A generic utility class for managing subscribers for a particular event. This class is usually instantiated inside of a container class and exposed as a property for others to subscribe to.
MyObject.prototype.myListener = function(arg1, arg2) {
    this.myArg1Copy = arg1;
    this.myArg2Copy = arg2;

const myObjectInstance = new MyObject();
const evt = new Cesium.Event();
evt.addEventListener(MyObject.prototype.myListener, myObjectInstance);
evt.raiseEvent('1', '2');


readonly numberOfListeners : number

The number of listeners currently subscribed to the event.


addEventListener(listener, scope)Event.RemoveCallback

Registers a callback function to be executed whenever the event is raised. An optional scope can be provided to serve as the this pointer in which the function will execute.
Name Type Description
listener Listener The function to be executed when the event is raised.
scope object optional An optional object scope to serve as the this pointer in which the listener function will execute.
A function that will remove this event listener when invoked.
Raises the event by calling each registered listener with all supplied arguments.
Name Type Description
arguments Parameters.<Listener> repeatable This method takes any number of parameters and passes them through to the listener functions.

removeEventListener(listener, scope)boolean

Unregisters a previously registered callback.
Name Type Description
listener Listener The function to be unregistered.
scope object optional The scope that was originally passed to addEventListener.
true if the listener was removed; false if the listener and scope are not registered with the event.

Type Definitions


A function that removes a listener.
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