User Guide

Menu.change 909
Description
Event; broadcast to all registered listeners whenever a user causes a change in the menu.
Version 2 Macromedia Component Architecture components use a dispatcher-listener event
model. When a Menu component broadcasts a
change event, the event is handled by a
function (also called a handler) that is attached to a listener object (
listenerObject) that you
create. You call the
addEventListener() method and pass it the name of the handler as a
parameter.
When the event is triggered, it automatically passes an event object (
eventObject) to the
handler. Each event object has properties that contain information about the event. You can
use these properties to write code that handles the event. The
Menu.change event’s event
object has the following additional properties:
■ menuBar A reference to the MenuBar instance that is the parent of the target menu.
When the target menu does not belong to a MenuBar instance, this value is
undefined.
■ menu A reference to the Menu instance where the target item is located.
■ menuItem An XML node that is the menu item that was selected.
■ groupName A string indicating the name of the radio button group to which the item
belongs. If the item is not in a radio button group, this value is
undefined.
For more information, see “EventDispatcher class” on page 499.
Example
The following example creates a menu, my_menu, and defines an event listener for it,
menulistener, which listens for a change event. When a user causes a change event by
clicking a menu item, the example displays its label attribute in the Output panel.
You first drag a Menu component to the library and then add the following code to Frame 1:
/**
Requires:
- Menu component in library
*/
import mx.controls.Menu;
// Create an XML object to act as a factory.
var my_xml:XML = new XML();
// The item created next does not appear in the menu.
// The createMenu() method call (below) expects to
// receive a root element whose children will become
// the items. This is just a simple way to create that
// root element and give it a convenient name.
var menuDP_obj:Object = my_xml.addMenuItem("Edit");