Temporarially disable Find on Page until the feature is completed.
[PrivacyBrowser.git] / app / src / main / java / com / stoutner / privacybrowser / MainWebViewActivity.java
index 64dd8dbf31eddfafc785ef3c42bea88e50acb811..982ff2d254c1de5ad9df6e43a2e7a489d22c970d 100644 (file)
 package com.stoutner.privacybrowser;
 
 import android.annotation.SuppressLint;
-import android.annotation.TargetApi;
 import android.app.Activity;
+import android.app.DialogFragment;
 import android.app.DownloadManager;
+import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.content.res.Configuration;
 import android.graphics.Bitmap;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.Drawable;
 import android.net.Uri;
+import android.net.http.SslCertificate;
+import android.net.http.SslError;
 import android.os.Build;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
+import android.print.PrintDocumentAdapter;
+import android.print.PrintManager;
+import android.support.annotation.NonNull;
+import android.support.design.widget.NavigationView;
 import android.support.design.widget.Snackbar;
-import android.support.v4.app.DialogFragment;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.content.ContextCompat;
+import android.support.v4.view.GravityCompat;
+import android.support.v4.widget.DrawerLayout;
 import android.support.v4.widget.SwipeRefreshLayout;
 import android.support.v7.app.ActionBar;
+import android.support.v7.app.ActionBarDrawerToggle;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.app.AppCompatDialogFragment;
 import android.support.v7.widget.Toolbar;
@@ -45,75 +59,150 @@ import android.view.View;
 import android.view.inputmethod.InputMethodManager;
 import android.webkit.CookieManager;
 import android.webkit.DownloadListener;
+import android.webkit.SslErrorHandler;
 import android.webkit.WebChromeClient;
 import android.webkit.WebStorage;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
+import android.webkit.WebViewDatabase;
 import android.widget.EditText;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.ProgressBar;
-import android.widget.Toast;
 
 import java.io.UnsupportedEncodingException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLEncoder;
+import java.util.HashMap;
+import java.util.Map;
 
 // We need to use AppCompatActivity from android.support.v7.app.AppCompatActivity to have access to the SupportActionBar until the minimum API is >= 21.
-public class MainWebViewActivity extends AppCompatActivity implements CreateHomeScreenShortcut.CreateHomeScreenSchortcutListener {
-    // favoriteIcon is public static so it can be accessed from CreateHomeScreenShortcut.
+public class MainWebViewActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener, CreateHomeScreenShortcut.CreateHomeScreenSchortcutListener,
+        SslCertificateError.SslCertificateErrorListener, DownloadFile.DownloadFileListener {
+
+    // `appBar` is public static so it can be accessed from `OrbotProxyHelper`.
+    // It is also used in `onCreate()` and `onOptionsItemSelected()`.
+    public static ActionBar appBar;
+
+    // `favoriteIcon` is public static so it can be accessed from `CreateHomeScreenShortcut`, `BookmarksActivity`, `CreateBookmark`, `CreateBookmarkFolder`, and `EditBookmark`.
+    // It is also used in `onCreate()` and `onCreateHomeScreenShortcutCreate()`.
     public static Bitmap favoriteIcon;
-    // mainWebView is public static so it can be accessed from AboutDialog.  It is also used in onCreate(), onOptionsItemSelected(), and loadUrlFromTextBox().
-    public static WebView mainWebView;
 
-    // mainMenu is used in onCreateOptionsMenu() and onOptionsItemSelected().
-    private Menu mainMenu;
-    // formattedUrlString is used in onCreate(), onOptionsItemSelected(), onCreateHomeScreenShortcutCreate(), and loadUrlFromTextBox().
-    private String formattedUrlString;
-    // homepage is used in onCreate() and onOptionsItemSelected().
-    private String homepage;
-    // javaScriptEnabled is used in onCreate(), onCreateOptionsMenu(), onOptionsItemSelected(), and loadUrlFromTextBox().
-    private boolean javaScriptEnabled;
-    // domStorageEnabled is used in onCreate(), onCreateOptionsMenu(), and onOptionsItemSelected().
+    // `formattedUrlString` is public static so it can be accessed from `BookmarksActivity`.
+    // It is also used in `onCreate()`, `onOptionsItemSelected()`, `onCreateHomeScreenShortcutCreate()`, and `loadUrlFromTextBox()`.
+    public static String formattedUrlString;
+
+    // `sslCertificate` is public static so it can be accessed from `ViewSslCertificate`.  It is also used in `onCreate()`.
+    public static SslCertificate sslCertificate;
+
+
+    // 'mainWebView' is used in `onCreate()`, `onOptionsItemSelected()`, `onNavigationItemSelected()`, `onRestart()`, and `loadUrlFromTextBox()`.
+    private WebView mainWebView;
+
+    // `swipeRefreshLayout` is used in `onCreate()`, `onPrepareOptionsMenu`, and `onRestart()`.
+    private SwipeRefreshLayout swipeRefreshLayout;
+
+    // `cookieManager` is used in `onCreate()`, `onOptionsItemSelected()`, and `onNavigationItemSelected()`, and `onRestart()`.
+    private CookieManager cookieManager;
+
+    // `customHeader` is used in `onCreate()`, `onOptionsItemSelected()`, and `loadUrlFromTextBox()`.
+    private final Map<String, String> customHeaders = new HashMap<>();
+
+    // `javaScriptEnabled` is also used in `onCreate()`, `onCreateOptionsMenu()`, `onOptionsItemSelected()`, `loadUrlFromTextBox()`, and `applySettings()`.
+    // It is `Boolean` instead of `boolean` because `applySettings()` needs to know if it is `null`.
+    private Boolean javaScriptEnabled;
+
+    // `firstPartyCookiesEnabled` is used in `onCreate()`, `onCreateOptionsMenu()`, `onPrepareOptionsMenu()`, `onOptionsItemSelected()`, and `applySettings()`.
+    private boolean firstPartyCookiesEnabled;
+
+    // `thirdPartyCookiesEnabled` used in `onCreate()`, `onCreateOptionsMenu()`, `onPrepareOptionsMenu()`, `onOptionsItemSelected()`, and `applySettings()`.
+    private boolean thirdPartyCookiesEnabled;
+
+    // `domStorageEnabled` is used in `onCreate()`, `onCreateOptionsMenu()`, `onOptionsItemSelected()`, and `applySettings()`.
     private boolean domStorageEnabled;
 
-    /* saveFormDataEnabled does nothing until database storage is implemented.
-    // saveFormDataEnabled is used in onCreate(), onCreateOptionsMenu(), and onOptionsItemSelected().
+    // `saveFormDataEnabled` is used in `onCreate()`, `onCreateOptionsMenu()`, `onOptionsItemSelected()`, and `applySettings()`.
     private boolean saveFormDataEnabled;
-    */
 
-    // cookieManager is used in onCreate() and onOptionsItemSelected().
-    private CookieManager cookieManager;
-    // cookiesEnabled is used in onCreate(), onCreateOptionsMenu(), and onOptionsItemSelected().
-    private boolean cookiesEnabled;
+    // `swipeToRefreshEnabled` is used in `onPrepareOptionsMenu()` and `applySettings()`.
+    private boolean swipeToRefreshEnabled;
+
+    // 'homepage' is used in `onCreate()`, `onNavigationItemSelected()`, and `applySettings()`.
+    private String homepage;
+
+    // `javaScriptDisabledSearchURL` is used in `loadURLFromTextBox()` and `applySettings()`.
+    private String javaScriptDisabledSearchURL;
+
+    // `javaScriptEnabledSearchURL` is used in `loadURLFromTextBox()` and `applySettings()`.
+    private String javaScriptEnabledSearchURL;
 
-    // urlTextBox is used in onCreate(), onOptionsItemSelected(), and loadUrlFromTextBox().
+    // `mainMenu` is used in `onCreateOptionsMenu()` and `updatePrivacyIcons()`.
+    private Menu mainMenu;
+
+    // `drawerToggle` is used in `onCreate()`, `onPostCreate()`, `onConfigurationChanged()`, `onNewIntent()`, and `onNavigationItemSelected()`.
+    private ActionBarDrawerToggle drawerToggle;
+
+    // `drawerLayout` is used in `onCreate()`, `onNewIntent()`, and `onBackPressed()`.
+    private DrawerLayout drawerLayout;
+
+    // `urlTextBox` is used in `onCreate()`, `onOptionsItemSelected()`, and `loadUrlFromTextBox()`.
     private EditText urlTextBox;
 
+    // `adView` is used in `onCreate()` and `onConfigurationChanged()`.
+    private View adView;
+
+    // `sslErrorHandler` is used in `onCreate()`, `onSslErrorCancel()`, and `onSslErrorProceed`.
+    private SslErrorHandler sslErrorHandler;
+
+    private MenuItem toggleJavaScript;
+
     @Override
     // Remove Android Studio's warning about the dangers of using SetJavaScriptEnabled.  The whole premise of Privacy Browser is built around an understanding of these dangers.
     @SuppressLint("SetJavaScriptEnabled")
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_webview);
+        setContentView(R.layout.main_coordinatorlayout);
 
         // We need to use the SupportActionBar from android.support.v7.app.ActionBar until the minimum API is >= 21.
         Toolbar supportAppBar = (Toolbar) findViewById(R.id.appBar);
         setSupportActionBar(supportAppBar);
+        appBar = getSupportActionBar();
+
+        // This is needed to get rid of the Android Studio warning that appBar might be null.
+        assert appBar != null;
+
+        // Add the custom url_app_bar layout, which shows the favoriteIcon, urlTextBar, and progressBar.
+        appBar.setCustomView(R.layout.url_app_bar);
+        appBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
+
+        // Set the "go" button on the keyboard to load the URL in urlTextBox.
+        urlTextBox = (EditText) appBar.getCustomView().findViewById(R.id.urlTextBox);
+        urlTextBox.setOnKeyListener(new View.OnKeyListener() {
+            public boolean onKey(View v, int keyCode, KeyEvent event) {
+                // If the event is a key-down event on the "enter" button, load the URL.
+                if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) {
+                    // Load the URL into the mainWebView and consume the event.
+                    try {
+                        loadUrlFromTextBox();
+                    } catch (UnsupportedEncodingException e) {
+                        e.printStackTrace();
+                    }
+                    // If the enter key was pressed, consume the event.
+                    return true;
+                } else {
+                    // If any other key was pressed, do not consume the event.
+                    return false;
+                }
+            }
+        });
 
         final FrameLayout fullScreenVideoFrameLayout = (FrameLayout) findViewById(R.id.fullScreenVideoFrameLayout);
 
-        // We need to use the SupportActionBar from android.support.v7.app.ActionBar until the minimum API is >= 21.
-        final ActionBar appBar = getSupportActionBar();
-
-        // Setup AdView for the free flavor.
-        final View adView = findViewById(R.id.adView);
-
         // Implement swipe to refresh
-        final SwipeRefreshLayout swipeToRefresh = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
-        swipeToRefresh.setColorSchemeResources(R.color.blue);
-        swipeToRefresh.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
+        swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
+        swipeRefreshLayout.setColorSchemeResources(R.color.blue_700);
+        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
             @Override
             public void onRefresh() {
                 mainWebView.reload();
@@ -122,44 +211,51 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
 
         mainWebView = (WebView) findViewById(R.id.mainWebView);
 
-        if (appBar != null) {
-            // Add the custom url_bar layout, which shows the favoriteIcon, urlTextBar, and progressBar.
-            appBar.setCustomView(R.layout.url_bar);
-            appBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
-
-            // Set the "go" button on the keyboard to load the URL in urlTextBox.
-            urlTextBox = (EditText) appBar.getCustomView().findViewById(R.id.urlTextBox);
-            urlTextBox.setOnKeyListener(new View.OnKeyListener() {
-                public boolean onKey(View v, int keyCode, KeyEvent event) {
-                    // If the event is a key-down event on the "enter" button, load the URL.
-                    if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) {
-                        // Load the URL into the mainWebView and consume the event.
-                        try {
-                            loadUrlFromTextBox();
-                        } catch (UnsupportedEncodingException e) {
-                            e.printStackTrace();
-                        }
-                        // If the enter key was pressed, consume the event.
-                        return true;
-                    } else {
-                        // If any other key was pressed, do not consume the event.
-                        return false;
-                    }
-                }
-            });
-        }
+        // Create the navigation drawer.
+        drawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
+        // The DrawerTitle identifies the drawer in accessibility mode.
+        drawerLayout.setDrawerTitle(GravityCompat.START, getString(R.string.navigation_drawer));
+
+        // Listen for touches on the navigation menu.
+        final NavigationView navigationView = (NavigationView) findViewById(R.id.navigationView);
+        navigationView.setNavigationItemSelectedListener(this);
+
+        // drawerToggle creates the hamburger icon at the start of the AppBar.
+        drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, supportAppBar, R.string.open_navigation, R.string.close_navigation);
 
         mainWebView.setWebViewClient(new WebViewClient() {
-            // shouldOverrideUrlLoading makes this WebView the default handler for URLs inside the app, so that links are not kicked out to other apps.
+            // `shouldOverrideUrlLoading` makes this `WebView` the default handler for URLs inside the app, so that links are not kicked out to other apps.
+            // We have to use the deprecated `shouldOverrideUrlLoading` until API >= 24.
+            @SuppressWarnings("deprecation")
             @Override
             public boolean shouldOverrideUrlLoading(WebView view, String url) {
-                mainWebView.loadUrl(url);
-                return true;
+                // Use an external email program if the link begins with "mailto:".
+                if (url.startsWith("mailto:")) {
+                    // We use `ACTION_SENDTO` instead of `ACTION_SEND` so that only email programs are launched.
+                    Intent emailIntent = new Intent(Intent.ACTION_SENDTO);
+
+                    // Parse the url and set it as the data for the `Intent`.
+                    emailIntent.setData(Uri.parse(url));
+
+                    // `FLAG_ACTIVITY_NEW_TASK` opens the email program in a new task instead as part of Privacy Browser.
+                    emailIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+
+                    // Make it so.
+                    startActivity(emailIntent);
+                    return true;
+                } else {  // Load the URL in Privacy Browser.
+                    mainWebView.loadUrl(url, customHeaders);
+                    return true;
+                }
             }
 
             // Update the URL in urlTextBox when the page starts to load.
             @Override
             public void onPageStarted(WebView view, String url, Bitmap favicon) {
+                // We need to update `formattedUrlString` at the beginning of the load, so that if the user toggles JavaScript during the load the new website is reloaded.
+                formattedUrlString = url;
+
+                // Display the loading URL is the URL text box.
                 urlTextBox.setText(url);
             }
 
@@ -172,6 +268,20 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
                 if (!urlTextBox.hasFocus()) {
                     urlTextBox.setText(formattedUrlString);
                 }
+
+                // Store the SSL certificate so it can be accessed from `ViewSslCertificate`.
+                sslCertificate = mainWebView.getCertificate();
+            }
+
+            // Handle SSL Certificate errors.
+            @Override
+            public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
+                // Store `handler` so it can be accesses from `onSslErrorCancel()` and `onSslErrorProceed()`.
+                sslErrorHandler = handler;
+
+                // Display the SSL error `AlertDialog`.
+                DialogFragment sslCertificateErrorDialogFragment = SslCertificateError.displayDialog(error);
+                sslCertificateErrorDialogFragment.show(getFragmentManager(), getResources().getString(R.string.ssl_certificate_error));
             }
         });
 
@@ -179,18 +289,15 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
             // Update the progress bar when a page is loading.
             @Override
             public void onProgressChanged(WebView view, int progress) {
-                // Make sure that appBar is not null.
-                if (appBar != null) {
-                    ProgressBar progressBar = (ProgressBar) appBar.getCustomView().findViewById(R.id.progressBar);
-                    progressBar.setProgress(progress);
-                    if (progress < 100) {
-                        progressBar.setVisibility(View.VISIBLE);
-                    } else {
-                        progressBar.setVisibility(View.GONE);
+                ProgressBar progressBar = (ProgressBar) appBar.getCustomView().findViewById(R.id.progressBar);
+                progressBar.setProgress(progress);
+                if (progress < 100) {
+                    progressBar.setVisibility(View.VISIBLE);
+                } else {
+                    progressBar.setVisibility(View.GONE);
 
-                        //Stop the SwipeToRefresh indicator if it is running
-                        swipeToRefresh.setRefreshing(false);
-                    }
+                    //Stop the `SwipeToRefresh` indicator if it is running
+                    swipeRefreshLayout.setRefreshing(false);
                 }
             }
 
@@ -200,19 +307,15 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
                 // Save a copy of the favorite icon for use if a shortcut is added to the home screen.
                 favoriteIcon = icon;
 
-                // Place the favorite icon in the appBar if it is not null.
-                if (appBar != null) {
-                    ImageView imageViewFavoriteIcon = (ImageView) appBar.getCustomView().findViewById(R.id.favoriteIcon);
-                    imageViewFavoriteIcon.setImageBitmap(Bitmap.createScaledBitmap(icon, 64, 64, true));
-                }
+                // Place the favorite icon in the appBar.
+                ImageView imageViewFavoriteIcon = (ImageView) appBar.getCustomView().findViewById(R.id.favoriteIcon);
+                imageViewFavoriteIcon.setImageBitmap(Bitmap.createScaledBitmap(icon, 64, 64, true));
             }
 
             // Enter full screen video
             @Override
             public void onShowCustomView(View view, CustomViewCallback callback) {
-                if (appBar != null) {
-                    appBar.hide();
-                }
+                appBar.hide();
 
                 // Show the fullScreenVideoFrameLayout.
                 fullScreenVideoFrameLayout.addView(view);
@@ -225,29 +328,15 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
                 BannerAd.hideAd(adView);
 
                 /* SYSTEM_UI_FLAG_HIDE_NAVIGATION hides the navigation bars on the bottom or right of the screen.
-                ** SYSTEM_UI_FLAG_FULLSCREEN hides the status bar across the top of the screen.
-                ** SYSTEM_UI_FLAG_IMMERSIVE_STICKY makes the navigation and status bars ghosted overlays and automatically rehides them.
-                */
-
-                // Set the one flag supported by API >= 14.
-                view.setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
-
-                // Set the two flags that are supported by API >= 16.
-                if (Build.VERSION.SDK_INT >= 16) {
-                    view.setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN);
-                }
-
-                // Set all three flags that are supported by API >= 19.
-                if (Build.VERSION.SDK_INT >= 19) {
-                    view.setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
-                }
+                 * SYSTEM_UI_FLAG_FULLSCREEN hides the status bar across the top of the screen.
+                 * SYSTEM_UI_FLAG_IMMERSIVE_STICKY makes the navigation and status bars ghosted overlays and automatically rehides them.
+                 */
+                view.setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
             }
 
             // Exit full screen video
             public void onHideCustomView() {
-                if (appBar != null) {
-                    appBar.show();
-                }
+                appBar.show();
 
                 // Show the mainWebView.
                 mainWebView.setVisibility(View.VISIBLE);
@@ -263,21 +352,11 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
 
         // Allow the downloading of files.
         mainWebView.setDownloadListener(new DownloadListener() {
-            // Launch the Android download manager when a link leads to a download.
             @Override
             public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
-                DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
-                DownloadManager.Request requestUri = new DownloadManager.Request(Uri.parse(url));
-
-                // Add the URL as the description for the download.
-                requestUri.setDescription(url);
-
-                // Show the download notification after the download is completed.
-                requestUri.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
-
-                // Initiate the download and display a Snackbar.
-                downloadManager.enqueue(requestUri);
-                Snackbar.make(findViewById(R.id.mainWebView), R.string.download_started, Snackbar.LENGTH_SHORT).show();
+                // Show the `DownloadFile` `AlertDialog` and name this instance `@string/download`.
+                AppCompatDialogFragment downloadFileDialogFragment = DownloadFile.fromUrl(url, contentDisposition, contentLength);
+                downloadFileDialogFragment.show(getSupportFragmentManager(), getResources().getString(R.string.download));
             }
         });
 
@@ -287,33 +366,17 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
         // Hide zoom controls.
         mainWebView.getSettings().setDisplayZoomControls(false);
 
-        // Initialize the default preference values the first time the program is run.
-        PreferenceManager.setDefaultValues(this, R.xml.preferences, false);
-
-        // Get the shared preference values.
-        SharedPreferences savedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
-
-        // Set JavaScript initial status.
-        javaScriptEnabled = savedPreferences.getBoolean("javascript_enabled", false);
-        mainWebView.getSettings().setJavaScriptEnabled(javaScriptEnabled);
-
-        // Set DOM storage initial status.
-        domStorageEnabled = savedPreferences.getBoolean("dom_storage_enabled", false);
-        mainWebView.getSettings().setDomStorageEnabled(domStorageEnabled);
+        // Initialize cookieManager.
+        cookieManager = CookieManager.getInstance();
 
-        /* Save Form Data does nothing until database storage is implemented.
-        // Set Save Form Data initial status.
-        saveFormDataEnabled = true;
-        mainWebView.getSettings().setSaveFormData(saveFormDataEnabled);
-        */
+        // Replace the header that `WebView` creates for `X-Requested-With` with a null value.  The default value is the application ID (com.stoutner.privacybrowser.standard).
+        customHeaders.put("X-Requested-With", "");
 
-        // Set cookies initial status.
-        cookiesEnabled = savedPreferences.getBoolean("cookies_enabled", false);
-        cookieManager = CookieManager.getInstance();
-        cookieManager.setAcceptCookie(cookiesEnabled);
+        // Initialize the default preference values the first time the program is run.
+        PreferenceManager.setDefaultValues(this, R.xml.preferences, false);
 
-        // Set homepage initial status.
-        homepage = savedPreferences.getString("homepage", "https://www.duckduckgo.com");
+        // Apply the settings from the shared preferences.
+        applySettings();
 
         // Get the intent information that started the app.
         final Intent intent = getIntent();
@@ -330,15 +393,25 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
         }
 
         // Load the initial website.
-        mainWebView.loadUrl(formattedUrlString);
+        mainWebView.loadUrl(formattedUrlString, customHeaders);
+
+        // If the favorite icon is null, load the default.
+        if (favoriteIcon == null) {
+            // We have to use `ContextCompat` until API >= 21.
+            Drawable favoriteIconDrawable = ContextCompat.getDrawable(getApplicationContext(), R.drawable.world);
+            BitmapDrawable favoriteIconBitmapDrawable = (BitmapDrawable) favoriteIconDrawable;
+            favoriteIcon = favoriteIconBitmapDrawable.getBitmap();
+        }
 
-        // Load the ad if this is the free flavor.
+        // Initialize AdView for the free flavor and request an ad.  If this is not the free flavor BannerAd.requestAd() does nothing.
+        adView = findViewById(R.id.adView);
         BannerAd.requestAd(adView);
     }
 
+
     @Override
     protected void onNewIntent(Intent intent) {
-        // Sets the new intent as the activity intent, so that any future getIntent()s pick up this one instead of creating a new activity.
+        // Sets the new intent as the activity intent, so that any future `getIntent()`s pick up this one instead of creating a new activity.
         setIntent(intent);
 
         if (intent.getData() != null) {
@@ -347,8 +420,13 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
             formattedUrlString = intentUriData.toString();
         }
 
+        // Close the navigation drawer if it is open.
+        if (drawerLayout.isDrawerVisible(GravityCompat.START)) {
+            drawerLayout.closeDrawer(GravityCompat.START);
+        }
+
         // Load the website.
-        mainWebView.loadUrl(formattedUrlString);
+        mainWebView.loadUrl(formattedUrlString, customHeaders);
 
         // Clear the keyboard if displayed and remove the focus on the urlTextBar if it has it.
         mainWebView.requestFocus();
@@ -357,58 +435,131 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
-        getMenuInflater().inflate(R.menu.menu_webview, menu);
+        getMenuInflater().inflate(R.menu.webview_options_menu, menu);
 
-        // Set mainMenu so it can be used by onOptionsItemSelected.
+        // Set mainMenu so it can be used by `onOptionsItemSelected()` and `updatePrivacyIcons`.
         mainMenu = menu;
 
-        // Get MenuItems for checkable menu items.
-        MenuItem toggleJavaScript = menu.findItem(R.id.toggleJavaScript);
+        // Set the initial status of the privacy icons.  `false` does not call `invalidateOptionsMenu` as the last step.
+        updatePrivacyIcons(false);
+
+        // Get handles for the menu items.
+        toggleJavaScript = menu.findItem(R.id.toggleJavaScript);
+        MenuItem toggleFirstPartyCookies = menu.findItem(R.id.toggleFirstPartyCookies);
+        MenuItem toggleThirdPartyCookies = menu.findItem(R.id.toggleThirdPartyCookies);
         MenuItem toggleDomStorage = menu.findItem(R.id.toggleDomStorage);
-        /* toggleSaveFormData does nothing until database storage is implemented.
         MenuItem toggleSaveFormData = menu.findItem(R.id.toggleSaveFormData);
-        */
-        MenuItem toggleCookies = menu.findItem(R.id.toggleCookies);
 
-        // Set the initial icon for toggleJavaScript
-        if (javaScriptEnabled) {
-            toggleJavaScript.setIcon(R.drawable.javascript_enabled);
-        } else {
-            if (domStorageEnabled || cookiesEnabled) {
-                toggleJavaScript.setIcon(R.drawable.warning);
-            } else {
-                toggleJavaScript.setIcon(R.drawable.privacy_mode);
-            }
+        // Only display third-Party Cookies if SDK >= 21
+        toggleThirdPartyCookies.setVisible(Build.VERSION.SDK_INT >= 21);
+
+        // Get the shared preference values.  `this` references the current context.
+        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
+
+        // Set the status of the additional app bar icons.  The default is `false`.
+        if (sharedPreferences.getBoolean("display_additional_app_bar_icons", false)) {
+            toggleFirstPartyCookies.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
+            toggleDomStorage.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
+            toggleSaveFormData.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
+        } else { //Do not display the additional icons.
+            toggleFirstPartyCookies.setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
+            toggleDomStorage.setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
+            toggleSaveFormData.setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
         }
 
-        // Set the initial status of the menu item checkboxes.
-        toggleDomStorage.setChecked(domStorageEnabled);
-        /* toggleSaveFormData does nothing until database storage is implemented.
-        toggleSaveFormData.setChecked(saveFormDataEnabled);
-        */
-        toggleCookies.setChecked(cookiesEnabled);
-
         return true;
     }
 
     @Override
     public boolean onPrepareOptionsMenu(Menu menu) {
-        // Enable Clear Cookies if there are any.
+        // Get handles for the menu items.
+        MenuItem toggleFirstPartyCookies = menu.findItem(R.id.toggleFirstPartyCookies);
+        MenuItem toggleThirdPartyCookies = menu.findItem(R.id.toggleThirdPartyCookies);
+        MenuItem toggleDomStorage = menu.findItem(R.id.toggleDomStorage);
+        MenuItem toggleSaveFormData = menu.findItem(R.id.toggleSaveFormData);
         MenuItem clearCookies = menu.findItem(R.id.clearCookies);
+        MenuItem clearFormData = menu.findItem(R.id.clearFormData);
+        MenuItem refreshMenuItem = menu.findItem(R.id.refresh);
+
+        // Set the status of the menu item checkboxes.
+        toggleFirstPartyCookies.setChecked(firstPartyCookiesEnabled);
+        toggleThirdPartyCookies.setChecked(thirdPartyCookiesEnabled);
+        toggleDomStorage.setChecked(domStorageEnabled);
+        toggleSaveFormData.setChecked(saveFormDataEnabled);
+
+        // Enable third-party cookies if first-party cookies are enabled.
+        toggleThirdPartyCookies.setEnabled(firstPartyCookiesEnabled);
+
+        // Enable DOM Storage if JavaScript is enabled.
+        toggleDomStorage.setEnabled(javaScriptEnabled);
+
+        // Enable Clear Cookies if there are any.
         clearCookies.setEnabled(cookieManager.hasCookies());
 
-        // Enable Back if canGoBack().
-        MenuItem back = menu.findItem(R.id.back);
-        back.setEnabled(mainWebView.canGoBack());
+        // Enable Clear Form Data is there is any.
+        WebViewDatabase mainWebViewDatabase = WebViewDatabase.getInstance(this);
+        clearFormData.setEnabled(mainWebViewDatabase.hasFormData());
+
+        // Only show `Refresh` if `swipeToRefresh` is disabled.
+        refreshMenuItem.setVisible(!swipeToRefreshEnabled);
+
+        // Initialize font size variables.
+        int fontSize = mainWebView.getSettings().getTextZoom();
+        String fontSizeTitle;
+        MenuItem selectedFontSizeMenuItem;
+
+        // Prepare the font size title and current size menu item.
+        switch (fontSize) {
+            case 50:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.fifty_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeFiftyPercent);
+                break;
+
+            case 75:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.seventy_five_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeSeventyFivePercent);
+                break;
+
+            case 100:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.one_hundred_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeOneHundredPercent);
+                break;
+
+            case 125:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.one_hundred_twenty_five_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeOneHundredTwentyFivePercent);
+                break;
+
+            case 150:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.one_hundred_fifty_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeOneHundredFiftyPercent);
+                break;
+
+            case 175:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.one_hundred_seventy_five_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeOneHundredSeventyFivePercent);
+                break;
+
+            case 200:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.two_hundred_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeTwoHundredPercent);
+                break;
+
+            default:
+                fontSizeTitle = getResources().getString(R.string.font_size) + " - " + getResources().getString(R.string.one_hundred_percent);
+                selectedFontSizeMenuItem = menu.findItem(R.id.fontSizeOneHundredPercent);
+                break;
+        }
 
-        // Enable forward if canGoForward().
-        MenuItem forward = menu.findItem(R.id.forward);
-        forward.setEnabled(mainWebView.canGoForward());
+        // Set the font size title and select the current size menu item.
+        MenuItem fontSizeMenuItem = menu.findItem(R.id.fontSize);
+        fontSizeMenuItem.setTitle(fontSizeTitle);
+        selectedFontSizeMenuItem.setChecked(true);
 
         // Run all the other default commands.
         super.onPrepareOptionsMenu(menu);
 
-        // return true displays the menu.
+        // `return true` displays the menu.
         return true;
     }
 
@@ -420,120 +571,135 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
     public boolean onOptionsItemSelected(MenuItem menuItem) {
         int menuItemId = menuItem.getItemId();
 
-        // Some options need to update the drawable for toggleJavaScript.
-        MenuItem toggleJavaScript = mainMenu.findItem(R.id.toggleJavaScript);
-
         // Set the commands that relate to the menu entries.
         switch (menuItemId) {
             case R.id.toggleJavaScript:
-                if (javaScriptEnabled) {
-                    javaScriptEnabled = false;
-                    mainWebView.getSettings().setJavaScriptEnabled(false);
-                    mainWebView.reload();
+                // Switch the status of javaScriptEnabled.
+                javaScriptEnabled = !javaScriptEnabled;
 
-                    // Update the toggleJavaScript icon and display a snackbar.
-                    if (domStorageEnabled || cookiesEnabled) {
-                        menuItem.setIcon(R.drawable.warning);
-                        if (domStorageEnabled && cookiesEnabled) {
-                            Snackbar.make(findViewById(R.id.mainWebView), R.string.both_still_enabled, Snackbar.LENGTH_SHORT).show();
-                        } else {
-                            if (domStorageEnabled) {
-                                Snackbar.make(findViewById(R.id.mainWebView), R.string.dom_storage_still_enabled, Snackbar.LENGTH_SHORT).show();
-                            } else {
-                                Snackbar.make(findViewById(R.id.mainWebView), R.string.cookies_still_enabled, Snackbar.LENGTH_SHORT).show();
-                            }
-                        }
-                    } else {
-                        menuItem.setIcon(R.drawable.privacy_mode);
-                        Snackbar.make(findViewById(R.id.mainWebView), R.string.privacy_mode, Snackbar.LENGTH_SHORT).show();
-                    }
-                } else {
-                    javaScriptEnabled = true;
-                    menuItem.setIcon(R.drawable.javascript_enabled);
-                    mainWebView.getSettings().setJavaScriptEnabled(true);
-                    mainWebView.reload();
+                // Apply the new JavaScript status.
+                mainWebView.getSettings().setJavaScriptEnabled(javaScriptEnabled);
+
+                // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
+                updatePrivacyIcons(true);
+
+                // Display a `Snackbar`.
+                if (javaScriptEnabled) {  // JavaScrip is enabled.
                     Snackbar.make(findViewById(R.id.mainWebView), R.string.javascript_enabled, Snackbar.LENGTH_SHORT).show();
+                } else if (firstPartyCookiesEnabled) {  // JavaScript is disabled, but first-party cookies are enabled.
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.javascript_disabled, Snackbar.LENGTH_SHORT).show();
+                } else {  // Privacy mode.
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.privacy_mode, Snackbar.LENGTH_SHORT).show();
                 }
+
+                // Reload the WebView.
+                mainWebView.reload();
                 return true;
 
-            case R.id.toggleDomStorage:
-                if (domStorageEnabled) {
-                    domStorageEnabled = false;
-                    menuItem.setChecked(false);
-                    mainWebView.getSettings().setDomStorageEnabled(false);
-                    mainWebView.reload();
+            case R.id.toggleFirstPartyCookies:
+                // Switch the status of firstPartyCookiesEnabled.
+                firstPartyCookiesEnabled = !firstPartyCookiesEnabled;
+
+                // Update the menu checkbox.
+                menuItem.setChecked(firstPartyCookiesEnabled);
+
+                // Apply the new cookie status.
+                cookieManager.setAcceptCookie(firstPartyCookiesEnabled);
 
-                    // Update the toggleJavaScript icon and display a snackbar if appropriate.
-                    if (!javaScriptEnabled && !cookiesEnabled) {
-                        toggleJavaScript.setIcon(R.drawable.privacy_mode);
-                        Snackbar.make(findViewById(R.id.mainWebView), R.string.privacy_mode, Snackbar.LENGTH_SHORT).show();
+                // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
+                updatePrivacyIcons(true);
+
+                // Display a `Snackbar`.
+                if (firstPartyCookiesEnabled) {  // First-party cookies are enabled.
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.first_party_cookies_enabled, Snackbar.LENGTH_SHORT).show();
+                } else if (javaScriptEnabled){  // JavaScript is still enabled.
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.first_party_cookies_disabled, Snackbar.LENGTH_SHORT).show();
+                } else {  // Privacy mode.
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.privacy_mode, Snackbar.LENGTH_SHORT).show();
+                }
+
+                // Reload the WebView.
+                mainWebView.reload();
+                return true;
+
+            case R.id.toggleThirdPartyCookies:
+                if (Build.VERSION.SDK_INT >= 21) {
+                    // Switch the status of thirdPartyCookiesEnabled.
+                    thirdPartyCookiesEnabled = !thirdPartyCookiesEnabled;
+
+                    // Update the menu checkbox.
+                    menuItem.setChecked(thirdPartyCookiesEnabled);
+
+                    // Apply the new cookie status.
+                    cookieManager.setAcceptThirdPartyCookies(mainWebView, thirdPartyCookiesEnabled);
+
+                    // Display a `Snackbar`.
+                    if (thirdPartyCookiesEnabled) {
+                        Snackbar.make(findViewById(R.id.mainWebView), R.string.third_party_cookies_enabled, Snackbar.LENGTH_SHORT).show();
                     } else {
-                        if (cookiesEnabled) {
-                            toggleJavaScript.setIcon(R.drawable.warning);
-                            Snackbar.make(findViewById(R.id.mainWebView), R.string.cookies_still_enabled, Snackbar.LENGTH_SHORT).show();
-                        } // Else Do nothing because JavaScript is enabled.
+                        Snackbar.make(findViewById(R.id.mainWebView), R.string.third_party_cookies_disabled, Snackbar.LENGTH_SHORT).show();
                     }
-                } else {
-                    domStorageEnabled = true;
-                    menuItem.setChecked(true);
-                    mainWebView.getSettings().setDomStorageEnabled(true);
+
+                    // Reload the WebView.
                     mainWebView.reload();
+                } // Else do nothing because SDK < 21.
+                return true;
 
-                    // Update the toggleJavaScript icon if appropriate.
-                    if (!javaScriptEnabled) {
-                        toggleJavaScript.setIcon(R.drawable.warning);
-                    } // Else Do nothing because JavaScript is enabled.
+            case R.id.toggleDomStorage:
+                // Switch the status of domStorageEnabled.
+                domStorageEnabled = !domStorageEnabled;
 
+                // Update the menu checkbox.
+                menuItem.setChecked(domStorageEnabled);
+
+                // Apply the new DOM Storage status.
+                mainWebView.getSettings().setDomStorageEnabled(domStorageEnabled);
+
+                // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
+                updatePrivacyIcons(true);
+
+                // Display a `Snackbar`.
+                if (domStorageEnabled) {
                     Snackbar.make(findViewById(R.id.mainWebView), R.string.dom_storage_enabled, Snackbar.LENGTH_SHORT).show();
+                } else {
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.dom_storage_disabled, Snackbar.LENGTH_SHORT).show();
                 }
+
+                // Reload the WebView.
+                mainWebView.reload();
                 return true;
 
-            /* toggleSaveFormData does nothing until database storage is implemented.
             case R.id.toggleSaveFormData:
+                // Switch the status of saveFormDataEnabled.
+                saveFormDataEnabled = !saveFormDataEnabled;
+
+                // Update the menu checkbox.
+                menuItem.setChecked(saveFormDataEnabled);
+
+                // Apply the new form data status.
+                mainWebView.getSettings().setSaveFormData(saveFormDataEnabled);
+
+                // Display a `Snackbar`.
                 if (saveFormDataEnabled) {
-                    saveFormDataEnabled = false;
-                    menuItem.setChecked(false);
-                    mainWebView.getSettings().setSaveFormData(false);
-                    mainWebView.reload();
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.form_data_enabled, Snackbar.LENGTH_SHORT).show();
                 } else {
-                    saveFormDataEnabled = true;
-                    menuItem.setChecked(true);
-                    mainWebView.getSettings().setSaveFormData(true);
-                    mainWebView.reload();
+                    Snackbar.make(findViewById(R.id.mainWebView), R.string.form_data_disabled, Snackbar.LENGTH_SHORT).show();
                 }
-                return true;
-            */
-
-            case R.id.toggleCookies:
-                if (cookiesEnabled) {
-                    cookiesEnabled = false;
-                    menuItem.setChecked(false);
-                    cookieManager.setAcceptCookie(false);
-                    mainWebView.reload();
 
-                    // Update the toggleJavaScript icon and display a snackbar if appropriate.
-                    if (!javaScriptEnabled && !domStorageEnabled) {
-                        toggleJavaScript.setIcon(R.drawable.privacy_mode);
-                        Snackbar.make(findViewById(R.id.mainWebView), R.string.privacy_mode, Snackbar.LENGTH_SHORT).show();
-                    } else {
-                        if (domStorageEnabled) {
-                            toggleJavaScript.setIcon(R.drawable.warning);
-                            Snackbar.make(findViewById(R.id.mainWebView), R.string.dom_storage_enabled, Snackbar.LENGTH_SHORT).show();
-                        } // Else Do nothing because JavaScript is enabled.
-                    }
-                } else {
-                    cookiesEnabled = true;
-                    menuItem.setChecked(true);
-                    cookieManager.setAcceptCookie(true);
-                    mainWebView.reload();
+                // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
+                updatePrivacyIcons(true);
 
-                    // Update the toggleJavaScript icon if appropriate.
-                    if (!javaScriptEnabled) {
-                        toggleJavaScript.setIcon(R.drawable.warning);
-                    } // Else Do nothing because JavaScript is enabled.
+                // Reload the WebView.
+                mainWebView.reload();
+                return true;
 
-                    Snackbar.make(findViewById(R.id.mainWebView), R.string.cookies_enabled, Snackbar.LENGTH_SHORT).show();
+            case R.id.clearCookies:
+                if (Build.VERSION.SDK_INT < 21) {
+                    cookieManager.removeAllCookie();
+                } else {
+                    cookieManager.removeAllCookies(null);
                 }
+                Snackbar.make(findViewById(R.id.mainWebView), R.string.cookies_deleted, Snackbar.LENGTH_SHORT).show();
                 return true;
 
             case R.id.clearDomStorage:
@@ -542,44 +708,47 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
                 Snackbar.make(findViewById(R.id.mainWebView), R.string.dom_storage_deleted, Snackbar.LENGTH_SHORT).show();
                 return true;
 
-            case R.id.clearCookies:
-                if (Build.VERSION.SDK_INT < 21) {
-                    cookieManager.removeAllCookie();
-                } else {
-                    cookieManager.removeAllCookies(null);
-                }
-                Snackbar.make(findViewById(R.id.mainWebView), R.string.cookies_deleted, Snackbar.LENGTH_SHORT).show();
+            case R.id.clearFormData:
+                WebViewDatabase mainWebViewDatabase = WebViewDatabase.getInstance(this);
+                mainWebViewDatabase.clearFormData();
+                mainWebView.reload();
                 return true;
 
-            case R.id.addToHomescreen:
-                // Show the CreateHomeScreenShortcut AlertDialog and name this instance createShortcut.
-                AppCompatDialogFragment shortcutDialog = new CreateHomeScreenShortcut();
-                shortcutDialog.show(getSupportFragmentManager(), "createShortcut");
+            case R.id.fontSizeFiftyPercent:
+                mainWebView.getSettings().setTextZoom(50);
+                return true;
 
-                //Everything else will be handled by CreateHomeScreenShortcut and the associated listeners below.
+            case R.id.fontSizeSeventyFivePercent:
+                mainWebView.getSettings().setTextZoom(75);
                 return true;
 
-            case R.id.downloads:
-                // Launch the system Download Manager.
-                Intent downloadManagerIntent = new Intent(DownloadManager.ACTION_VIEW_DOWNLOADS);
+            case R.id.fontSizeOneHundredPercent:
+                mainWebView.getSettings().setTextZoom(100);
+                return true;
 
-                // Launch as a new task so that Download Manager and Privacy Browser show as separate windows in the recent tasks list.
-                downloadManagerIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+            case R.id.fontSizeOneHundredTwentyFivePercent:
+                mainWebView.getSettings().setTextZoom(125);
+                return true;
 
-                startActivity(downloadManagerIntent);
+            case R.id.fontSizeOneHundredFiftyPercent:
+                mainWebView.getSettings().setTextZoom(150);
                 return true;
 
-            case R.id.home:
-                mainWebView.loadUrl(homepage);
+            case R.id.fontSizeOneHundredSeventyFivePercent:
+                mainWebView.getSettings().setTextZoom(175);
                 return true;
 
-            case R.id.back:
-                mainWebView.goBack();
+            case R.id.fontSizeTwoHundredPercent:
+                mainWebView.getSettings().setTextZoom(200);
                 return true;
 
-            case R.id.forward:
-                mainWebView.goForward();
+            /*
+            case R.id.find_on_page:
+                appBar.setCustomView(R.layout.find_on_page_app_bar);
+                toggleJavaScript.setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
+                appBar.invalidateOptionsMenu();
                 return true;
+                */
 
             case R.id.share:
                 Intent shareIntent = new Intent();
@@ -589,23 +758,93 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
                 startActivity(Intent.createChooser(shareIntent, "Share URL"));
                 return true;
 
-            case R.id.settings:
-                // Launch SettingsActivity.
-                Intent intent = new Intent(this, SettingsActivity.class);
-                startActivity(intent);
+            case R.id.addToHomescreen:
+                // Show the `CreateHomeScreenShortcut` `AlertDialog` and name this instance `@string/create_shortcut`.
+                AppCompatDialogFragment createHomeScreenShortcutDialogFragment = new CreateHomeScreenShortcut();
+                createHomeScreenShortcutDialogFragment.show(getSupportFragmentManager(), getResources().getString(R.string.create_shortcut));
+
+                //Everything else will be handled by `CreateHomeScreenShortcut` and the associated listener below.
                 return true;
 
-            case R.id.about:
-                // Show the AboutDialog AlertDialog and name this instance aboutDialog.
-                AppCompatDialogFragment aboutDialog = new AboutDialog();
-                aboutDialog.show(getSupportFragmentManager(), "aboutDialog");
+            case R.id.print:
+                // Get a `PrintManager` instance.
+                PrintManager printManager = (PrintManager) getSystemService(Context.PRINT_SERVICE);
+
+                // Convert `mainWebView` to `printDocumentAdapter`.
+                PrintDocumentAdapter printDocumentAdapter = mainWebView.createPrintDocumentAdapter();
+
+                // Print the document.  The print attributes are `null`.
+                printManager.print(getResources().getString(R.string.privacy_browser_web_page), printDocumentAdapter, null);
                 return true;
 
-            case R.id.clearAndExit:
-                // Clear DOM storage.
-                WebStorage domStorage = WebStorage.getInstance();
-                domStorage.deleteAllData();
+            case R.id.refresh:
+                mainWebView.reload();
+                return true;
+
+            default:
+                // Don't consume the event.
+                return super.onOptionsItemSelected(menuItem);
+        }
+    }
 
+    // removeAllCookies is deprecated, but it is required for API < 21.
+    @SuppressWarnings("deprecation")
+    @Override
+    public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
+        int menuItemId = menuItem.getItemId();
+
+        switch (menuItemId) {
+            case R.id.home:
+                mainWebView.loadUrl(homepage, customHeaders);
+                break;
+
+            case R.id.back:
+                if (mainWebView.canGoBack()) {
+                    mainWebView.goBack();
+                }
+                break;
+
+            case R.id.forward:
+                if (mainWebView.canGoForward()) {
+                    mainWebView.goForward();
+                }
+                break;
+
+            case R.id.bookmarks:
+                // Launch BookmarksActivity.
+                Intent bookmarksIntent = new Intent(this, BookmarksActivity.class);
+                startActivity(bookmarksIntent);
+                break;
+
+            case R.id.downloads:
+                // Launch the system Download Manager.
+                Intent downloadManagerIntent = new Intent(DownloadManager.ACTION_VIEW_DOWNLOADS);
+
+                // Launch as a new task so that Download Manager and Privacy Browser show as separate windows in the recent tasks list.
+                downloadManagerIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+
+                startActivity(downloadManagerIntent);
+                break;
+
+            case R.id.settings:
+                // Launch `SettingsActivity`.
+                Intent settingsIntent = new Intent(this, SettingsActivity.class);
+                startActivity(settingsIntent);
+                break;
+
+            case R.id.guide:
+                // Launch `GuideActivity`.
+                Intent guideIntent = new Intent(this, GuideActivity.class);
+                startActivity(guideIntent);
+                break;
+
+            case R.id.about:
+                // Launch `AboutActivity`.
+                Intent aboutIntent = new Intent(this, AboutActivity.class);
+                startActivity(aboutIntent);
+                break;
+
+            case R.id.clearAndExit:
                 // Clear cookies.  The commands changed slightly in API 21.
                 if (Build.VERSION.SDK_INT >= 21) {
                     cookieManager.removeAllCookies(null);
@@ -613,6 +852,29 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
                     cookieManager.removeAllCookie();
                 }
 
+                // Clear DOM storage.
+                WebStorage domStorage = WebStorage.getInstance();
+                domStorage.deleteAllData();
+
+                // Clear form data.
+                WebViewDatabase formData = WebViewDatabase.getInstance(this);
+                formData.clearFormData();
+
+                // Clear cache.  The argument of "true" includes disk files.
+                mainWebView.clearCache(true);
+
+                // Clear the back/forward history.
+                mainWebView.clearHistory();
+
+                // Clear any SSL certificate preferences.
+                mainWebView.clearSslPreferences();
+
+                // Clear `formattedUrlString`.
+                formattedUrlString = null;
+
+                // Clear `customHeaders`.
+                customHeaders.clear();
+
                 // Destroy the internal state of the webview.
                 mainWebView.destroy();
 
@@ -622,22 +884,43 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
                 } else {
                     finish();
                 }
-                return true;
+                break;
 
             default:
-                return super.onOptionsItemSelected(menuItem);
+                break;
         }
+
+        // Close the navigation drawer.
+        drawerLayout.closeDrawer(GravityCompat.START);
+        return true;
     }
 
     @Override
-    public void onCreateHomeScreenShortcutCancel(DialogFragment dialog) {
-        // Do nothing because the user selected "Cancel".
+    public void onPostCreate(Bundle savedInstanceState) {
+        super.onPostCreate(savedInstanceState);
+
+        // Sync the state of the DrawerToggle after onRestoreInstanceState has finished.
+        drawerToggle.syncState();
+    }
+
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+
+        // Reload the ad if this is the free flavor.
+        BannerAd.reloadAfterRotate(adView, getApplicationContext(), getString(R.string.ad_id));
+
+        // Reinitialize the adView variable, as the View will have been removed and re-added in the free flavor by BannerAd.reloadAfterRotate().
+        adView = findViewById(R.id.adView);
+
+        // `invalidateOptionsMenu` should recalculate the number of action buttons from the menu to display on the app bar, but it doesn't because of the this bug:  https://code.google.com/p/android/issues/detail?id=20493#c8
+        // ActivityCompat.invalidateOptionsMenu(this);
     }
 
     @Override
-    public void onCreateHomeScreenShortcutCreate(DialogFragment dialog) {
+    public void onCreateHomeScreenShortcut(AppCompatDialogFragment dialogFragment) {
         // Get shortcutNameEditText from the alert dialog.
-        EditText shortcutNameEditText = (EditText) dialog.getDialog().findViewById(R.id.shortcutNameEditText);
+        EditText shortcutNameEditText = (EditText) dialogFragment.getDialog().findViewById(R.id.shortcut_name_edittext);
 
         // Create the bookmark shortcut based on formattedUrlString.
         Intent bookmarkShortcut = new Intent();
@@ -653,21 +936,102 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
         sendBroadcast(placeBookmarkShortcut);
     }
 
-    // Override onBackPressed so that if mainWebView can go back it does when the system back button is pressed.
+    @Override
+    public void onDownloadFile(AppCompatDialogFragment dialogFragment, String downloadUrl) {
+        DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
+        DownloadManager.Request downloadRequest = new DownloadManager.Request(Uri.parse(downloadUrl));
+
+        // Get the file name from `dialogFragment`.
+        EditText downloadFileNameEditText = (EditText) dialogFragment.getDialog().findViewById(R.id.download_file_name);
+        String fileName = downloadFileNameEditText.getText().toString();
+
+        // Once we have `WRITE_EXTERNAL_STORAGE` permissions we can use `setDestinationInExternalPublicDir`.
+        if (Build.VERSION.SDK_INT >= 23) { // If API >= 23, set the download save in the the `DIRECTORY_DOWNLOADS` using `fileName`.
+            downloadRequest.setDestinationInExternalFilesDir(this, "/", fileName);
+        } else { // Only set the title using `fileName`.
+            downloadRequest.setTitle(fileName);
+        }
+
+        // Allow `MediaScanner` to index the download if it is a media file.
+        downloadRequest.allowScanningByMediaScanner();
+
+        // Add the URL as the description for the download.
+        downloadRequest.setDescription(downloadUrl);
+
+        // Show the download notification after the download is completed.
+        downloadRequest.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
+
+        // Initiate the download and display a Snackbar.
+        downloadManager.enqueue(downloadRequest);
+    }
+
+    public void viewSslCertificate(View view) {
+        // Show the `ViewSslCertificate` `AlertDialog` and name this instance `@string/view_ssl_certificate`.
+        DialogFragment viewSslCertificateDialogFragment = new ViewSslCertificate();
+        viewSslCertificateDialogFragment.show(getFragmentManager(), getResources().getString(R.string.view_ssl_certificate));
+    }
+
+    @Override
+    public void onSslErrorCancel() {
+        sslErrorHandler.cancel();
+    }
+
+    @Override
+    public void onSslErrorProceed() {
+        sslErrorHandler.proceed();
+    }
+
+    // Override onBackPressed to handle the navigation drawer and mainWebView.
     @Override
     public void onBackPressed() {
         final WebView mainWebView = (WebView) findViewById(R.id.mainWebView);
 
-        if (mainWebView.canGoBack()) {
-            mainWebView.goBack();
+        // Close the navigation drawer if it is available.  GravityCompat.START is the drawer on the left on Left-to-Right layout text.
+        if (drawerLayout.isDrawerVisible(GravityCompat.START)) {
+            drawerLayout.closeDrawer(GravityCompat.START);
         } else {
-            super.onBackPressed();
+            // Load the previous URL if available.
+            if (mainWebView.canGoBack()) {
+                mainWebView.goBack();
+            } else {
+                // Pass onBackPressed to the system.
+                super.onBackPressed();
+            }
         }
     }
 
+    @Override
+    public void onPause() {
+        // We need to pause the adView or it will continue to consume resources in the background on the free flavor.
+        BannerAd.pauseAd(adView);
+
+        super.onPause();
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+
+        // We need to resume the adView for the free flavor.
+        BannerAd.resumeAd(adView);
+    }
+
+    @Override
+    public void onRestart() {
+        super.onRestart();
+
+        // Apply the settings from shared preferences, which might have been changed in `SettingsActivity`.
+        applySettings();
+
+        // Update the privacy icon.  `true` runs `invalidateOptionsMenu` as the last step.
+        updatePrivacyIcons(true);
+
+    }
+
     private void loadUrlFromTextBox() throws UnsupportedEncodingException {
-        // Get the text from urlTextBox and convert it to a string.
-        String unformattedUrlString = urlTextBox.getText().toString();
+        // Get the text from urlTextBox and convert it to a string.  trim() removes white spaces from the beginning and end of the string.
+        String unformattedUrlString = urlTextBox.getText().toString().trim();
+
         URL unformattedUrl = null;
         Uri.Builder formattedUri = new Uri.Builder();
 
@@ -698,18 +1062,154 @@ public class MainWebViewActivity extends AppCompatActivity implements CreateHome
             // Sanitize the search input and convert it to a DuckDuckGo search.
             final String encodedUrlString = URLEncoder.encode(unformattedUrlString, "UTF-8");
 
-            // Use the correct search URL based on javaScriptEnabled.
-            if (javaScriptEnabled) {
-                formattedUrlString = "https://duckduckgo.com/?q=" + encodedUrlString;
-            } else {
-                formattedUrlString = "https://duckduckgo.com/html/?q=" + encodedUrlString;
+            // Use the correct search URL.
+            if (javaScriptEnabled) {  // JavaScript is enabled.
+                formattedUrlString = javaScriptEnabledSearchURL + encodedUrlString;
+            } else { // JavaScript is disabled.
+                formattedUrlString = javaScriptDisabledSearchURL + encodedUrlString;
             }
         }
 
-        mainWebView.loadUrl(formattedUrlString);
+        mainWebView.loadUrl(formattedUrlString, customHeaders);
 
         // Hides the keyboard so we can see the webpage.
         InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Activity.INPUT_METHOD_SERVICE);
         inputMethodManager.hideSoftInputFromWindow(mainWebView.getWindowToken(), 0);
     }
+
+    private void applySettings() {
+        // Get the shared preference values.  `this` references the current context.
+        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
+
+        // Store the values from `sharedPreferences` in variables.
+        String userAgentString = sharedPreferences.getString("user_agent", "Default user agent");
+        String customUserAgentString = sharedPreferences.getString("custom_user_agent", "PrivacyBrowser/1.0");
+        String javaScriptDisabledSearchString = sharedPreferences.getString("javascript_disabled_search", "https://duckduckgo.com/html/?q=");
+        String javaScriptDisabledCustomSearchString = sharedPreferences.getString("javascript_disabled_search_custom_url", "");
+        String javaScriptEnabledSearchString = sharedPreferences.getString("javascript_enabled_search", "https://duckduckgo.com/?q=");
+        String javaScriptEnabledCustomSearchString = sharedPreferences.getString("javascript_enabled_search_custom_url", "");
+        String homepageString = sharedPreferences.getString("homepage", "https://www.duckduckgo.com");
+        String defaultFontSizeString = sharedPreferences.getString("default_font_size", "100");
+        swipeToRefreshEnabled = sharedPreferences.getBoolean("swipe_to_refresh_enabled", false);
+        boolean doNotTrackEnabled = sharedPreferences.getBoolean("do_not_track", true);
+        boolean proxyThroughOrbot = sharedPreferences.getBoolean("proxy_through_orbot", false);
+
+        // Because they can be modified on-the-fly by the user, these default settings are only applied when the program first runs.
+        if (javaScriptEnabled == null) {  // If `javaScriptEnabled` is null the program is just starting.
+            // Get the values from `sharedPreferences`.
+            javaScriptEnabled = sharedPreferences.getBoolean("javascript_enabled", false);
+            firstPartyCookiesEnabled = sharedPreferences.getBoolean("first_party_cookies_enabled", false);
+            thirdPartyCookiesEnabled = sharedPreferences.getBoolean("third_party_cookies_enabled", false);
+            domStorageEnabled = sharedPreferences.getBoolean("dom_storage_enabled", false);
+            saveFormDataEnabled = sharedPreferences.getBoolean("save_form_data_enabled", false);
+
+            // Apply the default settings.
+            mainWebView.getSettings().setJavaScriptEnabled(javaScriptEnabled);
+            cookieManager.setAcceptCookie(firstPartyCookiesEnabled);
+            mainWebView.getSettings().setDomStorageEnabled(domStorageEnabled);
+            mainWebView.getSettings().setSaveFormData(saveFormDataEnabled);
+            mainWebView.getSettings().setTextZoom(Integer.valueOf(defaultFontSizeString));
+
+            // Set third-party cookies status if API >= 21.
+            if (Build.VERSION.SDK_INT >= 21) {
+                cookieManager.setAcceptThirdPartyCookies(mainWebView, thirdPartyCookiesEnabled);
+            }
+        }
+
+        // Apply the other settings from `sharedPreferences`.
+        homepage = homepageString;
+        swipeRefreshLayout.setEnabled(swipeToRefreshEnabled);
+
+        // Set the user agent initial status.
+        switch (userAgentString) {
+            case "Default user agent":
+                // Set the user agent to `""`, which uses the default value.
+                mainWebView.getSettings().setUserAgentString("");
+                break;
+
+            case "Custom user agent":
+                // Set the custom user agent.
+                mainWebView.getSettings().setUserAgentString(customUserAgentString);
+                break;
+
+            default:
+                // Use the selected user agent.
+                mainWebView.getSettings().setUserAgentString(userAgentString);
+                break;
+        }
+
+        // Set JavaScript disabled search.
+        if (javaScriptDisabledSearchString.equals("Custom URL")) {  // Get the custom URL string.
+            javaScriptDisabledSearchURL = javaScriptDisabledCustomSearchString;
+        } else {  // Use the string from the pre-built list.
+            javaScriptDisabledSearchURL = javaScriptDisabledSearchString;
+        }
+
+        // Set JavaScript enabled search.
+        if (javaScriptEnabledSearchString.equals("Custom URL")) {  // Get the custom URL string.
+            javaScriptEnabledSearchURL = javaScriptEnabledCustomSearchString;
+        } else {  // Use the string from the pre-built list.
+            javaScriptEnabledSearchURL = javaScriptEnabledSearchString;
+        }
+
+        // Set Do Not Track status.
+        if (doNotTrackEnabled) {
+            customHeaders.put("DNT", "1");
+        } else {
+            customHeaders.remove("DNT");
+        }
+
+        // Set Orbot proxy status.
+        if (proxyThroughOrbot) {
+            // Set the proxy.  `this` refers to the current activity where an `AlertDialog` might be displayed.
+            OrbotProxyHelper.setProxy(getApplicationContext(), this, "localhost", "8118");
+        } else {  // Reset the proxy to default.  The host is `""` and the port is `"0"`.
+            OrbotProxyHelper.setProxy(getApplicationContext(), this, "", "0");
+        }
+    }
+
+    private void updatePrivacyIcons(boolean runInvalidateOptionsMenu) {
+        // Get handles for the icons.
+        MenuItem privacyIcon = mainMenu.findItem(R.id.toggleJavaScript);
+        MenuItem firstPartyCookiesIcon = mainMenu.findItem(R.id.toggleFirstPartyCookies);
+        MenuItem domStorageIcon = mainMenu.findItem(R.id.toggleDomStorage);
+        MenuItem formDataIcon = mainMenu.findItem(R.id.toggleSaveFormData);
+
+        // Update `privacyIcon`.
+        if (javaScriptEnabled) {  // JavaScript is enabled.
+            privacyIcon.setIcon(R.drawable.javascript_enabled);
+        } else if (firstPartyCookiesEnabled) {  // JavaScript is disabled but cookies are enabled.
+            privacyIcon.setIcon(R.drawable.warning);
+        } else {  // All the dangerous features are disabled.
+            privacyIcon.setIcon(R.drawable.privacy_mode);
+        }
+
+        // Update `firstPartyCookiesIcon`.
+        if (firstPartyCookiesEnabled) {  // First-party cookies are enabled.
+            firstPartyCookiesIcon.setIcon(R.drawable.cookies_enabled);
+        } else {  // First-party cookies are disabled.
+            firstPartyCookiesIcon.setIcon(R.drawable.cookies_disabled);
+        }
+
+        // Update `domStorageIcon`.
+        if (javaScriptEnabled && domStorageEnabled) {  // Both JavaScript and DOM storage are enabled.
+            domStorageIcon.setIcon(R.drawable.dom_storage_enabled);
+        } else if (javaScriptEnabled) {  // JavaScript is enabled but DOM storage is disabled.
+            domStorageIcon.setIcon(R.drawable.dom_storage_disabled);
+        } else {  // JavaScript is disabled, so DOM storage is ghosted.
+            domStorageIcon.setIcon(R.drawable.dom_storage_ghosted);
+        }
+
+        // Update `formDataIcon`.
+        if (saveFormDataEnabled) {  // Form data is enabled.
+            formDataIcon.setIcon(R.drawable.form_data_enabled);
+        } else {  // Form data is disabled.
+            formDataIcon.setIcon(R.drawable.form_data_disabled);
+        }
+
+        // `invalidateOptionsMenu` calls `onPrepareOptionsMenu()` and redraws the icons in the `AppBar`.  `this` references the current activity.
+        if (runInvalidateOptionsMenu) {
+            ActivityCompat.invalidateOptionsMenu(this);
+        }
+    }
 }