# AlphaAnimation
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
Summary:[Inherited XML Attrs](https://developer.android.com/reference/android/view/animation/AlphaAnimation#inhattrs)\|[Inherited Constants](https://developer.android.com/reference/android/view/animation/AlphaAnimation#inhconstants)\|[Ctors](https://developer.android.com/reference/android/view/animation/AlphaAnimation#pubctors)\|[Methods](https://developer.android.com/reference/android/view/animation/AlphaAnimation#pubmethods)\|[Protected Methods](https://developer.android.com/reference/android/view/animation/AlphaAnimation#promethods)\|[Inherited Methods](https://developer.android.com/reference/android/view/animation/AlphaAnimation#inhmethods)
# AlphaAnimation
*** ** * ** ***
[Kotlin](https://developer.android.com/reference/kotlin/android/view/animation/AlphaAnimation "View this page in Kotlin")\|Java
`
public
class
AlphaAnimation
`
`
``
extends `[Animation](https://developer.android.com/reference/android/view/animation/Animation)`
``
`
|---|---|---------------------------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) |||
| ↳ | [android.view.animation.Animation](https://developer.android.com/reference/android/view/animation/Animation) ||
| | ↳ | android.view.animation.AlphaAnimation |
*** ** * ** ***
An animation that controls the alpha level of an object. Useful for fading things in and out. This animation ends up changing the alpha property of a[Transformation](https://developer.android.com/reference/android/view/animation/Transformation)
## Summary
| ### Inherited XML attributes |
|------------------------------|---|
| From class[android.view.animation.Animation](https://developer.android.com/reference/android/view/animation/Animation) |------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------| | [`android:backdropColor`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:backdropColor) | Special option for window animations: whether the window's background should be used as a background to the animation. | | [`android:detachWallpaper`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:detachWallpaper) | Special option for window animations: if this window is on top of a wallpaper, don't animate the wallpaper with it. | | [`android:duration`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:duration) | Amount of time (in milliseconds) for the animation to run. | | [`android:fillAfter`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:fillAfter) | When set to true, the animation transformation is applied after the animation is over. | | [`android:fillBefore`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:fillBefore) | When set to true or when fillEnabled is not set to true, the animation transformation is applied before the animation has started. | | [`android:fillEnabled`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:fillEnabled) | When set to true, the value of fillBefore is taken into account. | | [`android:interpolator`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:interpolator) | Defines the interpolator used to smooth the animation movement in time. | | [`android:repeatCount`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:repeatCount) | Defines how many times the animation should repeat. | | [`android:repeatMode`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:repeatMode) | Defines the animation behavior when it reaches the end and the repeat count is greater than 0 or infinite. | | [`android:showBackdrop`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:showBackdrop) | Special option for window animations: whether to show a background behind the animating windows. | | [`android:startOffset`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:startOffset) | Delay in milliseconds before the animation runs, once start time is reached. | | [`android:zAdjustment`](https://developer.android.com/reference/android/view/animation/Animation#attr_android:zAdjustment) | Allows for an adjustment of the Z ordering of the content being animated for the duration of the animation. | ||
| ### Inherited constants |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| From class[android.view.animation.Animation](https://developer.android.com/reference/android/view/animation/Animation) |-------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `int` | [ABSOLUTE](https://developer.android.com/reference/android/view/animation/Animation#ABSOLUTE) The specified dimension is an absolute number of pixels. | | `int` | [INFINITE](https://developer.android.com/reference/android/view/animation/Animation#INFINITE) Repeat the animation indefinitely. | | `int` | [RELATIVE_TO_PARENT](https://developer.android.com/reference/android/view/animation/Animation#RELATIVE_TO_PARENT) The specified dimension holds a float and should be multiplied by the height or width of the parent of the object being animated. | | `int` | [RELATIVE_TO_SELF](https://developer.android.com/reference/android/view/animation/Animation#RELATIVE_TO_SELF) The specified dimension holds a float and should be multiplied by the height or width of the object being animated. | | `int` | [RESTART](https://developer.android.com/reference/android/view/animation/Animation#RESTART) When the animation reaches the end and the repeat count is INFINTE_REPEAT or a positive value, the animation restarts from the beginning. | | `int` | [REVERSE](https://developer.android.com/reference/android/view/animation/Animation#REVERSE) When the animation reaches the end and the repeat count is INFINTE_REPEAT or a positive value, the animation plays backward (and then forward again). | | `int` | [START_ON_FIRST_FRAME](https://developer.android.com/reference/android/view/animation/Animation#START_ON_FIRST_FRAME) Can be used as the start time to indicate the start time should be the current time when[getTransformation(long, android.view.animation.Transformation)](https://developer.android.com/reference/android/view/animation/Animation#getTransformation(long,%20android.view.animation.Transformation))is invoked for the first animation frame. | | `int` | [ZORDER_BOTTOM](https://developer.android.com/reference/android/view/animation/Animation#ZORDER_BOTTOM) Requests that the content being animated be forced under all other content for the duration of the animation. | | `int` | [ZORDER_NORMAL](https://developer.android.com/reference/android/view/animation/Animation#ZORDER_NORMAL) Requests that the content being animated be kept in its current Z order. | | `int` | [ZORDER_TOP](https://developer.android.com/reference/android/view/animation/Animation#ZORDER_TOP) Requests that the content being animated be forced on top of all other content for the duration of the animation. | |
| ### Public constructors ||
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[AlphaAnimation](https://developer.android.com/reference/android/view/animation/AlphaAnimation#AlphaAnimation(android.content.Context,%20android.util.AttributeSet))`(`[Context](https://developer.android.com/reference/android/content/Context)` context, `[AttributeSet](https://developer.android.com/reference/android/util/AttributeSet)` attrs) ` Constructor used when an AlphaAnimation is loaded from a resource. |
| ` `[AlphaAnimation](https://developer.android.com/reference/android/view/animation/AlphaAnimation#AlphaAnimation(float,%20float))`(float fromAlpha, float toAlpha) ` Constructor to use when building an AlphaAnimation from code |
| ### Public methods ||
|------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` boolean` | ` `[willChangeBounds](https://developer.android.com/reference/android/view/animation/AlphaAnimation#willChangeBounds())`() `
Indicates whether or not this animation will affect the bounds of the animated view. |
| ` boolean` | ` `[willChangeTransformationMatrix](https://developer.android.com/reference/android/view/animation/AlphaAnimation#willChangeTransformationMatrix())`() `
Indicates whether or not this animation will affect the transformation matrix. |
| ### Protected methods ||
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` void` | ` `[applyTransformation](https://developer.android.com/reference/android/view/animation/AlphaAnimation#applyTransformation(float,%20android.view.animation.Transformation))`(float interpolatedTime, `[Transformation](https://developer.android.com/reference/android/view/animation/Transformation)` t) ` Changes the alpha property of the supplied[Transformation](https://developer.android.com/reference/android/view/animation/Transformation) |
| ### Inherited methods |
|-----------------------|---|
| From class` `[android.view.animation.Animation](https://developer.android.com/reference/android/view/animation/Animation)` ` |------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` void` | ` `[applyTransformation](https://developer.android.com/reference/android/view/animation/Animation#applyTransformation(float,%20android.view.animation.Transformation))`(float interpolatedTime, `[Transformation](https://developer.android.com/reference/android/view/animation/Transformation)` t) ` Helper for getTransformation. | | ` void` | ` `[cancel](https://developer.android.com/reference/android/view/animation/Animation#cancel())`() ` Cancel the animation. | | ` `[Animation](https://developer.android.com/reference/android/view/animation/Animation) | ` `[clone](https://developer.android.com/reference/android/view/animation/Animation#clone())`() ` Creates and returns a copy of this object. | | ` long` | ` `[computeDurationHint](https://developer.android.com/reference/android/view/animation/Animation#computeDurationHint())`() ` Compute a hint at how long the entire animation may last, in milliseconds. | | ` void` | ` `[ensureInterpolator](https://developer.android.com/reference/android/view/animation/Animation#ensureInterpolator())`() ` Gurantees that this animation has an interpolator. | | ` void` | ` `[finalize](https://developer.android.com/reference/android/view/animation/Animation#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` int` | ` `[getBackdropColor](https://developer.android.com/reference/android/view/animation/Animation#getBackdropColor())`() ` Returns the background color to show behind the animating windows. | | ` int` | ` `[getBackgroundColor](https://developer.android.com/reference/android/view/animation/Animation#getBackgroundColor())`() ` *This method was deprecated in API level 30. None of window animations are running with background color.* | | ` boolean` | ` `[getDetachWallpaper](https://developer.android.com/reference/android/view/animation/Animation#getDetachWallpaper())`() ` *This method was deprecated in API level 29. All window animations are running with detached wallpaper.* | | ` long` | ` `[getDuration](https://developer.android.com/reference/android/view/animation/Animation#getDuration())`() ` How long this animation should last | | ` boolean` | ` `[getFillAfter](https://developer.android.com/reference/android/view/animation/Animation#getFillAfter())`() ` If fillAfter is true, this animation will apply its transformation after the end time of the animation. | | ` boolean` | ` `[getFillBefore](https://developer.android.com/reference/android/view/animation/Animation#getFillBefore())`() ` If fillBefore is true, this animation will apply its transformation before the start time of the animation. | | ` `[Interpolator](https://developer.android.com/reference/android/view/animation/Interpolator) | ` `[getInterpolator](https://developer.android.com/reference/android/view/animation/Animation#getInterpolator())`() ` Gets the acceleration curve type for this animation. | | ` int` | ` `[getRepeatCount](https://developer.android.com/reference/android/view/animation/Animation#getRepeatCount())`() ` Defines how many times the animation should repeat. | | ` int` | ` `[getRepeatMode](https://developer.android.com/reference/android/view/animation/Animation#getRepeatMode())`() ` Defines what this animation should do when it reaches the end. | | ` float` | ` `[getScaleFactor](https://developer.android.com/reference/android/view/animation/Animation#getScaleFactor())`() ` The scale factor is set by the call to`getTransformation`. | | ` boolean` | ` `[getShowBackdrop](https://developer.android.com/reference/android/view/animation/Animation#getShowBackdrop())`() ` If showBackdrop is`true`and this animation is applied on a window, then the windows in the animation will animate with the background associated with this window behind them. | | ` long` | ` `[getStartOffset](https://developer.android.com/reference/android/view/animation/Animation#getStartOffset())`() ` When this animation should start, relative to StartTime | | ` long` | ` `[getStartTime](https://developer.android.com/reference/android/view/animation/Animation#getStartTime())`() ` When this animation should start. | | ` boolean` | ` `[getTransformation](https://developer.android.com/reference/android/view/animation/Animation#getTransformation(long,%20android.view.animation.Transformation,%20float))`(long currentTime, `[Transformation](https://developer.android.com/reference/android/view/animation/Transformation)` outTransformation, float scale) ` Gets the transformation to apply at a specified point in time. | | ` boolean` | ` `[getTransformation](https://developer.android.com/reference/android/view/animation/Animation#getTransformation(long,%20android.view.animation.Transformation))`(long currentTime, `[Transformation](https://developer.android.com/reference/android/view/animation/Transformation)` outTransformation) ` Gets the transformation to apply at a specified point in time. | | ` int` | ` `[getZAdjustment](https://developer.android.com/reference/android/view/animation/Animation#getZAdjustment())`() ` Returns the Z ordering mode to use while running the animation as previously set by[setZAdjustment(int)](https://developer.android.com/reference/android/view/animation/Animation#setZAdjustment(int)). | | ` boolean` | ` `[hasEnded](https://developer.android.com/reference/android/view/animation/Animation#hasEnded())`() `
Indicates whether this animation has ended or not. | | ` boolean` | ` `[hasStarted](https://developer.android.com/reference/android/view/animation/Animation#hasStarted())`() `
Indicates whether this animation has started or not. | | ` void` | ` `[initialize](https://developer.android.com/reference/android/view/animation/Animation#initialize(int,%20int,%20int,%20int))`(int width, int height, int parentWidth, int parentHeight) ` Initialize this animation with the dimensions of the object being animated as well as the objects parents. | | ` boolean` | ` `[isFillEnabled](https://developer.android.com/reference/android/view/animation/Animation#isFillEnabled())`() ` If fillEnabled is true, this animation will apply the value of fillBefore. | | ` boolean` | ` `[isInitialized](https://developer.android.com/reference/android/view/animation/Animation#isInitialized())`() ` Whether or not the animation has been initialized. | | ` void` | ` `[reset](https://developer.android.com/reference/android/view/animation/Animation#reset())`() ` Reset the initialization state of this animation. | | ` float` | ` `[resolveSize](https://developer.android.com/reference/android/view/animation/Animation#resolveSize(int,%20float,%20int,%20int))`(int type, float value, int size, int parentSize) ` Convert the information in the description of a size to an actual dimension | | ` void` | ` `[restrictDuration](https://developer.android.com/reference/android/view/animation/Animation#restrictDuration(long))`(long durationMillis) ` Ensure that the duration that this animation will run is not longer thandurationMillis. | | ` void` | ` `[scaleCurrentDuration](https://developer.android.com/reference/android/view/animation/Animation#scaleCurrentDuration(float))`(float scale) ` How much to scale the duration by. | | ` void` | ` `[setAnimationListener](https://developer.android.com/reference/android/view/animation/Animation#setAnimationListener(android.view.animation.Animation.AnimationListener))`(`[Animation.AnimationListener](https://developer.android.com/reference/android/view/animation/Animation.AnimationListener)` listener) `
Binds an animation listener to this animation. | | ` void` | ` `[setBackdropColor](https://developer.android.com/reference/android/view/animation/Animation#setBackdropColor(int))`(int backdropColor) ` Set the color to use for the backdrop shown behind the animating windows. | | ` void` | ` `[setBackgroundColor](https://developer.android.com/reference/android/view/animation/Animation#setBackgroundColor(int))`(int bg) ` *This method was deprecated in API level 30. None of window animations are running with background color.* | | ` void` | ` `[setDetachWallpaper](https://developer.android.com/reference/android/view/animation/Animation#setDetachWallpaper(boolean))`(boolean detachWallpaper) ` *This method was deprecated in API level 29. All window animations are running with detached wallpaper.* | | ` void` | ` `[setDuration](https://developer.android.com/reference/android/view/animation/Animation#setDuration(long))`(long durationMillis) ` How long this animation should last. | | ` void` | ` `[setFillAfter](https://developer.android.com/reference/android/view/animation/Animation#setFillAfter(boolean))`(boolean fillAfter) ` If fillAfter is true, the transformation that this animation performed will persist when it is finished. | | ` void` | ` `[setFillBefore](https://developer.android.com/reference/android/view/animation/Animation#setFillBefore(boolean))`(boolean fillBefore) ` If fillBefore is true, this animation will apply its transformation before the start time of the animation. | | ` void` | ` `[setFillEnabled](https://developer.android.com/reference/android/view/animation/Animation#setFillEnabled(boolean))`(boolean fillEnabled) ` If fillEnabled is true, the animation will apply the value of fillBefore. | | ` void` | ` `[setInterpolator](https://developer.android.com/reference/android/view/animation/Animation#setInterpolator(android.view.animation.Interpolator))`(`[Interpolator](https://developer.android.com/reference/android/view/animation/Interpolator)` i) ` Sets the acceleration curve for this animation. | | ` void` | ` `[setInterpolator](https://developer.android.com/reference/android/view/animation/Animation#setInterpolator(android.content.Context,%20int))`(`[Context](https://developer.android.com/reference/android/content/Context)` context, int resID) ` Sets the acceleration curve for this animation. | | ` void` | ` `[setRepeatCount](https://developer.android.com/reference/android/view/animation/Animation#setRepeatCount(int))`(int repeatCount) ` Sets how many times the animation should be repeated. | | ` void` | ` `[setRepeatMode](https://developer.android.com/reference/android/view/animation/Animation#setRepeatMode(int))`(int repeatMode) ` Defines what this animation should do when it reaches the end. | | ` void` | ` `[setShowBackdrop](https://developer.android.com/reference/android/view/animation/Animation#setShowBackdrop(boolean))`(boolean showBackdrop) ` If showBackdrop is`true`and this animation is applied on a window, then the windows in the animation will animate with the background associated with this window behind them. | | ` void` | ` `[setStartOffset](https://developer.android.com/reference/android/view/animation/Animation#setStartOffset(long))`(long startOffset) ` When this animation should start relative to the start time. | | ` void` | ` `[setStartTime](https://developer.android.com/reference/android/view/animation/Animation#setStartTime(long))`(long startTimeMillis) ` When this animation should start. | | ` void` | ` `[setZAdjustment](https://developer.android.com/reference/android/view/animation/Animation#setZAdjustment(int))`(int zAdjustment) ` Set the Z ordering mode to use while running the animation. | | ` void` | ` `[start](https://developer.android.com/reference/android/view/animation/Animation#start())`() ` Convenience method to start the animation the first time[getTransformation(long, android.view.animation.Transformation)](https://developer.android.com/reference/android/view/animation/Animation#getTransformation(long,%20android.view.animation.Transformation))is invoked. | | ` void` | ` `[startNow](https://developer.android.com/reference/android/view/animation/Animation#startNow())`() ` Convenience method to start the animation at the current time in milliseconds. | | ` boolean` | ` `[willChangeBounds](https://developer.android.com/reference/android/view/animation/Animation#willChangeBounds())`() `
Indicates whether or not this animation will affect the bounds of the animated view. | | ` boolean` | ` `[willChangeTransformationMatrix](https://developer.android.com/reference/android/view/animation/Animation#willChangeTransformationMatrix())`() `
Indicates whether or not this animation will affect the transformation matrix. | ||
| From class` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object) | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object. | | ` boolean` | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this`Object`. | | ` int` | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object. | | ` final void` | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor. | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long))`(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*. | ||
## Public constructors
### AlphaAnimation
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public AlphaAnimation (Context context,
AttributeSet attrs)
```
Constructor used when an AlphaAnimation is loaded from a resource.
| Parameters ||
|-----------|----------------------------------------------------------------|
| `context` | `Context`: Application context to use
|
| `attrs` | `AttributeSet`: Attribute set from which to read values
|
### AlphaAnimation
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public AlphaAnimation (float fromAlpha,
float toAlpha)
```
Constructor to use when building an AlphaAnimation from code
| Parameters ||
|-------------|-----------------------------------------------------------------------------------------------------------------------|
| `fromAlpha` | `float`: Starting alpha value for the animation, where 1.0 means fully opaque and 0.0 means fully transparent.
|
| `toAlpha` | `float`: Ending alpha value for the animation.
|
## Public methods
### willChangeBounds
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public boolean willChangeBounds ()
```
Indicates whether or not this animation will affect the bounds of the animated view. For instance, a fade animation will not affect the bounds whereas a 200% scale animation will.
| Returns ||
|-----------|-------------------------------------------------------------|
| `boolean` | true if this animation will change the view's bounds
|
### willChangeTransformationMatrix
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public boolean willChangeTransformationMatrix ()
```
Indicates whether or not this animation will affect the transformation matrix. For instance, a fade animation will not affect the matrix whereas a scale animation will.
| Returns ||
|-----------|---------------------------------------------------------------------|
| `boolean` | true if this animation will change the transformation matrix
|
## Protected methods
### applyTransformation
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected void applyTransformation (float interpolatedTime,
Transformation t)
```
Changes the alpha property of the supplied[Transformation](https://developer.android.com/reference/android/view/animation/Transformation)
| Parameters ||
|--------------------|-------------------------------------------------------------------------------------------------------------------------|
| `interpolatedTime` | `float`: The value of the normalized time (0.0 to 1.0) after it has been run through the interpolation function.
|
| `t` | `Transformation`: The Transformation object to fill in with the current transforms.
|