import * as i0 from "@angular/core";
/**
 * Enterprise virtualization engine for the DataGrid.
 * Handles both row (vertical) and column (horizontal) virtualization
 * for high-performance rendering of massive datasets (100K+ rows, 200+ columns).
 *
 * Row virtualization renders only the visible rows plus a configurable buffer,
 * using spacer elements to maintain correct scroll position.
 *
 * Column virtualization renders only the visible columns plus a buffer,
 * using left/right spacer cells to maintain correct horizontal scroll position.
 */
export declare class GridVirtualizationService {
    readonly rowHeight: import("@angular/core").WritableSignal<number>;
    readonly viewportHeight: import("@angular/core").WritableSignal<number>;
    readonly viewportWidth: import("@angular/core").WritableSignal<number>;
    readonly scrollTop: import("@angular/core").WritableSignal<number>;
    readonly scrollLeft: import("@angular/core").WritableSignal<number>;
    readonly totalRows: import("@angular/core").WritableSignal<number>;
    readonly columnWidths: import("@angular/core").WritableSignal<number[]>;
    readonly rowBuffer: import("@angular/core").WritableSignal<number>;
    readonly colBuffer: import("@angular/core").WritableSignal<number>;
    private readonly rowHeightCache;
    readonly useVariableHeight: import("@angular/core").WritableSignal<boolean>;
    readonly infiniteScrollEnabled: import("@angular/core").WritableSignal<boolean>;
    readonly infiniteScrollThreshold: import("@angular/core").WritableSignal<number>;
    readonly isLoadingMore: import("@angular/core").WritableSignal<boolean>;
    private loadedBlockRanges;
    /** Index of the first visible row (0-based) */
    readonly startRowIndex: import("@angular/core").Signal<number>;
    /** Index of the last visible row (0-based, exclusive) */
    readonly endRowIndex: import("@angular/core").Signal<number>;
    /** Total virtual content height for the scrollbar */
    readonly totalContentHeight: import("@angular/core").Signal<number>;
    /** Top spacer height (space before the first rendered row) */
    readonly topSpacerHeight: import("@angular/core").Signal<number>;
    /** Bottom spacer height (space after the last rendered row) */
    readonly bottomSpacerHeight: import("@angular/core").Signal<number>;
    /** Number of rows currently rendered in the DOM */
    readonly renderedRowCount: import("@angular/core").Signal<number>;
    /** Index of the first visible column (0-based) */
    readonly startColIndex: import("@angular/core").Signal<number>;
    /** Index of the last visible column (0-based, exclusive) */
    readonly endColIndex: import("@angular/core").Signal<number>;
    /** Total virtual content width for horizontal scrollbar */
    readonly totalContentWidth: import("@angular/core").Signal<number>;
    /** Left spacer width (space before first rendered column) */
    readonly leftSpacerWidth: import("@angular/core").Signal<number>;
    /** Right spacer width (space after last rendered column) */
    readonly rightSpacerWidth: import("@angular/core").Signal<number>;
    /** Update scroll position from the viewport scroll event */
    onScroll(scrollTop: number, scrollLeft: number): void;
    /** Update viewport dimensions (e.g., on resize) */
    updateViewportSize(width: number, height: number): void;
    /** Set or update the measured height for a specific row (variable height mode) */
    setRowHeight(rowIndex: number, height: number): void;
    /** Get the height of a specific row */
    getRowHeight(rowIndex: number): number;
    /** Clear the variable row height cache */
    clearHeightCache(): void;
    /** Scroll to a specific row index */
    scrollToRow(rowIndex: number): number;
    /** Scroll to a specific column index */
    scrollToColumn(colIndex: number): number;
    /** Check if we should trigger loading more data */
    shouldLoadMore(): boolean;
    /** Register a loaded block range */
    registerLoadedBlock(start: number, end: number): void;
    /** Check if a row index has been loaded */
    isRowLoaded(rowIndex: number): boolean;
    /** Reset infinite scroll state */
    resetInfiniteScroll(): void;
    /** Find the row index at a given pixel offset (variable height) */
    private findRowAtOffset;
    /** Compute the total height of all rows (variable height) */
    private computeTotalVariableHeight;
    /** Compute the combined height of rows in a range [startIdx, endIdx) */
    private computeHeightRange;
    static ɵfac: i0.ɵɵFactoryDeclaration<GridVirtualizationService, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<GridVirtualizationService>;
}