spark.filters

# DropShadowFilter - AS3 Flex

Package | spark.filters
Class | public class DropShadowFilter
Inheritance | DropShadowFilter BaseDimensionFilter BaseFilter EventDispatcher Object
Implements | IBitmapFilter

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

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.) 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.

MXML Syntax Show MXML Syntax
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The `<s:DropShadowFilter>` tag inherits all of the tag attributes of its superclass and adds the following tag attributes:

      <s:DropShadowFilter
        Properties
        alpha="1"
        angle="45"
        color="0xFF0000"
        distance="4"
        hideObject="false"
        inner="false"
      />

View the examples

More examples

Using filters with chart controls
Using filters

Learn more

Filters in FXG and MXML graphics

Related API Elements

flash.filters.DropShadowFilter

Public Properties
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| Property | Defined By
--- | --- | ---
|  | alpha : Number The alpha transparency value for the color. | DropShadowFilter
|  | angle : Number The angle of the bevel. | DropShadowFilter
|  | blurX : Number The amount of horizontal blur. | BaseDimensionFilter
|  | blurY : Number The amount of vertical blur. | BaseDimensionFilter
|  | color : uint The color of the glow. | DropShadowFilter
|  | constructor : Object A reference to the class object or constructor function for a given object instance. | Object
|  | distance : Number The offset distance of the bevel. | DropShadowFilter
|  | hideObject : Boolean Indicates whether or not the object is hidden. | DropShadowFilter
|  | inner : Boolean Specifies whether the glow is an inner glow. | DropShadowFilter
|  | knockout : Boolean Specifies whether the object has a knockout effect. | BaseDimensionFilter
|  | quality : int The number of times to apply the filter. | BaseDimensionFilter
|  | strength : Number The strength of the imprint or spread. | BaseDimensionFilter

Public Methods
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| Method | Defined By
--- | --- | ---
|  | 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) Constructor. | DropShadowFilter
|  | addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event. | EventDispatcher
|  | clone():BitmapFilter Returns a copy of this filter object. | DropShadowFilter
|  | dispatchEvent(event:Event):Boolean Dispatches an event into the event flow. | EventDispatcher
|  | hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event. | EventDispatcher
|  | hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined. | Object
|  | isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter. | Object
|  | notifyFilterChanged():void Propagates a change event when the filter has changed. | BaseFilter
|  | propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable. | Object
|  | removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object. | EventDispatcher
|  | setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations. | Object
|  | toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions. | Object
|  | toString():String Returns the string representation of the specified object. | Object
|  | valueOf():Object Returns the primitive value of the specified object. | Object
|  | willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type. | EventDispatcher

Events
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| Event | Summary | Defined By
--- | --- | --- | ---
|  | activate | [broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active. | EventDispatcher
|  | deactivate | [broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive. | EventDispatcher

Public Constants
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| Constant | Defined By
--- | --- | ---

Property Detail

### alpha

property

`alpha:Number`

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

The alpha transparency value for the color. Valid values are 0 to 1. For example, .25 sets a transparency value of 25%.

The default value is `1.`

Implementation
`public function get alpha():Number`
`public function set alpha(value:Number):void`

### angle

property

`angle:Number`

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

The angle of the bevel. Valid values are from 0 to 360°. The angle value represents the angle of the theoretical light source falling on the object and determines the placement of the effect relative to the object. If the distance property is set to 0, the effect is not offset from the object and, therefore, the angle property has no effect.

The default value is `45.`

Implementation
`public function get angle():Number`
`public function set angle(value:Number):void`

### color

property

`color:uint`

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

The color of the glow. Valid values are in the hexadecimal format 0xRRGGBB.

The default value is `0xFF0000.`

Implementation
`public function get color():uint`
`public function set color(value:uint):void`

### distance

property

`distance:Number`

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

The offset distance of the bevel. Valid values are in pixels (floating point).

The default value is `4.`

Implementation
`public function get distance():Number`
`public function set distance(value:Number):void`

### hideObject

property

`hideObject:Boolean`

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

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`, meaning that the object is shown.

The default value is `false.`

Implementation
`public function get hideObject():Boolean`
`public function set hideObject(value:Boolean):void`

### inner

property

`inner:Boolean`

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

Specifies whether the glow is an inner glow. The value `true` indicates an inner glow. The default is `false` that creates an outer glow (a glow around the outer edges of the object).

The default value is `false.`

Implementation
`public function get inner():Boolean`
`public function set inner(value:Boolean):void`
Constructor Detail

### DropShadowFilter

()
Constructor

`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

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

Constructor.

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.

Related API Elements

flash.filters.BitmapFilterQuality
Method Detail

### clone

()
method

`public function clone():BitmapFilter`

Language Version: | ActionScript 3.0

Product Version: | Flex 4

Runtime Versions: | Flash Player 10, AIR 1.5

Returns a copy of this filter object.

Returns

| `BitmapFilter` — A new DropShadowFilter instance with all the properties of the original DropShadowFilter instance.

Examples How to use this example
DropShadowFilterExample.mxml
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    <?xml version="1.0"?>
    <!-- filters/examples/DropShadowFilterExample.mxml -->
    <s:Application
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:mx="library://ns.adobe.com/flex/mx"
        xmlns:s="library://ns.adobe.com/flex/spark"
        creationComplete="createFilters()">

      <fx:Script><![CDATA[
         import spark.filters.*;
         import flash.filters.BitmapFilterQuality;
         import flash.filters.BitmapFilterType;

         private var myDropShadowFilter:DropShadowFilter;
         private var color:Number = 0xFF33FF;

         public function createFilters():void {
            myDropShadowFilter = new DropShadowFilter(15, 45,
                color, 0.8, 8, 8, 0.65, BitmapFilterQuality.MEDIUM, false, false);
            b1.filters = [myDropShadowFilter];
         }

      ]]></fx:Script>

        <s:VGroup>
            <!-- This button has a filter applied in ActionScript. -->
            <s:Button id="b1" label="Click me"/>

            <!-- This button has a filter applied in MXML. -->
            <s:Button id="b2" label="Click me">
                <s:filters>
                    <s:DropShadowFilter
                        distance="15"
                        angle="45"
                        color="0xFF33FF"
                        alpha=".8"
                        blurX="8"
                        blurY="8"
                        strength=".65"
                        quality="{BitmapFilterQuality.MEDIUM}"
                        inner="false"
                        knockout="false"/>
                </s:filters>
            </s:Button>

        </s:VGroup>
    </s:Application>

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Mon Apr 10 2017, 12:28 PM -07:00