import type { OptionProp } from "./SelectProps";
export type GroupedRow = {
    kind: "header";
    key: string;
    group: string;
} | {
    kind: "option";
    key: string | number;
    option: OptionProp;
    index: number;
};
export type GroupedLayout = {
    tops: number[];
    optionRows: number[];
};
export declare const buildGroupedRows: (options: OptionProp[]) => GroupedRow[];
export declare const layoutGroupedRows: (rows: GroupedRow[], headerPx: number, optionPx: number) => GroupedLayout;
export declare const groupedWindow: (tops: number[], scrollTop: number, viewportPx: number, overscan: number) => {
    start: number;
    end: number;
};