import { ComponentController, ComponentInstance } from 'maverick.js/element';
export declare class IntersectionObserverController extends ComponentController {
    private _init;
    private _observer;
    constructor(instance: ComponentInstance, _init: IntersectionObserverInit);
    protected onConnect(el: HTMLElement): () => void;
    /**
     * Disconnect any active intersection observers.
     */
    _disconnect(): void;
}
export interface IntersectionObserverInit {
    /**
     * The element that is used as the viewport for checking visibility of the target. Must be the
     * ancestor of the target. Defaults to the browser viewport if not specified or if `null`.
     */
    root?: Element | Document | null;
    /**
     * Margin around the root. Can have values similar to the CSS margin property, e.g.
     * "10px 20px 30px 40px" (top, right, bottom, left). The values can be percentages. This set
     * of values serves to grow or shrink each side of the root element's bounding box before
     * computing intersections. Defaults to all zeros.
     */
    rootMargin?: string;
    /**
     * Either a single number or an array of numbers which indicate at what percentage of the
     * target's visibility the observer's callback should be executed. If you only want to detect
     * when visibility passes the `50%` mark, you can use a value of `0.5`. If you want the callback
     * to run every time visibility passes another `25%`, you would specify the array
     * `[0, 0.25, 0.5, 0.75, 1]`.
     *
     * The default is `0` (meaning as soon as even one pixel is visible, the callback will be run).
     * A value of `1.0` means that the threshold isn't considered passed until every pixel is
     * visible.
     */
    threshold?: number | number[];
    /**
     * Invoked when an intersection event occurs.
     */
    callback?: IntersectionObserverCallback;
}