Use FooterPreference in xml explicitly

Removed the FooterPreferenceMixin from the DeviceAdminSettings page.

Fixes: 140015273
Test: manual test
Test: make RunSettingsRoboTests ROBOTEST_FILTER=com.android.settings.applications
Change-Id: I91c10946ae35f9a5cde30399e231dbc8a1481b23

res/xml/device_admin_settings.xml

@@ -20,4 +20,11 @@
     xmlns:settings="http://schemas.android.com/apk/res-auto"
     android:title="@string/manage_device_admin"
     android:key="device_admin_settings"
-    settings:controller="com.android.settings.applications.specialaccess.deviceadmin.DeviceAdminListPreferenceController" />
+    settings:controller="com.android.settings.applications.specialaccess.deviceadmin.DeviceAdminListPreferenceController">
+
+    <com.android.settingslib.widget.FooterPreference
+        android:key="device_admin_footer"
+        android:title="@string/no_device_admins"
+        android:selectable="false"
+        settings:searchable="false"/>
+</PreferenceScreen>

src/com/android/settings/applications/specialaccess/deviceadmin/DeviceAdminListPreferenceController.java

@@ -45,13 +45,11 @@ import androidx.preference.PreferenceGroup;
 import androidx.preference.PreferenceScreen;
 import androidx.preference.SwitchPreference;
 
-import com.android.settings.R;
 import com.android.settings.core.BasePreferenceController;
 import com.android.settingslib.core.lifecycle.LifecycleObserver;
 import com.android.settingslib.core.lifecycle.events.OnStart;
 import com.android.settingslib.core.lifecycle.events.OnStop;
 import com.android.settingslib.widget.FooterPreference;
-import com.android.settingslib.widget.FooterPreferenceMixinCompat;
 
 import org.xmlpull.v1.XmlPullParserException;
 
@@ -67,6 +65,7 @@ public class DeviceAdminListPreferenceController extends BasePreferenceControlle
 
     private static final IntentFilter FILTER = new IntentFilter();
     private static final String TAG = "DeviceAdminListPrefCtrl";
+    private static final String KEY_DEVICE_ADMIN_FOOTER = "device_admin_footer";
 
     private final DevicePolicyManager mDPM;
     private final UserManager mUm;
@@ -91,7 +90,7 @@ public class DeviceAdminListPreferenceController extends BasePreferenceControlle
     };
 
     private PreferenceGroup mPreferenceGroup;
-    private FooterPreferenceMixinCompat mFooterPreferenceMixin;
+    private FooterPreference mFooterPreference;
 
     static {
         FILTER.addAction(ACTION_DEVICE_POLICY_MANAGER_STATE_CHANGED);
@@ -105,12 +104,6 @@ public class DeviceAdminListPreferenceController extends BasePreferenceControlle
         mIPackageManager = AppGlobals.getPackageManager();
     }
 
-    public DeviceAdminListPreferenceController setFooterPreferenceMixin(
-            FooterPreferenceMixinCompat mixin) {
-        mFooterPreferenceMixin = mixin;
-        return this;
-    }
-
     @Override
     public int getAvailabilityStatus() {
         return AVAILABLE;
@@ -120,6 +113,7 @@ public class DeviceAdminListPreferenceController extends BasePreferenceControlle
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
         mPreferenceGroup = screen.findPreference(getPreferenceKey());
+        mFooterPreference = mPreferenceGroup.findPreference(KEY_DEVICE_ADMIN_FOOTER);
     }
 
     @Override
@@ -167,10 +161,8 @@ public class DeviceAdminListPreferenceController extends BasePreferenceControlle
         if (mPreferenceGroup == null) {
             return;
         }
-        if (mFooterPreferenceMixin != null) {
+        if (mFooterPreference != null) {
-            final FooterPreference footer = mFooterPreferenceMixin.createFooterPreference();
+            mFooterPreference.setVisible(mAdmins.isEmpty());
-            footer.setTitle(R.string.no_device_admins);
-            footer.setVisible(mAdmins.isEmpty());
         }
         final Map<String, SwitchPreference> preferenceCache = new ArrayMap<>();
         final Context prefContext = mPreferenceGroup.getContext();

src/com/android/settings/applications/specialaccess/deviceadmin/DeviceAdminSettings.java

@@ -37,13 +37,6 @@ public class DeviceAdminSettings extends DashboardFragment {
         return SettingsEnums.DEVICE_ADMIN_SETTINGS;
     }
 
-    @Override
-    public void onAttach(Context context) {
-        super.onAttach(context);
-        use(DeviceAdminListPreferenceController.class).setFooterPreferenceMixin(
-                mFooterPreferenceMixin);
-    }
-
     @Override
     protected int getPreferenceScreenResId() {
         return R.xml.device_admin_settings;

tests/robotests/src/com/android/settings/applications/specialaccess/deviceadmin/DeviceAdminListPreferenceControllerTest.java

@@ -33,37 +33,26 @@ import android.os.UserHandle;
 import androidx.lifecycle.LifecycleOwner;
 
 import com.android.settingslib.core.lifecycle.Lifecycle;
-import com.android.settingslib.widget.FooterPreferenceMixinCompat;
 
 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;
 
 @RunWith(RobolectricTestRunner.class)
 public class DeviceAdminListPreferenceControllerTest {
-
-    @Mock
-    private FooterPreferenceMixinCompat mFooterPreferenceMixin;
     private Context mContext;
-    private DeviceAdminListPreferenceController mController;
-    private LifecycleOwner mLifecycleOwner;
     private Lifecycle mLifecycle;
 
     @Before
     public void setUp() {
-        MockitoAnnotations.initMocks(this);
         mContext = spy(RuntimeEnvironment.application);
 
-        mLifecycleOwner = () -> mLifecycle;
+        final LifecycleOwner lifecycleOwner = () -> mLifecycle;
-        mLifecycle = new Lifecycle(mLifecycleOwner);
+        mLifecycle = new Lifecycle(lifecycleOwner);
 
-        mController = spy(new DeviceAdminListPreferenceController(mContext, "test_key")
+        mLifecycle.addObserver(new DeviceAdminListPreferenceController(mContext, "test_key"));
-                .setFooterPreferenceMixin(mFooterPreferenceMixin));
-        mLifecycle.addObserver(mController);
     }
 
     @Test