appeerjs/lib/eventdispatcher.js

A basic encapsulation of Native WebRTC, this would offer an easy to use and understand API for beginners out there

/**
 * @author mrdoob / http://mrdoob.com/
 */


'use strict';

function EventDispatcher() {}

Object.assign(EventDispatcher.prototype, {

    addEventListener: function (type, listener) {
        if (this._listeners === undefined) this._listeners = {};

        var listeners = this._listeners;

        if (listeners[type] === undefined) {
            listeners[type] = [];
        }

        if (listeners[type].indexOf(listener) === - 1) {
            listeners[type].push(listener);
        }
    },

    hasEventListener: function (type, listener) {
        if (this._listeners === undefined) return false;

        var listeners = this._listeners;

        if (listeners[type] !== undefined && listeners[type].indexOf(listener) !== -1) {
            return true;
        }

        return false;
    },

    removeEventListener: function (type, listener) {
        if (this._listeners === undefined) return;

        var listeners = this._listeners;
        var listenerArray = listeners[ type ];

        if (listenerArray !== undefined) {
            var index = listenerArray.indexOf(listener);

            if (index !== -1) {
                listenerArray.splice(index, 1);
            }
        }
    },

    dispatchEvent: function (event) {
        if (this._listeners === undefined) return;

        var listeners = this._listeners;
        var listenerArray = listeners[event.type];

        if (listenerArray !== undefined) {
            event.target = this;

            var i = 0,
                array = [],
                length = listenerArray.length;

            for (i = 0; i < length; i++) {
                array[i] = listenerArray[i];
            }

            for (i = 0; i < length; i++) {
                array[i].call(this, event);
            }
        }
    },

    on: function (eventName, listener) {
        this.addEventListener(eventName, listener);
    },

    emit: function (eventName, data) {
        var event = {
            type: eventName,
            data: data
        };

        this.dispatchEvent(event);
    }

});

module.exports = EventDispatcher;