import { HeaderItem } from '../../../../domains/shared/header';
/**
 * Builds the widget header's skeleton: one item per slot of {@link WIDGET_HEADER_SLOTS}, in that
 * order.
 *
 * A slot is filled by the header's own item for it if there is one (only the spacers are the
 * header's own — everything with content is contributed), otherwise by a contributed item claiming
 * that id, otherwise by a hidden anchor. Contributed items get the slot's `fill`, so a feature
 * decides *what* its item draws and the header decides how wide it sits.
 *
 * Both ways a contribution can be wrong are authoring bugs in SDK code — a marked item is only ever
 * created by `asBuiltInHeaderItem`, never by a consumer — so both **throw** rather than degrade:
 * every built-in item has to claim a slot registered here, and the header's own spacer slots cannot
 * be taken over (use `onBeforeRender` to change those).
 *
 * @param ownItems - The items the header builds itself: the two alignment spacers.
 * @param contributedItems - The widget's own items plus those contributed through
 * `config.header.items`.
 * @throws When a contributed item claims an unregistered id, or one the header owns.
 * @returns The full, ordered skeleton, including hidden anchors for the empty slots.
 * @internal
 */
export declare const buildWidgetHeaderSkeleton: (ownItems: readonly HeaderItem[], contributedItems?: readonly HeaderItem[]) => HeaderItem[];