Android framework配置默认屏幕亮度值源码分析_framework亮度调节

1、概述

在Android中，config.xml文件用于配置各种系统设置和资源。对于屏幕亮度的配置，config.xml并不是直接用于设置屏幕亮度的地方，但它可以包含默认的系统设置和一些相关的参数。以下是如何在config.xml中配置一些与屏幕亮度相关的设置的详细步骤。

2、找到或创建config.xml

在Android系统源码中，config.xml通常位于以下路径：
frameworks/base/core/res/res/values/config.xml
如果项目中没有config.xml文件，可以在相应的路径下创建一个。

3、配置屏幕亮度相关参数

在config.xml中，可以定义与屏幕亮度相关的参数，例如默认亮度值、自动亮度调节参数等。以下是一个示例配置：

<?xml version="1.0" encoding="utf-8"?>
<!--
/*
** Copyright 2009, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
**     http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
-->

<!-- These resources are around just to allow their values to be customized
     for different hardware and product builds. -->
<resources>
    <!-- Software blur is too slow on this device. -->
    <bool name="config_sf_slowBlur">true</bool>

    <!-- This device is not "voice capable"; it's data-only. -->
    <bool name="config_voice_capable">true</bool>

    <!-- This device does not allow sms service. -->
    <bool name="config_sms_capable">true</bool>

    <!-- Enable puk unlockscreen -->
    <bool name="config_enable_puk_unlock_screen">true</bool>

    <!-- An Array of "[Connection name],[ConnectivityManager.TYPE_xxxx],
         [associated radio-type],[priority],[restoral-timer(ms)],[dependencyMet]  -->
    <!-- the 5th element "resore-time" indicates the number of milliseconds to delay
         before automatically restore the default connection.  Set -1 if the connection
         does not require auto-restore. -->
    <!-- the 6th element indicates boot-time dependency-met value. -->
    <string-array translatable="false" name="networkAttributes">
        <item>"wifi,1,1,1,-1,true"</item>
        <item>"mobile,0,0,0,-1,true"</item>
        <item>"mobile_mms,2,0,2,60000,true"</item>
        <item>"mobile_supl,3,0,2,60000,true"</item>
        <item>"mobile_hipri,5,0,3,60000,true"</item>
        <item>"mobile_fota,10,0,2,60000,true"</item>
        <item>"mobile_ims,11,0,2,60000,true"</item>
        <item>"mobile_cbs,12,0,2,60000,true"</item>
        <item>"wifi_p2p,13,1,0,-1,true"</item>
        <item>"eth,9,9,4,60000,true"</item>
    </string-array>

    <!-- An Array of "[ConnectivityManager connectionType],
                      [# simultaneous connection types]"  -->
    <string-array translatable="false" name="radioAttributes">
        <item>"1,1"</item>
        <item>"0,1"</item>
        <item>"9,1"</item>
    </string-array>

	<!-- Minimum screen brightness setting allowed by the power manager.
	     The user is forbidden from setting the brightness below this level. -->
    <integer name="config_screenBrightnessSettingMinimum">10</integer>

    <!-- Maximum screen brightness allowed by the power manager.
         The user is forbidden from setting the brightness above this level. -->
    <integer name="config_screenBrightnessSettingMaximum">222</integer>

	<!-- Default screen brightness setting.
	     Must be in the range specified by minimum and maximum. -->
	<integer name="config_screenBrightnessSettingDefault">115</integer>


    <!-- Screen brightness used to dim the screen when the user activity
         timeout expires.  May be less than the minimum allowed brightness setting
         that can be set by the user. -->
    <integer name="config_screenBrightnessDim">1</integer>

    <!-- Whether a software navigation bar should be shown. NOTE: in the future this may be
         autodetected from the Configuration. -->
    <bool name="config_showNavigationBar">false</bool>

    <!-- If this is true, the screen will come on when you unplug usb/power/whatever. -->
    <bool name="config_unplugTurnsOnScreen">true</bool>

    <!--
       Sets the package names whose certificates should be used to
       verify location providers are allowed to be loaded.
    -->
    <string-array name="config_locationProviderPackageNames" translatable="false">
        <item>com.google.android.location</item>
        <item>com.android.location.fused</item>
    </string-array>

    <!--  Maximum number of supported users -->
    <integer name="config_multiuserMaximumUsers">1</integer>

    <!-- we don't want use hard menu key to unlock keyguard --> 
    <bool name="config_disableMenuKeyInLockScreen">true</bool>


    <!-- out side base package resource, we add it -->
    <add-resource type="integer" name="config_immersive_mode_confirmation_panic" />  
    <add-resource type="integer" name="config_max_over_scroll" />  

    <integer name="config_immersive_mode_confirmation_panic">5000</integer>
    <integer name="config_max_over_scroll">200</integer>

</resources>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111

4、部分参数解读

config_screenBrightnessSettingDefault：设置屏幕亮度的默认值。这个值会在系统初始化时使用，范围是0到255。

config_screenBrightnessSettingMinimum：设置屏幕亮度的最低值。这个值确保屏幕亮度不会低于这个值，范围是0到255。

config_screenBrightnessSettingMaximum：设置屏幕亮度的最高值。这个值确保屏幕亮度不会高于这个值，范围是0到255。

5、使用配置

这些配置会被系统服务（如PowerManagerService、DisplayManagerService）读取并应用，具体实现可以参考前面提到的服务类。

例如，在PowerManagerService中，可以读取配置并应用默认亮度值：

 public void systemReady(TwilightService twilight, DreamManagerService dreamManager) {
        synchronized (mLock) {
            mSystemReady = true;
            mDreamManager = dreamManager;

            PowerManager pm = (PowerManager)mContext.getSystemService(Context.POWER_SERVICE);
            mScreenBrightnessSettingMinimum = pm.getMinimumScreenBrightnessSetting();
            mScreenBrightnessSettingMaximum = pm.getMaximumScreenBrightnessSetting();
            mScreenBrightnessSettingDefault = pm.getDefaultScreenBrightnessSetting();

            SensorManager sensorManager = new SystemSensorManager(mHandler.getLooper());

            // The notifier runs on the system server's main looper so as not to interfere
            // with the animations and other critical functions of the power manager.
            mNotifier = new Notifier(Looper.getMainLooper(), mContext, mBatteryStats,
                    createSuspendBlockerLocked("PowerManagerService.Broadcasts"),
                    mScreenOnBlocker, mPolicy);

            // The display power controller runs on the power manager service's
            // own handler thread to ensure timely operation.
            mDisplayPowerController = new DisplayPowerController(mHandler.getLooper(),
                    mContext, mNotifier, mLightsService, twilight, sensorManager,
                    mDisplayManagerService, mDisplayBlanker,
                    mDisplayPowerControllerCallbacks, mHandler);

            mWirelessChargerDetector = new WirelessChargerDetector(sensorManager,
                    createSuspendBlockerLocked("PowerManagerService.WirelessChargerDetector"));
            mSettingsObserver = new SettingsObserver(mHandler);
            mAttentionLight = mLightsService.getLight(LightsService.LIGHT_ID_ATTENTION);

            // Register for broadcasts from other components of the system.
            IntentFilter filter = new IntentFilter();
            filter.addAction(Intent.ACTION_BATTERY_CHANGED);
            mContext.registerReceiver(new BatteryReceiver(), filter, null, mHandler);

            filter = new IntentFilter();
            filter.addAction(Intent.ACTION_BOOT_COMPLETED);
            mContext.registerReceiver(new BootCompletedReceiver(), filter, null, mHandler);

            filter = new IntentFilter();
            filter.addAction(Intent.ACTION_DREAMING_STARTED);
            filter.addAction(Intent.ACTION_DREAMING_STOPPED);
            mContext.registerReceiver(new DreamReceiver(), filter, null, mHandler);

            filter = new IntentFilter();
            filter.addAction(Intent.ACTION_USER_SWITCHED);
            mContext.registerReceiver(new UserSwitchedReceiver(), filter, null, mHandler);

            filter = new IntentFilter();
            filter.addAction(Intent.ACTION_DOCK_EVENT);
            mContext.registerReceiver(new DockReceiver(), filter, null, mHandler);

            // Register for settings changes.
            final ContentResolver resolver = mContext.getContentResolver();
            resolver.registerContentObserver(Settings.Secure.getUriFor(
                    Settings.Secure.SCREENSAVER_ENABLED),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            resolver.registerContentObserver(Settings.Secure.getUriFor(
                    Settings.Secure.SCREENSAVER_ACTIVATE_ON_SLEEP),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            resolver.registerContentObserver(Settings.Secure.getUriFor(
                    Settings.Secure.SCREENSAVER_ACTIVATE_ON_DOCK),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            resolver.registerContentObserver(Settings.System.getUriFor(
                    Settings.System.SCREEN_OFF_TIMEOUT),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            resolver.registerContentObserver(Settings.Global.getUriFor(
                    Settings.Global.STAY_ON_WHILE_PLUGGED_IN),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            resolver.registerContentObserver(Settings.System.getUriFor(
                    Settings.System.SCREEN_BRIGHTNESS),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            resolver.registerContentObserver(Settings.System.getUriFor(
                    Settings.System.SCREEN_BRIGHTNESS_MODE),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            //--------------for hdmi timeout add by dzy
            resolver.registerContentObserver(Settings.System.getUriFor(
                    Settings.System.HDMI_LCD_TIMEOUT),
                    false, mSettingsObserver, UserHandle.USER_ALL);
            //-----------------end------------------
            // Go.
            readConfigurationLocked();
            updateSettingsLocked();
            mDirty |= DIRTY_BATTERY_STATE;
            updatePowerStateLocked();
            
            new Thread() {
            public void run() {
                boolean waitSuspendOK;
                while(true) {
                    waitSuspendOK = false;
                    try {
                        Slog.d(TAG, "--- nativeWaitSuspendTimeout");
                        nativeWaitSuspendTimeout();
                        waitSuspendOK = true;
                    } catch (IOException e) {
                        Slog.e(TAG, "--- nativeWaitSuspendTimeout: " + e);
                    }


                    if (waitSuspendOK) {
                        int status = -1;
                        try {
                            status = nativeGetChargingStatus();
                            Slog.d(TAG, "--- charging status=" + status);
                        }  catch (IOException e) {
                            Slog.e(TAG, "--- nativeGetChargingStatus: " + e);
                        }

                        if (status != 1) {
                            PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
                            PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "suspend timeout to shutdownNormal");
                            wl.acquire(5000);

                            Slog.d(TAG, "--- shutdown now");

                            shutdownNormal();
                        }
                    } else {
                        try {
                            Thread.sleep(500);
                        } catch (InterruptedException e) {
                        }
                    }
                }
            }
        }.start();
        }
    }
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129

6、总结

通过在config.xml中配置屏幕亮度相关的参数，可以为Android系统提供默认的亮度设置和自动亮度调节的参数。这些配置会在系统服务中被读取并应用，从而影响系统的亮度控制行为。通过这种方式，开发者可以灵活地配置和管理屏幕亮度，确保提供良好的用户体验。

觉得本文对您有用，麻烦点赞、关注、收藏，您的肯定是我创作的无限动力，谢谢！！！