commit 908b86c796443ba4ec55c669e8a0297fc80574a6
author Justin Klaassen <justinklaassen@google.com> Mon Aug 08 09:18:42 2016 -0700
committer Justin Klaassen <justinklaassen@google.com> Tue Aug 09 21:19:54 2016 -0700
tree bf59593581d66c8233310441e0bb686e2b780079
parent 3cc5d047a7f295a3cd444d0b59dbd9214d37641a

TwilightService v2.0

- Switched to using CalendarAstronomer for more accurate sunrise/sunset
  times.
- Exposed sunrise/sunset times via TwilightState so that clients can
  track the current twilight period and perform their own
  interpolations.
- Adopted LocationRequest API for fused location updates:
  (low power, min 1h, max 10m).
- TwilightService is now only activated when a listener is registered,
  minimizing impact to system health on platforms / configurations
  where twilight state is not needed.

Bug: 28588307
Bug: 30190450
Bug: 30282370
Bug: 30650316
Change-Id: Ic5c94d8608e8bb3a3d895e623676a1468d4abdcd

services/core/java/com/android/server/display/AutomaticBrightnessController.java

diff --git a/services/core/java/com/android/server/display/AutomaticBrightnessController.java b/services/core/java/com/android/server/display/AutomaticBrightnessController.java
index c16dac2..15ae846 100644
--- a/services/core/java/com/android/server/display/AutomaticBrightnessController.java
+++ b/services/core/java/com/android/server/display/AutomaticBrightnessController.java
@@ -22,6 +22,7 @@
 import com.android.server.twilight.TwilightManager;
 import com.android.server.twilight.TwilightState;
 
+import android.annotation.Nullable;
 import android.hardware.Sensor;
 import android.hardware.SensorEvent;
 import android.hardware.SensorEventListener;
@@ -268,7 +269,7 @@
         pw.println();
         pw.println("Automatic Brightness Controller State:");
         pw.println("  mLightSensor=" + mLightSensor);
-        pw.println("  mTwilight.getCurrentState()=" + mTwilight.getCurrentState());
+        pw.println("  mTwilight.getLastTwilightState()=" + mTwilight.getLastTwilightState());
         pw.println("  mLightSensorEnabled=" + mLightSensorEnabled);
         pw.println("  mLightSensorEnableTime=" + TimeUtils.formatUptime(mLightSensorEnableTime));
         pw.println("  mAmbientLux=" + mAmbientLux);
@@ -495,12 +496,14 @@
         }
 
         if (mUseTwilight) {
-            TwilightState state = mTwilight.getCurrentState();
+            TwilightState state = mTwilight.getLastTwilightState();
             if (state != null && state.isNight()) {
-                final long now = System.currentTimeMillis();
-                gamma *= 1 + state.getAmount() * TWILIGHT_ADJUSTMENT_MAX_GAMMA;
+                final long duration = state.sunriseTimeMillis() - state.sunsetTimeMillis();
+                final long progress = System.currentTimeMillis() - state.sunsetTimeMillis();
+                final float amount = (float) Math.pow(2.0 * progress / duration - 1.0, 2.0);
+                gamma *= 1 + amount * TWILIGHT_ADJUSTMENT_MAX_GAMMA;
                 if (DEBUG) {
-                    Slog.d(TAG, "updateAutoBrightness: twilight amount=" + state.getAmount());
+                    Slog.d(TAG, "updateAutoBrightness: twilight amount=" + amount);
                 }
             }
         }
@@ -621,7 +624,7 @@
 
     private final TwilightListener mTwilightListener = new TwilightListener() {
         @Override
-        public void onTwilightStateChanged() {
+        public void onTwilightStateChanged(@Nullable TwilightState state) {
             updateAutoBrightness(true /*sendUpdate*/);
         }
     };