Move Magnification Mode Settings to the main page

We move the mode settings because currently there is
only one item in the settings page. To fully test all logic,
we don't use fragament anymore in the controllerTest, and
test the interaction between the controller and the fragment
in the test of these two fragments.

Bug: 182992338
Test: atest ToggleScreenMagnificationPreferenceFragmentTest
      atest MagnificationModePreferenceControllerTest
      atest MagnificationSettingsFragmentTest
      manually test
Change-Id: Ia6b0ea4f116f3215407637d7aeaddb8d8196d8fb

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);
-        // TODO(b/177371954): "magnification area" should be brought up to the highest level of the
-        // settings UI so that it appears below "shortcut" to replace "settings.
-        mSettingsPreference.setFragment(MagnificationSettingsFragment.class.getName());
+        mSettingsPreference.setTitle(R.string.accessibility_magnification_mode_title);
+        mSettingsPreference.setKey(MagnificationModePreferenceController.PREF_KEY);
         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;