Merge "Move Magnification Mode Settings to the main page" into sc-dev am: 194015b774

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/14327003

Change-Id: I227793e9d91307a221ec6e307ced5acfd4321e8f

res/values/styles.xml

@@ -715,8 +715,8 @@
            parent="@*android:style/Widget.DeviceDefault.Button.ButtonBar.AlertDialog">
         <item name="android:layout_width">match_parent</item>
         <item name="android:layout_height">56dp</item>
-        <item name="android:paddingLeft">8dp</item>
+        <item name="android:paddingEnd">8dp</item>
-        <item name="android:paddingRight">8dp</item>
+        <item name="android:paddingStart">8dp</item>
         <item name="android:background">?android:attr/selectableItemBackground</item>
     </style>
 

src/com/android/settings/accessibility/AccessibilityEditDialogUtils.java

@@ -118,16 +118,16 @@ public class AccessibilityEditDialogUtils {
      * Method to show the magnification edit shortcut dialog in Magnification.
      *
      * @param context A valid context
-     * @param dialogTitle The title of magnify edit shortcut dialog
      * @param positiveBtnListener The positive button listener
      * @return A magnification edit shortcut dialog in Magnification
      */
     public static Dialog createMagnificationSwitchShortcutDialog(Context context,
-            CharSequence dialogTitle, CustomButtonsClickListener positiveBtnListener) {
+            CustomButtonsClickListener positiveBtnListener) {
         final View contentView = createSwitchShortcutDialogContentView(context);
         final AlertDialog alertDialog = new AlertDialog.Builder(context)
                 .setView(contentView)
-                .setTitle(dialogTitle)
+                .setTitle(context.getString(
+                        R.string.accessibility_magnification_switch_shortcut_title))
                 .create();
         setCustomButtonsClickListener(alertDialog, contentView,
                 positiveBtnListener, /* negativeBtnListener= */ null);

src/com/android/settings/accessibility/MagnificationModePreferenceController.java

@@ -47,6 +47,7 @@ import com.android.settings.accessibility.MagnificationCapabilities.Magnificatio
 import com.android.settings.core.BasePreferenceController;
 import com.android.settingslib.core.lifecycle.LifecycleObserver;
 import com.android.settingslib.core.lifecycle.events.OnCreate;
+import com.android.settingslib.core.lifecycle.events.OnResume;
 import com.android.settingslib.core.lifecycle.events.OnSaveInstanceState;
 
 import java.util.ArrayList;
@@ -55,8 +56,9 @@ import java.util.StringJoiner;
 
 /** Controller that shows the magnification area mode summary and the preference click behavior. */
 public class MagnificationModePreferenceController extends BasePreferenceController implements
-        DialogCreatable, LifecycleObserver, OnCreate, OnSaveInstanceState {
+        DialogCreatable, LifecycleObserver, OnCreate, OnResume, OnSaveInstanceState {
 
+    static final String PREF_KEY = "screen_magnification_mode";
     private static final int DIALOG_ID_BASE = 10;
     @VisibleForTesting
     static final int DIALOG_MAGNIFICATION_MODE = DIALOG_ID_BASE + 1;
@@ -68,7 +70,7 @@ public class MagnificationModePreferenceController extends BasePreferenceControl
     private static final String TAG = "MagnificationModePreferenceController";
     private static final char COMPONENT_NAME_SEPARATOR = ':';
 
-    private MagnificationSettingsFragment mParentFragment;
+    private DialogHelper mDialogHelper;
     // The magnification mode in the dialog.
     private int mMode = MagnificationMode.NONE;
     private Preference mModePreference;
@@ -121,7 +123,7 @@ public class MagnificationModePreferenceController extends BasePreferenceControl
         mModePreference = screen.findPreference(getPreferenceKey());
         mModePreference.setOnPreferenceClickListener(preference -> {
             mMode = MagnificationCapabilities.getCapabilities(mContext);
-            mParentFragment.showDialog(DIALOG_MAGNIFICATION_MODE);
+            mDialogHelper.showDialog(DIALOG_MAGNIFICATION_MODE);
             return true;
         });
     }
@@ -131,8 +133,12 @@ public class MagnificationModePreferenceController extends BasePreferenceControl
         outState.putInt(EXTRA_MODE, mMode);
     }
 
-    public void setParentFragment(MagnificationSettingsFragment parentFragment) {
+    /**
-        mParentFragment = parentFragment;
+     * Sets {@link DialogHelper} used to show the dialog.
+     */
+    public void setDialogHelper(DialogHelper dialogHelper) {
+        mDialogHelper = dialogHelper;
+        mDialogHelper.setDialogDelegate(this);
     }
 
     @Override
@@ -207,7 +213,7 @@ public class MagnificationModePreferenceController extends BasePreferenceControl
         }
         mMode = modeInfo.mMagnificationMode;
         if (isTripleTapEnabled(mContext) && mMode != MagnificationMode.FULLSCREEN) {
-            mParentFragment.showDialog(DIALOG_MAGNIFICATION_SWITCH_SHORTCUT);
+            mDialogHelper.showDialog(DIALOG_MAGNIFICATION_SWITCH_SHORTCUT);
         }
     }
 
@@ -229,9 +235,7 @@ public class MagnificationModePreferenceController extends BasePreferenceControl
     }
 
     private Dialog createMagnificationShortCutConfirmDialog() {
-        final String title = mContext.getString(
+        return AccessibilityEditDialogUtils.createMagnificationSwitchShortcutDialog(mContext,
-                R.string.accessibility_magnification_switch_shortcut_title);
-        return AccessibilityEditDialogUtils.createMagnificationSwitchShortcutDialog(mContext, title,
                 this::onSwitchShortcutDialogButtonClicked);
     }
 
@@ -267,6 +271,21 @@ public class MagnificationModePreferenceController extends BasePreferenceControl
                 joiner.toString());
     }
 
+    // TODO(b/186731461): Remove it when this controller is used in DashBoardFragment only.
+    @Override
+    public void onResume() {
+        updateState(mModePreference);
+    }
+
+
+    /**
+     * An interface to help the delegate to show the dialog. It will be injected to the delegate.
+     */
+    interface DialogHelper extends DialogCreatable {
+        void showDialog(int dialogId);
+        void setDialogDelegate(DialogCreatable delegate);
+    }
+
     @VisibleForTesting
     static class MagnificationModeInfo extends ItemInfoArrayAdapter.ItemInfo {
         @MagnificationMode

src/com/android/settings/accessibility/MagnificationSettingsFragment.java

@@ -20,6 +20,7 @@ import android.app.Dialog;
 import android.app.settings.SettingsEnums;
 import android.content.Context;
 
+import com.android.settings.DialogCreatable;
 import com.android.settings.R;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.search.BaseSearchIndexProvider;
@@ -27,11 +28,13 @@ import com.android.settingslib.search.SearchIndexable;
 
 /** Settings page for magnification. */
 @SearchIndexable(forTarget = SearchIndexable.ALL & ~SearchIndexable.ARC)
-public class MagnificationSettingsFragment extends DashboardFragment {
+public class MagnificationSettingsFragment extends DashboardFragment implements
+        MagnificationModePreferenceController.DialogHelper {
 
     private static final String TAG = "MagnificationSettingsFragment";
 
-    private MagnificationModePreferenceController mMagnificationModePreferenceController;
+    private DialogCreatable mDialogDelegate;
+
 
     @Override
     public int getMetricsCategory() {
@@ -41,19 +44,23 @@ public class MagnificationSettingsFragment extends DashboardFragment {
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
-        mMagnificationModePreferenceController = use(MagnificationModePreferenceController.class);
+        use(MagnificationModePreferenceController.class).setDialogHelper(this);
-        mMagnificationModePreferenceController.setParentFragment(this);
     }
 
     @Override
-    protected void showDialog(int dialogId) {
+    public void showDialog(int dialogId) {
         super.showDialog(dialogId);
     }
 
+    @Override
+    public void setDialogDelegate(DialogCreatable delegate) {
+        mDialogDelegate = delegate;
+    }
+
     @Override
     public int getDialogMetricsCategory(int dialogId) {
-        if (mMagnificationModePreferenceController != null) {
+        if (mDialogDelegate != null) {
-            return mMagnificationModePreferenceController.getDialogMetricsCategory(dialogId);
+            return mDialogDelegate.getDialogMetricsCategory(dialogId);
         }
         return 0;
     }
@@ -70,8 +77,8 @@ public class MagnificationSettingsFragment extends DashboardFragment {
 
     @Override
     public Dialog onCreateDialog(int dialogId) {
-        if (mMagnificationModePreferenceController != null) {
+        if (mDialogDelegate != null) {
-            final Dialog dialog = mMagnificationModePreferenceController.onCreateDialog(dialogId);
+            final Dialog dialog = mDialogDelegate.onCreateDialog(dialogId);
             if (dialog != null) {
                 return dialog;
             }

src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java

@@ -42,6 +42,7 @@ import androidx.preference.Preference;
 import androidx.preference.PreferenceCategory;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.settings.DialogCreatable;
 import com.android.settings.R;
 import com.android.settings.accessibility.AccessibilityUtil.UserShortcutType;
 
@@ -55,7 +56,8 @@ import java.util.StringJoiner;
  * and does not have toggle bar to turn on service to use.
  */
 public class ToggleScreenMagnificationPreferenceFragment extends
-        ToggleFeaturePreferenceFragment {
+        ToggleFeaturePreferenceFragment implements
+        MagnificationModePreferenceController.DialogHelper {
     // TODO(b/147021230): Move duplicated functions with android/internal/accessibility into util.
     private TouchExplorationStateChangeListener mTouchExplorationStateChangeListener;
 
@@ -67,6 +69,9 @@ public class ToggleScreenMagnificationPreferenceFragment extends
     private static final TextUtils.SimpleStringSplitter sStringColonSplitter =
             new TextUtils.SimpleStringSplitter(COMPONENT_NAME_SEPARATOR);
 
+    private MagnificationModePreferenceController mModePreferenceController;
+    private DialogCreatable mDialogDelegate;
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -108,6 +113,12 @@ public class ToggleScreenMagnificationPreferenceFragment extends
 
     @Override
     public Dialog onCreateDialog(int dialogId) {
+        if (mDialogDelegate != null) {
+            final Dialog dialog = mDialogDelegate.onCreateDialog(dialogId);
+            if (dialog != null) {
+                return dialog;
+            }
+        }
         final AlertDialog dialog;
         switch (dialogId) {
             case DialogEnums.GESTURE_NAVIGATION_TUTORIAL:
@@ -128,20 +139,35 @@ public class ToggleScreenMagnificationPreferenceFragment extends
 
     @Override
     protected void initSettingsPreference() {
+
         // If the device doesn't support magnification area, it should hide the settings preference.
         if (!getContext().getResources().getBoolean(
                 com.android.internal.R.bool.config_magnification_area)) {
             return;
         }
         mSettingsPreference = new Preference(getPrefContext());
-        mSettingsPreference.setTitle(R.string.accessibility_menu_item_settings);
+        mSettingsPreference.setTitle(R.string.accessibility_magnification_mode_title);
-        // TODO(b/177371954): "magnification area" should be brought up to the highest level of the
+        mSettingsPreference.setKey(MagnificationModePreferenceController.PREF_KEY);
-        // settings UI so that it appears below "shortcut" to replace "settings.
-        mSettingsPreference.setFragment(MagnificationSettingsFragment.class.getName());
         mSettingsPreference.setPersistent(false);
 
         final PreferenceCategory generalCategory = findPreference(KEY_GENERAL_CATEGORY);
         generalCategory.addPreference(mSettingsPreference);
+
+        mModePreferenceController = new MagnificationModePreferenceController(getContext(),
+                MagnificationModePreferenceController.PREF_KEY);
+        mModePreferenceController.setDialogHelper(this);
+        getSettingsLifecycle().addObserver(mModePreferenceController);
+        mModePreferenceController.displayPreference(getPreferenceScreen());
+    }
+
+    @Override
+    public void showDialog(int dialogId) {
+        super.showDialog(dialogId);
+    }
+
+    @Override
+    public void setDialogDelegate(DialogCreatable delegate) {
+        mDialogDelegate = delegate;
     }
 
     @Override
@@ -278,6 +304,13 @@ public class ToggleScreenMagnificationPreferenceFragment extends
 
     @Override
     public int getDialogMetricsCategory(int dialogId) {
+        if (mDialogDelegate != null) {
+            final int category = mDialogDelegate.getDialogMetricsCategory(dialogId);
+            if (category != 0) {
+                return category;
+            }
+        }
+
         switch (dialogId) {
             case DialogEnums.GESTURE_NAVIGATION_TUTORIAL:
                 return SettingsEnums.DIALOG_TOGGLE_SCREEN_MAGNIFICATION_GESTURE_NAVIGATION;

tests/robotests/src/com/android/settings/accessibility/MagnificationModePreferenceControllerTest.java

@@ -16,8 +16,6 @@
 
 package com.android.settings.accessibility;
 
-import static androidx.lifecycle.Lifecycle.Event.ON_CREATE;
-
 import static com.android.settings.accessibility.AccessibilityEditDialogUtils.CustomButton;
 import static com.android.settings.accessibility.MagnificationCapabilities.MagnificationMode;
 import static com.android.settings.accessibility.MagnificationModePreferenceController.MagnificationModeInfo;
@@ -25,41 +23,35 @@ import static com.android.settings.accessibility.MagnificationPreferenceFragment
 
 import static com.google.common.truth.Truth.assertThat;
 
-import static org.mockito.Mockito.doReturn;
-import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
-import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 
+import android.app.Dialog;
 import android.content.Context;
 import android.os.Bundle;
 import android.provider.Settings;
 import android.widget.AdapterView;
 import android.widget.ListView;
 
-import androidx.fragment.app.FragmentManager;
 import androidx.preference.Preference;
+import androidx.preference.PreferenceManager;
 import androidx.preference.PreferenceScreen;
 
+import com.android.settings.DialogCreatable;
 import com.android.settings.R;
-import com.android.settings.testutils.shadow.ShadowDashboardFragment;
-import com.android.settingslib.core.AbstractPreferenceController;
 
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.mockito.Answers;
+import org.mockito.Spy;
-import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnit;
 import org.mockito.junit.MockitoRule;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.RuntimeEnvironment;
-import org.robolectric.annotation.Config;
-
 
+/** Tests for {@link MagnificationModePreferenceController}. */
 @RunWith(RobolectricTestRunner.class)
-@Config(shadows = ShadowDashboardFragment.class)
 public class MagnificationModePreferenceControllerTest {
     private static final String PREF_KEY = "screen_magnification_mode";
     private static final int MAGNIFICATION_MODE_DEFAULT = MagnificationMode.ALL;
@@ -67,39 +59,38 @@ public class MagnificationModePreferenceControllerTest {
     @Rule
     public MockitoRule mocks = MockitoJUnit.rule();
 
-    @Mock
     private PreferenceScreen mScreen;
     private Context mContext;
-    private TestMagnificationSettingsFragment mFragment;
     private MagnificationModePreferenceController mController;
     private Preference mModePreference;
+    @Spy
+    private TestDialogHelper mDialogHelper = new TestDialogHelper();
 
     @Before
     public void setUp() {
         mContext = RuntimeEnvironment.application;
-        mController = new MagnificationModePreferenceController(mContext, PREF_KEY);
+        final PreferenceManager preferenceManager = new PreferenceManager(mContext);
-        mScreen = spy(new PreferenceScreen(mContext, null));
+        mScreen = preferenceManager.createPreferenceScreen(mContext);
         mModePreference = new Preference(mContext);
-        mFragment = spy(new TestMagnificationSettingsFragment(mController));
+        mModePreference.setKey(PREF_KEY);
-
+        mScreen.addPreference(mModePreference);
-        doReturn(mScreen).when(mFragment).getPreferenceScreen();
-        doReturn(mock(FragmentManager.class, Answers.RETURNS_DEEP_STUBS)).when(
-                mFragment).getChildFragmentManager();
-        mContext.setTheme(R.style.Theme_AppCompat);
-        doReturn(mModePreference).when(mScreen).findPreference(PREF_KEY);
         MagnificationCapabilities.setCapabilities(mContext, MAGNIFICATION_MODE_DEFAULT);
+        mController = new MagnificationModePreferenceController(mContext, PREF_KEY);
         showPreferenceOnTheScreen(null);
-        mModePreference.getOnPreferenceClickListener().onPreferenceClick(mModePreference);
     }
 
     @Test
-    public void settingsModeIsDefault_checkedModeInDialogIsDefault() {
+    public void clickPreference_settingsModeIsDefault_checkedModeInDialogIsDefault() {
+        mModePreference.getOnPreferenceClickListener().onPreferenceClick(mModePreference);
+
         assertThat(getCheckedModeFromDialog()).isEqualTo(
                 MAGNIFICATION_MODE_DEFAULT);
     }
 
     @Test
     public void choseModeIsDifferentFromInSettings_checkedModeInDialogIsExpected() {
+        mModePreference.getOnPreferenceClickListener().onPreferenceClick(mModePreference);
+
         performItemClickWith(MagnificationMode.WINDOW);
 
         assertThat(getCheckedModeFromDialog()).isEqualTo(MagnificationMode.WINDOW);
@@ -107,11 +98,11 @@ public class MagnificationModePreferenceControllerTest {
 
     @Test
     public void dialogIsReCreated_settingsModeIsAllAndChoseWindowMode_checkedModeIsWindow() {
-        showPreferenceOnTheScreen(null);
+        mModePreference.getOnPreferenceClickListener().onPreferenceClick(mModePreference);
         performItemClickWith(MagnificationMode.WINDOW);
 
         reshowPreferenceOnTheScreen();
-        mFragment.showDialog(MagnificationModePreferenceController.DIALOG_MAGNIFICATION_MODE);
+        mDialogHelper.showDialog(MagnificationModePreferenceController.DIALOG_MAGNIFICATION_MODE);
 
         assertThat(getCheckedModeFromDialog()).isEqualTo(
                 MagnificationMode.WINDOW);
@@ -120,24 +111,22 @@ public class MagnificationModePreferenceControllerTest {
     @Test
     public void chooseWindowMode_tripleTapEnabled_showSwitchShortcutDialog() {
         enableTripleTap();
+        mModePreference.getOnPreferenceClickListener().onPreferenceClick(mModePreference);
 
         performItemClickWith(MagnificationMode.WINDOW);
 
-        verify(mFragment).showDialog(
+        verify(mDialogHelper).showDialog(
                 MagnificationModePreferenceController.DIALOG_MAGNIFICATION_SWITCH_SHORTCUT);
     }
 
     @Test
     public void chooseModeAll_modeAllInSettingsAndTripleTapEnabled_notShowShortcutDialog() {
         enableTripleTap();
-        MagnificationCapabilities.setCapabilities(mContext,
+        mModePreference.getOnPreferenceClickListener().onPreferenceClick(mModePreference);
-                Settings.Secure.ACCESSIBILITY_MAGNIFICATION_MODE_ALL);
-        mFragment.onCreate(Bundle.EMPTY);
-        mFragment.onCreateDialog(MagnificationModePreferenceController.DIALOG_MAGNIFICATION_MODE);
 
         performItemClickWith(MagnificationMode.ALL);
 
-        verify(mFragment, never()).showDialog(
+        verify(mDialogHelper, never()).showDialog(
                 MagnificationModePreferenceController.DIALOG_MAGNIFICATION_SWITCH_SHORTCUT);
     }
 
@@ -206,48 +195,38 @@ public class MagnificationModePreferenceControllerTest {
 
     private void reshowPreferenceOnTheScreen() {
         final Bundle bundle = new Bundle();
-        mFragment.onSaveInstanceState(bundle);
+        mController.onSaveInstanceState(bundle);
-        mFragment.onDetach();
         showPreferenceOnTheScreen(bundle);
-
     }
 
     private void showPreferenceOnTheScreen(Bundle savedInstanceState) {
-        mFragment.onAttach(mContext);
+        mController.setDialogHelper(mDialogHelper);
-        mFragment.onCreate(savedInstanceState);
+        mController.onCreate(savedInstanceState);
         mController.displayPreference(mScreen);
     }
 
-    private static class TestMagnificationSettingsFragment extends MagnificationSettingsFragment {
+    private static class TestDialogHelper implements DialogCreatable,
-
+            MagnificationModePreferenceController.DialogHelper {
-        TestMagnificationSettingsFragment(AbstractPreferenceController... controllers) {
+        private DialogCreatable mDialogDelegate;
-            // Add given controllers for injection. Although controllers will be added in
-            // onAttach(). use(AbstractPreferenceController.class) returns the first added one.
-            for (int i = 0; i < controllers.length; i++) {
-                addPreferenceController(controllers[i]);
-            }
-        }
 
         @Override
-        public void onCreate(Bundle icicle) {
+        public void showDialog(int dialogId) {
-            super.onCreate(icicle);
-            // Simulate the observable behaviour because ShadowDashFragment doesn't call
-            // super.create.
-
-            getSettingsLifecycle().onCreate(icicle);
-            getSettingsLifecycle().handleLifecycleEvent(ON_CREATE);
-        }
-
-        @Override
-        protected void showDialog(int dialogId) {
-            super.showDialog(dialogId);
-            // In current fragment architecture, we could assume onCreateDialog is called directly.
             onCreateDialog(dialogId);
         }
 
         @Override
-        protected void addPreferenceController(AbstractPreferenceController controller) {
+        public void setDialogDelegate(DialogCreatable delegate) {
-            super.addPreferenceController(controller);
+            mDialogDelegate = delegate;
+        }
+
+        @Override
+        public Dialog onCreateDialog(int dialogId) {
+            return mDialogDelegate.onCreateDialog(dialogId);
+        }
+
+        @Override
+        public int getDialogMetricsCategory(int dialogId) {
+            return mDialogDelegate.getDialogMetricsCategory(dialogId);
         }
     }
 }

tests/robotests/src/com/android/settings/accessibility/MagnificationSettingsFragmentTest.java

@@ -18,23 +18,78 @@ package com.android.settings.accessibility;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import android.content.Context;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
+import android.content.Context;
+import android.os.Bundle;
+
+import androidx.fragment.app.FragmentManager;
+import androidx.preference.PreferenceScreen;
 import androidx.test.core.app.ApplicationProvider;
 
+import com.android.settings.DialogCreatable;
 import com.android.settings.R;
 import com.android.settings.testutils.XmlTestUtils;
+import com.android.settings.testutils.shadow.ShadowDashboardFragment;
 
+import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Answers;
 import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
 
 import java.util.List;
 
 /** Tests for {@link MagnificationSettingsFragment} */
 @RunWith(RobolectricTestRunner.class)
+@Config(shadows = ShadowDashboardFragment.class)
 public class MagnificationSettingsFragmentTest {
+
     private final Context mContext = ApplicationProvider.getApplicationContext();
+    private MagnificationSettingsFragment mFragment;
+    private PreferenceScreen mScreen;
+
+    @Before
+    public void setup() {
+        mContext.setTheme(R.style.Theme_AppCompat);
+        mFragment = spy(new MagnificationSettingsFragment());
+        mScreen = new PreferenceScreen(mContext, null);
+
+        doReturn(mContext).when(mFragment).getContext();
+        doReturn(mScreen).when(mFragment).getPreferenceScreen();
+        doReturn(mock(FragmentManager.class, Answers.RETURNS_DEEP_STUBS)).when(
+                mFragment).getChildFragmentManager();
+
+    }
+
+    @Test
+    public void showPreferenceOnTheScreen_setDialogHelper() {
+        showPreferenceOnTheScreen(null);
+
+        verify(mFragment).setDialogDelegate(any(MagnificationModePreferenceController.class));
+    }
+
+    @Test
+    public void onCreateDialog_setDialogDelegate_invokeDialogDelegate() {
+        final DialogCreatable dialogDelegate = mock(DialogCreatable.class, RETURNS_DEEP_STUBS);
+        when(dialogDelegate.getDialogMetricsCategory(anyInt())).thenReturn(1);
+
+        mFragment.setDialogDelegate(dialogDelegate);
+
+        mFragment.onCreateDialog(1);
+        mFragment.getDialogMetricsCategory(1);
+
+        verify(dialogDelegate).onCreateDialog(1);
+        verify(dialogDelegate).getDialogMetricsCategory(1);
+    }
 
     @Test
     public void getNonIndexableKeys_existInXmlLayout() {
@@ -46,4 +101,10 @@ public class MagnificationSettingsFragmentTest {
                         R.xml.accessibility_magnification_service_settings);
         assertThat(keys).containsAtLeastElementsIn(niks);
     }
+
+    private void showPreferenceOnTheScreen(Bundle savedInstanceState) {
+        mFragment.onAttach(mContext);
+        mFragment.onCreate(savedInstanceState);
+        mFragment.onResume();
+    }
 }

tests/robotests/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragmentTest.java

@@ -23,9 +23,13 @@ import static com.android.settings.accessibility.ToggleFeaturePreferenceFragment
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import android.content.ComponentName;
@@ -34,6 +38,7 @@ import android.content.DialogInterface;
 import android.content.res.Resources;
 import android.os.Bundle;
 import android.provider.Settings;
+import android.text.TextUtils;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -41,21 +46,28 @@ import android.view.ViewGroup;
 import androidx.annotation.XmlRes;
 import androidx.appcompat.app.AlertDialog;
 import androidx.fragment.app.FragmentActivity;
+import androidx.preference.Preference;
 import androidx.preference.PreferenceManager;
+import androidx.preference.PreferenceScreen;
 import androidx.test.core.app.ApplicationProvider;
 
+import com.android.settings.DialogCreatable;
 import com.android.settings.R;
 import com.android.settings.testutils.shadow.ShadowFragment;
+import com.android.settings.testutils.shadow.ShadowSettingsPreferenceFragment;
+import com.android.settingslib.core.lifecycle.Lifecycle;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
+import org.robolectric.Robolectric;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
 
 @RunWith(RobolectricTestRunner.class)
+@Config(shadows = {ShadowSettingsPreferenceFragment.class})
 public class ToggleScreenMagnificationPreferenceFragmentTest {
 
     private static final String PLACEHOLDER_PACKAGE_NAME = "com.mock.example";
@@ -79,9 +91,6 @@ public class ToggleScreenMagnificationPreferenceFragmentTest {
     private Context mContext;
     private Resources mResources;
 
-    @Mock
-    private PreferenceManager mPreferenceManager;
-    @Mock
     private FragmentActivity mActivity;
 
     @Before
@@ -89,14 +98,11 @@ public class ToggleScreenMagnificationPreferenceFragmentTest {
         MockitoAnnotations.initMocks(this);
 
         mContext = spy(ApplicationProvider.getApplicationContext());
-        mFragment = spy(new TestToggleScreenMagnificationPreferenceFragment());
+        mActivity = Robolectric.setupActivity(FragmentActivity.class);
-        when(mFragment.getPreferenceManager()).thenReturn(mPreferenceManager);
+        mFragment = spy(new TestToggleScreenMagnificationPreferenceFragment(mContext));
-        when(mFragment.getPreferenceManager().getContext()).thenReturn(mContext);
-        when(mFragment.getContext()).thenReturn(mContext);
         mResources = spy(mContext.getResources());
         when(mContext.getResources()).thenReturn(mResources);
         when(mFragment.getContext().getResources()).thenReturn(mResources);
-        doReturn(null).when(mFragment).getPreferenceScreen();
         doReturn(mActivity).when(mFragment).getActivity();
     }
 
@@ -257,15 +263,38 @@ public class ToggleScreenMagnificationPreferenceFragmentTest {
     }
 
     @Test
-    public void initSettingsPreference_notSupportsMagnificationArea_settingsPreferenceIsNull() {
+    public void onCreateView_notSupportsMagnificationArea_settingsPreferenceIsNull() {
         when(mResources.getBoolean(
                 com.android.internal.R.bool.config_magnification_area))
                 .thenReturn(false);
-        mFragment.initSettingsPreference();
+
+        mFragment.onCreateView(LayoutInflater.from(mContext), mock(ViewGroup.class), Bundle.EMPTY);
 
         assertThat(mFragment.mSettingsPreference).isNull();
     }
 
+    @Test
+    public void onCreateView_setDialogDelegateAndAddTheControllerToLifeCycleObserver() {
+        mFragment.onCreateView(LayoutInflater.from(mContext), mock(ViewGroup.class), Bundle.EMPTY);
+
+        verify(mFragment).setDialogDelegate(any(MagnificationModePreferenceController.class));
+        verify(mFragment.mSpyLifeyCycle).addObserver(
+                any(MagnificationModePreferenceController.class));
+    }
+
+    @Test
+    public void onCreateDialog_setDialogDelegate_invokeDialogDelegate() {
+        final DialogCreatable dialogDelegate = mock(DialogCreatable.class, RETURNS_DEEP_STUBS);
+        when(dialogDelegate.getDialogMetricsCategory(anyInt())).thenReturn(1);
+        mFragment.setDialogDelegate(dialogDelegate);
+
+        mFragment.onCreateDialog(1);
+        mFragment.getDialogMetricsCategory(1);
+
+        verify(dialogDelegate).onCreateDialog(1);
+        verify(dialogDelegate).getDialogMetricsCategory(1);
+    }
+
     private void putStringIntoSettings(String key, String componentName) {
         Settings.Secure.putString(mContext.getContentResolver(), key, componentName);
     }
@@ -291,8 +320,25 @@ public class ToggleScreenMagnificationPreferenceFragmentTest {
 
     private void callEmptyOnClicked(DialogInterface dialog, int which) {}
 
-    public static class TestToggleScreenMagnificationPreferenceFragment
+    /**
+     * a test fragment that initializes PreferenceScreen for testing.
+     */
+    static class TestToggleScreenMagnificationPreferenceFragment
             extends ToggleScreenMagnificationPreferenceFragment {
+
+        private final Lifecycle mSpyLifeyCycle = Mockito.mock(Lifecycle.class);
+
+        private final Context mContext;
+        private final PreferenceManager mPreferenceManager;
+
+        TestToggleScreenMagnificationPreferenceFragment(Context context) {
+            super();
+            mContext = context;
+            mPreferenceManager = new PreferenceManager(context);
+            mPreferenceManager.setPreferences(mPreferenceManager.createPreferenceScreen(context));
+            setArguments(new Bundle());
+        }
+
         @Override
         protected void onPreferenceToggled(String preferenceKey, boolean enabled) {
         }
@@ -313,9 +359,21 @@ public class ToggleScreenMagnificationPreferenceFragmentTest {
         }
 
         @Override
-        public View onCreateView(LayoutInflater inflater, ViewGroup container,
+        public PreferenceScreen getPreferenceScreen() {
-                Bundle savedInstanceState) {
+            return mPreferenceManager.getPreferenceScreen();
-            return mock(View.class);
+        }
+
+        @Override
+        public <T extends Preference> T findPreference(CharSequence key) {
+            if (TextUtils.isEmpty(key)) {
+                return null;
+            }
+            return getPreferenceScreen().findPreference(key);
+        }
+
+        @Override
+        public PreferenceManager getPreferenceManager() {
+            return mPreferenceManager;
         }
 
         @Override
@@ -337,5 +395,15 @@ public class ToggleScreenMagnificationPreferenceFragmentTest {
         protected void updateShortcutPreference() {
             // UI related function, do nothing in tests
         }
+
+        @Override
+        public Lifecycle getSettingsLifecycle() {
+            return mSpyLifeyCycle;
+        }
+
+        @Override
+        public Context getContext() {
+            return mContext;
+        }
     }
 }

tests/robotests/src/com/android/settings/testutils/shadow/ShadowSettingsPreferenceFragment.java

@@ -0,0 +1,43 @@
+/*
+ * 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.testutils.shadow;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.android.settings.SettingsPreferenceFragment;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+
+/**
+ * Shadow of {@link SettingsPreferenceFragment}.
+ *
+ * Override the {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}} to skip inflating
+ * a View from a xml.
+ */
+@Implements(SettingsPreferenceFragment.class)
+public class ShadowSettingsPreferenceFragment extends ShadowFragment {
+
+    @Implementation
+    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+            Bundle savedInstanceState) {
+        return container;
+    }
+}