1 /*
2  * Copyright (C) 2019 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.server.wm;
18 
19 import android.util.ArraySet;
20 import android.view.Display.Mode;
21 import android.view.DisplayInfo;
22 
23 /**
24  * Policy to select a lower refresh rate for the display if applicable.
25  */
26 class RefreshRatePolicy {
27 
28     private final int mLowRefreshRateId;
29     private final ArraySet<String> mNonHighRefreshRatePackages = new ArraySet<>();
30     private final HighRefreshRateBlacklist mHighRefreshRateBlacklist;
31     private final WindowManagerService mWmService;
32 
RefreshRatePolicy(WindowManagerService wmService, DisplayInfo displayInfo, HighRefreshRateBlacklist blacklist)33     RefreshRatePolicy(WindowManagerService wmService, DisplayInfo displayInfo,
34             HighRefreshRateBlacklist blacklist) {
35         mLowRefreshRateId = findLowRefreshRateModeId(displayInfo);
36         mHighRefreshRateBlacklist = blacklist;
37         mWmService = wmService;
38     }
39 
40     /**
41      * Finds the mode id with the lowest refresh rate which is >= 60hz and same resolution as the
42      * default mode.
43      */
findLowRefreshRateModeId(DisplayInfo displayInfo)44     private int findLowRefreshRateModeId(DisplayInfo displayInfo) {
45         Mode mode = displayInfo.getDefaultMode();
46         float[] refreshRates = displayInfo.getDefaultRefreshRates();
47         float bestRefreshRate = mode.getRefreshRate();
48         for (int i = refreshRates.length - 1; i >= 0; i--) {
49             if (refreshRates[i] >= 60f && refreshRates[i] < bestRefreshRate) {
50                 bestRefreshRate = refreshRates[i];
51             }
52         }
53         return displayInfo.findDefaultModeByRefreshRate(bestRefreshRate);
54     }
55 
addNonHighRefreshRatePackage(String packageName)56     void addNonHighRefreshRatePackage(String packageName) {
57         mNonHighRefreshRatePackages.add(packageName);
58         mWmService.requestTraversal();
59     }
60 
removeNonHighRefreshRatePackage(String packageName)61     void removeNonHighRefreshRatePackage(String packageName) {
62         mNonHighRefreshRatePackages.remove(packageName);
63         mWmService.requestTraversal();
64     }
65 
getPreferredModeId(WindowState w)66     int getPreferredModeId(WindowState w) {
67 
68         // If app is animating, it's not able to control refresh rate because we want the animation
69         // to run in default refresh rate.
70         if (w.isAnimating()) {
71             return 0;
72         }
73 
74         // If app requests a certain refresh rate or mode, don't override it.
75         if (w.mAttrs.preferredRefreshRate != 0 || w.mAttrs.preferredDisplayModeId != 0) {
76             return w.mAttrs.preferredDisplayModeId;
77         }
78 
79         final String packageName = w.getOwningPackage();
80 
81         // If app is using Camera, force it to default (lower) refresh rate.
82         if (mNonHighRefreshRatePackages.contains(packageName)) {
83             return mLowRefreshRateId;
84         }
85 
86         // If app is blacklisted using higher refresh rate, return default (lower) refresh rate
87         if (mHighRefreshRateBlacklist.isBlacklisted(packageName)) {
88             return mLowRefreshRateId;
89         }
90         return 0;
91     }
92 }
93