/**
 * A "selection mode" state machine for a multi-select list (files, table rows, …):
 * enter a mode, toggle items, select-or-clear all, exit. Agnostic — items are
 * string ids, no domain coupling. Pairs with any list that renders a selection
 * overlay from `selected` (e.g. `<FileThumbnailGrid selectedIds>`).
 *
 * It is the reusable LOGIC behind a gated-delete file field; the action bar, the
 * layout, and the confirm Dialog are presentation the consumer composes locally.
 */
export interface SelectionMode {
    /** Whether selection mode is active. */
    active: boolean;
    /** The currently-selected ids. */
    selected: ReadonlySet<string>;
    enter: () => void;
    /** Leave selection mode AND clear the selection. */
    exit: () => void;
    toggle: (id: string) => void;
    /** Select all `ids` when they aren't all already selected, else clear (stay in mode). */
    toggleAll: (ids: readonly string[]) => void;
}
export declare function useSelectionMode(): SelectionMode;