export declare enum CallbackType {
    enter = "enter",
    exit = "exit"
}
export default abstract class Notifications {
    private registry;
    constructor();
    /**
     * Adds an EventListener as a callback for an event key.
     * @param type 'enter' or 'exit'
     * @param key The key of the event
     * @param callback The callback function to invoke when the event occurs
     */
    addCallback(type: CallbackType, element: HTMLElement | Window, callback: (data?: any) => void): void;
    removeElementNotification(element: HTMLElement | Window): void;
    elementNotificationExists(element: HTMLElement | Window): boolean;
    /**
     * @hidden
     * Executes registered callbacks for key.
     * @param type
     * @param element
     * @param data
     */
    dispatchCallback(type: CallbackType, element: HTMLElement | Window, data?: any): void;
}