1 /*
2  * Copyright (C) 2022 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.display.brightness.strategy;
18 
19 import android.os.PowerManager;
20 
21 import com.android.server.display.DisplayBrightnessState;
22 import com.android.server.display.brightness.BrightnessReason;
23 import com.android.server.display.brightness.BrightnessUtils;
24 import com.android.server.display.brightness.StrategyExecutionRequest;
25 import com.android.server.display.brightness.StrategySelectionNotifyRequest;
26 
27 import java.io.PrintWriter;
28 
29 /**
30  * Manages the brightness of an additional display that copies the brightness value from the lead
31  * display when the device is using concurrent displays.
32  */
33 public class FollowerBrightnessStrategy implements DisplayBrightnessStrategy {
34 
35     // The ID of the LogicalDisplay using this strategy.
36     private final int mDisplayId;
37 
38     // Set to PowerManager.BRIGHTNESS_INVALID_FLOAT when there's no brightness to follow set.
39     private float mBrightnessToFollow;
40 
41     // Indicates whether we should ramp slowly to the brightness value to follow.
42     private boolean mBrightnessToFollowSlowChange;
43 
FollowerBrightnessStrategy(int displayId)44     public FollowerBrightnessStrategy(int displayId) {
45         mDisplayId = displayId;
46         mBrightnessToFollow = PowerManager.BRIGHTNESS_INVALID_FLOAT;
47         mBrightnessToFollowSlowChange = false;
48     }
49 
50     @Override
updateBrightness( StrategyExecutionRequest strategyExecutionRequest)51     public DisplayBrightnessState updateBrightness(
52             StrategyExecutionRequest strategyExecutionRequest) {
53         // Todo(b/241308599): Introduce a validator class and add validations before setting
54         // the brightness
55         return BrightnessUtils.constructDisplayBrightnessState(BrightnessReason.REASON_FOLLOWER,
56                 mBrightnessToFollow, mBrightnessToFollow, getName(), mBrightnessToFollowSlowChange);
57     }
58 
59     @Override
getName()60     public String getName() {
61         return "FollowerBrightnessStrategy";
62     }
63 
getBrightnessToFollow()64     public float getBrightnessToFollow() {
65         return mBrightnessToFollow;
66     }
67 
68     /**
69      * Updates brightness value and brightness slowChange flag
70      **/
setBrightnessToFollow(float brightnessToFollow, boolean slowChange)71     public void setBrightnessToFollow(float brightnessToFollow, boolean slowChange) {
72         mBrightnessToFollow = brightnessToFollow;
73         mBrightnessToFollowSlowChange = slowChange;
74     }
75 
76     /**
77      * Dumps the state of this class.
78      */
79     @Override
dump(PrintWriter writer)80     public void dump(PrintWriter writer) {
81         writer.println("FollowerBrightnessStrategy:");
82         writer.println("  mDisplayId=" + mDisplayId);
83         writer.println("  mBrightnessToFollow:" + mBrightnessToFollow);
84         writer.println("  mBrightnessToFollowSlowChange:" + mBrightnessToFollowSlowChange);
85     }
86 
87     @Override
strategySelectionPostProcessor( StrategySelectionNotifyRequest strategySelectionNotifyRequest)88     public void strategySelectionPostProcessor(
89             StrategySelectionNotifyRequest strategySelectionNotifyRequest) {
90         // DO NOTHING
91     }
92 
93     @Override
getReason()94     public int getReason() {
95         return BrightnessReason.REASON_FOLLOWER;
96     }
97 }
98