meeting_memory/frontend_nanobot/src/components/thread/ThreadViewport.tsx

588 lines
21 KiB
TypeScript

import {
forwardRef,
type ReactNode,
useCallback,
useEffect,
useImperativeHandle,
useLayoutEffect,
useMemo,
useRef,
useState,
} from "react";
import { ArrowDown } from "lucide-react";
import { useTranslation } from "react-i18next";
import { PromptRail } from "@/components/thread/PromptRail";
import { ThreadMessages } from "@/components/thread/ThreadMessages";
import { isAgentActivityMember } from "@/components/thread/AgentActivityCluster";
import { Button } from "@/components/ui/button";
import {
findPromptElement,
jumpToPrompt,
promptTop,
} from "@/components/thread/promptNavigation";
import { cn } from "@/lib/utils";
import type { CliAppInfo, McpPresetInfo, UIMessage } from "@/lib/types";
export interface ThreadViewportHandle {
jumpToUserPrompt: (promptId: string) => void;
}
interface ThreadViewportProps {
messages: UIMessage[];
isStreaming: boolean;
composer: ReactNode;
emptyState?: ReactNode;
scrollToBottomSignal?: number;
scrollToLatestUserPromptSignal?: number;
conversationKey?: string | null;
showScrollToBottomButton?: boolean;
cliApps?: CliAppInfo[];
mcpPresets?: McpPresetInfo[];
forkBoundaryMessageCount?: number | null;
hasMoreBefore?: boolean;
loadingOlder?: boolean;
userMessageOffset?: number;
onLoadOlder?: () => Promise<void> | void;
onOpenFilePreview?: (path: string) => void;
onForkFromMessage?: (beforeUserIndex: number) => void;
}
const NEAR_BOTTOM_PX = 48;
const NEAR_TOP_PX = 96;
const DEFAULT_SCROLL_BUTTON_BOTTOM_PX = 192;
const SCROLL_BUTTON_COMPOSER_GAP_PX = 16;
const SOFT_KEYBOARD_MIN_INSET_PX = 80;
const KEYBOARD_SCROLL_FRAMES = 18;
export const INITIAL_HISTORY_WINDOW = 160;
export const HISTORY_WINDOW_INCREMENT = 120;
export function windowMessages(messages: UIMessage[], visibleCount: number): UIMessage[] {
if (messages.length <= visibleCount) return messages;
let start = Math.max(0, messages.length - visibleCount);
while (
start > 0
&& isAgentActivityMember(messages[start])
&& isAgentActivityMember(messages[start - 1])
) {
start -= 1;
}
return messages.slice(start);
}
function isKeyboardEditableElement(element: Element | null): element is HTMLElement {
if (!(element instanceof HTMLElement)) return false;
if (element.isContentEditable) return true;
if (element instanceof HTMLTextAreaElement) return true;
if (!(element instanceof HTMLInputElement)) return false;
return ![
"button",
"checkbox",
"color",
"file",
"hidden",
"image",
"radio",
"range",
"reset",
"submit",
].includes(element.type);
}
function readSoftKeyboardInsetBottom(container: HTMLElement | null): number {
const viewport = window.visualViewport;
if (!viewport) return 0;
const active = document.activeElement;
if (!isKeyboardEditableElement(active) || !container?.contains(active)) return 0;
const layoutHeight = window.innerHeight || document.documentElement.clientHeight;
const inset = layoutHeight - viewport.height - viewport.offsetTop;
return inset >= SOFT_KEYBOARD_MIN_INSET_PX ? Math.ceil(inset) : 0;
}
export const ThreadViewport = forwardRef<ThreadViewportHandle, ThreadViewportProps>(function ThreadViewport({
messages,
isStreaming,
composer,
emptyState,
scrollToBottomSignal = 0,
scrollToLatestUserPromptSignal = 0,
conversationKey = null,
showScrollToBottomButton = true,
cliApps = [],
mcpPresets = [],
forkBoundaryMessageCount = null,
hasMoreBefore = false,
loadingOlder = false,
userMessageOffset = 0,
onLoadOlder,
onOpenFilePreview,
onForkFromMessage,
}, ref) {
const { t } = useTranslation();
const scrollRef = useRef<HTMLDivElement>(null);
const contentRef = useRef<HTMLDivElement>(null);
const composerDockRef = useRef<HTMLDivElement>(null);
const bottomRef = useRef<HTMLDivElement>(null);
const lastConversationKeyRef = useRef<string | null>(conversationKey);
const pendingConversationScrollRef = useRef(true);
const pendingPromptJumpRef = useRef<string | null>(null);
const scrollFrameIdsRef = useRef<number[]>([]);
const programmaticPromptScrollTopRef = useRef<number | null>(null);
const handledLatestPromptSignalRef = useRef(0);
const activeTurnPromptRef = useRef<string | null>(null);
const restoreScrollAfterPrependRef =
useRef<{ height: number; top: number } | null>(null);
/** User scrolled away from the bottom; do not auto-yank until they return or we reset (new chat / send). */
const userReadingHistoryRef = useRef(false);
const [atBottom, setAtBottom] = useState(true);
const [composerDockHeight, setComposerDockHeight] = useState(0);
const [keyboardInsetBottom, setKeyboardInsetBottom] = useState(0);
const [visibleMessageCount, setVisibleMessageCount] =
useState(INITIAL_HISTORY_WINDOW);
const hasMessages = messages.length > 0;
const visibleMessages = useMemo(
() => windowMessages(messages, visibleMessageCount),
[messages, visibleMessageCount],
);
const hiddenMessageCount = messages.length - visibleMessages.length;
const hiddenUserMessageCount =
userMessageOffset
+ (hiddenMessageCount > 0
? messages.slice(0, hiddenMessageCount).filter((message) => message.role === "user").length
: 0);
const visibleForkBoundaryMessageCount =
forkBoundaryMessageCount !== null && forkBoundaryMessageCount > hiddenMessageCount
? forkBoundaryMessageCount - hiddenMessageCount
: null;
const scrollButtonBottom =
keyboardInsetBottom
+ (composerDockHeight > 0
? composerDockHeight + SCROLL_BUTTON_COMPOSER_GAP_PX
: DEFAULT_SCROLL_BUTTON_BOTTOM_PX);
const scrollViewportStyle =
keyboardInsetBottom > 0 ? { bottom: keyboardInsetBottom } : undefined;
const cancelScheduledBottomScroll = useCallback(() => {
for (const id of scrollFrameIdsRef.current) {
window.cancelAnimationFrame(id);
}
scrollFrameIdsRef.current = [];
}, []);
const markProgrammaticPromptScroll = useCallback((top: number) => {
programmaticPromptScrollTopRef.current = top;
}, []);
const scrollToBottomNow = useCallback((smooth = false) => {
const el = scrollRef.current;
const marker = bottomRef.current;
const behavior: ScrollBehavior = smooth ? "smooth" : "auto";
if (el) {
const top = Math.max(0, el.scrollHeight - el.clientHeight);
try {
el.scrollTo?.({ top, behavior });
if (!smooth) el.scrollTop = top;
} catch {
try {
el.scrollTop = top;
} catch {
// Test DOMs can expose read-only scrollTop; browsers keep this writable.
}
}
} else if (marker) {
marker.scrollIntoView({ block: "end", behavior });
}
userReadingHistoryRef.current = false;
setAtBottom(true);
}, []);
const scrollToPromptTopNow = useCallback((promptId: string) => {
const el = scrollRef.current;
if (!el) return false;
const target = findPromptElement(el, promptId);
if (!target) return false;
const top = Math.max(0, promptTop(el, target) - 16);
markProgrammaticPromptScroll(top);
try {
el.scrollTo?.({ top, behavior: "auto" });
el.scrollTop = top;
} catch {
try {
el.scrollTop = top;
} catch {
// Test DOMs can expose read-only scrollTop; browsers keep this writable.
}
}
const near = el.scrollHeight - top - el.clientHeight < NEAR_BOTTOM_PX;
userReadingHistoryRef.current = false;
setAtBottom(near);
return true;
}, [markProgrammaticPromptScroll]);
const scrollToBottom = useCallback(
(smooth = false, frames = 1, options?: { force?: boolean }) => {
const force = options?.force ?? false;
cancelScheduledBottomScroll();
const run = () => {
if (!force && userReadingHistoryRef.current) return;
scrollToBottomNow(smooth);
};
const scheduleNext = (remainingFrames: number) => {
if (remainingFrames <= 0) return;
const id = window.requestAnimationFrame(() => {
scrollFrameIdsRef.current = scrollFrameIdsRef.current.filter((frameId) => frameId !== id);
if (!force && userReadingHistoryRef.current) return;
scrollToBottomNow(smooth);
scheduleNext(remainingFrames - 1);
});
scrollFrameIdsRef.current.push(id);
};
run();
scheduleNext(frames - 1);
},
[cancelScheduledBottomScroll, scrollToBottomNow],
);
const loadEarlierMessages = useCallback(() => {
const el = scrollRef.current;
if (el) {
restoreScrollAfterPrependRef.current = {
height: el.scrollHeight,
top: el.scrollTop,
};
}
userReadingHistoryRef.current = true;
activeTurnPromptRef.current = null;
setAtBottom(false);
if (hiddenMessageCount > 0) {
setVisibleMessageCount((count) =>
Math.min(messages.length, count + HISTORY_WINDOW_INCREMENT),
);
return;
}
if (hasMoreBefore && onLoadOlder && !loadingOlder) {
setVisibleMessageCount((count) => count + HISTORY_WINDOW_INCREMENT);
void onLoadOlder();
}
}, [hasMoreBefore, hiddenMessageCount, loadingOlder, messages.length, onLoadOlder]);
const maybeLoadEarlierFromScroll = useCallback(() => {
const el = scrollRef.current;
if (!el || !hasMessages || pendingConversationScrollRef.current) return;
if (!userReadingHistoryRef.current) return;
if (el.scrollTop > NEAR_TOP_PX) return;
if (hiddenMessageCount <= 0 && !hasMoreBefore) return;
loadEarlierMessages();
}, [hasMessages, hasMoreBefore, hiddenMessageCount, loadEarlierMessages]);
const jumpToUserPrompt = useCallback((promptId: string) => {
const scrollEl = scrollRef.current;
if (scrollEl && findPromptElement(scrollEl, promptId)) {
jumpToPrompt(scrollEl, promptId);
return;
}
const index = messages.findIndex((message) => message.id === promptId);
if (index < 0) return;
pendingPromptJumpRef.current = promptId;
userReadingHistoryRef.current = true;
activeTurnPromptRef.current = null;
setAtBottom(false);
setVisibleMessageCount((count) => Math.max(count, messages.length - index));
}, [messages]);
useImperativeHandle(ref, () => ({ jumpToUserPrompt }), [jumpToUserPrompt]);
const measureComposerDock = useCallback(() => {
const el = composerDockRef.current;
if (!el) return;
const height = el.getBoundingClientRect().height || el.offsetHeight;
setComposerDockHeight((current) =>
Math.abs(current - height) < 1 ? current : height,
);
}, []);
useLayoutEffect(() => {
const updateKeyboardInset = () => {
const scrollEl = scrollRef.current;
const next = readSoftKeyboardInsetBottom(scrollEl);
const active = document.activeElement;
const composerFocused =
hasMessages && isKeyboardEditableElement(active) && Boolean(scrollEl?.contains(active));
setKeyboardInsetBottom((current) =>
Math.abs(current - next) < 1 ? current : next,
);
if (composerFocused) {
userReadingHistoryRef.current = false;
scrollToBottom(false, KEYBOARD_SCROLL_FRAMES, { force: true });
}
};
updateKeyboardInset();
const viewport = window.visualViewport;
viewport?.addEventListener("resize", updateKeyboardInset);
viewport?.addEventListener("scroll", updateKeyboardInset);
window.addEventListener("resize", updateKeyboardInset);
document.addEventListener("focusin", updateKeyboardInset);
document.addEventListener("focusout", updateKeyboardInset);
return () => {
viewport?.removeEventListener("resize", updateKeyboardInset);
viewport?.removeEventListener("scroll", updateKeyboardInset);
window.removeEventListener("resize", updateKeyboardInset);
document.removeEventListener("focusin", updateKeyboardInset);
document.removeEventListener("focusout", updateKeyboardInset);
};
}, [hasMessages, scrollToBottom]);
useLayoutEffect(() => {
if (keyboardInsetBottom > 0) {
userReadingHistoryRef.current = false;
scrollToBottom(false, KEYBOARD_SCROLL_FRAMES, { force: true });
return;
}
if (userReadingHistoryRef.current) return;
scrollToBottom(false, 4);
}, [keyboardInsetBottom, scrollToBottom]);
useEffect(() => {
const scrollEl = scrollRef.current;
if (!scrollEl) return;
const onComposerFocus = () => {
const active = document.activeElement;
if (!hasMessages || !isKeyboardEditableElement(active) || !scrollEl.contains(active)) return;
userReadingHistoryRef.current = false;
scrollToBottom(false, KEYBOARD_SCROLL_FRAMES, { force: true });
};
document.addEventListener("focusin", onComposerFocus);
return () => document.removeEventListener("focusin", onComposerFocus);
}, [hasMessages, scrollToBottom]);
useEffect(() => {
if (scrollToBottomSignal <= 0) return;
userReadingHistoryRef.current = false;
scrollToBottom(false, 8);
}, [scrollToBottomSignal, scrollToBottom]);
useLayoutEffect(() => {
if (scrollToLatestUserPromptSignal <= handledLatestPromptSignalRef.current) return;
const latest = messages[messages.length - 1];
if (!latest || latest.role !== "user") return;
handledLatestPromptSignalRef.current = scrollToLatestUserPromptSignal;
cancelScheduledBottomScroll();
activeTurnPromptRef.current = latest.id;
if (!scrollToPromptTopNow(latest.id)) activeTurnPromptRef.current = null;
}, [
cancelScheduledBottomScroll,
messages,
scrollToLatestUserPromptSignal,
scrollToPromptTopNow,
]);
useLayoutEffect(() => {
if (lastConversationKeyRef.current === conversationKey) return;
lastConversationKeyRef.current = conversationKey;
pendingConversationScrollRef.current = true;
userReadingHistoryRef.current = false;
activeTurnPromptRef.current = null;
setAtBottom(true);
setVisibleMessageCount(INITIAL_HISTORY_WINDOW);
}, [conversationKey]);
useLayoutEffect(() => {
const promptId = activeTurnPromptRef.current;
if (!promptId || userReadingHistoryRef.current) return;
const promptIndex = messages.findIndex((message) => message.id === promptId);
if (promptIndex < 0) {
activeTurnPromptRef.current = null;
return;
}
const hasAgentOutput = messages
.slice(promptIndex + 1)
.some((message) => message.role !== "user");
if (!hasAgentOutput) return;
scrollToBottom(false, isStreaming ? 3 : 1);
}, [isStreaming, messages, scrollToBottom]);
useLayoutEffect(() => {
if (!hasMessages) return;
if (userReadingHistoryRef.current) return;
scrollToBottom(false, isStreaming ? 4 : 2);
}, [hasMessages, isStreaming, scrollToBottom, visibleMessages]);
useLayoutEffect(() => {
const pending = restoreScrollAfterPrependRef.current;
if (!pending) return;
const el = scrollRef.current;
restoreScrollAfterPrependRef.current = null;
if (!el) return;
const delta = el.scrollHeight - pending.height;
const nextTop = pending.top + delta;
try {
el.scrollTop = nextTop;
} catch {
try {
el.scrollTo?.({ top: nextTop, behavior: "auto" });
} catch {
// Test DOMs can expose read-only scrollTop; browsers keep this writable.
}
}
}, [visibleMessages.length, messages.length]);
useLayoutEffect(() => {
const promptId = pendingPromptJumpRef.current;
const scrollEl = scrollRef.current;
if (!promptId || !scrollEl || !findPromptElement(scrollEl, promptId)) return;
pendingPromptJumpRef.current = null;
const frame = window.requestAnimationFrame(() => jumpToPrompt(scrollEl, promptId));
return () => window.cancelAnimationFrame(frame);
}, [visibleMessages.length]);
useLayoutEffect(() => {
if (!pendingConversationScrollRef.current) return;
if (!conversationKey) {
pendingConversationScrollRef.current = false;
scrollToBottom(false, 4);
return;
}
scrollToBottom(false, 8);
if (!hasMessages) return;
pendingConversationScrollRef.current = false;
}, [conversationKey, hasMessages, messages, scrollToBottom]);
useLayoutEffect(() => {
measureComposerDock();
}, [composer, hasMessages, measureComposerDock]);
useEffect(() => cancelScheduledBottomScroll, [cancelScheduledBottomScroll]);
useEffect(() => {
const target = composerDockRef.current;
if (!target || typeof ResizeObserver === "undefined") return;
const observer = new ResizeObserver(() => measureComposerDock());
observer.observe(target);
return () => observer.disconnect();
}, [hasMessages, measureComposerDock]);
useEffect(() => {
const el = scrollRef.current;
if (!el) return;
const onScroll = (allowHistoryLoad = true) => {
const distance = el.scrollHeight - el.scrollTop - el.clientHeight;
const near = distance < NEAR_BOTTOM_PX;
const programmaticPromptTop = programmaticPromptScrollTopRef.current;
const programmatic =
programmaticPromptTop !== null && Math.abs(el.scrollTop - programmaticPromptTop) < 2;
setAtBottom(near);
if (programmatic) {
programmaticPromptScrollTopRef.current = null;
if (near) userReadingHistoryRef.current = false;
return;
}
programmaticPromptScrollTopRef.current = null;
userReadingHistoryRef.current = !near;
if (!near) activeTurnPromptRef.current = null;
if (allowHistoryLoad && !near) maybeLoadEarlierFromScroll();
};
onScroll(false);
const handleScroll = () => onScroll(true);
el.addEventListener("scroll", handleScroll, { passive: true });
return () => el.removeEventListener("scroll", handleScroll);
}, [maybeLoadEarlierFromScroll]);
return (
<div className="relative flex min-h-0 flex-1 overflow-hidden">
<div
ref={scrollRef}
className={cn(
"thread-viewport-scrollbar absolute inset-0 overflow-y-auto scroll-auto scrollbar-thin",
"[&::-webkit-scrollbar]:w-1.5",
"[&::-webkit-scrollbar-thumb]:rounded-full",
"[&::-webkit-scrollbar-thumb]:bg-muted-foreground/30",
"[&::-webkit-scrollbar-track]:bg-transparent",
)}
style={scrollViewportStyle}
>
{hasMessages ? (
<div ref={contentRef} className="mx-auto flex min-h-full w-full max-w-[64rem] flex-col">
<div
data-testid="thread-message-region"
className="flex min-h-0 flex-1 flex-col justify-start px-3 pb-4 pt-4 sm:px-4"
>
<div className="mx-auto w-full max-w-[49.5rem]">
<ThreadMessages
messages={visibleMessages}
isStreaming={isStreaming}
hiddenUserMessageCount={hiddenUserMessageCount}
cliApps={cliApps}
mcpPresets={mcpPresets}
forkBoundaryMessageCount={visibleForkBoundaryMessageCount}
onOpenFilePreview={onOpenFilePreview}
onForkFromMessage={onForkFromMessage}
/>
</div>
</div>
<div
ref={composerDockRef}
data-testid="thread-composer-dock"
className="sticky bottom-0 z-10 bg-background"
>
<div className="px-3 pb-[calc(0.75rem+env(safe-area-inset-bottom))] sm:px-4">
{composer}
</div>
</div>
</div>
) : (
<div ref={contentRef} className="mx-auto flex min-h-full w-full max-w-[72rem] flex-col px-3 sm:px-4">
<div className="flex w-full flex-1 items-center justify-center py-6 sm:py-12">
<div className="relative flex w-full max-w-[58rem] flex-col items-center gap-5 sm:block">
<div className="flex justify-center sm:absolute sm:inset-x-0 sm:bottom-[calc(100%+1.5rem)]">
{emptyState}
</div>
<div className="w-full">{composer}</div>
</div>
</div>
</div>
)}
<div ref={bottomRef} aria-hidden className="h-px" />
</div>
<div
aria-hidden
className="pointer-events-none absolute inset-x-0 top-0 h-6 bg-gradient-to-b from-background to-transparent"
/>
{hasMessages ? (
<PromptRail
messages={visibleMessages}
scrollRef={scrollRef}
bottomOffset={scrollButtonBottom}
/>
) : null}
{showScrollToBottomButton && !atBottom && (
<div
className="absolute left-1/2 z-20 -translate-x-1/2"
style={{ bottom: scrollButtonBottom }}
>
<Button
variant="outline"
size="icon"
onClick={() => scrollToBottom(true, 1, { force: true })}
className={cn(
"h-8 w-8 rounded-full shadow-md",
"bg-background/90 backdrop-blur",
"animate-in fade-in-0 zoom-in-95",
)}
aria-label={t("thread.scrollToBottom")}
>
<ArrowDown className="h-4 w-4" />
</Button>
</div>
)}
</div>
);
});