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

DisplayManager.java

public void setTemporaryBrightness(int brightness) {

mGlobal.setTemporaryBrightness(brightness);

}

DisplayManagerGlobal.java

public void setTemporaryBrightness(int brightness) {

try {

mDm.setTemporaryBrightness(brightness);

} catch (RemoteException ex) {

throw ex.rethrowFromSystemServer();

}

}

DisplayManagerService.java

public void setTemporaryBrightness(int brightness) {

...

mDisplayPowerController.setTemporaryBrightness(brightness);

...

}

DisplayPowerController.java

public void setTemporaryBrightness(int brightness) {

Message msg = mHandler.obtainMessage(MSG_SET_TEMPORARY_BRIGHTNESS,

brightness, 0 /*unused*/);

msg.sendToTarget();

}

...

private void updatePowerState() {

//此方法比较长，里面有大量的判断，下面只写关键语句

...

animateScreenBrightness(brightness, 0);

...

}

...

private void animateScreenBrightness(int target, int rate) {

//这一句就是关键的设置语句

if (mScreenBrightnessRampAnimator.animateTo(target, rate)) {

}

}

下面的就不太好跟了，直接贴图 RampAnimator.java

DisplayPowerState.java

setScreenBrightness(int brightness){...}

scheduleScreenUpdate() {...}

postScreenUpdateThreadSafe(){...}

Runnable mScreenUpdateRunnable = new Runnable() {

...

mPhotonicModulator.setState(mScreenState, brightness)

...

}

PhotonicModulator.java

又调回到了DisplayManagerService.java

LocalDisplayAdapter.java

LightsService.java

com_android_server_lights_LightsService.cpp