User Guide
798 Chapter 6: Components Dictionary
The second usage example uses a dispatcher/listener event model. A component instance
(
componentInstance) dispatches an event (in this case, focusOut) and the event is handled by a
function, also called a handler, on a listener object (
listenerObject) that you create. You define
a method with the same name as the event on the listener object; the method is called when the
event is triggered. When the event is triggered, it automatically passes an event object
(
eventObject) to the listener object method. Each event object has properties that contain
information about the event. You can use these properties to write code that handles the event.
Finally, you call the
EventDispatcher.addEventListener()method on the component
instance that broadcasts the event to register the listener with the instance. When the instance
dispatches the event, the listener is called.
For more information, see “EventDispatcher class” on page 415.
Example
The following code disables a Button component, btn, while a user types in the TextInput
component,
txt, and enables the button when the user click on it:
var txt:mx.controls.TextInput;
var btn:mx.controls.Button;
var txtListener:Object = new Object();
txtListener.focusOut = function() {
_root.btn.enabled = true;
}
txt.addEventListener("focusOut", txtListener);
var txtListener2:Object = new Object();
txtListener2.focusIn = function() {
_root.btn.enabled = false;
}
txt.addEventListener("focusIn", txtListener2);
See also
EventDispatcher.addEventListener()
, UIComponent.focusIn
UIComponent.getFocus()
Availability
Flash Player 6 (6.0 79.0).
Edition
Flash MX 2004.
Usage
componentInstance.getFocus();
Parameters
None.