Move LowLightMonitor operations to background thread.

LowLightMonitor contains a number of callbacks that are triggered by
events such as screen turning on and off (triggered during unfolding as
well). This changelist moves these operations to a background thread to
not block the main thread.

Test: atest LowLightMonitorTest
Flag: EXEMPT bugfix
Fixes: 394520234
Change-Id: I435c21e2c1e0827c8de24cd0737cfa55c1fab403

2 files changed, 73 insertions, 43 deletions

diff --git a/packages/SystemUI/tests/src/com/android/systemui/lowlightclock/LowLightMonitorTest.java b/packages/SystemUI/multivalentTests/src/com/android/systemui/lowlightclock/LowLightMonitorTest.java
index 69485e848a6a..b177e07d09b6 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/lowlightclock/LowLightMonitorTest.java
+++ b/packages/SystemUI/multivalentTests/src/com/android/systemui/lowlightclock/LowLightMonitorTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2024 The Android Open Source Project
+ * Copyright (C) 2025 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,8 +30,9 @@ import static org.mockito.Mockito.when;
 
 import android.content.ComponentName;
 import android.content.pm.PackageManager;
-import android.testing.AndroidTestingRunner;
+import android.testing.TestableLooper;
 
+import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.filters.SmallTest;
 
 import com.android.dream.lowlight.LowLightDreamManager;
@@ -39,6 +40,8 @@ import com.android.systemui.SysuiTestCase;
 import com.android.systemui.keyguard.ScreenLifecycle;
 import com.android.systemui.shared.condition.Condition;
 import com.android.systemui.shared.condition.Monitor;
+import com.android.systemui.util.concurrency.FakeExecutor;
+import com.android.systemui.util.time.FakeSystemClock;
 
 import dagger.Lazy;
 
@@ -53,7 +56,8 @@ import org.mockito.MockitoAnnotations;
 import java.util.Set;
 
 @SmallTest
-@RunWith(AndroidTestingRunner.class)
+@RunWith(AndroidJUnit4.class)
+@TestableLooper.RunWithLooper()
 public class LowLightMonitorTest extends SysuiTestCase {
 
     @Mock
@@ -78,6 +82,8 @@ public class LowLightMonitorTest extends SysuiTestCase {
     @Mock
     private ComponentName mDreamComponent;
 
+    FakeExecutor mBackgroundExecutor = new FakeExecutor(new FakeSystemClock());
+
     Condition mCondition = mock(Condition.class);
     Set<Condition> mConditionSet = Set.of(mCondition);
 
@@ -91,12 +97,13 @@ public class LowLightMonitorTest extends SysuiTestCase {
         when(mLazyConditions.get()).thenReturn(mConditionSet);
         mLowLightMonitor = new LowLightMonitor(mLowLightDreamManagerLazy,
             mMonitor, mLazyConditions, mScreenLifecycle, mLogger, mDreamComponent,
-                mPackageManager);
+                mPackageManager, mBackgroundExecutor);
     }
 
     @Test
     public void testSetAmbientLowLightWhenInLowLight() {
         mLowLightMonitor.onConditionsChanged(true);
+        mBackgroundExecutor.runAllReady();
         // Verify setting low light when condition is true
         verify(mLowLightDreamManager).setAmbientLightMode(AMBIENT_LIGHT_MODE_LOW_LIGHT);
     }
@@ -105,6 +112,7 @@ public class LowLightMonitorTest extends SysuiTestCase {
     public void testExitAmbientLowLightWhenNotInLowLight() {
         mLowLightMonitor.onConditionsChanged(true);
         mLowLightMonitor.onConditionsChanged(false);
+        mBackgroundExecutor.runAllReady();
         // Verify ambient light toggles back to light mode regular
         verify(mLowLightDreamManager).setAmbientLightMode(AMBIENT_LIGHT_MODE_REGULAR);
     }
@@ -112,6 +120,7 @@ public class LowLightMonitorTest extends SysuiTestCase {
     @Test
     public void testStartMonitorLowLightConditionsWhenScreenTurnsOn() {
         mLowLightMonitor.onScreenTurnedOn();
+        mBackgroundExecutor.runAllReady();
 
         // Verify subscribing to low light conditions monitor when screen turns on.
         verify(mMonitor).addSubscription(any());
@@ -125,6 +134,7 @@ public class LowLightMonitorTest extends SysuiTestCase {
 
         // Verify removing subscription when screen turns off.
         mLowLightMonitor.onScreenTurnedOff();
+        mBackgroundExecutor.runAllReady();
         verify(mMonitor).removeSubscription(token);
     }
 
@@ -135,6 +145,7 @@ public class LowLightMonitorTest extends SysuiTestCase {
 
         mLowLightMonitor.onScreenTurnedOn();
         mLowLightMonitor.onScreenTurnedOn();
+        mBackgroundExecutor.runAllReady();
         // Verify subscription is only added once.
         verify(mMonitor, times(1)).addSubscription(any());
     }
@@ -146,6 +157,7 @@ public class LowLightMonitorTest extends SysuiTestCase {
 
         mLowLightMonitor.onScreenTurnedOn();
         mLowLightMonitor.onScreenTurnedOn();
+        mBackgroundExecutor.runAllReady();
         Set<Condition> conditions = captureConditions();
         // Verify Monitor is subscribed to the expected conditions
         assertThat(conditions).isEqualTo(mConditionSet);
@@ -154,7 +166,7 @@ public class LowLightMonitorTest extends SysuiTestCase {
     @Test
     public void testNotUnsubscribeIfNotSubscribedWhenScreenTurnsOff() {
         mLowLightMonitor.onScreenTurnedOff();
-
+        mBackgroundExecutor.runAllReady();
         // Verify doesn't remove subscription since there is none.
         verify(mMonitor, never()).removeSubscription(any());
     }
@@ -163,6 +175,7 @@ public class LowLightMonitorTest extends SysuiTestCase {
     public void testSubscribeIfScreenIsOnWhenStarting() {
         when(mScreenLifecycle.getScreenState()).thenReturn(SCREEN_ON);
         mLowLightMonitor.start();
+        mBackgroundExecutor.runAllReady();
         // Verify to add subscription on start if the screen state is on
         verify(mMonitor, times(1)).addSubscription(any());
     }
@@ -170,9 +183,11 @@ public class LowLightMonitorTest extends SysuiTestCase {
     @Test
     public void testNoSubscribeIfDreamNotPresent() {
         LowLightMonitor lowLightMonitor = new LowLightMonitor(mLowLightDreamManagerLazy,
-                mMonitor, mLazyConditions, mScreenLifecycle, mLogger, null, mPackageManager);
+                mMonitor, mLazyConditions, mScreenLifecycle, mLogger, null, mPackageManager,
+                mBackgroundExecutor);
         when(mScreenLifecycle.getScreenState()).thenReturn(SCREEN_ON);
         lowLightMonitor.start();
+        mBackgroundExecutor.runAllReady();
         verify(mScreenLifecycle, never()).addObserver(any());
     }
 
diff --git a/packages/SystemUI/src/com/android/systemui/lowlightclock/LowLightMonitor.java b/packages/SystemUI/src/com/android/systemui/lowlightclock/LowLightMonitor.java
index 912ace7675d5..e5eec64ac615 100644
--- a/packages/SystemUI/src/com/android/systemui/lowlightclock/LowLightMonitor.java
+++ b/packages/SystemUI/src/com/android/systemui/lowlightclock/LowLightMonitor.java
@@ -27,6 +27,7 @@ import android.content.pm.PackageManager;
 import androidx.annotation.Nullable;
 
 import com.android.dream.lowlight.LowLightDreamManager;
+import com.android.systemui.dagger.qualifiers.Background;
 import com.android.systemui.dagger.qualifiers.SystemUser;
 import com.android.systemui.keyguard.ScreenLifecycle;
 import com.android.systemui.shared.condition.Condition;
@@ -36,6 +37,7 @@ import com.android.systemui.util.condition.ConditionalCoreStartable;
 import dagger.Lazy;
 
 import java.util.Set;
+import java.util.concurrent.Executor;
 
 import javax.inject.Inject;
 import javax.inject.Named;
@@ -59,6 +61,8 @@ public class LowLightMonitor extends ConditionalCoreStartable implements Monitor
 
     private final PackageManager mPackageManager;
 
+    private final Executor mExecutor;
+
     @Inject
     public LowLightMonitor(Lazy<LowLightDreamManager> lowLightDreamManager,
             @SystemUser Monitor conditionsMonitor,
@@ -66,7 +70,8 @@ public class LowLightMonitor extends ConditionalCoreStartable implements Monitor
             ScreenLifecycle screenLifecycle,
             LowLightLogger lowLightLogger,
             @Nullable @Named(LOW_LIGHT_DREAM_SERVICE) ComponentName lowLightDreamService,
-            PackageManager packageManager) {
+            PackageManager packageManager,
+            @Background Executor backgroundExecutor) {
         super(conditionsMonitor);
         mLowLightDreamManager = lowLightDreamManager;
         mConditionsMonitor = conditionsMonitor;
@@ -75,59 +80,69 @@ public class LowLightMonitor extends ConditionalCoreStartable implements Monitor
         mLogger = lowLightLogger;
         mLowLightDreamService = lowLightDreamService;
         mPackageManager = packageManager;
+        mExecutor = backgroundExecutor;
     }
 
     @Override
     public void onConditionsChanged(boolean allConditionsMet) {
-        mLogger.d(TAG, "Low light enabled: " + allConditionsMet);
+        mExecutor.execute(() -> {
+            mLogger.d(TAG, "Low light enabled: " + allConditionsMet);
 
-        mLowLightDreamManager.get().setAmbientLightMode(allConditionsMet
-                ? AMBIENT_LIGHT_MODE_LOW_LIGHT : AMBIENT_LIGHT_MODE_REGULAR);
+            mLowLightDreamManager.get().setAmbientLightMode(allConditionsMet
+                    ? AMBIENT_LIGHT_MODE_LOW_LIGHT : AMBIENT_LIGHT_MODE_REGULAR);
+        });
     }
 
     @Override
     public void onScreenTurnedOn() {
-        if (mSubscriptionToken == null) {
-            mLogger.d(TAG, "Screen turned on. Subscribing to low light conditions.");
-
-            mSubscriptionToken = mConditionsMonitor.addSubscription(
-                new Monitor.Subscription.Builder(this)
-                    .addConditions(mLowLightConditions.get())
-                    .build());
-        }
+        mExecutor.execute(() -> {
+            if (mSubscriptionToken == null) {
+                mLogger.d(TAG, "Screen turned on. Subscribing to low light conditions.");
+
+                mSubscriptionToken = mConditionsMonitor.addSubscription(
+                        new Monitor.Subscription.Builder(this)
+                                .addConditions(mLowLightConditions.get())
+                                .build());
+            }
+        });
     }
 
 
     @Override
     public void onScreenTurnedOff() {
-        if (mSubscriptionToken != null) {
-            mLogger.d(TAG, "Screen turned off. Removing subscription to low light conditions.");
-
-            mConditionsMonitor.removeSubscription(mSubscriptionToken);
-            mSubscriptionToken = null;
-        }
+        mExecutor.execute(() -> {
+            if (mSubscriptionToken != null) {
+                mLogger.d(TAG, "Screen turned off. Removing subscription to low light conditions.");
+
+                mConditionsMonitor.removeSubscription(mSubscriptionToken);
+                mSubscriptionToken = null;
+            }
+        });
     }
 
     @Override
     protected void onStart() {
-        if (mLowLightDreamService != null) {
-            // Note that the dream service is disabled by default. This prevents the dream from
-            // appearing in settings on devices that don't have it explicitly excluded (done in
-            // the settings overlay). Therefore, the component is enabled if it is to be used
-            // here.
-            mPackageManager.setComponentEnabledSetting(
-                    mLowLightDreamService,
-                    PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
-                    PackageManager.DONT_KILL_APP
-            );
-        } else {
-            // If there is no low light dream service, do not observe conditions.
-            return;
-        }
-
-        mScreenLifecycle.addObserver(this);
-        if (mScreenLifecycle.getScreenState() == SCREEN_ON) {
-            onScreenTurnedOn();
-        }
+        mExecutor.execute(() -> {
+            if (mLowLightDreamService != null) {
+                // Note that the dream service is disabled by default. This prevents the dream from
+                // appearing in settings on devices that don't have it explicitly excluded (done in
+                // the settings overlay). Therefore, the component is enabled if it is to be used
+                // here.
+                mPackageManager.setComponentEnabledSetting(
+                        mLowLightDreamService,
+                        PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
+                        PackageManager.DONT_KILL_APP
+                );
+            } else {
+                // If there is no low light dream service, do not observe conditions.
+                return;
+            }
+
+            mScreenLifecycle.addObserver(this);
+            if (mScreenLifecycle.getScreenState() == SCREEN_ON) {
+                onScreenTurnedOn();
+            }
+        });
+
     }
 }