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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.view;
     18 
     19 import android.animation.Animator;
     20 import android.animation.Animator.AnimatorListener;
     21 import android.animation.RevealAnimator;
     22 
     23 /**
     24  * Defines common utilities for working with View's animations.
     25  *
     26  */
     27 public final class ViewAnimationUtils {
     28     private ViewAnimationUtils() {}
     29     /**
     30      * Returns an Animator which can animate a clipping circle.
     31      * <p>
     32      * Any shadow cast by the View will respect the circular clip from this animator.
     33      * <p>
     34      * Only a single non-rectangular clip can be applied on a View at any time.
     35      * Views clipped by a circular reveal animation take priority over
     36      * {@link View#setClipToOutline(boolean) View Outline clipping}.
     37      * <p>
     38      * Note that the animation returned here is a one-shot animation. It cannot
     39      * be re-used, and once started it cannot be paused or resumed. It is also
     40      * an asynchronous animation that automatically runs off of the UI thread.
     41      * As a result {@link AnimatorListener#onAnimationEnd(Animator)}
     42      * will occur after the animation has ended, but it may be delayed depending
     43      * on thread responsiveness.
     44      * <p>
     45      * Note that if any start delay is set on the reveal animator, the start radius
     46      * will not be applied to the reveal circle until the start delay has passed.
     47      * If it's desired to set a start radius on the reveal circle during the start
     48      * delay, one workaround could be adding an animator with the same start and
     49      * end radius. For example:
     50      * <pre><code>
     51      * public static Animator createRevealWithDelay(View view, int centerX, int centerY, float startRadius, float endRadius) {
     52      *     Animator delayAnimator = ViewAnimationUtils.createCircularReveal(view, centerX, centerY, startRadius, startRadius);
     53      *     delayAnimator.setDuration(delayTimeMS);
     54      *     Animator revealAnimator = ViewAnimationUtils.createCircularReveal(view, centerX, centerY, startRadius, endRadius);
     55      *     AnimatorSet set = new AnimatorSet();
     56      *     set.playSequentially(delayAnimator, revealAnimator);
     57      *     return set;
     58      * }
     59      * </code></pre>
     60      *
     61      * @param view The View will be clipped to the animating circle.
     62      * @param centerX The x coordinate of the center of the animating circle, relative to
     63      *                <code>view</code>.
     64      * @param centerY The y coordinate of the center of the animating circle, relative to
     65      *                <code>view</code>.
     66      * @param startRadius The starting radius of the animating circle.
     67      * @param endRadius The ending radius of the animating circle.
     68      */
     69     public static Animator createCircularReveal(View view,
     70             int centerX,  int centerY, float startRadius, float endRadius) {
     71         return new RevealAnimator(view, centerX, centerY, startRadius, endRadius);
     72     }
     73 }
     74