diff --git a/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java b/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java
index 56d25f2..641e108 100644
--- a/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java
+++ b/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java
@@ -86,7 +86,7 @@
     private @Nullable TaskbarController mTaskbarController;
     private final TaskbarStateHandler mTaskbarStateHandler = new TaskbarStateHandler(this);
     // Will be updated when dragging from taskbar.
-    private DragOptions mWorkspaceDragOptions = new DragOptions();
+    private @Nullable DragOptions mNextWorkspaceDragOptions = null;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -272,11 +272,16 @@
 
     @Override
     public DragOptions getDefaultWorkspaceDragOptions() {
-        return mWorkspaceDragOptions;
+        if (mNextWorkspaceDragOptions != null) {
+            DragOptions options = mNextWorkspaceDragOptions;
+            mNextWorkspaceDragOptions = null;
+            return options;
+        }
+        return super.getDefaultWorkspaceDragOptions();
     }
 
-    public void setWorkspaceDragOptions(DragOptions dragOptions) {
-        mWorkspaceDragOptions = dragOptions;
+    public void setNextWorkspaceDragOptions(DragOptions dragOptions) {
+        mNextWorkspaceDragOptions = dragOptions;
     }
 
     @Override
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarContainerView.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarContainerView.java
index 1e5e3e7..528f43e 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarContainerView.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarContainerView.java
@@ -83,10 +83,15 @@
 
     private ViewTreeObserverWrapper.OnComputeInsetsListener createTaskbarInsetsComputer() {
         return insetsInfo -> {
-            if (getAlpha() < AlphaUpdateListener.ALPHA_CUTOFF_THRESHOLD) {
-                // We're invisible, let touches pass through us.
+            if (getAlpha() < AlphaUpdateListener.ALPHA_CUTOFF_THRESHOLD
+                    || mTaskbarView.isDraggingItem()) {
+                // We're invisible or dragging out of taskbar, let touches pass through us.
                 insetsInfo.touchableRegion.setEmpty();
                 insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_REGION);
+                // TODO(b/182234653): Shouldn't need to do this, but for the meantime, reporting
+                // that visibleInsets is empty allows DragEvents through. Setting them as completely
+                // empty reverts to default behavior, so set 1 px instead.
+                insetsInfo.visibleInsets.set(0, 0, 0, 1);
             } else {
                  // We're visible again, accept touches anywhere in our bounds.
                 insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_FRAME);
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarController.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarController.java
index 544835c..fb7d85f 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarController.java
@@ -246,6 +246,11 @@
      * Removes the Taskbar from the screen, and removes any obsolete listeners etc.
      */
     public void cleanup() {
+        if (mAnimator != null) {
+            // End this first, in case it relies on properties that are about to be cleaned up.
+            mAnimator.end();
+        }
+
         mTaskbarView.cleanup();
         mTaskbarContainerView.cleanup();
         removeFromWindowManager();
@@ -253,10 +258,6 @@
         mTaskbarVisibilityController.cleanup();
         mHotseatController.cleanup();
         mRecentsController.cleanup();
-
-        if (mAnimator != null) {
-            mAnimator.end();
-        }
     }
 
     private void removeFromWindowManager() {
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java
index 2bd5861..9d203fb 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java
@@ -37,7 +37,6 @@
 
     private final BaseQuickstepLauncher mLauncher;
     private final ItemInfo mDraggedItem;
-    private final DragOptions mDragOptions;
     // Randomly generated id used to verify the drag event.
     private final String mId;
 
@@ -51,8 +50,6 @@
     public TaskbarDragListener(BaseQuickstepLauncher launcher, ItemInfo draggedItem) {
         mLauncher = launcher;
         mDraggedItem = draggedItem;
-        mDragOptions = new DragOptions();
-        mDragOptions.simulatedDndStartPoint = new Point();
         mId = UUID.randomUUID().toString();
     }
 
@@ -63,7 +60,7 @@
 
     private void cleanup() {
         mDragLayer.setOnDragListener(null);
-        mLauncher.setWorkspaceDragOptions(new DragOptions());
+        mLauncher.setNextWorkspaceDragOptions(null);
     }
 
     /**
@@ -88,8 +85,10 @@
                 cleanup();
                 return false;
             }
-            mDragOptions.simulatedDndStartPoint.set((int) dragEvent.getX(), (int) dragEvent.getY());
-            mLauncher.setWorkspaceDragOptions(mDragOptions);
+            DragOptions dragOptions = new DragOptions();
+            dragOptions.simulatedDndStartPoint = new Point((int) dragEvent.getX(),
+                    (int) dragEvent.getY());
+            mLauncher.setNextWorkspaceDragOptions(dragOptions);
             hotseatView.performLongClick();
         } else if (dragEvent.getAction() == DragEvent.ACTION_DRAG_ENDED) {
             cleanup();
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarHotseatController.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarHotseatController.java
index 082343e..b1bafdb 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarHotseatController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarHotseatController.java
@@ -78,7 +78,10 @@
                 CellLayout.LayoutParams lp = (CellLayout.LayoutParams) child.getLayoutParams();
                 // Since the hotseat might be laid out vertically or horizontally, use whichever
                 // index is higher.
-                hotseatItemInfos[Math.max(lp.cellX, lp.cellY)] = itemInfo;
+                int index = Math.max(lp.cellX, lp.cellY);
+                if (0 <= index && index < hotseatItemInfos.length) {
+                    hotseatItemInfos[index] = itemInfo;
+                }
             }
         }
 
diff --git a/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithmTest.java b/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithmTest.java
new file mode 100644
index 0000000..c2bf1ae
--- /dev/null
+++ b/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithmTest.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2021 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.widget.picker.search;
+
+import static android.os.Looper.getMainLooper;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.matches;
+import static org.mockito.Mockito.verify;
+import static org.robolectric.Shadows.shadowOf;
+
+import com.android.launcher3.search.SearchCallback;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+@RunWith(RobolectricTestRunner.class)
+public class SimpleWidgetsSearchAlgorithmTest {
+
+    private SimpleWidgetsSearchAlgorithm mSimpleWidgetsSearchAlgorithm;
+    @Mock
+    private WidgetsPickerSearchPipeline mSearchPipeline;
+    @Mock
+    private SearchCallback<WidgetsListBaseEntry> mSearchCallback;
+    @Captor
+    private ArgumentCaptor<Consumer<List<WidgetsListBaseEntry>>> mConsumerCaptor;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mSimpleWidgetsSearchAlgorithm = new SimpleWidgetsSearchAlgorithm(mSearchPipeline);
+    }
+
+    @Test
+    public void doSearch_shouldQueryPipeline() {
+        mSimpleWidgetsSearchAlgorithm.doSearch("abc", mSearchCallback);
+
+        verify(mSearchPipeline).query(eq("abc"), any());
+    }
+
+    @Test
+    public void doSearch_shouldInformSearchCallbackOnQueryResult() {
+        ArrayList<WidgetsListBaseEntry> baseEntries = new ArrayList<>();
+
+        mSimpleWidgetsSearchAlgorithm.doSearch("abc", mSearchCallback);
+
+        verify(mSearchPipeline).query(eq("abc"), mConsumerCaptor.capture());
+        mConsumerCaptor.getValue().accept(baseEntries);
+        shadowOf(getMainLooper()).idle();
+        // Verify SearchCallback#onSearchResult receives a query token along with the search
+        // results. The query token is the original query string concatenated with the query
+        // timestamp.
+        verify(mSearchCallback).onSearchResult(matches("abc\t\\d*"), eq(baseEntries));
+    }
+}
diff --git a/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipelineTest.java b/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipelineTest.java
new file mode 100644
index 0000000..8aebf12
--- /dev/null
+++ b/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipelineTest.java
@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2021 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.widget.picker.search;
+
+import static android.os.Looper.getMainLooper;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.robolectric.Shadows.shadowOf;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.os.UserHandle;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.icons.BitmapInfo;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.model.WidgetsListContentEntry;
+import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.shadows.ShadowPackageManager;
+import org.robolectric.util.ReflectionHelpers;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@RunWith(RobolectricTestRunner.class)
+public class SimpleWidgetsSearchPipelineTest {
+    private static final SimpleWidgetsSearchPipeline.StringMatcher MATCHER =
+            SimpleWidgetsSearchPipeline.StringMatcher.getInstance();
+
+    @Mock private IconCache mIconCache;
+
+    private InvariantDeviceProfile mTestProfile;
+    private WidgetsListHeaderEntry mCalendarHeaderEntry;
+    private WidgetsListContentEntry mCalendarContentEntry;
+    private WidgetsListHeaderEntry mCameraHeaderEntry;
+    private WidgetsListContentEntry mCameraContentEntry;
+    private WidgetsListHeaderEntry mClockHeaderEntry;
+    private WidgetsListContentEntry mClockContentEntry;
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        doAnswer(invocation -> ((ComponentWithLabel) invocation.getArgument(0))
+                .getComponent().getPackageName())
+                .when(mIconCache).getTitleNoCache(any());
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+        mContext = RuntimeEnvironment.application;
+
+        mCalendarHeaderEntry =
+                createWidgetsHeaderEntry("com.example.android.Calendar", "Calendar", 2);
+        mCalendarContentEntry =
+                createWidgetsContentEntry("com.example.android.Calendar", "Calendar", 2);
+        mCameraHeaderEntry = createWidgetsHeaderEntry("com.example.android.Camera", "Camera", 5);
+        mCameraContentEntry = createWidgetsContentEntry("com.example.android.Camera", "Camera", 5);
+        mClockHeaderEntry = createWidgetsHeaderEntry("com.example.android.Clock", "Clock", 3);
+        mClockContentEntry = createWidgetsContentEntry("com.example.android.Clock", "Clock", 3);
+    }
+
+    @Test
+    public void query_shouldInformCallbackWithResultsMatchedOnAppName() {
+        SimpleWidgetsSearchPipeline pipeline = new SimpleWidgetsSearchPipeline(
+                List.of(mCalendarHeaderEntry, mCalendarContentEntry, mCameraHeaderEntry,
+                        mCameraContentEntry, mClockHeaderEntry, mClockContentEntry));
+
+        pipeline.query("Ca", results ->
+                assertEquals(results, List.of(mCalendarHeaderEntry, mCalendarContentEntry,
+                        mCameraHeaderEntry, mCameraContentEntry)));
+        shadowOf(getMainLooper()).idle();
+    }
+
+    @Test
+    public void testMatches() {
+        assertTrue(MATCHER.matches("q", "Q"));
+        assertTrue(MATCHER.matches("q", "  Q"));
+        assertTrue(MATCHER.matches("e", "elephant"));
+        assertTrue(MATCHER.matches("eL", "Elephant"));
+        assertTrue(MATCHER.matches("elephant ", "elephant"));
+        assertTrue(MATCHER.matches("whitec", "white cow"));
+        assertTrue(MATCHER.matches("white  c", "white cow"));
+        assertTrue(MATCHER.matches("white ", "white cow"));
+        assertTrue(MATCHER.matches("white c", "white cow"));
+        assertTrue(MATCHER.matches("电", "电子邮件"));
+        assertTrue(MATCHER.matches("电子", "电子邮件"));
+        assertTrue(MATCHER.matches("다", "다운로드"));
+        assertTrue(MATCHER.matches("드", "드라이브"));
+        assertTrue(MATCHER.matches("åbç", "abc"));
+        assertTrue(MATCHER.matches("ål", "Alpha"));
+
+        assertFalse(MATCHER.matches("phant", "elephant"));
+        assertFalse(MATCHER.matches("elephants", "elephant"));
+        assertFalse(MATCHER.matches("cow", "white cow"));
+        assertFalse(MATCHER.matches("cow", "whiteCow"));
+        assertFalse(MATCHER.matches("dog", "cats&Dogs"));
+        assertFalse(MATCHER.matches("ba", "Bot"));
+        assertFalse(MATCHER.matches("ba", "bot"));
+        assertFalse(MATCHER.matches("子", "电子邮件"));
+        assertFalse(MATCHER.matches("邮件", "电子邮件"));
+        assertFalse(MATCHER.matches("ㄷ", "다운로드 드라이브"));
+        assertFalse(MATCHER.matches("ㄷㄷ", "다운로드 드라이브"));
+        assertFalse(MATCHER.matches("åç", "abc"));
+    }
+
+    private WidgetsListHeaderEntry createWidgetsHeaderEntry(String packageName, String appName,
+            int numOfWidgets) {
+        List<WidgetItem> widgetItems = generateWidgetItems(packageName, numOfWidgets);
+        PackageItemInfo pInfo = createPackageItemInfo(packageName, appName,
+                widgetItems.get(0).user);
+
+        return new WidgetsListHeaderEntry(pInfo, /* titleSectionName= */ "", widgetItems);
+    }
+
+    private WidgetsListContentEntry createWidgetsContentEntry(String packageName, String appName,
+            int numOfWidgets) {
+        List<WidgetItem> widgetItems = generateWidgetItems(packageName, numOfWidgets);
+        PackageItemInfo pInfo = createPackageItemInfo(packageName, appName,
+                widgetItems.get(0).user);
+
+        return new WidgetsListContentEntry(pInfo, /* titleSectionName= */ "", widgetItems);
+    }
+
+    private PackageItemInfo createPackageItemInfo(String packageName, String appName,
+            UserHandle userHandle) {
+        PackageItemInfo pInfo = new PackageItemInfo(packageName);
+        pInfo.title = appName;
+        pInfo.user = userHandle;
+        pInfo.bitmap = BitmapInfo.of(Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8), 0);
+        return pInfo;
+    }
+
+    private List<WidgetItem> generateWidgetItems(String packageName, int numOfWidgets) {
+        ShadowPackageManager packageManager = shadowOf(mContext.getPackageManager());
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        for (int i = 0; i < numOfWidgets; i++) {
+            ComponentName cn = ComponentName.createRelative(packageName, ".SampleWidget" + i);
+            AppWidgetProviderInfo widgetInfo = new AppWidgetProviderInfo();
+            widgetInfo.provider = cn;
+            ReflectionHelpers.setField(widgetInfo, "providerInfo",
+                    packageManager.addReceiverIfNotPresent(cn));
+
+            WidgetItem widgetItem = new WidgetItem(
+                    LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, widgetInfo),
+                    mTestProfile, mIconCache);
+            widgetItems.add(widgetItem);
+        }
+        return widgetItems;
+    }
+}
diff --git a/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithm.java b/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithm.java
new file mode 100644
index 0000000..15d2454
--- /dev/null
+++ b/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithm.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2021 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.widget.picker.search;
+
+import android.os.Handler;
+import android.util.Log;
+
+import com.android.launcher3.search.SearchAlgorithm;
+import com.android.launcher3.search.SearchCallback;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+
+import java.util.ArrayList;
+
+/**
+ * Implementation of {@link SearchAlgorithm} that posts a task to query on the main thread.
+ */
+public final class SimpleWidgetsSearchAlgorithm implements SearchAlgorithm<WidgetsListBaseEntry> {
+
+    private static final boolean DEBUG = false;
+    private static final String TAG = "SimpleWidgetsSearchAlgo";
+    private static final String DELIM = "\t";
+
+    private final Handler mResultHandler;
+    private final WidgetsPickerSearchPipeline mSearchPipeline;
+
+    public SimpleWidgetsSearchAlgorithm(WidgetsPickerSearchPipeline searchPipeline) {
+        mResultHandler = new Handler();
+        mSearchPipeline = searchPipeline;
+    }
+
+    @Override
+    public void doSearch(String query, SearchCallback<WidgetsListBaseEntry> callback) {
+        long startTime = System.currentTimeMillis();
+        String queryToken = query + DELIM + startTime;
+        if (DEBUG) {
+            Log.d(TAG, "doSearch queryToken:" + queryToken);
+        }
+        mSearchPipeline.query(query,
+                results -> mResultHandler.post(
+                        () -> callback.onSearchResult(queryToken, new ArrayList(results))));
+    }
+
+    @Override
+    public void cancel(boolean interruptActiveRequests) {
+        if (interruptActiveRequests) {
+            mResultHandler.removeCallbacksAndMessages(/*token= */null);
+        }
+    }
+}
diff --git a/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipeline.java b/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipeline.java
new file mode 100644
index 0000000..9911495
--- /dev/null
+++ b/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipeline.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2021 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.widget.picker.search;
+
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+
+import java.text.Collator;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+/**
+ * Implementation of {@link WidgetsPickerSearchPipeline} that performs search by prefix matching on
+ * app names and widget labels.
+ */
+public final class SimpleWidgetsSearchPipeline implements WidgetsPickerSearchPipeline {
+
+    private final List<WidgetsListBaseEntry> mAllEntries;
+
+    public SimpleWidgetsSearchPipeline(List<WidgetsListBaseEntry> allEntries) {
+        mAllEntries = allEntries;
+    }
+
+    @Override
+    public void query(String input, Consumer<List<WidgetsListBaseEntry>> callback) {
+        StringMatcher matcher =  StringMatcher.getInstance();
+        ArrayList<WidgetsListBaseEntry> results = new ArrayList<>();
+        // TODO(b/157286785): Filter entries based on query prefix matching on widget labels also.
+        for (WidgetsListBaseEntry e : mAllEntries) {
+            if (matcher.matches(input, e.mPkgItem.title.toString())) {
+                results.add(e);
+            }
+        }
+        callback.accept(results);
+    }
+
+    /**
+     * Performs locale sensitive string comparison using {@link Collator}.
+     */
+    public static class StringMatcher {
+
+        private static final char MAX_UNICODE = '\uFFFF';
+
+        private final Collator mCollator;
+
+        StringMatcher() {
+            mCollator = Collator.getInstance();
+            mCollator.setStrength(Collator.PRIMARY);
+            mCollator.setDecomposition(Collator.CANONICAL_DECOMPOSITION);
+        }
+
+        /**
+         * Returns true if {@param query} is a prefix of {@param target}.
+         */
+        public boolean matches(String query, String target) {
+            switch (mCollator.compare(query, target)) {
+                case 0:
+                    return true;
+                case -1:
+                    // The target string can contain a modifier which would make it larger than
+                    // the query string (even though the length is same). If the query becomes
+                    // larger after appending a unicode character, it was originally a prefix of
+                    // the target string and hence should match.
+                    return mCollator.compare(query + MAX_UNICODE, target) > -1;
+                default:
+                    return false;
+            }
+        }
+
+        public static StringMatcher getInstance() {
+            return new StringMatcher();
+        }
+    }
+}