diff --git a/quickstep/src/com/android/launcher3/model/PredictionUpdateTask.java b/quickstep/src/com/android/launcher3/model/PredictionUpdateTask.java
index 7e3ee7d..bc3253f 100644
--- a/quickstep/src/com/android/launcher3/model/PredictionUpdateTask.java
+++ b/quickstep/src/com/android/launcher3/model/PredictionUpdateTask.java
@@ -27,6 +27,8 @@
 import android.content.pm.ShortcutInfo;
 import android.os.UserHandle;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.model.BgDataModel.FixedContainerItems;
@@ -52,7 +54,8 @@
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList apps) {
         Context context = app.getContext();
 
         // TODO: remove this
diff --git a/quickstep/src/com/android/launcher3/model/WidgetsPredictionUpdateTask.java b/quickstep/src/com/android/launcher3/model/WidgetsPredictionUpdateTask.java
index 9cd9d85..7a483a8 100644
--- a/quickstep/src/com/android/launcher3/model/WidgetsPredictionUpdateTask.java
+++ b/quickstep/src/com/android/launcher3/model/WidgetsPredictionUpdateTask.java
@@ -21,6 +21,8 @@
 import android.content.ComponentName;
 import android.text.TextUtils;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.model.BgDataModel.FixedContainerItems;
@@ -52,7 +54,8 @@
      * workspace.
      */
     @Override
-    public void execute(LauncherAppState appState, BgDataModel dataModel, AllAppsList apps) {
+    public void execute(@NonNull final LauncherAppState appState,
+            @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
         Set<ComponentKey> widgetsInWorkspace = dataModel.appWidgets.stream().map(
                 widget -> new ComponentKey(widget.providerName, widget.user)).collect(
                 Collectors.toSet());
diff --git a/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java b/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
index 2e4e739..8fb7030 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
@@ -88,6 +88,11 @@
             return;
         }
         setStateWithAnimationInternal(toState, config, builder);
+        builder.addEndListener(success -> {
+            if (!success) {
+                mRecentsView.reset();
+            }
+        });
     }
 
     /**
diff --git a/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java b/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java
index cf0cae4..1316ddd 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java
@@ -586,6 +586,8 @@
     public void onWidgetsTransition(float progress) {
         super.onWidgetsTransition(progress);
         onTaskbarInAppDisplayProgressUpdate(progress, WIDGETS_PAGE_PROGRESS_INDEX);
+        // Change of wallpaper depth in widget picker is disabled for tests as it causes flakiness
+        // on very slow cuttlefish devices.
         if (ENABLE_WIDGET_PICKER_DEPTH.get() && !Utilities.IS_RUNNING_IN_TEST_HARNESS) {
             WIDGET_DEPTH.set(getDepthController(),
                     Utilities.mapToRange(progress, 0f, 1f, 0f, getDeviceProfile().bottomSheetDepth,
diff --git a/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java b/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java
index 420c64a..0723f8a 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java
@@ -27,6 +27,7 @@
 import static com.android.quickstep.views.RecentsView.TASK_SECONDARY_SPLIT_TRANSLATION;
 import static com.android.quickstep.views.TaskView.FLAG_UPDATE_ALL;
 
+import android.animation.AnimatorSet;
 import android.annotation.TargetApi;
 import android.os.Build;
 import android.util.FloatProperty;
@@ -108,6 +109,13 @@
      */
     private void handleSplitSelectionState(@NonNull LauncherState toState,
             @NonNull PendingAnimation builder, boolean animate) {
+        if (toState != OVERVIEW_SPLIT_SELECT) {
+            // Not going to split, nothing to do but ensure taskviews are at correct offset
+            mRecentsView.resetSplitPrimaryScrollOffset();
+            return;
+        }
+
+        // Create transition animations to split select
         PagedOrientationHandler orientationHandler =
                 ((RecentsView) mLauncher.getOverviewPanel()).getPagedOrientationHandler();
         Pair<FloatProperty, FloatProperty> taskViewsFloat =
@@ -115,22 +123,20 @@
                         TASK_PRIMARY_SPLIT_TRANSLATION, TASK_SECONDARY_SPLIT_TRANSLATION,
                         mLauncher.getDeviceProfile());
 
-        if (toState == OVERVIEW_SPLIT_SELECT) {
-            mRecentsView.createSplitSelectInitAnimation(builder,
-                    toState.getTransitionDuration(mLauncher, true /* isToState */));
-            // Add properties to shift remaining taskViews to get out of placeholder view
-            builder.setFloat(mRecentsView, taskViewsFloat.first,
-                    toState.getSplitSelectTranslation(mLauncher), LINEAR);
-            builder.setFloat(mRecentsView, taskViewsFloat.second, 0, LINEAR);
+        mRecentsView.createSplitSelectInitAnimation(builder,
+                toState.getTransitionDuration(mLauncher, true /* isToState */));
+        // Add properties to shift remaining taskViews to get out of placeholder view
+        builder.setFloat(mRecentsView, taskViewsFloat.first,
+                toState.getSplitSelectTranslation(mLauncher), LINEAR);
+        builder.setFloat(mRecentsView, taskViewsFloat.second, 0, LINEAR);
 
-            if (!animate) {
-                builder.buildAnim().start();
-            }
-
-            mRecentsView.applySplitPrimaryScrollOffset();
-        } else {
-            mRecentsView.resetSplitPrimaryScrollOffset();
+        if (!animate) {
+            AnimatorSet as = builder.buildAnim();
+            as.start();
+            as.end();
         }
+
+        mRecentsView.applySplitPrimaryScrollOffset();
     }
 
     private void setAlphas(PropertySetter propertySetter, StateAnimationConfig config,
diff --git a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
index a389035..4e635a7 100644
--- a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
+++ b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
@@ -1444,6 +1444,7 @@
         }
     }
 
+    @Nullable
     private SwipePipToHomeAnimator createWindowAnimationToPip(HomeAnimationFactory homeAnimFactory,
             RemoteAnimationTargetCompat runningTaskTarget, float startProgress) {
         // Directly animate the app to PiP (picture-in-picture) mode
@@ -1469,6 +1470,10 @@
                         runningTaskTarget.taskInfo.pictureInPictureParams,
                         homeRotation,
                         hotseatKeepClearArea);
+        if (destinationBounds == null) {
+            // No destination bounds returned from SystemUI, bail early.
+            return null;
+        }
         final Rect appBounds = new Rect();
         final WindowConfiguration winConfig = taskInfo.configuration.windowConfiguration;
         // Adjust the appBounds for TaskBar by using the calculated window crop Rect
diff --git a/quickstep/src/com/android/quickstep/SystemUiProxy.java b/quickstep/src/com/android/quickstep/SystemUiProxy.java
index 944e2f9..24d2b9b 100644
--- a/quickstep/src/com/android/quickstep/SystemUiProxy.java
+++ b/quickstep/src/com/android/quickstep/SystemUiProxy.java
@@ -45,6 +45,7 @@
 import android.view.SurfaceControl;
 import android.window.IOnBackInvokedCallback;
 
+import androidx.annotation.Nullable;
 import androidx.annotation.WorkerThread;
 
 import com.android.internal.logging.InstanceId;
@@ -481,6 +482,10 @@
         mPipAnimationListener = listener;
     }
 
+    /**
+     * @return Destination bounds of auto-pip animation, {@code null} if the animation is not ready.
+     */
+    @Nullable
     public Rect startSwipePipToHome(ComponentName componentName, ActivityInfo activityInfo,
             PictureInPictureParams pictureInPictureParams, int launcherRotation,
             Rect hotseatKeepClearArea) {
diff --git a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java
index 1e0ceed..19a6c38 100644
--- a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java
+++ b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java
@@ -78,6 +78,11 @@
         }
         // While animating into recents, update the visible task data as needed
         setter.addOnFrameCallback(() -> mRecentsView.loadVisibleTaskData(FLAG_UPDATE_ALL));
+        setter.addEndListener(success -> {
+            if (!success) {
+                mRecentsView.reset();
+            }
+        });
         mRecentsView.updateEmptyMessage();
 
         setProperties(toState, config, setter);
diff --git a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
index 93eb0f1..e32aaee 100644
--- a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
+++ b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
@@ -232,11 +232,6 @@
     }
 
     @Override
-    public void onStateTransitionFailed(RecentsState toState) {
-        reset();
-    }
-
-    @Override
     public void onStateTransitionComplete(RecentsState finalState) {
         if (finalState == HOME) {
             // Clean-up logic that occurs when recents is no longer in use/visible.
diff --git a/quickstep/src/com/android/quickstep/logging/StatsLogCompatManager.java b/quickstep/src/com/android/quickstep/logging/StatsLogCompatManager.java
index 45c8036..37a28e5 100644
--- a/quickstep/src/com/android/quickstep/logging/StatsLogCompatManager.java
+++ b/quickstep/src/com/android/quickstep/logging/StatsLogCompatManager.java
@@ -336,8 +336,9 @@
                 appState.getModel().enqueueModelUpdateTask(
                         new BaseModelUpdateTask() {
                             @Override
-                            public void execute(LauncherAppState app, BgDataModel dataModel,
-                                    AllAppsList apps) {
+                            public void execute(@NonNull final LauncherAppState app,
+                                    @NonNull final BgDataModel dataModel,
+                                    @NonNull final AllAppsList apps) {
                                 FolderInfo folderInfo = dataModel.folders.get(mItemInfo.container);
                                 write(event, applyOverwrites(mItemInfo.buildProto(folderInfo)));
                             }
diff --git a/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java b/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java
index 364cf7b..bb8506d 100644
--- a/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java
@@ -120,11 +120,6 @@
     }
 
     @Override
-    public void onStateTransitionFailed(LauncherState toState) {
-        reset();
-    }
-
-    @Override
     public void onStateTransitionComplete(LauncherState finalState) {
         if (finalState == NORMAL || finalState == SPRING_LOADED) {
             // Clean-up logic that occurs when recents is no longer in use/visible.
diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index 28a358e..6a94094 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -2859,6 +2859,7 @@
                 mSplitSelectStateController.getActiveSplitStagePosition(), mTempRect);
 
         RectF startingTaskRect = new RectF();
+        safeRemoveDragLayerView(mFirstFloatingTaskView);
         if (mSplitHiddenTaskView != null) {
             // Split staging is initiated
             mSplitHiddenTaskView.setThumbnailVisibility(INVISIBLE);
@@ -2882,6 +2883,7 @@
         }
 
         // SplitInstructionsView: animate in
+        safeRemoveDragLayerView(mSplitInstructionsView);
         mSplitInstructionsView = SplitInstructionsView.getSplitInstructionsView(mActivity);
         mSplitInstructionsView.setAlpha(0);
         anim.setViewAlpha(mSplitInstructionsView, 1, clampToProgress(LINEAR,
@@ -4237,6 +4239,7 @@
                 new RectF(firstTaskStartingBounds), firstTaskEndingBounds,
                 false /* fadeWithThumbnail */, true /* isStagedTask */);
 
+        safeRemoveDragLayerView(mSecondFloatingTaskView);
         mSecondFloatingTaskView = FloatingTaskView.getFloatingTaskView(mActivity,
                 thumbnailView, thumbnailView.getThumbnail(),
                 iconView.getDrawable(), secondTaskStartingBounds);
@@ -4269,17 +4272,13 @@
     @SuppressLint("WrongCall")
     protected void resetFromSplitSelectionState() {
         if (mSplitSelectSource != null || mSplitHiddenTaskViewIndex != -1) {
-            if (mSplitInstructionsView != null) {
-                mActivity.getDragLayer().removeView(mSplitInstructionsView);
-                mSplitInstructionsView = null;
-            }
-            if (mFirstFloatingTaskView != null) {
-                mActivity.getDragLayer().removeView(mFirstFloatingTaskView);
-                mFirstFloatingTaskView = null;
-            }
-            if (mSecondFloatingTaskView != null) {
-                mActivity.getDragLayer().removeView(mSecondFloatingTaskView);
-                mSecondFloatingTaskView = null;
+            safeRemoveDragLayerView(mFirstFloatingTaskView);
+            safeRemoveDragLayerView(mSecondFloatingTaskView);
+            safeRemoveDragLayerView(mSplitInstructionsView);
+            mFirstFloatingTaskView = null;
+            mSecondFloatingTaskView = null;
+            mSplitInstructionsView = null;
+            if (mSecondSplitHiddenView != null) {
                 mSecondSplitHiddenView.setVisibility(VISIBLE);
                 mSecondSplitHiddenView = null;
             }
@@ -4307,6 +4306,12 @@
         }
     }
 
+    private void safeRemoveDragLayerView(@Nullable View viewToRemove) {
+        if (viewToRemove != null) {
+            mActivity.getDragLayer().removeView(viewToRemove);
+        }
+    }
+
     /**
      * Returns how much additional translation there should be for each of the child TaskViews.
      * Note that the translation can be its primary or secondary dimension.
diff --git a/src/com/android/launcher3/FastScrollRecyclerView.java b/src/com/android/launcher3/FastScrollRecyclerView.java
index 747b755..2f927d3 100644
--- a/src/com/android/launcher3/FastScrollRecyclerView.java
+++ b/src/com/android/launcher3/FastScrollRecyclerView.java
@@ -24,7 +24,6 @@
 import android.view.accessibility.AccessibilityNodeInfo;
 
 import androidx.annotation.Nullable;
-import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.launcher3.compat.AccessibilityManagerCompat;
@@ -92,8 +91,7 @@
     protected int getAvailableScrollHeight() {
         // AvailableScrollHeight = Total height of the all items - first page height
         int firstPageHeight = getMeasuredHeight() - getPaddingTop() - getPaddingBottom();
-        int totalHeightOfAllItems = getItemsHeight(/* untilIndex= */ getAdapter().getItemCount());
-        int availableScrollHeight = totalHeightOfAllItems - firstPageHeight;
+        int availableScrollHeight = computeVerticalScrollRange() - firstPageHeight;
         return Math.max(0, availableScrollHeight);
     }
 
@@ -146,10 +144,7 @@
 
         // IF scroller is at the very top OR there is no scroll bar because there is probably not
         // enough items to scroll, THEN it's okay for the container to be pulled down.
-        if (getCurrentScrollY() == 0) {
-            return true;
-        }
-        return getAdapter() == null || getAdapter().getItemCount() == 0;
+        return computeVerticalScrollOffset() == 0;
     }
 
     /**
@@ -160,53 +155,6 @@
     }
 
     /**
-     * @return the scroll top of this recycler view.
-     */
-    public int getCurrentScrollY() {
-        Adapter adapter = getAdapter();
-        if (adapter == null) {
-            return -1;
-        }
-        if (adapter.getItemCount() == 0 || getChildCount() == 0) {
-            return -1;
-        }
-
-        int itemPosition = NO_POSITION;
-        View child = null;
-
-        LayoutManager layoutManager = getLayoutManager();
-        if (layoutManager instanceof LinearLayoutManager) {
-            // Use the LayoutManager as the source of truth for visible positions. During
-            // animations, the view group child may not correspond to the visible views that appear
-            // at the top.
-            itemPosition = ((LinearLayoutManager) layoutManager).findFirstVisibleItemPosition();
-            child = layoutManager.findViewByPosition(itemPosition);
-        }
-
-        if (child == null) {
-            // If the layout manager returns null for any reason, which can happen before layout
-            // has occurred for the position, then look at the child of this view as a ViewGroup.
-            child = getChildAt(0);
-            itemPosition = getChildAdapterPosition(child);
-        }
-        if (itemPosition == NO_POSITION) {
-            return -1;
-        }
-        return getPaddingTop() + getItemsHeight(itemPosition)
-                - layoutManager.getDecoratedTop(child);
-    }
-
-    /**
-     * Returns the sum of the height, in pixels, of this list adapter's items from index
-     * 0 (inclusive) until {@code untilIndex} (exclusive). If untilIndex is same as the itemCount,
-     * it returns the full height of all the items.
-     *
-     * <p>If the untilIndex is larger than the total number of items in this adapter, returns the
-     * sum of all items' height.
-     */
-    protected abstract int getItemsHeight(int untilIndex);
-
-    /**
      * Maps the touch (from 0..1) to the adapter position that should be visible.
      * <p>Override in each subclass of this base class.
      */
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index ce95b15..17fb7eb 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -114,6 +114,7 @@
 import android.view.animation.OvershootInterpolator;
 import android.widget.ImageView;
 import android.widget.Toast;
+import android.window.OnBackInvokedDispatcher;
 
 import androidx.annotation.CallSuper;
 import androidx.annotation.NonNull;
@@ -543,6 +544,8 @@
             getWindow().setSoftInputMode(LayoutParams.SOFT_INPUT_ADJUST_NOTHING);
         }
         setTitle(R.string.home_screen);
+
+        registerOnBackInvokedCallback();
     }
 
     protected LauncherOverlayManager getDefaultOverlay() {
@@ -2062,6 +2065,17 @@
         mStateManager.getState().onBackPressed(this);
     }
 
+    private void registerOnBackInvokedCallback() {
+        if (Utilities.ATLEAST_T) {
+            getOnBackInvokedDispatcher().registerOnBackInvokedCallback(
+                    OnBackInvokedDispatcher.PRIORITY_DEFAULT,
+                    () -> {
+                        onBackPressed();
+                        TestLogging.recordEvent(TestProtocol.SEQUENCE_MAIN, "onBackInvoked");
+                    });
+        }
+    }
+
     protected void onScreenOff() {
         // Reset AllApps to its initial state only if we are not in the middle of
         // processing a multi-step drop
@@ -2780,7 +2794,7 @@
             View v = getFirstMatch(Collections.singletonList(activeRecyclerView),
                     preferredItem, packageAndUserAndApp);
 
-            if (v != null && activeRecyclerView.getCurrentScrollY() > 0) {
+            if (v != null && activeRecyclerView.computeVerticalScrollOffset() > 0) {
                 RectF locationBounds = new RectF();
                 FloatingIconView.getLocationBoundsForView(this, v, false, locationBounds,
                         new Rect());
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index 68b7701..20df897 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -33,6 +33,7 @@
 import android.util.Log;
 import android.util.Pair;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.WorkerThread;
 
@@ -89,9 +90,11 @@
 
     static final String TAG = "Launcher.Model";
 
+    @NonNull
     private final LauncherAppState mApp;
+    @NonNull
     private final Object mLock = new Object();
-
+    @Nullable
     private LoaderTask mLoaderTask;
     private boolean mIsLoaderTaskRunning;
 
@@ -107,20 +110,25 @@
         }
     }
 
+    @NonNull
     private final ArrayList<Callbacks> mCallbacksList = new ArrayList<>(1);
 
     // < only access in worker thread >
+    @NonNull
     private final AllAppsList mBgAllAppsList;
 
     /**
      * All the static data should be accessed on the background thread, A lock should be acquired
      * on this object when accessing any data from this model.
      */
+    @NonNull
     private final BgDataModel mBgDataModel = new BgDataModel();
 
+    @NonNull
     private final ModelDelegate mModelDelegate;
 
     // Runnable to check if the shortcuts permission has changed.
+    @NonNull
     private final Runnable mDataValidationCheck = new Runnable() {
         @Override
         public void run() {
@@ -130,14 +138,16 @@
         }
     };
 
-    LauncherModel(Context context, LauncherAppState app, IconCache iconCache, AppFilter appFilter,
-            boolean isPrimaryInstance) {
+    LauncherModel(@NonNull final Context context, @NonNull final LauncherAppState app,
+            @NonNull final IconCache iconCache, @NonNull final AppFilter appFilter,
+            final boolean isPrimaryInstance) {
         mApp = app;
         mBgAllAppsList = new AllAppsList(iconCache, appFilter);
         mModelDelegate = ModelDelegate.newInstance(context, app, mBgAllAppsList, mBgDataModel,
                 isPrimaryInstance);
     }
 
+    @NonNull
     public ModelDelegate getModelDelegate() {
         return mModelDelegate;
     }
@@ -145,52 +155,57 @@
     /**
      * Adds the provided items to the workspace.
      */
-    public void addAndBindAddedWorkspaceItems(List<Pair<ItemInfo, Object>> itemList) {
+    public void addAndBindAddedWorkspaceItems(
+            @NonNull final List<Pair<ItemInfo, Object>> itemList) {
         for (Callbacks cb : getCallbacks()) {
             cb.preAddApps();
         }
         enqueueModelUpdateTask(new AddWorkspaceItemsTask(itemList));
     }
 
-    public ModelWriter getWriter(boolean hasVerticalHotseat, boolean verifyChanges,
-            @Nullable Callbacks owner) {
+    @NonNull
+    public ModelWriter getWriter(final boolean hasVerticalHotseat, final boolean verifyChanges,
+            @Nullable final Callbacks owner) {
         return new ModelWriter(mApp.getContext(), this, mBgDataModel,
                 hasVerticalHotseat, verifyChanges, owner);
     }
 
     @Override
-    public void onPackageChanged(String packageName, UserHandle user) {
+    public void onPackageChanged(
+            @NonNull final String packageName, @NonNull final UserHandle user) {
         int op = PackageUpdatedTask.OP_UPDATE;
         enqueueModelUpdateTask(new PackageUpdatedTask(op, user, packageName));
     }
 
     @Override
-    public void onPackageRemoved(String packageName, UserHandle user) {
+    public void onPackageRemoved(
+            @NonNull final String packageName, @NonNull final UserHandle user) {
         onPackagesRemoved(user, packageName);
     }
 
-    public void onPackagesRemoved(UserHandle user, String... packages) {
+    public void onPackagesRemoved(
+            @NonNull final UserHandle user, @NonNull final String... packages) {
         int op = PackageUpdatedTask.OP_REMOVE;
         FileLog.d(TAG, "package removed received " + TextUtils.join(",", packages));
         enqueueModelUpdateTask(new PackageUpdatedTask(op, user, packages));
     }
 
     @Override
-    public void onPackageAdded(String packageName, UserHandle user) {
+    public void onPackageAdded(@NonNull final String packageName, @NonNull final UserHandle user) {
         int op = PackageUpdatedTask.OP_ADD;
         enqueueModelUpdateTask(new PackageUpdatedTask(op, user, packageName));
     }
 
     @Override
-    public void onPackagesAvailable(String[] packageNames, UserHandle user,
-            boolean replacing) {
+    public void onPackagesAvailable(@NonNull final String[] packageNames,
+            @NonNull final UserHandle user, final boolean replacing) {
         enqueueModelUpdateTask(
                 new PackageUpdatedTask(PackageUpdatedTask.OP_UPDATE, user, packageNames));
     }
 
     @Override
-    public void onPackagesUnavailable(String[] packageNames, UserHandle user,
-            boolean replacing) {
+    public void onPackagesUnavailable(@NonNull final String[] packageNames,
+            @NonNull final UserHandle user, final boolean replacing) {
         if (!replacing) {
             enqueueModelUpdateTask(new PackageUpdatedTask(
                     PackageUpdatedTask.OP_UNAVAILABLE, user, packageNames));
@@ -198,20 +213,22 @@
     }
 
     @Override
-    public void onPackagesSuspended(String[] packageNames, UserHandle user) {
+    public void onPackagesSuspended(
+            @NonNull final String[] packageNames, @NonNull final UserHandle user) {
         enqueueModelUpdateTask(new PackageUpdatedTask(
                 PackageUpdatedTask.OP_SUSPEND, user, packageNames));
     }
 
     @Override
-    public void onPackagesUnsuspended(String[] packageNames, UserHandle user) {
+    public void onPackagesUnsuspended(
+            @NonNull final String[] packageNames, @NonNull final UserHandle user) {
         enqueueModelUpdateTask(new PackageUpdatedTask(
                 PackageUpdatedTask.OP_UNSUSPEND, user, packageNames));
     }
 
     @Override
-    public void onPackageLoadingProgressChanged(
-                String packageName, UserHandle user, float progress) {
+    public void onPackageLoadingProgressChanged(@NonNull final String packageName,
+            @NonNull final UserHandle user, final float progress) {
         if (Utilities.ATLEAST_S) {
             enqueueModelUpdateTask(new PackageIncrementalDownloadUpdatedTask(
                     packageName, user, progress));
@@ -219,8 +236,8 @@
     }
 
     @Override
-    public void onShortcutsChanged(String packageName, List<ShortcutInfo> shortcuts,
-            UserHandle user) {
+    public void onShortcutsChanged(@NonNull final String packageName,
+            @NonNull final List<ShortcutInfo> shortcuts, @NonNull final UserHandle user) {
         enqueueModelUpdateTask(new ShortcutsChangedTask(packageName, shortcuts, user, true));
     }
 
@@ -228,7 +245,8 @@
      * Called when the icon for an app changes, outside of package event
      */
     @WorkerThread
-    public void onAppIconChanged(String packageName, UserHandle user) {
+    public void onAppIconChanged(@NonNull final String packageName,
+            @NonNull final UserHandle user) {
         // Update the icon for the calendar package
         Context context = mApp.getContext();
         onPackageChanged(packageName, user);
@@ -256,7 +274,7 @@
         MODEL_EXECUTOR.execute(mModelDelegate::destroy);
     }
 
-    public void onBroadcastIntent(Intent intent) {
+    public void onBroadcastIntent(@NonNull final Intent intent) {
         if (DEBUG_RECEIVER) Log.d(TAG, "onReceive intent=" + intent);
         final String action = intent.getAction();
         if (Intent.ACTION_LOCALE_CHANGED.equals(action)) {
@@ -322,7 +340,7 @@
     /**
      * Removes an existing callback
      */
-    public void removeCallbacks(Callbacks callbacks) {
+    public void removeCallbacks(@NonNull final Callbacks callbacks) {
         synchronized (mCallbacksList) {
             Preconditions.assertUIThread();
             if (mCallbacksList.remove(callbacks)) {
@@ -338,7 +356,7 @@
      * Adds a callbacks to receive model updates
      * @return true if workspace load was performed synchronously
      */
-    public boolean addCallbacksAndLoad(Callbacks callbacks) {
+    public boolean addCallbacksAndLoad(@NonNull final Callbacks callbacks) {
         synchronized (mLock) {
             addCallbacks(callbacks);
             return startLoader(new Callbacks[] { callbacks });
@@ -349,7 +367,7 @@
     /**
      * Adds a callbacks to receive model updates
      */
-    public void addCallbacks(Callbacks callbacks) {
+    public void addCallbacks(@NonNull final Callbacks callbacks) {
         Preconditions.assertUIThread();
         synchronized (mCallbacksList) {
             if (TestProtocol.sDebugTracing) {
@@ -370,7 +388,7 @@
         return startLoader(new Callbacks[0]);
     }
 
-    private boolean startLoader(Callbacks[] newCallbacks) {
+    private boolean startLoader(@NonNull final Callbacks[] newCallbacks) {
         // Enable queue before starting loader. It will get disabled in Launcher#finishBindingItems
         ItemInstallQueue.INSTANCE.get(mApp.getContext())
                 .pauseModelPush(ItemInstallQueue.FLAG_LOADER_RUNNING);
@@ -433,7 +451,7 @@
      * Loads the model if not loaded
      * @param callback called with the data model upon successful load or null on model thread.
      */
-    public void loadAsync(Consumer<BgDataModel> callback) {
+    public void loadAsync(@NonNull final Consumer<BgDataModel> callback) {
         synchronized (mLock) {
             if (!mModelLoaded && !mIsLoaderTaskRunning) {
                 startLoader();
@@ -443,11 +461,12 @@
     }
 
     @Override
-    public void onInstallSessionCreated(final PackageInstallInfo sessionInfo) {
+    public void onInstallSessionCreated(@NonNull final PackageInstallInfo sessionInfo) {
         if (FeatureFlags.PROMISE_APPS_IN_ALL_APPS.get()) {
             enqueueModelUpdateTask(new BaseModelUpdateTask() {
                 @Override
-                public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+                public void execute(@NonNull final LauncherAppState app,
+                        @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
                     apps.addPromiseApp(app.getContext(), sessionInfo);
                     bindApplicationsIfNeeded();
                 }
@@ -456,10 +475,12 @@
     }
 
     @Override
-    public void onSessionFailure(String packageName, UserHandle user) {
+    public void onSessionFailure(@NonNull final String packageName,
+            @NonNull final UserHandle user) {
         enqueueModelUpdateTask(new BaseModelUpdateTask() {
             @Override
-            public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+            public void execute(@NonNull final LauncherAppState app,
+                    @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
                 final IntSet removedIds = new IntSet();
                 synchronized (dataModel) {
                     for (ItemInfo info : dataModel.itemsIdMap) {
@@ -483,7 +504,7 @@
     }
 
     @Override
-    public void onPackageStateChanged(PackageInstallInfo installInfo) {
+    public void onPackageStateChanged(@NonNull final PackageInstallInfo installInfo) {
         enqueueModelUpdateTask(new PackageInstallStateChangedTask(installInfo));
     }
 
@@ -491,7 +512,8 @@
      * Updates the icons and label of all pending icons for the provided package name.
      */
     @Override
-    public void onUpdateSessionDisplay(PackageUserKey key, PackageInstaller.SessionInfo info) {
+    public void onUpdateSessionDisplay(@NonNull final PackageUserKey key,
+            @NonNull final PackageInstaller.SessionInfo info) {
         mApp.getIconCache().updateSessionCache(key, info);
 
         HashSet<String> packages = new HashSet<>();
@@ -502,9 +524,10 @@
 
     public class LoaderTransaction implements AutoCloseable {
 
+        @NonNull
         private final LoaderTask mTask;
 
-        private LoaderTransaction(LoaderTask task) throws CancellationException {
+        private LoaderTransaction(@NonNull final LoaderTask task) throws CancellationException {
             synchronized (mLock) {
                 if (mLoaderTask != task) {
                     throw new CancellationException("Loader already stopped");
@@ -534,7 +557,8 @@
         }
     }
 
-    public LoaderTransaction beginLoader(LoaderTask task) throws CancellationException {
+    public LoaderTransaction beginLoader(@NonNull final LoaderTask task)
+            throws CancellationException {
         return new LoaderTransaction(task);
     }
 
@@ -551,7 +575,8 @@
     /**
      * Called when the icons for packages have been updated in the icon cache.
      */
-    public void onPackageIconsUpdated(HashSet<String> updatedPackages, UserHandle user) {
+    public void onPackageIconsUpdated(@NonNull final HashSet<String> updatedPackages,
+            @NonNull final UserHandle user) {
         // If any package icon has changed (app was updated while launcher was dead),
         // update the corresponding shortcuts.
         enqueueModelUpdateTask(new CacheDataUpdatedTask(
@@ -561,17 +586,19 @@
     /**
      * Called when the labels for the widgets has updated in the icon cache.
      */
-    public void onWidgetLabelsUpdated(HashSet<String> updatedPackages, UserHandle user) {
+    public void onWidgetLabelsUpdated(@NonNull final HashSet<String> updatedPackages,
+            @NonNull final UserHandle user) {
         enqueueModelUpdateTask(new BaseModelUpdateTask() {
             @Override
-            public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+            public void execute(@NonNull final LauncherAppState app,
+                    @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
                 dataModel.widgetsModel.onPackageIconsUpdated(updatedPackages, user, app);
                 bindUpdatedWidgets(dataModel);
             }
         });
     }
 
-    public void enqueueModelUpdateTask(ModelUpdateTask task) {
+    public void enqueueModelUpdateTask(@NonNull final ModelUpdateTask task) {
         if (mModelDestroyed) {
             return;
         }
@@ -585,7 +612,7 @@
      */
     public interface CallbackTask {
 
-        void execute(Callbacks callbacks);
+        void execute(@NonNull Callbacks callbacks);
     }
 
     /**
@@ -596,12 +623,14 @@
         /**
          * Called before the task is posted to initialize the internal state.
          */
-        void init(LauncherAppState app, LauncherModel model,
-                BgDataModel dataModel, AllAppsList allAppsList, Executor uiExecutor);
+        void init(@NonNull LauncherAppState app, @NonNull LauncherModel model,
+                @NonNull BgDataModel dataModel, @NonNull AllAppsList allAppsList,
+                @NonNull Executor uiExecutor);
 
     }
 
-    public void updateAndBindWorkspaceItem(WorkspaceItemInfo si, ShortcutInfo info) {
+    public void updateAndBindWorkspaceItem(@NonNull final WorkspaceItemInfo si,
+            @NonNull final ShortcutInfo info) {
         updateAndBindWorkspaceItem(() -> {
             si.updateFromDeepShortcutInfo(info, mApp.getContext());
             mApp.getIconCache().getShortcutIcon(si, info);
@@ -612,10 +641,12 @@
     /**
      * Utility method to update a shortcut on the background thread.
      */
-    public void updateAndBindWorkspaceItem(final Supplier<WorkspaceItemInfo> itemProvider) {
+    public void updateAndBindWorkspaceItem(
+            @NonNull final Supplier<WorkspaceItemInfo> itemProvider) {
         enqueueModelUpdateTask(new BaseModelUpdateTask() {
             @Override
-            public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+            public void execute(@NonNull final LauncherAppState app,
+                    @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
                 WorkspaceItemInfo info = itemProvider.get();
                 getModelWriter().updateItemInDatabase(info);
                 ArrayList<WorkspaceItemInfo> update = new ArrayList<>();
@@ -628,14 +659,16 @@
     public void refreshAndBindWidgetsAndShortcuts(@Nullable final PackageUserKey packageUser) {
         enqueueModelUpdateTask(new BaseModelUpdateTask() {
             @Override
-            public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+            public void execute(@NonNull final LauncherAppState app,
+                    @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
                 dataModel.widgetsModel.update(app, packageUser);
                 bindUpdatedWidgets(dataModel);
             }
         });
     }
 
-    public void dumpState(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
+    public void dumpState(@Nullable final String prefix, @Nullable final FileDescriptor fd,
+            @NonNull final PrintWriter writer, @NonNull final String[] args) {
         if (args.length > 0 && TextUtils.equals(args[0], "--all")) {
             writer.println(prefix + "All apps list: size=" + mBgAllAppsList.data.size());
             for (AppInfo info : mBgAllAppsList.data) {
@@ -661,6 +694,7 @@
     /**
      * Returns an array of currently attached callbacks
      */
+    @NonNull
     public Callbacks[] getCallbacks() {
         synchronized (mCallbacksList) {
             return mCallbacksList.toArray(new Callbacks[mCallbacksList.size()]);
diff --git a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
index aa9cfd1..c1eaa16 100644
--- a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
+++ b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
@@ -84,6 +84,7 @@
 
     /** Invoke when the current search session is finished. */
     public void onClearSearchResult() {
+        getMainAdapterProvider().clearHighlightedItem();
         animateToSearchState(false);
         rebindAdapters();
     }
@@ -92,6 +93,7 @@
      * Sets results list for search
      */
     public void setSearchResults(ArrayList<AdapterItem> results) {
+        getMainAdapterProvider().clearHighlightedItem();
         if (getSearchResultList().setSearchResults(results)) {
             getSearchRecyclerView().onSearchResultsChanged();
         }
diff --git a/src/com/android/launcher3/allapps/AllAppsGridAdapter.java b/src/com/android/launcher3/allapps/AllAppsGridAdapter.java
index 33d2f2b..e0b4951 100644
--- a/src/com/android/launcher3/allapps/AllAppsGridAdapter.java
+++ b/src/com/android/launcher3/allapps/AllAppsGridAdapter.java
@@ -26,7 +26,9 @@
 import androidx.core.view.accessibility.AccessibilityRecordCompat;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.RecyclerView.Adapter;
 
+import com.android.launcher3.util.ScrollableLayoutManager;
 import com.android.launcher3.views.ActivityContext;
 
 import java.util.List;
@@ -62,10 +64,10 @@
     /**
      * A subclass of GridLayoutManager that overrides accessibility values during app search.
      */
-    public class AppsGridLayoutManager extends GridLayoutManager {
+    public class AppsGridLayoutManager extends ScrollableLayoutManager {
 
         public AppsGridLayoutManager(Context context) {
-            super(context, 1, GridLayoutManager.VERTICAL, false);
+            super(context);
         }
 
         @Override
@@ -125,6 +127,15 @@
             }
             return extraRows;
         }
+
+        @Override
+        protected int incrementTotalHeight(Adapter adapter, int position, int heightUntilLastPos) {
+            AllAppsGridAdapter.AdapterItem item = mApps.getAdapterItems().get(position);
+            // only account for the first icon in the row since they are the same size within a row
+            return (isIconViewType(item.viewType) && item.rowAppIndex != 0)
+                    ? heightUntilLastPos
+                    : (heightUntilLastPos + mCachedSizes.get(item.viewType));
+        }
     }
 
     @Override
diff --git a/src/com/android/launcher3/allapps/AllAppsRecyclerView.java b/src/com/android/launcher3/allapps/AllAppsRecyclerView.java
index 21a7dfb..3d06fb5 100644
--- a/src/com/android/launcher3/allapps/AllAppsRecyclerView.java
+++ b/src/com/android/launcher3/allapps/AllAppsRecyclerView.java
@@ -15,8 +15,6 @@
  */
 package com.android.launcher3.allapps;
 
-import static android.view.View.MeasureSpec.UNSPECIFIED;
-
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_SCROLLED;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_VERTICAL_SWIPE_BEGIN;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_VERTICAL_SWIPE_END;
@@ -26,7 +24,6 @@
 import android.graphics.Canvas;
 import android.util.AttributeSet;
 import android.util.Log;
-import android.util.SparseIntArray;
 
 import androidx.recyclerview.widget.RecyclerView;
 
@@ -49,40 +46,10 @@
     private static final boolean DEBUG = false;
     private static final boolean DEBUG_LATENCY = Utilities.isPropertyEnabled(SEARCH_LOGGING);
 
-    protected AlphabeticalAppsList<?> mApps;
     protected final int mNumAppsPerRow;
-
-    // The specific view heights that we use to calculate scroll
-    private final SparseIntArray mViewHeights = new SparseIntArray();
-    private final SparseIntArray mCachedScrollPositions = new SparseIntArray();
     private final AllAppsFastScrollHelper mFastScrollHelper;
 
-
-    private final AdapterDataObserver mObserver = new RecyclerView.AdapterDataObserver() {
-        public void onChanged() {
-            mCachedScrollPositions.clear();
-        }
-
-        @Override
-        public void onItemRangeChanged(int positionStart, int itemCount) {
-            onChanged();
-        }
-
-        @Override
-        public void onItemRangeInserted(int positionStart, int itemCount) {
-            onChanged();
-        }
-
-        @Override
-        public void onItemRangeRemoved(int positionStart, int itemCount) {
-            onChanged();
-        }
-
-        @Override
-        public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
-            onChanged();
-        }
-    };
+    protected AlphabeticalAppsList<?> mApps;
 
     public AllAppsRecyclerView(Context context) {
         this(context, null);
@@ -122,12 +89,8 @@
         pool.setMaxRecycledViews(AllAppsGridAdapter.VIEW_TYPE_ALL_APPS_DIVIDER, 1);
         pool.setMaxRecycledViews(AllAppsGridAdapter.VIEW_TYPE_ICON, approxRows
                 * (mNumAppsPerRow + 1));
-
-        mViewHeights.clear();
-        mViewHeights.put(AllAppsGridAdapter.VIEW_TYPE_ICON, grid.allAppsCellHeightPx);
     }
 
-
     @Override
     public void onDraw(Canvas c) {
         if (DEBUG) {
@@ -200,17 +163,6 @@
     }
 
     @Override
-    public void setAdapter(Adapter adapter) {
-        if (getAdapter() != null) {
-            getAdapter().unregisterAdapterDataObserver(mObserver);
-        }
-        super.setAdapter(adapter);
-        if (adapter != null) {
-            adapter.registerAdapterDataObserver(mObserver);
-        }
-    }
-
-    @Override
     protected boolean isPaddingOffsetRequired() {
         return true;
     }
@@ -231,13 +183,13 @@
         List<AllAppsGridAdapter.AdapterItem> items = mApps.getAdapterItems();
 
         // Skip early if there are no items or we haven't been measured
-        if (items.isEmpty() || mNumAppsPerRow == 0) {
+        if (items.isEmpty() || mNumAppsPerRow == 0 || getChildCount() == 0) {
             mScrollbar.setThumbOffsetY(-1);
             return;
         }
 
         // Skip early if, there no child laid out in the container.
-        int scrollY = getCurrentScrollY();
+        int scrollY = computeVerticalScrollOffset();
         if (scrollY < 0) {
             mScrollbar.setThumbOffsetY(-1);
             return;
@@ -292,51 +244,6 @@
         }
     }
 
-    @Override
-    protected int getItemsHeight(int position) {
-        List<AllAppsGridAdapter.AdapterItem> items = mApps.getAdapterItems();
-        AllAppsGridAdapter.AdapterItem posItem = position < items.size()
-                ? items.get(position) : null;
-        int y = mCachedScrollPositions.get(position, -1);
-        if (y < 0) {
-            y = 0;
-            for (int i = 0; i < position; i++) {
-                AllAppsGridAdapter.AdapterItem item = items.get(i);
-                if (AllAppsGridAdapter.isIconViewType(item.viewType)) {
-                    // Break once we reach the desired row
-                    if (posItem != null && posItem.viewType == item.viewType &&
-                            posItem.rowIndex == item.rowIndex) {
-                        break;
-                    }
-                    // Otherwise, only account for the first icon in the row since they are the same
-                    // size within a row
-                    if (item.rowAppIndex == 0) {
-                        y += mViewHeights.get(item.viewType, 0);
-                    }
-                } else {
-                    // Rest of the views span the full width
-                    int elHeight = mViewHeights.get(item.viewType);
-                    if (elHeight == 0) {
-                        ViewHolder holder = findViewHolderForAdapterPosition(i);
-                        if (holder == null) {
-                            holder = getAdapter().createViewHolder(this, item.viewType);
-                            getAdapter().onBindViewHolder(holder, i);
-                            holder.itemView.measure(UNSPECIFIED, UNSPECIFIED);
-                            elHeight = holder.itemView.getMeasuredHeight();
-
-                            getRecycledViewPool().putRecycledView(holder);
-                        } else {
-                            elHeight = holder.itemView.getMeasuredHeight();
-                        }
-                    }
-                    y += elHeight;
-                }
-            }
-            mCachedScrollPositions.put(position, y);
-        }
-        return y;
-    }
-
     public int getScrollBarTop() {
         return getResources().getDimensionPixelOffset(R.dimen.all_apps_header_top_padding);
     }
diff --git a/src/com/android/launcher3/allapps/AllAppsTransitionController.java b/src/com/android/launcher3/allapps/AllAppsTransitionController.java
index 22e8bcf..391de8d 100644
--- a/src/com/android/launcher3/allapps/AllAppsTransitionController.java
+++ b/src/com/android/launcher3/allapps/AllAppsTransitionController.java
@@ -228,6 +228,11 @@
     public void setStateWithAnimation(LauncherState toState,
             StateAnimationConfig config, PendingAnimation builder) {
         if (mLauncher.isInState(ALL_APPS) && !ALL_APPS.equals(toState)) {
+            // For atomic animations, we close the keyboard immediately.
+            if (!config.userControlled && !FeatureFlags.ENABLE_KEYBOARD_TRANSITION_SYNC.get()) {
+                mLauncher.getAppsView().getSearchUiManager().getEditText().hideKeyboard();
+            }
+
             builder.addEndListener(success -> {
                 // Reset pull back progress and alpha after switching states.
                 ALL_APPS_PULL_BACK_TRANSLATION.set(this, 0f);
@@ -238,7 +243,7 @@
                 // the keyboard open and then changes their mind and swipes back up, we want the
                 // keyboard to remain open. However an onCancel signal is sent to the listeners
                 // (success = false), so we need to check for that.
-                if (success) {
+                if (config.userControlled && success) {
                     mLauncher.getAppsView().getSearchUiManager().getEditText().hideKeyboard();
                 }
             });
diff --git a/src/com/android/launcher3/allapps/BaseAllAppsContainerView.java b/src/com/android/launcher3/allapps/BaseAllAppsContainerView.java
index d8d3fa3..3983f40 100644
--- a/src/com/android/launcher3/allapps/BaseAllAppsContainerView.java
+++ b/src/com/android/launcher3/allapps/BaseAllAppsContainerView.java
@@ -103,7 +103,8 @@
             new RecyclerView.OnScrollListener() {
                 @Override
                 public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
-                    updateHeaderScroll(((AllAppsRecyclerView) recyclerView).getCurrentScrollY());
+                    updateHeaderScroll(
+                            ((AllAppsRecyclerView) recyclerView).computeVerticalScrollOffset());
                 }
             };
 
diff --git a/src/com/android/launcher3/allapps/FloatingHeaderView.java b/src/com/android/launcher3/allapps/FloatingHeaderView.java
index 8ec2aeb..73efd3f 100644
--- a/src/com/android/launcher3/allapps/FloatingHeaderView.java
+++ b/src/com/android/launcher3/allapps/FloatingHeaderView.java
@@ -68,7 +68,7 @@
                         mAnimator.cancel();
                     }
 
-                    int current = -mCurrentRV.getCurrentScrollY();
+                    int current = -mCurrentRV.computeVerticalScrollOffset();
                     boolean headerCollapsed = mHeaderCollapsed;
                     moved(current);
                     applyVerticalMove();
diff --git a/src/com/android/launcher3/allapps/SearchTransitionController.java b/src/com/android/launcher3/allapps/SearchTransitionController.java
index 03529af..4be715b 100644
--- a/src/com/android/launcher3/allapps/SearchTransitionController.java
+++ b/src/com/android/launcher3/allapps/SearchTransitionController.java
@@ -233,6 +233,7 @@
     private void onSearchChildAttached(View child) {
         // Avoid allocating hardware layers for alpha changes.
         child.forceHasOverlappingRendering(false);
+        child.setPivotY(0);
         if (mSearchToAzProgress > 0) {
             // Before the child is rendered, apply the animation including it to avoid flicker.
             updateSearchRecyclerViewProgress();
diff --git a/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java b/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java
index d2d7a6c..ab47097 100644
--- a/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java
+++ b/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java
@@ -22,6 +22,7 @@
 import android.os.Handler;
 
 import androidx.annotation.AnyThread;
+import androidx.annotation.NonNull;
 
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.allapps.BaseAllAppsAdapter.AdapterItem;
@@ -68,7 +69,8 @@
     public void doSearch(String query, SearchCallback<AdapterItem> callback) {
         mAppState.getModel().enqueueModelUpdateTask(new BaseModelUpdateTask() {
             @Override
-            public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+            public void execute(@NonNull final LauncherAppState app,
+                    @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
                 ArrayList<AdapterItem> result = getTitleMatchResult(apps.data, query);
                 if (mAddNoResultsMessage && result.isEmpty()) {
                     result.add(getEmptyMessageAdapterItem(query));
diff --git a/src/com/android/launcher3/allapps/search/DefaultSearchAdapterProvider.java b/src/com/android/launcher3/allapps/search/DefaultSearchAdapterProvider.java
index a95bd51..4fb732d 100644
--- a/src/com/android/launcher3/allapps/search/DefaultSearchAdapterProvider.java
+++ b/src/com/android/launcher3/allapps/search/DefaultSearchAdapterProvider.java
@@ -84,4 +84,9 @@
     public RecyclerView.ItemDecoration getDecorator() {
         return mDecoration;
     }
+
+    @Override
+    public void clearHighlightedItem() {
+        mHighlightedView = null;
+    }
 }
diff --git a/src/com/android/launcher3/allapps/search/SearchAdapterProvider.java b/src/com/android/launcher3/allapps/search/SearchAdapterProvider.java
index bc52784..3890741 100644
--- a/src/com/android/launcher3/allapps/search/SearchAdapterProvider.java
+++ b/src/com/android/launcher3/allapps/search/SearchAdapterProvider.java
@@ -58,4 +58,9 @@
      * Returns the item decorator.
      */
     public abstract RecyclerView.ItemDecoration getDecorator();
+
+    /**
+     * Clear the highlighted view.
+     */
+    public abstract void clearHighlightedItem();
 }
diff --git a/src/com/android/launcher3/config/FeatureFlags.java b/src/com/android/launcher3/config/FeatureFlags.java
index 0e36dc0..ef6350e 100644
--- a/src/com/android/launcher3/config/FeatureFlags.java
+++ b/src/com/android/launcher3/config/FeatureFlags.java
@@ -289,10 +289,8 @@
             "Enable option to log the keyboard latency for both atomic and controlled keyboard "
                     + "animations on an EditText");
 
-    // Change of wallpaper depth in widget picker is disabled for tests as it causes flakiness on
-    // very slow cuttlefish devices.
     public static final BooleanFlag ENABLE_WIDGET_PICKER_DEPTH = new DeviceFlag(
-            "ENABLE_WIDGET_PICKER_DEPTH", true, "Enable changing depth in widget picker.");
+            "ENABLE_WIDGET_PICKER_DEPTH", false, "Enable changing depth in widget picker.");
 
     public static void initialize(Context context) {
         synchronized (sDebugFlags) {
diff --git a/src/com/android/launcher3/dragndrop/AddItemActivity.java b/src/com/android/launcher3/dragndrop/AddItemActivity.java
index 466b268..05b1984 100644
--- a/src/com/android/launcher3/dragndrop/AddItemActivity.java
+++ b/src/com/android/launcher3/dragndrop/AddItemActivity.java
@@ -31,6 +31,7 @@
 import android.content.ClipData;
 import android.content.ClipDescription;
 import android.content.Intent;
+import android.content.pm.ApplicationInfo;
 import android.content.pm.LauncherApps.PinItemRequest;
 import android.content.pm.ShortcutInfo;
 import android.content.res.Configuration;
@@ -62,6 +63,8 @@
 import com.android.launcher3.model.WidgetItem;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.pm.PinRequestHelper;
+import com.android.launcher3.util.PackageManagerHelper;
+import com.android.launcher3.util.PackageUserKey;
 import com.android.launcher3.util.SystemUiController;
 import com.android.launcher3.views.AbstractSlideInView;
 import com.android.launcher3.views.BaseDragLayer;
@@ -136,13 +139,25 @@
         mAccessibilityManager =
                 getApplicationContext().getSystemService(AccessibilityManager.class);
 
-        if (mRequest.getRequestType() == PinItemRequest.REQUEST_TYPE_SHORTCUT) {
-            setupShortcut();
-        } else {
-            if (!setupWidget()) {
-                // TODO: show error toast?
-                finish();
-            }
+        PackageUserKey targetApp = null;
+        switch (mRequest.getRequestType()) {
+            case PinItemRequest.REQUEST_TYPE_SHORTCUT:
+                targetApp = setupShortcut();
+                break;
+            case PinItemRequest.REQUEST_TYPE_APPWIDGET:
+                targetApp = setupWidget();
+                break;
+        }
+        if (targetApp == null) {
+            // TODO: show error toast?
+            finish();
+            return;
+        }
+        ApplicationInfo info = new PackageManagerHelper(this)
+                .getApplicationInfo(targetApp.mPackageName, targetApp.mUser, 0);
+        if (info == null) {
+            finish();
+            return;
         }
 
         WidgetCellPreview previewContainer = mWidgetCell.findViewById(
@@ -156,8 +171,10 @@
             logCommand(LAUNCHER_ADD_EXTERNAL_ITEM_START);
         }
 
+        // Set the label synchronously instead of via IconCache as this is the first thing
+        // user sees
         TextView widgetAppName = findViewById(R.id.widget_appName);
-        widgetAppName.setText(getApplicationInfo().labelRes);
+        widgetAppName.setText(info.loadLabel(getPackageManager()));
 
         mSlideInView = findViewById(R.id.add_item_bottom_sheet);
         mSlideInView.addOnCloseListener(this);
@@ -246,20 +263,23 @@
         }
     }
 
-    private void setupShortcut() {
+    private PackageUserKey setupShortcut() {
         PinShortcutRequestActivityInfo shortcutInfo =
                 new PinShortcutRequestActivityInfo(mRequest, this);
         mWidgetCell.getWidgetView().setTag(new PendingAddShortcutInfo(shortcutInfo));
         applyWidgetItemAsync(
                 () -> new WidgetItem(shortcutInfo, mApp.getIconCache(), getPackageManager()));
+        return new PackageUserKey(
+                mRequest.getShortcutInfo().getPackage(),
+                mRequest.getShortcutInfo().getUserHandle());
     }
 
-    private boolean setupWidget() {
+    private PackageUserKey setupWidget() {
         LauncherAppWidgetProviderInfo widgetInfo = LauncherAppWidgetProviderInfo
                 .fromProviderInfo(this, mRequest.getAppWidgetProviderInfo(this));
         if (widgetInfo.minSpanX > mIdp.numColumns || widgetInfo.minSpanY > mIdp.numRows) {
             // Cannot add widget
-            return false;
+            return null;
         }
         mWidgetCell.setRemoteViewsPreview(PinItemDragListener.getPreview(mRequest));
 
@@ -274,7 +294,7 @@
         mWidgetCell.getWidgetView().setTag(pendingInfo);
 
         applyWidgetItemAsync(() -> new WidgetItem(widgetInfo, mIdp, mApp.getIconCache()));
-        return true;
+        return new PackageUserKey(widgetInfo.provider.getPackageName(), widgetInfo.getUser());
     }
 
     private void applyWidgetItemAsync(final Supplier<WidgetItem> itemProvider) {
diff --git a/src/com/android/launcher3/folder/FolderNameProvider.java b/src/com/android/launcher3/folder/FolderNameProvider.java
index 5021644..bf59594 100644
--- a/src/com/android/launcher3/folder/FolderNameProvider.java
+++ b/src/com/android/launcher3/folder/FolderNameProvider.java
@@ -24,6 +24,7 @@
 import android.text.TextUtils;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.WorkerThread;
 
 import com.android.launcher3.LauncherAppState;
@@ -192,7 +193,8 @@
 
     private class FolderNameWorker extends BaseModelUpdateTask {
         @Override
-        public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+        public void execute(@NonNull final LauncherAppState app,
+                @NonNull final BgDataModel dataModel, @NonNull final AllAppsList apps) {
             mFolderInfos = dataModel.folders.clone();
             mAppInfos = Arrays.asList(apps.copyData());
         }
diff --git a/src/com/android/launcher3/model/AddWorkspaceItemsTask.java b/src/com/android/launcher3/model/AddWorkspaceItemsTask.java
index 4c0f1ae..0d978e1 100644
--- a/src/com/android/launcher3/model/AddWorkspaceItemsTask.java
+++ b/src/com/android/launcher3/model/AddWorkspaceItemsTask.java
@@ -23,6 +23,9 @@
 import android.util.Log;
 import android.util.Pair;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.LauncherModel.CallbackTask;
 import com.android.launcher3.LauncherSettings;
@@ -42,6 +45,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * Task to add auto-created workspace items.
@@ -50,14 +54,16 @@
 
     private static final String LOG = "AddWorkspaceItemsTask";
 
+    @NonNull
     private final List<Pair<ItemInfo, Object>> mItemList;
 
+    @NonNull
     private final WorkspaceItemSpaceFinder mItemSpaceFinder;
 
     /**
      * @param itemList items to add on the workspace
      */
-    public AddWorkspaceItemsTask(List<Pair<ItemInfo, Object>> itemList) {
+    public AddWorkspaceItemsTask(@NonNull final List<Pair<ItemInfo, Object>> itemList) {
         this(itemList, new WorkspaceItemSpaceFinder());
     }
 
@@ -65,14 +71,15 @@
      * @param itemList items to add on the workspace
      * @param itemSpaceFinder inject WorkspaceItemSpaceFinder dependency for testing
      */
-    public AddWorkspaceItemsTask(List<Pair<ItemInfo, Object>> itemList,
-            WorkspaceItemSpaceFinder itemSpaceFinder) {
+    public AddWorkspaceItemsTask(@NonNull final List<Pair<ItemInfo, Object>> itemList,
+            @NonNull final WorkspaceItemSpaceFinder itemSpaceFinder) {
         mItemList = itemList;
         mItemSpaceFinder = itemSpaceFinder;
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList apps) {
         if (mItemList.isEmpty()) {
             return;
         }
@@ -98,7 +105,8 @@
                     }
 
                     // b/139663018 Short-circuit this logic if the icon is a system app
-                    if (PackageManagerHelper.isSystemApp(app.getContext(), item.getIntent())) {
+                    if (PackageManagerHelper.isSystemApp(app.getContext(),
+                            Objects.requireNonNull(item.getIntent()))) {
                         if (TestProtocol.sDebugTracing) {
                             Log.d(TestProtocol.MISSING_PROMISE_ICON,
                                     LOG + " Item is a system app.");
@@ -159,7 +167,7 @@
                         continue;
                     }
 
-                    List<LauncherActivityInfo> activities = launcherApps
+                    List<LauncherActivityInfo> activities = Objects.requireNonNull(launcherApps)
                             .getActivityList(packageName, item.user);
                     boolean hasActivity = activities != null && !activities.isEmpty();
 
@@ -218,7 +226,7 @@
         if (!addedItemsFinal.isEmpty()) {
             scheduleCallbackTask(new CallbackTask() {
                 @Override
-                public void execute(Callbacks callbacks) {
+                public void execute(@NonNull Callbacks callbacks) {
                     final ArrayList<ItemInfo> addAnimated = new ArrayList<>();
                     final ArrayList<ItemInfo> addNotAnimated = new ArrayList<>();
                     if (!addedItemsFinal.isEmpty()) {
@@ -243,7 +251,8 @@
      * Returns true if the shortcuts already exists on the workspace. This must be called after
      * the workspace has been loaded. We identify a shortcut by its intent.
      */
-    protected boolean shortcutExists(BgDataModel dataModel, Intent intent, UserHandle user) {
+    protected boolean shortcutExists(@NonNull final BgDataModel dataModel,
+            @Nullable final Intent intent, @NonNull final UserHandle user) {
         final String compPkgName, intentWithPkg, intentWithoutPkg;
         if (intent == null) {
             // Skip items with null intents
diff --git a/src/com/android/launcher3/model/AllAppsList.java b/src/com/android/launcher3/model/AllAppsList.java
index 95150dc..6da948c 100644
--- a/src/com/android/launcher3/model/AllAppsList.java
+++ b/src/com/android/launcher3/model/AllAppsList.java
@@ -66,7 +66,10 @@
     /** The list off all apps. */
     public final ArrayList<AppInfo> data = new ArrayList<>(DEFAULT_APPLICATIONS_NUMBER);
 
+    @NonNull
     private IconCache mIconCache;
+
+    @NonNull
     private AppFilter mAppFilter;
 
     private boolean mDataChanged = false;
diff --git a/src/com/android/launcher3/model/BaseModelUpdateTask.java b/src/com/android/launcher3/model/BaseModelUpdateTask.java
index 2a6a691..5b6f9f6 100644
--- a/src/com/android/launcher3/model/BaseModelUpdateTask.java
+++ b/src/com/android/launcher3/model/BaseModelUpdateTask.java
@@ -17,6 +17,7 @@
 
 import android.util.Log;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 import com.android.launcher3.LauncherAppState;
@@ -47,14 +48,17 @@
     private static final boolean DEBUG_TASKS = false;
     private static final String TAG = "BaseModelUpdateTask";
 
+    // Nullabilities are explicitly omitted here because these are late-init fields,
+    // They will be non-null after init(), which is always the case in enqueueModelUpdateTask().
     private LauncherAppState mApp;
     private LauncherModel mModel;
     private BgDataModel mDataModel;
     private AllAppsList mAllAppsList;
     private Executor mUiExecutor;
 
-    public void init(LauncherAppState app, LauncherModel model,
-            BgDataModel dataModel, AllAppsList allAppsList, Executor uiExecutor) {
+    public void init(@NonNull final LauncherAppState app, @NonNull final LauncherModel model,
+            @NonNull final BgDataModel dataModel, @NonNull final AllAppsList allAppsList,
+            @NonNull final Executor uiExecutor) {
         mApp = app;
         mModel = model;
         mDataModel = dataModel;
@@ -64,7 +68,7 @@
 
     @Override
     public final void run() {
-        if (!mModel.isModelLoaded()) {
+        if (!Objects.requireNonNull(mModel).isModelLoaded()) {
             if (DEBUG_TASKS) {
                 Log.d(TAG, "Ignoring model task since loader is pending=" + this);
             }
@@ -77,13 +81,13 @@
     /**
      * Execute the actual task. Called on the worker thread.
      */
-    public abstract void execute(
-            LauncherAppState app, BgDataModel dataModel, AllAppsList apps);
+    public abstract void execute(@NonNull LauncherAppState app,
+            @NonNull BgDataModel dataModel, @NonNull AllAppsList apps);
 
     /**
      * Schedules a {@param task} to be executed on the current callbacks.
      */
-    public final void scheduleCallbackTask(final CallbackTask task) {
+    public final void scheduleCallbackTask(@NonNull final CallbackTask task) {
         for (final Callbacks cb : mModel.getCallbacks()) {
             mUiExecutor.execute(() -> task.execute(cb));
         }
@@ -95,7 +99,7 @@
         return mModel.getWriter(false /* hasVerticalHotseat */, false /* verifyChanges */, null);
     }
 
-    public void bindUpdatedWorkspaceItems(List<WorkspaceItemInfo> allUpdates) {
+    public void bindUpdatedWorkspaceItems(@NonNull final List<WorkspaceItemInfo> allUpdates) {
         // Bind workspace items
         List<WorkspaceItemInfo> workspaceUpdates = allUpdates.stream()
                 .filter(info -> info.id != ItemInfo.NO_ID)
@@ -113,18 +117,18 @@
                 .forEach(this::bindExtraContainerItems);
     }
 
-    public void bindExtraContainerItems(FixedContainerItems item) {
+    public void bindExtraContainerItems(@NonNull final FixedContainerItems item) {
         FixedContainerItems copy = item.clone();
         scheduleCallbackTask(c -> c.bindExtraContainerItems(copy));
     }
 
-    public void bindDeepShortcuts(BgDataModel dataModel) {
+    public void bindDeepShortcuts(@NonNull final BgDataModel dataModel) {
         final HashMap<ComponentKey, Integer> shortcutMapCopy =
                 new HashMap<>(dataModel.deepShortcutMap);
         scheduleCallbackTask(callbacks -> callbacks.bindDeepShortcutMap(shortcutMapCopy));
     }
 
-    public void bindUpdatedWidgets(BgDataModel dataModel) {
+    public void bindUpdatedWidgets(@NonNull final BgDataModel dataModel) {
         final ArrayList<WidgetsListBaseEntry> widgets =
                 dataModel.widgetsModel.getWidgetsListForPicker(mApp.getContext());
         scheduleCallbackTask(c -> c.bindAllWidgets(widgets));
diff --git a/src/com/android/launcher3/model/CacheDataUpdatedTask.java b/src/com/android/launcher3/model/CacheDataUpdatedTask.java
index f644d49..57fefaa 100644
--- a/src/com/android/launcher3/model/CacheDataUpdatedTask.java
+++ b/src/com/android/launcher3/model/CacheDataUpdatedTask.java
@@ -18,6 +18,8 @@
 import android.content.ComponentName;
 import android.os.UserHandle;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.LauncherSettings;
 import com.android.launcher3.icons.IconCache;
@@ -35,17 +37,23 @@
     public static final int OP_SESSION_UPDATE = 2;
 
     private final int mOp;
+
+    @NonNull
     private final UserHandle mUser;
+
+    @NonNull
     private final HashSet<String> mPackages;
 
-    public CacheDataUpdatedTask(int op, UserHandle user, HashSet<String> packages) {
+    public CacheDataUpdatedTask(final int op, @NonNull final UserHandle user,
+            @NonNull final HashSet<String> packages) {
         mOp = op;
         mUser = user;
         mPackages = packages;
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList apps) {
         IconCache iconCache = app.getIconCache();
         ArrayList<WorkspaceItemInfo> updatedShortcuts = new ArrayList<>();
 
@@ -65,7 +73,7 @@
         bindApplicationsIfNeeded();
     }
 
-    public boolean isValidShortcut(WorkspaceItemInfo si) {
+    public boolean isValidShortcut(@NonNull final WorkspaceItemInfo si) {
         switch (mOp) {
             case OP_CACHE_UPDATE:
                 return true;
diff --git a/src/com/android/launcher3/model/PackageIncrementalDownloadUpdatedTask.java b/src/com/android/launcher3/model/PackageIncrementalDownloadUpdatedTask.java
index c0dc34a..b9fba9d 100644
--- a/src/com/android/launcher3/model/PackageIncrementalDownloadUpdatedTask.java
+++ b/src/com/android/launcher3/model/PackageIncrementalDownloadUpdatedTask.java
@@ -17,6 +17,8 @@
 
 import android.os.UserHandle;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.model.data.AppInfo;
 import com.android.launcher3.model.data.ItemInfoWithIcon;
@@ -31,19 +33,24 @@
  */
 public class PackageIncrementalDownloadUpdatedTask extends BaseModelUpdateTask {
 
+    @NonNull
     private final UserHandle mUser;
+
     private final int mProgress;
+
+    @NonNull
     private final String mPackageName;
 
-    public PackageIncrementalDownloadUpdatedTask(
-            String packageName, UserHandle user, float progress) {
+    public PackageIncrementalDownloadUpdatedTask(@NonNull final String packageName,
+            @NonNull final UserHandle user, final float progress) {
         mUser = user;
         mProgress = 1 - progress > 0.001 ? (int) (100 * progress) : 100;
         mPackageName = packageName;
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList appsList) {
+    public void execute(@NonNull LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList appsList) {
         PackageInstallInfo downloadInfo = new PackageInstallInfo(
                 mPackageName,
                 PackageInstallInfo.STATUS_INSTALLED_DOWNLOADING,
diff --git a/src/com/android/launcher3/model/PackageInstallStateChangedTask.java b/src/com/android/launcher3/model/PackageInstallStateChangedTask.java
index b74d0fc..76a87ed 100644
--- a/src/com/android/launcher3/model/PackageInstallStateChangedTask.java
+++ b/src/com/android/launcher3/model/PackageInstallStateChangedTask.java
@@ -18,6 +18,8 @@
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.model.data.AppInfo;
 import com.android.launcher3.model.data.ItemInfo;
@@ -33,14 +35,16 @@
  */
 public class PackageInstallStateChangedTask extends BaseModelUpdateTask {
 
+    @NonNull
     private final PackageInstallInfo mInstallInfo;
 
-    public PackageInstallStateChangedTask(PackageInstallInfo installInfo) {
+    public PackageInstallStateChangedTask(@NonNull final PackageInstallInfo installInfo) {
         mInstallInfo = installInfo;
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList apps) {
         if (mInstallInfo.state == PackageInstallInfo.STATUS_INSTALLED) {
             try {
                 // For instant apps we do not get package-add. Use setting events to update
diff --git a/src/com/android/launcher3/model/PackageUpdatedTask.java b/src/com/android/launcher3/model/PackageUpdatedTask.java
index a9d272e..3d9d81f 100644
--- a/src/com/android/launcher3/model/PackageUpdatedTask.java
+++ b/src/com/android/launcher3/model/PackageUpdatedTask.java
@@ -29,6 +29,8 @@
 import android.os.UserManager;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.Launcher;
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.LauncherSettings;
@@ -80,17 +82,23 @@
     public static final int OP_USER_AVAILABILITY_CHANGE = 7; // user available/unavailable
 
     private final int mOp;
+
+    @NonNull
     private final UserHandle mUser;
+
+    @NonNull
     private final String[] mPackages;
 
-    public PackageUpdatedTask(int op, UserHandle user, String... packages) {
+    public PackageUpdatedTask(final int op, @NonNull final UserHandle user,
+            @NonNull final String... packages) {
         mOp = op;
         mUser = user;
         mPackages = packages;
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList appsList) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList appsList) {
         final Context context = app.getContext();
         final IconCache iconCache = app.getIconCache();
 
diff --git a/src/com/android/launcher3/model/ReloadStringCacheTask.java b/src/com/android/launcher3/model/ReloadStringCacheTask.java
index f4d4298..34f7057 100644
--- a/src/com/android/launcher3/model/ReloadStringCacheTask.java
+++ b/src/com/android/launcher3/model/ReloadStringCacheTask.java
@@ -15,6 +15,8 @@
  */
 package com.android.launcher3.model;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 
 /**
@@ -22,14 +24,17 @@
  * {@link android.app.admin.DevicePolicyManager#ACTION_DEVICE_POLICY_RESOURCE_UPDATED}.
  */
 public class ReloadStringCacheTask extends BaseModelUpdateTask {
+
+    @NonNull
     private ModelDelegate mModelDelegate;
 
-    public ReloadStringCacheTask(ModelDelegate modelDelegate) {
+    public ReloadStringCacheTask(@NonNull final ModelDelegate modelDelegate) {
         mModelDelegate = modelDelegate;
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList appsList) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList appsList) {
         synchronized (dataModel) {
             mModelDelegate.loadStringCache(dataModel.stringCache);
             StringCache cloneSC = dataModel.stringCache.clone();
diff --git a/src/com/android/launcher3/model/ShortcutsChangedTask.java b/src/com/android/launcher3/model/ShortcutsChangedTask.java
index 1026e0b..a6a04a7 100644
--- a/src/com/android/launcher3/model/ShortcutsChangedTask.java
+++ b/src/com/android/launcher3/model/ShortcutsChangedTask.java
@@ -19,6 +19,8 @@
 import android.content.pm.ShortcutInfo;
 import android.os.UserHandle;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.LauncherSettings;
 import com.android.launcher3.model.data.WorkspaceItemInfo;
@@ -38,13 +40,20 @@
  */
 public class ShortcutsChangedTask extends BaseModelUpdateTask {
 
+    @NonNull
     private final String mPackageName;
+
+    @NonNull
     private final List<ShortcutInfo> mShortcuts;
+
+    @NonNull
     private final UserHandle mUser;
+
     private final boolean mUpdateIdMap;
 
-    public ShortcutsChangedTask(String packageName, List<ShortcutInfo> shortcuts,
-            UserHandle user, boolean updateIdMap) {
+    public ShortcutsChangedTask(@NonNull final String packageName,
+            @NonNull final List<ShortcutInfo> shortcuts, @NonNull final UserHandle user,
+            final boolean updateIdMap) {
         mPackageName = packageName;
         mShortcuts = shortcuts;
         mUser = user;
@@ -52,7 +61,8 @@
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList apps) {
         final Context context = app.getContext();
         // Find WorkspaceItemInfo's that have changed on the workspace.
         ArrayList<WorkspaceItemInfo> matchingWorkspaceItems = new ArrayList<>();
diff --git a/src/com/android/launcher3/model/UserLockStateChangedTask.java b/src/com/android/launcher3/model/UserLockStateChangedTask.java
index 1565b19..63ca35b 100644
--- a/src/com/android/launcher3/model/UserLockStateChangedTask.java
+++ b/src/com/android/launcher3/model/UserLockStateChangedTask.java
@@ -21,6 +21,8 @@
 import android.content.pm.ShortcutInfo;
 import android.os.UserHandle;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.LauncherSettings;
 import com.android.launcher3.model.data.WorkspaceItemInfo;
@@ -40,16 +42,18 @@
  */
 public class UserLockStateChangedTask extends BaseModelUpdateTask {
 
+    @NonNull
     private final UserHandle mUser;
     private boolean mIsUserUnlocked;
 
-    public UserLockStateChangedTask(UserHandle user, boolean isUserUnlocked) {
+    public UserLockStateChangedTask(@NonNull final UserHandle user, final boolean isUserUnlocked) {
         mUser = user;
         mIsUserUnlocked = isUserUnlocked;
     }
 
     @Override
-    public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList apps) {
+    public void execute(@NonNull final LauncherAppState app, @NonNull final BgDataModel dataModel,
+            @NonNull final AllAppsList apps) {
         Context context = app.getContext();
 
         HashMap<ShortcutKey, ShortcutInfo> pinnedShortcuts = new HashMap<>();
diff --git a/src/com/android/launcher3/model/data/WorkspaceItemInfo.java b/src/com/android/launcher3/model/data/WorkspaceItemInfo.java
index 1f16474..59ef320 100644
--- a/src/com/android/launcher3/model/data/WorkspaceItemInfo.java
+++ b/src/com/android/launcher3/model/data/WorkspaceItemInfo.java
@@ -24,7 +24,6 @@
 import android.text.TextUtils;
 
 import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 
 import com.android.launcher3.LauncherSettings;
 import com.android.launcher3.LauncherSettings.Favorites;
@@ -76,6 +75,7 @@
     /**
      * The intent used to start the application.
      */
+    @NonNull
     public Intent intent;
 
     /**
@@ -148,7 +148,7 @@
     }
 
     @Override
-    @Nullable
+    @NonNull
     public Intent getIntent() {
         return intent;
     }
@@ -166,7 +166,8 @@
         return isPromise() && !hasStatusFlag(FLAG_SUPPORTS_WEB_UI);
     }
 
-    public void updateFromDeepShortcutInfo(ShortcutInfo shortcutInfo, Context context) {
+    public void updateFromDeepShortcutInfo(@NonNull final ShortcutInfo shortcutInfo,
+            @NonNull final Context context) {
         // {@link ShortcutInfo#getActivity} can change during an update. Recreate the intent
         intent = ShortcutKey.makeIntent(shortcutInfo);
         title = shortcutInfo.getShortLabel();
diff --git a/src/com/android/launcher3/pm/InstallSessionHelper.java b/src/com/android/launcher3/pm/InstallSessionHelper.java
index b695194..16bb868 100644
--- a/src/com/android/launcher3/pm/InstallSessionHelper.java
+++ b/src/com/android/launcher3/pm/InstallSessionHelper.java
@@ -30,6 +30,7 @@
 import android.util.Log;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.annotation.WorkerThread;
 
@@ -51,38 +52,50 @@
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * Utility class to tracking install sessions
  */
 public class InstallSessionHelper {
 
+    @NonNull
     private static final String LOG = "InstallSessionHelper";
 
     // Set<String> of session ids of promise icons that have been added to the home screen
     // as FLAG_PROMISE_NEW_INSTALLS.
+    @NonNull
     protected static final String PROMISE_ICON_IDS = "promise_icon_ids";
 
     private static final boolean DEBUG = false;
 
+    @NonNull
     public static final MainThreadInitializedObject<InstallSessionHelper> INSTANCE =
             new MainThreadInitializedObject<>(InstallSessionHelper::new);
 
+    @Nullable
     private final LauncherApps mLauncherApps;
+
+    @NonNull
     private final Context mAppContext;
 
+    @NonNull
     private final PackageInstaller mInstaller;
+
+    @NonNull
     private final HashMap<String, Boolean> mSessionVerifiedMap = new HashMap<>();
 
+    @Nullable
     private IntSet mPromiseIconIds;
 
-    public InstallSessionHelper(Context context) {
+    public InstallSessionHelper(@NonNull final Context context) {
         mInstaller = context.getPackageManager().getPackageInstaller();
         mAppContext = context.getApplicationContext();
         mLauncherApps = context.getSystemService(LauncherApps.class);
     }
 
     @WorkerThread
+    @NonNull
     private IntSet getPromiseIconIds() {
         Preconditions.assertWorkerThread();
         if (mPromiseIconIds != null) {
@@ -108,6 +121,7 @@
         return mPromiseIconIds;
     }
 
+    @NonNull
     public HashMap<PackageUserKey, SessionInfo> getActiveSessions() {
         HashMap<PackageUserKey, SessionInfo> activePackages = new HashMap<>();
         for (SessionInfo info : getAllVerifiedSessions()) {
@@ -117,6 +131,7 @@
         return activePackages;
     }
 
+    @Nullable
     public SessionInfo getActiveSessionInfo(UserHandle user, String pkg) {
         for (SessionInfo info : getAllVerifiedSessions()) {
             boolean match = pkg.equals(info.getAppPackageName());
@@ -136,11 +151,13 @@
                 .apply();
     }
 
-    SessionInfo getVerifiedSessionInfo(int sessionId) {
+    @Nullable
+    SessionInfo getVerifiedSessionInfo(final int sessionId) {
         return verify(mInstaller.getSessionInfo(sessionId));
     }
 
-    private SessionInfo verify(SessionInfo sessionInfo) {
+    @Nullable
+    private SessionInfo verify(@Nullable final SessionInfo sessionInfo) {
         if (sessionInfo == null
                 || sessionInfo.getInstallerPackageName() == null
                 || TextUtils.isEmpty(sessionInfo.getAppPackageName())) {
@@ -167,9 +184,10 @@
         return mSessionVerifiedMap.get(pkg) ? sessionInfo : null;
     }
 
+    @NonNull
     public List<SessionInfo> getAllVerifiedSessions() {
         List<SessionInfo> list = new ArrayList<>(Utilities.ATLEAST_Q
-                ? mLauncherApps.getAllPackageInstallerSessions()
+                ? Objects.requireNonNull(mLauncherApps).getAllPackageInstallerSessions()
                 : mInstaller.getAllSessions());
         Iterator<SessionInfo> it = list.iterator();
         while (it.hasNext()) {
@@ -201,12 +219,12 @@
     }
 
     @WorkerThread
-    public boolean promiseIconAddedForId(int sessionId) {
+    public boolean promiseIconAddedForId(final int sessionId) {
         return getPromiseIconIds().contains(sessionId);
     }
 
     @WorkerThread
-    public void removePromiseIconId(int sessionId) {
+    public void removePromiseIconId(final int sessionId) {
         if (promiseIconAddedForId(sessionId)) {
             getPromiseIconIds().getArray().removeValue(sessionId);
             updatePromiseIconPrefs();
@@ -222,7 +240,7 @@
      * - A promise icon for the session has not already been created
      */
     @WorkerThread
-    void tryQueuePromiseAppIcon(PackageInstaller.SessionInfo sessionInfo) {
+    void tryQueuePromiseAppIcon(@Nullable final PackageInstaller.SessionInfo sessionInfo) {
         if (TestProtocol.sDebugTracing) {
             Log.d(TestProtocol.MISSING_PROMISE_ICON, LOG + " tryQueuePromiseAppIcon"
                     + ", SessionCommitReceiveEnabled" + SessionCommitReceiver.isEnabled(mAppContext)
@@ -244,7 +262,7 @@
         }
     }
 
-    public boolean verifySessionInfo(PackageInstaller.SessionInfo sessionInfo) {
+    public boolean verifySessionInfo(@Nullable final PackageInstaller.SessionInfo sessionInfo) {
         if (TestProtocol.sDebugTracing) {
             boolean appNotInstalled = sessionInfo == null
                     || !new PackageManagerHelper(mAppContext)
@@ -267,14 +285,15 @@
                         sessionInfo.getAppPackageName(), getUserHandle(sessionInfo));
     }
 
-    public InstallSessionTracker registerInstallTracker(InstallSessionTracker.Callback callback) {
+    public InstallSessionTracker registerInstallTracker(
+            @Nullable final InstallSessionTracker.Callback callback) {
         InstallSessionTracker tracker = new InstallSessionTracker(
                 this, callback, mInstaller, mLauncherApps);
         tracker.register();
         return tracker;
     }
 
-    public static UserHandle getUserHandle(SessionInfo info) {
+    public static UserHandle getUserHandle(@NonNull final SessionInfo info) {
         return Utilities.ATLEAST_Q ? info.getUser() : Process.myUserHandle();
     }
 }
diff --git a/src/com/android/launcher3/pm/InstallSessionTracker.java b/src/com/android/launcher3/pm/InstallSessionTracker.java
index b16aaa2..aeaa320 100644
--- a/src/com/android/launcher3/pm/InstallSessionTracker.java
+++ b/src/com/android/launcher3/pm/InstallSessionTracker.java
@@ -28,12 +28,15 @@
 import android.util.Log;
 import android.util.SparseArray;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.WorkerThread;
 
 import com.android.launcher3.testing.shared.TestProtocol;
 import com.android.launcher3.util.PackageUserKey;
 
 import java.lang.ref.WeakReference;
+import java.util.Objects;
 
 @WorkerThread
 public class InstallSessionTracker extends PackageInstaller.SessionCallback {
@@ -41,14 +44,22 @@
     // Lazily initialized
     private SparseArray<PackageUserKey> mActiveSessions = null;
 
+    @NonNull
     private final WeakReference<InstallSessionHelper> mWeakHelper;
+
+    @NonNull
     private final WeakReference<Callback> mWeakCallback;
+
+    @NonNull
     private final PackageInstaller mInstaller;
+
+    @Nullable
     private final LauncherApps mLauncherApps;
 
 
-    InstallSessionTracker(InstallSessionHelper installerCompat, Callback callback,
-            PackageInstaller installer, LauncherApps launcherApps) {
+    InstallSessionTracker(@Nullable final InstallSessionHelper installerCompat,
+            @Nullable final Callback callback, @NonNull final PackageInstaller installer,
+            @Nullable LauncherApps launcherApps) {
         mWeakHelper = new WeakReference<>(installerCompat);
         mWeakCallback = new WeakReference<>(callback);
         mInstaller = installer;
@@ -56,7 +67,7 @@
     }
 
     @Override
-    public void onCreated(int sessionId) {
+    public void onCreated(final int sessionId) {
         InstallSessionHelper helper = mWeakHelper.get();
         Callback callback = mWeakCallback.get();
         if (TestProtocol.sDebugTracing) {
@@ -80,7 +91,7 @@
     }
 
     @Override
-    public void onFinished(int sessionId, boolean success) {
+    public void onFinished(final int sessionId, final boolean success) {
         InstallSessionHelper helper = mWeakHelper.get();
         Callback callback = mWeakCallback.get();
         if (callback == null || helper == null) {
@@ -108,7 +119,7 @@
     }
 
     @Override
-    public void onProgressChanged(int sessionId, float progress) {
+    public void onProgressChanged(final int sessionId, final float progress) {
         InstallSessionHelper helper = mWeakHelper.get();
         Callback callback = mWeakCallback.get();
         if (callback == null || helper == null) {
@@ -121,10 +132,10 @@
     }
 
     @Override
-    public void onActiveChanged(int sessionId, boolean active) { }
+    public void onActiveChanged(final int sessionId, final boolean active) { }
 
     @Override
-    public void onBadgingChanged(int sessionId) {
+    public void onBadgingChanged(final int sessionId) {
         InstallSessionHelper helper = mWeakHelper.get();
         Callback callback = mWeakCallback.get();
         if (callback == null || helper == null) {
@@ -136,8 +147,9 @@
         }
     }
 
-    private SessionInfo pushSessionDisplayToLauncher(
-            int sessionId, InstallSessionHelper helper, Callback callback) {
+    @Nullable
+    private SessionInfo pushSessionDisplayToLauncher(final int sessionId,
+            @NonNull final InstallSessionHelper helper, @NonNull final Callback callback) {
         SessionInfo session = helper.getVerifiedSessionInfo(sessionId);
         if (session != null && session.getAppPackageName() != null) {
             PackageUserKey key =
@@ -149,7 +161,9 @@
         return null;
     }
 
-    private SparseArray<PackageUserKey> getActiveSessionMap(InstallSessionHelper helper) {
+    @NonNull
+    private SparseArray<PackageUserKey> getActiveSessionMap(
+            @NonNull final InstallSessionHelper helper) {
         if (mActiveSessions == null) {
             mActiveSessions = new SparseArray<>();
             helper.getActiveSessions().forEach(
@@ -162,7 +176,8 @@
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
             mInstaller.registerSessionCallback(this, MODEL_EXECUTOR.getHandler());
         } else {
-            mLauncherApps.registerPackageInstallerSessionCallback(MODEL_EXECUTOR, this);
+            Objects.requireNonNull(mLauncherApps).registerPackageInstallerSessionCallback(
+                    MODEL_EXECUTOR, this);
         }
     }
 
@@ -170,18 +185,18 @@
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
             mInstaller.unregisterSessionCallback(this);
         } else {
-            mLauncherApps.unregisterPackageInstallerSessionCallback(this);
+            Objects.requireNonNull(mLauncherApps).unregisterPackageInstallerSessionCallback(this);
         }
     }
 
     public interface Callback {
 
-        void onSessionFailure(String packageName, UserHandle user);
+        void onSessionFailure(@NonNull String packageName, @NonNull UserHandle user);
 
-        void onUpdateSessionDisplay(PackageUserKey key, SessionInfo info);
+        void onUpdateSessionDisplay(@NonNull PackageUserKey key, @NonNull SessionInfo info);
 
-        void onPackageStateChanged(PackageInstallInfo info);
+        void onPackageStateChanged(@NonNull PackageInstallInfo info);
 
-        void onInstallSessionCreated(PackageInstallInfo info);
+        void onInstallSessionCreated(@NonNull PackageInstallInfo info);
     }
 }
diff --git a/src/com/android/launcher3/statemanager/StateManager.java b/src/com/android/launcher3/statemanager/StateManager.java
index 54e8e5b..86277a7 100644
--- a/src/com/android/launcher3/statemanager/StateManager.java
+++ b/src/com/android/launcher3/statemanager/StateManager.java
@@ -343,11 +343,6 @@
                 onStateTransitionEnd(state);
             }
 
-            @Override
-            public void onAnimationCancel(Animator animation) {
-                super.onAnimationCancel(animation);
-                onStateTransitionFailed(state);
-            }
         };
     }
 
@@ -360,12 +355,6 @@
         }
     }
 
-    private void onStateTransitionFailed(STATE_TYPE state) {
-        for (int i = mListeners.size() - 1; i >= 0; i--) {
-            mListeners.get(i).onStateTransitionFailed(state);
-        }
-    }
-
     private void onStateTransitionEnd(STATE_TYPE state) {
         // Only change the stable states after the transitions have finished
         if (state != mCurrentStableState) {
@@ -600,11 +589,6 @@
 
         default void onStateTransitionStart(STATE_TYPE toState) { }
 
-        /**
-         * If the state transition animation fails (e.g. is canceled by the user), this fires.
-         */
-        default void onStateTransitionFailed(STATE_TYPE toState) { }
-
         default void onStateTransitionComplete(STATE_TYPE finalState) { }
     }
 
diff --git a/src/com/android/launcher3/testing/TestInformationHandler.java b/src/com/android/launcher3/testing/TestInformationHandler.java
index d3c9bc9..269baf0 100644
--- a/src/com/android/launcher3/testing/TestInformationHandler.java
+++ b/src/com/android/launcher3/testing/TestInformationHandler.java
@@ -112,12 +112,12 @@
 
             case TestProtocol.REQUEST_APPS_LIST_SCROLL_Y: {
                 return getLauncherUIProperty(Bundle::putInt,
-                        l -> l.getAppsView().getActiveRecyclerView().getCurrentScrollY());
+                        l -> l.getAppsView().getActiveRecyclerView().computeVerticalScrollOffset());
             }
 
             case TestProtocol.REQUEST_WIDGETS_SCROLL_Y: {
                 return getLauncherUIProperty(Bundle::putInt,
-                        l -> WidgetsFullSheet.getWidgetsView(l).getCurrentScrollY());
+                        l -> WidgetsFullSheet.getWidgetsView(l).computeVerticalScrollOffset());
             }
 
             case TestProtocol.REQUEST_TARGET_INSETS: {
diff --git a/src/com/android/launcher3/util/PackageManagerHelper.java b/src/com/android/launcher3/util/PackageManagerHelper.java
index f42d304..12e8b54 100644
--- a/src/com/android/launcher3/util/PackageManagerHelper.java
+++ b/src/com/android/launcher3/util/PackageManagerHelper.java
@@ -43,6 +43,9 @@
 import android.util.Pair;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import com.android.launcher3.PendingAddItemInfo;
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
@@ -54,6 +57,7 @@
 
 import java.net.URISyntaxException;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * Utility methods using package manager
@@ -62,22 +66,28 @@
 
     private static final String TAG = "PackageManagerHelper";
 
+    @NonNull
     private final Context mContext;
+
+    @NonNull
     private final PackageManager mPm;
+
+    @NonNull
     private final LauncherApps mLauncherApps;
 
-    public PackageManagerHelper(Context context) {
+    public PackageManagerHelper(@NonNull final Context context) {
         mContext = context;
         mPm = context.getPackageManager();
-        mLauncherApps = context.getSystemService(LauncherApps.class);
+        mLauncherApps = Objects.requireNonNull(context.getSystemService(LauncherApps.class));
     }
 
     /**
      * Returns true if the app can possibly be on the SDCard. This is just a workaround and doesn't
      * guarantee that the app is on SD card.
      */
-    public boolean isAppOnSdcard(String packageName, UserHandle user) {
-        ApplicationInfo info = getApplicationInfo(
+    public boolean isAppOnSdcard(@NonNull final String packageName,
+            @NonNull final UserHandle user) {
+        final ApplicationInfo info = getApplicationInfo(
                 packageName, user, PackageManager.MATCH_UNINSTALLED_PACKAGES);
         return info != null && (info.flags & ApplicationInfo.FLAG_EXTERNAL_STORAGE) != 0;
     }
@@ -86,23 +96,27 @@
      * Returns whether the target app is suspended for a given user as per
      * {@link android.app.admin.DevicePolicyManager#isPackageSuspended}.
      */
-    public boolean isAppSuspended(String packageName, UserHandle user) {
-        ApplicationInfo info = getApplicationInfo(packageName, user, 0);
+    public boolean isAppSuspended(@NonNull final String packageName,
+            @NonNull final UserHandle user) {
+        final ApplicationInfo info = getApplicationInfo(packageName, user, 0);
         return info != null && isAppSuspended(info);
     }
 
     /**
      * Returns whether the target app is installed for a given user
      */
-    public boolean isAppInstalled(String packageName, UserHandle user) {
-        ApplicationInfo info = getApplicationInfo(packageName, user, 0);
+    public boolean isAppInstalled(@NonNull final String packageName,
+            @NonNull final UserHandle user) {
+        final ApplicationInfo info = getApplicationInfo(packageName, user, 0);
         return info != null;
     }
 
     /**
      * Returns the application info for the provided package or null
      */
-    public ApplicationInfo getApplicationInfo(String packageName, UserHandle user, int flags) {
+    @Nullable
+    public ApplicationInfo getApplicationInfo(@NonNull final String packageName,
+            @NonNull final UserHandle user, final int flags) {
         try {
             ApplicationInfo info = mLauncherApps.getApplicationInfo(packageName, flags, user);
             return (info.flags & ApplicationInfo.FLAG_INSTALLED) == 0 || !info.enabled
@@ -116,7 +130,8 @@
         return mPm.isSafeMode();
     }
 
-    public Intent getAppLaunchIntent(String pkg, UserHandle user) {
+    @Nullable
+    public Intent getAppLaunchIntent(@Nullable final String pkg, @NonNull final UserHandle user) {
         List<LauncherActivityInfo> activities = mLauncherApps.getActivityList(pkg, user);
         return activities.isEmpty() ? null :
                 AppInfo.makeLaunchIntent(activities.get(0));
@@ -251,7 +266,8 @@
         return packageFilter;
     }
 
-    public static boolean isSystemApp(Context context, Intent intent) {
+    public static boolean isSystemApp(@NonNull final Context context,
+            @NonNull final Intent intent) {
         PackageManager pm = context.getPackageManager();
         ComponentName cn = intent.getComponent();
         String packageName = null;
diff --git a/src/com/android/launcher3/util/ScrollableLayoutManager.java b/src/com/android/launcher3/util/ScrollableLayoutManager.java
new file mode 100644
index 0000000..17eaefd
--- /dev/null
+++ b/src/com/android/launcher3/util/ScrollableLayoutManager.java
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2022 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.util;
+
+import android.content.Context;
+import android.util.SparseIntArray;
+import android.view.View;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.GridLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.RecyclerView.Adapter;
+import androidx.recyclerview.widget.RecyclerView.State;
+import androidx.recyclerview.widget.RecyclerView.ViewHolder;
+
+/**
+ * Extension of {@link GridLayoutManager} with support for smooth scrolling
+ */
+public class ScrollableLayoutManager extends GridLayoutManager {
+
+    // keyed on item type
+    protected final SparseIntArray mCachedSizes = new SparseIntArray();
+
+    private RecyclerView mRv;
+
+    /**
+     * Precalculated total height keyed on the item position. This is always incremental.
+     * Subclass can override {@link #incrementTotalHeight} to incorporate the layout logic.
+     * For example all-apps should have same values for items in same row,
+     *     sample values: 0, 10, 10, 10, 10, 20, 20, 20, 20
+     * whereas widgets will have strictly increasing values
+     *     sample values: 0, 10, 50, 60, 110
+     */
+
+    //
+    private int[] mTotalHeightCache = new int[1];
+    private int mLastValidHeightIndex = 0;
+
+    public ScrollableLayoutManager(Context context) {
+        super(context, 1, GridLayoutManager.VERTICAL, false);
+    }
+
+    @Override
+    public void onAttachedToWindow(RecyclerView view) {
+        super.onAttachedToWindow(view);
+        mRv = view;
+    }
+
+    @Override
+    public void layoutDecorated(@NonNull View child, int left, int top, int right, int bottom) {
+        super.layoutDecorated(child, left, top, right, bottom);
+        mCachedSizes.put(
+                mRv.getChildViewHolder(child).getItemViewType(), child.getMeasuredHeight());
+    }
+
+    @Override
+    public void layoutDecoratedWithMargins(@NonNull View child, int left, int top, int right,
+            int bottom) {
+        super.layoutDecoratedWithMargins(child, left, top, right, bottom);
+        mCachedSizes.put(
+                mRv.getChildViewHolder(child).getItemViewType(), child.getMeasuredHeight());
+    }
+
+    @Override
+    public int computeVerticalScrollExtent(State state) {
+        return mRv == null ? 0 : mRv.getHeight();
+    }
+
+    @Override
+    public int computeVerticalScrollOffset(State state) {
+        Adapter adapter = mRv == null ? null : mRv.getAdapter();
+        if (adapter == null) {
+            return 0;
+        }
+        if (adapter.getItemCount() == 0 || getChildCount() == 0) {
+            return 0;
+        }
+        View child = getChildAt(0);
+        ViewHolder holder = mRv.findContainingViewHolder(child);
+        if (holder == null) {
+            return 0;
+        }
+        int itemPosition = holder.getLayoutPosition();
+        if (itemPosition < 0) {
+            return 0;
+        }
+        return getPaddingTop() + getItemsHeight(adapter, itemPosition) - getDecoratedTop(child);
+    }
+
+    @Override
+    public int computeVerticalScrollRange(State state) {
+        Adapter adapter = mRv == null ? null : mRv.getAdapter();
+        return adapter == null ? 0 : getItemsHeight(adapter, adapter.getItemCount());
+    }
+
+    /**
+     * Returns the sum of the height, in pixels, of this list adapter's items from index
+     * 0 (inclusive) until {@code untilIndex} (exclusive). If untilIndex is same as the itemCount,
+     * it returns the full height of all the items.
+     *
+     * <p>If the untilIndex is larger than the total number of items in this adapter, returns the
+     * sum of all items' height.
+     */
+    private int getItemsHeight(Adapter adapter, int untilIndex) {
+        final int totalItems = adapter.getItemCount();
+        if (mTotalHeightCache.length < (totalItems + 1)) {
+            mTotalHeightCache = new int[totalItems + 1];
+            mLastValidHeightIndex = 0;
+        }
+        if (untilIndex > totalItems) {
+            untilIndex = totalItems;
+        } else if (untilIndex < 0) {
+            untilIndex = 0;
+        }
+        if (untilIndex <= mLastValidHeightIndex) {
+            return mTotalHeightCache[untilIndex];
+        }
+
+        int totalItemsHeight = mTotalHeightCache[mLastValidHeightIndex];
+        for (int i = mLastValidHeightIndex; i < untilIndex; i++) {
+            totalItemsHeight = incrementTotalHeight(adapter, i, totalItemsHeight);
+            mTotalHeightCache[i + 1] = totalItemsHeight;
+        }
+        mLastValidHeightIndex = untilIndex;
+        return totalItemsHeight;
+    }
+
+    /**
+     * The current implementation assumes a linear list with every item taking up the whole row.
+     * Subclasses should override this method to account for any spanning logic
+     */
+    protected int incrementTotalHeight(Adapter adapter, int position, int heightUntilLastPos) {
+        return heightUntilLastPos + mCachedSizes.get(adapter.getItemViewType(position));
+    }
+
+    private void invalidateScrollCache() {
+        mLastValidHeightIndex = 0;
+    }
+
+    @Override
+    public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) {
+        super.onItemsAdded(recyclerView, positionStart, itemCount);
+        invalidateScrollCache();
+    }
+
+    @Override
+    public void onItemsChanged(RecyclerView recyclerView) {
+        super.onItemsChanged(recyclerView);
+        invalidateScrollCache();
+    }
+
+    @Override
+    public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) {
+        super.onItemsRemoved(recyclerView, positionStart, itemCount);
+        invalidateScrollCache();
+    }
+
+    @Override
+    public void onItemsMoved(RecyclerView recyclerView, int from, int to, int itemCount) {
+        super.onItemsMoved(recyclerView, from, to, itemCount);
+        invalidateScrollCache();
+    }
+
+    @Override
+    public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount,
+            Object payload) {
+        super.onItemsUpdated(recyclerView, positionStart, itemCount, payload);
+        invalidateScrollCache();
+    }
+}
diff --git a/src/com/android/launcher3/views/RecyclerViewFastScroller.java b/src/com/android/launcher3/views/RecyclerViewFastScroller.java
index 40e4ce1..3af2e3c 100644
--- a/src/com/android/launcher3/views/RecyclerViewFastScroller.java
+++ b/src/com/android/launcher3/views/RecyclerViewFastScroller.java
@@ -119,7 +119,6 @@
     // prevent jumping, this offset is applied as the user scrolls.
     protected int mTouchOffsetY;
     protected int mThumbOffsetY;
-    protected int mRvOffsetY;
 
     // Fast scroller popup
     private TextView mPopupView;
@@ -207,16 +206,11 @@
 
     public void setThumbOffsetY(int y) {
         if (mThumbOffsetY == y) {
-            int rvCurrentOffsetY = mRv.getCurrentScrollY();
-            if (mRvOffsetY != rvCurrentOffsetY) {
-                mRvOffsetY = mRv.getCurrentScrollY();
-            }
             return;
         }
         updatePopupY(y);
         mThumbOffsetY = y;
         invalidate();
-        mRvOffsetY = mRv.getCurrentScrollY();
     }
 
     public int getThumbOffsetY() {
diff --git a/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java b/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java
index 35fa7a4..5969e3e 100644
--- a/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java
+++ b/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java
@@ -19,7 +19,6 @@
 import android.content.Context;
 import android.graphics.Point;
 import android.util.AttributeSet;
-import android.util.SparseIntArray;
 import android.view.MotionEvent;
 
 import androidx.recyclerview.widget.LinearLayoutManager;
@@ -28,6 +27,7 @@
 
 import com.android.launcher3.FastScrollRecyclerView;
 import com.android.launcher3.R;
+import com.android.launcher3.util.ScrollableLayoutManager;
 
 /**
  * The widgets recycler view.
@@ -42,14 +42,6 @@
     private boolean mTouchDownOnScroller;
     private HeaderViewDimensionsProvider mHeaderViewDimensionsProvider;
 
-    /**
-     * There is always 1 or 0 item of VIEW_TYPE_WIDGETS_LIST. Other types have fixes sizes, so the
-     * the size can be used for all other items of same type. Caching the last know size for
-     * VIEW_TYPE_WIDGETS_LIST allows us to use it to estimate full size even when
-     * VIEW_TYPE_WIDGETS_LIST is not visible on the screen.
-     */
-    private final SparseIntArray mCachedSizes = new SparseIntArray();
-
     public WidgetsRecyclerView(Context context) {
         this(context, null);
     }
@@ -68,9 +60,7 @@
     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();
-        // create a layout manager with Launcher's context so that scroll position
-        // can be preserved during screen rotation.
-        setLayoutManager(new LinearLayoutManager(getContext()));
+        setLayoutManager(new ScrollableLayoutManager(getContext()));
     }
 
     @Override
@@ -114,7 +104,7 @@
         }
 
         // Skip early if, there no child laid out in the container.
-        int scrollY = getCurrentScrollY();
+        int scrollY = computeVerticalScrollOffset();
         if (scrollY < 0) {
             mScrollbar.setThumbOffsetY(-1);
             return;
@@ -164,39 +154,6 @@
     }
 
     /**
-     * Returns the sum of the height, in pixels, of this list adapter's items from index 0 until
-     * {@code untilIndex}.
-     *
-     * <p>If the untilIndex is larger than the total number of items in this adapter, returns the
-     * sum of all items' height.
-     */
-    @Override
-    protected int getItemsHeight(int untilIndex) {
-        // Initialize cache
-        int childCount = getChildCount();
-        int startPosition;
-        if (childCount > 0
-                && ((startPosition = getChildAdapterPosition(getChildAt(0))) != NO_POSITION)) {
-            int loopCount = Math.min(getChildCount(), getAdapter().getItemCount() - startPosition);
-            for (int i = 0; i < loopCount; i++) {
-                mCachedSizes.put(
-                        mAdapter.getItemViewType(startPosition + i),
-                        getChildAt(i).getMeasuredHeight());
-            }
-        }
-
-        if (untilIndex > mAdapter.getItems().size()) {
-            untilIndex = mAdapter.getItems().size();
-        }
-        int totalItemsHeight = 0;
-        for (int i = 0; i < untilIndex; i++) {
-            int type = mAdapter.getItemViewType(i);
-            totalItemsHeight += mCachedSizes.get(type);
-        }
-        return totalItemsHeight;
-    }
-
-    /**
      * Provides dimensions of the header view that is shown at the top of a
      * {@link WidgetsRecyclerView}.
      */
diff --git a/tests/src/com/android/launcher3/celllayout/ReorderWidgets.java b/tests/src/com/android/launcher3/celllayout/ReorderWidgets.java
index 8f095bc..2846cae 100644
--- a/tests/src/com/android/launcher3/celllayout/ReorderWidgets.java
+++ b/tests/src/com/android/launcher3/celllayout/ReorderWidgets.java
@@ -35,6 +35,7 @@
 import com.android.launcher3.tapl.WidgetResizeFrame;
 import com.android.launcher3.ui.AbstractLauncherUiTest;
 import com.android.launcher3.ui.TaplTestsLauncher3;
+import com.android.launcher3.util.rule.ScreenRecordRule.ScreenRecord;
 import com.android.launcher3.util.rule.ShellCommandRule;
 import com.android.launcher3.views.DoubleShadowBubbleTextView;
 import com.android.launcher3.widget.LauncherAppWidgetHostView;
@@ -145,22 +146,26 @@
         runTestCase(testCaseMap.get(iconGridDimensions));
     }
 
+    @ScreenRecord // b/242323136
     @Test
     public void simpleReorder()  throws ExecutionException, InterruptedException {
         runTestCaseMap(SimpleReorderCase.TEST_BY_GRID_SIZE,
                 SimpleReorderCase.class.getSimpleName());
     }
 
+    @ScreenRecord // b/242323136
     @Test
     public void pushTest()  throws ExecutionException, InterruptedException {
         runTestCaseMap(PushReorderCase.TEST_BY_GRID_SIZE, PushReorderCase.class.getSimpleName());
     }
 
+    @ScreenRecord // b/242323136
     @Test
     public void fullReorder()  throws ExecutionException, InterruptedException {
         runTestCaseMap(FullReorderCase.TEST_BY_GRID_SIZE, FullReorderCase.class.getSimpleName());
     }
 
+    @ScreenRecord // b/242323136
     @Test
     public void moveOutReorder()  throws ExecutionException, InterruptedException {
         runTestCaseMap(MoveOutReorderCase.TEST_BY_GRID_SIZE,
diff --git a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
index a66b09a..df3cbff 100644
--- a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
+++ b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
@@ -525,7 +525,7 @@
     }
 
     protected int getAllAppsScroll(Launcher launcher) {
-        return launcher.getAppsView().getActiveRecyclerView().getCurrentScrollY();
+        return launcher.getAppsView().getActiveRecyclerView().computeVerticalScrollOffset();
     }
 
     private void checkLauncherIntegrity(
diff --git a/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java b/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java
index be49974..07bfe4c 100644
--- a/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java
+++ b/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java
@@ -303,7 +303,7 @@
     }
 
     private int getWidgetsScroll(Launcher launcher) {
-        return getWidgetsView(launcher).getCurrentScrollY();
+        return getWidgetsView(launcher).computeVerticalScrollOffset();
     }
 
     private boolean isOptionsPopupVisible(Launcher launcher) {
diff --git a/tests/src/com/android/launcher3/util/LauncherModelHelper.java b/tests/src/com/android/launcher3/util/LauncherModelHelper.java
index 3324959..e7e551f 100644
--- a/tests/src/com/android/launcher3/util/LauncherModelHelper.java
+++ b/tests/src/com/android/launcher3/util/LauncherModelHelper.java
@@ -47,6 +47,7 @@
 import android.test.mock.MockContentResolver;
 import android.util.ArrayMap;
 
+import androidx.annotation.NonNull;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.uiautomator.UiDevice;
 
@@ -194,8 +195,9 @@
         Executor mockExecutor = mock(Executor.class);
         model.enqueueModelUpdateTask(new ModelUpdateTask() {
             @Override
-            public void init(LauncherAppState app, LauncherModel model, BgDataModel dataModel,
-                    AllAppsList allAppsList, Executor uiExecutor) {
+            public void init(@NonNull final LauncherAppState app,
+                    @NonNull final LauncherModel model, @NonNull final BgDataModel dataModel,
+                    @NonNull final AllAppsList allAppsList, @NonNull final Executor uiExecutor) {
                 task.init(app, model, dataModel, allAppsList, mockExecutor);
             }
 
diff --git a/tests/tapl/com/android/launcher3/tapl/Launchable.java b/tests/tapl/com/android/launcher3/tapl/Launchable.java
index 15f74dc..3dcb437 100644
--- a/tests/tapl/com/android/launcher3/tapl/Launchable.java
+++ b/tests/tapl/com/android/launcher3/tapl/Launchable.java
@@ -85,10 +85,9 @@
     }
 
     Point startDrag(long downTime, Runnable expectLongClickEvents, boolean runToSpringLoadedState) {
-        Point iconCenter = getObject().getVisibleCenter();
-        final Point displaySize = mLauncher.getRealDisplaySize();
-        final Point dragStartCenter = new Point(displaySize.x / 2,
-                displaySize.y / 2 - getStartDragThreshold());
+        final Point iconCenter = getObject().getVisibleCenter();
+        final Point dragStartCenter = new Point(iconCenter.x,
+                iconCenter.y - getStartDragThreshold());
 
         if (runToSpringLoadedState) {
             mLauncher.runToState(() -> movePointerForStartDrag(
diff --git a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
index 80bc402..43766bf 100644
--- a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
+++ b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
@@ -110,8 +110,11 @@
     static final Pattern EVENT_TOUCH_UP_TIS = getTouchEventPatternTIS("ACTION_UP");
     static final Pattern EVENT_TOUCH_CANCEL_TIS = getTouchEventPatternTIS("ACTION_CANCEL");
 
-    static final Pattern EVENT_KEY_BACK_DOWN = getKeyEventPattern("ACTION_DOWN", "KEYCODE_BACK");
-    static final Pattern EVENT_KEY_BACK_UP = getKeyEventPattern("ACTION_UP", "KEYCODE_BACK");
+    private static final Pattern EVENT_KEY_BACK_DOWN =
+            getKeyEventPattern("ACTION_DOWN", "KEYCODE_BACK");
+    private static final Pattern EVENT_KEY_BACK_UP =
+            getKeyEventPattern("ACTION_UP", "KEYCODE_BACK");
+    private static final Pattern EVENT_ON_BACK_INVOKED = Pattern.compile("onBackInvoked");
 
     private final String mLauncherPackage;
     private Boolean mIsLauncher3;
@@ -983,8 +986,12 @@
                 }
             }
             if (launcherVisible) {
-                expectEvent(TestProtocol.SEQUENCE_MAIN, EVENT_KEY_BACK_DOWN);
-                expectEvent(TestProtocol.SEQUENCE_MAIN, EVENT_KEY_BACK_UP);
+                if (getContext().getApplicationInfo().isOnBackInvokedCallbackEnabled()) {
+                    expectEvent(TestProtocol.SEQUENCE_MAIN, EVENT_ON_BACK_INVOKED);
+                } else {
+                    expectEvent(TestProtocol.SEQUENCE_MAIN, EVENT_KEY_BACK_DOWN);
+                    expectEvent(TestProtocol.SEQUENCE_MAIN, EVENT_KEY_BACK_UP);
+                }
             }
         }
     }
diff --git a/tests/tapl/com/android/launcher3/tapl/Workspace.java b/tests/tapl/com/android/launcher3/tapl/Workspace.java
index 5fab7eb..2c9fdb3 100644
--- a/tests/tapl/com/android/launcher3/tapl/Workspace.java
+++ b/tests/tapl/com/android/launcher3/tapl/Workspace.java
@@ -475,7 +475,9 @@
             // Since the destination can be on another page, we need to drag to the edge first
             // until we reach the target page
             while (targetDest.x > displayX || targetDest.x < 0) {
-                int edgeX = targetDest.x > 0 ? displayX : 0;
+                // Don't drag all the way to the edge to prevent touch events from getting out of
+                //screen bounds.
+                int edgeX = targetDest.x > 0 ? displayX - 1 : 1;
                 Point screenEdge = new Point(edgeX, targetDest.y);
                 Point finalDragStart = dragStart;
                 executeAndWaitForPageScroll(launcher,