Allow specifying any font size. https://redmine.stoutner.com/issues/504

[PrivacyBrowser.git] / app / src / main / java / com / stoutner / privacybrowser / activities / MainWebViewActivity.java

/*
 * Copyright © 2015-2019 Soren Stoutner <soren@stoutner.com>.
 *
 * Download cookie code contributed 2017 Hendrik Knackstedt.  Copyright assigned to Soren Stoutner <soren@stoutner.com>.
 *
 * This file is part of Privacy Browser <https://www.stoutner.com/privacy-browser>.
 *
 * Privacy Browser is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Privacy Browser is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Privacy Browser.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.stoutner.privacybrowser.activities;

import android.Manifest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Dialog;
import android.app.DownloadManager;
import android.app.SearchManager;
import android.content.ActivityNotFoundException;
import android.content.BroadcastReceiver;
import android.content.ClipData;
import android.content.ClipboardManager;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Typeface;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.net.http.SslCertificate;
import android.net.http.SslError;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.preference.PreferenceManager;
import android.print.PrintDocumentAdapter;
import android.print.PrintManager;
import android.text.Editable;
import android.text.Spanned;
import android.text.TextWatcher;
import android.text.style.ForegroundColorSpan;
import android.util.Patterns;
import android.view.ContextMenu;
import android.view.GestureDetector;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.view.inputmethod.InputMethodManager;
import android.webkit.CookieManager;
import android.webkit.HttpAuthHandler;
import android.webkit.SslErrorHandler;
import android.webkit.ValueCallback;
import android.webkit.WebBackForwardList;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceResponse;
import android.webkit.WebSettings;
import android.webkit.WebStorage;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.webkit.WebViewDatabase;
import android.widget.ArrayAdapter;
import android.widget.CursorAdapter;
import android.widget.EditText;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.RadioButton;
import android.widget.RelativeLayout;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.coordinatorlayout.widget.CoordinatorLayout;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.fragment.app.DialogFragment;
import androidx.fragment.app.FragmentManager;
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
import androidx.viewpager.widget.ViewPager;

import com.google.android.material.appbar.AppBarLayout;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.navigation.NavigationView;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.tabs.TabLayout;

import com.stoutner.privacybrowser.BuildConfig;
import com.stoutner.privacybrowser.R;
import com.stoutner.privacybrowser.adapters.WebViewPagerAdapter;
import com.stoutner.privacybrowser.asynctasks.GetHostIpAddresses;
import com.stoutner.privacybrowser.asynctasks.PopulateBlocklists;
import com.stoutner.privacybrowser.asynctasks.SaveWebpageImage;
import com.stoutner.privacybrowser.dialogs.AdConsentDialog;
import com.stoutner.privacybrowser.dialogs.CreateBookmarkDialog;
import com.stoutner.privacybrowser.dialogs.CreateBookmarkFolderDialog;
import com.stoutner.privacybrowser.dialogs.CreateHomeScreenShortcutDialog;
import com.stoutner.privacybrowser.dialogs.DownloadFileDialog;
import com.stoutner.privacybrowser.dialogs.DownloadImageDialog;
import com.stoutner.privacybrowser.dialogs.DownloadLocationPermissionDialog;
import com.stoutner.privacybrowser.dialogs.EditBookmarkDialog;
import com.stoutner.privacybrowser.dialogs.EditBookmarkFolderDialog;
import com.stoutner.privacybrowser.dialogs.FontSizeDialog;
import com.stoutner.privacybrowser.dialogs.HttpAuthenticationDialog;
import com.stoutner.privacybrowser.dialogs.PinnedMismatchDialog;
import com.stoutner.privacybrowser.dialogs.SaveWebpageImageDialog;
import com.stoutner.privacybrowser.dialogs.SslCertificateErrorDialog;
import com.stoutner.privacybrowser.dialogs.StoragePermissionDialog;
import com.stoutner.privacybrowser.dialogs.UrlHistoryDialog;
import com.stoutner.privacybrowser.dialogs.ViewSslCertificateDialog;
import com.stoutner.privacybrowser.fragments.WebViewTabFragment;
import com.stoutner.privacybrowser.helpers.AdHelper;
import com.stoutner.privacybrowser.helpers.BlocklistHelper;
import com.stoutner.privacybrowser.helpers.BookmarksDatabaseHelper;
import com.stoutner.privacybrowser.helpers.CheckPinnedMismatchHelper;
import com.stoutner.privacybrowser.helpers.DomainsDatabaseHelper;
import com.stoutner.privacybrowser.helpers.FileNameHelper;
import com.stoutner.privacybrowser.helpers.OrbotProxyHelper;
import com.stoutner.privacybrowser.views.NestedScrollWebView;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;

// AppCompatActivity from android.support.v7.app.AppCompatActivity must be used to have access to the SupportActionBar until the minimum API is >= 21.
public class MainWebViewActivity extends AppCompatActivity implements CreateBookmarkDialog.CreateBookmarkListener, CreateBookmarkFolderDialog.CreateBookmarkFolderListener,
        DownloadFileDialog.DownloadFileListener, DownloadImageDialog.DownloadImageListener, DownloadLocationPermissionDialog.DownloadLocationPermissionDialogListener, EditBookmarkDialog.EditBookmarkListener,
        EditBookmarkFolderDialog.EditBookmarkFolderListener, FontSizeDialog.UpdateFontSizeListener, NavigationView.OnNavigationItemSelectedListener, PinnedMismatchDialog.PinnedMismatchListener, PopulateBlocklists.PopulateBlocklistsListener, SaveWebpageImageDialog.SaveWebpageImageListener,
        StoragePermissionDialog.StoragePermissionDialogListener, UrlHistoryDialog.NavigateHistoryListener, WebViewTabFragment.NewTabListener {

    // `orbotStatus` is public static so it can be accessed from `OrbotProxyHelper`.  It is also used in `onCreate()`, `onResume()`, and `applyProxyThroughOrbot()`.
    public static String orbotStatus;

    // The WebView pager adapter is accessed from `HttpAuthenticationDialog`, `PinnedMismatchDialog`, and `SslCertificateErrorDialog`.  It is also used in `onCreate()`, `onResume()`, and `addTab()`.
    public static WebViewPagerAdapter webViewPagerAdapter;

    // The load URL on restart variables are public static so they can be accessed from `BookmarksActivity`.  They are used in `onRestart()`.
    public static boolean loadUrlOnRestart;
    public static String urlToLoadOnRestart;

    // `restartFromBookmarksActivity` is public static so it can be accessed from `BookmarksActivity`.  It is also used in `onRestart()`.
    public static boolean restartFromBookmarksActivity;

    // `currentBookmarksFolder` is public static so it can be accessed from `BookmarksActivity`.  It is also used in `onCreate()`, `onBackPressed()`, `onCreateBookmark()`, `onCreateBookmarkFolder()`,
    // `onSaveEditBookmark()`, `onSaveEditBookmarkFolder()`, and `loadBookmarksFolder()`.
    public static String currentBookmarksFolder;

    // The user agent constants are public static so they can be accessed from `SettingsFragment`, `DomainsActivity`, and `DomainSettingsFragment`.
    public final static int UNRECOGNIZED_USER_AGENT = -1;
    public final static int SETTINGS_WEBVIEW_DEFAULT_USER_AGENT = 1;
    public final static int SETTINGS_CUSTOM_USER_AGENT = 12;
    public final static int DOMAINS_SYSTEM_DEFAULT_USER_AGENT = 0;
    public final static int DOMAINS_WEBVIEW_DEFAULT_USER_AGENT = 2;
    public final static int DOMAINS_CUSTOM_USER_AGENT = 13;

    // Start activity for result request codes.
    private final int FILE_UPLOAD_REQUEST_CODE = 0;
    public final static int BROWSE_SAVE_WEBPAGE_IMAGE_REQUEST_CODE = 1;


    // The current WebView is used in `onCreate()`, `onPrepareOptionsMenu()`, `onOptionsItemSelected()`, `onNavigationItemSelected()`, `onRestart()`, `onCreateContextMenu()`, `findPreviousOnPage()`,
    // `findNextOnPage()`, `closeFindOnPage()`, `loadUrlFromTextBox()`, `onSslMismatchBack()`, `applyProxyThroughOrbot()`, and `applyDomainSettings()`.
    private NestedScrollWebView currentWebView;

    // `customHeader` is used in `onCreate()`, `onOptionsItemSelected()`, `onCreateContextMenu()`, and `loadUrl()`.
    private final Map<String, String> customHeaders = new HashMap<>();

    // The search URL is set in `applyProxyThroughOrbot()` and used in `onCreate()`, `onNewIntent()`, `loadURLFromTextBox()`, and `initializeWebView()`.
    private String searchURL;

    // The options menu is set in `onCreateOptionsMenu()` and used in `onOptionsItemSelected()`, `updatePrivacyIcons()`, and `initializeWebView()`.
    private Menu optionsMenu;

    // The blocklists are populated in `finishedPopulatingBlocklists()` and accessed from `initializeWebView()`.
    private ArrayList<List<String[]>> easyList;
    private ArrayList<List<String[]>> easyPrivacy;
    private ArrayList<List<String[]>> fanboysAnnoyanceList;
    private ArrayList<List<String[]>> fanboysSocialList;
    private ArrayList<List<String[]>> ultraList;
    private ArrayList<List<String[]>> ultraPrivacy;

    // `webViewDefaultUserAgent` is used in `onCreate()` and `onPrepareOptionsMenu()`.
    private String webViewDefaultUserAgent;

    // `proxyThroughOrbot` is used in `onRestart()`, `onOptionsItemSelected()`, `applyAppSettings()`, and `applyProxyThroughOrbot()`.
    private boolean proxyThroughOrbot;

    // The incognito mode is set in `applyAppSettings()` and used in `initializeWebView()`.
    private boolean incognitoModeEnabled;

    // The full screen browsing mode tracker is set it `applyAppSettings()` and used in `initializeWebView()`.
    private boolean fullScreenBrowsingModeEnabled;

    // `inFullScreenBrowsingMode` is used in `onCreate()`, `onConfigurationChanged()`, and `applyAppSettings()`.
    private boolean inFullScreenBrowsingMode;

    // The app bar trackers are set in `applyAppSettings()` and used in `initializeWebView()`.
    private boolean hideAppBar;
    private boolean scrollAppBar;

    // The loading new intent tracker is set in `onNewIntent()` and used in `setCurrentWebView()`.
    private boolean loadingNewIntent;

    // `reapplyDomainSettingsOnRestart` is used in `onCreate()`, `onOptionsItemSelected()`, `onNavigationItemSelected()`, `onRestart()`, and `onAddDomain()`, .
    private boolean reapplyDomainSettingsOnRestart;

    // `reapplyAppSettingsOnRestart` is used in `onNavigationItemSelected()` and `onRestart()`.
    private boolean reapplyAppSettingsOnRestart;

    // `displayingFullScreenVideo` is used in `onCreate()` and `onResume()`.
    private boolean displayingFullScreenVideo;

    // `orbotStatusBroadcastReceiver` is used in `onCreate()` and `onDestroy()`.
    private BroadcastReceiver orbotStatusBroadcastReceiver;

    // `waitingForOrbot` is used in `onCreate()`, `onResume()`, and `applyProxyThroughOrbot()`.
    private boolean waitingForOrbot;

    // The action bar drawer toggle is initialized in `onCreate()` and used in `onResume()`.
    private ActionBarDrawerToggle actionBarDrawerToggle;

    // The color spans are used in `onCreate()` and `highlightUrlText()`.
    private ForegroundColorSpan redColorSpan;
    private ForegroundColorSpan initialGrayColorSpan;
    private ForegroundColorSpan finalGrayColorSpan;

    // The drawer header padding variables are used in `onCreate()` and `onConfigurationChanged()`.
    private int drawerHeaderPaddingLeftAndRight;
    private int drawerHeaderPaddingTop;
    private int drawerHeaderPaddingBottom;

    // `bookmarksDatabaseHelper` is used in `onCreate()`, `onDestroy`, `onOptionsItemSelected()`, `onCreateBookmark()`, `onCreateBookmarkFolder()`, `onSaveEditBookmark()`, `onSaveEditBookmarkFolder()`,
    // and `loadBookmarksFolder()`.
    private BookmarksDatabaseHelper bookmarksDatabaseHelper;

    // `bookmarksCursor` is used in `onDestroy()`, `onOptionsItemSelected()`, `onCreateBookmark()`, `onCreateBookmarkFolder()`, `onSaveEditBookmark()`, `onSaveEditBookmarkFolder()`, and `loadBookmarksFolder()`.
    private Cursor bookmarksCursor;

    // `bookmarksCursorAdapter` is used in `onCreateBookmark()`, `onCreateBookmarkFolder()` `onSaveEditBookmark()`, `onSaveEditBookmarkFolder()`, and `loadBookmarksFolder()`.
    private CursorAdapter bookmarksCursorAdapter;

    // `oldFolderNameString` is used in `onCreate()` and `onSaveEditBookmarkFolder()`.
    private String oldFolderNameString;

    // `fileChooserCallback` is used in `onCreate()` and `onActivityResult()`.
    private ValueCallback<Uri[]> fileChooserCallback;

    // The default progress view offsets are set in `onCreate()` and used in `initializeWebView()`.
    private int defaultProgressViewStartOffset;
    private int defaultProgressViewEndOffset;

    // The swipe refresh layout top padding is used when exiting full screen browsing mode.  It is used in an inner class in `initializeWebView()`.
    private int swipeRefreshLayoutPaddingTop;

    // The URL sanitizers are set in `applyAppSettings()` and used in `sanitizeUrl()`.
    private boolean sanitizeGoogleAnalytics;
    private boolean sanitizeFacebookClickIds;
    private boolean sanitizeTwitterAmpRedirects;

    // The download strings are used in `onCreate()`, `onRequestPermissionResult()` and `initializeWebView()`.
    private String downloadUrl;
    private String downloadContentDisposition;
    private long downloadContentLength;

    // `downloadImageUrl` is used in `onCreateContextMenu()` and `onRequestPermissionResult()`.
    private String downloadImageUrl;

    // The save website image file path string is used in `onSaveWebpageImage()` and `onRequestPermissionResult()`
    private String saveWebsiteImageFilePath;

    // The permission result request codes are used in `onCreateContextMenu()`, `onCloseDownloadLocationPermissionDialog()`, `onRequestPermissionResult()`, `onSaveWebpageImage()`,
    // `onCloseStoragePermissionDialog()`, and `initializeWebView()`.
    private final int DOWNLOAD_FILE_REQUEST_CODE = 1;
    private final int DOWNLOAD_IMAGE_REQUEST_CODE = 2;
    private final int SAVE_WEBPAGE_IMAGE_REQUEST_CODE = 3;

    @Override
    // Remove the warning about needing to override `performClick()` when using an `OnTouchListener` with `WebView`.
    @SuppressLint("ClickableViewAccessibility")
    protected void onCreate(Bundle savedInstanceState) {
        if (Build.VERSION.SDK_INT >= 21) {
            WebView.enableSlowWholeDocumentDraw();
        }

        // Initialize the default preference values the first time the program is run.  `false` keeps this command from resetting any current preferences back to default.
        PreferenceManager.setDefaultValues(this, R.xml.preferences, false);

        // Get a handle for the shared preferences.
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        // Get the theme and screenshot preferences.
        boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);
        boolean allowScreenshots = sharedPreferences.getBoolean("allow_screenshots", false);

        // Disable screenshots if not allowed.
        if (!allowScreenshots) {
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);
        }

        // Set the activity theme.
        if (darkTheme) {
            setTheme(R.style.PrivacyBrowserDark);
        } else {
            setTheme(R.style.PrivacyBrowserLight);
        }

        // Run the default commands.
        super.onCreate(savedInstanceState);

        // Set the content view.
        setContentView(R.layout.main_framelayout);

        // Get handles for the views that need to be modified.
        DrawerLayout drawerLayout = findViewById(R.id.drawerlayout);
        Toolbar toolbar = findViewById(R.id.toolbar);
        ViewPager webViewPager = findViewById(R.id.webviewpager);

        // Set the action bar.  `SupportActionBar` must be used until the minimum API is >= 21.
        setSupportActionBar(toolbar);

        // Get a handle for the action bar.
        ActionBar actionBar = getSupportActionBar();

        // This is needed to get rid of the Android Studio warning that the action bar might be null.
        assert actionBar != null;

        // Add the custom layout, which shows the URL text bar.
        actionBar.setCustomView(R.layout.url_app_bar);
        actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);

        // Initially disable the sliding drawers.  They will be enabled once the blocklists are loaded.
        drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED);

        // Create the hamburger icon at the start of the AppBar.
        actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.open_navigation_drawer, R.string.close_navigation_drawer);

        // Initialize the web view pager adapter.
        webViewPagerAdapter = new WebViewPagerAdapter(getSupportFragmentManager());

        // Set the pager adapter on the web view pager.
        webViewPager.setAdapter(webViewPagerAdapter);

        // Store up to 100 tabs in memory.
        webViewPager.setOffscreenPageLimit(100);

        // Populate the blocklists.
        new PopulateBlocklists(this, this).execute();
    }

    @Override
    protected void onNewIntent(Intent intent) {
        // Run the default commands.
        super.onNewIntent(intent);

        // Replace the intent that started the app with this one.
        setIntent(intent);

        // Process the intent here if Privacy Browser is fully initialized.  If the process has been killed by the system while sitting in the background, this will be handled in `initializeWebView()`.
        if (ultraPrivacy != null) {
            // Get the information from the intent.
            String intentAction = intent.getAction();
            Uri intentUriData = intent.getData();

            // Determine if this is a web search.
            boolean isWebSearch = ((intentAction != null) && intentAction.equals(Intent.ACTION_WEB_SEARCH));

            // Only process the URI if it contains data or it is a web search.  If the user pressed the desktop icon after the app was already running the URI will be null.
            if (intentUriData != null || isWebSearch) {
                // Get the shared preferences.
                SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

                // Create a URL string.
                String url;

                // If the intent action is a web search, perform the search.
                if (isWebSearch) {
                    // Create an encoded URL string.
                    String encodedUrlString;

                    // Sanitize the search input and convert it to a search.
                    try {
                        encodedUrlString = URLEncoder.encode(intent.getStringExtra(SearchManager.QUERY), "UTF-8");
                    } catch (UnsupportedEncodingException exception) {
                        encodedUrlString = "";
                    }

                    // Add the base search URL.
                    url = searchURL + encodedUrlString;
                } else {  // The intent should contain a URL.
                    // Set the intent data as the URL.
                    url = intentUriData.toString();
                }

                // Add a new tab if specified in the preferences.
                if (sharedPreferences.getBoolean("open_intents_in_new_tab", true)) {  // Load the URL in a new tab.
                    // Set the loading new intent flag.
                    loadingNewIntent = true;

                    // Add a new tab.
                    addNewTab(url, true);
                } else {  // Load the URL in the current tab.
                    // Make it so.
                    loadUrl(url);
                }

                // Get a handle for the drawer layout.
                DrawerLayout drawerLayout = findViewById(R.id.drawerlayout);

                // Close the navigation drawer if it is open.
                if (drawerLayout.isDrawerVisible(GravityCompat.START)) {
                    drawerLayout.closeDrawer(GravityCompat.START);
                }

                // Close the bookmarks drawer if it is open.
                if (drawerLayout.isDrawerVisible(GravityCompat.END)) {
                    drawerLayout.closeDrawer(GravityCompat.END);
                }
            }
        }
    }

    @Override
    public void onRestart() {
        // Run the default commands.
        super.onRestart();

        // Make sure Orbot is running if Privacy Browser is proxying through Orbot.
        if (proxyThroughOrbot) {
            // Request Orbot to start.  If Orbot is already running no hard will be caused by this request.
            Intent orbotIntent = new Intent("org.torproject.android.intent.action.START");

            // Send the intent to the Orbot package.
            orbotIntent.setPackage("org.torproject.android");

            // Make it so.
            sendBroadcast(orbotIntent);
        }

        // Apply the app settings if returning from the Settings activity.
        if (reapplyAppSettingsOnRestart) {
            // Reset the reapply app settings on restart tracker.
            reapplyAppSettingsOnRestart = false;

            // Apply the app settings.
            applyAppSettings();
        }

        // Apply the domain settings if returning from the settings or domains activity.
        if (reapplyDomainSettingsOnRestart) {
            // Reset the reapply domain settings on restart tracker.
            reapplyDomainSettingsOnRestart = false;

            // Reapply the domain settings for each tab.
            for (int i = 0; i < webViewPagerAdapter.getCount(); i++) {
                // Get the WebView tab fragment.
                WebViewTabFragment webViewTabFragment = webViewPagerAdapter.getPageFragment(i);

                // Get the fragment view.
                View fragmentView = webViewTabFragment.getView();

                // Only reload the WebViews if they exist.
                if (fragmentView != null) {
                    // Get the nested scroll WebView from the tab fragment.
                    NestedScrollWebView nestedScrollWebView = fragmentView.findViewById(R.id.nestedscroll_webview);

                    // Reset the current domain name so the domain settings will be reapplied.
                    nestedScrollWebView.resetCurrentDomainName();

                    // Reapply the domain settings if the URL is not null, which can happen if an empty tab is active when returning from settings.
                    if (nestedScrollWebView.getUrl() != null) {
                        applyDomainSettings(nestedScrollWebView, nestedScrollWebView.getUrl(), false, true);
                    }
                }
            }
        }

        // Load the URL on restart (used when loading a bookmark).
        if (loadUrlOnRestart) {
            // Load the specified URL.
            loadUrl(urlToLoadOnRestart);

            // Reset the load on restart tracker.
            loadUrlOnRestart = false;
        }

        // Update the bookmarks drawer if returning from the Bookmarks activity.
        if (restartFromBookmarksActivity) {
            // Get a handle for the drawer layout.
            DrawerLayout drawerLayout = findViewById(R.id.drawerlayout);

            // Close the bookmarks drawer.
            drawerLayout.closeDrawer(GravityCompat.END);

            // Reload the bookmarks drawer.
            loadBookmarksFolder();

            // Reset `restartFromBookmarksActivity`.
            restartFromBookmarksActivity = false;
        }

        // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.  This can be important if the screen was rotated.
        updatePrivacyIcons(true);
    }

    // `onResume()` runs after `onStart()`, which runs after `onCreate()` and `onRestart()`.
    @Override
    public void onResume() {
        // Run the default commands.
        super.onResume();

        for (int i = 0; i < webViewPagerAdapter.getCount(); i++) {
            // Get the WebView tab fragment.
            WebViewTabFragment webViewTabFragment = webViewPagerAdapter.getPageFragment(i);

            // Get the fragment view.
            View fragmentView = webViewTabFragment.getView();

            // Only resume the WebViews if they exist (they won't when the app is first created).
            if (fragmentView != null) {
                // Get the nested scroll WebView from the tab fragment.
                NestedScrollWebView nestedScrollWebView = fragmentView.findViewById(R.id.nestedscroll_webview);

                // Resume the nested scroll WebView JavaScript timers.
                nestedScrollWebView.resumeTimers();

                // Resume the nested scroll WebView.
                nestedScrollWebView.onResume();
            }
        }

        // Display a message to the user if waiting for Orbot.
        if (waitingForOrbot && !orbotStatus.equals("ON")) {
            // Disable the wide view port so that the waiting for Orbot text is displayed correctly.
            currentWebView.getSettings().setUseWideViewPort(false);

            // Load a waiting page.  `null` specifies no encoding, which defaults to ASCII.
            currentWebView.loadData("<html><body><br/><center><h1>" + getString(R.string.waiting_for_orbot) + "</h1></center></body></html>", "text/html", null);
        }

        if (displayingFullScreenVideo || inFullScreenBrowsingMode) {
            // Get a handle for the root frame layouts.
            FrameLayout rootFrameLayout = findViewById(R.id.root_framelayout);

            // Remove the translucent status flag.  This is necessary so the root frame layout can fill the entire screen.
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);

            /* Hide the system bars.
             * SYSTEM_UI_FLAG_FULLSCREEN hides the status bar at the top of the screen.
             * SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN makes the root frame layout fill the area that is normally reserved for the status bar.
             * SYSTEM_UI_FLAG_HIDE_NAVIGATION hides the navigation bar on the bottom or right of the screen.
             * SYSTEM_UI_FLAG_IMMERSIVE_STICKY makes the status and navigation bars translucent and automatically re-hides them after they are shown.
             */
            rootFrameLayout.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
                    View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
        } else if (BuildConfig.FLAVOR.contentEquals("free")) {  // Resume the adView for the free flavor.
            // Resume the ad.
            AdHelper.resumeAd(findViewById(R.id.adview));
        }
    }

    @Override
    public void onPause() {
        // Run the default commands.
        super.onPause();

        for (int i = 0; i < webViewPagerAdapter.getCount(); i++) {
            // Get the WebView tab fragment.
            WebViewTabFragment webViewTabFragment = webViewPagerAdapter.getPageFragment(i);

            // Get the fragment view.
            View fragmentView = webViewTabFragment.getView();

            // Only pause the WebViews if they exist (they won't when the app is first created).
            if (fragmentView != null) {
                // Get the nested scroll WebView from the tab fragment.
                NestedScrollWebView nestedScrollWebView = fragmentView.findViewById(R.id.nestedscroll_webview);

                // Pause the nested scroll WebView.
                nestedScrollWebView.onPause();

                // Pause the nested scroll WebView JavaScript timers.
                nestedScrollWebView.pauseTimers();
            }
        }

        // Pause the ad or it will continue to consume resources in the background on the free flavor.
        if (BuildConfig.FLAVOR.contentEquals("free")) {
            // Pause the ad.
            AdHelper.pauseAd(findViewById(R.id.adview));
        }
    }

    @Override
    public void onDestroy() {
        // Unregister the Orbot status broadcast receiver.
        this.unregisterReceiver(orbotStatusBroadcastReceiver);

        // Close the bookmarks cursor and database.
        bookmarksCursor.close();
        bookmarksDatabaseHelper.close();

        // Run the default commands.
        super.onDestroy();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu.  This adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.webview_options_menu, menu);

        // Store a handle for the options menu so it can be used by `onOptionsItemSelected()` and `updatePrivacyIcons()`.
        optionsMenu = menu;

        // Set the initial status of the privacy icons.  `false` does not call `invalidateOptionsMenu` as the last step.
        updatePrivacyIcons(false);

        // Get handles for the menu items.
        MenuItem toggleFirstPartyCookiesMenuItem = menu.findItem(R.id.toggle_first_party_cookies);
        MenuItem toggleThirdPartyCookiesMenuItem = menu.findItem(R.id.toggle_third_party_cookies);
        MenuItem toggleDomStorageMenuItem = menu.findItem(R.id.toggle_dom_storage);
        MenuItem toggleSaveFormDataMenuItem = menu.findItem(R.id.toggle_save_form_data);  // Form data can be removed once the minimum API >= 26.
        MenuItem clearFormDataMenuItem = menu.findItem(R.id.clear_form_data);  // Form data can be removed once the minimum API >= 26.
        MenuItem refreshMenuItem = menu.findItem(R.id.refresh);
        MenuItem adConsentMenuItem = menu.findItem(R.id.ad_consent);

        // Only display third-party cookies if API >= 21
        toggleThirdPartyCookiesMenuItem.setVisible(Build.VERSION.SDK_INT >= 21);

        // Only display the form data menu items if the API < 26.
        toggleSaveFormDataMenuItem.setVisible(Build.VERSION.SDK_INT < 26);
        clearFormDataMenuItem.setVisible(Build.VERSION.SDK_INT < 26);

        // Disable the clear form data menu item if the API >= 26 so that the status of the main Clear Data is calculated correctly.
        clearFormDataMenuItem.setEnabled(Build.VERSION.SDK_INT < 26);

        // Only show Ad Consent if this is the free flavor.
        adConsentMenuItem.setVisible(BuildConfig.FLAVOR.contentEquals("free"));

        // Get the shared preferences.
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        // Get the dark theme and app bar preferences..
        boolean displayAdditionalAppBarIcons = sharedPreferences.getBoolean("display_additional_app_bar_icons", false);
        boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);

        // Set the status of the additional app bar icons.  Setting the refresh menu item to `SHOW_AS_ACTION_ALWAYS` makes it appear even on small devices like phones.
        if (displayAdditionalAppBarIcons) {
            toggleFirstPartyCookiesMenuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            toggleDomStorageMenuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            refreshMenuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
        } else { //Do not display the additional icons.
            toggleFirstPartyCookiesMenuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
            toggleDomStorageMenuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
            refreshMenuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
        }

        // Replace Refresh with Stop if a URL is already loading.
        if (currentWebView != null && currentWebView.getProgress() != 100) {
            // Set the title.
            refreshMenuItem.setTitle(R.string.stop);

            // If the icon is displayed in the AppBar, set it according to the theme.
            if (displayAdditionalAppBarIcons) {
                if (darkTheme) {
                    refreshMenuItem.setIcon(R.drawable.close_dark);
                } else {
                    refreshMenuItem.setIcon(R.drawable.close_light);
                }
            }
        }

        // Done.
        return true;
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // Get handles for the menu items.
        MenuItem addOrEditDomain = menu.findItem(R.id.add_or_edit_domain);
        MenuItem firstPartyCookiesMenuItem = menu.findItem(R.id.toggle_first_party_cookies);
        MenuItem thirdPartyCookiesMenuItem = menu.findItem(R.id.toggle_third_party_cookies);
        MenuItem domStorageMenuItem = menu.findItem(R.id.toggle_dom_storage);
        MenuItem saveFormDataMenuItem = menu.findItem(R.id.toggle_save_form_data);  // Form data can be removed once the minimum API >= 26.
        MenuItem clearDataMenuItem = menu.findItem(R.id.clear_data);
        MenuItem clearCookiesMenuItem = menu.findItem(R.id.clear_cookies);
        MenuItem clearDOMStorageMenuItem = menu.findItem(R.id.clear_dom_storage);
        MenuItem clearFormDataMenuItem = menu.findItem(R.id.clear_form_data);  // Form data can be removed once the minimum API >= 26.
        MenuItem blocklistsMenuItem = menu.findItem(R.id.blocklists);
        MenuItem easyListMenuItem = menu.findItem(R.id.easylist);
        MenuItem easyPrivacyMenuItem = menu.findItem(R.id.easyprivacy);
        MenuItem fanboysAnnoyanceListMenuItem = menu.findItem(R.id.fanboys_annoyance_list);
        MenuItem fanboysSocialBlockingListMenuItem = menu.findItem(R.id.fanboys_social_blocking_list);
        MenuItem ultraListMenuItem = menu.findItem(R.id.ultralist);
        MenuItem ultraPrivacyMenuItem = menu.findItem(R.id.ultraprivacy);
        MenuItem blockAllThirdPartyRequestsMenuItem = menu.findItem(R.id.block_all_third_party_requests);
        MenuItem fontSizeMenuItem = menu.findItem(R.id.font_size);
        MenuItem swipeToRefreshMenuItem = menu.findItem(R.id.swipe_to_refresh);
        MenuItem wideViewportMenuItem = menu.findItem(R.id.wide_viewport);
        MenuItem displayImagesMenuItem = menu.findItem(R.id.display_images);
        MenuItem nightModeMenuItem = menu.findItem(R.id.night_mode);
        MenuItem proxyThroughOrbotMenuItem = menu.findItem(R.id.proxy_through_orbot);

        // Get a handle for the cookie manager.
        CookieManager cookieManager = CookieManager.getInstance();

        // Initialize the current user agent string and the font size.
        String currentUserAgent = getString(R.string.user_agent_privacy_browser);
        int fontSize = 100;

        // Set items that require the current web view to be populated.  It will be null when the program is first opened, as `onPrepareOptionsMenu()` is called before the first WebView is initialized.
        if (currentWebView != null) {
            // Set the add or edit domain text.
            if (currentWebView.getDomainSettingsApplied()) {
                addOrEditDomain.setTitle(R.string.edit_domain_settings);
            } else {
                addOrEditDomain.setTitle(R.string.add_domain_settings);
            }

            // Get the current user agent from the WebView.
            currentUserAgent = currentWebView.getSettings().getUserAgentString();

            // Get the current font size from the
            fontSize = currentWebView.getSettings().getTextZoom();

            // Set the status of the menu item checkboxes.
            domStorageMenuItem.setChecked(currentWebView.getSettings().getDomStorageEnabled());
            saveFormDataMenuItem.setChecked(currentWebView.getSettings().getSaveFormData());  // Form data can be removed once the minimum API >= 26.
            easyListMenuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.EASYLIST));
            easyPrivacyMenuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.EASYPRIVACY));
            fanboysAnnoyanceListMenuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.FANBOYS_ANNOYANCE_LIST));
            fanboysSocialBlockingListMenuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.FANBOYS_SOCIAL_BLOCKING_LIST));
            ultraListMenuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.ULTRALIST));
            ultraPrivacyMenuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.ULTRAPRIVACY));
            blockAllThirdPartyRequestsMenuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.THIRD_PARTY_REQUESTS));
            swipeToRefreshMenuItem.setChecked(currentWebView.getSwipeToRefresh());
            wideViewportMenuItem.setChecked(currentWebView.getSettings().getUseWideViewPort());
            displayImagesMenuItem.setChecked(currentWebView.getSettings().getLoadsImagesAutomatically());
            nightModeMenuItem.setChecked(currentWebView.getNightMode());

            // Initialize the display names for the blocklists with the number of blocked requests.
            blocklistsMenuItem.setTitle(getString(R.string.blocklists) + " - " + currentWebView.getRequestsCount(NestedScrollWebView.BLOCKED_REQUESTS));
            easyListMenuItem.setTitle(currentWebView.getRequestsCount(NestedScrollWebView.EASYLIST) + " - " + getString(R.string.easylist));
            easyPrivacyMenuItem.setTitle(currentWebView.getRequestsCount(NestedScrollWebView.EASYPRIVACY) + " - " + getString(R.string.easyprivacy));
            fanboysAnnoyanceListMenuItem.setTitle(currentWebView.getRequestsCount(NestedScrollWebView.FANBOYS_ANNOYANCE_LIST) + " - " + getString(R.string.fanboys_annoyance_list));
            fanboysSocialBlockingListMenuItem.setTitle(currentWebView.getRequestsCount(NestedScrollWebView.FANBOYS_SOCIAL_BLOCKING_LIST) + " - " + getString(R.string.fanboys_social_blocking_list));
            ultraListMenuItem.setTitle(currentWebView.getRequestsCount(NestedScrollWebView.ULTRALIST) + " - " + getString(R.string.ultralist));
            ultraPrivacyMenuItem.setTitle(currentWebView.getRequestsCount(NestedScrollWebView.ULTRAPRIVACY) + " - " + getString(R.string.ultraprivacy));
            blockAllThirdPartyRequestsMenuItem.setTitle(currentWebView.getRequestsCount(NestedScrollWebView.THIRD_PARTY_REQUESTS) + " - " + getString(R.string.block_all_third_party_requests));

            // Only modify third-party cookies if the API >= 21.
            if (Build.VERSION.SDK_INT >= 21) {
                // Set the status of the third-party cookies checkbox.
                thirdPartyCookiesMenuItem.setChecked(cookieManager.acceptThirdPartyCookies(currentWebView));

                // Enable third-party cookies if first-party cookies are enabled.
                thirdPartyCookiesMenuItem.setEnabled(cookieManager.acceptCookie());
            }

            // Enable DOM Storage if JavaScript is enabled.
            domStorageMenuItem.setEnabled(currentWebView.getSettings().getJavaScriptEnabled());
        }

        // Set the status of the menu item checkboxes.
        firstPartyCookiesMenuItem.setChecked(cookieManager.acceptCookie());
        proxyThroughOrbotMenuItem.setChecked(proxyThroughOrbot);

        // Enable Clear Cookies if there are any.
        clearCookiesMenuItem.setEnabled(cookieManager.hasCookies());

        // Get the application's private data directory, which will be something like `/data/user/0/com.stoutner.privacybrowser.standard`, which links to `/data/data/com.stoutner.privacybrowser.standard`.
        String privateDataDirectoryString = getApplicationInfo().dataDir;

        // Get a count of the number of files in the Local Storage directory.
        File localStorageDirectory = new File (privateDataDirectoryString + "/app_webview/Local Storage/");
        int localStorageDirectoryNumberOfFiles = 0;
        if (localStorageDirectory.exists()) {
            // `Objects.requireNonNull` removes a lint warning that `localStorageDirectory.list` might produce a null pointed exception if it is dereferenced.
            localStorageDirectoryNumberOfFiles = Objects.requireNonNull(localStorageDirectory.list()).length;
        }

        // Get a count of the number of files in the IndexedDB directory.
        File indexedDBDirectory = new File (privateDataDirectoryString + "/app_webview/IndexedDB");
        int indexedDBDirectoryNumberOfFiles = 0;
        if (indexedDBDirectory.exists()) {
            // `Objects.requireNonNull` removes a lint warning that `indexedDBDirectory.list` might produce a null pointed exception if it is dereferenced.
            indexedDBDirectoryNumberOfFiles = Objects.requireNonNull(indexedDBDirectory.list()).length;
        }

        // Enable Clear DOM Storage if there is any.
        clearDOMStorageMenuItem.setEnabled(localStorageDirectoryNumberOfFiles > 0 || indexedDBDirectoryNumberOfFiles > 0);

        // Enable Clear Form Data is there is any.  This can be removed once the minimum API >= 26.
        if (Build.VERSION.SDK_INT < 26) {
            // Get the WebView database.
            WebViewDatabase webViewDatabase = WebViewDatabase.getInstance(this);

            // Enable the clear form data menu item if there is anything to clear.
            clearFormDataMenuItem.setEnabled(webViewDatabase.hasFormData());
        }

        // Enable Clear Data if any of the submenu items are enabled.
        clearDataMenuItem.setEnabled(clearCookiesMenuItem.isEnabled() || clearDOMStorageMenuItem.isEnabled() || clearFormDataMenuItem.isEnabled());

        // Disable Fanboy's Social Blocking List menu item if Fanboy's Annoyance List is checked.
        fanboysSocialBlockingListMenuItem.setEnabled(!fanboysAnnoyanceListMenuItem.isChecked());

        // Select the current user agent menu item.  A switch statement cannot be used because the user agents are not compile time constants.
        if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[0])) {  // Privacy Browser.
            menu.findItem(R.id.user_agent_privacy_browser).setChecked(true);
        } else if (currentUserAgent.equals(webViewDefaultUserAgent)) {  // WebView Default.
            menu.findItem(R.id.user_agent_webview_default).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[2])) {  // Firefox on Android.
            menu.findItem(R.id.user_agent_firefox_on_android).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[3])) {  // Chrome on Android.
            menu.findItem(R.id.user_agent_chrome_on_android).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[4])) {  // Safari on iOS.
            menu.findItem(R.id.user_agent_safari_on_ios).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[5])) {  // Firefox on Linux.
            menu.findItem(R.id.user_agent_firefox_on_linux).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[6])) {  // Chromium on Linux.
            menu.findItem(R.id.user_agent_chromium_on_linux).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[7])) {  // Firefox on Windows.
            menu.findItem(R.id.user_agent_firefox_on_windows).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[8])) {  // Chrome on Windows.
            menu.findItem(R.id.user_agent_chrome_on_windows).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[9])) {  // Edge on Windows.
            menu.findItem(R.id.user_agent_edge_on_windows).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[10])) {  // Internet Explorer on Windows.
            menu.findItem(R.id.user_agent_internet_explorer_on_windows).setChecked(true);
        } else if (currentUserAgent.equals(getResources().getStringArray(R.array.user_agent_data)[11])) {  // Safari on macOS.
            menu.findItem(R.id.user_agent_safari_on_macos).setChecked(true);
        } else {  // Custom user agent.
            menu.findItem(R.id.user_agent_custom).setChecked(true);
        }

        // Set the font size title.
        fontSizeMenuItem.setTitle(getString(R.string.font_size) + " - " + fontSize + "%");

        // Run all the other default commands.
        super.onPrepareOptionsMenu(menu);

        // Display the menu.
        return true;
    }

    @Override
    // Remove Android Studio's warning about the dangers of using SetJavaScriptEnabled.
    @SuppressLint("SetJavaScriptEnabled")
    public boolean onOptionsItemSelected(MenuItem menuItem) {
        // Get the selected menu item ID.
        int menuItemId = menuItem.getItemId();

        // Get a handle for the shared preferences.
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        // Get a handle for the cookie manager.
        CookieManager cookieManager = CookieManager.getInstance();

        // Run the commands that correlate to the selected menu item.
        switch (menuItemId) {
            case R.id.toggle_javascript:
                // Toggle the JavaScript status.
                currentWebView.getSettings().setJavaScriptEnabled(!currentWebView.getSettings().getJavaScriptEnabled());

                // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
                updatePrivacyIcons(true);

                // Display a `Snackbar`.
                if (currentWebView.getSettings().getJavaScriptEnabled()) {  // JavaScrip is enabled.
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.javascript_enabled, Snackbar.LENGTH_SHORT).show();
                } else if (cookieManager.acceptCookie()) {  // JavaScript is disabled, but first-party cookies are enabled.
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.javascript_disabled, Snackbar.LENGTH_SHORT).show();
                } else {  // Privacy mode.
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.privacy_mode, Snackbar.LENGTH_SHORT).show();
                }

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.add_or_edit_domain:
                if (currentWebView.getDomainSettingsApplied()) {  // Edit the current domain settings.
                    // Reapply the domain settings on returning to `MainWebViewActivity`.
                    reapplyDomainSettingsOnRestart = true;

                    // Create an intent to launch the domains activity.
                    Intent domainsIntent = new Intent(this, DomainsActivity.class);

                    // Add the extra information to the intent.
                    domainsIntent.putExtra("load_domain", currentWebView.getDomainSettingsDatabaseId());
                    domainsIntent.putExtra("close_on_back", true);
                    domainsIntent.putExtra("current_url", currentWebView.getUrl());

                    // Get the current certificate.
                    SslCertificate sslCertificate = currentWebView.getCertificate();

                    // Check to see if the SSL certificate is populated.
                    if (sslCertificate != null) {
                        // Extract the certificate to strings.
                        String issuedToCName = sslCertificate.getIssuedTo().getCName();
                        String issuedToOName = sslCertificate.getIssuedTo().getOName();
                        String issuedToUName = sslCertificate.getIssuedTo().getUName();
                        String issuedByCName = sslCertificate.getIssuedBy().getCName();
                        String issuedByOName = sslCertificate.getIssuedBy().getOName();
                        String issuedByUName = sslCertificate.getIssuedBy().getUName();
                        long startDateLong = sslCertificate.getValidNotBeforeDate().getTime();
                        long endDateLong = sslCertificate.getValidNotAfterDate().getTime();

                        // Add the certificate to the intent.
                        domainsIntent.putExtra("ssl_issued_to_cname", issuedToCName);
                        domainsIntent.putExtra("ssl_issued_to_oname", issuedToOName);
                        domainsIntent.putExtra("ssl_issued_to_uname", issuedToUName);
                        domainsIntent.putExtra("ssl_issued_by_cname", issuedByCName);
                        domainsIntent.putExtra("ssl_issued_by_oname", issuedByOName);
                        domainsIntent.putExtra("ssl_issued_by_uname", issuedByUName);
                        domainsIntent.putExtra("ssl_start_date", startDateLong);
                        domainsIntent.putExtra("ssl_end_date", endDateLong);
                    }

                    // Check to see if the current IP addresses have been received.
                    if (currentWebView.hasCurrentIpAddresses()) {
                        // Add the current IP addresses to the intent.
                        domainsIntent.putExtra("current_ip_addresses", currentWebView.getCurrentIpAddresses());
                    }

                    // Make it so.
                    startActivity(domainsIntent);
                } else {  // Add a new domain.
                    // Apply the new domain settings on returning to `MainWebViewActivity`.
                    reapplyDomainSettingsOnRestart = true;

                    // Get the current domain
                    Uri currentUri = Uri.parse(currentWebView.getUrl());
                    String currentDomain = currentUri.getHost();

                    // Initialize the database handler.  The `0` specifies the database version, but that is ignored and set instead using a constant in `DomainsDatabaseHelper`.
                    DomainsDatabaseHelper domainsDatabaseHelper = new DomainsDatabaseHelper(this, null, null, 0);

                    // Create the domain and store the database ID.
                    int newDomainDatabaseId = domainsDatabaseHelper.addDomain(currentDomain);

                    // Create an intent to launch the domains activity.
                    Intent domainsIntent = new Intent(this, DomainsActivity.class);

                    // Add the extra information to the intent.
                    domainsIntent.putExtra("load_domain", newDomainDatabaseId);
                    domainsIntent.putExtra("close_on_back", true);
                    domainsIntent.putExtra("current_url", currentWebView.getUrl());

                    // Get the current certificate.
                    SslCertificate sslCertificate = currentWebView.getCertificate();

                    // Check to see if the SSL certificate is populated.
                    if (sslCertificate != null) {
                        // Extract the certificate to strings.
                        String issuedToCName = sslCertificate.getIssuedTo().getCName();
                        String issuedToOName = sslCertificate.getIssuedTo().getOName();
                        String issuedToUName = sslCertificate.getIssuedTo().getUName();
                        String issuedByCName = sslCertificate.getIssuedBy().getCName();
                        String issuedByOName = sslCertificate.getIssuedBy().getOName();
                        String issuedByUName = sslCertificate.getIssuedBy().getUName();
                        long startDateLong = sslCertificate.getValidNotBeforeDate().getTime();
                        long endDateLong = sslCertificate.getValidNotAfterDate().getTime();

                        // Add the certificate to the intent.
                        domainsIntent.putExtra("ssl_issued_to_cname", issuedToCName);
                        domainsIntent.putExtra("ssl_issued_to_oname", issuedToOName);
                        domainsIntent.putExtra("ssl_issued_to_uname", issuedToUName);
                        domainsIntent.putExtra("ssl_issued_by_cname", issuedByCName);
                        domainsIntent.putExtra("ssl_issued_by_oname", issuedByOName);
                        domainsIntent.putExtra("ssl_issued_by_uname", issuedByUName);
                        domainsIntent.putExtra("ssl_start_date", startDateLong);
                        domainsIntent.putExtra("ssl_end_date", endDateLong);
                    }

                    // Check to see if the current IP addresses have been received.
                    if (currentWebView.hasCurrentIpAddresses()) {
                        // Add the current IP addresses to the intent.
                        domainsIntent.putExtra("current_ip_addresses", currentWebView.getCurrentIpAddresses());
                    }

                    // Make it so.
                    startActivity(domainsIntent);
                }

                // Consume the event.
                return true;

            case R.id.toggle_first_party_cookies:
                // Switch the first-party cookie status.
                cookieManager.setAcceptCookie(!cookieManager.acceptCookie());

                // Store the first-party cookie status.
                currentWebView.setAcceptFirstPartyCookies(cookieManager.acceptCookie());

                // Update the menu checkbox.
                menuItem.setChecked(cookieManager.acceptCookie());

                // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
                updatePrivacyIcons(true);

                // Display a snackbar.
                if (cookieManager.acceptCookie()) {  // First-party cookies are enabled.
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.first_party_cookies_enabled, Snackbar.LENGTH_SHORT).show();
                } else if (currentWebView.getSettings().getJavaScriptEnabled()) {  // JavaScript is still enabled.
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.first_party_cookies_disabled, Snackbar.LENGTH_SHORT).show();
                } else {  // Privacy mode.
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.privacy_mode, Snackbar.LENGTH_SHORT).show();
                }

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.toggle_third_party_cookies:
                if (Build.VERSION.SDK_INT >= 21) {
                    // Switch the status of thirdPartyCookiesEnabled.
                    cookieManager.setAcceptThirdPartyCookies(currentWebView, !cookieManager.acceptThirdPartyCookies(currentWebView));

                    // Update the menu checkbox.
                    menuItem.setChecked(cookieManager.acceptThirdPartyCookies(currentWebView));

                    // Display a snackbar.
                    if (cookieManager.acceptThirdPartyCookies(currentWebView)) {
                        Snackbar.make(findViewById(R.id.webviewpager), R.string.third_party_cookies_enabled, Snackbar.LENGTH_SHORT).show();
                    } else {
                        Snackbar.make(findViewById(R.id.webviewpager), R.string.third_party_cookies_disabled, Snackbar.LENGTH_SHORT).show();
                    }

                    // Reload the current WebView.
                    currentWebView.reload();
                } // Else do nothing because SDK < 21.

                // Consume the event.
                return true;

            case R.id.toggle_dom_storage:
                // Toggle the status of domStorageEnabled.
                currentWebView.getSettings().setDomStorageEnabled(!currentWebView.getSettings().getDomStorageEnabled());

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.getSettings().getDomStorageEnabled());

                // Update the privacy icon.  `true` refreshes the app bar icons.
                updatePrivacyIcons(true);

                // Display a snackbar.
                if (currentWebView.getSettings().getDomStorageEnabled()) {
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.dom_storage_enabled, Snackbar.LENGTH_SHORT).show();
                } else {
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.dom_storage_disabled, Snackbar.LENGTH_SHORT).show();
                }

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            // Form data can be removed once the minimum API >= 26.
            case R.id.toggle_save_form_data:
                // Switch the status of saveFormDataEnabled.
                currentWebView.getSettings().setSaveFormData(!currentWebView.getSettings().getSaveFormData());

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.getSettings().getSaveFormData());

                // Display a snackbar.
                if (currentWebView.getSettings().getSaveFormData()) {
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.form_data_enabled, Snackbar.LENGTH_SHORT).show();
                } else {
                    Snackbar.make(findViewById(R.id.webviewpager), R.string.form_data_disabled, Snackbar.LENGTH_SHORT).show();
                }

                // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
                updatePrivacyIcons(true);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.clear_cookies:
                Snackbar.make(findViewById(R.id.webviewpager), R.string.cookies_deleted, Snackbar.LENGTH_LONG)
                        .setAction(R.string.undo, v -> {
                            // Do nothing because everything will be handled by `onDismissed()` below.
                        })
                        .addCallback(new Snackbar.Callback() {
                            @SuppressLint("SwitchIntDef")  // Ignore the lint warning about not handling the other possible events as they are covered by `default:`.
                            @Override
                            public void onDismissed(Snackbar snackbar, int event) {
                                if (event != Snackbar.Callback.DISMISS_EVENT_ACTION) {  // The snackbar was dismissed without the undo button being pushed.
                                    // Delete the cookies, which command varies by SDK.
                                    if (Build.VERSION.SDK_INT < 21) {
                                        cookieManager.removeAllCookie();
                                    } else {
                                        cookieManager.removeAllCookies(null);
                                    }
                                }
                            }
                        })
                        .show();

                // Consume the event.
                return true;

            case R.id.clear_dom_storage:
                Snackbar.make(findViewById(R.id.webviewpager), R.string.dom_storage_deleted, Snackbar.LENGTH_LONG)
                        .setAction(R.string.undo, v -> {
                            // Do nothing because everything will be handled by `onDismissed()` below.
                        })
                        .addCallback(new Snackbar.Callback() {
                            @SuppressLint("SwitchIntDef")  // Ignore the lint warning about not handling the other possible events as they are covered by `default:`.
                            @Override
                            public void onDismissed(Snackbar snackbar, int event) {
                                if (event != Snackbar.Callback.DISMISS_EVENT_ACTION) {  // The snackbar was dismissed without the undo button being pushed.
                                    // Delete the DOM Storage.
                                    WebStorage webStorage = WebStorage.getInstance();
                                    webStorage.deleteAllData();

                                    // Initialize a handler to manually delete the DOM storage files and directories.
                                    Handler deleteDomStorageHandler = new Handler();

                                    // Setup a runnable to manually delete the DOM storage files and directories.
                                    Runnable deleteDomStorageRunnable = () -> {
                                        try {
                                            // Get a handle for the runtime.
                                            Runtime runtime = Runtime.getRuntime();

                                            // Get the application's private data directory, which will be something like `/data/user/0/com.stoutner.privacybrowser.standard`,
                                            // which links to `/data/data/com.stoutner.privacybrowser.standard`.
                                            String privateDataDirectoryString = getApplicationInfo().dataDir;

                                            // A string array must be used because the directory contains a space and `Runtime.exec` will otherwise not escape the string correctly.
                                            Process deleteLocalStorageProcess = runtime.exec(new String[]{"rm", "-rf", privateDataDirectoryString + "/app_webview/Local Storage/"});

                                            // Multiple commands must be used because `Runtime.exec()` does not like `*`.
                                            Process deleteIndexProcess = runtime.exec("rm -rf " + privateDataDirectoryString + "/app_webview/IndexedDB");
                                            Process deleteQuotaManagerProcess = runtime.exec("rm -f " + privateDataDirectoryString + "/app_webview/QuotaManager");
                                            Process deleteQuotaManagerJournalProcess = runtime.exec("rm -f " + privateDataDirectoryString + "/app_webview/QuotaManager-journal");
                                            Process deleteDatabasesProcess = runtime.exec("rm -rf " + privateDataDirectoryString + "/app_webview/databases");

                                            // Wait for the processes to finish.
                                            deleteLocalStorageProcess.waitFor();
                                            deleteIndexProcess.waitFor();
                                            deleteQuotaManagerProcess.waitFor();
                                            deleteQuotaManagerJournalProcess.waitFor();
                                            deleteDatabasesProcess.waitFor();
                                        } catch (Exception exception) {
                                            // Do nothing if an error is thrown.
                                        }
                                    };

                                    // Manually delete the DOM storage files after 200 milliseconds.
                                    deleteDomStorageHandler.postDelayed(deleteDomStorageRunnable, 200);
                                }
                            }
                        })
                        .show();

                // Consume the event.
                return true;

            // Form data can be remove once the minimum API >= 26.
            case R.id.clear_form_data:
                Snackbar.make(findViewById(R.id.webviewpager), R.string.form_data_deleted, Snackbar.LENGTH_LONG)
                        .setAction(R.string.undo, v -> {
                            // Do nothing because everything will be handled by `onDismissed()` below.
                        })
                        .addCallback(new Snackbar.Callback() {
                            @SuppressLint("SwitchIntDef")  // Ignore the lint warning about not handling the other possible events as they are covered by `default:`.
                            @Override
                            public void onDismissed(Snackbar snackbar, int event) {
                                if (event != Snackbar.Callback.DISMISS_EVENT_ACTION) {  // The snackbar was dismissed without the undo button being pushed.
                                    // Delete the form data.
                                    WebViewDatabase mainWebViewDatabase = WebViewDatabase.getInstance(getApplicationContext());
                                    mainWebViewDatabase.clearFormData();
                                }
                            }
                        })
                        .show();

                // Consume the event.
                return true;

            case R.id.easylist:
                // Toggle the EasyList status.
                currentWebView.enableBlocklist(NestedScrollWebView.EASYLIST, !currentWebView.isBlocklistEnabled(NestedScrollWebView.EASYLIST));

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.EASYLIST));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.easyprivacy:
                // Toggle the EasyPrivacy status.
                currentWebView.enableBlocklist(NestedScrollWebView.EASYPRIVACY, !currentWebView.isBlocklistEnabled(NestedScrollWebView.EASYPRIVACY));

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.EASYPRIVACY));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.fanboys_annoyance_list:
                // Toggle Fanboy's Annoyance List status.
                currentWebView.enableBlocklist(NestedScrollWebView.FANBOYS_ANNOYANCE_LIST, !currentWebView.isBlocklistEnabled(NestedScrollWebView.FANBOYS_ANNOYANCE_LIST));

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.FANBOYS_ANNOYANCE_LIST));

                // Update the staus of Fanboy's Social Blocking List.
                MenuItem fanboysSocialBlockingListMenuItem = optionsMenu.findItem(R.id.fanboys_social_blocking_list);
                fanboysSocialBlockingListMenuItem.setEnabled(!currentWebView.isBlocklistEnabled(NestedScrollWebView.FANBOYS_ANNOYANCE_LIST));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.fanboys_social_blocking_list:
                // Toggle Fanboy's Social Blocking List status.
                currentWebView.enableBlocklist(NestedScrollWebView.FANBOYS_SOCIAL_BLOCKING_LIST, !currentWebView.isBlocklistEnabled(NestedScrollWebView.FANBOYS_SOCIAL_BLOCKING_LIST));

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.FANBOYS_SOCIAL_BLOCKING_LIST));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.ultralist:
                // Toggle the UltraList status.
                currentWebView.enableBlocklist(NestedScrollWebView.ULTRALIST, !currentWebView.isBlocklistEnabled(NestedScrollWebView.ULTRALIST));

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.ULTRALIST));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.ultraprivacy:
                // Toggle the UltraPrivacy status.
                currentWebView.enableBlocklist(NestedScrollWebView.ULTRAPRIVACY, !currentWebView.isBlocklistEnabled(NestedScrollWebView.ULTRAPRIVACY));

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.ULTRAPRIVACY));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.block_all_third_party_requests:
                //Toggle the third-party requests blocker status.
                currentWebView.enableBlocklist(NestedScrollWebView.THIRD_PARTY_REQUESTS, !currentWebView.isBlocklistEnabled(NestedScrollWebView.THIRD_PARTY_REQUESTS));

                // Update the menu checkbox.
                menuItem.setChecked(currentWebView.isBlocklistEnabled(NestedScrollWebView.THIRD_PARTY_REQUESTS));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_privacy_browser:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[0]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_webview_default:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString("");

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_firefox_on_android:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[2]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_chrome_on_android:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[3]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_safari_on_ios:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[4]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_firefox_on_linux:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[5]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_chromium_on_linux:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[6]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_firefox_on_windows:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[7]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_chrome_on_windows:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[8]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_edge_on_windows:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[9]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_internet_explorer_on_windows:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[10]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_safari_on_macos:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(getResources().getStringArray(R.array.user_agent_data)[11]);

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.user_agent_custom:
                // Update the user agent.
                currentWebView.getSettings().setUserAgentString(sharedPreferences.getString("custom_user_agent", getString(R.string.custom_user_agent_default_value)));

                // Reload the current WebView.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.font_size:
                // Instantiate the font size dialog.
                DialogFragment fontSizeDialogFragment = FontSizeDialog.displayDialog(currentWebView.getSettings().getTextZoom());

                // Show the font size dialog.
                fontSizeDialogFragment.show(getSupportFragmentManager(), getString(R.string.font_size));

                // Consume the event.
                return true;

            case R.id.swipe_to_refresh:
                // Toggle the stored status of swipe to refresh.
                currentWebView.setSwipeToRefresh(!currentWebView.getSwipeToRefresh());

                // Get a handle for the swipe refresh layout.
                SwipeRefreshLayout swipeRefreshLayout = findViewById(R.id.swiperefreshlayout);

                // Update the swipe refresh layout.
                if (currentWebView.getSwipeToRefresh()) {  // Swipe to refresh is enabled.
                    // Only enable the swipe refresh layout if the WebView is scrolled to the top.  It is updated every time the scroll changes.
                    swipeRefreshLayout.setEnabled(currentWebView.getY() == 0);
                } else {  // Swipe to refresh is disabled.
                    // Disable the swipe refresh layout.
                    swipeRefreshLayout.setEnabled(false);
                }

                // Consume the event.
                return true;

            case R.id.wide_viewport:
                // Toggle the viewport.
                currentWebView.getSettings().setUseWideViewPort(!currentWebView.getSettings().getUseWideViewPort());

                // Consume the event.
                return true;

            case R.id.display_images:
                if (currentWebView.getSettings().getLoadsImagesAutomatically()) {  // Images are currently loaded automatically.
                    // Disable loading of images.
                    currentWebView.getSettings().setLoadsImagesAutomatically(false);

                    // Reload the website to remove existing images.
                    currentWebView.reload();
                } else {  // Images are not currently loaded automatically.
                    // Enable loading of images.  Missing images will be loaded without the need for a reload.
                    currentWebView.getSettings().setLoadsImagesAutomatically(true);
                }

                // Consume the event.
                return true;

            case R.id.night_mode:
                // Toggle night mode.
                currentWebView.setNightMode(!currentWebView.getNightMode());

                // Enable or disable JavaScript according to night mode, the global preference, and any domain settings.
                if (currentWebView.getNightMode()) {  // Night mode is enabled, which requires JavaScript.
                    // Enable JavaScript.
                    currentWebView.getSettings().setJavaScriptEnabled(true);
                } else if (currentWebView.getDomainSettingsApplied()) {  // Night mode is disabled and domain settings are applied.  Set JavaScript according to the domain settings.
                    // Apply the JavaScript preference that was stored the last time domain settings were loaded.
                    currentWebView.getSettings().setJavaScriptEnabled(currentWebView.getDomainSettingsJavaScriptEnabled());
                } else {  // Night mode is disabled and domain settings are not applied.  Set JavaScript according to the global preference.
                    // Apply the JavaScript preference.
                    currentWebView.getSettings().setJavaScriptEnabled(sharedPreferences.getBoolean("javascript", false));
                }

                // Update the privacy icons.
                updatePrivacyIcons(false);

                // Reload the website.
                currentWebView.reload();

                // Consume the event.
                return true;

            case R.id.find_on_page:
                // Get a handle for the views.
                Toolbar toolbar = findViewById(R.id.toolbar);
                LinearLayout findOnPageLinearLayout = findViewById(R.id.find_on_page_linearlayout);
                EditText findOnPageEditText = findViewById(R.id.find_on_page_edittext);

                // Set the minimum height of the find on page linear layout to match the toolbar.
                findOnPageLinearLayout.setMinimumHeight(toolbar.getHeight());

                // Hide the toolbar.
                toolbar.setVisibility(View.GONE);

                // Show the find on page linear layout.
                findOnPageLinearLayout.setVisibility(View.VISIBLE);

                // Display the keyboard.  The app must wait 200 ms before running the command to work around a bug in Android.
                // http://stackoverflow.com/questions/5520085/android-show-softkeyboard-with-showsoftinput-is-not-working
                findOnPageEditText.postDelayed(() -> {
                    // Set the focus on `findOnPageEditText`.
                    findOnPageEditText.requestFocus();

                    // Get a handle for the input method manager.
                    InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

                    // Remove the lint warning below that the input method manager might be null.
                    assert inputMethodManager != null;

                    // Display the keyboard.  `0` sets no input flags.
                    inputMethodManager.showSoftInput(findOnPageEditText, 0);
                }, 200);

                // Consume the event.
                return true;

            case R.id.print:
                // Get a print manager instance.
                PrintManager printManager = (PrintManager) getSystemService(Context.PRINT_SERVICE);

                // Remove the lint error below that print manager might be null.
                assert printManager != null;

                // Create a print document adapter from the current WebView.
                PrintDocumentAdapter printDocumentAdapter = currentWebView.createPrintDocumentAdapter();

                // Print the document.
                printManager.print(getString(R.string.privacy_browser_web_page), printDocumentAdapter, null);

                // Consume the event.
                return true;

            case R.id.save_as_image:
                // Instantiate the save webpage image dialog.
                DialogFragment saveWebpageImageDialogFragment = new SaveWebpageImageDialog();

                // Show the save webpage image dialog.
                saveWebpageImageDialogFragment.show(getSupportFragmentManager(), getString(R.string.save_as_image));

                // Consume the event.
                return true;

            case R.id.add_to_homescreen:
                // Instantiate the create home screen shortcut dialog.
                DialogFragment createHomeScreenShortcutDialogFragment = CreateHomeScreenShortcutDialog.createDialog(currentWebView.getTitle(), currentWebView.getUrl(),
                        currentWebView.getFavoriteOrDefaultIcon());

                // Show the create home screen shortcut dialog.
                createHomeScreenShortcutDialogFragment.show(getSupportFragmentManager(), getString(R.string.create_shortcut));

                // Consume the event.
                return true;

            case R.id.view_source:
                // Create an intent to launch the view source activity.
                Intent viewSourceIntent = new Intent(this, ViewSourceActivity.class);

                // Add the variables to the intent.
                viewSourceIntent.putExtra("user_agent", currentWebView.getSettings().getUserAgentString());
                viewSourceIntent.putExtra("current_url", currentWebView.getUrl());

                // Make it so.
                startActivity(viewSourceIntent);

                // Consume the event.
                return true;

            case R.id.share_url:
                // Setup the share string.
                String shareString = currentWebView.getTitle() + " – " + currentWebView.getUrl();

                // Create the share intent.
                Intent shareIntent = new Intent(Intent.ACTION_SEND);
                shareIntent.putExtra(Intent.EXTRA_TEXT, shareString);
                shareIntent.setType("text/plain");

                // Make it so.
                startActivity(Intent.createChooser(shareIntent, getString(R.string.share_url)));

                // Consume the event.
                return true;

            case R.id.open_with_app:
                // Open the URL with an outside app.
                openWithApp(currentWebView.getUrl());

                // Consume the event.
                return true;

            case R.id.open_with_browser:
                // Open the URL with an outside browser.
                openWithBrowser(currentWebView.getUrl());

                // Consume the event.
                return true;

            case R.id.proxy_through_orbot:
                // Toggle the proxy through Orbot variable.
                proxyThroughOrbot = !proxyThroughOrbot;

                // Apply the proxy through Orbot settings.
                applyProxyThroughOrbot(true);

                // Consume the event.
                return true;

            case R.id.refresh:
                if (menuItem.getTitle().equals(getString(R.string.refresh))) {  // The refresh button was pushed.
                    // Reload the current WebView.
                    currentWebView.reload();
                } else {  // The stop button was pushed.
                    // Stop the loading of the WebView.
                    currentWebView.stopLoading();
                }

                // Consume the event.
                return true;

            case R.id.ad_consent:
                // Instantiate the ad consent dialog.
                DialogFragment adConsentDialogFragment = new AdConsentDialog();

                // Display the ad consent dialog.
                adConsentDialogFragment.show(getSupportFragmentManager(), getString(R.string.ad_consent));

                // Consume the event.
                return true;

            default:
                // Don't consume the event.
                return super.onOptionsItemSelected(menuItem);
        }
    }

    // removeAllCookies is deprecated, but it is required for API < 21.
    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
        // Get the menu item ID.
        int menuItemId = menuItem.getItemId();

        // Get a handle for the shared preferences.
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        // Run the commands that correspond to the selected menu item.
        switch (menuItemId) {
            case R.id.clear_and_exit:
                // Clear and exit Privacy Browser.
                clearAndExit();
                break;

            case R.id.home:
                // Select the homepage based on the proxy through Orbot status.
                if (proxyThroughOrbot) {
                    // Load the Tor homepage.
                    loadUrl(sharedPreferences.getString("tor_homepage", getString(R.string.tor_homepage_default_value)));
                } else {
                    // Load the normal homepage.
                    loadUrl(sharedPreferences.getString("homepage", getString(R.string.homepage_default_value)));
                }
                break;

            case R.id.back:
                if (currentWebView.canGoBack()) {
                    // Get the current web back forward list.
                    WebBackForwardList webBackForwardList = currentWebView.copyBackForwardList();

                    // Get the previous entry URL.
                    String previousUrl = webBackForwardList.getItemAtIndex(webBackForwardList.getCurrentIndex() - 1).getUrl();

                    // Apply the domain settings.
                    applyDomainSettings(currentWebView, previousUrl, false, false);

                    // Load the previous website in the history.
                    currentWebView.goBack();
                }
                break;

            case R.id.forward:
                if (currentWebView.canGoForward()) {
                    // Get the current web back forward list.
                    WebBackForwardList webBackForwardList = currentWebView.copyBackForwardList();

                    // Get the next entry URL.
                    String nextUrl = webBackForwardList.getItemAtIndex(webBackForwardList.getCurrentIndex() + 1).getUrl();

                    // Apply the domain settings.
                    applyDomainSettings(currentWebView, nextUrl, false, false);

                    // Load the next website in the history.
                    currentWebView.goForward();
                }
                break;

            case R.id.history:
                // Instantiate the URL history dialog.
                DialogFragment urlHistoryDialogFragment = UrlHistoryDialog.loadBackForwardList(currentWebView.getWebViewFragmentId());

                // Show the URL history dialog.
                urlHistoryDialogFragment.show(getSupportFragmentManager(), getString(R.string.history));
                break;

            case R.id.requests:
                // Populate the resource requests.
                RequestsActivity.resourceRequests = currentWebView.getResourceRequests();

                // Create an intent to launch the Requests activity.
                Intent requestsIntent = new Intent(this, RequestsActivity.class);

                // Add the block third-party requests status to the intent.
                requestsIntent.putExtra("block_all_third_party_requests", currentWebView.isBlocklistEnabled(NestedScrollWebView.THIRD_PARTY_REQUESTS));

                // Make it so.
                startActivity(requestsIntent);
                break;

            case R.id.downloads:
                // Launch the system Download Manager.
                Intent downloadManagerIntent = new Intent(DownloadManager.ACTION_VIEW_DOWNLOADS);

                // Launch as a new task so that Download Manager and Privacy Browser show as separate windows in the recent tasks list.
                downloadManagerIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

                startActivity(downloadManagerIntent);
                break;

            case R.id.domains:
                // Set the flag to reapply the domain settings on restart when returning from Domain Settings.
                reapplyDomainSettingsOnRestart = true;

                // Launch the domains activity.
                Intent domainsIntent = new Intent(this, DomainsActivity.class);

                // Add the extra information to the intent.
                domainsIntent.putExtra("current_url", currentWebView.getUrl());

                // Get the current certificate.
                SslCertificate sslCertificate = currentWebView.getCertificate();

                // Check to see if the SSL certificate is populated.
                if (sslCertificate != null) {
                    // Extract the certificate to strings.
                    String issuedToCName = sslCertificate.getIssuedTo().getCName();
                    String issuedToOName = sslCertificate.getIssuedTo().getOName();
                    String issuedToUName = sslCertificate.getIssuedTo().getUName();
                    String issuedByCName = sslCertificate.getIssuedBy().getCName();
                    String issuedByOName = sslCertificate.getIssuedBy().getOName();
                    String issuedByUName = sslCertificate.getIssuedBy().getUName();
                    long startDateLong = sslCertificate.getValidNotBeforeDate().getTime();
                    long endDateLong = sslCertificate.getValidNotAfterDate().getTime();

                    // Add the certificate to the intent.
                    domainsIntent.putExtra("ssl_issued_to_cname", issuedToCName);
                    domainsIntent.putExtra("ssl_issued_to_oname", issuedToOName);
                    domainsIntent.putExtra("ssl_issued_to_uname", issuedToUName);
                    domainsIntent.putExtra("ssl_issued_by_cname", issuedByCName);
                    domainsIntent.putExtra("ssl_issued_by_oname", issuedByOName);
                    domainsIntent.putExtra("ssl_issued_by_uname", issuedByUName);
                    domainsIntent.putExtra("ssl_start_date", startDateLong);
                    domainsIntent.putExtra("ssl_end_date", endDateLong);
                }

                // Check to see if the current IP addresses have been received.
                if (currentWebView.hasCurrentIpAddresses()) {
                    // Add the current IP addresses to the intent.
                    domainsIntent.putExtra("current_ip_addresses", currentWebView.getCurrentIpAddresses());
                }

                // Make it so.
                startActivity(domainsIntent);
                break;

            case R.id.settings:
                // Set the flag to reapply app settings on restart when returning from Settings.
                reapplyAppSettingsOnRestart = true;

                // Set the flag to reapply the domain settings on restart when returning from Settings.
                reapplyDomainSettingsOnRestart = true;

                // Launch the settings activity.
                Intent settingsIntent = new Intent(this, SettingsActivity.class);
                startActivity(settingsIntent);
                break;

            case R.id.import_export:
                // Launch the import/export activity.
                Intent importExportIntent = new Intent (this, ImportExportActivity.class);
                startActivity(importExportIntent);
                break;

            case R.id.logcat:
                // Launch the logcat activity.
                Intent logcatIntent = new Intent(this, LogcatActivity.class);
                startActivity(logcatIntent);
                break;

            case R.id.guide:
                // Launch `GuideActivity`.
                Intent guideIntent = new Intent(this, GuideActivity.class);
                startActivity(guideIntent);
                break;

            case R.id.about:
                // Create an intent to launch the about activity.
                Intent aboutIntent = new Intent(this, AboutActivity.class);

                // Create a string array for the blocklist versions.
                String[] blocklistVersions = new String[] {easyList.get(0).get(0)[0], easyPrivacy.get(0).get(0)[0], fanboysAnnoyanceList.get(0).get(0)[0], fanboysSocialList.get(0).get(0)[0],
                        ultraList.get(0).get(0)[0], ultraPrivacy.get(0).get(0)[0]};

                // Add the blocklist versions to the intent.
                aboutIntent.putExtra("blocklist_versions", blocklistVersions);

                // Make it so.
                startActivity(aboutIntent);
                break;
        }

        // Get a handle for the drawer layout.
        DrawerLayout drawerLayout = findViewById(R.id.drawerlayout);

        // Close the navigation drawer.
        drawerLayout.closeDrawer(GravityCompat.START);
        return true;
    }

    @Override
    public void onPostCreate(Bundle savedInstanceState) {
        // Run the default commands.
        super.onPostCreate(savedInstanceState);

        // Sync the state of the DrawerToggle after the default `onRestoreInstanceState()` has finished.  This creates the navigation drawer icon.
        actionBarDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(@NonNull Configuration newConfig) {
        // Run the default commands.
        super.onConfigurationChanged(newConfig);

        // Get the status bar pixel size.
        int statusBarResourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
        int statusBarPixelSize = getResources().getDimensionPixelSize(statusBarResourceId);

        // Get the resource density.
        float screenDensity = getResources().getDisplayMetrics().density;

        // Recalculate the drawer header padding.
        drawerHeaderPaddingLeftAndRight = (int) (15 * screenDensity);
        drawerHeaderPaddingTop = statusBarPixelSize + (int) (4 * screenDensity);
        drawerHeaderPaddingBottom = (int) (8 * screenDensity);

        // Reload the ad for the free flavor if not in full screen mode.
        if (BuildConfig.FLAVOR.contentEquals("free") && !inFullScreenBrowsingMode) {
            // Reload the ad.  The AdView is destroyed and recreated, which changes the ID, every time it is reloaded to handle possible rotations.
            AdHelper.loadAd(findViewById(R.id.adview), getApplicationContext(), getString(R.string.ad_unit_id));
        }

        // `invalidateOptionsMenu` should recalculate the number of action buttons from the menu to display on the app bar, but it doesn't because of the this bug:
        // https://code.google.com/p/android/issues/detail?id=20493#c8
        // ActivityCompat.invalidateOptionsMenu(this);
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View view, ContextMenu.ContextMenuInfo menuInfo) {
        // Store the hit test result.
        final WebView.HitTestResult hitTestResult = currentWebView.getHitTestResult();

        // Define the URL strings.
        final String imageUrl;
        final String linkUrl;

        // Get handles for the system managers.
        final ClipboardManager clipboardManager = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
        FragmentManager fragmentManager = getSupportFragmentManager();
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        // Remove the lint errors below that the clipboard manager might be null.
        assert clipboardManager != null;

        // Process the link according to the type.
        switch (hitTestResult.getType()) {
            // `SRC_ANCHOR_TYPE` is a link.
            case WebView.HitTestResult.SRC_ANCHOR_TYPE:
                // Get the target URL.
                linkUrl = hitTestResult.getExtra();

                // Set the target URL as the title of the `ContextMenu`.
                menu.setHeaderTitle(linkUrl);

                // Add an Open in New Tab entry.
                menu.add(R.string.open_in_new_tab).setOnMenuItemClickListener((MenuItem item) -> {
                    // Load the link URL in a new tab and move to it.
                    addNewTab(linkUrl, true);

                    // Consume the event.
                    return true;
                });

                // Add an Open in Background entry.
                menu.add(R.string.open_in_background).setOnMenuItemClickListener((MenuItem item) -> {
                    // Load the link URL in a new tab but do not move to it.
                    addNewTab(linkUrl, false);

                    // Consume the event.
                    return true;
                });

                // Add an Open with App entry.
                menu.add(R.string.open_with_app).setOnMenuItemClickListener((MenuItem item) -> {
                    openWithApp(linkUrl);

                    // Consume the event.
                    return true;
                });

                // Add an Open with Browser entry.
                menu.add(R.string.open_with_browser).setOnMenuItemClickListener((MenuItem item) -> {
                    openWithBrowser(linkUrl);

                    // Consume the event.
                    return true;
                });

                // Add a Copy URL entry.
                menu.add(R.string.copy_url).setOnMenuItemClickListener((MenuItem item) -> {
                    // Save the link URL in a `ClipData`.
                    ClipData srcAnchorTypeClipData = ClipData.newPlainText(getString(R.string.url), linkUrl);

                    // Set the `ClipData` as the clipboard's primary clip.
                    clipboardManager.setPrimaryClip(srcAnchorTypeClipData);

                    // Consume the event.
                    return true;
                });

                // Add a Download URL entry.
                menu.add(R.string.download_url).setOnMenuItemClickListener((MenuItem item) -> {
                    // Check if the download should be processed by an external app.
                    if (sharedPreferences.getBoolean("download_with_external_app", false)) {  // Download with an external app.
                        openUrlWithExternalApp(linkUrl);
                    } else {  // Download with Android's download manager.
                        // Check to see if the storage permission has already been granted.
                        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED) {  // The storage permission needs to be requested.
                            // Store the variables for future use by `onRequestPermissionsResult()`.
                            downloadUrl = linkUrl;
                            downloadContentDisposition = "none";
                            downloadContentLength = -1;

                            // Show a dialog if the user has previously denied the permission.
                            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {  // Show a dialog explaining the request first.
                                // Instantiate the download location permission alert dialog and set the download type to DOWNLOAD_FILE.
                                DialogFragment downloadLocationPermissionDialogFragment = DownloadLocationPermissionDialog.downloadType(DownloadLocationPermissionDialog.DOWNLOAD_FILE);

                                // Show the download location permission alert dialog.  The permission will be requested when the the dialog is closed.
                                downloadLocationPermissionDialogFragment.show(fragmentManager, getString(R.string.download_location));
                            } else {  // Show the permission request directly.
                                // Request the permission.  The download dialog will be launched by `onRequestPermissionResult()`.
                                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, DOWNLOAD_FILE_REQUEST_CODE);
                            }
                        } else {  // The storage permission has already been granted.
                            // Get a handle for the download file alert dialog.
                            DialogFragment downloadFileDialogFragment = DownloadFileDialog.fromUrl(linkUrl, "none", -1);

                            // Show the download file alert dialog.
                            downloadFileDialogFragment.show(fragmentManager, getString(R.string.download));
                        }
                    }

                    // Consume the event.
                    return true;
                });

                // Add a Cancel entry, which by default closes the context menu.
                menu.add(R.string.cancel);
                break;

            case WebView.HitTestResult.EMAIL_TYPE:
                // Get the target URL.
                linkUrl = hitTestResult.getExtra();

                // Set the target URL as the title of the `ContextMenu`.
                menu.setHeaderTitle(linkUrl);

                // Add a Write Email entry.
                menu.add(R.string.write_email).setOnMenuItemClickListener(item -> {
                    // Use `ACTION_SENDTO` instead of `ACTION_SEND` so that only email programs are launched.
                    Intent emailIntent = new Intent(Intent.ACTION_SENDTO);

                    // Parse the url and set it as the data for the `Intent`.
                    emailIntent.setData(Uri.parse("mailto:" + linkUrl));

                    // `FLAG_ACTIVITY_NEW_TASK` opens the email program in a new task instead as part of Privacy Browser.
                    emailIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

                    // Make it so.
                    startActivity(emailIntent);

                    // Consume the event.
                    return true;
                });

                // Add a Copy Email Address entry.
                menu.add(R.string.copy_email_address).setOnMenuItemClickListener(item -> {
                    // Save the email address in a `ClipData`.
                    ClipData srcEmailTypeClipData = ClipData.newPlainText(getString(R.string.email_address), linkUrl);

                    // Set the `ClipData` as the clipboard's primary clip.
                    clipboardManager.setPrimaryClip(srcEmailTypeClipData);

                    // Consume the event.
                    return true;
                });

                // Add a `Cancel` entry, which by default closes the `ContextMenu`.
                menu.add(R.string.cancel);
                break;

            // `IMAGE_TYPE` is an image.
            case WebView.HitTestResult.IMAGE_TYPE:
                // Get the image URL.
                imageUrl = hitTestResult.getExtra();

                // Set the image URL as the title of the context menu.
                menu.setHeaderTitle(imageUrl);

                // Add an Open in New Tab entry.
                menu.add(R.string.open_image_in_new_tab).setOnMenuItemClickListener((MenuItem item) -> {
                    // Load the image in a new tab.
                    addNewTab(imageUrl, true);

                    // Consume the event.
                    return true;
                });

                // Add a View Image entry.
                menu.add(R.string.view_image).setOnMenuItemClickListener(item -> {
                    // Load the image in the current tab.
                    loadUrl(imageUrl);

                    // Consume the event.
                    return true;
                });

                // Add a Download Image entry.
                menu.add(R.string.download_image).setOnMenuItemClickListener((MenuItem item) -> {
                    // Check if the download should be processed by an external app.
                    if (sharedPreferences.getBoolean("download_with_external_app", false)) {  // Download with an external app.
                        openUrlWithExternalApp(imageUrl);
                    } else {  // Download with Android's download manager.
                        // Check to see if the storage permission has already been granted.
                        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED) {  // The storage permission needs to be requested.
                            // Store the image URL for use by `onRequestPermissionResult()`.
                            downloadImageUrl = imageUrl;

                            // Show a dialog if the user has previously denied the permission.
                            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {  // Show a dialog explaining the request first.
                                // Instantiate the download location permission alert dialog and set the download type to DOWNLOAD_IMAGE.
                                DialogFragment downloadLocationPermissionDialogFragment = DownloadLocationPermissionDialog.downloadType(DownloadLocationPermissionDialog.DOWNLOAD_IMAGE);

                                // Show the download location permission alert dialog.  The permission will be requested when the dialog is closed.
                                downloadLocationPermissionDialogFragment.show(fragmentManager, getString(R.string.download_location));
                            } else {  // Show the permission request directly.
                                // Request the permission.  The download dialog will be launched by `onRequestPermissionResult()`.
                                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, DOWNLOAD_IMAGE_REQUEST_CODE);
                            }
                        } else {  // The storage permission has already been granted.
                            // Get a handle for the download image alert dialog.
                            DialogFragment downloadImageDialogFragment = DownloadImageDialog.imageUrl(imageUrl);

                            // Show the download image alert dialog.
                            downloadImageDialogFragment.show(fragmentManager, getString(R.string.download));
                        }
                    }

                    // Consume the event.
                    return true;
                });

                // Add a Copy URL entry.
                menu.add(R.string.copy_url).setOnMenuItemClickListener((MenuItem item) -> {
                    // Save the image URL in a clip data.
                    ClipData imageTypeClipData = ClipData.newPlainText(getString(R.string.url), imageUrl);

                    // Set the clip data as the clipboard's primary clip.
                    clipboardManager.setPrimaryClip(imageTypeClipData);

                    // Consume the event.
                    return true;
                });

                // Add an Open with App entry.
                menu.add(R.string.open_with_app).setOnMenuItemClickListener((MenuItem item) -> {
                    // Open the image URL with an external app.
                    openWithApp(imageUrl);

                    // Consume the event.
                    return true;
                });

                // Add an Open with Browser entry.
                menu.add(R.string.open_with_browser).setOnMenuItemClickListener((MenuItem item) -> {
                    // Open the image URL with an external browser.
                    openWithBrowser(imageUrl);

                    // Consume the event.
                    return true;
                });

                // Add a Cancel entry, which by default closes the context menu.
                menu.add(R.string.cancel);
                break;

            // `SRC_IMAGE_ANCHOR_TYPE` is an image that is also a link.
            case WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE:
                // Get the image URL.
                imageUrl = hitTestResult.getExtra();

                // Instantiate a handler.
                Handler handler = new Handler();

                // Get a message from the handler.
                Message message = handler.obtainMessage();

                // Request the image details from the last touched node be returned in the message.
                currentWebView.requestFocusNodeHref(message);

                // Get the link URL from the message data.
                linkUrl = message.getData().getString("url");

                // Set the link URL as the title of the context menu.
                menu.setHeaderTitle(linkUrl);

                // Add an Open in New Tab entry.
                menu.add(R.string.open_in_new_tab).setOnMenuItemClickListener((MenuItem item) -> {
                    // Load the link URL in a new tab and move to it.
                    addNewTab(linkUrl, true);

                    // Consume the event.
                    return true;
                });

                // Add an Open in Background entry.
                menu.add(R.string.open_in_background).setOnMenuItemClickListener((MenuItem item) -> {
                    // Lod the link URL in a new tab but do not move to it.
                    addNewTab(linkUrl, false);

                    // Consume the event.
                    return true;
                });

                // Add an Open Image in New Tab entry.
                menu.add(R.string.open_image_in_new_tab).setOnMenuItemClickListener((MenuItem item) -> {
                    // Load the image in a new tab and move to it.
                    addNewTab(imageUrl, true);

                    // Consume the event.
                    return true;
                });

                // Add a View Image entry.
                menu.add(R.string.view_image).setOnMenuItemClickListener((MenuItem item) -> {
                   // View the image in the current tab.
                   loadUrl(imageUrl);

                   // Consume the event.
                   return true;
                });

                // Add a Download Image entry.
                menu.add(R.string.download_image).setOnMenuItemClickListener((MenuItem item) -> {
                    // Check if the download should be processed by an external app.
                    if (sharedPreferences.getBoolean("download_with_external_app", false)) {  // Download with an external app.
                        openUrlWithExternalApp(imageUrl);
                    } else {  // Download with Android's download manager.
                        // Check to see if the storage permission has already been granted.
                        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED) {  // The storage permission needs to be requested.
                            // Store the image URL for use by `onRequestPermissionResult()`.
                            downloadImageUrl = imageUrl;

                            // Show a dialog if the user has previously denied the permission.
                            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {  // Show a dialog explaining the request first.
                                // Instantiate the download location permission alert dialog and set the download type to DOWNLOAD_IMAGE.
                                DialogFragment downloadLocationPermissionDialogFragment = DownloadLocationPermissionDialog.downloadType(DownloadLocationPermissionDialog.DOWNLOAD_IMAGE);

                                // Show the download location permission alert dialog.  The permission will be requested when the dialog is closed.
                                downloadLocationPermissionDialogFragment.show(fragmentManager, getString(R.string.download_location));
                            } else {  // Show the permission request directly.
                                // Request the permission.  The download dialog will be launched by `onRequestPermissionResult()`.
                                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, DOWNLOAD_IMAGE_REQUEST_CODE);
                            }
                        } else {  // The storage permission has already been granted.
                            // Get a handle for the download image alert dialog.
                            DialogFragment downloadImageDialogFragment = DownloadImageDialog.imageUrl(imageUrl);

                            // Show the download image alert dialog.
                            downloadImageDialogFragment.show(fragmentManager, getString(R.string.download));
                        }
                    }

                    // Consume the event.
                    return true;
                });

                // Add a Copy URL entry.
                menu.add(R.string.copy_url).setOnMenuItemClickListener((MenuItem item) -> {
                    // Save the link URL in a clip data.
                    ClipData srcImageAnchorTypeClipData = ClipData.newPlainText(getString(R.string.url), linkUrl);

                    // Set the clip data as the clipboard's primary clip.
                    clipboardManager.setPrimaryClip(srcImageAnchorTypeClipData);

                    // Consume the event.
                    return true;
                });

                // Add an Open with App entry.
                menu.add(R.string.open_with_app).setOnMenuItemClickListener((MenuItem item) -> {
                    // Open the link URL with an external app.
                    openWithApp(linkUrl);

                    // Consume the event.
                    return true;
                });

                // Add an Open with Browser entry.
                menu.add(R.string.open_with_browser).setOnMenuItemClickListener((MenuItem item) -> {
                    // Open the link URL with an external browser.
                    openWithBrowser(linkUrl);

                    // Consume the event.
                    return true;
                });

                // Add a cancel entry, which by default closes the context menu.
                menu.add(R.string.cancel);
                break;
        }
    }

    @Override
    public void onCreateBookmark(DialogFragment dialogFragment, Bitmap favoriteIconBitmap) {
        // Get a handle for the bookmarks list view.
        ListView bookmarksListView = findViewById(R.id.bookmarks_drawer_listview);

        // Get the dialog.
        Dialog dialog = dialogFragment.getDialog();

        // Remove the incorrect lint warning below that the dialog might be null.
        assert dialog != null;

        // Get the views from the dialog fragment.
        EditText createBookmarkNameEditText = dialog.findViewById(R.id.create_bookmark_name_edittext);
        EditText createBookmarkUrlEditText = dialog.findViewById(R.id.create_bookmark_url_edittext);

        // Extract the strings from the edit texts.
        String bookmarkNameString = createBookmarkNameEditText.getText().toString();
        String bookmarkUrlString = createBookmarkUrlEditText.getText().toString();

        // Create a favorite icon byte array output stream.
        ByteArrayOutputStream favoriteIconByteArrayOutputStream = new ByteArrayOutputStream();

        // Convert the favorite icon bitmap to a byte array.  `0` is for lossless compression (the only option for a PNG).
        favoriteIconBitmap.compress(Bitmap.CompressFormat.PNG, 0, favoriteIconByteArrayOutputStream);

        // Convert the favorite icon byte array stream to a byte array.
        byte[] favoriteIconByteArray = favoriteIconByteArrayOutputStream.toByteArray();

        // Display the new bookmark below the current items in the (0 indexed) list.
        int newBookmarkDisplayOrder = bookmarksListView.getCount();

        // Create the bookmark.
        bookmarksDatabaseHelper.createBookmark(bookmarkNameString, bookmarkUrlString, currentBookmarksFolder, newBookmarkDisplayOrder, favoriteIconByteArray);

        // Update the bookmarks cursor with the current contents of this folder.
        bookmarksCursor = bookmarksDatabaseHelper.getBookmarksByDisplayOrder(currentBookmarksFolder);

        // Update the list view.
        bookmarksCursorAdapter.changeCursor(bookmarksCursor);

        // Scroll to the new bookmark.
        bookmarksListView.setSelection(newBookmarkDisplayOrder);
    }

    @Override
    public void onCreateBookmarkFolder(DialogFragment dialogFragment, Bitmap favoriteIconBitmap) {
        // Get a handle for the bookmarks list view.
        ListView bookmarksListView = findViewById(R.id.bookmarks_drawer_listview);

        // Get the dialog.
        Dialog dialog = dialogFragment.getDialog();

        // Remove the incorrect lint warning below that the dialog might be null.
        assert dialog != null;

        // Get handles for the views in the dialog fragment.
        EditText createFolderNameEditText = dialog.findViewById(R.id.create_folder_name_edittext);
        RadioButton defaultFolderIconRadioButton = dialog.findViewById(R.id.create_folder_default_icon_radiobutton);
        ImageView folderIconImageView = dialog.findViewById(R.id.create_folder_default_icon);

        // Get new folder name string.
        String folderNameString = createFolderNameEditText.getText().toString();

        // Create a folder icon bitmap.
        Bitmap folderIconBitmap;

        // Set the folder icon bitmap according to the dialog.
        if (defaultFolderIconRadioButton.isChecked()) {  // Use the default folder icon.
            // Get the default folder icon drawable.
            Drawable folderIconDrawable = folderIconImageView.getDrawable();

            // Convert the folder icon drawable to a bitmap drawable.
            BitmapDrawable folderIconBitmapDrawable = (BitmapDrawable) folderIconDrawable;

            // Convert the folder icon bitmap drawable to a bitmap.
            folderIconBitmap = folderIconBitmapDrawable.getBitmap();
        } else {  // Use the WebView favorite icon.
            // Copy the favorite icon bitmap to the folder icon bitmap.
            folderIconBitmap = favoriteIconBitmap;
        }

        // Create a folder icon byte array output stream.
        ByteArrayOutputStream folderIconByteArrayOutputStream = new ByteArrayOutputStream();

        // Convert the folder icon bitmap to a byte array.  `0` is for lossless compression (the only option for a PNG).
        folderIconBitmap.compress(Bitmap.CompressFormat.PNG, 0, folderIconByteArrayOutputStream);

        // Convert the folder icon byte array stream to a byte array.
        byte[] folderIconByteArray = folderIconByteArrayOutputStream.toByteArray();

        // Move all the bookmarks down one in the display order.
        for (int i = 0; i < bookmarksListView.getCount(); i++) {
            int databaseId = (int) bookmarksListView.getItemIdAtPosition(i);
            bookmarksDatabaseHelper.updateDisplayOrder(databaseId, i + 1);
        }

        // Create the folder, which will be placed at the top of the `ListView`.
        bookmarksDatabaseHelper.createFolder(folderNameString, currentBookmarksFolder, folderIconByteArray);

        // Update the bookmarks cursor with the current contents of this folder.
        bookmarksCursor = bookmarksDatabaseHelper.getBookmarksByDisplayOrder(currentBookmarksFolder);

        // Update the `ListView`.
        bookmarksCursorAdapter.changeCursor(bookmarksCursor);

        // Scroll to the new folder.
        bookmarksListView.setSelection(0);
    }

    @Override
    public void onSaveBookmark(DialogFragment dialogFragment, int selectedBookmarkDatabaseId, Bitmap favoriteIconBitmap) {
        // Get the dialog.
        Dialog dialog = dialogFragment.getDialog();

        // Remove the incorrect lint warning below that the dialog might be null.
        assert dialog != null;

        // Get handles for the views from the dialog.
        EditText editBookmarkNameEditText = dialog.findViewById(R.id.edit_bookmark_name_edittext);
        EditText editBookmarkUrlEditText = dialog.findViewById(R.id.edit_bookmark_url_edittext);
        RadioButton currentBookmarkIconRadioButton = dialog.findViewById(R.id.edit_bookmark_current_icon_radiobutton);

        // Store the bookmark strings.
        String bookmarkNameString = editBookmarkNameEditText.getText().toString();
        String bookmarkUrlString = editBookmarkUrlEditText.getText().toString();

        // Update the bookmark.
        if (currentBookmarkIconRadioButton.isChecked()) {  // Update the bookmark without changing the favorite icon.
            bookmarksDatabaseHelper.updateBookmark(selectedBookmarkDatabaseId, bookmarkNameString, bookmarkUrlString);
        } else {  // Update the bookmark using the `WebView` favorite icon.
            // Create a favorite icon byte array output stream.
            ByteArrayOutputStream newFavoriteIconByteArrayOutputStream = new ByteArrayOutputStream();

            // Convert the favorite icon bitmap to a byte array.  `0` is for lossless compression (the only option for a PNG).
            favoriteIconBitmap.compress(Bitmap.CompressFormat.PNG, 0, newFavoriteIconByteArrayOutputStream);

            // Convert the favorite icon byte array stream to a byte array.
            byte[] newFavoriteIconByteArray = newFavoriteIconByteArrayOutputStream.toByteArray();

            //  Update the bookmark and the favorite icon.
            bookmarksDatabaseHelper.updateBookmark(selectedBookmarkDatabaseId, bookmarkNameString, bookmarkUrlString, newFavoriteIconByteArray);
        }

        // Update the bookmarks cursor with the current contents of this folder.
        bookmarksCursor = bookmarksDatabaseHelper.getBookmarksByDisplayOrder(currentBookmarksFolder);

        // Update the list view.
        bookmarksCursorAdapter.changeCursor(bookmarksCursor);
    }

    @Override
    public void onSaveBookmarkFolder(DialogFragment dialogFragment, int selectedFolderDatabaseId, Bitmap favoriteIconBitmap) {
        // Get the dialog.
        Dialog dialog = dialogFragment.getDialog();

        // Remove the incorrect lint warning below that the dialog might be null.
        assert dialog != null;

        // Get handles for the views from `dialogFragment`.
        EditText editFolderNameEditText = dialog.findViewById(R.id.edit_folder_name_edittext);
        RadioButton currentFolderIconRadioButton = dialog.findViewById(R.id.edit_folder_current_icon_radiobutton);
        RadioButton defaultFolderIconRadioButton = dialog.findViewById(R.id.edit_folder_default_icon_radiobutton);
        ImageView defaultFolderIconImageView = dialog.findViewById(R.id.edit_folder_default_icon_imageview);

        // Get the new folder name.
        String newFolderNameString = editFolderNameEditText.getText().toString();

        // Check if the favorite icon has changed.
        if (currentFolderIconRadioButton.isChecked()) {  // Only the name has changed.
            // Update the name in the database.
            bookmarksDatabaseHelper.updateFolder(selectedFolderDatabaseId, oldFolderNameString, newFolderNameString);
        } else if (!currentFolderIconRadioButton.isChecked() && newFolderNameString.equals(oldFolderNameString)) {  // Only the icon has changed.
            // Create the new folder icon Bitmap.
            Bitmap folderIconBitmap;

            // Populate the new folder icon bitmap.
            if (defaultFolderIconRadioButton.isChecked()) {
                // Get the default folder icon drawable.
                Drawable folderIconDrawable = defaultFolderIconImageView.getDrawable();

                // Convert the folder icon drawable to a bitmap drawable.
                BitmapDrawable folderIconBitmapDrawable = (BitmapDrawable) folderIconDrawable;

                // Convert the folder icon bitmap drawable to a bitmap.
                folderIconBitmap = folderIconBitmapDrawable.getBitmap();
            } else {  // Use the `WebView` favorite icon.
                // Copy the favorite icon bitmap to the folder icon bitmap.
                folderIconBitmap = favoriteIconBitmap;
            }

            // Create a folder icon byte array output stream.
            ByteArrayOutputStream newFolderIconByteArrayOutputStream = new ByteArrayOutputStream();

            // Convert the folder icon bitmap to a byte array.  `0` is for lossless compression (the only option for a PNG).
            folderIconBitmap.compress(Bitmap.CompressFormat.PNG, 0, newFolderIconByteArrayOutputStream);

            // Convert the folder icon byte array stream to a byte array.
            byte[] newFolderIconByteArray = newFolderIconByteArrayOutputStream.toByteArray();

            // Update the folder icon in the database.
            bookmarksDatabaseHelper.updateFolder(selectedFolderDatabaseId, newFolderIconByteArray);
        } else {  // The folder icon and the name have changed.
            // Get the new folder icon `Bitmap`.
            Bitmap folderIconBitmap;
            if (defaultFolderIconRadioButton.isChecked()) {
                // Get the default folder icon drawable.
                Drawable folderIconDrawable = defaultFolderIconImageView.getDrawable();

                // Convert the folder icon drawable to a bitmap drawable.
                BitmapDrawable folderIconBitmapDrawable = (BitmapDrawable) folderIconDrawable;

                // Convert the folder icon bitmap drawable to a bitmap.
                folderIconBitmap = folderIconBitmapDrawable.getBitmap();
            } else {  // Use the `WebView` favorite icon.
                // Copy the favorite icon bitmap to the folder icon bitmap.
                folderIconBitmap = favoriteIconBitmap;
            }

            // Create a folder icon byte array output stream.
            ByteArrayOutputStream newFolderIconByteArrayOutputStream = new ByteArrayOutputStream();

            // Convert the folder icon bitmap to a byte array.  `0` is for lossless compression (the only option for a PNG).
            folderIconBitmap.compress(Bitmap.CompressFormat.PNG, 0, newFolderIconByteArrayOutputStream);

            // Convert the folder icon byte array stream to a byte array.
            byte[] newFolderIconByteArray = newFolderIconByteArrayOutputStream.toByteArray();

            // Update the folder name and icon in the database.
            bookmarksDatabaseHelper.updateFolder(selectedFolderDatabaseId, oldFolderNameString, newFolderNameString, newFolderIconByteArray);
        }

        // Update the bookmarks cursor with the current contents of this folder.
        bookmarksCursor = bookmarksDatabaseHelper.getBookmarksByDisplayOrder(currentBookmarksFolder);

        // Update the `ListView`.
        bookmarksCursorAdapter.changeCursor(bookmarksCursor);
    }

    @Override
    public void onCloseDownloadLocationPermissionDialog(int downloadType) {
        switch (downloadType) {
            case DownloadLocationPermissionDialog.DOWNLOAD_FILE:
                // Request the WRITE_EXTERNAL_STORAGE permission with a file request code.
                ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, DOWNLOAD_FILE_REQUEST_CODE);
                break;

            case DownloadLocationPermissionDialog.DOWNLOAD_IMAGE:
                // Request the WRITE_EXTERNAL_STORAGE permission with an image request code.
                ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, DOWNLOAD_IMAGE_REQUEST_CODE);
                break;
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        // Get a handle for the fragment manager.
        FragmentManager fragmentManager = getSupportFragmentManager();

        switch (requestCode) {
            case DOWNLOAD_FILE_REQUEST_CODE:
                // Show the download file alert dialog.  When the dialog closes, the correct command will be used based on the permission status.
                DialogFragment downloadFileDialogFragment = DownloadFileDialog.fromUrl(downloadUrl, downloadContentDisposition, downloadContentLength);

                // On API 23, displaying the fragment must be delayed or the app will crash.
                if (Build.VERSION.SDK_INT == 23) {
                    new Handler().postDelayed(() -> downloadFileDialogFragment.show(fragmentManager, getString(R.string.download)), 500);
                } else {
                    downloadFileDialogFragment.show(fragmentManager, getString(R.string.download));
                }

                // Reset the download variables.
                downloadUrl = "";
                downloadContentDisposition = "";
                downloadContentLength = 0;
                break;

            case DOWNLOAD_IMAGE_REQUEST_CODE:
                // Show the download image alert dialog.  When the dialog closes, the correct command will be used based on the permission status.
                DialogFragment downloadImageDialogFragment = DownloadImageDialog.imageUrl(downloadImageUrl);

                // On API 23, displaying the fragment must be delayed or the app will crash.
                if (Build.VERSION.SDK_INT == 23) {
                    new Handler().postDelayed(() -> downloadImageDialogFragment.show(fragmentManager, getString(R.string.download)), 500);
                } else {
                    downloadImageDialogFragment.show(fragmentManager, getString(R.string.download));
                }

                // Reset the image URL variable.
                downloadImageUrl = "";
                break;

            case SAVE_WEBPAGE_IMAGE_REQUEST_CODE:
                // Check to see if the storage permission was granted.  If the dialog was canceled the grant result will be empty.
                if ((grantResults.length > 0) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) {  // The storage permission was granted.
                    // Save the webpage image.
                    new SaveWebpageImage(this, currentWebView).execute(saveWebsiteImageFilePath);
                } else {  // The storage permission was not granted.
                    // Display an error snackbar.
                    Snackbar.make(currentWebView, getString(R.string.cannot_use_location), Snackbar.LENGTH_LONG).show();
                }

                // Reset the save website image file path.
                saveWebsiteImageFilePath = "";
                break;
        }
    }

    @Override
    public void onDownloadImage(DialogFragment dialogFragment, String imageUrl) {
        // Download the image if it has an HTTP or HTTPS URI.
        if (imageUrl.startsWith("http")) {
            // Get a handle for the system `DOWNLOAD_SERVICE`.
            DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

            // Parse `imageUrl`.
            DownloadManager.Request downloadRequest = new DownloadManager.Request(Uri.parse(imageUrl));

            // Get a handle for the cookie manager.
            CookieManager cookieManager = CookieManager.getInstance();

            // Pass cookies to download manager if cookies are enabled.  This is required to download images from websites that require a login.
            // Code contributed 2017 Hendrik Knackstedt.  Copyright assigned to Soren Stoutner <soren@stoutner.com>.
            if (cookieManager.acceptCookie()) {
                // Get the cookies for `imageUrl`.
                String cookies = cookieManager.getCookie(imageUrl);

                // Add the cookies to `downloadRequest`.  In the HTTP request header, cookies are named `Cookie`.
                downloadRequest.addRequestHeader("Cookie", cookies);
            }

            // Get the dialog.
            Dialog dialog = dialogFragment.getDialog();

            // Remove the incorrect lint warning below that the dialog might be null.
            assert dialog != null;

            // Get the file name from the dialog fragment.
            EditText downloadImageNameEditText = dialog.findViewById(R.id.download_image_name);
            String imageName = downloadImageNameEditText.getText().toString();

            // Specify the download location.
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // External write permission granted.
                // Download to the public download directory.
                downloadRequest.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, imageName);
            } else {  // External write permission denied.
                // Download to the app's external download directory.
                downloadRequest.setDestinationInExternalFilesDir(this, Environment.DIRECTORY_DOWNLOADS, imageName);
            }

            // Allow `MediaScanner` to index the download if it is a media file.
            downloadRequest.allowScanningByMediaScanner();

            // Add the URL as the description for the download.
            downloadRequest.setDescription(imageUrl);

            // Show the download notification after the download is completed.
            downloadRequest.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);

            // Remove the lint warning below that `downloadManager` might be `null`.
            assert downloadManager != null;

            // Initiate the download.
            downloadManager.enqueue(downloadRequest);
        } else {  // The image is not an HTTP or HTTPS URI.
            Snackbar.make(currentWebView, R.string.cannot_download_image, Snackbar.LENGTH_INDEFINITE).show();
        }
    }

    @Override
    public void onDownloadFile(DialogFragment dialogFragment, String downloadUrl) {
        // Download the file if it has an HTTP or HTTPS URI.
        if (downloadUrl.startsWith("http")) {
            // Get a handle for the system `DOWNLOAD_SERVICE`.
            DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

            // Parse `downloadUrl`.
            DownloadManager.Request downloadRequest = new DownloadManager.Request(Uri.parse(downloadUrl));

            // Get a handle for the cookie manager.
            CookieManager cookieManager = CookieManager.getInstance();

            // Pass cookies to download manager if cookies are enabled.  This is required to download files from websites that require a login.
            // Code contributed 2017 Hendrik Knackstedt.  Copyright assigned to Soren Stoutner <soren@stoutner.com>.
            if (cookieManager.acceptCookie()) {
                // Get the cookies for `downloadUrl`.
                String cookies = cookieManager.getCookie(downloadUrl);

                // Add the cookies to `downloadRequest`.  In the HTTP request header, cookies are named `Cookie`.
                downloadRequest.addRequestHeader("Cookie", cookies);
            }

            // Get the dialog.
            Dialog dialog = dialogFragment.getDialog();

            // Remove the incorrect lint warning below that the dialog might be null.
            assert dialog != null;

            // Get the file name from the dialog.
            EditText downloadFileNameEditText = dialog.findViewById(R.id.download_file_name);
            String fileName = downloadFileNameEditText.getText().toString();

            // Specify the download location.
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // External write permission granted.
                // Download to the public download directory.
                downloadRequest.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);
            } else {  // External write permission denied.
                // Download to the app's external download directory.
                downloadRequest.setDestinationInExternalFilesDir(this, Environment.DIRECTORY_DOWNLOADS, fileName);
            }

            // Allow `MediaScanner` to index the download if it is a media file.
            downloadRequest.allowScanningByMediaScanner();

            // Add the URL as the description for the download.
            downloadRequest.setDescription(downloadUrl);

            // Show the download notification after the download is completed.
            downloadRequest.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);

            // Remove the lint warning below that `downloadManager` might be `null`.
            assert downloadManager != null;

            // Initiate the download.
            downloadManager.enqueue(downloadRequest);
        } else {  // The download is not an HTTP or HTTPS URI.
            Snackbar.make(currentWebView, R.string.cannot_download_file, Snackbar.LENGTH_INDEFINITE).show();
        }
    }

    // Override `onBackPressed` to handle the navigation drawer and and the WebViews.
    @Override
    public void onBackPressed() {
        // Get a handle for the drawer layout and the tab layout.
        DrawerLayout drawerLayout = findViewById(R.id.drawerlayout);
        TabLayout tabLayout = findViewById(R.id.tablayout);

        if (drawerLayout.isDrawerVisible(GravityCompat.START)) {  // The navigation drawer is open.
            // Close the navigation drawer.
            drawerLayout.closeDrawer(GravityCompat.START);
        } else if (drawerLayout.isDrawerVisible(GravityCompat.END)){  // The bookmarks drawer is open.
            if (currentBookmarksFolder.isEmpty()) {  // The home folder is displayed.
                // close the bookmarks drawer.
                drawerLayout.closeDrawer(GravityCompat.END);
            } else {  // A subfolder is displayed.
                // Place the former parent folder in `currentFolder`.
                currentBookmarksFolder = bookmarksDatabaseHelper.getParentFolderName(currentBookmarksFolder);

                // Load the new folder.
                loadBookmarksFolder();
            }
        } else if (displayingFullScreenVideo) {  // A full screen video is shown.
            // Get a handle for the layouts.
            FrameLayout rootFrameLayout = findViewById(R.id.root_framelayout);
            RelativeLayout mainContentRelativeLayout = findViewById(R.id.main_content_relativelayout);
            FrameLayout fullScreenVideoFrameLayout = findViewById(R.id.full_screen_video_framelayout);

            // Re-enable the screen timeout.
            fullScreenVideoFrameLayout.setKeepScreenOn(false);

            // Unset the full screen video flag.
            displayingFullScreenVideo = false;

            // Remove all the views from the full screen video frame layout.
            fullScreenVideoFrameLayout.removeAllViews();

            // Hide the full screen video frame layout.
            fullScreenVideoFrameLayout.setVisibility(View.GONE);

            // Enable the sliding drawers.
            drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED);

            // Show the main content relative layout.
            mainContentRelativeLayout.setVisibility(View.VISIBLE);

            // Apply the appropriate full screen mode flags.
            if (fullScreenBrowsingModeEnabled && inFullScreenBrowsingMode) {  // Privacy Browser is currently in full screen browsing mode.
                // Hide the app bar if specified.
                if (hideAppBar) {
                    // Get handles for the views.
                    LinearLayout tabsLinearLayout = findViewById(R.id.tabs_linearlayout);
                    ActionBar actionBar = getSupportActionBar();

                    // Remove the incorrect lint warning below that the action bar might be null.
                    assert actionBar != null;

                    // Hide the tab linear layout.
                    tabsLinearLayout.setVisibility(View.GONE);

                    // Hide the action bar.
                    actionBar.hide();
                }

                // Hide the banner ad in the free flavor.
                if (BuildConfig.FLAVOR.contentEquals("free")) {
                    AdHelper.hideAd(findViewById(R.id.adview));
                }

                // Remove the translucent status flag.  This is necessary so the root frame layout can fill the entire screen.
                getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);

                /* Hide the system bars.
                 * SYSTEM_UI_FLAG_FULLSCREEN hides the status bar at the top of the screen.
                 * SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN makes the root frame layout fill the area that is normally reserved for the status bar.
                 * SYSTEM_UI_FLAG_HIDE_NAVIGATION hides the navigation bar on the bottom or right of the screen.
                 * SYSTEM_UI_FLAG_IMMERSIVE_STICKY makes the status and navigation bars translucent and automatically re-hides them after they are shown.
                 */
                rootFrameLayout.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
                        View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
            } else {  // Switch to normal viewing mode.
                // Remove the `SYSTEM_UI` flags from the root frame layout.
                rootFrameLayout.setSystemUiVisibility(0);

                // Add the translucent status flag.
                getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            }

            // Reload the ad for the free flavor if not in full screen mode.
            if (BuildConfig.FLAVOR.contentEquals("free") && !inFullScreenBrowsingMode) {
                // Reload the ad.
                AdHelper.loadAd(findViewById(R.id.adview), getApplicationContext(), getString(R.string.ad_unit_id));
            }
        } else if (currentWebView.canGoBack()) {  // There is at least one item in the current WebView history.
            // Get the current web back forward list.
            WebBackForwardList webBackForwardList = currentWebView.copyBackForwardList();

            // Get the previous entry URL.
            String previousUrl = webBackForwardList.getItemAtIndex(webBackForwardList.getCurrentIndex() - 1).getUrl();

            // Apply the domain settings.
            applyDomainSettings(currentWebView, previousUrl, false, false);

            // Go back.
            currentWebView.goBack();
        } else if (tabLayout.getTabCount() > 1) {  // There are at least two tabs.
            // Close the current tab.
            closeCurrentTab();
        } else {  // There isn't anything to do in Privacy Browser.
            // Close Privacy Browser.  `finishAndRemoveTask()` also removes Privacy Browser from the recent app list.
            if (Build.VERSION.SDK_INT >= 21) {
                finishAndRemoveTask();
            } else {
                finish();
            }

            // Manually kill Privacy Browser.  Otherwise, it is glitchy when restarted.
            System.exit(0);
        }
    }

    // Process the results of a file browse.
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        // Run the default commands.
        super.onActivityResult(requestCode, resultCode, data);

        // Run the commands that correlate to the specified request code.
        switch (requestCode) {
            case FILE_UPLOAD_REQUEST_CODE:
                // File uploads only work on API >= 21.
                if (Build.VERSION.SDK_INT >= 21) {
                    // Pass the file to the WebView.
                    fileChooserCallback.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, data));
                }
                break;

            case BROWSE_SAVE_WEBPAGE_IMAGE_REQUEST_CODE:
                // Don't do anything if the user pressed back from the file picker.
                if (resultCode == Activity.RESULT_OK) {
                    // Get a handle for the save dialog fragment.
                    DialogFragment saveWebpageImageDialogFragment= (DialogFragment) getSupportFragmentManager().findFragmentByTag(getString(R.string.save_as_image));

                    // Only update the file name if the dialog still exists.
                    if (saveWebpageImageDialogFragment != null) {
                        // Get a handle for the save webpage image dialog.
                        Dialog saveWebpageImageDialog = saveWebpageImageDialogFragment.getDialog();

                        // Remove the incorrect lint warning below that the dialog might be null.
                        assert saveWebpageImageDialog != null;

                        // Get a handle for the file name edit text.
                        EditText fileNameEditText = saveWebpageImageDialog.findViewById(R.id.file_name_edittext);

                        // Instantiate the file name helper.
                        FileNameHelper fileNameHelper = new FileNameHelper();

                        // Get the file path if it isn't null.
                        if (data.getData() != null) {
                            // Convert the file name URI to a file name path.
                            String fileNamePath = fileNameHelper.convertUriToFileNamePath(data.getData());

                            // Set the file name path as the text of the file name edit text.
                            fileNameEditText.setText(fileNamePath);
                        }
                    }
                }
                break;
        }
    }

    private void loadUrlFromTextBox() {
        // Get a handle for the URL edit text.
        EditText urlEditText = findViewById(R.id.url_edittext);

        // Get the text from urlTextBox and convert it to a string.  trim() removes white spaces from the beginning and end of the string.
        String unformattedUrlString = urlEditText.getText().toString().trim();

        // Initialize the formatted URL string.
        String url = "";

        // Check to see if `unformattedUrlString` is a valid URL.  Otherwise, convert it into a search.
        if (unformattedUrlString.startsWith("content://")) {  // This is a Content URL.
            // Load the entire content URL.
            url = unformattedUrlString;
        } else if (Patterns.WEB_URL.matcher(unformattedUrlString).matches() || unformattedUrlString.startsWith("http://") || unformattedUrlString.startsWith("https://") ||
                unformattedUrlString.startsWith("file://")) {  // This is a standard URL.
            // Add `https://` at the beginning if there is no protocol.  Otherwise the app will segfault.
            if (!unformattedUrlString.startsWith("http") && !unformattedUrlString.startsWith("file://") && !unformattedUrlString.startsWith("content://")) {
                unformattedUrlString = "https://" + unformattedUrlString;
            }

            // Initialize `unformattedUrl`.
            URL unformattedUrl = null;

            // Convert `unformattedUrlString` to a `URL`, then to a `URI`, and then back to a `String`, which sanitizes the input and adds in any missing components.
            try {
                unformattedUrl = new URL(unformattedUrlString);
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }

            // The ternary operator (? :) makes sure that a null pointer exception is not thrown, which would happen if `.get` was called on a `null` value.
            String scheme = unformattedUrl != null ? unformattedUrl.getProtocol() : null;
            String authority = unformattedUrl != null ? unformattedUrl.getAuthority() : null;
            String path = unformattedUrl != null ? unformattedUrl.getPath() : null;
            String query = unformattedUrl != null ? unformattedUrl.getQuery() : null;
            String fragment = unformattedUrl != null ? unformattedUrl.getRef() : null;

            // Build the URI.
            Uri.Builder uri = new Uri.Builder();
            uri.scheme(scheme).authority(authority).path(path).query(query).fragment(fragment);

            // Decode the URI as a UTF-8 string in.
            try {
                url = URLDecoder.decode(uri.build().toString(), "UTF-8");
            } catch (UnsupportedEncodingException exception) {
                // Do nothing.  The formatted URL string will remain blank.
            }
        } else if (!unformattedUrlString.isEmpty()){  // This is not a URL, but rather a search string.
            // Create an encoded URL String.
            String encodedUrlString;

            // Sanitize the search input.
            try {
                encodedUrlString = URLEncoder.encode(unformattedUrlString, "UTF-8");
            } catch (UnsupportedEncodingException exception) {
                encodedUrlString = "";
            }

            // Add the base search URL.
            url = searchURL + encodedUrlString;
        }

        // Clear the focus from the URL edit text.  Otherwise, proximate typing in the box will retain the colorized formatting instead of being reset during refocus.
        urlEditText.clearFocus();

        // Make it so.
        loadUrl(url);
    }

    private void loadUrl(String url) {
        // Sanitize the URL.
        url = sanitizeUrl(url);

        // Apply the domain settings.
        applyDomainSettings(currentWebView, url, true, false);

        // Load the URL.
        currentWebView.loadUrl(url, customHeaders);
    }

    public void findPreviousOnPage(View view) {
        // Go to the previous highlighted phrase on the page.  `false` goes backwards instead of forwards.
        currentWebView.findNext(false);
    }

    public void findNextOnPage(View view) {
        // Go to the next highlighted phrase on the page. `true` goes forwards instead of backwards.
        currentWebView.findNext(true);
    }

    public void closeFindOnPage(View view) {
        // Get a handle for the views.
        Toolbar toolbar = findViewById(R.id.toolbar);
        LinearLayout findOnPageLinearLayout = findViewById(R.id.find_on_page_linearlayout);
        EditText findOnPageEditText = findViewById(R.id.find_on_page_edittext);

        // Delete the contents of `find_on_page_edittext`.
        findOnPageEditText.setText(null);

        // Clear the highlighted phrases if the WebView is not null.
        if (currentWebView != null) {
            currentWebView.clearMatches();
        }

        // Hide the find on page linear layout.
        findOnPageLinearLayout.setVisibility(View.GONE);

        // Show the toolbar.
        toolbar.setVisibility(View.VISIBLE);

        // Get a handle for the input method manager.
        InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

        // Remove the lint warning below that the input method manager might be null.
        assert inputMethodManager != null;

        // Hide the keyboard.
        inputMethodManager.hideSoftInputFromWindow(toolbar.getWindowToken(), 0);
    }

    @Override
    public void onApplyNewFontSize(DialogFragment dialogFragment) {
        // Get the dialog.
        Dialog dialog = dialogFragment.getDialog();

        // Remove the incorrect lint warning below tha the dialog might be null.
        assert dialog != null;

        // Get a handle for the font size edit text.
        EditText fontSizeEditText = dialog.findViewById(R.id.font_size_edittext);

        // Initialize the new font size variable with the current font size.
        int newFontSize = currentWebView.getSettings().getTextZoom();

        // Get the font size from the edit text.
        try {
            newFontSize = Integer.valueOf(fontSizeEditText.getText().toString());
        } catch (Exception exception) {
            // If the edit text does not contain a valid font size do nothing.
        }

        // Apply the new font size.
        currentWebView.getSettings().setTextZoom(newFontSize);
    }

    @Override
    public void onSaveWebpageImage(DialogFragment dialogFragment) {
        // Get the dialog.
        Dialog dialog = dialogFragment.getDialog();

        // Remove the incorrect lint warning below that the dialog might be null.
        assert dialog != null;

        // Get a handle for the file name edit text.
        EditText fileNameEditText = dialog.findViewById(R.id.file_name_edittext);

        // Get the file path string.
        saveWebsiteImageFilePath = fileNameEditText.getText().toString();

        // Check to see if the storage permission is needed.
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // The storage permission has been granted.
            // Save the webpage image.
            new SaveWebpageImage(this, currentWebView).execute(saveWebsiteImageFilePath);
        } else {  // The storage permission has not been granted.
            // Get the external private directory `File`.
            File externalPrivateDirectoryFile = getExternalFilesDir(null);

            // Remove the incorrect lint error below that the file might be null.
            assert externalPrivateDirectoryFile != null;

            // Get the external private directory string.
            String externalPrivateDirectory = externalPrivateDirectoryFile.toString();

            // Check to see if the file path is in the external private directory.
            if (saveWebsiteImageFilePath.startsWith(externalPrivateDirectory)) {  // The file path is in the external private directory.
                // Save the webpage image.
                new SaveWebpageImage(this, currentWebView).execute(saveWebsiteImageFilePath);
            } else {  // The file path is in a public directory.
                // Check if the user has previously denied the storage permission.
                if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {  // Show a dialog explaining the request first.
                    // Instantiate the storage permission alert dialog.
                    DialogFragment storagePermissionDialogFragment = new StoragePermissionDialog();

                    // Show the storage permission alert dialog.  The permission will be requested when the dialog is closed.
                    storagePermissionDialogFragment.show(getSupportFragmentManager(), getString(R.string.storage_permission));
                } else {  // Show the permission request directly.
                    // Request the write external storage permission.  The webpage image will be saved when it finishes.
                    ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, SAVE_WEBPAGE_IMAGE_REQUEST_CODE);
                }
            }
        }
    }

    @Override
    public void onCloseStoragePermissionDialog() {
        // Request the write external storage permission.  The webpage image will be saved when it finishes.
        ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, SAVE_WEBPAGE_IMAGE_REQUEST_CODE);
    }

    private void applyAppSettings() {
        // Initialize the app if this is the first run.  This is done here instead of in `onCreate()` to shorten the time that an unthemed background is displayed on app startup.
        if (webViewDefaultUserAgent == null) {
            initializeApp();
        }

        // Get a handle for the shared preferences.
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        // Store the values from the shared preferences in variables.
        incognitoModeEnabled = sharedPreferences.getBoolean("incognito_mode", false);
        boolean doNotTrackEnabled = sharedPreferences.getBoolean("do_not_track", false);
        sanitizeGoogleAnalytics = sharedPreferences.getBoolean("google_analytics", true);
        sanitizeFacebookClickIds = sharedPreferences.getBoolean("facebook_click_ids", true);
        sanitizeTwitterAmpRedirects = sharedPreferences.getBoolean("twitter_amp_redirects", true);
        proxyThroughOrbot = sharedPreferences.getBoolean("proxy_through_orbot", false);
        fullScreenBrowsingModeEnabled = sharedPreferences.getBoolean("full_screen_browsing_mode", false);
        hideAppBar = sharedPreferences.getBoolean("hide_app_bar", true);
        scrollAppBar = sharedPreferences.getBoolean("scroll_app_bar", true);

        // Get handles for the views that need to be modified.
        FrameLayout rootFrameLayout = findViewById(R.id.root_framelayout);
        AppBarLayout appBarLayout = findViewById(R.id.appbar_layout);
        ActionBar actionBar = getSupportActionBar();
        Toolbar toolbar = findViewById(R.id.toolbar);
        LinearLayout findOnPageLinearLayout = findViewById(R.id.find_on_page_linearlayout);
        LinearLayout tabsLinearLayout = findViewById(R.id.tabs_linearlayout);
        SwipeRefreshLayout swipeRefreshLayout = findViewById(R.id.swiperefreshlayout);

        // Remove the incorrect lint warning below that the action bar might be null.
        assert actionBar != null;

        // Apply the proxy through Orbot settings.
        applyProxyThroughOrbot(false);

        // Set Do Not Track status.
        if (doNotTrackEnabled) {
            customHeaders.put("DNT", "1");
        } else {
            customHeaders.remove("DNT");
        }

        // Get the current layout parameters.  Using coordinator layout parameters allows the `setBehavior()` command and using app bar layout parameters allows the `setScrollFlags()` command.
        CoordinatorLayout.LayoutParams swipeRefreshLayoutParams = (CoordinatorLayout.LayoutParams) swipeRefreshLayout.getLayoutParams();
        AppBarLayout.LayoutParams toolbarLayoutParams = (AppBarLayout.LayoutParams) toolbar.getLayoutParams();
        AppBarLayout.LayoutParams findOnPageLayoutParams = (AppBarLayout.LayoutParams) findOnPageLinearLayout.getLayoutParams();
        AppBarLayout.LayoutParams tabsLayoutParams = (AppBarLayout.LayoutParams) tabsLinearLayout.getLayoutParams();

        // Add the scrolling behavior to the layout parameters.
        if (scrollAppBar) {
            // Enable scrolling of the app bar.
            swipeRefreshLayoutParams.setBehavior(new AppBarLayout.ScrollingViewBehavior());
            toolbarLayoutParams.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS | AppBarLayout.LayoutParams.SCROLL_FLAG_SNAP);
            findOnPageLayoutParams.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS | AppBarLayout.LayoutParams.SCROLL_FLAG_SNAP);
            tabsLayoutParams.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS | AppBarLayout.LayoutParams.SCROLL_FLAG_SNAP);
        } else {
            // Disable scrolling of the app bar.
            swipeRefreshLayoutParams.setBehavior(null);
            toolbarLayoutParams.setScrollFlags(0);
            findOnPageLayoutParams.setScrollFlags(0);
            tabsLayoutParams.setScrollFlags(0);

            // Expand the app bar if it is currently collapsed.
            appBarLayout.setExpanded(true);
        }

        // Apply the modified layout parameters.
        swipeRefreshLayout.setLayoutParams(swipeRefreshLayoutParams);
        toolbar.setLayoutParams(toolbarLayoutParams);
        findOnPageLinearLayout.setLayoutParams(findOnPageLayoutParams);
        tabsLinearLayout.setLayoutParams(tabsLayoutParams);

        // Set the app bar scrolling for each WebView.
        for (int i = 0; i < webViewPagerAdapter.getCount(); i++) {
            // Get the WebView tab fragment.
            WebViewTabFragment webViewTabFragment = webViewPagerAdapter.getPageFragment(i);

            // Get the fragment view.
            View fragmentView = webViewTabFragment.getView();

            // Only modify the WebViews if they exist.
            if (fragmentView != null) {
                // Get the nested scroll WebView from the tab fragment.
                NestedScrollWebView nestedScrollWebView = fragmentView.findViewById(R.id.nestedscroll_webview);

                // Set the app bar scrolling.
                nestedScrollWebView.setNestedScrollingEnabled(scrollAppBar);
            }
        }

        // Update the full screen browsing mode settings.
        if (fullScreenBrowsingModeEnabled && inFullScreenBrowsingMode) {  // Privacy Browser is currently in full screen browsing mode.
            // Update the visibility of the app bar, which might have changed in the settings.
            if (hideAppBar) {
                // Hide the tab linear layout.
                tabsLinearLayout.setVisibility(View.GONE);

                // Hide the action bar.
                actionBar.hide();
            } else {
                // Show the tab linear layout.
                tabsLinearLayout.setVisibility(View.VISIBLE);

                // Show the action bar.
                actionBar.show();
            }

            // Hide the banner ad in the free flavor.
            if (BuildConfig.FLAVOR.contentEquals("free")) {
                AdHelper.hideAd(findViewById(R.id.adview));
            }

            // Remove the translucent status flag.  This is necessary so the root frame layout can fill the entire screen.
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);

            /* Hide the system bars.
             * SYSTEM_UI_FLAG_FULLSCREEN hides the status bar at the top of the screen.
             * SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN makes the root frame layout fill the area that is normally reserved for the status bar.
             * SYSTEM_UI_FLAG_HIDE_NAVIGATION hides the navigation bar on the bottom or right of the screen.
             * SYSTEM_UI_FLAG_IMMERSIVE_STICKY makes the status and navigation bars translucent and automatically re-hides them after they are shown.
             */
            rootFrameLayout.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
                    View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
        } else {  // Privacy Browser is not in full screen browsing mode.
            // Reset the full screen tracker, which could be true if Privacy Browser was in full screen mode before entering settings and full screen browsing was disabled.
            inFullScreenBrowsingMode = false;

            // Show the tab linear layout.
            tabsLinearLayout.setVisibility(View.VISIBLE);

            // Show the action bar.
            actionBar.show();

            // Show the banner ad in the free flavor.
            if (BuildConfig.FLAVOR.contentEquals("free")) {
                // Initialize the ads.  If this isn't the first run, `loadAd()` will be automatically called instead.
                AdHelper.initializeAds(findViewById(R.id.adview), getApplicationContext(), getSupportFragmentManager(), getString(R.string.google_app_id), getString(R.string.ad_unit_id));
            }

            // Remove the `SYSTEM_UI` flags from the root frame layout.
            rootFrameLayout.setSystemUiVisibility(0);

            // Add the translucent status flag.
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }
    }

    private void initializeApp() {
        // Get a handle for the shared preferences.
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        // Get the theme preference.
        boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);

        // Get a handle for the input method.
        InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

        // Remove the lint warning below that the input method manager might be null.
        assert inputMethodManager != null;

        // Initialize the foreground color spans for highlighting the URLs.  We have to use the deprecated `getColor()` until API >= 23.
        redColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.red_a700));
        initialGrayColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.gray_500));
        finalGrayColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.gray_500));

        // Get handles for the URL views.
        EditText urlEditText = findViewById(R.id.url_edittext);

        // Remove the formatting from the URL edit text when the user is editing the text.
        urlEditText.setOnFocusChangeListener((View v, boolean hasFocus) -> {
            if (hasFocus) {  // The user is editing the URL text box.
                // Remove the highlighting.
                urlEditText.getText().removeSpan(redColorSpan);
                urlEditText.getText().removeSpan(initialGrayColorSpan);
                urlEditText.getText().removeSpan(finalGrayColorSpan);
            } else {  // The user has stopped editing the URL text box.
                // Move to the beginning of the string.
                urlEditText.setSelection(0);

                // Reapply the highlighting.
                highlightUrlText();
            }
        });

        // Set the go button on the keyboard to load the URL in `urlTextBox`.
        urlEditText.setOnKeyListener((View v, int keyCode, KeyEvent event) -> {
            // If the event is a key-down event on the `enter` button, load the URL.
            if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) {
                // Load the URL into the mainWebView and consume the event.
                loadUrlFromTextBox();

                // If the enter key was pressed, consume the event.
                return true;
            } else {
                // If any other key was pressed, do not consume the event.
                return false;
            }
        });

        // Initialize the Orbot status and the waiting for Orbot trackers.
        orbotStatus = "unknown";
        waitingForOrbot = false;

        // Create an Orbot status `BroadcastReceiver`.
        orbotStatusBroadcastReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                // Store the content of the status message in `orbotStatus`.
                orbotStatus = intent.getStringExtra("org.torproject.android.intent.extra.STATUS");