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