import { ItemSize, VirtualRange } from '../types';
export declare class VirtualizationEngine {
    private tree;
    private estimatedItemSize;
    private itemCount;
    constructor(estimatedItemSize?: number);
    setItemCount(count: number): void;
    recordItemSize(index: number, size: number): void;
    /**
     * Invalidate cached measurements from `fromIndex` onward
     * (inclusive), or everything if omitted. Affected indices fall
     * back to `estimatedItemSize` until re-measured.
     *
     * Each reset index is a single O(log n) point update - so
     * invalidating a suffix of k items is O(k log n), not a full
     * array rebuild. A full invalidate (no fromIndex) is the one
     * intentionally O(n) path in this class, reserved for "the whole
     * dataset changed" situations, not the scroll hot path.
     */
    invalidateFrom(fromIndex?: number): void;
    getItemSize(index: number): number;
    getItemOffset(index: number): number;
    getTotalSize(): number;
    getVisibleRange(scrollOffset: number, containerSize: number, itemCount: number, overscan?: number): VirtualRange;
    getVisibleItems(scrollOffset: number, containerSize: number, itemCount: number, overscan: number): ItemSize[];
    getScrollOffsetForIndex(index: number, containerSize: number, alignment?: 'start' | 'center' | 'end'): number;
}
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