OpenLayers 3 API Documentation

Class: Observable

ol.Observable

Abstract base class; normally only used for creating subclasses and not instantiated in apps. An event target providing convenient methods for listener registration and unregistration. A generic change event is always available through ol.Observable#changed.

new ol.Observable()

src/ol/observable.js, line 23

Subclasses

Extends

  • goog.events.EventTarget

Methods

ol.Observable.unByKey(key)

src/ol/observable.js, line 42

Removes an event listener using the key returned by on() or once().

Name Type Description
key goog.events.Key

The key returned by on() or once().

changed() experimental

src/ol/observable.js, line 52

Increases the revision counter and disptches a 'change' event.

Fires:
  • change experimental

getRevision(){number} experimental

src/ol/observable.js, line 62
Returns:
Revision.

on(type, listener, opt_this){goog.events.Key}

src/ol/observable.js, line 75

Listen for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object

The object to use as this in listener.
Returns:
Unique key for the listener.

once(type, listener, opt_this){goog.events.Key}

src/ol/observable.js, line 88

Listen once for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object

The object to use as this in listener.
Returns:
Unique key for the listener.

un(type, listener, opt_this)

src/ol/observable.js, line 101

Unlisten for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object

The object which was used as this by the listener.

unByKey(key)

src/ol/observable.js, line 114

Removes an event listener using the key returned by on() or once(). Note that using the ol.Observable.unByKey static function is to be preferred.

Name Type Description
key goog.events.Key

The key returned by on() or once().