diff --git a/packages/SystemUI/Android.bp b/packages/SystemUI/Android.bp
index 7cf562f..c2c5e00 100644
--- a/packages/SystemUI/Android.bp
+++ b/packages/SystemUI/Android.bp
@@ -190,6 +190,7 @@
         "androidx.room_room-runtime",
         "androidx.room_room-ktx",
         "com.google.android.material_material",
+        "device_state_flags_lib",
         "kotlinx_coroutines_android",
         "kotlinx_coroutines",
         "iconloader_base",
@@ -302,6 +303,7 @@
         "androidx.exifinterface_exifinterface",
         "androidx.room_room-runtime",
         "androidx.room_room-ktx",
+        "device_state_flags_lib",
         "kotlinx-coroutines-android",
         "kotlinx-coroutines-core",
         "kotlinx_coroutines_test",
diff --git a/packages/SystemUI/res/layout/connected_display_dialog.xml b/packages/SystemUI/res/layout/connected_display_dialog.xml
index 3f65aa7..8d7f7eb 100644
--- a/packages/SystemUI/res/layout/connected_display_dialog.xml
+++ b/packages/SystemUI/res/layout/connected_display_dialog.xml
@@ -45,6 +45,15 @@
         android:text="@string/connected_display_dialog_start_mirroring"
         android:textAppearance="@style/TextAppearance.Dialog.Title" />
 
+    <TextView
+        android:id="@+id/dual_display_warning"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:visibility="gone"
+        android:text="@string/connected_display_dialog_dual_display_stop_warning"
+        android:textAppearance="@style/TextAppearance.Dialog.Body" />
+
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
diff --git a/packages/SystemUI/res/values/strings.xml b/packages/SystemUI/res/values/strings.xml
index f49d2a1..7ca0b6e 100644
--- a/packages/SystemUI/res/values/strings.xml
+++ b/packages/SystemUI/res/values/strings.xml
@@ -3245,6 +3245,8 @@
 
     <!--- Title of the dialog appearing when an external display is connected, asking whether to start mirroring [CHAR LIMIT=NONE]-->
     <string name="connected_display_dialog_start_mirroring">Mirror to external display?</string>
+    <!--- Body of the mirroring dialog, shown when dual display is enabled. This signals that enabling mirroring will stop concurrent displays on a foldable device. [CHAR LIMIT=NONE]-->
+    <string name="connected_display_dialog_dual_display_stop_warning">Any dual screen activity currently running will be stopped</string>
     <!--- Label of the "enable display" button of the dialog appearing when an external display is connected [CHAR LIMIT=NONE]-->
     <string name="mirror_display">Mirror display</string>
     <!--- Label of the dismiss button of the dialog appearing when an external display is connected [CHAR LIMIT=NONE]-->
diff --git a/packages/SystemUI/src/com/android/systemui/biometrics/data/repository/DisplayStateRepository.kt b/packages/SystemUI/src/com/android/systemui/biometrics/data/repository/DisplayStateRepository.kt
index ff23837..b0143f5 100644
--- a/packages/SystemUI/src/com/android/systemui/biometrics/data/repository/DisplayStateRepository.kt
+++ b/packages/SystemUI/src/com/android/systemui/biometrics/data/repository/DisplayStateRepository.kt
@@ -60,6 +60,8 @@
     val currentRotation: StateFlow<DisplayRotation>
 }
 
+// TODO(b/296211844): This class could directly use DeviceStateRepository and DisplayRepository
+// instead.
 @SysUISingleton
 class DisplayStateRepositoryImpl
 @Inject
diff --git a/packages/SystemUI/src/com/android/systemui/display/DisplayModule.kt b/packages/SystemUI/src/com/android/systemui/display/DisplayModule.kt
index 65cd84b..373279c 100644
--- a/packages/SystemUI/src/com/android/systemui/display/DisplayModule.kt
+++ b/packages/SystemUI/src/com/android/systemui/display/DisplayModule.kt
@@ -16,6 +16,8 @@
 
 package com.android.systemui.display
 
+import com.android.systemui.display.data.repository.DeviceStateRepository
+import com.android.systemui.display.data.repository.DeviceStateRepositoryImpl
 import com.android.systemui.display.data.repository.DisplayRepository
 import com.android.systemui.display.data.repository.DisplayRepositoryImpl
 import com.android.systemui.display.domain.interactor.ConnectedDisplayInteractor
@@ -32,4 +34,9 @@
     ): ConnectedDisplayInteractor
 
     @Binds fun bindsDisplayRepository(displayRepository: DisplayRepositoryImpl): DisplayRepository
+
+    @Binds
+    fun bindsDeviceStateRepository(
+        deviceStateRepository: DeviceStateRepositoryImpl
+    ): DeviceStateRepository
 }
diff --git a/packages/SystemUI/src/com/android/systemui/display/data/repository/DeviceStateRepository.kt b/packages/SystemUI/src/com/android/systemui/display/data/repository/DeviceStateRepository.kt
new file mode 100644
index 0000000..83337f7
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/display/data/repository/DeviceStateRepository.kt
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2023 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.systemui.display.data.repository
+
+import android.content.Context
+import android.hardware.devicestate.DeviceStateManager
+import com.android.internal.R
+import com.android.systemui.common.coroutine.ConflatedCallbackFlow.conflatedCallbackFlow
+import com.android.systemui.dagger.qualifiers.Background
+import com.android.systemui.display.data.repository.DeviceStateRepository.DeviceState
+import java.util.concurrent.Executor
+import javax.inject.Inject
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.stateIn
+
+interface DeviceStateRepository {
+    val state: StateFlow<DeviceState>
+
+    enum class DeviceState {
+        /** Device state in [R.array.config_foldedDeviceStates] */
+        FOLDED,
+        /** Device state in [R.array.config_halfFoldedDeviceStates] */
+        HALF_FOLDED,
+        /** Device state in [R.array.config_openDeviceStates] */
+        UNFOLDED,
+        /** Device state in [R.array.config_rearDisplayDeviceStates] */
+        REAR_DISPLAY,
+        /** Device state in [R.array.config_concurrentDisplayDeviceStates] */
+        CONCURRENT_DISPLAY,
+        /** Device state in none of the other arrays. */
+        UNKNOWN,
+    }
+}
+
+class DeviceStateRepositoryImpl
+@Inject
+constructor(
+    context: Context,
+    deviceStateManager: DeviceStateManager,
+    @Background bgScope: CoroutineScope,
+    @Background executor: Executor
+) : DeviceStateRepository {
+
+    override val state: StateFlow<DeviceState> =
+        conflatedCallbackFlow {
+                val callback =
+                    DeviceStateManager.DeviceStateCallback { state ->
+                        trySend(deviceStateToPosture(state))
+                    }
+                deviceStateManager.registerCallback(executor, callback)
+                awaitClose { deviceStateManager.unregisterCallback(callback) }
+            }
+            .stateIn(bgScope, started = SharingStarted.WhileSubscribed(), DeviceState.UNKNOWN)
+
+    private fun deviceStateToPosture(deviceStateId: Int): DeviceState {
+        return deviceStateMap.firstOrNull { (ids, _) -> deviceStateId in ids }?.deviceState
+            ?: DeviceState.UNKNOWN
+    }
+
+    private val deviceStateMap =
+        listOf(
+                R.array.config_foldedDeviceStates to DeviceState.FOLDED,
+                R.array.config_halfFoldedDeviceStates to DeviceState.HALF_FOLDED,
+                R.array.config_openDeviceStates to DeviceState.UNFOLDED,
+                R.array.config_rearDisplayDeviceStates to DeviceState.REAR_DISPLAY,
+                R.array.config_concurrentDisplayDeviceStates to DeviceState.CONCURRENT_DISPLAY,
+            )
+            .map { IdsPerDeviceState(context.resources.getIntArray(it.first).toSet(), it.second) }
+
+    private data class IdsPerDeviceState(val ids: Set<Int>, val deviceState: DeviceState)
+}
diff --git a/packages/SystemUI/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractor.kt b/packages/SystemUI/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractor.kt
index 20a9e5d..73b7a8a 100644
--- a/packages/SystemUI/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractor.kt
+++ b/packages/SystemUI/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractor.kt
@@ -21,6 +21,7 @@
 import android.view.Display
 import com.android.systemui.dagger.SysUISingleton
 import com.android.systemui.dagger.qualifiers.Background
+import com.android.systemui.display.data.repository.DeviceStateRepository
 import com.android.systemui.display.data.repository.DisplayRepository
 import com.android.systemui.display.domain.interactor.ConnectedDisplayInteractor.PendingDisplay
 import com.android.systemui.display.domain.interactor.ConnectedDisplayInteractor.State
@@ -55,6 +56,9 @@
     /** Pending display that can be enabled to be used by the system. */
     val pendingDisplay: Flow<PendingDisplay?>
 
+    /** Pending display that can be enabled to be used by the system. */
+    val concurrentDisplaysInProgress: Flow<Boolean>
+
     /** Possible connected display state. */
     enum class State {
         DISCONNECTED,
@@ -84,6 +88,7 @@
     private val virtualDeviceManager: VirtualDeviceManager,
     keyguardRepository: KeyguardRepository,
     displayRepository: DisplayRepository,
+    deviceStateRepository: DeviceStateRepository,
     @Background backgroundCoroutineDispatcher: CoroutineDispatcher,
 ) : ConnectedDisplayInteractor {
 
@@ -128,9 +133,16 @@
             }
         }
 
+    override val concurrentDisplaysInProgress: Flow<Boolean> =
+        deviceStateRepository.state
+            .map { it == DeviceStateRepository.DeviceState.CONCURRENT_DISPLAY }
+            .distinctUntilChanged()
+            .flowOn(backgroundCoroutineDispatcher)
+
     private fun DisplayRepository.PendingDisplay.toInteractorPendingDisplay(): PendingDisplay =
         object : PendingDisplay {
             override suspend fun enable() = this@toInteractorPendingDisplay.enable()
+
             override suspend fun ignore() = this@toInteractorPendingDisplay.ignore()
         }
 
diff --git a/packages/SystemUI/src/com/android/systemui/display/ui/view/MirroringConfirmationDialog.kt b/packages/SystemUI/src/com/android/systemui/display/ui/view/MirroringConfirmationDialog.kt
index d500d1c2..c0a873a 100644
--- a/packages/SystemUI/src/com/android/systemui/display/ui/view/MirroringConfirmationDialog.kt
+++ b/packages/SystemUI/src/com/android/systemui/display/ui/view/MirroringConfirmationDialog.kt
@@ -37,11 +37,13 @@
     private val onCancelMirroring: View.OnClickListener,
     private val navbarBottomInsetsProvider: () -> Int,
     configurationController: ConfigurationController? = null,
+    private val showConcurrentDisplayInfo: Boolean = false,
     theme: Int = R.style.Theme_SystemUI_Dialog,
 ) : SystemUIBottomSheetDialog(context, configurationController, theme) {
 
     private lateinit var mirrorButton: TextView
     private lateinit var dismissButton: TextView
+    private lateinit var dualDisplayWarning: TextView
     private var enabledPressed = false
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -56,6 +58,11 @@
         dismissButton =
             requireViewById<TextView>(R.id.cancel).apply { setOnClickListener(onCancelMirroring) }
 
+        dualDisplayWarning =
+            requireViewById<TextView>(R.id.dual_display_warning).apply {
+                visibility = if (showConcurrentDisplayInfo) View.VISIBLE else View.GONE
+            }
+
         setOnDismissListener {
             if (!enabledPressed) {
                 onCancelMirroring.onClick(null)
diff --git a/packages/SystemUI/src/com/android/systemui/display/ui/viewmodel/ConnectingDisplayViewModel.kt b/packages/SystemUI/src/com/android/systemui/display/ui/viewmodel/ConnectingDisplayViewModel.kt
index 19b4d22..10aa703 100644
--- a/packages/SystemUI/src/com/android/systemui/display/ui/viewmodel/ConnectingDisplayViewModel.kt
+++ b/packages/SystemUI/src/com/android/systemui/display/ui/viewmodel/ConnectingDisplayViewModel.kt
@@ -17,6 +17,7 @@
 
 import android.app.Dialog
 import android.content.Context
+import com.android.server.policy.feature.flags.Flags
 import com.android.systemui.biometrics.Utils
 import com.android.systemui.dagger.SysUISingleton
 import com.android.systemui.dagger.qualifiers.Application
@@ -28,8 +29,9 @@
 import javax.inject.Inject
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.launchIn
-import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 
 /**
@@ -44,25 +46,33 @@
     private val connectedDisplayInteractor: ConnectedDisplayInteractor,
     @Application private val scope: CoroutineScope,
     @Background private val bgDispatcher: CoroutineDispatcher,
-    private val configurationController: ConfigurationController
+    private val configurationController: ConfigurationController,
 ) {
 
     private var dialog: Dialog? = null
 
     /** Starts listening for pending displays. */
     fun init() {
-        connectedDisplayInteractor.pendingDisplay
-            .onEach { pendingDisplay ->
+        val pendingDisplayFlow = connectedDisplayInteractor.pendingDisplay
+        val concurrentDisplaysInProgessFlow =
+            if (Flags.enableDualDisplayBlocking()) {
+                connectedDisplayInteractor.concurrentDisplaysInProgress
+            } else {
+                flow { emit(false) }
+            }
+        pendingDisplayFlow
+            .combine(concurrentDisplaysInProgessFlow) { pendingDisplay, concurrentDisplaysInProgress
+                ->
                 if (pendingDisplay == null) {
                     hideDialog()
                 } else {
-                    showDialog(pendingDisplay)
+                    showDialog(pendingDisplay, concurrentDisplaysInProgress)
                 }
             }
             .launchIn(scope)
     }
 
-    private fun showDialog(pendingDisplay: PendingDisplay) {
+    private fun showDialog(pendingDisplay: PendingDisplay, concurrentDisplaysInProgess: Boolean) {
         hideDialog()
         dialog =
             MirroringConfirmationDialog(
@@ -77,6 +87,7 @@
                     },
                     navbarBottomInsetsProvider = { Utils.getNavbarInsets(context).bottom },
                     configurationController,
+                    showConcurrentDisplayInfo = concurrentDisplaysInProgess
                 )
                 .apply { show() }
     }
diff --git a/packages/SystemUI/tests/src/com/android/systemui/display/data/repository/DeviceStateRepositoryTest.kt b/packages/SystemUI/tests/src/com/android/systemui/display/data/repository/DeviceStateRepositoryTest.kt
new file mode 100644
index 0000000..21b8aca
--- /dev/null
+++ b/packages/SystemUI/tests/src/com/android/systemui/display/data/repository/DeviceStateRepositoryTest.kt
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2023 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.systemui.display.data.repository
+
+import android.hardware.devicestate.DeviceStateManager
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import androidx.test.filters.SmallTest
+import com.android.internal.R
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.coroutines.FlowValue
+import com.android.systemui.coroutines.collectLastValue
+import com.android.systemui.display.data.repository.DeviceStateRepository.DeviceState
+import com.android.systemui.util.concurrency.FakeExecutor
+import com.android.systemui.util.mockito.any
+import com.android.systemui.util.mockito.kotlinArgumentCaptor
+import com.android.systemui.util.mockito.mock
+import com.android.systemui.util.time.FakeSystemClock
+import com.google.common.truth.Truth.assertThat
+import kotlin.test.Test
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.runner.RunWith
+import org.mockito.Mockito.never
+import org.mockito.Mockito.verify
+
+@RunWith(AndroidTestingRunner::class)
+@TestableLooper.RunWithLooper
+@OptIn(ExperimentalCoroutinesApi::class)
+@SmallTest
+class DeviceStateRepositoryTest : SysuiTestCase() {
+
+    private val deviceStateManager = mock<DeviceStateManager>()
+    private val deviceStateManagerListener =
+        kotlinArgumentCaptor<DeviceStateManager.DeviceStateCallback>()
+
+    private val testScope = TestScope(UnconfinedTestDispatcher())
+    private val fakeExecutor = FakeExecutor(FakeSystemClock())
+
+    private lateinit var deviceStateRepository: DeviceStateRepositoryImpl
+
+    @Before
+    fun setup() {
+        mContext.orCreateTestableResources.apply {
+            addOverride(R.array.config_foldedDeviceStates, listOf(TEST_FOLDED).toIntArray())
+            addOverride(R.array.config_halfFoldedDeviceStates, TEST_HALF_FOLDED.toIntArray())
+            addOverride(R.array.config_openDeviceStates, TEST_UNFOLDED.toIntArray())
+            addOverride(R.array.config_rearDisplayDeviceStates, TEST_REAR_DISPLAY.toIntArray())
+            addOverride(
+                R.array.config_concurrentDisplayDeviceStates,
+                TEST_CONCURRENT_DISPLAY.toIntArray()
+            )
+        }
+        deviceStateRepository =
+            DeviceStateRepositoryImpl(
+                mContext,
+                deviceStateManager,
+                TestScope(UnconfinedTestDispatcher()),
+                fakeExecutor
+            )
+
+        // It should register only after there are clients collecting the flow
+        verify(deviceStateManager, never()).registerCallback(any(), any())
+    }
+
+    @Test
+    fun folded_receivesFoldedState() =
+        testScope.runTest {
+            val state = displayState()
+
+            deviceStateManagerListener.value.onStateChanged(TEST_FOLDED)
+
+            assertThat(state()).isEqualTo(DeviceState.FOLDED)
+        }
+
+    @Test
+    fun halfFolded_receivesHalfFoldedState() =
+        testScope.runTest {
+            val state = displayState()
+
+            deviceStateManagerListener.value.onStateChanged(TEST_HALF_FOLDED)
+
+            assertThat(state()).isEqualTo(DeviceState.HALF_FOLDED)
+        }
+
+    @Test
+    fun unfolded_receivesUnfoldedState() =
+        testScope.runTest {
+            val state = displayState()
+
+            deviceStateManagerListener.value.onStateChanged(TEST_UNFOLDED)
+
+            assertThat(state()).isEqualTo(DeviceState.UNFOLDED)
+        }
+
+    @Test
+    fun rearDisplay_receivesRearDisplayState() =
+        testScope.runTest {
+            val state = displayState()
+
+            deviceStateManagerListener.value.onStateChanged(TEST_REAR_DISPLAY)
+
+            assertThat(state()).isEqualTo(DeviceState.REAR_DISPLAY)
+        }
+
+    @Test
+    fun concurrentDisplay_receivesConcurrentDisplayState() =
+        testScope.runTest {
+            val state = displayState()
+
+            deviceStateManagerListener.value.onStateChanged(TEST_CONCURRENT_DISPLAY)
+
+            assertThat(state()).isEqualTo(DeviceState.CONCURRENT_DISPLAY)
+        }
+
+    @Test
+    fun unknownState_receivesUnknownState() =
+        testScope.runTest {
+            val state = displayState()
+
+            deviceStateManagerListener.value.onStateChanged(123456)
+
+            assertThat(state()).isEqualTo(DeviceState.UNKNOWN)
+        }
+
+    private fun TestScope.displayState(): FlowValue<DeviceState?> {
+        val flowValue = collectLastValue(deviceStateRepository.state)
+        verify(deviceStateManager)
+            .registerCallback(
+                any(),
+                deviceStateManagerListener.capture(),
+            )
+        return flowValue
+    }
+
+    private fun Int.toIntArray() = listOf(this).toIntArray()
+
+    private companion object {
+        // Used to fake the ids in the test. Note that there is no guarantees different devices will
+        // have the same ids (that's why the ones in this test start from 41)
+        const val TEST_FOLDED = 41
+        const val TEST_HALF_FOLDED = 42
+        const val TEST_UNFOLDED = 43
+        const val TEST_REAR_DISPLAY = 44
+        const val TEST_CONCURRENT_DISPLAY = 45
+    }
+}
diff --git a/packages/SystemUI/tests/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractorTest.kt b/packages/SystemUI/tests/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractorTest.kt
index 1f18705..42b0f50 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractorTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/display/domain/interactor/ConnectedDisplayInteractorTest.kt
@@ -28,6 +28,9 @@
 import com.android.systemui.SysuiTestCase
 import com.android.systemui.coroutines.FlowValue
 import com.android.systemui.coroutines.collectLastValue
+import com.android.systemui.display.data.repository.DeviceStateRepository
+import com.android.systemui.display.data.repository.DeviceStateRepository.DeviceState.CONCURRENT_DISPLAY
+import com.android.systemui.display.data.repository.FakeDeviceStateRepository
 import com.android.systemui.display.data.repository.FakeDisplayRepository
 import com.android.systemui.display.data.repository.createPendingDisplay
 import com.android.systemui.display.data.repository.display
@@ -59,11 +62,13 @@
 
     private val fakeDisplayRepository = FakeDisplayRepository()
     private val fakeKeyguardRepository = FakeKeyguardRepository()
+    private val fakeDeviceStateRepository = FakeDeviceStateRepository()
     private val connectedDisplayStateProvider: ConnectedDisplayInteractor =
         ConnectedDisplayInteractorImpl(
             virtualDeviceManager,
             fakeKeyguardRepository,
             fakeDisplayRepository,
+            fakeDeviceStateRepository,
             UnconfinedTestDispatcher(),
         )
     private val testScope = TestScope(UnconfinedTestDispatcher())
@@ -283,6 +288,44 @@
             assertThat(pendingDisplay).isNull()
         }
 
+    @Test
+    fun concurrentDisplaysInProgress_started_returnsTrue() =
+        testScope.runTest {
+            val concurrentDisplaysInProgress =
+                collectLastValue(connectedDisplayStateProvider.concurrentDisplaysInProgress)
+
+            fakeDeviceStateRepository.emit(CONCURRENT_DISPLAY)
+
+            assertThat(concurrentDisplaysInProgress()).isTrue()
+        }
+
+    @Test
+    fun concurrentDisplaysInProgress_stopped_returnsFalse() =
+        testScope.runTest {
+            val concurrentDisplaysInProgress =
+                collectLastValue(connectedDisplayStateProvider.concurrentDisplaysInProgress)
+
+            fakeDeviceStateRepository.emit(CONCURRENT_DISPLAY)
+            fakeDeviceStateRepository.emit(DeviceStateRepository.DeviceState.UNKNOWN)
+
+            assertThat(concurrentDisplaysInProgress()).isFalse()
+        }
+
+    @Test
+    fun concurrentDisplaysInProgress_otherStates_returnsFalse() =
+        testScope.runTest {
+            val concurrentDisplaysInProgress =
+                collectLastValue(connectedDisplayStateProvider.concurrentDisplaysInProgress)
+
+            DeviceStateRepository.DeviceState.entries
+                .filter { it != CONCURRENT_DISPLAY }
+                .forEach { deviceState ->
+                    fakeDeviceStateRepository.emit(deviceState)
+
+                    assertThat(concurrentDisplaysInProgress()).isFalse()
+                }
+        }
+
     private fun TestScope.lastValue(): FlowValue<State?> =
         collectLastValue(connectedDisplayStateProvider.connectedDisplayState)
 
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/events/SystemEventCoordinatorTest.kt b/packages/SystemUI/tests/src/com/android/systemui/statusbar/events/SystemEventCoordinatorTest.kt
index bbc63f2..ae84df5 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/events/SystemEventCoordinatorTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/events/SystemEventCoordinatorTest.kt
@@ -21,7 +21,6 @@
 import com.android.systemui.SysuiTestCase
 import com.android.systemui.display.domain.interactor.ConnectedDisplayInteractor
 import com.android.systemui.display.domain.interactor.ConnectedDisplayInteractor.PendingDisplay
-import com.android.systemui.display.domain.interactor.ConnectedDisplayInteractor.State.CONNECTED
 import com.android.systemui.privacy.PrivacyItemController
 import com.android.systemui.statusbar.policy.BatteryController
 import com.android.systemui.util.mockito.any
@@ -107,5 +106,7 @@
             get() = flow
         override val pendingDisplay: Flow<PendingDisplay?>
             get() = MutableSharedFlow<PendingDisplay>()
+        override val concurrentDisplaysInProgress: Flow<Boolean>
+            get() = TODO("Not yet implemented")
     }
 }
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/PhoneStatusBarPolicyTest.kt b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/PhoneStatusBarPolicyTest.kt
index da6c28a..7deee5a 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/PhoneStatusBarPolicyTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/PhoneStatusBarPolicyTest.kt
@@ -321,5 +321,7 @@
             get() = TODO("Not yet implemented")
         override val pendingDisplay: Flow<PendingDisplay?>
             get() = TODO("Not yet implemented")
+        override val concurrentDisplaysInProgress: Flow<Boolean>
+            get() = TODO("Not yet implemented")
     }
 }
diff --git a/packages/SystemUI/tests/utils/src/com/android/systemui/display/data/repository/FakeDeviceStateRepository.kt b/packages/SystemUI/tests/utils/src/com/android/systemui/display/data/repository/FakeDeviceStateRepository.kt
new file mode 100644
index 0000000..5f6dc6e
--- /dev/null
+++ b/packages/SystemUI/tests/utils/src/com/android/systemui/display/data/repository/FakeDeviceStateRepository.kt
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2023 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.systemui.display.data.repository
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/** Fake [DeviceStateRepository] implementation for testing. */
+class FakeDeviceStateRepository : DeviceStateRepository {
+    private val flow = MutableStateFlow(DeviceStateRepository.DeviceState.UNKNOWN)
+
+    /** Emits [value] as [displays] flow value. */
+    suspend fun emit(value: DeviceStateRepository.DeviceState) = flow.emit(value)
+
+    override val state: StateFlow<DeviceStateRepository.DeviceState>
+        get() = flow
+}