Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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
filters
property (inherited from DisplayObject). Setting the filters
property of an object does not modify the object, and you can remove the filter by clearing the
filters
property.
- To apply filters to BitmapData objects, use the
BitmapData.applyFilter()
method.
Calling applyFilter()
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.
View the examples
alpha:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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.
Implementation public function get alpha():Number
public function set alpha(value:Number):void
angle:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The angle of the shadow. Valid values are 0 to 360 degrees (floating point). The
default value is 45.
Implementation public function get angle():Number
public function set angle(value:Number):void
blurX:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The amount of horizontal blur. Valid values are 0 to 255.0 (floating point). The
default value is 4.0.
Implementation public function get blurX():Number
public function set blurX(value:Number):void
blurY:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The amount of vertical blur. Valid values are 0 to 255.0 (floating point). The
default value is 4.0.
Implementation public function get blurY():Number
public function set blurY(value:Number):void
color:uint
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The color of the shadow. Valid values are in hexadecimal format 0xRRGGBB. The
default value is 0x000000.
Implementation public function get color():uint
public function set color(value:uint):void
distance:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The offset distance for the shadow, in pixels. The default
value is 4.0 (floating point).
Implementation public function get distance():Number
public function set distance(value:Number):void
hideObject:Boolean
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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).
Implementation public function get hideObject():Boolean
public function set hideObject(value:Boolean):void
inner:Boolean
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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).
Implementation public function get inner():Boolean
public function set inner(value:Boolean):void
knockout:Boolean
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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).
Implementation public function get knockout():Boolean
public function set knockout(value:Boolean):void
quality:int
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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.
Implementation public function get quality():int
public function set quality(value:int):void
See also
strength:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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 from 0 to 255.0. The default is 1.0.
Implementation public function get strength():Number
public function set strength(value:Number):void
public function DropShadowFilter(distance:Number = 4.0, angle:Number = 45, color:uint = 0, alpha:Number = 1.0, blurX:Number = 4.0, blurY:Number = 4.0, strength:Number = 1.0, quality:int = 1, inner:Boolean = false, knockout:Boolean = false, hideObject:Boolean = false)
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
Creates a new DropShadowFilter instance with the specified parameters.
Parameters | distance:Number (default = 4.0 ) — Offset distance for the shadow, in pixels.
|
|
| angle:Number (default = 45 ) — Angle of the shadow, 0 to 360 degrees (floating point).
|
|
| color:uint (default = 0 ) — Color of the shadow, in hexadecimal format
0xRRGGBB. The default value is 0x000000.
|
|
| alpha:Number (default = 1.0 ) — 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:Number (default = 4.0 ) — Amount of horizontal blur. Valid values are 0 to 255.0 (floating point).
|
|
| blurY:Number (default = 4.0 ) — Amount of vertical blur. Valid values are 0 to 255.0 (floating point).
|
|
| strength:Number (default = 1.0 ) — 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:int (default = 1 ) — The number of times to apply the filter. Use the BitmapFilterQuality constants:
BitmapFilterQuality.LOW BitmapFilterQuality.MEDIUM BitmapFilterQuality.HIGH
For more information about these values, see the quality property description.
|
|
| inner:Boolean (default = false ) — Indicates whether or not the shadow is an inner shadow. A value of true specifies
an inner shadow. A value of false specifies an outer shadow (a
shadow around the outer edges of the object).
|
|
| knockout:Boolean (default = false ) — Applies a knockout effect (true ), which effectively
makes the object's fill transparent and reveals the background color of the document.
|
|
| hideObject:Boolean (default = false ) — Indicates whether or not the object is hidden. A value of true
indicates that the object itself is not drawn; only the shadow is visible.
|
See also
override public function clone():BitmapFilter
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
Returns a copy of this filter object.
Returns | BitmapFilter — A new DropShadowFilter instance with all the
properties of the original DropShadowFilter instance.
|
The following example creates a yellow square and applies a drop shadow to it.
The general workflow of this example is as follows:
- Declare three properties that are used to draw the square to which the
filter is applied.
- Create the constructor function. The constructor calls the
draw()
method,
which uses methods of the Graphics class accessed through the graphics
property of Sprite to draw an orange square. - In the constructor, declare a variable
filter
as a BitmapFilter object
and assign it to the return value of a call to getBitmapFilter()
.
The getBitmapFilter()
method defines the drop shadow filter used. - Create a new Array object
myFilters
and add filter
to
the array. Assign the myFilters
array to the filters
property of
the DropShadowFilterExample object. This applies all filters found in myFilters
, which in this case
is only filter
.
package {
import flash.display.Sprite;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.filters.BitmapFilter;
import flash.filters.BitmapFilterQuality;
import flash.filters.DropShadowFilter;
public class DropShadowFilterExample extends Sprite {
private var bgColor:uint = 0xFFCC00;
private var size:uint = 80;
private var offset:uint = 50;
public function DropShadowFilterExample() {
draw();
var filter:BitmapFilter = getBitmapFilter();
var myFilters:Array = new Array();
myFilters.push(filter);
filters = myFilters;
}
private function getBitmapFilter():BitmapFilter {
var color:Number = 0x000000;
var angle:Number = 45;
var alpha:Number = 0.8;
var blurX:Number = 8;
var blurY:Number = 8;
var distance:Number = 15;
var strength:Number = 0.65;
var inner:Boolean = false;
var knockout:Boolean = false;
var quality:Number = BitmapFilterQuality.HIGH;
return new DropShadowFilter(distance,
angle,
color,
alpha,
blurX,
blurY,
strength,
quality,
inner,
knockout);
}
private function draw():void {
graphics.beginFill(bgColor);
graphics.drawRect(offset, offset, size, size);
graphics.endFill();
}
}
}
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Sat Oct 3 2009, 04:15 AM -07:00