app/src/main/java/com/stoutner/privacybrowser/fragments/AboutTabFragment.java

   1 /*
   2  * Copyright © 2016-2019 Soren Stoutner <soren@stoutner.com>.
   3  *
   4  * This file is part of Privacy Browser <https://www.stoutner.com/privacy-browser>.
   5  *
   6  * Privacy Browser is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Privacy Browser is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with Privacy Browser.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 package com.stoutner.privacybrowser.fragments;
  21
  22 import android.annotation.SuppressLint;
  23 import android.content.Context;
  24 import android.content.SharedPreferences;
  25 import android.content.pm.PackageManager;
  26 import android.content.pm.Signature;
  27 import android.os.Build;
  28 import android.os.Bundle;
  29 import android.preference.PreferenceManager;
  30 import android.text.SpannableStringBuilder;
  31 import android.text.Spanned;
  32 import android.text.style.ForegroundColorSpan;
  33 import android.view.LayoutInflater;
  34 import android.view.View;
  35 import android.view.ViewGroup;
  36 import android.webkit.WebView;
  37 import android.widget.TextView;
  38
  39 import androidx.annotation.NonNull;
  40 import androidx.fragment.app.Fragment;
  41
  42 import com.stoutner.privacybrowser.BuildConfig;
  43 import com.stoutner.privacybrowser.R;
  44
  45 import java.io.ByteArrayInputStream;
  46 import java.io.InputStream;
  47 import java.math.BigInteger;
  48 import java.security.Principal;
  49 import java.security.cert.CertificateException;
  50 import java.security.cert.CertificateFactory;
  51 import java.security.cert.X509Certificate;
  52 import java.text.DateFormat;
  53 import java.util.Date;
  54
  55 public class AboutTabFragment extends Fragment {
  56     // Declare the class variables.
  57     private int tabNumber;
  58     private String[] blocklistVersions;
  59
  60     public static AboutTabFragment createTab(int tabNumber, String[] blocklistVersions) {
  61         // Create a bundle.
  62         Bundle argumentsBundle = new Bundle();
  63
  64         // Store the tab number in the bundle.
  65         argumentsBundle.putInt("tab_number", tabNumber);
  66         argumentsBundle.putStringArray("blocklist_versions", blocklistVersions);
  67
  68         // Create a new instance of the tab fragment.
  69         AboutTabFragment aboutTabFragment = new AboutTabFragment();
  70
  71         // Add the arguments bundle to the fragment.
  72         aboutTabFragment.setArguments(argumentsBundle);
  73
  74         // Return the new fragment.
  75         return aboutTabFragment;
  76     }
  77
  78     @Override
  79     public void onCreate(Bundle savedInstanceState) {
  80         // Run the default commands.
  81         super.onCreate(savedInstanceState);
  82
  83         // Get a handle for the arguments.
  84         Bundle arguments = getArguments();
  85
  86         // Remove the incorrect lint warning below that arguments might be null.
  87         assert arguments != null;
  88
  89         // Store the arguments in class variables.
  90         tabNumber = getArguments().getInt("tab_number");
  91         blocklistVersions = getArguments().getStringArray("blocklist_versions");
  92     }
  93
  94     @Override
  95     public View onCreateView(@NonNull LayoutInflater layoutInflater, ViewGroup container, Bundle savedInstanceState) {
  96         // Create a tab layout view.
  97         View tabLayout;
  98
  99         // Get a handle for the context and assert that it isn't null.
 100         Context context = getContext();
 101         assert context != null;
 102
 103         // Get a handle for the shared preferences.
 104         SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
 105
 106         // Get the theme preference.
 107         boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);
 108
 109         // Load the tabs.  Tab numbers start at 0.
 110         if (tabNumber == 0) {  // Load the about tab.
 111             // Setting false at the end of inflater.inflate does not attach the inflated layout as a child of container.  The fragment will take care of attaching the root automatically.
 112             tabLayout = layoutInflater.inflate(R.layout.about_tab_version, container, false);
 113
 114             // Get handles for the `TextViews`.
 115             TextView versionTextView = tabLayout.findViewById(R.id.version);
 116             TextView brandTextView = tabLayout.findViewById(R.id.brand);
 117             TextView manufacturerTextView = tabLayout.findViewById(R.id.manufacturer);
 118             TextView modelTextView = tabLayout.findViewById(R.id.model);
 119             TextView deviceTextView = tabLayout.findViewById(R.id.device);
 120             TextView bootloaderTextView = tabLayout.findViewById(R.id.bootloader);
 121             TextView radioTextView = tabLayout.findViewById(R.id.radio);
 122             TextView androidTextView = tabLayout.findViewById(R.id.android);
 123             TextView securityPatchTextView = tabLayout.findViewById(R.id.security_patch);
 124             TextView buildTextView = tabLayout.findViewById(R.id.build);
 125             TextView webViewTextView = tabLayout.findViewById(R.id.webview);
 126             TextView orbotTextView = tabLayout.findViewById(R.id.orbot);
 127             TextView openKeychainTextView = tabLayout.findViewById(R.id.open_keychain);
 128             TextView easyListTextView = tabLayout.findViewById(R.id.easylist);
 129             TextView easyPrivacyTextView = tabLayout.findViewById(R.id.easyprivacy);
 130             TextView fanboyAnnoyanceTextView = tabLayout.findViewById(R.id.fanboy_annoyance);
 131             TextView fanboySocialTextView = tabLayout.findViewById(R.id.fanboy_social);
 132             TextView ultraPrivacyTextView = tabLayout.findViewById(R.id.ultraprivacy);
 133             TextView certificateIssuerDNTextView = tabLayout.findViewById(R.id.certificate_issuer_dn);
 134             TextView certificateSubjectDNTextView = tabLayout.findViewById(R.id.certificate_subject_dn);
 135             TextView certificateStartDateTextView = tabLayout.findViewById(R.id.certificate_start_date);
 136             TextView certificateEndDateTextView = tabLayout.findViewById(R.id.certificate_end_date);
 137             TextView certificateVersionTextView = tabLayout.findViewById(R.id.certificate_version);
 138             TextView certificateSerialNumberTextView = tabLayout.findViewById(R.id.certificate_serial_number);
 139             TextView certificateSignatureAlgorithmTextView = tabLayout.findViewById(R.id.certificate_signature_algorithm);
 140
 141             // Setup the labels.
 142             String version = getString(R.string.version) + " " + BuildConfig.VERSION_NAME + " (" + getString(R.string.version_code) + " " + BuildConfig.VERSION_CODE + ")";
 143             String brandLabel = getString(R.string.brand) + "  ";
 144             String manufacturerLabel = getString(R.string.manufacturer) + "  ";
 145             String modelLabel = getString(R.string.model) + "  ";
 146             String deviceLabel = getString(R.string.device) + "  ";
 147             String bootloaderLabel = getString(R.string.bootloader) + "  ";
 148             String androidLabel = getString(R.string.android) + "  ";
 149             String buildLabel = getString(R.string.build) + "  ";
 150             String webViewLabel = getString(R.string.webview) + "  ";
 151             String easyListLabel = getString(R.string.easylist_label) + "  ";
 152             String easyPrivacyLabel = getString(R.string.easyprivacy_label) + "  ";
 153             String fanboyAnnoyanceLabel = getString(R.string.fanboy_annoyance_label) + "  ";
 154             String fanboySocialLabel = getString(R.string.fanboy_social_label) + "  ";
 155             String ultraPrivacyLabel = getString(R.string.ultraprivacy_label) + "  ";
 156             String issuerDNLabel = getString(R.string.issuer_dn) + "  ";
 157             String subjectDNLabel = getString(R.string.subject_dn) + "  ";
 158             String startDateLabel = getString(R.string.start_date) + "  ";
 159             String endDateLabel = getString(R.string.end_date) + "  ";
 160             String certificateVersionLabel = getString(R.string.certificate_version) + "  ";
 161             String serialNumberLabel = getString(R.string.serial_number) + "  ";
 162             String signatureAlgorithmLabel = getString(R.string.signature_algorithm) + "  ";
 163
 164             // `webViewLayout` is only used to get the default user agent from `bare_webview`.  It is not used to render content on the screen.
 165             View webViewLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 166             WebView tabLayoutWebView = webViewLayout.findViewById(R.id.bare_webview);
 167             String userAgentString =  tabLayoutWebView.getSettings().getUserAgentString();
 168
 169             // Get the device's information and store it in strings.
 170             String brand = Build.BRAND;
 171             String manufacturer = Build.MANUFACTURER;
 172             String model = Build.MODEL;
 173             String device = Build.DEVICE;
 174             String bootloader = Build.BOOTLOADER;
 175             String radio = Build.getRadioVersion();
 176             String android = Build.VERSION.RELEASE + " (" + getString(R.string.api) + " " + Build.VERSION.SDK_INT + ")";
 177             String build = Build.DISPLAY;
 178             // Select the substring that begins after `Chrome/` and goes until the next ` `.
 179             String webView = userAgentString.substring(userAgentString.indexOf("Chrome/") + 7, userAgentString.indexOf(" ", userAgentString.indexOf("Chrome/")));
 180
 181             // Get the Orbot version name if Orbot is installed.
 182             String orbot;
 183             try {
 184                 // Store the version name.
 185                 orbot = context.getPackageManager().getPackageInfo("org.torproject.android", 0).versionName;
 186             } catch (PackageManager.NameNotFoundException exception) {  // Orbot is not installed.
 187                 orbot = "";
 188             }
 189
 190             // Get the OpenKeychain version name if it is installed.
 191             String openKeychain;
 192             try {
 193                 // Store the version name.
 194                 openKeychain = context.getPackageManager().getPackageInfo("org.sufficientlysecure.keychain", 0).versionName;
 195             } catch (PackageManager.NameNotFoundException exception) {  // OpenKeychain is not installed.
 196                 openKeychain = "";
 197             }
 198
 199             // Create a `SpannableStringBuilder` for the hardware and software `TextViews` that needs multiple colors of text.
 200             SpannableStringBuilder brandStringBuilder = new SpannableStringBuilder(brandLabel + brand);
 201             SpannableStringBuilder manufacturerStringBuilder = new SpannableStringBuilder(manufacturerLabel + manufacturer);
 202             SpannableStringBuilder modelStringBuilder = new SpannableStringBuilder(modelLabel + model);
 203             SpannableStringBuilder deviceStringBuilder = new SpannableStringBuilder(deviceLabel + device);
 204             SpannableStringBuilder bootloaderStringBuilder = new SpannableStringBuilder(bootloaderLabel + bootloader);
 205             SpannableStringBuilder androidStringBuilder = new SpannableStringBuilder(androidLabel + android);
 206             SpannableStringBuilder buildStringBuilder = new SpannableStringBuilder(buildLabel + build);
 207             SpannableStringBuilder webViewStringBuilder = new SpannableStringBuilder(webViewLabel + webView);
 208             SpannableStringBuilder easyListStringBuilder = new SpannableStringBuilder(easyListLabel + blocklistVersions[0]);
 209             SpannableStringBuilder easyPrivacyStringBuilder = new SpannableStringBuilder(easyPrivacyLabel + blocklistVersions[1]);
 210             SpannableStringBuilder fanboyAnnoyanceStringBuilder = new SpannableStringBuilder(fanboyAnnoyanceLabel + blocklistVersions[2]);
 211             SpannableStringBuilder fanboySocialStringBuilder = new SpannableStringBuilder(fanboySocialLabel + blocklistVersions[3]);
 212             SpannableStringBuilder ultraPrivacyStringBuilder = new SpannableStringBuilder(ultraPrivacyLabel + blocklistVersions[4]);
 213
 214             // Create the `blueColorSpan` variable.
 215             ForegroundColorSpan blueColorSpan;
 216
 217             // Set `blueColorSpan` according to the theme.  We have to use the deprecated `getColor()` until API >= 23.
 218             if (darkTheme) {
 219                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_400));
 220             } else {
 221                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_700));
 222             }
 223
 224             // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 225             brandStringBuilder.setSpan(blueColorSpan, brandLabel.length(), brandStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 226             manufacturerStringBuilder.setSpan(blueColorSpan, manufacturerLabel.length(), manufacturerStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 227             modelStringBuilder.setSpan(blueColorSpan, modelLabel.length(), modelStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 228             deviceStringBuilder.setSpan(blueColorSpan, deviceLabel.length(), deviceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 229             bootloaderStringBuilder.setSpan(blueColorSpan, bootloaderLabel.length(), bootloaderStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 230             androidStringBuilder.setSpan(blueColorSpan, androidLabel.length(), androidStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 231             buildStringBuilder.setSpan(blueColorSpan, buildLabel.length(), buildStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 232             webViewStringBuilder.setSpan(blueColorSpan, webViewLabel.length(), webViewStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 233             easyListStringBuilder.setSpan(blueColorSpan, easyListLabel.length(), easyListStringBuilder.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
 234             easyPrivacyStringBuilder.setSpan(blueColorSpan, easyPrivacyLabel.length(), easyPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 235             fanboyAnnoyanceStringBuilder.setSpan(blueColorSpan, fanboyAnnoyanceLabel.length(), fanboyAnnoyanceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 236             fanboySocialStringBuilder.setSpan(blueColorSpan, fanboySocialLabel.length(), fanboySocialStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 237             ultraPrivacyStringBuilder.setSpan(blueColorSpan, ultraPrivacyLabel.length(), ultraPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 238
 239             // Display the strings in the text boxes.
 240             versionTextView.setText(version);
 241             brandTextView.setText(brandStringBuilder);
 242             manufacturerTextView.setText(manufacturerStringBuilder);
 243             modelTextView.setText(modelStringBuilder);
 244             deviceTextView.setText(deviceStringBuilder);
 245             bootloaderTextView.setText(bootloaderStringBuilder);
 246             androidTextView.setText(androidStringBuilder);
 247             buildTextView.setText(buildStringBuilder);
 248             webViewTextView.setText(webViewStringBuilder);
 249             easyListTextView.setText(easyListStringBuilder);
 250             easyPrivacyTextView.setText(easyPrivacyStringBuilder);
 251             fanboyAnnoyanceTextView.setText(fanboyAnnoyanceStringBuilder);
 252             fanboySocialTextView.setText(fanboySocialStringBuilder);
 253             ultraPrivacyTextView.setText(ultraPrivacyStringBuilder);
 254
 255             // Build.VERSION.SECURITY_PATCH is only available for SDK_INT >= 23.
 256             if (Build.VERSION.SDK_INT >= 23) {
 257                 String securityPatchLabel = getString(R.string.security_patch) + "  ";
 258                 String securityPatch = Build.VERSION.SECURITY_PATCH;
 259                 SpannableStringBuilder securityPatchStringBuilder = new SpannableStringBuilder(securityPatchLabel + securityPatch);
 260                 securityPatchStringBuilder.setSpan(blueColorSpan, securityPatchLabel.length(), securityPatchStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 261                 securityPatchTextView.setText(securityPatchStringBuilder);
 262             } else {  // SDK_INT < 23.
 263                 securityPatchTextView.setVisibility(View.GONE);
 264             }
 265
 266             // Only populate the radio text view if there is a radio in the device.
 267             if (!radio.isEmpty()) {
 268                 String radioLabel = getString(R.string.radio) + "  ";
 269                 SpannableStringBuilder radioStringBuilder = new SpannableStringBuilder(radioLabel + radio);
 270                 radioStringBuilder.setSpan(blueColorSpan, radioLabel.length(), radioStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 271                 radioTextView.setText(radioStringBuilder);
 272             } else {  // This device does not have a radio.
 273                 radioTextView.setVisibility(View.GONE);
 274             }
 275
 276             // Only populate the Orbot text view if it is installed.
 277             if (!orbot.isEmpty()) {
 278                 String orbotLabel = getString(R.string.orbot) + "  ";
 279                 SpannableStringBuilder orbotStringBuilder = new SpannableStringBuilder(orbotLabel + orbot);
 280                 orbotStringBuilder.setSpan(blueColorSpan, orbotLabel.length(), orbotStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 281                 orbotTextView.setText(orbotStringBuilder);
 282             } else {  // Orbot is not installed.
 283                 orbotTextView.setVisibility(View.GONE);
 284             }
 285
 286             // Only populate the OpenKeychain text view if it is installed.
 287             if (!openKeychain.isEmpty()) {
 288                 String openKeychainLabel = getString(R.string.openkeychain) + "  ";
 289                 SpannableStringBuilder openKeychainStringBuilder = new SpannableStringBuilder(openKeychainLabel + openKeychain);
 290                 openKeychainStringBuilder.setSpan(blueColorSpan, openKeychainLabel.length(), openKeychainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 291                 openKeychainTextView.setText(openKeychainStringBuilder);
 292             } else {  //OpenKeychain is not installed.
 293                 openKeychainTextView.setVisibility(View.GONE);
 294             }
 295
 296             // Display the package signature.
 297             try {
 298                 // Get the first package signature.  Suppress the lint warning about the need to be careful in implementing comparison of certificates for security purposes.
 299                 @SuppressLint("PackageManagerGetSignatures") Signature packageSignature = getContext().getPackageManager().getPackageInfo(getContext().getPackageName(), PackageManager.GET_SIGNATURES).signatures[0];
 300
 301                 // Convert the signature to a `byte[]` `InputStream`.
 302                 InputStream certificateByteArrayInputStream = new ByteArrayInputStream(packageSignature.toByteArray());
 303
 304                 // Display the certificate information on the screen.
 305                 try {
 306                     // Instantiate a `CertificateFactory`.
 307                     CertificateFactory certificateFactory = CertificateFactory.getInstance("X509");
 308
 309                     // Generate an `X509Certificate`.
 310                     X509Certificate x509Certificate = (X509Certificate) certificateFactory.generateCertificate(certificateByteArrayInputStream);
 311
 312                     // Store the individual sections of the certificate that we are interested in.
 313                     Principal issuerDNPrincipal = x509Certificate.getIssuerDN();
 314                     Principal subjectDNPrincipal = x509Certificate.getSubjectDN();
 315                     Date startDate = x509Certificate.getNotBefore();
 316                     Date endDate = x509Certificate.getNotAfter();
 317                     int certificateVersion = x509Certificate.getVersion();
 318                     BigInteger serialNumberBigInteger = x509Certificate.getSerialNumber();
 319                     String signatureAlgorithmNameString = x509Certificate.getSigAlgName();
 320
 321                     // Create a `SpannableStringBuilder` for each `TextView` that needs multiple colors of text.
 322                     SpannableStringBuilder issuerDNStringBuilder = new SpannableStringBuilder(issuerDNLabel + issuerDNPrincipal.toString());
 323                     SpannableStringBuilder subjectDNStringBuilder = new SpannableStringBuilder(subjectDNLabel + subjectDNPrincipal.toString());
 324                     SpannableStringBuilder startDateStringBuilder = new SpannableStringBuilder(startDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(startDate));
 325                     SpannableStringBuilder endDataStringBuilder = new SpannableStringBuilder(endDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(endDate));
 326                     SpannableStringBuilder certificateVersionStringBuilder = new SpannableStringBuilder(certificateVersionLabel + certificateVersion);
 327                     SpannableStringBuilder serialNumberStringBuilder = new SpannableStringBuilder(serialNumberLabel + serialNumberBigInteger);
 328                     SpannableStringBuilder signatureAlgorithmStringBuilder = new SpannableStringBuilder(signatureAlgorithmLabel + signatureAlgorithmNameString);
 329
 330                     // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 331                     issuerDNStringBuilder.setSpan(blueColorSpan, issuerDNLabel.length(), issuerDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 332                     subjectDNStringBuilder.setSpan(blueColorSpan, subjectDNLabel.length(), subjectDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 333                     startDateStringBuilder.setSpan(blueColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 334                     endDataStringBuilder.setSpan(blueColorSpan, endDateLabel.length(), endDataStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 335                     certificateVersionStringBuilder.setSpan(blueColorSpan, certificateVersionLabel.length(), certificateVersionStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 336                     serialNumberStringBuilder.setSpan(blueColorSpan, serialNumberLabel.length(), serialNumberStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 337                     signatureAlgorithmStringBuilder.setSpan(blueColorSpan, signatureAlgorithmLabel.length(), signatureAlgorithmStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 338
 339                     // Display the strings in the text boxes.
 340                     certificateIssuerDNTextView.setText(issuerDNStringBuilder);
 341                     certificateSubjectDNTextView.setText(subjectDNStringBuilder);
 342                     certificateStartDateTextView.setText(startDateStringBuilder);
 343                     certificateEndDateTextView.setText(endDataStringBuilder);
 344                     certificateVersionTextView.setText(certificateVersionStringBuilder);
 345                     certificateSerialNumberTextView.setText(serialNumberStringBuilder);
 346                     certificateSignatureAlgorithmTextView.setText(signatureAlgorithmStringBuilder);
 347                 } catch (CertificateException e) {
 348                     // Do nothing if there is a certificate error.
 349                 }
 350             } catch (PackageManager.NameNotFoundException e) {
 351                 // Do nothing if `PackageManager` says Privacy Browser isn't installed.
 352             }
 353         } else { // load a `WebView` for all the other tabs.  Tab numbers start at 0.
 354             // Setting false at the end of inflater.inflate does not attach the inflated layout as a child of container.  The fragment will take care of attaching the root automatically.
 355             tabLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 356
 357             // Get a handle for `tabWebView`.
 358             WebView tabWebView = (WebView) tabLayout;
 359
 360             // Load the tabs according to the theme.
 361             if (darkTheme) {  // The dark theme is applied.
 362                 // Set the background color.  The deprecated `.getColor()` must be used until the minimum API >= 23.
 363                 tabWebView.setBackgroundColor(getResources().getColor(R.color.gray_850));
 364
 365                 switch (tabNumber) {
 366                     case 1:
 367                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_dark.html");
 368                         break;
 369
 370                     case 2:
 371                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_dark.html");
 372                         break;
 373
 374                     case 3:
 375                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_dark.html");
 376                         break;
 377
 378                     case 4:
 379                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_dark.html");
 380                         break;
 381
 382                     case 5:
 383                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_dark.html");
 384                         break;
 385
 386                     case 6:
 387                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_dark.html");
 388                         break;
 389                 }
 390             } else {  // The light theme is applied.
 391                 switch (tabNumber) {
 392                     case 1:
 393                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_light.html");
 394                         break;
 395
 396                     case 2:
 397                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_light.html");
 398                         break;
 399
 400                     case 3:
 401                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_light.html");
 402                         break;
 403
 404                     case 4:
 405                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_light.html");
 406                         break;
 407
 408                     case 5:
 409                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_light.html");
 410                         break;
 411
 412                     case 6:
 413                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_light.html");
 414                         break;
 415                 }
 416             }
 417         }
 418
 419         // Return the formatted `tabLayout`.
 420         return tabLayout;
 421     }
 422 }