import type { ProposalPreviewSource } from './proposal-preview.js';
/**
 * Where a proposal card finds the page to read its before values from.
 *
 * A getter rather than the data itself, so the host is not re-rendered on every
 * keystroke: the card reads the page when it renders and not otherwise. Whoever
 * mounts the thread inside the editor provides one; anywhere else the card reads
 * only what the operations themselves say.
 */
export type ProposalPreviewLookup = () => ProposalPreviewSource;
export declare const ProposalPreviewContext: import("react").Context<ProposalPreviewLookup>;
export declare function useProposalPreviewSource(): ProposalPreviewSource;