Android 9.0 (P版本) 亮度控制接口变更

1. Android 9.0 之前的亮度控制接口

import android.os.IPowerManager;import android.provider.Settings;import android.content.Context;    /**     * Used by the settings application and brightness control widgets to     * temporarily override the current screen brightness setting so that the     * user can observe the effect of an intended settings change without     * applying it immediately.     *      * The override will be canceled when the setting value is next updated.     *     * brightness The overridden brightness.     * @see android.provider.Settings.System#SCREEN_BRIGHTNESS     */    public static void setBrightnessValue(Context mContext, int value) {        try {            IPowerManager power = IPowerManager.Stub.asInterface(ServiceManager.getService(Context.POWER_SERVICE));            if (power != null) {                power.setTemporaryScreenBrightnessSettingOverride(value);            }        } catch (RemoteException doe) {            Log.w(TAG, doe);        }        Settings.System.putInt(mContext.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, value);    }    public static void setBrightnessValueBg(Context mContext, int value) {        try {            IPowerManager power = IPowerManager.Stub.asInterface(ServiceManager.getService(Context.POWER_SERVICE));            if (power != null) {                power.setTemporaryScreenBrightnessSettingOverride(value);            }        } catch (RemoteException doe) {            Log.w(TAG, doe);        }    }

1.1 参见Android 8.0的SystemUI代码

frameworks/base/packages/SystemUI/src/com/android/systemui/settings/BrightnessController.java:419: mPower.setTemporaryScreenBrightnessSettingOverride(brightness);

package com.android.systemui.settings;public class BrightnessController implements ToggleSlider.Listener {    private void setBrightness(int brightness) {        try {            mPower.setTemporaryScreenBrightnessSettingOverride(brightness);        } catch (RemoteException ex) {        }    }

2. Android 9.0 的亮度控制接口

2.1 参考Android 9.0的SystemUI代码

package com.android.systemui.settings;import android.hardware.display.DisplayManager;public class BrightnessController implements ToggleSlider.Listener {    private final DisplayManager mDisplayManager;    private void setBrightness(int brightness) {        mDisplayManager.setTemporaryBrightness(brightness);    }

2.2 查看 DisplayManager.setTemporaryBrightness源码

源码路径

frameworks/base/core/java/android/hardware/display/DisplayManager.java

root@69959bbb90c6:/home/suhuazhi/9.1# find frameworks/ -name  "DisplayManager.java"frameworks/base/core/java/android/hardware/display/DisplayManager.java

查看实现方式 -DisplayManager.setTemporaryBrightness

package android.hardware.display;@SystemService(Context.DISPLAY_SERVICE)public final class DisplayManager {    private final DisplayManagerGlobal mGlobal;    /**     * Temporarily sets the brightness of the display.     *      * Requires the {@link android.Manifest.permission#CONTROL_DISPLAY_BRIGHTNESS} permission.     * 
     *     * @param brightness The brightness value from 0 to 255.     *     * @hide Requires signature permission.     */    public void setTemporaryBrightness(int brightness) {        mGlobal.setTemporaryBrightness(brightness);    }

源码路径
frameworks/base/core/java/android/hardware/display/DisplayManagerGlobal.java

root@69959bbb90c6:/home/suhuazhi/9.1# find frameworks/ -name  "DisplayManagerGlobal.java"frameworks/base/core/java/android/hardware/display/DisplayManagerGlobal.java

查看实现方式 -DisplayManagerGlobal.setTemporaryBrightness

package android.hardware.display;public final class DisplayManagerGlobal {    private final IDisplayManager mDm;    /**     * Temporarily sets the brightness of the display.     *      * Requires the {@link android.Manifest.permission#CONTROL_DISPLAY_BRIGHTNESS} permission.     * 
     *     * @param brightness The brightness value from 0 to 255.     *     * @hide Requires signature permission.     */    public void setTemporaryBrightness(int brightness) {        try {            mDm.setTemporaryBrightness(brightness);        } catch (RemoteException ex) {            throw ex.rethrowFromSystemServer();        }    }

查看实现方式 -DisplayManagerService.setTemporaryBrightness
./frameworks/base/services/core/java/com/android/server/display/DisplayManagerService.java

上述 IDisplayManager 是一个aidl接口，对应找DisplayManagerService即可

package com.android.server.display;public final class DisplayManagerService extends SystemService {        @Override // Binder call        public void setTemporaryBrightness(int brightness) {            mContext.enforceCallingOrSelfPermission(                    Manifest.permission.CONTROL_DISPLAY_BRIGHTNESS,                    "Permission required to set the display's brightness");            final long token = Binder.clearCallingIdentity();            try {                synchronized (mSyncRoot) {                    mDisplayPowerController.setTemporaryBrightness(brightness);                }            } finally {                Binder.restoreCallingIdentity(token);            }        }

上述需要权限

3. 综合上述Android 9.0 的亮度控制接口

权限

软件接口

import android.hardware.display.DisplayManager;import android.content.Context;import android.os.ServiceManager;import android.os.IPowerManager;    /**     * Used by the settings application and brightness control widgets to     * temporarily override the current screen brightness setting so that the     * user can observe the effect of an intended settings change without     * applying it immediately.     *      * The override will be canceled when the setting value is next updated.     *     * brightness The overridden brightness.     * @see android.provider.Settings.System#SCREEN_BRIGHTNESS     */    public static void setBrightnessValue(Context mContext, int value) {        setBrightnessValueBg(mContext, value);        Settings.System.putInt(mContext.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, value);    }    public static void setBrightnessValueBg(Context mContext, int value) {        if (android.os.Build.VERSION.SDK_INT >= 27) {            //             DisplayManager mDisplayManager = mContext.getSystemService(DisplayManager.class);            mDisplayManager.setTemporaryBrightness(value);        } else {            /*try {                IPowerManager power = IPowerManager.Stub.asInterface(ServiceManager.getService(Context.POWER_SERVICE));                if (power != null) {                    power.setTemporaryScreenBrightnessSettingOverride(value);                }            } catch (RemoteException doe) {                Log.w(TAG, doe);            }*/        }    }