Refactor Domains with one activity and two fragments. https://redmine.stoutner.com...
[PrivacyBrowser.git] / app / src / main / java / com / stoutner / privacybrowser / activities / DomainsActivity.java
index e98b5fc13cbdd4e8fbe110681505a0ed87056fa6..7c0b17a6369533694389d4a203765add3d077991 100644 (file)
 package com.stoutner.privacybrowser.activities;
 
 import android.content.Context;
-import android.content.Intent;
 import android.database.Cursor;
 import android.os.Bundle;
 import android.support.design.widget.FloatingActionButton;
 import android.support.design.widget.Snackbar;
+import android.support.v4.app.FragmentManager;
 import android.support.v4.app.NavUtils;
 import android.support.v7.app.ActionBar;
 import android.support.v7.app.AppCompatActivity;
@@ -34,7 +34,6 @@ import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.AdapterView;
 import android.widget.CursorAdapter;
 import android.widget.EditText;
 import android.widget.ListView;
@@ -45,29 +44,36 @@ import android.widget.TextView;
 import com.stoutner.privacybrowser.R;
 import com.stoutner.privacybrowser.dialogs.AddDomainDialog;
 import com.stoutner.privacybrowser.fragments.DomainSettingsFragment;
+import com.stoutner.privacybrowser.fragments.DomainsListFragment;
 import com.stoutner.privacybrowser.helpers.DomainsDatabaseHelper;
 
 public class DomainsActivity extends AppCompatActivity implements AddDomainDialog.AddDomainListener {
-    // `context` is used in `onCreate()` and `onOptionsItemSelected()`.
-    private Context context;
+    // `twoPanedMode` is public static so it can be accessed from `DomainsListFragment`.  It is also used in `onCreate()` and `populateDomainsListView()`.
+    public static boolean twoPanedMode;
 
-    // `domainsDatabaseHelper` is used in `onCreate()`, `onOptionsItemSelected()`, `onAddDomain()`, and `updateDomainsRecyclerView()`.
-    private static DomainsDatabaseHelper domainsDatabaseHelper;
+    // `databaseId` is public static so it can be accessed from `DomainsListFragment`.  It is also used in `saveDomainSettings()` and `populateDomainsListView()`.
+    public static int currentDomainDatabaseId;
 
-    // `twoPaneMode` is used in `onCreate()` and `updateDomainsListView()`.
-    private boolean twoPaneMode;
+    // `domainSettingsFragmentDisplayed` is public static so it can be accessed from `DomainsListFragment`.  It is also used in `onCreate()`, `onOptionsItemSelected()`, and `onBackPressed()`.
+    public static boolean domainSettingsFragmentDisplayed;
 
-    // `domainsListView` is used in `onCreate()`, `onOptionsItemSelected()`, and `updateDomainsListView()`.
-    private ListView domainsListView;
+    // `deleteMenuItem` is public static so it can be accessed from `DomainsListFragment`.  It is also used in `onCreateOptionsMenu()`, `onOptionsItemSelected()`, and `onBackPressed()`.
+    public static MenuItem deleteMenuItem;
+
+    // `context` is used in `onCreate()`, `onOptionsItemSelected()`, and `onAddDomain()`.
+    private Context context;
+
+    // `supportFragmentManager` is used in `onCreate()`.
+    private FragmentManager supportFragmentManager;
 
-    // `databaseId` is used in `onCreate()` and `onOptionsItemSelected()`.
-    private int databaseId;
+    // `domainsDatabaseHelper` is used in `onCreate()` and `saveDomainSettings()`.
+    private static DomainsDatabaseHelper domainsDatabaseHelper;
 
-    // `saveMenuItem` is used in `onCreate()`, `onOptionsItemSelected()`, and `onCreateOptionsMenu()`.
-    private MenuItem saveMenuItem;
+    // `domainsListView` is used in `onCreate()` and `populateDomainsList()`.
+    private ListView domainsListView;
 
-    // `deleteMenuItem` is used in `onCreate()`, `onOptionsItemSelected()`, and `onCreateOptionsMenu()`.
-    private MenuItem deleteMenuItem;
+    // `addDomainFAB` is used in `onCreate()`, `onOptionsItemSelected()`, and `onBackPressed()`.
+    private FloatingActionButton addDomainFAB;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -87,6 +93,9 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
         // Get a handle for the context.
         context = this;
 
+        // Get a handle for the fragment manager.
+        supportFragmentManager = getSupportFragmentManager();
+
         // We need to use the `SupportActionBar` from `android.support.v7.app.ActionBar` until the minimum API is >= 21.
         final Toolbar domainsAppBar = (Toolbar) findViewById(R.id.domains_toolbar);
         setSupportActionBar(domainsAppBar);
@@ -96,52 +105,25 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
         assert appBar != null;// This assert removes the incorrect warning in Android Studio on the following line that `appBar` might be null.
         appBar.setDisplayHomeAsUpEnabled(true);
 
-        // Initialize the database handler.  `this` specifies the context.  The two `nulls` do not specify the database name or a `CursorFactory`.
-        // The `0` specifies the database version, but that is ignored and set instead using a constant in `DomainsDatabaseHelper`.
-        domainsDatabaseHelper = new DomainsDatabaseHelper(this, null, null, 0);
+        // Initialize the database handler.  The two `nulls` do not specify the database name or a `CursorFactory`.  The `0` specifies the database version, but that is ignored and set instead using a constant in `DomainsDatabaseHelper`.
+        domainsDatabaseHelper = new DomainsDatabaseHelper(context, null, null, 0);
 
-        // Determine if we are in two pane mode.  `domains_settings_scrollview` is only populated if two panes are present.
-        twoPaneMode = ((findViewById(R.id.domain_settings_scrollview)) != null);
+        // Determine if we are in two pane mode.  `domain_settings_fragment_container` does not exist on devices with a width less than 900dp.
+        twoPanedMode = (findViewById(R.id.domain_settings_fragment_container) != null);
 
-        // Initialize `domainsListView`.
-        domainsListView = (ListView) findViewById(R.id.domains_listview);
-
-        domainsListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
-            @Override
-            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-                // Convert the id from `long` to `int` to match the format of the domains database.
-                databaseId = (int) id;
-
-                // Display the Domain Settings.
-                if (twoPaneMode) {  // Display a fragment in two paned mode.
-                    // Store `databaseId` in `argumentsBundle`.
-                    Bundle argumentsBundle = new Bundle();
-                    argumentsBundle.putInt(DomainSettingsFragment.DATABASE_ID, databaseId);
-
-                    // Add `argumentsBundle` to `domainSettingsFragment`.
-                    DomainSettingsFragment domainSettingsFragment = new DomainSettingsFragment();
-                    domainSettingsFragment.setArguments(argumentsBundle);
-
-                    // Display `domainSettingsFragment`.
-                    getSupportFragmentManager().beginTransaction().replace(R.id.domain_settings_scrollview, domainSettingsFragment).commit();
-                } else { // Load the second activity on smaller screens.
-                    // Create `domainSettingsActivityIntent` with the `databaseId`.
-                    Intent domainSettingsActivityIntent = new Intent(context, DomainSettingsActivity.class);
-                    domainSettingsActivityIntent.putExtra(DomainSettingsFragment.DATABASE_ID, databaseId);
-
-                    // Start `DomainSettingsActivity`.
-                    context.startActivity(domainSettingsActivityIntent);
-                }
-            }
-        });
+        // Display `DomainsListFragment`.
+        DomainsListFragment domainsListFragment = new DomainsListFragment();
+        supportFragmentManager.beginTransaction().replace(R.id.domains_listview_fragment_container, domainsListFragment).commit();
+        supportFragmentManager.executePendingTransactions();
 
-        FloatingActionButton addDomainFAB = (FloatingActionButton) findViewById(R.id.add_domain_fab);
+        // Configure `addDomainFAB`.
+        addDomainFAB = (FloatingActionButton) findViewById(R.id.add_domain_fab);
         addDomainFAB.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
                 // Show the `AddDomainDialog` `AlertDialog` and name the instance `@string/add_domain`.
                 AppCompatDialogFragment addDomainDialog = new AddDomainDialog();
-                addDomainDialog.show(getSupportFragmentManager(), getResources().getString(R.string.add_domain));
+                addDomainDialog.show(supportFragmentManager, getResources().getString(R.string.add_domain));
             }
         });
     }
@@ -151,16 +133,14 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
         // Inflate the menu.
         getMenuInflater().inflate(R.menu.domains_options_menu, menu);
 
-        // Store the `MenuItems` for future use.
+        // Store `deleteMenuItem` for future use.
         deleteMenuItem = menu.findItem(R.id.delete_domain);
-        saveMenuItem = menu.findItem(R.id.save_domain);
 
-        // Only display the options `MenuItems` in two pane mode.
-        deleteMenuItem.setVisible(twoPaneMode);
-        saveMenuItem.setVisible(twoPaneMode);
+        // Only display `deleteMenuItem` (initially) in two-paned mode.
+        deleteMenuItem.setVisible(twoPanedMode);
 
-        // Load the `ListView`.  We have to do this from `onCreateOptionsMenu()` instead of `onCreate()` because `updateDomainsListView()` needs the `MenuItems` to be inflated.
-        updateDomainsListView();
+        // Populate the list of domains.  We have to do this from `onCreateOptionsMenu()` instead of `onCreate()` because `populateDomainsListView()` needs the `deleteMenuItem` to be inflated.
+        populateDomainsListView();
 
         // Success!
         return true;
@@ -173,61 +153,73 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
 
         switch (menuItemID) {
             case android.R.id.home:  // The home arrow is identified as `android.R.id.home`, not just `R.id.home`.
-                // Go home.
-                NavUtils.navigateUpFromSameTask(this);
-                break;
+                if (twoPanedMode) {  // The device is in two-paned mode.
+                    // If there is at least one domain, save the current domain settings.
+                    if (domainsListView.getCount() > 0) {
+                        saveDomainSettings();
+                    }
 
-            case R.id.save_domain:
-                // Get handles for the domain settings.
-                EditText domainNameEditText = (EditText) findViewById(R.id.domain_settings_name_edittext);
-                Switch javaScriptEnabledSwitch = (Switch) findViewById(R.id.domain_settings_javascript_switch);
-                Switch firstPartyCookiesEnabledSwitch = (Switch) findViewById(R.id.domain_settings_first_party_cookies_switch);
-                Switch thirdPartyCookiesEnabledSwitch = (Switch) findViewById(R.id.domain_settings_third_party_cookies_switch);
-                Switch domStorageEnabledSwitch = (Switch) findViewById(R.id.domain_settings_dom_storage_switch);
-                Switch formDataEnabledSwitch = (Switch) findViewById(R.id.domain_settings_form_data_switch);
-                Spinner userAgentSpinner = (Spinner) findViewById(R.id.domain_settings_user_agent_spinner);
-                EditText customUserAgentEditText = (EditText) findViewById(R.id.domain_settings_custom_user_agent_edittext);
-                Spinner fontSizeSpinner = (Spinner) findViewById(R.id.domain_settings_font_size_spinner);
-                Spinner displayWebpageImagesSpinner = (Spinner) findViewById(R.id.domain_settings_display_webpage_images_spinner);
-
-                // Extract the data for the domain settings.
-                String domainNameString = domainNameEditText.getText().toString();
-                boolean javaScriptEnabledBoolean = javaScriptEnabledSwitch.isChecked();
-                boolean firstPartyCookiesEnabledBoolean = firstPartyCookiesEnabledSwitch.isChecked();
-                boolean thirdPartyCookiesEnabledBoolean = thirdPartyCookiesEnabledSwitch.isChecked();
-                boolean domStorageEnabledEnabledBoolean  = domStorageEnabledSwitch.isChecked();
-                boolean formDataEnabledBoolean = formDataEnabledSwitch.isChecked();
-                int userAgentPositionInt = userAgentSpinner.getSelectedItemPosition();
-                int fontSizePositionInt = fontSizeSpinner.getSelectedItemPosition();
-                int displayWebpageImagesInt = displayWebpageImagesSpinner.getSelectedItemPosition();
-
-                // Get the data for the `Spinners` from the entry values string arrays.
-                String userAgentString = getResources().getStringArray(R.array.user_agent_entry_values)[userAgentPositionInt];
-                int fontSizeInt = Integer.parseInt(getResources().getStringArray(R.array.default_font_size_entry_values)[fontSizePositionInt]);
-
-                // Check to see if we are using a custom user agent.
-                if (userAgentString.equals("Custom user agent")) {
-                    // Set `userAgentString` to the custom user agent string.
-                    userAgentString = customUserAgentEditText.getText().toString();
-                }
+                    // Go home.
+                    NavUtils.navigateUpFromSameTask(this);
+                } else if (domainSettingsFragmentDisplayed) {  // The device is in single-paned mode and `DomainSettingsFragment` is displayed.
+                    // Save the current domain settings.
+                    saveDomainSettings();
 
-                // Save the domain settings.
-                domainsDatabaseHelper.saveDomain(databaseId, domainNameString, javaScriptEnabledBoolean, firstPartyCookiesEnabledBoolean, thirdPartyCookiesEnabledBoolean, domStorageEnabledEnabledBoolean, formDataEnabledBoolean, userAgentString, fontSizeInt,
-                        displayWebpageImagesInt);
+                    // Display `DomainsListFragment`.
+                    DomainsListFragment domainsListFragment = new DomainsListFragment();
+                    supportFragmentManager.beginTransaction().replace(R.id.domains_listview_fragment_container, domainsListFragment).commit();
+                    supportFragmentManager.executePendingTransactions();
 
-                // Display a `Snackbar`.
-                Snackbar.make(domainsListView, R.string.domain_settings_saved, Snackbar.LENGTH_SHORT).show();
+                    // Populate the list of domains.
+                    populateDomainsListView();
+
+                    // Update `domainSettingsFragmentDisplayed`.
+                    domainSettingsFragmentDisplayed = false;
+
+                    // Display `addDomainFAB`.
+                    addDomainFAB.setVisibility(View.VISIBLE);
 
-                // update the domains `ListView`.
-                updateDomainsListView();
+                    // Hide `deleteMenuItem`.
+                    deleteMenuItem.setVisible(false);
+                } else {  // The device is in single-paned mode and `DomainsListFragment` is displayed.
+                    // Go home.
+                    NavUtils.navigateUpFromSameTask(this);
+                }
                 break;
 
             case R.id.delete_domain:
-                // Save the `ListView` `currentPosition`.
-                final int currentPosition = domainsListView.getCheckedItemPosition();
+                // Store a copy of `currentDomainDatabaseId` because it could change while the `Snackbar` is displayed.
+                final int databaseIdToDelete = currentDomainDatabaseId;
+
+                // Store the deleted domain position, which is needed if `Undo` is selected in the `Snackbar`.
+                final int deletedDomainPosition = domainsListView.getCheckedItemPosition();
+
+                // Update the fragments and menu items.
+                if (twoPanedMode) {  // Two-paned mode.
+                    // Disable the options `MenuItems`.
+                    deleteMenuItem.setEnabled(false);
+                    deleteMenuItem.setIcon(R.drawable.delete_blue);
+
+                    // Remove the domain settings fragment.
+                    supportFragmentManager.beginTransaction().remove(supportFragmentManager.findFragmentById(R.id.domain_settings_fragment_container)).commit();
+                } else {  // Single-paned mode.
+                    // Display `DomainsListFragment`.
+                    DomainsListFragment domainsListFragment = new DomainsListFragment();
+                    supportFragmentManager.beginTransaction().replace(R.id.domains_listview_fragment_container, domainsListFragment).commit();
+                    supportFragmentManager.executePendingTransactions();
+
+                    // Update `domainSettingsFragmentDisplayed`.
+                    domainSettingsFragmentDisplayed = false;
+
+                    // Display `addDomainFAB`.
+                    addDomainFAB.setVisibility(View.VISIBLE);
+
+                    // Hide `deleteMenuItem`.
+                    deleteMenuItem.setVisible(false);
+                }
 
                 // Get a `Cursor` that does not show the domain to be deleted.
-                Cursor domainsPendingDeleteCursor = domainsDatabaseHelper.getDomainNameCursorOrderedByDomainExcept(databaseId);
+                Cursor domainsPendingDeleteCursor = domainsDatabaseHelper.getDomainNameCursorOrderedByDomainExcept(databaseIdToDelete);
 
                 // Setup `domainsPendingDeleteCursorAdapter` with `this` context.  `false` disables `autoRequery`.
                 CursorAdapter domainsPendingDeleteCursorAdapter = new CursorAdapter(this, domainsPendingDeleteCursor, false) {
@@ -246,17 +238,12 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
                     }
                 };
 
+                // Update the handle for the current `domains_listview`.
+                domainsListView = (ListView) findViewById(R.id.domains_listview);
+
                 // Update the `ListView`.
                 domainsListView.setAdapter(domainsPendingDeleteCursorAdapter);
 
-                // Detach the domain settings `Fragment`.
-                getSupportFragmentManager().beginTransaction().detach(getSupportFragmentManager().findFragmentById(R.id.domain_settings_scrollview)).commit();
-
-                // Disable the options `MenuItems`.
-                deleteMenuItem.setEnabled(false);
-                deleteMenuItem.setIcon(R.drawable.delete_blue);
-                saveMenuItem.setEnabled(false);
-
                 // Display a `Snackbar`.
                 Snackbar.make(domainsListView, R.string.domain_deleted, Snackbar.LENGTH_LONG)
                         .setAction(R.string.undo, new View.OnClickListener() {
@@ -271,53 +258,70 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
                                 switch (event) {
                                     // The user pushed the `Undo` button.
                                     case Snackbar.Callback.DISMISS_EVENT_ACTION:
-                                        // Get a `Cursor` with the current contents of the domains database.
-                                        Cursor undoDeleteDomainsCursor = domainsDatabaseHelper.getDomainNameCursorOrderedByDomain();
-
-                                        // Setup `domainsCursorAdapter` with `this` context.  `false` disables `autoRequery`.
-                                        CursorAdapter undoDeleteDomainsCursorAdapter = new CursorAdapter(context, undoDeleteDomainsCursor, false) {
-                                            @Override
-                                            public View newView(Context context, Cursor cursor, ViewGroup parent) {
-                                                // Inflate the individual item layout.  `false` does not attach it to the root.
-                                                return getLayoutInflater().inflate(R.layout.domain_name_linearlayout, parent, false);
-                                            }
-
-                                            @Override
-                                            public void bindView(View view, Context context, Cursor cursor) {
-                                                // Set the domain name.
-                                                String domainNameString = cursor.getString(cursor.getColumnIndex(DomainsDatabaseHelper.DOMAIN_NAME));
-                                                TextView domainNameTextView = (TextView) view.findViewById(R.id.domain_name_textview);
-                                                domainNameTextView.setText(domainNameString);
-                                            }
-                                        };
-
-                                        // Update the `ListView`.
-                                        domainsListView.setAdapter(undoDeleteDomainsCursorAdapter);
-
-                                        // Select the entry in the domain list at `currentPosition`.
-                                        domainsListView.setItemChecked(currentPosition, true);
-
                                         // Store `databaseId` in `argumentsBundle`.
                                         Bundle argumentsBundle = new Bundle();
-                                        argumentsBundle.putInt(DomainSettingsFragment.DATABASE_ID, databaseId);
+                                        argumentsBundle.putInt(DomainSettingsFragment.DATABASE_ID, databaseIdToDelete);
 
                                         // Add `argumentsBundle` to `domainSettingsFragment`.
                                         DomainSettingsFragment domainSettingsFragment = new DomainSettingsFragment();
                                         domainSettingsFragment.setArguments(argumentsBundle);
 
-                                        // Display `domainSettingsFragment`.
-                                        getSupportFragmentManager().beginTransaction().replace(R.id.domain_settings_scrollview, domainSettingsFragment).commit();
-
-                                        // Enable the options `MenuItems`.
-                                        deleteMenuItem.setEnabled(true);
-                                        deleteMenuItem.setIcon(R.drawable.delete_light);
-                                        saveMenuItem.setEnabled(true);
+                                        // Display the correct fragments.
+                                        if (twoPanedMode) {  // The device in in two-paned mode.
+                                            // Get a `Cursor` with the current contents of the domains database.
+                                            Cursor undoDeleteDomainsCursor = domainsDatabaseHelper.getDomainNameCursorOrderedByDomain();
+
+                                            // Setup `domainsCursorAdapter` with `this` context.  `false` disables `autoRequery`.
+                                            CursorAdapter undoDeleteDomainsCursorAdapter = new CursorAdapter(context, undoDeleteDomainsCursor, false) {
+                                                @Override
+                                                public View newView(Context context, Cursor cursor, ViewGroup parent) {
+                                                    // Inflate the individual item layout.  `false` does not attach it to the root.
+                                                    return getLayoutInflater().inflate(R.layout.domain_name_linearlayout, parent, false);
+                                                }
+
+                                                @Override
+                                                public void bindView(View view, Context context, Cursor cursor) {
+                                                    // Set the domain name.
+                                                    String domainNameString = cursor.getString(cursor.getColumnIndex(DomainsDatabaseHelper.DOMAIN_NAME));
+                                                    TextView domainNameTextView = (TextView) view.findViewById(R.id.domain_name_textview);
+                                                    domainNameTextView.setText(domainNameString);
+                                                }
+                                            };
+
+                                            // Update the `ListView`.
+                                            domainsListView.setAdapter(undoDeleteDomainsCursorAdapter);
+                                            // Select the previously deleted domain in `domainsListView`.
+                                            domainsListView.setItemChecked(deletedDomainPosition, true);
+
+                                            // Display `domainSettingsFragment`.
+                                            supportFragmentManager.beginTransaction().replace(R.id.domain_settings_fragment_container, domainSettingsFragment).commit();
+
+                                            // Enable the options `MenuItems`.
+                                            deleteMenuItem.setEnabled(true);
+                                            deleteMenuItem.setIcon(R.drawable.delete_light);
+                                        } else {  // The device in in one-paned mode.
+                                            // Display `domainSettingsFragment`.
+                                            supportFragmentManager.beginTransaction().replace(R.id.domains_listview_fragment_container, domainSettingsFragment).commit();
+
+                                            // Hide `add_domain_fab`.
+                                            FloatingActionButton addDomainFAB = (FloatingActionButton) findViewById(R.id.add_domain_fab);
+                                            addDomainFAB.setVisibility(View.GONE);
+
+                                            // Show and enable `deleteMenuItem`.
+                                            deleteMenuItem.setVisible(true);
+
+                                            // Set `domainSettingsFragmentDisplayed`.
+                                            domainSettingsFragmentDisplayed = true;
+
+                                            // Display `domainSettingsFragment`.
+                                            supportFragmentManager.beginTransaction().replace(R.id.domains_listview_fragment_container, domainSettingsFragment).commit();
+                                        }
                                         break;
 
                                     // The `Snackbar` was dismissed without the `Undo` button being pushed.
                                     default:
                                         // Delete the selected domain.
-                                        domainsDatabaseHelper.deleteDomain(databaseId);
+                                        domainsDatabaseHelper.deleteDomain(databaseIdToDelete);
                                         break;
                                 }
                             }
@@ -330,6 +334,43 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
         return true;
     }
 
+    // Control what the navigation bar back button does.
+    @Override
+    public void onBackPressed() {
+        if (twoPanedMode) {  // The device is in two-paned mode.
+            // If there is at least one domain, save the current domain settings.
+            if (domainsListView.getCount() > 0) {
+                saveDomainSettings();
+            }
+
+            // Go home.
+            NavUtils.navigateUpFromSameTask(this);
+        } else if (domainSettingsFragmentDisplayed) {  // The device is in single-paned mode and `DomainSettingsFragment` is displayed.
+            // Save the current domain settings.
+            saveDomainSettings();
+
+            // Display `DomainsListFragment`.
+            DomainsListFragment domainsListFragment = new DomainsListFragment();
+            supportFragmentManager.beginTransaction().replace(R.id.domains_listview_fragment_container, domainsListFragment).commit();
+            supportFragmentManager.executePendingTransactions();
+
+            // Populate the list of domains.
+            populateDomainsListView();
+
+            // Update `domainSettingsFragmentDisplayed`.
+            domainSettingsFragmentDisplayed = false;
+
+            // Display `addDomainFAB`.
+            addDomainFAB.setVisibility(View.VISIBLE);
+
+            // Hide `deleteMenuItem`.
+            deleteMenuItem.setVisible(false);
+        } else {  // The device is in single-paned mode and `DomainsListFragment` is displayed.
+            // Pass `onBackPressed()` to the system.
+            super.onBackPressed();
+        }
+    }
+
     @Override
     public void onAddDomain(AppCompatDialogFragment dialogFragment) {
         // Get the `domainNameEditText` from `dialogFragment` and extract the string.
@@ -339,27 +380,58 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
         // Create the domain.
         domainsDatabaseHelper.addDomain(domainNameString);
 
-        // Refresh the `ListView`.
-        updateDomainsListView();
+        // Populate the `ListView`.
+        populateDomainsListView();
     }
 
-    private void updateDomainsListView() {
-        // Initialize `currentPosition`.
-        int currentPosition;
-
-        // Store the current position of `domainsListView` if it is already populated.
-        if (domainsListView.getCount() > 0){
-            currentPosition = domainsListView.getCheckedItemPosition();
-        } else {
-            // Set `currentPosition` to 0;
-            currentPosition = 0;
+    private void saveDomainSettings() {
+        // Get handles for the domain settings.
+        EditText domainNameEditText = (EditText) findViewById(R.id.domain_settings_name_edittext);
+        Switch javaScriptEnabledSwitch = (Switch) findViewById(R.id.domain_settings_javascript_switch);
+        Switch firstPartyCookiesEnabledSwitch = (Switch) findViewById(R.id.domain_settings_first_party_cookies_switch);
+        Switch thirdPartyCookiesEnabledSwitch = (Switch) findViewById(R.id.domain_settings_third_party_cookies_switch);
+        Switch domStorageEnabledSwitch = (Switch) findViewById(R.id.domain_settings_dom_storage_switch);
+        Switch formDataEnabledSwitch = (Switch) findViewById(R.id.domain_settings_form_data_switch);
+        Spinner userAgentSpinner = (Spinner) findViewById(R.id.domain_settings_user_agent_spinner);
+        EditText customUserAgentEditText = (EditText) findViewById(R.id.domain_settings_custom_user_agent_edittext);
+        Spinner fontSizeSpinner = (Spinner) findViewById(R.id.domain_settings_font_size_spinner);
+        Spinner displayWebpageImagesSpinner = (Spinner) findViewById(R.id.domain_settings_display_webpage_images_spinner);
+
+        // Extract the data for the domain settings.
+        String domainNameString = domainNameEditText.getText().toString();
+        boolean javaScriptEnabledBoolean = javaScriptEnabledSwitch.isChecked();
+        boolean firstPartyCookiesEnabledBoolean = firstPartyCookiesEnabledSwitch.isChecked();
+        boolean thirdPartyCookiesEnabledBoolean = thirdPartyCookiesEnabledSwitch.isChecked();
+        boolean domStorageEnabledEnabledBoolean  = domStorageEnabledSwitch.isChecked();
+        boolean formDataEnabledBoolean = formDataEnabledSwitch.isChecked();
+        int userAgentPositionInt = userAgentSpinner.getSelectedItemPosition();
+        int fontSizePositionInt = fontSizeSpinner.getSelectedItemPosition();
+        int displayWebpageImagesInt = displayWebpageImagesSpinner.getSelectedItemPosition();
+
+        // Get the data for the `Spinners` from the entry values string arrays.
+        String userAgentString = getResources().getStringArray(R.array.domain_settings_user_agent_entry_values)[userAgentPositionInt];
+        int fontSizeInt = Integer.parseInt(getResources().getStringArray(R.array.domain_settings_font_size_entry_values)[fontSizePositionInt]);
+
+        // Check to see if we are using a custom user agent.
+        if (userAgentString.equals("Custom user agent")) {
+            // Set `userAgentString` to the custom user agent string.
+            userAgentString = customUserAgentEditText.getText().toString();
         }
 
+        // Save the domain settings.
+        domainsDatabaseHelper.saveDomain(currentDomainDatabaseId, domainNameString, javaScriptEnabledBoolean, firstPartyCookiesEnabledBoolean, thirdPartyCookiesEnabledBoolean, domStorageEnabledEnabledBoolean, formDataEnabledBoolean, userAgentString, fontSizeInt,
+                displayWebpageImagesInt);
+    }
+
+    private void populateDomainsListView() {
+        // get a handle for the current `domains_listview`.
+        domainsListView = (ListView) findViewById(R.id.domains_listview);
+
         // Get a `Cursor` with the current contents of the domains database.
         Cursor domainsCursor = domainsDatabaseHelper.getDomainNameCursorOrderedByDomain();
 
         // Setup `domainsCursorAdapter` with `this` context.  `false` disables `autoRequery`.
-        CursorAdapter domainsCursorAdapter = new CursorAdapter(this, domainsCursor, false) {
+        CursorAdapter domainsCursorAdapter = new CursorAdapter(context, domainsCursor, false) {
             @Override
             public View newView(Context context, Cursor cursor, ViewGroup parent) {
                 // Inflate the individual item layout.  `false` does not attach it to the root.
@@ -379,28 +451,27 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
         domainsListView.setAdapter(domainsCursorAdapter);
 
         // Display the domain settings in the second pane if operating in two pane mode and the database contains at least one domain.
-        if (twoPaneMode && (domainsCursor.getCount() > 0)) {
-            // Select the entry in the domain list at `currentPosition`.
-            domainsListView.setItemChecked(currentPosition, true);
+        if (DomainsActivity.twoPanedMode && (domainsCursor.getCount() > 0)) {  // Two-paned mode is enabled and there is at least one domain.
+            // Select the first domain.
+            domainsListView.setItemChecked(0, true);
 
-            // Get the `databaseId` for `currentPosition`.
-            domainsCursor.moveToPosition(currentPosition);
-            databaseId = domainsCursor.getInt(domainsCursor.getColumnIndex(DomainsDatabaseHelper._ID));
+            // Get the `databaseId` for the first domain.
+            domainsCursor.moveToPosition(0);
+            currentDomainDatabaseId = domainsCursor.getInt(domainsCursor.getColumnIndex(DomainsDatabaseHelper._ID));
 
             // Store `databaseId` in `argumentsBundle`.
             Bundle argumentsBundle = new Bundle();
-            argumentsBundle.putInt(DomainSettingsFragment.DATABASE_ID, databaseId);
+            argumentsBundle.putInt(DomainSettingsFragment.DATABASE_ID, currentDomainDatabaseId);
 
             // Add `argumentsBundle` to `domainSettingsFragment`.
             DomainSettingsFragment domainSettingsFragment = new DomainSettingsFragment();
             domainSettingsFragment.setArguments(argumentsBundle);
 
             // Display `domainSettingsFragment`.
-            getSupportFragmentManager().beginTransaction().replace(R.id.domain_settings_scrollview, domainSettingsFragment).commit();
+            supportFragmentManager.beginTransaction().replace(R.id.domain_settings_fragment_container, domainSettingsFragment).commit();
 
             // Enable the options `MenuItems`.
             deleteMenuItem.setEnabled(true);
-            saveMenuItem.setEnabled(true);
 
             // Set the delete icon according to the theme.
             if (MainWebViewActivity.darkTheme) {
@@ -408,11 +479,10 @@ public class DomainsActivity extends AppCompatActivity implements AddDomainDialo
             } else {
                 deleteMenuItem.setIcon(R.drawable.delete_light);
             }
-        } else {
+        } else if (twoPanedMode) {  // Two-paned mode is enabled but there are no domains.
             // Disable the options `MenuItems`.
             deleteMenuItem.setEnabled(false);
             deleteMenuItem.setIcon(R.drawable.delete_blue);
-            saveMenuItem.setEnabled(false);
         }
     }
 }
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