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.
Example:
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');
evt.removeEventListener(MyObject.prototype.myListener);Members
The number of listeners currently subscribed to the event.
Methods
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. |
Returns:
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. |
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. |
Returns:
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.