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ScrollPane.scroll

Availability

Flash Player 6 (6.0 79.0).

Edition

Flash MX 2004.

Usage

Usage 1:

on(scroll){
   ...
}

Usage 2:

listenerObject = new Object();
listenerObject.scroll = function(eventObject){
   ...
}
scrollPaneInstance.addEventListener("scroll", listenerObject)

Event object

In addition to the standard event object properties, there are two additional properties defined for the scroll event: a type property whose value is "scroll", and a direction property whose value can be "vertical" or "horizontal".

In addition to the standard event object properties, there are two additional properties defined for the ProgressBar.progress event: current (the loaded value equals total), and total (the total value).

Description

Event; broadcast to all registered listeners when a user clicks the scroll bar buttons, scroll box (thumb), or scroll track. Unlike other events, the scroll event is broadcast when a user presses the mouse button on the scroll bar and continues broadcasting until the mouse is released.

The first usage example uses an on() handler and must be attached directly to a ScrollPane 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 instance sp, sends "_level0.sp" to the Output panel:

on(scroll){
   trace(this);
}

The second usage example uses a dispatcher/listener event model. A component instance (scrollPaneInstance) 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. 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.

Example

This example creates a form listener object with a scroll callback function that's registered to the spInstance instance. You must fill spInstance with content.

spInstance.contentPath = "mouse3.jpg";
form = new Object();
form.scroll = function(eventObj){
   trace("ScrollPane scrolled");
}
spInstance.addEventListener("scroll", form);

See also

EventDispatcher.addEventListener()

Comments


KeithW said on May 2, 2006 at 11:03 AM :
There is another undocumented event object property, "position".
This is a better property to use if you are updating the position of moviclips outside of the scrollPane to reflect the position of the scrollPane content.
The reason is that the scrollPane's vPosition and hPosition properties give different values depending on whether you clicked a scrollBar's arrow or its thumb and also lag behind during the process of scrolling, whereas the "position" event object property always provides the correct value - during the action of scrolling and upon mouse release of either an arrow or thumb.

 

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