The DropShadowFilter class lets you add a drop shadow to display objects. The shadow algorithm is based on the same box filter that the blur filter uses. You have several options for the style of the drop shadow, including inner or outer shadow and knockout mode. You can apply the filter to any display object(that is, objects that inherit from the DisplayObject class), such as MovieClip, SimpleButton, TextField, and Video objects, as well as to BitmapData objects.
The use of filters depends on the object to which you apply the filter:
- To apply filters to display objects use the
filtersproperty(inherited from DisplayObject). Setting thefiltersproperty of an object does not modify the object, and you can remove the filter by clearing thefiltersproperty. - To apply filters to BitmapData objects, use the
BitmapData.applyFilter()method. CallingapplyFilter()on a BitmapData object takes the source BitmapData object and the filter object and generates a filtered image as a result.
If you apply a filter to a display object, the value of the
cacheAsBitmap property of the display object is set to
true. If you clear all filters, the original value of
cacheAsBitmap is restored.
This filter supports Stage scaling. However, it does not support general
scaling, rotation, and skewing. If the object itself is scaled(if
scaleX and scaleY are set to a value other than
1.0), the filter is not scaled. It is scaled only when the user zooms in on
the Stage.
A filter is not applied if the resulting image exceeds the maximum dimensions. In AIR 1.5 and Flash Player 10, the maximum is 8,191 pixels in width or height, and the total number of pixels cannot exceed 16,777,215 pixels.(So, if an image is 8,191 pixels wide, it can only be 2,048 pixels high.) In Flash Player 9 and earlier and AIR 1.1 and earlier, the limitation is 2,880 pixels in height and 2,880 pixels in width. If, for example, you zoom in on a large movie clip with a filter applied, the filter is turned off if the resulting image exceeds the maximum dimensions.
Constructor
new (distance:Float = 4, angle:Float = 45, color:Int = 0, alpha:Float = 1, blurX:Float = 4, blurY:Float = 4, strength:Float = 1, quality:Int = 1, inner:Bool = false, knockout:Bool = false, hideObject:Bool = false)
Creates a new DropShadowFilter instance with the specified parameters.
Parameters:
distance | Offset distance for the shadow, in pixels. |
|---|---|
angle | Angle of the shadow, 0 to 360 degrees(floating point). |
color | Color of the shadow, in hexadecimal format 0xRRGGBB. The default value is 0x000000. |
alpha | Alpha transparency value for the shadow color. Valid values are 0.0 to 1.0. For example, .25 sets a transparency value of 25%. |
blurX | Amount of horizontal blur. Valid values are 0 to 255.0 (floating point). |
blurY | Amount of vertical blur. Valid values are 0 to 255.0 (floating point). |
strength | The strength of the imprint or spread. The higher the value, the more color is imprinted and the stronger the contrast between the shadow and the background. Valid values are 0 to 255.0. |
quality | The number of times to apply the filter. Use the BitmapFilterQuality constants:
For more information about these values, see the
|
inner | Indicates whether or not the shadow is an inner shadow.
A value of |
knockout | Applies a knockout effect( |
hideObject | Indicates whether or not the object is hidden. A value
of |
Variables
The alpha transparency value for the shadow color. Valid values are 0.0 to 1.0. For example, .25 sets a transparency value of 25%. The default value is 1.0.
The angle of the shadow. Valid values are 0 to 360 degrees(floating point). The default value is 45.
The amount of horizontal blur. Valid values are 0 to 255.0(floating point). The default value is 4.0.
The color of the shadow. Valid values are in hexadecimal format 0xRRGGBB. The default value is 0x000000.
read onlyhideObject:Bool
Indicates whether or not the object is hidden. The value true
indicates that the object itself is not drawn; only the shadow is visible.
The default is false(the object is shown).
Indicates whether or not the shadow is an inner shadow. The value
true indicates an inner shadow. The default is
false, an outer shadow(a shadow around the outer edges of
the object).
Applies a knockout effect(true), which effectively makes the
object's fill transparent and reveals the background color of the
document. The default is false(no knockout).
The number of times to apply the filter. The default value is
BitmapFilterQuality.LOW, which is equivalent to applying the
filter once. The value BitmapFilterQuality.MEDIUM applies the
filter twice; the value BitmapFilterQuality.HIGH applies it
three times. Filters with lower values are rendered more quickly.
For most applications, a quality value of low, medium, or high is
sufficient. Although you can use additional numeric values up to 15 to
achieve different effects, higher values are rendered more slowly. Instead
of increasing the value of quality, you can often get a
similar effect, and with faster rendering, by simply increasing the values
of the blurX and blurY properties.