import { Observable, EventData } from '../observable';
import { ChangedData } from '../observable-array';
/**
 * Event args for "itemsLoading" event.
 */
export interface ItemsLoading extends EventData {
    /**
     * Start index.
     */
    index: number;
    /**
     * Number of items to load.
     */
    count: number;
}
/**
 * Advanced array like class that helps loading items on demand.
 */
export declare class VirtualArray<T> extends Observable {
    /**
     * String value used when hooking to change event.
     */
    static changeEvent: string;
    /**
     * String value used when hooking to itemsLoading event.
     */
    static itemsLoadingEvent: string;
    private _requestedIndexes;
    private _loadedIndexes;
    private _length;
    private _cache;
    constructor(length?: number);
    /**
     * Gets or sets length for the virtual array.
     */
    get length(): number;
    set length(value: number);
    /**
     * Gets or sets load size for the virtual array.
     */
    private _loadSize;
    get loadSize(): number;
    set loadSize(value: number);
    getItem(index: number): T;
    setItem(index: number, value: T): void;
    /**
     * Loads items from an array starting at index.
     */
    load(index: number, items: T[]): void;
    private requestItems;
}
export interface VirtualArray<T> {
    /**
     * Adds a listener for the specified event name.
     *
     * @param eventName The name of the event.
     * @param callback The event listener to add. Will be called when an event of
     * the given name is raised.
     * @param thisArg An optional parameter which, when set, will be bound as the
     * `this` context when the callback is called. Falsy values will be not be
     * bound.
     */
    on(eventName: string, callback: (data: EventData) => void, thisArg?: any): void;
    /**
     * Raised when still not loaded items are requested.
     */
    on(event: 'itemsLoading', callback: (args: ItemsLoading) => void, thisArg?: any): void;
    /**
     * Raised when a change occurs.
     */
    on(event: 'change', callback: (args: ChangedData<T>) => void, thisArg?: any): void;
}