/* * Copyright (C) 2014 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.support.v4.view; import android.view.View; import android.view.animation.Interpolator; import java.lang.ref.WeakReference; public class ViewPropertyAnimatorCompat { private static final String TAG = "ViewAnimatorCompat"; private WeakReference mView; ViewPropertyAnimatorCompat(View view) { mView = new WeakReference(view); } interface ViewPropertyAnimatorCompatImpl { public void setDuration(View view, long value); public long getDuration(View view); public void setInterpolator(View view, Interpolator value); public Interpolator getInterpolator(View view); public void setStartDelay(View view, long value); public long getStartDelay(View view); public void alpha(View view, float value); public void alphaBy(View view, float value); public void rotation(View view, float value); public void rotationBy(View view, float value); public void rotationX(View view, float value); public void rotationXBy(View view, float value); public void rotationY(View view, float value); public void rotationYBy(View view, float value); public void scaleX(View view, float value); public void scaleXBy(View view, float value); public void scaleY(View view, float value); public void scaleYBy(View view, float value); public void cancel(View view); public void x(View view, float value); public void xBy(View view, float value); public void y(View view, float value); public void yBy(View view, float value); public void translationX(View view, float value); public void translationXBy(View view, float value); public void translationY(View view, float value); public void translationYBy(View view, float value); public void start(View view); public void withLayer(View view); public void withStartAction(View view, Runnable runnable); public void withEndAction(View view, Runnable runnable); public void setListener(View view, ViewPropertyAnimatorListener listener); }; static class BaseViewPropertyAnimatorCompatImpl implements ViewPropertyAnimatorCompatImpl { @Override public void setDuration(View view, long value) { // noop on versions prior to ICS } @Override public void alpha(View view, float value) { // noop on versions prior to ICS } @Override public void translationX(View view, float value) { // noop on versions prior to ICS } @Override public void translationY(View view, float value) { // noop on versions prior to ICS } @Override public void withEndAction(View view, Runnable runnable) { // Other VPA calls are noops pre-ICS; just run the runnable immediately runnable.run(); } @Override public long getDuration(View view) { return 0; } @Override public void setInterpolator(View view, Interpolator value) { // noop on versions prior to ICS } @Override public Interpolator getInterpolator(View view) { return null; } @Override public void setStartDelay(View view, long value) { // noop on versions prior to ICS } @Override public long getStartDelay(View view) { return 0; } @Override public void alphaBy(View view, float value) { // noop on versions prior to ICS } @Override public void rotation(View view, float value) { // noop on versions prior to ICS } @Override public void rotationBy(View view, float value) { // noop on versions prior to ICS } @Override public void rotationX(View view, float value) { // noop on versions prior to ICS } @Override public void rotationXBy(View view, float value) { // noop on versions prior to ICS } @Override public void rotationY(View view, float value) { // noop on versions prior to ICS } @Override public void rotationYBy(View view, float value) { // noop on versions prior to ICS } @Override public void scaleX(View view, float value) { // noop on versions prior to ICS } @Override public void scaleXBy(View view, float value) { // noop on versions prior to ICS } @Override public void scaleY(View view, float value) { // noop on versions prior to ICS } @Override public void scaleYBy(View view, float value) { // noop on versions prior to ICS } @Override public void cancel(View view) { // noop on versions prior to ICS } @Override public void x(View view, float value) { // noop on versions prior to ICS } @Override public void xBy(View view, float value) { // noop on versions prior to ICS } @Override public void y(View view, float value) { // noop on versions prior to ICS } @Override public void yBy(View view, float value) { // noop on versions prior to ICS } @Override public void translationXBy(View view, float value) { // noop on versions prior to ICS } @Override public void translationYBy(View view, float value) { // noop on versions prior to ICS } @Override public void start(View view) { // noop on versions prior to ICS } @Override public void withLayer(View view) { // noop on versions prior to ICS } @Override public void withStartAction(View view, Runnable runnable) { // Other VPA calls are noops pre-ICS; just run the runnable immediately runnable.run(); } @Override public void setListener(View view, ViewPropertyAnimatorListener listener) { // Noop } } static class ICSViewPropertyAnimatorCompatImpl extends BaseViewPropertyAnimatorCompatImpl { @Override public void setDuration(View view, long value) { ViewPropertyAnimatorCompatICS.setDuration(view, value); } @Override public void alpha(View view, float value) { ViewPropertyAnimatorCompatICS.alpha(view, value); } @Override public void translationX(View view, float value) { ViewPropertyAnimatorCompatICS.translationX(view, value); } @Override public void translationY(View view, float value) { ViewPropertyAnimatorCompatICS.translationY(view, value); } @Override public long getDuration(View view) { return ViewPropertyAnimatorCompatICS.getDuration(view); } @Override public void setInterpolator(View view, Interpolator value) { ViewPropertyAnimatorCompatICS.setInterpolator(view, value); } @Override public void setStartDelay(View view, long value) { ViewPropertyAnimatorCompatICS.setStartDelay(view, value); } @Override public long getStartDelay(View view) { return ViewPropertyAnimatorCompatICS.getStartDelay(view); } @Override public void alphaBy(View view, float value) { ViewPropertyAnimatorCompatICS.alphaBy(view, value); } @Override public void rotation(View view, float value) { ViewPropertyAnimatorCompatICS.rotation(view, value); } @Override public void rotationBy(View view, float value) { ViewPropertyAnimatorCompatICS.rotationBy(view, value); } @Override public void rotationX(View view, float value) { ViewPropertyAnimatorCompatICS.rotationX(view, value); } @Override public void rotationXBy(View view, float value) { ViewPropertyAnimatorCompatICS.rotationXBy(view, value); } @Override public void rotationY(View view, float value) { ViewPropertyAnimatorCompatICS.rotationY(view, value); } @Override public void rotationYBy(View view, float value) { ViewPropertyAnimatorCompatICS.rotationYBy(view, value); } @Override public void scaleX(View view, float value) { ViewPropertyAnimatorCompatICS.scaleX(view, value); } @Override public void scaleXBy(View view, float value) { ViewPropertyAnimatorCompatICS.scaleXBy(view, value); } @Override public void scaleY(View view, float value) { ViewPropertyAnimatorCompatICS.scaleY(view, value); } @Override public void scaleYBy(View view, float value) { ViewPropertyAnimatorCompatICS.scaleYBy(view, value); } @Override public void cancel(View view) { ViewPropertyAnimatorCompatICS.cancel(view); } @Override public void x(View view, float value) { ViewPropertyAnimatorCompatICS.x(view, value); } @Override public void xBy(View view, float value) { ViewPropertyAnimatorCompatICS.xBy(view, value); } @Override public void y(View view, float value) { ViewPropertyAnimatorCompatICS.y(view, value); } @Override public void yBy(View view, float value) { ViewPropertyAnimatorCompatICS.yBy(view, value); } @Override public void translationXBy(View view, float value) { ViewPropertyAnimatorCompatICS.translationXBy(view, value); } @Override public void translationYBy(View view, float value) { ViewPropertyAnimatorCompatICS.translationYBy(view, value); } @Override public void start(View view) { ViewPropertyAnimatorCompatICS.start(view); } @Override public void setListener(View view, ViewPropertyAnimatorListener listener) { ViewPropertyAnimatorCompatICS.setListener(view, listener); } @Override public void withEndAction(View view, final Runnable runnable) { setListener(view, new ViewPropertyAnimatorListener() { @Override public void onAnimationStart(View view) { } @Override public void onAnimationEnd(View view) { runnable.run(); setListener(view, null); } @Override public void onAnimationCancel(View view) { } }); } @Override public void withStartAction(View view, final Runnable runnable) { setListener(view, new ViewPropertyAnimatorListener() { @Override public void onAnimationStart(View view) { runnable.run(); setListener(view, null); } @Override public void onAnimationEnd(View view) { } @Override public void onAnimationCancel(View view) { } }); } @Override public void withLayer(View view) { final int currentLayerType = ViewCompat.getLayerType(view); setListener(view, new ViewPropertyAnimatorListener() { @Override public void onAnimationStart(View view) { ViewCompat.setLayerType(view, ViewCompat.LAYER_TYPE_HARDWARE, null); } @Override public void onAnimationEnd(View view) { ViewCompat.setLayerType(view, currentLayerType, null); setListener(view, null); } @Override public void onAnimationCancel(View view) { } }); } } static class JBViewPropertyAnimatorCompatImpl extends ICSViewPropertyAnimatorCompatImpl { @Override public void withStartAction(View view, Runnable runnable) { ViewPropertyAnimatorCompatJB.withStartAction(view, runnable); } @Override public void withEndAction(View view, Runnable runnable) { ViewPropertyAnimatorCompatJB.withEndAction(view, runnable); } @Override public void withLayer(View view) { ViewPropertyAnimatorCompatJB.withLayer(view); } } static class JBMr2ViewPropertyAnimatorCompatImpl extends JBViewPropertyAnimatorCompatImpl { @Override public Interpolator getInterpolator(View view) { return (Interpolator) ViewPropertyAnimatorCompatJellybeanMr2.getInterpolator(view); } } static final ViewPropertyAnimatorCompatImpl IMPL; static { final int version = android.os.Build.VERSION.SDK_INT; if (version >= 18) { IMPL = new JBMr2ViewPropertyAnimatorCompatImpl(); } else if (version >= 16) { IMPL = new JBViewPropertyAnimatorCompatImpl(); } else if (version >= 14) { IMPL = new ICSViewPropertyAnimatorCompatImpl(); } else { IMPL = new BaseViewPropertyAnimatorCompatImpl(); } } /** * 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. * *

Prior to API 14, this method will do nothing.

* * @param value 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 ViewPropertyAnimatorCompat setDuration(long value) { View view; if ((view = mView.get()) != null) { IMPL.setDuration(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat alpha(float value) { View view; if ((view = mView.get()) != null) { IMPL.alpha(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat alphaBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.alphaBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat translationX(float value) { View view; if ((view = mView.get()) != null) { IMPL.translationX(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat translationY(float value) { View view; if ((view = mView.get()) != null) { IMPL.translationY(view, value); } 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 {@link #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);
     * 
* *

Prior to API 14, this method will run the action immediately.

* *

For API 14 and 15, this method will run by setting * a listener on the ViewPropertyAnimatorCompat object and running the action * in that listener's {@link ViewPropertyAnimatorListener#onAnimationEnd(View)} method.

* * @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 ViewPropertyAnimatorCompat withEndAction(Runnable runnable) { View view; if ((view = mView.get()) != null) { IMPL.withEndAction(view, runnable); } 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. * *

Prior to API 14, this method will return 0.

* * @see #setDuration(long) * @return The duration of animations, in milliseconds. */ public long getDuration() { View view; if ((view = mView.get()) != null) { return IMPL.getDuration(view); } else { return 0; } } /** * 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. * *

Prior to API 14, this method will do nothing.

* * @param value The TimeInterpolator to be used for ensuing property animations. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat setInterpolator(Interpolator value) { View view; if ((view = mView.get()) != null) { IMPL.setInterpolator(view, value); } return this; } /** * Returns the timing interpolator that this animation uses. * *

Prior to API 14, this method will return null.

* * @return The timing interpolator for this animation. */ public Interpolator getInterpolator() { View view; if ((view = mView.get()) != null) { return IMPL.getInterpolator(view); } else return null; } /** * 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. * *

Prior to API 14, this method will do nothing.

* * @param value 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 ViewPropertyAnimatorCompat setStartDelay(long value) { View view; if ((view = mView.get()) != null) { IMPL.setStartDelay(view, value); } return this; } /** * 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. * *

Prior to API 14, this method will return 0.

* * @see #setStartDelay(long) * @return The startDelay of animations, in milliseconds. */ public long getStartDelay() { View view; if ((view = mView.get()) != null) { return IMPL.getStartDelay(view); } else { return 0; } } /** * 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat rotation(float value) { View view; if ((view = mView.get()) != null) { IMPL.rotation(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat rotationBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.rotationBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat rotationX(float value) { View view; if ((view = mView.get()) != null) { IMPL.rotationX(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat rotationXBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.rotationXBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat rotationY(float value) { View view; if ((view = mView.get()) != null) { IMPL.rotationY(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat rotationYBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.rotationYBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat scaleX(float value) { View view; if ((view = mView.get()) != null) { IMPL.scaleX(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat scaleXBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.scaleXBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat scaleY(float value) { View view; if ((view = mView.get()) != null) { IMPL.scaleY(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat scaleYBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.scaleYBy(view, value); } return this; } /** * Cancels all property animations that are currently running or pending. */ public void cancel() { View view; if ((view = mView.get()) != null) { IMPL.cancel(view); } } /** * 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat x(float value) { View view; if ((view = mView.get()) != null) { IMPL.x(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat xBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.xBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The value to be animated to. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat y(float value) { View view; if ((view = mView.get()) != null) { IMPL.y(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat yBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.yBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat translationXBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.translationXBy(view, 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. * *

Prior to API 14, this method will do nothing.

* * @param value The amount to be animated by, as an offset from the current value. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat translationYBy(float value) { View view; if ((view = mView.get()) != null) { IMPL.translationYBy(view, value); } return this; } /** * 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. * *

Prior to API 14, this method will do nothing.

*/ public void start() { View view; if ((view = mView.get()) != null) { IMPL.start(view); } } /** * The View associated with this ViewPropertyAnimator will have its * {@link ViewCompat#setLayerType(View, int, android.graphics.Paint) layer type} set to * {@link ViewCompat#LAYER_TYPE_HARDWARE} for the duration of the next animation. * As stated in the documentation for {@link ViewCompat#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 ViewCompat#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 * {@link ViewCompat#setLayerType(View, int, android.graphics.Paint)}) will result in some * inconsistency, including having the layer type restored to its pre-withLayer() * value when the animation ends.

* *

Prior to API 14, this method will do nothing.

* *

For API 14 and 15, this method will run by setting * a listener on the ViewPropertyAnimatorCompat object, setting a hardware layer in * the listener's {@link ViewPropertyAnimatorListener#onAnimationStart(View)} method, * and then restoring the orignal layer type in the listener's * {@link ViewPropertyAnimatorListener#onAnimationEnd(View)} method.

* * @see View#setLayerType(int, android.graphics.Paint) * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat withLayer() { View view; if ((view = mView.get()) != null) { IMPL.withLayer(view); } return this; } /** * 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. * *

Prior to API 14, this method will run the action immediately.

* *

For API 14 and 15, this method will run by setting * a listener on the ViewPropertyAnimatorCompat object and running the action * in that listener's {@link ViewPropertyAnimatorListener#onAnimationStart(View)} method.

* * @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 ViewPropertyAnimatorCompat withStartAction(Runnable runnable) { View view; if ((view = mView.get()) != null) { IMPL.withStartAction(view, runnable); } return this; } /** * Sets a listener for events in the underlying Animators that run the property * animations. * *

Prior to API 14, this method will do nothing.

* * @param listener The listener to be called with AnimatorListener events. A value of * null removes any existing listener. * @return This object, allowing calls to methods in this class to be chained. */ public ViewPropertyAnimatorCompat setListener(ViewPropertyAnimatorListener listener) { View view; if ((view = mView.get()) != null) { IMPL.setListener(view, listener); } return this; } }