events.EventTarget Extends goog.Disposable
An implementation of goog.events.Listenable with full W3C EventTarget-like support (capture/bubble mechanism, stopping event propagation, preventing default actions). You may subclass this class to turn your class into a Listenable. Unless propagation is stopped, an event dispatched by an EventTarget will bubble to the parent returned by getParentEventTarget. To set the parent, call setParentEventTarget. Subclasses that don't support changing the parent can override the setter to throw an error. Example usage:
  var source = new goog.events.EventTarget();
  function handleEvent(e) {
    alert('Type: ' + e.type + '; Target: ' + e.target);
  }
  source.listen('foo', handleEvent);
  // Or: goog.events.listen(source, 'foo', handleEvent);
  ...
  source.dispatchEvent('foo');  // will call handleEvent
  ...
  source.unlisten('foo', handleEvent);
  // Or: goog.events.unlisten(source, 'foo', handleEvent);

Inheritance

Constructor

goog.events.EventTarget()

Instance Methods

Public Protected Private
addEventListener(typeopt_captureopt_handlerScope)
Use #listen instead, when possible. Otherwise, use goog.events.listen if you are passing Object (instead of Function) as handler. Adds an event listener to the event target. The same handler can only be added once per the type. Even if you add the same handler multiple times using the same type then it will only be called once when the event is dispatched.
Arguments:
type : string
The type of the event to listen for.
: ?function():? | ?{handleEvent:function():?
No description.
opt_capture : boolean=
In DOM-compliant browsers, this determines whether the listener is fired during the capture or bubble phase of the event.
opt_handlerScope : Object=
Object in whose scope to call the listener.
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assertInitialized_()
Asserts that the event target instance is initialized properly.
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dispatchEvent()
No description.
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disposeInternal()
Removes listeners from this object. Classes that extend EventTarget may need to override this method in order to remove references to DOM Elements and additional listeners.
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fireListeners()
No description.
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getListener()
No description.
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getListeners()
No description.
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getParentEventTarget() goog.events.EventTarget
Returns the parent of this event target to use for bubbling.
Returns: goog.events.EventTarget  The parent EventTarget or null if there is no parent.
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hasListener()
No description.
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listen()
No description.
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listenOnce()
No description.
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removeAllListeners()
No description.
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removeEventListener(typeopt_captureopt_handlerScope)
Use #unlisten instead, when possible. Otherwise, use goog.events.unlisten if you are passing Object (instead of Function) as handler. Removes an event listener from the event target. The handler must be the same object as the one added. If the handler has not been added then nothing is done.
Arguments:
type : string
The type of the event to listen for.
: ?function():? | ?{handleEvent:function():?
No description.
opt_capture : boolean=
In DOM-compliant browsers, this determines whether the listener is fired during the capture or bubble phase of the event.
opt_handlerScope : Object=
Object in whose scope to call the listener.
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setParentEventTarget(parent)
Sets the parent of this event target to use for capture/bubble mechanism.
Arguments:
parent : goog.events.EventTarget
Parent listenable (null if none).
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setTargetForTesting(target)
Sets the target to be used for event.target when firing event. Mainly used for testing. For example, see goog.testing.events.mixinListenable.
Arguments:
target : !Object
The target.
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unlisten()
No description.
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unlistenByKey()
No description.
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addOnDisposeCallback(callbackopt_scope)
Invokes a callback function when this object is disposed. Callbacks are invoked in the order in which they were added.
Arguments:
callback : function(this:T):?
The callback function.
opt_scope : T=
An optional scope to call the callback in.
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dispose() void
Disposes of the object. If the object hasn't already been disposed of, calls #disposeInternal. Classes that extend goog.Disposable should override #disposeInternal in order to delete references to COM objects, DOM nodes, and other disposable objects. Reentrant.
Returns: void  Nothing.
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disposeInternal()
Deletes or nulls out any references to COM objects, DOM nodes, or other disposable objects. Classes that extend goog.Disposable should override this method. Not reentrant. To avoid calling it twice, it must only be called from the subclass' disposeInternal method. Everywhere else the public dispose method must be used. For example:
  mypackage.MyClass = function() {
    goog.base(this);
    // Constructor logic specific to MyClass.
    ...
  };
  goog.inherits(mypackage.MyClass, goog.Disposable);

  mypackage.MyClass.prototype.disposeInternal = function() {
    // Dispose logic specific to MyClass.
    ...
    // Call superclass's disposeInternal at the end of the subclass's, like
    // in C++, to avoid hard-to-catch issues.
    goog.base(this, 'disposeInternal');
  };
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getDisposed() boolean
Use #isDisposed instead. No description.
Returns: boolean  Whether the object has been disposed of.
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isDisposed() boolean
No description.
Returns: boolean  Whether the object has been disposed of.
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registerDisposable(disposable)
Associates a disposable object with this object so that they will be disposed together.
Arguments:
disposable : goog.disposable.IDisposable
that will be disposed when this object is disposed.
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Instance Properties

actualEventTarget_ : goog.events.EventTarget
The object to use for event.target. Useful when mixing in an EventTarget to another object.
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constructor :
No description.
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eventTargetListeners_ : goog.events.ListenerMap
Maps of event type to an array of listeners.
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parentEventTarget_ : goog.events.EventTarget
Parent event target, used during event bubbling. TODO(user): Change this to goog.events.Listenable. This currently breaks people who expect getParentEventTarget to return goog.events.EventTarget.
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creationStack :
If monitoring the goog.Disposable instances is enabled, stores the creation stack trace of the Disposable instance.
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disposed_ :
Whether the object has been disposed of.
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onDisposeCallbacks_ :
Callbacks to invoke when this object is disposed.
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Static Methods

goog.events.EventTarget.dispatchEventInternal_(targeteopt_ancestorsTree) boolean
Dispatches the given event on the ancestorsTree.
Arguments:
target : !Object
The target to dispatch on.
e : goog.events.Event | Object | string
The event object.
opt_ancestorsTree : Array.<goog.events.Listenable>>
The ancestors tree of the target, in reverse order from the closest ancestor to the root event target. May be null if the target has no ancestor.
Returns: boolean  If anyone called preventDefault on the event object (or if any of the listeners returns false) this will also return false.
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Static Properties

goog.events.EventTarget.MAX_ANCESTORS_ :
An artificial cap on the number of ancestors you can have. This is mainly for loop detection.
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goog.events.EventTarget.superClass_ :
No description.
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Package events

Package Reference