User Guide

356 ActionScript classes

To clear the filters for a button, set filters to an empty array ([]).

At load time, if a button has an associated filter, it is marked to cache itself as a transparent

bitmap. From this point forward, as long as the button has a valid filter list, the player caches

the button as a bitmap. This bitmap is used as a source image for the filter effects. Each

button usually has two sets of bitmaps: one with the original unfiltered source button and

another for the final images (in each of the four button states) after filtering. The final image

set is used when rendering. As long as the button does not change, the final image does not

need updating.

If you are working with a

filters array that contains multiple filters and you need to track

the type of filter assigned to each array index, you can maintain your own

filters array and

use a separate data structure to track the type of filter associated with each array index. There

is no simple way to determine the type of filter associated with each

filters array index.

Availability: ActionScript 1.0; Flash Player 8

Example

The following example adds a drop shadow filter to a button named

myButton.

import flash.filters.DropShadowFilter;

var myDropFilter:DropShadowFilter = new DropShadowFilter(6, 45, 0x000000,

50, 5, 5, 1, 2, false, false, false);

var myFilters:Array = myButton.filters;

myFilters.push(myDropFilter);

myButton.filters = myFilters;

The following example changes the quality setting of the first filter in the array to 15 (this

example works only if at least one filter object has been associated with the

myButton text

field).

var myList:Array = myButton.filters;

myList[0].quality = 15;

myButton.filters = myList;