"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
/**
 * Handles events.
 */
class EventTarget {
    constructor() {
        this._listeners = {};
        this._listenerOptions = {};
    }
    /**
     * 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, listener, options) {
        this._listeners[type] = this._listeners[type] || [];
        this._listenerOptions[type] = this._listenerOptions[type] || [];
        this._listeners[type].push(listener);
        this._listenerOptions[type].push(options || null);
    }
    /**
     * Adds an event listener.
     *
     * @param type Event type.
     * @param listener Listener.
     */
    removeEventListener(type, listener) {
        if (this._listeners[type]) {
            const index = this._listeners[type].indexOf(listener);
            if (index !== -1) {
                this._listeners[type].splice(index, 1);
                this._listenerOptions[type].splice(index, 1);
            }
        }
    }
    /**
     * 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) {
        if (!event._target) {
            event._target = this;
        }
        event._currentTarget = this;
        const onEventName = 'on' + event.type.toLowerCase();
        if (typeof this[onEventName] === 'function') {
            this[onEventName].call(this, event);
        }
        if (this._listeners[event.type]) {
            for (let i = 0, max = this._listeners[event.type].length; i < max; i++) {
                const listener = this._listeners[event.type][i];
                const options = this._listenerOptions[event.type][i];
                if (listener.handleEvent) {
                    listener.handleEvent(event);
                }
                else {
                    listener.call(this, event);
                }
                if (options?.once) {
                    this.removeEventListener(event.type, listener);
                }
                if (event._immediatePropagationStopped) {
                    return !(event.cancelable && event.defaultPrevented);
                }
            }
        }
        return !(event.cancelable && event.defaultPrevented);
    }
    /**
     * 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, listener) {
        this.addEventListener(type.replace('on', ''), listener);
    }
    /**
     * 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, listener) {
        this.removeEventListener(type.replace('on', ''), listener);
    }
}
exports.default = EventTarget;
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