Add a WidgetsSearchBar(Launcher3) and a WidgetsSearchController.

- Make WidgetsSearchBar in Launcher3 initialize WidgetsSearchController with SimpleWidgetsSearchPipeline
- Modify SimpleWidgetsSearchPipeline to filter widgets entries on widgets/shortcut labels also.

Test: Tested prototype locally. Also added robolectric test.
Bug: b/157286785
Change-Id: I65f5fa0240ffb6d22023167e4e86d94d83bbd9f7
diff --git a/res/drawable/ic_gm_close_24.xml b/res/drawable/ic_gm_close_24.xml
new file mode 100644
index 0000000..2c9c932
--- /dev/null
+++ b/res/drawable/ic_gm_close_24.xml
@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="?android:attr/textColorTertiary"
+        android:pathData="M19,6.41L17.59,5 12,10.59 6.41,5 5,6.41 10.59,12 5,17.59 6.41,19 12,13.41 17.59,19 19,17.59 13.41,12 19,6.41z"/>
+</vector>
diff --git a/res/layout/widgets_full_sheet_search_and_recommendations.xml b/res/layout/widgets_full_sheet_search_and_recommendations.xml
index 9a6f922..6182255 100644
--- a/res/layout/widgets_full_sheet_search_and_recommendations.xml
+++ b/res/layout/widgets_full_sheet_search_and_recommendations.xml
@@ -34,16 +34,5 @@
         android:textSize="24sp"
         android:layout_marginTop="16dp"
         android:text="@string/widget_button_text"/>
-    <!-- Disable the search bar because it has not been implemented. -->
-    <EditText
-        android:id="@+id/widgets_search_bar"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:visibility="gone"
-        android:layout_marginTop="16dp"
-        android:background="@drawable/bg_widgets_searchbox"
-        android:drawablePadding="8dp"
-        android:drawableStart="@drawable/ic_allapps_search"
-        android:hint="@string/widgets_full_sheet_search_bar_hint"
-        android:padding="12dp" />
+    <include layout="@layout/widgets_search_bar"/>
 </LinearLayout>
diff --git a/res/layout/widgets_search_bar.xml b/res/layout/widgets_search_bar.xml
new file mode 100644
index 0000000..252637d
--- /dev/null
+++ b/res/layout/widgets_search_bar.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8"?>
+<com.android.launcher3.widget.picker.search.WidgetsSearchBar
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/widgets_search_bar"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="horizontal"
+    android:layout_marginTop="16dp"
+    android:background="@drawable/bg_widgets_searchbox"
+    android:padding="12dp"
+    android:visibility="gone">
+
+    <EditText
+        android:id="@+id/widgets_search_bar_edit_text"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:drawablePadding="8dp"
+        android:drawableStart="@drawable/ic_allapps_search"
+        android:background="@null"
+        android:hint="@string/widgets_full_sheet_search_bar_hint"
+        android:maxLines="1"
+        android:layout_weight="1"
+        android:inputType="text"/>
+
+    <ImageButton
+        android:id="@+id/widgets_search_cancel_button"
+        android:layout_height="wrap_content"
+        android:layout_width="wrap_content"
+        android:src="@drawable/ic_gm_close_24"
+        android:background="?android:selectableItemBackground"
+        android:layout_gravity="center"
+        android:visibility="gone"/>
+</com.android.launcher3.widget.picker.search.WidgetsSearchBar>
\ No newline at end of file
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
index 8aebf12..17ededd 100644
--- a/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipelineTest.java
+++ b/robolectric_tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipelineTest.java
@@ -19,8 +19,6 @@
 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;
@@ -40,6 +38,7 @@
 import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
 import com.android.launcher3.widget.model.WidgetsListContentEntry;
 import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
+import com.android.launcher3.widget.model.WidgetsListSearchHeaderEntry;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -56,9 +55,6 @@
 
 @RunWith(RobolectricTestRunner.class)
 public class SimpleWidgetsSearchPipelineTest {
-    private static final SimpleWidgetsSearchPipeline.StringMatcher MATCHER =
-            SimpleWidgetsSearchPipeline.StringMatcher.getInstance();
-
     @Mock private IconCache mIconCache;
 
     private InvariantDeviceProfile mTestProfile;
@@ -73,9 +69,10 @@
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
-        doAnswer(invocation -> ((ComponentWithLabel) invocation.getArgument(0))
-                .getComponent().getPackageName())
-                .when(mIconCache).getTitleNoCache(any());
+        doAnswer(invocation -> {
+            ComponentWithLabel componentWithLabel = (ComponentWithLabel) invocation.getArgument(0);
+            return componentWithLabel.getComponent().getShortClassName();
+        }).when(mIconCache).getTitleNoCache(any());
         mTestProfile = new InvariantDeviceProfile();
         mTestProfile.numRows = 5;
         mTestProfile.numColumns = 5;
@@ -85,54 +82,60 @@
                 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);
+        mCameraHeaderEntry = createWidgetsHeaderEntry("com.example.android.Camera", "Camera", 11);
+        mCameraContentEntry = createWidgetsContentEntry("com.example.android.Camera", "Camera", 11);
         mClockHeaderEntry = createWidgetsHeaderEntry("com.example.android.Clock", "Clock", 3);
         mClockContentEntry = createWidgetsContentEntry("com.example.android.Clock", "Clock", 3);
     }
 
     @Test
-    public void query_shouldInformCallbackWithResultsMatchedOnAppName() {
+    public void query_shouldMatchOnAppName() {
         SimpleWidgetsSearchPipeline pipeline = new SimpleWidgetsSearchPipeline(
                 List.of(mCalendarHeaderEntry, mCalendarContentEntry, mCameraHeaderEntry,
                         mCameraContentEntry, mClockHeaderEntry, mClockContentEntry));
 
         pipeline.query("Ca", results ->
-                assertEquals(results, List.of(mCalendarHeaderEntry, mCalendarContentEntry,
-                        mCameraHeaderEntry, mCameraContentEntry)));
+                assertEquals(results,
+                        List.of(
+                                new WidgetsListSearchHeaderEntry(
+                                        mCalendarHeaderEntry.mPkgItem,
+                                        mCalendarHeaderEntry.mTitleSectionName,
+                                        mCalendarHeaderEntry.mWidgets),
+                                mCalendarContentEntry,
+                                new WidgetsListSearchHeaderEntry(
+                                        mCameraHeaderEntry.mPkgItem,
+                                        mCameraHeaderEntry.mTitleSectionName,
+                                        mCameraHeaderEntry.mWidgets),
+                                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"));
+    public void query_shouldMatchOnWidgetLabel() {
+        SimpleWidgetsSearchPipeline pipeline = new SimpleWidgetsSearchPipeline(
+                List.of(mCalendarHeaderEntry, mCalendarContentEntry, mCameraHeaderEntry,
+                        mCameraContentEntry));
 
-        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"));
+        pipeline.query("Widget1", results ->
+                assertEquals(results,
+                        List.of(
+                                new WidgetsListSearchHeaderEntry(
+                                        mCalendarHeaderEntry.mPkgItem,
+                                        mCalendarHeaderEntry.mTitleSectionName,
+                                        mCalendarHeaderEntry.mWidgets.subList(1, 2)),
+                                new WidgetsListContentEntry(
+                                        mCalendarHeaderEntry.mPkgItem,
+                                        mCalendarHeaderEntry.mTitleSectionName,
+                                        mCalendarHeaderEntry.mWidgets.subList(1, 2)),
+                                new WidgetsListSearchHeaderEntry(
+                                        mCameraHeaderEntry.mPkgItem,
+                                        mCameraHeaderEntry.mTitleSectionName,
+                                        mCameraHeaderEntry.mWidgets.subList(1, 3)),
+                                new WidgetsListContentEntry(
+                                        mCameraHeaderEntry.mPkgItem,
+                                        mCameraHeaderEntry.mTitleSectionName,
+                                        mCameraHeaderEntry.mWidgets.subList(1, 3)))));
+        shadowOf(getMainLooper()).idle();
     }
 
     private WidgetsListHeaderEntry createWidgetsHeaderEntry(String packageName, String appName,
diff --git a/robolectric_tests/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarControllerTest.java b/robolectric_tests/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarControllerTest.java
new file mode 100644
index 0000000..7fc9650
--- /dev/null
+++ b/robolectric_tests/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarControllerTest.java
@@ -0,0 +1,140 @@
+/*
+ * 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 org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+import android.content.Context;
+import android.view.View;
+import android.widget.EditText;
+import android.widget.ImageButton;
+
+import com.android.launcher3.search.SearchAlgorithm;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+
+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 java.util.ArrayList;
+
+@RunWith(RobolectricTestRunner.class)
+public class WidgetsSearchBarControllerTest {
+
+    private WidgetsSearchBarController mController;
+    private Context mContext;
+    private EditText mEditText;
+    private ImageButton mCancelButton;
+    @Mock
+    private SearchModeListener mSearchModeListener;
+    @Mock
+    private SearchAlgorithm<WidgetsListBaseEntry> mSearchAlgorithm;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = RuntimeEnvironment.application;
+        mEditText = new EditText(mContext);
+        mCancelButton = new ImageButton(mContext);
+        mController = new WidgetsSearchBarController(
+                mSearchAlgorithm, mEditText, mCancelButton, mSearchModeListener);
+    }
+
+    @Test
+    public void onSearchResult_shouldInformSearchModeListener() {
+        ArrayList<WidgetsListBaseEntry> entries = new ArrayList<>();
+        mController.onSearchResult("abc", entries);
+
+        verify(mSearchModeListener).onSearchResults(entries);
+    }
+
+    @Test
+    public void afterTextChanged_shouldInformSearchModeListenerToEnterSearch() {
+        mEditText.setText("abc");
+
+        verify(mSearchModeListener).enterSearchMode();
+        verifyNoMoreInteractions(mSearchModeListener);
+    }
+
+    @Test
+    public void afterTextChanged_shouldDoSearch() {
+        mEditText.setText("abc");
+
+        verify(mSearchAlgorithm).doSearch(eq("abc"), any());
+    }
+
+    @Test
+    public void afterTextChanged_shouldShowCancelButton() {
+        mEditText.setText("abc");
+
+        assertEquals(mCancelButton.getVisibility(), View.VISIBLE);
+    }
+
+    @Test
+    public void afterTextChanged_empty_shouldInformSearchModeListenerToExitSearch() {
+        mEditText.setText("");
+
+        verify(mSearchModeListener).exitSearchMode();
+        verifyNoMoreInteractions(mSearchModeListener);
+    }
+
+    @Test
+    public void afterTextChanged_empty_shouldCancelSearch() {
+        mEditText.setText("");
+
+        verify(mSearchAlgorithm).cancel(true);
+        verifyNoMoreInteractions(mSearchAlgorithm);
+    }
+
+    @Test
+    public void afterTextChanged_empty_shouldHideCancelButton() {
+        mEditText.setText("");
+
+        assertEquals(mCancelButton.getVisibility(), View.GONE);
+    }
+
+    @Test
+    public void cancelSearch_shouldInformSearchModeListenerToExitSearch() {
+        mCancelButton.performClick();
+
+        verify(mSearchModeListener).exitSearchMode();
+        verifyNoMoreInteractions(mSearchModeListener);
+    }
+
+    @Test
+    public void cancelSearch_shouldCancelSearch() {
+        mCancelButton.performClick();
+
+        verify(mSearchAlgorithm).cancel(true);
+        verifyNoMoreInteractions(mSearchAlgorithm);
+    }
+
+    @Test
+    public void cancelSearch_shouldClearSearchBar() {
+        mCancelButton.performClick();
+
+        assertEquals(mEditText.getText().toString(), "");
+    }
+}
diff --git a/src/com/android/launcher3/allapps/search/AppsSearchPipeline.java b/src/com/android/launcher3/allapps/search/AppsSearchPipeline.java
index f9fb22e..34895ed 100644
--- a/src/com/android/launcher3/allapps/search/AppsSearchPipeline.java
+++ b/src/com/android/launcher3/allapps/search/AppsSearchPipeline.java
@@ -25,6 +25,7 @@
 import com.android.launcher3.model.BaseModelUpdateTask;
 import com.android.launcher3.model.BgDataModel;
 import com.android.launcher3.model.data.AppInfo;
+import com.android.launcher3.search.StringMatcherUtility;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -67,10 +68,10 @@
         // apps that don't match all of the words in the query.
         final String queryTextLower = query.toLowerCase();
         final ArrayList<AppInfo> result = new ArrayList<>();
-        DefaultAppSearchAlgorithm.StringMatcher matcher =
-                DefaultAppSearchAlgorithm.StringMatcher.getInstance();
+        StringMatcherUtility.StringMatcher matcher =
+                StringMatcherUtility.StringMatcher.getInstance();
         for (AppInfo info : apps) {
-            if (DefaultAppSearchAlgorithm.matches(info, queryTextLower, matcher)) {
+            if (StringMatcherUtility.matches(queryTextLower, info.title.toString(), matcher)) {
                 result.add(info);
             }
         }
diff --git a/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java b/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java
index 4e213b0..a386ef8 100644
--- a/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java
+++ b/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java
@@ -20,12 +20,9 @@
 
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.allapps.AllAppsGridAdapter.AdapterItem;
-import com.android.launcher3.model.data.AppInfo;
 import com.android.launcher3.search.SearchAlgorithm;
 import com.android.launcher3.search.SearchCallback;
 
-import java.text.Collator;
-
 /**
  * The default search implementation.
  */
@@ -54,132 +51,4 @@
                         () -> callback.onSearchResult(query, results)),
                 null);
     }
-
-    public static boolean matches(AppInfo info, String query, StringMatcher matcher) {
-        int queryLength = query.length();
-
-        String title = info.title.toString();
-        int titleLength = title.length();
-
-        if (titleLength < queryLength || queryLength <= 0) {
-            return false;
-        }
-
-        if (requestSimpleFuzzySearch(query)) {
-            return title.toLowerCase().contains(query);
-        }
-
-        int lastType;
-        int thisType = Character.UNASSIGNED;
-        int nextType = Character.getType(title.codePointAt(0));
-
-        int end = titleLength - queryLength;
-        for (int i = 0; i <= end; i++) {
-            lastType = thisType;
-            thisType = nextType;
-            nextType = i < (titleLength - 1) ?
-                    Character.getType(title.codePointAt(i + 1)) : Character.UNASSIGNED;
-            if (isBreak(thisType, lastType, nextType) &&
-                    matcher.matches(query, title.substring(i, i + queryLength))) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    /**
-     * Returns true if the current point should be a break point. Following cases
-     * are considered as break points:
-     *      1) Any non space character after a space character
-     *      2) Any digit after a non-digit character
-     *      3) Any capital character after a digit or small character
-     *      4) Any capital character before a small character
-     */
-    private static boolean isBreak(int thisType, int prevType, int nextType) {
-        switch (prevType) {
-            case Character.UNASSIGNED:
-            case Character.SPACE_SEPARATOR:
-            case Character.LINE_SEPARATOR:
-            case Character.PARAGRAPH_SEPARATOR:
-                return true;
-        }
-        switch (thisType) {
-            case Character.UPPERCASE_LETTER:
-                if (nextType == Character.UPPERCASE_LETTER) {
-                    return true;
-                }
-                // Follow through
-            case Character.TITLECASE_LETTER:
-                // Break point if previous was not a upper case
-                return prevType != Character.UPPERCASE_LETTER;
-            case Character.LOWERCASE_LETTER:
-                // Break point if previous was not a letter.
-                return prevType > Character.OTHER_LETTER || prevType <= Character.UNASSIGNED;
-            case Character.DECIMAL_DIGIT_NUMBER:
-            case Character.LETTER_NUMBER:
-            case Character.OTHER_NUMBER:
-                // Break point if previous was not a number
-                return !(prevType == Character.DECIMAL_DIGIT_NUMBER
-                        || prevType == Character.LETTER_NUMBER
-                        || prevType == Character.OTHER_NUMBER);
-            case Character.MATH_SYMBOL:
-            case Character.CURRENCY_SYMBOL:
-            case Character.OTHER_PUNCTUATION:
-            case Character.DASH_PUNCTUATION:
-                // Always a break point for a symbol
-                return true;
-            default:
-                return  false;
-        }
-    }
-
-    public static class StringMatcher {
-
-        private static final char MAX_UNICODE = '\uFFFF';
-
-        private final Collator mCollator;
-
-        StringMatcher() {
-            // On android N and above, Collator uses ICU implementation which has a much better
-            // support for non-latin locales.
-            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();
-        }
-    }
-
-    private static boolean requestSimpleFuzzySearch(String s) {
-        for (int i = 0; i < s.length(); ) {
-            int codepoint = s.codePointAt(i);
-            i += Character.charCount(codepoint);
-            switch (Character.UnicodeScript.of(codepoint)) {
-                case HAN:
-                    //Character.UnicodeScript.HAN: use String.contains to match
-                    return true;
-            }
-        }
-        return false;
-    }
 }
diff --git a/src/com/android/launcher3/search/SearchAlgorithm.java b/src/com/android/launcher3/search/SearchAlgorithm.java
index 1665354..a1720c7 100644
--- a/src/com/android/launcher3/search/SearchAlgorithm.java
+++ b/src/com/android/launcher3/search/SearchAlgorithm.java
@@ -31,4 +31,9 @@
      * Cancels any active request.
      */
     void cancel(boolean interruptActiveRequests);
+
+    /**
+     * Cleans up after search is no longer needed.
+     */
+    default void destroy() {};
 }
diff --git a/src/com/android/launcher3/search/StringMatcherUtility.java b/src/com/android/launcher3/search/StringMatcherUtility.java
new file mode 100644
index 0000000..acab52b
--- /dev/null
+++ b/src/com/android/launcher3/search/StringMatcherUtility.java
@@ -0,0 +1,162 @@
+/*
+ * 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.search;
+
+import java.text.Collator;
+
+/**
+ * Utilities for matching query string to target string.
+ */
+public class StringMatcherUtility {
+
+    /**
+     * Returns {@code true} is {@code query} is a prefix substring of a complete word/phrase in
+     * {@code target}.
+     */
+    public static boolean matches(String query, String target, StringMatcher matcher) {
+        int queryLength = query.length();
+
+        int targetLength = target.length();
+
+        if (targetLength < queryLength || queryLength <= 0) {
+            return false;
+        }
+
+        if (requestSimpleFuzzySearch(query)) {
+            return target.toLowerCase().contains(query);
+        }
+
+        int lastType;
+        int thisType = Character.UNASSIGNED;
+        int nextType = Character.getType(target.codePointAt(0));
+
+        int end = targetLength - queryLength;
+        for (int i = 0; i <= end; i++) {
+            lastType = thisType;
+            thisType = nextType;
+            nextType = i < (targetLength - 1)
+                    ? Character.getType(target.codePointAt(i + 1)) : Character.UNASSIGNED;
+            if (isBreak(thisType, lastType, nextType)
+                    && matcher.matches(query, target.substring(i, i + queryLength))) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Returns true if the current point should be a break point. Following cases
+     * are considered as break points:
+     *      1) Any non space character after a space character
+     *      2) Any digit after a non-digit character
+     *      3) Any capital character after a digit or small character
+     *      4) Any capital character before a small character
+     */
+    private static boolean isBreak(int thisType, int prevType, int nextType) {
+        switch (prevType) {
+            case Character.UNASSIGNED:
+            case Character.SPACE_SEPARATOR:
+            case Character.LINE_SEPARATOR:
+            case Character.PARAGRAPH_SEPARATOR:
+                return true;
+        }
+        switch (thisType) {
+            case Character.UPPERCASE_LETTER:
+                if (nextType == Character.UPPERCASE_LETTER) {
+                    return true;
+                }
+                // Follow through
+            case Character.TITLECASE_LETTER:
+                // Break point if previous was not a upper case
+                return prevType != Character.UPPERCASE_LETTER;
+            case Character.LOWERCASE_LETTER:
+                // Break point if previous was not a letter.
+                return prevType > Character.OTHER_LETTER || prevType <= Character.UNASSIGNED;
+            case Character.DECIMAL_DIGIT_NUMBER:
+            case Character.LETTER_NUMBER:
+            case Character.OTHER_NUMBER:
+                // Break point if previous was not a number
+                return !(prevType == Character.DECIMAL_DIGIT_NUMBER
+                        || prevType == Character.LETTER_NUMBER
+                        || prevType == Character.OTHER_NUMBER);
+            case Character.MATH_SYMBOL:
+            case Character.CURRENCY_SYMBOL:
+            case Character.OTHER_PUNCTUATION:
+            case Character.DASH_PUNCTUATION:
+                // Always a break point for a symbol
+                return true;
+            default:
+                return  false;
+        }
+    }
+
+    /**
+     * Performs locale sensitive string comparison using {@link Collator}.
+     */
+    public static class StringMatcher {
+
+        private static final char MAX_UNICODE = '\uFFFF';
+
+        private final Collator mCollator;
+
+        StringMatcher() {
+            // On android N and above, Collator uses ICU implementation which has a much better
+            // support for non-latin locales.
+            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();
+        }
+    }
+
+    /**
+     * Matching optimization to search in Chinese.
+     */
+    private static boolean requestSimpleFuzzySearch(String s) {
+        for (int i = 0; i < s.length(); ) {
+            int codepoint = s.codePointAt(i);
+            i += Character.charCount(codepoint);
+            switch (Character.UnicodeScript.of(codepoint)) {
+                case HAN:
+                    //Character.UnicodeScript.HAN: use String.contains to match
+                    return true;
+            }
+        }
+        return false;
+    }
+}
diff --git a/src/com/android/launcher3/widget/model/WidgetsListBaseEntry.java b/src/com/android/launcher3/widget/model/WidgetsListBaseEntry.java
index d09fd49..73bae6f 100644
--- a/src/com/android/launcher3/widget/model/WidgetsListBaseEntry.java
+++ b/src/com/android/launcher3/widget/model/WidgetsListBaseEntry.java
@@ -20,10 +20,14 @@
 
 import androidx.annotation.IntDef;
 
+import com.android.launcher3.model.WidgetItem;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.widget.WidgetItemComparator;
 
 import java.lang.annotation.Retention;
+import java.util.List;
+import java.util.stream.Collectors;
 
 /** Holder class to store the package information of an entry shown in the widgets list. */
 public abstract class WidgetsListBaseEntry {
@@ -35,9 +39,14 @@
      */
     public final String mTitleSectionName;
 
-    public WidgetsListBaseEntry(PackageItemInfo pkgItem, String titleSectionName) {
+    public final List<WidgetItem> mWidgets;
+
+    public WidgetsListBaseEntry(PackageItemInfo pkgItem, String titleSectionName,
+            List<WidgetItem> items) {
         mPkgItem = pkgItem;
         mTitleSectionName = titleSectionName;
+        this.mWidgets =
+                items.stream().sorted(new WidgetItemComparator()).collect(Collectors.toList());
     }
 
     /**
diff --git a/src/com/android/launcher3/widget/model/WidgetsListContentEntry.java b/src/com/android/launcher3/widget/model/WidgetsListContentEntry.java
index afc0f44..0328cf6 100644
--- a/src/com/android/launcher3/widget/model/WidgetsListContentEntry.java
+++ b/src/com/android/launcher3/widget/model/WidgetsListContentEntry.java
@@ -17,10 +17,8 @@
 
 import com.android.launcher3.model.WidgetItem;
 import com.android.launcher3.model.data.PackageItemInfo;
-import com.android.launcher3.widget.WidgetItemComparator;
 
 import java.util.List;
-import java.util.stream.Collectors;
 
 /**
  * Holder class to store all the information related to a list of widgets from the same app which is
@@ -28,13 +26,9 @@
  */
 public final class WidgetsListContentEntry extends WidgetsListBaseEntry {
 
-    public final List<WidgetItem> mWidgets;
-
     public WidgetsListContentEntry(PackageItemInfo pkgItem, String titleSectionName,
             List<WidgetItem> items) {
-        super(pkgItem, titleSectionName);
-        this.mWidgets =
-                items.stream().sorted(new WidgetItemComparator()).collect(Collectors.toList());
+        super(pkgItem, titleSectionName, items);
     }
 
     @Override
@@ -47,4 +41,12 @@
     public int getRank() {
         return RANK_WIDGETS_LIST_CONTENT;
     }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (!(obj instanceof WidgetsListContentEntry)) return false;
+        WidgetsListContentEntry otherEntry = (WidgetsListContentEntry) obj;
+        return mWidgets.equals(otherEntry.mWidgets) && mPkgItem.equals(otherEntry.mPkgItem)
+                && mTitleSectionName.equals(otherEntry.mTitleSectionName);
+    }
 }
diff --git a/src/com/android/launcher3/widget/model/WidgetsListHeaderEntry.java b/src/com/android/launcher3/widget/model/WidgetsListHeaderEntry.java
index 309b678..1fdc399 100644
--- a/src/com/android/launcher3/widget/model/WidgetsListHeaderEntry.java
+++ b/src/com/android/launcher3/widget/model/WidgetsListHeaderEntry.java
@@ -17,25 +17,21 @@
 
 import com.android.launcher3.model.WidgetItem;
 import com.android.launcher3.model.data.PackageItemInfo;
-import com.android.launcher3.widget.WidgetItemComparator;
 
 import java.util.List;
-import java.util.stream.Collectors;
 
 /** An information holder for an app which has widgets or/and shortcuts. */
 public final class WidgetsListHeaderEntry extends WidgetsListBaseEntry {
 
     public final int widgetsCount;
     public final int shortcutsCount;
-    public final List<WidgetItem> mWidgets;
 
     private boolean mIsWidgetListShown = false;
     private boolean mHasEntryUpdated = false;
 
     public WidgetsListHeaderEntry(PackageItemInfo pkgItem, String titleSectionName,
             List<WidgetItem> items) {
-        super(pkgItem, titleSectionName);
-        mWidgets = items.stream().sorted(new WidgetItemComparator()).collect(Collectors.toList());
+        super(pkgItem, titleSectionName, items);
         widgetsCount = (int) items.stream().filter(item -> item.widgetInfo != null).count();
         shortcutsCount = Math.max(0, items.size() - widgetsCount);
     }
diff --git a/src/com/android/launcher3/widget/model/WidgetsListSearchHeaderEntry.java b/src/com/android/launcher3/widget/model/WidgetsListSearchHeaderEntry.java
index a8b887b..2aec3f8 100644
--- a/src/com/android/launcher3/widget/model/WidgetsListSearchHeaderEntry.java
+++ b/src/com/android/launcher3/widget/model/WidgetsListSearchHeaderEntry.java
@@ -17,23 +17,18 @@
 
 import com.android.launcher3.model.WidgetItem;
 import com.android.launcher3.model.data.PackageItemInfo;
-import com.android.launcher3.widget.WidgetItemComparator;
 
 import java.util.List;
-import java.util.stream.Collectors;
 
 /** An information holder for an app which has widgets or/and shortcuts, to be shown in search. */
 public final class WidgetsListSearchHeaderEntry extends WidgetsListBaseEntry {
 
-    public final List<WidgetItem> mWidgets;
-
     private boolean mIsWidgetListShown = false;
     private boolean mHasEntryUpdated = false;
 
     public WidgetsListSearchHeaderEntry(PackageItemInfo pkgItem, String titleSectionName,
             List<WidgetItem> items) {
-        super(pkgItem, titleSectionName);
-        mWidgets = items.stream().sorted(new WidgetItemComparator()).collect(Collectors.toList());
+        super(pkgItem, titleSectionName, items);
     }
 
     /** Sets if the widgets list associated with this header is shown. */
diff --git a/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipeline.java b/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipeline.java
index 9911495..5222e8e 100644
--- a/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipeline.java
+++ b/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchPipeline.java
@@ -16,12 +16,19 @@
 
 package com.android.launcher3.widget.picker.search;
 
-import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+import static com.android.launcher3.search.StringMatcherUtility.matches;
 
-import java.text.Collator;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.search.StringMatcherUtility.StringMatcher;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+import com.android.launcher3.widget.model.WidgetsListContentEntry;
+import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
+import com.android.launcher3.widget.model.WidgetsListSearchHeaderEntry;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
+import java.util.stream.Collectors;
 
 /**
  * Implementation of {@link WidgetsPickerSearchPipeline} that performs search by prefix matching on
@@ -37,52 +44,29 @@
 
     @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);
-            }
-        }
+        mAllEntries.stream().filter(entry -> entry instanceof WidgetsListHeaderEntry)
+                .forEach(headerEntry -> {
+                    List<WidgetItem> matchedWidgetItems = filterWidgetItems(
+                            input, headerEntry.mPkgItem.title.toString(), headerEntry.mWidgets);
+                    if (matchedWidgetItems.size() > 0) {
+                        results.add(new WidgetsListSearchHeaderEntry(headerEntry.mPkgItem,
+                                headerEntry.mTitleSectionName, matchedWidgetItems));
+                        results.add(new WidgetsListContentEntry(headerEntry.mPkgItem,
+                                headerEntry.mTitleSectionName, matchedWidgetItems));
+                    }
+                });
         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);
+    private List<WidgetItem> filterWidgetItems(String query, String packageTitle,
+            List<WidgetItem> items) {
+        StringMatcher matcher = StringMatcher.getInstance();
+        if (matches(query, packageTitle, matcher)) {
+            return items;
         }
-
-        /**
-         * 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();
-        }
+        return items.stream()
+                .filter(item -> matches(query, item.label, matcher))
+                .collect(Collectors.toList());
     }
 }
diff --git a/src/com/android/launcher3/widget/picker/search/WidgetsSearchBar.java b/src/com/android/launcher3/widget/picker/search/WidgetsSearchBar.java
new file mode 100644
index 0000000..d8e9733
--- /dev/null
+++ b/src/com/android/launcher3/widget/picker/search/WidgetsSearchBar.java
@@ -0,0 +1,79 @@
+/*
+ * 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.content.Context;
+import android.util.AttributeSet;
+import android.widget.EditText;
+import android.widget.ImageButton;
+import android.widget.LinearLayout;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.android.launcher3.R;
+import com.android.launcher3.search.SearchAlgorithm;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+
+import java.util.List;
+
+/**
+ * View for a search bar with an edit text with a cancel button.
+ */
+public class WidgetsSearchBar extends LinearLayout {
+    private WidgetsSearchBarController mController;
+    private EditText mEditText;
+    private ImageButton mCancelButton;
+
+    public WidgetsSearchBar(Context context) {
+        this(context, null, 0);
+    }
+
+    public WidgetsSearchBar(@NonNull Context context,
+            @Nullable AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public WidgetsSearchBar(@NonNull Context context, @Nullable AttributeSet attrs,
+            int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    /**
+     * Attaches a controller to the search bar which interacts with {@code searchModeListener}.
+     */
+    public void initialize(List<WidgetsListBaseEntry> allWidgets,
+            SearchModeListener searchModeListener) {
+        SearchAlgorithm<WidgetsListBaseEntry> algo =
+                new SimpleWidgetsSearchAlgorithm(new SimpleWidgetsSearchPipeline(allWidgets));
+        mController = new WidgetsSearchBarController(
+                algo, mEditText, mCancelButton, searchModeListener);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+        mEditText = findViewById(R.id.widgets_search_bar_edit_text);
+        mCancelButton = findViewById(R.id.widgets_search_cancel_button);
+    }
+
+    @Override
+    protected void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        mController.onDestroy();
+    }
+}
diff --git a/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarController.java b/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarController.java
new file mode 100644
index 0000000..6c37484
--- /dev/null
+++ b/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarController.java
@@ -0,0 +1,111 @@
+/*
+ * 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.view.View.GONE;
+import static android.view.View.VISIBLE;
+
+import android.text.Editable;
+import android.text.TextWatcher;
+import android.util.Log;
+import android.widget.EditText;
+import android.widget.ImageButton;
+
+import com.android.launcher3.search.SearchAlgorithm;
+import com.android.launcher3.search.SearchCallback;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+
+import java.util.ArrayList;
+
+/**
+ * Controller for a search bar with an edit text and a cancel button.
+ */
+public class WidgetsSearchBarController implements TextWatcher,
+        SearchCallback<WidgetsListBaseEntry> {
+    private static final String TAG = "WidgetsSearchBarController";
+    private static final boolean DEBUG = false;
+
+    protected SearchAlgorithm<WidgetsListBaseEntry> mSearchAlgorithm;
+    protected EditText mInput;
+    protected ImageButton mCancelButton;
+    protected SearchModeListener mSearchModeListener;
+    protected String mQuery;
+
+    public WidgetsSearchBarController(
+            SearchAlgorithm<WidgetsListBaseEntry> algo, EditText editText, ImageButton cancelButton,
+            SearchModeListener searchModeListener) {
+        mSearchAlgorithm = algo;
+        mInput = editText;
+        mInput.addTextChangedListener(this);
+        mCancelButton = cancelButton;
+        mCancelButton.setOnClickListener(v -> clearSearchResult());
+        mSearchModeListener = searchModeListener;
+    }
+
+    @Override
+    public void afterTextChanged(final Editable s) {
+        mQuery = s.toString();
+        if (mQuery.isEmpty()) {
+            mSearchAlgorithm.cancel(/* interruptActiveRequests= */ true);
+            mSearchModeListener.exitSearchMode();
+            mCancelButton.setVisibility(GONE);
+        } else {
+            mSearchAlgorithm.cancel(/* interruptActiveRequests= */ false);
+            mSearchModeListener.enterSearchMode();
+            mSearchAlgorithm.doSearch(mQuery, this);
+            mCancelButton.setVisibility(VISIBLE);
+        }
+    }
+
+    @Override
+    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+        // Do nothing.
+    }
+
+    @Override
+    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+        // Do nothing.
+    }
+
+    @Override
+    public void onSearchResult(String query, ArrayList<WidgetsListBaseEntry> items) {
+        if (DEBUG) {
+            Log.d(TAG, "onSearchResult query: " + query + " items: " + items);
+        }
+        mSearchModeListener.onSearchResults(items);
+    }
+
+    @Override
+    public void onAppendSearchResult(String query, ArrayList<WidgetsListBaseEntry> items) {
+        // Not needed.
+    }
+
+    @Override
+    public void clearSearchResult() {
+        mSearchAlgorithm.cancel(/* interruptActiveRequests= */ true);
+        mInput.getText().clear();
+        mInput.clearFocus();
+        mSearchModeListener.exitSearchMode();
+    }
+
+    /**
+     * Cleans up after search is no longer needed.
+     */
+    public void onDestroy() {
+        mSearchAlgorithm.destroy();
+    }
+}
diff --git a/tests/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithmTest.java b/tests/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithmTest.java
deleted file mode 100644
index 39709a9..0000000
--- a/tests/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithmTest.java
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.android.launcher3.allapps.search;
-
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-import android.content.ComponentName;
-
-import androidx.test.filters.SmallTest;
-import androidx.test.runner.AndroidJUnit4;
-
-import com.android.launcher3.model.data.AppInfo;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-/**
- * Unit tests for {@link DefaultAppSearchAlgorithm}
- */
-@SmallTest
-@RunWith(AndroidJUnit4.class)
-public class DefaultAppSearchAlgorithmTest {
-    private static final DefaultAppSearchAlgorithm.StringMatcher MATCHER =
-            DefaultAppSearchAlgorithm.StringMatcher.getInstance();
-
-    @Test
-    public void testMatches() {
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("white cow"), "cow", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("whiteCow"), "cow", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("whiteCOW"), "cow", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("whitecowCOW"), "cow", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("white2cow"), "cow", MATCHER));
-
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("whitecow"), "cow", MATCHER));
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("whitEcow"), "cow", MATCHER));
-
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("whitecowCow"), "cow", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("whitecow cow"), "cow", MATCHER));
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("whitecowcow"), "cow", MATCHER));
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("whit ecowcow"), "cow", MATCHER));
-
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("cats&dogs"), "dog", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("cats&Dogs"), "dog", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("cats&Dogs"), "&", MATCHER));
-
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("2+43"), "43", MATCHER));
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("2+43"), "3", MATCHER));
-
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("Q"), "q", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("  Q"), "q", MATCHER));
-
-        // match lower case words
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("elephant"), "e", MATCHER));
-
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("电子邮件"), "电", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("电子邮件"), "电子", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("电子邮件"), "子", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("电子邮件"), "邮件", MATCHER));
-
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("Bot"), "ba", MATCHER));
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("bot"), "ba", MATCHER));
-    }
-
-    @Test
-    public void testMatchesVN() {
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("다운로드"), "다", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("드라이브"), "드", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("다운로드 드라이브"), "ㄷ", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("운로 드라이브"), "ㄷ", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("abc"), "åbç", MATCHER));
-        assertTrue(DefaultAppSearchAlgorithm.matches(getInfo("Alpha"), "ål", MATCHER));
-
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("다운로드 드라이브"), "ㄷㄷ", MATCHER));
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("로드라이브"), "ㄷ", MATCHER));
-        assertFalse(DefaultAppSearchAlgorithm.matches(getInfo("abc"), "åç", MATCHER));
-    }
-
-    private AppInfo getInfo(String title) {
-        AppInfo info = new AppInfo();
-        info.title = title;
-        info.componentName = new ComponentName("Test", title);
-        return info;
-    }
-}
diff --git a/tests/src/com/android/launcher3/search/StringMatcherUtilityTest.java b/tests/src/com/android/launcher3/search/StringMatcherUtilityTest.java
new file mode 100644
index 0000000..413f404
--- /dev/null
+++ b/tests/src/com/android/launcher3/search/StringMatcherUtilityTest.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2016 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.search;
+
+import static com.android.launcher3.search.StringMatcherUtility.matches;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import com.android.launcher3.search.StringMatcherUtility.StringMatcher;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/**
+ * Unit tests for {@link StringMatcherUtility}
+ */
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class StringMatcherUtilityTest {
+    private static final StringMatcher MATCHER =
+            StringMatcher.getInstance();
+
+    @Test
+    public void testMatches() {
+        assertTrue(matches("white ", "white cow", MATCHER));
+        assertTrue(matches("white c", "white cow", MATCHER));
+        assertTrue(matches("cow", "white cow", MATCHER));
+        assertTrue(matches("cow", "whiteCow", MATCHER));
+        assertTrue(matches("cow", "whiteCOW", MATCHER));
+        assertTrue(matches("cow", "whitecowCOW", MATCHER));
+        assertTrue(matches("cow", "white2cow", MATCHER));
+
+        assertFalse(matches("cow", "whitecow", MATCHER));
+        assertFalse(matches("cow", "whitEcow", MATCHER));
+
+        assertTrue(matches("cow", "whitecowCow", MATCHER));
+        assertTrue(matches("cow", "whitecow cow", MATCHER));
+        assertFalse(matches("cow", "whitecowcow", MATCHER));
+        assertFalse(matches("cow", "whit ecowcow", MATCHER));
+
+        assertTrue(matches("dog", "cats&dogs", MATCHER));
+        assertTrue(matches("dog", "cats&Dogs", MATCHER));
+        assertTrue(matches("&", "cats&Dogs", MATCHER));
+
+        assertTrue(matches("43", "2+43", MATCHER));
+        assertFalse(matches("3", "2+43", MATCHER));
+
+        assertTrue(matches("q", "Q", MATCHER));
+        assertTrue(matches("q", "  Q", MATCHER));
+
+        // match lower case words
+        assertTrue(matches("e", "elephant", MATCHER));
+        assertTrue(matches("eL", "Elephant", MATCHER));
+
+        assertTrue(matches("电", "电子邮件", MATCHER));
+        assertTrue(matches("电子", "电子邮件", MATCHER));
+        assertTrue(matches("子", "电子邮件", MATCHER));
+        assertTrue(matches("邮件", "电子邮件", MATCHER));
+
+        assertFalse(matches("ba", "Bot", MATCHER));
+        assertFalse(matches("ba", "bot", MATCHER));
+        assertFalse(matches("phant", "elephant", MATCHER));
+        assertFalse(matches("elephants", "elephant", MATCHER));
+    }
+
+    @Test
+    public void testMatchesVN() {
+        assertTrue(matches("다", "다운로드", MATCHER));
+        assertTrue(matches("드", "드라이브", MATCHER));
+        assertTrue(matches("ㄷ", "다운로드 드라이브", MATCHER));
+        assertTrue(matches("ㄷ", "운로 드라이브", MATCHER));
+        assertTrue(matches("åbç", "abc", MATCHER));
+        assertTrue(matches("ål", "Alpha", MATCHER));
+
+        assertFalse(matches("ㄷㄷ", "다운로드 드라이브", MATCHER));
+        assertFalse(matches("ㄷ", "로드라이브", MATCHER));
+        assertFalse(matches("åç", "abc", MATCHER));
+    }
+}