mx.effects.MaskEffect - Adobe® Flex® 4 Language Reference (Flex 4)

Package	mx.effects
Class	public class MaskEffect
Inheritance	MaskEffect Effect EventDispatcher Object
Subclasses	Iris, WipeDown, WipeLeft, WipeRight, WipeUp

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The MaskEffect class is an abstract base class for all effects that animate a mask, such as the wipe effects and the Iris effect. This class encapsulates methods and properties that are common among all mask-based effects.

A mask effect uses an overlay, called a mask, to perform the effect. By default, the mask is a rectangle with the same size as the target component.

The before or after state of the target component of a mask effect must be invisible. That means a mask effect always makes a target component appear on the screen, or disappear from the screen.

You use the scaleXFrom, scaleYFrom, scaleXTo, and scaleX properties to specify the initial and final scale of the mask, where a value of 1.0 corresponds to scaling the mask to the size of the target component, 2.0 scales the mask to twice the size of the component, 0.5 scales the mask to half the size of the component, and so on. To use any one of these properties, you must specify all four.

You use the xFrom, yFrom, xTo, and yTo properties to specify the coordinates of the initial position and final position of the mask relative to the target component, where (0, 0) corresponds to the upper left corner of the target. To use any one of these properties, you must specify all four.

The coordinates of the initial and final position of the mask depend on the type of effect and whether the show property is true or false. For example, for the WipeLeft effect with a show value of false, the coordinates of the initial mask position are (0, 0),corresponding to the upper-left corner of the target, and the coordinates of the final position are the upper-right corner of the target (width, 0), where width is the width of the target.

For a show value of true for the WipeLeft effect, the coordinates of the initial mask position are (width, 0), and the coordinates of the final position are (0, 0).

MXML Syntax expanded

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The MaskEffect class defines the following properties, which all of its subclasses inherit:

  <mx:tagname
    createMaskFunction=""
    moveEasingFunction=""
    scaleEasingFunction=""
    scaleXFrom=""
    scaleXTo=""
    scaleYFrom=""
    scaleYTo=""
    show="true|false"
    xFrom=""
    xTo=""
    yFrom=""
    yTo=""
  />

Public Properties

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	Property		Defined By
		className : String [read-only] The name of the effect class, such as "Fade".	Effect
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		createMaskFunction : Function Function called when the effect creates the mask.	MaskEffect
		customFilter : mx.effects:EffectTargetFilter Specifies a custom filter object, of type EffectTargetFilter, used by the effect to determine the targets on which to play the effect.	Effect
		duration : Number Duration of the effect in milliseconds.	Effect
		effectTargetHost : mx.effects:IEffectTargetHost A property that lets you access the target list-based control of a data effect.	Effect
		filter : String Specifies an algorithm for filtering targets for an effect.	Effect
		hideFocusRing : Boolean Determines whether the effect should hide the focus ring when starting the effect.	Effect
		instanceClass : Class An object of type Class that specifies the effect instance class class for this effect class.	Effect
		isPlaying : Boolean [read-only] A read-only flag which is true if any instances of the effect are currently playing, and false if none are.	Effect
		moveEasingFunction : Function Easing function to use for moving the mask.	MaskEffect
		perElementOffset : Number Additional delay, in milliseconds, for effect targets after the first target of the effect.	Effect
		playheadTime : Number Current time position of the effect.	Effect
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object
		relevantProperties : Array An Array of property names to use when performing filtering.	Effect
		relevantStyles : Array An Array of style names to use when performing filtering.	Effect
		repeatCount : int = 1 Number of times to repeat the effect.	Effect
		repeatDelay : int = 0 Amount of time, in milliseconds, to wait before repeating the effect.	Effect
		scaleEasingFunction : Function Easing function to use for scaling the mask.	MaskEffect
		scaleXFrom : Number Initial scaleX for mask.	MaskEffect
		scaleXTo : Number Ending scaleX for mask.	MaskEffect
		scaleYFrom : Number Initial scaleY for mask.	MaskEffect
		scaleYTo : Number Ending scaleY for mask.	MaskEffect
		showTarget : Boolean Specifies that the target component is becoming visible, true, or invisible, false.	MaskEffect
		startDelay : int = 0 Amount of time, in milliseconds, to wait before starting the effect.	Effect
		suspendBackgroundProcessing : Boolean = false If true, blocks all background processing while the effect is playing.	Effect
		target : Object The object to which this effect is applied.	Effect
		targets : Array An Array of objects that are targets for the effect.	Effect
		triggerEvent : Event The Event object passed to this Effect by the EffectManager when an effect is triggered, or null if the effect is not being played by the EffectManager.	Effect
		xFrom : Number Initial position's x coordinate for mask.	MaskEffect
		xTo : Number Destination position's x coordinate for mask.	MaskEffect
		yFrom : Number Initial position's y coordinate for mask.	MaskEffect
		yTo : Number Destination position's y coordinate for mask.	MaskEffect

Protected Properties

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	Property		Defined By
		applyTransitionEndProperties : Boolean This flag controls whether the effect, when run in a transition, automatically applies the property values according to the end state, as opposed to leaving values as set by the effect itself.	Effect
		endValuesCaptured : Boolean = false A flag containing true if the end values of an effect have already been determined, or false if they should be acquired from the current properties of the effect targets when the effect runs.	Effect

Public Methods

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	Method		Defined By
		MaskEffect(target:Object = null) Constructor.	MaskEffect
		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
		captureEndValues():void Captures the current values of the relevant properties on the effect's targets and saves them as end values.	Effect
		captureMoreStartValues(targets:Array):void Captures the current values of the relevant properties of an additional set of targets Flex uses this function when a data change effect is run.	Effect
		captureStartValues():void Captures the current values of the relevant properties on the effect's targets.	Effect
		createInstance(target:Object = null):IEffectInstance Creates a single effect instance and initializes it.	Effect
		createInstances(targets:Array = null):Array Takes an Array of target objects and invokes the createInstance() method on each target.	Effect
		deleteInstance(instance:IEffectInstance):void Removes event listeners from an instance and removes it from the list of instances.	Effect
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	EventDispatcher
		end(effectInstance:IEffectInstance = null):void Interrupts an effect that is currently playing, and jumps immediately to the end of the effect.	Effect
		getAffectedProperties():Array [override] Returns the component properties modified by this effect.	MaskEffect
		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
		pause():void Pauses the effect until you call the resume() method.	Effect
		play(targets:Array = null, playReversedFromEnd:Boolean = false):Array Begins playing the effect.	Effect
		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
		resume():void Resumes the effect after it has been paused by a call to the pause() method.	Effect
		reverse():void Plays the effect in reverse, if the effect is currently playing, starting from the current position of the effect.	Effect
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		stop():void Stops the effect, leaving the effect targets in their current state.	Effect
		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

Protected Methods

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	Method		Defined By
		applyValueToTarget(target:Object, property:String, value:*, props:Object):void Used internally by the Effect infrastructure.	Effect
		effectEndHandler(event:EffectEvent):void Called when an effect instance has finished playing.	Effect
		effectStartHandler(event:EffectEvent):void This method is called when the effect instance starts playing.	Effect
		effectStopHandler(event:EffectEvent):void Called when an effect instance has stopped by a call to the stop() method.	Effect
		filterInstance(propChanges:Array, target:Object):Boolean Determines the logic for filtering out an effect instance.	Effect
		getValueFromTarget(target:Object, property:String):* Called by the captureStartValues() method to get the value of a property from the target.	Effect
		initInstance(instance:IEffectInstance):void Copies properties of the effect to the effect instance.	Effect
		tweenEventHandler(event:mx.events:TweenEvent):void Called when the TweenEffect dispatches a TweenEvent.	MaskEffect

Events

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	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
effectEnd	Dispatched when one of the effect's instances finishes playing, either when the instance finishes playing or when the effect is interrupted by a call to the end() method.	Effect
effectStart	Dispatched when the effect starts playing.	Effect
effectStop	Dispatched when the effect has been stopped, which only occurs when the effect is interrupted by a call to the stop() method.	Effect
tweenEnd	Dispatched when the effect ends.	MaskEffect
tweenStart	Dispatched when the effect starts, which corresponds to the first call to the onMoveTweenUpdate() and onScaleTweenUpdate() methods.	MaskEffect
tweenUpdate	Dispatched every time the effect updates the target.	MaskEffect

Property Detail

createMaskFunction

property

public var createMaskFunction:Function

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Function called when the effect creates the mask. The default value is a function that returns a Rectangle with the same dimensions as the target.

The custom mask function has the following signature:

      public function createLargeMask(targ:Object, bounds:Rectangle):Shape
      {
          var myMask:Shape = new FlexShape();
     
          // Create mask.
     
          return myMask;
      }

Your custom mask function takes an argument corresponding to the target component of the effect, and a second argument that defines the dimensions of the target so that you can correctly size the mask. You use that argument to access properties of the target component, such as width and height, so that you can create a mask with the correct size.

The function returns a single Shape object that defines the mask.

moveEasingFunction

property

public var moveEasingFunction:Function

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Easing function to use for moving the mask.

The default value is null.

scaleEasingFunction

property

public var scaleEasingFunction:Function

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Easing function to use for scaling the mask.

The default value is null.

scaleXFrom

property

public var scaleXFrom:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Initial scaleX for mask.

To specify this property, you must specify all four of these properties: scaleXFrom, scaleYFrom, scaleXTo, and scaleX.

scaleXTo

property

public var scaleXTo:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Ending scaleX for mask.

To specify this property, you must specify all four of these properties: scaleXFrom, scaleYFrom, scaleXTo, and scaleX.

scaleYFrom

property

public var scaleYFrom:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Initial scaleY for mask.

To specify this property, you must specify all four of these properties: scaleXFrom, scaleYFrom, scaleXTo, and scaleX.

scaleYTo

property

public var scaleYTo:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Ending scaleY for mask.

To specify this property, you must specify all four of these properties: scaleXFrom, scaleYFrom, scaleXTo, and scaleX.

showTarget

property

showTarget:Boolean

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Specifies that the target component is becoming visible, true, or invisible, false. If you specify this effect for a showEffect or hideEffect trigger, Flex sets the showTarget property for you, either to true if the component becomes visible, or false if the component becomes invisible. If you use this effect with a different effect trigger, you should set it yourself, often within the event listener for the startEffect event.

The default value is true.

Implementation
public function get showTarget():Boolean
public function set showTarget(value:Boolean):void

xFrom

property

public var xFrom:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Initial position's x coordinate for mask.

To specify this property, you must specify all four of these properties: xFrom, yFrom, xTo, and yTo.

xTo

property

public var xTo:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Destination position's x coordinate for mask.

To specify this property, you must specify all four of these properties: xFrom, yFrom, xTo, and yTo.

yFrom

property

public var yFrom:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Initial position's y coordinate for mask.

To specify this property, you must specify all four of these properties: xFrom, yFrom, xTo, and yTo.

yTo

property

public var yTo:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Destination position's y coordinate for mask.

To specify this property, you must specify all four of these properties: xFrom, yFrom, xTo, and yTo.

Constructor Detail

MaskEffect

()

Constructor

public function MaskEffect(target:Object = null)

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constructor.

Parameters

target:Object (default = null) — The Object to animate with this effect.

Method Detail

getAffectedProperties

()

method

override public function getAffectedProperties():Array

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Returns the component properties modified by this effect. This method returns an Array containing: [ "visible", "width", "height" ]. Since the WipeDown, WipeLeft, WipeRight, and WipeDown effect subclasses all modify these same properties, those classes do not implement this method.

If you subclass the MaskEffect class to create a custom effect, and it modifies a different set of properties on the target, you must override this method and return an Array containing a list of the properties modified by your subclass.

Returns

Array — An Array of Strings specifying the names of the properties modified by this effect.

tweenEventHandler

()

method

protected function tweenEventHandler(event:mx.events:TweenEvent):void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Called when the TweenEffect dispatches a TweenEvent. If you override this method, ensure that you call the super method.

Parameters

event:mx.events:TweenEvent — An event object of type TweenEvent.

Event Detail

tweenEnd

Event

Event Object Type: mx.events.TweenEvent
property TweenEvent.type = mx.events.TweenEvent.TWEEN_END

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Dispatched when the effect ends.

When an effect plays a single time, this event occurs at the same time as an effectEnd event. If you configure the effect to repeat, it occurs at the end of every repetition of the effect, and the endEffect event occurs after the effect plays for the final time.

The TweenEvent.TWEEN_END constant defines the value of the event object's type property for a tweenEnd event.

The properties of the event object have the following values:

Property	Value
`bubbles`	false
`cancelable`	false
`currentTarget`	The Object that defines the event listener that handles the event. For example, if you use `myButton.addEventListener()` to register an event listener, myButton is the value of the `currentTarget`.
`target`	The Object that dispatched the event; it is not always the Object listening for the event. Use the `currentTarget` property to always access the Object listening for the event.
`value`	The value passed to the `onTweenEnd()` method.

tweenStart

Event

Event Object Type: mx.events.TweenEvent
property TweenEvent.type = mx.events.TweenEvent.TWEEN_START

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Dispatched when the effect starts, which corresponds to the first call to the onMoveTweenUpdate() and onScaleTweenUpdate() methods. Flex also dispatches the first tweenUpdate event for the effect at the same time.

The Effect.effectStart event is dispatched before the tweenStart event.

The TweenEvent.TWEEN_START constant defines the value of the event object's type property for a tweenStart event.

The properties of the event object have the following values:

Property	Value
`bubbles`	false
`cancelable`	false
`currentTarget`	The Object that defines the event listener that handles the event. For example, if you use `myButton.addEventListener()` to register an event listener, myButton is the value of the `currentTarget`.
`target`	The Object that dispatched the event; it is not always the Object listening for the event. Use the `currentTarget` property to always access the Object listening for the event.
`value`	The value passed to the `onTweenUpdate()` method.

tweenUpdate

Event

Event Object Type: mx.events.TweenEvent
property TweenEvent.type = mx.events.TweenEvent.TWEEN_UPDATE

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Dispatched every time the effect updates the target. The dispatching of this event corresponds to the calls to the onMoveTweenUpdate() and onScaleTweenUpdate() methods.

The TweenEvent.TWEEN_UPDATE constant defines the value of the event object's type property for a tweenUpdate event.

The properties of the event object have the following values:

Property	Value
`bubbles`	false
`cancelable`	false
`currentTarget`	The Object that defines the event listener that handles the event. For example, if you use `myButton.addEventListener()` to register an event listener, myButton is the value of the `currentTarget`.
`target`	The Object that dispatched the event; it is not always the Object listening for the event. Use the `currentTarget` property to always access the Object listening for the event.
`value`	The value passed to the `onTweenUpdate()` method.