src/com/android/launcher3/settings/SettingsActivity.java - platform/packages/apps/Launcher3 - Git at Google

 /*
  * Copyright (C) 2015 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.settings;

 import static android.provider.Settings.Global.DEVELOPMENT_SETTINGS_ENABLED;

 import static androidx.preference.PreferenceFragmentCompat.ARG_PREFERENCE_ROOT;

 import static com.android.launcher3.BuildConfig.IS_DEBUG_DEVICE;
 import static com.android.launcher3.BuildConfig.IS_STUDIO_BUILD;
 import static com.android.launcher3.states.RotationHelper.ALLOW_ROTATION_PREFERENCE_KEY;

 import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
 import android.provider.Settings;
 import android.text.TextUtils;
 import android.view.MenuItem;
 import android.view.View;

 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import androidx.core.view.WindowCompat;
 import androidx.fragment.app.DialogFragment;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceCategory;
 import androidx.preference.PreferenceFragmentCompat;
 import androidx.preference.PreferenceFragmentCompat.OnPreferenceStartFragmentCallback;
 import androidx.preference.PreferenceFragmentCompat.OnPreferenceStartScreenCallback;
 import androidx.preference.PreferenceGroup.PreferencePositionCallback;
 import androidx.preference.PreferenceScreen;
 import androidx.recyclerview.widget.RecyclerView;

 import com.android.launcher3.BuildConfig;
 import com.android.launcher3.LauncherFiles;
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.model.WidgetsModel;
 import com.android.launcher3.states.RotationHelper;
 import com.android.launcher3.uioverrides.flags.DeveloperOptionsUI;
 import com.android.launcher3.util.DisplayController;
 import com.android.launcher3.util.Executors;
 import com.android.launcher3.util.SettingsCache;

 /**
  * Settings activity for Launcher. Currently implements the following setting: Allow rotation
  */
 public class SettingsActivity extends FragmentActivity
         implements OnPreferenceStartFragmentCallback, OnPreferenceStartScreenCallback {

     @VisibleForTesting
     static final String DEVELOPER_OPTIONS_KEY = "pref_developer_options";

     private static final String NOTIFICATION_DOTS_PREFERENCE_KEY = "pref_icon_badging";

     public static final String EXTRA_FRAGMENT_ARGS = ":settings:fragment_args";

     // Intent extra to indicate the pref-key to highlighted when opening the settings activity
     public static final String EXTRA_FRAGMENT_HIGHLIGHT_KEY = ":settings:fragment_args_key";
     // Intent extra to indicate the pref-key of the root screen when opening the settings activity
     public static final String EXTRA_FRAGMENT_ROOT_KEY = ARG_PREFERENCE_ROOT;

     private static final int DELAY_HIGHLIGHT_DURATION_MILLIS = 600;
     public static final String SAVE_HIGHLIGHTED_KEY = "android:preference_highlighted";

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.settings_activity);

         setActionBar(findViewById(R.id.action_bar));
         WindowCompat.setDecorFitsSystemWindows(getWindow(), false);

         Intent intent = getIntent();
         if (intent.hasExtra(EXTRA_FRAGMENT_ROOT_KEY) || intent.hasExtra(EXTRA_FRAGMENT_ARGS)
                 || intent.hasExtra(EXTRA_FRAGMENT_HIGHLIGHT_KEY)) {
             getActionBar().setDisplayHomeAsUpEnabled(true);
         }

         if (savedInstanceState == null) {
             Bundle args = intent.getBundleExtra(EXTRA_FRAGMENT_ARGS);
             if (args == null) {
                 args = new Bundle();
             }

             String highlight = intent.getStringExtra(EXTRA_FRAGMENT_HIGHLIGHT_KEY);
             if (!TextUtils.isEmpty(highlight)) {
                 args.putString(EXTRA_FRAGMENT_HIGHLIGHT_KEY, highlight);
             }
             String root = intent.getStringExtra(EXTRA_FRAGMENT_ROOT_KEY);
             if (!TextUtils.isEmpty(root)) {
                 args.putString(EXTRA_FRAGMENT_ROOT_KEY, root);
             }

             final FragmentManager fm = getSupportFragmentManager();
             final Fragment f = fm.getFragmentFactory().instantiate(getClassLoader(),
                     getString(R.string.settings_fragment_name));
             f.setArguments(args);
             // Display the fragment as the main content.
             fm.beginTransaction().replace(R.id.content_frame, f).commit();
         }
     }

     private boolean startPreference(String fragment, Bundle args, String key) {
         if (Utilities.ATLEAST_P && getSupportFragmentManager().isStateSaved()) {
             // Sometimes onClick can come after onPause because of being posted on the handler.
             // Skip starting new preferences in that case.
             return false;
         }
         final FragmentManager fm = getSupportFragmentManager();
         final Fragment f = fm.getFragmentFactory().instantiate(getClassLoader(), fragment);
         if (f instanceof DialogFragment) {
             f.setArguments(args);
             ((DialogFragment) f).show(fm, key);
         } else {
             startActivity(new Intent(this, SettingsActivity.class)
                     .putExtra(EXTRA_FRAGMENT_ARGS, args));
         }
         return true;
     }

     @Override
     public boolean onPreferenceStartFragment(
             PreferenceFragmentCompat preferenceFragment, Preference pref) {
         return startPreference(pref.getFragment(), pref.getExtras(), pref.getKey());
     }

     @Override
     public boolean onPreferenceStartScreen(PreferenceFragmentCompat caller, PreferenceScreen pref) {
         Bundle args = new Bundle();
         args.putString(ARG_PREFERENCE_ROOT, pref.getKey());
         return startPreference(getString(R.string.settings_fragment_name), args, pref.getKey());
     }

     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         if (item.getItemId() == android.R.id.home) {
             onBackPressed();
             return true;
         }
         return super.onOptionsItemSelected(item);
     }

     /**
      * This fragment shows the launcher preferences.
      */
     public static class LauncherSettingsFragment extends PreferenceFragmentCompat implements
             SettingsCache.OnChangeListener {

         protected boolean mDeveloperOptionsEnabled = false;

         private boolean mRestartOnResume = false;

         private String mHighLightKey;
         private boolean mPreferenceHighlighted = false;

         @Override
         public void onCreate(@Nullable Bundle savedInstanceState) {
             if (BuildConfig.IS_DEBUG_DEVICE) {
                 Uri devUri = Settings.Global.getUriFor(DEVELOPMENT_SETTINGS_ENABLED);
                 SettingsCache settingsCache = SettingsCache.INSTANCE.get(getContext());
                 mDeveloperOptionsEnabled = settingsCache.getValue(devUri);
                 settingsCache.register(devUri, this);
             }
             super.onCreate(savedInstanceState);
         }

         @Override
         public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
             final Bundle args = getArguments();
             mHighLightKey = args == null ? null : args.getString(EXTRA_FRAGMENT_HIGHLIGHT_KEY);

             if (savedInstanceState != null) {
                 mPreferenceHighlighted = savedInstanceState.getBoolean(SAVE_HIGHLIGHTED_KEY);
             }

             getPreferenceManager().setSharedPreferencesName(LauncherFiles.SHARED_PREFERENCES_KEY);
             setPreferencesFromResource(R.xml.launcher_preferences, rootKey);

             PreferenceScreen screen = getPreferenceScreen();
             for (int i = screen.getPreferenceCount() - 1; i >= 0; i--) {
                 Preference preference = screen.getPreference(i);
                 if (!initPreference(preference)) {
                     screen.removePreference(preference);
                 }
             }

             if (getActivity() != null && !TextUtils.isEmpty(getPreferenceScreen().getTitle())) {
                 getActivity().setTitle(getPreferenceScreen().getTitle());
             }
         }

         @Override
         public void onViewCreated(View view, Bundle savedInstanceState) {
             super.onViewCreated(view, savedInstanceState);
             View listView = getListView();
             final int bottomPadding = listView.getPaddingBottom();
             listView.setOnApplyWindowInsetsListener((v, insets) -> {
                 v.setPadding(
                         v.getPaddingLeft(),
                         v.getPaddingTop(),
                         v.getPaddingRight(),
                         bottomPadding + insets.getSystemWindowInsetBottom());
                 return insets.consumeSystemWindowInsets();
             });

             // Overriding Text Direction in the Androidx preference library to support RTL
             view.setTextDirection(View.TEXT_DIRECTION_LOCALE);
         }

         @Override
         public void onSaveInstanceState(Bundle outState) {
             super.onSaveInstanceState(outState);
             outState.putBoolean(SAVE_HIGHLIGHTED_KEY, mPreferenceHighlighted);
         }

         /**
          * Initializes a preference. This is called for every preference. Returning false here
          * will remove that preference from the list.
          */
         protected boolean initPreference(Preference preference) {
             switch (preference.getKey()) {
                 case NOTIFICATION_DOTS_PREFERENCE_KEY:
                     return !WidgetsModel.GO_DISABLE_NOTIFICATION_DOTS;

                 case ALLOW_ROTATION_PREFERENCE_KEY:
                     DisplayController.Info info =
                             DisplayController.INSTANCE.get(getContext()).getInfo();
                     if (info.isTablet(info.realBounds)) {
                         // Launcher supports rotation by default. No need to show this setting.
                         return false;
                     }
                     // Initialize the UI once
                     preference.setDefaultValue(RotationHelper.getAllowRotationDefaultValue(info));
                     return true;

                 case DEVELOPER_OPTIONS_KEY:
                     if (IS_STUDIO_BUILD) {
                         preference.setOrder(0);
                     }
                     return mDeveloperOptionsEnabled;
                 case "pref_developer_flags":
                     if (mDeveloperOptionsEnabled && preference instanceof PreferenceCategory pc) {
                         Executors.MAIN_EXECUTOR.post(() -> new DeveloperOptionsUI(this, pc));
                         return true;
                     }
                     return false;
             }

             return true;
         }

         @Override
         public void onResume() {
             super.onResume();

             if (isAdded() && !mPreferenceHighlighted) {
                 PreferenceHighlighter highlighter = createHighlighter();
                 if (highlighter != null) {
                     getView().postDelayed(highlighter, DELAY_HIGHLIGHT_DURATION_MILLIS);
                     mPreferenceHighlighted = true;
                 }
             }

             if (mRestartOnResume) {
                 recreateActivityNow();
             }
         }

         @Override
         public void onSettingsChanged(boolean isEnabled) {
             // Developer options changed, try recreate
             tryRecreateActivity();
         }

         @Override
         public void onDestroy() {
             super.onDestroy();
             if (IS_DEBUG_DEVICE) {
                 SettingsCache.INSTANCE.get(getContext())
                         .unregister(Settings.Global.getUriFor(DEVELOPMENT_SETTINGS_ENABLED), this);
             }
         }

         /**
          * Tries to recreate the preference
          */
         protected void tryRecreateActivity() {
             if (isResumed()) {
                 recreateActivityNow();
             } else {
                 mRestartOnResume = true;
             }
         }

         private void recreateActivityNow() {
             Activity activity = getActivity();
             if (activity != null) {
                 activity.recreate();
             }
         }

         private PreferenceHighlighter createHighlighter() {
             if (TextUtils.isEmpty(mHighLightKey)) {
                 return null;
             }

             PreferenceScreen screen = getPreferenceScreen();
             if (screen == null) {
                 return null;
             }

             RecyclerView list = getListView();
             PreferencePositionCallback callback = (PreferencePositionCallback) list.getAdapter();
             int position = callback.getPreferenceAdapterPosition(mHighLightKey);
             return position >= 0 ? new PreferenceHighlighter(
                     list, position, screen.findPreference(mHighLightKey))
                     : null;
         }
     }
 }
	/*
	* Copyright (C) 2015 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.settings;

	import static android.provider.Settings.Global.DEVELOPMENT_SETTINGS_ENABLED;

	import static androidx.preference.PreferenceFragmentCompat.ARG_PREFERENCE_ROOT;

	import static com.android.launcher3.BuildConfig.IS_DEBUG_DEVICE;
	import static com.android.launcher3.BuildConfig.IS_STUDIO_BUILD;
	import static com.android.launcher3.states.RotationHelper.ALLOW_ROTATION_PREFERENCE_KEY;

	import android.app.Activity;
	import android.content.Intent;
	import android.net.Uri;
	import android.os.Bundle;
	import android.provider.Settings;
	import android.text.TextUtils;
	import android.view.MenuItem;
	import android.view.View;

	import androidx.annotation.Nullable;
	import androidx.annotation.VisibleForTesting;
	import androidx.core.view.WindowCompat;
	import androidx.fragment.app.DialogFragment;
	import androidx.fragment.app.Fragment;
	import androidx.fragment.app.FragmentActivity;
	import androidx.fragment.app.FragmentManager;
	import androidx.preference.Preference;
	import androidx.preference.PreferenceCategory;
	import androidx.preference.PreferenceFragmentCompat;
	import androidx.preference.PreferenceFragmentCompat.OnPreferenceStartFragmentCallback;
	import androidx.preference.PreferenceFragmentCompat.OnPreferenceStartScreenCallback;
	import androidx.preference.PreferenceGroup.PreferencePositionCallback;
	import androidx.preference.PreferenceScreen;
	import androidx.recyclerview.widget.RecyclerView;

	import com.android.launcher3.BuildConfig;
	import com.android.launcher3.LauncherFiles;
	import com.android.launcher3.R;
	import com.android.launcher3.Utilities;
	import com.android.launcher3.model.WidgetsModel;
	import com.android.launcher3.states.RotationHelper;
	import com.android.launcher3.uioverrides.flags.DeveloperOptionsUI;
	import com.android.launcher3.util.DisplayController;
	import com.android.launcher3.util.Executors;
	import com.android.launcher3.util.SettingsCache;

	/**
	* Settings activity for Launcher. Currently implements the following setting: Allow rotation
	*/
	public class SettingsActivity extends FragmentActivity
	implements OnPreferenceStartFragmentCallback, OnPreferenceStartScreenCallback {

	@VisibleForTesting
	static final String DEVELOPER_OPTIONS_KEY = "pref_developer_options";

	private static final String NOTIFICATION_DOTS_PREFERENCE_KEY = "pref_icon_badging";

	public static final String EXTRA_FRAGMENT_ARGS = ":settings:fragment_args";

	// Intent extra to indicate the pref-key to highlighted when opening the settings activity
	public static final String EXTRA_FRAGMENT_HIGHLIGHT_KEY = ":settings:fragment_args_key";
	// Intent extra to indicate the pref-key of the root screen when opening the settings activity
	public static final String EXTRA_FRAGMENT_ROOT_KEY = ARG_PREFERENCE_ROOT;

	private static final int DELAY_HIGHLIGHT_DURATION_MILLIS = 600;
	public static final String SAVE_HIGHLIGHTED_KEY = "android:preference_highlighted";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.settings_activity);

	setActionBar(findViewById(R.id.action_bar));
	WindowCompat.setDecorFitsSystemWindows(getWindow(), false);

	Intent intent = getIntent();
	if (intent.hasExtra(EXTRA_FRAGMENT_ROOT_KEY) \|\| intent.hasExtra(EXTRA_FRAGMENT_ARGS)
	\|\| intent.hasExtra(EXTRA_FRAGMENT_HIGHLIGHT_KEY)) {
	getActionBar().setDisplayHomeAsUpEnabled(true);
	}

	if (savedInstanceState == null) {
	Bundle args = intent.getBundleExtra(EXTRA_FRAGMENT_ARGS);
	if (args == null) {
	args = new Bundle();
	}

	String highlight = intent.getStringExtra(EXTRA_FRAGMENT_HIGHLIGHT_KEY);
	if (!TextUtils.isEmpty(highlight)) {
	args.putString(EXTRA_FRAGMENT_HIGHLIGHT_KEY, highlight);
	}
	String root = intent.getStringExtra(EXTRA_FRAGMENT_ROOT_KEY);
	if (!TextUtils.isEmpty(root)) {
	args.putString(EXTRA_FRAGMENT_ROOT_KEY, root);
	}

	final FragmentManager fm = getSupportFragmentManager();
	final Fragment f = fm.getFragmentFactory().instantiate(getClassLoader(),
	getString(R.string.settings_fragment_name));
	f.setArguments(args);
	// Display the fragment as the main content.
	fm.beginTransaction().replace(R.id.content_frame, f).commit();
	}
	}

	private boolean startPreference(String fragment, Bundle args, String key) {
	if (Utilities.ATLEAST_P && getSupportFragmentManager().isStateSaved()) {
	// Sometimes onClick can come after onPause because of being posted on the handler.
	// Skip starting new preferences in that case.
	return false;
	}
	final FragmentManager fm = getSupportFragmentManager();
	final Fragment f = fm.getFragmentFactory().instantiate(getClassLoader(), fragment);
	if (f instanceof DialogFragment) {
	f.setArguments(args);
	((DialogFragment) f).show(fm, key);
	} else {
	startActivity(new Intent(this, SettingsActivity.class)
	.putExtra(EXTRA_FRAGMENT_ARGS, args));
	}
	return true;
	}

	@Override
	public boolean onPreferenceStartFragment(
	PreferenceFragmentCompat preferenceFragment, Preference pref) {
	return startPreference(pref.getFragment(), pref.getExtras(), pref.getKey());
	}

	@Override
	public boolean onPreferenceStartScreen(PreferenceFragmentCompat caller, PreferenceScreen pref) {
	Bundle args = new Bundle();
	args.putString(ARG_PREFERENCE_ROOT, pref.getKey());
	return startPreference(getString(R.string.settings_fragment_name), args, pref.getKey());
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
	if (item.getItemId() == android.R.id.home) {
	onBackPressed();
	return true;
	}
	return super.onOptionsItemSelected(item);
	}

	/**
	* This fragment shows the launcher preferences.
	*/
	public static class LauncherSettingsFragment extends PreferenceFragmentCompat implements
	SettingsCache.OnChangeListener {

	protected boolean mDeveloperOptionsEnabled = false;

	private boolean mRestartOnResume = false;

	private String mHighLightKey;
	private boolean mPreferenceHighlighted = false;

	@Override
	public void onCreate(@Nullable Bundle savedInstanceState) {
	if (BuildConfig.IS_DEBUG_DEVICE) {
	Uri devUri = Settings.Global.getUriFor(DEVELOPMENT_SETTINGS_ENABLED);
	SettingsCache settingsCache = SettingsCache.INSTANCE.get(getContext());
	mDeveloperOptionsEnabled = settingsCache.getValue(devUri);
	settingsCache.register(devUri, this);
	}
	super.onCreate(savedInstanceState);
	}

	@Override
	public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
	final Bundle args = getArguments();
	mHighLightKey = args == null ? null : args.getString(EXTRA_FRAGMENT_HIGHLIGHT_KEY);

	if (savedInstanceState != null) {
	mPreferenceHighlighted = savedInstanceState.getBoolean(SAVE_HIGHLIGHTED_KEY);
	}

	getPreferenceManager().setSharedPreferencesName(LauncherFiles.SHARED_PREFERENCES_KEY);
	setPreferencesFromResource(R.xml.launcher_preferences, rootKey);

	PreferenceScreen screen = getPreferenceScreen();
	for (int i = screen.getPreferenceCount() - 1; i >= 0; i--) {
	Preference preference = screen.getPreference(i);
	if (!initPreference(preference)) {
	screen.removePreference(preference);
	}
	}

	if (getActivity() != null && !TextUtils.isEmpty(getPreferenceScreen().getTitle())) {
	getActivity().setTitle(getPreferenceScreen().getTitle());
	}
	}

	@Override
	public void onViewCreated(View view, Bundle savedInstanceState) {
	super.onViewCreated(view, savedInstanceState);
	View listView = getListView();
	final int bottomPadding = listView.getPaddingBottom();
	listView.setOnApplyWindowInsetsListener((v, insets) -> {
	v.setPadding(
	v.getPaddingLeft(),
	v.getPaddingTop(),
	v.getPaddingRight(),
	bottomPadding + insets.getSystemWindowInsetBottom());
	return insets.consumeSystemWindowInsets();
	});

	// Overriding Text Direction in the Androidx preference library to support RTL
	view.setTextDirection(View.TEXT_DIRECTION_LOCALE);
	}

	@Override
	public void onSaveInstanceState(Bundle outState) {
	super.onSaveInstanceState(outState);
	outState.putBoolean(SAVE_HIGHLIGHTED_KEY, mPreferenceHighlighted);
	}

	/**
	* Initializes a preference. This is called for every preference. Returning false here
	* will remove that preference from the list.
	*/
	protected boolean initPreference(Preference preference) {
	switch (preference.getKey()) {
	case NOTIFICATION_DOTS_PREFERENCE_KEY:
	return !WidgetsModel.GO_DISABLE_NOTIFICATION_DOTS;

	case ALLOW_ROTATION_PREFERENCE_KEY:
	DisplayController.Info info =
	DisplayController.INSTANCE.get(getContext()).getInfo();
	if (info.isTablet(info.realBounds)) {
	// Launcher supports rotation by default. No need to show this setting.
	return false;
	}
	// Initialize the UI once
	preference.setDefaultValue(RotationHelper.getAllowRotationDefaultValue(info));
	return true;

	case DEVELOPER_OPTIONS_KEY:
	if (IS_STUDIO_BUILD) {
	preference.setOrder(0);
	}
	return mDeveloperOptionsEnabled;
	case "pref_developer_flags":
	if (mDeveloperOptionsEnabled && preference instanceof PreferenceCategory pc) {
	Executors.MAIN_EXECUTOR.post(() -> new DeveloperOptionsUI(this, pc));
	return true;
	}
	return false;
	}

	return true;
	}

	@Override
	public void onResume() {
	super.onResume();

	if (isAdded() && !mPreferenceHighlighted) {
	PreferenceHighlighter highlighter = createHighlighter();
	if (highlighter != null) {
	getView().postDelayed(highlighter, DELAY_HIGHLIGHT_DURATION_MILLIS);
	mPreferenceHighlighted = true;
	}
	}

	if (mRestartOnResume) {
	recreateActivityNow();
	}
	}

	@Override
	public void onSettingsChanged(boolean isEnabled) {
	// Developer options changed, try recreate
	tryRecreateActivity();
	}

	@Override
	public void onDestroy() {
	super.onDestroy();
	if (IS_DEBUG_DEVICE) {
	SettingsCache.INSTANCE.get(getContext())
	.unregister(Settings.Global.getUriFor(DEVELOPMENT_SETTINGS_ENABLED), this);
	}
	}

	/**
	* Tries to recreate the preference
	*/
	protected void tryRecreateActivity() {
	if (isResumed()) {
	recreateActivityNow();
	} else {
	mRestartOnResume = true;
	}
	}

	private void recreateActivityNow() {
	Activity activity = getActivity();
	if (activity != null) {
	activity.recreate();
	}
	}

	private PreferenceHighlighter createHighlighter() {
	if (TextUtils.isEmpty(mHighLightKey)) {
	return null;
	}

	PreferenceScreen screen = getPreferenceScreen();
	if (screen == null) {
	return null;
	}

	RecyclerView list = getListView();
	PreferencePositionCallback callback = (PreferencePositionCallback) list.getAdapter();
	int position = callback.getPreferenceAdapterPosition(mHighLightKey);
	return position >= 0 ? new PreferenceHighlighter(
	list, position, screen.findPreference(mHighLightKey))
	: null;
	}
	}
	}