import { InjectionToken } from '@angular/core';
import { Subscription } from 'rxjs';
import { TreeModel, TreeNode } from '../models';
export declare const VIRTUAL_SCROLL_NODE_HEIGHT_QUOTA: InjectionToken<unknown>;
export interface PosPair {
    startPos: number;
    endPos: number;
}
export declare class TreeVirtualScroll {
    private quota;
    id: number;
    averageNodeHeight: number;
    hasEnoughNodeHeight: boolean;
    private currentViewport;
    private lastScrollTop;
    private disabled;
    private collectionMonitor$;
    private nodeHeightAnalytics$;
    constructor(quota: number);
    adjustViewport(viewport: ClientRect, scrollTop: number): void;
    waitForCollection(observer: any): Subscription;
    reportNodeHeight(data: number): void;
    reCalcPositions(treeModel: TreeModel): void;
    setDisabled(isDisabled: boolean): void;
    isDisabled(): boolean;
    scrollIntoView(node: TreeNode, force: boolean, scrollToMiddle?: boolean): number | null;
    private getPositionAfter;
    private getPositionAfterNode;
    private collectAverageNodeHeight;
}