diff --git a/aconfig/launcher.aconfig b/aconfig/launcher.aconfig
index 15ac9e3..31a9009 100644
--- a/aconfig/launcher.aconfig
+++ b/aconfig/launcher.aconfig
@@ -323,3 +323,11 @@
     description: "Search bar persists at the bottom of the screen across Launcher states"
     bug: "346408388"
 }
+
+flag {
+    name: "multiline_search_bar"
+    namespace: "launcher"
+    description: "Search bar can wrap to multi-line"
+    bug: "341795751"
+}
+
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltip.kt b/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltip.kt
index c45c667..7f9d8a3 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltip.kt
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltip.kt
@@ -27,6 +27,7 @@
 import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.view.animation.Interpolator
+import android.window.OnBackInvokedDispatcher
 import androidx.core.view.updateLayoutParams
 import com.android.app.animation.Interpolators.EMPHASIZED_ACCELERATE
 import com.android.app.animation.Interpolators.EMPHASIZED_DECELERATE
@@ -66,11 +67,14 @@
     /** Container where the tooltip's body should be inflated. */
     lateinit var content: ViewGroup
         private set
+
     private lateinit var arrow: View
 
     /** Callback invoked when the tooltip is being closed. */
     var onCloseCallback: () -> Unit = {}
     private var openCloseAnimator: AnimatorSet? = null
+    /** Used to set whether users can tap outside the current tooltip window to dismiss it */
+    var allowTouchDismissal = true
 
     /** Animates the tooltip into view. */
     fun show() {
@@ -134,14 +138,25 @@
     override fun isOfType(type: Int): Boolean = type and TYPE_TASKBAR_EDUCATION_DIALOG != 0
 
     override fun onControllerInterceptTouchEvent(ev: MotionEvent?): Boolean {
-        if (ev?.action == ACTION_DOWN && !activityContext.dragLayer.isEventOverView(this, ev)) {
+        if (
+            ev?.action == ACTION_DOWN &&
+                !activityContext.dragLayer.isEventOverView(this, ev) &&
+                allowTouchDismissal
+        ) {
             close(true)
         }
         return false
     }
 
+    override fun onAttachedToWindow() {
+        super.onAttachedToWindow()
+        findOnBackInvokedDispatcher()
+            ?.registerOnBackInvokedCallback(OnBackInvokedDispatcher.PRIORITY_DEFAULT, this)
+    }
+
     override fun onDetachedFromWindow() {
         super.onDetachedFromWindow()
+        findOnBackInvokedDispatcher()?.unregisterOnBackInvokedCallback(this)
         Settings.Secure.putInt(mContext.contentResolver, LAUNCHER_TASKBAR_EDUCATION_SHOWING, 0)
     }
 
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltipController.kt b/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltipController.kt
index 5cbd5c9..d57c483 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltipController.kt
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarEduTooltipController.kt
@@ -86,10 +86,13 @@
                 !activityContext.isPhoneMode &&
                 !activityContext.isTinyTaskbar
         }
+
     private val isOpen: Boolean
         get() = tooltip?.isOpen ?: false
+
     val isBeforeTooltipFeaturesStep: Boolean
         get() = isTooltipEnabled && tooltipStep <= TOOLTIP_STEP_FEATURES
+
     private lateinit var controllers: TaskbarControllers
 
     // Keep track of whether the user has seen the Search Edu
@@ -152,6 +155,7 @@
         tooltipStep = TOOLTIP_STEP_NONE
         inflateTooltip(R.layout.taskbar_edu_features)
         tooltip?.run {
+            allowTouchDismissal = false
             val splitscreenAnim = requireViewById<LottieAnimationView>(R.id.splitscreen_animation)
             val suggestionsAnim = requireViewById<LottieAnimationView>(R.id.suggestions_animation)
             val pinningAnim = requireViewById<LottieAnimationView>(R.id.pinning_animation)
@@ -216,6 +220,7 @@
         inflateTooltip(R.layout.taskbar_edu_pinning)
 
         tooltip?.run {
+            allowTouchDismissal = true
             requireViewById<LottieAnimationView>(R.id.standalone_pinning_animation)
                 .supportLightTheme()
 
@@ -260,6 +265,7 @@
         userHasSeenSearchEdu = true
         inflateTooltip(R.layout.taskbar_edu_search)
         tooltip?.run {
+            allowTouchDismissal = true
             requireViewById<LottieAnimationView>(R.id.search_edu_animation).supportLightTheme()
             val eduSubtitle: TextView = requireViewById(R.id.search_edu_text)
             showDisclosureText(eduSubtitle)
@@ -332,7 +338,9 @@
     }
 
     /** Closes the current [tooltip]. */
-    fun hide() = tooltip?.close(true)
+    fun hide() {
+        tooltip?.close(true)
+    }
 
     /** Initializes [tooltip] with content from [contentResId]. */
     private fun inflateTooltip(@LayoutRes contentResId: Int) {
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java
index b294208..8a62bf8 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java
@@ -648,8 +648,7 @@
         }
     }
 
-    @VisibleForTesting
-    void addTaskbarRootViewToWindow() {
+    private void addTaskbarRootViewToWindow() {
         if (enableTaskbarNoRecreate() && !mAddedWindow && mTaskbarActivityContext != null) {
             mWindowManager.addView(mTaskbarRootLayout,
                     mTaskbarActivityContext.getWindowLayoutParams());
@@ -657,8 +656,7 @@
         }
     }
 
-    @VisibleForTesting
-    void removeTaskbarRootViewFromWindow() {
+    private void removeTaskbarRootViewFromWindow() {
         if (enableTaskbarNoRecreate() && mAddedWindow) {
             mWindowManager.removeViewImmediate(mTaskbarRootLayout);
             mAddedWindow = false;
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java
index 07481a2..753237a 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java
@@ -895,16 +895,18 @@
                 // where the bubble will end up when the animation ends
                 final float targetX = expandedX + expandedBarShift;
                 bv.setTranslationX(widthState * (targetX - collapsedX) + collapsedX);
-                // When we're expanded, we're not stacked so we're not behind the stack
-                bv.setBehindStack(false, animate);
+                // When we're expanded, the badge is visible for all bubbles
+                bv.updateBadgeVisibility(/* show= */ true);
+                bv.setDotScale(widthState);
                 bv.setAlpha(1);
             } else {
                 // If bar is on the right, account for bubble bar expanding and shifting left
                 final float collapsedBarShift = onLeft ? 0 : currentWidth - collapsedWidth;
                 final float targetX = collapsedX + collapsedBarShift;
                 bv.setTranslationX(widthState * (expandedX - targetX) + targetX);
-                // If we're not the first bubble we're behind the stack
-                bv.setBehindStack(i > 0, animate);
+                // The badge is always visible for the first bubble
+                bv.updateBadgeVisibility(/* show= */ i == 0);
+                bv.setDotScale(widthState);
                 // If we're fully collapsed, hide all bubbles except for the first 2. If there are
                 // only 2 bubbles, hide the second bubble as well because it's the overflow.
                 if (widthState == 0) {
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleView.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleView.java
index 2f92fbb..0e26c54 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleView.java
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleView.java
@@ -35,8 +35,6 @@
 import com.android.launcher3.icons.IconNormalizer;
 import com.android.wm.shell.animation.Interpolators;
 
-import java.util.EnumSet;
-
 // TODO: (b/276978250) This is will be similar to WMShell's BadgedImageView, it'd be nice to share.
 
 /**
@@ -47,22 +45,6 @@
 
     public static final int DEFAULT_PATH_SIZE = 100;
 
-    /**
-     * Flags that suppress the visibility of the 'new' dot or the app badge, for one reason or
-     * another. If any of these flags are set, the dot will not be shown.
-     * If {@link SuppressionFlag#BEHIND_STACK} then the app badge will not be shown.
-     */
-    enum SuppressionFlag {
-        // TODO: (b/277815200) implement flyout
-        // Suppressed because the flyout is visible - it will morph into the dot via animation.
-        FLYOUT_VISIBLE,
-        // Suppressed because this bubble is behind others in the collapsed stack.
-        BEHIND_STACK,
-    }
-
-    private final EnumSet<SuppressionFlag> mSuppressionFlags =
-            EnumSet.noneOf(SuppressionFlag.class);
-
     private final ImageView mBubbleIcon;
     private final ImageView mAppIcon;
     private final int mBubbleSize;
@@ -230,7 +212,7 @@
         }
     }
 
-    void updateBadgeVisibility() {
+    void updateBadgeVisibility(boolean show) {
         if (mBubble instanceof BubbleBarOverflow) {
             // The overflow bubble does not have a badge, so just bail.
             return;
@@ -241,39 +223,24 @@
                 ? -(bubble.getIcon().getWidth() - appBadgeBitmap.getWidth())
                 : 0;
         mAppIcon.setTranslationX(translationX);
-        mAppIcon.setVisibility(isBehindStack() ? GONE : VISIBLE);
-    }
-
-    /** Sets whether this bubble is in the stack & not the first bubble. **/
-    void setBehindStack(boolean behindStack, boolean animate) {
-        if (behindStack) {
-            mSuppressionFlags.add(SuppressionFlag.BEHIND_STACK);
-        } else {
-            mSuppressionFlags.remove(SuppressionFlag.BEHIND_STACK);
-        }
-        updateDotVisibility(animate);
-        updateBadgeVisibility();
-    }
-
-    /** Whether this bubble is in the stack & not the first bubble. **/
-    boolean isBehindStack() {
-        return mSuppressionFlags.contains(SuppressionFlag.BEHIND_STACK);
+        mAppIcon.setVisibility(show ? VISIBLE : GONE);
     }
 
     /** Whether the dot indicating unseen content in a bubble should be shown. */
     private boolean shouldDrawDot() {
         boolean bubbleHasUnseenContent = mBubble != null
                 && mBubble instanceof BubbleBarBubble
-                && mSuppressionFlags.isEmpty()
                 && !((BubbleBarBubble) mBubble).getInfo().isNotificationSuppressed();
-
         // Always render the dot if it's animating, since it could be animating out. Otherwise, show
         // it if the bubble wants to show it, and we aren't suppressing it.
         return bubbleHasUnseenContent || mDotIsAnimating;
     }
 
     /** How big the dot should be, fraction from 0 to 1. */
-    private void setDotScale(float fraction) {
+    void setDotScale(float fraction) {
+        if (!shouldDrawDot()) {
+            return;
+        }
         mDotScale = fraction;
         invalidate();
     }
@@ -283,14 +250,14 @@
      */
     private void animateDotScale() {
         float toScale = shouldDrawDot() ? 1f : 0f;
-        mDotIsAnimating = true;
+        boolean isDotScaleChanging = Float.compare(mDotScale, toScale) != 0;
 
-        // Don't restart the animation if we're already animating to the given value.
-        if (mAnimatingToDotScale == toScale || !shouldDrawDot()) {
-            mDotIsAnimating = false;
+        // Don't restart the animation if we're already animating to the given value or if the dot
+        // scale is not changing
+        if ((mDotIsAnimating && mAnimatingToDotScale == toScale) || !isDotScaleChanging) {
             return;
         }
-
+        mDotIsAnimating = true;
         mAnimatingToDotScale = toScale;
 
         final boolean showDot = toScale > 0f;
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 bfad697..9ecd935 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
@@ -27,9 +27,10 @@
 import com.android.launcher3.model.data.AppInfo
 import com.android.launcher3.model.data.WorkspaceItemInfo
 import com.android.launcher3.notification.NotificationKeyData
-import com.android.launcher3.taskbar.TaskbarUnitTestRule
-import com.android.launcher3.taskbar.TaskbarUnitTestRule.InjectController
 import com.android.launcher3.taskbar.overlay.TaskbarOverlayController
+import com.android.launcher3.taskbar.rules.TaskbarUnitTestRule
+import com.android.launcher3.taskbar.rules.TaskbarUnitTestRule.InjectController
+import com.android.launcher3.taskbar.rules.TaskbarWindowSandboxContext
 import com.android.launcher3.util.LauncherMultivalentJUnit
 import com.android.launcher3.util.LauncherMultivalentJUnit.EmulatedDevices
 import com.android.launcher3.util.PackageUserKey
@@ -43,7 +44,11 @@
 class TaskbarAllAppsControllerTest {
 
     @get:Rule
-    val taskbarUnitTestRule = TaskbarUnitTestRule(this, getInstrumentation().targetContext)
+    val taskbarUnitTestRule =
+        TaskbarUnitTestRule(
+            this,
+            TaskbarWindowSandboxContext.create(getInstrumentation().targetContext),
+        )
     @get:Rule val animatorTestRule = AnimatorTestRule(this)
 
     @InjectController lateinit var allAppsController: TaskbarAllAppsController
@@ -65,9 +70,8 @@
     }
 
     @Test
-    @UiThreadTest
     fun testToggle_taskbarRecreated_allAppsReopened() {
-        allAppsController.toggle()
+        getInstrumentation().runOnMainSync { allAppsController.toggle() }
         taskbarUnitTestRule.recreateTaskbar()
         assertThat(allAppsController.isOpen).isTrue()
     }
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 72bdc16..fae5562 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
@@ -26,8 +26,9 @@
 import com.android.launcher3.AbstractFloatingView.TYPE_TASKBAR_OVERLAY_PROXY
 import com.android.launcher3.AbstractFloatingView.hasOpenView
 import com.android.launcher3.taskbar.TaskbarActivityContext
-import com.android.launcher3.taskbar.TaskbarUnitTestRule
-import com.android.launcher3.taskbar.TaskbarUnitTestRule.InjectController
+import com.android.launcher3.taskbar.rules.TaskbarUnitTestRule
+import com.android.launcher3.taskbar.rules.TaskbarUnitTestRule.InjectController
+import com.android.launcher3.taskbar.rules.TaskbarWindowSandboxContext
 import com.android.launcher3.util.LauncherMultivalentJUnit
 import com.android.launcher3.util.LauncherMultivalentJUnit.EmulatedDevices
 import com.android.launcher3.views.BaseDragLayer
@@ -42,7 +43,11 @@
 class TaskbarOverlayControllerTest {
 
     @get:Rule
-    val taskbarUnitTestRule = TaskbarUnitTestRule(this, getInstrumentation().targetContext)
+    val taskbarUnitTestRule =
+        TaskbarUnitTestRule(
+            this,
+            TaskbarWindowSandboxContext.create(getInstrumentation().targetContext),
+        )
     @InjectController lateinit var overlayController: TaskbarOverlayController
 
     private val taskbarContext: TaskbarActivityContext
@@ -150,9 +155,10 @@
     }
 
     @Test
-    @UiThreadTest
     fun testRecreateTaskbar_closesWindow() {
-        TestOverlayView.show(overlayController.requestWindow())
+        getInstrumentation().runOnMainSync {
+            TestOverlayView.show(overlayController.requestWindow())
+        }
         taskbarUnitTestRule.recreateTaskbar()
         assertThat(hasOpenView(taskbarContext, TYPE_TASKBAR_OVERLAY_PROXY)).isFalse()
     }
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRule.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarModeRule.kt
similarity index 89%
rename from quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRule.kt
rename to quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarModeRule.kt
index 3b53cdc..6638736 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRule.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarModeRule.kt
@@ -14,13 +14,12 @@
  * limitations under the License.
  */
 
-package com.android.launcher3.taskbar
+package com.android.launcher3.taskbar.rules
 
-import com.android.launcher3.taskbar.TaskbarModeRule.Mode
-import com.android.launcher3.taskbar.TaskbarModeRule.TaskbarMode
+import com.android.launcher3.taskbar.rules.TaskbarModeRule.Mode
+import com.android.launcher3.taskbar.rules.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
@@ -40,7 +39,7 @@
  * 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 {
+class TaskbarModeRule(private val context: TaskbarWindowSandboxContext) : TestRule {
     /** The selected Taskbar mode. */
     enum class Mode {
         TRANSIENT,
@@ -60,7 +59,7 @@
             override fun evaluate() {
                 val mode = taskbarMode.mode
 
-                context.putObject(
+                context.applicationContext.putObject(
                     DisplayController.INSTANCE,
                     object : DisplayController(context) {
                         override fun getInfo(): Info {
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRuleTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarModeRuleTest.kt
similarity index 87%
rename from quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRuleTest.kt
rename to quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarModeRuleTest.kt
index 7dfbb9a..f75e542 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarModeRuleTest.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarModeRuleTest.kt
@@ -14,17 +14,16 @@
  * limitations under the License.
  */
 
-package com.android.launcher3.taskbar
+package com.android.launcher3.taskbar.rules
 
 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.taskbar.rules.TaskbarModeRule.Mode.PINNED
+import com.android.launcher3.taskbar.rules.TaskbarModeRule.Mode.THREE_BUTTONS
+import com.android.launcher3.taskbar.rules.TaskbarModeRule.Mode.TRANSIENT
+import com.android.launcher3.taskbar.rules.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
@@ -34,7 +33,7 @@
 @RunWith(LauncherMultivalentJUnit::class)
 class TaskbarModeRuleTest {
 
-    private val context = SandboxContext(getInstrumentation().targetContext)
+    private val context = TaskbarWindowSandboxContext.create(getInstrumentation().targetContext)
 
     @get:Rule val taskbarModeRule = TaskbarModeRule(context)
 
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarUnitTestRule.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRule.kt
similarity index 91%
rename from quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarUnitTestRule.kt
rename to quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRule.kt
index bbf738e..74c2390 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarUnitTestRule.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRule.kt
@@ -14,16 +14,17 @@
  * limitations under the License.
  */
 
-package com.android.launcher3.taskbar
+package com.android.launcher3.taskbar.rules
 
 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
 import androidx.test.rule.ServiceTestRule
 import com.android.launcher3.LauncherAppState
+import com.android.launcher3.taskbar.TaskbarActivityContext
+import com.android.launcher3.taskbar.TaskbarManager
 import com.android.launcher3.taskbar.TaskbarNavButtonController.TaskbarNavButtonCallbacks
 import com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR
 import com.android.launcher3.util.LauncherMultivalentJUnit.Companion.isRunningInRobolectric
@@ -62,7 +63,11 @@
  * }
  * ```
  */
-class TaskbarUnitTestRule(private val testInstance: Any, private val context: Context) : TestRule {
+class TaskbarUnitTestRule(
+    private val testInstance: Any,
+    private val context: TaskbarWindowSandboxContext,
+) : TestRule {
+
     private val instrumentation = InstrumentationRegistry.getInstrumentation()
     private val serviceTestRule = ServiceTestRule()
 
@@ -114,18 +119,14 @@
                 try {
                     // Replace Launcher Taskbar window with test instance.
                     instrumentation.runOnMainSync {
-                        launcherTaskbarManager?.removeTaskbarRootViewFromWindow()
+                        launcherTaskbarManager?.destroy()
                         taskbarManager.onUserUnlocked() // Required to complete initialization.
                     }
 
                     injectControllers()
                     base.evaluate()
                 } finally {
-                    // Revert Taskbar window.
-                    instrumentation.runOnMainSync {
-                        taskbarManager.destroy()
-                        launcherTaskbarManager?.addTaskbarRootViewToWindow()
-                    }
+                    instrumentation.runOnMainSync { taskbarManager.destroy() }
                 }
             }
         }
@@ -133,7 +134,7 @@
 
     /** Simulates Taskbar recreation lifecycle. */
     fun recreateTaskbar() {
-        taskbarManager.recreateTaskbar()
+        instrumentation.runOnMainSync { taskbarManager.recreateTaskbar() }
         injectControllers()
     }
 
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRuleTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRuleTest.kt
new file mode 100644
index 0000000..8262e0f
--- /dev/null
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRuleTest.kt
@@ -0,0 +1,151 @@
+/*
+ * 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.rules
+
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
+import com.android.launcher3.taskbar.TaskbarActivityContext
+import com.android.launcher3.taskbar.TaskbarKeyguardController
+import com.android.launcher3.taskbar.TaskbarManager
+import com.android.launcher3.taskbar.TaskbarStashController
+import com.android.launcher3.taskbar.rules.TaskbarUnitTestRule.InjectController
+import com.android.launcher3.util.LauncherMultivalentJUnit
+import com.android.launcher3.util.LauncherMultivalentJUnit.EmulatedDevices
+import com.google.common.truth.Truth.assertThat
+import org.junit.Assert.assertThrows
+import org.junit.Test
+import org.junit.runner.Description
+import org.junit.runner.RunWith
+import org.junit.runners.model.Statement
+
+@RunWith(LauncherMultivalentJUnit::class)
+@EmulatedDevices(["pixelFoldable2023"])
+class TaskbarUnitTestRuleTest {
+
+    private val context = TaskbarWindowSandboxContext.create(getInstrumentation().targetContext)
+
+    @Test
+    fun testSetup_taskbarInitialized() {
+        onSetup { assertThat(activityContext).isInstanceOf(TaskbarActivityContext::class.java) }
+    }
+
+    @Test
+    fun testRecreateTaskbar_activityContextChanged() {
+        onSetup {
+            val context1 = activityContext
+            recreateTaskbar()
+            val context2 = activityContext
+            assertThat(context1).isNotSameInstanceAs(context2)
+        }
+    }
+
+    @Test
+    fun testTeardown_taskbarDestroyed() {
+        val testRule = TaskbarUnitTestRule(this, context)
+        testRule.apply(EMPTY_STATEMENT, DESCRIPTION).evaluate()
+        assertThrows(RuntimeException::class.java) { testRule.activityContext }
+    }
+
+    @Test
+    fun testInjectController_validControllerType_isInjected() {
+        val testClass =
+            object {
+                @InjectController lateinit var controller: TaskbarStashController
+                val isInjected: Boolean
+                    get() = ::controller.isInitialized
+            }
+
+        TaskbarUnitTestRule(testClass, context).apply(EMPTY_STATEMENT, DESCRIPTION).evaluate()
+
+        onSetup(TaskbarUnitTestRule(testClass, context)) {
+            assertThat(testClass.isInjected).isTrue()
+        }
+    }
+
+    @Test
+    fun testInjectController_multipleControllers_areInjected() {
+        val testClass =
+            object {
+                @InjectController lateinit var controller1: TaskbarStashController
+                @InjectController lateinit var controller2: TaskbarKeyguardController
+                val areInjected: Boolean
+                    get() = ::controller1.isInitialized && ::controller2.isInitialized
+            }
+
+        onSetup(TaskbarUnitTestRule(testClass, context)) {
+            assertThat(testClass.areInjected).isTrue()
+        }
+    }
+
+    @Test
+    fun testInjectController_invalidControllerType_exceptionThrown() {
+        val testClass =
+            object {
+                @InjectController lateinit var manager: TaskbarManager // Not a controller.
+            }
+
+        // We cannot use #assertThrows because we also catch an assumption violated exception when
+        // running #evaluate on devices that do not support Taskbar.
+        val result =
+            try {
+                TaskbarUnitTestRule(testClass, context)
+                    .apply(EMPTY_STATEMENT, DESCRIPTION)
+                    .evaluate()
+            } catch (e: NoSuchElementException) {
+                e
+            }
+        assertThat(result).isInstanceOf(NoSuchElementException::class.java)
+    }
+
+    @Test
+    fun testInjectController_recreateTaskbar_controllerChanged() {
+        val testClass =
+            object {
+                @InjectController lateinit var controller: TaskbarStashController
+            }
+
+        onSetup(TaskbarUnitTestRule(testClass, context)) {
+            val controller1 = testClass.controller
+            recreateTaskbar()
+            val controller2 = testClass.controller
+            assertThat(controller1).isNotSameInstanceAs(controller2)
+        }
+    }
+
+    /** Executes [runTest] after the [testRule] setup phase completes. */
+    private fun onSetup(
+        testRule: TaskbarUnitTestRule = TaskbarUnitTestRule(this, context),
+        runTest: TaskbarUnitTestRule.() -> Unit,
+    ) {
+        testRule
+            .apply(
+                object : Statement() {
+                    override fun evaluate() = runTest(testRule)
+                },
+                DESCRIPTION,
+            )
+            .evaluate()
+    }
+
+    private companion object {
+        private val EMPTY_STATEMENT =
+            object : Statement() {
+                override fun evaluate() = Unit
+            }
+        private val DESCRIPTION =
+            Description.createSuiteDescription(TaskbarUnitTestRuleTest::class.java)
+    }
+}
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarWindowSandboxContext.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarWindowSandboxContext.kt
new file mode 100644
index 0000000..321e7a9
--- /dev/null
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarWindowSandboxContext.kt
@@ -0,0 +1,61 @@
+/*
+ * 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.rules
+
+import android.content.Context
+import android.content.ContextWrapper
+import android.os.Bundle
+import android.view.Display
+import com.android.launcher3.util.MainThreadInitializedObject
+import com.android.launcher3.util.MainThreadInitializedObject.SandboxContext
+
+/**
+ * Sandbox wrapper where [createWindowContext] provides contexts that are still sandboxed within
+ * [application].
+ *
+ * Taskbar can create window contexts, which need to operate under the same sandbox application, but
+ * [Context.getApplicationContext] by default returns the actual application. For this reason,
+ * [SandboxContext] overrides [getApplicationContext] to return itself, which prevents leaving the
+ * sandbox. [SandboxContext] and the real application have different sets of
+ * [MainThreadInitializedObject] instances, so overriding the application prevents the latter set
+ * from leaking into the sandbox. Similarly, this implementation overrides [getApplicationContext]
+ * to return the original sandboxed [application], and it wraps created windowed contexts to
+ * propagate this [application].
+ */
+class TaskbarWindowSandboxContext
+private constructor(private val application: SandboxContext, base: Context) : ContextWrapper(base) {
+
+    override fun createWindowContext(type: Int, options: Bundle?): Context {
+        return TaskbarWindowSandboxContext(application, super.createWindowContext(type, options))
+    }
+
+    override fun createWindowContext(display: Display, type: Int, options: Bundle?): Context {
+        return TaskbarWindowSandboxContext(
+            application,
+            super.createWindowContext(display, type, options),
+        )
+    }
+
+    override fun getApplicationContext() = application
+
+    companion object {
+        /** Creates a [TaskbarWindowSandboxContext] to sandbox [base] for Taskbar tests. */
+        fun create(base: Context): TaskbarWindowSandboxContext {
+            return SandboxContext(base).let { TaskbarWindowSandboxContext(it, it) }
+        }
+    }
+}
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarWindowSandboxContextTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarWindowSandboxContextTest.kt
new file mode 100644
index 0000000..ad4b4de
--- /dev/null
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarWindowSandboxContextTest.kt
@@ -0,0 +1,44 @@
+/*
+ * 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.rules
+
+import android.view.WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
+import com.android.launcher3.util.LauncherMultivalentJUnit
+import com.android.launcher3.util.MainThreadInitializedObject.SandboxContext
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(LauncherMultivalentJUnit::class)
+class TaskbarWindowSandboxContextTest {
+
+    private val context = TaskbarWindowSandboxContext.create(getInstrumentation().targetContext)
+
+    @Test
+    fun testCreateWindowContext_applicationContextSandboxed() {
+        val windowContext = context.createWindowContext(TYPE_APPLICATION_OVERLAY, null)
+        assertThat(windowContext.applicationContext).isInstanceOf(SandboxContext::class.java)
+    }
+
+    @Test
+    fun testCreateWindowContext_nested_applicationContextSandboxed() {
+        val windowContext = context.createWindowContext(TYPE_APPLICATION_OVERLAY, null)
+        val nestedContext = windowContext.createWindowContext(TYPE_APPLICATION_OVERLAY, null)
+        assertThat(nestedContext.applicationContext).isInstanceOf(SandboxContext::class.java)
+    }
+}