* Copyright (C) 2024 Red Hat, Inc.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
export class EventEmitter<EM extends { [E in keyof EM]: (...args: never[]) => void }> {
#listeners: { [E in keyof EM]?: EM[E][] } = {};
public on<E extends keyof EM>(event: E, listener: EM[E]) {
const listeners = this.#listeners[event] ||= [];
listeners.push(listener);
return () => {
listeners.splice(listeners.indexOf(listener), 1);
};
}
protected emit<E extends keyof EM>(event: E, ...args: Parameters<EM[E]>) {
for (const listener of this.#listeners[event] || []) {
listener(...args);
}
}
}
