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.hardware.display.DisplayManagerInternal;
20 import android.os.PowerManager;
21 
22 import com.android.server.display.DisplayBrightnessState;
23 import com.android.server.display.brightness.BrightnessReason;
24 import com.android.server.display.brightness.BrightnessUtils;
25 
26 import java.io.PrintWriter;
27 
28 /**
29  * Manages the brightness of an additional display that copies the brightness value from the lead
30  * display when the device is using concurrent displays.
31  */
32 public class FollowerBrightnessStrategy implements DisplayBrightnessStrategy {
33 
34     // The ID of the LogicalDisplay using this strategy.
35     private final int mDisplayId;
36 
37     // Set to PowerManager.BRIGHTNESS_INVALID_FLOAT when there's no brightness to follow set.
38     private float mBrightnessToFollow;
39 
40     // Indicates whether we should ramp slowly to the brightness value to follow.
41     private boolean mBrightnessToFollowSlowChange;
42 
FollowerBrightnessStrategy(int displayId)43     public FollowerBrightnessStrategy(int displayId) {
44         mDisplayId = displayId;
45         mBrightnessToFollow = PowerManager.BRIGHTNESS_INVALID_FLOAT;
46         mBrightnessToFollowSlowChange = false;
47     }
48 
49     @Override
updateBrightness( DisplayManagerInternal.DisplayPowerRequest displayPowerRequest)50     public DisplayBrightnessState updateBrightness(
51             DisplayManagerInternal.DisplayPowerRequest displayPowerRequest) {
52         // Todo(b/241308599): Introduce a validator class and add validations before setting
53         // the brightness
54         return BrightnessUtils.constructDisplayBrightnessState(BrightnessReason.REASON_FOLLOWER,
55                 mBrightnessToFollow, mBrightnessToFollow, getName(), mBrightnessToFollowSlowChange);
56     }
57 
58     @Override
getName()59     public String getName() {
60         return "FollowerBrightnessStrategy";
61     }
62 
getBrightnessToFollow()63     public float getBrightnessToFollow() {
64         return mBrightnessToFollow;
65     }
66 
67     /**
68      * Updates brightness value and brightness slowChange flag
69      **/
setBrightnessToFollow(float brightnessToFollow, boolean slowChange)70     public void setBrightnessToFollow(float brightnessToFollow, boolean slowChange) {
71         mBrightnessToFollow = brightnessToFollow;
72         mBrightnessToFollowSlowChange = slowChange;
73     }
74 
75     /**
76      * Dumps the state of this class.
77      */
dump(PrintWriter writer)78     public void dump(PrintWriter writer) {
79         writer.println("FollowerBrightnessStrategy:");
80         writer.println("  mDisplayId=" + mDisplayId);
81         writer.println("  mBrightnessToFollow:" + mBrightnessToFollow);
82         writer.println("  mBrightnessToFollowSlowChange:" + mBrightnessToFollowSlowChange);
83     }
84 }
85