AnimatorSet

Kotlin |Java

class AnimatorSet : Animator, AnimationFrameCallback

kotlin.Any
↳	androidx.core.animation.Animator
	↳	androidx.core.animation.AnimatorSet

This class plays a set of Animator objects in the specified order. Animations can be set up to play together, in sequence, or after a specified delay.

There are two different approaches to adding animations to a AnimatorSet: either the playTogether() or playSequentially() methods can be called to add a set of animations all at once, or the AnimatorSet#play(Animator) can be used in conjunction with methods in the Builder class to add animations one by one.

It is possible to set up a AnimatorSet with circular dependencies between its animations. For example, an animation a1 could be set up to start before animation a2, a2 before a3, and a3 before a1. The results of this configuration are undefined, but will typically result in none of the affected animations being played. Because of this (and because circular dependencies do not make logical sense anyway), circular dependencies should be avoided, and the dependency flow of animations should only be in one direction.

Developer Guides

For more information about animating with AnimatorSet, read the Property Animation developer guide.

Summary

Nested classes
	Builder The Builder object is a utility class to facilitate adding animations to a AnimatorSet along with the relationships between the various animations.

Inherited constants
From class Animator Long DURATION_INFINITE The value used to indicate infinite duration (e.g. when Animators repeat infinitely).

Public constructors
<init>()

Public methods
Boolean	canReverse() AnimatorSet is only reversible when the set contains no infinitely-repeating animation (e.g. a child animation with repeatCount =
Unit	cancel() Cancels the animation.
AnimatorSet	clone()
Unit	end() Ends the animation.
ArrayList<Animator!>	getChildAnimations() Returns the current list of child Animator objects controlled by this AnimatorSet.
Long	getCurrentPlayTime() Returns the milliseconds elapsed since the start of the animation.
Long	getDuration() Gets the length of each of the child animations of this AnimatorSet.
Interpolator?	getInterpolator()
Long	getStartDelay() The amount of time, in milliseconds, to delay starting the animation after start() is called.
Long	getTotalDuration() Gets the total duration of the animation, accounting for animation sequences, start delay, and repeating.
Boolean	isRunning() Returns true if any of the child animations of this AnimatorSet have been started and have not yet ended.
Boolean	isStarted()
Unit	pause()
AnimatorSet.Builder	play(@NonNull anim: Animator) This method creates a Builder object, which is used to set up playing constraints.
Unit	playSequentially(@NonNull vararg items: Animator!) Sets up this AnimatorSet to play each of the supplied animations when the previous animation ends.
Unit	playSequentially(@NonNull items: MutableList<Animator!>) Sets up this AnimatorSet to play each of the supplied animations when the previous animation ends.
Unit	playTogether(@NonNull vararg items: Animator!) Sets up this AnimatorSet to play all of the supplied animations at the same time.
Unit	playTogether(@NonNull items: MutableCollection<Animator!>) Sets up this AnimatorSet to play all of the supplied animations at the same time.
Unit	resume()
Unit	reverse() Plays the AnimatorSet in reverse.
Unit	setCurrentPlayTime(playTime: Long) Sets the position of the animation to the specified point in time.
AnimatorSet	setDuration(duration: Long) Sets the length of each of the current child animations of this AnimatorSet.
Unit	setInterpolator(@Nullable interpolator: Interpolator?) Sets the Interpolator for all current child animations of this AnimatorSet.
Unit	setStartDelay(startDelay: Long) The amount of time, in milliseconds, to delay starting the animation after start() is called.
Unit	setTarget(@Nullable target: Any?) Sets the target object for all current child animations of this AnimatorSet that take targets (ObjectAnimator and AnimatorSet).
Unit	setupEndValues()
Unit	setupStartValues()
Unit	start() Starts this animation.
String	toString()

Inherited functions

From class Animator Unit addListener(@NonNull listener: Animator.AnimatorListener) Adds a listener to the set of listeners that are sent events through the life of an animation, such as start, repeat, and end. Unit addPauseListener(@NonNull listener: Animator.AnimatorPauseListener) Adds a pause listener to this animator. Unit addUpdateListener(@NonNull listener: Animator.AnimatorUpdateListener) Adds a listener to the set of listeners that are sent update events through the life of an animation. This method is called on all listeners for every frame of the animation, after the values for the animation have been calculated. Boolean isPaused() Returns whether this animator is currently in a paused state. Unit removeAllListeners() Removes all listeners and pauseListeners from this object. Unit removeAllUpdateListeners() Removes all listeners from the set listening to frame updates for this animation. Unit removeListener(@NonNull listener: Animator.AnimatorListener) Removes a listener from the set listening to this animation. Unit removePauseListener(@NonNull listener: Animator.AnimatorPauseListener) Removes a pause listener from the set listening to this animation. Unit removeUpdateListener(@NonNull listener: Animator.AnimatorUpdateListener) Removes a listener from the set listening to frame updates for this animation.

Public constructors

<init>

AnimatorSet()

Public methods

canReverse

fun canReverse(): Boolean

AnimatorSet is only reversible when the set contains no infinitely-repeating animation (e.g. a child animation with repeatCount = ValueAnimator#INFINITE

Return
Boolean	true if the animator set is reversible, false otherwise.

cancel

fun cancel(): Unit

Cancels the animation. Unlike end(), cancel() causes the animation to stop in its tracks, sending an AnimatorListener#onAnimationCancel(Animator) to its listeners, followed by an AnimatorListener#onAnimationEnd(Animator) message.

This method must be called on the thread that is running the animation.

Note that canceling a AnimatorSet also cancels all of the animations that it is responsible for.

clone

@NonNull fun clone(): AnimatorSet

end

fun end(): Unit

Ends the animation. This causes the animation to assign the end value of the property being animated, then calling the AnimatorListener#onAnimationEnd(Animator) method on its listeners.

This method must be called on the thread that is running the animation.

Note that ending a AnimatorSet also ends all of the animations that it is responsible for.

getChildAnimations

@NonNull fun getChildAnimations(): ArrayList<Animator!>

Returns the current list of child Animator objects controlled by this AnimatorSet. This is a copy of the internal list; modifications to the returned list will not affect the AnimatorSet, although changes to the underlying Animator objects will affect those objects being managed by the AnimatorSet.

Return
ArrayList<Animator!>	ArrayList The list of child animations of this AnimatorSet.

getCurrentPlayTime

fun getCurrentPlayTime(): Long

Returns the milliseconds elapsed since the start of the animation.

For ongoing animations, this method returns the current progress of the animation in terms of play time. For an animation that has not yet been started: if the animation has been seeked to a certain time via setCurrentPlayTime(long), the seeked play time will be returned; otherwise, this method will return 0.

Return
Long	the current position in time of the animation in milliseconds

getDuration

fun getDuration(): Long

Gets the length of each of the child animations of this AnimatorSet. This value may be less than 0, which indicates that no duration has been set on this AnimatorSet and each of the child animations will use their own duration.

Return
Long	The length of the animation, in milliseconds, of each of the child animations of this AnimatorSet.

getInterpolator

@Nullable fun getInterpolator(): Interpolator?

getStartDelay

fun getStartDelay(): Long

The amount of time, in milliseconds, to delay starting the animation after start() is called.

Return
Long	the number of milliseconds to delay running the animation

getTotalDuration

fun getTotalDuration(): Long

Gets the total duration of the animation, accounting for animation sequences, start delay, and repeating.

When the animation repeats infinite times, or when any of the child animators does (via ValueAnimator#setRepeatCount(int)} to ValueAnimator#INFINITE), the total duration will be DURATION_INFINITE. Otherwise, the total duration is the sum of start delay and animation running time (i.e. duration of one iteration multiplied by the number of iterations).

Return
Long	Total time an animation takes to finish, starting from the time start() is called. DURATION_INFINITE will be returned if the animation or any child animation repeats infinite times.

isRunning

fun isRunning(): Boolean

Returns true if any of the child animations of this AnimatorSet have been started and have not yet ended. Child animations will not be started until the AnimatorSet has gone past its initial delay set through setStartDelay(long).

Return
Boolean	Whether this AnimatorSet has gone past the initial delay, and at least one child animation has been started and not yet ended.

isStarted

fun isStarted(): Boolean

pause

fun pause(): Unit

play

@NonNull fun play(@NonNull anim: Animator): AnimatorSet.Builder

This method creates a Builder object, which is used to set up playing constraints. This initial play() method tells the Builder the animation that is the dependency for the succeeding commands to the Builder. For example, calling play(a1).with(a2) sets up the AnimatorSet to play a1 and a2 at the same time, play(a1).before(a2) sets up the AnimatorSet to play a1 first, followed by a2, and play(a1).after(a2) sets up the AnimatorSet to play a2 first, followed by a1.

Note that play() is the only way to tell the Builder the animation upon which the dependency is created, so successive calls to the various functions in Builder will all refer to the initial parameter supplied in play() as the dependency of the other animations. For example, calling play(a1).before(a2).before(a3) will play both a2 and a3 when a1 ends; it does not set up a dependency between a2 and a3.

Parameters
anim	Animator: The animation that is the dependency used in later calls to the methods in the returned Builder object. A null parameter will result in a null Builder return value.

Return
AnimatorSet.Builder	Builder The object that constructs the AnimatorSet based on the dependencies outlined in the calls to play and the other methods in the Builder

playSequentially

fun playSequentially(@NonNull vararg items: Animator!): Unit

Sets up this AnimatorSet to play each of the supplied animations when the previous animation ends.

Parameters
items	Animator!: The animations that will be started one after another.

playSequentially

fun playSequentially(@NonNull items: MutableList<Animator!>): Unit

Sets up this AnimatorSet to play each of the supplied animations when the previous animation ends.

Parameters
items	MutableList<Animator!>: The animations that will be started one after another.

playTogether

fun playTogether(@NonNull vararg items: Animator!): Unit

Sets up this AnimatorSet to play all of the supplied animations at the same time. This is equivalent to calling play(Animator) with the first animator in the set and then Builder#with(Animator) with each of the other animators. Note that an Animator with a startDelay will not actually start until that delay elapses, which means that if the first animator in the list supplied to this constructor has a startDelay, none of the other animators will start until that first animator's startDelay has elapsed.

Parameters
items	Animator!: The animations that will be started simultaneously.

playTogether

fun playTogether(@NonNull items: MutableCollection<Animator!>): Unit

Sets up this AnimatorSet to play all of the supplied animations at the same time.

Parameters
items	MutableCollection<Animator!>: The animations that will be started simultaneously.

resume

fun resume(): Unit

reverse

fun reverse(): Unit

Plays the AnimatorSet in reverse. If the animation has been seeked to a specific play time using setCurrentPlayTime(long), it will play backwards from the point seeked when reverse was called. Otherwise, then it will start from the end and play backwards. This behavior is only set for the current animation; future playing of the animation will use the default behavior of playing forward.

Note: reverse is not supported for infinite AnimatorSet.

setCurrentPlayTime

fun setCurrentPlayTime(playTime: Long): Unit

Sets the position of the animation to the specified point in time. This time should be between 0 and the total duration of the animation, including any repetition. If the animation has not yet been started, then it will not advance forward after it is set to this time; it will simply set the time to this value and perform any appropriate actions based on that time. If the animation is already running, then setCurrentPlayTime() will set the current playing time to this value and continue playing from that point.

Parameters
playTime	Long: The time, in milliseconds, to which the animation is advanced or rewound. Unless the animation is reversing, the playtime is considered the time since the end of the start delay of the AnimatorSet in a forward playing direction.

setDuration

@NonNull fun setDuration(duration: Long): AnimatorSet

Sets the length of each of the current child animations of this AnimatorSet. By default, each child animation will use its own duration. If the duration is set on the AnimatorSet, then each child animation inherits this duration.

Parameters
duration	Long: The length of the animation, in milliseconds, of each of the child animations of this AnimatorSet.

setInterpolator

fun setInterpolator(@Nullable interpolator: Interpolator?): Unit

Sets the Interpolator for all current child animations of this AnimatorSet. The default value is null, which means that no interpolator is set on this AnimatorSet. Setting the interpolator to any non-null value will cause that interpolator to be set on the child animations when the set is started.

Parameters
value	the interpolator to be used by this animation, or null to use the default one.
interpolator	Interpolator?: the interpolator to be used by each child animation of this AnimatorSet

setStartDelay

fun setStartDelay(startDelay: Long): Unit

The amount of time, in milliseconds, to delay starting the animation after start() is called. Note that the start delay should always be non-negative. Any negative start delay will be clamped to 0 on N and above.

Parameters
startDelay	Long: The amount of the delay, in milliseconds

setTarget

fun setTarget(@Nullable target: Any?): Unit

Sets the target object for all current child animations of this AnimatorSet that take targets (ObjectAnimator and AnimatorSet).

Parameters
target	Any?: The object being animated

setupEndValues

fun setupEndValues(): Unit

setupStartValues

fun setupStartValues(): Unit

start

fun start(): Unit

Starts this animation. If the animation has a nonzero startDelay, the animation will start running after that delay elapses. A non-delayed animation will have its initial value(s) set immediately, followed by calls to AnimatorListener#onAnimationStart(Animator) for any listeners of this animator.

The animation started by calling this method will be run on the thread that called this method. This thread should have a Looper on it (a runtime exception will be thrown if this is not the case). Also, if the animation will animate properties of objects in the view hierarchy, then the calling thread should be the UI thread for that view hierarchy.

Starting this AnimatorSet will, in turn, start the animations for which it is responsible. The details of when exactly those animations are started depends on the dependency relationships that have been set up between the animations. Note: Manipulating AnimatorSet's lifecycle in the child animators' listener callbacks will lead to undefined behaviors. Also, AnimatorSet will ignore any seeking in the child animators once start() is called.

toString

fun toString(): String