AOD: Add support for dimming in software

Some devices cannot dim low enough in hardware in low power states.
To work around that, keep the front scrim at higher opacity when needed
to simulate lower brightness.

Bug: 63995944
Test: Configure scrim in config.xml; use device in very dim light at night, observe AOD is sufficiently dim.
Change-Id: I92fffedeea89b9327d76dfb184c5c761364ead11
diff --git a/packages/SystemUI/res/values/config.xml b/packages/SystemUI/res/values/config.xml
index 3c86c87..30b1692 100644
--- a/packages/SystemUI/res/values/config.xml
+++ b/packages/SystemUI/res/values/config.xml
@@ -277,6 +277,18 @@
         <item>28</item> <!-- 4: SUN -->
     </integer-array>
 
+    <!-- Doze: Table that translates sensor values from the doze_brightness_sensor_type sensor
+               to an opacity value for a black scrim that is overlayed in AOD1.
+               Valid range is from 0 (transparent) to 255 (opaque).
+               -1 means keeping the current opacity. -->
+    <integer-array name="config_doze_brightness_sensor_to_scrim_opacity">
+        <item>-1</item> <!-- 0: OFF -->
+        <item>0</item> <!-- 1: NIGHT -->
+        <item>0</item> <!-- 2: LOW -->
+        <item>0</item> <!-- 3: HIGH -->
+        <item>0</item> <!-- 4: SUN -->
+    </integer-array>
+
     <!-- Doze: whether the double tap sensor reports 2D touch coordinates -->
     <bool name="doze_double_tap_reports_touch_coordinates">false</bool>
 
diff --git a/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java b/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java
index cbdabf5..302bc2d 100644
--- a/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java
+++ b/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java
@@ -65,7 +65,7 @@
                         handler, wakeLock, machine),
                 createDozeUi(context, host, wakeLock, machine, handler, alarmManager),
                 createDozeScreenState(wrappedService),
-                createDozeScreenBrightness(context, wrappedService, sensorManager, handler),
+                createDozeScreenBrightness(context, wrappedService, sensorManager, host, handler),
         });
 
         return machine;
@@ -76,10 +76,11 @@
     }
 
     private DozeMachine.Part createDozeScreenBrightness(Context context,
-            DozeMachine.Service service, SensorManager sensorManager, Handler handler) {
+            DozeMachine.Service service, SensorManager sensorManager, DozeHost host,
+            Handler handler) {
         Sensor sensor = DozeSensors.findSensorWithType(sensorManager,
                 context.getString(R.string.doze_brightness_sensor_type));
-        return new DozeScreenBrightness(context, service, sensorManager, sensor, handler);
+        return new DozeScreenBrightness(context, service, sensorManager, sensor, host, handler);
     }
 
     private DozeTriggers createDozeTriggers(Context context, SensorManager sensorManager,
diff --git a/packages/SystemUI/src/com/android/systemui/doze/DozeHost.java b/packages/SystemUI/src/com/android/systemui/doze/DozeHost.java
index 9b97634..7db118d 100644
--- a/packages/SystemUI/src/com/android/systemui/doze/DozeHost.java
+++ b/packages/SystemUI/src/com/android/systemui/doze/DozeHost.java
@@ -42,6 +42,7 @@
 
     void onDoubleTap(float x, float y);
 
+    default void setAodDimmingScrim(float scrimOpacity) {}
     void setDozeScreenBrightness(int value);
 
     void onIgnoreTouchWhilePulsing(boolean ignore);
diff --git a/packages/SystemUI/src/com/android/systemui/doze/DozeScreenBrightness.java b/packages/SystemUI/src/com/android/systemui/doze/DozeScreenBrightness.java
index 32baf94..30420529 100644
--- a/packages/SystemUI/src/com/android/systemui/doze/DozeScreenBrightness.java
+++ b/packages/SystemUI/src/com/android/systemui/doze/DozeScreenBrightness.java
@@ -32,22 +32,28 @@
 public class DozeScreenBrightness implements DozeMachine.Part, SensorEventListener {
     private final Context mContext;
     private final DozeMachine.Service mDozeService;
+    private final DozeHost mDozeHost;
     private final Handler mHandler;
     private final SensorManager mSensorManager;
     private final Sensor mLightSensor;
     private final int[] mSensorToBrightness;
+    private final int[] mSensorToScrimOpacity;
     private boolean mRegistered;
 
     public DozeScreenBrightness(Context context, DozeMachine.Service service,
-            SensorManager sensorManager, Sensor lightSensor, Handler handler) {
+            SensorManager sensorManager, Sensor lightSensor, DozeHost host,
+            Handler handler) {
         mContext = context;
         mDozeService = service;
         mSensorManager = sensorManager;
         mLightSensor = lightSensor;
+        mDozeHost = host;
         mHandler = handler;
 
         mSensorToBrightness = context.getResources().getIntArray(
                 R.array.config_doze_brightness_sensor_to_brightness);
+        mSensorToScrimOpacity = context.getResources().getIntArray(
+                R.array.config_doze_brightness_sensor_to_scrim_opacity);
     }
 
     @Override
@@ -74,13 +80,26 @@
     @Override
     public void onSensorChanged(SensorEvent event) {
         if (mRegistered) {
-            int brightness = computeBrightness((int) event.values[0]);
+            int sensorValue = (int) event.values[0];
+            int brightness = computeBrightness(sensorValue);
             if (brightness > 0) {
                 mDozeService.setDozeScreenBrightness(brightness);
             }
+
+            int scrimOpacity = computeScrimOpacity(sensorValue);
+            if (scrimOpacity >= 0) {
+                mDozeHost.setAodDimmingScrim(scrimOpacity / 255f);
+            }
         }
     }
 
+    private int computeScrimOpacity(int sensorValue) {
+        if (sensorValue < 0 || sensorValue >= mSensorToScrimOpacity.length) {
+            return -1;
+        }
+        return mSensorToScrimOpacity[sensorValue];
+    }
+
     private int computeBrightness(int sensorValue) {
         if (sensorValue < 0 || sensorValue >= mSensorToBrightness.length) {
             return -1;
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/DozeScrimController.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/DozeScrimController.java
index 2283c13..3794ac6 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/DozeScrimController.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/DozeScrimController.java
@@ -56,6 +56,8 @@
     private boolean mWakeAndUnlocking;
     private boolean mFullyPulsing;
 
+    private float mAodFrontScrimOpacity = 0;
+
     public DozeScrimController(ScrimController scrimController, Context context) {
         mContext = context;
         mScrimController = scrimController;
@@ -70,7 +72,8 @@
             mDozingAborted = false;
             abortAnimations();
             mScrimController.setDozeBehindAlpha(1f);
-            mScrimController.setDozeInFrontAlpha(mDozeParameters.getAlwaysOn() ? 0f : 1f);
+            mScrimController.setDozeInFrontAlpha(
+                    mDozeParameters.getAlwaysOn() ? mAodFrontScrimOpacity : 1f);
         } else {
             cancelPulsing();
             if (animate) {
@@ -88,6 +91,19 @@
         }
     }
 
+    /**
+     * Set the opacity of the front scrim when showing AOD1
+     *
+     * Used to emulate lower brightness values than the hardware supports natively.
+     */
+    public void setAodDimmingScrim(float scrimOpacity) {
+        mAodFrontScrimOpacity = scrimOpacity;
+        if (mDozing && !isPulsing() && !mDozingAborted && !mWakeAndUnlocking
+                && mDozeParameters.getAlwaysOn()) {
+            mScrimController.setDozeInFrontAlpha(mAodFrontScrimOpacity);
+        }
+    }
+
     public void setWakeAndUnlocking() {
         // Immediately abort the doze scrims in case of wake-and-unlock
         // for pulsing so the Keyguard fade-out animation scrim can take over.
@@ -126,7 +142,8 @@
         if (mDozing && !mWakeAndUnlocking) {
             mScrimController.setDozeBehindAlpha(1f);
             mScrimController.setDozeInFrontAlpha(
-                    mDozeParameters.getAlwaysOn() && !mDozingAborted ? 0f : 1f);
+                    mDozeParameters.getAlwaysOn() && !mDozingAborted ?
+                            mAodFrontScrimOpacity : 1f);
         }
     }
 
@@ -337,7 +354,7 @@
             // Signal that the pulse is all finished so we can turn the screen off now.
             pulseFinished();
             if (mDozeParameters.getAlwaysOn()) {
-                mScrimController.setDozeInFrontAlpha(0);
+                mScrimController.setDozeInFrontAlpha(mAodFrontScrimOpacity);
             }
         }
     };
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/StatusBar.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/StatusBar.java
index db84cff..8dc4b38 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/StatusBar.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/StatusBar.java
@@ -5555,6 +5555,11 @@
             mStatusBarWindowManager.setDozeScreenBrightness(value);
         }
 
+        @Override
+        public void setAodDimmingScrim(float scrimOpacity) {
+            mDozeScrimController.setAodDimmingScrim(scrimOpacity);
+        }
+
         public void dispatchDoubleTap(float viewX, float viewY) {
             dispatchTap(mAmbientIndicationContainer, viewX, viewY);
             dispatchTap(mAmbientIndicationContainer, viewX, viewY);
diff --git a/packages/SystemUI/tests/src/com/android/systemui/doze/DozeScreenBrightnessTest.java b/packages/SystemUI/tests/src/com/android/systemui/doze/DozeScreenBrightnessTest.java
index fe3221a..c275806 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/doze/DozeScreenBrightnessTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/doze/DozeScreenBrightnessTest.java
@@ -51,14 +51,16 @@
     DozeScreenBrightness mScreen;
     FakeSensorManager.FakeGenericSensor mSensor;
     FakeSensorManager mSensorManager;
+    DozeHostFake mHostFake;
 
     @Before
     public void setUp() throws Exception {
         mServiceFake = new DozeServiceFake();
+        mHostFake = new DozeHostFake();
         mSensorManager = new FakeSensorManager(mContext);
         mSensor = mSensorManager.getFakeLightSensor();
         mScreen = new DozeScreenBrightness(mContext, mServiceFake, mSensorManager,
-                mSensor.getSensor(), null /* handler */);
+                mSensor.getSensor(), mHostFake, null /* handler */);
     }
 
     @Test
@@ -133,7 +135,7 @@
     @Test
     public void testNullSensor() throws Exception {
         mScreen = new DozeScreenBrightness(mContext, mServiceFake, mSensorManager,
-                null /* sensor */, null /* handler */);
+                null /* sensor */, mHostFake, null /* handler */);
 
         mScreen.transitionTo(UNINITIALIZED, INITIALIZED);
         mScreen.transitionTo(INITIALIZED, DOZE_AOD);