com.nineoldandroids.animation.ValueAnimator Maven / Gradle / Ivy
/*
* 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 com.nineoldandroids.animation;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.AndroidRuntimeException;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.AnimationUtils;
import android.view.animation.Interpolator;
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.
*
* 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)}.
*/
public class ValueAnimator extends Animator {
/**
* Internal constants
*/
/*
* The default amount of time in ms between animation frames
*/
private static final long DEFAULT_FRAME_DELAY = 10;
/**
* Messages sent to timing handler: START is sent when an animation first begins, FRAME is sent
* by the handler to itself to process the next animation frame
*/
static final int ANIMATION_START = 0;
static final int ANIMATION_FRAME = 1;
/**
* 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()
long mStartTime;
/**
* Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked
* to a value.
*/
long mSeekTime = -1;
// TODO: We access the following ThreadLocal variables often, some of them on every update.
// If ThreadLocal access is significantly expensive, we may want to put all of these
// fields into a structure sot hat we just access ThreadLocal once to get the reference
// to that structure, then access the structure directly for each field.
// The static sAnimationHandler processes the internal timing loop on which all animations
// are based
private static ThreadLocal sAnimationHandler =
new ThreadLocal();
// The per-thread list of all active animations
private static final ThreadLocal> sAnimations =
new ThreadLocal>() {
@Override
protected ArrayList initialValue() {
return new ArrayList();
}
};
// The per-thread set of animations to be started on the next animation frame
private static final ThreadLocal> sPendingAnimations =
new ThreadLocal>() {
@Override
protected ArrayList initialValue() {
return new ArrayList();
}
};
/**
* Internal per-thread collections used to avoid set collisions as animations start and end
* while being processed.
*/
private static final ThreadLocal> sDelayedAnims =
new ThreadLocal>() {
@Override
protected ArrayList initialValue() {
return new ArrayList();
}
};
private static final ThreadLocal> sEndingAnims =
new ThreadLocal>() {
@Override
protected ArrayList initialValue() {
return new ArrayList();
}
};
private static final ThreadLocal> sReadyAnims =
new ThreadLocal>() {
@Override
protected ArrayList initialValue() {
return new ArrayList();
}
};
// The time interpolator to be used if none is set on the animation
private static final /*Time*/Interpolator sDefaultInterpolator =
new AccelerateDecelerateInterpolator();
// type evaluators for the primitive types handled by this implementation
private static final TypeEvaluator sIntEvaluator = new IntEvaluator();
private static final TypeEvaluator sFloatEvaluator = new FloatEvaluator();
/**
* 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;
/**
* 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;
/**
* 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 = 300;
// The amount of time in ms to delay starting the animation after start() is called
private long mStartDelay = 0;
// The number of milliseconds between animation frames
private static long sFrameDelay = DEFAULT_FRAME_DELAY;
// 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 /*Time*/Interpolator mInterpolator = sDefaultInterpolator;
/**
* The set of listeners to be sent events through the life of an animation.
*/
private ArrayList 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 mValuesMap;
/**
* Public constants
*/
/**
* When the animation reaches the end and 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;
/**
* 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 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.
*
* 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(new PropertyValuesHolder[]{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(new PropertyValuesHolder[]{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.
*
* 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(new PropertyValuesHolder[]{PropertyValuesHolder.ofObject("",
(TypeEvaluator)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 an 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(numValues);
for (int i = 0; i < numValues; ++i) {
PropertyValuesHolder valuesHolder = (PropertyValuesHolder) 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 startDelay, 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.
*/
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 ValueAnimator.ofInt(0, 10).setDuration(500).start().
*/
public ValueAnimator setDuration(long duration) {
if (duration < 0) {
throw new IllegalArgumentException("Animators cannot have negative duration: " +
duration);
}
mDuration = duration;
return this;
}
/**
* Gets the length of the animation. The default duration is 300 milliseconds.
*
* @return The length of the animation, in milliseconds.
*/
public long getDuration() {
return mDuration;
}
/**
* 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) {
initAnimation();
long currentTime = AnimationUtils.currentAnimationTimeMillis();
if (mPlayingState != RUNNING) {
mSeekTime = playTime;
mPlayingState = SEEKED;
}
mStartTime = currentTime - playTime;
animationFrame(currentTime);
}
/**
* 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.
*
*/
private static class AnimationHandler extends Handler {
/**
* There are only two messages that we care about: ANIMATION_START and
* ANIMATION_FRAME. The START message is sent when an animation's start()
* method is called. It cannot start synchronously when start() is called
* because the call may be on the wrong thread, and it would also not be
* synchronized with other animations because it would not start on a common
* timing pulse. So each animation sends a START message to the handler, which
* causes the handler to place the animation on the active animations queue and
* start processing frames for that animation.
* The FRAME message is the one that is sent over and over while there are any
* active animations to process.
*/
@Override
public void handleMessage(Message msg) {
boolean callAgain = true;
ArrayList animations = sAnimations.get();
ArrayList delayedAnims = sDelayedAnims.get();
switch (msg.what) {
// TODO: should we avoid sending frame message when starting if we
// were already running?
case ANIMATION_START:
ArrayList pendingAnimations = sPendingAnimations.get();
if (animations.size() > 0 || delayedAnims.size() > 0) {
callAgain = false;
}
// pendingAnims holds any animations that have requested to be started
// We're going to clear sPendingAnimations, 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 sPendingAnimations
// is empty.
while (pendingAnimations.size() > 0) {
ArrayList pendingCopy =
(ArrayList) pendingAnimations.clone();
pendingAnimations.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();
} else {
delayedAnims.add(anim);
}
}
}
// fall through to process first frame of new animations
case ANIMATION_FRAME:
// currentTime holds the common time for all animations processed
// during this frame
long currentTime = AnimationUtils.currentAnimationTimeMillis();
ArrayList readyAnims = sReadyAnims.get();
ArrayList endingAnims = sEndingAnims.get();
// First, process animations currently sitting on the delayed queue, adding
// them to the active animations if they are ready
int numDelayedAnims = delayedAnims.size();
for (int i = 0; i < numDelayedAnims; ++i) {
ValueAnimator anim = delayedAnims.get(i);
if (anim.delayedAnimationFrame(currentTime)) {
readyAnims.add(anim);
}
}
int numReadyAnims = readyAnims.size();
if (numReadyAnims > 0) {
for (int i = 0; i < numReadyAnims; ++i) {
ValueAnimator anim = readyAnims.get(i);
anim.startAnimation();
anim.mRunning = true;
delayedAnims.remove(anim);
}
readyAnims.clear();
}
// Now process all active animations. The return value from animationFrame()
// tells the handler whether it should now be ended
int numAnims = animations.size();
int i = 0;
while (i < numAnims) {
ValueAnimator anim = animations.get(i);
if (anim.animationFrame(currentTime)) {
endingAnims.add(anim);
}
if (animations.size() == numAnims) {
++i;
} else {
// An animation might be canceled or ended by client code
// during the animation frame. Check to see if this happened by
// seeing whether the current index is the same as it was before
// calling animationFrame(). Another approach would be to copy
// animations to a temporary list and process that list instead,
// but that entails garbage and processing overhead that would
// be nice to avoid.
--numAnims;
endingAnims.remove(anim);
}
}
if (endingAnims.size() > 0) {
for (i = 0; i < endingAnims.size(); ++i) {
endingAnims.get(i).endAnimation();
}
endingAnims.clear();
}
// If there are still active or delayed animations, call the handler again
// after the frameDelay
if (callAgain && (!animations.isEmpty() || !delayedAnims.isEmpty())) {
sendEmptyMessageDelayed(ANIMATION_FRAME, Math.max(0, sFrameDelay -
(AnimationUtils.currentAnimationTimeMillis() - currentTime)));
}
break;
}
}
}
/**
* 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
*/
public long getStartDelay() {
return mStartDelay;
}
/**
* 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
*/
public void setStartDelay(long startDelay) {
this.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.
*
* @return the requested time between frames, in milliseconds
*/
public static long getFrameDelay() {
return sFrameDelay;
}
/**
* 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.
*
* @param frameDelay the requested time between frames, in milliseconds
*/
public static void setFrameDelay(long frameDelay) {
sFrameDelay = 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(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();
}
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 null
* will result in linear interpolation.
*/
@Override
public void setInterpolator(/*Time*/Interpolator 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.
*/
public /*Time*/Interpolator 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);
}
}
/**
* 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.
*
* 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.
*
* @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");
}
mPlayingBackwards = playBackwards;
mCurrentIteration = 0;
mPlayingState = STOPPED;
mStarted = true;
mStartedDelay = false;
sPendingAnimations.get().add(this);
if (mStartDelay == 0) {
// This sets the initial value of the animation, prior to actually starting it running
setCurrentPlayTime(getCurrentPlayTime());
mPlayingState = STOPPED;
mRunning = true;
if (mListeners != null) {
ArrayList tmpListeners =
(ArrayList) mListeners.clone();
int numListeners = tmpListeners.size();
for (int i = 0; i < numListeners; ++i) {
tmpListeners.get(i).onAnimationStart(this);
}
}
}
AnimationHandler animationHandler = sAnimationHandler.get();
if (animationHandler == null) {
animationHandler = new AnimationHandler();
sAnimationHandler.set(animationHandler);
}
animationHandler.sendEmptyMessage(ANIMATION_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
if (mPlayingState != STOPPED || sPendingAnimations.get().contains(this) ||
sDelayedAnims.get().contains(this)) {
// Only notify listeners if the animator has actually started
if (mRunning && mListeners != null) {
ArrayList tmpListeners =
(ArrayList) mListeners.clone();
for (AnimatorListener listener : tmpListeners) {
listener.onAnimationCancel(this);
}
}
endAnimation();
}
}
@Override
public void end() {
if (!sAnimations.get().contains(this) && !sPendingAnimations.get().contains(this)) {
// Special case if the animation has not yet started; get it ready for ending
mStartedDelay = false;
startAnimation();
} else if (!mInitialized) {
initAnimation();
}
// The final value set on the target varies, depending on whether the animation
// was supposed to repeat an odd number of times
if (mRepeatCount > 0 && (mRepeatCount & 0x01) == 1) {
animateValue(0f);
} else {
animateValue(1f);
}
endAnimation();
}
@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.
*/
public void reverse() {
mPlayingBackwards = !mPlayingBackwards;
if (mPlayingState == RUNNING) {
long currentTime = AnimationUtils.currentAnimationTimeMillis();
long currentPlayTime = currentTime - mStartTime;
long timeLeft = mDuration - currentPlayTime;
mStartTime = currentTime - timeLeft;
} else {
start(true);
}
}
/**
* Called internally to end an animation by removing it from the animations list. Must be
* called on the UI thread.
*/
private void endAnimation() {
sAnimations.get().remove(this);
sPendingAnimations.get().remove(this);
sDelayedAnims.get().remove(this);
mPlayingState = STOPPED;
if (mRunning && mListeners != null) {
ArrayList tmpListeners =
(ArrayList) mListeners.clone();
int numListeners = tmpListeners.size();
for (int i = 0; i < numListeners; ++i) {
tmpListeners.get(i).onAnimationEnd(this);
}
}
mRunning = false;
mStarted = false;
}
/**
* Called internally to start an animation by adding it to the active animations list. Must be
* called on the UI thread.
*/
private void startAnimation() {
initAnimation();
sAnimations.get().add(this);
if (mStartDelay > 0 && mListeners != null) {
// Listeners were already notified in start() if startDelay is 0; this is
// just for delayed animations
ArrayList tmpListeners =
(ArrayList) mListeners.clone();
int numListeners = tmpListeners.size();
for (int i = 0; i < numListeners; ++i) {
tmpListeners.get(i).onAnimationStart(this);
}
}
}
/**
* Internal function called to process an animation frame on an animation that is currently
* sleeping through its startDelay 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 startDelay and should be started.
* @return True if the animation's startDelay 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;
} else {
long deltaTime = currentTime - mDelayStartTime;
if (deltaTime > mStartDelay) {
// startDelay ended - start the anim and record the
// mStartTime appropriately
mStartTime = currentTime - (deltaTime - mStartDelay);
mPlayingState = RUNNING;
return true;
}
}
return false;
}
/**
* 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
* repeatCount has been exceeded and the animation should be ended.
*/
boolean animationFrame(long currentTime) {
boolean done = false;
if (mPlayingState == STOPPED) {
mPlayingState = RUNNING;
if (mSeekTime < 0) {
mStartTime = currentTime;
} else {
mStartTime = currentTime - mSeekTime;
// Now that we're playing, reset the seek time
mSeekTime = -1;
}
}
switch (mPlayingState) {
case RUNNING:
case SEEKED:
float fraction = mDuration > 0 ? (float)(currentTime - mStartTime) / mDuration : 1f;
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 ? false : true;
}
mCurrentIteration += (int)fraction;
fraction = fraction % 1f;
mStartTime += mDuration;
} else {
done = true;
fraction = Math.min(fraction, 1.0f);
}
}
if (mPlayingBackwards) {
fraction = 1f - fraction;
}
animateValue(fraction);
break;
}
return done;
}
/**
* 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.
*/
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) {
ArrayList oldListeners = mUpdateListeners;
anim.mUpdateListeners = new ArrayList();
int numListeners = oldListeners.size();
for (int i = 0; i < numListeners; ++i) {
anim.mUpdateListeners.add(oldListeners.get(i));
}
}
anim.mSeekTime = -1;
anim.mPlayingBackwards = false;
anim.mCurrentIteration = 0;
anim.mInitialized = false;
anim.mPlayingState = STOPPED;
anim.mStartedDelay = false;
PropertyValuesHolder[] oldValues = mValues;
if (oldValues != null) {
int numValues = oldValues.length;
anim.mValues = new PropertyValuesHolder[numValues];
anim.mValuesMap = new HashMap(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 ValueAnimator 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. Only
* called on the main thread.
*
* @hide
*/
public static int getCurrentAnimationsCount() {
return sAnimations.get().size();
}
/**
* Clear all animations on this thread, without canceling or ending them.
* This should be used with caution.
*
* @hide
*/
public static void clearAllAnimations() {
sAnimations.get().clear();
sPendingAnimations.get().clear();
sDelayedAnims.get().clear();
}
@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;
}
}