import type { DataTableRowId } from './DataTableController.js';
/**
 * Fixed-height virtualization configuration for the DataTable body.
 *
 * Header groups and summary rows remain normal table sections and are not
 * included in the virtual row count. Body rows must have a fixed height.
 */
export interface DataTableVirtualizationOptions {
    /** The measured, fixed height of each data row in CSS pixels. */
    rowHeight: number;
    /**
     * The visible height of the scrolling data viewport in CSS pixels. The
     * component adds measured caption and header height around this body region.
     */
    viewportHeight: number;
    /** Extra rows rendered before and after the visible range. Defaults to 3. */
    overscan?: number;
    /** Controlled scroll position, used to restore a table after remounting. */
    scrollTop?: number;
    /**
     * Receives the current virtual scroll position. When a footer is present,
     * its measured height extends the range so it remains reachable.
     */
    onScrollTopChange?: (scrollTop: number) => void;
    /**
     * A stable row id that must remain visible. Use this with
     * `onFocusedRowIdChange` to restore keyboard focus after a data refresh.
     */
    focusedRowId?: DataTableRowId | null;
    /** Receives the stable id of a row when focus enters that row. */
    onFocusedRowIdChange?: (rowId: DataTableRowId) => void;
}
export type DataTableVirtualizationReason = 'disabled' | 'variable-row-height';
export interface DataTableVirtualizationContext {
    options?: DataTableVirtualizationOptions;
    rowCount: number;
    scrollTop: number;
    /** Expansion and body group rows produce variable heights and disable the window. */
    hasVariableRowHeight?: boolean;
    /** Structural header rows, including grouped headers. Excluded from the window. */
    headerRowCount?: number;
    /** Structural summary rows. Excluded from the window. */
    summaryRowCount?: number;
}
export interface DataTableVirtualWindow {
    enabled: boolean;
    reason?: DataTableVirtualizationReason;
    startIndex: number;
    endIndex: number;
    topSpacerHeight: number;
    bottomSpacerHeight: number;
    totalBodyHeight: number;
    headerRowCount: number;
    summaryRowCount: number;
}
/**
 * Returns the maximum scroll position for a virtual body and an optional
 * measured summary footer. Header and caption height are outside this range.
 */
export declare function maximumDataTableVirtualScrollTop(rowCount: number, options: Pick<DataTableVirtualizationOptions, 'rowHeight' | 'viewportHeight'>, footerHeight?: number): number;
/**
 * Resolves the renderable data-row window without using source order as an
 * identity. The caller retains the rows and slices by the returned indexes.
 */
export declare function resolveDataTableVirtualWindow(context: DataTableVirtualizationContext): DataTableVirtualWindow;
/**
 * Returns the smallest fixed-height scroll position that reveals a stable row
 * index, clamped to the body extent. Callers resolve the index from `rowKey`.
 */
export declare function scrollTopForDataTableRow(rowIndex: number, rowCount: number, options: Pick<DataTableVirtualizationOptions, 'rowHeight' | 'viewportHeight'>, currentScrollTop?: number): number;
//# sourceMappingURL=DataTableVirtualization.d.ts.map