import { default as GridModel } from './gridModel';
/** Windowing parameters for the virtualized body. Rows are sliced by the adapter from these. */
export interface ViewportWindow {
    /** Index of the first row to render. */
    startIndex: number;
    /** Number of rows to render starting at `startIndex`. */
    take: number;
    /** Pixel offset to translate the rendered slice down to its scroll position. */
    translateY: number;
    /** Total scrollable height of all rows. */
    totalHeight: number;
    /** Fixed viewport height, or undefined when rendering all rows. */
    viewHeight: number | undefined;
}
/**
 * Headless virtualization: given a scrollTop, computes which rows are visible and how
 * to position them. Pure math — `scrollTop` is owned by the adapter (so scrolling does
 * not notify the store / re-render the whole grid).
 */
export default class ViewportModel<TRow> {
    readonly grid: GridModel<TRow>;
    static readonly DEFAULT_VISIBLE_ROWS_COUNT = 10;
    static readonly ROWS_TO_PRELOAD = 20;
    constructor(grid: GridModel<TRow>);
    get showAll(): boolean;
    get hasDetailRows(): boolean;
    get isEmpty(): boolean;
    /** Number of rows the viewport shows at once (all rows when `visibleRowsCount === 'all'`). */
    get visibleRowsCount(): number;
    get viewHeight(): number | undefined;
    get totalHeight(): number;
    /** Height to reserve for the empty/no-data state. */
    get emptyHeight(): number;
    /** Binary search for the first row whose offset is <= scrollTop (variable-height rows). */
    private findStartIndex;
    window(scrollTop: number): ViewportWindow;
}