Adobe FLEX 2 - CREATING AND EXTENDING COMPONENTS Manual page 230

The following table lists the methods and properties that you define in a factory class:
Factory method/property
constructor
Effect.initInstance()
Effect.getAffectedProperties()
Effect.instanceClass
Effect.effectEndHandler()
Effect.effectStartHandler()
Additional methods and properties
230 Creating Effects
Description
(Required) The class constructor. You typically call
the method to invoke the superclass
super()
constructor to initialize the inherited items from the
superclasses.
Your constructor must take at least one optional
argument, of type Object. This argument specifies the
target component of the effect.
(Required) Copies properties of the factory class to
the instance class. Flex calls this protected method
from the
Effect.createInstance()
not have to call it yourself.
In your override, you must call the
super.initInstance()
(Required) Returns an Array of Strings, where each
String is the name of a property of the target object
that is changed by this effect. If the effect does not
modify any properties, it should return an empty
Array.
(Required) Contains an object of type Class that
specifies the name of the instance class for this effect
class.
All subclasses of the Effect class must set this
property, typically in the constructor.
(Optional) Called when an effect instance finishes
playing. If you override this method, ensure that you
call the method.
super()
(Optional) Called when the effect instance starts
playing. If you override this method, ensure that you
call the method.
super()
(Optional) Define any additional methods and
properties that the user requires to configure the
effect.
method; you do
method.