events.EventTarget Extends goog.Disposable
This implements the EventTarget interface as defined by W3C DOM 2/3. The main difference from the spec is that the this does not know about event propagation and therefore the flag whether to use bubbling or capturing is not used. Another difference is that event objects do not really have to implement the Event interface. An object is treated as an event object if it has a type property. It also allows you to pass a string instead of an event object and in that case an event like object is created with the type set to the string value. Unless propagation is stopped, events dispatched by an EventTarget bubble to its parent event target, returned by getParentEventTarget. To set the parent event target, call setParentEventTarget or override getParentEventTarget in a subclass. Subclasses that don't support changing the parent event target should override the setter to throw an error. Example usage: 
var et = new goog.events.EventTarget;
function f(e) {
alert("Type: " + e.type + "\nTarget: " + e.target);
}
et.addEventListener("foo", f);
...
et.dispatchEvent({type: "foo"}); // will call f
// or et.dispatchEvent("foo");
...
et.removeEventListener("foo", f);

// You can also use the EventHandler interface:
var eh = {
handleEvent: function(e) {
...
}
};
et.addEventListener("bar", eh);

Inheritance

Object
     goog.Disposable
          goog.events.EventTarget

Constructor

goog.events.EventTarget()

Instance Methods

Public Protected Private
Defined in goog.events.EventTarget
addEventListener(type, handler, opt_capture, opt_handlerScope)
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. Supported for legacy but use goog.events.listen(src, type, handler) instead.
Arguments:
type :
string
The type of the event to listen for.
handler :
Function | Object
The function to handle the event. The handler can also be an object that implements the handleEvent method which takes the event object as argument.
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.
code »
dispatchEvent(e) ⇒
boolean
Dispatches an event (or event like object) and calls all listeners listening for events of this type. The type of the event is decided by the type property on the event object. If any of the listeners returns false OR calls preventDefault then this function will return false. If one of the capture listeners calls stopPropagation, then the bubble listeners won't fire.
Arguments:
e :
string | Object | goog.events.Event
Event object.
Returns: 
boolean
  If anyone called preventDefault on the event object (or if any of the handlers returns false this will also return false.
code »
disposeInternal()
Unattach 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, it should be something like this: 
MyClass.prototype.disposeInternal = function() {
MyClass.superClass_.disposeInternal.call(this);
// Dispose logic for MyClass
};
code »
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.
code »
removeEventListener(type, handler, opt_capture, opt_handlerScope)
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.
handler :
Function | Object
The function to handle the event. The handler can also be an object that implements the handleEvent method which takes the event object as argument.
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.
code »
setParentEventTarget(parent)
Sets the parent of this event target to use for bubbling.
Arguments:
parent :
?goog.events.EventTarget
Parent EventTarget (null if none).
code »
Defined in goog.Disposable
dispose()
No description.
code »
disposeInternal()
Deletes or nulls out any references to COM objects, DOM nodes, or other disposable objects. Classes that extend {@code goog.Disposable} should override this method. For example: 
mypackage.MyClass = function() {
goog.Disposable.call(this);
// Constructor logic specific to MyClass.
...
};
goog.inherits(mypackage.MyClass, goog.Disposable);

mypackage.MyClass.prototype.disposeInternal = function() {
mypackage.MyClass.superClass_.disposeInternal.call(this);
// Dispose logic specific to MyClass.
...
};
code »
getDisposed() ⇒
boolean
No description.
Returns: 
boolean
  Whether the object has been disposed of.
code »
isDisposed() ⇒
boolean
No description.
Returns: 
boolean
  Whether the object has been disposed of.
code »

Instance Properties

Defined in goog.events.EventTarget
customEvent_ :
boolean
Used to tell if an event is a real event in goog.events.listen() so we don't get listen() calling addEventListener() and vice-versa.
Code »
parentEventTarget_ :
?goog.events.EventTarget
Parent event target, used during event bubbling.
Code »
Defined in goog.Disposable
disposed_ :
boolean
Whether the object has been disposed of.
Code »

Package events

Package Reference