From 335c5bcee65dcb5acea6a752e084fefa9b67c0fa Mon Sep 17 00:00:00 2001
From: Martin Rotter <rotter.martinos@gmail.com>
Date: Mon, 20 Jun 2016 07:58:29 +0200
Subject: [PATCH] Unified NULL macros for C++ 11.

---
 rssguard.pro                                  | 15 ++--
 src/core/feedsmodel.cpp                       | 34 +++----
 src/core/feedsproxymodel.cpp                  |  2 +-
 src/core/message.cpp                          |  4 +-
 src/core/messagesmodel.cpp                    |  4 +-
 src/core/parsingfactory.cpp                   |  2 +-
 src/gui/basetoolbar.cpp                       |  2 +-
 src/gui/dialogs/formaddaccount.cpp            |  2 +-
 src/gui/dialogs/formdatabasecleanup.cpp       |  4 +-
 src/gui/dialogs/formmain.cpp                  |  2 +-
 src/gui/dialogs/formsettings.cpp              |  8 +-
 src/gui/dialogs/formupdate.cpp                |  4 +-
 src/gui/edittableview.cpp                     |  2 +-
 src/gui/feedmessageviewer.cpp                 |  8 +-
 src/gui/feedstoolbar.cpp                      |  2 +-
 src/gui/feedsview.cpp                         | 26 +++---
 src/gui/messagestoolbar.cpp                   |  2 +-
 src/gui/messagesview.cpp                      |  6 +-
 src/gui/plaintoolbutton.cpp                   |  4 +-
 src/gui/statusbar.cpp                         | 14 +--
 src/gui/systemtrayicon.cpp                    | 10 +--
 src/gui/tabbar.cpp                            |  2 +-
 src/gui/tabwidget.cpp                         |  4 +-
 src/gui/webbrowser.h                          |  8 --
 src/gui/webbrowser.ui                         | 46 ----------
 src/gui/widgetwithstatus.cpp                  |  2 +-
 src/miscellaneous/application.cpp             | 20 ++---
 src/miscellaneous/databasefactory.cpp         |  2 +-
 src/miscellaneous/databasequeries.cpp         | 90 +++++++++----------
 src/miscellaneous/skinfactory.cpp             |  2 +-
 src/miscellaneous/systemfactory.cpp           |  2 +-
 src/network-web/downloader.cpp                |  8 +-
 src/network-web/downloadmanager.cpp           |  6 +-
 src/qtsingleapplication/qtlocalpeer.cpp       |  4 +-
 src/services/abstract/accountcheckmodel.cpp   | 12 +--
 src/services/abstract/feed.cpp                |  2 +-
 src/services/abstract/gui/formfeeddetails.cpp | 10 +--
 src/services/abstract/rootitem.cpp            | 10 +--
 src/services/abstract/serviceroot.cpp         | 12 +--
 .../owncloud/gui/formeditowncloudaccount.cpp  |  4 +-
 .../owncloud/gui/formowncloudfeeddetails.cpp  |  2 +-
 src/services/owncloud/owncloudcategory.cpp    |  2 +-
 src/services/owncloud/owncloudfeed.cpp        |  4 +-
 src/services/owncloud/owncloudserviceroot.cpp |  6 +-
 .../gui/formstandardcategorydetails.cpp       | 10 +--
 .../standard/gui/formstandardfeeddetails.cpp  |  2 +-
 src/services/standard/standardcategory.cpp    |  6 +-
 src/services/standard/standardfeed.cpp        | 16 ++--
 .../standardfeedsimportexportmodel.cpp        |  6 +-
 .../standard/standardserviceentrypoint.cpp    |  2 +-
 src/services/standard/standardserviceroot.cpp | 14 +--
 src/services/tt-rss/gui/formeditaccount.cpp   |  4 +-
 .../tt-rss/gui/formttrssfeeddetails.cpp       |  2 +-
 src/services/tt-rss/ttrsscategory.cpp         |  2 +-
 src/services/tt-rss/ttrssfeed.cpp             |  4 +-
 src/services/tt-rss/ttrssserviceroot.cpp      |  6 +-
 56 files changed, 218 insertions(+), 273 deletions(-)
 delete mode 100644 src/gui/webbrowser.ui
 mode change 100644 => 100755 src/miscellaneous/databasequeries.cpp
 mode change 100644 => 100755 src/qtsingleapplication/qtlocalpeer.cpp
 mode change 100644 => 100755 src/services/abstract/accountcheckmodel.cpp
 mode change 100644 => 100755 src/services/abstract/gui/formfeeddetails.cpp
 mode change 100644 => 100755 src/services/owncloud/gui/formowncloudfeeddetails.cpp
 mode change 100644 => 100755 src/services/tt-rss/gui/formttrssfeeddetails.cpp

diff --git a/rssguard.pro b/rssguard.pro
index 4fda47db0..8bad137fc 100755
--- a/rssguard.pro
+++ b/rssguard.pro
@@ -266,9 +266,9 @@ HEADERS += src/core/feeddownloader.h \
            src/gui/webviewer.h \
            src/gui/webbrowser.h \
            src/network-web/webpage.h \
-    src/gui/locationlineedit.h \
-    src/network-web/googlesuggest.h \
-    src/gui/discoverfeedsbutton.h
+           src/gui/locationlineedit.h \
+           src/network-web/googlesuggest.h \
+           src/gui/discoverfeedsbutton.h
 
 SOURCES += src/core/feeddownloader.cpp \
            src/core/feedsmodel.cpp \
@@ -377,9 +377,9 @@ SOURCES += src/core/feeddownloader.cpp \
            src/gui/webviewer.cpp \
            src/gui/webbrowser.cpp \
            src/network-web/webpage.cpp \
-    src/gui/locationlineedit.cpp \
-    src/network-web/googlesuggest.cpp \
-    src/gui/discoverfeedsbutton.cpp
+           src/gui/locationlineedit.cpp \
+           src/network-web/googlesuggest.cpp \
+           src/gui/discoverfeedsbutton.cpp
 
 FORMS += \
          src/gui/toolbareditor.ui \
@@ -397,8 +397,7 @@ FORMS += \
          src/services/owncloud/gui/formeditowncloudaccount.ui \
          src/services/standard/gui/formstandardcategorydetails.ui \
          src/services/standard/gui/formstandardimportexport.ui \
-         src/services/tt-rss/gui/formeditaccount.ui \
-         src/gui/webbrowser.ui
+         src/services/tt-rss/gui/formeditaccount.ui
 
 TRANSLATIONS += localization/qtbase-cs_CZ.ts \
                 localization/qtbase-da_DK.ts \
diff --git a/src/core/feedsmodel.cpp b/src/core/feedsmodel.cpp
index d7a371d68..3d16dfc79 100755
--- a/src/core/feedsmodel.cpp
+++ b/src/core/feedsmodel.cpp
@@ -46,8 +46,8 @@
 
 FeedsModel::FeedsModel(QObject *parent)
   : QAbstractItemModel(parent), m_autoUpdateTimer(new QTimer(this)),
-    m_feedDownloaderThread(NULL), m_feedDownloader(NULL),
-    m_dbCleanerThread(NULL), m_dbCleaner(NULL) {
+    m_feedDownloaderThread(nullptr), m_feedDownloader(nullptr),
+    m_dbCleanerThread(nullptr), m_dbCleaner(nullptr) {
   setObjectName(QSL("FeedsModel"));
 
   // Create root item.
@@ -87,7 +87,7 @@ void FeedsModel::quit() {
   }
 
   // Close worker threads.
-  if (m_feedDownloaderThread != NULL && m_feedDownloaderThread->isRunning()) {
+  if (m_feedDownloaderThread != nullptr && m_feedDownloaderThread->isRunning()) {
     m_feedDownloader->stopRunningUpdate();
 
     qDebug("Quitting feed downloader thread.");
@@ -99,7 +99,7 @@ void FeedsModel::quit() {
     }
   }
 
-  if (m_dbCleanerThread != NULL && m_dbCleanerThread->isRunning()) {
+  if (m_dbCleanerThread != nullptr && m_dbCleanerThread->isRunning()) {
     qDebug("Quitting database cleaner thread.");
     m_dbCleanerThread->quit();
 
@@ -110,12 +110,12 @@ void FeedsModel::quit() {
   }
 
   // Close workers.
-  if (m_feedDownloader != NULL) {
+  if (m_feedDownloader != nullptr) {
     qDebug("Feed downloader exists. Deleting it from memory.");
     m_feedDownloader->deleteLater();
   }
 
-  if (m_dbCleaner != NULL) {
+  if (m_dbCleaner != nullptr) {
     qDebug("Database cleaner exists. Deleting it from memory.");
     m_dbCleaner->deleteLater();
   }
@@ -133,7 +133,7 @@ void FeedsModel::updateFeeds(const QList<Feed*> &feeds) {
     return;
   }
 
-  if (m_feedDownloader == NULL) {
+  if (m_feedDownloader == nullptr) {
     m_feedDownloader = new FeedDownloader();
     m_feedDownloaderThread = new QThread();
 
@@ -185,7 +185,7 @@ void FeedsModel::updateAllFeeds() {
 }
 
 DatabaseCleaner *FeedsModel::databaseCleaner() {
-  if (m_dbCleaner == NULL) {
+  if (m_dbCleaner == nullptr) {
     m_dbCleaner = new DatabaseCleaner();
     m_dbCleanerThread = new QThread();
 
@@ -446,7 +446,7 @@ void FeedsModel::removeItem(const QModelIndex &index) {
 }
 
 void FeedsModel::removeItem(RootItem *deleting_item) {
-  if (deleting_item != NULL) {
+  if (deleting_item != nullptr) {
     QModelIndex index = indexForItem(deleting_item);
     QModelIndex parent_index = index.parent();
     RootItem *parent_item = deleting_item->parent();
@@ -464,7 +464,7 @@ void FeedsModel::reassignNodeToNewParent(RootItem *original_node, RootItem *new_
   RootItem *original_parent = original_node->parent();
 
   if (original_parent != new_parent) {
-    if (original_parent != NULL) {
+    if (original_parent != nullptr) {
       int original_index_of_item = original_parent->childItems().indexOf(original_node);
 
       if (original_index_of_item >= 0) {
@@ -510,12 +510,12 @@ StandardServiceRoot *FeedsModel::standardServiceRoot() const {
   foreach (ServiceRoot *root, serviceRoots()) {
     StandardServiceRoot *std_service_root;
 
-    if ((std_service_root = dynamic_cast<StandardServiceRoot*>(root)) != NULL) {
+    if ((std_service_root = dynamic_cast<StandardServiceRoot*>(root)) != nullptr) {
       return std_service_root;
     }
   }
 
-  return NULL;
+  return nullptr;
 }
 
 QList<Feed*> FeedsModel::feedsForScheduledUpdate(bool auto_update_now) {
@@ -577,7 +577,7 @@ RootItem *FeedsModel::itemForIndex(const QModelIndex &index) const {
 }
 
 QModelIndex FeedsModel::indexForItem(const RootItem *item) const {
-  if (item == NULL || item->kind() == RootItemKind::Root) {
+  if (item == nullptr || item->kind() == RootItemKind::Root) {
     // Root item lies on invalid index.
     return QModelIndex();
   }
@@ -612,7 +612,7 @@ bool FeedsModel::hasAnyFeedNewMessages() const {
 }
 
 bool FeedsModel::isFeedUpdateRunning() const {
-  return m_feedDownloader != NULL && m_feedDownloader->isUpdateRunning();
+  return m_feedDownloader != nullptr && m_feedDownloader->isUpdateRunning();
 }
 
 void FeedsModel::reloadChangedLayout(QModelIndexList list) {
@@ -687,7 +687,7 @@ bool FeedsModel::restoreAllBins() {
   foreach (ServiceRoot *root, serviceRoots()) {
     RecycleBin *bin_of_root = root->recycleBin();
 
-    if (bin_of_root != NULL) {
+    if (bin_of_root != nullptr) {
       result &= bin_of_root->restore();
     }
   }
@@ -701,7 +701,7 @@ bool FeedsModel::emptyAllBins() {
   foreach (ServiceRoot *root, serviceRoots()) {
     RecycleBin *bin_of_root = root->recycleBin();
 
-    if (bin_of_root != NULL) {
+    if (bin_of_root != nullptr) {
       result &= bin_of_root->empty();
     }
   }
@@ -727,7 +727,7 @@ void FeedsModel::loadActivatedServiceAccounts() {
 }
 
 void FeedsModel::stopRunningFeedUpdate() {
-  if (m_feedDownloader != NULL) {
+  if (m_feedDownloader != nullptr) {
     m_feedDownloader->stopRunningUpdate();
   }
 }
diff --git a/src/core/feedsproxymodel.cpp b/src/core/feedsproxymodel.cpp
index 122958217..7ca4bb519 100755
--- a/src/core/feedsproxymodel.cpp
+++ b/src/core/feedsproxymodel.cpp
@@ -28,7 +28,7 @@
 
 
 FeedsProxyModel::FeedsProxyModel(QObject *parent)
-  : QSortFilterProxyModel(parent), m_selectedItem(NULL), m_showUnreadOnly(false), m_hiddenIndices(QList<QPair<int,QModelIndex> >()) {
+  : QSortFilterProxyModel(parent), m_selectedItem(nullptr), m_showUnreadOnly(false), m_hiddenIndices(QList<QPair<int,QModelIndex> >()) {
   m_sourceModel = new FeedsModel(this);
 
   setObjectName(QSL("FeedsProxyModel"));
diff --git a/src/core/message.cpp b/src/core/message.cpp
index 758b03abe..d4f0824f6 100755
--- a/src/core/message.cpp
+++ b/src/core/message.cpp
@@ -73,7 +73,7 @@ Message::Message() {
 
 Message Message::fromSqlRecord(const QSqlRecord &record, bool *result) {
   if (record.count() != MSG_DB_CUSTOM_HASH_INDEX + 1) {
-    if (result != NULL) {
+    if (result != nullptr) {
       *result = false;
       return Message();
     }
@@ -95,7 +95,7 @@ Message Message::fromSqlRecord(const QSqlRecord &record, bool *result) {
   message.m_customId = record.value(MSG_DB_CUSTOM_ID_INDEX).toString();
   message.m_customHash = record.value(MSG_DB_CUSTOM_HASH_INDEX).toString();
 
-  if (result != NULL) {
+  if (result != nullptr) {
     *result = true;
   }
 
diff --git a/src/core/messagesmodel.cpp b/src/core/messagesmodel.cpp
index 76647f9e7..21809167e 100755
--- a/src/core/messagesmodel.cpp
+++ b/src/core/messagesmodel.cpp
@@ -40,7 +40,7 @@ MessagesModel::MessagesModel(QObject *parent)
   // via model, but via DIRECT SQL calls are used to do persistent messages.
   setEditStrategy(QSqlTableModel::OnManualSubmit);
   setTable(QSL("Messages"));
-  loadMessages(NULL);
+  loadMessages(nullptr);
 }
 
 MessagesModel::~MessagesModel() {
@@ -70,7 +70,7 @@ void MessagesModel::setupFonts() {
 void MessagesModel::loadMessages(RootItem *item) {
   m_selectedItem = item;
 
-  if (item == NULL) {
+  if (item == nullptr) {
     setFilter("true != true");
   }
   else {
diff --git a/src/core/parsingfactory.cpp b/src/core/parsingfactory.cpp
index b367c39f4..e7ac46ae1 100755
--- a/src/core/parsingfactory.cpp
+++ b/src/core/parsingfactory.cpp
@@ -99,7 +99,7 @@ QList<Message> ParsingFactory::parseAsATOM10(const QString &data) {
       new_message.m_created = current_time;
     }
 
-    // WARNING: There is a difference between "" and QString() in terms of NULL SQL values!
+    // WARNING: There is a difference between "" and QString() in terms of nullptr SQL values!
     // This is because of difference in QString::isNull() and QString::isEmpty(), the "" is not null
     // while QString() is.
     if (new_message.m_author.isNull()) {
diff --git a/src/gui/basetoolbar.cpp b/src/gui/basetoolbar.cpp
index 332c69600..99ec763d8 100755
--- a/src/gui/basetoolbar.cpp
+++ b/src/gui/basetoolbar.cpp
@@ -42,5 +42,5 @@ QAction *BaseBar::findMatchingAction(const QString &action, const QList<QAction*
     }
   }
 
-  return NULL;
+  return nullptr;
 }
diff --git a/src/gui/dialogs/formaddaccount.cpp b/src/gui/dialogs/formaddaccount.cpp
index af26e324e..1949449ab 100755
--- a/src/gui/dialogs/formaddaccount.cpp
+++ b/src/gui/dialogs/formaddaccount.cpp
@@ -47,7 +47,7 @@ void FormAddAccount::addSelectedAccount() {
   ServiceEntryPoint *point = selectedEntryPoint();
   ServiceRoot *new_root = point->createNewRoot();
 
-  if (new_root != NULL) {
+  if (new_root != nullptr) {
     m_model->addServiceAccount(new_root, true);
   }
   else {
diff --git a/src/gui/dialogs/formdatabasecleanup.cpp b/src/gui/dialogs/formdatabasecleanup.cpp
index 8ad506cb9..6d0422276 100755
--- a/src/gui/dialogs/formdatabasecleanup.cpp
+++ b/src/gui/dialogs/formdatabasecleanup.cpp
@@ -24,7 +24,7 @@
 #include <QCloseEvent>
 
 
-FormDatabaseCleanup::FormDatabaseCleanup(QWidget *parent) : QDialog(parent), m_ui(new Ui::FormDatabaseCleanup), m_cleaner(NULL) {
+FormDatabaseCleanup::FormDatabaseCleanup(QWidget *parent) : QDialog(parent), m_ui(new Ui::FormDatabaseCleanup), m_cleaner(nullptr) {
   m_ui->setupUi(this);
 
   // Set flags and attributes.
@@ -42,7 +42,7 @@ FormDatabaseCleanup::~FormDatabaseCleanup() {
 }
 
 void FormDatabaseCleanup::setCleaner(DatabaseCleaner *cleaner) {
-  if (m_cleaner != NULL) {
+  if (m_cleaner != nullptr) {
     disconnect(this, 0, m_cleaner, 0);
     disconnect(m_cleaner, 0, this, 0);
   }
diff --git a/src/gui/dialogs/formmain.cpp b/src/gui/dialogs/formmain.cpp
index 6fce5d30d..649c7ed8c 100755
--- a/src/gui/dialogs/formmain.cpp
+++ b/src/gui/dialogs/formmain.cpp
@@ -231,7 +231,7 @@ void FormMain::updateRecycleBinMenu() {
     RecycleBin *bin = activated_root->recycleBin();
     QList<QAction*> context_menu;
 
-    if (bin == NULL) {
+    if (bin == nullptr) {
       QAction *no_action = new QAction(qApp->icons()->fromTheme(QSL("dialog-error")),
                                        tr("No recycle bin"),
                                        m_ui->m_menuRecycleBin);
diff --git a/src/gui/dialogs/formsettings.cpp b/src/gui/dialogs/formsettings.cpp
index 85de1d35f..b558d386a 100755
--- a/src/gui/dialogs/formsettings.cpp
+++ b/src/gui/dialogs/formsettings.cpp
@@ -52,7 +52,7 @@
 #include <QDir>
 
 
-FormSettings::FormSettings(QWidget *parent) : QDialog(parent), m_ui(new Ui::FormSettings), m_settings(NULL) {
+FormSettings::FormSettings(QWidget *parent) : QDialog(parent), m_ui(new Ui::FormSettings), m_settings(nullptr) {
   m_ui->setupUi(this);
 
   m_settings = qApp->settings();
@@ -145,7 +145,7 @@ void FormSettings::changeDefaultBrowserArguments(int index) {
 void FormSettings::onSkinSelected(QTreeWidgetItem *current, QTreeWidgetItem *previous) {
   Q_UNUSED(previous)
 
-  if (current != NULL) {
+  if (current != nullptr) {
     const Skin skin = current->data(0, Qt::UserRole).value<Skin>();
     m_ui->m_lblSelectedContents->setText(skin.m_visibleName);
   }
@@ -456,7 +456,7 @@ void FormSettings::loadLanguage() {
 }
 
 void FormSettings::saveLanguage() {
-  if (m_ui->m_treeLanguages->currentItem() == NULL) {
+  if (m_ui->m_treeLanguages->currentItem() == nullptr) {
     qDebug("No localizations loaded in settings dialog, so no saving for them.");
     return;
   }
@@ -737,7 +737,7 @@ void FormSettings::loadInterface() {
     }
   }
 
-  if (m_ui->m_treeSkins->currentItem() == NULL &&
+  if (m_ui->m_treeSkins->currentItem() == nullptr &&
       m_ui->m_treeSkins->topLevelItemCount() > 0) {
     // Currently active skin is NOT available, select another one as selected
     // if possible.
diff --git a/src/gui/dialogs/formupdate.cpp b/src/gui/dialogs/formupdate.cpp
index 5ab514e83..e6a236692 100755
--- a/src/gui/dialogs/formupdate.cpp
+++ b/src/gui/dialogs/formupdate.cpp
@@ -32,7 +32,7 @@
 
 
 FormUpdate::FormUpdate(QWidget *parent)
-  : QDialog(parent), m_downloader(NULL), m_readyToInstall(false), m_ui(new Ui::FormUpdate) {
+  : QDialog(parent), m_downloader(nullptr), m_readyToInstall(false), m_ui(new Ui::FormUpdate) {
   m_ui->setupUi(this);
   m_btnUpdate = m_ui->m_buttonBox->addButton(tr("Download update"), QDialogButtonBox::ActionRole);
   m_btnUpdate->setToolTip(tr("Download new installation files."));
@@ -190,7 +190,7 @@ void FormUpdate::startUpdate() {
     // Nothing is downloaded yet, but update for this system
     // is available and self-update feature is present.
 
-    if (m_downloader == NULL) {
+    if (m_downloader == nullptr) {
       // Initialie downloader.
       m_downloader = new Downloader(this);
 
diff --git a/src/gui/edittableview.cpp b/src/gui/edittableview.cpp
index 9f3b6fcc5..2e628dd8e 100755
--- a/src/gui/edittableview.cpp
+++ b/src/gui/edittableview.cpp
@@ -62,7 +62,7 @@ void EditTableView::removeSelected() {
 }
 
 void EditTableView::removeAll() {
-  if (model() != NULL) {
+  if (model() != nullptr) {
     model()->removeRows(0, model()->rowCount(rootIndex()), rootIndex());
   }
 }
diff --git a/src/gui/feedmessageviewer.cpp b/src/gui/feedmessageviewer.cpp
index e8ed9b959..475d50fe9 100755
--- a/src/gui/feedmessageviewer.cpp
+++ b/src/gui/feedmessageviewer.cpp
@@ -157,7 +157,7 @@ void FeedMessageViewer::setListHeadersEnabled(bool enable) {
 void FeedMessageViewer::switchFeedComponentVisibility() {
   QAction *sen = qobject_cast<QAction*>(sender());
 
-  if (sen != NULL) {
+  if (sen != nullptr) {
     m_feedsWidget->setVisible(sen->isChecked());
   }
   else {
@@ -168,7 +168,7 @@ void FeedMessageViewer::switchFeedComponentVisibility() {
 void FeedMessageViewer::toggleShowOnlyUnreadFeeds() {
   const QAction *origin = qobject_cast<QAction*>(sender());
   
-  if (origin == NULL) {
+  if (origin == nullptr) {
     m_feedsView->model()->invalidateReadFeedsFilter(true, false);
   }
   else {
@@ -179,7 +179,7 @@ void FeedMessageViewer::toggleShowOnlyUnreadFeeds() {
 void FeedMessageViewer::updateMessageButtonsAvailability() {
   const bool one_message_selected = m_messagesView->selectionModel()->selectedRows().size() == 1;
   const bool atleast_one_message_selected = !m_messagesView->selectionModel()->selectedRows().isEmpty();
-  const bool bin_loaded = m_messagesView->sourceModel()->loadedItem() != NULL && m_messagesView->sourceModel()->loadedItem()->kind() == RootItemKind::Bin;
+  const bool bin_loaded = m_messagesView->sourceModel()->loadedItem() != nullptr && m_messagesView->sourceModel()->loadedItem()->kind() == RootItemKind::Bin;
   const FormMain *form_main = qApp->mainForm();
   
   form_main->m_ui->m_actionDeleteSelectedMessages->setEnabled(atleast_one_message_selected);
@@ -196,7 +196,7 @@ void FeedMessageViewer::updateFeedButtonsAvailability() {
   const bool is_update_running = feedsView()->sourceModel()->isFeedUpdateRunning();
   const bool critical_action_running = qApp->feedUpdateLock()->isLocked();
   const RootItem *selected_item = feedsView()->selectedItem();
-  const bool anything_selected = selected_item != NULL;
+  const bool anything_selected = selected_item != nullptr;
   const bool feed_selected = anything_selected && selected_item->kind() == RootItemKind::Feed;
   const bool category_selected = anything_selected && selected_item->kind() == RootItemKind::Category;
   const bool service_selected = anything_selected && selected_item->kind() == RootItemKind::ServiceRoot;
diff --git a/src/gui/feedstoolbar.cpp b/src/gui/feedstoolbar.cpp
index be0dc3e85..32c56aeb1 100755
--- a/src/gui/feedstoolbar.cpp
+++ b/src/gui/feedstoolbar.cpp
@@ -61,7 +61,7 @@ void FeedsToolBar::loadChangeableActions(const QStringList &actions) {
   foreach (const QString &action_name, actions) {
     QAction *matching_action = findMatchingAction(action_name, available_actions);
 
-    if (matching_action != NULL) {
+    if (matching_action != nullptr) {
       // Add existing standard action.
       addAction(matching_action);
     }
diff --git a/src/gui/feedsview.cpp b/src/gui/feedsview.cpp
index bcbdd5331..7bcba81ba 100755
--- a/src/gui/feedsview.cpp
+++ b/src/gui/feedsview.cpp
@@ -43,10 +43,10 @@
 
 FeedsView::FeedsView(QWidget *parent)
   : QTreeView(parent),
-    m_contextMenuCategories(NULL),
-    m_contextMenuFeeds(NULL),
-    m_contextMenuEmptySpace(NULL),
-    m_contextMenuOtherItems(NULL) {
+    m_contextMenuCategories(nullptr),
+    m_contextMenuFeeds(nullptr),
+    m_contextMenuEmptySpace(nullptr),
+    m_contextMenuOtherItems(nullptr) {
   setObjectName(QSL("FeedsView"));
 
   // Allocate models.
@@ -89,11 +89,11 @@ RootItem *FeedsView::selectedItem() const {
   const QModelIndexList selected_rows = selectionModel()->selectedRows();
 
   if (selected_rows.isEmpty()) {
-    return NULL;
+    return nullptr;
   }
   else {
     RootItem *selected_item = m_sourceModel->itemForIndex(m_proxyModel->mapToSource(selected_rows.at(0)));
-    return selected_item == m_sourceModel->rootItem() ? NULL : selected_item;
+    return selected_item == m_sourceModel->rootItem() ? nullptr : selected_item;
   }
 }
 
@@ -155,7 +155,7 @@ void FeedsView::sortByColumn(int column, Qt::SortOrder order) {
 void FeedsView::addFeedIntoSelectedAccount() {
   const RootItem *selected = selectedItem();
 
-  if (selected != NULL) {
+  if (selected != nullptr) {
     ServiceRoot *root = selected->getParentServiceRoot();
 
     if (root->supportsFeedAdding()) {
@@ -173,7 +173,7 @@ void FeedsView::addFeedIntoSelectedAccount() {
 void FeedsView::addCategoryIntoSelectedAccount() {
   const RootItem *selected = selectedItem();
 
-  if (selected != NULL) {
+  if (selected != nullptr) {
     ServiceRoot *root = selected->getParentServiceRoot();
 
     if (root->supportsCategoryAdding()) {
@@ -265,7 +265,7 @@ void FeedsView::deleteSelectedItem() {
 
   RootItem *selected_item = selectedItem();
 
-  if (selected_item != NULL) {
+  if (selected_item != nullptr) {
     if (selected_item->canBeDeleted()) {
       // Ask user first.
       if (MessageBox::show(qApp->mainForm(),
@@ -360,7 +360,7 @@ void FeedsView::expandItemDelayed(const QModelIndex &idx) {
 }
 
 QMenu *FeedsView::initializeContextMenuCategories(RootItem *clicked_item) {
-  if (m_contextMenuCategories == NULL) {
+  if (m_contextMenuCategories == nullptr) {
     m_contextMenuCategories = new QMenu(tr("Context menu for categories"), this);
   }
   else {
@@ -386,7 +386,7 @@ QMenu *FeedsView::initializeContextMenuCategories(RootItem *clicked_item) {
 }
 
 QMenu *FeedsView::initializeContextMenuFeeds(RootItem *clicked_item) {
-  if (m_contextMenuFeeds == NULL) {
+  if (m_contextMenuFeeds == nullptr) {
     m_contextMenuFeeds = new QMenu(tr("Context menu for categories"), this);
   }
   else {
@@ -412,7 +412,7 @@ QMenu *FeedsView::initializeContextMenuFeeds(RootItem *clicked_item) {
 }
 
 QMenu *FeedsView::initializeContextMenuEmptySpace() {
-  if (m_contextMenuEmptySpace == NULL) {
+  if (m_contextMenuEmptySpace == nullptr) {
     m_contextMenuEmptySpace = new QMenu(tr("Context menu for empty space"), this);
     m_contextMenuEmptySpace->addAction(qApp->mainForm()->m_ui->m_actionUpdateAllItems);
     m_contextMenuEmptySpace->addSeparator();
@@ -422,7 +422,7 @@ QMenu *FeedsView::initializeContextMenuEmptySpace() {
 }
 
 QMenu *FeedsView::initializeContextMenuOtherItem(RootItem *clicked_item) {
-  if (m_contextMenuOtherItems == NULL) {
+  if (m_contextMenuOtherItems == nullptr) {
     m_contextMenuOtherItems = new QMenu(tr("Context menu for other items"), this);
   }
   else {
diff --git a/src/gui/messagestoolbar.cpp b/src/gui/messagestoolbar.cpp
index d14f5f7f6..053e99674 100755
--- a/src/gui/messagestoolbar.cpp
+++ b/src/gui/messagestoolbar.cpp
@@ -70,7 +70,7 @@ void MessagesToolBar::loadChangeableActions(const QStringList& actions) {
   foreach (const QString &action_name, actions) {
     QAction *matching_action = findMatchingAction(action_name, available_actions);
 
-    if (matching_action != NULL) {
+    if (matching_action != nullptr) {
       // Add existing standard action.
       addAction(matching_action);
     }
diff --git a/src/gui/messagesview.cpp b/src/gui/messagesview.cpp
index ee0067ddf..f651ec6ac 100755
--- a/src/gui/messagesview.cpp
+++ b/src/gui/messagesview.cpp
@@ -35,7 +35,7 @@
 
 MessagesView::MessagesView(QWidget *parent)
   : QTreeView(parent),
-    m_contextMenu(NULL),
+    m_contextMenu(nullptr),
     m_columnsAdjusted(false),
     m_batchUnreadSwitch(false) {
   m_proxyModel = new MessagesProxyModel(this);
@@ -147,7 +147,7 @@ void MessagesView::contextMenuEvent(QContextMenuEvent *event) {
 }
 
 void MessagesView::initializeContextMenu() {
-  if (m_contextMenu == NULL) {
+  if (m_contextMenu == nullptr) {
     m_contextMenu = new QMenu(tr("Context menu for messages"), this);
   }
 
@@ -161,7 +161,7 @@ void MessagesView::initializeContextMenu() {
                             qApp->mainForm()->m_ui->m_actionSwitchImportanceOfSelectedMessages <<
                             qApp->mainForm()->m_ui->m_actionDeleteSelectedMessages);
 
-  if (m_sourceModel->loadedItem() != NULL && m_sourceModel->loadedItem()->kind() == RootItemKind::Bin) {
+  if (m_sourceModel->loadedItem() != nullptr && m_sourceModel->loadedItem()->kind() == RootItemKind::Bin) {
     m_contextMenu->addAction(qApp->mainForm()->m_ui->m_actionRestoreSelectedMessages);
   }
 }
diff --git a/src/gui/plaintoolbutton.cpp b/src/gui/plaintoolbutton.cpp
index fdb71f5be..eaed35b8d 100755
--- a/src/gui/plaintoolbutton.cpp
+++ b/src/gui/plaintoolbutton.cpp
@@ -67,9 +67,9 @@ void PlainToolButton::setChecked(bool checked) {
 }
 
 void PlainToolButton::reactOnActionChange(QAction *action) {
-  QAction *real_action = action == NULL ? qobject_cast<QAction*>(sender()) : action;
+  QAction *real_action = action == nullptr ? qobject_cast<QAction*>(sender()) : action;
 
-  if (real_action != NULL) {
+  if (real_action != nullptr) {
     setEnabled(real_action->isEnabled());
     setCheckable(real_action->isCheckable());
     setChecked(real_action->isChecked());
diff --git a/src/gui/statusbar.cpp b/src/gui/statusbar.cpp
index d01592e0d..01cc3f63a 100755
--- a/src/gui/statusbar.cpp
+++ b/src/gui/statusbar.cpp
@@ -156,7 +156,7 @@ void StatusBar::loadChangeableActions(const QStringList &action_names) {
         action_to_add->setProperty("type", SPACER_ACTION_NAME);
         action_to_add->setProperty("name", tr("Toolbar spacer"));
       }
-      else if (matching_action != NULL) {
+      else if (matching_action != nullptr) {
         // Add originally toolbar action.
         PlainToolButton *tool_button = new PlainToolButton(this);
         tool_button->reactOnActionChange(matching_action);
@@ -168,16 +168,16 @@ void StatusBar::loadChangeableActions(const QStringList &action_names) {
         connect(matching_action, SIGNAL(changed()), tool_button, SLOT(reactOnActionChange()));
       }
       else {
-        action_to_add = NULL;
-        widget_to_add = NULL;
+        action_to_add = nullptr;
+        widget_to_add = nullptr;
       }
 
-      if (action_to_add != NULL) {
+      if (action_to_add != nullptr) {
         action_to_add->setProperty("should_remove_widget", true);
       }
     }
 
-    if (action_to_add != NULL && widget_to_add != NULL) {
+    if (action_to_add != nullptr && widget_to_add != nullptr) {
       action_to_add->setProperty("widget", QVariant::fromValue((void*) widget_to_add));
       addPermanentWidget(widget_to_add);
       addAction(action_to_add);
@@ -198,13 +198,13 @@ bool StatusBar::eventFilter(QObject *watched, QEvent *event) {
 void StatusBar::clear() {
   while (!actions().isEmpty()) {
     QAction *act = actions().at(0);
-    QWidget *widget = act->property("widget").isValid() ? static_cast<QWidget*>(act->property("widget").value<void*>()) : NULL;
+    QWidget *widget = act->property("widget").isValid() ? static_cast<QWidget*>(act->property("widget").value<void*>()) : nullptr;
     bool should_remove_widget = act->property("should_remove_widget").isValid();
     bool should_remove_action = act->property("should_remove_action").isValid();
 
     removeAction(act);
 
-    if (widget != NULL) {
+    if (widget != nullptr) {
       removeWidget(widget);
       widget->setVisible(false);
 
diff --git a/src/gui/systemtrayicon.cpp b/src/gui/systemtrayicon.cpp
index 116c7db75..b4a142a50 100755
--- a/src/gui/systemtrayicon.cpp
+++ b/src/gui/systemtrayicon.cpp
@@ -35,7 +35,7 @@ TrayIconMenu::~TrayIconMenu() {
 }
 
 bool TrayIconMenu::event(QEvent *event) {
-  if (event->type() == QEvent::Show && Application::activeModalWidget() != NULL) {
+  if (event->type() == QEvent::Show && Application::activeModalWidget() != nullptr) {
     QTimer::singleShot(0, this, SLOT(hide()));
     qApp->showGuiMessage(QSL(STRFY(APP_LONG_NAME)),
                          tr("Close opened modal dialogs first."),
@@ -51,8 +51,8 @@ SystemTrayIcon::SystemTrayIcon(const QString &normal_icon, const QString &plain_
     m_normalIcon(normal_icon),
     m_plainPixmap(plain_icon),
     m_font(QFont()),
-    m_bubbleClickTarget(NULL),
-    m_bubbleClickSlot(NULL) {
+    m_bubbleClickTarget(nullptr),
+    m_bubbleClickSlot(nullptr) {
   qDebug("Creating SystemTrayIcon instance.");
 
   m_font.setBold(true);
@@ -167,7 +167,7 @@ void SystemTrayIcon::setNumber(int number, bool any_new_message) {
 
 void SystemTrayIcon::showMessage(const QString &title, const QString &message, QSystemTrayIcon::MessageIcon icon,
                                  int milliseconds_timeout_hint, QObject *click_target, const char *click_slot) {
-  if (m_bubbleClickTarget != NULL && m_bubbleClickSlot != NULL) {
+  if (m_bubbleClickTarget != nullptr && m_bubbleClickSlot != nullptr) {
     // Disconnect previous bubble click signalling.
     disconnect(this, SIGNAL(messageClicked()), m_bubbleClickTarget, m_bubbleClickSlot);
   }
@@ -175,7 +175,7 @@ void SystemTrayIcon::showMessage(const QString &title, const QString &message, Q
   m_bubbleClickSlot = (char*) click_slot;
   m_bubbleClickTarget = click_target;
 
-  if (click_target != NULL && click_slot != NULL) {
+  if (click_target != nullptr && click_slot != nullptr) {
     // Establish new connection for bubble click.
     connect(this, SIGNAL(messageClicked()), click_target, click_slot);
   }
diff --git a/src/gui/tabbar.cpp b/src/gui/tabbar.cpp
index d205cbcb9..c55be72b5 100755
--- a/src/gui/tabbar.cpp
+++ b/src/gui/tabbar.cpp
@@ -68,7 +68,7 @@ void TabBar::closeTabViaButton() {
                                                                                                  0,
                                                                                                  this));
 
-  if (close_button != NULL) {
+  if (close_button != nullptr) {
     // Find index of tab for this close button.
     for (int i = 0; i < count(); i++) {
       if (tabButton(i, button_position) == close_button) {
diff --git a/src/gui/tabwidget.cpp b/src/gui/tabwidget.cpp
index a55052c8e..d7b0a3905 100755
--- a/src/gui/tabwidget.cpp
+++ b/src/gui/tabwidget.cpp
@@ -31,7 +31,7 @@
 #include <QToolButton>
 
 
-TabWidget::TabWidget(QWidget *parent) : QTabWidget(parent), m_menuMain(NULL) {
+TabWidget::TabWidget(QWidget *parent) : QTabWidget(parent), m_menuMain(nullptr) {
   setTabBar(new TabBar(this));
   setupMainMenuButton();
   createConnections();
@@ -53,7 +53,7 @@ void TabWidget::setupMainMenuButton() {
 }
 
 void TabWidget::openMainMenu() {
-  if (m_menuMain == NULL) {
+  if (m_menuMain == nullptr) {
     m_menuMain = new QMenu(tr("Main menu"), this);
     m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuFile);
     m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuView);
diff --git a/src/gui/webbrowser.h b/src/gui/webbrowser.h
index 1b339d890..c5d810488 100755
--- a/src/gui/webbrowser.h
+++ b/src/gui/webbrowser.h
@@ -20,8 +20,6 @@
 
 #include "gui/tabcontent.h"
 
-//#include "ui_webbrowser.h"
-
 #include "core/message.h"
 #include "network-web/webpage.h"
 #include "services/abstract/rootitem.h"
@@ -30,10 +28,6 @@
 #include <QToolBar>
 
 
-/*namespace Ui {
-  class MessagePreviewer;
-}*/
-
 class QToolButton;
 class QVBoxLayout;
 class QHBoxLayout;
@@ -99,8 +93,6 @@ class WebBrowser : public TabContent {
     QAction *m_actionReload;
     QAction *m_actionStop;
 
-    //QScopedPointer<Ui::WebBrowser> m_ui;
-
     QList<Message> m_messages;
     QPointer<RootItem> m_root;
 };
diff --git a/src/gui/webbrowser.ui b/src/gui/webbrowser.ui
deleted file mode 100644
index b719c3478..000000000
--- a/src/gui/webbrowser.ui
+++ /dev/null
@@ -1,46 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ui version="4.0">
- <class>WebBrowser</class>
- <widget class="QWidget" name="WebBrowser">
-  <property name="geometry">
-   <rect>
-    <x>0</x>
-    <y>0</y>
-    <width>502</width>
-    <height>396</height>
-   </rect>
-  </property>
-  <property name="windowTitle">
-   <string/>
-  </property>
-  <property name="autoFillBackground">
-   <bool>true</bool>
-  </property>
-  <layout class="QGridLayout" name="m_layout">
-   <property name="leftMargin">
-    <number>0</number>
-   </property>
-   <property name="topMargin">
-    <number>0</number>
-   </property>
-   <property name="rightMargin">
-    <number>0</number>
-   </property>
-   <property name="bottomMargin">
-    <number>0</number>
-   </property>
-   <item row="0" column="1">
-    <widget class="WebViewer" name="m_webMessage" native="true"/>
-   </item>
-  </layout>
- </widget>
- <customwidgets>
-  <customwidget>
-   <class>WebViewer</class>
-   <extends>QWidget</extends>
-   <header>webviewer.h</header>
-  </customwidget>
- </customwidgets>
- <resources/>
- <connections/>
-</ui>
diff --git a/src/gui/widgetwithstatus.cpp b/src/gui/widgetwithstatus.cpp
index 794e13ac3..ff2dcb2d9 100755
--- a/src/gui/widgetwithstatus.cpp
+++ b/src/gui/widgetwithstatus.cpp
@@ -24,7 +24,7 @@
 
 
 WidgetWithStatus::WidgetWithStatus(QWidget *parent)
-  : QWidget(parent), m_wdgInput(NULL) {
+  : QWidget(parent), m_wdgInput(nullptr) {
   m_layout = new QHBoxLayout(this);
   m_btnStatus = new PlainToolButton(this);
   m_btnStatus->setFocusPolicy(Qt::NoFocus);
diff --git a/src/miscellaneous/application.cpp b/src/miscellaneous/application.cpp
index 12dd36052..37ae29f23 100755
--- a/src/miscellaneous/application.cpp
+++ b/src/miscellaneous/application.cpp
@@ -42,9 +42,9 @@
 
 Application::Application(const QString &id, int &argc, char **argv)
   : QtSingleApplication(id, argc, argv),
-    m_updateFeedsLock(NULL), m_updateMessagesLock(NULL), m_feedServices(QList<ServiceEntryPoint*>()), m_userActions(QList<QAction*>()), m_mainForm(NULL),
-    m_trayIcon(NULL), m_settings(NULL), m_system(NULL), m_skins(NULL),
-    m_localization(NULL), m_icons(NULL), m_database(NULL), m_downloadManager(NULL) {
+    m_updateFeedsLock(nullptr), m_updateMessagesLock(nullptr), m_feedServices(QList<ServiceEntryPoint*>()), m_userActions(QList<QAction*>()), m_mainForm(nullptr),
+    m_trayIcon(nullptr), m_settings(nullptr), m_system(nullptr), m_skins(nullptr),
+    m_localization(nullptr), m_icons(nullptr), m_database(nullptr), m_downloadManager(nullptr) {
   connect(this, SIGNAL(aboutToQuit()), this, SLOT(onAboutToQuit()));
   connect(this, SIGNAL(commitDataRequest(QSessionManager&)), this, SLOT(onCommitData(QSessionManager&)));
   connect(this, SIGNAL(saveStateRequest(QSessionManager&)), this, SLOT(onSaveState(QSessionManager&)));
@@ -69,7 +69,7 @@ QList<ServiceEntryPoint*> Application::feedServices() {
 }
 
 QList<QAction*> Application::userActions() {
-  if (m_mainForm != NULL && m_userActions.isEmpty()) {
+  if (m_mainForm != nullptr && m_userActions.isEmpty()) {
     m_userActions = m_mainForm->allActions();
   }
 
@@ -99,7 +99,7 @@ void Application::eliminateFirstRun(const QString &version) {
 }
 
 IconFactory *Application::icons() {
-  if (m_icons == NULL) {
+  if (m_icons == nullptr) {
     m_icons = new IconFactory(this);
   }
 
@@ -107,7 +107,7 @@ IconFactory *Application::icons() {
 }
 
 DownloadManager *Application::downloadManager() {
-  if (m_downloadManager == NULL) {
+  if (m_downloadManager == nullptr) {
     m_downloadManager = new DownloadManager();
 
     connect(m_downloadManager, SIGNAL(downloadFinished()), mainForm()->statusBar(), SLOT(clearProgressDownload()));
@@ -193,7 +193,7 @@ void Application::processExecutionMessage(const QString &message) {
       // Application was running, and someone wants to add new feed.
       StandardServiceRoot *root = qApp->mainForm()->tabWidget()->feedMessageViewer()->feedsView()->sourceModel()->standardServiceRoot();
 
-      if (root != NULL) {
+      if (root != nullptr) {
         root->checkArgumentForFeedAdding(msg);
       }
       else {
@@ -207,7 +207,7 @@ void Application::processExecutionMessage(const QString &message) {
 }
 
 SystemTrayIcon *Application::trayIcon() {
-  if (m_trayIcon == NULL) {
+  if (m_trayIcon == nullptr) {
     m_trayIcon = new SystemTrayIcon(APP_ICON_PATH, APP_ICON_PLAIN_PATH, m_mainForm);
     connect(m_trayIcon, SIGNAL(shown()),
             m_mainForm->tabWidget()->feedMessageViewer()->feedsView()->sourceModel(), SLOT(notifyWithCounts()));
@@ -222,11 +222,11 @@ void Application::showTrayIcon() {
 }
 
 void Application::deleteTrayIcon() {
-  if (m_trayIcon != NULL) {
+  if (m_trayIcon != nullptr) {
     qDebug("Disabling tray icon, deleting it and raising main application window.");
     m_mainForm->display();
     delete m_trayIcon;
-    m_trayIcon = NULL;
+    m_trayIcon = nullptr;
 
     // Make sure that application quits when last window is closed.
     setQuitOnLastWindowClosed(true);
diff --git a/src/miscellaneous/databasefactory.cpp b/src/miscellaneous/databasefactory.cpp
index 50ec7f25d..cec4c234b 100755
--- a/src/miscellaneous/databasefactory.cpp
+++ b/src/miscellaneous/databasefactory.cpp
@@ -645,7 +645,7 @@ QSqlDatabase DatabaseFactory::mysqlInitializeDatabase(const QString &connection_
     // Also, we set the SQLite driver as active one.
     qApp->settings()->setValue(GROUP(Database), Database::ActiveDriver, APP_DB_SQLITE_DRIVER);
     determineDriver();
-    MessageBox::show(NULL, QMessageBox::Critical, tr("MySQL database not available"),
+    MessageBox::show(nullptr, QMessageBox::Critical, tr("MySQL database not available"),
                      tr("%1 cannot use MySQL storage, it is not available. %1 is now switching to SQLite database. Start your MySQL server "
                         "and make adjustments in application settings.").arg(STRFY(APP_NAME)));
 
diff --git a/src/miscellaneous/databasequeries.cpp b/src/miscellaneous/databasequeries.cpp
old mode 100644
new mode 100755
index 2a291f839..cc86080b8
--- a/src/miscellaneous/databasequeries.cpp
+++ b/src/miscellaneous/databasequeries.cpp
@@ -214,12 +214,12 @@ QMap<int,QPair<int,int> > DatabaseQueries::getMessageCountsForCategory(QSqlDatab
       }
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -261,12 +261,12 @@ QMap<int,QPair<int,int> > DatabaseQueries::getMessageCountsForAccount(QSqlDataba
       }
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -292,14 +292,14 @@ int DatabaseQueries::getMessageCountsForFeed(QSqlDatabase db, int feed_custom_id
   q.bindValue(QSL(":account_id"), account_id);
 
   if (q.exec() && q.next()) {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
 
     return q.value(0).toInt();
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
 
@@ -323,14 +323,14 @@ int DatabaseQueries::getMessageCountsForBin(QSqlDatabase db, int account_id, boo
   q.bindValue(QSL(":account_id"), account_id);
 
   if (q.exec() && q.next()) {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
 
     return q.value(0).toInt();
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
 
@@ -359,12 +359,12 @@ QList<Message> DatabaseQueries::getUndeletedMessagesForFeed(QSqlDatabase db, int
       }
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -392,12 +392,12 @@ QList<Message> DatabaseQueries::getUndeletedMessagesForBin(QSqlDatabase db, int
       }
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -424,12 +424,12 @@ QList<Message> DatabaseQueries::getUndeletedMessagesForAccount(QSqlDatabase db,
       }
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -606,7 +606,7 @@ int DatabaseQueries::updateMessages(QSqlDatabase db,
   // just to keep the data consistent.
   if (db.exec("UPDATE Messages "
               "SET custom_id = (SELECT id FROM Messages t WHERE t.id = Messages.id) "
-              "WHERE Messages.custom_id IS NULL OR Messages.custom_id = '';").lastError().isValid()) {
+              "WHERE Messages.custom_id IS nullptr OR Messages.custom_id = '';").lastError().isValid()) {
     qWarning("Failed to set custom ID for all messages.");
   }
 
@@ -614,12 +614,12 @@ int DatabaseQueries::updateMessages(QSqlDatabase db,
     db.rollback();
     qDebug("Transaction commit for message downloader failed.");
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
@@ -794,7 +794,7 @@ QStringList DatabaseQueries::customIdsOfMessagesFromAccount(QSqlDatabase db, int
   q.prepare(QSL("SELECT custom_id FROM Messages WHERE is_deleted = 0 AND is_pdeleted = 0 AND account_id = :account_id;"));
   q.bindValue(QSL(":account_id"), account_id);
 
-  if (ok != NULL) {
+  if (ok != nullptr) {
     *ok = q.exec();
   }
   else {
@@ -815,7 +815,7 @@ QStringList DatabaseQueries::customIdsOfMessagesFromBin(QSqlDatabase db, int acc
   q.prepare(QSL("SELECT custom_id FROM Messages WHERE is_deleted = 1 AND is_pdeleted = 0 AND account_id = :account_id;"));
   q.bindValue(QSL(":account_id"), account_id);
 
-  if (ok != NULL) {
+  if (ok != nullptr) {
     *ok = q.exec();
   }
   else {
@@ -837,7 +837,7 @@ QStringList DatabaseQueries::customIdsOfMessagesFromFeed(QSqlDatabase db, int fe
   q.bindValue(QSL(":account_id"), account_id);
   q.bindValue(QSL(":feed"), feed_custom_id);
 
-  if (ok != NULL) {
+  if (ok != nullptr) {
     *ok = q.exec();
   }
   else {
@@ -869,14 +869,14 @@ QList<ServiceRoot*> DatabaseQueries::getOwnCloudAccounts(QSqlDatabase db, bool *
       roots.append(root);
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
     qWarning("OwnCloud: Getting list of activated accounts failed: '%s'.", qPrintable(query.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -905,14 +905,14 @@ QList<ServiceRoot*> DatabaseQueries::getTtRssAccounts(QSqlDatabase db, bool *ok)
       roots.append(root);
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
     qWarning("TT-RSS: Getting list of activated accounts failed: '%s'.", qPrintable(query.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -981,7 +981,7 @@ int DatabaseQueries::createAccount(QSqlDatabase db, const QString &code, bool *o
   if (!q.exec("SELECT max(id) FROM Accounts;") || !q.next()) {
     qWarning("Getting max ID from Accounts table failed: '%s'.", qPrintable(q.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
 
@@ -995,14 +995,14 @@ int DatabaseQueries::createAccount(QSqlDatabase db, const QString &code, bool *o
   q.bindValue(QSL(":type"), code);
 
   if (q.exec()) {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
 
     return id_to_assign;
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
 
@@ -1023,7 +1023,7 @@ Assignment DatabaseQueries::getOwnCloudCategories(QSqlDatabase db, int account_i
   if (!q.exec()) {
     qFatal("ownCloud: Query for obtaining categories failed. Error message: '%s'.", qPrintable(q.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -1036,7 +1036,7 @@ Assignment DatabaseQueries::getOwnCloudCategories(QSqlDatabase db, int account_i
     categories << pair;
   }
 
-  if (ok != NULL) {
+  if (ok != nullptr) {
     *ok = true;
   }
 
@@ -1054,7 +1054,7 @@ Assignment DatabaseQueries::getOwnCloudFeeds(QSqlDatabase db, int account_id, bo
   if (!q.exec()) {
     qFatal("ownCloud: Query for obtaining feeds failed. Error message: '%s'.", qPrintable(q.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -1067,7 +1067,7 @@ Assignment DatabaseQueries::getOwnCloudFeeds(QSqlDatabase db, int account_id, bo
     feeds << pair;
   }
 
-  if (ok != NULL) {
+  if (ok != nullptr) {
     *ok = true;
   }
 
@@ -1125,7 +1125,7 @@ int DatabaseQueries::addCategory(QSqlDatabase db, int parent_id, int account_id,
   if (!q.exec()) {
     qDebug("Failed to add category to database: '%s'.", qPrintable(q.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
 
@@ -1133,7 +1133,7 @@ int DatabaseQueries::addCategory(QSqlDatabase db, int parent_id, int account_id,
     return 0;
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
 
@@ -1209,14 +1209,14 @@ int DatabaseQueries::addFeed(QSqlDatabase db, int parent_id, int account_id, con
     q.bindValue(QSL(":id"), new_id);
     q.exec();
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
 
     return new_id;
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
 
@@ -1292,12 +1292,12 @@ QList<ServiceRoot*> DatabaseQueries::getAccounts(QSqlDatabase db, bool *ok) {
       roots.append(root);
     }
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
@@ -1318,12 +1318,12 @@ Assignment DatabaseQueries::getCategories(QSqlDatabase db, int account_id, bool
     qFatal("Query for obtaining categories failed. Error message: '%s'.",
            qPrintable(q.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
@@ -1351,12 +1351,12 @@ Assignment DatabaseQueries::getFeeds(QSqlDatabase db, int account_id, bool *ok)
     qFatal("Query for obtaining feeds failed. Error message: '%s'.",
            qPrintable(q.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
 
-  if (ok != NULL) {
+  if (ok != nullptr) {
     *ok = true;
   }
 
@@ -1463,12 +1463,12 @@ Assignment DatabaseQueries::getTtRssCategories(QSqlDatabase db, int account_id,
   if (!query_categories.exec()) {
     qFatal("Query for obtaining categories failed. Error message: '%s'.", qPrintable(query_categories.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
@@ -1496,12 +1496,12 @@ Assignment DatabaseQueries::getTtRssFeeds(QSqlDatabase db, int account_id, bool
   if (!query_feeds.exec()) {
     qFatal("Query for obtaining feeds failed. Error message: '%s'.", qPrintable(query_feeds.lastError().text()));
 
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = false;
     }
   }
   else {
-    if (ok != NULL) {
+    if (ok != nullptr) {
       *ok = true;
     }
   }
diff --git a/src/miscellaneous/skinfactory.cpp b/src/miscellaneous/skinfactory.cpp
index 51ae5ea0b..0a6955dfe 100755
--- a/src/miscellaneous/skinfactory.cpp
+++ b/src/miscellaneous/skinfactory.cpp
@@ -142,7 +142,7 @@ Skin SkinFactory::skinInfo(const QString &skin_name, bool *ok) const {
   skin_file.close();
   skin_file.deleteLater();
 
-  if (ok != NULL) {
+  if (ok != nullptr) {
     *ok = !skin.m_author.isEmpty() && !skin.m_version.isEmpty() &&
           !skin.m_baseName.isEmpty() && !skin.m_email.isEmpty() &&
           !skin.m_layoutMarkup.isEmpty();
diff --git a/src/miscellaneous/systemfactory.cpp b/src/miscellaneous/systemfactory.cpp
index d5a5743fb..cf534d314 100755
--- a/src/miscellaneous/systemfactory.cpp
+++ b/src/miscellaneous/systemfactory.cpp
@@ -291,6 +291,6 @@ void SystemFactory::checkForUpdatesOnStartup() {
     qApp->showGuiMessage(tr("New version available"),
                          tr("Click the bubble for more information."),
                          QSystemTrayIcon::Information,
-                         NULL, true, qApp->mainForm(), SLOT(showUpdates()));
+                         nullptr, true, qApp->mainForm(), SLOT(showUpdates()));
   }
 }
diff --git a/src/network-web/downloader.cpp b/src/network-web/downloader.cpp
index 56e99d611..572455eba 100755
--- a/src/network-web/downloader.cpp
+++ b/src/network-web/downloader.cpp
@@ -23,7 +23,7 @@
 
 
 Downloader::Downloader(QObject *parent)
-  : QObject(parent), m_activeReply(NULL), m_downloadManager(new SilentNetworkAccessManager(this)),
+  : QObject(parent), m_activeReply(nullptr), m_downloadManager(new SilentNetworkAccessManager(this)),
     m_timer(new QTimer(this)), m_customHeaders(QHash<QByteArray, QByteArray>()), m_inputData(QByteArray()),
     m_targetProtected(false), m_targetUsername(QString()), m_targetPassword(QString()),
     m_lastOutputData(QByteArray()), m_lastOutputError(QNetworkReply::NoError), m_lastContentType(QVariant()) {
@@ -110,7 +110,7 @@ void Downloader::finished() {
     }
 
     m_activeReply->deleteLater();
-    m_activeReply = NULL;
+    m_activeReply = nullptr;
 
     if (reply_operation == QNetworkAccessManager::GetOperation) {
       runGetRequest(request);
@@ -133,7 +133,7 @@ void Downloader::finished() {
     m_lastOutputError = reply->error();
 
     m_activeReply->deleteLater();
-    m_activeReply = NULL;
+    m_activeReply = nullptr;
 
     emit completed(m_lastOutputError, m_lastOutputData);
   }
@@ -204,7 +204,7 @@ QVariant Downloader::lastContentType() const {
 }
 
 void Downloader::cancel() {
-  if (m_activeReply != NULL) {
+  if (m_activeReply != nullptr) {
     // Download action timed-out, too slow connection or target is not reachable.
     m_activeReply->abort();
   }
diff --git a/src/network-web/downloadmanager.cpp b/src/network-web/downloadmanager.cpp
index 56a89bcc0..73b0dcc08 100755
--- a/src/network-web/downloadmanager.cpp
+++ b/src/network-web/downloadmanager.cpp
@@ -61,7 +61,7 @@ DownloadItem::~DownloadItem() {
 }
 
 void DownloadItem::init() {
-  if (m_reply == NULL) {
+  if (m_reply == nullptr) {
     return;
   }
 
@@ -442,7 +442,7 @@ void DownloadItem::updateInfoAndUrlLabel() {
 
 DownloadManager::DownloadManager(QWidget *parent) : TabContent(parent), m_ui(new Ui::DownloadManager),
   m_autoSaver(new AutoSaver(this)), m_model(new DownloadModel(this)),
-  m_networkManager(SilentNetworkAccessManager::instance()), m_iconProvider(NULL), m_removePolicy(Never) {
+  m_networkManager(SilentNetworkAccessManager::instance()), m_iconProvider(nullptr), m_removePolicy(Never) {
   m_ui->setupUi(this);
   m_ui->m_viewDownloads->setShowGrid(false);
   m_ui->m_viewDownloads->verticalHeader()->hide();
@@ -505,7 +505,7 @@ void DownloadManager::download(const QUrl &url) {
 }
 
 void DownloadManager::handleUnsupportedContent(QNetworkReply *reply) {
-  if (reply == NULL || reply->url().isEmpty()) {
+  if (reply == nullptr || reply->url().isEmpty()) {
     return;
   }
 
diff --git a/src/qtsingleapplication/qtlocalpeer.cpp b/src/qtsingleapplication/qtlocalpeer.cpp
old mode 100644
new mode 100755
index 47f01205c..516042991
--- a/src/qtsingleapplication/qtlocalpeer.cpp
+++ b/src/qtsingleapplication/qtlocalpeer.cpp
@@ -109,7 +109,7 @@ QtLocalPeer::QtLocalPeer(QObject* parent, const QString &appId)
 }
 
 QtLocalPeer::~QtLocalPeer() {
-  if (server != NULL) {
+  if (server != nullptr) {
     server->close();
   }
 }
@@ -157,7 +157,7 @@ bool QtLocalPeer::sendMessage(const QString &message, int timeout)
         Sleep(DWORD(ms));
 #else
         struct timespec ts = { ms / 1000, (ms % 1000) * 1000 * 1000 };
-        nanosleep(&ts, NULL);
+        nanosleep(&ts, nullptr);
 #endif
     }
     if (!connOk)
diff --git a/src/services/abstract/accountcheckmodel.cpp b/src/services/abstract/accountcheckmodel.cpp
old mode 100644
new mode 100755
index d7713a172..6b797141a
--- a/src/services/abstract/accountcheckmodel.cpp
+++ b/src/services/abstract/accountcheckmodel.cpp
@@ -23,7 +23,7 @@
 
 
 AccountCheckModel::AccountCheckModel(QObject *parent)
-  : QAbstractItemModel(parent), m_rootItem(NULL), m_checkStates(QHash<RootItem*, Qt::CheckState>()), m_recursiveChange(false) {
+  : QAbstractItemModel(parent), m_rootItem(nullptr), m_checkStates(QHash<RootItem*, Qt::CheckState>()), m_recursiveChange(false) {
 }
 
 AccountCheckModel::~AccountCheckModel() {
@@ -43,7 +43,7 @@ RootItem *AccountCheckModel::rootItem() const {
 }
 
 void AccountCheckModel::setRootItem(RootItem *root_item) {
-  if (m_rootItem != NULL) {
+  if (m_rootItem != nullptr) {
     delete m_rootItem;
   }
 
@@ -51,7 +51,7 @@ void AccountCheckModel::setRootItem(RootItem *root_item) {
 }
 
 void AccountCheckModel::checkAllItems() {
-  if (m_rootItem != NULL) {
+  if (m_rootItem != nullptr) {
     foreach (RootItem *root_child, m_rootItem->childItems()) {
       if (root_child->kind() == RootItemKind::Feed || root_child->kind() == RootItemKind::Category) {
         setItemChecked(root_child, Qt::Checked);
@@ -61,7 +61,7 @@ void AccountCheckModel::checkAllItems() {
 }
 
 void AccountCheckModel::uncheckAllItems() {
-  if (m_rootItem != NULL) {
+  if (m_rootItem != nullptr) {
     foreach (RootItem *root_child, m_rootItem->childItems()) {
       if (root_child->kind() == RootItemKind::Feed || root_child->kind() == RootItemKind::Category) {
         setData(indexForItem(root_child), Qt::Unchecked, Qt::CheckStateRole);
@@ -87,7 +87,7 @@ QModelIndex AccountCheckModel::index(int row, int column, const QModelIndex &par
 }
 
 QModelIndex AccountCheckModel::indexForItem(RootItem *item) const {
-  if (item == NULL || item->kind() == RootItemKind::ServiceRoot || item->kind() == RootItemKind::Root) {
+  if (item == nullptr || item->kind() == RootItemKind::ServiceRoot || item->kind() == RootItemKind::Root) {
     // Root item lies on invalid index.
     return QModelIndex();
   }
@@ -150,7 +150,7 @@ int AccountCheckModel::rowCount(const QModelIndex &parent) const {
   else {
     RootItem *item = itemForIndex(parent);
 
-    if (item != NULL) {
+    if (item != nullptr) {
       return item->childCount();
     }
     else {
diff --git a/src/services/abstract/feed.cpp b/src/services/abstract/feed.cpp
index c147eada8..3f7a36c45 100755
--- a/src/services/abstract/feed.cpp
+++ b/src/services/abstract/feed.cpp
@@ -168,7 +168,7 @@ int Feed::updateMessages(const QList<Message> &messages) {
     updateCounts(true);
     items_to_update.append(this);
 
-    if (getParentServiceRoot()->recycleBin() != NULL && anything_updated) {
+    if (getParentServiceRoot()->recycleBin() != nullptr && anything_updated) {
       getParentServiceRoot()->recycleBin()->updateCounts(true);
       items_to_update.append(getParentServiceRoot()->recycleBin());
     }
diff --git a/src/services/abstract/gui/formfeeddetails.cpp b/src/services/abstract/gui/formfeeddetails.cpp
old mode 100644
new mode 100755
index b955f24d2..f1e84573c
--- a/src/services/abstract/gui/formfeeddetails.cpp
+++ b/src/services/abstract/gui/formfeeddetails.cpp
@@ -42,7 +42,7 @@
 
 FormFeedDetails::FormFeedDetails(ServiceRoot *service_root, QWidget *parent)
   : QDialog(parent),
-    m_editableFeed(NULL),
+    m_editableFeed(nullptr),
     m_serviceRoot(service_root) {
   initialize();
   createConnections();
@@ -62,7 +62,7 @@ int FormFeedDetails::exec(Feed *input_feed, RootItem *parent_to_select, const QS
   // Load categories.
   loadCategories(m_serviceRoot->getSubTreeCategories(), m_serviceRoot);
 
-  if (input_feed == NULL) {
+  if (input_feed == nullptr) {
     // User is adding new category.
     setWindowTitle(tr("Add new feed"));
 
@@ -76,7 +76,7 @@ int FormFeedDetails::exec(Feed *input_feed, RootItem *parent_to_select, const QS
       m_ui->m_cmbEncoding->setCurrentIndex(default_encoding_index);
     }
 
-    if (parent_to_select != NULL) {
+    if (parent_to_select != nullptr) {
       if (parent_to_select->kind() == RootItemKind::Category) {
         m_ui->m_cmbParentCategory->setCurrentIndex(m_ui->m_cmbParentCategory->findData(QVariant::fromValue((void*) parent_to_select)));
       }
@@ -217,7 +217,7 @@ void FormFeedDetails::guessFeed() {
                                                                                       m_ui->m_txtUsername->lineEdit()->text(),
                                                                                       m_ui->m_txtPassword->lineEdit()->text());
 
-  if (result.first != NULL) {
+  if (result.first != nullptr) {
     // Icon or whole feed was guessed.
     m_ui->m_btnIcon->setIcon(result.first->icon());
     m_ui->m_txtTitle->lineEdit()->setText(result.first->title());
@@ -261,7 +261,7 @@ void FormFeedDetails::guessIconOnly() {
                                                                                      m_ui->m_txtUsername->lineEdit()->text(),
                                                                                      m_ui->m_txtPassword->lineEdit()->text());
 
-  if (result.first != NULL) {
+  if (result.first != nullptr) {
     // Icon or whole feed was guessed.
     m_ui->m_btnIcon->setIcon(result.first->icon());
 
diff --git a/src/services/abstract/rootitem.cpp b/src/services/abstract/rootitem.cpp
index 05e0901eb..8d3677f20 100755
--- a/src/services/abstract/rootitem.cpp
+++ b/src/services/abstract/rootitem.cpp
@@ -27,7 +27,7 @@
 
 
 RootItem::RootItem(RootItem *parent_item)
-  : QObject(NULL),
+  : QObject(nullptr),
     m_kind(RootItemKind::Root),
     m_id(NO_PARENT_CATEGORY),
     m_customId(NO_PARENT_CATEGORY),
@@ -46,7 +46,7 @@ RootItem::~RootItem() {
 
 QString RootItem::hashCode() const {
   ServiceRoot *root = getParentServiceRoot();
-  int acc_id = root == NULL ? 0 : root->accountId();
+  int acc_id = root == nullptr ? 0 : root->accountId();
 
   return
       QString::number(acc_id) + QL1S("-") +
@@ -217,7 +217,7 @@ int RootItem::countOfAllMessages() const {
 }
 
 bool RootItem::isChildOf(const RootItem *root) const {
-  if (root == NULL) {
+  if (root == nullptr) {
     return false;
   }
 
@@ -236,7 +236,7 @@ bool RootItem::isChildOf(const RootItem *root) const {
 }
 
 bool RootItem::isParentOf(const RootItem *child) const {
-  if (child == NULL) {
+  if (child == nullptr) {
     return false;
   }
   else {
@@ -373,7 +373,7 @@ ServiceRoot *RootItem::getParentServiceRoot() const {
     }
   }
 
-  return NULL;
+  return nullptr;
 }
 
 bool RootItem::removeChild(RootItem *child) {
diff --git a/src/services/abstract/serviceroot.cpp b/src/services/abstract/serviceroot.cpp
index 021532002..a31269c61 100755
--- a/src/services/abstract/serviceroot.cpp
+++ b/src/services/abstract/serviceroot.cpp
@@ -152,7 +152,7 @@ bool ServiceRoot::cleanFeeds(QList<Feed*> items, bool clean_read_only) {
 
     RecycleBin *bin = recycleBin();
 
-    if (bin != NULL) {
+    if (bin != nullptr) {
       bin->updateCounts(true);
       itemss.append(bin);
     }
@@ -172,7 +172,7 @@ void ServiceRoot::storeNewFeedTree(RootItem *root) {
   if (DatabaseQueries::storeAccountTree(database, root, accountId())) {
     RecycleBin *bin = recycleBin();
 
-    if (bin != NULL && !childItems().contains(bin)) {
+    if (bin != nullptr && !childItems().contains(bin)) {
       // As the last item, add recycle bin, which is needed.
       appendChild(bin);
       bin->updateCounts(true);
@@ -224,7 +224,7 @@ void ServiceRoot::syncIn() {
 
   RootItem *new_tree = obtainNewTreeForSyncIn();
 
-  if (new_tree != NULL) {
+  if (new_tree != nullptr) {
     // Purge old data from SQL and clean all model items.
     requestItemExpandStateSave(this);
 
@@ -243,7 +243,7 @@ void ServiceRoot::syncIn() {
     removeLeftOverMessages();
 
     foreach (RootItem *top_level_item, new_tree->childItems()) {
-      top_level_item->setParent(NULL);
+      top_level_item->setParent(nullptr);
       requestItemReassignment(top_level_item, this);
     }
 
@@ -278,7 +278,7 @@ void ServiceRoot::syncIn() {
 }
 
 RootItem *ServiceRoot::obtainNewTreeForSyncIn() const {
-  return NULL;
+  return nullptr;
 }
 
 QStringList ServiceRoot::customIDSOfMessagesForItem(RootItem *item) {
@@ -449,7 +449,7 @@ bool ServiceRoot::onAfterMessagesDelete(RootItem *selected_item, const QList<Mes
     itemChanged(QList<RootItem*>() << bin);
   }
   else {
-    if (bin != NULL) {
+    if (bin != nullptr) {
       bin->updateCounts(true);
       itemChanged(QList<RootItem*>() << selected_item << bin);
     }
diff --git a/src/services/owncloud/gui/formeditowncloudaccount.cpp b/src/services/owncloud/gui/formeditowncloudaccount.cpp
index 29cb34e3a..7cddeadf9 100755
--- a/src/services/owncloud/gui/formeditowncloudaccount.cpp
+++ b/src/services/owncloud/gui/formeditowncloudaccount.cpp
@@ -25,7 +25,7 @@
 
 
 FormEditOwnCloudAccount::FormEditOwnCloudAccount(QWidget *parent)
-  : QDialog(parent), m_ui(new Ui::FormEditOwnCloudAccount), m_editableRoot(NULL) {
+  : QDialog(parent), m_ui(new Ui::FormEditOwnCloudAccount), m_editableRoot(nullptr) {
   m_ui->setupUi(this);
   m_btnOk = m_ui->m_buttonBox->button(QDialogButtonBox::Ok);
 
@@ -131,7 +131,7 @@ void FormEditOwnCloudAccount::performTest() {
 void FormEditOwnCloudAccount::onClickedOk() {
   bool editing_account = true;
 
-  if (m_editableRoot == NULL) {
+  if (m_editableRoot == nullptr) {
     // We want to confirm newly created account.
     // So save new account into DB, setup its properties.
     m_editableRoot = new OwnCloudServiceRoot();
diff --git a/src/services/owncloud/gui/formowncloudfeeddetails.cpp b/src/services/owncloud/gui/formowncloudfeeddetails.cpp
old mode 100644
new mode 100755
index a22b25dfc..312dcf05f
--- a/src/services/owncloud/gui/formowncloudfeeddetails.cpp
+++ b/src/services/owncloud/gui/formowncloudfeeddetails.cpp
@@ -40,7 +40,7 @@ FormOwnCloudFeedDetails::FormOwnCloudFeedDetails(ServiceRoot *service_root, QWid
 }
 
 void FormOwnCloudFeedDetails::apply() {
-  if (m_editableFeed != NULL) {
+  if (m_editableFeed != nullptr) {
     bool renamed = false;
 
     if (m_ui->m_txtTitle->lineEdit()->text() != m_editableFeed->title()) {
diff --git a/src/services/owncloud/owncloudcategory.cpp b/src/services/owncloud/owncloudcategory.cpp
index 147a10aff..e229e8538 100755
--- a/src/services/owncloud/owncloudcategory.cpp
+++ b/src/services/owncloud/owncloudcategory.cpp
@@ -26,7 +26,7 @@ OwnCloudCategory::OwnCloudCategory(RootItem *parent) : Category(parent) {
   setIcon(qApp->icons()->fromTheme(QSL("folder")));
 }
 
-OwnCloudCategory::OwnCloudCategory(const QSqlRecord &record) : Category(NULL) {
+OwnCloudCategory::OwnCloudCategory(const QSqlRecord &record) : Category(nullptr) {
   setIcon(qApp->icons()->fromTheme(QSL("folder")));
   setId(record.value(CAT_DB_ID_INDEX).toInt());
   setTitle(record.value(CAT_DB_TITLE_INDEX).toString());
diff --git a/src/services/owncloud/owncloudfeed.cpp b/src/services/owncloud/owncloudfeed.cpp
index 2e8394f31..ecef6f216 100755
--- a/src/services/owncloud/owncloudfeed.cpp
+++ b/src/services/owncloud/owncloudfeed.cpp
@@ -30,7 +30,7 @@
 OwnCloudFeed::OwnCloudFeed(RootItem *parent) : Feed(parent) {
 }
 
-OwnCloudFeed::OwnCloudFeed(const QSqlRecord &record) : Feed(NULL) {
+OwnCloudFeed::OwnCloudFeed(const QSqlRecord &record) : Feed(nullptr) {
   setTitle(record.value(FDS_DB_TITLE_INDEX).toString());
   setId(record.value(FDS_DB_ID_INDEX).toInt());
   setIcon(qApp->icons()->fromByteArray(record.value(FDS_DB_ICON_INDEX).toByteArray()));
@@ -49,7 +49,7 @@ bool OwnCloudFeed::canBeEdited() const {
 bool OwnCloudFeed::editViaGui() {
   QPointer<FormOwnCloudFeedDetails> form_pointer = new FormOwnCloudFeedDetails(serviceRoot(), qApp->mainForm());
 
-  form_pointer.data()->exec(this, NULL);
+  form_pointer.data()->exec(this, nullptr);
   delete form_pointer.data();
   return false;
 }
diff --git a/src/services/owncloud/owncloudserviceroot.cpp b/src/services/owncloud/owncloudserviceroot.cpp
index bf9bcba1c..b1b398a33 100755
--- a/src/services/owncloud/owncloudserviceroot.cpp
+++ b/src/services/owncloud/owncloudserviceroot.cpp
@@ -35,7 +35,7 @@
 
 OwnCloudServiceRoot::OwnCloudServiceRoot(RootItem *parent)
   : ServiceRoot(parent), m_recycleBin(new OwnCloudRecycleBin(this)),
-    m_actionSyncIn(NULL), m_serviceMenu(QList<QAction*>()), m_network(new OwnCloudNetworkFactory()) {
+    m_actionSyncIn(nullptr), m_serviceMenu(QList<QAction*>()), m_network(new OwnCloudNetworkFactory()) {
   setIcon(OwnCloudServiceEntryPoint().icon());
 }
 
@@ -210,7 +210,7 @@ void OwnCloudServiceRoot::addNewFeed(const QString &url) {
 
   QScopedPointer<FormOwnCloudFeedDetails> form_pointer(new FormOwnCloudFeedDetails(this, qApp->mainForm()));
 
-  form_pointer.data()->exec(NULL, this, url);
+  form_pointer.data()->exec(nullptr, this, url);
   qApp->feedUpdateLock()->unlock();
 }
 
@@ -251,7 +251,7 @@ RootItem *OwnCloudServiceRoot::obtainNewTreeForSyncIn() const {
     return feed_cats_response.feedsCategories(true);
   }
   else {
-    return NULL;
+    return nullptr;
   }
 }
 
diff --git a/src/services/standard/gui/formstandardcategorydetails.cpp b/src/services/standard/gui/formstandardcategorydetails.cpp
index 7bf83c78a..53ed4b0a7 100755
--- a/src/services/standard/gui/formstandardcategorydetails.cpp
+++ b/src/services/standard/gui/formstandardcategorydetails.cpp
@@ -41,7 +41,7 @@
 
 
 FormStandardCategoryDetails::FormStandardCategoryDetails(StandardServiceRoot *service_root, QWidget *parent)
-  : QDialog(parent), m_editableCategory(NULL), m_serviceRoot(service_root)  {
+  : QDialog(parent), m_editableCategory(nullptr), m_serviceRoot(service_root)  {
   initialize();
   createConnections();
 
@@ -79,7 +79,7 @@ int FormStandardCategoryDetails::exec(StandardCategory *input_category, RootItem
   // Load categories.
   loadCategories(m_serviceRoot->getSubTreeCategories(), m_serviceRoot, input_category);
 
-  if (input_category == NULL) {
+  if (input_category == nullptr) {
     // User is adding new category.
     setWindowTitle(tr("Add new category"));
 
@@ -88,7 +88,7 @@ int FormStandardCategoryDetails::exec(StandardCategory *input_category, RootItem
     m_actionUseDefaultIcon->trigger();
 
     // Load parent from suggested item.
-    if (parent_to_select != NULL) {
+    if (parent_to_select != nullptr) {
       if (parent_to_select->kind() == RootItemKind::Category) {
         m_ui->m_cmbParentCategory->setCurrentIndex(m_ui->m_cmbParentCategory->findData(QVariant::fromValue((void*) parent_to_select)));
       }
@@ -120,7 +120,7 @@ void FormStandardCategoryDetails::apply() {
   new_category->setDescription(m_ui->m_txtDescription->lineEdit()->text());
   new_category->setIcon(m_ui->m_btnIcon->icon());
 
-  if (m_editableCategory == NULL) {
+  if (m_editableCategory == nullptr) {
     // Add the category.
     if (new_category->addItself(parent)) {
       m_serviceRoot->requestItemReassignment(new_category, parent);
@@ -251,7 +251,7 @@ void FormStandardCategoryDetails::loadCategories(const QList<Category*> categori
                                      QVariant::fromValue((void*) root_item));
 
   foreach (Category *category, categories) {
-    if (input_category != NULL && (category == input_category || category->isChildOf(input_category))) {
+    if (input_category != nullptr && (category == input_category || category->isChildOf(input_category))) {
       // This category cannot be selected as the new
       // parent for currently edited category, so
       // don't add it.
diff --git a/src/services/standard/gui/formstandardfeeddetails.cpp b/src/services/standard/gui/formstandardfeeddetails.cpp
index 4af48ad4d..13c0d0752 100755
--- a/src/services/standard/gui/formstandardfeeddetails.cpp
+++ b/src/services/standard/gui/formstandardfeeddetails.cpp
@@ -45,7 +45,7 @@ void FormStandardFeedDetails::apply() {
   new_feed->setAutoUpdateType(static_cast<Feed::AutoUpdateType>(m_ui->m_cmbAutoUpdateType->itemData(m_ui->m_cmbAutoUpdateType->currentIndex()).toInt()));
   new_feed->setAutoUpdateInitialInterval(m_ui->m_spinAutoUpdateInterval->value());
 
-  if (m_editableFeed == NULL) {
+  if (m_editableFeed == nullptr) {
     // Add the feed.
     if (new_feed->addItself(parent)) {
       m_serviceRoot->requestItemReassignment(new_feed, parent);
diff --git a/src/services/standard/standardcategory.cpp b/src/services/standard/standardcategory.cpp
index 5d3a9becc..ac1ce03bb 100755
--- a/src/services/standard/standardcategory.cpp
+++ b/src/services/standard/standardcategory.cpp
@@ -37,7 +37,7 @@ StandardCategory::StandardCategory(RootItem *parent_item) : Category(parent_item
 }
 
 StandardCategory::StandardCategory(const StandardCategory &other)
-  : Category(NULL) {
+  : Category(nullptr) {
   setId(other.id());
   setCustomId(other.customId());
   setTitle(other.title());
@@ -100,7 +100,7 @@ bool StandardCategory::performDragDropChange(RootItem *target_item) {
 bool StandardCategory::editViaGui() {
   QScopedPointer<FormStandardCategoryDetails> form_pointer(new FormStandardCategoryDetails(serviceRoot(), qApp->mainForm()));
 
-  form_pointer.data()->exec(this, NULL);
+  form_pointer.data()->exec(this, nullptr);
   return false;
 }
 
@@ -185,7 +185,7 @@ bool StandardCategory::editItself(StandardCategory *new_category_data) {
   }
 }
 
-StandardCategory::StandardCategory(const QSqlRecord &record) : Category(NULL) {
+StandardCategory::StandardCategory(const QSqlRecord &record) : Category(nullptr) {
   setId(record.value(CAT_DB_ID_INDEX).toInt());
   setCustomId(id());
   setTitle(record.value(CAT_DB_TITLE_INDEX).toString());
diff --git a/src/services/standard/standardfeed.cpp b/src/services/standard/standardfeed.cpp
index 6a0677716..c15061391 100755
--- a/src/services/standard/standardfeed.cpp
+++ b/src/services/standard/standardfeed.cpp
@@ -53,7 +53,7 @@ StandardFeed::StandardFeed(RootItem *parent_item)
 }
 
 StandardFeed::StandardFeed(const StandardFeed &other)
-  : Feed(NULL) {
+  : Feed(nullptr) {
   m_passwordProtected = other.passwordProtected();
   m_username = other.username();
   m_password = other.password();
@@ -94,7 +94,7 @@ StandardServiceRoot *StandardFeed::serviceRoot() const {
 
 bool StandardFeed::editViaGui() {
   QScopedPointer<FormStandardFeedDetails> form_pointer(new FormStandardFeedDetails(serviceRoot(), qApp->mainForm()));
-  form_pointer.data()->exec(this, NULL);
+  form_pointer.data()->exec(this, nullptr);
   return false;
 }
 
@@ -184,7 +184,7 @@ QString StandardFeed::typeToString(StandardFeed::Type type) {
 void StandardFeed::fetchMetadataForItself() {
   QPair<StandardFeed*,QNetworkReply::NetworkError> metadata = guessFeed(url(), username(), password());
 
-  if (metadata.first != NULL && metadata.second == QNetworkReply::NoError) {
+  if (metadata.first != nullptr && metadata.second == QNetworkReply::NoError) {
     // Some properties are not updated when new metadata are fetched.
     metadata.first->setParent(parent());
     metadata.first->setUrl(url());
@@ -211,7 +211,7 @@ void StandardFeed::fetchMetadataForItself() {
 QPair<StandardFeed*,QNetworkReply::NetworkError> StandardFeed::guessFeed(const QString &url,
                                                                          const QString &username,
                                                                          const QString &password) {
-  QPair<StandardFeed*,QNetworkReply::NetworkError> result; result.first = NULL;
+  QPair<StandardFeed*,QNetworkReply::NetworkError> result; result.first = nullptr;
 
   QByteArray feed_contents;
   NetworkResult network_result = NetworkFactory::downloadFeedFile(url,
@@ -239,13 +239,13 @@ QPair<StandardFeed*,QNetworkReply::NetworkError> StandardFeed::guessFeed(const Q
       xml_schema_encoding = encoding_rexp.cap(0);
     }
 
-    if (result.first == NULL) {
+    if (result.first == nullptr) {
       result.first = new StandardFeed();
     }
 
     QTextCodec *custom_codec = QTextCodec::codecForName(xml_schema_encoding.toLocal8Bit());
 
-    if (custom_codec != NULL) {
+    if (custom_codec != nullptr) {
       // Feed encoding was probably guessed.
       xml_contents_encoded = custom_codec->toUnicode(feed_contents);
       result.first->setEncoding(xml_schema_encoding);
@@ -450,7 +450,7 @@ QList<Message> StandardFeed::obtainNewMessages() {
   QTextCodec *codec = QTextCodec::codecForName(encoding().toLocal8Bit());
   QString formatted_feed_contents;
 
-  if (codec == NULL) {
+  if (codec == nullptr) {
     // No suitable codec for this encoding was found.
     // Use non-converted data.
     formatted_feed_contents = feed_contents;
@@ -487,7 +487,7 @@ QNetworkReply::NetworkError StandardFeed::networkError() const {
   return m_networkError;
 }
 
-StandardFeed::StandardFeed(const QSqlRecord &record) : Feed(NULL) {
+StandardFeed::StandardFeed(const QSqlRecord &record) : Feed(nullptr) {
   setTitle(record.value(FDS_DB_TITLE_INDEX).toString());
   setId(record.value(FDS_DB_ID_INDEX).toInt());
   setCustomId(id());
diff --git a/src/services/standard/standardfeedsimportexportmodel.cpp b/src/services/standard/standardfeedsimportexportmodel.cpp
index 90a9e1acd..76b4f3f33 100755
--- a/src/services/standard/standardfeedsimportexportmodel.cpp
+++ b/src/services/standard/standardfeedsimportexportmodel.cpp
@@ -36,7 +36,7 @@ FeedsImportExportModel::FeedsImportExportModel(QObject *parent)
 }
 
 FeedsImportExportModel::~FeedsImportExportModel() {
-  if (m_rootItem != NULL && m_mode == Import) {
+  if (m_rootItem != nullptr && m_mode == Import) {
     // Delete all model items, but only if we are in import mode. Export mode shares
     // root item with main feed model, thus cannot be deleted from memory now.
     delete m_rootItem;
@@ -139,7 +139,7 @@ bool FeedsImportExportModel::exportToOMPL20(QByteArray &result) {
 void FeedsImportExportModel::importAsOPML20(const QByteArray &data, bool fetch_metadata_online) {
   emit parsingStarted();
   emit layoutAboutToBeChanged();
-  setRootItem(NULL);
+  setRootItem(nullptr);
   emit layoutChanged();
 
   QDomDocument opml_document;
@@ -279,7 +279,7 @@ bool FeedsImportExportModel::exportToTxtURLPerLine(QByteArray &result) {
 void FeedsImportExportModel::importAsTxtURLPerLine(const QByteArray &data, bool fetch_metadata_online) {
   emit parsingStarted();
   emit layoutAboutToBeChanged();
-  setRootItem(NULL);
+  setRootItem(nullptr);
   emit layoutChanged();
 
   int completed = 0, succeded = 0, failed = 0;
diff --git a/src/services/standard/standardserviceentrypoint.cpp b/src/services/standard/standardserviceentrypoint.cpp
index 4f76c6a21..0fe58c983 100755
--- a/src/services/standard/standardserviceentrypoint.cpp
+++ b/src/services/standard/standardserviceentrypoint.cpp
@@ -70,7 +70,7 @@ ServiceRoot *StandardServiceEntryPoint::createNewRoot() const {
     return root;
   }
   else {
-    return NULL;
+    return nullptr;
   }
 }
 
diff --git a/src/services/standard/standardserviceroot.cpp b/src/services/standard/standardserviceroot.cpp
index 9c01f37c2..50db70bfb 100755
--- a/src/services/standard/standardserviceroot.cpp
+++ b/src/services/standard/standardserviceroot.cpp
@@ -44,8 +44,8 @@
 
 StandardServiceRoot::StandardServiceRoot(RootItem *parent)
   : ServiceRoot(parent), m_recycleBin(new RecycleBin(this)),
-    m_actionExportFeeds(NULL), m_actionImportFeeds(NULL), m_serviceMenu(QList<QAction*>()),
-    m_feedContextMenu(QList<QAction*>()), m_actionFeedFetchMetadata(NULL) {
+    m_actionExportFeeds(nullptr), m_actionImportFeeds(nullptr), m_serviceMenu(QList<QAction*>()),
+    m_feedContextMenu(QList<QAction*>()), m_actionFeedFetchMetadata(nullptr) {
 
   setTitle(qApp->system()->getUsername() + QL1S("@") + QL1S(STRFY(APP_LOW_NAME)));
   setIcon(StandardServiceEntryPoint().icon());
@@ -142,7 +142,7 @@ void StandardServiceRoot::addNewFeed(const QString &url) {
   }
 
   QScopedPointer<FormStandardFeedDetails> form_pointer(new FormStandardFeedDetails(this, qApp->mainForm()));
-  form_pointer.data()->exec(NULL, NULL, url);
+  form_pointer.data()->exec(nullptr, nullptr, url);
 
   qApp->feedUpdateLock()->unlock();
 }
@@ -224,7 +224,7 @@ void StandardServiceRoot::checkArgumentForFeedAdding(const QString &argument) {
 QList<QAction*> StandardServiceRoot::getContextMenuForFeed(StandardFeed *feed) {
   if (m_feedContextMenu.isEmpty()) {
     // Initialize.
-    m_actionFeedFetchMetadata = new QAction(qApp->icons()->fromTheme(QSL("emblem-downloads")), tr("Fetch metadata"), NULL);
+    m_actionFeedFetchMetadata = new QAction(qApp->icons()->fromTheme(QSL("emblem-downloads")), tr("Fetch metadata"), nullptr);
     m_feedContextMenu.append(m_actionFeedFetchMetadata);
   }
 
@@ -273,14 +273,14 @@ bool StandardServiceRoot::mergeImportExportModel(FeedsImportExportModel *model,
           // Add category failed, but this can mean that the same category (with same title)
           // already exists. If such a category exists in current parent, then find it and
           // add descendants to it.
-          RootItem *existing_category = NULL;
+          RootItem *existing_category = nullptr;
           foreach (RootItem *child, target_parent->childItems()) {
             if (child->kind() == RootItemKind::Category && child->title() == new_category_title) {
               existing_category = child;
             }
           }
 
-          if (existing_category != NULL) {
+          if (existing_category != nullptr) {
             original_parents.push(existing_category);
             new_parents.push(source_category);
           }
@@ -328,7 +328,7 @@ void StandardServiceRoot::addNewCategory() {
   }
 
   QScopedPointer<FormStandardCategoryDetails> form_pointer(new FormStandardCategoryDetails(this, qApp->mainForm()));
-  form_pointer.data()->exec(NULL, NULL);
+  form_pointer.data()->exec(nullptr, nullptr);
 
   qApp->feedUpdateLock()->unlock();
 }
diff --git a/src/services/tt-rss/gui/formeditaccount.cpp b/src/services/tt-rss/gui/formeditaccount.cpp
index 6f47fa030..076841cd1 100755
--- a/src/services/tt-rss/gui/formeditaccount.cpp
+++ b/src/services/tt-rss/gui/formeditaccount.cpp
@@ -26,7 +26,7 @@
 
 
 FormEditAccount::FormEditAccount(QWidget *parent)
-  : QDialog(parent), m_ui(new Ui::FormEditAccount), m_editableRoot(NULL) {
+  : QDialog(parent), m_ui(new Ui::FormEditAccount), m_editableRoot(nullptr) {
   m_ui->setupUi(this);
   m_btnOk = m_ui->m_buttonBox->button(QDialogButtonBox::Ok);
 
@@ -175,7 +175,7 @@ void FormEditAccount::performTest() {
 void FormEditAccount::onClickedOk() {
   bool editing_account = true;
 
-  if (m_editableRoot == NULL) {
+  if (m_editableRoot == nullptr) {
     // We want to confirm newly created account.
     // So save new account into DB, setup its properties.
     m_editableRoot = new TtRssServiceRoot();
diff --git a/src/services/tt-rss/gui/formttrssfeeddetails.cpp b/src/services/tt-rss/gui/formttrssfeeddetails.cpp
old mode 100644
new mode 100755
index 3c6e52cac..27fe01d74
--- a/src/services/tt-rss/gui/formttrssfeeddetails.cpp
+++ b/src/services/tt-rss/gui/formttrssfeeddetails.cpp
@@ -41,7 +41,7 @@ FormTtRssFeedDetails::FormTtRssFeedDetails(ServiceRoot *service_root, QWidget *p
 }
 
 void FormTtRssFeedDetails::apply() {
-  if (m_editableFeed != NULL) {
+  if (m_editableFeed != nullptr) {
     // User edited auto-update status. Save it.
     TtRssFeed *new_feed_data = new TtRssFeed();
 
diff --git a/src/services/tt-rss/ttrsscategory.cpp b/src/services/tt-rss/ttrsscategory.cpp
index c132b1cf4..55736060b 100755
--- a/src/services/tt-rss/ttrsscategory.cpp
+++ b/src/services/tt-rss/ttrsscategory.cpp
@@ -31,7 +31,7 @@ TtRssCategory::TtRssCategory(RootItem *parent) : Category(parent) {
   setIcon(qApp->icons()->fromTheme(QSL("folder")));
 }
 
-TtRssCategory::TtRssCategory(const QSqlRecord &record) : Category(NULL) {
+TtRssCategory::TtRssCategory(const QSqlRecord &record) : Category(nullptr) {
   setIcon(qApp->icons()->fromTheme(QSL("folder")));
   setId(record.value(CAT_DB_ID_INDEX).toInt());
   setTitle(record.value(CAT_DB_TITLE_INDEX).toString());
diff --git a/src/services/tt-rss/ttrssfeed.cpp b/src/services/tt-rss/ttrssfeed.cpp
index 9edcbc831..20addb27a 100755
--- a/src/services/tt-rss/ttrssfeed.cpp
+++ b/src/services/tt-rss/ttrssfeed.cpp
@@ -36,7 +36,7 @@ TtRssFeed::TtRssFeed(RootItem *parent)
   : Feed(parent) {
 }
 
-TtRssFeed::TtRssFeed(const QSqlRecord &record) : Feed(NULL) {
+TtRssFeed::TtRssFeed(const QSqlRecord &record) : Feed(nullptr) {
   setTitle(record.value(FDS_DB_TITLE_INDEX).toString());
   setId(record.value(FDS_DB_ID_INDEX).toInt());
   setIcon(qApp->icons()->fromByteArray(record.value(FDS_DB_ICON_INDEX).toByteArray()));
@@ -102,7 +102,7 @@ bool TtRssFeed::canBeEdited() const {
 bool TtRssFeed::editViaGui() {
   QPointer<FormTtRssFeedDetails> form_pointer = new FormTtRssFeedDetails(serviceRoot(), qApp->mainForm());
 
-  form_pointer.data()->exec(this, NULL);
+  form_pointer.data()->exec(this, nullptr);
   delete form_pointer.data();
   return false;
 }
diff --git a/src/services/tt-rss/ttrssserviceroot.cpp b/src/services/tt-rss/ttrssserviceroot.cpp
index 45703d890..ec2cdfa5c 100755
--- a/src/services/tt-rss/ttrssserviceroot.cpp
+++ b/src/services/tt-rss/ttrssserviceroot.cpp
@@ -40,7 +40,7 @@
 
 TtRssServiceRoot::TtRssServiceRoot(RootItem *parent)
   : ServiceRoot(parent), m_recycleBin(new TtRssRecycleBin(this)),
-    m_actionSyncIn(NULL), m_serviceMenu(QList<QAction*>()), m_network(new TtRssNetworkFactory()) {
+    m_actionSyncIn(nullptr), m_serviceMenu(QList<QAction*>()), m_network(new TtRssNetworkFactory()) {
   setIcon(TtRssServiceEntryPoint().icon());
 }
 
@@ -124,7 +124,7 @@ void TtRssServiceRoot::addNewFeed(const QString &url) {
 
   QScopedPointer<FormTtRssFeedDetails> form_pointer(new FormTtRssFeedDetails(this, qApp->mainForm()));
 
-  form_pointer.data()->exec(NULL, this, url);
+  form_pointer.data()->exec(nullptr, this, url);
   qApp->feedUpdateLock()->unlock();
 }
 
@@ -277,7 +277,7 @@ RootItem *TtRssServiceRoot::obtainNewTreeForSyncIn() const {
     return feed_cats_response.feedsCategories(true, m_network->url());
   }
   else {
-    return NULL;
+    return nullptr;
   }
 }