1 /*
2  * Copyright (C) 2015 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 com.android.systemui;
18 
19 import android.os.Handler;
20 import android.view.Choreographer;
21 
22 import com.android.internal.annotations.VisibleForTesting;
23 import com.android.systemui.util.Assert;
24 
25 import java.util.ArrayList;
26 
27 /**
28  * Utility class for methods used to dejank the UI.
29  */
30 public class DejankUtils {
31 
32     private static final Choreographer sChoreographer = Choreographer.getInstance();
33     private static final Handler sHandler = new Handler();
34     private static final ArrayList<Runnable> sPendingRunnables = new ArrayList<>();
35 
36     /**
37      * Only for testing.
38      */
39     private static boolean sImmediate;
40 
41     private static final Runnable sAnimationCallbackRunnable = new Runnable() {
42         @Override
43         public void run() {
44             for (int i = 0; i < sPendingRunnables.size(); i++) {
45                 sHandler.post(sPendingRunnables.get(i));
46             }
47             sPendingRunnables.clear();
48         }
49     };
50 
51     /**
52      * Executes {@code r} after performTraversals. Use this do to CPU heavy work for which the
53      * timing is not critical for animation. The work is then scheduled at the same time
54      * RenderThread is doing its thing, leading to better parallelization.
55      *
56      * <p>Needs to be called from the main thread.
57      */
postAfterTraversal(Runnable r)58     public static void postAfterTraversal(Runnable r) {
59         if (sImmediate) {
60             r.run();
61             return;
62         }
63         Assert.isMainThread();
64         sPendingRunnables.add(r);
65         postAnimationCallback();
66     }
67 
68     /**
69      * Removes a previously scheduled runnable.
70      *
71      * <p>Needs to be called from the main thread.
72      */
removeCallbacks(Runnable r)73     public static void removeCallbacks(Runnable r) {
74         Assert.isMainThread();
75         sPendingRunnables.remove(r);
76         sHandler.removeCallbacks(r);
77     }
78 
postAnimationCallback()79     private static void postAnimationCallback() {
80         sChoreographer.postCallback(Choreographer.CALLBACK_ANIMATION, sAnimationCallbackRunnable,
81                 null);
82     }
83 
84     @VisibleForTesting
setImmediate(boolean immediate)85     public static void setImmediate(boolean immediate) {
86         sImmediate = immediate;
87     }
88 }
89