tsparticles-engine/esm/Utils/EventDispatcher.js

Easily create highly customizable particle, confetti and fireworks animations and use them as animated backgrounds for your website. Ready to use components available also for React, Vue.js (2.x and 3.x), Angular, Svelte, jQuery, Preact, Riot.js, Inferno.

export class EventDispatcher {
    constructor() {
        this._listeners = new Map();
    }
    addEventListener(type, listener) {
        this.removeEventListener(type, listener);
        let arr = this._listeners.get(type);
        if (!arr) {
            arr = [];
            this._listeners.set(type, arr);
        }
        arr.push(listener);
    }
    dispatchEvent(type, args) {
        const listeners = this._listeners.get(type);
        listeners && listeners.forEach((handler) => handler(args));
    }
    hasEventListener(type) {
        return !!this._listeners.get(type);
    }
    removeAllEventListeners(type) {
        if (!type) {
            this._listeners = new Map();
        }
        else {
            this._listeners.delete(type);
        }
    }
    removeEventListener(type, listener) {
        const arr = this._listeners.get(type);
        if (!arr) {
            return;
        }
        const length = arr.length, idx = arr.indexOf(listener);
        if (idx < 0) {
            return;
        }
        if (length === 1) {
            this._listeners.delete(type);
        }
        else {
            arr.splice(idx, 1);
        }
    }
}