diff --git a/libs/dream/lowlight/Android.bp b/libs/dream/lowlight/Android.bp
new file mode 100644
index 0000000000000..5b5b0f07cabdc
--- /dev/null
+++ b/libs/dream/lowlight/Android.bp
@@ -0,0 +1,47 @@
+// Copyright (C) 2022 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.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package {
+ // See: http://go/android-license-faq
+ // A large-scale-change added 'default_applicable_licenses' to import
+ // all of the 'license_kinds' from "frameworks_base_license"
+ // to get the below license kinds:
+ // SPDX-license-identifier-Apache-2.0
+ default_applicable_licenses: ["frameworks_base_license"],
+}
+
+filegroup {
+ name: "low_light_dream_lib-sources",
+ srcs: [
+ "src/**/*.java",
+ ],
+ path: "src",
+}
+
+android_library {
+ name: "LowLightDreamLib",
+ srcs: [
+ ":low_light_dream_lib-sources",
+ ],
+ resource_dirs: [
+ "res",
+ ],
+ static_libs: [
+ "androidx.arch.core_core-runtime",
+ "dagger2",
+ "jsr330",
+ ],
+ manifest: "AndroidManifest.xml",
+ plugins: ["dagger2-compiler"],
+}
diff --git a/libs/dream/lowlight/AndroidManifest.xml b/libs/dream/lowlight/AndroidManifest.xml
new file mode 100644
index 0000000000000..a8d9526999431
--- /dev/null
+++ b/libs/dream/lowlight/AndroidManifest.xml
@@ -0,0 +1,18 @@
+
+
+
+
diff --git a/libs/dream/lowlight/res/values/config.xml b/libs/dream/lowlight/res/values/config.xml
new file mode 100644
index 0000000000000..70fe0738a6f41
--- /dev/null
+++ b/libs/dream/lowlight/res/values/config.xml
@@ -0,0 +1,20 @@
+
+
+
+
+
+
diff --git a/libs/dream/lowlight/src/com/android/dream/lowlight/LowLightDreamManager.java b/libs/dream/lowlight/src/com/android/dream/lowlight/LowLightDreamManager.java
new file mode 100644
index 0000000000000..5ecec4ddd1adf
--- /dev/null
+++ b/libs/dream/lowlight/src/com/android/dream/lowlight/LowLightDreamManager.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2022 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.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.dream.lowlight;
+
+import static com.android.dream.lowlight.dagger.LowLightDreamModule.LOW_LIGHT_DREAM_COMPONENT;
+
+import android.annotation.IntDef;
+import android.annotation.RequiresPermission;
+import android.app.DreamManager;
+import android.content.ComponentName;
+import android.util.Log;
+
+import androidx.annotation.Nullable;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+import javax.inject.Inject;
+import javax.inject.Named;
+
+/**
+ * Maintains the ambient light mode of the environment the device is in, and sets a low light dream
+ * component, if present, as the system dream when the ambient light mode is low light.
+ *
+ * @hide
+ */
+public final class LowLightDreamManager {
+ private static final String TAG = "LowLightDreamManager";
+ private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
+
+ /**
+ * @hide
+ */
+ @Retention(RetentionPolicy.SOURCE)
+ @IntDef(prefix = { "AMBIENT_LIGHT_MODE_" }, value = {
+ AMBIENT_LIGHT_MODE_UNKNOWN,
+ AMBIENT_LIGHT_MODE_REGULAR,
+ AMBIENT_LIGHT_MODE_LOW_LIGHT
+ })
+ public @interface AmbientLightMode {}
+
+ /**
+ * Constant for ambient light mode being unknown.
+ * @hide
+ */
+ public static final int AMBIENT_LIGHT_MODE_UNKNOWN = 0;
+
+ /**
+ * Constant for ambient light mode being regular / bright.
+ * @hide
+ */
+ public static final int AMBIENT_LIGHT_MODE_REGULAR = 1;
+
+ /**
+ * Constant for ambient light mode being low light / dim.
+ * @hide
+ */
+ public static final int AMBIENT_LIGHT_MODE_LOW_LIGHT = 2;
+
+ private final DreamManager mDreamManager;
+
+ @Nullable
+ private final ComponentName mLowLightDreamComponent;
+
+ private int mAmbientLightMode = AMBIENT_LIGHT_MODE_UNKNOWN;
+
+ @Inject
+ public LowLightDreamManager(
+ DreamManager dreamManager,
+ @Named(LOW_LIGHT_DREAM_COMPONENT) @Nullable ComponentName lowLightDreamComponent) {
+ mDreamManager = dreamManager;
+ mLowLightDreamComponent = lowLightDreamComponent;
+ }
+
+ /**
+ * Sets the current ambient light mode.
+ * @hide
+ */
+ @RequiresPermission(android.Manifest.permission.WRITE_DREAM_STATE)
+ public void setAmbientLightMode(@AmbientLightMode int ambientLightMode) {
+ if (mLowLightDreamComponent == null) {
+ if (DEBUG) {
+ Log.d(TAG, "ignore ambient light mode change because low light dream component "
+ + "is empty");
+ }
+ return;
+ }
+
+ if (mAmbientLightMode == ambientLightMode) {
+ return;
+ }
+
+ if (DEBUG) {
+ Log.d(TAG, "ambient light mode changed from " + mAmbientLightMode + " to "
+ + ambientLightMode);
+ }
+
+ mAmbientLightMode = ambientLightMode;
+
+ mDreamManager.setSystemDreamComponent(mAmbientLightMode == AMBIENT_LIGHT_MODE_LOW_LIGHT
+ ? mLowLightDreamComponent : null);
+ }
+}
diff --git a/libs/dream/lowlight/src/com/android/dream/lowlight/dagger/LowLightDreamModule.java b/libs/dream/lowlight/src/com/android/dream/lowlight/dagger/LowLightDreamModule.java
new file mode 100644
index 0000000000000..c183a04cb2f9b
--- /dev/null
+++ b/libs/dream/lowlight/src/com/android/dream/lowlight/dagger/LowLightDreamModule.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2022 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.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.dream.lowlight.dagger;
+
+import android.app.DreamManager;
+import android.content.ComponentName;
+import android.content.Context;
+
+import androidx.annotation.Nullable;
+
+import com.android.dream.lowlight.R;
+
+import javax.inject.Named;
+
+import dagger.Module;
+import dagger.Provides;
+
+/**
+ * Dagger module for low light dream.
+ *
+ * @hide
+ */
+@Module
+public interface LowLightDreamModule {
+ String LOW_LIGHT_DREAM_COMPONENT = "low_light_dream_component";
+
+ /**
+ * Provides dream manager.
+ */
+ @Provides
+ static DreamManager providesDreamManager(Context context) {
+ return context.getSystemService(DreamManager.class);
+ }
+
+ /**
+ * Provides the component name of the low light dream, or null if not configured.
+ */
+ @Provides
+ @Named(LOW_LIGHT_DREAM_COMPONENT)
+ @Nullable
+ static ComponentName providesLowLightDreamComponent(Context context) {
+ final String lowLightDreamComponent = context.getResources().getString(
+ R.string.config_lowLightDreamComponent);
+ return lowLightDreamComponent.isEmpty() ? null
+ : ComponentName.unflattenFromString(lowLightDreamComponent);
+ }
+}
diff --git a/libs/dream/lowlight/tests/Android.bp b/libs/dream/lowlight/tests/Android.bp
new file mode 100644
index 0000000000000..bd6f05eabac5c
--- /dev/null
+++ b/libs/dream/lowlight/tests/Android.bp
@@ -0,0 +1,45 @@
+// Copyright (C) 2022 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.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package {
+ default_applicable_licenses: ["frameworks_base_license"],
+}
+
+android_test {
+ name: "LowLightDreamTests",
+ srcs: [
+ "**/*.java",
+ ],
+ static_libs: [
+ "LowLightDreamLib",
+ "androidx.test.runner",
+ "androidx.test.rules",
+ "androidx.test.ext.junit",
+ "frameworks-base-testutils",
+ "junit",
+ "mockito-target-extended-minus-junit4",
+ "platform-test-annotations",
+ "testables",
+ "truth-prebuilt",
+ ],
+ libs: [
+ "android.test.mock",
+ "android.test.base",
+ "android.test.runner",
+ ],
+ jni_libs: [
+ "libdexmakerjvmtiagent",
+ "libstaticjvmtiagent",
+ ],
+}
diff --git a/libs/dream/lowlight/tests/AndroidManifest.xml b/libs/dream/lowlight/tests/AndroidManifest.xml
new file mode 100644
index 0000000000000..abb71fb53b49e
--- /dev/null
+++ b/libs/dream/lowlight/tests/AndroidManifest.xml
@@ -0,0 +1,33 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/libs/dream/lowlight/tests/AndroidTest.xml b/libs/dream/lowlight/tests/AndroidTest.xml
new file mode 100644
index 0000000000000..10800333add29
--- /dev/null
+++ b/libs/dream/lowlight/tests/AndroidTest.xml
@@ -0,0 +1,31 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/libs/dream/lowlight/tests/src/com.android.dream.lowlight/LowLightDreamManagerTest.java b/libs/dream/lowlight/tests/src/com.android.dream.lowlight/LowLightDreamManagerTest.java
new file mode 100644
index 0000000000000..91a170f7ae143
--- /dev/null
+++ b/libs/dream/lowlight/tests/src/com.android.dream.lowlight/LowLightDreamManagerTest.java
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2022 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.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.dream.lowlight;
+
+import static com.android.dream.lowlight.LowLightDreamManager.AMBIENT_LIGHT_MODE_LOW_LIGHT;
+import static com.android.dream.lowlight.LowLightDreamManager.AMBIENT_LIGHT_MODE_REGULAR;
+import static com.android.dream.lowlight.LowLightDreamManager.AMBIENT_LIGHT_MODE_UNKNOWN;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.clearInvocations;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import android.app.DreamManager;
+import android.content.ComponentName;
+import android.testing.AndroidTestingRunner;
+
+import androidx.test.filters.SmallTest;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+@SmallTest
+@RunWith(AndroidTestingRunner.class)
+public class LowLightDreamManagerTest {
+ @Mock
+ private DreamManager mDreamManager;
+
+ @Mock
+ private ComponentName mDreamComponent;
+
+ @Before
+ public void setUp() {
+ MockitoAnnotations.initMocks(this);
+ }
+
+ @Test
+ public void setAmbientLightMode_lowLight_setSystemDream() {
+ final LowLightDreamManager lowLightDreamManager = new LowLightDreamManager(mDreamManager,
+ mDreamComponent);
+
+ lowLightDreamManager.setAmbientLightMode(AMBIENT_LIGHT_MODE_LOW_LIGHT);
+
+ verify(mDreamManager).setSystemDreamComponent(mDreamComponent);
+ }
+
+ @Test
+ public void setAmbientLightMode_regularLight_clearSystemDream() {
+ final LowLightDreamManager lowLightDreamManager = new LowLightDreamManager(mDreamManager,
+ mDreamComponent);
+
+ lowLightDreamManager.setAmbientLightMode(AMBIENT_LIGHT_MODE_REGULAR);
+
+ verify(mDreamManager).setSystemDreamComponent(null);
+ }
+
+ @Test
+ public void setAmbientLightMode_defaultUnknownMode_clearSystemDream() {
+ final LowLightDreamManager lowLightDreamManager = new LowLightDreamManager(mDreamManager,
+ mDreamComponent);
+
+ // Set to low light first.
+ lowLightDreamManager.setAmbientLightMode(AMBIENT_LIGHT_MODE_LOW_LIGHT);
+ clearInvocations(mDreamManager);
+
+ // Return to default unknown mode.
+ lowLightDreamManager.setAmbientLightMode(AMBIENT_LIGHT_MODE_UNKNOWN);
+
+ verify(mDreamManager).setSystemDreamComponent(null);
+ }
+
+ @Test
+ public void setAmbientLightMode_dreamComponentNotSet_doNothing() {
+ final LowLightDreamManager lowLightDreamManager = new LowLightDreamManager(mDreamManager,
+ null /*dream component*/);
+
+ lowLightDreamManager.setAmbientLightMode(AMBIENT_LIGHT_MODE_LOW_LIGHT);
+
+ verify(mDreamManager, never()).setSystemDreamComponent(any());
+ }
+}