diff options
Diffstat (limited to 'services/java')
| -rw-r--r-- | services/java/com/android/server/power/DisplayPowerController.java | 122 |
1 files changed, 65 insertions, 57 deletions
diff --git a/services/java/com/android/server/power/DisplayPowerController.java b/services/java/com/android/server/power/DisplayPowerController.java index 976a328..60d44c7 100644 --- a/services/java/com/android/server/power/DisplayPowerController.java +++ b/services/java/com/android/server/power/DisplayPowerController.java @@ -298,6 +298,10 @@ final class DisplayPowerController { // True if mAmbientLux holds a valid value. private boolean mAmbientLuxValid; + // The ambient light level threshold at which to brighten or darken the screen. + private float mBrighteningLuxThreshold; + private float mDarkeningLuxThreshold; + // The most recent light sample. private float mLastObservedLux; @@ -945,12 +949,24 @@ final class DisplayPowerController { mLastObservedLuxTime = time; } + private void setAmbientLux(float lux) { + mAmbientLux = lux; + mBrighteningLuxThreshold = mAmbientLux * (1.0f + BRIGHTENING_LIGHT_HYSTERESIS); + mDarkeningLuxThreshold = mAmbientLux * (1.0f - DARKENING_LIGHT_HYSTERESIS); + } + private void updateAmbientLux(long time) { // If the light sensor was just turned on then immediately update our initial // estimate of the current ambient light level. - if (!mAmbientLuxValid - || (time - mLightSensorEnableTime) < mLightSensorWarmUpTimeConfig) { - mAmbientLux = mRecentShortTermAverageLux; + if (!mAmbientLuxValid) { + final long timeWhenSensorWarmedUp = + mLightSensorWarmUpTimeConfig + mLightSensorEnableTime; + if (time < timeWhenSensorWarmedUp) { + mHandler.sendEmptyMessageAtTime(MSG_LIGHT_SENSOR_DEBOUNCED, + timeWhenSensorWarmedUp); + return; + } + setAmbientLux(mRecentShortTermAverageLux); mAmbientLuxValid = true; mDebounceLuxDirection = 0; mDebounceLuxTime = time; @@ -961,98 +977,90 @@ final class DisplayPowerController { + ", mAmbientLux=" + mAmbientLux); } updateAutoBrightness(true); - return; - } - - // Determine whether the ambient environment appears to be brightening. - float brighteningLuxThreshold = mAmbientLux * (1.0f + BRIGHTENING_LIGHT_HYSTERESIS); - if (mRecentShortTermAverageLux > brighteningLuxThreshold - && mRecentLongTermAverageLux > brighteningLuxThreshold) { + } else if (mRecentShortTermAverageLux > mBrighteningLuxThreshold + && mRecentLongTermAverageLux > mBrighteningLuxThreshold) { + // The ambient environment appears to be brightening. if (mDebounceLuxDirection <= 0) { mDebounceLuxDirection = 1; mDebounceLuxTime = time; if (DEBUG) { Slog.d(TAG, "updateAmbientLux: Possibly brightened, waiting for " + BRIGHTENING_LIGHT_DEBOUNCE + " ms: " - + "brighteningLuxThreshold=" + brighteningLuxThreshold + + "mBrighteningLuxThreshold=" + mBrighteningLuxThreshold + ", mRecentShortTermAverageLux=" + mRecentShortTermAverageLux + ", mRecentLongTermAverageLux=" + mRecentLongTermAverageLux + ", mAmbientLux=" + mAmbientLux); } } long debounceTime = mDebounceLuxTime + BRIGHTENING_LIGHT_DEBOUNCE; - if (time >= debounceTime) { - mAmbientLux = mRecentShortTermAverageLux; - if (DEBUG) { - Slog.d(TAG, "updateAmbientLux: Brightened: " - + "brighteningLuxThreshold=" + brighteningLuxThreshold - + ", mRecentShortTermAverageLux=" + mRecentShortTermAverageLux - + ", mRecentLongTermAverageLux=" + mRecentLongTermAverageLux - + ", mAmbientLux=" + mAmbientLux); - } - updateAutoBrightness(true); - } else { + if (time < debounceTime) { mHandler.sendEmptyMessageAtTime(MSG_LIGHT_SENSOR_DEBOUNCED, debounceTime); + return; } - return; - } - - // Determine whether the ambient environment appears to be darkening. - float darkeningLuxThreshold = mAmbientLux * (1.0f - DARKENING_LIGHT_HYSTERESIS); - if (mRecentShortTermAverageLux < darkeningLuxThreshold - && mRecentLongTermAverageLux < darkeningLuxThreshold) { + setAmbientLux(mRecentShortTermAverageLux); + if (DEBUG) { + Slog.d(TAG, "updateAmbientLux: Brightened: " + + "mBrighteningLuxThreshold=" + mBrighteningLuxThreshold + + ", mRecentShortTermAverageLux=" + mRecentShortTermAverageLux + + ", mRecentLongTermAverageLux=" + mRecentLongTermAverageLux + + ", mAmbientLux=" + mAmbientLux); + } + updateAutoBrightness(true); + } else if (mRecentShortTermAverageLux < mDarkeningLuxThreshold + && mRecentLongTermAverageLux < mDarkeningLuxThreshold) { + // The ambient environment appears to be darkening. if (mDebounceLuxDirection >= 0) { mDebounceLuxDirection = -1; mDebounceLuxTime = time; if (DEBUG) { Slog.d(TAG, "updateAmbientLux: Possibly darkened, waiting for " + DARKENING_LIGHT_DEBOUNCE + " ms: " - + "darkeningLuxThreshold=" + darkeningLuxThreshold + + "mDarkeningLuxThreshold=" + mDarkeningLuxThreshold + ", mRecentShortTermAverageLux=" + mRecentShortTermAverageLux + ", mRecentLongTermAverageLux=" + mRecentLongTermAverageLux + ", mAmbientLux=" + mAmbientLux); } } long debounceTime = mDebounceLuxTime + DARKENING_LIGHT_DEBOUNCE; - if (time >= debounceTime) { - // Be conservative about reducing the brightness, only reduce it a little bit - // at a time to avoid having to bump it up again soon. - mAmbientLux = Math.max(mRecentShortTermAverageLux, mRecentLongTermAverageLux); - if (DEBUG) { - Slog.d(TAG, "updateAmbientLux: Darkened: " - + "darkeningLuxThreshold=" + darkeningLuxThreshold - + ", mRecentShortTermAverageLux=" + mRecentShortTermAverageLux - + ", mRecentLongTermAverageLux=" + mRecentLongTermAverageLux - + ", mAmbientLux=" + mAmbientLux); - } - updateAutoBrightness(true); - } else { + if (time < debounceTime) { mHandler.sendEmptyMessageAtTime(MSG_LIGHT_SENSOR_DEBOUNCED, debounceTime); + return; } - return; - } - - // No change or change is within the hysteresis thresholds. - if (mDebounceLuxDirection != 0) { + // Be conservative about reducing the brightness, only reduce it a little bit + // at a time to avoid having to bump it up again soon. + setAmbientLux(Math.max(mRecentShortTermAverageLux, mRecentLongTermAverageLux)); + if (DEBUG) { + Slog.d(TAG, "updateAmbientLux: Darkened: " + + "mDarkeningLuxThreshold=" + mDarkeningLuxThreshold + + ", mRecentShortTermAverageLux=" + mRecentShortTermAverageLux + + ", mRecentLongTermAverageLux=" + mRecentLongTermAverageLux + + ", mAmbientLux=" + mAmbientLux); + } + updateAutoBrightness(true); + } else if (mDebounceLuxDirection != 0) { + // No change or change is within the hysteresis thresholds. mDebounceLuxDirection = 0; mDebounceLuxTime = time; if (DEBUG) { Slog.d(TAG, "updateAmbientLux: Canceled debounce: " - + "brighteningLuxThreshold=" + brighteningLuxThreshold - + ", darkeningLuxThreshold=" + darkeningLuxThreshold + + "mBrighteningLuxThreshold=" + mBrighteningLuxThreshold + + ", mDarkeningLuxThreshold=" + mDarkeningLuxThreshold + ", mRecentShortTermAverageLux=" + mRecentShortTermAverageLux + ", mRecentLongTermAverageLux=" + mRecentLongTermAverageLux + ", mAmbientLux=" + mAmbientLux); } } - // If the light level does not change, then the sensor may not report - // a new value. This can cause problems for the auto-brightness algorithm - // because the filters might not be updated. To work around it, we want to - // make sure to update the filters whenever the observed light level could - // possibly exceed one of the hysteresis thresholds. - if (mLastObservedLux > brighteningLuxThreshold - || mLastObservedLux < darkeningLuxThreshold) { + // Now that we've done all of that, we haven't yet posted a debounce + // message. So consider the case where current lux is beyond the + // threshold. It's possible that the light sensor may not report values + // if the light level does not change, so we need to occasionally + // synthesize sensor readings in order to make sure the brightness is + // adjusted accordingly. Note these thresholds may have changed since + // we entered the function because we called setAmbientLux and + // updateAutoBrightness along the way. + if (mLastObservedLux > mBrighteningLuxThreshold + || mLastObservedLux < mDarkeningLuxThreshold) { mHandler.sendEmptyMessageAtTime(MSG_LIGHT_SENSOR_DEBOUNCED, time + SYNTHETIC_LIGHT_SENSOR_RATE_MILLIS); } |