基于Android P 背光流程
一、SystemUI、Settings中手动调节
/frameworks/base/packages/SystemUI/src/com/android/systemui/settings/BrightnessController.java
@Override
public void onChanged(ToggleSlider toggleSlider, boolean tracking, boolean automatic,
int value, boolean stopTracking) {
final String setting;
if (mIsVrModeEnabled) {
setting = Settings.System.SCREEN_BRIGHTNESS_FOR_VR;
} else {
setting = Settings.System.SCREEN_BRIGHTNESS;
}
//获取亮度值
final int val = convertGammaToLinear(value, min, max);
//设置亮度值
setBrightness(val);
if (!tracking) {
//在异步任务中将新的亮度值保存在SettingsProvider中
AsyncTask.execute(new Runnable() {
public void run() {
Settings.System.putIntForUser(mContext.getContentResolver(),
setting, val, UserHandle.USER_CURRENT);
}
});
}
}
private void setBrightness(int brightness) {
mDisplayManager.setTemporaryBrightness(brightness);
}
//frameworks/base/core/java/android/hardware/display/DisplayManager.java
public void setTemporaryBrightness(int brightness) {
mGlobal.setTemporaryBrightness(brightness);
}
//frameworks/base/core/java/android/hardware/display/DisplayManagerGlobal.java
public void setTemporaryBrightness(int brightness) {
try {
mDm.setTemporaryBrightness(brightness);
} catch (RemoteException ex) {
throw ex.rethrowFromSystemServer();
}
}
//frameworks/base/services/core/java/com/android/server/display/DisplayManagerService.java
@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);
}
}
/frameworks/base/services/core/java/com/android/server/display/DisplayPowerController.java
public void setTemporaryBrightness(int brightness) {
Message msg = mHandler.obtainMessage(MSG_SET_TEMPORARY_BRIGHTNESS,
brightness, 0 /*unused*/);
msg.sendToTarget();
}
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_SET_TEMPORARY_BRIGHTNESS:
// TODO: Should we have a a timeout for the temporary brightness?
//将brightness赋值给了mTemporaryScreenBrightness
mTemporaryScreenBrightness = msg.arg1;
updatePowerState();
break;
}
}
}
private void updatePowerState() {
// ......
//手动设置亮度是否改变
final boolean userSetBrightnessChanged = updateUserSetScreenBrightness();
if (userSetBrightnessChanged) {
mTemporaryScreenBrightness = -1;
}
// ......
// Apply manual brightness.
if (brightness < 0) {
brightness = clampScreenBrightness(mCurrentScreenBrightnessSetting);
}
// ......
// Use the temporary screen brightness if there isn't an override, either from
// WindowManager or based on the display state.
if (mTemporaryScreenBrightness > 0) {
//使用手动设置的亮度
brightness = mTemporaryScreenBrightness;
mAppliedTemporaryBrightness = true;
} else {
mAppliedTemporaryBrightness = false;
}
//........
if (!mPendingScreenOff) {
final boolean isDisplayContentVisible = mColorFadeEnabled ?
(mColorFadeEnabled && mPowerState.getColorFadeLevel() == 1.0f) :
(state == Display.STATE_ON && mSkipRampState == RAMP_STATE_SKIP_NONE);
if (initialRampSkip || hasBrightnessBuckets
|| wasOrWillBeInVr || !isDisplayContentVisible || brightnessIsTemporary) {
//设置亮度值到底层驱动，调节背光值，不设置背光动画
animateScreenBrightness(brightness, 0);
} else {
//设置亮度值到底层驱动，调节背光值，根据slowChange设置快动画还是慢动画
animateScreenBrightness(brightness,
slowChange ? mBrightnessRampRateSlow : mBrightnessRampRateFast);
}
//......
}
private boolean updateUserSetScreenBrightness() {
if (mPendingScreenBrightnessSetting < 0) {
return false;
}
//add for bug BEG
if (mPendingScreenBrightnessSetting > 0 && (mCurrentScreenBrightnessSetting == mTemporaryScreenBrightness)){
return true;
}
//add for bug END
if (mCurrentScreenBrightnessSetting == mPendingScreenBrightnessSetting) {
mPendingScreenBrightnessSetting = -1;
return false;
}
mCurrentScreenBrightnessSetting = mPendingScreenBrightnessSetting;
mLastUserSetScreenBrightness = mPendingScreenBrightnessSetting;
mPendingScreenBrightnessSetting = -1;
return true;
}
//监听SettingsProvider中Settings.System.SCREEN_BRIGHTNESS的值变化（对应systemUI，Settings中seekbar的拖动）
private final class SettingsObserver extends ContentObserver {
public SettingsObserver(Handler handler) {
super(handler);
}
@Override
public void onChange(boolean selfChange, Uri uri) {
handleSettingsChange(false /* userSwitch */);
}
}
private void handleSettingsChange(boolean userSwitch) {
mPendingScreenBrightnessSetting = getScreenBrightnessSetting();
sendUpdatePowerState();
}
private int getScreenBrightnessSetting() {
final int brightness = Settings.System.getIntForUser(mContext.getContentResolver(),
Settings.System.SCREEN_BRIGHTNESS, mScreenBrightnessDefault,
UserHandle.USER_CURRENT);
return clampAbsoluteBrightness(brightness);
}
二、视频背光调节
播放视频时，可以通过上下滑动界面来设置亮度，当退出播放界面时，又会恢复到原亮度，其调用接口正是PMS中的setScreenBrightnessOverrideFromWindowManager()方法。
/frameworks/base/services/core/java/com/android/server/wm/RootWindowContainer.java
public void handleMessage(Message msg) {
switch (msg.what) {
case SET_SCREEN_BRIGHTNESS_OVERRIDE:
//调用PMS相关接口 mService.mPowerManagerInternal.setScreenBrightnessOverrideFromWindowManager(
msg.arg1);
break;
......
}
}
}
/frameworks/base/services/core/java/com/android/server/power/PowerManagerService.java
@Override
public void setScreenBrightnessOverrideFromWindowManager(int screenBrightness) {
if (screenBrightness < PowerManager.BRIGHTNESS_DEFAULT
|| screenBrightness > PowerManager.BRIGHTNESS_ON) {
screenBrightness = PowerManager.BRIGHTNESS_DEFAULT;
}
setScreenBrightnessOverrideFromWindowManagerInternal(screenBrightness);
}
private void setScreenBrightnessOverrideFromWindowManagerInternal(int brightness) {
synchronized (mLock) {
//将亮度值设置给了mScreenBrightnessOverrideFromWindowManager变量
if (mScreenBrightnessOverrideFromWindowManager != brightness) {
mScreenBrightnessOverrideFromWindowManager = brightness;
mDirty |= DIRTY_SETTINGS;
updatePowerStateLocked();
}
}
}
private void updatePowerStateLocked() {
if (!mSystemReady || mDirty == 0) {
return;
}
if (!Thread.holdsLock(mLock)) {
Slog.wtf(TAG, "Power manager lock was not held when calling updatePowerStateLocked");
}
Trace.traceBegin(Trace.TRACE_TAG_POWER, "updatePowerState");
try {
// Phase 0: Basic state updates.
updateIsPoweredLocked(mDirty);
updateStayOnLocked(mDirty);
updateScreenBrightnessBoostLocked(mDirty);
// Phase 1: Update wakefulness.
// Loop because the wake lock and user activity computations are influenced
// by changes in wakefulness.
final long now = SystemClock.uptimeMillis();
int dirtyPhase2 = 0;
for (;;) {
int dirtyPhase1 = mDirty;
dirtyPhase2 |= dirtyPhase1;
mDirty = 0;
updateWakeLockSummaryLocked(dirtyPhase1);
updateUserActivitySummaryLocked(now, dirtyPhase1);
if (!updateWakefulnessLocked(dirtyPhase1)) {
break;
}
}
// Phase 2: Lock profiles that became inactive/not kept awake.
updateProfilesLocked(now);
// Phase 3: Update display power state.
final boolean displayBecameReady = updateDisplayPowerStateLocked(dirtyPhase2);
// Phase 4: Update dream state (depends on display ready signal).
updateDreamLocked(dirtyPhase2, displayBecameReady);
// Phase 5: Send notifications, if needed.
finishWakefulnessChangeIfNeededLocked();
// Phase 6: Update suspend blocker.
// Because we might release the last suspend blocker here, we need to make sure
// we finished everything else first!
updateSuspendBlockerLocked();
} finally {
Trace.traceEnd(Trace.TRACE_TAG_POWER);
}
}
private boolean updateDisplayPowerStateLocked(int dirty) {
final boolean oldDisplayReady = mDisplayReady;
if ((dirty & (DIRTY_WAKE_LOCKS | DIRTY_USER_ACTIVITY | DIRTY_WAKEFULNESS
| DIRTY_ACTUAL_DISPLAY_POWER_STATE_UPDATED | DIRTY_BOOT_COMPLETED| DIRTY_SETTINGS | DIRTY_SCREEN_BRIGHTNESS_BOOST | DIRTY_VR_MODE_CHANGED |DIRTY_QUIESCENT)) != 0) {
mDisplayPowerRequest.policy = getDesiredScreenPolicyLocked();
// Determine appropriate screen brightness and auto-brightness adjustments.
final boolean autoBrightness;
final int screenBrightnessOverride;
if (!mBootCompleted) {
// Keep the brightness steady during boot. This requires the
// bootloader brightness and the default brightness to be identical.
autoBrightness = false;
screenBrightnessOverride = mScreenBrightnessSettingDefault;
} else if (isValidBrightness(mScreenBrightnessOverrideFromWindowManager)) {
autoBrightness = false;
screenBrightnessOverride = mScreenBrightnessOverrideFromWindowManager;
} else {
autoBrightness = (mScreenBrightnessModeSetting == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
screenBrightnessOverride = -1;
}
// Update display power request.
mDisplayPowerRequest.screenBrightnessOverride = screenBrightnessOverride;
mDisplayPowerRequest.useAutoBrightness = autoBrightness;
mDisplayPowerRequest.useProximitySensor = shouldUseProximitySensorLocked();
mDisplayPowerRequest.boostScreenBrightness = shouldBoostScreenBrightness();
updatePowerRequestFromBatterySaverPolicy(mDisplayPowerRequest);
if (mDisplayPowerRequest.policy == DisplayPowerRequest.POLICY_DOZE) {
mDisplayPowerRequest.dozeScreenState = mDozeScreenStateOverrideFromDreamManager;
if ((mWakeLockSummary & WAKE_LOCK_DRAW) != 0
&& !mDrawWakeLockOverrideFromSidekick) {
if (mDisplayPowerRequest.dozeScreenState == Display.STATE_DOZE_SUSPEND) {
mDisplayPowerRequest.dozeScreenState = Display.STATE_DOZE;
}
if (mDisplayPowerRequest.dozeScreenState == Display.STATE_ON_SUSPEND) {
mDisplayPowerRequest.dozeScreenState = Display.STATE_ON;
}
}
mDisplayPowerRequest.dozeScreenBrightness =
mDozeScreenBrightnessOverrideFromDreamManager;
} else {
mDisplayPowerRequest.dozeScreenState = Display.STATE_UNKNOWN;
mDisplayPowerRequest.dozeScreenBrightness = PowerManager.BRIGHTNESS_DEFAULT;
}
mDisplayReady = mDisplayManagerInternal.requestPowerState(mDisplayPowerRequest,
mRequestWaitForNegativeProximity);
mRequestWaitForNegativeProximity = false;
if ((dirty & DIRTY_QUIESCENT) != 0) {
sQuiescent = false;
}
}
return mDisplayReady && !oldDisplayReady;
}
/frameworks/base/services/core/java/com/android/server/display/DisplayPowerController.java
public boolean requestPowerState(DisplayPowerRequest request,
boolean waitForNegativeProximity) {
if (DEBUG) {
Slog.d(TAG, "requestPowerState: "
+ request + ", waitForNegativeProximity=" + waitForNegativeProximity);
}
synchronized (mLock) {
boolean changed = false;
if (waitForNegativeProximity
&& !mPendingWaitForNegativeProximityLocked) {
mPendingWaitForNegativeProximityLocked = true;
changed = true;
}
if (mPendingRequestLocked == null) {
mPendingRequestLocked = new DisplayPowerRequest(request);
changed = true;
} else if (!mPendingRequestLocked.equals(request)) {
mPendingRequestLocked.copyFrom(request);
changed = true;
if (changed) {
mDisplayReadyLocked = false;
}
if (changed && !mPendingRequestChangedLocked) {
mPendingRequestChangedLocked = true;
sendUpdatePowerStateLocked();
}
return mDisplayReadyLocked;
}
}
private void sendUpdatePowerStateLocked() {
if (!mPendingUpdatePowerStateLocked) {
mPendingUpdatePowerStateLocked = true;
Message msg = mHandler.obtainMessage(MSG_UPDATE_POWER_STATE);
mHandler.sendMessage(msg);
}
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_UPDATE_POWER_STATE:
updatePowerState();
break;
}
}
三、自动背光
自动背光流程跟前面的介绍背光流程分叉口就在updatePowerState（）。
private void updatePowerState() {
…
if (mAutomaticBrightnessController != null) {
hadUserBrightnessPoint = mAutomaticBrightnessController.hasUserDataPoints();
mAutomaticBrightnessController.configure(autoBrightnessEnabled,
mBrightnessConfiguration,
mLastUserSetScreenBrightness / (float)PowerManager.BRIGHTNESS_ON,
userSetBrightnessChanged, autoBrightnessAdjustment,
autoBrightnessAdjustmentChanged, mPowerRequest.policy);
}
// Apply auto-brightness.
boolean slowChange = false;
if (brightness < 0) {
float newAutoBrightnessAdjustment = autoBrightnessAdjustment;
if (autoBrightnessEnabled) {
brightness = mAutomaticBrightnessController.getAutomaticScreenBrightness();
newAutoBrightnessAdjustment = mAutomaticBrightnessController.getAutomaticScreenBrightnessAdjustment();
}
if (brightness >= 0) {
// Use current auto-brightness value and slowly adjust to changes.
brightness = clampScreenBrightness(brightness);
if (mAppliedAutoBrightness && !autoBrightnessAdjustmentChanged) {
slowChange = true; // slowly adapt to auto-brightness
}
putScreenBrightnessSetting(brightness);
mAppliedAutoBrightness = true;
} else {
mAppliedAutoBrightness = false;
}
if (autoBrightnessAdjustment != newAutoBrightnessAdjustment) {
putAutoBrightnessAdjustmentSetting(newAutoBrightnessAdjustment);
}
} else {
mAppliedAutoBrightness = false;
}
…
if (!mPendingScreenOff) {
final boolean isDisplayContentVisible = mColorFadeEnabled ?
(mColorFadeEnabled && mPowerState.getColorFadeLevel() == 1.0f) :
(state == Display.STATE_ON && mSkipRampState == RAMP_STATE_SKIP_NONE);
if (initialRampSkip || hasBrightnessBuckets
|| wasOrWillBeInVr || !isDisplayContentVisible || brightnessIsTemporary) {
animateScreenBrightness(brightness, 0);
} else {
animateScreenBrightness(brightness,
slowChange ? mBrightnessRampRateSlow : mBrightnessRampRateFast);
}
…
}
public void configure(boolean enable, @Nullable BrightnessConfiguration configuration,
float brightness, boolean userChangedBrightness, float adjustment,
boolean userChangedAutoBrightnessAdjustment, int displayPolicy) {
boolean dozing = (displayPolicy == DisplayPowerRequest.POLICY_DOZE);
boolean changed = setBrightnessConfiguration(configuration);
changed |= setDisplayPolicy(displayPolicy);
if (userChangedAutoBrightnessAdjustment) {
changed |= setAutoBrightnessAdjustment(adjustment);
}
if (userChangedBrightness && enable) {
changed |= setScreenBrightnessByUser(brightness);
}
final boolean userInitiatedChange =
userChangedBrightness || userChangedAutoBrightnessAdjustment;
if (userInitiatedChange && enable && !dozing) {
prepareBrightnessAdjustmentSample();
}
//注册/解除注册LightSensor,即开启自动调节亮度且非Doze状态下才可用
changed |= setLightSensorEnabled(enable && !dozing);
//changed为true则说明自动调节亮度状态发生改变或自动亮度调整值发生改变，则更新亮度
if (changed) {
updateAutoBrightness(false /*sendUpdate*/);
}
}
private boolean setLightSensorEnabled(boolean enable) {
if (enable) {
if (!mLightSensorEnabled) {
mLightSensorEnabled = true;
mLightSensorEnableTime = SystemClock.uptimeMillis();
mCurrentLightSensorRate = mInitialLightSensorRate;
mSensorManager.registerListener(mLightSensorListener, mLightSensor, mCurrentLightSensorRate * 1000, mHandler);
return true;
}
} else if (mLightSensorEnabled) {
mLightSensorEnabled = false;
mAmbientLuxValid = !mResetAmbientLuxAfterWarmUpConfig;
mRecentLightSamples = 0;
mAmbientLightRingBuffer.clear();
mCurrentLightSensorRate = -1;
mHandler.removeMessages(MSG_UPDATE_AMBIENT_LUX);
mSensorManager.unregisterListener(mLightSensorListener);
}
return false;
}
private final SensorEventListener mLightSensorListener = new SensorEventListener() {
@Override
public void onSensorChanged(SensorEvent event) {
if (mLightSensorEnabled) {
final long time = SystemClock.uptimeMillis();
final float lux = event.values[0];
handleLightSensorEvent(time, lux);
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// Not used.
}
};
private void handleLightSensorEvent(long time, float lux) {
Trace.traceCounter(Trace.TRACE_TAG_POWER, "ALS", (int) lux);
mHandler.removeMessages(MSG_UPDATE_AMBIENT_LUX);
if (mAmbientLightRingBuffer.size() == 0) {
adjustLightSensorRate(mNormalLightSensorRate);
}
applyLightSensorMeasurement(time, lux);
updateAmbientLux(time);
}
private void applyLightSensorMeasurement(long time, float lux) {
mRecentLightSamples++;
//删除距离当前mAmbientLightHorizon(10s)秒的数据
//LSensor500ms上报一次值，因此存储10s内可存储21组数据
mAmbientLightRingBuffer.prune(time - mAmbientLightHorizon);
//添加此次数据
mAmbientLightRingBuffer.push(time, lux);
mLastObservedLux = lux;
mLastObservedLuxTime = time;
}
private void updateAmbientLux() {
long time = SystemClock.uptimeMillis();
mAmbientLightRingBuffer.prune(time - mAmbientLightHorizon);
updateAmbientLux(time);
}
private void updateAmbientLux(long time) {
if (!mAmbientLuxValid) {
final long timeWhenSensorWarmedUp =
mLightSensorWarmUpTimeConfig + mLightSensorEnableTime;
if (time < timeWhenSensorWarmedUp) {
mHandler.sendEmptyMessageAtTime(MSG_UPDATE_AMBIENT_LUX,
timeWhenSensorWarmedUp);
return;
} setAmbientLux(calculateAmbientLux(time,AMBIENT_LIGHT_SHORT_HORIZON_MILLIS));
mAmbientLuxValid = true;
updateAutoBrightness(true);
}
long nextBrightenTransition = nextAmbientLightBrighteningTransition(time);
long nextDarkenTransition = nextAmbientLightDarkeningTransition(time);
float slowAmbientLux = calculateAmbientLux(time, AMBIENT_LIGHT_LONG_HORIZON_MILLIS);
float fastAmbientLux = calculateAmbientLux(time, AMBIENT_LIGHT_SHORT_HORIZON_MILLIS);
if ((slowAmbientLux >= mBrighteningLuxThreshold &&
fastAmbientLux >= mBrighteningLuxThreshold &&
nextBrightenTransition <= time)
||(slowAmbientLux <= mDarkeningLuxThreshold &&
fastAmbientLux <= mDarkeningLuxThreshold &&
nextDarkenTransition <= time)) {
setAmbientLux(fastAmbientLux);
updateAutoBrightness(true);
nextBrightenTransition = nextAmbientLightBrighteningTransition(time);
nextDarkenTransition = nextAmbientLightDarkeningTransition(time);
}
long nextTransitionTime = Math.min(nextDarkenTransition, nextBrightenTransition);
nextTransitionTime =
nextTransitionTime > time ? nextTransitionTime : time + mNormalLightSensorRate;
mHandler.sendEmptyMessageAtTime(MSG_UPDATE_AMBIENT_LUX, nextTransitionTime);
}
private void updateAutoBrightness(boolean sendUpdate) {
if (!mAmbientLuxValid) {
return;
}
float value = mBrightnessMapper.getBrightness(mAmbientLux);
int newScreenAutoBrightness =
clampScreenBrightness(Math.round(value * PowerManager.BRIGHTNESS_ON));
if (mScreenAutoBrightness != newScreenAutoBrightness) {
mScreenAutoBrightness = newScreenAutoBrightness;
if (sendUpdate) {
mCallbacks.updateBrightness();
}
}
}
public int getAutomaticScreenBrightness() {
if (!mAmbientLuxValid) {
return -1;
}
if (mDisplayPolicy == DisplayPowerRequest.POLICY_DOZE) {
return (int) (mScreenAutoBrightness * mDozeScaleFactor);
}
return mScreenAutoBrightness;
}
/frameworks/base/services/core/java/com/android/server/display/DisplayPowerController.java
@Override
public void updateBrightness() {
sendUpdatePowerState();
}
private void sendUpdatePowerState() {
synchronized (mLock) {
sendUpdatePowerStateLocked();
}
}
private void sendUpdatePowerStateLocked() {
if (!mPendingUpdatePowerStateLocked) {
mPendingUpdatePowerStateLocked = true;
Message msg = mHandler.obtainMessage(MSG_UPDATE_POWER_STATE);
mHandler.sendMessage(msg);
}
}
//最后又是重新调用updatepowerstate（）去更新背光值到底层
上面各种背光流程，我们都已经将具体流程介绍了一遍，最后得将在他们各个模式下的背光值设置到底层驱动中，而取的值，则要看当前是属于那种模式下，使用animateScreenBrightness（）改变屏幕亮度。
if (initialRampSkip || hasBrightnessBuckets
|| wasOrWillBeInVr || !isDisplayContentVisible || brightnessIsTemporary) {
//直接设置亮度值，不需要亮度动画
animateScreenBrightness(brightness, 0);
} else {
//设置亮度值，根据slowChange设置快速或慢速动画
animateScreenBrightness(brightness, ? mBrightnessRampRateSlow : mBrightnessRampRateFast);
}
private void animateScreenBrightness(int target, int rate) {
if (DEBUG) {
Slog.d(TAG, "Animating brightness: target=" + target +", rate=" + rate);
}
if (mScreenBrightnessRampAnimator.animateTo(target, rate)) {
Trace.traceCounter(Trace.TRACE_TAG_POWER, "TargetScreenBrightness", target);
try {
mBatteryStats.noteScreenBrightness(target);
} catch (RemoteException ex) {
// same process
}
}
}
/frameworks/base/services/core/java/com/android/server/display/RampAnimator.java
public boolean animateTo(int target, int rate) {
// Immediately jump to the target the first time.
if (mFirstTime || rate <= 0) {
if (mFirstTime || target != mCurrentValue) {
mFirstTime = false;
mRate = 0;
mTargetValue = target;
mCurrentValue = target;
mProperty.setValue(mObject, target);
if (mAnimating) {
mAnimating = false;
cancelAnimationCallback();
}
if (mListener != null) {
mListener.onAnimationEnd();
}
return true;
}
return false;
}
if (!mAnimating
|| rate > mRate
|| (target <= mCurrentValue && mCurrentValue <= mTargetValue)
|| (mTargetValue <= mCurrentValue && mCurrentValue <= target)) {
mRate = rate;
}
final boolean changed = (mTargetValue != target);
mTargetValue = target;
// Start animating.
if (!mAnimating && target != mCurrentValue) {
mAnimating = true;
mAnimatedValue = mCurrentValue;
mLastFrameTimeNanos = System.nanoTime();
postAnimationCallback();
}
return changed;
}
private void postAnimationCallback() {
mChoreographer.postCallback(Choreographer.CALLBACK_ANIMATION, mAnimationCallback, null);
}
private final Runnable mAnimationCallback = new Runnable() {
@Override // Choreographer callback
public void run() {
final long frameTimeNanos = mChoreographer.getFrameTimeNanos();
final float timeDelta = (frameTimeNanos - mLastFrameTimeNanos)* 0.000000001f;
mLastFrameTimeNanos = frameTimeNanos;
final float scale = ValueAnimator.getDurationScale();
if (scale == 0) {
// Animation off.
mAnimatedValue = mTargetValue;
} else {
final float amount = timeDelta * mRate / scale;
if (mTargetValue > mCurrentValue) {
mAnimatedValue = Math.min(mAnimatedValue + amount, mTargetValue);
} else {
mAnimatedValue = Math.max(mAnimatedValue - amount, mTargetValue);
}
}
final int oldCurrentValue = mCurrentValue;
mCurrentValue = Math.round(mAnimatedValue);
if (oldCurrentValue != mCurrentValue) {
mProperty.setValue(mObject, mCurrentValue);
}
if (mTargetValue != mCurrentValue) {
postAnimationCallback();
} else {
mAnimating = false;
if (mListener != null) {
mListener.onAnimationEnd();
}
}
}
};
public RampAnimator(T object, IntProperty property) {
mObject = object;
mProperty = property;
mChoreographer = Choreographer.getInstance();
}
/frameworks/base/services/core/java/com/android/server/display/DisplayPowerController.java
mScreenBrightnessRampAnimator = new RampAnimator(
mPowerState, DisplayPowerState.SCREEN_BRIGHTNESS);
/frameworks/base/services/core/java/com/android/server/display/DisplayPowerState.java
public static final IntProperty SCREEN_BRIGHTNESS = new IntProperty("screenBrightness") {
@Override
public void setValue(DisplayPowerState object, int value) {
object.setScreenBrightness(value);
}
@Override
public Integer get(DisplayPowerState object) {
return object.getScreenBrightness();
}
};
public void setScreenBrightness(int brightness) {
if (mScreenBrightness != brightness) {
mScreenBrightness = brightness;
if (mScreenState != Display.STATE_OFF) {
mScreenReady = false;
scheduleScreenUpdate();
}
}
}
private void scheduleScreenUpdate() {
if (!mScreenUpdatePending) {
mScreenUpdatePending = true;
postScreenUpdateThreadSafe();
}
}
private void postScreenUpdateThreadSafe() {
mHandler.removeCallbacks(mScreenUpdateRunnable);
mHandler.post(mScreenUpdateRunnable);
}
private final Runnable mScreenUpdateRunnable = new Runnable() {
@Override
public void run() {
mScreenUpdatePending = false;
int brightness = mScreenState != Display.STATE_OFF
&& mColorFadeLevel > 0f ? mScreenBrightness : 0;
if (mPhotonicModulator.setState(mScreenState, brightness)) {
if (DEBUG) {
Slog.d(TAG, "Screen ready");
}
mScreenReady = true;
invokeCleanListenerIfNeeded();
} else {
if (DEBUG) {
Slog.d(TAG, "Screen not ready");
}
}
}
};
public boolean setState(int state, int backlight) {
synchronized (mLock) {
boolean stateChanged = state != mPendingState;
boolean backlightChanged = backlight != mPendingBacklight;
mPendingState = state;
mPendingBacklight = backlight;
boolean changeInProgress = mStateChangeInProgress || mBacklightChangeInProgress;
mStateChangeInProgress = stateChanged || mStateChangeInProgress;
mBacklightChangeInProgress = backlightChanged || mBacklightChangeInProgress;
if (!changeInProgress) {
mLock.notifyAll();
}
}
return !mStateChangeInProgress;
}
}
@Override
public void run() {
for (;;) {
// Get pending change.
final int state;
final boolean stateChanged;
final int backlight;
final boolean backlightChanged;
synchronized (mLock) {
state = mPendingState;
stateChanged = (state != mActualState);
backlight = mPendingBacklight;
backlightChanged = (backlight != mActualBacklight);
if (!stateChanged) {
postScreenUpdateThreadSafe();
mStateChangeInProgress = false;
}
if (!backlightChanged) {
mBacklightChangeInProgress = false;
}
if (!stateChanged && !backlightChanged) {
try {
mLock.wait();
} catch (InterruptedException ex) { }
continue;
}
mActualState = state;
mActualBacklight = backlight;
}
mBlanker.requestDisplayState(state, backlight);
}
}
}
/frameworks/base/services/core/java/com/android/server/display/DisplayManagerService.java
public void initPowerManagement(final DisplayPowerCallbacks callbacks, Handler handler,
SensorManager sensorManager) {
synchronized (mSyncRoot) {
DisplayBlanker blanker = new DisplayBlanker() {
@Override
public void requestDisplayState(int state, int brightness) {
// The order of operations is important for legacy reasons.
//对于灭屏和非灭屏状态,调用callback的顺序不同
if (state == Display.STATE_OFF) {
requestGlobalDisplayStateInternal(state, brightness);
}
//PMS中调用native层方法
callbacks.onDisplayStateChange(state);
if (state != Display.STATE_OFF) {
requestGlobalDisplayStateInternal(state, brightness);
}
}
};
mDisplayPowerController = new DisplayPowerController(
mContext, callbacks, handler, sensorManager, blanker);
}
}private void requestGlobalDisplayStateInternal(int state, int brightness) {
if (state == Display.STATE_UNKNOWN) {
state = Display.STATE_ON;
}
if (state == Display.STATE_OFF) {
brightness = PowerManager.BRIGHTNESS_OFF;
} else if (brightness < 0) {
brightness = PowerManager.BRIGHTNESS_DEFAULT;
} else if (brightness > PowerManager.BRIGHTNESS_ON) {
brightness = PowerManager.BRIGHTNESS_ON;
}
synchronized (mTempDisplayStateWorkQueue) {
try {
synchronized (mSyncRoot) {
if (mGlobalDisplayState == state
&& mGlobalDisplayBrightness == brightness) {
return; // no change
}
Trace.traceBegin(Trace.TRACE_TAG_POWER, "requestGlobalDisplayState("
+ Display.stateToString(state)
+ ", brightness=" + brightness + ")");
mGlobalDisplayState = state;
mGlobalDisplayBrightness = brightness;
applyGlobalDisplayStateLocked(mTempDisplayStateWorkQueue);
}
for (int i = 0; i < mTempDisplayStateWorkQueue.size(); i++) {
mTempDisplayStateWorkQueue.get(i).run();
}
Trace.traceEnd(Trace.TRACE_TAG_POWER);
} finally {
mTempDisplayStateWorkQueue.clear();
}
}
}
private void applyGlobalDisplayStateLocked(List workQueue) {
final int count = mDisplayDevices.size();
for (int i = 0; i < count; i++) {
DisplayDevice device = mDisplayDevices.get(i);
Runnable runnable = updateDisplayStateLocked(device);
if (runnable != null) {
workQueue.add(runnable);
}
}
}
private Runnable updateDisplayStateLocked(DisplayDevice device) {
DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked();
if ((info.flags & DisplayDeviceInfo.FLAG_NEVER_BLANK) == 0) {
return device.requestDisplayStateLocked(mGlobalDisplayState, mGlobalDisplayBrightness);
}
return null;
}
/frameworks/base/services/core/java/com/android/server/display/LocalDisplayAdapter.java
@Override
public Runnable requestDisplayStateLocked(final int state, final int brightness) {
assert state != Display.STATE_OFF || brightness == PowerManager.BRIGHTNESS_OFF;
final boolean stateChanged = (mState != state);
final boolean brightnessChanged = (mBrightness != brightness) && mBacklight != null;
if (stateChanged || brightnessChanged) {
final int displayId = mBuiltInDisplayId;
final IBinder token = getDisplayTokenLocked();
final int oldState = mState;
if (stateChanged) {
mState = state;
updateDeviceInfoLocked();
}
if (brightnessChanged) {
mBrightness = brightness;
}
return new Runnable() {
@Override
public void run() {
int currentState = oldState;
if (Display.isSuspendedState(oldState)
|| oldState == Display.STATE_UNKNOWN) {
if (!Display.isSuspendedState(state)) {
setDisplayState(state);
currentState = state;
} else if (state == Display.STATE_DOZE_SUSPEND
|| oldState == Display.STATE_DOZE_SUSPEND) {
setDisplayState(Display.STATE_DOZE);
currentState = Display.STATE_DOZE;
} else if (state == Display.STATE_ON_SUSPEND
|| oldState == Display.STATE_ON_SUSPEND) {
setDisplayState(Display.STATE_ON);
currentState = Display.STATE_ON;
} else {
return;
}
}
boolean vrModeChange = false;
if ((state == Display.STATE_VR || currentState == Display.STATE_VR) &&
currentState != state) {
setVrMode(state == Display.STATE_VR);
vrModeChange = true;
}
if (brightnessChanged || vrModeChange) {
setDisplayBrightness(brightness);
}
if (state != currentState) {
setDisplayState(state);
}
}
private void setVrMode(boolean isVrEnabled) {
mBacklight.setVrMode(isVrEnabled);
}
private void setDisplayState(int state) {
if (mSidekickActive) {
Trace.traceBegin(Trace.TRACE_TAG_POWER, "SidekickInternal#endDisplayControl");
try {
mSidekickInternal.endDisplayControl();
} finally {
Trace.traceEnd(Trace.TRACE_TAG_POWER);
}
mSidekickActive = false;
}
final int mode = getPowerModeForState(state);
Trace.traceBegin(Trace.TRACE_TAG_POWER, "setDisplayState("
+ "id=" + displayId
+ ", state=" + Display.stateToString(state) + ")");
try {
SurfaceControl.setDisplayPowerMode(token, mode);
Trace.traceCounter(Trace.TRACE_TAG_POWER, "DisplayPowerMode", mode);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_POWER);
}
if (Display.isSuspendedState(state) && state != Display.STATE_OFF
&& mSidekickInternal != null && !mSidekickActive) {
Trace.traceBegin(Trace.TRACE_TAG_POWER, "SidekickInternal#startDisplayControl");
try {
mSidekickActive = mSidekickInternal.startDisplayControl(state);
} finally { Trace.traceEnd(Trace.TRACE_TAG_POWER);
}
}
}
private void setDisplayBrightness(int brightness) {
Trace.traceBegin(Trace.TRACE_TAG_POWER, "setDisplayBrightness("+ "id=" + displayId + ", brightness=" + brightness + ")");
try {
mBacklight.setBrightness(brightness);
Trace.traceCounter(Trace.TRACE_TAG_POWER,
"ScreenBrightness", brightness);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_POWER);
}
}
};
}
return null;
}
/frameworks/base/services/core/java/com/android/server/lights/LightsService.java
@Override
public void setBrightness(int brightness, int brightnessMode) {
synchronized (this) {
// LOW_PERSISTENCE cannot be manually set
if (brightnessMode == BRIGHTNESS_MODE_LOW_PERSISTENCE) {
return;
}
int color = brightness & 0x000000ff;
color = 0xff000000 | (color << 16) | (color << 8) | color;
setLightLocked(color, LIGHT_FLASH_NONE, 0, 0, brightnessMode);
}
}
private void setLightLocked(int color, int mode, int onMS, int offMS, int brightnessMode) {
if (shouldBeInLowPersistenceMode()) {
brightnessMode = BRIGHTNESS_MODE_LOW_PERSISTENCE;
} else if (brightnessMode == BRIGHTNESS_MODE_LOW_PERSISTENCE) {
brightnessMode = mLastBrightnessMode;
}
if (!mInitialized || color != mColor || mode != mMode || onMS != mOnMS ||
offMS != mOffMS || mBrightnessMode != brightnessMode) {
mInitialized = true;
mLastColor = mColor;
mColor = color;
mMode = mode;
mOnMS = onMS;
mOffMS = offMS;
mBrightnessMode = brightnessMode;
Trace.traceBegin(Trace.TRACE_TAG_POWER, "setLight(" + mId + ", 0x"
+ Integer.toHexString(color) + ")");
try {
setLight_native(mId, color, mode, onMS, offMS, brightnessMode);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_POWER);
}
}
}
static native void setLight_native(int light, int color, int mode,
int onMS, int offMS, int brightnessMode);
}
/frameworks/base/services/core/jni/com_android_server_lights_LightsService.cpp
static void setLight_native(
JNIEnv* /* env */,
jobject /* clazz */,
jint light,
jint colorARGB,
jint flashMode,
jint onMS,
jint offMS,
jint brightnessMode) {
if (!validate(light, flashMode, brightnessMode)) {
return;
}
sp hal = LightHal::associate();
if (hal == nullptr) {
return;
}
Type type = static_cast(light);
LightState state = constructState(
colorARGB, flashMode, onMS, offMS, brightnessMode);
{
android::base::Timer t;
//将背光值传递到HAL层，设置到驱动文件中
Return ret = hal->setLight(type, state);
processReturn(ret, type, state);
if (t.duration() > 50ms) ALOGD("Excessive delay setting light");
}
}