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);