Files

134 lines
3.9 KiB
TypeScript

"use client";
/**
* VirtualPostGrid — window-virtualised, infinite-scroll 2-up thumbnail grid for
* the profile Posts tabs (/u/me and /u/[handle]).
*
* Mirrors HomeFeed's window virtualization, but the unit of virtualization is a
* GRID ROW (two square cards) rather than a single card. Data (keyset paging +
* the bottom sentinel) comes from usePostScrollFeed; this component only owns
* rendering + windowing, so a profile with hundreds of posts stays cheap.
*/
import { useEffect, useMemo, useRef, useState } from "react";
import { useWindowVirtualizer } from "@tanstack/react-virtual";
import { Loader2 } from "lucide-react";
import type { Post } from "@/lib/social";
import { PostGridCard } from "./post-grid-card";
const COLS = 2;
export function VirtualPostGrid({
posts,
loading,
hasMore,
sentinelRef,
emptyMessage,
hrefFor,
onDelete,
onUpdated,
}: {
posts: Post[];
loading: boolean;
hasMore: boolean;
/** Bottom sentinel observed by usePostScrollFeed to load the next page. */
sentinelRef: React.RefObject<HTMLDivElement | null>;
emptyMessage?: string;
hrefFor?: (post: Post) => string;
onDelete?: (id: string) => void;
onUpdated?: (updated: Post) => void;
}) {
// Chunk the flat post list into rows of COLS for row-level virtualization.
const rows = useMemo(() => {
const out: Post[][] = [];
for (let i = 0; i < posts.length; i += COLS) out.push(posts.slice(i, i + COLS));
return out;
}, [posts]);
// Document-absolute top of the grid, so the window virtualizer can map window
// scroll → visible rows (the profile header/tabs sit above us). Re-measured
// on resize and any body reflow. Same approach as HomeFeed.
const parentRef = useRef<HTMLDivElement>(null);
const [offsetTop, setOffsetTop] = useState(0);
useEffect(() => {
const measure = () => {
const el = parentRef.current;
if (el) setOffsetTop(el.getBoundingClientRect().top + window.scrollY);
};
measure();
window.addEventListener("resize", measure);
const ro = new ResizeObserver(measure);
ro.observe(document.body);
return () => {
window.removeEventListener("resize", measure);
ro.disconnect();
};
}, []);
const virtualizer = useWindowVirtualizer({
count: rows.length,
estimateSize: () => 240, // square card + gap; measureElement corrects it
overscan: 6,
scrollMargin: offsetTop,
});
if (loading && posts.length === 0) {
return (
<div className="flex justify-center py-16">
<Loader2 className="size-6 animate-spin text-muted-foreground" />
</div>
);
}
if (!loading && posts.length === 0) {
return (
<p className="text-sm text-muted-foreground">
{emptyMessage ?? "Nothing here yet."}
</p>
);
}
const virtualRows = virtualizer.getVirtualItems();
return (
<div>
<div
ref={parentRef}
className="relative w-full"
style={{ height: virtualizer.getTotalSize() }}
>
{virtualRows.map((vr) => {
const row = rows[vr.index];
return (
<div
key={row[0]?.id ?? vr.index}
data-index={vr.index}
ref={virtualizer.measureElement}
className="absolute left-0 top-0 w-full"
style={{ transform: `translateY(${vr.start - offsetTop}px)` }}
>
<div className="grid grid-cols-2 gap-2 sm:gap-3 pb-2 sm:pb-3">
{row.map((p) => (
<PostGridCard
key={p.id}
post={p}
href={hrefFor?.(p)}
onDelete={onDelete}
onUpdated={onUpdated}
/>
))}
</div>
</div>
);
})}
</div>
{hasMore ? (
<div ref={sentinelRef} className="flex justify-center py-6">
<Loader2 className="size-5 animate-spin text-muted-foreground" />
</div>
) : null}
</div>
);
}