]> gitweb.stoutner.com Git - PrivacyBrowserAndroid.git/blobdiff - app/src/main/java/com/stoutner/privacybrowser/activities/MainWebViewActivity.java
Workaround scrolling bug in WebView >= 99.0.4844.48. https://redmine.stoutner.com...
[PrivacyBrowserAndroid.git] / app / src / main / java / com / stoutner / privacybrowser / activities / MainWebViewActivity.java
index 0fd451611a28312b03479e36194e921e89c08878..3d27a4cf61d0782be71bbe673cc29dad58082b41 100644 (file)
@@ -1,26 +1,27 @@
 /*
- * Copyright © 2015-2021 Soren Stoutner <soren@stoutner.com>.
+ * Copyright © 2015-2022 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>.
+ * This file is part of Privacy Browser Android <https://www.stoutner.com/privacy-browser-android>.
  *
- * Privacy Browser is free software: you can redistribute it and/or modify
+ * Privacy Browser Android 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,
+ * Privacy Browser Android 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/>.
+ * along with Privacy Browser Android.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 package com.stoutner.privacybrowser.activities;
 
+import android.animation.ObjectAnimator;
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.app.Dialog;
@@ -78,6 +79,7 @@ import android.webkit.SslErrorHandler;
 import android.webkit.ValueCallback;
 import android.webkit.WebBackForwardList;
 import android.webkit.WebChromeClient;
+import android.webkit.WebResourceRequest;
 import android.webkit.WebResourceResponse;
 import android.webkit.WebSettings;
 import android.webkit.WebStorage;
@@ -123,7 +125,6 @@ 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;
@@ -132,7 +133,6 @@ import com.stoutner.privacybrowser.asynctasks.PrepareSaveDialog;
 import com.stoutner.privacybrowser.asynctasks.SaveUrl;
 import com.stoutner.privacybrowser.asynctasks.SaveWebpageImage;
 import com.stoutner.privacybrowser.dataclasses.PendingDialog;
-import com.stoutner.privacybrowser.dialogs.AdConsentDialog;
 import com.stoutner.privacybrowser.dialogs.CreateBookmarkDialog;
 import com.stoutner.privacybrowser.dialogs.CreateBookmarkFolderDialog;
 import com.stoutner.privacybrowser.dialogs.CreateHomeScreenShortcutDialog;
@@ -148,7 +148,6 @@ import com.stoutner.privacybrowser.dialogs.UrlHistoryDialog;
 import com.stoutner.privacybrowser.dialogs.ViewSslCertificateDialog;
 import com.stoutner.privacybrowser.dialogs.WaitingForProxyDialog;
 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.DomainsDatabaseHelper;
@@ -173,7 +172,6 @@ import java.net.URLEncoder;
 import java.text.NumberFormat;
 
 import java.util.ArrayList;
-import java.util.Calendar;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -189,42 +187,32 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         PinnedMismatchDialog.PinnedMismatchListener, PopulateBlocklists.PopulateBlocklistsListener, SaveDialog.SaveListener, UrlHistoryDialog.NavigateHistoryListener,
         WebViewTabFragment.NewTabListener {
 
-    // The executor service handles background tasks.  It is accessed from `ViewSourceActivity`.
+    // Define the public static variables.
     public static ExecutorService executorService = Executors.newFixedThreadPool(4);
-
-    // `orbotStatus` is public static so it can be accessed from `OrbotProxyHelper`.  It is also used in `onCreate()`, `onResume()`, and `applyProxy()`.
     public static String orbotStatus = "unknown";
-
-    // The WebView pager adapter is accessed from `HttpAuthenticationDialog`, `PinnedMismatchDialog`, and `SslCertificateErrorDialog`.  It is also used in `onCreate()`, `onResume()`, and `addTab()`.
-    public static WebViewPagerAdapter webViewPagerAdapter;
-
-    // `restartFromBookmarksActivity` is public static so it can be accessed from `BookmarksActivity`.  It is also used in `onRestart()`.
-    public static boolean restartFromBookmarksActivity;
-
-    // Define the public static variables.
     public static ArrayList<PendingDialog> pendingDialogsArrayList =  new ArrayList<>();
+    public static String proxyMode = ProxyHelper.NONE;
 
-    // `currentBookmarksFolder` is public static so it can be accessed from `BookmarksActivity`.  It is also used in `onCreate()`, `onBackPressed()`, `onCreateBookmark()`, `onCreateBookmarkFolder()`,
-    // `onSaveEditBookmark()`, `onSaveEditBookmarkFolder()`, and `loadBookmarksFolder()`.
+    // Declare the public static variables.
     public static String currentBookmarksFolder;
+    public static boolean restartFromBookmarksActivity;
+    public static WebViewPagerAdapter webViewPagerAdapter;
+
+    // Declare the public static views.
+    public static AppBarLayout appBarLayout;
 
     // 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 SETTINGS_CUSTOM_USER_AGENT = 11;
     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;
+    public final static int DOMAINS_CUSTOM_USER_AGENT = 12;
 
     // Define the start activity for result request codes.  The public static entry is accessed from `OpenDialog()`.
     private final int BROWSE_FILE_UPLOAD_REQUEST_CODE = 0;
     public final static int BROWSE_OPEN_REQUEST_CODE = 1;
 
-    // The proxy mode is public static so it can be accessed from `ProxyHelper()`.
-    // It is also used in `onRestart()`, `onPrepareOptionsMenu()`, `onOptionsItemSelected()`, `applyAppSettings()`, and `applyProxy()`.
-    // It will be updated in `applyAppSettings()`, but it needs to be initialized here or the first run of `onPrepareOptionsMenu()` crashes.
-    public static String proxyMode = ProxyHelper.NONE;
-
     // Define the saved instance state constants.
     private final String SAVED_STATE_ARRAY_LIST = "saved_state_array_list";
     private final String SAVED_NESTED_SCROLL_WEBVIEW_STATE_ARRAY_LIST = "saved_nested_scroll_webview_state_array_list";
@@ -267,10 +255,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
     private ForegroundColorSpan initialGrayColorSpan;
     private ForegroundColorSpan finalGrayColorSpan;
 
-    // `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;
 
@@ -294,30 +278,31 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
     private boolean sanitizeTwitterAmpRedirects;
 
     // Declare the class variables
-    private BroadcastReceiver orbotStatusBroadcastReceiver;
-    private String webViewDefaultUserAgent;
-    private boolean incognitoModeEnabled;
-    private boolean fullScreenBrowsingModeEnabled;
-    private boolean inFullScreenBrowsingMode;
+    private BookmarksDatabaseHelper bookmarksDatabaseHelper;
+    private boolean bottomAppBar;
+    private boolean displayingFullScreenVideo;
     private boolean downloadWithExternalApp;
+    private boolean fullScreenBrowsingModeEnabled;
     private boolean hideAppBar;
-    private boolean scrollAppBar;
-    private boolean bottomAppBar;
+    private boolean incognitoModeEnabled;
+    private boolean inFullScreenBrowsingMode;
     private boolean loadingNewIntent;
-    private boolean reapplyDomainSettingsOnRestart;
+    private BroadcastReceiver orbotStatusBroadcastReceiver;
+    private ProxyHelper proxyHelper;
     private boolean reapplyAppSettingsOnRestart;
-    private boolean displayingFullScreenVideo;
+    private boolean reapplyDomainSettingsOnRestart;
+    private boolean scrollAppBar;
     private boolean waitingForProxy;
+    private String webViewDefaultUserAgent;
 
     // Define the class variables.
-    private long lastScrollUpdate = 0;
+    private ObjectAnimator objectAnimator = new ObjectAnimator();
     private String saveUrlString = "";
 
     // Declare the class views.
     private FrameLayout rootFrameLayout;
     private DrawerLayout drawerLayout;
-    private RelativeLayout mainContentRelativeLayout;
-    private AppBarLayout appBarLayout;
+    private CoordinatorLayout coordinatorLayout;
     private Toolbar toolbar;
     private RelativeLayout urlRelativeLayout;
     private EditText urlEditText;
@@ -446,7 +431,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                                             contentResolverCursor.moveToFirst();
 
                                             // Get the file name from the cursor.
-                                            fileNameString = contentResolverCursor.getString(contentResolverCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
+                                            fileNameString = contentResolverCursor.getString(contentResolverCursor.getColumnIndexOrThrow(OpenableColumns.DISPLAY_NAME));
 
                                             // Close the cursor.
                                             contentResolverCursor.close();
@@ -456,7 +441,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                                         Snackbar.make(currentWebView, getString(R.string.file_saved) + "  " + fileNameString, Snackbar.LENGTH_SHORT).show();
                                     } catch (Exception exception) {
                                         // Display a snackbar with the exception.
-                                        Snackbar.make(currentWebView, getString(R.string.error_saving_file) + "  " + exception.toString(), Snackbar.LENGTH_INDEFINITE).show();
+                                        Snackbar.make(currentWebView, getString(R.string.error_saving_file) + "  " + exception, Snackbar.LENGTH_INDEFINITE).show();
                                     } finally {
                                         // Delete the temporary MHT file.
                                         //noinspection ResultOfMethodCallIgnored
@@ -469,7 +454,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                             });
                         } catch (IOException ioException) {
                             // Display a snackbar with the IO exception.
-                            Snackbar.make(currentWebView, getString(R.string.error_saving_file) + "  " + ioException.toString(), Snackbar.LENGTH_INDEFINITE).show();
+                            Snackbar.make(currentWebView, getString(R.string.error_saving_file) + "  " + ioException, Snackbar.LENGTH_INDEFINITE).show();
                         }
                     }
                 }
@@ -544,9 +529,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         }
 
         // Enable the drawing of the entire webpage.  This makes it possible to save a website image.  This must be done before anything else happens with the WebView.
-        if (Build.VERSION.SDK_INT >= 21) {
-            WebView.enableSlowWholeDocumentDraw();
-        }
+        //WebView.enableSlowWholeDocumentDraw();    Temporarily disabled due to <https://redmine.stoutner.com/issues/811>.
 
         // Set the theme.
         setTheme(R.style.PrivacyBrowser);
@@ -561,7 +544,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Get handles for the views.
         rootFrameLayout = findViewById(R.id.root_framelayout);
         drawerLayout = findViewById(R.id.drawerlayout);
-        mainContentRelativeLayout = findViewById(R.id.main_content_relativelayout);
+        coordinatorLayout = findViewById(R.id.coordinatorlayout);
         appBarLayout = findViewById(R.id.appbar_layout);
         toolbar = findViewById(R.id.toolbar);
         findOnPageLinearLayout = findViewById(R.id.find_on_page_linearlayout);
@@ -619,6 +602,9 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Store up to 100 tabs in memory.
         webViewPager.setOffscreenPageLimit(100);
 
+        // Instantiate the proxy helper.
+        proxyHelper = new ProxyHelper();
+
         // Initialize the app.
         initializeApp();
 
@@ -804,7 +790,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             applyProxy(false);
         }
 
-        // Reapply any system UI flags and the ad in the free flavor.
+        // Reapply any system UI flags.
         if (displayingFullScreenVideo || inFullScreenBrowsingMode) {  // The system is displaying a website or a video in full screen mode.
             /* Hide the system bars.
              * SYSTEM_UI_FLAG_FULLSCREEN hides the status bar at the top of the screen.
@@ -814,12 +800,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
              */
             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")) {  // The system in not in full screen mode.
-            // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-            View adView = findViewById(R.id.adview);
-
-            // Resume the ad.
-            AdHelper.resumeAd(adView);
         }
 
         // Show any pending dialogs.
@@ -862,15 +842,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         if (currentWebView != null) {
             currentWebView.pauseTimers();
         }
-
-        // Pause the ad or it will continue to consume resources in the background on the free flavor.
-        if (BuildConfig.FLAVOR.contentEquals("free")) {
-            // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-            View adView = findViewById(R.id.adview);
-
-            // Pause the ad.
-            AdHelper.pauseAd(adView);
-        }
     }
 
     @Override
@@ -951,9 +922,10 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Store a handle for the options menu so it can be used by `onOptionsItemSelected()` and `updatePrivacyIcons()`.
         optionsMenu = menu;
 
-        // Get handles for the class menu items.
+        // Get handles for the menu items.
         optionsPrivacyMenuItem = menu.findItem(R.id.javascript);
         optionsRefreshMenuItem = menu.findItem(R.id.refresh);
+        MenuItem bookmarksMenuItem = menu.findItem(R.id.bookmarks);
         optionsCookiesMenuItem = menu.findItem(R.id.cookies);
         optionsDomStorageMenuItem = menu.findItem(R.id.dom_storage);
         optionsSaveFormDataMenuItem = menu.findItem(R.id.save_form_data);  // Form data can be removed once the minimum API >= 26.
@@ -995,10 +967,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         optionsFontSizeMenuItem = menu.findItem(R.id.font_size);
         optionsAddOrEditDomainMenuItem = menu.findItem(R.id.add_or_edit_domain);
 
-        // Get handles for the method menu items.
-        MenuItem bookmarksMenuItem = menu.findItem(R.id.bookmarks);
-        MenuItem adConsentMenuItem = menu.findItem(R.id.ad_consent);
-
         // Set the initial status of the privacy icons.  `false` does not call `invalidateOptionsMenu` as the last step.
         updatePrivacyIcons(false);
 
@@ -1009,12 +977,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Disable the clear form data menu item if the API >= 26 so that the status of the main Clear Data is calculated correctly.
         optionsClearFormDataMenuItem.setEnabled(Build.VERSION.SDK_INT < 26);
 
-        // Only display the dark WebView menu item if API >= 21.
-        optionsDarkWebViewMenuItem.setVisible(Build.VERSION.SDK_INT >= 21);
-
-        // 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);
 
@@ -1037,17 +999,9 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             // Set the title.
             optionsRefreshMenuItem.setTitle(R.string.stop);
 
-            // Set the icon if it is displayed in the app bar.
+            // Set the icon if it is displayed in the app bar.  Once the minimum API is >= 26, the blue and black icons can be combined with a tint list.
             if (displayAdditionalAppBarIcons) {
-                // Get the current theme status.
-                int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
-
-                // Set the icon according to the current theme status.
-                if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                    optionsRefreshMenuItem.setIcon(R.drawable.close_blue_day);
-                } else {
-                    optionsRefreshMenuItem.setIcon(R.drawable.close_blue_night);
-                }
+                optionsRefreshMenuItem.setIcon(R.drawable.close_blue);
             }
         }
 
@@ -1413,12 +1367,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                         @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);
-                                }
+                                // Delete the cookies.
+                                cookieManager.removeAllCookies(null);
                             }
                         }
                     })
@@ -1845,7 +1795,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             assert printManager != null;
 
             // Create a print document adapter from the current WebView.
-            PrintDocumentAdapter printDocumentAdapter = currentWebView.createPrintDocumentAdapter();
+            PrintDocumentAdapter printDocumentAdapter = currentWebView.createPrintDocumentAdapter(getString(R.string.print));
 
             // Print the document.
             printManager.print(getString(R.string.privacy_browser_webpage), printDocumentAdapter, null);
@@ -2028,15 +1978,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 startActivity(domainsIntent);
             }
 
-            // Consume the event.
-            return true;
-        } else if (menuItemId == R.id.ad_consent) {  // 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;
         } else {  // There is no match with the options menu.  Pass the event up to the parent method.
@@ -2256,26 +2197,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         actionBarDrawerToggle.syncState();
     }
 
-    @Override
-    public void onConfigurationChanged(@NonNull Configuration newConfig) {
-        // Run the default commands.
-        super.onConfigurationChanged(newConfig);
-
-        // Reload the ad for the free flavor if not in full screen mode.
-        if (BuildConfig.FLAVOR.contentEquals("free") && !inFullScreenBrowsingMode) {
-            // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-            View adView = findViewById(R.id.adview);
-
-            // Reload the ad.  The AdView is destroyed and recreated, which changes the ID, every time it is reloaded to handle possible rotations.
-            // `getContext()` can be used instead of `getActivity.getApplicationContext()` once the minimum API >= 23.
-            AdHelper.loadAd(adView, getApplicationContext(), this, 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) {
         // Get the hit test result.
@@ -2848,11 +2769,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             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();
-            }
+            finishAndRemoveTask();
 
             // Manually kill Privacy Browser.  Otherwise, it is glitchy when restarted.
             System.exit(0);
@@ -2868,11 +2785,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Run the commands that correlate to the specified request code.
         switch (requestCode) {
             case BROWSE_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, returnedIntent));
-                }
+                // Pass the file to the WebView.
+                fileChooserCallback.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, returnedIntent));
                 break;
 
             case BROWSE_OPEN_REQUEST_CODE:
@@ -2916,21 +2830,21 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Initialize the formatted URL string.
         String url = "";
 
-        // Check to see if `unformattedUrlString` is a valid URL.  Otherwise, convert it into a search.
+        // Check to see if the unformatted URL string 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://")) {
+            if (!unformattedUrlString.startsWith("http") && !unformattedUrlString.startsWith("file://")) {
                 unformattedUrlString = "https://" + unformattedUrlString;
             }
 
-            // Initialize `unformattedUrl`.
+            // Initialize the unformatted URL.
             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.
+            // Convert the unformatted URL string 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) {
@@ -3104,7 +3018,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 currentWebView.loadUrl(temporaryMhtFile.toString());
             } catch (Exception exception) {
                 // Display a snackbar.
-                Snackbar.make(currentWebView, getString(R.string.error) + "  " + exception.toString(), Snackbar.LENGTH_INDEFINITE).show();
+                Snackbar.make(currentWebView, getString(R.string.error) + "  " + exception, Snackbar.LENGTH_INDEFINITE).show();
             }
         } else {  // Let the WebView handle opening of the file.
             // Open the file.
@@ -3158,18 +3072,18 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Remove the lint warning below that the input method manager might be null.
         assert inputMethodManager != null;
 
-        // Initialize the gray foreground color spans for highlighting the URLs.  The deprecated `getResources()` must be used until API >= 23.
-        initialGrayColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.gray_500));
-        finalGrayColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.gray_500));
+        // Initialize the gray foreground color spans for highlighting the URLs.
+        initialGrayColorSpan = new ForegroundColorSpan(getColor(R.color.gray_500));
+        finalGrayColorSpan = new ForegroundColorSpan(getColor(R.color.gray_500));
 
         // Get the current theme status.
         int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
 
         // Set the red color span according to the theme.
         if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-            redColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.red_a700));
+            redColorSpan = new ForegroundColorSpan(getColor(R.color.red_a700));
         } else {
-            redColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.red_900));
+            redColorSpan = new ForegroundColorSpan(getColor(R.color.red_900));
         }
 
         // Remove the formatting from the URL edit text when the user is editing the text.
@@ -3211,7 +3125,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 orbotStatus = intent.getStringExtra("org.torproject.android.intent.extra.STATUS");
 
                 // If Privacy Browser is waiting on the proxy, load the website now that Orbot is connected.
-                if ((orbotStatus != null) && orbotStatus.equals("ON") && waitingForProxy) {
+                if ((orbotStatus != null) && orbotStatus.equals(ProxyHelper.ORBOT_STATUS_ON) && waitingForProxy) {
                     // Reset the waiting for proxy status.
                     waitingForProxy = false;
 
@@ -3422,17 +3336,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
 
         // Implement swipe to refresh.
         swipeRefreshLayout.setOnRefreshListener(() -> {
-            // Check the visibility of the bottom app bar.  Sometimes it is hidden if the WebView is the same size as the visible screen.
-            if (bottomAppBar && scrollAppBar && (appBarLayout.getVisibility() == View.GONE)) {  // The bottom app bar is currently hidden.
-                // Show the app bar.
-                appBarLayout.setVisibility(View.VISIBLE);
-
-                // Disable the refreshing animation.
-                swipeRefreshLayout.setRefreshing(false);
-            } else {  // A bottom app bar is not currently hidden.
-                // Reload the website.
-                currentWebView.reload();
-            }
+            // Reload the website.
+            currentWebView.reload();
         });
 
         // Store the default progress view offsets for use later in `initializeWebView()`.
@@ -3478,15 +3383,15 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             bookmarkCursor.moveToFirst();
 
             // Act upon the bookmark according to the type.
-            if (bookmarkCursor.getInt(bookmarkCursor.getColumnIndex(BookmarksDatabaseHelper.IS_FOLDER)) == 1) {  // The selected bookmark is a folder.
+            if (bookmarkCursor.getInt(bookmarkCursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.IS_FOLDER)) == 1) {  // The selected bookmark is a folder.
                 // Store the new folder name in `currentBookmarksFolder`.
-                currentBookmarksFolder = bookmarkCursor.getString(bookmarkCursor.getColumnIndex(BookmarksDatabaseHelper.BOOKMARK_NAME));
+                currentBookmarksFolder = bookmarkCursor.getString(bookmarkCursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.BOOKMARK_NAME));
 
                 // Load the new folder.
                 loadBookmarksFolder();
             } else {  // The selected bookmark is not a folder.
                 // Load the bookmark URL.
-                loadUrl(currentWebView, bookmarkCursor.getString(bookmarkCursor.getColumnIndex(BookmarksDatabaseHelper.BOOKMARK_URL)));
+                loadUrl(currentWebView, bookmarkCursor.getString(bookmarkCursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.BOOKMARK_URL)));
 
                 // Close the bookmarks drawer.
                 drawerLayout.closeDrawer(GravityCompat.END);
@@ -3506,7 +3411,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             // Check to see if the bookmark is a folder.
             if (isFolder) {  // The bookmark is a folder.
                 // Save the current folder name, which is used in `onSaveEditBookmarkFolder()`.
-                oldFolderNameString = bookmarksCursor.getString(bookmarksCursor.getColumnIndex(BookmarksDatabaseHelper.BOOKMARK_NAME));
+                oldFolderNameString = bookmarksCursor.getString(bookmarksCursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.BOOKMARK_NAME));
 
                 // Instantiate the edit folder bookmark dialog.
                 DialogFragment editBookmarkFolderDialog = EditBookmarkFolderDialog.folderDatabaseId(databaseId, currentWebView.getFavoriteOrDefaultIcon());
@@ -3521,7 +3426,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 bookmarkCursor.moveToFirst();
 
                 // Load the bookmark in a new tab but do not switch to the tab or close the drawer.
-                addNewTab(bookmarkCursor.getString(bookmarkCursor.getColumnIndex(BookmarksDatabaseHelper.BOOKMARK_URL)), false);
+                addNewTab(bookmarkCursor.getString(bookmarkCursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.BOOKMARK_URL)), false);
 
                 // Display a snackbar.
                 Snackbar.make(currentWebView, R.string.bookmark_opened_in_background, Snackbar.LENGTH_SHORT).show();
@@ -3602,7 +3507,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         fullScreenBrowsingModeEnabled = sharedPreferences.getBoolean("full_screen_browsing_mode", false);
         downloadWithExternalApp = sharedPreferences.getBoolean(getString(R.string.download_with_external_app_key), false);
         hideAppBar = sharedPreferences.getBoolean("hide_app_bar", true);
-        scrollAppBar = sharedPreferences.getBoolean("scroll_app_bar", true);
+        scrollAppBar = sharedPreferences.getBoolean(getString(R.string.scroll_app_bar_key), true);
 
         // Apply the saved proxy mode if the app has been restarted.
         if (savedProxyMode != null) {
@@ -3688,15 +3593,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 actionBar.show();
             }
 
-            // Hide the banner ad in the free flavor.
-            if (BuildConfig.FLAVOR.contentEquals("free")) {
-                // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-                View adView = findViewById(R.id.adview);
-
-                // Hide the banner ad.
-                AdHelper.hideAd(adView);
-            }
-
             /* 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.
@@ -3715,16 +3611,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             // Show the action bar.
             actionBar.show();
 
-            // Show the banner ad in the free flavor.
-            if (BuildConfig.FLAVOR.contentEquals("free")) {
-                // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-                View adView = findViewById(R.id.adview);
-
-                // Initialize the ads.  If this isn't the first run, `loadAd()` will be automatically called instead.
-                // `getContext()` can be used instead of `getActivity.getApplicationContext()` once the minimum API >= 23.
-                AdHelper.initializeAds(adView, getApplicationContext(), this, getSupportFragmentManager(), getString(R.string.ad_unit_id));
-            }
-
             // Remove the `SYSTEM_UI` flags from the root frame layout.
             rootFrameLayout.setSystemUiVisibility(0);
         }
@@ -3824,14 +3710,14 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             Set<String> domainSettingsSet = new HashSet<>();
 
             // Get the domain name column index.
-            int domainNameColumnIndex = domainNameCursor.getColumnIndex(DomainsDatabaseHelper.DOMAIN_NAME);
+            int domainNameColumnIndex = domainNameCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.DOMAIN_NAME);
 
             // Populate `domainSettingsSet`.
             for (int i = 0; i < domainNameCursor.getCount(); i++) {
-                // Move `domainsCursor` to the current row.
+                // Move the domains cursor to the current row.
                 domainNameCursor.moveToPosition(i);
 
-                // Store the domain name in `domainSettingsSet`.
+                // Store the domain name in the domain settings set.
                 domainSettingsSet.add(domainNameCursor.getString(domainNameColumnIndex));
             }
 
@@ -3895,37 +3781,37 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 currentDomainSettingsCursor.moveToFirst();
 
                 // Get the settings from the cursor.
-                nestedScrollWebView.setDomainSettingsDatabaseId(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper._ID)));
-                nestedScrollWebView.getSettings().setJavaScriptEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ENABLE_JAVASCRIPT)) == 1);
-                nestedScrollWebView.setAcceptCookies(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.COOKIES)) == 1);
-                nestedScrollWebView.getSettings().setDomStorageEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ENABLE_DOM_STORAGE)) == 1);
+                nestedScrollWebView.setDomainSettingsDatabaseId(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper._ID)));
+                nestedScrollWebView.getSettings().setJavaScriptEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ENABLE_JAVASCRIPT)) == 1);
+                nestedScrollWebView.setAcceptCookies(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.COOKIES)) == 1);
+                nestedScrollWebView.getSettings().setDomStorageEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ENABLE_DOM_STORAGE)) == 1);
                 // Form data can be removed once the minimum API >= 26.
-                boolean saveFormData = (currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ENABLE_FORM_DATA)) == 1);
-                nestedScrollWebView.setEasyListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ENABLE_EASYLIST)) == 1);
-                nestedScrollWebView.setEasyPrivacyEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ENABLE_EASYPRIVACY)) == 1);
-                nestedScrollWebView.setFanboysAnnoyanceListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ENABLE_FANBOYS_ANNOYANCE_LIST)) == 1);
-                nestedScrollWebView.setFanboysSocialBlockingListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(
+                boolean saveFormData = (currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ENABLE_FORM_DATA)) == 1);
+                nestedScrollWebView.setEasyListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ENABLE_EASYLIST)) == 1);
+                nestedScrollWebView.setEasyPrivacyEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ENABLE_EASYPRIVACY)) == 1);
+                nestedScrollWebView.setFanboysAnnoyanceListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ENABLE_FANBOYS_ANNOYANCE_LIST)) == 1);
+                nestedScrollWebView.setFanboysSocialBlockingListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(
                         DomainsDatabaseHelper.ENABLE_FANBOYS_SOCIAL_BLOCKING_LIST)) == 1);
-                nestedScrollWebView.setUltraListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ULTRALIST)) == 1);
-                nestedScrollWebView.setUltraPrivacyEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.ENABLE_ULTRAPRIVACY)) == 1);
-                nestedScrollWebView.setBlockAllThirdPartyRequests(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.BLOCK_ALL_THIRD_PARTY_REQUESTS)) == 1);
-                String userAgentName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.USER_AGENT));
-                int fontSize = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.FONT_SIZE));
-                int swipeToRefreshInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SWIPE_TO_REFRESH));
-                int webViewThemeInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.WEBVIEW_THEME));
-                int wideViewportInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.WIDE_VIEWPORT));
-                int displayWebpageImagesInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.DISPLAY_IMAGES));
-                boolean pinnedSslCertificate = (currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.PINNED_SSL_CERTIFICATE)) == 1);
-                String pinnedSslIssuedToCName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_ISSUED_TO_COMMON_NAME));
-                String pinnedSslIssuedToOName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_ISSUED_TO_ORGANIZATION));
-                String pinnedSslIssuedToUName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_ISSUED_TO_ORGANIZATIONAL_UNIT));
-                String pinnedSslIssuedByCName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_ISSUED_BY_COMMON_NAME));
-                String pinnedSslIssuedByOName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_ISSUED_BY_ORGANIZATION));
-                String pinnedSslIssuedByUName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_ISSUED_BY_ORGANIZATIONAL_UNIT));
-                Date pinnedSslStartDate = new Date(currentDomainSettingsCursor.getLong(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_START_DATE)));
-                Date pinnedSslEndDate = new Date(currentDomainSettingsCursor.getLong(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.SSL_END_DATE)));
-                boolean pinnedIpAddresses = (currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.PINNED_IP_ADDRESSES)) == 1);
-                String pinnedHostIpAddresses = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndex(DomainsDatabaseHelper.IP_ADDRESSES));
+                nestedScrollWebView.setUltraListEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ULTRALIST)) == 1);
+                nestedScrollWebView.setUltraPrivacyEnabled(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.ENABLE_ULTRAPRIVACY)) == 1);
+                nestedScrollWebView.setBlockAllThirdPartyRequests(currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.BLOCK_ALL_THIRD_PARTY_REQUESTS)) == 1);
+                String userAgentName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.USER_AGENT));
+                int fontSize = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.FONT_SIZE));
+                int swipeToRefreshInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SWIPE_TO_REFRESH));
+                int webViewThemeInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.WEBVIEW_THEME));
+                int wideViewportInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.WIDE_VIEWPORT));
+                int displayWebpageImagesInt = currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.DISPLAY_IMAGES));
+                boolean pinnedSslCertificate = (currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.PINNED_SSL_CERTIFICATE)) == 1);
+                String pinnedSslIssuedToCName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_ISSUED_TO_COMMON_NAME));
+                String pinnedSslIssuedToOName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_ISSUED_TO_ORGANIZATION));
+                String pinnedSslIssuedToUName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_ISSUED_TO_ORGANIZATIONAL_UNIT));
+                String pinnedSslIssuedByCName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_ISSUED_BY_COMMON_NAME));
+                String pinnedSslIssuedByOName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_ISSUED_BY_ORGANIZATION));
+                String pinnedSslIssuedByUName = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_ISSUED_BY_ORGANIZATIONAL_UNIT));
+                Date pinnedSslStartDate = new Date(currentDomainSettingsCursor.getLong(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_START_DATE)));
+                Date pinnedSslEndDate = new Date(currentDomainSettingsCursor.getLong(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.SSL_END_DATE)));
+                boolean pinnedIpAddresses = (currentDomainSettingsCursor.getInt(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.PINNED_IP_ADDRESSES)) == 1);
+                String pinnedHostIpAddresses = currentDomainSettingsCursor.getString(currentDomainSettingsCursor.getColumnIndexOrThrow(DomainsDatabaseHelper.IP_ADDRESSES));
 
                 // Close the current host domain settings cursor.
                 currentDomainSettingsCursor.close();
@@ -4109,15 +3995,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                         break;
                 }
 
-                // Get the current theme status.
-                int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
-
                 // Set a background on the URL relative layout to indicate that custom domain settings are being used.
-                if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                    urlRelativeLayout.setBackground(ResourcesCompat.getDrawable(getResources(), R.drawable.url_bar_background_light_green, null));
-                } else {
-                    urlRelativeLayout.setBackground(ResourcesCompat.getDrawable(getResources(), R.drawable.url_bar_background_dark_blue, null));
-                }
+                urlRelativeLayout.setBackground(ResourcesCompat.getDrawable(getResources(), R.drawable.domain_settings_url_background, null));
             } else {  // The new URL does not have custom domain settings.  Load the defaults.
                 // Store the values from the shared preferences.
                 nestedScrollWebView.getSettings().setJavaScriptEnabled(sharedPreferences.getBoolean("javascript", false));
@@ -4242,8 +4121,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
     }
 
     private void applyProxy(boolean reloadWebViews) {
-        // Set the proxy according to the mode.  `this` refers to the current activity where an alert dialog might be displayed.
-        ProxyHelper.setProxy(getApplicationContext(), appBarLayout, proxyMode);
+        // Set the proxy according to the mode.
+        proxyHelper.setProxy(getApplicationContext(), appBarLayout, proxyMode);
 
         // Reset the waiting for proxy tracker.
         waitingForProxy = false;
@@ -4284,7 +4163,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                     packageManager.getPackageInfo("org.torproject.android", 0);
 
                     // Check to see if the proxy is ready.
-                    if (!orbotStatus.equals("ON")) {  // Orbot is not ready.
+                    if (!orbotStatus.equals(ProxyHelper.ORBOT_STATUS_ON)) {  // Orbot is not ready.
                         // Set the waiting for proxy status.
                         waitingForProxy = true;
 
@@ -4398,35 +4277,20 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 optionsPrivacyMenuItem.setIcon(R.drawable.privacy_mode);
             }
 
-            // Get the current theme status.
-            int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
-
             // Update the cookies icon.
-            if (currentWebView.getAcceptCookies()) {  // Cookies are enabled.
+            if (currentWebView.getAcceptCookies()) {
                 optionsCookiesMenuItem.setIcon(R.drawable.cookies_enabled);
-            } else {  // Cookies are disabled.
-                if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                    optionsCookiesMenuItem.setIcon(R.drawable.cookies_disabled_day);
-                } else {
-                    optionsCookiesMenuItem.setIcon(R.drawable.cookies_disabled_night);
-                }
+            } else {
+                optionsCookiesMenuItem.setIcon(R.drawable.cookies_disabled);
             }
 
             // Update the refresh icon.
             if (optionsRefreshMenuItem.getTitle() == getString(R.string.refresh)) {  // The refresh icon is displayed.
-                // Set the icon according to the theme.
-                if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                    optionsRefreshMenuItem.setIcon(R.drawable.refresh_enabled_day);
-                } else {
-                    optionsRefreshMenuItem.setIcon(R.drawable.refresh_enabled_night);
-                }
+                // Set the icon.  Once the minimum API is >= 26, the blue and black icons can be combined with a tint list.
+                optionsRefreshMenuItem.setIcon(R.drawable.refresh_enabled);
             } else {  // The stop icon is displayed.
-                // Set the icon according to the theme.
-                if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                    optionsRefreshMenuItem.setIcon(R.drawable.close_blue_day);
-                } else {
-                    optionsRefreshMenuItem.setIcon(R.drawable.close_blue_night);
-                }
+                // Set the icon.  Once the minimum API is >= 26, the blue and black icons can be combined with a tint list.
+                optionsRefreshMenuItem.setIcon(R.drawable.close_blue);
             }
 
             // `invalidateOptionsMenu()` calls `onPrepareOptionsMenu()` and redraws the icons in the app bar.
@@ -4513,7 +4377,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 TextView bookmarkNameTextView = view.findViewById(R.id.bookmark_name);
 
                 // Get the favorite icon byte array from the cursor.
-                byte[] favoriteIconByteArray = cursor.getBlob(cursor.getColumnIndex(BookmarksDatabaseHelper.FAVORITE_ICON));
+                byte[] favoriteIconByteArray = cursor.getBlob(cursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.FAVORITE_ICON));
 
                 // Convert the byte array to a `Bitmap` beginning at the first byte and ending at the last.
                 Bitmap favoriteIconBitmap = BitmapFactory.decodeByteArray(favoriteIconByteArray, 0, favoriteIconByteArray.length);
@@ -4522,11 +4386,11 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 bookmarkFavoriteIcon.setImageBitmap(favoriteIconBitmap);
 
                 // Get the bookmark name from the cursor and display it in `bookmarkNameTextView`.
-                String bookmarkNameString = cursor.getString(cursor.getColumnIndex(BookmarksDatabaseHelper.BOOKMARK_NAME));
+                String bookmarkNameString = cursor.getString(cursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.BOOKMARK_NAME));
                 bookmarkNameTextView.setText(bookmarkNameString);
 
                 // Make the font bold for folders.
-                if (cursor.getInt(cursor.getColumnIndex(BookmarksDatabaseHelper.IS_FOLDER)) == 1) {
+                if (cursor.getInt(cursor.getColumnIndexOrThrow(BookmarksDatabaseHelper.IS_FOLDER)) == 1) {
                     bookmarkNameTextView.setTypeface(Typeface.DEFAULT_BOLD);
                 } else {  // Reset the font to default for normal bookmarks.
                     bookmarkNameTextView.setTypeface(Typeface.DEFAULT);
@@ -4772,8 +4636,12 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         webViewPagerAdapter.addPage(newTabNumber, webViewPager, url, moveToTab);
 
         // Show the app bar if it is at the bottom of the screen and the new tab is taking focus.
-        if (bottomAppBar && moveToTab) {
-            appBarLayout.setVisibility(View.VISIBLE);
+        if (bottomAppBar && moveToTab && (appBarLayout.getTranslationY() != 0)) {
+            // Animate the bottom app bar onto the screen.
+            objectAnimator = ObjectAnimator.ofFloat(appBarLayout, "translationY", 0);
+
+            // Make it so.
+            objectAnimator.start();
         }
     }
 
@@ -4817,8 +4685,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         // Enable the sliding drawers.
         drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED);
 
-        // Show the main content relative layout.
-        mainContentRelativeLayout.setVisibility(View.VISIBLE);
+        // Show the coordinator layout.
+        coordinatorLayout.setVisibility(View.VISIBLE);
 
         // Apply the appropriate full screen mode flags.
         if (fullScreenBrowsingModeEnabled && inFullScreenBrowsingMode) {  // Privacy Browser is currently in full screen browsing mode.
@@ -4831,15 +4699,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 actionBar.hide();
             }
 
-            // Hide the banner ad in the free flavor.
-            if (BuildConfig.FLAVOR.contentEquals("free")) {
-                // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-                View adView = findViewById(R.id.adview);
-
-                // Hide the banner ad.
-                AdHelper.hideAd(adView);
-            }
-
             /* 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.
@@ -4852,15 +4711,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             // Remove the `SYSTEM_UI` flags from the root frame layout.
             rootFrameLayout.setSystemUiVisibility(0);
         }
-
-        // Reload the ad for the free flavor if not in full screen mode.
-        if (BuildConfig.FLAVOR.contentEquals("free") && !inFullScreenBrowsingMode) {
-            // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-            View adView = findViewById(R.id.adview);
-
-            // Reload the ad.
-            AdHelper.loadAd(adView, this, this, getString(R.string.ad_unit_id));
-        }
     }
 
     private void clearAndExit() {
@@ -4883,12 +4733,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
 
         // Clear cookies.
         if (clearEverything || sharedPreferences.getBoolean("clear_cookies", true)) {
-            // The command to remove cookies changed slightly in API 21.
-            if (Build.VERSION.SDK_INT >= 21) {
-                CookieManager.getInstance().removeAllCookies(null);
-            } else {
-                CookieManager.getInstance().removeAllCookie();
-            }
+            // Request the cookies be deleted.
+            CookieManager.getInstance().removeAllCookies(null);
 
             // Manually delete the cookies database, as `CookieManager` sometimes will not flush its changes to disk before `System.exit(0)` is run.
             try {
@@ -5046,11 +4892,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         }
 
         // Close Privacy Browser.  `finishAndRemoveTask` also removes Privacy Browser from the recent app list.
-        if (Build.VERSION.SDK_INT >= 21) {
-            finishAndRemoveTask();
-        } else {
-            finish();
-        }
+        finishAndRemoveTask();
 
         // Remove the terminated program from RAM.  The status code is `0`.
         System.exit(0);
@@ -5142,16 +4984,10 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
 
             // Set the background to indicate the domain settings status.
             if (currentWebView.getDomainSettingsApplied()) {
-                // Get the current theme status.
-                int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
-
-                // Set a green background on the URL relative layout to indicate that custom domain settings are being used.
-                if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                    urlRelativeLayout.setBackground(ResourcesCompat.getDrawable(getResources(), R.drawable.url_bar_background_light_green, null));
-                } else {
-                    urlRelativeLayout.setBackground(ResourcesCompat.getDrawable(getResources(), R.drawable.url_bar_background_dark_blue, null));
-                }
+                // Set a background on the URL relative layout to indicate that custom domain settings are being used.
+                urlRelativeLayout.setBackground(ResourcesCompat.getDrawable(getResources(), R.drawable.domain_settings_url_background, null));
             } else {
+                // Remove any background on the URL relative layout.
                 urlRelativeLayout.setBackground(ResourcesCompat.getDrawable(getResources(), R.color.transparent, null));
             }
         } else {  // The fragment has not been populated.  Try again in 100 milliseconds.
@@ -5226,7 +5062,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         assert inputMethodManager != null;
 
         // Set the app bar scrolling.
-        nestedScrollWebView.setNestedScrollingEnabled(sharedPreferences.getBoolean("scroll_app_bar", true));
+        nestedScrollWebView.setNestedScrollingEnabled(scrollAppBar);
 
         // Allow pinch to zoom.
         nestedScrollWebView.getSettings().setBuiltInZoomControls(true);
@@ -5235,9 +5071,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         nestedScrollWebView.getSettings().setDisplayZoomControls(false);
 
         // Don't allow mixed content (HTTP and HTTPS) on the same website.
-        if (Build.VERSION.SDK_INT >= 21) {
-            nestedScrollWebView.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_NEVER_ALLOW);
-        }
+        nestedScrollWebView.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_NEVER_ALLOW);
 
         // Set the WebView to load in overview mode (zoomed out to the maximum width).
         nestedScrollWebView.getSettings().setLoadWithOverviewMode(true);
@@ -5289,15 +5123,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                             }
                         }
 
-                        // Hide the banner ad in the free flavor.
-                        if (BuildConfig.FLAVOR.contentEquals("free")) {
-                            // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-                            View adView = findViewById(R.id.adview);
-
-                            // Hide the banner ad.
-                            AdHelper.hideAd(adView);
-                        }
-
                         /* 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.
@@ -5334,15 +5159,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                             }
                         }
 
-                        // Show the banner ad in the free flavor.
-                        if (BuildConfig.FLAVOR.contentEquals("free")) {
-                            // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-                            View adView = findViewById(R.id.adview);
-
-                            // Reload the ad.  `getContext()` can be used instead of `getActivity.getApplicationContext()` once the minimum API >= 23.
-                            AdHelper.loadAd(adView, getApplicationContext(), activity, getString(R.string.ad_unit_id));
-                        }
-
                         // Remove the `SYSTEM_UI` flags from the root frame layout.
                         rootFrameLayout.setSystemUiVisibility(0);
                     }
@@ -5427,67 +5243,46 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
         });
 
         // Update the status of swipe to refresh based on the scroll position of the nested scroll WebView.  Also reinforce full screen browsing mode.
-        // On API < 23, `getViewTreeObserver().addOnScrollChangedListener()` must be used, but it is a little bit buggy and appears to get garbage collected from time to time.
-        if (Build.VERSION.SDK_INT >= 23) {
-            nestedScrollWebView.setOnScrollChangeListener((view, scrollX, scrollY, oldScrollX, oldScrollY) -> {
-                // Set the swipe to refresh status.
-                if (nestedScrollWebView.getSwipeToRefresh()) {
-                    // Only enable swipe to refresh if the WebView is scrolled to the top.
-                    swipeRefreshLayout.setEnabled(nestedScrollWebView.getScrollY() == 0);
-                } else {
-                    // Disable swipe to refresh.
-                    swipeRefreshLayout.setEnabled(false);
-                }
+        nestedScrollWebView.setOnScrollChangeListener((view, scrollX, scrollY, oldScrollX, oldScrollY) -> {
+            // Set the swipe to refresh status.
+            if (nestedScrollWebView.getSwipeToRefresh()) {
+                // Only enable swipe to refresh if the WebView is scrolled to the top.
+                swipeRefreshLayout.setEnabled(nestedScrollWebView.getScrollY() == 0);
+            } else {
+                // Disable swipe to refresh.
+                swipeRefreshLayout.setEnabled(false);
+            }
 
-                //  Set the visibility of the bottom app bar.
-                if (bottomAppBar && scrollAppBar && (Calendar.getInstance().getTimeInMillis() - lastScrollUpdate > 100)) {
-                    if (scrollY - oldScrollY > 25) {  // The WebView was scrolled down.
-                        appBarLayout.setVisibility(View.GONE);
-                    } else if (scrollY - oldScrollY < -25) {  // The WebView was scrolled up.
-                        appBarLayout.setVisibility(View.VISIBLE);
-                    }
+            //  Scroll the bottom app bar if enabled.
+            if (bottomAppBar && scrollAppBar && !objectAnimator.isRunning()) {
+                if (scrollY < oldScrollY) {  // The WebView was scrolled down.
+                    // Animate the bottom app bar onto the screen.
+                    objectAnimator = ObjectAnimator.ofFloat(appBarLayout, "translationY", 0);
 
-                    // Update the last scroll update variable.  This prevents the app bar from flashing on and off at the bottom of the screen.
-                    lastScrollUpdate = Calendar.getInstance().getTimeInMillis();
-                }
+                    // Make it so.
+                    objectAnimator.start();
+                } else if (scrollY > oldScrollY) {  // The WebView was scrolled up.
+                    // Animate the bottom app bar off the screen.
+                    objectAnimator = ObjectAnimator.ofFloat(appBarLayout, "translationY", appBarLayout.getHeight());
 
-                // Reinforce the system UI visibility flags if in full screen browsing mode.
-                // This hides the status and navigation bars, which are displayed if other elements are shown, like dialog boxes, the options menu, or the keyboard.
-                if (inFullScreenBrowsingMode) {
-                    /* 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 {
-            nestedScrollWebView.getViewTreeObserver().addOnScrollChangedListener(() -> {
-                if (nestedScrollWebView.getSwipeToRefresh()) {
-                    // Only enable swipe to refresh if the WebView is scrolled to the top.
-                    swipeRefreshLayout.setEnabled(nestedScrollWebView.getScrollY() == 0);
-                } else {
-                    // Disable swipe to refresh.
-                    swipeRefreshLayout.setEnabled(false);
+                    // Make it so.
+                    objectAnimator.start();
                 }
+            }
 
-                // Reinforce the system UI visibility flags if in full screen browsing mode.
-                // This hides the status and navigation bars, which are displayed if other elements are shown, like dialog boxes, the options menu, or the keyboard.
-                if (inFullScreenBrowsingMode) {
-                    /* 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);
-                }
-            });
-        }
+            // Reinforce the system UI visibility flags if in full screen browsing mode.
+            // This hides the status and navigation bars, which are displayed if other elements are shown, like dialog boxes, the options menu, or the keyboard.
+            if (inFullScreenBrowsingMode) {
+                /* 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);
+            }
+        });
 
         // Set the web chrome client.
         nestedScrollWebView.setWebChromeClient(new WebChromeClient() {
@@ -5581,20 +5376,11 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 // Set the full screen video flag.
                 displayingFullScreenVideo = true;
 
-                // Pause the ad if this is the free flavor.
-                if (BuildConfig.FLAVOR.contentEquals("free")) {
-                    // Get a handle for the ad view.  This cannot be a class variable because it changes with each ad load.
-                    View adView = findViewById(R.id.adview);
-
-                    // The AdView is destroyed and recreated, which changes the ID, every time it is reloaded to handle possible rotations.
-                    AdHelper.pauseAd(adView);
-                }
-
                 // Hide the keyboard.
                 inputMethodManager.hideSoftInputFromWindow(nestedScrollWebView.getWindowToken(), 0);
 
-                // Hide the main content relative layout.
-                mainContentRelativeLayout.setVisibility(View.GONE);
+                // Hide the coordinator layout.
+                coordinatorLayout.setVisibility(View.GONE);
 
                 /* Hide the system bars.
                  * SYSTEM_UI_FLAG_FULLSCREEN hides the status bar at the top of the screen.
@@ -5628,34 +5414,31 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             // Upload files.
             @Override
             public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
-                // Show the file chooser if the device is running API >= 21.
-                if (Build.VERSION.SDK_INT >= 21) {
-                    // Store the file path callback.
-                    fileChooserCallback = filePathCallback;
+                // Store the file path callback.
+                fileChooserCallback = filePathCallback;
 
-                    // Create an intent to open a chooser based on the file chooser parameters.
-                    Intent fileChooserIntent = fileChooserParams.createIntent();
+                // Create an intent to open a chooser based on the file chooser parameters.
+                Intent fileChooserIntent = fileChooserParams.createIntent();
 
-                    // Get a handle for the package manager.
-                    PackageManager packageManager = getPackageManager();
+                // Get a handle for the package manager.
+                PackageManager packageManager = getPackageManager();
 
-                    // Check to see if the file chooser intent resolves to an installed package.
-                    if (fileChooserIntent.resolveActivity(packageManager) != null) {  // The file chooser intent is fine.
-                        // Start the file chooser intent.
-                        startActivityForResult(fileChooserIntent, BROWSE_FILE_UPLOAD_REQUEST_CODE);
-                    } else {  // The file chooser intent will cause a crash.
-                        // Create a generic intent to open a chooser.
-                        Intent genericFileChooserIntent = new Intent(Intent.ACTION_GET_CONTENT);
+                // Check to see if the file chooser intent resolves to an installed package.
+                if (fileChooserIntent.resolveActivity(packageManager) != null) {  // The file chooser intent is fine.
+                    // Start the file chooser intent.
+                    startActivityForResult(fileChooserIntent, BROWSE_FILE_UPLOAD_REQUEST_CODE);
+                } else {  // The file chooser intent will cause a crash.
+                    // Create a generic intent to open a chooser.
+                    Intent genericFileChooserIntent = new Intent(Intent.ACTION_GET_CONTENT);
 
-                        // Request an openable file.
-                        genericFileChooserIntent.addCategory(Intent.CATEGORY_OPENABLE);
+                    // Request an openable file.
+                    genericFileChooserIntent.addCategory(Intent.CATEGORY_OPENABLE);
 
-                        // Set the file type to everything.
-                        genericFileChooserIntent.setType("*/*");
+                    // Set the file type to everything.
+                    genericFileChooserIntent.setType("*/*");
 
-                        // Start the generic file chooser intent.
-                        startActivityForResult(genericFileChooserIntent, BROWSE_FILE_UPLOAD_REQUEST_CODE);
-                    }
+                    // Start the generic file chooser intent.
+                    startActivityForResult(genericFileChooserIntent, BROWSE_FILE_UPLOAD_REQUEST_CODE);
                 }
                 return true;
             }
@@ -5745,7 +5528,10 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
 
             // Check requests against the block lists.  The deprecated `shouldInterceptRequest()` must be used until minimum API >= 21.
             @Override
-            public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
+            public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest webResourceRequest) {
+                // Get the URL.
+                String url = webResourceRequest.getUrl().toString();
+
                 // Check to see if the resource request is for the main URL.
                 if (url.equals(nestedScrollWebView.getCurrentUrl())) {
                     // `return null` loads the resource request, which should never be blocked if it is the main URL.
@@ -5765,9 +5551,6 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                     }
                 }
 
-                // Sanitize the URL.
-                url = sanitizeUrl(url);
-
                 // Create an empty web resource response to be used if the resource request is blocked.
                 WebResourceResponse emptyWebResourceResponse = new WebResourceResponse("text/plain", "utf8", new ByteArrayInputStream("".getBytes()));
 
@@ -5783,31 +5566,25 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 // Store a copy of the current domain for use in later requests.
                 String currentDomain = currentBaseDomain;
 
-                // Nobody is happy when comparing null strings.
-                if (url != null) {
-                    // Convert the request URL to a URI.
-                    Uri requestUri = Uri.parse(url);
-
-                    // Get the request host name.
-                    String requestBaseDomain = requestUri.getHost();
+                // Get the request host name.
+                String requestBaseDomain = webResourceRequest.getUrl().getHost();
 
-                    // Only check for third-party requests if the current base domain is not empty and the request domain is not null.
-                    if (!currentBaseDomain.isEmpty() && (requestBaseDomain != null)) {
-                        // Determine the current base domain.
-                        while (currentBaseDomain.indexOf(".", currentBaseDomain.indexOf(".") + 1) > 0) {  // There is at least one subdomain.
-                            // Remove the first subdomain.
-                            currentBaseDomain = currentBaseDomain.substring(currentBaseDomain.indexOf(".") + 1);
-                        }
-
-                        // Determine the request base domain.
-                        while (requestBaseDomain.indexOf(".", requestBaseDomain.indexOf(".") + 1) > 0) {  // There is at least one subdomain.
-                            // Remove the first subdomain.
-                            requestBaseDomain = requestBaseDomain.substring(requestBaseDomain.indexOf(".") + 1);
-                        }
+                // Only check for third-party requests if the current base domain is not empty and the request domain is not null.
+                if (!currentBaseDomain.isEmpty() && (requestBaseDomain != null)) {
+                    // Determine the current base domain.
+                    while (currentBaseDomain.indexOf(".", currentBaseDomain.indexOf(".") + 1) > 0) {  // There is at least one subdomain.
+                        // Remove the first subdomain.
+                        currentBaseDomain = currentBaseDomain.substring(currentBaseDomain.indexOf(".") + 1);
+                    }
 
-                        // Update the third party request tracker.
-                        isThirdPartyRequest = !currentBaseDomain.equals(requestBaseDomain);
+                    // Determine the request base domain.
+                    while (requestBaseDomain.indexOf(".", requestBaseDomain.indexOf(".") + 1) > 0) {  // There is at least one subdomain.
+                        // Remove the first subdomain.
+                        requestBaseDomain = requestBaseDomain.substring(requestBaseDomain.indexOf(".") + 1);
                     }
+
+                    // Update the third party request tracker.
+                    isThirdPartyRequest = !currentBaseDomain.equals(requestBaseDomain);
                 }
 
                 // Get the current WebView page position.
@@ -6164,17 +5941,9 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                     // Get the app bar and theme preferences.
                     boolean displayAdditionalAppBarIcons = sharedPreferences.getBoolean(getString(R.string.display_additional_app_bar_icons_key), false);
 
-                    // If the icon is displayed in the AppBar, set it according to the theme.
+                    // Set the icon if it is displayed in the AppBar.  Once the minimum API is >= 26, the blue and black icons can be combined with a tint list.
                     if (displayAdditionalAppBarIcons) {
-                        // Get the current theme status.
-                        int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
-
-                        // Set the stop icon according to the theme.
-                        if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                            optionsRefreshMenuItem.setIcon(R.drawable.close_blue_day);
-                        } else {
-                            optionsRefreshMenuItem.setIcon(R.drawable.close_blue_night);
-                        }
+                        optionsRefreshMenuItem.setIcon(R.drawable.close_blue);
                     }
                 }
             }
@@ -6182,7 +5951,7 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
             @Override
             public void onPageFinished(WebView view, String url) {
                 // Flush any cookies to persistent storage.  The cookie manager has become very lazy about flushing cookies in recent versions.
-                if (nestedScrollWebView.getAcceptCookies() && Build.VERSION.SDK_INT >= 21) {
+                if (nestedScrollWebView.getAcceptCookies()) {
                     CookieManager.getInstance().flush();
                 }
 
@@ -6196,15 +5965,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
 
                     // If the icon is displayed in the app bar, reset it according to the theme.
                     if (displayAdditionalAppBarIcons) {
-                        // Get the current theme status.
-                        int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
-
-                        // Set the icon according to the theme.
-                        if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
-                            optionsRefreshMenuItem.setIcon(R.drawable.refresh_enabled_day);
-                        } else {
-                            optionsRefreshMenuItem.setIcon(R.drawable.refresh_enabled_night);
-                        }
+                        // Set the icon.
+                        optionsRefreshMenuItem.setIcon(R.drawable.refresh_enabled);
                     }
                 }
 
@@ -6313,7 +6075,8 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateBook
                 }
             }
 
-            // Handle SSL Certificate errors.
+            // Handle SSL Certificate errors.  Suppress the lint warning that ignoring the error might be dangerous.
+            @SuppressLint("WebViewClientOnReceivedSslError")
             @Override
             public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
                 // Get the current website SSL certificate.