interface SourceHeaderCell {
    colspan?: number;
    origColspan?: number;
    isPlaceholder?: boolean;
    [key: string]: unknown;
}
/**
 * List of properties which are configurable. That properties can be changed using public API.
 *
 * @type {string[]}
 */
export declare const HEADER_CONFIGURABLE_PROPS: string[];
/**
 * The class manages and normalizes settings passed by the developer
 * into the nested headers plugin. The SourceSettings class is a
 * source of truth for tree builder (HeaderTree) module.
 *
 * @private
 * @class SourceSettings
 */
export default class SourceSettings {
    #private;
    /**
     * Sets columns limit to the source settings will be trimmed.
     *
     * @param {number} columnsCount The number of columns to limit to.
     */
    setColumnsLimit(columnsCount: number): void;
    /**
     * Sets a new nested header configuration.
     *
     * @param {Array[]} [nestedHeadersSettings=[]] The user-defined nested headers settings.
     */
    setData(nestedHeadersSettings?: unknown[][]): void;
    /**
     * Gets normalized source settings.
     *
     * @returns {Array[]}
     */
    getData(): SourceHeaderCell[][];
    /**
     * Merges settings with current source settings.
     *
     * @param {object[]} additionalSettings An array of objects with `row`, `col` and additional
     *                                      properties to merge with current source settings.
     */
    mergeWith(additionalSettings: {
        row: number;
        col: number;
        [key: string]: unknown;
    }[]): void;
    /**
     * Maps the current state with a callback.
     *
     * @param {Function} callback A function that is called for every header settings.
     */
    map(callback: (headerSettings: Record<string, unknown>) => unknown): void;
    /**
     * Gets source column header settings for a specified header.
     *
     * @param {number} headerLevel Header level (0 = most distant to the table).
     * @param {number} columnIndex A visual column index.
     * @returns {object|null}
     */
    getHeaderSettings(headerLevel: number, columnIndex: number): SourceHeaderCell | null;
    /**
     * Gets source of column headers settings for specified headers.
     *
     * @param {number} headerLevel Header level (0 = most distant to the table).
     * @param {number} columnIndex A visual column index from which the settings will be extracted.
     * @param {number} [columnsLength=1] The number of columns involved in the extraction of settings.
     * @returns {object}
     */
    getHeadersSettings(headerLevel: number, columnIndex: number, columnsLength?: number): unknown[];
    /**
     * Inserts `amount` columns into the normalized settings starting at the visual `columnIndex`.
     *
     * The behavior mirrors the MergeCells plugin: a column inserted strictly inside a header's span
     * extends that header (and every ancestor that also spans the point), while a column inserted at a
     * header's left boundary (or before/after the whole structure) is added as a standalone header.
     * In the normalized representation "strictly inside a span" is exactly "the cell at the insert
     * index is a placeholder".
     *
     * @param {number} columnIndex A visual column index at which the new columns are inserted.
     * @param {number} amount The number of columns to insert.
     */
    insertColumns(columnIndex: number, amount: number): void;
    /**
     * Removes `amount` columns from the normalized settings starting at the visual `columnIndex`.
     *
     * Every header that overlaps the removed range is shrunk by the number of removed columns it
     * covered. A header that loses all its columns is dropped; a header whose leftmost (labeled)
     * column is removed but which still has surviving columns is re-anchored to the first surviving
     * column, keeping its label and configurable properties.
     *
     * @param {number} columnIndex A visual column index from which the columns are removed.
     * @param {number} amount The number of columns to remove.
     */
    removeColumns(columnIndex: number, amount: number): void;
    /**
     * Gets a total number of headers levels.
     *
     * @returns {number}
     */
    getLayersCount(): number;
    /**
     * Gets a total number of columns count.
     *
     * @returns {number}
     */
    getColumnsCount(): number;
    /**
     * Clears the data.
     */
    clear(): void;
}
export {};