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

   1 /*
   2  * Copyright © 2016-2020 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.app.Activity;
  24 import android.app.ActivityManager;
  25 import android.content.Context;
  26 import android.content.pm.PackageInfo;
  27 import android.content.pm.PackageManager;
  28 import android.content.pm.Signature;
  29 import android.content.res.Configuration;
  30 import android.os.Build;
  31 import android.os.Bundle;
  32 import android.os.Handler;
  33 import android.text.SpannableStringBuilder;
  34 import android.text.Spanned;
  35 import android.text.style.ForegroundColorSpan;
  36 import android.view.LayoutInflater;
  37 import android.view.View;
  38 import android.view.ViewGroup;
  39 import android.webkit.WebView;
  40 import android.widget.TextView;
  41
  42 import androidx.annotation.NonNull;
  43 import androidx.fragment.app.Fragment;
  44 import androidx.webkit.WebViewCompat;
  45
  46 import com.stoutner.privacybrowser.BuildConfig;
  47 import com.stoutner.privacybrowser.R;
  48
  49 import java.io.ByteArrayInputStream;
  50 import java.io.InputStream;
  51 import java.math.BigInteger;
  52 import java.security.Principal;
  53 import java.security.cert.CertificateException;
  54 import java.security.cert.CertificateFactory;
  55 import java.security.cert.X509Certificate;
  56 import java.text.DateFormat;
  57 import java.text.NumberFormat;
  58 import java.util.Date;
  59
  60 public class AboutTabFragment extends Fragment {
  61     // Declare the class constants.
  62     final static String TAB_NUMBER = "tab_number";
  63     final static String BLOCKLIST_VERSIONS = "blocklist_versions";
  64     final long MEBIBYTE = 1048576;
  65
  66     // Declare the class variables.
  67     private boolean updateMemoryUsageBoolean = true;
  68     private int tabNumber;
  69     private String[] blocklistVersions;
  70     private View tabLayout;
  71     private String appConsumedMemoryLabel;
  72     private String appAvailableMemoryLabel;
  73     private String appTotalMemoryLabel;
  74     private String appMaximumMemoryLabel;
  75     private String systemConsumedMemoryLabel;
  76     private String systemAvailableMemoryLabel;
  77     private String systemTotalMemoryLabel;
  78     private Runtime runtime;
  79     private ActivityManager activityManager;
  80     private ActivityManager.MemoryInfo memoryInfo;
  81     private NumberFormat numberFormat;
  82     private ForegroundColorSpan blueColorSpan;
  83
  84     // Declare the class views.
  85     private TextView appConsumedMemoryTextView;
  86     private TextView appAvailableMemoryTextView;
  87     private TextView appTotalMemoryTextView;
  88     private TextView appMaximumMemoryTextView;
  89     private TextView systemConsumedMemoryTextView;
  90     private TextView systemAvailableMemoryTextView;
  91     private TextView systemTotalMemoryTextView;
  92
  93     public static AboutTabFragment createTab(int tabNumber, String[] blocklistVersions) {
  94         // Create a bundle.
  95         Bundle argumentsBundle = new Bundle();
  96
  97         // Store the tab number in the bundle.
  98         argumentsBundle.putInt(TAB_NUMBER, tabNumber);
  99         argumentsBundle.putStringArray(BLOCKLIST_VERSIONS, blocklistVersions);
 100
 101         // Create a new instance of the tab fragment.
 102         AboutTabFragment aboutTabFragment = new AboutTabFragment();
 103
 104         // Add the arguments bundle to the fragment.
 105         aboutTabFragment.setArguments(argumentsBundle);
 106
 107         // Return the new fragment.
 108         return aboutTabFragment;
 109     }
 110
 111     @Override
 112     public void onCreate(Bundle savedInstanceState) {
 113         // Run the default commands.
 114         super.onCreate(savedInstanceState);
 115
 116         // Get a handle for the arguments.
 117         Bundle arguments = getArguments();
 118
 119         // Remove the incorrect lint warning below that arguments might be null.
 120         assert arguments != null;
 121
 122         // Store the arguments in class variables.
 123         tabNumber = getArguments().getInt(TAB_NUMBER);
 124         blocklistVersions = getArguments().getStringArray(BLOCKLIST_VERSIONS);
 125     }
 126
 127     @Override
 128     public View onCreateView(@NonNull LayoutInflater layoutInflater, ViewGroup container, Bundle savedInstanceState) {
 129         // Get a handle for the context and assert that it isn't null.
 130         Context context = getContext();
 131         assert context != null;
 132
 133         // Get the current theme status.
 134         int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
 135
 136         // Load the tabs.  Tab numbers start at 0.
 137         if (tabNumber == 0) {  // Load the about tab.
 138             // 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.
 139             tabLayout = layoutInflater.inflate(R.layout.about_tab_version, container, false);
 140
 141             // Get handles for the text views.
 142             TextView versionTextView = tabLayout.findViewById(R.id.version);
 143             TextView brandTextView = tabLayout.findViewById(R.id.brand);
 144             TextView manufacturerTextView = tabLayout.findViewById(R.id.manufacturer);
 145             TextView modelTextView = tabLayout.findViewById(R.id.model);
 146             TextView deviceTextView = tabLayout.findViewById(R.id.device);
 147             TextView bootloaderTextView = tabLayout.findViewById(R.id.bootloader);
 148             TextView radioTextView = tabLayout.findViewById(R.id.radio);
 149             TextView androidTextView = tabLayout.findViewById(R.id.android);
 150             TextView securityPatchTextView = tabLayout.findViewById(R.id.security_patch);
 151             TextView buildTextView = tabLayout.findViewById(R.id.build);
 152             TextView webViewProviderTextView = tabLayout.findViewById(R.id.webview_provider);
 153             TextView webViewVersionTextView = tabLayout.findViewById(R.id.webview_version);
 154             TextView orbotTextView = tabLayout.findViewById(R.id.orbot);
 155             TextView i2pTextView = tabLayout.findViewById(R.id.i2p);
 156             TextView openKeychainTextView = tabLayout.findViewById(R.id.open_keychain);
 157             appConsumedMemoryTextView = tabLayout.findViewById(R.id.app_consumed_memory);
 158             appAvailableMemoryTextView = tabLayout.findViewById(R.id.app_available_memory);
 159             appTotalMemoryTextView = tabLayout.findViewById(R.id.app_total_memory);
 160             appMaximumMemoryTextView = tabLayout.findViewById(R.id.app_maximum_memory);
 161             systemConsumedMemoryTextView = tabLayout.findViewById(R.id.system_consumed_memory);
 162             systemAvailableMemoryTextView = tabLayout.findViewById(R.id.system_available_memory);
 163             systemTotalMemoryTextView = tabLayout.findViewById(R.id.system_total_memory);
 164             TextView easyListTextView = tabLayout.findViewById(R.id.easylist);
 165             TextView easyPrivacyTextView = tabLayout.findViewById(R.id.easyprivacy);
 166             TextView fanboyAnnoyanceTextView = tabLayout.findViewById(R.id.fanboy_annoyance);
 167             TextView fanboySocialTextView = tabLayout.findViewById(R.id.fanboy_social);
 168             TextView ultraListTextView = tabLayout.findViewById(R.id.ultralist);
 169             TextView ultraPrivacyTextView = tabLayout.findViewById(R.id.ultraprivacy);
 170             TextView certificateIssuerDNTextView = tabLayout.findViewById(R.id.certificate_issuer_dn);
 171             TextView certificateSubjectDNTextView = tabLayout.findViewById(R.id.certificate_subject_dn);
 172             TextView certificateStartDateTextView = tabLayout.findViewById(R.id.certificate_start_date);
 173             TextView certificateEndDateTextView = tabLayout.findViewById(R.id.certificate_end_date);
 174             TextView certificateVersionTextView = tabLayout.findViewById(R.id.certificate_version);
 175             TextView certificateSerialNumberTextView = tabLayout.findViewById(R.id.certificate_serial_number);
 176             TextView certificateSignatureAlgorithmTextView = tabLayout.findViewById(R.id.certificate_signature_algorithm);
 177
 178             // Setup the labels.
 179             String version = getString(R.string.version) + " " + BuildConfig.VERSION_NAME + " (" + getString(R.string.version_code) + " " + BuildConfig.VERSION_CODE + ")";
 180             String brandLabel = getString(R.string.brand) + "  ";
 181             String manufacturerLabel = getString(R.string.manufacturer) + "  ";
 182             String modelLabel = getString(R.string.model) + "  ";
 183             String deviceLabel = getString(R.string.device) + "  ";
 184             String bootloaderLabel = getString(R.string.bootloader) + "  ";
 185             String androidLabel = getString(R.string.android) + "  ";
 186             String buildLabel = getString(R.string.build) + "  ";
 187             String webViewVersionLabel = getString(R.string.webview_version) + "  ";
 188             appConsumedMemoryLabel = getString(R.string.app_consumed_memory) + "  ";
 189             appAvailableMemoryLabel = getString(R.string.app_available_memory) + "  ";
 190             appTotalMemoryLabel = getString(R.string.app_total_memory) + "  ";
 191             appMaximumMemoryLabel = getString(R.string.app_maximum_memory) + "  ";
 192             systemConsumedMemoryLabel = getString(R.string.system_consumed_memory) + "  ";
 193             systemAvailableMemoryLabel = getString(R.string.system_available_memory) + "  ";
 194             systemTotalMemoryLabel = getString(R.string.system_total_memory) + "  ";
 195             String easyListLabel = getString(R.string.easylist_label) + "  ";
 196             String easyPrivacyLabel = getString(R.string.easyprivacy_label) + "  ";
 197             String fanboyAnnoyanceLabel = getString(R.string.fanboy_annoyance_label) + "  ";
 198             String fanboySocialLabel = getString(R.string.fanboy_social_label) + "  ";
 199             String ultraListLabel = getString(R.string.ultralist_label) + "  ";
 200             String ultraPrivacyLabel = getString(R.string.ultraprivacy_label) + "  ";
 201             String issuerDNLabel = getString(R.string.issuer_dn) + "  ";
 202             String subjectDNLabel = getString(R.string.subject_dn) + "  ";
 203             String startDateLabel = getString(R.string.start_date) + "  ";
 204             String endDateLabel = getString(R.string.end_date) + "  ";
 205             String certificateVersionLabel = getString(R.string.certificate_version) + "  ";
 206             String serialNumberLabel = getString(R.string.serial_number) + "  ";
 207             String signatureAlgorithmLabel = getString(R.string.signature_algorithm) + "  ";
 208
 209             // The WebView layout is only used to get the default user agent from `bare_webview`.  It is not used to render content on the screen.
 210             // Once the minimum API >= 26 this can be accomplished with the WebView package info.
 211             View webViewLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 212             WebView tabLayoutWebView = webViewLayout.findViewById(R.id.bare_webview);
 213             String userAgentString =  tabLayoutWebView.getSettings().getUserAgentString();
 214
 215             // Get the device's information and store it in strings.
 216             String brand = Build.BRAND;
 217             String manufacturer = Build.MANUFACTURER;
 218             String model = Build.MODEL;
 219             String device = Build.DEVICE;
 220             String bootloader = Build.BOOTLOADER;
 221             String radio = Build.getRadioVersion();
 222             String android = Build.VERSION.RELEASE + " (" + getString(R.string.api) + " " + Build.VERSION.SDK_INT + ")";
 223             String build = Build.DISPLAY;
 224             // Select the substring that begins after `Chrome/` and goes until the next ` `.
 225             String webView = userAgentString.substring(userAgentString.indexOf("Chrome/") + 7, userAgentString.indexOf(" ", userAgentString.indexOf("Chrome/")));
 226
 227             // Get the Orbot version name if Orbot is installed.
 228             String orbot;
 229             try {
 230                 // Store the version name.
 231                 orbot = context.getPackageManager().getPackageInfo("org.torproject.android", 0).versionName;
 232             } catch (PackageManager.NameNotFoundException exception) {  // Orbot is not installed.
 233                 orbot = "";
 234             }
 235
 236             // Get the I2P version name if I2P is installed.
 237             String i2p;
 238             try {
 239                 // Store the version name.
 240                 i2p = context.getPackageManager().getPackageInfo("net.i2p.android.router", 0).versionName;
 241             } catch (PackageManager.NameNotFoundException exception) {  // I2P is not installed.
 242                 i2p = "";
 243             }
 244
 245             // Get the OpenKeychain version name if it is installed.
 246             String openKeychain;
 247             try {
 248                 // Store the version name.
 249                 openKeychain = context.getPackageManager().getPackageInfo("org.sufficientlysecure.keychain", 0).versionName;
 250             } catch (PackageManager.NameNotFoundException exception) {  // OpenKeychain is not installed.
 251                 openKeychain = "";
 252             }
 253
 254             // Create a spannable string builder for the hardware and software text views that needs multiple colors of text.
 255             SpannableStringBuilder brandStringBuilder = new SpannableStringBuilder(brandLabel + brand);
 256             SpannableStringBuilder manufacturerStringBuilder = new SpannableStringBuilder(manufacturerLabel + manufacturer);
 257             SpannableStringBuilder modelStringBuilder = new SpannableStringBuilder(modelLabel + model);
 258             SpannableStringBuilder deviceStringBuilder = new SpannableStringBuilder(deviceLabel + device);
 259             SpannableStringBuilder bootloaderStringBuilder = new SpannableStringBuilder(bootloaderLabel + bootloader);
 260             SpannableStringBuilder androidStringBuilder = new SpannableStringBuilder(androidLabel + android);
 261             SpannableStringBuilder buildStringBuilder = new SpannableStringBuilder(buildLabel + build);
 262             SpannableStringBuilder webViewVersionStringBuilder = new SpannableStringBuilder(webViewVersionLabel + webView);
 263             SpannableStringBuilder easyListStringBuilder = new SpannableStringBuilder(easyListLabel + blocklistVersions[0]);
 264             SpannableStringBuilder easyPrivacyStringBuilder = new SpannableStringBuilder(easyPrivacyLabel + blocklistVersions[1]);
 265             SpannableStringBuilder fanboyAnnoyanceStringBuilder = new SpannableStringBuilder(fanboyAnnoyanceLabel + blocklistVersions[2]);
 266             SpannableStringBuilder fanboySocialStringBuilder = new SpannableStringBuilder(fanboySocialLabel + blocklistVersions[3]);
 267             SpannableStringBuilder ultraListStringBuilder = new SpannableStringBuilder(ultraListLabel + blocklistVersions[4]);
 268             SpannableStringBuilder ultraPrivacyStringBuilder = new SpannableStringBuilder(ultraPrivacyLabel + blocklistVersions[5]);
 269
 270             // Set the blue color span according to the theme.  The deprecated `getResources()` must be used until the minimum API >= 23.
 271             if (currentThemeStatus == Configuration.UI_MODE_NIGHT_NO) {
 272                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_700));
 273             } else {
 274                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.violet_500));
 275             }
 276
 277             // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 278             brandStringBuilder.setSpan(blueColorSpan, brandLabel.length(), brandStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 279             manufacturerStringBuilder.setSpan(blueColorSpan, manufacturerLabel.length(), manufacturerStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 280             modelStringBuilder.setSpan(blueColorSpan, modelLabel.length(), modelStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 281             deviceStringBuilder.setSpan(blueColorSpan, deviceLabel.length(), deviceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 282             bootloaderStringBuilder.setSpan(blueColorSpan, bootloaderLabel.length(), bootloaderStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 283             androidStringBuilder.setSpan(blueColorSpan, androidLabel.length(), androidStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 284             buildStringBuilder.setSpan(blueColorSpan, buildLabel.length(), buildStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 285             webViewVersionStringBuilder.setSpan(blueColorSpan, webViewVersionLabel.length(), webViewVersionStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 286             easyListStringBuilder.setSpan(blueColorSpan, easyListLabel.length(), easyListStringBuilder.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
 287             easyPrivacyStringBuilder.setSpan(blueColorSpan, easyPrivacyLabel.length(), easyPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 288             fanboyAnnoyanceStringBuilder.setSpan(blueColorSpan, fanboyAnnoyanceLabel.length(), fanboyAnnoyanceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 289             fanboySocialStringBuilder.setSpan(blueColorSpan, fanboySocialLabel.length(), fanboySocialStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 290             ultraListStringBuilder.setSpan(blueColorSpan, ultraListLabel.length(), ultraListStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 291             ultraPrivacyStringBuilder.setSpan(blueColorSpan, ultraPrivacyLabel.length(), ultraPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 292
 293             // Display the strings in the text boxes.
 294             versionTextView.setText(version);
 295             brandTextView.setText(brandStringBuilder);
 296             manufacturerTextView.setText(manufacturerStringBuilder);
 297             modelTextView.setText(modelStringBuilder);
 298             deviceTextView.setText(deviceStringBuilder);
 299             bootloaderTextView.setText(bootloaderStringBuilder);
 300             androidTextView.setText(androidStringBuilder);
 301             buildTextView.setText(buildStringBuilder);
 302             webViewVersionTextView.setText(webViewVersionStringBuilder);
 303             easyListTextView.setText(easyListStringBuilder);
 304             easyPrivacyTextView.setText(easyPrivacyStringBuilder);
 305             fanboyAnnoyanceTextView.setText(fanboyAnnoyanceStringBuilder);
 306             fanboySocialTextView.setText(fanboySocialStringBuilder);
 307             ultraListTextView.setText(ultraListStringBuilder);
 308             ultraPrivacyTextView.setText(ultraPrivacyStringBuilder);
 309
 310             // Only populate the radio text view if there is a radio in the device.
 311             if (!radio.isEmpty()) {
 312                 String radioLabel = getString(R.string.radio) + "  ";
 313                 SpannableStringBuilder radioStringBuilder = new SpannableStringBuilder(radioLabel + radio);
 314                 radioStringBuilder.setSpan(blueColorSpan, radioLabel.length(), radioStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 315                 radioTextView.setText(radioStringBuilder);
 316             } else {  // This device does not have a radio.
 317                 radioTextView.setVisibility(View.GONE);
 318             }
 319
 320             // Build.VERSION.SECURITY_PATCH is only available for SDK_INT >= 23.
 321             if (Build.VERSION.SDK_INT >= 23) {
 322                 String securityPatchLabel = getString(R.string.security_patch) + "  ";
 323                 String securityPatch = Build.VERSION.SECURITY_PATCH;
 324                 SpannableStringBuilder securityPatchStringBuilder = new SpannableStringBuilder(securityPatchLabel + securityPatch);
 325                 securityPatchStringBuilder.setSpan(blueColorSpan, securityPatchLabel.length(), securityPatchStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 326                 securityPatchTextView.setText(securityPatchStringBuilder);
 327             } else {  // The API < 23.
 328                 // Hide the security patch text view.
 329                 securityPatchTextView.setVisibility(View.GONE);
 330             }
 331
 332             // Only populate the WebView provider if the SDK >= 21.
 333             if (Build.VERSION.SDK_INT >= 21) {
 334                 // Create the WebView provider label.
 335                 String webViewProviderLabel = getString(R.string.webview_provider) + "  ";
 336
 337                 // Get the current WebView package info.
 338                 PackageInfo webViewPackageInfo = WebViewCompat.getCurrentWebViewPackage(context);
 339
 340                 // Remove the warning below that the package info might be null.
 341                 assert webViewPackageInfo != null;
 342
 343                 // Get the WebView provider name.
 344                 String webViewPackageName = webViewPackageInfo.packageName;
 345
 346                 // Create the spannable string builder.
 347                 SpannableStringBuilder webViewProviderStringBuilder = new SpannableStringBuilder(webViewProviderLabel + webViewPackageName);
 348
 349                 // Apply the coloration.
 350                 webViewProviderStringBuilder.setSpan(blueColorSpan, webViewProviderLabel.length(), webViewProviderStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 351
 352                 // Display the WebView provider.
 353                 webViewProviderTextView.setText(webViewProviderStringBuilder);
 354             } else {  // The API < 21.
 355                 // Hide the WebView provider text view.
 356                 webViewProviderTextView.setVisibility(View.GONE);
 357             }
 358
 359             // Only populate the Orbot text view if it is installed.
 360             if (!orbot.isEmpty()) {
 361                 String orbotLabel = getString(R.string.orbot) + "  ";
 362                 SpannableStringBuilder orbotStringBuilder = new SpannableStringBuilder(orbotLabel + orbot);
 363                 orbotStringBuilder.setSpan(blueColorSpan, orbotLabel.length(), orbotStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 364                 orbotTextView.setText(orbotStringBuilder);
 365             } else {  // Orbot is not installed.
 366                 orbotTextView.setVisibility(View.GONE);
 367             }
 368
 369             // Only populate the I2P text view if it is installed.
 370             if (!i2p.isEmpty()) {
 371                 String i2pLabel = getString(R.string.i2p)  + "  ";
 372                 SpannableStringBuilder i2pStringBuilder = new SpannableStringBuilder(i2pLabel + i2p);
 373                 i2pStringBuilder.setSpan(blueColorSpan, i2pLabel.length(), i2pStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 374                 i2pTextView.setText(i2pStringBuilder);
 375             } else {  // I2P is not installed.
 376                 i2pTextView.setVisibility(View.GONE);
 377             }
 378
 379             // Only populate the OpenKeychain text view if it is installed.
 380             if (!openKeychain.isEmpty()) {
 381                 String openKeychainLabel = getString(R.string.openkeychain) + "  ";
 382                 SpannableStringBuilder openKeychainStringBuilder = new SpannableStringBuilder(openKeychainLabel + openKeychain);
 383                 openKeychainStringBuilder.setSpan(blueColorSpan, openKeychainLabel.length(), openKeychainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 384                 openKeychainTextView.setText(openKeychainStringBuilder);
 385             } else {  //OpenKeychain is not installed.
 386                 openKeychainTextView.setVisibility(View.GONE);
 387             }
 388
 389             // Display the package signature.
 390             try {
 391                 // Get the first package signature.  Suppress the lint warning about the need to be careful in implementing comparison of certificates for security purposes.
 392                 @SuppressLint("PackageManagerGetSignatures") Signature packageSignature = getContext().getPackageManager().getPackageInfo(getContext().getPackageName(),
 393                         PackageManager.GET_SIGNATURES).signatures[0];
 394
 395                 // Convert the signature to a byte array input stream.
 396                 InputStream certificateByteArrayInputStream = new ByteArrayInputStream(packageSignature.toByteArray());
 397
 398                 // Display the certificate information on the screen.
 399                 try {
 400                     // Instantiate a `CertificateFactory`.
 401                     CertificateFactory certificateFactory = CertificateFactory.getInstance("X509");
 402
 403                     // Generate an `X509Certificate`.
 404                     X509Certificate x509Certificate = (X509Certificate) certificateFactory.generateCertificate(certificateByteArrayInputStream);
 405
 406                     // Store the individual sections of the certificate that we are interested in.
 407                     Principal issuerDNPrincipal = x509Certificate.getIssuerDN();
 408                     Principal subjectDNPrincipal = x509Certificate.getSubjectDN();
 409                     Date startDate = x509Certificate.getNotBefore();
 410                     Date endDate = x509Certificate.getNotAfter();
 411                     int certificateVersion = x509Certificate.getVersion();
 412                     BigInteger serialNumberBigInteger = x509Certificate.getSerialNumber();
 413                     String signatureAlgorithmNameString = x509Certificate.getSigAlgName();
 414
 415                     // Create a `SpannableStringBuilder` for each `TextView` that needs multiple colors of text.
 416                     SpannableStringBuilder issuerDNStringBuilder = new SpannableStringBuilder(issuerDNLabel + issuerDNPrincipal.toString());
 417                     SpannableStringBuilder subjectDNStringBuilder = new SpannableStringBuilder(subjectDNLabel + subjectDNPrincipal.toString());
 418                     SpannableStringBuilder startDateStringBuilder = new SpannableStringBuilder(startDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(startDate));
 419                     SpannableStringBuilder endDataStringBuilder = new SpannableStringBuilder(endDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(endDate));
 420                     SpannableStringBuilder certificateVersionStringBuilder = new SpannableStringBuilder(certificateVersionLabel + certificateVersion);
 421                     SpannableStringBuilder serialNumberStringBuilder = new SpannableStringBuilder(serialNumberLabel + serialNumberBigInteger);
 422                     SpannableStringBuilder signatureAlgorithmStringBuilder = new SpannableStringBuilder(signatureAlgorithmLabel + signatureAlgorithmNameString);
 423
 424                     // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 425                     issuerDNStringBuilder.setSpan(blueColorSpan, issuerDNLabel.length(), issuerDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 426                     subjectDNStringBuilder.setSpan(blueColorSpan, subjectDNLabel.length(), subjectDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 427                     startDateStringBuilder.setSpan(blueColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 428                     endDataStringBuilder.setSpan(blueColorSpan, endDateLabel.length(), endDataStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 429                     certificateVersionStringBuilder.setSpan(blueColorSpan, certificateVersionLabel.length(), certificateVersionStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 430                     serialNumberStringBuilder.setSpan(blueColorSpan, serialNumberLabel.length(), serialNumberStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 431                     signatureAlgorithmStringBuilder.setSpan(blueColorSpan, signatureAlgorithmLabel.length(), signatureAlgorithmStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 432
 433                     // Display the strings in the text boxes.
 434                     certificateIssuerDNTextView.setText(issuerDNStringBuilder);
 435                     certificateSubjectDNTextView.setText(subjectDNStringBuilder);
 436                     certificateStartDateTextView.setText(startDateStringBuilder);
 437                     certificateEndDateTextView.setText(endDataStringBuilder);
 438                     certificateVersionTextView.setText(certificateVersionStringBuilder);
 439                     certificateSerialNumberTextView.setText(serialNumberStringBuilder);
 440                     certificateSignatureAlgorithmTextView.setText(signatureAlgorithmStringBuilder);
 441                 } catch (CertificateException e) {
 442                     // Do nothing if there is a certificate error.
 443                 }
 444
 445                 // Get a handle for the runtime.
 446                 runtime = Runtime.getRuntime();
 447
 448                 // Get a handle for the activity.
 449                 Activity activity = getActivity();
 450
 451                 // Remove the incorrect lint warning below that the activity might be null.
 452                 assert activity != null;
 453
 454                 // Get a handle for the activity manager.
 455                 activityManager = (ActivityManager) activity.getSystemService(Context.ACTIVITY_SERVICE);
 456
 457                 // Remove the incorrect lint warning below that the activity manager might be null.
 458                 assert activityManager != null;
 459
 460                 // Instantiate a memory info variable.
 461                 memoryInfo = new ActivityManager.MemoryInfo();
 462
 463                 // Define a number format.
 464                 numberFormat = NumberFormat.getInstance();
 465
 466                 // Set the minimum and maximum number of fraction digits.
 467                 numberFormat.setMinimumFractionDigits(2);
 468                 numberFormat.setMaximumFractionDigits(2);
 469
 470                 // Update the memory usage.
 471                 updateMemoryUsage(getActivity());
 472             } catch (PackageManager.NameNotFoundException e) {
 473                 // Do nothing if `PackageManager` says Privacy Browser isn't installed.
 474             }
 475         } else { // load a WebView for all the other tabs.  Tab numbers start at 0.
 476             // 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.
 477             tabLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 478
 479             // Get a handle for `tabWebView`.
 480             WebView tabWebView = (WebView) tabLayout;
 481
 482             // Load the tabs according to the theme.
 483             if (currentThemeStatus == Configuration.UI_MODE_NIGHT_YES) {  // The dark theme is applied.
 484                 // Set the background color.  The deprecated `.getColor()` must be used until the minimum API >= 23.
 485                 tabWebView.setBackgroundColor(getResources().getColor(R.color.gray_850));
 486
 487                 switch (tabNumber) {
 488                     case 1:
 489                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_dark.html");
 490                         break;
 491
 492                     case 2:
 493                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_dark.html");
 494                         break;
 495
 496                     case 3:
 497                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_dark.html");
 498                         break;
 499
 500                     case 4:
 501                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_dark.html");
 502                         break;
 503
 504                     case 5:
 505                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_dark.html");
 506                         break;
 507
 508                     case 6:
 509                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_dark.html");
 510                         break;
 511                 }
 512             } else {  // The light theme is applied.
 513                 switch (tabNumber) {
 514                     case 1:
 515                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_light.html");
 516                         break;
 517
 518                     case 2:
 519                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_light.html");
 520                         break;
 521
 522                     case 3:
 523                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_light.html");
 524                         break;
 525
 526                     case 4:
 527                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_light.html");
 528                         break;
 529
 530                     case 5:
 531                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_light.html");
 532                         break;
 533
 534                     case 6:
 535                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_light.html");
 536                         break;
 537                 }
 538             }
 539         }
 540
 541         // Scroll the tab if the saved instance state is not null.
 542         if (savedInstanceState != null) {
 543             tabLayout.post(() -> {
 544                 tabLayout.setScrollX(savedInstanceState.getInt("scroll_x"));
 545                 tabLayout.setScrollY(savedInstanceState.getInt("scroll_y"));
 546             });
 547         }
 548
 549         // Return the formatted `tabLayout`.
 550         return tabLayout;
 551     }
 552
 553     @Override
 554     public void onPause() {
 555         // Run the default commands.
 556         super.onPause();
 557
 558         // Pause the updating of the memory usage.
 559         updateMemoryUsageBoolean = false;
 560     }
 561
 562     @Override
 563     public void onResume() {
 564         // Run the default commands.
 565         super.onResume();
 566
 567         // Resume the updating of the memory usage.
 568         updateMemoryUsageBoolean = true;
 569     }
 570
 571     @Override
 572     public void onSaveInstanceState(@NonNull Bundle savedInstanceState) {
 573         // Run the default commands.
 574         super.onSaveInstanceState(savedInstanceState);
 575
 576         // Save the scroll positions if the tab layout is not null, which can happen if a tab is not currently selected.
 577         if (tabLayout != null) {
 578             savedInstanceState.putInt("scroll_x", tabLayout.getScrollX());
 579             savedInstanceState.putInt("scroll_y", tabLayout.getScrollY());
 580         }
 581     }
 582
 583     public void updateMemoryUsage(Activity activity) {
 584         try {
 585             // Update the memory usage if enabled.
 586             if (updateMemoryUsageBoolean) {
 587                 // Populate the memory info variable.
 588                 activityManager.getMemoryInfo(memoryInfo);
 589
 590                 // Get the app memory information.
 591                 long appAvailableMemoryLong = runtime.freeMemory();
 592                 long appTotalMemoryLong = runtime.totalMemory();
 593                 long appMaximumMemoryLong = runtime.maxMemory();
 594
 595                 // Calculate the app consumed memory.
 596                 long appConsumedMemoryLong = appTotalMemoryLong - appAvailableMemoryLong;
 597
 598                 // Get the system memory information.
 599                 long systemTotalMemoryLong = memoryInfo.totalMem;
 600                 long systemAvailableMemoryLong = memoryInfo.availMem;
 601
 602                 // Calculate the system consumed memory.
 603                 long systemConsumedMemoryLong = systemTotalMemoryLong - systemAvailableMemoryLong;
 604
 605                 // Convert the memory information into mebibytes.
 606                 float appConsumedMemoryFloat = (float) appConsumedMemoryLong / MEBIBYTE;
 607                 float appAvailableMemoryFloat = (float) appAvailableMemoryLong / MEBIBYTE;
 608                 float appTotalMemoryFloat = (float) appTotalMemoryLong / MEBIBYTE;
 609                 float appMaximumMemoryFloat = (float) appMaximumMemoryLong / MEBIBYTE;
 610                 float systemConsumedMemoryFloat = (float) systemConsumedMemoryLong / MEBIBYTE;
 611                 float systemAvailableMemoryFloat = (float) systemAvailableMemoryLong / MEBIBYTE;
 612                 float systemTotalMemoryFloat = (float) systemTotalMemoryLong / MEBIBYTE;
 613
 614                 // Get the mebibyte string.
 615                 String mebibyte = getString(R.string.mebibyte);
 616
 617                 // Calculate the mebibyte length.
 618                 int mebibyteLength = mebibyte.length();
 619
 620                 // Create spannable string builders.
 621                 SpannableStringBuilder appConsumedMemoryStringBuilder = new SpannableStringBuilder(appConsumedMemoryLabel + numberFormat.format(appConsumedMemoryFloat) + " " + mebibyte);
 622                 SpannableStringBuilder appAvailableMemoryStringBuilder = new SpannableStringBuilder(appAvailableMemoryLabel + numberFormat.format(appAvailableMemoryFloat) + " " + mebibyte);
 623                 SpannableStringBuilder appTotalMemoryStringBuilder = new SpannableStringBuilder(appTotalMemoryLabel + numberFormat.format(appTotalMemoryFloat) + " " + mebibyte);
 624                 SpannableStringBuilder appMaximumMemoryStringBuilder = new SpannableStringBuilder(appMaximumMemoryLabel + numberFormat.format(appMaximumMemoryFloat) + " " + mebibyte);
 625                 SpannableStringBuilder systemConsumedMemoryStringBuilder = new SpannableStringBuilder(systemConsumedMemoryLabel + numberFormat.format(systemConsumedMemoryFloat) + " " + mebibyte);
 626                 SpannableStringBuilder systemAvailableMemoryStringBuilder = new SpannableStringBuilder(systemAvailableMemoryLabel + numberFormat.format(systemAvailableMemoryFloat) + " " + mebibyte);
 627                 SpannableStringBuilder systemTotalMemoryStringBuilder = new SpannableStringBuilder(systemTotalMemoryLabel + numberFormat.format(systemTotalMemoryFloat) + " " + mebibyte);
 628
 629                 // Setup the spans to display the memory information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 630                 appConsumedMemoryStringBuilder.setSpan(blueColorSpan, appConsumedMemoryLabel.length(), appConsumedMemoryStringBuilder.length() - mebibyteLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 631                 appAvailableMemoryStringBuilder.setSpan(blueColorSpan, appAvailableMemoryLabel.length(), appAvailableMemoryStringBuilder.length() - mebibyteLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 632                 appTotalMemoryStringBuilder.setSpan(blueColorSpan, appTotalMemoryLabel.length(), appTotalMemoryStringBuilder.length() - mebibyteLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 633                 appMaximumMemoryStringBuilder.setSpan(blueColorSpan, appMaximumMemoryLabel.length(), appMaximumMemoryStringBuilder.length() - mebibyteLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 634                 systemConsumedMemoryStringBuilder.setSpan(blueColorSpan, systemConsumedMemoryLabel.length(), systemConsumedMemoryStringBuilder.length() - mebibyteLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 635                 systemAvailableMemoryStringBuilder.setSpan(blueColorSpan, systemAvailableMemoryLabel.length(), systemAvailableMemoryStringBuilder.length() - mebibyteLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 636                 systemTotalMemoryStringBuilder.setSpan(blueColorSpan, systemTotalMemoryLabel.length(), systemTotalMemoryStringBuilder.length() - mebibyteLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 637
 638                 // Display the string in the text boxes.
 639                 appConsumedMemoryTextView.setText(appConsumedMemoryStringBuilder);
 640                 appAvailableMemoryTextView.setText(appAvailableMemoryStringBuilder);
 641                 appTotalMemoryTextView.setText(appTotalMemoryStringBuilder);
 642                 appMaximumMemoryTextView.setText(appMaximumMemoryStringBuilder);
 643                 systemConsumedMemoryTextView.setText(systemConsumedMemoryStringBuilder);
 644                 systemAvailableMemoryTextView.setText(systemAvailableMemoryStringBuilder);
 645                 systemTotalMemoryTextView.setText(systemTotalMemoryStringBuilder);
 646             }
 647
 648             // Schedule another memory update if the activity has not been destroyed.
 649             if (!activity.isDestroyed()) {
 650                 // Create a handler to update the memory usage.
 651                 Handler updateMemoryUsageHandler = new Handler();
 652
 653                 // Create a runnable to update the memory usage.
 654                 Runnable updateMemoryUsageRunnable = () -> updateMemoryUsage(activity);
 655
 656                 // Update the memory usage after 1000 milliseconds
 657                 updateMemoryUsageHandler.postDelayed(updateMemoryUsageRunnable, 1000);
 658             }
 659         } catch (Exception exception) {
 660             // Do nothing.
 661         }
 662     }
 663 }