diff --git a/src/com/android/launcher3/AllAppsList.java b/src/com/android/launcher3/AllAppsList.java
index c431593..c427ddc 100644
--- a/src/com/android/launcher3/AllAppsList.java
+++ b/src/com/android/launcher3/AllAppsList.java
@@ -23,7 +23,7 @@
 import com.android.launcher3.compat.LauncherAppsCompat;
 import com.android.launcher3.compat.UserHandleCompat;
 import com.android.launcher3.util.FlagOp;
-import com.android.launcher3.util.StringFilter;
+import com.android.launcher3.util.ItemInfoMatcher;
 
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -121,14 +121,13 @@
     }
 
     /**
-     * Updates the apps for the given packageName and user based on {@param op}.
+     * Updates the disabled flags of apps matching {@param matcher} based on {@param op}.
      */
-    public void updatePackageFlags(StringFilter pkgFilter, UserHandleCompat user, FlagOp op) {
+    public void updateDisabledFlags(ItemInfoMatcher matcher, FlagOp op) {
         final List<AppInfo> data = this.data;
         for (int i = data.size() - 1; i >= 0; i--) {
             AppInfo info = data.get(i);
-            final ComponentName component = info.intent.getComponent();
-            if (info.user.equals(user) && pkgFilter.matches(component.getPackageName())) {
+            if (matcher.matches(info, info.intent.getComponent())) {
                 info.isDisabled = op.apply(info.isDisabled);
                 modified.add(info);
             }
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 901900e..13911b8 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -4449,14 +4449,6 @@
         return sCustomAppWidgets;
     }
 
-    public static List<View> getFolderContents(View icon) {
-        if (icon instanceof FolderIcon) {
-            return ((FolderIcon) icon).getFolder().getItemsInReadingOrder();
-        } else {
-            return Collections.EMPTY_LIST;
-        }
-    }
-
     public static Launcher getLauncher(Context context) {
         if (context instanceof Launcher) {
             return (Launcher) context;
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index 2e3d603..5e57aa4 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -71,12 +71,12 @@
 import com.android.launcher3.util.CursorIconInfo;
 import com.android.launcher3.util.FlagOp;
 import com.android.launcher3.util.GridOccupancy;
+import com.android.launcher3.util.ItemInfoMatcher;
 import com.android.launcher3.util.LongArrayMap;
 import com.android.launcher3.util.ManagedProfileHeuristic;
 import com.android.launcher3.util.MultiHashMap;
 import com.android.launcher3.util.PackageManagerHelper;
 import com.android.launcher3.util.Preconditions;
-import com.android.launcher3.util.StringFilter;
 import com.android.launcher3.util.Thunk;
 import com.android.launcher3.util.ViewOnDrawExecutor;
 
@@ -230,10 +230,6 @@
         public void bindDeepShortcutMap(MultiHashMap<ComponentKey, String> deepShortcutMap);
     }
 
-    public interface ItemInfoFilter {
-        public boolean filterItem(ItemInfo parent, ItemInfo info, ComponentName cn);
-    }
-
     LauncherModel(LauncherAppState app, IconCache iconCache, AppFilter appFilter,
             DeepShortcutManager deepShortcutManager) {
         Context context = app.getContext();
@@ -942,38 +938,26 @@
         runOnWorkerThread(r);
     }
 
-    private static ArrayList<ItemInfo> getItemsByPackageName(
-            final String pn, final UserHandleCompat user) {
-        ItemInfoFilter filter  = new ItemInfoFilter() {
-            @Override
-            public boolean filterItem(ItemInfo parent, ItemInfo info, ComponentName cn) {
-                return cn.getPackageName().equals(pn) && info.user.equals(user);
-            }
-        };
-        return filterItemInfos(sBgItemsIdMap, filter);
-    }
-
-    /**
-     * Removes all the items from the database corresponding to the specified package.
-     */
-    static void deletePackageFromDatabase(Context context, final String pn,
-            final UserHandleCompat user) {
-        deleteItemsFromDatabase(context, getItemsByPackageName(pn, user));
-    }
-
     /**
      * Removes the specified item from the database
      */
     public static void deleteItemFromDatabase(Context context, final ItemInfo item) {
-        ArrayList<ItemInfo> items = new ArrayList<ItemInfo>();
+        ArrayList<ItemInfo> items = new ArrayList<>();
         items.add(item);
         deleteItemsFromDatabase(context, items);
     }
 
     /**
+     * Removes all the items from the database matching {@param matcher}.
+     */
+    public static void deleteItemsFromDatabase(Context context, ItemInfoMatcher matcher) {
+        deleteItemsFromDatabase(context, matcher.filterItemInfos(sBgItemsIdMap));
+    }
+
+    /**
      * Removes the specified items from the database
      */
-    static void deleteItemsFromDatabase(Context context, final ArrayList<? extends ItemInfo> items) {
+    static void deleteItemsFromDatabase(Context context, final Iterable<? extends ItemInfo> items) {
         final ContentResolver cr = context.getContentResolver();
         Runnable r = new Runnable() {
             public void run() {
@@ -2972,9 +2956,9 @@
     }
 
     private class PackageUpdatedTask implements Runnable {
-        int mOp;
-        String[] mPackages;
-        UserHandleCompat mUser;
+        final int mOp;
+        final String[] mPackages;
+        final UserHandleCompat mUser;
 
         public static final int OP_NONE = 0;
         public static final int OP_ADD = 1;
@@ -3001,7 +2985,7 @@
             final String[] packages = mPackages;
             final int N = packages.length;
             FlagOp flagOp = FlagOp.NO_OP;
-            StringFilter pkgFilter = StringFilter.of(new HashSet<>(Arrays.asList(packages)));
+            final HashSet<String> packageSet = new HashSet<>(Arrays.asList(packages));
             switch (mOp) {
                 case OP_ADD: {
                     for (int i=0; i<N; i++) {
@@ -3051,15 +3035,15 @@
                             FlagOp.addFlag(ShortcutInfo.FLAG_DISABLED_SUSPENDED) :
                                     FlagOp.removeFlag(ShortcutInfo.FLAG_DISABLED_SUSPENDED);
                     if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.(un)suspend " + N);
-                    mBgAllAppsList.updatePackageFlags(pkgFilter, mUser, flagOp);
+                    mBgAllAppsList.updateDisabledFlags(
+                            ItemInfoMatcher.ofPackages(packageSet, mUser), flagOp);
                     break;
                 case OP_USER_AVAILABILITY_CHANGE:
                     flagOp = UserManagerCompat.getInstance(context).isQuietModeEnabled(mUser)
                             ? FlagOp.addFlag(ShortcutInfo.FLAG_DISABLED_QUIET_USER)
                             : FlagOp.removeFlag(ShortcutInfo.FLAG_DISABLED_QUIET_USER);
                     // We want to update all packages for this user.
-                    pkgFilter = StringFilter.matchesAll();
-                    mBgAllAppsList.updatePackageFlags(pkgFilter, mUser, flagOp);
+                    mBgAllAppsList.updateDisabledFlags(ItemInfoMatcher.ofUser(mUser), flagOp);
                     break;
             }
 
@@ -3108,9 +3092,9 @@
 
             // Update shortcut infos
             if (mOp == OP_ADD || flagOp != FlagOp.NO_OP) {
-                final ArrayList<ShortcutInfo> updatedShortcuts = new ArrayList<ShortcutInfo>();
-                final ArrayList<ShortcutInfo> removedShortcuts = new ArrayList<ShortcutInfo>();
-                final ArrayList<LauncherAppWidgetInfo> widgets = new ArrayList<LauncherAppWidgetInfo>();
+                final ArrayList<ShortcutInfo> updatedShortcuts = new ArrayList<>();
+                final ArrayList<ShortcutInfo> removedShortcuts = new ArrayList<>();
+                final ArrayList<LauncherAppWidgetInfo> widgets = new ArrayList<>();
 
                 synchronized (sBgLock) {
                     for (ItemInfo info : sBgItemsIdMap) {
@@ -3121,7 +3105,7 @@
 
                             // Update shortcuts which use iconResource.
                             if ((si.iconResource != null)
-                                    && pkgFilter.matches(si.iconResource.packageName)) {
+                                    && packageSet.contains(si.iconResource.packageName)) {
                                 Bitmap icon = LauncherIcons.createIconBitmap(
                                         si.iconResource.packageName,
                                         si.iconResource.resourceName, context);
@@ -3133,7 +3117,7 @@
                             }
 
                             ComponentName cn = si.getTargetComponent();
-                            if (cn != null && pkgFilter.matches(cn.getPackageName())) {
+                            if (cn != null && packageSet.contains(cn.getPackageName())) {
                                 AppInfo appInfo = addedOrUpdatedApps.get(cn);
 
                                 if (si.isPromise()) {
@@ -3198,7 +3182,7 @@
                             LauncherAppWidgetInfo widgetInfo = (LauncherAppWidgetInfo) info;
                             if (mUser.equals(widgetInfo.user)
                                     && widgetInfo.hasRestoreFlag(LauncherAppWidgetInfo.FLAG_PROVIDER_NOT_READY)
-                                    && pkgFilter.matches(widgetInfo.providerName.getPackageName())) {
+                                    && packageSet.contains(widgetInfo.providerName.getPackageName())) {
                                 widgetInfo.restoreStatus &=
                                         ~LauncherAppWidgetInfo.FLAG_PROVIDER_NOT_READY &
                                         ~LauncherAppWidgetInfo.FLAG_RESTORE_STARTED;
@@ -3256,12 +3240,10 @@
             }
 
             if (!removedPackages.isEmpty() || !removedComponents.isEmpty()) {
-                for (String pn : removedPackages) {
-                    deletePackageFromDatabase(context, pn, mUser);
-                }
-                for (ComponentName cn : removedComponents) {
-                    deleteItemsFromDatabase(context, getItemInfoForComponentName(cn, mUser));
-                }
+                deleteItemsFromDatabase(
+                        context, ItemInfoMatcher.ofPackages(removedPackages, mUser));
+                deleteItemsFromDatabase(
+                        context, ItemInfoMatcher.ofComponents(removedComponents, mUser));
 
                 // Remove any queued items from the install queue
                 InstallShortcutReceiver.removeFromInstallQueue(context, removedPackages, mUser);
@@ -3497,18 +3479,6 @@
         return !launcherApps.isPackageEnabledForProfile(packageName, user);
     }
 
-    public static boolean isValidPackageActivity(Context context, ComponentName cn,
-            UserHandleCompat user) {
-        if (cn == null) {
-            return false;
-        }
-        final LauncherAppsCompat launcherApps = LauncherAppsCompat.getInstance(context);
-        if (!launcherApps.isPackageEnabledForProfile(cn.getPackageName(), user)) {
-            return false;
-        }
-        return launcherApps.isActivityEnabledForProfile(cn, user);
-    }
-
     public static boolean isValidPackage(Context context, String packageName,
             UserHandleCompat user) {
         if (packageName == null) {
@@ -3631,50 +3601,6 @@
         return info;
     }
 
-    static ArrayList<ItemInfo> filterItemInfos(Iterable<ItemInfo> infos,
-            ItemInfoFilter f) {
-        HashSet<ItemInfo> filtered = new HashSet<ItemInfo>();
-        for (ItemInfo i : infos) {
-            if (i instanceof ShortcutInfo) {
-                ShortcutInfo info = (ShortcutInfo) i;
-                ComponentName cn = info.getTargetComponent();
-                if (cn != null && f.filterItem(null, info, cn)) {
-                    filtered.add(info);
-                }
-            } else if (i instanceof FolderInfo) {
-                FolderInfo info = (FolderInfo) i;
-                for (ShortcutInfo s : info.contents) {
-                    ComponentName cn = s.getTargetComponent();
-                    if (cn != null && f.filterItem(info, s, cn)) {
-                        filtered.add(s);
-                    }
-                }
-            } else if (i instanceof LauncherAppWidgetInfo) {
-                LauncherAppWidgetInfo info = (LauncherAppWidgetInfo) i;
-                ComponentName cn = info.providerName;
-                if (cn != null && f.filterItem(null, info, cn)) {
-                    filtered.add(info);
-                }
-            }
-        }
-        return new ArrayList<ItemInfo>(filtered);
-    }
-
-    @Thunk ArrayList<ItemInfo> getItemInfoForComponentName(final ComponentName cname,
-            final UserHandleCompat user) {
-        ItemInfoFilter filter  = new ItemInfoFilter() {
-            @Override
-            public boolean filterItem(ItemInfo parent, ItemInfo info, ComponentName cn) {
-                if (info.user == null) {
-                    return cn.equals(cname);
-                } else {
-                    return cn.equals(cname) && info.user.equals(user);
-                }
-            }
-        };
-        return filterItemInfos(sBgItemsIdMap, filter);
-    }
-
     /**
      * Make an ShortcutInfo object for a shortcut that isn't an application.
      */
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index d5f1363..02c561f 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -29,7 +29,6 @@
 import android.app.WallpaperManager;
 import android.appwidget.AppWidgetHostView;
 import android.appwidget.AppWidgetProviderInfo;
-import android.content.ComponentName;
 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
@@ -3976,63 +3975,34 @@
         for (final CellLayout layoutParent: cellLayouts) {
             final ViewGroup layout = layoutParent.getShortcutsAndWidgets();
 
-            final HashMap<ItemInfo, View> children = new HashMap<>();
+            LongArrayMap<View> idToViewMap = new LongArrayMap<>();
+            ArrayList<ItemInfo> items = new ArrayList<>();
             for (int j = 0; j < layout.getChildCount(); j++) {
                 final View view = layout.getChildAt(j);
-                children.put((ItemInfo) view.getTag(), view);
+                if (view.getTag() instanceof ItemInfo) {
+                    ItemInfo item = (ItemInfo) view.getTag();
+                    items.add(item);
+                    idToViewMap.put(item.id, view);
+                }
             }
 
-            final ArrayList<View> childrenToRemove = new ArrayList<>();
-            final HashMap<FolderInfo, ArrayList<ShortcutInfo>> folderAppsToRemove = new HashMap<>();
-            LauncherModel.ItemInfoFilter filter = new LauncherModel.ItemInfoFilter() {
-                @Override
-                public boolean filterItem(ItemInfo parent, ItemInfo info,
-                        ComponentName cn) {
-                    if (parent instanceof FolderInfo) {
-                        if (matcher.matches(info, cn)) {
-                            FolderInfo folder = (FolderInfo) parent;
-                            ArrayList<ShortcutInfo> appsToRemove;
-                            if (folderAppsToRemove.containsKey(folder)) {
-                                appsToRemove = folderAppsToRemove.get(folder);
-                            } else {
-                                appsToRemove = new ArrayList<ShortcutInfo>();
-                                folderAppsToRemove.put(folder, appsToRemove);
-                            }
-                            appsToRemove.add((ShortcutInfo) info);
-                            return true;
-                        }
-                    } else {
-                        if (matcher.matches(info, cn)) {
-                            childrenToRemove.add(children.get(info));
-                            return true;
-                        }
+            for (ItemInfo itemToRemove : matcher.filterItemInfos(items)) {
+                View child = idToViewMap.get(itemToRemove.id);
+
+                if (child != null) {
+                    // Note: We can not remove the view directly from CellLayoutChildren as this
+                    // does not re-mark the spaces as unoccupied.
+                    layoutParent.removeViewInLayout(child);
+                    if (child instanceof DropTarget) {
+                        mDragController.removeDropTarget((DropTarget) child);
                     }
-                    return false;
+                } else if (itemToRemove.container >= 0) {
+                    // The item may belong to a folder.
+                    View parent = idToViewMap.get(itemToRemove.container);
+                    if (parent != null) {
+                        ((FolderInfo) parent.getTag()).remove((ShortcutInfo) itemToRemove, false);
+                    }
                 }
-            };
-            LauncherModel.filterItemInfos(children.keySet(), filter);
-
-            // Remove all the apps from their folders
-            for (FolderInfo folder : folderAppsToRemove.keySet()) {
-                ArrayList<ShortcutInfo> appsToRemove = folderAppsToRemove.get(folder);
-                for (ShortcutInfo info : appsToRemove) {
-                    folder.remove(info, false);
-                }
-            }
-
-            // Remove all the other children
-            for (View child : childrenToRemove) {
-                // Note: We can not remove the view directly from CellLayoutChildren as this
-                // does not re-mark the spaces as unoccupied.
-                layoutParent.removeViewInLayout(child);
-                if (child instanceof DropTarget) {
-                    mDragController.removeDropTarget((DropTarget) child);
-                }
-            }
-
-            if (childrenToRemove.size() > 0) {
-                layout.requestLayout();
-                layout.invalidate();
             }
         }
 
@@ -4133,8 +4103,9 @@
     public void removeAbandonedPromise(String packageName, UserHandleCompat user) {
         HashSet<String> packages = new HashSet<>(1);
         packages.add(packageName);
-        LauncherModel.deletePackageFromDatabase(mLauncher, packageName, user);
-        removeItemsByMatcher(ItemInfoMatcher.ofPackages(packages, user));
+        ItemInfoMatcher matcher = ItemInfoMatcher.ofPackages(packages, user);
+        LauncherModel.deleteItemsFromDatabase(mLauncher, matcher);
+        removeItemsByMatcher(matcher);
     }
 
     public void updateRestoreItems(final HashSet<ItemInfo> updates) {
@@ -4311,7 +4282,6 @@
                 @Override
                 public boolean evaluate(ItemInfo info, View view) {
                     if (view instanceof PendingAppWidgetHostView && mInfos.contains(info)) {
-                        PendingAppWidgetHostView hostView = (PendingAppWidgetHostView) view;
                         mLauncher.removeItem(view, info, false /* deleteFromDb */);
                         mLauncher.bindAppWidget((LauncherAppWidgetInfo) info);
                     }
diff --git a/src/com/android/launcher3/util/ItemInfoMatcher.java b/src/com/android/launcher3/util/ItemInfoMatcher.java
index 46e9184..8f985c3 100644
--- a/src/com/android/launcher3/util/ItemInfoMatcher.java
+++ b/src/com/android/launcher3/util/ItemInfoMatcher.java
@@ -18,7 +18,9 @@
 
 import android.content.ComponentName;
 
+import com.android.launcher3.FolderInfo;
 import com.android.launcher3.ItemInfo;
+import com.android.launcher3.LauncherAppWidgetInfo;
 import com.android.launcher3.LauncherSettings.Favorites;
 import com.android.launcher3.ShortcutInfo;
 import com.android.launcher3.compat.UserHandleCompat;
@@ -33,6 +35,46 @@
 
     public abstract boolean matches(ItemInfo info, ComponentName cn);
 
+    /**
+     * Filters {@param infos} to those satisfying the {@link #matches(ItemInfo, ComponentName)}.
+     */
+    public final HashSet<ItemInfo> filterItemInfos(Iterable<ItemInfo> infos) {
+        HashSet<ItemInfo> filtered = new HashSet<>();
+        for (ItemInfo i : infos) {
+            if (i instanceof ShortcutInfo) {
+                ShortcutInfo info = (ShortcutInfo) i;
+                ComponentName cn = info.getTargetComponent();
+                if (cn != null && matches(info, cn)) {
+                    filtered.add(info);
+                }
+            } else if (i instanceof FolderInfo) {
+                FolderInfo info = (FolderInfo) i;
+                for (ShortcutInfo s : info.contents) {
+                    ComponentName cn = s.getTargetComponent();
+                    if (cn != null && matches(s, cn)) {
+                        filtered.add(s);
+                    }
+                }
+            } else if (i instanceof LauncherAppWidgetInfo) {
+                LauncherAppWidgetInfo info = (LauncherAppWidgetInfo) i;
+                ComponentName cn = info.providerName;
+                if (cn != null && matches(info, cn)) {
+                    filtered.add(info);
+                }
+            }
+        }
+        return filtered;
+    }
+
+    public static ItemInfoMatcher ofUser(final UserHandleCompat user) {
+        return new ItemInfoMatcher() {
+            @Override
+            public boolean matches(ItemInfo info, ComponentName cn) {
+                return info.user.equals(user);
+            }
+        };
+    }
+
     public static ItemInfoMatcher ofComponents(
             final HashSet<ComponentName> components, final UserHandleCompat user) {
         return new ItemInfoMatcher() {
diff --git a/src/com/android/launcher3/util/StringFilter.java b/src/com/android/launcher3/util/StringFilter.java
deleted file mode 100644
index f539ad1..0000000
--- a/src/com/android/launcher3/util/StringFilter.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package com.android.launcher3.util;
-
-import java.util.Set;
-
-/**
- * Abstract class to filter a set of strings.
- */
-public abstract class StringFilter {
-
-    private StringFilter() { }
-
-    public abstract boolean matches(String str);
-
-    public static StringFilter matchesAll() {
-        return new StringFilter() {
-            @Override
-            public boolean matches(String str) {
-                return true;
-            }
-        };
-    }
-
-    public static StringFilter of(final Set<String> validEntries) {
-        return new StringFilter() {
-            @Override
-            public boolean matches(String str) {
-                return validEntries.contains(str);
-            }
-        };
-    }
-}