@humanspeak/svelte-headless-table/dist/utils/HeightManager.d.ts

A powerful, headless table library for Svelte that provides complete control over table UI while handling complex data operations like sorting, filtering, pagination, grouping, and row expansion. Build custom, accessible data tables with zero styling opin

/**
 * 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;
}