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Android APIs
public abstract class

Animation

extends Object
implements Cloneable
java.lang.Object
   ↳ android.view.animation.Animation
Known Direct Subclasses

Class Overview

Abstraction for an Animation that can be applied to Views, Surfaces, or other objects. See the animation package description file.

Summary

Nested Classes
interface Animation.AnimationListener

An animation listener receives notifications from an animation. 

class Animation.Description Utility class to parse a string description of a size. 
XML Attributes
Attribute Name Related Method Description
android:detachWallpaper setDetachWallpaper(boolean) Special option for window animations: if this window is on top of a wallpaper, don't animate the wallpaper with it. 
android:duration setDuration(long) Amount of time (in milliseconds) for the animation to run. 
android:fillAfter setFillAfter(boolean) When set to true, the animation transformation is applied after the animation is over. 
android:fillBefore setFillBefore(boolean) When set to true or when fillEnabled is not set to true, the animation transformation is applied before the animation has started. 
android:fillEnabled setFillEnabled(boolean) When set to true, the value of fillBefore is taken into account. 
android:interpolator setInterpolator(Interpolator) Defines the interpolator used to smooth the animation movement in time. 
android:repeatCount setRepeatCount(int) Defines how many times the animation should repeat. 
android:repeatMode setRepeatMode(int) Defines the animation behavior when it reaches the end and the repeat count is greater than 0 or infinite. 
android:startOffset setStartOffset(long) Delay in milliseconds before the animation runs, once start time is reached. 
android:zAdjustment setZAdjustment(int) Allows for an adjustment of the Z ordering of the content being animated for the duration of the animation. 
Constants
int ABSOLUTE The specified dimension is an absolute number of pixels.
int INFINITE Repeat the animation indefinitely.
int 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 The specified dimension holds a float and should be multiplied by the height or width of the object being animated.
int 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 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 Can be used as the start time to indicate the start time should be the current time when getTransformation(long, Transformation) is invoked for the first animation frame.
int ZORDER_BOTTOM Requests that the content being animated be forced under all other content for the duration of the animation.
int ZORDER_NORMAL Requests that the content being animated be kept in its current Z order.
int ZORDER_TOP Requests that the content being animated be forced on top of all other content for the duration of the animation.
Public Constructors
Animation()
Creates a new animation with a duration of 0ms, the default interpolator, with fillBefore set to true and fillAfter set to false
Animation(Context context, AttributeSet attrs)
Creates a new animation whose parameters come from the specified context and attributes set.
Public Methods
void cancel()
Cancel the animation.
long computeDurationHint()
Compute a hint at how long the entire animation may last, in milliseconds.
int getBackgroundColor()
Returns the background color behind the animation.
boolean getDetachWallpaper()
long getDuration()
How long this animation should last
boolean getFillAfter()
If fillAfter is true, this animation will apply its transformation after the end time of the animation.
boolean getFillBefore()
If fillBefore is true, this animation will apply its transformation before the start time of the animation.
Interpolator getInterpolator()
Gets the acceleration curve type for this animation.
int getRepeatCount()
Defines how many times the animation should repeat.
int getRepeatMode()
Defines what this animation should do when it reaches the end.
long getStartOffset()
When this animation should start, relative to StartTime
long getStartTime()
When this animation should start.
boolean getTransformation(long currentTime, Transformation outTransformation, float scale)
Gets the transformation to apply at a specified point in time.
boolean getTransformation(long currentTime, Transformation outTransformation)
Gets the transformation to apply at a specified point in time.
int getZAdjustment()
Returns the Z ordering mode to use while running the animation as previously set by setZAdjustment(int).
boolean hasEnded()

Indicates whether this animation has ended or not.

boolean hasStarted()

Indicates whether this animation has started or not.

void initialize(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()
If fillEnabled is true, this animation will apply the value of fillBefore.
boolean isInitialized()
Whether or not the animation has been initialized.
void reset()
Reset the initialization state of this animation.
void restrictDuration(long durationMillis)
Ensure that the duration that this animation will run is not longer than durationMillis.
void scaleCurrentDuration(float scale)
How much to scale the duration by.
void setAnimationListener(Animation.AnimationListener listener)

Binds an animation listener to this animation.

void setBackgroundColor(int bg)
Set background behind animation.
void setDetachWallpaper(boolean detachWallpaper)
If detachWallpaper is true, and this is a window animation of a window that has a wallpaper background, then the window will be detached from the wallpaper while it runs.
void setDuration(long durationMillis)
How long this animation should last.
void setFillAfter(boolean fillAfter)
If fillAfter is true, the transformation that this animation performed will persist when it is finished.
void setFillBefore(boolean fillBefore)
If fillBefore is true, this animation will apply its transformation before the start time of the animation.
void setFillEnabled(boolean fillEnabled)
If fillEnabled is true, the animation will apply the value of fillBefore.
void setInterpolator(Context context, int resID)
Sets the acceleration curve for this animation.
void setInterpolator(Interpolator i)
Sets the acceleration curve for this animation.
void setRepeatCount(int repeatCount)
Sets how many times the animation should be repeated.
void setRepeatMode(int repeatMode)
Defines what this animation should do when it reaches the end.
void setStartOffset(long startOffset)
When this animation should start relative to the start time.
void setStartTime(long startTimeMillis)
When this animation should start.
void setZAdjustment(int zAdjustment)
Set the Z ordering mode to use while running the animation.
void start()
Convenience method to start the animation the first time getTransformation(long, Transformation) is invoked.
void startNow()
Convenience method to start the animation at the current time in milliseconds.
boolean willChangeBounds()

Indicates whether or not this animation will affect the bounds of the animated view.

boolean willChangeTransformationMatrix()

Indicates whether or not this animation will affect the transformation matrix.

Protected Methods
void applyTransformation(float interpolatedTime, Transformation t)
Helper for getTransformation.
Animation clone()
Creates and returns a copy of this Object.
void ensureInterpolator()
Gurantees that this animation has an interpolator.
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
float getScaleFactor()
The scale factor is set by the call to getTransformation.
float resolveSize(int type, float value, int size, int parentSize)
Convert the information in the description of a size to an actual dimension
[Expand]
Inherited Methods
From class java.lang.Object

XML Attributes

android:detachWallpaper

Special option for window animations: if this window is on top of a wallpaper, don't animate the wallpaper with it.

Must be a boolean value, either "true" or "false".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol detachWallpaper.

Related Methods

android:duration

Amount of time (in milliseconds) for the animation to run.

Must be an integer value, such as "100".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol duration.

Related Methods

android:fillAfter

When set to true, the animation transformation is applied after the animation is over. The default value is false. If fillEnabled is not set to true and the animation is not set on a View, fillAfter is assumed to be true.

Must be a boolean value, either "true" or "false".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol fillAfter.

Related Methods

android:fillBefore

When set to true or when fillEnabled is not set to true, the animation transformation is applied before the animation has started. The default value is true.

Must be a boolean value, either "true" or "false".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol fillBefore.

Related Methods

android:fillEnabled

When set to true, the value of fillBefore is taken into account.

Must be a boolean value, either "true" or "false".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol fillEnabled.

Related Methods

android:interpolator

Defines the interpolator used to smooth the animation movement in time.

Must be a reference to another resource, in the form "@[+][package:]type:name" or to a theme attribute in the form "?[package:][type:]name".

This corresponds to the global attribute resource symbol interpolator.

android:repeatCount

Defines how many times the animation should repeat. The default value is 0.

May be an integer value, such as "100".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

May be one of the following constant values.

ConstantValueDescription
infinite-1

This corresponds to the global attribute resource symbol repeatCount.

Related Methods

android:repeatMode

Defines the animation behavior when it reaches the end and the repeat count is greater than 0 or infinite. The default value is restart.

Must be one of the following constant values.

ConstantValueDescription
restart1 The animation starts again from the beginning.
reverse2 The animation plays backward.

This corresponds to the global attribute resource symbol repeatMode.

Related Methods

android:startOffset

Delay in milliseconds before the animation runs, once start time is reached.

Must be an integer value, such as "100".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol startOffset.

Related Methods

android:zAdjustment

Allows for an adjustment of the Z ordering of the content being animated for the duration of the animation. The default value is normal.

Must be one of the following constant values.

ConstantValueDescription
normal0 The content being animated be kept in its current Z order.
top1 The content being animated is forced on top of all other content for the duration of the animation.
bottom-1 The content being animated is forced under all other content for the duration of the animation.

This corresponds to the global attribute resource symbol zAdjustment.

Related Methods

Constants

public static final int ABSOLUTE

Added in API level 1

The specified dimension is an absolute number of pixels.

Constant Value: 0 (0x00000000)

public static final int INFINITE

Added in API level 1

Repeat the animation indefinitely.

Constant Value: -1 (0xffffffff)

public static final int RELATIVE_TO_PARENT

Added in API level 1

The specified dimension holds a float and should be multiplied by the height or width of the parent of the object being animated.

Constant Value: 2 (0x00000002)

public static final int RELATIVE_TO_SELF

Added in API level 1

The specified dimension holds a float and should be multiplied by the height or width of the object being animated.

Constant Value: 1 (0x00000001)

public static final int RESTART

Added in API level 1

When the animation reaches the end and the repeat count is INFINTE_REPEAT or a positive value, the animation restarts from the beginning.

Constant Value: 1 (0x00000001)

public static final int REVERSE

Added in API level 1

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).

Constant Value: 2 (0x00000002)

public static final int START_ON_FIRST_FRAME

Added in API level 1

Can be used as the start time to indicate the start time should be the current time when getTransformation(long, Transformation) is invoked for the first animation frame. This can is useful for short animations.

Constant Value: -1 (0xffffffff)

public static final int ZORDER_BOTTOM

Added in API level 1

Requests that the content being animated be forced under all other content for the duration of the animation.

Constant Value: -1 (0xffffffff)

public static final int ZORDER_NORMAL

Added in API level 1

Requests that the content being animated be kept in its current Z order.

Constant Value: 0 (0x00000000)

public static final int ZORDER_TOP

Added in API level 1

Requests that the content being animated be forced on top of all other content for the duration of the animation.

Constant Value: 1 (0x00000001)

Public Constructors

public Animation ()

Added in API level 1

Creates a new animation with a duration of 0ms, the default interpolator, with fillBefore set to true and fillAfter set to false

public Animation (Context context, AttributeSet attrs)

Added in API level 1

Creates a new animation whose parameters come from the specified context and attributes set.

Parameters
context the application environment
attrs the set of attributes holding the animation parameters

Public Methods

public void cancel ()

Added in API level 8

Cancel the animation. Cancelling an animation invokes the animation listener, if set, to notify the end of the animation. If you cancel an animation manually, you must call reset() before starting the animation again.

public long computeDurationHint ()

Added in API level 3

Compute a hint at how long the entire animation may last, in milliseconds. Animations can be written to cause themselves to run for a different duration than what is computed here, but generally this should be accurate.

public int getBackgroundColor ()

Added in API level 12

Returns the background color behind the animation.

public boolean getDetachWallpaper ()

Added in API level 5
Related XML Attributes

public long getDuration ()

Added in API level 1

How long this animation should last

Related XML Attributes
Returns
  • the duration in milliseconds of the animation

public boolean getFillAfter ()

Added in API level 1

If fillAfter is true, this animation will apply its transformation after the end time of the animation.

Related XML Attributes
Returns
  • true if the animation applies its transformation after it ends

public boolean getFillBefore ()

Added in API level 1

If fillBefore is true, this animation will apply its transformation before the start time of the animation. If fillBefore is false and fillEnabled is true, the transformation will not be applied until the start time of the animation.

Related XML Attributes
Returns
  • true if the animation applies its transformation before it starts

public Interpolator getInterpolator ()

Added in API level 1

Gets the acceleration curve type for this animation.

Related XML Attributes
Returns

public int getRepeatCount ()

Added in API level 1

Defines how many times the animation should repeat. The default value is 0.

Related XML Attributes
Returns
  • the number of times the animation should repeat, or INFINITE

public int getRepeatMode ()

Added in API level 1

Defines what this animation should do when it reaches the end.

Related XML Attributes
Returns

public long getStartOffset ()

Added in API level 1

When this animation should start, relative to StartTime

Related XML Attributes
Returns
  • the start offset in milliseconds

public long getStartTime ()

Added in API level 1

When this animation should start. If the animation has not startet yet, this method might return START_ON_FIRST_FRAME.

Returns

public boolean getTransformation (long currentTime, Transformation outTransformation, float scale)

Added in API level 11

Gets the transformation to apply at a specified point in time. Implementations of this method should always replace the specified Transformation or document they are doing otherwise.

Parameters
currentTime Where we are in the animation. This is wall clock time.
outTransformation A transformation object that is provided by the caller and will be filled in by the animation.
scale Scaling factor to apply to any inputs to the transform operation, such pivot points being rotated or scaled around.
Returns
  • True if the animation is still running

public boolean getTransformation (long currentTime, Transformation outTransformation)

Added in API level 1

Gets the transformation to apply at a specified point in time. Implementations of this method should always replace the specified Transformation or document they are doing otherwise.

Parameters
currentTime Where we are in the animation. This is wall clock time.
outTransformation A transformation object that is provided by the caller and will be filled in by the animation.
Returns
  • True if the animation is still running

public int getZAdjustment ()

Added in API level 1

Returns the Z ordering mode to use while running the animation as previously set by setZAdjustment(int).

Related XML Attributes
Returns

public boolean hasEnded ()

Added in API level 1

Indicates whether this animation has ended or not.

Returns
  • true if the animation has ended, false otherwise

public boolean hasStarted ()

Added in API level 1

Indicates whether this animation has started or not.

Returns
  • true if the animation has started, false otherwise

public void initialize (int width, int height, int parentWidth, int parentHeight)

Added in API level 1

Initialize this animation with the dimensions of the object being animated as well as the objects parents. (This is to support animation sizes being specified relative to these dimensions.)

Objects that interpret Animations should call this method when the sizes of the object being animated and its parent are known, and before calling getTransformation(long, Transformation).

Parameters
width Width of the object being animated
height Height of the object being animated
parentWidth Width of the animated object's parent
parentHeight Height of the animated object's parent

public boolean isFillEnabled ()

Added in API level 3

If fillEnabled is true, this animation will apply the value of fillBefore.

Related XML Attributes
Returns
  • true if the animation will take fillBefore into account

public boolean isInitialized ()

Added in API level 1

Whether or not the animation has been initialized.

Returns
  • Has this animation been initialized.

public void reset ()

Added in API level 1

Reset the initialization state of this animation.

public void restrictDuration (long durationMillis)

Added in API level 1

Ensure that the duration that this animation will run is not longer than durationMillis. In addition to adjusting the duration itself, this ensures that the repeat count also will not make it run longer than the given time.

Parameters
durationMillis The maximum duration the animation is allowed to run.

public void scaleCurrentDuration (float scale)

Added in API level 1

How much to scale the duration by.

Parameters
scale The amount to scale the duration.

public void setAnimationListener (Animation.AnimationListener listener)

Added in API level 1

Binds an animation listener to this animation. The animation listener is notified of animation events such as the end of the animation or the repetition of the animation.

Parameters
listener the animation listener to be notified

public void setBackgroundColor (int bg)

Added in API level 12

Set background behind animation.

Parameters
bg The background color. If 0, no background. Currently must be black, with any desired alpha level.

public void setDetachWallpaper (boolean detachWallpaper)

Added in API level 5

If detachWallpaper is true, and this is a window animation of a window that has a wallpaper background, then the window will be detached from the wallpaper while it runs. That is, the animation will only be applied to the window, and the wallpaper behind it will remain static.

Related XML Attributes
Parameters
detachWallpaper true if the wallpaper should be detached from the animation

public void setDuration (long durationMillis)

Added in API level 1

How long this animation should last. The duration cannot be negative.

Related XML Attributes
Parameters
durationMillis Duration in milliseconds
Throws
IllegalArgumentException if the duration is < 0

public void setFillAfter (boolean fillAfter)

Added in API level 1

If fillAfter is true, the transformation that this animation performed will persist when it is finished. Defaults to false if not set. Note that this applies to individual animations and when using an AnimationSet to chain animations.

Related XML Attributes
Parameters
fillAfter true if the animation should apply its transformation after it ends

public void setFillBefore (boolean fillBefore)

Added in API level 1

If fillBefore is true, this animation will apply its transformation before the start time of the animation. Defaults to true if setFillEnabled(boolean) is not set to true. Note that this applies when using an AnimationSet to chain animations. The transformation is not applied before the AnimationSet itself starts.

Related XML Attributes
Parameters
fillBefore true if the animation should apply its transformation before it starts

public void setFillEnabled (boolean fillEnabled)

Added in API level 3

If fillEnabled is true, the animation will apply the value of fillBefore. Otherwise, fillBefore is ignored and the animation transformation is always applied until the animation ends.

Related XML Attributes
Parameters
fillEnabled true if the animation should take the value of fillBefore into account

public void setInterpolator (Context context, int resID)

Added in API level 1

Sets the acceleration curve for this animation. The interpolator is loaded as a resource from the specified context.

Related XML Attributes
Parameters
context The application environment
resID The resource identifier of the interpolator to load

public void setInterpolator (Interpolator i)

Added in API level 1

Sets the acceleration curve for this animation. Defaults to a linear interpolation.

Related XML Attributes
Parameters
i The interpolator which defines the acceleration curve

public void setRepeatCount (int repeatCount)

Added in API level 1

Sets how many times the animation should be repeated. If the repeat count is 0, the animation is never repeated. If the repeat count is greater than 0 or INFINITE, the repeat mode will be taken into account. The repeat count is 0 by default.

Related XML Attributes
Parameters
repeatCount the number of times the animation should be repeated

public void setRepeatMode (int repeatMode)

Added in API level 1

Defines what this animation should do when it reaches the end. This setting is applied only when the repeat count is either greater than 0 or INFINITE. Defaults to RESTART.

Related XML Attributes
Parameters
repeatMode RESTART or REVERSE

public void setStartOffset (long startOffset)

Added in API level 1

When this animation should start relative to the start time. This is most useful when composing complex animations using an AnimationSet where some of the animations components start at different times.

Related XML Attributes
Parameters
startOffset When this Animation should start, in milliseconds from the start time of the root AnimationSet.

public void setStartTime (long startTimeMillis)

Added in API level 1

When this animation should start. When the start time is set to START_ON_FIRST_FRAME, the animation will start the first time getTransformation(long, Transformation) is invoked. The time passed to this method should be obtained by calling currentAnimationTimeMillis() instead of currentTimeMillis().

Parameters
startTimeMillis the start time in milliseconds

public void setZAdjustment (int zAdjustment)

Added in API level 1

Set the Z ordering mode to use while running the animation.

Related XML Attributes
Parameters
zAdjustment The desired mode, one of ZORDER_NORMAL, ZORDER_TOP, or ZORDER_BOTTOM.

public void start ()

Added in API level 1

Convenience method to start the animation the first time getTransformation(long, Transformation) is invoked.

public void startNow ()

Added in API level 1

Convenience method to start the animation at the current time in milliseconds.

public boolean willChangeBounds ()

Added in API level 1

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
  • true if this animation will change the view's bounds

public boolean willChangeTransformationMatrix ()

Added in API level 1

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
  • true if this animation will change the transformation matrix

Protected Methods

protected void applyTransformation (float interpolatedTime, Transformation t)

Added in API level 1

Helper for getTransformation. Subclasses should implement this to apply their transforms given an interpolation value. Implementations of this method should always replace the specified Transformation or document they are doing otherwise.

Parameters
interpolatedTime The value of the normalized time (0.0 to 1.0) after it has been run through the interpolation function.
t The Transformation object to fill in with the current transforms.

protected Animation clone ()

Added in API level 1

Creates and returns a copy of this Object. The default implementation returns a so-called "shallow" copy: It creates a new instance of the same class and then copies the field values (including object references) from this instance to the new instance. A "deep" copy, in contrast, would also recursively clone nested objects. A subclass that needs to implement this kind of cloning should call super.clone() to create the new instance and then create deep copies of the nested, mutable objects.

Returns
  • a copy of this object.

protected void ensureInterpolator ()

Added in API level 1

Gurantees that this animation has an interpolator. Will use a AccelerateDecelerateInterpolator is nothing else was specified.

protected void finalize ()

Added in API level 1

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable

protected float getScaleFactor ()

Added in API level 11

The scale factor is set by the call to getTransformation. Overrides of getTransformation(long, Transformation, float) will get this value directly. Overrides of applyTransformation(float, Transformation) can call this method to get the value.

Returns
  • float The scale factor that should be applied to pre-scaled values in an Animation such as the pivot points in ScaleAnimation and RotateAnimation.

protected float resolveSize (int type, float value, int size, int parentSize)

Added in API level 1

Convert the information in the description of a size to an actual dimension

Parameters
type One of Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or Animation.RELATIVE_TO_PARENT.
value The dimension associated with the type parameter
size The size of the object being animated
parentSize The size of the parent of the object being animated
Returns
  • The dimension to use for the animation