ValueAnimator

INFINITE

public static final int INFINITE

This value used used with the setRepeatCount(int) property to repeat the animation indefinitely.

Constant Value: -1 (0xffffffff)

RESTART

public static final int RESTART

When the animation reaches the end and repeatCount is INFINITE or a positive value, the animation restarts from the beginning.

Constant Value: 1 (0x00000001)

REVERSE

public static final int REVERSE

When the animation reaches the end and repeatCount is INFINITE or a positive value, the animation reverses direction on every iteration.

Constant Value: 2 (0x00000002)

ValueAnimator

public ValueAnimator ()

Creates a new ValueAnimator object. This default constructor is primarily for use internally; the factory methods which take parameters are more generally useful.

addUpdateListener

public void addUpdateListener (ValueAnimator.AnimatorUpdateListener listener)

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.

areAnimatorsEnabled

public static boolean areAnimatorsEnabled ()

Returns whether animators are currently enabled, system-wide. By default, all animators are enabled. This can change if either the user sets a Developer Option to set the animator duration scale to 0 or by Battery Savery mode being enabled (which disables all animations).

Developers should not typically need to call this method, but should an app wish to show a different experience when animators are disabled, this return value can be used as a decider of which experience to offer.

cancel

public void cancel ()

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

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

clone

public ValueAnimator clone ()

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

 x.clone() != x

 x.clone().getClass() == x.getClass()

 x.clone().equals(x)

By convention, the returned object should be obtained by calling super.clone. If a class and all of its superclasses (except Object) obey this convention, it will be the case that x.clone().getClass() == x.getClass().

By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by super.clone before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by super.clone need to be modified.

end

public void end ()

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

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

getAnimatedFraction

public float getAnimatedFraction ()

Returns the current animation fraction, which is the elapsed/interpolated fraction used in the most recent frame update on the animation.

getAnimatedValue

public Object getAnimatedValue ()

The most recent value calculated by this ValueAnimator when there is just one property being animated. This value is only sensible while the animation is running. The main purpose for this read-only property is to retrieve the value from the ValueAnimator during a call to AnimatorUpdateListener.onAnimationUpdate(ValueAnimator), which is called during each animation frame, immediately after the value is calculated.

getAnimatedValue

public Object getAnimatedValue (String propertyName)

The most recent value calculated by this ValueAnimator for propertyName. The main purpose for this read-only property is to retrieve the value from the ValueAnimator during a call to AnimatorUpdateListener.onAnimationUpdate(ValueAnimator), which is called during each animation frame, immediately after the value is calculated.

getCurrentPlayTime

public long getCurrentPlayTime ()

Gets the current position of the animation in time, which is equal to the current time minus the time that the animation started. An animation that is not yet started will return a value of zero, unless the animation has has its play time set via setCurrentPlayTime(long) or setCurrentFraction(float), in which case it will return the time that was set.

getDuration

public long getDuration ()

Gets the length of the animation. The default duration is 300 milliseconds.

getDurationScale

public static float getDurationScale ()

Returns the system-wide scaling factor for Animator-based animations. This affects both the start delay and duration of all such animations. Setting to 0 will cause animations to end immediately. The default value is 1.0f.

getFrameDelay

public static long getFrameDelay ()

The amount of time, in milliseconds, between each frame of the animation. This is a requested time that the animation will attempt to honor, but the actual delay between frames may be different, depending on system load and capabilities. This is a static function because the same delay will be applied to all animations, since they are all run off of a single timing loop. The frame delay may be ignored when the animation system uses an external timing source, such as the display refresh rate (vsync), to govern animations. Note that this method should be called from the same thread that start() is called in order to check the frame delay for that animation. A runtime exception will be thrown if the calling thread does not have a Looper.

getInterpolator

public TimeInterpolator getInterpolator ()

Returns the timing interpolator that this ValueAnimator uses.

getRepeatCount

public int getRepeatCount ()

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

getRepeatMode

public int getRepeatMode ()

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

getStartDelay

public long getStartDelay ()

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

getTotalDuration

public long getTotalDuration ()

Gets the total duration of the animation, accounting for animation sequences, start delay, and repeating. Return DURATION_INFINITE if the duration is infinite.

getValues

public PropertyValuesHolder[] getValues ()

Returns the values that this ValueAnimator animates between. These values are stored in PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list of value objects instead.

isRunning

public boolean isRunning ()

Returns whether this Animator is currently running (having been started and gone past any initial startDelay period and not yet ended).

isStarted

public boolean isStarted ()

Returns whether this Animator has been started and not yet ended. For reusable Animators (which most Animators are, apart from the one-shot animator produced by createCircularReveal()), this state is a superset of isRunning(), because an Animator with a nonzero startDelay will return true for isStarted() during the delay phase, whereas isRunning() will return true only after the delay phase is complete. Non-reusable animators will always return true after they have been started, because they cannot return to a non-started state.

ofArgb

public static ValueAnimator ofArgb (int... values)

Constructs and returns a ValueAnimator that animates between color values. A single value implies that that value is the one being animated to. However, this is not typically useful in a ValueAnimator object because there is no way for the object to determine the starting value for the animation (unlike ObjectAnimator, which can derive that value from the target object and property being animated). Therefore, there should typically be two or more values.

ofFloat

public static ValueAnimator ofFloat (float... values)

Constructs and returns a ValueAnimator that animates between float values. A single value implies that that value is the one being animated to. However, this is not typically useful in a ValueAnimator object because there is no way for the object to determine the starting value for the animation (unlike ObjectAnimator, which can derive that value from the target object and property being animated). Therefore, there should typically be two or more values.

ofInt

public static ValueAnimator ofInt (int... values)

Constructs and returns a ValueAnimator that animates between int values. A single value implies that that value is the one being animated to. However, this is not typically useful in a ValueAnimator object because there is no way for the object to determine the starting value for the animation (unlike ObjectAnimator, which can derive that value from the target object and property being animated). Therefore, there should typically be two or more values.

ofObject

public static ValueAnimator ofObject (TypeEvaluator<T> evaluator, 
                Object... values)

Constructs and returns a ValueAnimator that animates between Object values. A single value implies that that value is the one being animated to. However, this is not typically useful in a ValueAnimator object because there is no way for the object to determine the starting value for the animation (unlike ObjectAnimator, which can derive that value from the target object and property being animated). Therefore, there should typically be two or more values.

Note: The Object values are stored as references to the original objects, which means that changes to those objects after this method is called will affect the values on the animator. If the objects will be mutated externally after this method is called, callers should pass a copy of those objects instead.

Since ValueAnimator does not know how to animate between arbitrary Objects, this factory method also takes a TypeEvaluator object that the ValueAnimator will use to perform that interpolation.

ofPropertyValuesHolder

public static ValueAnimator ofPropertyValuesHolder (PropertyValuesHolder... values)

Constructs and returns a ValueAnimator that animates between the values specified in the PropertyValuesHolder objects.

pause

public void pause ()

Pauses a running animation. This method should only be called on the same thread on which the animation was started. If the animation has not yet been started or has since ended, then the call is ignored. Paused animations can be resumed by calling resume().

registerDurationScaleChangeListener

public static boolean registerDurationScaleChangeListener (ValueAnimator.DurationScaleChangeListener listener)

Registers a DurationScaleChangeListener This listens for changes to the system-wide scaling factor for Animator-based animations. Listeners will be called on the main thread.

removeAllUpdateListeners

public void removeAllUpdateListeners ()

Removes all listeners from the set listening to frame updates for this animation.

removeUpdateListener

public void removeUpdateListener (ValueAnimator.AnimatorUpdateListener listener)

Removes a listener from the set listening to frame updates for this animation.

resume

public void resume ()

Resumes a paused animation, causing the animator to pick up where it left off when it was paused. This method should only be called on the same thread on which the animation was started. Calls to resume() on an animator that is not currently paused will be ignored.

reverse

public void reverse ()

Plays the ValueAnimator in reverse. If the animation is already running, it will stop itself and play backwards from the point reached when reverse was called. If the animation is not currently running, 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.

setCurrentFraction

public void setCurrentFraction (float fraction)

Sets the position of the animation to the specified fraction. This fraction should be between 0 and the total fraction of the animation, including any repetition. That is, a fraction of 0 will position the animation at the beginning, a value of 1 at the end, and a value of 2 at the end of a reversing animator that repeats once. If the animation has not yet been started, then it will not advance forward after it is set to this fraction; it will simply set the fraction to this value and perform any appropriate actions based on that fraction. If the animation is already running, then setCurrentFraction() will set the current fraction to this value and continue playing from that point. Animator.AnimatorListener events are not called due to changing the fraction; those events are only processed while the animation is running.

setCurrentPlayTime

public void setCurrentPlayTime (long playTime)

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.

setDuration

public ValueAnimator setDuration (long duration)

Sets the length of the animation. The default duration is 300 milliseconds.

setEvaluator

public void setEvaluator (TypeEvaluator<T> value)

The type evaluator to be used when calculating the animated values of this animation. The system will automatically assign a float or int evaluator based on the type of startValue and endValue in the constructor. But if these values are not one of these primitive types, or if different evaluation is desired (such as is necessary with int values that represent colors), a custom evaluator needs to be assigned. For example, when running an animation on color values, the ArgbEvaluator should be used to get correct RGB color interpolation.

If this ValueAnimator has only one set of values being animated between, this evaluator will be used for that set. If there are several sets of values being animated, which is the case if PropertyValuesHolder objects were set on the ValueAnimator, then the evaluator is assigned just to the first PropertyValuesHolder object.

setFloatValues

public void setFloatValues (float... values)

Sets float values that will be animated between. A single value implies that that value is the one being animated to. However, this is not typically useful in a ValueAnimator object because there is no way for the object to determine the starting value for the animation (unlike ObjectAnimator, which can derive that value from the target object and property being animated). Therefore, there should typically be two or more values.

If there are already multiple sets of values defined for this ValueAnimator via more than one PropertyValuesHolder object, this method will set the values for the first of those objects.

setFrameDelay

public static void setFrameDelay (long frameDelay)

The amount of time, in milliseconds, between each frame of the animation. This is a requested time that the animation will attempt to honor, but the actual delay between frames may be different, depending on system load and capabilities. This is a static function because the same delay will be applied to all animations, since they are all run off of a single timing loop. The frame delay may be ignored when the animation system uses an external timing source, such as the display refresh rate (vsync), to govern animations. Note that this method should be called from the same thread that start() is called in order to have the new frame delay take effect on that animation. A runtime exception will be thrown if the calling thread does not have a Looper.

setIntValues

public void setIntValues (int... values)

Sets int values that will be animated between. A single value implies that that value is the one being animated to. However, this is not typically useful in a ValueAnimator object because there is no way for the object to determine the starting value for the animation (unlike ObjectAnimator, which can derive that value from the target object and property being animated). Therefore, there should typically be two or more values.

If there are already multiple sets of values defined for this ValueAnimator via more than one PropertyValuesHolder object, this method will set the values for the first of those objects.

setInterpolator

public void setInterpolator (TimeInterpolator value)

The time interpolator used in calculating the elapsed fraction of this animation. The interpolator determines whether the animation runs with linear or non-linear motion, such as acceleration and deceleration. The default value is AccelerateDecelerateInterpolator

setObjectValues

public void setObjectValues (Object... values)

Sets the values to animate between for this animation. A single value implies that that value is the one being animated to. However, this is not typically useful in a ValueAnimator object because there is no way for the object to determine the starting value for the animation (unlike ObjectAnimator, which can derive that value from the target object and property being animated). Therefore, there should typically be two or more values.

Note: The Object values are stored as references to the original objects, which means that changes to those objects after this method is called will affect the values on the animator. If the objects will be mutated externally after this method is called, callers should pass a copy of those objects instead.

If there are already multiple sets of values defined for this ValueAnimator via more than one PropertyValuesHolder object, this method will set the values for the first of those objects.

There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate between these value objects. ValueAnimator only knows how to interpolate between the primitive types specified in the other setValues() methods.

setRepeatCount

public void setRepeatCount (int value)

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.

setRepeatMode

public void setRepeatMode (int value)

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.

setStartDelay

public void setStartDelay (long startDelay)

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.

setValues

public void setValues (PropertyValuesHolder... values)

Sets the values, per property, being animated between. This function is called internally by the constructors of ValueAnimator that take a list of values. But a ValueAnimator can be constructed without values and this method can be called to set the values manually instead.

start

public void start ()

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.

toString

public String toString ()

Returns a string representation of the object.

unregisterDurationScaleChangeListener

public static boolean unregisterDurationScaleChangeListener (ValueAnimator.DurationScaleChangeListener listener)

Unregisters a DurationScaleChangeListener.