Merge "Implement the V2 notification minimalism prototype" into main
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinatorTest.java b/packages/SystemUI/multivalentTests/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinatorTest.java
similarity index 98%
rename from packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinatorTest.java
rename to packages/SystemUI/multivalentTests/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinatorTest.java
index 50ae985..ce134e6 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinatorTest.java
+++ b/packages/SystemUI/multivalentTests/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinatorTest.java
@@ -31,9 +31,9 @@
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
-import android.testing.AndroidTestingRunner;
 import android.testing.TestableLooper;
 
+import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.filters.SmallTest;
 
 import com.android.compose.animation.scene.ObservableTransitionState;
@@ -57,6 +57,7 @@
 import com.android.systemui.statusbar.notification.collection.listbuilder.pluggable.NotifStabilityManager;
 import com.android.systemui.statusbar.notification.collection.listbuilder.pluggable.Pluggable;
 import com.android.systemui.statusbar.notification.collection.provider.VisualStabilityProvider;
+import com.android.systemui.statusbar.notification.domain.interactor.SeenNotificationsInteractor;
 import com.android.systemui.statusbar.policy.HeadsUpManager;
 import com.android.systemui.util.concurrency.FakeExecutor;
 import com.android.systemui.util.kotlin.JavaAdapter;
@@ -75,7 +76,7 @@
 import org.mockito.verification.VerificationMode;
 
 @SmallTest
-@RunWith(AndroidTestingRunner.class)
+@RunWith(AndroidJUnit4.class)
 @TestableLooper.RunWithLooper
 public class VisualStabilityCoordinatorTest extends SysuiTestCase {
 
@@ -86,6 +87,7 @@
     @Mock private WakefulnessLifecycle mWakefulnessLifecycle;
     @Mock private StatusBarStateController mStatusBarStateController;
     @Mock private Pluggable.PluggableListener<NotifStabilityManager> mInvalidateListener;
+    @Mock private SeenNotificationsInteractor mSeenNotificationsInteractor;
     @Mock private HeadsUpManager mHeadsUpManager;
     @Mock private VisibilityLocationProvider mVisibilityLocationProvider;
     @Mock private VisualStabilityProvider mVisualStabilityProvider;
@@ -121,6 +123,7 @@
                 mHeadsUpManager,
                 mShadeAnimationInteractor,
                 mJavaAdapter,
+                mSeenNotificationsInteractor,
                 mStatusBarStateController,
                 mVisibilityLocationProvider,
                 mVisualStabilityProvider,
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/KeyguardCoordinator.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/KeyguardCoordinator.kt
index 933eb20..42bf4e7 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/KeyguardCoordinator.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/KeyguardCoordinator.kt
@@ -31,15 +31,20 @@
 import com.android.systemui.plugins.statusbar.StatusBarStateController
 import com.android.systemui.statusbar.StatusBarState
 import com.android.systemui.statusbar.expansionChanges
+import com.android.systemui.statusbar.notification.collection.GroupEntry
+import com.android.systemui.statusbar.notification.collection.ListEntry
 import com.android.systemui.statusbar.notification.collection.NotifPipeline
 import com.android.systemui.statusbar.notification.collection.NotificationEntry
 import com.android.systemui.statusbar.notification.collection.coordinator.dagger.CoordinatorScope
 import com.android.systemui.statusbar.notification.collection.listbuilder.pluggable.NotifFilter
+import com.android.systemui.statusbar.notification.collection.listbuilder.pluggable.NotifPromoter
+import com.android.systemui.statusbar.notification.collection.listbuilder.pluggable.NotifSectioner
 import com.android.systemui.statusbar.notification.collection.notifcollection.NotifCollectionListener
 import com.android.systemui.statusbar.notification.collection.provider.SectionHeaderVisibilityProvider
 import com.android.systemui.statusbar.notification.domain.interactor.SeenNotificationsInteractor
 import com.android.systemui.statusbar.notification.interruption.KeyguardNotificationVisibilityProvider
 import com.android.systemui.statusbar.notification.shared.NotificationMinimalismPrototype
+import com.android.systemui.statusbar.notification.stack.BUCKET_FOREGROUND_SERVICE
 import com.android.systemui.statusbar.policy.HeadsUpManager
 import com.android.systemui.statusbar.policy.headsUpEvents
 import com.android.systemui.util.asIndenting
@@ -106,6 +111,10 @@
     }
 
     private fun attachUnseenFilter(pipeline: NotifPipeline) {
+        if (NotificationMinimalismPrototype.V2.isEnabled) {
+            pipeline.addPromoter(unseenNotifPromoter)
+            pipeline.addOnBeforeTransformGroupsListener(::pickOutTopUnseenNotif)
+        }
         pipeline.addFinalizeFilter(unseenNotifFilter)
         pipeline.addCollectionListener(collectionListener)
         scope.launch { trackUnseenFilterSettingChanges() }
@@ -263,7 +272,10 @@
     }
 
     private fun unseenFeatureEnabled(): Flow<Boolean> {
-        if (NotificationMinimalismPrototype.V1.isEnabled) {
+        if (
+            NotificationMinimalismPrototype.V1.isEnabled ||
+                NotificationMinimalismPrototype.V2.isEnabled
+        ) {
             return flowOf(true)
         }
         return secureSettings
@@ -334,6 +346,57 @@
             }
         }
 
+    private fun pickOutTopUnseenNotif(list: List<ListEntry>) {
+        if (NotificationMinimalismPrototype.V2.isUnexpectedlyInLegacyMode()) return
+        // Only ever elevate a top unseen notification on keyguard, not even locked shade
+        if (statusBarStateController.state != StatusBarState.KEYGUARD) {
+            seenNotificationsInteractor.setTopUnseenNotification(null)
+            return
+        }
+        // On keyguard pick the top-ranked unseen or ongoing notification to elevate
+        seenNotificationsInteractor.setTopUnseenNotification(
+            list
+                .asSequence()
+                .flatMap {
+                    when (it) {
+                        is NotificationEntry -> listOfNotNull(it)
+                        is GroupEntry -> it.children
+                        else -> error("unhandled type of $it")
+                    }
+                }
+                .filter { shouldIgnoreUnseenCheck(it) || it in unseenNotifications }
+                .minByOrNull { it.ranking.rank }
+        )
+    }
+
+    @VisibleForTesting
+    internal val unseenNotifPromoter =
+        object : NotifPromoter("$TAG-unseen") {
+            override fun shouldPromoteToTopLevel(child: NotificationEntry): Boolean =
+                if (NotificationMinimalismPrototype.V2.isUnexpectedlyInLegacyMode()) false
+                else
+                    seenNotificationsInteractor.isTopUnseenNotification(child) &&
+                        NotificationMinimalismPrototype.V2.ungroupTopUnseen
+        }
+
+    val unseenNotifSectioner =
+        object : NotifSectioner("Unseen", BUCKET_FOREGROUND_SERVICE) {
+            override fun isInSection(entry: ListEntry): Boolean {
+                if (NotificationMinimalismPrototype.V2.isUnexpectedlyInLegacyMode()) return false
+                if (
+                    seenNotificationsInteractor.isTopUnseenNotification(entry.representativeEntry)
+                ) {
+                    return true
+                }
+                if (entry !is GroupEntry) {
+                    return false
+                }
+                return entry.children.any {
+                    seenNotificationsInteractor.isTopUnseenNotification(it)
+                }
+            }
+        }
+
     @VisibleForTesting
     internal val unseenNotifFilter =
         object : NotifFilter("$TAG-unseen") {
@@ -351,7 +414,9 @@
              * allow seen notifications to appear in the locked shade.
              */
             private fun isOnKeyguard(): Boolean =
-                if (
+                if (NotificationMinimalismPrototype.V2.isEnabled) {
+                    false // disable this feature under this prototype
+                } else if (
                     NotificationMinimalismPrototype.V1.isEnabled &&
                         NotificationMinimalismPrototype.V1.showOnLockedShade
                 ) {
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/NotifCoordinators.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/NotifCoordinators.kt
index 36c12a7..387444b 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/NotifCoordinators.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/NotifCoordinators.kt
@@ -24,47 +24,50 @@
 import com.android.systemui.statusbar.notification.collection.coordinator.dagger.CoordinatorScope
 import com.android.systemui.statusbar.notification.collection.listbuilder.pluggable.NotifSectioner
 import com.android.systemui.statusbar.notification.collection.provider.SectionStyleProvider
+import com.android.systemui.statusbar.notification.shared.NotificationMinimalismPrototype
 import com.android.systemui.statusbar.notification.shared.NotificationsLiveDataStoreRefactor
 import javax.inject.Inject
 
 /**
- * Handles the attachment of [Coordinator]s to the [NotifPipeline] so that the
- * Coordinators can register their respective callbacks.
+ * Handles the attachment of [Coordinator]s to the [NotifPipeline] so that the Coordinators can
+ * register their respective callbacks.
  */
 interface NotifCoordinators : Coordinator, PipelineDumpable
 
 @CoordinatorScope
-class NotifCoordinatorsImpl @Inject constructor(
-        sectionStyleProvider: SectionStyleProvider,
-        featureFlags: FeatureFlags,
-        dataStoreCoordinator: DataStoreCoordinator,
-        hideLocallyDismissedNotifsCoordinator: HideLocallyDismissedNotifsCoordinator,
-        hideNotifsForOtherUsersCoordinator: HideNotifsForOtherUsersCoordinator,
-        keyguardCoordinator: KeyguardCoordinator,
-        rankingCoordinator: RankingCoordinator,
-        colorizedFgsCoordinator: ColorizedFgsCoordinator,
-        deviceProvisionedCoordinator: DeviceProvisionedCoordinator,
-        bubbleCoordinator: BubbleCoordinator,
-        headsUpCoordinator: HeadsUpCoordinator,
-        gutsCoordinator: GutsCoordinator,
-        conversationCoordinator: ConversationCoordinator,
-        debugModeCoordinator: DebugModeCoordinator,
-        groupCountCoordinator: GroupCountCoordinator,
-        groupWhenCoordinator: GroupWhenCoordinator,
-        mediaCoordinator: MediaCoordinator,
-        preparationCoordinator: PreparationCoordinator,
-        remoteInputCoordinator: RemoteInputCoordinator,
-        rowAlertTimeCoordinator: RowAlertTimeCoordinator,
-        rowAppearanceCoordinator: RowAppearanceCoordinator,
-        stackCoordinator: StackCoordinator,
-        shadeEventCoordinator: ShadeEventCoordinator,
-        smartspaceDedupingCoordinator: SmartspaceDedupingCoordinator,
-        viewConfigCoordinator: ViewConfigCoordinator,
-        visualStabilityCoordinator: VisualStabilityCoordinator,
-        sensitiveContentCoordinator: SensitiveContentCoordinator,
-        dismissibilityCoordinator: DismissibilityCoordinator,
-        dreamCoordinator: DreamCoordinator,
-        statsLoggerCoordinator: NotificationStatsLoggerCoordinator,
+class NotifCoordinatorsImpl
+@Inject
+constructor(
+    sectionStyleProvider: SectionStyleProvider,
+    featureFlags: FeatureFlags,
+    dataStoreCoordinator: DataStoreCoordinator,
+    hideLocallyDismissedNotifsCoordinator: HideLocallyDismissedNotifsCoordinator,
+    hideNotifsForOtherUsersCoordinator: HideNotifsForOtherUsersCoordinator,
+    keyguardCoordinator: KeyguardCoordinator,
+    rankingCoordinator: RankingCoordinator,
+    colorizedFgsCoordinator: ColorizedFgsCoordinator,
+    deviceProvisionedCoordinator: DeviceProvisionedCoordinator,
+    bubbleCoordinator: BubbleCoordinator,
+    headsUpCoordinator: HeadsUpCoordinator,
+    gutsCoordinator: GutsCoordinator,
+    conversationCoordinator: ConversationCoordinator,
+    debugModeCoordinator: DebugModeCoordinator,
+    groupCountCoordinator: GroupCountCoordinator,
+    groupWhenCoordinator: GroupWhenCoordinator,
+    mediaCoordinator: MediaCoordinator,
+    preparationCoordinator: PreparationCoordinator,
+    remoteInputCoordinator: RemoteInputCoordinator,
+    rowAlertTimeCoordinator: RowAlertTimeCoordinator,
+    rowAppearanceCoordinator: RowAppearanceCoordinator,
+    stackCoordinator: StackCoordinator,
+    shadeEventCoordinator: ShadeEventCoordinator,
+    smartspaceDedupingCoordinator: SmartspaceDedupingCoordinator,
+    viewConfigCoordinator: ViewConfigCoordinator,
+    visualStabilityCoordinator: VisualStabilityCoordinator,
+    sensitiveContentCoordinator: SensitiveContentCoordinator,
+    dismissibilityCoordinator: DismissibilityCoordinator,
+    dreamCoordinator: DreamCoordinator,
+    statsLoggerCoordinator: NotificationStatsLoggerCoordinator,
 ) : NotifCoordinators {
 
     private val mCoreCoordinators: MutableList<CoreCoordinator> = ArrayList()
@@ -114,6 +117,9 @@
         // Manually add Ordered Sections
         mOrderedSections.add(headsUpCoordinator.sectioner) // HeadsUp
         mOrderedSections.add(colorizedFgsCoordinator.sectioner) // ForegroundService
+        if (NotificationMinimalismPrototype.V2.isEnabled) {
+            mOrderedSections.add(keyguardCoordinator.unseenNotifSectioner) // Unseen (FGS)
+        }
         mOrderedSections.add(conversationCoordinator.peopleAlertingSectioner) // People Alerting
         if (!SortBySectionTimeFlag.isEnabled) {
             mOrderedSections.add(conversationCoordinator.peopleSilentSectioner) // People Silent
@@ -124,22 +130,26 @@
 
         sectionStyleProvider.setMinimizedSections(setOf(rankingCoordinator.minimizedSectioner))
         if (SortBySectionTimeFlag.isEnabled) {
-            sectionStyleProvider.setSilentSections(listOf(
+            sectionStyleProvider.setSilentSections(
+                listOf(
                     rankingCoordinator.silentSectioner,
                     rankingCoordinator.minimizedSectioner,
-            ))
+                )
+            )
         } else {
-            sectionStyleProvider.setSilentSections(listOf(
+            sectionStyleProvider.setSilentSections(
+                listOf(
                     conversationCoordinator.peopleSilentSectioner,
                     rankingCoordinator.silentSectioner,
                     rankingCoordinator.minimizedSectioner,
-            ))
+                )
+            )
         }
     }
 
     /**
-     * Sends the pipeline to each coordinator when the pipeline is ready to accept
-     * [Pluggable]s, [NotifCollectionListener]s and [NotifLifetimeExtender]s.
+     * Sends the pipeline to each coordinator when the pipeline is ready to accept [Pluggable]s,
+     * [NotifCollectionListener]s and [NotifLifetimeExtender]s.
      */
     override fun attach(pipeline: NotifPipeline) {
         for (c in mCoreCoordinators) {
@@ -155,10 +165,11 @@
      * As part of the NotifPipeline dumpable, dumps the list of coordinators; sections are omitted
      * as they are dumped in the RenderStageManager instead.
      */
-    override fun dumpPipeline(d: PipelineDumper) = with(d) {
-        dump("core coordinators", mCoreCoordinators)
-        dump("normal coordinators", mCoordinators)
-    }
+    override fun dumpPipeline(d: PipelineDumper) =
+        with(d) {
+            dump("core coordinators", mCoreCoordinators)
+            dump("normal coordinators", mCoordinators)
+        }
 
     companion object {
         private const val TAG = "NotifCoordinators"
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinator.java b/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinator.java
index 350e88e..caa6c17 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinator.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/VisualStabilityCoordinator.java
@@ -38,6 +38,8 @@
 import com.android.systemui.statusbar.notification.collection.NotificationEntry;
 import com.android.systemui.statusbar.notification.collection.listbuilder.pluggable.NotifStabilityManager;
 import com.android.systemui.statusbar.notification.collection.provider.VisualStabilityProvider;
+import com.android.systemui.statusbar.notification.domain.interactor.SeenNotificationsInteractor;
+import com.android.systemui.statusbar.notification.shared.NotificationMinimalismPrototype;
 import com.android.systemui.statusbar.policy.HeadsUpManager;
 import com.android.systemui.util.Compile;
 import com.android.systemui.util.concurrency.DelayableExecutor;
@@ -63,6 +65,7 @@
     public static final boolean DEBUG = Compile.IS_DEBUG && Log.isLoggable(TAG, Log.VERBOSE);
     private final DelayableExecutor mDelayableExecutor;
     private final HeadsUpManager mHeadsUpManager;
+    private final SeenNotificationsInteractor mSeenNotificationsInteractor;
     private final ShadeAnimationInteractor mShadeAnimationInteractor;
     private final StatusBarStateController mStatusBarStateController;
     private final JavaAdapter mJavaAdapter;
@@ -101,6 +104,7 @@
             HeadsUpManager headsUpManager,
             ShadeAnimationInteractor shadeAnimationInteractor,
             JavaAdapter javaAdapter,
+            SeenNotificationsInteractor seenNotificationsInteractor,
             StatusBarStateController statusBarStateController,
             VisibilityLocationProvider visibilityLocationProvider,
             VisualStabilityProvider visualStabilityProvider,
@@ -109,6 +113,7 @@
         mHeadsUpManager = headsUpManager;
         mShadeAnimationInteractor = shadeAnimationInteractor;
         mJavaAdapter = javaAdapter;
+        mSeenNotificationsInteractor = seenNotificationsInteractor;
         mVisibilityLocationProvider = visibilityLocationProvider;
         mVisualStabilityProvider = visualStabilityProvider;
         mWakefulnessLifecycle = wakefulnessLifecycle;
@@ -142,8 +147,15 @@
     private final NotifStabilityManager mNotifStabilityManager =
             new NotifStabilityManager("VisualStabilityCoordinator") {
                 private boolean canMoveForHeadsUp(NotificationEntry entry) {
-                    return entry != null && mHeadsUpManager.isHeadsUpEntry(entry.getKey())
-                            && !mVisibilityLocationProvider.isInVisibleLocation(entry);
+                    if (entry == null) {
+                        return false;
+                    }
+                    boolean isTopUnseen = NotificationMinimalismPrototype.V2.isEnabled()
+                            && mSeenNotificationsInteractor.isTopUnseenNotification(entry);
+                    if (isTopUnseen || mHeadsUpManager.isHeadsUpEntry(entry.getKey())) {
+                        return !mVisibilityLocationProvider.isInVisibleLocation(entry);
+                    }
+                    return false;
                 }
 
                 @Override
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/data/repository/ActiveNotificationListRepository.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/data/repository/ActiveNotificationListRepository.kt
index 5c844bc..e2c9e02 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/data/repository/ActiveNotificationListRepository.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/data/repository/ActiveNotificationListRepository.kt
@@ -41,6 +41,9 @@
 
     /** Stats about the list of notifications attached to the shade */
     val notifStats = MutableStateFlow(NotifStats.empty)
+
+    /** The key of the top unseen notification */
+    val topUnseenNotificationKey = MutableStateFlow<String?>(null)
 }
 
 /** Represents the notification list, comprised of groups and individual notifications. */
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/domain/interactor/SeenNotificationsInteractor.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/domain/interactor/SeenNotificationsInteractor.kt
index 1f7ab96..42828d9 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/domain/interactor/SeenNotificationsInteractor.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/domain/interactor/SeenNotificationsInteractor.kt
@@ -17,7 +17,9 @@
 package com.android.systemui.statusbar.notification.domain.interactor
 
 import com.android.systemui.dagger.SysUISingleton
+import com.android.systemui.statusbar.notification.collection.NotificationEntry
 import com.android.systemui.statusbar.notification.data.repository.ActiveNotificationListRepository
+import com.android.systemui.statusbar.notification.shared.NotificationMinimalismPrototype
 import javax.inject.Inject
 import kotlinx.coroutines.flow.StateFlow
 
@@ -36,4 +38,15 @@
     fun setHasFilteredOutSeenNotifications(value: Boolean) {
         notificationListRepository.hasFilteredOutSeenNotifications.value = value
     }
+
+    /** Set the entry that is identified as the top unseen notification. */
+    fun setTopUnseenNotification(entry: NotificationEntry?) {
+        if (NotificationMinimalismPrototype.V2.isUnexpectedlyInLegacyMode()) return
+        notificationListRepository.topUnseenNotificationKey.value = entry?.key
+    }
+
+    /** Determine if the given notification is the top unseen notification. */
+    fun isTopUnseenNotification(entry: NotificationEntry?): Boolean =
+        if (NotificationMinimalismPrototype.V2.isUnexpectedlyInLegacyMode()) false
+        else entry != null && notificationListRepository.topUnseenNotificationKey.value == entry.key
 }
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/shared/NotificationMinimalismPrototype.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/shared/NotificationMinimalismPrototype.kt
index 8889a10..bf37036 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/shared/NotificationMinimalismPrototype.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/shared/NotificationMinimalismPrototype.kt
@@ -24,6 +24,11 @@
 /** Helper for reading or using the minimalism prototype flag state. */
 @Suppress("NOTHING_TO_INLINE")
 object NotificationMinimalismPrototype {
+
+    val version: Int by lazy {
+        SystemProperties.getInt("persist.notification_minimalism_prototype.version", 2)
+    }
+
     object V1 {
         /** The aconfig flag name */
         const val FLAG_NAME = Flags.FLAG_NOTIFICATION_MINIMALISM_PROTOTYPE
@@ -35,7 +40,7 @@
         /** Is the heads-up cycling animation enabled */
         @JvmStatic
         inline val isEnabled
-            get() = Flags.notificationMinimalismPrototype()
+            get() = Flags.notificationMinimalismPrototype() && version == 1
 
         /**
          * the prototype will now show seen notifications on the locked shade by default, but this
@@ -76,4 +81,45 @@
         @JvmStatic
         inline fun assertInLegacyMode() = RefactorFlagUtils.assertInLegacyMode(isEnabled, FLAG_NAME)
     }
+    object V2 {
+        const val FLAG_NAME = Flags.FLAG_NOTIFICATION_MINIMALISM_PROTOTYPE
+
+        /** A token used for dependency declaration */
+        val token: FlagToken
+            get() = FlagToken(FLAG_NAME, isEnabled)
+
+        /** Is the heads-up cycling animation enabled */
+        @JvmStatic
+        inline val isEnabled
+            get() = Flags.notificationMinimalismPrototype() && version == 2
+
+        /**
+         * The prototype will (by default) use a promoter to ensure that the top unseen notification
+         * is not grouped, but this property read allows that behavior to be disabled.
+         */
+        val ungroupTopUnseen: Boolean
+            get() =
+                if (isUnexpectedlyInLegacyMode()) false
+                else
+                    SystemProperties.getBoolean(
+                        "persist.notification_minimalism_prototype.ungroup_top_unseen",
+                        true
+                    )
+
+        /**
+         * Called to ensure code is only run when the flag is enabled. This protects users from the
+         * unintended behaviors caused by accidentally running new logic, while also crashing on an
+         * eng build to ensure that the refactor author catches issues in testing.
+         */
+        @JvmStatic
+        inline fun isUnexpectedlyInLegacyMode() =
+            RefactorFlagUtils.isUnexpectedlyInLegacyMode(isEnabled, FLAG_NAME)
+
+        /**
+         * Called to ensure code is only run when the flag is disabled. This will throw an exception
+         * if the flag is enabled to ensure that the refactor author catches issues in testing.
+         */
+        @JvmStatic
+        inline fun assertInLegacyMode() = RefactorFlagUtils.assertInLegacyMode(isEnabled, FLAG_NAME)
+    }
 }
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt
index a446745..749c241 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt
@@ -72,6 +72,9 @@
      */
     private var maxNotificationsExcludesMedia = false
 
+    /** Whether we allow keyguard to show less important notifications above the shelf. */
+    private var limitLockScreenToImportant = false
+
     /** Minimum space between two notifications, see [calculateGapAndDividerHeight]. */
     private var dividerHeight by notNull<Float>()
 
@@ -85,6 +88,14 @@
         updateResources()
     }
 
+    private fun allowedByPolicy(stackHeight: StackHeight): Boolean =
+        if (limitLockScreenToImportant && stackHeight.includesLessImportantNotification) {
+            log { "\tallowedByPolicy = false" }
+            false
+        } else {
+            true
+        }
+
     /**
      * Returns whether notifications and (shelf if visible) can fit in total space available.
      * [shelfSpace] is extra vertical space allowed for the shelf to overlap the lock icon.
@@ -183,11 +194,12 @@
         log { "\tGet maxNotifWithoutSavingSpace ---" }
         val maxNotifWithoutSavingSpace =
             stackHeightSequence.lastIndexWhile { heightResult ->
-                canStackFitInSpace(
-                    heightResult,
-                    notifSpace = notifSpace,
-                    shelfSpace = shelfSpace
-                ) == FitResult.FIT
+                allowedByPolicy(heightResult) &&
+                    canStackFitInSpace(
+                        heightResult,
+                        notifSpace = notifSpace,
+                        shelfSpace = shelfSpace
+                    ) == FitResult.FIT
             }
 
         // How many notifications we can show at heightWithoutLockscreenConstraints
@@ -212,11 +224,12 @@
             saveSpaceOnLockscreen = true
             maxNotifications =
                 stackHeightSequence.lastIndexWhile { heightResult ->
-                    canStackFitInSpace(
-                        heightResult,
-                        notifSpace = notifSpace,
-                        shelfSpace = shelfSpace
-                    ) != FitResult.NO_FIT
+                    allowedByPolicy(heightResult) &&
+                        canStackFitInSpace(
+                            heightResult,
+                            notifSpace = notifSpace,
+                            shelfSpace = shelfSpace
+                        ) != FitResult.NO_FIT
                 }
             log { "\t--- maxNotifications=$maxNotifications" }
         }
@@ -318,7 +331,10 @@
 
         // Float height of shelf (0 if shelf is not showing), and space before the shelf that
         // changes during the lockscreen <=> full shade transition.
-        val shelfHeightWithSpaceBefore: Float
+        val shelfHeightWithSpaceBefore: Float,
+
+        /** Whether this stack height includes less at least one important notification. */
+        val includesLessImportantNotification: Boolean
     )
 
     private fun computeHeightPerNotificationLimit(
@@ -331,12 +347,15 @@
         var previous: ExpandableView? = null
         val onLockscreen = onLockscreen()
 
+        var includesLessImportantNotification = false
+
         // Only shelf. This should never happen, since we allow 1 view minimum (EmptyViewState).
         yield(
             StackHeight(
                 notifsHeight = 0f,
                 notifsHeightSavingSpace = 0f,
-                shelfHeightWithSpaceBefore = shelfHeight
+                shelfHeightWithSpaceBefore = shelfHeight,
+                includesLessImportantNotification = includesLessImportantNotification,
             )
         )
 
@@ -362,6 +381,18 @@
                     spaceBeforeShelf + shelfHeight
                 }
 
+            if (limitLockScreenToImportant && !includesLessImportantNotification) {
+                val bucket = (currentNotification as? ExpandableNotificationRow)?.entry?.bucket
+                includesLessImportantNotification =
+                    when (bucket) {
+                        null,
+                        BUCKET_MEDIA_CONTROLS,
+                        BUCKET_HEADS_UP,
+                        BUCKET_FOREGROUND_SERVICE -> false
+                        else -> true
+                    }
+            }
+
             log {
                 "\tcomputeHeightPerNotificationLimit i=$i notifs=$notifications " +
                     "notifsHeightSavingSpace=$notifsWithCollapsedHun" +
@@ -371,7 +402,8 @@
                 StackHeight(
                     notifsHeight = notifications,
                     notifsHeightSavingSpace = notifsWithCollapsedHun,
-                    shelfHeightWithSpaceBefore = shelfWithSpaceBefore
+                    shelfHeightWithSpaceBefore = shelfWithSpaceBefore,
+                    includesLessImportantNotification = includesLessImportantNotification,
                 )
             )
         }
@@ -382,11 +414,16 @@
             infiniteIfNegative(
                 if (NotificationMinimalismPrototype.V1.isEnabled) {
                     NotificationMinimalismPrototype.V1.maxNotifs
+                } else if (NotificationMinimalismPrototype.V2.isEnabled) {
+                    1
                 } else {
                     resources.getInteger(R.integer.keyguard_max_notification_count)
                 }
             )
-        maxNotificationsExcludesMedia = NotificationMinimalismPrototype.V1.isEnabled
+        maxNotificationsExcludesMedia =
+            NotificationMinimalismPrototype.V1.isEnabled ||
+                NotificationMinimalismPrototype.V2.isEnabled
+        limitLockScreenToImportant = NotificationMinimalismPrototype.V2.isEnabled
 
         dividerHeight =
             max(1f, resources.getDimensionPixelSize(R.dimen.notification_divider_height).toFloat())