User Guide

DateChooser component (Flash Professional only) 363
...
}
Usage 2:
listenerObject = new Object();
listenerObject.scroll = function(eventObject){
...
}
myDC.addEventListener("scroll", listenerObject)
Description
Event; broadcast to all registered listeners when a month button is clicked.
The first usage example uses an
on() handler and must be attached directly to a DateChooser
instance. The keyword
this, used inside an on() handler attached to a component, refers to the
component instance. For example, the following code, attached to the date chooser
myDC, sends
“_level0.myDC” to the Output panel:
on(scroll){
trace(this);
}
The second usage example uses a dispatcher/listener event model. A component instance (myDC)
dispatches an event (in this case,
scroll) 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. The scroll event’s event object has an
additional property,
detail, that can have one of the following values: nextMonth,
previousMonth, nextYear, previousYear.
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
This example, written on a frame of the Timeline, sends a message to the Output panel when a
month button is clicked on a DateChooser instance called
myDC. The first line of code creates a
listener object called
form. The second line defines a function for the scroll event on the listener
object. Inside the function is a
trace() statement that uses the event object that is automatically
passed to the function, in this example
eventObj, to generate a message. The target property of
an event object is the component that generated the event—in this example,
myDC. The last line
calls
EventDispatcher.addEventListener() from myDC and passes it the scroll event and the
form listener object as parameters.
form = new Object();
form.scroll = function(eventObj){
trace(eventObj.detail);