Create a new apps page for silky home

- Change recent apps to the list view.
- Remove Conversations, Notifications and Permission manager.
- Remove Wireless emergency alerts and Special app access.
- Show App info preference if there's no recent apps.
- Show general category with recent apps.
- Use this page as the new apps entry on homepage for silky home.
- Make old apps page unsearchable when silky home is enabled.
- Exported new apps page in AndroidManifest.

Bug: 168166015
Bug: 174964405
Test: robotest & visual
Change-Id: I50d35a9d4723612214fce45a9e129fc175bc6831
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 2eaebb1..d6847fd 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -3206,6 +3206,15 @@
         </activity>
 
         <activity
+            android:name=".Settings$AppDashboardActivity"
+            android:label="@string/apps_dashboard_title"
+            android:icon="@drawable/ic_homepage_apps"
+            android:exported="true">
+            <meta-data android:name="com.android.settings.FRAGMENT_CLASS"
+                       android:value="com.android.settings.applications.AppDashboardFragment"/>
+        </activity>
+
+        <activity
             android:name=".Settings$AccountDashboardActivity"
             android:label="@string/account_dashboard_title"
             android:exported="true"
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 1270281..df40697 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -12605,4 +12605,6 @@
     <!-- Do not translate. Title for battery saver main switch preferences. [CHAR LIMIT=50] -->
     <string name="battery_saver_main_switch_title" translatable="false">Use battery saver</string>
 
+    <!-- Default preference title for showing all apps on device [CHAR_LIMIT=50]-->
+    <string name="default_see_all_apps_title">See all apps</string>
 </resources>
diff --git a/res/xml/apps.xml b/res/xml/apps.xml
index 3ec4a29..54af67b 100644
--- a/res/xml/apps.xml
+++ b/res/xml/apps.xml
@@ -18,80 +18,52 @@
 <PreferenceScreen
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:settings="http://schemas.android.com/apk/res-auto"
-    android:key="apps_and_notification_screen"
-    android:title="@string/app_and_notification_dashboard_title"
-    settings:initialExpandedChildrenCount="4">
-    <!-- the initial count should include the dynamic tiles -->
+    android:key="apps_screen"
+    android:title="@string/apps_dashboard_title">
 
     <Preference
         android:key="all_app_info"
         android:title="@string/applications_settings"
+        android:summary="@string/summary_placeholder"
         android:order="-999"
         android:fragment="com.android.settings.applications.manageapplications.ManageApplications"
-        settings:controller="com.android.settings.applications.AllAppsInfoPreferenceController"
         settings:keywords="@string/keywords_applications_settings"/>
 
-    <com.android.settingslib.widget.LayoutPreference
-        android:key="recent_open_apps"
+    <PreferenceCategory
+        android:key="recent_apps_category"
         android:title="@string/recent_app_category_title"
-        android:layout="@layout/app_entities_header"
-        android:selectable="false"
         android:order="-998"
-        settings:allowDividerBelow="true"
-        settings:controller="com.android.settings.applications.RecentAppsPreferenceController"/>
+        settings:searchable="false">
+        <!-- Placeholder for a list of recent apps -->
 
-    <!-- Empty category to draw divider -->
+        <!-- See all apps -->
+        <Preference
+            android:key="see_all_apps"
+            android:title="@string/default_see_all_apps_title"
+            android:icon="@drawable/ic_chevron_right_24dp"
+            android:fragment="com.android.settings.applications.manageapplications.ManageApplications"
+            android:order="5"
+            settings:searchable="false">
+        </Preference>
+    </PreferenceCategory>
+
     <PreferenceCategory
-        android:key="recent_apps_divider"
-        android:layout="@layout/preference_category_no_label"
-        android:order="-997"/>
-
-    <Preference
-        android:key="conversations"
-        android:title="@string/conversations_category_title"
-        android:order="-550"
-        settings:controller="com.android.settings.notification.ConversationListSummaryPreferenceController"
-        android:fragment="com.android.settings.notification.app.ConversationListSettings"
-    />
-
-    <!-- Notifications (appears before manage_perms), default apps (appears after) -->
-    <PreferenceCategory
-        android:key="dashboard_tile_placeholder"
-        android:order="10"/>
+        android:key="general_category"
+        android:title="@string/category_name_general"
+        android:order="-997"
+        android:visibility="gone"
+        settings:searchable="false"/>
 
     <Preference
         android:key="default_apps"
         android:title="@string/app_default_dashboard_title"
-        android:order="11"
+        android:order="-996"
         settings:controller="com.android.settings.applications.DefaultAppsPreferenceController">
         <intent android:action="android.settings.MANAGE_DEFAULT_APPS_SETTINGS"/>
     </Preference>
 
-    <Preference
-        android:key="manage_perms"
-        android:title="@string/app_permissions"
-        android:summary="@string/runtime_permissions_summary_control_app_access"
-        android:order="12"
-        settings:keywords="@string/keywords_app_permissions">
-        <intent android:action="android.intent.action.MANAGE_PERMISSIONS"/>
-    </Preference>
-
-    <com.android.settingslib.RestrictedPreference
-        android:key="app_and_notif_cell_broadcast_settings"
-        android:title="@string/cell_broadcast_settings"
-        android:order="15"
-        settings:useAdminDisabledSummary="true">
-        <intent
-            android:action="android.intent.action.MAIN"
-            android:targetPackage="@string/cell_broadcast_receiver_package"
-            android:targetClass="com.android.cellbroadcastreceiver.CellBroadcastSettings"/>
-    </com.android.settingslib.RestrictedPreference>
-
-    <Preference
-        android:key="special_access"
-        android:fragment="com.android.settings.applications.specialaccess.SpecialAccessSettings"
-        android:title="@string/special_access"
-        android:order="20"
-        settings:controller="com.android.settings.applications.SpecialAppAccessPreferenceController"/>
+    <PreferenceCategory
+        android:key="dashboard_tile_placeholder"
+        android:order="10"/>
 
 </PreferenceScreen>
diff --git a/res/xml/top_level_settings_grouped.xml b/res/xml/top_level_settings_grouped.xml
index ad634ed..d6564b7 100644
--- a/res/xml/top_level_settings_grouped.xml
+++ b/res/xml/top_level_settings_grouped.xml
@@ -41,9 +41,9 @@
         android:order="-120"
         settings:allowDividerAbove="false">
         <com.android.settings.homepage.HomepagePreference
-            android:fragment="com.android.settings.applications.AppAndNotificationDashboardFragment"
+            android:fragment="com.android.settings.applications.AppDashboardFragment"
             android:icon="@drawable/ic_homepage_apps_v2"
-            android:key="top_level_apps_and_notifs"
+            android:key="top_level_apps"
             android:order="-120"
             android:title="@string/apps_dashboard_title"/>
 
@@ -53,8 +53,6 @@
             android:key="top_level_notification"
             android:order="-110"
             android:title="@string/configure_notification_settings"/>
-
-
     </PreferenceCategory>
 
     <PreferenceCategory
diff --git a/src/com/android/settings/Settings.java b/src/com/android/settings/Settings.java
index 8389d84..acf1848 100644
--- a/src/com/android/settings/Settings.java
+++ b/src/com/android/settings/Settings.java
@@ -251,4 +251,8 @@
      */
     public static class MediaControlsSettingsActivity extends SettingsActivity {}
 
+    /**
+     * Activity for AppDashboard.
+     */
+    public static class AppDashboardActivity extends SettingsActivity {}
 }
diff --git a/src/com/android/settings/applications/AppAndNotificationDashboardFragment.java b/src/com/android/settings/applications/AppAndNotificationDashboardFragment.java
index 84e7bf7..ddb3951 100644
--- a/src/com/android/settings/applications/AppAndNotificationDashboardFragment.java
+++ b/src/com/android/settings/applications/AppAndNotificationDashboardFragment.java
@@ -67,10 +67,6 @@
 
     @Override
     protected int getPreferenceScreenResId() {
-        // TODO(b/168166015): Remove this when the new Apps page ready.
-        if (FeatureFlagUtils.isEnabled(getContext(), FeatureFlags.SILKY_HOME)) {
-            return R.xml.apps;
-        }
         return R.xml.app_and_notification;
     }
 
@@ -142,5 +138,14 @@
                         Context context) {
                     return buildPreferenceControllers(context);
                 }
+
+                @Override
+                protected boolean isPageSearchEnabled(Context context) {
+                    // TODO(b/174964405): This method should be removed when silky home launched.
+                    // This page is going to deprecate, we should make this page unsearchable
+                    // when the silky home is enabled, otherwise search results will contain the
+                    // old data and launch this page even if the silky home is enabled.
+                    return !FeatureFlagUtils.isEnabled(context, FeatureFlags.SILKY_HOME);
+                }
             };
 }
diff --git a/src/com/android/settings/applications/AppDashboardFragment.java b/src/com/android/settings/applications/AppDashboardFragment.java
new file mode 100644
index 0000000..d513cc7
--- /dev/null
+++ b/src/com/android/settings/applications/AppDashboardFragment.java
@@ -0,0 +1,89 @@
+/*
+ * 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.settings.applications;
+
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+
+import com.android.settings.R;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.search.BaseSearchIndexProvider;
+import com.android.settingslib.core.AbstractPreferenceController;
+import com.android.settingslib.drawer.CategoryKey;
+import com.android.settingslib.search.SearchIndexable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** Settings page for apps. */
+@SearchIndexable
+public class AppDashboardFragment extends DashboardFragment {
+
+    private static final String TAG = "AppDashboardFragment";
+    private AppsPreferenceController mAppsPreferenceController;
+
+    private static List<AbstractPreferenceController> buildPreferenceControllers(Context context) {
+        final List<AbstractPreferenceController> controllers = new ArrayList<>();
+        controllers.add(new AppsPreferenceController(context));
+        return controllers;
+    }
+
+    @Override
+    public int getMetricsCategory() {
+        return SettingsEnums.SETTINGS_APP_NOTIF_CATEGORY;
+    }
+
+    @Override
+    protected String getLogTag() {
+        return TAG;
+    }
+
+    @Override
+    public int getHelpResource() {
+        return R.string.help_url_apps_and_notifications;
+    }
+
+    @Override
+    protected int getPreferenceScreenResId() {
+        return R.xml.apps;
+    }
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        mAppsPreferenceController = use(AppsPreferenceController.class);
+        mAppsPreferenceController.setFragment(this /* fragment */);
+    }
+
+    @Override
+    protected List<AbstractPreferenceController> createPreferenceControllers(Context context) {
+        return buildPreferenceControllers(context);
+    }
+
+    @Override
+    public String getCategoryKey() {
+        // TODO(b/174964405): Remove this function when the silky flag was deprecated.
+        // To include injection tiles, map this app fragment to the app category in the short term.
+        // When we deprecate the silky flag, we have to:
+        // 1. Remove this method.
+        // 2. Update the mapping in DashboardFragmentRegistry.PARENT_TO_CATEGORY_KEY_MAP.
+        return CategoryKey.CATEGORY_APPS;
+    }
+
+    public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
+            new BaseSearchIndexProvider(R.xml.apps);
+}
diff --git a/src/com/android/settings/applications/AppsPreferenceController.java b/src/com/android/settings/applications/AppsPreferenceController.java
new file mode 100644
index 0000000..08fd9c5
--- /dev/null
+++ b/src/com/android/settings/applications/AppsPreferenceController.java
@@ -0,0 +1,210 @@
+/*
+ * 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.settings.applications;
+
+import android.app.Application;
+import android.app.usage.UsageStats;
+import android.content.Context;
+import android.icu.text.RelativeDateTimeFormatter;
+import android.os.UserHandle;
+import android.text.TextUtils;
+import android.util.ArrayMap;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.fragment.app.Fragment;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceCategory;
+import androidx.preference.PreferenceScreen;
+
+import com.android.settings.R;
+import com.android.settings.applications.appinfo.AppInfoDashboardFragment;
+import com.android.settings.core.BasePreferenceController;
+import com.android.settingslib.Utils;
+import com.android.settingslib.applications.ApplicationsState;
+import com.android.settingslib.utils.StringUtil;
+import com.android.settingslib.widget.AppPreference;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * This controller displays up to four recently used apps.
+ * If there is no recently used app, we only show up an "App Info" preference.
+ */
+public class AppsPreferenceController extends BasePreferenceController {
+
+    public static final int SHOW_RECENT_APP_COUNT = 4;
+
+    @VisibleForTesting
+    static final String KEY_RECENT_APPS_CATEGORY = "recent_apps_category";
+    @VisibleForTesting
+    static final String KEY_GENERAL_CATEGORY = "general_category";
+    @VisibleForTesting
+    static final String KEY_ALL_APP_INFO = "all_app_info";
+    @VisibleForTesting
+    static final String KEY_SEE_ALL = "see_all_apps";
+
+    private final ApplicationsState mApplicationsState;
+    private final int mUserId;
+
+    @VisibleForTesting
+    List<UsageStats> mRecentApps;
+    @VisibleForTesting
+    PreferenceCategory mRecentAppsCategory;
+    @VisibleForTesting
+    PreferenceCategory mGeneralCategory;
+    @VisibleForTesting
+    Preference mAllAppsInfoPref;
+    @VisibleForTesting
+    Preference mSeeAllPref;
+
+    private Fragment mHost;
+
+    public AppsPreferenceController(Context context) {
+        super(context, KEY_RECENT_APPS_CATEGORY);
+        mApplicationsState = ApplicationsState.getInstance(
+                (Application) mContext.getApplicationContext());
+        mUserId = UserHandle.myUserId();
+    }
+
+    public void setFragment(Fragment fragment) {
+        mHost = fragment;
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return AVAILABLE_UNSEARCHABLE;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        initPreferences(screen);
+        refreshUi();
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        super.updateState(preference);
+        refreshUi();
+    }
+
+    @VisibleForTesting
+    void refreshUi() {
+        loadAllAppsCount();
+        mRecentApps = loadRecentApps();
+        if (!mRecentApps.isEmpty()) {
+            displayRecentApps();
+            mRecentAppsCategory.setVisible(true);
+            mGeneralCategory.setVisible(true);
+            mSeeAllPref.setVisible(true);
+        } else {
+            mAllAppsInfoPref.setVisible(true);
+        }
+    }
+
+    @VisibleForTesting
+    void loadAllAppsCount() {
+        // Show total number of installed apps as See all's summary.
+        new InstalledAppCounter(mContext, InstalledAppCounter.IGNORE_INSTALL_REASON,
+                mContext.getPackageManager()) {
+            @Override
+            protected void onCountComplete(int num) {
+                if (!mRecentApps.isEmpty()) {
+                    mSeeAllPref.setTitle(
+                            mContext.getResources().getQuantityString(R.plurals.see_all_apps_title,
+                                    num, num));
+                } else {
+                    mAllAppsInfoPref.setSummary(mContext.getString(R.string.apps_summary, num));
+                }
+            }
+        }.execute();
+    }
+
+    @VisibleForTesting
+    List<UsageStats> loadRecentApps() {
+        final RecentAppStatsMixin recentAppStatsMixin = new RecentAppStatsMixin(mContext,
+                SHOW_RECENT_APP_COUNT);
+        recentAppStatsMixin.loadDisplayableRecentApps(SHOW_RECENT_APP_COUNT);
+        return recentAppStatsMixin.mRecentApps;
+    }
+
+    private void initPreferences(PreferenceScreen screen) {
+        mRecentAppsCategory = screen.findPreference(KEY_RECENT_APPS_CATEGORY);
+        mGeneralCategory = screen.findPreference(KEY_GENERAL_CATEGORY);
+        mAllAppsInfoPref = screen.findPreference(KEY_ALL_APP_INFO);
+        mSeeAllPref = screen.findPreference(KEY_SEE_ALL);
+        mRecentAppsCategory.setVisible(false);
+        mGeneralCategory.setVisible(false);
+        mAllAppsInfoPref.setVisible(false);
+        mSeeAllPref.setVisible(false);
+    }
+
+    private void displayRecentApps() {
+        if (mRecentAppsCategory != null) {
+            final Map<String, Preference> existedAppPreferences = new ArrayMap<>();
+            final int prefCount = mRecentAppsCategory.getPreferenceCount();
+            for (int i = 0; i < prefCount; i++) {
+                final Preference pref = mRecentAppsCategory.getPreference(i);
+                final String key = pref.getKey();
+                if (!TextUtils.equals(key, KEY_SEE_ALL)) {
+                    existedAppPreferences.put(key, pref);
+                }
+            }
+
+            int showAppsCount = 0;
+            for (UsageStats stat : mRecentApps) {
+                final String pkgName = stat.getPackageName();
+                final ApplicationsState.AppEntry appEntry =
+                        mApplicationsState.getEntry(pkgName, mUserId);
+                if (appEntry == null) {
+                    continue;
+                }
+
+                boolean rebindPref = true;
+                Preference pref = existedAppPreferences.remove(pkgName);
+                if (pref == null) {
+                    pref = new AppPreference(mContext);
+                    rebindPref = false;
+                }
+
+                pref.setKey(pkgName);
+                pref.setTitle(appEntry.label);
+                pref.setIcon(Utils.getBadgedIcon(mContext, appEntry.info));
+                pref.setSummary(StringUtil.formatRelativeTime(mContext,
+                        System.currentTimeMillis() - stat.getLastTimeUsed(), false,
+                        RelativeDateTimeFormatter.Style.SHORT));
+                pref.setOrder(showAppsCount++);
+                pref.setOnPreferenceClickListener(preference -> {
+                    AppInfoBase.startAppInfoFragment(AppInfoDashboardFragment.class,
+                            R.string.application_info_label, pkgName, appEntry.info.uid,
+                            mHost, 1001 /*RequestCode*/, getMetricsCategory());
+                    return true;
+                });
+
+                if (!rebindPref) {
+                    mRecentAppsCategory.addPreference(pref);
+                }
+            }
+
+            // Remove unused preferences from pref category.
+            for (Preference unusedPref : existedAppPreferences.values()) {
+                mRecentAppsCategory.removePreference(unusedPref);
+            }
+        }
+    }
+}
diff --git a/src/com/android/settings/core/gateway/SettingsGateway.java b/src/com/android/settings/core/gateway/SettingsGateway.java
index 2c21771..0e0d3eb 100644
--- a/src/com/android/settings/core/gateway/SettingsGateway.java
+++ b/src/com/android/settings/core/gateway/SettingsGateway.java
@@ -35,6 +35,7 @@
 import com.android.settings.accounts.ChooseAccountFragment;
 import com.android.settings.accounts.ManagedProfileSettings;
 import com.android.settings.applications.AppAndNotificationDashboardFragment;
+import com.android.settings.applications.AppDashboardFragment;
 import com.android.settings.applications.ProcessStatsSummary;
 import com.android.settings.applications.ProcessStatsUi;
 import com.android.settings.applications.UsageAccessDetails;
@@ -289,6 +290,7 @@
             ConnectedDeviceDashboardFragment.class.getName(),
             UsbDetailsFragment.class.getName(),
             AppAndNotificationDashboardFragment.class.getName(),
+            AppDashboardFragment.class.getName(),
             WifiCallingDisclaimerFragment.class.getName(),
             AccountDashboardFragment.class.getName(),
             EnterprisePrivacySettings.class.getName(),
@@ -317,6 +319,7 @@
             Settings.NetworkDashboardActivity.class.getName(),
             Settings.ConnectedDeviceDashboardActivity.class.getName(),
             Settings.AppAndNotificationDashboardActivity.class.getName(),
+            Settings.AppDashboardActivity.class.getName(),
             Settings.DisplaySettingsActivity.class.getName(),
             Settings.SoundSettingsActivity.class.getName(),
             Settings.StorageDashboardActivity.class.getName(),
diff --git a/tests/robotests/src/com/android/settings/applications/AppDashboardFragmentTest.java b/tests/robotests/src/com/android/settings/applications/AppDashboardFragmentTest.java
new file mode 100644
index 0000000..0eca43c
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/applications/AppDashboardFragmentTest.java
@@ -0,0 +1,69 @@
+/*
+ * 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.settings.applications;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+
+import com.android.settings.testutils.XmlTestUtils;
+import com.android.settings.testutils.shadow.ShadowUserManager;
+import com.android.settingslib.core.AbstractPreferenceController;
+import com.android.settingslib.drawer.CategoryKey;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@RunWith(RobolectricTestRunner.class)
+public class AppDashboardFragmentTest {
+
+    private Context mContext;
+    private AppDashboardFragment mFragment;
+
+    @Before
+    public void setUp() {
+        mContext = RuntimeEnvironment.application;
+        mFragment = new AppDashboardFragment();
+    }
+
+    @Test
+    public void testCategory_isApps() {
+        assertThat(mFragment.getCategoryKey()).isEqualTo(CategoryKey.CATEGORY_APPS);
+    }
+
+    @Test
+    @Config(shadows = ShadowUserManager.class)
+    public void testPreferenceControllers_existInPreferenceScreen() {
+        final List<String> preferenceScreenKeys = XmlTestUtils.getKeysFromPreferenceXml(mContext,
+                mFragment.getPreferenceScreenResId());
+        final List<String> preferenceKeys = new ArrayList<>();
+
+        for (AbstractPreferenceController controller : mFragment.createPreferenceControllers(
+                mContext)) {
+            preferenceKeys.add(controller.getPreferenceKey());
+        }
+
+        assertThat(preferenceScreenKeys).containsAtLeastElementsIn(preferenceKeys);
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/applications/AppsPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/applications/AppsPreferenceControllerTest.java
new file mode 100644
index 0000000..75da4d8
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/applications/AppsPreferenceControllerTest.java
@@ -0,0 +1,167 @@
+/*
+ * 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.settings.applications;
+
+import static com.android.settings.applications.AppsPreferenceController.KEY_ALL_APP_INFO;
+import static com.android.settings.applications.AppsPreferenceController.KEY_GENERAL_CATEGORY;
+import static com.android.settings.applications.AppsPreferenceController.KEY_RECENT_APPS_CATEGORY;
+import static com.android.settings.applications.AppsPreferenceController.KEY_SEE_ALL;
+import static com.android.settings.core.BasePreferenceController.AVAILABLE_UNSEARCHABLE;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.app.usage.UsageStats;
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.os.UserHandle;
+
+import androidx.fragment.app.Fragment;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceCategory;
+import androidx.preference.PreferenceScreen;
+
+import com.android.settingslib.applications.ApplicationsState;
+
+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.util.ReflectionHelpers;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@RunWith(RobolectricTestRunner.class)
+public class AppsPreferenceControllerTest {
+
+    @Mock
+    private ApplicationsState mAppState;
+    @Mock
+    private ApplicationsState.AppEntry mAppEntry;
+    @Mock
+    private ApplicationInfo mApplicationInfo;
+    @Mock
+    private Fragment mFragment;
+    @Mock
+    private PreferenceScreen mScreen;
+
+    private AppsPreferenceController mController;
+    private List<UsageStats> mUsageStats;
+    private PreferenceCategory mRecentAppsCategory;
+    private PreferenceCategory mGeneralCategory;
+    private Preference mSeeAllPref;
+    private Preference mAllAppsInfoPref;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        final Context context = RuntimeEnvironment.application;
+        ReflectionHelpers.setStaticField(ApplicationsState.class, "sInstance", mAppState);
+
+        mRecentAppsCategory = spy(new PreferenceCategory(context));
+        mGeneralCategory = new PreferenceCategory(context);
+        mSeeAllPref = new Preference(context);
+        mAllAppsInfoPref = new Preference(context);
+        when(mScreen.findPreference(KEY_RECENT_APPS_CATEGORY)).thenReturn(mRecentAppsCategory);
+        when(mScreen.findPreference(KEY_GENERAL_CATEGORY)).thenReturn(mGeneralCategory);
+        when(mScreen.findPreference(KEY_SEE_ALL)).thenReturn(mSeeAllPref);
+        when(mScreen.findPreference(KEY_ALL_APP_INFO)).thenReturn(mAllAppsInfoPref);
+
+        mController = spy(new AppsPreferenceController(context));
+        mController.setFragment(mFragment);
+        mController.mRecentAppsCategory = mRecentAppsCategory;
+        mController.mGeneralCategory = mGeneralCategory;
+        mController.mSeeAllPref = mSeeAllPref;
+        mController.mAllAppsInfoPref = mAllAppsInfoPref;
+    }
+
+    @Test
+    public void getAvailabilityStatus_shouldReturnAVAILABLE_UNSEARCHABLE() {
+        assertThat(mController.getAvailabilityStatus()).isEqualTo(AVAILABLE_UNSEARCHABLE);
+    }
+
+    @Test
+    public void displayPreference_noRecentApps_showAllAppsInfo() {
+        doNothing().when(mController).loadAllAppsCount();
+
+        mController.displayPreference(mScreen);
+
+        assertThat(mAllAppsInfoPref.isVisible()).isTrue();
+        assertThat(mRecentAppsCategory.isVisible()).isFalse();
+        assertThat(mGeneralCategory.isVisible()).isFalse();
+        assertThat(mSeeAllPref.isVisible()).isFalse();
+    }
+
+    @Test
+    public void displayPreference_hasRecentApps_showRecentApps() {
+        doNothing().when(mController).loadAllAppsCount();
+        doReturn(true).when(mRecentAppsCategory).addPreference(any());
+        initRecentApps();
+        doReturn(mUsageStats).when(mController).loadRecentApps();
+
+        mController.displayPreference(mScreen);
+
+        assertThat(mAllAppsInfoPref.isVisible()).isFalse();
+        assertThat(mRecentAppsCategory.isVisible()).isTrue();
+        assertThat(mGeneralCategory.isVisible()).isTrue();
+        assertThat(mSeeAllPref.isVisible()).isTrue();
+    }
+
+    @Test
+    public void updateState_shouldRefreshUi() {
+        doNothing().when(mController).loadAllAppsCount();
+
+        mController.updateState(mRecentAppsCategory);
+
+        verify(mController).refreshUi();
+    }
+
+    private void initRecentApps() {
+        mUsageStats = new ArrayList<>();
+        final UsageStats stat1 = new UsageStats();
+        final UsageStats stat2 = new UsageStats();
+        final UsageStats stat3 = new UsageStats();
+        stat1.mLastTimeUsed = System.currentTimeMillis();
+        stat1.mPackageName = "pkg.class";
+        mUsageStats.add(stat1);
+
+        stat2.mLastTimeUsed = System.currentTimeMillis();
+        stat2.mPackageName = "pkg.class2";
+        mUsageStats.add(stat2);
+
+        stat3.mLastTimeUsed = System.currentTimeMillis();
+        stat3.mPackageName = "pkg.class3";
+        mUsageStats.add(stat3);
+        when(mAppState.getEntry(stat1.mPackageName, UserHandle.myUserId()))
+                .thenReturn(mAppEntry);
+        when(mAppState.getEntry(stat2.mPackageName, UserHandle.myUserId()))
+                .thenReturn(mAppEntry);
+        when(mAppState.getEntry(stat3.mPackageName, UserHandle.myUserId()))
+                .thenReturn(mAppEntry);
+        mAppEntry.info = mApplicationInfo;
+    }
+}