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
17package com.android.systemui;
18
19import com.android.systemui.util.Assert;
20
21import android.os.Handler;
22import android.view.Choreographer;
23
24import java.util.ArrayList;
25
26/**
27 * Utility class for methods used to dejank the UI.
28 */
29public class DejankUtils {
30
31    private static final Choreographer sChoreographer = Choreographer.getInstance();
32    private static final Handler sHandler = new Handler();
33
34    private static final ArrayList<Runnable> sPendingRunnables = new ArrayList<>();
35
36    private static final Runnable sAnimationCallbackRunnable = new Runnable() {
37        @Override
38        public void run() {
39            for (int i = 0; i < sPendingRunnables.size(); i++) {
40                sHandler.post(sPendingRunnables.get(i));
41            }
42            sPendingRunnables.clear();
43        }
44    };
45
46    /**
47     * Executes {@code r} after performTraversals. Use this do to CPU heavy work for which the
48     * timing is not critical for animation. The work is then scheduled at the same time
49     * RenderThread is doing its thing, leading to better parallelization.
50     *
51     * <p>Needs to be called from the main thread.
52     */
53    public static void postAfterTraversal(Runnable r) {
54        Assert.isMainThread();
55        sPendingRunnables.add(r);
56        postAnimationCallback();
57    }
58
59    /**
60     * Removes a previously scheduled runnable.
61     *
62     * <p>Needs to be called from the main thread.
63     */
64    public static void removeCallbacks(Runnable r) {
65        Assert.isMainThread();
66        sPendingRunnables.remove(r);
67        sHandler.removeCallbacks(r);
68    }
69
70    private static void postAnimationCallback() {
71        sChoreographer.postCallback(Choreographer.CALLBACK_ANIMATION, sAnimationCallbackRunnable,
72                null);
73    }
74}
75