/**
 * HeightManager handles row height caching and calculations for virtual scrolling.
 * It maintains a cache of measured row heights and provides methods to calculate
 * scroll positions, visible ranges, and total heights.
 */
export declare class HeightManager {
    /** Cache of measured row heights by row ID. */
    private heightCache;
    /** Estimated height for unmeasured rows. */
    private estimatedRowHeight;
    /** Sum of all measured heights. */
    private totalMeasuredHeight;
    /** Number of measured rows. */
    private measuredCount;
    /**
     * Creates a new HeightManager.
     *
     * @param estimatedRowHeight - Initial estimated height for unmeasured rows.
     */
    constructor(estimatedRowHeight?: number);
    /**
     * Set or update the height for a specific row.
     *
     * @param rowId - The unique identifier of the row.
     * @param height - The measured height of the row in pixels.
     * @returns True if the height changed, false otherwise.
     */
    setHeight(rowId: string, height: number): boolean;
    /**
     * Get the height for a specific row.
     * Returns the measured height if available, otherwise the estimated height.
     *
     * @param rowId - The unique identifier of the row.
     * @returns The height of the row in pixels.
     */
    getHeight(rowId: string): number;
    /**
     * Check if a row has been measured.
     *
     * @param rowId - The unique identifier of the row.
     * @returns True if the row has been measured.
     */
    hasMeasurement(rowId: string): boolean;
    /**
     * Get the average height of measured rows.
     * Falls back to the estimated height if no rows have been measured.
     *
     * @returns The average row height in pixels.
     */
    getAverageHeight(): number;
    /**
     * Calculate the total height for a given number of rows.
     *
     * @param rowIds - Array of row IDs in order.
     * @returns The total height in pixels.
     */
    getTotalHeight(rowIds: string[]): number;
    /**
     * Calculate the offset (top position) for a given row index.
     *
     * @param rowIds - Array of row IDs in order.
     * @param index - The index of the target row.
     * @returns The offset from the top in pixels.
     */
    getOffsetForIndex(rowIds: string[], index: number): number;
    /**
     * Calculate which rows are visible given a scroll position and viewport height.
     *
     * @param rowIds - Array of row IDs in order.
     * @param scrollTop - Current scroll position.
     * @param viewportHeight - Height of the visible area.
     * @param bufferSize - Number of extra rows to render above/below.
     * @returns Object with start and end indices of visible rows.
     */
    getVisibleRange(rowIds: string[], scrollTop: number, viewportHeight: number, bufferSize: number): {
        start: number;
        end: number;
    };
    /**
     * Find the row index at a given scroll position.
     *
     * @param rowIds - Array of row IDs in order.
     * @param scrollTop - The scroll position to find.
     * @returns The index of the row at that position.
     */
    getIndexAtOffset(rowIds: string[], scrollTop: number): number;
    /**
     * Clear all cached heights.
     */
    clear(): void;
    /**
     * Remove a specific row from the cache.
     *
     * @param rowId - The unique identifier of the row to remove.
     */
    remove(rowId: string): void;
    /**
     * Get the number of measured rows.
     */
    get size(): number;
    /**
     * Update the estimated row height.
     *
     * @param height - New estimated height in pixels.
     */
    setEstimatedRowHeight(height: number): void;
}