/* * 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.annotation.IntDef; import android.os.Looper; import android.os.Trace; import android.util.AndroidRuntimeException; import android.util.Log; import android.view.animation.AccelerateDecelerateInterpolator; import android.view.animation.AnimationUtils; import android.view.animation.LinearInterpolator; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; 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. * *
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.
* *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)}.
* *Animators can be created from either code or resource files. Here is an example * of a ValueAnimator resource file:
* * {@sample development/samples/ApiDemos/res/anim/animator.xml ValueAnimatorResources} * *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:
* * {@sample development/samples/ApiDemos/res/anim/value_animator_pvh_kf.xml * ValueAnimatorKeyframeResources} * *For more information about animating with {@code ValueAnimator}, read the * Property * Animation developer guide.
*repeatCount
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 repeatCount
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.
*
* 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. * * @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. * *
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.
* * @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. * *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.
* * @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. * *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.
* * @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 HashMapstartDelay
, the
* function is called after that delay ends.
* It takes care of the final initialization steps for the
* animation.
*
* Overrides of this method should call the superclass method to ensure * that internal mechanisms for the animation are set up correctly.
*/ @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 inValueAnimator.ofInt(0, 10).setDuration(500).start()
.
*/
@Override
public ValueAnimator setDuration(long duration) {
if (duration < 0) {
throw new IllegalArgumentException("Animators cannot have negative duration: " +
duration);
}
mDuration = duration;
return this;
}
private long getScaledDuration() {
return (long)(mDuration * 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 mDuration;
}
@Override
public long getTotalDuration() {
if (mRepeatCount == INFINITE) {
return DURATION_INFINITE;
} else {
return mStartDelay + (mDuration * (mRepeatCount + 1));
}
}
/**
* 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 = mDuration > 0 ? (float) playTime / mDuration : 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();
fraction = clampFraction(fraction);
long seekTime = (long) (getScaledDuration() * fraction);
long currentTime = AnimationUtils.currentAnimationTimeMillis();
mStartTime = currentTime - seekTime;
mStartTimeCommitted = true; // do not allow start time to be compensated for jank
if (!isPulsingInternal()) {
// If the animation loop hasn't started, the startTime will be adjusted in the first
// frame based on seek fraction.
mSeekFraction = fraction;
}
mOverallFraction = fraction;
final float currentIterationFraction = getCurrentIterationFraction(fraction);
animateValue(currentIterationFraction);
}
/**
* Calculates current iteration based on the overall fraction. The overall fraction will be
* in the range of [0, mRepeatCount + 1]. Both current iteration and fraction in the current
* iteration can be derived from it.
*/
private int getCurrentIteration(float fraction) {
fraction = clampFraction(fraction);
// If the overall fraction is a positive integer, we consider the current iteration to be
// complete. In other words, the fraction for the current iteration would be 1, and the
// current iteration would be overall fraction - 1.
double iteration = Math.floor(fraction);
if (fraction == iteration && fraction > 0) {
iteration--;
}
return (int) iteration;
}
/**
* Calculates the fraction of the current iteration, taking into account whether the animation
* should be played backwards. E.g. When the animation is played backwards in an iteration,
* the fraction for that iteration will go from 1f to 0f.
*/
private float getCurrentIterationFraction(float fraction) {
fraction = clampFraction(fraction);
int iteration = getCurrentIteration(fraction);
float currentFraction = fraction - iteration;
return shouldPlayBackward(iteration) ? 1f - currentFraction : currentFraction;
}
/**
* Clamps fraction into the correct range: [0, mRepeatCount + 1]. If repeat count is infinite,
* no upper bound will be set for the fraction.
*
* @param fraction fraction to be clamped
* @return fraction clamped into the range of [0, mRepeatCount + 1]
*/
private float clampFraction(float fraction) {
if (fraction < 0) {
fraction = 0;
} else if (mRepeatCount != INFINITE) {
fraction = Math.min(fraction, mRepeatCount + 1);
}
return fraction;
}
/**
* Calculates the direction of animation playing (i.e. forward or backward), based on 1)
* whether the entire animation is being reversed, 2) repeat mode applied to the current
* iteration.
*/
private boolean shouldPlayBackward(int iteration) {
if (iteration > 0 && mRepeatMode == REVERSE &&
(iteration < (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 (mReversing) {
return (iteration % 2) == 0;
} else {
return (iteration % 2) != 0;
}
} else {
return mReversing;
}
}
/**
* 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
* {@link #setCurrentPlayTime(long)} or {@link #setCurrentFraction(float)}, in which case
* it will return the time that was set.
*
* @return The current position in time of the animation.
*/
public long getCurrentPlayTime() {
if (!mInitialized || (!mStarted && mSeekFraction < 0)) {
return 0;
}
if (mSeekFraction >= 0) {
return (long) (mDuration * mSeekFraction);
}
float durationScale = sDurationScale == 0 ? 1 : sDurationScale;
return (long) ((AnimationUtils.currentAnimationTimeMillis() - mStartTime) / durationScale);
}
/**
* 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 mStartDelay;
}
/**
* The amount of time, in milliseconds, to delay starting the animation after
* {@link #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.
*
* @param startDelay The amount of the delay, in milliseconds
*/
@Override
public void setStartDelay(long startDelay) {
// Clamp start delay to non-negative range.
if (startDelay < 0) {
Log.w(TAG, "Start delay should always be non-negative");
startDelay = 0;
}
mStartDelay = 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.
*
* Note that this method should be called from the same thread that {@link #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.
*
* @return the requested time between frames, in milliseconds
*/
public static long getFrameDelay() {
return AnimationHandler.getInstance().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 {@link #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.
*
* @param frameDelay the requested time between frames, in milliseconds
*/
public static void setFrameDelay(long frameDelay) {
AnimationHandler.getInstance().setFrameDelay(frameDelay);
}
/**
* 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 {@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 ValueAnimator
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 ValueAnimator
for propertyName
.
* The main purpose for this read-only property is to retrieve the value from the
* ValueAnimator
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 ValueAnimator
.
*/
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(@RepeatMode int value) {
mRepeatMode = value;
}
/**
* Defines what this animation should do when it reaches the end.
*
* @return either one of {@link #REVERSE} or {@link #RESTART}
*/
@RepeatMode
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 ArrayListnull
* 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 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 {@link 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.
* * @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) { ArrayListThe 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.
* * @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; // Special case: reversing from seek-to-0 should act as if not seeked at all. if (playBackwards && mSeekFraction != -1 && mSeekFraction != 0) { if (mRepeatCount == INFINITE) { // Calculate the fraction of the current iteration. float fraction = (float) (mSeekFraction - Math.floor(mSeekFraction)); mSeekFraction = 1 - fraction; } else { mSeekFraction = 1 + mRepeatCount - mSeekFraction; } } mStarted = true; mPaused = false; mRunning = false; // Resets mLastFrameTime when start() is called, so that if the animation was running, // calling start() would put the animation in the // started-but-not-yet-reached-the-first-frame phase. mLastFrameTime = 0; AnimationHandler animationHandler = AnimationHandler.getInstance(); animationHandler.addAnimationFrameCallback(this, (long) (mStartDelay * sDurationScale)); if (mStartDelay == 0 || mSeekFraction >= 0) { // If there's no start delay, init the animation and notify start listeners right away // to be consistent with the previous behavior. Otherwise, postpone this until the first // frame after the start delay. startAnimation(); if (mSeekFraction == -1) { // No seek, start at play time 0. Note that the reason we are not using fraction 0 // is because for animations with 0 duration, we want to be consistent with pre-N // behavior: skip to the final value immediately. setCurrentPlayTime(0); } else { setCurrentFraction(mSeekFraction); } } } @Override public void start() { start(false); } @Override public void cancel() { if (Looper.myLooper() == null) { throw new AndroidRuntimeException("Animators may only be run on Looper threads"); } // If end has already been requested, through a previous end() or cancel() call, no-op // until animation starts again. if (mAnimationEndRequested) { return; } // Only cancel if the animation is actually running or has been started and is about // to run // 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(); } ArrayListrepeatCount
has been exceeded and the animation should be ended.
*/
boolean animateBasedOnTime(long currentTime) {
boolean done = false;
if (mRunning) {
final long scaledDuration = getScaledDuration();
final float fraction = scaledDuration > 0 ?
(float)(currentTime - mStartTime) / scaledDuration : 1f;
final float lastFraction = mOverallFraction;
final boolean newIteration = (int) fraction > (int) lastFraction;
final boolean lastIterationFinished = (fraction >= mRepeatCount + 1) &&
(mRepeatCount != INFINITE);
if (scaledDuration == 0) {
// 0 duration animator, ignore the repeat count and skip to the end
done = true;
} else if (newIteration && !lastIterationFinished) {
// Time to repeat
if (mListeners != null) {
int numListeners = mListeners.size();
for (int i = 0; i < numListeners; ++i) {
mListeners.get(i).onAnimationRepeat(this);
}
}
} else if (lastIterationFinished) {
done = true;
}
mOverallFraction = clampFraction(fraction);
float currentIterationFraction = getCurrentIterationFraction(mOverallFraction);
animateValue(currentIterationFraction);
}
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.
* @hide
*/
public final void doAnimationFrame(long frameTime) {
AnimationHandler handler = AnimationHandler.getInstance();
if (mLastFrameTime == 0) {
// First frame
handler.addOneShotCommitCallback(this);
if (mStartDelay > 0) {
startAnimation();
}
if (mSeekFraction < 0) {
mStartTime = frameTime;
} else {
long seekTime = (long) (getScaledDuration() * mSeekFraction);
mStartTime = frameTime - seekTime;
mSeekFraction = -1;
}
mStartTimeCommitted = false; // allow start time to be compensated for jank
}
mLastFrameTime = frameTime;
if (mPaused) {
mPauseTime = frameTime;
handler.removeCallback(this);
return;
} 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
}
handler.addOneShotCommitCallback(this);
}
// 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);
boolean finished = animateBasedOnTime(currentTime);
if (finished) {
endAnimation();
}
}
/**
* 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 end()
* function is called, to set the final value on the property.
*
* Overrides of this method must call the superclass to perform the calculation * of the animated value.
* * @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 ArrayListValueAnimator
instance to receive callbacks on every animation
* frame, after the current frame's values have been calculated for that
* ValueAnimator
.
*/
public static interface AnimatorUpdateListener {
/**
* Notifies the occurrence of another frame of the animation.
* * @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() { return AnimationHandler.getAnimationCount(); } @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; } /** *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.
* *Regardless of whether or not the animation runs asynchronously, all * listener callbacks will be called on the UI thread.
* *To be able to use this hint the following must be true:
*