https://source.android.com/ 
/*
 * Copyright (C) 2011 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.view;

import android.animation.Animator;
import android.animation.TimeInterpolator;
import android.animation.ValueAnimator;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Set;


This class enables automatic and optimized animation of select properties on View objects. If only one or two properties on a View object are being animated, then using an ObjectAnimator is fine; the property setters called by ObjectAnimator are well equipped to do the right thing to set the property and invalidate the view appropriately. But if several properties are animated simultaneously, or if you just want a more convenient syntax to animate a specific property, then ViewPropertyAnimator might be more well-suited to the task. 
This class may provide better performance for several simultaneous animations, because
it will optimize invalidate calls to take place only once for several properties instead of each
animated property independently causing its own invalidation. Also, the syntax of using this
class could be easier to use because the caller need only tell the View object which
property to animate, and the value to animate either to or by, and this class handles the
details of configuring the underlying Animator class and starting it.


This class is not constructed by the caller, but rather by the View whose properties it will animate. Calls to View.animate() will return a reference to the appropriate ViewPropertyAnimator object for that View.


/**
 * This class enables automatic and optimized animation of select properties on View objects.
 * If only one or two properties on a View object are being animated, then using an
 * {@link android.animation.ObjectAnimator} is fine; the property setters called by ObjectAnimator
 * are well equipped to do the right thing to set the property and invalidate the view
 * appropriately. But if several properties are animated simultaneously, or if you just want a
 * more convenient syntax to animate a specific property, then ViewPropertyAnimator might be
 * more well-suited to the task.
 *
 * <p>This class may provide better performance for several simultaneous animations, because
 * it will optimize invalidate calls to take place only once for several properties instead of each
 * animated property independently causing its own invalidation. Also, the syntax of using this
 * class could be easier to use because the caller need only tell the View object which
 * property to animate, and the value to animate either to or by, and this class handles the
 * details of configuring the underlying Animator class and starting it.</p>
 *
 * <p>This class is not constructed by the caller, but rather by the View whose properties
 * it will animate. Calls to {@link android.view.View#animate()} will return a reference
 * to the appropriate ViewPropertyAnimator object for that View.</p>
 *
 */
public class ViewPropertyAnimator {

    
The View whose properties are being animated by this class. This is set at
construction time.

/**
     * The View whose properties are being animated by this class. This is set at
     * construction time.
     */
    final View mView;

    
The duration of the underlying Animator object. By default, we don't set the duration
on the Animator and just use its default duration. If the duration is ever set on this
Animator, then we use the duration that it was set to.

/**
     * The duration of the underlying Animator object. By default, we don't set the duration
     * on the Animator and just use its default duration. If the duration is ever set on this
     * Animator, then we use the duration that it was set to.
     */
    private long mDuration;

    
A flag indicating whether the duration has been set on this object. If not, we don't set
the duration on the underlying Animator, but instead just use its default duration.

/**
     * A flag indicating whether the duration has been set on this object. If not, we don't set
     * the duration on the underlying Animator, but instead just use its default duration.
     */
    private boolean mDurationSet = false;

    
The startDelay of the underlying Animator object. By default, we don't set the startDelay
on the Animator and just use its default startDelay. If the startDelay is ever set on this
Animator, then we use the startDelay that it was set to.

/**
     * The startDelay of the underlying Animator object. By default, we don't set the startDelay
     * on the Animator and just use its default startDelay. If the startDelay is ever set on this
     * Animator, then we use the startDelay that it was set to.
     */
    private long mStartDelay = 0;

    
A flag indicating whether the startDelay has been set on this object. If not, we don't set
the startDelay on the underlying Animator, but instead just use its default startDelay.

/**
     * A flag indicating whether the startDelay has been set on this object. If not, we don't set
     * the startDelay on the underlying Animator, but instead just use its default startDelay.
     */
    private boolean mStartDelaySet = false;

    
The interpolator of the underlying Animator object. By default, we don't set the interpolator
on the Animator and just use its default interpolator. If the interpolator is ever set on
this Animator, then we use the interpolator that it was set to.

/**
     * The interpolator of the underlying Animator object. By default, we don't set the interpolator
     * on the Animator and just use its default interpolator. If the interpolator is ever set on
     * this Animator, then we use the interpolator that it was set to.
     */
    private TimeInterpolator mInterpolator;

    
A flag indicating whether the interpolator has been set on this object. If not, we don't set
the interpolator on the underlying Animator, but instead just use its default interpolator.

/**
     * A flag indicating whether the interpolator has been set on this object. If not, we don't set
     * the interpolator on the underlying Animator, but instead just use its default interpolator.
     */
    private boolean mInterpolatorSet = false;

    
Listener for the lifecycle events of the underlying ValueAnimator object.

/**
     * Listener for the lifecycle events of the underlying ValueAnimator object.
     */
    private Animator.AnimatorListener mListener = null;

    
Listener for the update events of the underlying ValueAnimator object.

/**
     * Listener for the update events of the underlying ValueAnimator object.
     */
    private ValueAnimator.AnimatorUpdateListener mUpdateListener = null;

    
A lazily-created ValueAnimator used in order to get some default animator properties
(duration, start delay, interpolator, etc.).

/**
     * A lazily-created ValueAnimator used in order to get some default animator properties
     * (duration, start delay, interpolator, etc.).
     */
    private ValueAnimator mTempValueAnimator;

    
A RenderThread-driven backend that may intercept startAnimation

/**
     * A RenderThread-driven backend that may intercept startAnimation
     */
    private ViewPropertyAnimatorRT mRTBackend;

    
This listener is the mechanism by which the underlying Animator causes changes to the
properties currently being animated, as well as the cleanup after an animation is
complete.

/**
     * This listener is the mechanism by which the underlying Animator causes changes to the
     * properties currently being animated, as well as the cleanup after an animation is
     * complete.
     */
    private AnimatorEventListener mAnimatorEventListener = new AnimatorEventListener();

    
This list holds the properties that have been asked to animate. We allow the caller to
request several animations prior to actually starting the underlying animator. This
enables us to run one single animator to handle several properties in parallel. Each
property is tossed onto the pending list until the animation actually starts (which is
done by posting it onto mView), at which time the pending list is cleared and the properties
on that list are added to the list of properties associated with that animator.

/**
     * This list holds the properties that have been asked to animate. We allow the caller to
     * request several animations prior to actually starting the underlying animator. This
     * enables us to run one single animator to handle several properties in parallel. Each
     * property is tossed onto the pending list until the animation actually starts (which is
     * done by posting it onto mView), at which time the pending list is cleared and the properties
     * on that list are added to the list of properties associated with that animator.
     */
    ArrayList<NameValuesHolder> mPendingAnimations = new ArrayList<NameValuesHolder>();
    private Runnable mPendingSetupAction;
    private Runnable mPendingCleanupAction;
    private Runnable mPendingOnStartAction;
    private Runnable mPendingOnEndAction;

    
Constants used to associate a property being requested and the mechanism used to set
the property (this class calls directly into View to set the properties in question).

/**
     * Constants used to associate a property being requested and the mechanism used to set
     * the property (this class calls directly into View to set the properties in question).
     */
    static final int NONE           = 0x0000;
    static final int TRANSLATION_X  = 0x0001;
    static final int TRANSLATION_Y  = 0x0002;
    static final int TRANSLATION_Z  = 0x0004;
    static final int SCALE_X        = 0x0008;
    static final int SCALE_Y        = 0x0010;
    static final int ROTATION       = 0x0020;
    static final int ROTATION_X     = 0x0040;
    static final int ROTATION_Y     = 0x0080;
    static final int X              = 0x0100;
    static final int Y              = 0x0200;
    static final int Z              = 0x0400;
    static final int ALPHA          = 0x0800;

    private static final int TRANSFORM_MASK = TRANSLATION_X | TRANSLATION_Y | TRANSLATION_Z |
            SCALE_X | SCALE_Y | ROTATION | ROTATION_X | ROTATION_Y | X | Y | Z;

    
The mechanism by which the user can request several properties that are then animated
together works by posting this Runnable to start the underlying Animator. Every time
a property animation is requested, we cancel any previous postings of the Runnable
and re-post it. This means that we will only ever run the Runnable (and thus start the
underlying animator) after the caller is done setting the properties that should be
animated together.

/**
     * The mechanism by which the user can request several properties that are then animated
     * together works by posting this Runnable to start the underlying Animator. Every time
     * a property animation is requested, we cancel any previous postings of the Runnable
     * and re-post it. This means that we will only ever run the Runnable (and thus start the
     * underlying animator) after the caller is done setting the properties that should be
     * animated together.
     */
    private Runnable mAnimationStarter = new Runnable() {
        @Override
        public void run() {
            startAnimation();
        }
    };

    
This class holds information about the overall animation being run on the set of
properties. The mask describes which properties are being animated and the
values holder is the list of all property/value objects.

/**
     * This class holds information about the overall animation being run on the set of
     * properties. The mask describes which properties are being animated and the
     * values holder is the list of all property/value objects.
     */
    private static class PropertyBundle {
        int mPropertyMask;
        ArrayList<NameValuesHolder> mNameValuesHolder;

        PropertyBundle(int propertyMask, ArrayList<NameValuesHolder> nameValuesHolder) {
            mPropertyMask = propertyMask;
            mNameValuesHolder = nameValuesHolder;
        }

        
Removes the given property from being animated as a part of this
PropertyBundle. If the property was a part of this bundle, it returns
true to indicate that it was, in fact, canceled. This is an indication
to the caller that a cancellation actually occurred.

Params:
  • propertyConstant – The property whose cancellation is requested.
Returns:true if the given property is a part of this bundle and if it
has therefore been canceled.
/**
         * Removes the given property from being animated as a part of this
         * PropertyBundle. If the property was a part of this bundle, it returns
         * true to indicate that it was, in fact, canceled. This is an indication
         * to the caller that a cancellation actually occurred.
         *
         * @param propertyConstant The property whose cancellation is requested.
         * @return true if the given property is a part of this bundle and if it
         * has therefore been canceled.
         */
        boolean cancel(int propertyConstant) {
            if ((mPropertyMask & propertyConstant) != 0 && mNameValuesHolder != null) {
                int count = mNameValuesHolder.size();
                for (int i = 0; i < count; ++i) {
                    NameValuesHolder nameValuesHolder = mNameValuesHolder.get(i);
                    if (nameValuesHolder.mNameConstant == propertyConstant) {
                        mNameValuesHolder.remove(i);
                        mPropertyMask &= ~propertyConstant;
                        return true;
                    }
                }
            }
            return false;
        }
    }

    
This list tracks the list of properties being animated by any particular animator.
In most situations, there would only ever be one animator running at a time. But it is
possible to request some properties to animate together, then while those properties
are animating, to request some other properties to animate together. The way that
works is by having this map associate the group of properties being animated with the
animator handling the animation. On every update event for an Animator, we ask the
map for the associated properties and set them accordingly.

/**
     * This list tracks the list of properties being animated by any particular animator.
     * In most situations, there would only ever be one animator running at a time. But it is
     * possible to request some properties to animate together, then while those properties
     * are animating, to request some other properties to animate together. The way that
     * works is by having this map associate the group of properties being animated with the
     * animator handling the animation. On every update event for an Animator, we ask the
     * map for the associated properties and set them accordingly.
     */
    private HashMap<Animator, PropertyBundle> mAnimatorMap =
            new HashMap<Animator, PropertyBundle>();
    private HashMap<Animator, Runnable> mAnimatorSetupMap;
    private HashMap<Animator, Runnable> mAnimatorCleanupMap;
    private HashMap<Animator, Runnable> mAnimatorOnStartMap;
    private HashMap<Animator, Runnable> mAnimatorOnEndMap;

    
This is the information we need to set each property during the animation.
mNameConstant is used to set the appropriate field in View, and the from/delta
values are used to calculate the animated value for a given animation fraction
during the animation.

/**
     * This is the information we need to set each property during the animation.
     * mNameConstant is used to set the appropriate field in View, and the from/delta
     * values are used to calculate the animated value for a given animation fraction
     * during the animation.
     */
    static class NameValuesHolder {
        int mNameConstant;
        float mFromValue;
        float mDeltaValue;
        NameValuesHolder(int nameConstant, float fromValue, float deltaValue) {
            mNameConstant = nameConstant;
            mFromValue = fromValue;
            mDeltaValue = deltaValue;
        }
    }

    
Constructor, called by View. This is private by design, as the user should only
get a ViewPropertyAnimator by calling View.animate().

Params:
  • view – The View associated with this ViewPropertyAnimator
/**
     * Constructor, called by View. This is private by design, as the user should only
     * get a ViewPropertyAnimator by calling View.animate().
     *
     * @param view The View associated with this ViewPropertyAnimator
     */
    ViewPropertyAnimator(View view) {
        mView = view;
        view.ensureTransformationInfo();
    }

    
Sets the duration for the underlying animator that animates the requested properties.
By default, the animator uses the default value for ValueAnimator. Calling this method
will cause the declared value to be used instead.

Params:
  • duration – The length of ensuing property animations, in milliseconds. The value
cannot be negative.
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * Sets the duration for the underlying animator that animates the requested properties.
     * By default, the animator uses the default value for ValueAnimator. Calling this method
     * will cause the declared value to be used instead.
     * @param duration The length of ensuing property animations, in milliseconds. The value
     * cannot be negative.
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator setDuration(long duration) {
        if (duration < 0) {
            throw new IllegalArgumentException("Animators cannot have negative duration: " +
                    duration);
        }
        mDurationSet = true;
        mDuration = duration;
        return this;
    }

    
Returns the current duration of property animations. If the duration was set on this
object, that value is returned. Otherwise, the default value of the underlying Animator
is returned.

See Also:
  • setDuration(long)
Returns:The duration of animations, in milliseconds.
/**
     * Returns the current duration of property animations. If the duration was set on this
     * object, that value is returned. Otherwise, the default value of the underlying Animator
     * is returned.
     *
     * @see #setDuration(long)
     * @return The duration of animations, in milliseconds.
     */
    public long getDuration() {
        if (mDurationSet) {
            return mDuration;
        } else {
            // Just return the default from ValueAnimator, since that's what we'd get if
            // the value has not been set otherwise
            if (mTempValueAnimator == null) {
                mTempValueAnimator = new ValueAnimator();
            }
            return mTempValueAnimator.getDuration();
        }
    }

    
Returns the current startDelay of property animations. If the startDelay was set on this
object, that value is returned. Otherwise, the default value of the underlying Animator
is returned.

See Also:
  • setStartDelay(long)
Returns:The startDelay of animations, in milliseconds.
/**
     * Returns the current startDelay of property animations. If the startDelay was set on this
     * object, that value is returned. Otherwise, the default value of the underlying Animator
     * is returned.
     *
     * @see #setStartDelay(long)
     * @return The startDelay of animations, in milliseconds.
     */
    public long getStartDelay() {
        if (mStartDelaySet) {
            return mStartDelay;
        } else {
            // Just return the default from ValueAnimator (0), since that's what we'd get if
            // the value has not been set otherwise
            return 0;
        }
    }

    
Sets the startDelay for the underlying animator that animates the requested properties.
By default, the animator uses the default value for ValueAnimator. Calling this method
will cause the declared value to be used instead.

Params:
  • startDelay – The delay of ensuing property animations, in milliseconds. The value
cannot be negative.
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * Sets the startDelay for the underlying animator that animates the requested properties.
     * By default, the animator uses the default value for ValueAnimator. Calling this method
     * will cause the declared value to be used instead.
     * @param startDelay The delay of ensuing property animations, in milliseconds. The value
     * cannot be negative.
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator setStartDelay(long startDelay) {
        if (startDelay < 0) {
            throw new IllegalArgumentException("Animators cannot have negative start " +
                "delay: " + startDelay);
        }
        mStartDelaySet = true;
        mStartDelay = startDelay;
        return this;
    }

    
Sets the interpolator for the underlying animator that animates the requested properties.
By default, the animator uses the default interpolator for ValueAnimator. Calling this method
will cause the declared object to be used instead.

Params:
  • interpolator – The TimeInterpolator to be used for ensuing property animations. A value
of null will result in linear interpolation.
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * Sets the interpolator for the underlying animator that animates the requested properties.
     * By default, the animator uses the default interpolator for ValueAnimator. Calling this method
     * will cause the declared object to be used instead.
     *
     * @param interpolator The TimeInterpolator to be used for ensuing property animations. A value
     * of <code>null</code> will result in linear interpolation.
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator setInterpolator(TimeInterpolator interpolator) {
        mInterpolatorSet = true;
        mInterpolator = interpolator;
        return this;
    }

    
Returns the timing interpolator that this animation uses.

Returns:The timing interpolator for this animation.
/**
     * Returns the timing interpolator that this animation uses.
     *
     * @return The timing interpolator for this animation.
     */
    public TimeInterpolator getInterpolator() {
        if (mInterpolatorSet) {
            return mInterpolator;
        } else {
            // Just return the default from ValueAnimator, since that's what we'd get if
            // the value has not been set otherwise
            if (mTempValueAnimator == null) {
                mTempValueAnimator = new ValueAnimator();
            }
            return mTempValueAnimator.getInterpolator();
        }
    }

    
Sets a listener for events in the underlying Animators that run the property
animations.

Params:
  • listener – The listener to be called with AnimatorListener events. A value of
null removes any existing listener.
See Also:
  • AnimatorListener
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * Sets a listener for events in the underlying Animators that run the property
     * animations.
     *
     * @see Animator.AnimatorListener
     *
     * @param listener The listener to be called with AnimatorListener events. A value of
     * <code>null</code> removes any existing listener.
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator setListener(Animator.AnimatorListener listener) {
        mListener = listener;
        return this;
    }

    Animator.AnimatorListener getListener() {
        return mListener;
    }

    
Sets a listener for update events in the underlying ValueAnimator that runs
the property animations. Note that the underlying animator is animating between
0 and 1 (these values are then turned into the actual property values internally
by ViewPropertyAnimator). So the animator cannot give information on the current
values of the properties being animated by this ViewPropertyAnimator, although
the view object itself can be queried to get the current values.

Params:
  • listener – The listener to be called with update events. A value of
null removes any existing listener.
See Also:
  • AnimatorUpdateListener
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * Sets a listener for update events in the underlying ValueAnimator that runs
     * the property animations. Note that the underlying animator is animating between
     * 0 and 1 (these values are then turned into the actual property values internally
     * by ViewPropertyAnimator). So the animator cannot give information on the current
     * values of the properties being animated by this ViewPropertyAnimator, although
     * the view object itself can be queried to get the current values.
     *
     * @see android.animation.ValueAnimator.AnimatorUpdateListener
     *
     * @param listener The listener to be called with update events. A value of
     * <code>null</code> removes any existing listener.
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator setUpdateListener(ValueAnimator.AnimatorUpdateListener listener) {
        mUpdateListener = listener;
        return this;
    }

    ValueAnimator.AnimatorUpdateListener getUpdateListener() {
        return mUpdateListener;
    }

    
Starts the currently pending property animations immediately. Calling start()
is optional because all animations start automatically at the next opportunity. However,
if the animations are needed to start immediately and synchronously (not at the time when
the next event is processed by the hierarchy, which is when the animations would begin
otherwise), then this method can be used.

/**
     * Starts the currently pending property animations immediately. Calling <code>start()</code>
     * is optional because all animations start automatically at the next opportunity. However,
     * if the animations are needed to start immediately and synchronously (not at the time when
     * the next event is processed by the hierarchy, which is when the animations would begin
     * otherwise), then this method can be used.
     */
    public void start() {
        mView.removeCallbacks(mAnimationStarter);
        startAnimation();
    }

    
Cancels all property animations that are currently running or pending.

/**
     * Cancels all property animations that are currently running or pending.
     */
    public void cancel() {
        if (mAnimatorMap.size() > 0) {
            HashMap<Animator, PropertyBundle> mAnimatorMapCopy =
                    (HashMap<Animator, PropertyBundle>)mAnimatorMap.clone();
            Set<Animator> animatorSet = mAnimatorMapCopy.keySet();
            for (Animator runningAnim : animatorSet) {
                runningAnim.cancel();
            }
        }
        mPendingAnimations.clear();
        mPendingSetupAction = null;
        mPendingCleanupAction = null;
        mPendingOnStartAction = null;
        mPendingOnEndAction = null;
        mView.removeCallbacks(mAnimationStarter);
        if (mRTBackend != null) {
            mRTBackend.cancelAll();
        }
    }

    
This method will cause the View's x property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>x</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator x(float value) {
        animateProperty(X, value);
        return this;
    }

    
This method will cause the View's x property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>x</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator xBy(float value) {
        animatePropertyBy(X, value);
        return this;
    }

    
This method will cause the View's y property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>y</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator y(float value) {
        animateProperty(Y, value);
        return this;
    }

    
This method will cause the View's y property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>y</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator yBy(float value) {
        animatePropertyBy(Y, value);
        return this;
    }

    
This method will cause the View's z property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>z</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setZ(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator z(float value) {
        animateProperty(Z, value);
        return this;
    }

    
This method will cause the View's z property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>z</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setZ(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator zBy(float value) {
        animatePropertyBy(Z, value);
        return this;
    }

    
This method will cause the View's rotation property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>rotation</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setRotation(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator rotation(float value) {
        animateProperty(ROTATION, value);
        return this;
    }

    
This method will cause the View's rotation property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>rotation</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setRotation(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator rotationBy(float value) {
        animatePropertyBy(ROTATION, value);
        return this;
    }

    
This method will cause the View's rotationX property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>rotationX</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setRotationX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator rotationX(float value) {
        animateProperty(ROTATION_X, value);
        return this;
    }

    
This method will cause the View's rotationX property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>rotationX</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setRotationX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator rotationXBy(float value) {
        animatePropertyBy(ROTATION_X, value);
        return this;
    }

    
This method will cause the View's rotationY property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>rotationY</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setRotationY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator rotationY(float value) {
        animateProperty(ROTATION_Y, value);
        return this;
    }

    
This method will cause the View's rotationY property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>rotationY</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setRotationY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator rotationYBy(float value) {
        animatePropertyBy(ROTATION_Y, value);
        return this;
    }

    
This method will cause the View's translationX property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>translationX</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setTranslationX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator translationX(float value) {
        animateProperty(TRANSLATION_X, value);
        return this;
    }

    
This method will cause the View's translationX property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>translationX</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setTranslationX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator translationXBy(float value) {
        animatePropertyBy(TRANSLATION_X, value);
        return this;
    }

    
This method will cause the View's translationY property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>translationY</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setTranslationY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator translationY(float value) {
        animateProperty(TRANSLATION_Y, value);
        return this;
    }

    
This method will cause the View's translationY property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>translationY</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setTranslationY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator translationYBy(float value) {
        animatePropertyBy(TRANSLATION_Y, value);
        return this;
    }

    
This method will cause the View's translationZ property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>translationZ</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setTranslationZ(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator translationZ(float value) {
        animateProperty(TRANSLATION_Z, value);
        return this;
    }

    
This method will cause the View's translationZ property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>translationZ</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setTranslationZ(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator translationZBy(float value) {
        animatePropertyBy(TRANSLATION_Z, value);
        return this;
    }
    
This method will cause the View's scaleX property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>scaleX</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setScaleX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator scaleX(float value) {
        animateProperty(SCALE_X, value);
        return this;
    }

    
This method will cause the View's scaleX property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>scaleX</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setScaleX(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator scaleXBy(float value) {
        animatePropertyBy(SCALE_X, value);
        return this;
    }

    
This method will cause the View's scaleY property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>scaleY</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setScaleY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator scaleY(float value) {
        animateProperty(SCALE_Y, value);
        return this;
    }

    
This method will cause the View's scaleY property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>scaleY</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setScaleY(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator scaleYBy(float value) {
        animatePropertyBy(SCALE_Y, value);
        return this;
    }

    
This method will cause the View's alpha property to be animated to the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The value to be animated to.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>alpha</code> property to be animated to the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The value to be animated to.
     * @see View#setAlpha(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator alpha(float value) {
        animateProperty(ALPHA, value);
        return this;
    }

    
This method will cause the View's alpha property to be animated by the
specified value. Animations already running on the property will be canceled.

Params:
  • value – The amount to be animated by, as an offset from the current value.
See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * This method will cause the View's <code>alpha</code> property to be animated by the
     * specified value. Animations already running on the property will be canceled.
     *
     * @param value The amount to be animated by, as an offset from the current value.
     * @see View#setAlpha(float)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator alphaBy(float value) {
        animatePropertyBy(ALPHA, value);
        return this;
    }

    
The View associated with this ViewPropertyAnimator will have its layer type set to View.LAYER_TYPE_HARDWARE for the duration of the next animation. As stated in the documentation for View.LAYER_TYPE_HARDWARE, the actual type of layer used internally depends on the runtime situation of the view. If the activity and this view are hardware-accelerated, then the layer will be accelerated as well. If the activity or the view is not accelerated, then the layer will effectively be the same as View.LAYER_TYPE_SOFTWARE. 
This state is not persistent, either on the View or on this ViewPropertyAnimator: the layer type of the View will be restored when the animation ends to what it was when this method was called, and this setting on ViewPropertyAnimator is only valid for the next animation. Note that calling this method and then independently setting the layer type of the View (by a direct call to View.setLayerType(int, Paint)) will result in some inconsistency, including having the layer type restored to its pre-withLayer() value when the animation ends.


See Also:
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * The View associated with this ViewPropertyAnimator will have its
     * {@link View#setLayerType(int, android.graphics.Paint) layer type} set to
     * {@link View#LAYER_TYPE_HARDWARE} for the duration of the next animation.
     * As stated in the documentation for {@link View#LAYER_TYPE_HARDWARE},
     * the actual type of layer used internally depends on the runtime situation of the
     * view. If the activity and this view are hardware-accelerated, then the layer will be
     * accelerated as well. If the activity or the view is not accelerated, then the layer will
     * effectively be the same as {@link View#LAYER_TYPE_SOFTWARE}.
     *
     * <p>This state is not persistent, either on the View or on this ViewPropertyAnimator: the
     * layer type of the View will be restored when the animation ends to what it was when this
     * method was called, and this setting on ViewPropertyAnimator is only valid for the next
     * animation. Note that calling this method and then independently setting the layer type of
     * the View (by a direct call to {@link View#setLayerType(int, android.graphics.Paint)}) will
     * result in some inconsistency, including having the layer type restored to its pre-withLayer()
     * value when the animation ends.</p>
     *
     * @see View#setLayerType(int, android.graphics.Paint)
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator withLayer() {
         mPendingSetupAction= new Runnable() {
            @Override
            public void run() {
                mView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
                if (mView.isAttachedToWindow()) {
                    mView.buildLayer();
                }
            }
        };
        final int currentLayerType = mView.getLayerType();
        mPendingCleanupAction = new Runnable() {
            @Override
            public void run() {
                mView.setLayerType(currentLayerType, null);
            }
        };
        if (mAnimatorSetupMap == null) {
            mAnimatorSetupMap = new HashMap<Animator, Runnable>();
        }
        if (mAnimatorCleanupMap == null) {
            mAnimatorCleanupMap = new HashMap<Animator, Runnable>();
        }

        return this;
    }

    
Specifies an action to take place when the next animation runs. If there is a startDelay set on this ViewPropertyAnimator, then the action will run after that startDelay expires, when the actual animation begins. This method, along with withEndAction(Runnable), is intended to help facilitate choreographing ViewPropertyAnimator animations with other animations or actions in the application. 
Params:
  • runnable – The action to run when the next animation starts.
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * Specifies an action to take place when the next animation runs. If there is a
     * {@link #setStartDelay(long) startDelay} set on this ViewPropertyAnimator, then the
     * action will run after that startDelay expires, when the actual animation begins.
     * This method, along with {@link #withEndAction(Runnable)}, is intended to help facilitate
     * choreographing ViewPropertyAnimator animations with other animations or actions
     * in the application.
     *
     * @param runnable The action to run when the next animation starts.
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator withStartAction(Runnable runnable) {
        mPendingOnStartAction = runnable;
        if (runnable != null && mAnimatorOnStartMap == null) {
            mAnimatorOnStartMap = new HashMap<Animator, Runnable>();
        }
        return this;
    }

    
Specifies an action to take place when the next animation ends. The action is only run if the animation ends normally; if the ViewPropertyAnimator is canceled during that animation, the runnable will not run. This method, along with withStartAction(Runnable), is intended to help facilitate choreographing ViewPropertyAnimator animations with other animations or actions in the application. 
For example, the following code animates a view to x=200 and then back to 0:


    Runnable endAction = new Runnable() {
        public void run() {
            view.animate().x(0);
        }
    };
    view.animate().x(200).withEndAction(endAction);



Params:
  • runnable – The action to run when the next animation ends.
Returns:This object, allowing calls to methods in this class to be chained.
/**
     * Specifies an action to take place when the next animation ends. The action is only
     * run if the animation ends normally; if the ViewPropertyAnimator is canceled during
     * that animation, the runnable will not run.
     * This method, along with {@link #withStartAction(Runnable)}, is intended to help facilitate
     * choreographing ViewPropertyAnimator animations with other animations or actions
     * in the application.
     *
     * <p>For example, the following code animates a view to x=200 and then back to 0:</p>
     * <pre>
     *     Runnable endAction = new Runnable() {
     *         public void run() {
     *             view.animate().x(0);
     *         }
     *     };
     *     view.animate().x(200).withEndAction(endAction);
     * </pre>
     *
     * @param runnable The action to run when the next animation ends.
     * @return This object, allowing calls to methods in this class to be chained.
     */
    public ViewPropertyAnimator withEndAction(Runnable runnable) {
        mPendingOnEndAction = runnable;
        if (runnable != null && mAnimatorOnEndMap == null) {
            mAnimatorOnEndMap = new HashMap<Animator, Runnable>();
        }
        return this;
    }

    boolean hasActions() {
        return mPendingSetupAction != null
                || mPendingCleanupAction != null
                || mPendingOnStartAction != null
                || mPendingOnEndAction != null;
    }

    
Starts the underlying Animator for a set of properties. We use a single animator that
simply runs from 0 to 1, and then use that fractional value to set each property
value accordingly.

/**
     * Starts the underlying Animator for a set of properties. We use a single animator that
     * simply runs from 0 to 1, and then use that fractional value to set each property
     * value accordingly.
     */
    private void startAnimation() {
        if (mRTBackend != null && mRTBackend.startAnimation(this)) {
            return;
        }
        mView.setHasTransientState(true);
        ValueAnimator animator = ValueAnimator.ofFloat(1.0f);
        ArrayList<NameValuesHolder> nameValueList =
                (ArrayList<NameValuesHolder>) mPendingAnimations.clone();
        mPendingAnimations.clear();
        int propertyMask = 0;
        int propertyCount = nameValueList.size();
        for (int i = 0; i < propertyCount; ++i) {
            NameValuesHolder nameValuesHolder = nameValueList.get(i);
            propertyMask |= nameValuesHolder.mNameConstant;
        }
        mAnimatorMap.put(animator, new PropertyBundle(propertyMask, nameValueList));
        if (mPendingSetupAction != null) {
            mAnimatorSetupMap.put(animator, mPendingSetupAction);
            mPendingSetupAction = null;
        }
        if (mPendingCleanupAction != null) {
            mAnimatorCleanupMap.put(animator, mPendingCleanupAction);
            mPendingCleanupAction = null;
        }
        if (mPendingOnStartAction != null) {
            mAnimatorOnStartMap.put(animator, mPendingOnStartAction);
            mPendingOnStartAction = null;
        }
        if (mPendingOnEndAction != null) {
            mAnimatorOnEndMap.put(animator, mPendingOnEndAction);
            mPendingOnEndAction = null;
        }
        animator.addUpdateListener(mAnimatorEventListener);
        animator.addListener(mAnimatorEventListener);
        if (mStartDelaySet) {
            animator.setStartDelay(mStartDelay);
        }
        if (mDurationSet) {
            animator.setDuration(mDuration);
        }
        if (mInterpolatorSet) {
            animator.setInterpolator(mInterpolator);
        }
        animator.start();
    }

    
Utility function, called by the various x(), y(), etc. methods. This stores the
constant name for the property along with the from/delta values that will be used to
calculate and set the property during the animation. This structure is added to the
pending animations, awaiting the eventual start() of the underlying animator. A
Runnable is posted to start the animation, and any pending such Runnable is canceled
(which enables us to end up starting just one animator for all of the properties
specified at one time).

Params:
  • constantName – The specifier for the property being animated
  • toValue – The value to which the property will animate
/**
     * Utility function, called by the various x(), y(), etc. methods. This stores the
     * constant name for the property along with the from/delta values that will be used to
     * calculate and set the property during the animation. This structure is added to the
     * pending animations, awaiting the eventual start() of the underlying animator. A
     * Runnable is posted to start the animation, and any pending such Runnable is canceled
     * (which enables us to end up starting just one animator for all of the properties
     * specified at one time).
     *
     * @param constantName The specifier for the property being animated
     * @param toValue The value to which the property will animate
     */
    private void animateProperty(int constantName, float toValue) {
        float fromValue = getValue(constantName);
        float deltaValue = toValue - fromValue;
        animatePropertyBy(constantName, fromValue, deltaValue);
    }

    
Utility function, called by the various xBy(), yBy(), etc. methods. This method is
just like animateProperty(), except the value is an offset from the property's
current value, instead of an absolute "to" value.

Params:
  • constantName – The specifier for the property being animated
  • byValue – The amount by which the property will change
/**
     * Utility function, called by the various xBy(), yBy(), etc. methods. This method is
     * just like animateProperty(), except the value is an offset from the property's
     * current value, instead of an absolute "to" value.
     *
     * @param constantName The specifier for the property being animated
     * @param byValue The amount by which the property will change
     */
    private void animatePropertyBy(int constantName, float byValue) {
        float fromValue = getValue(constantName);
        animatePropertyBy(constantName, fromValue, byValue);
    }

    
Utility function, called by animateProperty() and animatePropertyBy(), which handles the
details of adding a pending animation and posting the request to start the animation.

Params:
  • constantName – The specifier for the property being animated
  • startValue – The starting value of the property
  • byValue – The amount by which the property will change
/**
     * Utility function, called by animateProperty() and animatePropertyBy(), which handles the
     * details of adding a pending animation and posting the request to start the animation.
     *
     * @param constantName The specifier for the property being animated
     * @param startValue The starting value of the property
     * @param byValue The amount by which the property will change
     */
    private void animatePropertyBy(int constantName, float startValue, float byValue) {
        // First, cancel any existing animations on this property
        if (mAnimatorMap.size() > 0) {
            Animator animatorToCancel = null;
            Set<Animator> animatorSet = mAnimatorMap.keySet();
            for (Animator runningAnim : animatorSet) {
                PropertyBundle bundle = mAnimatorMap.get(runningAnim);
                if (bundle.cancel(constantName)) {
                    // property was canceled - cancel the animation if it's now empty
                    // Note that it's safe to break out here because every new animation
                    // on a property will cancel a previous animation on that property, so
                    // there can only ever be one such animation running.
                    if (bundle.mPropertyMask == NONE) {
                        // the animation is no longer changing anything - cancel it
                        animatorToCancel = runningAnim;
                        break;
                    }
                }
            }
            if (animatorToCancel != null) {
                animatorToCancel.cancel();
            }
        }

        NameValuesHolder nameValuePair = new NameValuesHolder(constantName, startValue, byValue);
        mPendingAnimations.add(nameValuePair);
        mView.removeCallbacks(mAnimationStarter);
        mView.postOnAnimation(mAnimationStarter);
    }

    
This method handles setting the property values directly in the View object's fields.
propertyConstant tells it which property should be set, value is the value to set
the property to.

Params:
  • propertyConstant – The property to be set
  • value – The value to set the property to
/**
     * This method handles setting the property values directly in the View object's fields.
     * propertyConstant tells it which property should be set, value is the value to set
     * the property to.
     *
     * @param propertyConstant The property to be set
     * @param value The value to set the property to
     */
    private void setValue(int propertyConstant, float value) {
        final View.TransformationInfo info = mView.mTransformationInfo;
        final RenderNode renderNode = mView.mRenderNode;
        switch (propertyConstant) {
            case TRANSLATION_X:
                renderNode.setTranslationX(value);
                break;
            case TRANSLATION_Y:
                renderNode.setTranslationY(value);
                break;
            case TRANSLATION_Z:
                renderNode.setTranslationZ(value);
                break;
            case ROTATION:
                renderNode.setRotation(value);
                break;
            case ROTATION_X:
                renderNode.setRotationX(value);
                break;
            case ROTATION_Y:
                renderNode.setRotationY(value);
                break;
            case SCALE_X:
                renderNode.setScaleX(value);
                break;
            case SCALE_Y:
                renderNode.setScaleY(value);
                break;
            case X:
                renderNode.setTranslationX(value - mView.mLeft);
                break;
            case Y:
                renderNode.setTranslationY(value - mView.mTop);
                break;
            case Z:
                renderNode.setTranslationZ(value - renderNode.getElevation());
                break;
            case ALPHA:
                info.mAlpha = value;
                renderNode.setAlpha(value);
                break;
        }
    }

    
This method gets the value of the named property from the View object.

Params:
  • propertyConstant – The property whose value should be returned
Returns:float The value of the named property
/**
     * This method gets the value of the named property from the View object.
     *
     * @param propertyConstant The property whose value should be returned
     * @return float The value of the named property
     */
    private float getValue(int propertyConstant) {
        final RenderNode node = mView.mRenderNode;
        switch (propertyConstant) {
            case TRANSLATION_X:
                return node.getTranslationX();
            case TRANSLATION_Y:
                return node.getTranslationY();
            case TRANSLATION_Z:
                return node.getTranslationZ();
            case ROTATION:
                return node.getRotation();
            case ROTATION_X:
                return node.getRotationX();
            case ROTATION_Y:
                return node.getRotationY();
            case SCALE_X:
                return node.getScaleX();
            case SCALE_Y:
                return node.getScaleY();
            case X:
                return mView.mLeft + node.getTranslationX();
            case Y:
                return mView.mTop + node.getTranslationY();
            case Z:
                return node.getElevation() + node.getTranslationZ();
            case ALPHA:
                return mView.mTransformationInfo.mAlpha;
        }
        return 0;
    }

    
Utility class that handles the various Animator events. The only ones we care
about are the end event (which we use to clean up the animator map when an animator
finishes) and the update event (which we use to calculate the current value of each
property and then set it on the view object).

/**
     * Utility class that handles the various Animator events. The only ones we care
     * about are the end event (which we use to clean up the animator map when an animator
     * finishes) and the update event (which we use to calculate the current value of each
     * property and then set it on the view object).
     */
    private class AnimatorEventListener
            implements Animator.AnimatorListener, ValueAnimator.AnimatorUpdateListener {
        @Override
        public void onAnimationStart(Animator animation) {
            if (mAnimatorSetupMap != null) {
                Runnable r = mAnimatorSetupMap.get(animation);
                if (r != null) {
                    r.run();
                }
                mAnimatorSetupMap.remove(animation);
            }
            if (mAnimatorOnStartMap != null) {
                Runnable r = mAnimatorOnStartMap.get(animation);
                if (r != null) {
                    r.run();
                }
                mAnimatorOnStartMap.remove(animation);
            }
            if (mListener != null) {
                mListener.onAnimationStart(animation);
            }
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            if (mListener != null) {
                mListener.onAnimationCancel(animation);
            }
            if (mAnimatorOnEndMap != null) {
                mAnimatorOnEndMap.remove(animation);
            }
        }

        @Override
        public void onAnimationRepeat(Animator animation) {
            if (mListener != null) {
                mListener.onAnimationRepeat(animation);
            }
        }

        @Override
        public void onAnimationEnd(Animator animation) {
            mView.setHasTransientState(false);
            if (mAnimatorCleanupMap != null) {
                Runnable r = mAnimatorCleanupMap.get(animation);
                if (r != null) {
                    r.run();
                }
                mAnimatorCleanupMap.remove(animation);
            }
            if (mListener != null) {
                mListener.onAnimationEnd(animation);
            }
            if (mAnimatorOnEndMap != null) {
                Runnable r = mAnimatorOnEndMap.get(animation);
                if (r != null) {
                    r.run();
                }
                mAnimatorOnEndMap.remove(animation);
            }
            mAnimatorMap.remove(animation);
        }

        
Calculate the current value for each property and set it on the view. Invalidate
the view object appropriately, depending on which properties are being animated.

Params:
  • animation – The animator associated with the properties that need to be
set. This animator holds the animation fraction which we will use to calculate
the current value of each property.
/**
         * Calculate the current value for each property and set it on the view. Invalidate
         * the view object appropriately, depending on which properties are being animated.
         *
         * @param animation The animator associated with the properties that need to be
         * set. This animator holds the animation fraction which we will use to calculate
         * the current value of each property.
         */
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            PropertyBundle propertyBundle = mAnimatorMap.get(animation);
            if (propertyBundle == null) {
                // Shouldn't happen, but just to play it safe
                return;
            }

            boolean hardwareAccelerated = mView.isHardwareAccelerated();

            // alpha requires slightly different treatment than the other (transform) properties.
            // The logic in setAlpha() is not simply setting mAlpha, plus the invalidation
            // logic is dependent on how the view handles an internal call to onSetAlpha().
            // We track what kinds of properties are set, and how alpha is handled when it is
            // set, and perform the invalidation steps appropriately.
            boolean alphaHandled = false;
            if (!hardwareAccelerated) {
                mView.invalidateParentCaches();
            }
            float fraction = animation.getAnimatedFraction();
            int propertyMask = propertyBundle.mPropertyMask;
            if ((propertyMask & TRANSFORM_MASK) != 0) {
                mView.invalidateViewProperty(hardwareAccelerated, false);
            }
            ArrayList<NameValuesHolder> valueList = propertyBundle.mNameValuesHolder;
            if (valueList != null) {
                int count = valueList.size();
                for (int i = 0; i < count; ++i) {
                    NameValuesHolder values = valueList.get(i);
                    float value = values.mFromValue + fraction * values.mDeltaValue;
                    if (values.mNameConstant == ALPHA) {
                        alphaHandled = mView.setAlphaNoInvalidation(value);
                    } else {
                        setValue(values.mNameConstant, value);
                    }
                }
            }
            if ((propertyMask & TRANSFORM_MASK) != 0) {
                if (!hardwareAccelerated) {
                    mView.mPrivateFlags |= View.PFLAG_DRAWN; // force another invalidation
                }
            }
            // invalidate(false) in all cases except if alphaHandled gets set to true
            // via the call to setAlphaNoInvalidation(), above
            if (alphaHandled) {
                mView.invalidate(true);
            } else {
                mView.invalidateViewProperty(false, false);
            }
            if (mUpdateListener != null) {
                mUpdateListener.onAnimationUpdate(animation);
            }
        }
    }
}