@lightningjs/renderer/src/common/IEventEmitter.ts

Lightning 3 Renderer

/*
 * Copyright 2023 Comcast Cable Communications Management, LLC
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

export interface IEventEmitter<
  T extends object = { [s: string]: (target: any, data: any) => void },
> {
  on<K extends keyof T>(event: Extract<K, string>, listener: T[K]): void;
  once<K extends keyof T>(event: Extract<K, string>, listener: T[K]): void;
  off<K extends keyof T>(event: Extract<K, string>, listener: T[K]): void;
  emit<K extends keyof T>(
    event: Extract<K, string>,
    data: Parameters<any>[1],
  ): void;
}