import { InternalDataItem, VirtualItemKey } from '../interface'; export declare function useItemHeight(props: { estimatedItemHeight?: number; data: InternalDataItem[]; }): { itemHeight: import("vue").ComputedRef; minItemHeight: import("vue").ComputedRef; estimatedItemHeight: import("vue").Ref; totalHeight: import("vue").ComputedRef; setItemHeight: (key: VirtualItemKey, height: number) => void; getItemHeight: (key: VirtualItemKey) => number | undefined; getItemHeightOrDefault: (key: VirtualItemKey) => number; getItemHeightByIndex: (index: number) => number | undefined; getItemHeightOrDefaultByIndex: (index: number) => number; };