/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.animation;
import android.annotation.CallSuper;
import android.os.Looper;
import android.os.Trace;
import android.util.AndroidRuntimeException;
import android.util.Log;
import android.view.Choreographer;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.AnimationUtils;
import android.view.animation.LinearInterpolator;
import java.util.ArrayList;
import java.util.HashMap;
/**
* This class provides a simple timing engine for running animations
* which calculate animated values and set them on target objects.
*
* <p>There is a single timing pulse that all animations use. It runs in a
* custom handler to ensure that property changes happen on the UI thread.</p>
*
* <p>By default, ValueAnimator uses non-linear time interpolation, via the
* {@link AccelerateDecelerateInterpolator} class, which accelerates into and decelerates
* out of an animation. This behavior can be changed by calling
* {@link ValueAnimator#setInterpolator(TimeInterpolator)}.</p>
*
* <p>Animators can be created from either code or resource files. Here is an example
* of a ValueAnimator resource file:</p>
*
* {@sample development/samples/ApiDemos/res/anim/animator.xml ValueAnimatorResources}
*
* <p>It is also possible to use a combination of {@link PropertyValuesHolder} and
* {@link Keyframe} resource tags to create a multi-step animation.
* Note that you can specify explicit fractional values (from 0 to 1) for
* each keyframe to determine when, in the overall duration, the animation should arrive at that
* value. Alternatively, you can leave the fractions off and the keyframes will be equally
* distributed within the total duration:</p>
*
* {@sample development/samples/ApiDemos/res/anim/value_animator_pvh_kf.xml
* ValueAnimatorKeyframeResources}
*
* <div class="special reference">
* <h3>Developer Guides</h3>
* <p>For more information about animating with {@code ValueAnimator}, read the
* <a href="{@docRoot}guide/topics/graphics/prop-animation.html#value-animator">Property
* Animation</a> developer guide.</p>
* </div>
*/
@SuppressWarnings("unchecked")
public class ValueAnimator extends Animator {
private static final String TAG = "ValueAnimator";
private static final boolean DEBUG = false;
/**
* Internal constants
*/
private static float sDurationScale = 1.0f;
/**
* Values used with internal variable mPlayingState to indicate the current state of an
* animation.
*/
static final int STOPPED = 0; // Not yet playing
static final int RUNNING = 1; // Playing normally
static final int SEEKED = 2; // Seeked to some time value
/**
* Internal variables
* NOTE: This object implements the clone() method, making a deep copy of any referenced
* objects. As other non-trivial fields are added to this class, make sure to add logic
* to clone() to make deep copies of them.
*/
/**
* The first time that the animation's animateFrame() method is called. This time is used to
* determine elapsed time (and therefore the elapsed fraction) in subsequent calls
* to animateFrame().
*
* Whenever mStartTime is set, you must also update mStartTimeCommitted.
*/
long mStartTime;
/**
* When true, the start time has been firmly committed as a chosen reference point in
* time by which the progress of the animation will be evaluated. When false, the
* start time may be updated when the first animation frame is committed so as
* to compensate for jank that may have occurred between when the start time was
* initialized and when the frame was actually drawn.
*
* This flag is generally set to false during the first frame of the animation
* when the animation playing state transitions from STOPPED to RUNNING or
* resumes after having been paused. This flag is set to true when the start time
* is firmly committed and should not be further compensated for jank.
*/
boolean mStartTimeCommitted;
/**
* Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked
* to a value.
*/
float mSeekFraction = -1;
/**
* Set on the next frame after pause() is called, used to calculate a new startTime
* or delayStartTime which allows the animator to continue from the point at which
* it was paused. If negative, has not yet been set.
*/
private long mPauseTime;
/**
* Set when an animator is resumed. This triggers logic in the next frame which
* actually resumes the animator.
*/
private boolean mResumed = false;
// The static sAnimationHandler processes the internal timing loop on which all animations
// are based
/**
* @hide
*/
protected static ThreadLocal<AnimationHandler> sAnimationHandler =
new ThreadLocal<AnimationHandler>();
// The time interpolator to be used if none is set on the animation
private static final TimeInterpolator sDefaultInterpolator =
new AccelerateDecelerateInterpolator();
/**
* Used to indicate whether the animation is currently playing in reverse. This causes the
* elapsed fraction to be inverted to calculate the appropriate values.
*/
private boolean mPlayingBackwards = false;
/**
* Flag to indicate whether this animator is playing in reverse mode, specifically
* by being started or interrupted by a call to reverse(). This flag is different than
* mPlayingBackwards, which indicates merely whether the current iteration of the
* animator is playing in reverse. It is used in corner cases to determine proper end
* behavior.
*/
private boolean mReversing;
/**
* This variable tracks the current iteration that is playing. When mCurrentIteration exceeds the
* repeatCount (if repeatCount!=INFINITE), the animation ends
*/
private int mCurrentIteration = 0;
/**
* Tracks current elapsed/eased fraction, for querying in getAnimatedFraction().
*/
private float mCurrentFraction = 0f;
/**
* Tracks whether a startDelay'd animation has begun playing through the startDelay.
*/
private boolean mStartedDelay = false;
/**
* Tracks the time at which the animation began playing through its startDelay. This is
* different from the mStartTime variable, which is used to track when the animation became
* active (which is when the startDelay expired and the animation was added to the active
* animations list).
*/
private long mDelayStartTime;
/**
* Flag that represents the current state of the animation. Used to figure out when to start
* an animation (if state == STOPPED). Also used to end an animation that
* has been cancel()'d or end()'d since the last animation frame. Possible values are
* STOPPED, RUNNING, SEEKED.
*/
int mPlayingState = STOPPED;
/**
* Additional playing state to indicate whether an animator has been start()'d. There is
* some lag between a call to start() and the first animation frame. We should still note
* that the animation has been started, even if it's first animation frame has not yet
* happened, and reflect that state in isRunning().
* Note that delayed animations are different: they are not started until their first
* animation frame, which occurs after their delay elapses.
*/
private boolean mRunning = false;
/**
* Additional playing state to indicate whether an animator has been start()'d, whether or
* not there is a nonzero startDelay.
*/
private boolean mStarted = false;
/**
* Tracks whether we've notified listeners of the onAnimationStart() event. This can be
* complex to keep track of since we notify listeners at different times depending on
* startDelay and whether start() was called before end().
*/
private boolean mStartListenersCalled = false;
/**
* Flag that denotes whether the animation is set up and ready to go. Used to
* set up animation that has not yet been started.
*/
boolean mInitialized = false;
//
// Backing variables
//
// How long the animation should last in ms
private long mDuration = (long)(300 * sDurationScale);
private long mUnscaledDuration = 300;
// The amount of time in ms to delay starting the animation after start() is called
private long mStartDelay = 0;
private long mUnscaledStartDelay = 0;
// The number of times the animation will repeat. The default is 0, which means the animation
// will play only once
private int mRepeatCount = 0;
/**
* The type of repetition that will occur when repeatMode is nonzero. RESTART means the
* animation will start from the beginning on every new cycle. REVERSE means the animation
* will reverse directions on each iteration.
*/
private int mRepeatMode = RESTART;
/**
* The time interpolator to be used. The elapsed fraction of the animation will be passed
* through this interpolator to calculate the interpolated fraction, which is then used to
* calculate the animated values.
*/
private TimeInterpolator mInterpolator = sDefaultInterpolator;
/**
* The set of listeners to be sent events through the life of an animation.
*/
ArrayList<AnimatorUpdateListener> mUpdateListeners = null;
/**
* The property/value sets being animated.
*/
PropertyValuesHolder[] mValues;
/**
* A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values
* by property name during calls to getAnimatedValue(String).
*/
HashMap<String, PropertyValuesHolder> mValuesMap;
/**
* Public constants
*/
/**
* When the animation reaches the end and <code>repeatCount</code> is INFINITE
* or a positive value, the animation restarts from the beginning.
*/
public static final int RESTART = 1;
/**
* When the animation reaches the end and <code>repeatCount</code> is INFINITE
* or a positive value, the animation reverses direction on every iteration.
*/
public static final int REVERSE = 2;
/**
* This value used used with the {@link #setRepeatCount(int)} property to repeat
* the animation indefinitely.
*/
public static final int INFINITE = -1;
/**
* @hide
*/
public static void setDurationScale(float durationScale) {
sDurationScale = durationScale;
}
/**
* @hide
*/
public static float getDurationScale() {
return sDurationScale;
}
/**
* Creates a new ValueAnimator object. This default constructor is primarily for
* use internally; the factory methods which take parameters are more generally
* useful.
*/
public ValueAnimator() {
}
/**
* 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.
*
* @param values A set of values that the animation will animate between over time.
* @return A ValueAnimator object that is set up to animate between the given values.
*/
public static ValueAnimator ofInt(int... values) {
ValueAnimator anim = new ValueAnimator();
anim.setIntValues(values);
return anim;
}
/**
* 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.
*
* @param values A set of values that the animation will animate between over time.
* @return A ValueAnimator object that is set up to animate between the given values.
*/
public static ValueAnimator ofArgb(int... values) {
ValueAnimator anim = new ValueAnimator();
anim.setIntValues(values);
anim.setEvaluator(ArgbEvaluator.getInstance());
return anim;
}
/**
* 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.
*
* @param values A set of values that the animation will animate between over time.
* @return A ValueAnimator object that is set up to animate between the given values.
*/
public static ValueAnimator ofFloat(float... values) {
ValueAnimator anim = new ValueAnimator();
anim.setFloatValues(values);
return anim;
}
/**
* Constructs and returns a ValueAnimator that animates between the values
* specified in the PropertyValuesHolder objects.
*
* @param values A set of PropertyValuesHolder objects whose values will be animated
* between over time.
* @return A ValueAnimator object that is set up to animate between the given values.
*/
public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) {
ValueAnimator anim = new ValueAnimator();
anim.setValues(values);
return anim;
}
/**
* 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.
*
* <p>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.
*
* @param evaluator A TypeEvaluator that will be called on each animation frame to
* provide the ncessry interpolation between the Object values to derive the animated
* value.
* @param values A set of values that the animation will animate between over time.
* @return A ValueAnimator object that is set up to animate between the given values.
*/
public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) {
ValueAnimator anim = new ValueAnimator();
anim.setObjectValues(values);
anim.setEvaluator(evaluator);
return anim;
}
/**
* 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.
*
* <p>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.</p>
*
* @param values A set of values that the animation will animate between over time.
*/
public void setIntValues(int... values) {
if (values == null || values.length == 0) {
return;
}
if (mValues == null || mValues.length == 0) {
setValues(PropertyValuesHolder.ofInt("", values));
} else {
PropertyValuesHolder valuesHolder = mValues[0];
valuesHolder.setIntValues(values);
}
// New property/values/target should cause re-initialization prior to starting
mInitialized = false;
}
/**
* 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.
*
* <p>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.</p>
*
* @param values A set of values that the animation will animate between over time.
*/
public void setFloatValues(float... values) {
if (values == null || values.length == 0) {
return;
}
if (mValues == null || mValues.length == 0) {
setValues(PropertyValuesHolder.ofFloat("", values));
} else {
PropertyValuesHolder valuesHolder = mValues[0];
valuesHolder.setFloatValues(values);
}
// New property/values/target should cause re-initialization prior to starting
mInitialized = false;
}
/**
* 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.
*
* <p>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.</p>
*
* <p>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.</p>
*
* @param values The set of values to animate between.
*/
public void setObjectValues(Object... values) {
if (values == null || values.length == 0) {
return;
}
if (mValues == null || mValues.length == 0) {
setValues(PropertyValuesHolder.ofObject("", null, values));
} else {
PropertyValuesHolder valuesHolder = mValues[0];
valuesHolder.setObjectValues(values);
}
// New property/values/target should cause re-initialization prior to starting
mInitialized = false;
}
/**
* 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.
*
* @param values The set of values, per property, being animated between.
*/
public void setValues(PropertyValuesHolder... values) {
int numValues = values.length;
mValues = values;
mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues);
for (int i = 0; i < numValues; ++i) {
PropertyValuesHolder valuesHolder = values[i];
mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder);
}
// New property/values/target should cause re-initialization prior to starting
mInitialized = false;
}
/**
* 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.
*
* @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the
* values, per property, that define the animation.
*/
public PropertyValuesHolder[] getValues() {
return mValues;
}
/**
* This function is called immediately before processing the first animation
* frame of an animation. If there is a nonzero <code>startDelay</code>, the
* function is called after that delay ends.
* It takes care of the final initialization steps for the
* animation.
*
* <p>Overrides of this method should call the superclass method to ensure
* that internal mechanisms for the animation are set up correctly.</p>
*/
@CallSuper
void initAnimation() {
if (!mInitialized) {
int numValues = mValues.length;
for (int i = 0; i < numValues; ++i) {
mValues[i].init();
}
mInitialized = true;
}
}
/**
* Sets the length of the animation. The default duration is 300 milliseconds.
*
* @param duration The length of the animation, in milliseconds. This value cannot
* be negative.
* @return ValueAnimator The object called with setDuration(). This return
* value makes it easier to compose statements together that construct and then set the
* duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>.
*/
@Override
public ValueAnimator setDuration(long duration) {
if (duration < 0) {
throw new IllegalArgumentException("Animators cannot have negative duration: " +
duration);
}
mUnscaledDuration = duration;
updateScaledDuration();
return this;
}
private void updateScaledDuration() {
mDuration = (long)(mUnscaledDuration * sDurationScale);
}
/**
* Gets the length of the animation. The default duration is 300 milliseconds.
*
* @return The length of the animation, in milliseconds.
*/
@Override
public long getDuration() {
return mUnscaledDuration;
}
/**
* 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.
*
* @param playTime The time, in milliseconds, to which the animation is advanced or rewound.
*/
public void setCurrentPlayTime(long playTime) {
float fraction = mUnscaledDuration > 0 ? (float) playTime / mUnscaledDuration : 1;
setCurrentFraction(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. {@link Animator.AnimatorListener} events are not called
* due to changing the fraction; those events are only processed while the animation
* is running.
*
* @param fraction The fraction to which the animation is advanced or rewound. Values
* outside the range of 0 to the maximum fraction for the animator will be clamped to
* the correct range.
*/
public void setCurrentFraction(float fraction) {
initAnimation();
if (fraction < 0) {
fraction = 0;
}
int iteration = (int) fraction;
if (fraction == 1) {
iteration -= 1;
} else if (fraction > 1) {
if (iteration < (mRepeatCount + 1) || mRepeatCount == INFINITE) {
if (mRepeatMode == REVERSE) {
mPlayingBackwards = (iteration % 2) != 0;
}
fraction = fraction % 1f;
} else {
fraction = 1;
iteration -= 1;
}
} else {
mPlayingBackwards = mReversing;
}
mCurrentIteration = iteration;
long seekTime = (long) (mDuration * fraction);
long currentTime = AnimationUtils.currentAnimationTimeMillis();
mStartTime = currentTime - seekTime;
mStartTimeCommitted = true; // do not allow start time to be compensated for jank
if (mPlayingState != RUNNING) {
mSeekFraction = fraction;
mPlayingState = SEEKED;
}
if (mPlayingBackwards) {
fraction = 1f - fraction;
}
animateValue(fraction);
}
/**
* 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.
*
* @return The current position in time of the animation.
*/
public long getCurrentPlayTime() {
if (!mInitialized || mPlayingState == STOPPED) {
return 0;
}
return AnimationUtils.currentAnimationTimeMillis() - mStartTime;
}
/**
* This custom, static handler handles the timing pulse that is shared by
* all active animations. This approach ensures that the setting of animation
* values will happen on the UI thread and that all animations will share
* the same times for calculating their values, which makes synchronizing
* animations possible.
*
* The handler uses the Choreographer for executing periodic callbacks.
*
* @hide
*/
@SuppressWarnings("unchecked")
protected static class AnimationHandler {
// The per-thread list of all active animations
/** @hide */
protected final ArrayList<ValueAnimator> mAnimations = new ArrayList<ValueAnimator>();
// Used in doAnimationFrame() to avoid concurrent modifications of mAnimations
private final ArrayList<ValueAnimator> mTmpAnimations = new ArrayList<ValueAnimator>();
// The per-thread set of animations to be started on the next animation frame
/** @hide */
protected final ArrayList<ValueAnimator> mPendingAnimations = new ArrayList<ValueAnimator>();
/**
* Internal per-thread collections used to avoid set collisions as animations start and end
* while being processed.
* @hide
*/
protected final ArrayList<ValueAnimator> mDelayedAnims = new ArrayList<ValueAnimator>();
private final ArrayList<ValueAnimator> mEndingAnims = new ArrayList<ValueAnimator>();
private final ArrayList<ValueAnimator> mReadyAnims = new ArrayList<ValueAnimator>();
private final Choreographer mChoreographer;
private boolean mAnimationScheduled;
private long mLastFrameTime;
private AnimationHandler() {
mChoreographer = Choreographer.getInstance();
}
/**
* Start animating on the next frame.
*/
public void start() {
scheduleAnimation();
}
void doAnimationFrame(long frameTime) {
mLastFrameTime = frameTime;
// mPendingAnimations holds any animations that have requested to be started
// We're going to clear mPendingAnimations, but starting animation may
// cause more to be added to the pending list (for example, if one animation
// starting triggers another starting). So we loop until mPendingAnimations
// is empty.
while (mPendingAnimations.size() > 0) {
ArrayList<ValueAnimator> pendingCopy =
(ArrayList<ValueAnimator>) mPendingAnimations.clone();
mPendingAnimations.clear();
int count = pendingCopy.size();
for (int i = 0; i < count; ++i) {
ValueAnimator anim = pendingCopy.get(i);
// If the animation has a startDelay, place it on the delayed list
if (anim.mStartDelay == 0) {
anim.startAnimation(this);
} else {
mDelayedAnims.add(anim);
}
}
}
// Next, process animations currently sitting on the delayed queue, adding
// them to the active animations if they are ready
int numDelayedAnims = mDelayedAnims.size();
for (int i = 0; i < numDelayedAnims; ++i) {
ValueAnimator anim = mDelayedAnims.get(i);
if (anim.delayedAnimationFrame(frameTime)) {
mReadyAnims.add(anim);
}
}
int numReadyAnims = mReadyAnims.size();
if (numReadyAnims > 0) {
for (int i = 0; i < numReadyAnims; ++i) {
ValueAnimator anim = mReadyAnims.get(i);
anim.startAnimation(this);
anim.mRunning = true;
mDelayedAnims.remove(anim);
}
mReadyAnims.clear();
}
// Now process all active animations. The return value from animationFrame()
// tells the handler whether it should now be ended
int numAnims = mAnimations.size();
for (int i = 0; i < numAnims; ++i) {
mTmpAnimations.add(mAnimations.get(i));
}
for (int i = 0; i < numAnims; ++i) {
ValueAnimator anim = mTmpAnimations.get(i);
if (mAnimations.contains(anim) && anim.doAnimationFrame(frameTime)) {
mEndingAnims.add(anim);
}
}
mTmpAnimations.clear();
if (mEndingAnims.size() > 0) {
for (int i = 0; i < mEndingAnims.size(); ++i) {
mEndingAnims.get(i).endAnimation(this);
}
mEndingAnims.clear();
}
// Schedule final commit for the frame.
mChoreographer.postCallback(Choreographer.CALLBACK_COMMIT, mCommit, null);
// If there are still active or delayed animations, schedule a future call to
// onAnimate to process the next frame of the animations.
if (!mAnimations.isEmpty() || !mDelayedAnims.isEmpty()) {
scheduleAnimation();
}
}
void commitAnimationFrame(long frameTime) {
final long adjustment = frameTime - mLastFrameTime;
final int numAnims = mAnimations.size();
for (int i = 0; i < numAnims; ++i) {
mAnimations.get(i).commitAnimationFrame(adjustment);
}
}
private void scheduleAnimation() {
if (!mAnimationScheduled) {
mChoreographer.postCallback(Choreographer.CALLBACK_ANIMATION, mAnimate, null);
mAnimationScheduled = true;
}
}
// Called by the Choreographer.
final Runnable mAnimate = new Runnable() {
@Override
public void run() {
mAnimationScheduled = false;
doAnimationFrame(mChoreographer.getFrameTime());
}
};
// Called by the Choreographer.
final Runnable mCommit = new Runnable() {
@Override
public void run() {
commitAnimationFrame(mChoreographer.getFrameTime());
}
};
}
/**
* The amount of time, in milliseconds, to delay starting the animation after
* {@link #start()} is called.
*
* @return the number of milliseconds to delay running the animation
*/
@Override
public long getStartDelay() {
return mUnscaledStartDelay;
}
/**
* The amount of time, in milliseconds, to delay starting the animation after
* {@link #start()} is called.
* @param startDelay The amount of the delay, in milliseconds
*/
@Override
public void setStartDelay(long startDelay) {
this.mStartDelay = (long)(startDelay * sDurationScale);
mUnscaledStartDelay = startDelay;
}
/**
* 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.
*
* @return the requested time between frames, in milliseconds
*/
public static long getFrameDelay() {
return Choreographer.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.
*
* @param frameDelay the requested time between frames, in milliseconds
*/
public static void setFrameDelay(long frameDelay) {
Choreographer.setFrameDelay(frameDelay);
}
/**
* The most recent value calculated by this <code>ValueAnimator</code> 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 <code>ValueAnimator</code>
* during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which
* is called during each animation frame, immediately after the value is calculated.
*
* @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for
* the single property being animated. If there are several properties being animated
* (specified by several PropertyValuesHolder objects in the constructor), this function
* returns the animated value for the first of those objects.
*/
public Object getAnimatedValue() {
if (mValues != null && mValues.length > 0) {
return mValues[0].getAnimatedValue();
}
// Shouldn't get here; should always have values unless ValueAnimator was set up wrong
return null;
}
/**
* The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>.
* The main purpose for this read-only property is to retrieve the value from the
* <code>ValueAnimator</code> during a call to
* {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which
* is called during each animation frame, immediately after the value is calculated.
*
* @return animatedValue The value most recently calculated for the named property
* by this <code>ValueAnimator</code>.
*/
public Object getAnimatedValue(String propertyName) {
PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName);
if (valuesHolder != null) {
return valuesHolder.getAnimatedValue();
} else {
// At least avoid crashing if called with bogus propertyName
return null;
}
}
/**
* 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 {@link #INFINITE}, the repeat mode will be taken
* into account. The repeat count is 0 by default.
*
* @param value the number of times the animation should be repeated
*/
public void setRepeatCount(int value) {
mRepeatCount = value;
}
/**
* Defines how many times the animation should repeat. The default value
* is 0.
*
* @return the number of times the animation should repeat, or {@link #INFINITE}
*/
public int getRepeatCount() {
return mRepeatCount;
}
/**
* 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 {@link #INFINITE}. Defaults to {@link #RESTART}.
*
* @param value {@link #RESTART} or {@link #REVERSE}
*/
public void setRepeatMode(int value) {
mRepeatMode = value;
}
/**
* Defines what this animation should do when it reaches the end.
*
* @return either one of {@link #REVERSE} or {@link #RESTART}
*/
public int getRepeatMode() {
return mRepeatMode;
}
/**
* 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.
*
* @param listener the listener to be added to the current set of listeners for this animation.
*/
public void addUpdateListener(AnimatorUpdateListener listener) {
if (mUpdateListeners == null) {
mUpdateListeners = new ArrayList<AnimatorUpdateListener>();
}
mUpdateListeners.add(listener);
}
/**
* Removes all listeners from the set listening to frame updates for this animation.
*/
public void removeAllUpdateListeners() {
if (mUpdateListeners == null) {
return;
}
mUpdateListeners.clear();
mUpdateListeners = null;
}
/**
* Removes a listener from the set listening to frame updates for this animation.
*
* @param listener the listener to be removed from the current set of update listeners
* for this animation.
*/
public void removeUpdateListener(AnimatorUpdateListener listener) {
if (mUpdateListeners == null) {
return;
}
mUpdateListeners.remove(listener);
if (mUpdateListeners.size() == 0) {
mUpdateListeners = null;
}
}
/**
* 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
* {@link android.view.animation.AccelerateDecelerateInterpolator}
*
* @param value the interpolator to be used by this animation. A value of <code>null</code>
* will result in linear interpolation.
*/
@Override
public void setInterpolator(TimeInterpolator value) {
if (value != null) {
mInterpolator = value;
} else {
mInterpolator = new LinearInterpolator();
}
}
/**
* Returns the timing interpolator that this ValueAnimator uses.
*
* @return The timing interpolator for this ValueAnimator.
*/
@Override
public TimeInterpolator getInterpolator() {
return mInterpolator;
}
/**
* 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 <code>startValue</code> and <code>endValue</code> 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 {@link ArgbEvaluator}
* should be used to get correct RGB color interpolation.
*
* <p>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.</p>
*
* @param value the evaluator to be used this animation
*/
public void setEvaluator(TypeEvaluator value) {
if (value != null && mValues != null && mValues.length > 0) {
mValues[0].setEvaluator(value);
}
}
private void notifyStartListeners() {
if (mListeners != null && !mStartListenersCalled) {
ArrayList<AnimatorListener> tmpListeners =
(ArrayList<AnimatorListener>) mListeners.clone();
int numListeners = tmpListeners.size();
for (int i = 0; i < numListeners; ++i) {
tmpListeners.get(i).onAnimationStart(this);
}
}
mStartListenersCalled = true;
}
/**
* Start the animation playing. This version of start() takes a boolean flag that indicates
* whether the animation should play in reverse. The flag is usually false, but may be set
* to true if called from the reverse() method.
*
* <p>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.</p>
*
* @param playBackwards Whether the ValueAnimator should start playing in reverse.
*/
private void start(boolean playBackwards) {
if (Looper.myLooper() == null) {
throw new AndroidRuntimeException("Animators may only be run on Looper threads");
}
mReversing = playBackwards;
mPlayingBackwards = playBackwards;
if (playBackwards && mSeekFraction != -1) {
if (mSeekFraction == 0 && mCurrentIteration == 0) {
// special case: reversing from seek-to-0 should act as if not seeked at all
mSeekFraction = 0;
} else if (mRepeatCount == INFINITE) {
mSeekFraction = 1 - (mSeekFraction % 1);
} else {
mSeekFraction = 1 + mRepeatCount - (mCurrentIteration + mSeekFraction);
}
mCurrentIteration = (int) mSeekFraction;
mSeekFraction = mSeekFraction % 1;
}
if (mCurrentIteration > 0 && mRepeatMode == REVERSE &&
(mCurrentIteration < (mRepeatCount + 1) || mRepeatCount == INFINITE)) {
// if we were seeked to some other iteration in a reversing animator,
// figure out the correct direction to start playing based on the iteration
if (playBackwards) {
mPlayingBackwards = (mCurrentIteration % 2) == 0;
} else {
mPlayingBackwards = (mCurrentIteration % 2) != 0;
}
}
int prevPlayingState = mPlayingState;
mPlayingState = STOPPED;
mStarted = true;
mStartedDelay = false;
mPaused = false;
updateScaledDuration(); // in case the scale factor has changed since creation time
AnimationHandler animationHandler = getOrCreateAnimationHandler();
animationHandler.mPendingAnimations.add(this);
if (mStartDelay == 0) {
// This sets the initial value of the animation, prior to actually starting it running
if (prevPlayingState != SEEKED) {
setCurrentPlayTime(0);
}
mPlayingState = STOPPED;
mRunning = true;
notifyStartListeners();
}
animationHandler.start();
}
@Override
public void start() {
start(false);
}
@Override
public void cancel() {
// Only cancel if the animation is actually running or has been started and is about
// to run
AnimationHandler handler = getOrCreateAnimationHandler();
if (mPlayingState != STOPPED
|| handler.mPendingAnimations.contains(this)
|| handler.mDelayedAnims.contains(this)) {
// Only notify listeners if the animator has actually started
if ((mStarted || mRunning) && mListeners != null) {
if (!mRunning) {
// If it's not yet running, then start listeners weren't called. Call them now.
notifyStartListeners();
}
ArrayList<AnimatorListener> tmpListeners =
(ArrayList<AnimatorListener>) mListeners.clone();
for (AnimatorListener listener : tmpListeners) {
listener.onAnimationCancel(this);
}
}
endAnimation(handler);
}
}
@Override
public void end() {
AnimationHandler handler = getOrCreateAnimationHandler();
if (!handler.mAnimations.contains(this) && !handler.mPendingAnimations.contains(this)) {
// Special case if the animation has not yet started; get it ready for ending
mStartedDelay = false;
startAnimation(handler);
mStarted = true;
} else if (!mInitialized) {
initAnimation();
}
animateValue(mPlayingBackwards ? 0f : 1f);
endAnimation(handler);
}
@Override
public void resume() {
if (mPaused) {
mResumed = true;
}
super.resume();
}
@Override
public void pause() {
boolean previouslyPaused = mPaused;
super.pause();
if (!previouslyPaused && mPaused) {
mPauseTime = -1;
mResumed = false;
}
}
@Override
public boolean isRunning() {
return (mPlayingState == RUNNING || mRunning);
}
@Override
public boolean isStarted() {
return mStarted;
}
/**
* 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.
*/
@Override
public void reverse() {
mPlayingBackwards = !mPlayingBackwards;
if (mPlayingState == RUNNING) {
long currentTime = AnimationUtils.currentAnimationTimeMillis();
long currentPlayTime = currentTime - mStartTime;
long timeLeft = mDuration - currentPlayTime;
mStartTime = currentTime - timeLeft;
mStartTimeCommitted = true; // do not allow start time to be compensated for jank
mReversing = !mReversing;
} else if (mStarted) {
end();
} else {
start(true);
}
}
/**
* @hide
*/
@Override
public boolean canReverse() {
return true;
}
/**
* Called internally to end an animation by removing it from the animations list. Must be
* called on the UI thread.
* @hide
*/
protected void endAnimation(AnimationHandler handler) {
handler.mAnimations.remove(this);
handler.mPendingAnimations.remove(this);
handler.mDelayedAnims.remove(this);
mPlayingState = STOPPED;
mPaused = false;
if ((mStarted || mRunning) && mListeners != null) {
if (!mRunning) {
// If it's not yet running, then start listeners weren't called. Call them now.
notifyStartListeners();
}
ArrayList<AnimatorListener> tmpListeners =
(ArrayList<AnimatorListener>) mListeners.clone();
int numListeners = tmpListeners.size();
for (int i = 0; i < numListeners; ++i) {
tmpListeners.get(i).onAnimationEnd(this);
}
}
mRunning = false;
mStarted = false;
mStartListenersCalled = false;
mPlayingBackwards = false;
mReversing = false;
mCurrentIteration = 0;
if (Trace.isTagEnabled(Trace.TRACE_TAG_VIEW)) {
Trace.asyncTraceEnd(Trace.TRACE_TAG_VIEW, getNameForTrace(),
System.identityHashCode(this));
}
}
/**
* Called internally to start an animation by adding it to the active animations list. Must be
* called on the UI thread.
*/
private void startAnimation(AnimationHandler handler) {
if (Trace.isTagEnabled(Trace.TRACE_TAG_VIEW)) {
Trace.asyncTraceBegin(Trace.TRACE_TAG_VIEW, getNameForTrace(),
System.identityHashCode(this));
}
initAnimation();
handler.mAnimations.add(this);
if (mStartDelay > 0 && mListeners != null) {
// Listeners were already notified in start() if startDelay is 0; this is
// just for delayed animations
notifyStartListeners();
}
}
/**
* Returns the name of this animator for debugging purposes.
*/
String getNameForTrace() {
return "animator";
}
/**
* Internal function called to process an animation frame on an animation that is currently
* sleeping through its <code>startDelay</code> phase. The return value indicates whether it
* should be woken up and put on the active animations queue.
*
* @param currentTime The current animation time, used to calculate whether the animation
* has exceeded its <code>startDelay</code> and should be started.
* @return True if the animation's <code>startDelay</code> has been exceeded and the animation
* should be added to the set of active animations.
*/
private boolean delayedAnimationFrame(long currentTime) {
if (!mStartedDelay) {
mStartedDelay = true;
mDelayStartTime = currentTime;
}
if (mPaused) {
if (mPauseTime < 0) {
mPauseTime = currentTime;
}
return false;
} else if (mResumed) {
mResumed = false;
if (mPauseTime > 0) {
// Offset by the duration that the animation was paused
mDelayStartTime += (currentTime - mPauseTime);
}
}
long deltaTime = currentTime - mDelayStartTime;
if (deltaTime > mStartDelay) {
// startDelay ended - start the anim and record the mStartTime appropriately
mStartTime = mDelayStartTime + mStartDelay;
mStartTimeCommitted = true; // do not allow start time to be compensated for jank
mPlayingState = RUNNING;
return true;
}
return false;
}
/**
* Applies an adjustment to the animation to compensate for jank between when
* the animation first ran and when the frame was drawn.
*/
void commitAnimationFrame(long adjustment) {
if (!mStartTimeCommitted) {
mStartTimeCommitted = true;
if (mPlayingState == RUNNING && adjustment > 0) {
mStartTime += adjustment;
if (DEBUG) {
Log.d(TAG, "Adjusted start time by " + adjustment + " ms: " + toString());
}
}
}
}
/**
* This internal function processes a single animation frame for a given animation. The
* currentTime parameter is the timing pulse sent by the handler, used to calculate the
* elapsed duration, and therefore
* the elapsed fraction, of the animation. The return value indicates whether the animation
* should be ended (which happens when the elapsed time of the animation exceeds the
* animation's duration, including the repeatCount).
*
* @param currentTime The current time, as tracked by the static timing handler
* @return true if the animation's duration, including any repetitions due to
* <code>repeatCount</code>, has been exceeded and the animation should be ended.
*/
boolean animationFrame(long currentTime) {
boolean done = false;
switch (mPlayingState) {
case RUNNING:
case SEEKED:
float fraction = mDuration > 0 ? (float)(currentTime - mStartTime) / mDuration : 1f;
if (mDuration == 0 && mRepeatCount != INFINITE) {
// Skip to the end
mCurrentIteration = mRepeatCount;
if (!mReversing) {
mPlayingBackwards = false;
}
}
if (fraction >= 1f) {
if (mCurrentIteration < mRepeatCount || mRepeatCount == INFINITE) {
// Time to repeat
if (mListeners != null) {
int numListeners = mListeners.size();
for (int i = 0; i < numListeners; ++i) {
mListeners.get(i).onAnimationRepeat(this);
}
}
if (mRepeatMode == REVERSE) {
mPlayingBackwards = !mPlayingBackwards;
}
mCurrentIteration += (int) fraction;
fraction = fraction % 1f;
mStartTime += mDuration;
// Note: We do not need to update the value of mStartTimeCommitted here
// since we just added a duration offset.
} else {
done = true;
fraction = Math.min(fraction, 1.0f);
}
}
if (mPlayingBackwards) {
fraction = 1f - fraction;
}
animateValue(fraction);
break;
}
return done;
}
/**
* Processes a frame of the animation, adjusting the start time if needed.
*
* @param frameTime The frame time.
* @return true if the animation has ended.
*/
final boolean doAnimationFrame(long frameTime) {
if (mPlayingState == STOPPED) {
mPlayingState = RUNNING;
if (mSeekFraction < 0) {
mStartTime = frameTime;
} else {
long seekTime = (long) (mDuration * mSeekFraction);
mStartTime = frameTime - seekTime;
mSeekFraction = -1;
}
mStartTimeCommitted = false; // allow start time to be compensated for jank
}
if (mPaused) {
if (mPauseTime < 0) {
mPauseTime = frameTime;
}
return false;
} else if (mResumed) {
mResumed = false;
if (mPauseTime > 0) {
// Offset by the duration that the animation was paused
mStartTime += (frameTime - mPauseTime);
mStartTimeCommitted = false; // allow start time to be compensated for jank
}
}
// The frame time might be before the start time during the first frame of
// an animation. The "current time" must always be on or after the start
// time to avoid animating frames at negative time intervals. In practice, this
// is very rare and only happens when seeking backwards.
final long currentTime = Math.max(frameTime, mStartTime);
return animationFrame(currentTime);
}
/**
* Returns the current animation fraction, which is the elapsed/interpolated fraction used in
* the most recent frame update on the animation.
*
* @return Elapsed/interpolated fraction of the animation.
*/
public float getAnimatedFraction() {
return mCurrentFraction;
}
/**
* This method is called with the elapsed fraction of the animation during every
* animation frame. This function turns the elapsed fraction into an interpolated fraction
* and then into an animated value (from the evaluator. The function is called mostly during
* animation updates, but it is also called when the <code>end()</code>
* function is called, to set the final value on the property.
*
* <p>Overrides of this method must call the superclass to perform the calculation
* of the animated value.</p>
*
* @param fraction The elapsed fraction of the animation.
*/
@CallSuper
void animateValue(float fraction) {
fraction = mInterpolator.getInterpolation(fraction);
mCurrentFraction = fraction;
int numValues = mValues.length;
for (int i = 0; i < numValues; ++i) {
mValues[i].calculateValue(fraction);
}
if (mUpdateListeners != null) {
int numListeners = mUpdateListeners.size();
for (int i = 0; i < numListeners; ++i) {
mUpdateListeners.get(i).onAnimationUpdate(this);
}
}
}
@Override
public ValueAnimator clone() {
final ValueAnimator anim = (ValueAnimator) super.clone();
if (mUpdateListeners != null) {
anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(mUpdateListeners);
}
anim.mSeekFraction = -1;
anim.mPlayingBackwards = false;
anim.mReversing = false;
anim.mCurrentIteration = 0;
anim.mInitialized = false;
anim.mPlayingState = STOPPED;
anim.mStartedDelay = false;
anim.mStarted = false;
anim.mRunning = false;
anim.mPaused = false;
anim.mResumed = false;
anim.mStartListenersCalled = false;
anim.mStartTime = 0;
anim.mStartTimeCommitted = false;
anim.mPauseTime = 0;
anim.mCurrentFraction = 0;
anim.mDelayStartTime = 0;
PropertyValuesHolder[] oldValues = mValues;
if (oldValues != null) {
int numValues = oldValues.length;
anim.mValues = new PropertyValuesHolder[numValues];
anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues);
for (int i = 0; i < numValues; ++i) {
PropertyValuesHolder newValuesHolder = oldValues[i].clone();
anim.mValues[i] = newValuesHolder;
anim.mValuesMap.put(newValuesHolder.getPropertyName(), newValuesHolder);
}
}
return anim;
}
/**
* Implementors of this interface can add themselves as update listeners
* to an <code>ValueAnimator</code> instance to receive callbacks on every animation
* frame, after the current frame's values have been calculated for that
* <code>ValueAnimator</code>.
*/
public static interface AnimatorUpdateListener {
/**
* <p>Notifies the occurrence of another frame of the animation.</p>
*
* @param animation The animation which was repeated.
*/
void onAnimationUpdate(ValueAnimator animation);
}
/**
* Return the number of animations currently running.
*
* Used by StrictMode internally to annotate violations.
* May be called on arbitrary threads!
*
* @hide
*/
public static int getCurrentAnimationsCount() {
AnimationHandler handler = sAnimationHandler.get();
return handler != null ? handler.mAnimations.size() : 0;
}
/**
* Clear all animations on this thread, without canceling or ending them.
* This should be used with caution.
*
* @hide
*/
public static void clearAllAnimations() {
AnimationHandler handler = sAnimationHandler.get();
if (handler != null) {
handler.mAnimations.clear();
handler.mPendingAnimations.clear();
handler.mDelayedAnims.clear();
}
}
private static AnimationHandler getOrCreateAnimationHandler() {
AnimationHandler handler = sAnimationHandler.get();
if (handler == null) {
handler = new AnimationHandler();
sAnimationHandler.set(handler);
}
return handler;
}
@Override
public String toString() {
String returnVal = "ValueAnimator@" + Integer.toHexString(hashCode());
if (mValues != null) {
for (int i = 0; i < mValues.length; ++i) {
returnVal += "\n " + mValues[i].toString();
}
}
return returnVal;
}
/**
* <p>Whether or not the ValueAnimator is allowed to run asynchronously off of
* the UI thread. This is a hint that informs the ValueAnimator that it is
* OK to run the animation off-thread, however ValueAnimator may decide
* that it must run the animation on the UI thread anyway. For example if there
* is an {@link AnimatorUpdateListener} the animation will run on the UI thread,
* regardless of the value of this hint.</p>
*
* <p>Regardless of whether or not the animation runs asynchronously, all
* listener callbacks will be called on the UI thread.</p>
*
* <p>To be able to use this hint the following must be true:</p>
* <ol>
* <li>{@link #getAnimatedFraction()} is not needed (it will return undefined values).</li>
* <li>The animator is immutable while {@link #isStarted()} is true. Requests
* to change values, duration, delay, etc... may be ignored.</li>
* <li>Lifecycle callback events may be asynchronous. Events such as
* {@link Animator.AnimatorListener#onAnimationEnd(Animator)} or
* {@link Animator.AnimatorListener#onAnimationRepeat(Animator)} may end up delayed
* as they must be posted back to the UI thread, and any actions performed
* by those callbacks (such as starting new animations) will not happen
* in the same frame.</li>
* <li>State change requests ({@link #cancel()}, {@link #end()}, {@link #reverse()}, etc...)
* may be asynchronous. It is guaranteed that all state changes that are
* performed on the UI thread in the same frame will be applied as a single
* atomic update, however that frame may be the current frame,
* the next frame, or some future frame. This will also impact the observed
* state of the Animator. For example, {@link #isStarted()} may still return true
* after a call to {@link #end()}. Using the lifecycle callbacks is preferred over
* queries to {@link #isStarted()}, {@link #isRunning()}, and {@link #isPaused()}
* for this reason.</li>
* </ol>
* @hide
*/
@Override
public void setAllowRunningAsynchronously(boolean mayRunAsync) {
// It is up to subclasses to support this, if they can.
}
}