Packagemx.graphics
Classpublic class RectangularDropShadow
InheritanceRectangularDropShadow Inheritance Object

Drop shadows are typically created using the DropShadowFilter class. However, the DropShadowFilter, like all bitmap filters, can be computationally expensive. If the DropShadowFilter is applied to a DisplayObject, then the drop shadow is recalculated whenever the appearance of the object changes. If the DisplayObject is animated (using a Resize effect, for example), then the presence of drop shadows hurts the animation refresh rate.

This class optimizes drop shadows for a common case. If you are applying a drop shadow to a rectangularly-shaped object whose edges fall on pixel boundaries, then this class should be used instead of using the DropShadowFilter directly.

This class accepts the first four parameters that are passed to DropShadowFilter: alpha, angle, color, and distance. In addition, this class accepts the corner radii for each of the four corners of the rectangularly-shaped object that is casting a shadow.

Once those 8 values have been set, this class pre-computes the drop shadow in an offscreen Bitmap. When the drawShadow() method is called, pieces of the precomputed drop shadow are copied onto the passed-in Graphics object.

See also

flash.filters.DropShadowFilter
flash.display.DisplayObject


Public Properties
 PropertyDefined By
  alpha : Number
The alpha transparency value for the shadow color.
RectangularDropShadow
  angle : Number
The angle of the shadow.
RectangularDropShadow
  blRadius : Number
The corner radius of the bottom left corner of the rounded rectangle that is casting the shadow.
RectangularDropShadow
  brRadius : Number
The corner radius of the bottom right corner of the rounded rectangle that is casting the shadow.
RectangularDropShadow
  color : int
The color of the shadow.
RectangularDropShadow
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  distance : Number
The offset distance for the shadow, in pixels.
RectangularDropShadow
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  tlRadius : Number
The corner radius of the top left corner of the rounded rectangle that is casting the shadow.
RectangularDropShadow
  trRadius : Number
The corner radius of the top right corner of the rounded rectangle that is casting the shadow.
RectangularDropShadow
Public Methods
 MethodDefined By
  
Constructor.
RectangularDropShadow
  
Renders the shadow on the screen.
RectangularDropShadow
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
Property Detail
alphaproperty
alpha:Number

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
angleproperty 
angle:Number

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
blRadiusproperty 
blRadius:Number

The corner radius of the bottom left corner of the rounded rectangle that is casting the shadow. May be zero for non-rounded rectangles.



Implementation
    public function get blRadius():Number
    public function set blRadius(value:Number):void
brRadiusproperty 
brRadius:Number

The corner radius of the bottom right corner of the rounded rectangle that is casting the shadow. May be zero for non-rounded rectangles.



Implementation
    public function get brRadius():Number
    public function set brRadius(value:Number):void
colorproperty 
color:int

The color of the shadow. Valid values are in hexadecimal format 0xRRGGBB. The default value is 0x000000.



Implementation
    public function get color():int
    public function set color(value:int):void
distanceproperty 
distance:Number

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
tlRadiusproperty 
tlRadius:Number

The corner radius of the top left corner of the rounded rectangle that is casting the shadow. May be zero for non-rounded rectangles.



Implementation
    public function get tlRadius():Number
    public function set tlRadius(value:Number):void
trRadiusproperty 
trRadius:Number

The corner radius of the top right corner of the rounded rectangle that is casting the shadow. May be zero for non-rounded rectangles.



Implementation
    public function get trRadius():Number
    public function set trRadius(value:Number):void
Constructor Detail
RectangularDropShadow()Constructor
public function RectangularDropShadow()

Constructor.

Method Detail
drawShadow()method
public function drawShadow(g:Graphics, x:Number, y:Number, width:Number, height:Number):void

Renders the shadow on the screen.

Parameters

g:Graphics — The Graphics object on which to draw the shadow.
 
x:Number — The horizontal offset of the drop shadow, based on the Graphics object's position.
 
y:Number — The vertical offset of the drop shadow, based on the Graphics object's position.
 
width:Number — The width of the shadow, in pixels.
 
height:Number — The height of the shadow, in pixels.