Product Shelf

2 columns
Features used
numColumns to reflow the shelf between different column counts.
overrideItemLayout to let section headers span the full row while products stay in the grid.
estimatedItemSize to give the mixed grid a rough initial size before real measurements are available.
stickyHeaderIndices to keep section headers pinned while the mixed grid scrolls.
example-web/src/examples/ProductShelfExample.tsx
import React from "react";import { LegendList } from "@legendapp/list/react";import { buildProductShelf, type ProductCard, type ProductShelfSection } from "@examples/commerce";import { CARD_CLASS, listViewportStyle, Shell } from "./shared";type ShelfRow =    | { id: string; subtitle: string; title: string; type: "header" }    | ({ badge: string; type: "product" } & ProductCard);function buildShelfRows(sections: ProductShelfSection[]) {    const rows: ShelfRow[] = [];    const stickyHeaderIndices: number[] = [];    for (const section of sections) {        stickyHeaderIndices.push(rows.length);        rows.push({            id: `${section.id}-header`,            subtitle: `${section.items.length} featured picks`,            title: section.title,            type: "header",        });        for (const [index, item] of section.items.entries()) {            rows.push({                ...item,                badge: index % 2 === 0 ? "Ready to ship" : "Popular",                type: "product",            });        }    }    return { rows, stickyHeaderIndices };}export function ProductShelfExample() {    const shelf = React.useMemo(() => buildShelfRows(buildProductShelf()), []);    const [columns, setColumns] = React.useState(2);    return (        <Shell title="Product Shelf">            <div className="flex min-h-0 flex-1 flex-col">                <div className="mb-3 flex items-center gap-3">                    <button                        className="cursor-pointer rounded-full border border-gray-300 px-[14px] py-[10px] font-bold disabled:opacity-40"                        disabled={columns <= 1}                        onClick={() => setColumns((value) => Math.max(1, value - 1))}                        type="button"                    >                        -                    </button>                    <div className="min-w-[96px] text-center text-[14px] font-bold text-slate-900">                        {columns} columns                    </div>                    <button                        className="cursor-pointer rounded-full border border-gray-300 px-[14px] py-[10px] font-bold disabled:opacity-40"                        disabled={columns >= 6}                        onClick={() => setColumns((value) => Math.min(6, value + 1))}                        type="button"                    >                        +                    </button>                </div>                <LegendList                    columnWrapperStyle={{ gap: 12 }}                    data={shelf.rows}                    estimatedItemSize={160}                    keyExtractor={(item) => item.id}                    numColumns={columns}                    overrideItemLayout={(layout, item) => {                        if (item.type === "header") {                            layout.span = columns;                        }                    }}                    recycleItems                    renderItem={({ item }: { item: ShelfRow }) =>                        item.type === "header" ? (                            <div                                className="mb-[10px] border border-slate-300 bg-indigo-50 px-3 py-[10px]"                                style={{                                    borderRadius: 0,                                }}                            >                                <div className="text-[18px] font-extrabold">{item.title}</div>                                <div className="mt-1 text-[13px] text-slate-500">{item.subtitle}</div>                            </div>                        ) : (                            <div                                className={`${CARD_CLASS} min-h-[132px]`}                                style={{                                    background: item.color,                                }}                            >                                <div className="font-extrabold">{item.title}</div>                                <div className="mt-1.5">{item.priceLabel}</div>                                <div className="mt-3 text-[13px] text-slate-600">{item.badge}</div>                            </div>                        )                    }                    stickyHeaderIndices={shelf.stickyHeaderIndices}                    style={listViewportStyle}                />            </div>        </Shell>    );}