Add support for disabling autobrightness when stylus under use

Bug: 352411468
Test: Manual
Test: atest DisplayPowerControllerTest
Flag: com.android.server.display.feature.flags.block_autobrightness_changes_on_stylus_usage
Change-Id: I99af48e4e380ede410f28cce7d4b68f2f6329bac

11 files changed, 129 insertions, 4 deletions

diff --git a/core/java/android/hardware/display/DisplayManagerInternal.java b/core/java/android/hardware/display/DisplayManagerInternal.java
index e5980972d590..36e816af8439 100644
--- a/core/java/android/hardware/display/DisplayManagerInternal.java
+++ b/core/java/android/hardware/display/DisplayManagerInternal.java
@@ -455,6 +455,11 @@ public abstract class DisplayManagerInternal {
     public abstract void onPresentation(int displayId, boolean isShown);
 
     /**
+     * Called upon the usage of stylus.
+     */
+    public abstract void stylusGestureStarted(long eventTime);
+
+    /**
      * Describes the requested power state of the display.
      *
      * This object is intended to describe the general characteristics of the
diff --git a/services/core/java/com/android/server/display/DisplayDeviceConfig.java b/services/core/java/com/android/server/display/DisplayDeviceConfig.java
index af9c9accb635..8d96ba93530b 100644
--- a/services/core/java/com/android/server/display/DisplayDeviceConfig.java
+++ b/services/core/java/com/android/server/display/DisplayDeviceConfig.java
@@ -377,6 +377,7 @@ import javax.xml.datatype.DatatypeConfigurationException;
  *              </point>
  *            </map>
  *          </luxToBrightnessMapping>
+ *          <idleStylusTimeoutMillis>10000</idleStylusTimeoutMillis>
  *      </autoBrightness>
  *
  *      <screenBrightnessRampFastDecrease>0.01</screenBrightnessRampFastDecrease>
@@ -708,6 +709,10 @@ public class DisplayDeviceConfig {
 
     private static final int KEEP_CURRENT_BRIGHTNESS = -1;
 
+    // The default value to 0 which will signify that the stylus usage immediately stopped
+    // after it was started. This will make the system behave as if the stylus was never used
+    private static final int DEFAULT_IDLE_STYLUS_TIMEOUT_MILLIS = 0;
+
     private final Context mContext;
 
     // The details of the ambient light sensor associated with this display.
@@ -754,6 +759,9 @@ public class DisplayDeviceConfig {
     @Nullable
     private DisplayBrightnessMappingConfig mDisplayBrightnessMapping;
 
+    private int mIdleStylusTimeoutMillis =
+            DEFAULT_IDLE_STYLUS_TIMEOUT_MILLIS;
+
     private float mBacklightMinimum = Float.NaN;
     private float mBacklightMaximum = Float.NaN;
     private float mBrightnessDefault = Float.NaN;
@@ -1730,6 +1738,7 @@ public class DisplayDeviceConfig {
                 + ", mDisplayBrightnessMapping= " + mDisplayBrightnessMapping
                 + ", mDdcAutoBrightnessAvailable= " + mDdcAutoBrightnessAvailable
                 + ", mAutoBrightnessAvailable= " + mAutoBrightnessAvailable
+                + ", mIdleStylusTimeoutMillis= " + mIdleStylusTimeoutMillis
                 + "\n"
                 + "mDefaultLowBlockingZoneRefreshRate= " + mDefaultLowBlockingZoneRefreshRate
                 + ", mDefaultHighBlockingZoneRefreshRate= " + mDefaultHighBlockingZoneRefreshRate
@@ -2389,10 +2398,19 @@ public class DisplayDeviceConfig {
         loadAutoBrightnessDarkeningLightDebounceIdle(autoBrightness);
         mDisplayBrightnessMapping = new DisplayBrightnessMappingConfig(mContext, mFlags,
                 autoBrightness, getBacklightToBrightnessSpline());
+        loadIdleStylusTimeoutMillis(autoBrightness);
         loadEnableAutoBrightness(autoBrightness);
     }
 
     /**
+     * Gets the timeout post the stylus usage after which the automatic brightness will be enabled
+     * again
+     */
+    public int getIdleStylusTimeoutMillis() {
+        return mIdleStylusTimeoutMillis;
+    }
+
+    /**
      * Loads the auto-brightness brightening light debounce. Internally, this takes care of loading
      * the value from the display config, and if not present, falls back to config.xml.
      */
@@ -2923,6 +2941,16 @@ public class DisplayDeviceConfig {
         return levels;
     }
 
+    private void loadIdleStylusTimeoutMillis(AutoBrightness autoBrightness) {
+        if (autoBrightness == null) {
+            return;
+        }
+        BigInteger idleStylusTimeoutMillis = autoBrightness.getIdleStylusTimeoutMillis();
+        if (idleStylusTimeoutMillis != null) {
+            mIdleStylusTimeoutMillis = idleStylusTimeoutMillis.intValue();
+        }
+    }
+
     private void loadEnableAutoBrightness(AutoBrightness autobrightness) {
         // mDdcAutoBrightnessAvailable is initialised to true, so that we fallback to using the
         // config.xml values if the autobrightness tag is not defined in the ddc file.
diff --git a/services/core/java/com/android/server/display/DisplayManagerService.java b/services/core/java/com/android/server/display/DisplayManagerService.java
index 4152ec9e26e3..e27df24350e6 100644
--- a/services/core/java/com/android/server/display/DisplayManagerService.java
+++ b/services/core/java/com/android/server/display/DisplayManagerService.java
@@ -5648,6 +5648,21 @@ public final class DisplayManagerService extends SystemService {
         public void onPresentation(int displayId, boolean isShown) {
             mExternalDisplayPolicy.onPresentation(displayId, isShown);
         }
+
+        @Override
+        public void stylusGestureStarted(long eventTime) {
+            if (mFlags.isBlockAutobrightnessChangesOnStylusUsage()) {
+                DisplayPowerController displayPowerController;
+                synchronized (mSyncRoot) {
+                    displayPowerController = mDisplayPowerControllers.get(
+                            Display.DEFAULT_DISPLAY);
+                }
+                // We assume that the stylus is being used on the default display. This should
+                // be changed to the displayId on which it is being used once we start getting this
+                // information from the input manager service
+                displayPowerController.stylusGestureStarted(eventTime);
+            }
+        }
     }
 
     class DesiredDisplayModeSpecsObserver
diff --git a/services/core/java/com/android/server/display/DisplayPowerController.java b/services/core/java/com/android/server/display/DisplayPowerController.java
index 03fec0115613..8f07bb37e2ff 100644
--- a/services/core/java/com/android/server/display/DisplayPowerController.java
+++ b/services/core/java/com/android/server/display/DisplayPowerController.java
@@ -167,12 +167,11 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
     private static final int MSG_SET_DWBC_LOGGING_ENABLED = 16;
     private static final int MSG_SET_BRIGHTNESS_FROM_OFFLOAD = 17;
     private static final int MSG_OFFLOADING_SCREEN_ON_UNBLOCKED = 18;
-
-
+    private static final int MSG_SET_STYLUS_BEING_USED = 19;
+    private static final int MSG_SET_STYLUS_USE_ENDED = 20;
 
     private static final int BRIGHTNESS_CHANGE_STATSD_REPORT_INTERVAL_MS = 500;
 
-
     // State machine constants for tracking initial brightness ramp skipping when enabled.
     private static final int RAMP_STATE_SKIP_NONE = 0;
     private static final int RAMP_STATE_SKIP_INITIAL = 1;
@@ -191,6 +190,10 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
         0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80,
         90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1200,
         1400, 1600, 1800, 2000, 2250, 2500, 2750, 3000};
+
+    private static final int STYLUS_USAGE_DEBOUNCE_TIME  = 1000;
+    private static final int NANO_SECONDS_TO_MILLI_SECONDS_RATIO  = 1_000_000;
+
     private static final int[] BRIGHTNESS_RANGE_INDEX = {
         FrameworkStatsLog.DISPLAY_BRIGHTNESS_CHANGED__BUCKET_INDEX__RANGE_UNKNOWN,
         FrameworkStatsLog.DISPLAY_BRIGHTNESS_CHANGED__BUCKET_INDEX__RANGE_0_1,
@@ -498,6 +501,11 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
     @GuardedBy("mLock")
     private int mPendingOverrideDozeScreenStateLocked;
 
+    private long mLastStylusUsageEventTime = -1;
+
+    // The time of inactivity after which the stylus can be assumed to be no longer in use.
+    private long mIdleStylusTimeoutMillisConfig = 0;
+
     /**
      * Creates the display power controller.
      */
@@ -518,6 +526,7 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
         mSensorManager = sensorManager;
         mHandler = new DisplayControllerHandler(handler.getLooper());
         mDisplayDeviceConfig = mDisplayDevice.getDisplayDeviceConfig();
+        mIdleStylusTimeoutMillisConfig = mDisplayDeviceConfig.getIdleStylusTimeoutMillis();
         mIsEnabled = logicalDisplay.isEnabledLocked();
         mIsInTransition = logicalDisplay.isInTransitionLocked();
         mIsDisplayInternal = displayDeviceInfo.type == Display.TYPE_INTERNAL;
@@ -893,6 +902,7 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
                 mPhysicalDisplayName = displayName;
                 mDisplayStatsId = mUniqueDisplayId.hashCode();
                 mDisplayDeviceConfig = config;
+                mIdleStylusTimeoutMillisConfig = mDisplayDeviceConfig.getIdleStylusTimeoutMillis();
                 mThermalBrightnessThrottlingDataId = thermalBrightnessThrottlingDataId;
                 loadFromDisplayDeviceConfig(token, info, hbmMetadata);
                 mDisplayPowerProximityStateController.notifyDisplayDeviceChanged(config);
@@ -2971,6 +2981,18 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
         return mDisplayId == Display.DEFAULT_DISPLAY || mBootCompleted;
     }
 
+    public void stylusGestureStarted(long eventTimeNanoSeconds) {
+        long eventTimeMs = eventTimeNanoSeconds / NANO_SECONDS_TO_MILLI_SECONDS_RATIO;
+        if (mLastStylusUsageEventTime == -1
+                || eventTimeMs > mLastStylusUsageEventTime + STYLUS_USAGE_DEBOUNCE_TIME) {
+            synchronized (mLock) {
+                // Add a message to notify the stylus usage has started
+                mHandler.sendEmptyMessageAtTime(MSG_SET_STYLUS_BEING_USED, mClock.uptimeMillis());
+            }
+            mLastStylusUsageEventTime = eventTimeMs;
+        }
+    }
+
     private final class DisplayControllerHandler extends Handler {
         DisplayControllerHandler(Looper looper) {
             super(looper, null, true /*async*/);
@@ -3087,6 +3109,20 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
                         updatePowerState();
                     }
                     break;
+                case MSG_SET_STYLUS_BEING_USED:
+                    // Remove any MSG_SET_STYLUS_USE_ENDED message from the handler queue and
+                    // post a delayed MSG_SET_STYLUS_USE_ENDED message to delay the stylus
+                    // usage ended event processing
+                    mHandler.removeMessages(MSG_SET_STYLUS_USE_ENDED);
+                    Message message = mHandler.obtainMessage(MSG_SET_STYLUS_USE_ENDED);
+                    mHandler.sendMessageAtTime(message,
+                            mClock.uptimeMillis() + mIdleStylusTimeoutMillisConfig);
+                    mDisplayBrightnessController.setStylusBeingUsed(true);
+                    break;
+                case MSG_SET_STYLUS_USE_ENDED:
+                    mDisplayBrightnessController.setStylusBeingUsed(false);
+                    updatePowerState();
+                    break;
             }
         }
     }
diff --git a/services/core/java/com/android/server/display/brightness/DisplayBrightnessController.java b/services/core/java/com/android/server/display/brightness/DisplayBrightnessController.java
index 72a91d59c911..71fdaf3f85b6 100644
--- a/services/core/java/com/android/server/display/brightness/DisplayBrightnessController.java
+++ b/services/core/java/com/android/server/display/brightness/DisplayBrightnessController.java
@@ -501,6 +501,13 @@ public final class DisplayBrightnessController {
         return true;
     }
 
+    /**
+     * Notifies if the stylus is currently being used or not.
+     */
+    public void setStylusBeingUsed(boolean isEnabled) {
+        // Todo(b/369977976) - Disable the auto-brightness strategy
+    }
+
     @VisibleForTesting
     static class Injector {
         DisplayBrightnessStrategySelector getDisplayBrightnessStrategySelector(Context context,
diff --git a/services/core/java/com/android/server/display/feature/DisplayManagerFlags.java b/services/core/java/com/android/server/display/feature/DisplayManagerFlags.java
index df66893a2f35..5284d1c423f6 100644
--- a/services/core/java/com/android/server/display/feature/DisplayManagerFlags.java
+++ b/services/core/java/com/android/server/display/feature/DisplayManagerFlags.java
@@ -203,6 +203,10 @@ public class DisplayManagerFlags {
             Flags.FLAG_NORMAL_BRIGHTNESS_FOR_DOZE_PARAMETER,
             Flags::normalBrightnessForDozeParameter
     );
+    private final FlagState mBlockAutobrightnessChangesOnStylusUsage = new FlagState(
+            Flags.FLAG_BLOCK_AUTOBRIGHTNESS_CHANGES_ON_STYLUS_USAGE,
+            Flags::blockAutobrightnessChangesOnStylusUsage
+    );
 
     private final FlagState mEnableBatteryStatsForAllDisplays = new FlagState(
             Flags.FLAG_ENABLE_BATTERY_STATS_FOR_ALL_DISPLAYS,
@@ -436,6 +440,13 @@ public class DisplayManagerFlags {
     }
 
     /**
+     * @return {@code true} if autobrightness is to be blocked when stylus is being used
+     */
+    public boolean isBlockAutobrightnessChangesOnStylusUsage() {
+        return mBlockAutobrightnessChangesOnStylusUsage.isEnabled();
+    }
+
+    /**
      * dumps all flagstates
      * @param pw printWriter
      */
@@ -479,6 +490,7 @@ public class DisplayManagerFlags {
         pw.println(" " + mNormalBrightnessForDozeParameter);
         pw.println(" " + mIdleScreenConfigInSubscribingLightSensor);
         pw.println(" " + mEnableBatteryStatsForAllDisplays);
+        pw.println(" " + mBlockAutobrightnessChangesOnStylusUsage);
     }
 
     private static class FlagState {
diff --git a/services/core/java/com/android/server/display/feature/display_flags.aconfig b/services/core/java/com/android/server/display/feature/display_flags.aconfig
index e3ebe5bcd9ed..252ed09fd125 100644
--- a/services/core/java/com/android/server/display/feature/display_flags.aconfig
+++ b/services/core/java/com/android/server/display/feature/display_flags.aconfig
@@ -364,4 +364,12 @@ flag {
     description: "Flag to enable battery stats for all displays."
     bug: "366112793"
     is_fixed_read_only: true
-}
\ No newline at end of file
+}
+
+flag {
+    name: "block_autobrightness_changes_on_stylus_usage"
+    namespace: "display_manager"
+    description: "Block the usage of ALS to control the display brightness when stylus is being used"
+    bug: "352411468"
+    is_fixed_read_only: true
+}
diff --git a/services/core/java/com/android/server/input/InputManagerService.java b/services/core/java/com/android/server/input/InputManagerService.java
index f04557665477..8acf583e0765 100644
--- a/services/core/java/com/android/server/input/InputManagerService.java
+++ b/services/core/java/com/android/server/input/InputManagerService.java
@@ -2694,6 +2694,9 @@ public class InputManagerService extends IInputManager.Stub
     @SuppressWarnings("unused")
     private void notifyStylusGestureStarted(int deviceId, long eventTime) {
         mBatteryController.notifyStylusGestureStarted(deviceId, eventTime);
+        if (mDisplayManagerInternal != null) {
+            mDisplayManagerInternal.stylusGestureStarted(eventTime);
+        }
     }
 
     /**
diff --git a/services/core/xsd/display-device-config/display-device-config.xsd b/services/core/xsd/display-device-config/display-device-config.xsd
index a07facf79423..776de2e52061 100644
--- a/services/core/xsd/display-device-config/display-device-config.xsd
+++ b/services/core/xsd/display-device-config/display-device-config.xsd
@@ -712,6 +712,12 @@
                         minOccurs="0" maxOccurs="unbounded">
                 <xs:annotation name="final"/>
             </xs:element>
+            <!-- The time after which the stylus is to be assumed to be not under use. This will
+             enable the logic of changing the brightness with ambient light changes -->
+            <xs:element name="idleStylusTimeoutMillis" type="xs:nonNegativeInteger"
+                minOccurs="0" maxOccurs="1">
+                <xs:annotation name="final"/>
+            </xs:element>
         </xs:sequence>
     </xs:complexType>
 
diff --git a/services/core/xsd/display-device-config/schema/current.txt b/services/core/xsd/display-device-config/schema/current.txt
index 5309263ed87c..110a5a20da6a 100644
--- a/services/core/xsd/display-device-config/schema/current.txt
+++ b/services/core/xsd/display-device-config/schema/current.txt
@@ -8,12 +8,14 @@ package com.android.server.display.config {
     method public final java.math.BigInteger getDarkeningLightDebounceIdleMillis();
     method public final java.math.BigInteger getDarkeningLightDebounceMillis();
     method public boolean getEnabled();
+    method public final java.math.BigInteger getIdleStylusTimeoutMillis();
     method public final java.util.List<com.android.server.display.config.LuxToBrightnessMapping> getLuxToBrightnessMapping();
     method public final void setBrighteningLightDebounceIdleMillis(java.math.BigInteger);
     method public final void setBrighteningLightDebounceMillis(java.math.BigInteger);
     method public final void setDarkeningLightDebounceIdleMillis(java.math.BigInteger);
     method public final void setDarkeningLightDebounceMillis(java.math.BigInteger);
     method public void setEnabled(boolean);
+    method public final void setIdleStylusTimeoutMillis(java.math.BigInteger);
   }
 
   public enum AutoBrightnessModeName {
diff --git a/services/tests/displayservicetests/src/com/android/server/display/DisplayDeviceConfigTest.java b/services/tests/displayservicetests/src/com/android/server/display/DisplayDeviceConfigTest.java
index 8e1be9a777fd..3976ea4fc86e 100644
--- a/services/tests/displayservicetests/src/com/android/server/display/DisplayDeviceConfigTest.java
+++ b/services/tests/displayservicetests/src/com/android/server/display/DisplayDeviceConfigTest.java
@@ -157,6 +157,7 @@ public final class DisplayDeviceConfigTest {
                 .getIdleScreenRefreshRateTimeoutLuxThresholdPoint());
         assertNull(mDisplayDeviceConfig.getTempSensor().name);
         assertTrue(mDisplayDeviceConfig.isAutoBrightnessAvailable());
+        assertEquals(0, mDisplayDeviceConfig.getIdleStylusTimeoutMillis());
     }
 
     @Test
@@ -253,6 +254,7 @@ public final class DisplayDeviceConfigTest {
                 .getLux().intValue());
         assertEquals(800, idleScreenRefreshRateTimeoutLuxThresholdPoints.get(1)
                 .getTimeout().intValue());
+        assertEquals(1000, mDisplayDeviceConfig.getIdleStylusTimeoutMillis());
     }
 
     @Test
@@ -1479,6 +1481,7 @@ public final class DisplayDeviceConfigTest {
                 +               "</point>\n"
                 +           "</map>\n"
                 +       "</luxToBrightnessMapping>\n"
+                +       "<idleStylusTimeoutMillis>1000</idleStylusTimeoutMillis>\n"
                 +   "</autoBrightness>\n"
                 +  getPowerThrottlingConfig()
                 +   "<highBrightnessMode enabled=\"true\">\n"