length === 0) {
+        element.innerHTML = props.html
+        return
+      }
+      const chunk = props.htmlChunk ?? ""
+      if (chunk.length > 0) {
+        element.insertAdjacentHTML("beforeend", chunk)
+      }
+      return
+    }
+    if (element.innerHTML !== props.html) {
+      element.innerHTML = props.html
+    }
+  })
+
+  onCleanup(() => {
+    preRef = undefined
+  })
+
+  return <pre ref={preRef} class="tool-call-content tool-call-ansi" dir="auto" />
+}
+
 export function createAnsiContentRenderer(params: {
   ansiRunningCache: CacheHandle
   ansiFinalCache: CacheHandle
@@ -46,6 +137,8 @@ export function createAnsiContentRenderer(params: {
     const isRunningVariant = options.variant === "running"
     const disableScrollTracking = !isRunningVariant
     const registerRef = disableScrollTracking ? registerUntracked : registerTracked
+    let updateMode: "replace" | "append" | "noop" = "replace"
+    let htmlChunk = ""
 
     let nextCache: AnsiRenderCache
 
@@ -54,6 +147,7 @@ export function createAnsiContentRenderer(params: {
       const resetStreaming = !cached || !cached.text || !content.startsWith(cached.text) || cached.text !== runningAnsiSource
 
       if (resetStreaming) {
+        updateMode = "replace"
         const detectedAnsi = hasAnsi(content)
         if (detectedAnsi) {
           runningAnsiRenderer.reset()
@@ -66,15 +160,21 @@ export function createAnsiContentRenderer(params: {
       } else {
         const delta = content.slice(cached.text.length)
         if (delta.length === 0) {
+          updateMode = "noop"
           nextCache = { ...cached, mode }
         } else if (!cached.hasAnsi && hasAnsi(delta)) {
+          updateMode = "replace"
           runningAnsiRenderer.reset()
           const html = runningAnsiRenderer.render(content)
           nextCache = { text: content, html, mode, hasAnsi: true }
         } else if (cached.hasAnsi) {
-          const htmlChunk = runningAnsiRenderer.render(delta)
-          nextCache = { text: content, html: `${cached.html}${htmlChunk}`, mode, hasAnsi: true }
+          const appendedHtml = runningAnsiRenderer.render(delta)
+          updateMode = "append"
+          htmlChunk = appendedHtml
+          nextCache = { text: content, html: `${cached.html}${appendedHtml}`, mode, hasAnsi: true }
         } else {
+          updateMode = "append"
+          htmlChunk = escapeHtml(delta)
           nextCache = { text: content, html: `${cached.html}${escapeHtml(delta)}`, mode, hasAnsi: false }
         }
       }
@@ -98,7 +198,7 @@ export function createAnsiContentRenderer(params: {
 
     return (
       <div class={messageClass} ref={registerRef} onScroll={disableScrollTracking ? undefined : params.scrollHelpers.handleScroll}>
-        <pre class="tool-call-content tool-call-ansi" dir="auto" innerHTML={nextCache.html} />
+        <StreamingAnsiContent html={nextCache.html} htmlChunk={htmlChunk} updateMode={updateMode} />
         {params.scrollHelpers.renderSentinel({ disableTracking: disableScrollTracking })}
       </div>
     )

packages/ui/src/components/tool-call/diff-render.tsx

@@ -129,9 +129,7 @@ export function createDiffContentRenderer(params: {
     const copyPatchTitle = () => params.t("toolCall.diff.copyPatch")
 
     const handleDiffRendered = () => {
-      if (!disableScrollTracking) {
-        params.handleScrollRendered()
-      }
+      params.handleScrollRendered()
       params.onContentRendered?.()
     }
 

packages/ui/src/components/tool-call/renderers/bash.tsx

@@ -1,6 +1,107 @@
-import type { ToolRenderer } from "../types"
+import { Show, createEffect, createMemo, onCleanup, type Accessor } from "solid-js"
+import type { ToolState } from "@opencode-ai/sdk/v2"
+import type { ToolRenderer, ToolScrollHelpers } from "../types"
 import { ensureMarkdownContent, formatUnknown, getToolName, isToolStateCompleted, isToolStateError, isToolStateRunning, readToolStatePayload } from "../utils"
 import { tGlobal } from "../../../lib/i18n"
+import { createStableAnsiStreamUpdater } from "../ansi-render"
+import { ansiToHtml, hasAnsi } from "../../../lib/ansi"
+
+function RunningBashOutput(props: {
+  content: Accessor<string>
+  scrollHelpers?: ToolScrollHelpers
+}) {
+  let preRef: HTMLPreElement | undefined
+  const updater = createStableAnsiStreamUpdater()
+
+  createEffect(() => {
+    const element = preRef
+    if (!element) return
+    updater.update(element, props.content())
+  })
+
+  onCleanup(() => {
+    preRef = undefined
+    updater.reset()
+  })
+
+  return (
+    <div
+      class="message-text tool-call-markdown"
+      ref={props.scrollHelpers?.registerContainer}
+      onScroll={props.scrollHelpers ? (event) => props.scrollHelpers!.handleScroll(event as Event & { currentTarget: HTMLDivElement }) : undefined}
+    >
+      <pre ref={preRef} class="tool-call-content tool-call-ansi" dir="auto" />
+      {props.scrollHelpers?.renderSentinel?.()}
+    </div>
+  )
+}
+
+function BashToolBody(props: {
+  toolState: Accessor<ToolState | undefined>
+  renderMarkdown: (options: { content: string }) => ReturnType<ToolRenderer["renderBody"]>
+  scrollHelpers?: ToolScrollHelpers
+}) {
+  const state = createMemo(() => props.toolState())
+
+  const joinedContent = createMemo(() => {
+    const current = state()
+    if (!current || current.status === "pending") return ""
+
+    const { input, metadata } = readToolStatePayload(current)
+    const command = typeof input.command === "string" && input.command.length > 0 ? `$ ${input.command}` : ""
+    const outputResult = formatUnknown(
+      isToolStateCompleted(current)
+        ? current.output
+        : (isToolStateRunning(current) || isToolStateError(current)) && metadata.output
+          ? metadata.output
+          : undefined,
+    )
+    return [command, outputResult?.text].filter(Boolean).join("\n")
+  })
+
+  const finalMarkdown = createMemo(() => {
+    const current = state()
+    const content = joinedContent()
+    if (!current || current.status === "pending" || current.status === "running" || content.length === 0) {
+      return null
+    }
+    if (hasAnsi(content)) {
+      return null
+    }
+    return ensureMarkdownContent(content, "bash", true)
+  })
+
+  const finalAnsiHtml = createMemo(() => {
+    const current = state()
+    const content = joinedContent()
+    if (!current || current.status === "pending" || current.status === "running" || content.length === 0) {
+      return null
+    }
+    if (!hasAnsi(content)) {
+      return null
+    }
+    return ansiToHtml(content)
+  })
+
+  return (
+    <Show when={state() && joinedContent().length > 0}>
+      <Show
+        when={state()?.status === "running"}
+        fallback={
+          <Show when={finalAnsiHtml()} fallback={finalMarkdown() ? props.renderMarkdown({ content: finalMarkdown()! as string }) : null}>
+            {(html) => (
+              <div class="message-text tool-call-markdown" ref={props.scrollHelpers?.registerContainer}>
+                <pre class="tool-call-content tool-call-ansi" dir="auto" innerHTML={html()} />
+              </div>
+            )}
+          </Show>
+        }
+      >
+        <RunningBashOutput content={joinedContent} scrollHelpers={props.scrollHelpers} />
+      </Show>
+    </Show>
+  )
+}
 
 export const bashRenderer: ToolRenderer = {
   tools: ["bash"],
@@ -21,35 +122,7 @@ export const bashRenderer: ToolRenderer = {
     const timeoutLabel = `${timeout}ms`
     return `${baseTitle} · ${tGlobal("toolCall.renderer.bash.title.timeout", { timeout: timeoutLabel })}`
   },
-  renderBody({ toolState, renderMarkdown, renderAnsi }) {
-    const state = toolState()
-    if (!state || state.status === "pending") return null
-
-    const { input, metadata } = readToolStatePayload(state)
-    const command = typeof input.command === "string" && input.command.length > 0 ? `$ ${input.command}` : ""
-    const outputResult = formatUnknown(
-      isToolStateCompleted(state)
-        ? state.output
-        : (isToolStateRunning(state) || isToolStateError(state)) && metadata.output
-          ? metadata.output
-          : undefined,
-    )
-    const parts = [command, outputResult?.text].filter(Boolean)
-    if (parts.length === 0) return null
-
-    const joined = parts.join("\n")
-    if (state.status === "running") {
-      return renderAnsi({ content: joined, variant: "running" })
-    }
-
-    const ansiBody = renderAnsi({ content: joined, requireAnsi: true, variant: "final" })
-    if (ansiBody) {
-      return ansiBody
-    }
-
-    const content = ensureMarkdownContent(joined, "bash", true)
-    if (!content) return null
-
-    return renderMarkdown({ content })
+  renderBody({ toolState, renderMarkdown, scrollHelpers }) {
+    return <BashToolBody toolState={toolState} renderMarkdown={renderMarkdown as any} scrollHelpers={scrollHelpers} />
   },
 }

packages/ui/src/components/tool-call/renderers/task.tsx

@@ -1,4 +1,4 @@
-import { For, Show, createEffect, createMemo, createSignal, untrack } from "solid-js"
+import { For, Index, Show, createEffect, createMemo, createSignal, untrack } from "solid-js"
 import type { ToolState } from "@opencode-ai/sdk/v2"
 import type { ToolRenderer } from "../types"
 import { ensureMarkdownContent, getDefaultToolAction, getToolIcon, getToolName, readToolStatePayload } from "../utils"
@@ -145,7 +145,7 @@ export const taskRenderer: ToolRenderer = {
     const { input } = readToolStatePayload(state)
     return describeTaskTitle(input)
   },
-  renderBody({ toolState, instanceId, renderToolCall, messageVersion, partVersion, scrollHelpers, renderMarkdown, t }) {
+  renderBody({ toolState, instanceId, renderToolCall, messageVersion, partVersion, scrollHelpers, renderMarkdown, t, onContentRendered }) {
     const store = messageStoreBus.getOrCreate(instanceId)
     const [requestedChildLoad, setRequestedChildLoad] = createSignal(false)
 
@@ -360,6 +360,14 @@ export const taskRenderer: ToolRenderer = {
       })
     })
 
+    createEffect(() => {
+      const childCount = childToolKeys().length
+      const legacyCount = legacyItems().length
+      if (childCount === 0 && legacyCount === 0) return
+      scrollHelpers?.restoreAfterRender()
+      onContentRendered?.()
+    })
+
     return (
       <div class="tool-call-task-sections">
         <Show when={promptContent()}>
@@ -443,12 +451,12 @@ export const taskRenderer: ToolRenderer = {
                   }
                 >
                     <div class="tool-call-task-summary">
-                    <For each={childToolKeys()}>
+                    <Index each={childToolKeys()}>
                       {(key) => (
                         <Show when={renderToolCall}>
                           {(render) => (
                             <TaskToolCallRow
-                              toolKey={key}
+                              toolKey={key()}
                               store={store}
                               sessionId={childSessionId()}
                               renderToolCall={render()}
@@ -456,7 +464,7 @@ export const taskRenderer: ToolRenderer = {
                           )}
                         </Show>
                       )}
-                    </For>
+                    </Index>
                   </div>
                   {scrollHelpers?.renderSentinel?.()}
                 </div>

packages/ui/src/components/tool-call/types.ts

@@ -47,6 +47,7 @@ export interface ToolScrollHelpers {
   registerContainer(element: HTMLDivElement | null, options?: { disableTracking?: boolean }): void
   handleScroll(event: Event & { currentTarget: HTMLDivElement }): void
   renderSentinel(options?: { disableTracking?: boolean }): JSXElement | null
+  restoreAfterRender(options?: { forceBottom?: boolean }): void
 }
 
 export interface ToolRendererContext {
@@ -74,6 +75,7 @@ export interface ToolRendererContext {
     forceCollapsed?: boolean
   }) => JSXElement | null
   scrollHelpers?: ToolScrollHelpers
+  onContentRendered?: () => void
 }
 
 export interface ToolRenderer {

packages/ui/src/lib/follow-scroll.tsx

@@ -0,0 +1,259 @@
+import { createEffect, createSignal, onCleanup, type Accessor, type JSXElement } from "solid-js"
+
+const DEFAULT_SCROLL_INTENT_WINDOW_MS = 600
+const DEFAULT_SCROLL_INTENT_KEYS = new Set(["ArrowUp", "ArrowDown", "PageUp", "PageDown", "Home", "End", " ", "Spacebar"])
+
+interface FollowScrollOptions {
+  getScrollTopSnapshot: Accessor<number>
+  setScrollTopSnapshot: (next: number) => void
+  sentinelMarginPx: number
+  sentinelClassName: string
+  intentWindowMs?: number
+  intentKeys?: ReadonlySet<string>
+}
+
+export interface FollowScrollHelpers {
+  registerContainer: (element: HTMLDivElement | null | undefined, options?: { disableTracking?: boolean }) => void
+  handleScroll: (event: Event & { currentTarget: HTMLDivElement }) => void
+  renderSentinel: (options?: { disableTracking?: boolean }) => JSXElement | null
+  restoreAfterRender: (options?: { forceBottom?: boolean }) => void
+  autoScroll: Accessor<boolean>
+}
+
+export function createFollowScroll(options: FollowScrollOptions): FollowScrollHelpers {
+  const [scrollContainer, setScrollContainer] = createSignal<HTMLDivElement | undefined>()
+  const [bottomSentinel, setBottomSentinel] = createSignal<HTMLDivElement | null>(null)
+  const [autoScroll, setAutoScroll] = createSignal(true)
+  const [bottomSentinelVisible, setBottomSentinelVisible] = createSignal(true)
+
+  let scrollContainerRef: HTMLDivElement | undefined
+  let detachScrollIntentListeners: (() => void) | undefined
+
+  let pendingScrollFrame: number | null = null
+  let pendingAnchorScroll: number | null = null
+  let userScrollIntentUntil = 0
+  let lastKnownScrollTop = options.getScrollTopSnapshot()
+  let pointerInteractionActive = false
+  let suppressNextScrollHandling = false
+
+  function restoreScrollPosition(forceBottom = false) {
+    const container = scrollContainerRef
+    if (!container) return
+    suppressNextScrollHandling = true
+    if (forceBottom) {
+      container.scrollTop = container.scrollHeight
+      lastKnownScrollTop = container.scrollTop
+      options.setScrollTopSnapshot(lastKnownScrollTop)
+    } else {
+      container.scrollTop = lastKnownScrollTop
+    }
+  }
+
+  function persistScrollSnapshot(element?: HTMLElement | null) {
+    if (!element) return
+    lastKnownScrollTop = element.scrollTop
+    options.setScrollTopSnapshot(lastKnownScrollTop)
+  }
+
+  function markUserScrollIntent() {
+    const now = typeof performance !== "undefined" ? performance.now() : Date.now()
+    userScrollIntentUntil = now + (options.intentWindowMs ?? DEFAULT_SCROLL_INTENT_WINDOW_MS)
+  }
+
+  function hasUserScrollIntent() {
+    if (pointerInteractionActive) {
+      return true
+    }
+    const now = typeof performance !== "undefined" ? performance.now() : Date.now()
+    return now <= userScrollIntentUntil
+  }
+
+  function attachScrollIntentListeners(element: HTMLDivElement) {
+    if (detachScrollIntentListeners) {
+      detachScrollIntentListeners()
+      detachScrollIntentListeners = undefined
+    }
+    const intentKeys = options.intentKeys ?? DEFAULT_SCROLL_INTENT_KEYS
+    const handlePointerIntent = () => {
+      pointerInteractionActive = true
+      markUserScrollIntent()
+    }
+    const clearPointerIntent = () => {
+      pointerInteractionActive = false
+    }
+    const handleKeyIntent = (event: KeyboardEvent) => {
+      if (intentKeys.has(event.key)) {
+        markUserScrollIntent()
+      }
+    }
+    element.addEventListener("wheel", handlePointerIntent, { passive: true })
+    element.addEventListener("pointerdown", handlePointerIntent)
+    element.addEventListener("touchstart", handlePointerIntent, { passive: true })
+    element.addEventListener("keydown", handleKeyIntent)
+    if (typeof window !== "undefined") {
+      window.addEventListener("pointerup", clearPointerIntent)
+      window.addEventListener("pointercancel", clearPointerIntent)
+      window.addEventListener("mouseup", clearPointerIntent)
+      window.addEventListener("touchend", clearPointerIntent)
+      window.addEventListener("touchcancel", clearPointerIntent)
+    }
+    detachScrollIntentListeners = () => {
+      element.removeEventListener("wheel", handlePointerIntent)
+      element.removeEventListener("pointerdown", handlePointerIntent)
+      element.removeEventListener("touchstart", handlePointerIntent)
+      element.removeEventListener("keydown", handleKeyIntent)
+      if (typeof window !== "undefined") {
+        window.removeEventListener("pointerup", clearPointerIntent)
+        window.removeEventListener("pointercancel", clearPointerIntent)
+        window.removeEventListener("mouseup", clearPointerIntent)
+        window.removeEventListener("touchend", clearPointerIntent)
+        window.removeEventListener("touchcancel", clearPointerIntent)
+      }
+      pointerInteractionActive = false
+    }
+  }
+
+  function scheduleAnchorScroll(immediate = false) {
+    if (!autoScroll()) return
+    const sentinel = bottomSentinel()
+    const container = scrollContainerRef
+    if (!sentinel || !container) return
+    if (pendingAnchorScroll !== null) {
+      cancelAnimationFrame(pendingAnchorScroll)
+      pendingAnchorScroll = null
+    }
+    pendingAnchorScroll = requestAnimationFrame(() => {
+      pendingAnchorScroll = null
+      const containerRect = container.getBoundingClientRect()
+      const sentinelRect = sentinel.getBoundingClientRect()
+      const delta = sentinelRect.bottom - containerRect.bottom + options.sentinelMarginPx
+      if (Math.abs(delta) > 1) {
+        suppressNextScrollHandling = true
+        container.scrollBy({ top: delta, behavior: immediate ? "auto" : "smooth" })
+      }
+      lastKnownScrollTop = container.scrollTop
+      options.setScrollTopSnapshot(lastKnownScrollTop)
+    })
+  }
+
+  function isAtBottom(container: HTMLDivElement) {
+    return container.scrollHeight - (container.scrollTop + container.clientHeight) <= options.sentinelMarginPx
+  }
+
+  function updateFollowModeFromScroll(containerOverride?: HTMLDivElement) {
+    const container = containerOverride ?? scrollContainer()
+    if (!container) return
+    if (suppressNextScrollHandling) {
+      suppressNextScrollHandling = false
+      return
+    }
+    const isUserScroll = hasUserScrollIntent()
+    const atBottomFromScroll = isAtBottom(container)
+    const atBottom = atBottomFromScroll || bottomSentinelVisible()
+
+    if (isUserScroll || !atBottom) {
+      if (atBottom) {
+        if (!autoScroll()) setAutoScroll(true)
+      } else if (autoScroll()) {
+        setAutoScroll(false)
+      }
+    }
+  }
+
+  const handleScroll = (event: Event & { currentTarget: HTMLDivElement }) => {
+    updateFollowModeFromScroll(event.currentTarget)
+    persistScrollSnapshot(event.currentTarget)
+  }
+
+  const registerContainer = (element: HTMLDivElement | null | undefined, config?: { disableTracking?: boolean }) => {
+    const next = element || undefined
+    if (next === scrollContainerRef) {
+      return
+    }
+    scrollContainerRef = next
+    setScrollContainer(scrollContainerRef)
+    if (scrollContainerRef) {
+      lastKnownScrollTop = options.getScrollTopSnapshot()
+      restoreScrollPosition(autoScroll())
+    }
+  }
+
+  const renderSentinel = (config?: { disableTracking?: boolean }) => {
+    if (config?.disableTracking) return null
+    return <div ref={setBottomSentinel} aria-hidden="true" class={options.sentinelClassName} style={{ height: "1px" }} />
+  }
+
+  const restoreAfterRender = (config?: { forceBottom?: boolean }) => {
+    const container = scrollContainerRef
+    if (container && hasUserScrollIntent() && !isAtBottom(container)) {
+      if (autoScroll()) {
+        setAutoScroll(false)
+      }
+      requestAnimationFrame(() => {
+        restoreScrollPosition(false)
+      })
+      return
+    }
+
+    const shouldFollow = config?.forceBottom ?? autoScroll()
+    requestAnimationFrame(() => {
+      restoreScrollPosition(shouldFollow)
+      if (shouldFollow) {
+        scheduleAnchorScroll(true)
+      }
+    })
+  }
+
+  createEffect(() => {
+    const container = scrollContainer()
+    if (!container) return
+    attachScrollIntentListeners(container)
+    onCleanup(() => {
+      if (detachScrollIntentListeners) {
+        detachScrollIntentListeners()
+        detachScrollIntentListeners = undefined
+      }
+    })
+  })
+
+  createEffect(() => {
+    const container = scrollContainer()
+    const sentinel = bottomSentinel()
+    if (!container || !sentinel) return
+    const observer = new IntersectionObserver(
+      (entries) => {
+        entries.forEach((entry) => {
+          if (entry.target === sentinel) {
+            setBottomSentinelVisible(entry.isIntersecting)
+          }
+        })
+      },
+      { root: container, threshold: 0, rootMargin: `0px 0px ${options.sentinelMarginPx}px 0px` },
+    )
+    observer.observe(sentinel)
+    onCleanup(() => observer.disconnect())
+  })
+
+  onCleanup(() => {
+    if (pendingScrollFrame !== null) {
+      cancelAnimationFrame(pendingScrollFrame)
+      pendingScrollFrame = null
+    }
+    if (pendingAnchorScroll !== null) {
+      cancelAnimationFrame(pendingAnchorScroll)
+      pendingAnchorScroll = null
+    }
+    if (detachScrollIntentListeners) {
+      detachScrollIntentListeners()
+      detachScrollIntentListeners = undefined
+    }
+  })
+
+  return {
+    registerContainer,
+    handleScroll,
+    renderSentinel,
+    restoreAfterRender,
+    autoScroll,
+  }
+}