import IEventListener from './IEventListener';
import Event from './Event';
import IEventTarget from './IEventTarget';
import IEventListenerOptions from './IEventListenerOptions';
/**
 * Handles events.
 */
export default abstract class EventTarget implements IEventTarget {
    readonly _listeners: {
        [k: string]: (((event: Event) => void) | IEventListener)[];
    };
    readonly _listenerOptions: {
        [k: string]: (IEventListenerOptions | null)[];
    };
    /**
     * Adds an event listener.
     *
     * @param type Event type.
     * @param listener Listener.
     * @param options An object that specifies characteristics about the event listener.(currently only once)
     * @param options.once
     */
    addEventListener(type: string, listener: ((event: Event) => void) | IEventListener, options?: IEventListenerOptions): void;
    /**
     * Adds an event listener.
     *
     * @param type Event type.
     * @param listener Listener.
     */
    removeEventListener(type: string, listener: ((event: Event) => void) | IEventListener): void;
    /**
     * Dispatches an event.
     *
     * @param event Event.
     * @returns The return value is false if event is cancelable and at least one of the event handlers which handled this event called Event.preventDefault().
     */
    dispatchEvent(event: Event): boolean;
    /**
     * Adds an event listener.
     *
     * TODO:
     * Was used by with IE8- and Opera. React believed Happy DOM was a legacy browser and used them, but that is no longer the case, so we should remove this method after that this is verified.
     *
     * @deprecated
     * @param type Event type.
     * @param listener Listener.
     */
    attachEvent(type: string, listener: ((event: Event) => void) | IEventListener): void;
    /**
     * Removes an event listener.
     *
     * TODO:
     * Was used by IE8- and Opera. React believed Happy DOM was a legacy browser and used them, but that is no longer the case, so we should remove this method after that this is verified.
     *
     * @deprecated
     * @param type Event type.
     * @param listener Listener.
     */
    detachEvent(type: string, listener: ((event: Event) => void) | IEventListener): void;
}