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

   1 /*
   2  * Copyright © 2016-2017 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.SharedPreferences;
  24 import android.os.Build;
  25 import android.os.Bundle;
  26 import android.preference.Preference;
  27 import android.preference.PreferenceFragment;
  28 import android.view.LayoutInflater;
  29 import android.view.View;
  30 import android.webkit.WebView;
  31
  32 import com.stoutner.privacybrowser.R;
  33
  34 public class SettingsFragment extends PreferenceFragment {
  35     private SharedPreferences.OnSharedPreferenceChangeListener preferencesListener;
  36     private SharedPreferences savedPreferences;
  37
  38     @Override
  39     public void onCreate(Bundle savedInstanceState) {
  40         super.onCreate(savedInstanceState);
  41         addPreferencesFromResource(R.xml.preferences);
  42
  43         // Initialize savedPreferences.
  44         savedPreferences = getPreferenceScreen().getSharedPreferences();
  45
  46         // Get handles for the preferences we need to modify.
  47         final Preference javaScriptPreference = findPreference("javascript_enabled");
  48         final Preference firstPartyCookiesPreference = findPreference("first_party_cookies_enabled");
  49         final Preference thirdPartyCookiesPreference = findPreference("third_party_cookies_enabled");
  50         final Preference domStoragePreference = findPreference("dom_storage_enabled");
  51         final Preference saveFormDataPreference = findPreference("save_form_data_enabled");
  52         final Preference userAgentPreference = findPreference("user_agent");
  53         final Preference customUserAgentPreference = findPreference("custom_user_agent");
  54         final Preference blockAdsPreference = findPreference("block_ads");
  55         final Preference incognitoModePreference = findPreference("incognito_mode");
  56         final Preference doNotTrackPreference = findPreference("do_not_track");
  57         final Preference proxyThroughOrbotPreference = findPreference("proxy_through_orbot");
  58         final Preference torHomepagePreference = findPreference("tor_homepage");
  59         final Preference torSearchPreference = findPreference("tor_search");
  60         final Preference torSearchCustomURLPreference = findPreference("tor_search_custom_url");
  61         final Preference searchPreference = findPreference("search");
  62         final Preference searchCustomURLPreference = findPreference("search_custom_url");
  63         final Preference hideSystemBarsPreference = findPreference("hide_system_bars");
  64         final Preference translucentNavigationBarPreference = findPreference("translucent_navigation_bar");
  65         final Preference homepagePreference = findPreference("homepage");
  66         final Preference defaultFontSizePreference = findPreference("default_font_size");
  67
  68         // Set dependencies.
  69         domStoragePreference.setDependency("javascript_enabled");
  70         torHomepagePreference.setDependency("proxy_through_orbot");
  71         torSearchPreference.setDependency("proxy_through_orbot");
  72         hideSystemBarsPreference.setDependency("enable_full_screen_browsing_mode");
  73
  74         // Get strings from the preferences.
  75         String torSearchString = savedPreferences.getString("tor_search", "https://3g2upl4pq6kufc4m.onion/html/?q=");
  76         String searchString = savedPreferences.getString("search", "https://duckduckgo.com/html/?q=");
  77
  78         // Get booleans from the preferences.
  79         boolean javaScriptEnabledBoolean = savedPreferences.getBoolean("javascript_enabled", false);
  80         boolean firstPartyCookiesEnabledBoolean = savedPreferences.getBoolean("first_party_cookies_enabled", false);
  81         boolean thirdPartyCookiesEnabledBoolean = savedPreferences.getBoolean("third_party_cookies_enabled", false);
  82         boolean proxyThroughOrbotBoolean = savedPreferences.getBoolean("proxy_through_orbot", false);
  83
  84         // Only enable `thirdPartyCookiesPreference` if `firstPartyCookiesEnabledBoolean` is `true` and API >= 21.
  85         thirdPartyCookiesPreference.setEnabled(firstPartyCookiesEnabledBoolean && (Build.VERSION.SDK_INT >= 21));
  86
  87         // We need to inflated a `WebView` to get the default user agent.
  88         LayoutInflater inflater = getActivity().getLayoutInflater();
  89         // `@SuppressLint("InflateParams")` removes the warning about using `null` as the `ViewGroup`, which in this case makes sense because we don't want to display `bare_webview` on the screen.  `false` does not attach the view to the root.
  90         @SuppressLint("InflateParams") View bareWebViewLayout = inflater.inflate(R.layout.bare_webview, null, false);
  91         final WebView bareWebView = (WebView) bareWebViewLayout.findViewById(R.id.bare_webview);
  92
  93         // Set the current user-agent as the summary text for the "user_agent" preference when the preference screen is loaded.
  94         switch (savedPreferences.getString("user_agent", "PrivacyBrowser/1.0")) {
  95             case "WebView default user agent":
  96                 // Get the user agent text from the webview (which changes based on the version of Android and WebView installed).
  97                 userAgentPreference.setSummary(bareWebView.getSettings().getUserAgentString());
  98                 break;
  99
 100             case "Custom user agent":
 101                 // We can't use the string from the array because it is referenced in code and can't be translated.
 102                 userAgentPreference.setSummary(R.string.custom_user_agent);
 103                 break;
 104
 105             default:
 106                 // Display the user agent from the preference as the summary text.
 107                 userAgentPreference.setSummary(savedPreferences.getString("user_agent", "PrivacyBrowser/1.0"));
 108                 break;
 109         }
 110
 111         // Set the summary text for "customUserAgentPreference" (the default is `PrivacyBrowser/1.0`) and enable it if `userAgentPreference` it set to `Custom user agent`.
 112         customUserAgentPreference.setSummary(savedPreferences.getString("custom_user_agent", "PrivacyBrowser/1.0"));
 113         customUserAgentPreference.setEnabled(userAgentPreference.getSummary().equals("Custom user agent"));
 114
 115
 116         // Set the Tor homepage URL as the summary text for the `tor_homepage` preference when the preference screen is loaded.  The default is DuckDuckGo: `https://3g2upl4pq6kufc4m.onion`.
 117         torHomepagePreference.setSummary(savedPreferences.getString("tor_homepage", "https://3g2upl4pq6kufc4m.onion"));
 118
 119
 120         // Set the Tor search URL as the summary text for the Tor preference when the preference screen is loaded.  The default is `https://3g2upl4pq6kufc4m.onion/html/?q=`
 121         if (torSearchString.equals("Custom URL")) {
 122             // Use R.string.custom_url, which will be translated, instead of the array value, which will not.
 123             torSearchPreference.setSummary(R.string.custom_url);
 124         } else {
 125             // Set the array value as the summary text.
 126             torSearchPreference.setSummary(torSearchString);
 127         }
 128
 129         // Set the summary text for `tor_search_custom_url`.  The default is `""`.
 130         torSearchCustomURLPreference.setSummary(savedPreferences.getString("tor_search_custom_url", ""));
 131
 132         // Enable the Tor custom URL search options only if proxying through Orbot and the search is set to `Custom URL`.
 133         torSearchCustomURLPreference.setEnabled(proxyThroughOrbotBoolean && torSearchString.equals("Custom URL"));
 134
 135
 136         // Set the search URL as the summary text for the search preference when the preference screen is loaded.  The default is `https://duckduckgo.com/html/?q=`.
 137         if (searchString.equals("Custom URL")) {
 138             // Use R.string.custom_url, which will be translated, instead of the array value, which will not.
 139             searchPreference.setSummary(R.string.custom_url);
 140         } else {
 141             // Set the array value as the summary text.
 142             searchPreference.setSummary(searchString);
 143         }
 144
 145         // Set the summary text for `search_custom_url` (the default is `""`) and enable it if `search` is set to `Custom URL`.
 146         searchCustomURLPreference.setSummary(savedPreferences.getString("search_custom_url", ""));
 147         searchCustomURLPreference.setEnabled(searchString.equals("Custom URL"));
 148
 149
 150         // Enable `transparent_navigation_bar` only if full screen browsing mode is enabled and `hide_system_bars` is disabled.
 151         translucentNavigationBarPreference.setEnabled(savedPreferences.getBoolean("enable_full_screen_browsing_mode", false) && !savedPreferences.getBoolean("hide_system_bars", false));
 152
 153
 154         // Set the homepage URL as the summary text for the `Homepage` preference when the preference screen is loaded.  The default is `https://duckduckgo.com`.
 155         homepagePreference.setSummary(savedPreferences.getString("homepage", "https://duckduckgo.com"));
 156
 157         // Set the default font size as the summary text for the `Default Font Size` preference when the preference screen is loaded.  The default is `100`.
 158         defaultFontSizePreference.setSummary(savedPreferences.getString("default_font_size", "100") + "%%");
 159
 160
 161         // Set the `javaScriptPreference` icon.
 162         if (javaScriptEnabledBoolean) {
 163             javaScriptPreference.setIcon(R.drawable.javascript_enabled);
 164         } else {
 165             javaScriptPreference.setIcon(R.drawable.privacy_mode);
 166         }
 167
 168         // Set the `firstPartyCookiesPreference` icon.
 169         if (firstPartyCookiesEnabledBoolean) {
 170             firstPartyCookiesPreference.setIcon(R.drawable.cookies_enabled);
 171         } else {
 172             firstPartyCookiesPreference.setIcon(R.drawable.cookies_disabled);
 173         }
 174
 175         // Set the `thirdPartyCookiesPreference` icon.
 176         if (firstPartyCookiesEnabledBoolean && Build.VERSION.SDK_INT >= 21) {
 177             if (thirdPartyCookiesEnabledBoolean) {
 178                 thirdPartyCookiesPreference.setIcon(R.drawable.cookies_warning);
 179             } else {
 180                 thirdPartyCookiesPreference.setIcon(R.drawable.cookies_disabled);
 181             }
 182         } else {
 183             thirdPartyCookiesPreference.setIcon(R.drawable.cookies_ghosted);
 184         }
 185
 186         // Set the `domStoragePreference` icon.
 187         if (javaScriptEnabledBoolean) {
 188             if (savedPreferences.getBoolean("dom_storage_enabled", false)) {
 189                 domStoragePreference.setIcon(R.drawable.dom_storage_enabled);
 190             } else {
 191                 domStoragePreference.setIcon(R.drawable.dom_storage_disabled);
 192             }
 193         } else {
 194             domStoragePreference.setIcon(R.drawable.dom_storage_ghosted);
 195         }
 196
 197         // Set the `saveFormDataPreference` icon.
 198         if (savedPreferences.getBoolean("save_form_data_enabled", false)) {
 199             saveFormDataPreference.setIcon(R.drawable.form_data_enabled);
 200         } else {
 201             saveFormDataPreference.setIcon(R.drawable.form_data_disabled);
 202         }
 203
 204         // Set the `customUserAgentPreference` icon.
 205         if (customUserAgentPreference.isEnabled()) {
 206             customUserAgentPreference.setIcon(R.drawable.custom_user_agent_enabled);
 207         } else {
 208             customUserAgentPreference.setIcon(R.drawable.custom_user_agent_ghosted);
 209         }
 210
 211         // Set the `blockAdsPreference` icon.
 212         if (savedPreferences.getBoolean("block_ads", true)) {
 213             blockAdsPreference.setIcon(R.drawable.block_ads_enabled);
 214         } else {
 215             blockAdsPreference.setIcon(R.drawable.block_ads_disabled);
 216         }
 217
 218         // Set the `incognitoModePreference` icon.
 219         if (savedPreferences.getBoolean("incognito_mode", false)) {
 220             incognitoModePreference.setIcon(R.drawable.incognito_mode_enabled);
 221         } else {
 222             incognitoModePreference.setIcon(R.drawable.incognito_mode_disabled);
 223         }
 224
 225         // Set the `doNotTrackPreference` icon.
 226         if (savedPreferences.getBoolean("do_not_track", false)) {
 227             doNotTrackPreference.setIcon(R.drawable.do_not_track_enabled);
 228         } else {
 229             doNotTrackPreference.setIcon(R.drawable.do_not_track_disabled);
 230         }
 231
 232         // Set the `proxyThroughOrbotPreference` icon.
 233         if (proxyThroughOrbotBoolean) {
 234             proxyThroughOrbotPreference.setIcon(R.drawable.orbot_enabled);
 235         } else {
 236             proxyThroughOrbotPreference.setIcon(R.drawable.orbot_disabled);
 237         }
 238
 239         // Set the `searchCustomURLPreference` icon.
 240         if (searchCustomURLPreference.isEnabled()) {
 241             searchCustomURLPreference.setIcon(R.drawable.search_custom_url_enabled);
 242         } else {
 243             searchCustomURLPreference.setIcon(R.drawable.search_custom_url_ghosted);
 244         }
 245
 246
 247         // Listen for preference changes.
 248         preferencesListener = new SharedPreferences.OnSharedPreferenceChangeListener() {
 249             @Override
 250             // Remove Android Studio's warning about the dangers of using SetJavaScriptEnabled.  We know.
 251             @SuppressLint("SetJavaScriptEnabled")
 252             public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
 253
 254                 switch (key) {
 255                     case "javascript_enabled":
 256                         // Update the icons.
 257                         if (sharedPreferences.getBoolean("javascript_enabled", false)) {
 258                             // Update the icon for `javascript_enabled`.
 259                             javaScriptPreference.setIcon(R.drawable.javascript_enabled);
 260
 261                             // Update the icon for `dom_storage_enabled`.
 262                             if (sharedPreferences.getBoolean("dom_storage_enabled", false)) {
 263                                 domStoragePreference.setIcon(R.drawable.dom_storage_enabled);
 264                             } else {
 265                                 domStoragePreference.setIcon(R.drawable.dom_storage_disabled);
 266                             }
 267                         } else {  // `javascript_enabled` is `false`.
 268                             // Update the icon for `javascript_enabled`.
 269                             javaScriptPreference.setIcon(R.drawable.privacy_mode);
 270
 271                             // Set the icon for `dom_storage_disabled` to be ghosted.
 272                             domStoragePreference.setIcon(R.drawable.dom_storage_ghosted);
 273                         }
 274                         break;
 275
 276                     case "first_party_cookies_enabled":
 277                         // Update the icons for `first_party_cookies_enabled` and `third_party_cookies_enabled`.
 278                         if (sharedPreferences.getBoolean("first_party_cookies_enabled", false)) {
 279                             // Set the icon for `first_party_cookies_enabled`.
 280                             firstPartyCookiesPreference.setIcon(R.drawable.cookies_enabled);
 281
 282                             // Update the icon for `third_party_cookies_enabled`.
 283                             if (Build.VERSION.SDK_INT >= 21) {
 284                                 if (sharedPreferences.getBoolean("third_party_cookies_enabled", false)) {
 285                                     thirdPartyCookiesPreference.setIcon(R.drawable.cookies_warning);
 286                                 } else {
 287                                     thirdPartyCookiesPreference.setIcon(R.drawable.cookies_disabled);
 288                                 }
 289                             } else {
 290                                 thirdPartyCookiesPreference.setIcon(R.drawable.cookies_ghosted);
 291                             }
 292                         } else {  // `first_party_cookies_enabled` is `false`.
 293                             // Update the icon for `first_party_cookies_enabled`.
 294                             firstPartyCookiesPreference.setIcon(R.drawable.cookies_disabled);
 295
 296                             // Set the icon for `third_party_cookies_enabled` to be ghosted.
 297                             thirdPartyCookiesPreference.setIcon(R.drawable.cookies_ghosted);
 298                         }
 299
 300                         // Enable `third_party_cookies_enabled` if `first_party_cookies_enabled` is `true` and API >= 21.
 301                         thirdPartyCookiesPreference.setEnabled(sharedPreferences.getBoolean("first_party_cookies_enabled", false) && (Build.VERSION.SDK_INT >= 21));
 302                         break;
 303
 304                     case "third_party_cookies_enabled":
 305                         // Update the icon.
 306                         if (sharedPreferences.getBoolean("third_party_cookies_enabled", false)) {
 307                             thirdPartyCookiesPreference.setIcon(R.drawable.cookies_warning);
 308                         } else {
 309                             thirdPartyCookiesPreference.setIcon(R.drawable.cookies_disabled);
 310                         }
 311                         break;
 312
 313                     case "dom_storage_enabled":
 314                         // Update the icon.
 315                         if (sharedPreferences.getBoolean("dom_storage_enabled", false)) {
 316                             domStoragePreference.setIcon(R.drawable.dom_storage_enabled);
 317                         } else {
 318                             domStoragePreference.setIcon(R.drawable.dom_storage_disabled);
 319                         }
 320                         break;
 321
 322                     case "save_form_data_enabled":
 323                         // Update the icon.
 324                         if (sharedPreferences.getBoolean("save_form_data_enabled", false)) {
 325                             saveFormDataPreference.setIcon(R.drawable.form_data_enabled);
 326                         } else {
 327                             saveFormDataPreference.setIcon(R.drawable.form_data_disabled);
 328                         }
 329
 330                     case "user_agent":
 331                         String userAgentString = sharedPreferences.getString("user_agent", "PrivacyBrowser/1.0");
 332
 333                         switch (userAgentString) {
 334                             case "WebView default user agent":
 335                                 // Display the user agent as the summary text for `userAgentPreference`.
 336                                 userAgentPreference.setSummary(bareWebView.getSettings().getUserAgentString());
 337
 338                                 // Update `customUserAgentPreference`.
 339                                 customUserAgentPreference.setEnabled(false);
 340                                 customUserAgentPreference.setIcon(R.drawable.custom_user_agent_ghosted);
 341                                 break;
 342
 343                             case "Custom user agent":
 344                                 // Display `Custom user agent` as the summary text for `userAgentPreference`.
 345                                 userAgentPreference.setSummary(R.string.custom_user_agent);
 346
 347                                 // Update `customUserAgentPreference`.
 348                                 customUserAgentPreference.setEnabled(true);
 349                                 customUserAgentPreference.setIcon(R.drawable.custom_user_agent_enabled);
 350                                 break;
 351
 352                             default:
 353                                 // Display the user agent as the summary text for `userAgentPreference`.
 354                                 userAgentPreference.setSummary(sharedPreferences.getString("user_agent", "PrivacyBrowser/1.0"));
 355
 356                                 // Update `customUserAgentPreference`.
 357                                 customUserAgentPreference.setEnabled(false);
 358                                 customUserAgentPreference.setIcon(R.drawable.custom_user_agent_ghosted);
 359                                 break;
 360                         }
 361                         break;
 362
 363                     case "custom_user_agent":
 364                         // Set the new custom user agent as the summary text for `custom_user_agent`.  The default is `PrivacyBrowser/1.0`.
 365                         customUserAgentPreference.setSummary(sharedPreferences.getString("custom_user_agent", "PrivacyBrowser/1.0"));
 366                         break;
 367
 368                     case "block_ads":
 369                         // Update the icon.
 370                         if (sharedPreferences.getBoolean("block_ads", true)) {
 371                             blockAdsPreference.setIcon(R.drawable.block_ads_enabled);
 372                         } else {
 373                             blockAdsPreference.setIcon(R.drawable.block_ads_disabled);
 374                         }
 375                         break;
 376
 377                     case "incognito_mode":
 378                         // Update the icon.
 379                         if (sharedPreferences.getBoolean("incognito_mode", false)) {
 380                             incognitoModePreference.setIcon(R.drawable.incognito_mode_enabled);
 381                         } else {
 382                             incognitoModePreference.setIcon(R.drawable.incognito_mode_disabled);
 383                         }
 384                         break;
 385
 386                     case "do_not_track":
 387                         // Update the icon.
 388                         if (sharedPreferences.getBoolean("do_not_track", false)) {
 389                             doNotTrackPreference.setIcon(R.drawable.do_not_track_enabled);
 390                         } else {
 391                             doNotTrackPreference.setIcon(R.drawable.do_not_track_disabled);
 392                         }
 393
 394                         break;
 395
 396                     case "proxy_through_orbot":
 397                         // Get current settings.
 398                         boolean currentProxyThroughOrbot = sharedPreferences.getBoolean("proxy_through_orbot", false);
 399                         String currentTorSearchString = sharedPreferences.getString("tor_search", "https://3g2upl4pq6kufc4m.onion/html/?q=");
 400
 401                         // Enable the Tor custom URL search option only if `currentProxyThroughOrbot` is true and the search is set to `Custom URL`.
 402                         torSearchCustomURLPreference.setEnabled(currentProxyThroughOrbot && currentTorSearchString.equals("Custom URL"));
 403
 404                         // Update the icon.
 405                         if (currentProxyThroughOrbot) {
 406                             proxyThroughOrbotPreference.setIcon(R.drawable.orbot_enabled);
 407                         } else {
 408                             proxyThroughOrbotPreference.setIcon(R.drawable.orbot_disabled);
 409                         }
 410                         break;
 411
 412                     case "tor_homepage":
 413                         // Set the new tor homepage URL as the summary text for the `tor_homepage` preference.  The default is DuckDuckGo:  `https://3g2upl4pq6kufc4m.onion`.
 414                         torHomepagePreference.setSummary(sharedPreferences.getString("tor_homepage", "https://3g2upl4pq6kufc4m.onion"));
 415                         break;
 416
 417                     case "tor_search":
 418                         // Get the present search string.
 419                         String presentTorSearchString = sharedPreferences.getString("tor_search", "https://3g2upl4pq6kufc4m.onion/html/?q=");
 420
 421                         // Set the summary text for `tor_search`.
 422                         if (presentTorSearchString.equals("Custom URL")) {
 423                             // Use R.string.custom_url, which is translated, instead of the array value, which isn't.
 424                             torSearchPreference.setSummary(R.string.custom_url);
 425                         } else {
 426                             // Set the array value as the summary text.
 427                             torSearchPreference.setSummary(presentTorSearchString);
 428                         }
 429
 430                         // Set the status of `torJavaScriptDisabledSearchCustomURLPreference`.
 431                         torSearchCustomURLPreference.setEnabled(presentTorSearchString.equals("Custom URL"));
 432                         break;
 433
 434                     case "tor_search_custom_url":
 435                         // Set the summary text for `tor_search_custom_url`.
 436                         torSearchCustomURLPreference.setSummary(sharedPreferences.getString("tor_search_custom_url", ""));
 437                         break;
 438
 439                     case "search":
 440                         // Store the new search string.
 441                         String newSearchString = sharedPreferences.getString("search", "https://duckduckgo.com/html/?q=");
 442
 443                         // Update `searchPreference` and `searchCustomURLPreference`.
 444                         if (newSearchString.equals("Custom URL")) {  // `Custom URL` is selected.
 445                             // Set the summary text to `R.string.custom_url`, which is translated.
 446                             searchPreference.setSummary(R.string.custom_url);
 447
 448                             // Update `searchCustomURLPreference`.
 449                             searchCustomURLPreference.setEnabled(true);
 450                             searchCustomURLPreference.setIcon(R.drawable.search_custom_url_enabled);
 451                         } else {  // `Custom URL` is not selected.
 452                             // Set the summary text to `newSearchString`.
 453                             searchPreference.setSummary(newSearchString);
 454
 455                             // Update `searchCustomURLPreference`.
 456                             searchCustomURLPreference.setEnabled(false);
 457                             searchCustomURLPreference.setIcon(R.drawable.search_custom_url_ghosted);
 458                         }
 459                         break;
 460
 461                     case "search_custom_url":
 462                         // Set the new custom search URL as the summary text for `search_custom_url`.  The default is `""`.
 463                         searchCustomURLPreference.setSummary(sharedPreferences.getString("search_custom_url", ""));
 464                         break;
 465
 466                     case "enable_full_screen_browsing_mode":
 467                         // Enable `transparent_navigation_bar` only if full screen browsing mode is enabled and `hide_system_bars` is disabled.
 468                         translucentNavigationBarPreference.setEnabled(sharedPreferences.getBoolean("enable_full_screen_browsing_mode", false) && !sharedPreferences.getBoolean("hide_system_bars", false));
 469                         break;
 470
 471                     case "hide_system_bars":
 472                         // Enable `translucentNavigationBarPreference` if `hide_system_bars` is disabled.
 473                         translucentNavigationBarPreference.setEnabled(!sharedPreferences.getBoolean("hide_system_bars", false));
 474                         break;
 475
 476                     case "homepage":
 477                         // Set the new homepage URL as the summary text for the Homepage preference.  The default is `https://www.duckduckgo.com`.
 478                         homepagePreference.setSummary(sharedPreferences.getString("homepage", "https://www.duckduckgo.com"));
 479                         break;
 480
 481                     case "default_font_size":
 482                         // Update the summary text of `default_font_size`.
 483                         defaultFontSizePreference.setSummary(sharedPreferences.getString("default_font_size", "100") + "%%");
 484                         break;
 485
 486                     default:
 487                         // If no match, do nothing.
 488                         break;
 489                 }
 490             }
 491         };
 492
 493         // Register the listener.
 494         savedPreferences.registerOnSharedPreferenceChangeListener(preferencesListener);
 495     }
 496
 497     // It is necessary to re-register the listener on every resume or it will randomly stop working because apps can be paused and resumed at any time
 498     // even while running in the foreground.
 499     @Override
 500     public void onPause() {
 501         super.onPause();
 502         savedPreferences.unregisterOnSharedPreferenceChangeListener(preferencesListener);
 503     }
 504
 505     @Override
 506     public void onResume() {
 507         super.onResume();
 508         savedPreferences.registerOnSharedPreferenceChangeListener(preferencesListener);
 509     }
 510 }