import type { ReactiveController } from 'lit';
import type { GridHost } from '../internal/types.js';
/**
 * The default expansion configuration used when the grid has none set.
 *
 * @remarks
 * `detailTemplate` defaults to `null` here — the controller will refuse to
 * toggle rows when the configuration is missing or no template is provided.
 */
export declare const DEFAULT_EXPANSION_CONFIG: Readonly<{
    enabled: false;
    showToggleColumn: true;
}>;
/**
 * Reactive controller backing row expansion (master-detail).
 *
 * @remarks
 * Expansion state is reference-based — the controller holds a `Set` of row
 * data references so the expansion set survives sort / filter / pagination as
 * long as those operations preserve row identity (the default in-place
 * pipeline does). Replacing {@link ApexGrid.data} wholesale invalidates any
 * expanded rows that are no longer present; consumers should call
 * {@link collapseAll} or re-apply expansion afterwards.
 *
 * Mutations go through the cancellable `rowExpanding` event and emit a
 * follow-up `rowExpanded` event, mirroring the pattern used by selection
 * and editing.
 */
export declare class ExpansionController<T extends object> implements ReactiveController {
    #private;
    protected host: GridHost<T>;
    /** Set of currently expanded row data references. */
    expanded: Set<T>;
    constructor(host: GridHost<T>);
    hostConnected(): void;
    /** Whether expansion is enabled at the grid level. */
    get enabled(): boolean;
    /** Whether the built-in chevron toggle column should be rendered. */
    get showToggleColumn(): boolean;
    /** Whether `row` is currently expanded. */
    isExpanded(row: T): boolean;
    /**
     * Whether `row` is permitted to expand. Combines the grid-wide `enabled`
     * flag, the presence of a `detailTemplate`, and the optional per-row
     * `isExpandable` predicate.
     */
    canExpand(row: T): boolean;
    /** Snapshot of currently expanded rows in insertion order. */
    expandedRows(): T[];
    /** Toggles the expansion of `row`. */
    toggleRow(row: T): Promise<boolean>;
    /** Expands `row`. No-op when the row is already expanded or not expandable. */
    expandRow(row: T): Promise<boolean>;
    /** Collapses `row`. No-op when the row is not expanded. */
    collapseRow(row: T): Promise<boolean>;
    /**
     * Expands every expandable row in {@link ApexGrid.dataView}. Skips rows
     * the optional `isExpandable` predicate rejects.
     */
    expandAll(): Promise<boolean>;
    /** Collapses every currently expanded row. */
    collapseAll(): Promise<boolean>;
    /**
     * Replaces the expansion set with `rows`. Used by the public
     * {@link ApexGrid.expandedRows} setter for programmatic control.
     */
    replaceExpansion(rows: ReadonlyArray<T>): Promise<boolean>;
}