/*
 * Copyright (C) 2013 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.accessibility;

import android.app.Dialog;
import android.app.settings.SettingsEnums;
import android.content.ComponentName;
import android.content.ContentResolver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ResolveInfo;
import android.graphics.drawable.Drawable;
import android.icu.text.CaseMap;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.UserHandle;
import android.provider.Settings;
import android.text.Html;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityManager;
import android.view.accessibility.AccessibilityManager.TouchExplorationStateChangeListener;
import android.widget.CheckBox;
import android.widget.ImageView;

import androidx.annotation.VisibleForTesting;
import androidx.preference.Preference;
import androidx.preference.PreferenceCategory;
import androidx.preference.PreferenceScreen;
import androidx.preference.SwitchPreference;

import com.android.settings.R;
import com.android.settings.SettingsActivity;
import com.android.settings.SettingsPreferenceFragment;
import com.android.settings.accessibility.AccessibilityUtil.UserShortcutType;
import com.android.settings.widget.SettingsMainSwitchBar;
import com.android.settingslib.accessibility.AccessibilityUtils;
import com.android.settingslib.widget.FooterPreference;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

/**
 * Base class for accessibility fragments with toggle, shortcut, some helper functions
 * and dialog management.
 */
public abstract class ToggleFeaturePreferenceFragment extends SettingsPreferenceFragment
        implements ShortcutPreference.OnClickCallback {

    protected DividerSwitchPreference mToggleServiceDividerSwitchPreference;
    protected ShortcutPreference mShortcutPreference;
    protected Preference mSettingsPreference;
    protected String mPreferenceKey;

    protected CharSequence mSettingsTitle;
    protected Intent mSettingsIntent;
    // The mComponentName maybe null, such as Magnify
    protected ComponentName mComponentName;
    protected CharSequence mPackageName;
    protected Uri mImageUri;
    private CharSequence mDescription;
    protected CharSequence mHtmlDescription;

    private static final String DRAWABLE_FOLDER = "drawable";
    protected static final String KEY_USE_SERVICE_PREFERENCE = "use_service";
    protected static final String KEY_GENERAL_CATEGORY = "general_categories";
    protected static final String KEY_INTRODUCTION_CATEGORY = "introduction_categories";
    private static final String KEY_SHORTCUT_PREFERENCE = "shortcut_preference";
    protected static final String KEY_SAVED_USER_SHORTCUT_TYPE = "shortcut_type";

    private TouchExplorationStateChangeListener mTouchExplorationStateChangeListener;
    private SettingsContentObserver mSettingsContentObserver;

    private CheckBox mSoftwareTypeCheckBox;
    private CheckBox mHardwareTypeCheckBox;

    public static final int NOT_SET = -1;
    // Save user's shortcutType value when savedInstance has value (e.g. device rotated).
    protected int mSavedCheckBoxValue = NOT_SET;

    // For html description of accessibility service, must follow the rule, such as
    // <img src="R.drawable.fileName"/>, a11y settings will get the resources successfully.
    private static final String IMG_PREFIX = "R.drawable.";

    private ImageView mImageGetterCacheView;

    private final Html.ImageGetter mImageGetter = (String str) -> {
        if (str != null && str.startsWith(IMG_PREFIX)) {
            final String fileName = str.substring(IMG_PREFIX.length());
            return getDrawableFromUri(Uri.parse(
                    ContentResolver.SCHEME_ANDROID_RESOURCE + "://"
                            + mComponentName.getPackageName() + "/" + DRAWABLE_FOLDER + "/"
                            + fileName));
        }
        return null;
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Restore the user shortcut type.
        if (savedInstanceState != null && savedInstanceState.containsKey(
                KEY_SAVED_USER_SHORTCUT_TYPE)) {
            mSavedCheckBoxValue = savedInstanceState.getInt(KEY_SAVED_USER_SHORTCUT_TYPE, NOT_SET);
        }

        setupDefaultShortcutIfNecessary(getPrefContext());
        final int resId = getPreferenceScreenResId();
        if (resId <= 0) {
            PreferenceScreen preferenceScreen = getPreferenceManager().createPreferenceScreen(
                    getPrefContext());
            setPreferenceScreen(preferenceScreen);
        }

        final List<String> shortcutFeatureKeys = new ArrayList<>();
        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_BUTTON_TARGETS);
        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_SHORTCUT_TARGET_SERVICE);
        mSettingsContentObserver = new SettingsContentObserver(new Handler(), shortcutFeatureKeys) {
            @Override
            public void onChange(boolean selfChange, Uri uri) {
                updateShortcutPreferenceData();
                updateShortcutPreference();
            }
        };
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // Need to be called as early as possible. Protected variables will be assigned here.
        onProcessArguments(getArguments());

        initAnimatedImagePreference();
        initToggleServiceDividerSwitchPreference();
        initGeneralCategory();
        initShortcutPreference();
        initSettingsPreference();
        initHtmlTextPreference();
        initFooterPreference();

        installActionBarToggleSwitch();

        updateToggleServiceTitle(mToggleServiceDividerSwitchPreference);

        mTouchExplorationStateChangeListener = isTouchExplorationEnabled -> {
            removeDialog(DialogEnums.EDIT_SHORTCUT);
            mShortcutPreference.setSummary(getShortcutTypeSummary(getPrefContext()));
        };
        return super.onCreateView(inflater, container, savedInstanceState);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        final SettingsActivity activity = (SettingsActivity) getActivity();
        final SettingsMainSwitchBar switchBar = activity.getSwitchBar();
        switchBar.hide();
    }

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

        final AccessibilityManager am = getPrefContext().getSystemService(
                AccessibilityManager.class);
        am.addTouchExplorationStateChangeListener(mTouchExplorationStateChangeListener);
        mSettingsContentObserver.register(getContentResolver());
        updateShortcutPreferenceData();
        updateShortcutPreference();
    }

    @Override
    public void onPause() {
        final AccessibilityManager am = getPrefContext().getSystemService(
                AccessibilityManager.class);
        am.removeTouchExplorationStateChangeListener(mTouchExplorationStateChangeListener);
        mSettingsContentObserver.unregister(getContentResolver());
        super.onPause();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        final int value = getShortcutTypeCheckBoxValue();
        if (value != NOT_SET) {
            outState.putInt(KEY_SAVED_USER_SHORTCUT_TYPE, value);
        }
        super.onSaveInstanceState(outState);
    }

    @Override
    public Dialog onCreateDialog(int dialogId) {
        Dialog dialog;
        switch (dialogId) {
            case DialogEnums.EDIT_SHORTCUT:
                final CharSequence dialogTitle = getPrefContext().getString(
                        R.string.accessibility_shortcut_title, mPackageName);
                dialog = AccessibilityEditDialogUtils.showEditShortcutDialog(
                        getPrefContext(), dialogTitle, this::callOnAlertDialogCheckboxClicked);
                setupEditShortcutDialog(dialog);
                return dialog;
            case DialogEnums.LAUNCH_ACCESSIBILITY_TUTORIAL:
                dialog = AccessibilityGestureNavigationTutorial
                        .createAccessibilityTutorialDialog(getPrefContext(),
                                getUserShortcutTypes());
                dialog.setCanceledOnTouchOutside(false);
                return dialog;
            default:
                throw new IllegalArgumentException("Unsupported dialogId " + dialogId);
        }
    }

    @Override
    public int getDialogMetricsCategory(int dialogId) {
        switch (dialogId) {
            case DialogEnums.EDIT_SHORTCUT:
                return SettingsEnums.DIALOG_ACCESSIBILITY_SERVICE_EDIT_SHORTCUT;
            case DialogEnums.LAUNCH_ACCESSIBILITY_TUTORIAL:
                return SettingsEnums.DIALOG_ACCESSIBILITY_TUTORIAL;
            default:
                return SettingsEnums.ACTION_UNKNOWN;
        }
    }

    /** Denotes the dialog emuns for show dialog */
    @Retention(RetentionPolicy.SOURCE)
    protected @interface DialogEnums {

        /** OPEN: Settings > Accessibility > Any toggle service > Shortcut > Settings. */
        int EDIT_SHORTCUT = 1;

        /** OPEN: Settings > Accessibility > Magnification > Shortcut > Settings. */
        int MAGNIFICATION_EDIT_SHORTCUT = 1001;

        /**
         * OPEN: Settings > Accessibility > Downloaded toggle service > Toggle use service to
         * enable service.
         */
        int ENABLE_WARNING_FROM_TOGGLE = 1002;

        /** OPEN: Settings > Accessibility > Downloaded toggle service > Shortcut checkbox. */
        int ENABLE_WARNING_FROM_SHORTCUT = 1003;

        /**
         * OPEN: Settings > Accessibility > Downloaded toggle service > Shortcut checkbox
         * toggle.
         */
        int ENABLE_WARNING_FROM_SHORTCUT_TOGGLE = 1004;

        /**
         * OPEN: Settings > Accessibility > Downloaded toggle service > Toggle use service to
         * disable service.
         */
        int DISABLE_WARNING_FROM_TOGGLE = 1005;

        /**
         * OPEN: Settings > Accessibility > Magnification > Toggle user service in button
         * navigation.
         */
        int ACCESSIBILITY_BUTTON_TUTORIAL = 1006;

        /**
         * OPEN: Settings > Accessibility > Magnification > Toggle user service in gesture
         * navigation.
         */
        int GESTURE_NAVIGATION_TUTORIAL = 1007;

        /**
         * OPEN: Settings > Accessibility > Downloaded toggle service > Toggle user service > Show
         * launch tutorial.
         */
        int LAUNCH_ACCESSIBILITY_TUTORIAL = 1008;
    }

    @Override
    public int getMetricsCategory() {
        return SettingsEnums.ACCESSIBILITY_SERVICE;
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        removeActionBarToggleSwitch();
    }

    /**
     * Returns the shortcut type list which has been checked by user.
     */
    abstract int getUserShortcutTypes();

    protected void updateToggleServiceTitle(SwitchPreference switchPreference) {
        switchPreference.setTitle(R.string.accessibility_service_primary_switch_title);
    }

    protected abstract void onPreferenceToggled(String preferenceKey, boolean enabled);

    protected void onInstallSwitchPreferenceToggleSwitch() {
        // Implement this to set a checked listener.
    }

    protected void onRemoveSwitchPreferenceToggleSwitch() {
        // Implement this to reset a checked listener.
    }

    private void installActionBarToggleSwitch() {
        onInstallSwitchPreferenceToggleSwitch();
    }

    private void removeActionBarToggleSwitch() {
        mToggleServiceDividerSwitchPreference.setOnPreferenceClickListener(null);
        onRemoveSwitchPreferenceToggleSwitch();
    }

    public void setTitle(String title) {
        getActivity().setTitle(title);
    }

    protected void onProcessArguments(Bundle arguments) {
        // Key.
        mPreferenceKey = arguments.getString(AccessibilitySettings.EXTRA_PREFERENCE_KEY);

        // Title.
        if (arguments.containsKey(AccessibilitySettings.EXTRA_RESOLVE_INFO)) {
            ResolveInfo info = arguments.getParcelable(AccessibilitySettings.EXTRA_RESOLVE_INFO);
            getActivity().setTitle(info.loadLabel(getPackageManager()).toString());
        } else if (arguments.containsKey(AccessibilitySettings.EXTRA_TITLE)) {
            setTitle(arguments.getString(AccessibilitySettings.EXTRA_TITLE));
        }

        // Summary.
        if (arguments.containsKey(AccessibilitySettings.EXTRA_SUMMARY)) {
            mDescription = arguments.getCharSequence(AccessibilitySettings.EXTRA_SUMMARY);
        }

        // Settings html description.
        if (arguments.containsKey(AccessibilitySettings.EXTRA_HTML_DESCRIPTION)) {
            mHtmlDescription = arguments.getCharSequence(
                    AccessibilitySettings.EXTRA_HTML_DESCRIPTION);
        }
    }

    private Drawable getDrawableFromUri(Uri imageUri) {
        if (mImageGetterCacheView == null) {
            mImageGetterCacheView = new ImageView(getPrefContext());
        }

        mImageGetterCacheView.setAdjustViewBounds(true);
        mImageGetterCacheView.setImageURI(imageUri);

        if (mImageGetterCacheView.getDrawable() == null) {
            return null;
        }

        final Drawable drawable =
                mImageGetterCacheView.getDrawable().mutate().getConstantState().newDrawable();
        mImageGetterCacheView.setImageURI(null);
        final int imageWidth = drawable.getIntrinsicWidth();
        final int imageHeight = drawable.getIntrinsicHeight();
        final int screenHalfHeight = AccessibilityUtil.getScreenHeightPixels(getPrefContext()) / 2;
        if ((imageWidth > AccessibilityUtil.getScreenWidthPixels(getPrefContext()))
                || (imageHeight > screenHalfHeight)) {
            return null;
        }

        drawable.setBounds(/* left= */0, /* top= */0, drawable.getIntrinsicWidth(),
                drawable.getIntrinsicHeight());

        return drawable;
    }

    private void initAnimatedImagePreference() {
        if (mImageUri == null) {
            return;
        }

        final int screenHalfHeight = AccessibilityUtil.getScreenHeightPixels(getPrefContext()) / 2;
        final AnimatedImagePreference animatedImagePreference =
                new AnimatedImagePreference(getPrefContext());
        animatedImagePreference.setImageUri(mImageUri);
        animatedImagePreference.setSelectable(false);
        animatedImagePreference.setMaxHeight(screenHalfHeight);

        getPreferenceScreen().addPreference(animatedImagePreference);
    }

    private void initToggleServiceDividerSwitchPreference() {
        mToggleServiceDividerSwitchPreference = new DividerSwitchPreference(getPrefContext());
        mToggleServiceDividerSwitchPreference.setKey(KEY_USE_SERVICE_PREFERENCE);
        if (getArguments().containsKey(AccessibilitySettings.EXTRA_CHECKED)) {
            final boolean enabled = getArguments().getBoolean(AccessibilitySettings.EXTRA_CHECKED);
            mToggleServiceDividerSwitchPreference.setChecked(enabled);
        }

        getPreferenceScreen().addPreference(mToggleServiceDividerSwitchPreference);
    }

    private void initGeneralCategory() {
        final PreferenceCategory generalCategory = new PreferenceCategory(getPrefContext());
        generalCategory.setKey(KEY_GENERAL_CATEGORY);
        generalCategory.setTitle(R.string.accessibility_screen_option);

        getPreferenceScreen().addPreference(generalCategory);
    }

    protected void initShortcutPreference() {
        // Initial the shortcut preference.
        mShortcutPreference = new ShortcutPreference(getPrefContext(), /* attrs= */ null);
        mShortcutPreference.setPersistent(false);
        mShortcutPreference.setKey(getShortcutPreferenceKey());
        mShortcutPreference.setOnClickCallback(this);

        final CharSequence title = getString(R.string.accessibility_shortcut_title, mPackageName);
        mShortcutPreference.setTitle(title);

        final PreferenceCategory generalCategory = findPreference(KEY_GENERAL_CATEGORY);
        generalCategory.addPreference(mShortcutPreference);
    }

    protected void initSettingsPreference() {
        if (mSettingsTitle == null || mSettingsIntent == null) {
            return;
        }

        // Show the "Settings" menu as if it were a preference screen.
        mSettingsPreference = new Preference(getPrefContext());
        mSettingsPreference.setTitle(mSettingsTitle);
        mSettingsPreference.setIconSpaceReserved(true);
        mSettingsPreference.setIntent(mSettingsIntent);

        final PreferenceCategory generalCategory = findPreference(KEY_GENERAL_CATEGORY);
        generalCategory.addPreference(mSettingsPreference);
    }

    private void initIntroductionCategory() {
        final PreferenceCategory introductionCategory = new PreferenceCategory(getPrefContext());
        final CharSequence title =
                getString(R.string.accessibility_introduction_title, mPackageName);
        introductionCategory.setKey(KEY_INTRODUCTION_CATEGORY);
        introductionCategory.setTitle(title);

        getPreferenceScreen().addPreference(introductionCategory);
    }

    private void initHtmlTextPreference() {
        if (TextUtils.isEmpty(mHtmlDescription)) {
            return;
        }

        initIntroductionCategory();

        final HtmlTextPreference htmlTextPreference = new HtmlTextPreference(getPrefContext());
        htmlTextPreference.setSummary(mHtmlDescription);
        htmlTextPreference.setImageGetter(mImageGetter);
        htmlTextPreference.setSelectable(false);

        final PreferenceCategory introductionCategory = findPreference(KEY_INTRODUCTION_CATEGORY);
        introductionCategory.addPreference(htmlTextPreference);
    }

    private void initFooterPreference() {
        if (!TextUtils.isEmpty(mDescription)) {
            createFooterPreference(mDescription);
        }

        if (TextUtils.isEmpty(mHtmlDescription) && TextUtils.isEmpty(mDescription)) {
            final CharSequence defaultDescription =
                    getText(R.string.accessibility_service_default_description);
            createFooterPreference(defaultDescription);
        }
    }

    @VisibleForTesting
    void setupEditShortcutDialog(Dialog dialog) {
        final View dialogSoftwareView = dialog.findViewById(R.id.software_shortcut);
        mSoftwareTypeCheckBox = dialogSoftwareView.findViewById(R.id.checkbox);
        setDialogTextAreaClickListener(dialogSoftwareView, mSoftwareTypeCheckBox);

        final View dialogHardwareView = dialog.findViewById(R.id.hardware_shortcut);
        mHardwareTypeCheckBox = dialogHardwareView.findViewById(R.id.checkbox);
        setDialogTextAreaClickListener(dialogHardwareView, mHardwareTypeCheckBox);

        updateEditShortcutDialogCheckBox();
    }

    private void setDialogTextAreaClickListener(View dialogView, CheckBox checkBox) {
        final View dialogTextArea = dialogView.findViewById(R.id.container);
        dialogTextArea.setOnClickListener(v -> checkBox.toggle());
    }

    private void updateEditShortcutDialogCheckBox() {
        // If it is during onConfigChanged process then restore the value, or get the saved value
        // when shortcutPreference is checked.
        int value = restoreOnConfigChangedValue();
        if (value == NOT_SET) {
            final int lastNonEmptyUserShortcutType = PreferredShortcuts.retrieveUserShortcutType(
                    getPrefContext(), mComponentName.flattenToString(), UserShortcutType.SOFTWARE);
            value = mShortcutPreference.isChecked() ? lastNonEmptyUserShortcutType
                    : UserShortcutType.EMPTY;
        }

        mSoftwareTypeCheckBox.setChecked(
                hasShortcutType(value, UserShortcutType.SOFTWARE));
        mHardwareTypeCheckBox.setChecked(
                hasShortcutType(value, UserShortcutType.HARDWARE));
    }

    private int restoreOnConfigChangedValue() {
        final int savedValue = mSavedCheckBoxValue;
        mSavedCheckBoxValue = NOT_SET;
        return savedValue;
    }

    private boolean hasShortcutType(int value, @UserShortcutType int type) {
        return (value & type) == type;
    }

    /**
     * Returns accumulated {@link UserShortcutType} checkbox value or {@code NOT_SET} if checkboxes
     * did not exist.
     */
    protected int getShortcutTypeCheckBoxValue() {
        if (mSoftwareTypeCheckBox == null || mHardwareTypeCheckBox == null) {
            return NOT_SET;
        }

        int value = UserShortcutType.EMPTY;
        if (mSoftwareTypeCheckBox.isChecked()) {
            value |= UserShortcutType.SOFTWARE;
        }
        if (mHardwareTypeCheckBox.isChecked()) {
            value |= UserShortcutType.HARDWARE;
        }
        return value;
    }

    protected CharSequence getShortcutTypeSummary(Context context) {
        if (!mShortcutPreference.isSettingsEditable()) {
            return context.getText(R.string.accessibility_shortcut_edit_dialog_title_hardware);
        }

        if (!mShortcutPreference.isChecked()) {
            return context.getText(R.string.switch_off_text);
        }

        final int shortcutTypes = PreferredShortcuts.retrieveUserShortcutType(context,
                mComponentName.flattenToString(), UserShortcutType.SOFTWARE);
        int resId = R.string.accessibility_shortcut_edit_summary_software;
        if (AccessibilityUtil.isGestureNavigateEnabled(context)) {
            resId = AccessibilityUtil.isTouchExploreEnabled(context)
                    ? R.string.accessibility_shortcut_edit_dialog_title_software_gesture_talkback
                    : R.string.accessibility_shortcut_edit_dialog_title_software_gesture;
        }
        final CharSequence softwareTitle = context.getText(resId);

        List<CharSequence> list = new ArrayList<>();
        if ((shortcutTypes & UserShortcutType.SOFTWARE) == UserShortcutType.SOFTWARE) {
            list.add(softwareTitle);
        }
        if ((shortcutTypes & UserShortcutType.HARDWARE) == UserShortcutType.HARDWARE) {
            final CharSequence hardwareTitle = context.getText(
                    R.string.accessibility_shortcut_hardware_keyword);
            list.add(hardwareTitle);
        }

        // Show software shortcut if first time to use.
        if (list.isEmpty()) {
            list.add(softwareTitle);
        }
        final String joinStrings = TextUtils.join(/* delimiter= */", ", list);

        return CaseMap.toTitle().wholeString().noLowercase().apply(Locale.getDefault(), /* iter= */
                null, joinStrings);
    }

    /**
     * This method will be invoked when a button in the edit shortcut dialog is clicked.
     *
     * @param dialog The dialog that received the click
     * @param which The button that was clicked
     */
    protected void callOnAlertDialogCheckboxClicked(DialogInterface dialog, int which) {
        if (mComponentName == null) {
            return;
        }

        final int value = getShortcutTypeCheckBoxValue();

        saveNonEmptyUserShortcutType(value);
        AccessibilityUtil.optInAllValuesToSettings(getPrefContext(), value, mComponentName);
        AccessibilityUtil.optOutAllValuesFromSettings(getPrefContext(), ~value, mComponentName);
        mShortcutPreference.setChecked(value != UserShortcutType.EMPTY);
        mShortcutPreference.setSummary(getShortcutTypeSummary(getPrefContext()));
    }

    protected void updateShortcutPreferenceData() {
        if (mComponentName == null) {
            return;
        }

        final int shortcutTypes = AccessibilityUtil.getUserShortcutTypesFromSettings(
                getPrefContext(), mComponentName);
        if (shortcutTypes != UserShortcutType.EMPTY) {
            final PreferredShortcut shortcut = new PreferredShortcut(
                    mComponentName.flattenToString(), shortcutTypes);
            PreferredShortcuts.saveUserShortcutType(getPrefContext(), shortcut);
        }
    }

    protected void updateShortcutPreference() {
        if (mComponentName == null) {
            return;
        }

        final int shortcutTypes = PreferredShortcuts.retrieveUserShortcutType(getPrefContext(),
                mComponentName.flattenToString(), UserShortcutType.SOFTWARE);
        mShortcutPreference.setChecked(
                AccessibilityUtil.hasValuesInSettings(getPrefContext(), shortcutTypes,
                        mComponentName));
        mShortcutPreference.setSummary(getShortcutTypeSummary(getPrefContext()));
    }

    protected String getShortcutPreferenceKey() {
        return KEY_SHORTCUT_PREFERENCE;
    }

    @Override
    public void onToggleClicked(ShortcutPreference preference) {
        if (mComponentName == null) {
            return;
        }

        final int shortcutTypes = PreferredShortcuts.retrieveUserShortcutType(getPrefContext(),
                mComponentName.flattenToString(), UserShortcutType.SOFTWARE);
        if (preference.isChecked()) {
            AccessibilityUtil.optInAllValuesToSettings(getPrefContext(), shortcutTypes,
                    mComponentName);
            showDialog(DialogEnums.LAUNCH_ACCESSIBILITY_TUTORIAL);
        } else {
            AccessibilityUtil.optOutAllValuesFromSettings(getPrefContext(), shortcutTypes,
                    mComponentName);
        }
        mShortcutPreference.setSummary(getShortcutTypeSummary(getPrefContext()));
    }

    @Override
    public void onSettingsClicked(ShortcutPreference preference) {
        showDialog(DialogEnums.EDIT_SHORTCUT);
    }

    private void createFooterPreference(CharSequence title) {
        final PreferenceScreen preferenceScreen = getPreferenceScreen();
        preferenceScreen.addPreference(new FooterPreference.Builder(getActivity()).setTitle(
                title).build());
    }

    /**
     *  Setups a configurable default if the setting has never been set.
     */
    private static void setupDefaultShortcutIfNecessary(Context context) {
        final String targetKey = Settings.Secure.ACCESSIBILITY_SHORTCUT_TARGET_SERVICE;
        String targetString = Settings.Secure.getString(context.getContentResolver(), targetKey);
        if (!TextUtils.isEmpty(targetString)) {
            // The shortcut setting has been set
            return;
        }

        // AccessibilityManager#getAccessibilityShortcutTargets may not return correct shortcut
        // targets during boot. Needs to read settings directly here.
        targetString = AccessibilityUtils.getShortcutTargetServiceComponentNameString(context,
                UserHandle.myUserId());
        if (TextUtils.isEmpty(targetString)) {
            // No configurable default accessibility service
            return;
        }

        // Only fallback to default accessibility service when setting is never updated.
        final ComponentName shortcutName = ComponentName.unflattenFromString(targetString);
        if (shortcutName != null) {
            Settings.Secure.putString(context.getContentResolver(), targetKey,
                    shortcutName.flattenToString());
        }
    }

    @VisibleForTesting
    void saveNonEmptyUserShortcutType(int type) {
        if (type == UserShortcutType.EMPTY) {
            return;
        }

        final PreferredShortcut shortcut = new PreferredShortcut(
                mComponentName.flattenToString(), type);
        PreferredShortcuts.saveUserShortcutType(getPrefContext(), shortcut);
    }
}