spark.effects.AnimateTransitionShader - Adobe® Flex® 4 Language Reference (Flex 4)

Package	spark.effects
Class	public class AnimateTransitionShader
Inheritance	AnimateTransitionShader Animate Effect EventDispatcher Object
Subclasses	CrossFade, Wipe

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The AnimateTransitionShader effect animates a transition between two bitmaps, one representing the start state (bitmapFrom), and the other representing the end state (bitmapTo).

The animation is performed by running a pixel-shader program, specified by the shader property, using the two bitmaps as input. The bitmaps are represented by an instance of the flash.display.BitmapData class. You can create your own pixel-shader program by using Adobe Pixel Bender Toolkit.

If either bitmap is not supplied, that value is determined dynamically from either the appropriate state of the target in a transition or, if the effect is not running in a transition, from the target directly. If the effect is run in a transition and the target object either goes away or comes into existence during that state change, then a fully-transparent bitmap is used to represent that object when it does not exist.

This effect can only be run on targets that are either UIComponents or GraphicElements, since capturing the bitmap of the object requires information about the object that only exists in these classes.

Because the effect is bitmap-based, and the underlying pixel-shader program expects both bitmaps to be the same size, the effect only works correctly when both bitmaps are of the same size. This means that if the target object changes size or changes orientation leading to a different size bounding box, then the effect might not play correctly.

This effect and its subclasses differ from other effects in Flex in that they are intended to work on their own, and may not have the intended result when run in parallel with other effects. This constraint comes from the fact that both of the before and after bitmaps are captured before the start of the effect. So if something happens to the target object after these bitmaps are calculated, such as another effect changing the target's properties, then those changes are not be accounted for in the pre-calculated bitmap and the results might not be as expected. To ensure correct playing of these bitmap-based effects, they should be played alone on their target objects.

MXML Syntax expanded

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The <s:AnimateTransitionShader> tag inherits all of the tag attributes of its superclass, and adds the following tag attributes:

  <s:AnimateTransitionShader
    Properties
    id="ID"
    bitmapFrom="no default"
    bitmapTo="no default"
    shaderByteCode="no default"
    sahderProperties="no default"
  />

Default MXML PropertymotionPaths

View the examples

Public Properties

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	Property		Defined By
		bitmapFrom : BitmapData The bitmap data representing the start state of this effect.	AnimateTransitionShader
		bitmapTo : BitmapData The bitmap data representing the end state of this effect.	AnimateTransitionShader
		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
		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
		disableLayout : Boolean If true, the effect disables layout on its targets' parent containers, setting the containers autoLayout property to false, and also disables any layout constraints on the target objects.	Animate
		duration : Number Duration of the effect in milliseconds.	Effect
		easer : IEaser The easing behavior for this effect.	Animate
		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
		interpolator : IInterpolator The interpolator used by this effect to calculate values between the start and end values of a property.	Animate
		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
		motionPaths : Vector.<MotionPath> A Vector of MotionPath objects, each of which holds the name of a property being animated and the values that the property takes during the animation.	Animate
		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
		repeatBehavior : String The behavior of a repeating effect, which means an effect with repeatCount equal to either 0 or > 1.	Animate
		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
		shaderByteCode : Object The bytecode for the pixel-shader program that the effect uses to animate between the two bitmaps.	AnimateTransitionShader
		shaderProperties : Object A map of parameter name/value pairs passed to the pixel-shader program before playing.	AnimateTransitionShader
		startDelay : int = 0 Amount of time, in milliseconds, to wait before starting the effect.	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

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
		AnimateTransitionShader(target:Object = null) Constructor.	AnimateTransitionShader
		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 Returns an Array of Strings, where each String is the name of a property changed by this effect.	Effect
		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

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
effectRepeat	Dispatched when the effect begins a new repetition, for any effect that is repeated more than once.	Animate
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
effectUpdate	Dispatched every time the effect updates the target.	Animate

Property Detail

bitmapFrom

property

public var bitmapFrom:BitmapData

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The bitmap data representing the start state of this effect. If this property is not set, it is calculated automatically when the effect is played by taking a snapshot of the target object, or by using a transparent bitmap if the object does not exist in the start view state of a transition.

bitmapTo

property

public var bitmapTo:BitmapData

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The bitmap data representing the end state of this effect. If this property is not set, it is calculated automatically when the effect is played by taking a snapshot of the target object, or by using a transparent bitmap if the object does not exist in the end view state of a transition.

shaderByteCode

property

public var shaderByteCode:Object

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The bytecode for the pixel-shader program that the effect uses to animate between the two bitmaps. This property can be represented as either a ByteArray or as a Class representing a ByteArray (which is what results when you embed a resource).

The pixel-shader program can have arbitrary functionality and inputs, but must, at a minimum, have three image4 inputs. The first input, which can be named anything, should go unused by your pixel-shader program code - it exists only to satisfy the Flash requirement of assigning a filtered object to the first input. Note that inputs that go completely unused in a pixel-shader program might be optimized out, so your code should at least reference this input once.

There must be at least two other input bitmaps named from and to which represent the before and after bitmap images. Finally, you must define one float parameter named progress that contains the elapsed fraction of the effect.

You can specify two optional parameters, width and height. If they exist, they are automatically set to the width and height of the effect target.

See the Pixel Bender Toolkit documentation for more information on writing pixel-shader programs for Flash. You can also look at the source code for the CrossFade.pbk file in the frameworks\projects\flex4\src\spark\effects directory of the Flex source code.

shaderProperties

property

public var shaderProperties:Object

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

A map of parameter name/value pairs passed to the pixel-shader program before playing. For example, to set a parameter named direction in a shader with a Pixel Bender pbj file in Wipe.pbj, the calling code could do the following:

       [Embed(source="Wipe.pbj", mimeType="application/octet-stream")]
       private var WipeCodeClass:Class;
       var shaderEffect = new AnimateTransitionShader();
       shaderEffect.shaderByteCode = WipeCodeClass;
       shaderEffect.shaderProperties = {direction : 1};

Constructor Detail

AnimateTransitionShader

()

Constructor

public function AnimateTransitionShader(target:Object = null)

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

Constructor.

Parameters

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

Examples How to use this example

AnimateTransitionShaderExample.mxml

<?xml version="1.0" encoding="utf-8"?>
<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">

    <s:states>
        <s:State name="default"/>
        <s:State name="flipped"/>
    </s:states>

    <s:transitions>
        <s:Transition id="t1">
            <s:AnimateTransitionShader
                target="{holder}"
                duration="1000"
                shaderByteCode="@Embed(source='assets/twist.pbj', mimeType='application/octet-stream')"/>
        </s:Transition>
    </s:transitions>

    <s:Panel title="AnimateTransitionShader Example"
        width="75%" height="75%" horizontalCenter="0" verticalCenter="0">

        <s:HGroup width="100%" height="100%" top="5" left="5" right="5">
            <s:Group id="holder">
                <s:BitmapImage
                    source="@Embed('assets/back2.png')"
                    visible="true" visible.flipped="false"/>
                <s:BitmapImage
                    source="@Embed('assets/c2.png')"
                    visible="false" visible.flipped="true"/>
            </s:Group>

            <!-- Directions -->
            <s:VGroup id="detailsBox"
                width="50%"
                left="0">
                <s:Label
                    width="99%"
                    color="blue"
                    text="AnimateShaderTransition animates a shader between two images. Click the 'Animate Shader' button to see the effect."/>
            </s:VGroup>
        </s:HGroup>

        <s:Rect left="0" right="0" bottom="0" height="30">
            <s:fill>
                <s:LinearGradient rotation="90">
                    <s:GradientEntry color="0xE2E2E2" />
                    <s:GradientEntry color="0xD9D9D9" />
                </s:LinearGradient>
            </s:fill>
        </s:Rect>
        <s:Button id="playButton"
            left="5" bottom="5"
            label="Animate Shader"
            click="currentState = (currentState == 'flipped') ? 'default' : 'flipped';"/>
    </s:Panel>

</s:Application>