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.internal.annotations.VisibleForTesting;
20import com.android.systemui.util.Assert;
21
22import android.os.Handler;
23import android.view.Choreographer;
24
25import java.util.ArrayList;
26
27/**
28 * Utility class for methods used to dejank the UI.
29 */
30public 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     */
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     */
73    public static void removeCallbacks(Runnable r) {
74        Assert.isMainThread();
75        sPendingRunnables.remove(r);
76        sHandler.removeCallbacks(r);
77    }
78
79    private static void postAnimationCallback() {
80        sChoreographer.postCallback(Choreographer.CALLBACK_ANIMATION, sAnimationCallbackRunnable,
81                null);
82    }
83
84    @VisibleForTesting
85    public static void setImmediate(boolean immediate) {
86        sImmediate = immediate;
87    }
88}
89