export declare type Predicate<TElement, TPageObject extends PageObject<TElement>> = (pageObject: TPageObject, index: number, pageObjects: TPageObject[]) => Promise<boolean>;
export interface Page<TElement> {
    findElements(selector: string, parent?: TElement): Promise<TElement[]>;
}
export interface PageObjectConstructor<TElement, TPageObject extends PageObject<TElement>> {
    new (page: Page<TElement>): TPageObject;
}
/**
 * ### Import
 *
 * **ES2015 modules**
 *
 * ```js
 * import {PageObject} from '@pageobject/core';
 * ```
 *
 * **CommonJS**
 *
 * ```js
 * const {PageObject} = require('@pageobject/core');
 * ```
 */
export declare abstract class PageObject<TElement> {
    /**
     * The [CSS selector](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Selectors) describing this page object.
     */
    readonly abstract selector: string;
    private readonly _page;
    private _element?;
    private _parent?;
    private _selectionCriterion?;
    constructor(page: Page<TElement>);
    /**
     * You can use this method to build a tree of page objects.
     * Each page object in the tree should be assignable to a unique DOM element.
     *
     * @returns A new page object as a descendant of this page object.
     */
    select<TPageObject extends PageObject<TElement>>(Descendant: PageObjectConstructor<TElement, TPageObject>): TPageObject;
    /**
     * If the position of this page object in a tree of page objects is not
     * sufficient to assign it a unique DOM element, you can use this method to
     * define a further selection criterion.
     *
     * @returns A copy of this page object with an additional selection criterion.
     *
     * @throws An error if this page object already has a selection criterion.
     */
    where(selectionCriterion: Predicate<TElement, this>): this;
    /**
     * @returns A promise that will be resolved with the number of DOM elements
     * currently assigned to this page object.
     */
    getSize(): Promise<number>;
    /**
     * @returns A promise that will be resolved with the representative of the
     * unique DOM element assigned to this page object or a promise that will be
     * rejected if there is no unique DOM element assignable to this page object.
     */
    protected getElement(): Promise<TElement>;
    private _findElements();
}