diff --git a/aconfig/launcher.aconfig b/aconfig/launcher.aconfig
index 0df6c36..be8ebbb 100644
--- a/aconfig/launcher.aconfig
+++ b/aconfig/launcher.aconfig
@@ -332,3 +332,10 @@
       purpose: PURPOSE_BUGFIX
     }
 }
+
+flag {
+    name: "letter_fast_scroller"
+    namespace: "launcher"
+    description: "Change fast scroller to a lettered list"
+    bug: "358673724"
+}
diff --git a/quickstep/src/com/android/launcher3/desktop/DesktopRecentsTransitionController.kt b/quickstep/src/com/android/launcher3/desktop/DesktopRecentsTransitionController.kt
index 189deda..f7da34a 100644
--- a/quickstep/src/com/android/launcher3/desktop/DesktopRecentsTransitionController.kt
+++ b/quickstep/src/com/android/launcher3/desktop/DesktopRecentsTransitionController.kt
@@ -30,7 +30,7 @@
 import com.android.quickstep.SystemUiProxy
 import com.android.quickstep.TaskViewUtils
 import com.android.quickstep.views.DesktopTaskView
-import com.android.wm.shell.common.desktopmode.DesktopModeTransitionSource
+import com.android.wm.shell.shared.desktopmode.DesktopModeTransitionSource
 import java.util.function.Consumer
 
 /** Manage recents related operations with desktop tasks */
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarInsetsController.kt b/quickstep/src/com/android/launcher3/taskbar/TaskbarInsetsController.kt
index ff1ea98..221504d 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarInsetsController.kt
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarInsetsController.kt
@@ -56,7 +56,6 @@
 import com.android.launcher3.util.Executors
 import java.io.PrintWriter
 import kotlin.jvm.optionals.getOrNull
-import kotlin.math.max
 
 /** Handles the insets that Taskbar provides to underlying apps and the IME. */
 class TaskbarInsetsController(val context: TaskbarActivityContext) : LoggableTaskbarController {
@@ -106,7 +105,8 @@
     }
 
     fun onTaskbarOrBubblebarWindowHeightOrInsetsChanged() {
-        val tappableHeight = controllers.taskbarStashController.tappableHeightToReportToApps
+        val taskbarStashController = controllers.taskbarStashController
+        val tappableHeight = taskbarStashController.tappableHeightToReportToApps
         // We only report tappableElement height for unstashed, persistent taskbar,
         // which is also when we draw the rounded corners above taskbar.
         val insetsRoundedCornerFlag =
@@ -133,7 +133,7 @@
         }
 
         val bubbleControllers = controllers.bubbleControllers.getOrNull()
-        val taskbarTouchableHeight = controllers.taskbarStashController.touchableHeight
+        val taskbarTouchableHeight = taskbarStashController.touchableHeight
         val bubblesTouchableHeight =
             bubbleControllers?.bubbleStashController?.getTouchableHeight() ?: 0
         // reset touch bounds
@@ -147,12 +147,10 @@
                 defaultTouchableRegion.addBoundsToRegion(bubbleBarViewController.bubbleBarBounds)
             }
         }
-        val taskbarUIController = controllers.uiController as? LauncherTaskbarUIController
-        if (taskbarUIController?.isOnHome != true) {
-            // only add the bars touch region if not on home
-            val touchableHeight = max(taskbarTouchableHeight, bubblesTouchableHeight)
+        if (taskbarStashController.isInApp || taskbarStashController.isInOverview) {
+            // only add the taskbar touch region if not on home
             val bottom = windowLayoutParams.height
-            val top = bottom - touchableHeight
+            val top = bottom - taskbarTouchableHeight
             val right = context.deviceProfile.widthPx
             defaultTouchableRegion.addBoundsToRegion(Rect(/* left= */ 0, top, right, bottom))
         }
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarStashController.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarStashController.java
index b48ed60..56f88d1 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarStashController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarStashController.java
@@ -424,6 +424,11 @@
         return hasAnyFlag(FLAGS_IN_APP);
     }
 
+    /** Returns whether the taskbar is currently in overview screen. */
+    public boolean isInOverview() {
+        return hasAnyFlag(FLAG_IN_OVERVIEW);
+    }
+
     /**
      * Returns the height that taskbar will be touchable.
      */
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarViewController.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarViewController.java
index d3b918e..aef21aa 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarViewController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarViewController.java
@@ -150,6 +150,7 @@
     private Runnable mOnControllerPreCreateCallback = NO_OP;
 
     // Stored here as signals to determine if the mIconAlignController needs to be recreated.
+    private boolean mIsIconAlignedWithHotseat;
     private boolean mIsHotseatIconOnTopWhenAligned;
     private boolean mIsStashed;
 
@@ -687,15 +688,17 @@
             mIconAlignControllerLazy = null;
             return;
         }
-
         boolean isHotseatIconOnTopWhenAligned =
                 mControllers.uiController.isHotseatIconOnTopWhenAligned();
+        boolean isIconAlignedWithHotseat = mControllers.uiController.isIconAlignedWithHotseat();
         boolean isStashed = mControllers.taskbarStashController.isStashed();
-        // Re-create animation when mIsHotseatIconOnTopWhenAligned or mIsStashed changes.
+        // Re-create animation when any of these values change.
         if (mIconAlignControllerLazy == null
                 || mIsHotseatIconOnTopWhenAligned != isHotseatIconOnTopWhenAligned
+                || mIsIconAlignedWithHotseat != isIconAlignedWithHotseat
                 || mIsStashed != isStashed) {
             mIsHotseatIconOnTopWhenAligned = isHotseatIconOnTopWhenAligned;
+            mIsIconAlignedWithHotseat = isIconAlignedWithHotseat;
             mIsStashed = isStashed;
             mIconAlignControllerLazy = createIconAlignmentController(launcherDp);
         }
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarController.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarController.java
index a36d5f0..cdd3e13 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarController.java
@@ -496,6 +496,11 @@
                 () -> mBubbleBarViewController.animateBubbleBarLocation(bubbleBarLocation));
     }
 
+    /** Notifies WMShell to show the expanded view. */
+    void showExpandedView() {
+        mSystemUiProxy.showExpandedView();
+    }
+
     //
     // Loading data for the bubbles
     //
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java
index 1f0851f..c458936 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarView.java
@@ -244,7 +244,7 @@
                     if (mIsBarExpanded && mSelectedBubbleView != null) {
                         mSelectedBubbleView.markSeen();
                     }
-                    updateWidth();
+                    updateLayoutParams();
                 },
                 /* onUpdate= */ animator -> {
                     updateBubblesLayoutProperties(mBubbleBarLocation);
@@ -733,7 +733,7 @@
 
                 @Override
                 public void onAnimationEnd() {
-                    updateWidth();
+                    updateLayoutParams();
                     mBubbleAnimator = null;
                 }
 
@@ -791,7 +791,7 @@
             @Override
             public void onAnimationEnd() {
                 removeView(removedBubble);
-                updateWidth();
+                updateLayoutParams();
                 mBubbleAnimator = null;
                 if (onEndRunnable != null) {
                     onEndRunnable.run();
@@ -823,7 +823,7 @@
     @Override
     public void addView(View child, int index, ViewGroup.LayoutParams params) {
         super.addView(child, index, params);
-        updateWidth();
+        updateLayoutParams();
         updateBubbleAccessibilityStates();
         updateContentDescription();
     }
@@ -887,7 +887,7 @@
             mSelectedBubbleView = null;
             mBubbleBarBackground.showArrow(false);
         }
-        updateWidth();
+        updateLayoutParams();
         updateBubbleAccessibilityStates();
         updateContentDescription();
         mDismissedByDragBubbleView = null;
@@ -937,12 +937,6 @@
         }
     }
 
-    private void updateWidth() {
-        LayoutParams lp = (FrameLayout.LayoutParams) getLayoutParams();
-        lp.width = (int) (mIsBarExpanded ? expandedWidth() : collapsedWidth());
-        setLayoutParams(lp);
-    }
-
     private void updateLayoutParams() {
         LayoutParams lp = (FrameLayout.LayoutParams) getLayoutParams();
         lp.height = (int) getBubbleBarExpandedHeight();
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java
index 1d74b28..5c1a546 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java
@@ -119,7 +119,8 @@
         mBubbleDragController = bubbleControllers.bubbleDragController;
         mTaskbarStashController = controllers.taskbarStashController;
         mTaskbarInsetsController = controllers.taskbarInsetsController;
-        mBubbleBarViewAnimator = new BubbleBarViewAnimator(mBarView, mBubbleStashController);
+        mBubbleBarViewAnimator = new BubbleBarViewAnimator(
+                mBarView, mBubbleStashController, mBubbleBarController::showExpandedView);
         mTaskbarViewPropertiesProvider = taskbarViewPropertiesProvider;
         onBubbleBarConfigurationChanged(/* animate= */ false);
         mActivity.addOnDeviceProfileChangeListener(
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimator.kt b/quickstep/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimator.kt
index 2ed88d8..99c50f2 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimator.kt
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimator.kt
@@ -36,6 +36,7 @@
 constructor(
     private val bubbleBarView: BubbleBarView,
     private val bubbleStashController: BubbleStashController,
+    private val onExpanded: Runnable,
     private val scheduler: Scheduler = HandlerScheduler(bubbleBarView)
 ) {
 
@@ -406,7 +407,7 @@
         springBackAnimation.spring(DynamicAnimation.TRANSLATION_Y, ty)
         springBackAnimation.addEndListener { _, _, _, _, _, _, _ ->
             if (animatingBubble?.expand == true) {
-                bubbleBarView.isExpanded = true
+                expandBubbleBar()
                 cancelHideAnimation()
             } else {
                 moveToState(AnimatingBubble.State.IN)
@@ -417,7 +418,7 @@
         ObjectAnimator.ofFloat(bubbleBarView, View.TRANSLATION_Y, ty - bubbleBarBounceDistanceInPx)
             .withDuration(BUBBLE_BAR_BOUNCE_ANIMATION_DURATION_MS)
             .withEndAction {
-                if (animatingBubble?.expand == true) bubbleBarView.isExpanded = true
+                if (animatingBubble?.expand == true) expandBubbleBar()
                 springBackAnimation.start()
             }
             .start()
@@ -451,7 +452,7 @@
         this.animatingBubble = animatingBubble.copy(expand = true)
         // if we're fully in and waiting to hide, cancel the hide animation and clean up
         if (animatingBubble.state == AnimatingBubble.State.IN) {
-            bubbleBarView.isExpanded = true
+            expandBubbleBar()
             cancelHideAnimation()
         }
     }
@@ -489,6 +490,11 @@
         this.animatingBubble = animatingBubble.copy(state = state)
     }
 
+    private fun expandBubbleBar() {
+        bubbleBarView.isExpanded = true
+        onExpanded.run()
+    }
+
     /**
      * Tracks the translation Y of the bubble bar during the animation. When the bubble bar expands
      * as part of the animation, the expansion should start after the bubble bar reaches the peak
@@ -510,7 +516,7 @@
             }
             val expand = animatingBubble?.expand ?: false
             if (reachedPeak && expand && !startedExpanding) {
-                bubbleBarView.isExpanded = true
+                expandBubbleBar()
                 startedExpanding = true
             }
             previousTy = ty
diff --git a/quickstep/src/com/android/quickstep/DesktopSystemShortcut.kt b/quickstep/src/com/android/quickstep/DesktopSystemShortcut.kt
index fbc0d14..94f4920 100644
--- a/quickstep/src/com/android/quickstep/DesktopSystemShortcut.kt
+++ b/quickstep/src/com/android/quickstep/DesktopSystemShortcut.kt
@@ -24,8 +24,8 @@
 import com.android.quickstep.views.RecentsView
 import com.android.quickstep.views.RecentsViewContainer
 import com.android.quickstep.views.TaskContainer
-import com.android.wm.shell.common.desktopmode.DesktopModeTransitionSource
 import com.android.wm.shell.shared.desktopmode.DesktopModeStatus
+import com.android.wm.shell.shared.desktopmode.DesktopModeTransitionSource
 
 /** A menu item, "Desktop", that allows the user to bring the current app into Desktop Windowing. */
 class DesktopSystemShortcut(
diff --git a/quickstep/src/com/android/quickstep/RecentTasksList.java b/quickstep/src/com/android/quickstep/RecentTasksList.java
index e66da52..05bef35 100644
--- a/quickstep/src/com/android/quickstep/RecentTasksList.java
+++ b/quickstep/src/com/android/quickstep/RecentTasksList.java
@@ -20,7 +20,7 @@
 
 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
 import static com.android.quickstep.util.SplitScreenUtils.convertShellSplitBoundsToLauncher;
-import static com.android.wm.shell.util.GroupedRecentTaskInfo.TYPE_FREEFORM;
+import static com.android.wm.shell.shared.GroupedRecentTaskInfo.TYPE_FREEFORM;
 
 import android.app.ActivityManager;
 import android.app.KeyguardManager;
@@ -40,8 +40,8 @@
 import com.android.quickstep.util.GroupTask;
 import com.android.systemui.shared.recents.model.Task;
 import com.android.wm.shell.recents.IRecentTasksListener;
+import com.android.wm.shell.shared.GroupedRecentTaskInfo;
 import com.android.wm.shell.shared.desktopmode.DesktopModeStatus;
-import com.android.wm.shell.util.GroupedRecentTaskInfo;
 
 import java.io.PrintWriter;
 import java.util.ArrayList;
diff --git a/quickstep/src/com/android/quickstep/RemoteTargetGluer.java b/quickstep/src/com/android/quickstep/RemoteTargetGluer.java
index 3dec381..1be60de 100644
--- a/quickstep/src/com/android/quickstep/RemoteTargetGluer.java
+++ b/quickstep/src/com/android/quickstep/RemoteTargetGluer.java
@@ -17,7 +17,7 @@
 package com.android.quickstep;
 
 import static com.android.quickstep.util.SplitScreenUtils.convertShellSplitBoundsToLauncher;
-import static com.android.wm.shell.util.SplitBounds.KEY_EXTRA_SPLIT_BOUNDS;
+import static com.android.wm.shell.shared.split.SplitBounds.KEY_EXTRA_SPLIT_BOUNDS;
 
 import android.app.WindowConfiguration;
 import android.content.Context;
@@ -33,7 +33,7 @@
 import com.android.quickstep.util.AnimatorControllerWithResistance;
 import com.android.quickstep.util.TaskViewSimulator;
 import com.android.quickstep.util.TransformParams;
-import com.android.wm.shell.util.SplitBounds;
+import com.android.wm.shell.shared.split.SplitBounds;
 
 import java.util.ArrayList;
 import java.util.Arrays;
diff --git a/quickstep/src/com/android/quickstep/SystemUiProxy.java b/quickstep/src/com/android/quickstep/SystemUiProxy.java
index ead5b7b..4392255 100644
--- a/quickstep/src/com/android/quickstep/SystemUiProxy.java
+++ b/quickstep/src/com/android/quickstep/SystemUiProxy.java
@@ -82,7 +82,6 @@
 import com.android.wm.shell.bubbles.IBubbles;
 import com.android.wm.shell.bubbles.IBubblesListener;
 import com.android.wm.shell.common.bubbles.BubbleBarLocation;
-import com.android.wm.shell.common.desktopmode.DesktopModeTransitionSource;
 import com.android.wm.shell.common.pip.IPip;
 import com.android.wm.shell.common.pip.IPipAnimationListener;
 import com.android.wm.shell.desktopmode.IDesktopMode;
@@ -91,16 +90,18 @@
 import com.android.wm.shell.onehanded.IOneHanded;
 import com.android.wm.shell.recents.IRecentTasks;
 import com.android.wm.shell.recents.IRecentTasksListener;
+import com.android.wm.shell.shared.GroupedRecentTaskInfo;
 import com.android.wm.shell.shared.IShellTransitions;
 import com.android.wm.shell.shared.desktopmode.DesktopModeFlags;
 import com.android.wm.shell.shared.desktopmode.DesktopModeStatus;
+import com.android.wm.shell.shared.desktopmode.DesktopModeTransitionSource;
+import com.android.wm.shell.shared.split.SplitBounds;
 import com.android.wm.shell.shared.split.SplitScreenConstants.PersistentSnapPosition;
 import com.android.wm.shell.splitscreen.ISplitScreen;
 import com.android.wm.shell.splitscreen.ISplitScreenListener;
 import com.android.wm.shell.splitscreen.ISplitSelectListener;
 import com.android.wm.shell.startingsurface.IStartingWindow;
 import com.android.wm.shell.startingsurface.IStartingWindowListener;
-import com.android.wm.shell.util.GroupedRecentTaskInfo;
 
 import java.io.PrintWriter;
 import java.util.ArrayList;
@@ -934,6 +935,17 @@
         }
     }
 
+    /** Tells SysUI to show the expanded view. */
+    public void showExpandedView() {
+        try {
+            if (mBubbles != null) {
+                mBubbles.showExpandedView();
+            }
+        } catch (RemoteException e) {
+            Log.w(TAG, "Failed to call showExpandedView");
+        }
+    }
+
     //
     // Splitscreen
     //
@@ -1517,7 +1529,7 @@
                 // Aidl bundles need to explicitly set class loader
                 // https://developer.android.com/guide/components/aidl#Bundles
                 if (extras != null) {
-                    extras.setClassLoader(getClass().getClassLoader());
+                    extras.setClassLoader(SplitBounds.class.getClassLoader());
                 }
                 listener.onAnimationStart(new RecentsAnimationControllerCompat(controller), apps,
                         wallpapers, homeContentInsets, minimizedHomeBounds, extras);
diff --git a/quickstep/src/com/android/quickstep/inputconsumers/DeviceLockedInputConsumer.java b/quickstep/src/com/android/quickstep/inputconsumers/DeviceLockedInputConsumer.java
index 3ca7191..14f47d1 100644
--- a/quickstep/src/com/android/quickstep/inputconsumers/DeviceLockedInputConsumer.java
+++ b/quickstep/src/com/android/quickstep/inputconsumers/DeviceLockedInputConsumer.java
@@ -277,7 +277,7 @@
     }
 
     private void endRemoteAnimation() {
-        if (mRecentsAnimationController != null) {
+        if (!mHomeLaunched && mRecentsAnimationController != null) {
             mRecentsAnimationController.finishController(
                     false /* toRecents */, null /* callback */, false /* sendUserLeaveHint */);
         }
diff --git a/quickstep/src/com/android/quickstep/util/AppPairsController.java b/quickstep/src/com/android/quickstep/util/AppPairsController.java
index ac4032c..e1013db 100644
--- a/quickstep/src/com/android/quickstep/util/AppPairsController.java
+++ b/quickstep/src/com/android/quickstep/util/AppPairsController.java
@@ -242,8 +242,7 @@
         WorkspaceItemInfo app2 = appPairIcon.getInfo().getSecondApp();
         ComponentKey app1Key = new ComponentKey(app1.getTargetComponent(), app1.user);
         ComponentKey app2Key = new ComponentKey(app2.getTargetComponent(), app2.user);
-        mSplitSelectStateController.setLaunchingCuj(cuj);
-        InteractionJankMonitorWrapper.begin(appPairIcon, cuj);
+        mSplitSelectStateController.setLaunchingCuj(appPairIcon, cuj);
 
         mSplitSelectStateController.findLastActiveTasksAndRunCallback(
                 Arrays.asList(app1Key, app2Key),
diff --git a/quickstep/src/com/android/quickstep/util/SplitScreenUtils.kt b/quickstep/src/com/android/quickstep/util/SplitScreenUtils.kt
index d58cb91..d982e81 100644
--- a/quickstep/src/com/android/quickstep/util/SplitScreenUtils.kt
+++ b/quickstep/src/com/android/quickstep/util/SplitScreenUtils.kt
@@ -17,14 +17,13 @@
 package com.android.quickstep.util
 
 import android.util.Log
-import android.view.WindowManager
 import android.view.WindowManager.TRANSIT_OPEN
 import android.view.WindowManager.TRANSIT_TO_FRONT
 import android.window.TransitionInfo
 import android.window.TransitionInfo.Change
 import android.window.TransitionInfo.FLAG_FIRST_CUSTOM
 import com.android.launcher3.util.SplitConfigurationOptions
-import com.android.wm.shell.util.SplitBounds
+import com.android.wm.shell.shared.split.SplitBounds
 import java.lang.IllegalStateException
 
 class SplitScreenUtils {
diff --git a/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java b/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java
index 431cfbe..ae6757f 100644
--- a/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java
+++ b/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java
@@ -59,6 +59,7 @@
 import android.util.Log;
 import android.util.Pair;
 import android.view.SurfaceControl;
+import android.view.View;
 import android.window.IRemoteTransitionFinishedCallback;
 import android.window.RemoteTransition;
 import android.window.RemoteTransitionStub;
@@ -148,9 +149,10 @@
 
     /**
      * Should be a constant from {@link com.android.internal.jank.Cuj} or -1, does not need to be
-     * set for all launches.
+     * set for all launches. Used in conjunction with {@link #mLaunchingViewCuj} below.
      */
     private int mLaunchCuj = -1;
+    private View mLaunchingViewCuj;
 
     private FloatingTaskView mFirstFloatingTaskView;
     private SplitInstructionsView mSplitInstructionsView;
@@ -650,7 +652,12 @@
         return mSplitAnimationController;
     }
 
-    public void setLaunchingCuj(int launchCuj) {
+    /**
+     * Set params to invoke a trace session for the given view and CUJ when we begin animating the
+     * split launch AFTER we get a response from Shell.
+     */
+    public void setLaunchingCuj(View launchingView, int launchCuj) {
+        mLaunchingViewCuj = launchingView;
         mLaunchCuj = launchCuj;
     }
 
@@ -688,6 +695,9 @@
                         && mLaunchingTaskView.getRecentsView() != null
                         && mLaunchingTaskView.getRecentsView().isTaskViewVisible(
                         mLaunchingTaskView);
+                if (mLaunchingViewCuj != null && mLaunchCuj != -1) {
+                    InteractionJankMonitorWrapper.begin(mLaunchingViewCuj, mLaunchCuj);
+                }
                 mSplitAnimationController.playSplitLaunchAnimation(
                         shouldLaunchFromTaskView ? mLaunchingTaskView : null,
                         mLaunchingIconView,
@@ -750,6 +760,7 @@
             InteractionJankMonitorWrapper.end(mLaunchCuj);
         }
         mLaunchCuj = -1;
+        mLaunchingViewCuj = null;
 
         if (mSessionInstanceIds != null) {
             mStatsLogManager.logger()
diff --git a/quickstep/src/com/android/quickstep/util/SwipePipToHomeAnimator.java b/quickstep/src/com/android/quickstep/util/SwipePipToHomeAnimator.java
index 56e91ed..828322b 100644
--- a/quickstep/src/com/android/quickstep/util/SwipePipToHomeAnimator.java
+++ b/quickstep/src/com/android/quickstep/util/SwipePipToHomeAnimator.java
@@ -39,7 +39,7 @@
 import com.android.quickstep.TaskAnimationManager;
 import com.android.systemui.shared.pip.PipSurfaceTransactionHelper;
 import com.android.systemui.shared.system.InteractionJankMonitorWrapper;
-import com.android.wm.shell.pip.PipContentOverlay;
+import com.android.wm.shell.shared.pip.PipContentOverlay;
 
 /**
  * Subclass of {@link RectFSpringAnim} that animates an Activity to PiP (picture-in-picture) window
diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index e3c52d7..f1ff026 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -231,9 +231,9 @@
 import com.android.systemui.shared.system.PackageManagerWrapper;
 import com.android.systemui.shared.system.TaskStackChangeListener;
 import com.android.systemui.shared.system.TaskStackChangeListeners;
-import com.android.wm.shell.common.desktopmode.DesktopModeTransitionSource;
 import com.android.wm.shell.common.pip.IPipAnimationListener;
 import com.android.wm.shell.shared.desktopmode.DesktopModeStatus;
+import com.android.wm.shell.shared.desktopmode.DesktopModeTransitionSource;
 
 import kotlin.Unit;
 
@@ -3273,12 +3273,12 @@
             longRowWidth = largeTaskWidthAndSpacing;
         }
 
-        if (longRowWidth < mLastComputedGridSize.width()) {
-            mClearAllShortTotalWidthTranslation =
-                    (mIsRtl
-                            ? mLastComputedTaskSize.right
-                            : deviceProfile.widthPx - mLastComputedTaskSize.left)
-                            - longRowWidth - deviceProfile.overviewGridSideMargin;
+        // If first task is not in the expected position (mLastComputedTaskSize) and being too close
+        // to ClearAllButton, then apply extra translation to ClearAllButton.
+        int firstTaskStart = mLastComputedGridSize.left + longRowWidth;
+        int expectedFirstTaskStart = mLastComputedTaskSize.right;
+        if (firstTaskStart < expectedFirstTaskStart) {
+            mClearAllShortTotalWidthTranslation = expectedFirstTaskStart - firstTaskStart;
             clearAllShortTotalWidthTranslation = mIsRtl
                     ? -mClearAllShortTotalWidthTranslation : mClearAllShortTotalWidthTranslation;
             if (snappedTaskRowWidth == longRowWidth) {
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimatorTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimatorTest.kt
index 4da06e1..7928ce9 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimatorTest.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/bubbles/animation/BubbleBarViewAnimatorTest.kt
@@ -64,6 +64,7 @@
     private lateinit var bubble: BubbleBarBubble
     private lateinit var bubbleBarView: BubbleBarView
     private lateinit var bubbleStashController: BubbleStashController
+    private val onExpandedNoOp = Runnable {}
 
     @Before
     fun setUp() {
@@ -81,7 +82,12 @@
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = false)
@@ -125,7 +131,12 @@
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = false)
@@ -168,7 +179,12 @@
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = false)
@@ -208,7 +224,12 @@
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = false)
@@ -249,7 +270,12 @@
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = false)
@@ -278,8 +304,15 @@
         val handleAnimator = PhysicsAnimator.getInstance(handle)
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = true)
@@ -303,6 +336,7 @@
         assertThat(animatorScheduler.delayedBlock).isNull()
 
         verify(bubbleStashController).showBubbleBarImmediate()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -314,8 +348,15 @@
         val handleAnimator = PhysicsAnimator.getInstance(handle)
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = false)
@@ -345,6 +386,7 @@
             .isEqualTo(DIFF_BETWEEN_HANDLE_AND_BAR_CENTERS + BAR_TRANSLATION_Y_FOR_TASKBAR)
         verifyBubbleBarIsExpandedWithTranslation(BAR_TRANSLATION_Y_FOR_TASKBAR)
         assertThat(animator.isAnimating).isFalse()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -356,8 +398,15 @@
         val handleAnimator = PhysicsAnimator.getInstance(handle)
         whenever(bubbleStashController.getStashedHandlePhysicsAnimator()).thenReturn(handleAnimator)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleInForStashed(bubble, isExpanding = false)
@@ -384,6 +433,7 @@
             .isEqualTo(DIFF_BETWEEN_HANDLE_AND_BAR_CENTERS + BAR_TRANSLATION_Y_FOR_TASKBAR)
         verifyBubbleBarIsExpandedWithTranslation(BAR_TRANSLATION_Y_FOR_TASKBAR)
         assertThat(animator.isAnimating).isFalse()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -400,7 +450,12 @@
         val barAnimator = PhysicsAnimator.getInstance(bubbleBarView)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateToInitialState(bubble, isInApp = true, isExpanding = false)
@@ -442,8 +497,15 @@
 
         val barAnimator = PhysicsAnimator.getInstance(bubbleBarView)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateToInitialState(bubble, isInApp = true, isExpanding = true)
@@ -459,6 +521,7 @@
 
         assertThat(animatorScheduler.delayedBlock).isNull()
         verify(bubbleStashController).showBubbleBarImmediate()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -471,7 +534,12 @@
         val barAnimator = PhysicsAnimator.getInstance(bubbleBarView)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateToInitialState(bubble, isInApp = false, isExpanding = false)
@@ -502,8 +570,15 @@
         whenever(bubbleStashController.bubbleBarTranslationY)
             .thenReturn(BAR_TRANSLATION_Y_FOR_HOTSEAT)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateToInitialState(bubble, isInApp = false, isExpanding = false)
@@ -533,6 +608,7 @@
         verifyBubbleBarIsExpandedWithTranslation(BAR_TRANSLATION_Y_FOR_HOTSEAT)
         assertThat(animator.isAnimating).isFalse()
         verify(bubbleStashController).showBubbleBarImmediate()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -542,8 +618,15 @@
         whenever(bubbleStashController.bubbleBarTranslationY)
             .thenReturn(BAR_TRANSLATION_Y_FOR_HOTSEAT)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateToInitialState(bubble, isInApp = false, isExpanding = false)
@@ -566,6 +649,7 @@
 
         verifyBubbleBarIsExpandedWithTranslation(BAR_TRANSLATION_Y_FOR_HOTSEAT)
         assertThat(animator.isAnimating).isFalse()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -578,7 +662,12 @@
         val barAnimator = PhysicsAnimator.getInstance(bubbleBarView)
 
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpandedNoOp,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleBarForCollapsed(bubble, isExpanding = false)
@@ -617,8 +706,15 @@
 
         val barAnimator = PhysicsAnimator.getInstance(bubbleBarView)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleBarForCollapsed(bubble, isExpanding = true)
@@ -645,6 +741,7 @@
         assertThat(bubbleBarView.translationY).isEqualTo(BAR_TRANSLATION_Y_FOR_HOTSEAT)
         assertThat(bubbleBarView.isExpanded).isTrue()
         verify(bubbleStashController).showBubbleBarImmediate()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -656,8 +753,15 @@
 
         val barAnimator = PhysicsAnimator.getInstance(bubbleBarView)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleBarForCollapsed(bubble, isExpanding = false)
@@ -695,6 +799,7 @@
         assertThat(bubbleBarView.translationY).isEqualTo(BAR_TRANSLATION_Y_FOR_HOTSEAT)
         assertThat(bubbleBarView.isExpanded).isTrue()
         verify(bubbleStashController).showBubbleBarImmediate()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     @Test
@@ -706,8 +811,15 @@
 
         val barAnimator = PhysicsAnimator.getInstance(bubbleBarView)
 
+        var notifiedExpanded = false
+        val onExpanded = Runnable { notifiedExpanded = true }
         val animator =
-            BubbleBarViewAnimator(bubbleBarView, bubbleStashController, animatorScheduler)
+            BubbleBarViewAnimator(
+                bubbleBarView,
+                bubbleStashController,
+                onExpanded,
+                animatorScheduler
+            )
 
         InstrumentationRegistry.getInstrumentation().runOnMainSync {
             animator.animateBubbleBarForCollapsed(bubble, isExpanding = false)
@@ -742,6 +854,7 @@
         assertThat(bubbleBarView.translationY).isEqualTo(BAR_TRANSLATION_Y_FOR_HOTSEAT)
         assertThat(bubbleBarView.isExpanded).isTrue()
         verify(bubbleStashController).showBubbleBarImmediate()
+        assertThat(notifiedExpanded).isTrue()
     }
 
     private fun setUpBubbleBar() {
diff --git a/quickstep/tests/src/com/android/quickstep/DesktopSystemShortcutTest.kt b/quickstep/tests/src/com/android/quickstep/DesktopSystemShortcutTest.kt
index d9d5585..885a7f6 100644
--- a/quickstep/tests/src/com/android/quickstep/DesktopSystemShortcutTest.kt
+++ b/quickstep/tests/src/com/android/quickstep/DesktopSystemShortcutTest.kt
@@ -39,8 +39,8 @@
 import com.android.systemui.shared.recents.model.Task
 import com.android.systemui.shared.recents.model.Task.TaskKey
 import com.android.window.flags.Flags
-import com.android.wm.shell.common.desktopmode.DesktopModeTransitionSource
 import com.android.wm.shell.shared.desktopmode.DesktopModeStatus
+import com.android.wm.shell.shared.desktopmode.DesktopModeTransitionSource
 import com.google.common.truth.Truth.assertThat
 import org.junit.After
 import org.junit.Before
diff --git a/quickstep/tests/src/com/android/quickstep/RecentTasksListTest.java b/quickstep/tests/src/com/android/quickstep/RecentTasksListTest.java
index cbc8441..244b897 100644
--- a/quickstep/tests/src/com/android/quickstep/RecentTasksListTest.java
+++ b/quickstep/tests/src/com/android/quickstep/RecentTasksListTest.java
@@ -39,7 +39,7 @@
 import com.android.quickstep.util.GroupTask;
 import com.android.quickstep.views.TaskViewType;
 import com.android.systemui.shared.recents.model.Task;
-import com.android.wm.shell.util.GroupedRecentTaskInfo;
+import com.android.wm.shell.shared.GroupedRecentTaskInfo;
 
 import org.junit.Before;
 import org.junit.Test;
diff --git a/res/drawable/bg_letter_list_text.xml b/res/drawable/bg_letter_list_text.xml
new file mode 100644
index 0000000..427702b
--- /dev/null
+++ b/res/drawable/bg_letter_list_text.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ 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.
+  -->
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="oval">
+    <solid android:color="?attr/materialColorSurfaceContainer" />
+    <corners android:radius="100dp"/>
+    <size
+        android:width="@dimen/bg_letter_list_text_size"
+        android:height="@dimen/bg_letter_list_text_size"/>
+</shape>
\ No newline at end of file
diff --git a/res/layout/all_apps_fast_scroller.xml b/res/layout/all_apps_fast_scroller.xml
index 0f1d933..7e16ca5 100644
--- a/res/layout/all_apps_fast_scroller.xml
+++ b/res/layout/all_apps_fast_scroller.xml
@@ -36,4 +36,17 @@
         android:layout_marginEnd="@dimen/fastscroll_end_margin"
         launcher:canThumbDetach="true" />
 
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:id="@+id/scroll_letter_layout"
+        android:layout_width="@dimen/fastscroll_width"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        android:layout_alignParentBottom="true"
+        android:layout_alignParentEnd="true"
+        android:layout_alignTop="@+id/all_apps_header"
+        android:layout_marginTop="@dimen/all_apps_header_bottom_padding"
+        android:layout_marginEnd="@dimen/fastscroll_list_letter_end_margin"
+        android:clipToPadding="false"
+        android:outlineProvider="none"
+        />
 </merge>
\ No newline at end of file
diff --git a/res/layout/fast_scroller_letter_list_text_view.xml b/res/layout/fast_scroller_letter_list_text_view.xml
new file mode 100644
index 0000000..493b6fc
--- /dev/null
+++ b/res/layout/fast_scroller_letter_list_text_view.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ 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.
+  -->
+
+<com.android.launcher3.allapps.LetterListTextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="@dimen/fastscroll_list_letter_size"
+    android:layout_height="@dimen/fastscroll_list_letter_size"
+    android:textSize="@dimen/fastscroll_list_letter_text_size"
+    android:importantForAccessibility="no"
+    android:gravity="center"
+    android:clickable="false">
+</com.android.launcher3.allapps.LetterListTextView>
\ No newline at end of file
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 3b239ac..5ba00c0 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -81,6 +81,11 @@
     <dimen name="fastscroll_popup_text_size">32dp</dimen>
     <dimen name="fastscroll_popup_margin">19dp</dimen>
 
+    <dimen name="fastscroll_list_letter_size">5dp</dimen>
+    <dimen name="fastscroll_list_letter_text_size">14sp</dimen>
+    <dimen name="fastscroll_list_letter_end_margin">-10dp</dimen>
+    <dimen name="bg_letter_list_text_size">20sp</dimen>
+
     <!--
       Fast scroller draws the content horizontally centered. The end of the track should be
       aligned at the end of the container.
diff --git a/src/com/android/launcher3/FastScrollRecyclerView.java b/src/com/android/launcher3/FastScrollRecyclerView.java
index de1748b..6622e11 100644
--- a/src/com/android/launcher3/FastScrollRecyclerView.java
+++ b/src/com/android/launcher3/FastScrollRecyclerView.java
@@ -25,6 +25,7 @@
 import android.view.accessibility.AccessibilityNodeInfo;
 
 import androidx.annotation.Nullable;
+import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.launcher3.compat.AccessibilityManagerCompat;
@@ -54,9 +55,11 @@
         super(context, attrs, defStyleAttr);
     }
 
-    public void bindFastScrollbar(RecyclerViewFastScroller scrollbar) {
+    public void bindFastScrollbar(RecyclerViewFastScroller scrollbar,
+            RecyclerViewFastScroller.FastScrollerLocation location) {
         mScrollbar = scrollbar;
         mScrollbar.setRecyclerView(this);
+        mScrollbar.setFastScrollerLocation(location);
         onUpdateScrollbar(0);
     }
 
@@ -163,6 +166,13 @@
     public abstract void onUpdateScrollbar(int dy);
 
     /**
+     * Return the fast scroll letter list view in the A-Z list.
+     */
+    public ConstraintLayout getLetterList() {
+        return null;
+    }
+
+    /**
      * <p>Override in each subclass of this base class.
      */
     public void onFastScrollCompleted() {}
diff --git a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
index 227ac2b..cc4724c 100644
--- a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
+++ b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
@@ -29,6 +29,7 @@
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_TAP_ON_WORK_TAB;
 import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
 import static com.android.launcher3.util.ScrollableLayoutManager.PREDICTIVE_BACK_MIN_SCALE;
+import static com.android.launcher3.views.RecyclerViewFastScroller.FastScrollerLocation.ALL_APPS_SCROLLER;
 
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
@@ -65,6 +66,7 @@
 import androidx.annotation.Nullable;
 import androidx.annotation.Px;
 import androidx.annotation.VisibleForTesting;
+import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.core.graphics.ColorUtils;
 import androidx.recyclerview.widget.RecyclerView;
 
@@ -168,6 +170,7 @@
     protected FloatingHeaderView mHeader;
     protected View mBottomSheetBackground;
     protected RecyclerViewFastScroller mFastScroller;
+    private ConstraintLayout mFastScrollLetterLayout;
 
     /**
      * View that defines the search box. Result is rendered inside {@link #mSearchRecyclerView}.
@@ -282,6 +285,13 @@
         mSearchRecyclerView = findViewById(R.id.search_results_list_view);
         mFastScroller = findViewById(R.id.fast_scroller);
         mFastScroller.setPopupView(findViewById(R.id.fast_scroller_popup));
+        mFastScrollLetterLayout = findViewById(R.id.scroll_letter_layout);
+        if (Flags.letterFastScroller()) {
+            // Set clip children to false otherwise the scroller letters will be clipped.
+            setClipChildren(false);
+        } else {
+            setClipChildren(true);
+        }
 
         mSearchContainer = inflateSearchBar();
         if (!isSearchBarFloating()) {
@@ -563,7 +573,8 @@
             mActivityContext.hideKeyboard();
         }
         if (mAH.get(currentActivePage).mRecyclerView != null) {
-            mAH.get(currentActivePage).mRecyclerView.bindFastScrollbar(mFastScroller);
+            mAH.get(currentActivePage).mRecyclerView.bindFastScrollbar(mFastScroller,
+                    ALL_APPS_SCROLLER);
         }
         // Header keeps track of active recycler view to properly render header protection.
         mHeader.setActiveRV(currentActivePage);
@@ -1500,6 +1511,10 @@
         }
     }
 
+    ConstraintLayout getFastScrollerLetterList() {
+        return mFastScrollLetterLayout;
+    }
+
     /**
      * redraws header protection
      */
@@ -1567,7 +1582,7 @@
         void setup(@NonNull View rv, @Nullable Predicate<ItemInfo> matcher) {
             mAppsList.updateItemFilter(matcher);
             mRecyclerView = (AllAppsRecyclerView) rv;
-            mRecyclerView.bindFastScrollbar(mFastScroller);
+            mRecyclerView.bindFastScrollbar(mFastScroller, ALL_APPS_SCROLLER);
             mRecyclerView.setEdgeEffectFactory(createEdgeEffectFactory());
             mRecyclerView.setApps(mAppsList);
             mRecyclerView.setLayoutManager(mLayoutManager);
diff --git a/src/com/android/launcher3/allapps/AllAppsRecyclerView.java b/src/com/android/launcher3/allapps/AllAppsRecyclerView.java
index 2a47222..ae45a35 100644
--- a/src/com/android/launcher3/allapps/AllAppsRecyclerView.java
+++ b/src/com/android/launcher3/allapps/AllAppsRecyclerView.java
@@ -15,6 +15,9 @@
  */
 package com.android.launcher3.allapps;
 
+import static androidx.constraintlayout.widget.ConstraintSet.MATCH_CONSTRAINT;
+import static androidx.constraintlayout.widget.ConstraintSet.WRAP_CONTENT;
+
 import static com.android.launcher3.config.FeatureFlags.ALL_APPS_GONE_VISIBILITY;
 import static com.android.launcher3.config.FeatureFlags.ENABLE_ALL_APPS_RV_PREINFLATION;
 import static com.android.launcher3.logger.LauncherAtom.ContainerInfo;
@@ -36,22 +39,29 @@
 import android.graphics.Canvas;
 import android.util.AttributeSet;
 import android.util.Log;
+import android.view.LayoutInflater;
 import android.view.View;
+import android.widget.TextView;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.constraintlayout.widget.ConstraintLayout;
+import androidx.constraintlayout.widget.ConstraintSet;
 import androidx.core.util.Consumer;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.launcher3.DeviceProfile;
 import com.android.launcher3.ExtendedEditText;
 import com.android.launcher3.FastScrollRecyclerView;
+import com.android.launcher3.Flags;
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.logging.StatsLogManager;
 import com.android.launcher3.views.ActivityContext;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -66,6 +76,7 @@
     protected final int mNumAppsPerRow;
     private final AllAppsFastScrollHelper mFastScrollHelper;
     private int mCumulativeVerticalScroll;
+    private ConstraintLayout mLetterList;
 
     protected AlphabeticalAppsList<?> mApps;
 
@@ -238,6 +249,9 @@
             return;
         }
 
+        if (Flags.letterFastScroller() && !mScrollbar.isDraggingThumb()) {
+            setLettersToScrollLayout(mApps.getFastScrollerSections());
+        }
         // Only show the scrollbar if there is height to be scrolled
         int availableScrollBarHeight = getAvailableScrollBarHeight();
         int availableScrollHeight = getAvailableScrollHeight();
@@ -319,6 +333,80 @@
         return false;
     }
 
+    public void setLettersToScrollLayout(
+            List<AlphabeticalAppsList.FastScrollSectionInfo> fastScrollSections) {
+        if (mLetterList != null) {
+            mLetterList.removeAllViews();
+        }
+        Context context = getContext();
+        ActivityAllAppsContainerView<?> allAppsContainerView =
+                ActivityContext.lookupContext(context).getAppsView();
+        mLetterList = allAppsContainerView.getFastScrollerLetterList();
+        mLetterList.setPadding(0, getScrollBarTop(), 0, getScrollBarMarginBottom());
+        List<LetterListTextView> textViews = new ArrayList<>();
+        for (int i = 0; i < fastScrollSections.size(); i++) {
+            AlphabeticalAppsList.FastScrollSectionInfo sectionInfo = fastScrollSections.get(i);
+            LetterListTextView textView =
+                    (LetterListTextView) LayoutInflater.from(context).inflate(
+                            R.layout.fast_scroller_letter_list_text_view, mLetterList, false);
+            int viewId = View.generateViewId();
+            textView.setId(viewId);
+            sectionInfo.setId(viewId);
+            textView.setText(sectionInfo.sectionName);
+            if (i == fastScrollSections.size() - 1) {
+                // The last section info is just a duplicate so that user can scroll to the bottom.
+                textView.setVisibility(INVISIBLE);
+            }
+            ConstraintLayout.LayoutParams lp = new ConstraintLayout.LayoutParams(
+                    MATCH_CONSTRAINT, WRAP_CONTENT);
+            lp.dimensionRatio = "v,1:1";
+            textView.setLayoutParams(lp);
+            textViews.add(textView);
+            mLetterList.addView(textView);
+        }
+        // Need to add an extra textview to be aligned.
+        LetterListTextView lastLetterListTextView = new LetterListTextView(context);
+        int currentId = View.generateViewId();
+        lastLetterListTextView.setId(currentId);
+        lastLetterListTextView.setVisibility(INVISIBLE);
+        textViews.add(lastLetterListTextView);
+        mLetterList.addView(lastLetterListTextView);
+        constraintTextViewsVertically(mLetterList, textViews);
+        mLetterList.setVisibility(VISIBLE);
+    }
+
+    private void constraintTextViewsVertically(ConstraintLayout constraintLayout,
+            List<LetterListTextView> textViews) {
+        ConstraintSet chain = new ConstraintSet();
+        chain.clone(constraintLayout);
+        for (int i = 0; i < textViews.size(); i++) {
+            LetterListTextView currentView = textViews.get(i);
+            if (i == 0) {
+                chain.connect(currentView.getId(), ConstraintSet.TOP, ConstraintSet.PARENT_ID,
+                        ConstraintSet.TOP);
+            } else {
+                chain.connect(currentView.getId(), ConstraintSet.TOP, textViews.get(i-1).getId(),
+                        ConstraintSet.BOTTOM);
+            }
+            chain.connect(currentView.getId(), ConstraintSet.START, constraintLayout.getId(),
+                    ConstraintSet.START);
+            chain.connect(currentView.getId(), ConstraintSet.END, constraintLayout.getId(),
+                    ConstraintSet.END);
+        }
+        int[] viewIds = textViews.stream().mapToInt(TextView::getId).toArray();
+        float[] weights = new float[textViews.size()];
+        Arrays.fill(weights,1); // fill with 1 for equal weights
+        chain.createVerticalChain(constraintLayout.getId(), ConstraintSet.TOP,
+                constraintLayout.getId(), ConstraintSet.BOTTOM, viewIds, weights,
+                ConstraintSet.CHAIN_SPREAD);
+        chain.applyTo(constraintLayout);
+    }
+
+    @Override
+    public ConstraintLayout getLetterList() {
+        return mLetterList;
+    }
+
     private void logCumulativeVerticalScroll() {
         ActivityContext context = ActivityContext.lookupContext(getContext());
         StatsLogManager mgr = context.getStatsLogManager();
diff --git a/src/com/android/launcher3/allapps/AlphabeticalAppsList.java b/src/com/android/launcher3/allapps/AlphabeticalAppsList.java
index 6dd811a..8e44d65 100644
--- a/src/com/android/launcher3/allapps/AlphabeticalAppsList.java
+++ b/src/com/android/launcher3/allapps/AlphabeticalAppsList.java
@@ -74,11 +74,17 @@
         public final CharSequence sectionName;
         // The item position
         public final int position;
+        // The view id associated with this section
+        public int id = -1;
 
         public FastScrollSectionInfo(CharSequence sectionName, int position) {
             this.sectionName = sectionName;
             this.position = position;
         }
+
+        public void setId(int id) {
+            this.id = id;
+        }
     }
 
 
diff --git a/src/com/android/launcher3/allapps/LetterListTextView.java b/src/com/android/launcher3/allapps/LetterListTextView.java
new file mode 100644
index 0000000..9326d79
--- /dev/null
+++ b/src/com/android/launcher3/allapps/LetterListTextView.java
@@ -0,0 +1,133 @@
+/*
+ * 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.allapps;
+
+import android.content.Context;
+import android.graphics.PorterDuff;
+import android.graphics.PorterDuffColorFilter;
+import android.graphics.drawable.Drawable;
+import android.util.AttributeSet;
+import android.widget.TextView;
+
+import androidx.core.graphics.ColorUtils;
+
+import com.android.launcher3.R;
+import com.android.launcher3.Utilities;
+import com.android.launcher3.util.Themes;
+
+/**
+ * A TextView that is used to display the letter list in the fast scroller.
+ */
+public class LetterListTextView extends TextView {
+    private static final float ABSOLUTE_TRANSLATION_X = 30f;
+    private static final float ABSOLUTE_SCALE = 1.4f;
+    private final Drawable mLetterBackground;
+    private final int mLetterListTextWidthAndHeight;
+    private final int mTextColor;
+    private final int mBackgroundColor;
+    private final int mSelectedColor;
+
+    public LetterListTextView(Context context) {
+        this(context, null, 0);
+    }
+
+    public LetterListTextView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public LetterListTextView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+        mLetterBackground = context.getDrawable(R.drawable.bg_letter_list_text);
+        mLetterListTextWidthAndHeight = context.getResources().getDimensionPixelSize(
+                R.dimen.fastscroll_list_letter_size);
+        mTextColor = Themes.getAttrColor(context, R.attr.materialColorOnSurface);
+        mBackgroundColor = Themes.getAttrColor(context, R.attr.materialColorSurfaceContainer);
+        mSelectedColor = Themes.getAttrColor(context, R.attr.materialColorOnSecondary);
+    }
+
+    @Override
+    public void onFinishInflate() {
+        super.onFinishInflate();
+        setBackground(mLetterBackground);
+        setTextColor(mTextColor);
+        setClickable(false);
+        setWidth(mLetterListTextWidthAndHeight);
+        setTextSize(mLetterListTextWidthAndHeight);
+        setVisibility(VISIBLE);
+    }
+
+    /**
+     * Animates the letter list text view based on the current finger position.
+     *
+     * @param currentFingerY The Y position of where the finger is placed on the fastScroller in
+     *                       pixels.
+     */
+    public void animateBasedOnYPosition(int currentFingerY) {
+        if (getBackground() == null) {
+            return;
+        }
+        float cutOffMin = currentFingerY - (getHeight() * 2);
+        float cutOffMax = currentFingerY + (getHeight() * 2);
+        float cutOffDistance = cutOffMax - cutOffMin;
+        // Update the background blend color
+        boolean isWithinAnimationBounds = getY() < cutOffMax && getY() > cutOffMin;
+        if (isWithinAnimationBounds) {
+            getBackground().setColorFilter(new PorterDuffColorFilter(
+                    getBlendColorBasedOnYPosition(currentFingerY, cutOffDistance),
+                    PorterDuff.Mode.MULTIPLY));
+        } else {
+            getBackground().setColorFilter(new PorterDuffColorFilter(
+                    mBackgroundColor, PorterDuff.Mode.MULTIPLY));
+        }
+        translateBasedOnYPosition(currentFingerY, cutOffDistance, isWithinAnimationBounds);
+        scaleBasedOnYPosition(currentFingerY, cutOffDistance, isWithinAnimationBounds);
+    }
+
+    private int getBlendColorBasedOnYPosition(int y, float cutOffDistance) {
+        float raisedCosineBlend = (float) Math.cos(((y - getY()) / (cutOffDistance)) * Math.PI);
+        float blendRatio = Utilities.boundToRange(raisedCosineBlend, 0f, 1f);
+        return ColorUtils.blendARGB(mBackgroundColor, mSelectedColor, blendRatio);
+    }
+
+    private void scaleBasedOnYPosition(int y, float cutOffDistance,
+            boolean isWithinAnimationBounds) {
+        float raisedCosineScale = (float) Math.cos(((y - getY()) / (cutOffDistance)) * Math.PI)
+                * ABSOLUTE_SCALE;
+        if (isWithinAnimationBounds) {
+            raisedCosineScale = Utilities.boundToRange(raisedCosineScale, 1f, ABSOLUTE_SCALE);
+            setScaleX(raisedCosineScale);
+            setScaleY(raisedCosineScale);
+        } else {
+            setScaleX(1);
+            setScaleY(1);
+        }
+    }
+
+    private void translateBasedOnYPosition(int y, float cutOffDistance,
+            boolean isWithinAnimationBounds) {
+        float raisedCosineTranslation =
+                (float) Math.cos(((y - getY()) / (cutOffDistance)) * Math.PI)
+                        * ABSOLUTE_TRANSLATION_X;
+        if (isWithinAnimationBounds) {
+            raisedCosineTranslation = -1 * Utilities.boundToRange(raisedCosineTranslation,
+                    0, ABSOLUTE_TRANSLATION_X);
+            setTranslationX(raisedCosineTranslation);
+        } else {
+            setTranslationX(0);
+        }
+    }
+}
diff --git a/src/com/android/launcher3/model/LoaderTask.java b/src/com/android/launcher3/model/LoaderTask.java
index 269cb9f..605accf 100644
--- a/src/com/android/launcher3/model/LoaderTask.java
+++ b/src/com/android/launcher3/model/LoaderTask.java
@@ -209,7 +209,10 @@
                 mApp.getContext().getContentResolver(),
                 "launcher_broadcast_installed_apps",
                 /* def= */ 0);
-        if (launcherBroadcastInstalledApps == 1 && mIsRestoreFromBackup) {
+        boolean shouldAttachArchivingExtras = mIsRestoreFromBackup
+                && (launcherBroadcastInstalledApps == 1
+                        || Flags.enableFirstScreenBroadcastArchivingExtras());
+        if (shouldAttachArchivingExtras) {
             List<FirstScreenBroadcastModel> broadcastModels =
                     FirstScreenBroadcastHelper.createModelsForFirstScreenBroadcast(
                             mPmHelper,
diff --git a/src/com/android/launcher3/views/RecyclerViewFastScroller.java b/src/com/android/launcher3/views/RecyclerViewFastScroller.java
index fa17b7b..63648dd 100644
--- a/src/com/android/launcher3/views/RecyclerViewFastScroller.java
+++ b/src/com/android/launcher3/views/RecyclerViewFastScroller.java
@@ -20,6 +20,9 @@
 
 import static androidx.recyclerview.widget.RecyclerView.SCROLL_STATE_IDLE;
 
+import static com.android.launcher3.views.RecyclerViewFastScroller.FastScrollerLocation.ALL_APPS_SCROLLER;
+import static com.android.launcher3.views.RecyclerViewFastScroller.FastScrollerLocation.WIDGET_SCROLLER;
+
 import android.animation.ObjectAnimator;
 import android.content.Context;
 import android.content.res.Resources;
@@ -40,11 +43,15 @@
 import android.view.WindowInsets;
 import android.widget.TextView;
 
+import androidx.annotation.NonNull;
+import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.launcher3.FastScrollRecyclerView;
+import com.android.launcher3.Flags;
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
+import com.android.launcher3.allapps.LetterListTextView;
 import com.android.launcher3.graphics.FastScrollThumbDrawable;
 import com.android.launcher3.util.Themes;
 
@@ -55,6 +62,19 @@
  * The track and scrollbar that shows when you scroll the list.
  */
 public class RecyclerViewFastScroller extends View {
+
+    /** FastScrollerLocation describes what RecyclerView the fast scroller is dedicated to. */
+    public enum FastScrollerLocation {
+        UNKNOWN_SCROLLER(0),
+        ALL_APPS_SCROLLER(1),
+        WIDGET_SCROLLER(2);
+
+        public final int location;
+
+        FastScrollerLocation(int location) {
+            this.location = location;
+        }
+    }
     private static final String TAG = "RecyclerViewFastScroller";
     private static final boolean DEBUG = false;
     private static final int FASTSCROLL_THRESHOLD_MILLIS = 40;
@@ -106,6 +126,8 @@
     private final Point mThumbDrawOffset = new Point();
 
     private final Paint mTrackPaint;
+    private final int mThumbColor;
+    private final int mThumbLetterScrollerColor;
 
     private float mLastTouchY;
     private boolean mIsDragging;
@@ -139,6 +161,7 @@
     private int mDownX;
     private int mDownY;
     private int mLastY;
+    private FastScrollerLocation mFastScrollerLocation;
 
     public RecyclerViewFastScroller(Context context) {
         this(context, null);
@@ -151,13 +174,16 @@
     public RecyclerViewFastScroller(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
 
+        mFastScrollerLocation = FastScrollerLocation.UNKNOWN_SCROLLER;
         mTrackPaint = new Paint();
         mTrackPaint.setColor(Themes.getAttrColor(context, android.R.attr.textColorPrimary));
         mTrackPaint.setAlpha(MAX_TRACK_ALPHA);
 
+        mThumbColor = Themes.getColorAccent(context);
+        mThumbLetterScrollerColor = Themes.getAttrColor(context, R.attr.materialColorSurfaceBright);
         mThumbPaint = new Paint();
         mThumbPaint.setAntiAlias(true);
-        mThumbPaint.setColor(Themes.getColorAccent(context));
+        mThumbPaint.setColor(mThumbColor);
         mThumbPaint.setStyle(Paint.Style.FILL);
 
         Resources res = getResources();
@@ -334,6 +360,18 @@
         animatePopupVisibility(!TextUtils.isEmpty(sectionName));
         mLastTouchY = boundedY;
         setThumbOffsetY((int) mLastTouchY);
+        updateFastScrollerLetterList(y);
+    }
+
+    private void updateFastScrollerLetterList(int y) {
+        if (!shouldUseLetterFastScroller()) {
+            return;
+        }
+        ConstraintLayout mLetterList = mRv.getLetterList();
+        for (int i = 0; i < mLetterList.getChildCount(); i++) {
+            LetterListTextView currentLetter = (LetterListTextView) mLetterList.getChildAt(i);
+            currentLetter.animateBasedOnYPosition(y + mTouchOffsetY);
+        }
     }
 
     /** End any active fast scrolling touch handling, if applicable. */
@@ -359,15 +397,35 @@
         mThumbDrawOffset.set(getWidth() / 2, mRv.getScrollBarTop());
         // Draw the track
         float halfW = mWidth / 2;
-        canvas.drawRoundRect(-halfW, 0, halfW, mRv.getScrollbarTrackHeight(),
-                mWidth, mWidth, mTrackPaint);
-
-        canvas.translate(0, mThumbOffsetY);
+        boolean useLetterFastScroller = shouldUseLetterFastScroller();
+        if (useLetterFastScroller) {
+            float translateX;
+            if (mIsDragging) {
+                // halfW * 3 is half circle.
+                translateX = halfW * 3;
+            } else {
+                translateX = halfW * 5;
+            }
+            canvas.translate(translateX, mThumbOffsetY);
+        } else {
+            canvas.drawRoundRect(-halfW, 0, halfW, mRv.getScrollbarTrackHeight(),
+                    mWidth, mWidth, mTrackPaint);
+            canvas.translate(0, mThumbOffsetY);
+        }
         mThumbDrawOffset.y += mThumbOffsetY;
+
+        /* Draw half circle */
         halfW += mThumbPadding;
         float r = getScrollThumbRadius();
-        mThumbBounds.set(-halfW, 0, halfW, mThumbHeight);
-        canvas.drawRoundRect(mThumbBounds, r, r, mThumbPaint);
+        if (useLetterFastScroller) {
+            mThumbPaint.setColor(mThumbLetterScrollerColor);
+            mThumbBounds.set(0, 0, 0, mThumbHeight);
+            canvas.drawCircle(-halfW, halfW, r * 2, mThumbPaint);
+        } else {
+            mThumbPaint.setColor(mThumbColor);
+            mThumbBounds.set(-halfW, 0, halfW, mThumbHeight);
+            canvas.drawRoundRect(mThumbBounds, r, r, mThumbPaint);
+        }
         mThumbBounds.roundOut(SYSTEM_GESTURE_EXCLUSION_RECT.get(0));
         // swiping very close to the thumb area (not just within it's bound)
         // will also prevent back gesture
@@ -380,6 +438,11 @@
         canvas.restoreToCount(saveCount);
     }
 
+    boolean shouldUseLetterFastScroller() {
+        return Flags.letterFastScroller()
+                && getScrollerLocation() == FastScrollerLocation.ALL_APPS_SCROLLER;
+    }
+
     @Override
     public WindowInsets onApplyWindowInsets(WindowInsets insets) {
         mSystemGestureInsets = insets.getSystemGestureInsets();
@@ -421,19 +484,25 @@
         return isNearThumb(x, y);
     }
 
-    /**
-     * Returns whether the specified x position is near the scroll bar.
-     */
-    public boolean isNearScrollBar(int x) {
-        return x >= (getWidth() - mMaxWidth) / 2 - mScrollbarLeftOffsetTouchDelegate
-                && x <= (getWidth() + mMaxWidth) / 2;
+    public FastScrollerLocation getScrollerLocation() {
+        return mFastScrollerLocation;
+    }
+
+    public void setFastScrollerLocation(@NonNull FastScrollerLocation location) {
+        mFastScrollerLocation = location;
     }
 
     private void animatePopupVisibility(boolean visible) {
         if (mPopupVisible != visible) {
             mPopupVisible = visible;
-            mPopupView.animate().cancel();
-            mPopupView.animate().alpha(visible ? 1f : 0f).setDuration(visible ? 200 : 150).start();
+            if (shouldUseLetterFastScroller()) {
+                mRv.getLetterList().animate().alpha(visible ? 1f : 0f)
+                        .setDuration(visible ? 200 : 150).start();
+            } else {
+                mPopupView.animate().cancel();
+                mPopupView.animate().alpha(visible ? 1f : 0f)
+                        .setDuration(visible ? 200 : 150).start();
+            }
         }
     }
 
diff --git a/src/com/android/launcher3/widget/picker/WidgetsFullSheet.java b/src/com/android/launcher3/widget/picker/WidgetsFullSheet.java
index 0e5307a..c8ad564 100644
--- a/src/com/android/launcher3/widget/picker/WidgetsFullSheet.java
+++ b/src/com/android/launcher3/widget/picker/WidgetsFullSheet.java
@@ -20,6 +20,7 @@
 import static com.android.launcher3.allapps.ActivityAllAppsContainerView.AdapterHolder.SEARCH;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_WIDGETSTRAY_SEARCHED;
 import static com.android.launcher3.testing.shared.TestProtocol.NORMAL_STATE_ORDINAL;
+import static com.android.launcher3.views.RecyclerViewFastScroller.FastScrollerLocation.WIDGET_SCROLLER;
 
 import android.animation.Animator;
 import android.content.Context;
@@ -119,7 +120,7 @@
                     WidgetsRecyclerView searchRecyclerView =
                             mAdapters.get(AdapterHolder.SEARCH).mWidgetsRecyclerView;
                     if (mIsInSearchMode && searchRecyclerView != null) {
-                        searchRecyclerView.bindFastScrollbar(mFastScroller);
+                        searchRecyclerView.bindFastScrollbar(mFastScroller, WIDGET_SCROLLER);
                     }
                 }
 
@@ -276,7 +277,7 @@
     }
 
     private void attachScrollbarToRecyclerView(WidgetsRecyclerView recyclerView) {
-        recyclerView.bindFastScrollbar(mFastScroller);
+        recyclerView.bindFastScrollbar(mFastScroller, WIDGET_SCROLLER);
         if (mCurrentWidgetsRecyclerView != recyclerView) {
             // Only reset the scroll position & expanded apps if the currently shown recycler view
             // has been updated.
@@ -1059,7 +1060,7 @@
             mWidgetsRecyclerView.setClipToOutline(true);
             mWidgetsRecyclerView.setClipChildren(false);
             mWidgetsRecyclerView.setAdapter(mWidgetsListAdapter);
-            mWidgetsRecyclerView.bindFastScrollbar(mFastScroller);
+            mWidgetsRecyclerView.bindFastScrollbar(mFastScroller, WIDGET_SCROLLER);
             mWidgetsRecyclerView.setItemAnimator(isTwoPane() ? null : mWidgetsListItemAnimator);
             mWidgetsRecyclerView.setHeaderViewDimensionsProvider(WidgetsFullSheet.this);
             if (!isTwoPane()) {
diff --git a/tests/Android.bp b/tests/Android.bp
index 9945570..1fa6e05 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -160,7 +160,7 @@
 }
 
 filegroup {
-    name: "launcher-testing-helpers-multivalent",
+    name: "launcher-testing-helpers-robo",
     srcs: [
         "src/**/*.java",
         "src/**/*.kt",
@@ -183,7 +183,7 @@
 filegroup {
     name: "launcher-testing-helpers",
     srcs: [
-        ":launcher-testing-helpers-multivalent",
+        ":launcher-testing-helpers-robo",
         "src/**/RoboApiWrapper.kt",
     ],
 }
@@ -195,7 +195,7 @@
         ":launcher3-robo-src",
 
         // Test util classes
-        ":launcher-testing-helpers-multivalent",
+        ":launcher-testing-helpers-robo",
         ":launcher-testing-shared",
     ],
     exclude_srcs: [
diff --git a/tests/src/com/android/launcher3/celllayout/integrationtest/TestUtils.kt b/tests/src/com/android/launcher3/celllayout/integrationtest/TestUtils.kt
index 4cecb5a..bcb9191 100644
--- a/tests/src/com/android/launcher3/celllayout/integrationtest/TestUtils.kt
+++ b/tests/src/com/android/launcher3/celllayout/integrationtest/TestUtils.kt
@@ -21,6 +21,7 @@
 import android.view.View
 import android.view.ViewGroup
 import com.android.launcher3.CellLayout
+import com.android.launcher3.Utilities
 import com.android.launcher3.Workspace
 import com.android.launcher3.util.CellAndSpan
 import com.android.launcher3.widget.LauncherAppWidgetHostView
@@ -54,7 +55,7 @@
         return view as LauncherAppWidgetHostView
     }
 
-    fun getCellTopLeftRelativeToCellLayout(
+    fun getCellTopLeftRelativeToWorkspace(
         workspace: Workspace<*>,
         cellAndSpan: CellAndSpan
     ): Point {
@@ -67,6 +68,8 @@
             cellAndSpan.spanY,
             target
         )
-        return Point(target.left, target.top)
+        val point = floatArrayOf(target.left.toFloat(), target.top.toFloat())
+        Utilities.getDescendantCoordRelativeToAncestor(cellLayout, workspace, point, false)
+        return Point(point[0].toInt(), point[1].toInt())
     }
 }