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 {
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      */
createCircularReveal(View view, int centerX, int centerY, float startRadius, float endRadius)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