diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRule.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRule.kt
new file mode 100644
index 0000000..3b53cdc
--- /dev/null
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRule.kt
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2024 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.launcher3.taskbar
+
+import com.android.launcher3.taskbar.TaskbarModeRule.Mode
+import com.android.launcher3.taskbar.TaskbarModeRule.TaskbarMode
+import com.android.launcher3.util.DisplayController
+import com.android.launcher3.util.MainThreadInitializedObject
+import com.android.launcher3.util.MainThreadInitializedObject.SandboxContext
+import com.android.launcher3.util.NavigationMode
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.spy
+
+/**
+ * Allows tests to specify which Taskbar [Mode] to run under.
+ *
+ * [context] should match the test's target context, so that [MainThreadInitializedObject] instances
+ * are properly sandboxed.
+ *
+ * Annotate tests with [TaskbarMode] to set a mode. If the annotation is omitted for any tests, this
+ * rule is a no-op.
+ *
+ * Make sure this rule precedes any rules that depend on [DisplayController], or else the instance
+ * might be inconsistent across the test lifecycle.
+ */
+class TaskbarModeRule(private val context: SandboxContext) : TestRule {
+    /** The selected Taskbar mode. */
+    enum class Mode {
+        TRANSIENT,
+        PINNED,
+        THREE_BUTTONS,
+    }
+
+    /** Overrides Taskbar [mode] for a test. */
+    @Retention(AnnotationRetention.RUNTIME)
+    @Target(AnnotationTarget.FUNCTION)
+    annotation class TaskbarMode(val mode: Mode)
+
+    override fun apply(base: Statement, description: Description): Statement {
+        val taskbarMode = description.getAnnotation(TaskbarMode::class.java) ?: return base
+
+        return object : Statement() {
+            override fun evaluate() {
+                val mode = taskbarMode.mode
+
+                context.putObject(
+                    DisplayController.INSTANCE,
+                    object : DisplayController(context) {
+                        override fun getInfo(): Info {
+                            return spy(super.getInfo()) {
+                                on { isTransientTaskbar } doReturn (mode == Mode.TRANSIENT)
+                                on { isPinnedTaskbar } doReturn (mode == Mode.PINNED)
+                                on { navigationMode } doReturn
+                                    when (mode) {
+                                        Mode.TRANSIENT,
+                                        Mode.PINNED -> NavigationMode.NO_BUTTON
+                                        Mode.THREE_BUTTONS -> NavigationMode.THREE_BUTTONS
+                                    }
+                            }
+                        }
+                    },
+                )
+
+                base.evaluate()
+            }
+        }
+    }
+}
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRuleTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRuleTest.kt
new file mode 100644
index 0000000..7dfbb9a
--- /dev/null
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRuleTest.kt
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2024 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.launcher3.taskbar
+
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
+import com.android.launcher3.InvariantDeviceProfile
+import com.android.launcher3.taskbar.TaskbarModeRule.Mode.PINNED
+import com.android.launcher3.taskbar.TaskbarModeRule.Mode.THREE_BUTTONS
+import com.android.launcher3.taskbar.TaskbarModeRule.Mode.TRANSIENT
+import com.android.launcher3.taskbar.TaskbarModeRule.TaskbarMode
+import com.android.launcher3.util.DisplayController
+import com.android.launcher3.util.LauncherMultivalentJUnit
+import com.android.launcher3.util.MainThreadInitializedObject.SandboxContext
+import com.android.launcher3.util.NavigationMode
+import com.google.common.truth.Truth.assertThat
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(LauncherMultivalentJUnit::class)
+class TaskbarModeRuleTest {
+
+    private val context = SandboxContext(getInstrumentation().targetContext)
+
+    @get:Rule val taskbarModeRule = TaskbarModeRule(context)
+
+    @Test
+    @TaskbarMode(TRANSIENT)
+    fun testTaskbarMode_transient_overridesDisplayController() {
+        assertThat(DisplayController.isTransientTaskbar(context)).isTrue()
+        assertThat(DisplayController.isPinnedTaskbar(context)).isFalse()
+        assertThat(DisplayController.getNavigationMode(context)).isEqualTo(NavigationMode.NO_BUTTON)
+    }
+
+    @Test
+    @TaskbarMode(TRANSIENT)
+    fun testTaskbarMode_transient_overridesDeviceProfile() {
+        val dp = InvariantDeviceProfile.INSTANCE.get(context).getDeviceProfile(context)
+        assertThat(dp.isTransientTaskbar).isTrue()
+        assertThat(dp.isGestureMode).isTrue()
+    }
+
+    @Test
+    @TaskbarMode(PINNED)
+    fun testTaskbarMode_pinned_overridesDisplayController() {
+        assertThat(DisplayController.isTransientTaskbar(context)).isFalse()
+        assertThat(DisplayController.isPinnedTaskbar(context)).isTrue()
+        assertThat(DisplayController.getNavigationMode(context)).isEqualTo(NavigationMode.NO_BUTTON)
+    }
+
+    @Test
+    @TaskbarMode(PINNED)
+    fun testTaskbarMode_pinned_overridesDeviceProfile() {
+        val dp = InvariantDeviceProfile.INSTANCE.get(context).getDeviceProfile(context)
+        assertThat(dp.isTransientTaskbar).isFalse()
+        assertThat(dp.isGestureMode).isTrue()
+    }
+
+    @Test
+    @TaskbarMode(THREE_BUTTONS)
+    fun testTaskbarMode_threeButtons_overridesDisplayController() {
+        assertThat(DisplayController.isTransientTaskbar(context)).isFalse()
+        assertThat(DisplayController.isPinnedTaskbar(context)).isFalse()
+        assertThat(DisplayController.getNavigationMode(context))
+            .isEqualTo(NavigationMode.THREE_BUTTONS)
+    }
+
+    @Test
+    @TaskbarMode(THREE_BUTTONS)
+    fun testTaskbarMode_threeButtons_overridesDeviceProfile() {
+        val dp = InvariantDeviceProfile.INSTANCE.get(context).getDeviceProfile(context)
+        assertThat(dp.isTransientTaskbar).isFalse()
+        assertThat(dp.isGestureMode).isFalse()
+    }
+}
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarUnitTestRule.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarUnitTestRule.kt
index a999e7f..1c900b8 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarUnitTestRule.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarUnitTestRule.kt
@@ -18,6 +18,7 @@
 
 import android.app.Instrumentation
 import android.app.PendingIntent
+import android.content.Context
 import android.content.IIntentSender
 import android.content.Intent
 import androidx.test.platform.app.InstrumentationRegistry
@@ -37,6 +38,8 @@
 /**
  * Manages the Taskbar lifecycle for unit tests.
  *
+ * Tests need to provide their target [context] through the constructor.
+ *
  * See [InjectController] for grabbing controller(s) under test with minimal boilerplate.
  *
  * The rule interacts with [TaskbarManager] on the main thread. A good rule of thumb for tests is
@@ -58,7 +61,7 @@
  * }
  * ```
  */
-class TaskbarUnitTestRule : MethodRule {
+class TaskbarUnitTestRule(private val context: Context) : MethodRule {
     private val instrumentation = InstrumentationRegistry.getInstrumentation()
     private val serviceTestRule = ServiceTestRule()
 
@@ -76,7 +79,6 @@
             override fun evaluate() {
                 this@TaskbarUnitTestRule.target = target
 
-                val context = instrumentation.targetContext
                 instrumentation.runOnMainSync {
                     assumeTrue(
                         LauncherAppState.getIDP(context).getDeviceProfile(context).isTaskbarPresent
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsControllerTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsControllerTest.kt
index fe4e2d2..9a514bf 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsControllerTest.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsControllerTest.kt
@@ -42,7 +42,7 @@
 @EmulatedDevices(["pixelFoldable2023", "pixelTablet2023"])
 class TaskbarAllAppsControllerTest {
 
-    @get:Rule val taskbarUnitTestRule = TaskbarUnitTestRule()
+    @get:Rule val taskbarUnitTestRule = TaskbarUnitTestRule(getInstrumentation().targetContext)
     @get:Rule val animatorTestRule = AnimatorTestRule(this)
 
     @InjectController lateinit var allAppsController: TaskbarAllAppsController
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/overlay/TaskbarOverlayControllerTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/overlay/TaskbarOverlayControllerTest.kt
index eebd8f9..918ec7d 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/overlay/TaskbarOverlayControllerTest.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/overlay/TaskbarOverlayControllerTest.kt
@@ -41,7 +41,7 @@
 @EmulatedDevices(["pixelFoldable2023"])
 class TaskbarOverlayControllerTest {
 
-    @get:Rule val taskbarUnitTestRule = TaskbarUnitTestRule()
+    @get:Rule val taskbarUnitTestRule = TaskbarUnitTestRule(getInstrumentation().targetContext)
     @InjectController lateinit var overlayController: TaskbarOverlayController
 
     private val taskbarContext: TaskbarActivityContext