Android9.0手动亮度调节流程

前言

最近在改平台的亮度设置，顺便整理一下亮度调节的过程，使他人能方便理解亮度流程。

Kernel: v4.4.179
Device: rk3328
Platform Version: Android 9.0

流程如下

1. frameworks/base/packages/SystemUI/src/com/android/systemui/settings/BrightnessController.java
   

2. DisplayManager.java

    public void setTemporaryBrightness(int brightness) {
   		 mGlobal.setTemporaryBrightness(brightness);
    }
   

3. DisplayManagerGlobal.java

    public void setTemporaryBrightness(int brightness) {
    	try {
        	mDm.setTemporaryBrightness(brightness);
    	} catch (RemoteException ex) {
        	throw ex.rethrowFromSystemServer();
    	}
    }
   

4. DisplayManagerService.java

    public void setTemporaryBrightness(int brightness) {
    ...
      	mDisp