Use qt5 connect() syntax

src/app/application.cpp

@@ -151,11 +151,11 @@ Application::Application(const QString &id, int &argc, char **argv)
 #endif
 
 #if defined(Q_OS_WIN) && !defined(DISABLE_GUI)
-    connect(this, SIGNAL(commitDataRequest(QSessionManager &)), this, SLOT(shutdownCleanup(QSessionManager &)), Qt::DirectConnection);
+    connect(this, &QGuiApplication::commitDataRequest, this, &Application::shutdownCleanup, Qt::DirectConnection);
 #endif
 
-    connect(this, SIGNAL(messageReceived(const QString &)), SLOT(processMessage(const QString &)));
-    connect(this, SIGNAL(aboutToQuit()), SLOT(cleanup()));
+    connect(this, &Application::messageReceived, this, &Application::processMessage);
+    connect(this, &QCoreApplication::aboutToQuit, this, &Application::cleanup);
 
     if (isFileLoggerEnabled())
         m_fileLogger = new FileLogger(fileLoggerPath(), isFileLoggerBackup(), fileLoggerMaxSize(), isFileLoggerDeleteOld(), fileLoggerAge(), static_cast<FileLogger::FileLogAgeType>(fileLoggerAgeType()));
@@ -489,8 +489,8 @@ int Application::exec(const QStringList &params)
 #endif
 
     BitTorrent::Session::initInstance();
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentFinished(BitTorrent::TorrentHandle *const)), SLOT(torrentFinished(BitTorrent::TorrentHandle *const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(allTorrentsFinished()), SLOT(allTorrentsFinished()), Qt::QueuedConnection);
+    connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentFinished, this, &Application::torrentFinished);
+    connect(BitTorrent::Session::instance(), &BitTorrent::Session::allTorrentsFinished, this, &Application::allTorrentsFinished, Qt::QueuedConnection);
 
 #ifndef DISABLE_COUNTRIES_RESOLUTION
     Net::GeoIPManager::initInstance();

src/app/filelogger.cpp

@@ -41,7 +41,7 @@ FileLogger::FileLogger(const QString &path, const bool backup, const int maxSize
 {
     m_flusher.setInterval(0);
     m_flusher.setSingleShot(true);
-    connect(&m_flusher, SIGNAL(timeout()), SLOT(flushLog()));
+    connect(&m_flusher, &QTimer::timeout, this, &FileLogger::flushLog);
 
     changePath(path);
     if (deleteOld)
@@ -51,7 +51,7 @@ FileLogger::FileLogger(const QString &path, const bool backup, const int maxSize
     foreach (const Log::Msg& msg, logger->getMessages())
         addLogMessage(msg);
 
-    connect(logger, SIGNAL(newLogMessage(const Log::Msg &)), SLOT(addLogMessage(const Log::Msg &)));
+    connect(logger, &Logger::newLogMessage, this, &FileLogger::addLogMessage);
 }
 
 FileLogger::~FileLogger()

src/base/bittorrent/private/statistics.cpp

@@ -22,7 +22,7 @@ Statistics::Statistics(Session *session)
     , m_dirty(false)
 {
     load();
-    connect(&m_timer, SIGNAL(timeout()), this, SLOT(gather()));
+    connect(&m_timer, &QTimer::timeout, this, &Statistics::gather);
     m_timer.start(60 * 1000);
 }
 

src/base/bittorrent/private/statistics.h

@@ -9,7 +9,7 @@ namespace BitTorrent
     class Session;
 }
 
-class Statistics : QObject
+class Statistics : public QObject
 {
     Q_OBJECT
     Q_DISABLE_COPY(Statistics)

src/base/bittorrent/session.cpp

@@ -517,13 +517,14 @@ Session::Session(QObject *parent)
 
     enableTracker(isTrackerEnabled());
 
-    connect(Net::ProxyConfigurationManager::instance(), SIGNAL(proxyConfigurationChanged()), SLOT(configureDeferred()));
+    connect(Net::ProxyConfigurationManager::instance(), &Net::ProxyConfigurationManager::proxyConfigurationChanged
+            , this, &Session::configureDeferred);
 
     // Network configuration monitor
-    connect(&m_networkManager, SIGNAL(onlineStateChanged(bool)), SLOT(networkOnlineStateChanged(bool)));
-    connect(&m_networkManager, SIGNAL(configurationAdded(const QNetworkConfiguration&)), SLOT(networkConfigurationChange(const QNetworkConfiguration&)));
-    connect(&m_networkManager, SIGNAL(configurationRemoved(const QNetworkConfiguration&)), SLOT(networkConfigurationChange(const QNetworkConfiguration&)));
-    connect(&m_networkManager, SIGNAL(configurationChanged(const QNetworkConfiguration&)), SLOT(networkConfigurationChange(const QNetworkConfiguration&)));
+    connect(&m_networkManager, &QNetworkConfigurationManager::onlineStateChanged, this, &Session::networkOnlineStateChanged);
+    connect(&m_networkManager, &QNetworkConfigurationManager::configurationAdded, this, &Session::networkConfigurationChange);
+    connect(&m_networkManager, &QNetworkConfigurationManager::configurationRemoved, this, &Session::networkConfigurationChange);
+    connect(&m_networkManager, &QNetworkConfigurationManager::configurationChanged, this, &Session::networkConfigurationChange);
 
     m_ioThread = new QThread(this);
     m_resumeDataSavingManager = new ResumeDataSavingManager(m_resumeFolderPath);
@@ -2073,9 +2074,10 @@ bool Session::addTorrent(QString source, const AddTorrentParams &params)
         Logger::instance()->addMessage(tr("Downloading '%1', please wait...", "e.g: Downloading 'xxx.torrent', please wait...").arg(source));
         // Launch downloader
         Net::DownloadHandler *handler = Net::DownloadManager::instance()->downloadUrl(source, true, 10485760 /* 10MB */, true);
-        connect(handler, SIGNAL(downloadFinished(QString, QString)), this, SLOT(handleDownloadFinished(QString, QString)));
-        connect(handler, SIGNAL(downloadFailed(QString, QString)), this, SLOT(handleDownloadFailed(QString, QString)));
-        connect(handler, SIGNAL(redirectedToMagnet(QString, QString)), this, SLOT(handleRedirectedToMagnet(QString, QString)));
+        connect(handler, static_cast<void (Net::DownloadHandler::*)(const QString &, const QString &)>(&Net::DownloadHandler::downloadFinished)
+                , this, &Session::handleDownloadFinished);
+        connect(handler, &Net::DownloadHandler::downloadFailed, this, &Session::handleDownloadFailed);
+        connect(handler, &Net::DownloadHandler::redirectedToMagnet, this, &Session::handleRedirectedToMagnet);
         m_downloadedTorrents[handler->url()] = params;
     }
     else {
@@ -3712,8 +3714,8 @@ void Session::enableIPFilter()
     //    set between clearing the old one and setting the new one.
     if (!m_filterParser) {
         m_filterParser = new FilterParserThread(this);
-        connect(m_filterParser.data(), SIGNAL(IPFilterParsed(int)), SLOT(handleIPFilterParsed(int)));
-        connect(m_filterParser.data(), SIGNAL(IPFilterError()), SLOT(handleIPFilterError()));
+        connect(m_filterParser.data(), &FilterParserThread::IPFilterParsed, this, &Session::handleIPFilterParsed);
+        connect(m_filterParser.data(), &FilterParserThread::IPFilterError, this, &Session::handleIPFilterError);
     }
     m_filterParser->processFilterFile(IPFilterFile());
 }

src/base/net/dnsupdater.cpp

@@ -52,7 +52,7 @@ DNSUpdater::DNSUpdater(QObject *parent)
 
     // Start IP checking timer
     m_ipCheckTimer.setInterval(IP_CHECK_INTERVAL_MS);
-    connect(&m_ipCheckTimer, SIGNAL(timeout()), SLOT(checkPublicIP()));
+    connect(&m_ipCheckTimer, &QTimer::timeout, this, &DNSUpdater::checkPublicIP);
     m_ipCheckTimer.start();
 
     // Check lastUpdate to avoid flooding
@@ -77,8 +77,9 @@ void DNSUpdater::checkPublicIP()
     DownloadHandler *handler = DownloadManager::instance()->downloadUrl(
                 "http://checkip.dyndns.org", false, 0, false,
                 "qBittorrent/" QBT_VERSION_2);
-    connect(handler, SIGNAL(downloadFinished(QString, QByteArray)), SLOT(ipRequestFinished(QString, QByteArray)));
-    connect(handler, SIGNAL(downloadFailed(QString, QString)), SLOT(ipRequestFailed(QString, QString)));
+    connect(handler, static_cast<void (Net::DownloadHandler::*)(const QString &, const QByteArray &)>(&Net::DownloadHandler::downloadFinished)
+            , this, &DNSUpdater::ipRequestFinished);
+    connect(handler, &Net::DownloadHandler::downloadFailed, this, &DNSUpdater::ipRequestFailed);
 
     m_lastIPCheckTime = QDateTime::currentDateTime();
 }
@@ -124,8 +125,9 @@ void DNSUpdater::updateDNSService()
     DownloadHandler *handler = DownloadManager::instance()->downloadUrl(
                 getUpdateUrl(), false, 0, false,
                 "qBittorrent/" QBT_VERSION_2);
-    connect(handler, SIGNAL(downloadFinished(QString, QByteArray)), SLOT(ipUpdateFinished(QString, QByteArray)));
-    connect(handler, SIGNAL(downloadFailed(QString, QString)), SLOT(ipUpdateFailed(QString, QString)));
+    connect(handler, static_cast<void (Net::DownloadHandler::*)(const QString &, const QByteArray &)>(&Net::DownloadHandler::downloadFinished)
+            , this, &DNSUpdater::ipUpdateFinished);
+    connect(handler, &Net::DownloadHandler::downloadFailed, this, &DNSUpdater::ipUpdateFailed);
 }
 
 QString DNSUpdater::getUpdateUrl() const

src/base/net/downloadhandler.cpp

@@ -124,7 +124,7 @@ void DownloadHandler::checkDownloadSize(qint64 bytesReceived, qint64 bytesTotal)
             emit downloadFailed(m_url, msg.arg(Utils::Misc::friendlyUnit(bytesTotal), Utils::Misc::friendlyUnit(m_sizeLimit)));
         }
         else {
-            disconnect(m_reply, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(checkDownloadSize(qint64, qint64)));
+            disconnect(m_reply, &QNetworkReply::downloadProgress, this, &Net::DownloadHandler::checkDownloadSize);
         }
     }
     else if (bytesReceived  > m_sizeLimit) {
@@ -137,8 +137,8 @@ void DownloadHandler::init()
 {
     m_reply->setParent(this);
     if (m_sizeLimit > 0)
-        connect(m_reply, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(checkDownloadSize(qint64, qint64)));
-    connect(m_reply, SIGNAL(finished()), this, SLOT(processFinishedDownload()));
+        connect(m_reply, &QNetworkReply::downloadProgress, this, &Net::DownloadHandler::checkDownloadSize);
+    connect(m_reply, &QNetworkReply::finished, this, &Net::DownloadHandler::processFinishedDownload);
 }
 
 bool DownloadHandler::saveToFile(const QByteArray &replyData, QString &filePath)

src/base/net/downloadmanager.cpp

@@ -113,7 +113,7 @@ DownloadManager::DownloadManager(QObject *parent)
     : QObject(parent)
 {
 #ifndef QT_NO_OPENSSL
-    connect(&m_networkManager, SIGNAL(sslErrors(QNetworkReply *, QList<QSslError>)), this, SLOT(ignoreSslErrors(QNetworkReply *, QList<QSslError>)));
+    connect(&m_networkManager, &QNetworkAccessManager::sslErrors, this, &Net::DownloadManager::ignoreSslErrors);
 #endif
     m_networkManager.setCookieJar(new NetworkCookieJar(this));
 }

src/base/net/geoipmanager.cpp

@@ -60,7 +60,7 @@ GeoIPManager::GeoIPManager()
     , m_geoIPDatabase(nullptr)
 {
     configure();
-    connect(Preferences::instance(), SIGNAL(changed()), SLOT(configure()));
+    connect(Preferences::instance(), &Preferences::changed, this, &GeoIPManager::configure);
 }
 
 GeoIPManager::~GeoIPManager()
@@ -119,8 +119,9 @@ void GeoIPManager::manageDatabaseUpdate()
 void GeoIPManager::downloadDatabaseFile()
 {
     DownloadHandler *handler = DownloadManager::instance()->downloadUrl(DATABASE_URL);
-    connect(handler, SIGNAL(downloadFinished(QString, QByteArray)), SLOT(downloadFinished(QString, QByteArray)));
-    connect(handler, SIGNAL(downloadFailed(QString, QString)), SLOT(downloadFailed(QString, QString)));
+    connect(handler, static_cast<void (Net::DownloadHandler::*)(const QString &, const QByteArray &)>(&Net::DownloadHandler::downloadFinished)
+            , this, &GeoIPManager::downloadFinished);
+    connect(handler, &Net::DownloadHandler::downloadFailed, this, &GeoIPManager::downloadFailed);
 }
 
 QString GeoIPManager::lookup(const QHostAddress &hostAddr) const

src/base/net/smtp.cpp

@@ -111,9 +111,10 @@ Smtp::Smtp(QObject *parent)
     m_socket = new QTcpSocket(this);
 #endif
 
-    connect(m_socket, SIGNAL(readyRead()), SLOT(readyRead()));
-    connect(m_socket, SIGNAL(disconnected()), SLOT(deleteLater()));
-    connect(m_socket, SIGNAL(error(QAbstractSocket::SocketError)), SLOT(error(QAbstractSocket::SocketError)));
+    connect(m_socket, &QIODevice::readyRead, this, &Smtp::readyRead);
+    connect(m_socket, &QAbstractSocket::disconnected, this, &QObject::deleteLater);
+    connect(m_socket, static_cast<void (QAbstractSocket::*)(QAbstractSocket::SocketError)>(&QAbstractSocket::error)
+            , this, &Smtp::error);
 
     // Test hmacMD5 function (http://www.faqs.org/rfcs/rfc2202.html)
     Q_ASSERT(hmacMD5("Jefe", "what do ya want for nothing?").toHex()

src/base/scanfoldersmodel.cpp

@@ -86,7 +86,7 @@ ScanFoldersModel::ScanFoldersModel(QObject *parent)
     , m_fsWatcher(nullptr)
 {
     configure();
-    connect(Preferences::instance(), SIGNAL(changed()), SLOT(configure()));
+    connect(Preferences::instance(), &Preferences::changed, this, &ScanFoldersModel::configure);
 }
 
 ScanFoldersModel::~ScanFoldersModel()
@@ -222,7 +222,7 @@ ScanFoldersModel::PathStatus ScanFoldersModel::addPath(const QString &watchPath,
 
     if (!m_fsWatcher) {
         m_fsWatcher = new FileSystemWatcher(this);
-        connect(m_fsWatcher, SIGNAL(torrentsAdded(const QStringList &)), this, SLOT(addTorrentsToSession(const QStringList  &)));
+        connect(m_fsWatcher, &FileSystemWatcher::torrentsAdded, this, &ScanFoldersModel::addTorrentsToSession);
     }
 
     beginInsertRows(QModelIndex(), rowCount(), rowCount());

src/base/search/searchhandler.cpp

@@ -76,7 +76,7 @@ SearchHandler::SearchHandler(const QString &pattern, const QString &category, co
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))
     connect(m_searchProcess, &QProcess::errorOccurred, this, &SearchHandler::processFailed);
 #else
-    connect(m_searchProcess, static_cast<void(QProcess::*)(QProcess::ProcessError)>(&QProcess::error)
+    connect(m_searchProcess, static_cast<void (QProcess::*)(QProcess::ProcessError)>(&QProcess::error)
             , this, &SearchHandler::processFailed);
 #endif
     connect(m_searchProcess, &QProcess::readyReadStandardOutput, this, &SearchHandler::readSearchOutput);

src/base/settingsstorage.cpp

@@ -163,7 +163,7 @@ SettingsStorage::SettingsStorage()
 {
     m_timer.setSingleShot(true);
     m_timer.setInterval(5 * 1000);
-    connect(&m_timer, SIGNAL(timeout()), SLOT(save()));
+    connect(&m_timer, &QTimer::timeout, this, &SettingsStorage::save);
 }
 
 SettingsStorage::~SettingsStorage()

src/gui/addnewtorrentdialog.cpp

@@ -146,11 +146,11 @@ AddNewTorrentDialog::AddNewTorrentDialog(const BitTorrent::AddTorrentParams &inP
     ui->contentTreeView->header()->setSortIndicator(0, Qt::AscendingOrder);
     loadState();
     // Signal / slots
-    connect(ui->adv_button, SIGNAL(clicked(bool)), SLOT(showAdvancedSettings(bool)));
-    connect(ui->doNotDeleteTorrentCheckBox, SIGNAL(clicked(bool)), SLOT(doNotDeleteTorrentClicked(bool)));
+    connect(ui->adv_button, &QToolButton::clicked, this, &AddNewTorrentDialog::showAdvancedSettings);
+    connect(ui->doNotDeleteTorrentCheckBox, &QCheckBox::clicked, this, &AddNewTorrentDialog::doNotDeleteTorrentClicked);
     QShortcut *editHotkey = new QShortcut(Qt::Key_F2, ui->contentTreeView, nullptr, nullptr, Qt::WidgetShortcut);
-    connect(editHotkey, SIGNAL(activated()), SLOT(renameSelectedFile()));
-    connect(ui->contentTreeView, SIGNAL(doubleClicked(QModelIndex)), SLOT(renameSelectedFile()));
+    connect(editHotkey, &QShortcut::activated, this, &AddNewTorrentDialog::renameSelectedFile);
+    connect(ui->contentTreeView, &QAbstractItemView::doubleClicked, this, &AddNewTorrentDialog::renameSelectedFile);
 
     ui->buttonBox->button(QDialogButtonBox::Ok)->setFocus();
 }
@@ -238,9 +238,10 @@ void AddNewTorrentDialog::show(QString source, const BitTorrent::AddTorrentParam
     if (Utils::Misc::isUrl(source)) {
         // Launch downloader
         Net::DownloadHandler *handler = Net::DownloadManager::instance()->downloadUrl(source, true, 10485760 /* 10MB */, true);
-        connect(handler, SIGNAL(downloadFinished(QString,QString)), dlg, SLOT(handleDownloadFinished(QString,QString)));
-        connect(handler, SIGNAL(downloadFailed(QString,QString)), dlg, SLOT(handleDownloadFailed(QString,QString)));
-        connect(handler, SIGNAL(redirectedToMagnet(QString,QString)), dlg, SLOT(handleRedirectedToMagnet(QString,QString)));
+        connect(handler, static_cast<void (Net::DownloadHandler::*)(const QString &, const QString &)>(&Net::DownloadHandler::downloadFinished)
+                , dlg, &AddNewTorrentDialog::handleDownloadFinished);
+        connect(handler, &Net::DownloadHandler::downloadFailed, dlg, &AddNewTorrentDialog::handleDownloadFailed);
+        connect(handler, &Net::DownloadHandler::redirectedToMagnet, dlg, &AddNewTorrentDialog::handleRedirectedToMagnet);
     }
     else {
         bool ok = false;
@@ -349,7 +350,7 @@ bool AddNewTorrentDialog::loadMagnet(const BitTorrent::MagnetUri &magnetUri)
         return false;
     }
 
-    connect(BitTorrent::Session::instance(), SIGNAL(metadataLoaded(BitTorrent::TorrentInfo)), SLOT(updateMetadata(BitTorrent::TorrentInfo)));
+    connect(BitTorrent::Session::instance(), &BitTorrent::Session::metadataLoaded, this, &AddNewTorrentDialog::updateMetadata);
 
     // Set dialog title
     QString torrent_name = magnetUri.name();
@@ -742,12 +743,13 @@ void AddNewTorrentDialog::setupTreeview()
 
         // Prepare content tree
         m_contentModel = new TorrentContentFilterModel(this);
-        connect(m_contentModel->model(), SIGNAL(filteredFilesChanged()), SLOT(updateDiskSpaceLabel()));
+        connect(m_contentModel->model(), &TorrentContentModel::filteredFilesChanged, this, &AddNewTorrentDialog::updateDiskSpaceLabel);
         ui->contentTreeView->setModel(m_contentModel);
         m_contentDelegate = new PropListDelegate(nullptr);
         ui->contentTreeView->setItemDelegate(m_contentDelegate);
-        connect(ui->contentTreeView, SIGNAL(clicked(const QModelIndex&)), ui->contentTreeView, SLOT(edit(const QModelIndex&)));
-        connect(ui->contentTreeView, SIGNAL(customContextMenuRequested(const QPoint&)), this, SLOT(displayContentTreeMenu(const QPoint&)));
+        connect(ui->contentTreeView, &QAbstractItemView::clicked, ui->contentTreeView
+                , static_cast<void (QAbstractItemView::*)(const QModelIndex &)>(&QAbstractItemView::edit));
+        connect(ui->contentTreeView, &QWidget::customContextMenuRequested, this, &AddNewTorrentDialog::displayContentTreeMenu);
 
         // List files in torrent
         m_contentModel->model()->setupModelData(m_torrentInfo);

src/gui/advancedsettings.cpp

@@ -125,8 +125,10 @@ AdvancedSettings::AdvancedSettings(QWidget *parent)
     setSelectionMode(QAbstractItemView::NoSelection);
     setEditTriggers(QAbstractItemView::NoEditTriggers);
     // Signals
-    connect(&spin_cache, SIGNAL(valueChanged(int)), SLOT(updateCacheSpinSuffix(int)));
-    connect(&combo_iface, SIGNAL(currentIndexChanged(int)), SLOT(updateInterfaceAddressCombo()));
+    connect(&spin_cache, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged)
+            , this, &AdvancedSettings::updateCacheSpinSuffix);
+    connect(&combo_iface, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
+            , this, &AdvancedSettings::updateInterfaceAddressCombo);
     // Load settings
     loadAdvancedSettings();
     resizeColumnToContents(0);

src/gui/categoryfiltermodel.cpp

@@ -174,17 +174,15 @@ CategoryFilterModel::CategoryFilterModel(QObject *parent)
     : QAbstractItemModel(parent)
     , m_rootItem(new CategoryModelItem)
 {
-    auto session = BitTorrent::Session::instance();
-
-    connect(session, SIGNAL(categoryAdded(QString)), SLOT(categoryAdded(QString)));
-    connect(session, SIGNAL(categoryRemoved(QString)), SLOT(categoryRemoved(QString)));
-    connect(session, SIGNAL(torrentCategoryChanged(BitTorrent::TorrentHandle *const, QString))
-            , SLOT(torrentCategoryChanged(BitTorrent::TorrentHandle *const, QString)));
-    connect(session, SIGNAL(subcategoriesSupportChanged()), SLOT(subcategoriesSupportChanged()));
-    connect(session, SIGNAL(torrentAdded(BitTorrent::TorrentHandle *const))
-            , SLOT(torrentAdded(BitTorrent::TorrentHandle *const)));
-    connect(session, SIGNAL(torrentAboutToBeRemoved(BitTorrent::TorrentHandle *const))
-            , SLOT(torrentAboutToBeRemoved(BitTorrent::TorrentHandle *const)));
+    using namespace BitTorrent;
+    auto session = Session::instance();
+
+    connect(session, &Session::categoryAdded, this, &CategoryFilterModel::categoryAdded);
+    connect(session, &Session::categoryRemoved, this, &CategoryFilterModel::categoryRemoved);
+    connect(session, &Session::torrentCategoryChanged, this, &CategoryFilterModel::torrentCategoryChanged);
+    connect(session, &Session::subcategoriesSupportChanged, this, &CategoryFilterModel::subcategoriesSupportChanged);
+    connect(session, &Session::torrentAdded, this, &CategoryFilterModel::torrentAdded);
+    connect(session, &Session::torrentAboutToBeRemoved, this, &CategoryFilterModel::torrentAboutToBeRemoved);
 
     populate();
 }

src/gui/deletionconfirmationdlg.h

@@ -59,7 +59,7 @@ class DeletionConfirmationDlg : public QDialog, private Ui::confirmDeletionDlg {
     rememberBtn->setIconSize(Utils::Gui::mediumIconSize());
 
     checkPermDelete->setChecked(defaultDeleteFiles || Preferences::instance()->deleteTorrentFilesAsDefault());
-    connect(checkPermDelete, SIGNAL(clicked()), this, SLOT(updateRememberButtonState()));
+    connect(checkPermDelete, &QCheckBox::clicked, this, &DeletionConfirmationDlg::updateRememberButtonState);
     buttonBox->button(QDialogButtonBox::Cancel)->setFocus();
 
     Utils::Gui::resize(this);

src/gui/executionlog.cpp

@@ -59,8 +59,8 @@ ExecutionLog::ExecutionLog(QWidget *parent, const Log::MsgTypes &types)
         addLogMessage(msg);
     foreach (const Log::Peer& peer, logger->getPeers())
         addPeerMessage(peer);
-    connect(logger, SIGNAL(newLogMessage(const Log::Msg &)), SLOT(addLogMessage(const Log::Msg &)));
-    connect(logger, SIGNAL(newLogPeer(const Log::Peer &)), SLOT(addPeerMessage(const Log::Peer &)));
+    connect(logger, &Logger::newLogMessage, this, &ExecutionLog::addLogMessage);
+    connect(logger, &Logger::newLogPeer, this, &ExecutionLog::addPeerMessage);
 }
 
 ExecutionLog::~ExecutionLog()

src/gui/guiiconprovider.cpp

@@ -40,7 +40,7 @@ GuiIconProvider::GuiIconProvider(QObject *parent)
     : IconProvider(parent)
 {
     configure();
-    connect(Preferences::instance(), SIGNAL(changed()), SLOT(configure()));
+    connect(Preferences::instance(), &Preferences::changed, this, &GuiIconProvider::configure);
 }
 
 GuiIconProvider::~GuiIconProvider() = default;

src/gui/loglistwidget.cpp

@@ -47,8 +47,8 @@ LogListWidget::LogListWidget(int maxLines, const Log::MsgTypes &types, QWidget *
     // Context menu
     QAction *copyAct = new QAction(GuiIconProvider::instance()->getIcon("edit-copy"), tr("Copy"), this);
     QAction *clearAct = new QAction(GuiIconProvider::instance()->getIcon("edit-clear"), tr("Clear"), this);
-    connect(copyAct, SIGNAL(triggered()), SLOT(copySelection()));
-    connect(clearAct, SIGNAL(triggered()), SLOT(clear()));
+    connect(copyAct, &QAction::triggered, this, &LogListWidget::copySelection);
+    connect(clearAct, &QAction::triggered, this, &LogListWidget::clear);
     addAction(copyAct);
     addAction(clearAct);
     setContextMenuPolicy(Qt::ActionsContextMenu);

src/gui/powermanagement/powermanagement_x11.cpp

@@ -86,8 +86,7 @@ void PowerManagementInhibitor::RequestIdle()
 
     QDBusPendingCall pcall = QDBusConnection::sessionBus().asyncCall(call, 1000);
     QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(pcall, this);
-    connect(watcher, SIGNAL(finished(QDBusPendingCallWatcher*)),
-            this, SLOT(OnAsyncReply(QDBusPendingCallWatcher*)));
+    connect(watcher, &QDBusPendingCallWatcher::finished, this, &PowerManagementInhibitor::OnAsyncReply);
 }
 
 
@@ -124,8 +123,7 @@ void PowerManagementInhibitor::RequestBusy()
 
     QDBusPendingCall pcall = QDBusConnection::sessionBus().asyncCall(call, 1000);
     QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(pcall, this);
-    connect(watcher, SIGNAL(finished(QDBusPendingCallWatcher*)),
-            this, SLOT(OnAsyncReply(QDBusPendingCallWatcher*)));
+    connect(watcher, &QDBusPendingCallWatcher::finished, this, &PowerManagementInhibitor::OnAsyncReply);
 }
 
 void PowerManagementInhibitor::OnAsyncReply(QDBusPendingCallWatcher *call)

src/gui/programupdater.cpp

@@ -67,8 +67,9 @@ void ProgramUpdater::checkForUpdates()
                 // Don't change this User-Agent. In case our updater goes haywire,
                 // the filehost can identify it and contact us.
                 "qBittorrent/" QBT_VERSION_2 " ProgramUpdater (www.qbittorrent.org)");
-    connect(handler, SIGNAL(downloadFinished(QString,QByteArray)), SLOT(rssDownloadFinished(QString,QByteArray)));
-    connect(handler, SIGNAL(downloadFailed(QString,QString)), SLOT(rssDownloadFailed(QString,QString)));
+    connect(handler, static_cast<void (Net::DownloadHandler::*)(const QString &, const QByteArray &)>(&Net::DownloadHandler::downloadFinished)
+            , this, &ProgramUpdater::rssDownloadFinished);
+    connect(handler, &Net::DownloadHandler::downloadFailed, this, &ProgramUpdater::rssDownloadFailed);
 }
 
 void ProgramUpdater::rssDownloadFinished(const QString &url, const QByteArray &data)

src/gui/properties/peerlistwidget.cpp

@@ -118,7 +118,7 @@ PeerListWidget::PeerListWidget(PropertiesWidget *parent)
             resizeColumnToContents(i);
     // Context menu
     setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(this, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(showPeerListMenu(QPoint)));
+    connect(this, &QWidget::customContextMenuRequested, this, &PeerListWidget::showPeerListMenu);
     // List delegate
     m_listDelegate = new PeerListDelegate(this);
     setItemDelegate(m_listDelegate);
@@ -128,10 +128,11 @@ PeerListWidget::PeerListWidget(PropertiesWidget *parent)
     updatePeerHostNameResolutionState();
     // SIGNAL/SLOT
     header()->setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(header(), SIGNAL(customContextMenuRequested(const QPoint&)), this, SLOT(displayToggleColumnsMenu(const QPoint&)));
-    connect(header(), SIGNAL(sectionClicked(int)), SLOT(handleSortColumnChanged(int)));
+    connect(header(), &QWidget::customContextMenuRequested, this, &PeerListWidget::displayToggleColumnsMenu);
+    connect(header(), &QHeaderView::sectionClicked, this, &PeerListWidget::handleSortColumnChanged);
     handleSortColumnChanged(header()->sortIndicatorSection());
-    m_copyHotkey = new QShortcut(QKeySequence::Copy, this, SLOT(copySelectedPeers()), nullptr, Qt::WidgetShortcut);
+    m_copyHotkey = new QShortcut(QKeySequence::Copy, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_copyHotkey, &QShortcut::activated, this, &PeerListWidget::copySelectedPeers);
 
     // This hack fixes reordering of first column with Qt5.
     // https://github.com/qtproject/qtbase/commit/e0fc088c0c8bc61dbcaf5928b24986cd61a22777
@@ -192,7 +193,7 @@ void PeerListWidget::updatePeerHostNameResolutionState()
     if (Preferences::instance()->resolvePeerHostNames()) {
         if (!m_resolver) {
             m_resolver = new Net::ReverseResolution(this);
-            connect(m_resolver, SIGNAL(ipResolved(QString,QString)), SLOT(handleResolved(QString,QString)));
+            connect(m_resolver.data(), &Net::ReverseResolution::ipResolved, this, &PeerListWidget::handleResolved);
             loadPeers(m_properties->getCurrentTorrent(), true);
         }
     }

src/gui/properties/peersadditiondlg.cpp

@@ -38,7 +38,7 @@ PeersAdditionDlg::PeersAdditionDlg(QWidget *parent)
     , m_ui(new Ui::addPeersDialog())
 {
     m_ui->setupUi(this);
-    connect(m_ui->buttonBox, SIGNAL(accepted()), this, SLOT(validateInput()));
+    connect(m_ui->buttonBox, &QDialogButtonBox::accepted, this, &PeersAdditionDlg::validateInput);
 }
 
 PeersAdditionDlg::~PeersAdditionDlg()

src/gui/properties/propertieswidget.cpp

@@ -93,25 +93,26 @@ PropertiesWidget::PropertiesWidget(QWidget *parent, MainWindow *mainWindow, Tran
     m_contentFilterLine = new LineEdit(this);
     m_contentFilterLine->setPlaceholderText(tr("Filter files..."));
     m_contentFilterLine->setFixedWidth(Utils::Gui::scaledSize(this, 300));
-    connect(m_contentFilterLine, SIGNAL(textChanged(QString)), this, SLOT(filterText(QString)));
+    connect(m_contentFilterLine, &LineEdit::textChanged, this, &PropertiesWidget::filterText);
     m_ui->contentFilterLayout->insertWidget(3, m_contentFilterLine);
 
     // SIGNAL/SLOTS
-    connect(m_ui->filesList, SIGNAL(clicked(const QModelIndex&)), m_ui->filesList, SLOT(edit(const QModelIndex&)));
-    connect(m_ui->selectAllButton, SIGNAL(clicked()), m_propListModel, SLOT(selectAll()));
-    connect(m_ui->selectNoneButton, SIGNAL(clicked()), m_propListModel, SLOT(selectNone()));
-    connect(m_ui->filesList, SIGNAL(customContextMenuRequested(const QPoint&)), this, SLOT(displayFilesListMenu(const QPoint&)));
-    connect(m_ui->filesList, SIGNAL(doubleClicked(const QModelIndex&)), this, SLOT(openDoubleClickedFile(const QModelIndex&)));
-    connect(m_propListModel, SIGNAL(filteredFilesChanged()), this, SLOT(filteredFilesChanged()));
-    connect(m_ui->listWebSeeds, SIGNAL(customContextMenuRequested(const QPoint&)), this, SLOT(displayWebSeedListMenu(const QPoint&)));
-    connect(transferList, SIGNAL(currentTorrentChanged(BitTorrent::TorrentHandle *const)), this, SLOT(loadTorrentInfos(BitTorrent::TorrentHandle *const)));
-    connect(m_propListDelegate, SIGNAL(filteredFilesChanged()), this, SLOT(filteredFilesChanged()));
-    connect(m_ui->stackedProperties, SIGNAL(currentChanged(int)), this, SLOT(loadDynamicData()));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentSavePathChanged(BitTorrent::TorrentHandle *const)), this, SLOT(updateSavePath(BitTorrent::TorrentHandle *const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentMetadataLoaded(BitTorrent::TorrentHandle *const)), this, SLOT(updateTorrentInfos(BitTorrent::TorrentHandle *const)));
-    connect(m_ui->filesList->header(), SIGNAL(sectionMoved(int,int,int)), this, SLOT(saveSettings()));
-    connect(m_ui->filesList->header(), SIGNAL(sectionResized(int,int,int)), this, SLOT(saveSettings()));
-    connect(m_ui->filesList->header(), SIGNAL(sortIndicatorChanged(int,Qt::SortOrder)), this, SLOT(saveSettings()));
+    connect(m_ui->filesList, &QAbstractItemView::clicked
+            , m_ui->filesList, static_cast<void (QAbstractItemView::*)(const QModelIndex &)>(&QAbstractItemView::edit));
+    connect(m_ui->selectAllButton, &QPushButton::clicked, m_propListModel, &TorrentContentFilterModel::selectAll);
+    connect(m_ui->selectNoneButton, &QPushButton::clicked, m_propListModel, &TorrentContentFilterModel::selectNone);
+    connect(m_ui->filesList, &QWidget::customContextMenuRequested, this, &PropertiesWidget::displayFilesListMenu);
+    connect(m_ui->filesList, &QAbstractItemView::doubleClicked, this, &PropertiesWidget::openDoubleClickedFile);
+    connect(m_propListModel, &TorrentContentFilterModel::filteredFilesChanged, this, &PropertiesWidget::filteredFilesChanged);
+    connect(m_ui->listWebSeeds, &QWidget::customContextMenuRequested, this, &PropertiesWidget::displayWebSeedListMenu);
+    connect(transferList, &TransferListWidget::currentTorrentChanged, this, &PropertiesWidget::loadTorrentInfos);
+    connect(m_propListDelegate, &PropListDelegate::filteredFilesChanged, this, &PropertiesWidget::filteredFilesChanged);
+    connect(m_ui->stackedProperties, &QStackedWidget::currentChanged, this, &PropertiesWidget::loadDynamicData);
+    connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentSavePathChanged, this, &PropertiesWidget::updateSavePath);
+    connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentMetadataLoaded, this, &PropertiesWidget::updateTorrentInfos);
+    connect(m_ui->filesList->header(), &QHeaderView::sectionMoved, this, &PropertiesWidget::saveSettings);
+    connect(m_ui->filesList->header(), &QHeaderView::sectionResized, this, &PropertiesWidget::saveSettings);
+    connect(m_ui->filesList->header(), &QHeaderView::sortIndicatorChanged, this, &PropertiesWidget::saveSettings);
 
     // set bar height relative to screen dpi
     const int barHeight = Utils::Gui::scaledSize(this, 18);
@@ -136,8 +137,8 @@ PropertiesWidget::PropertiesWidget(QWidget *parent, MainWindow *mainWindow, Tran
     m_ui->trackerUpButton->setIconSize(Utils::Gui::smallIconSize());
     m_ui->trackerDownButton->setIcon(GuiIconProvider::instance()->getIcon("go-down"));
     m_ui->trackerDownButton->setIconSize(Utils::Gui::smallIconSize());
-    connect(m_ui->trackerUpButton, SIGNAL(clicked()), m_trackerList, SLOT(moveSelectionUp()));
-    connect(m_ui->trackerDownButton, SIGNAL(clicked()), m_trackerList, SLOT(moveSelectionDown()));
+    connect(m_ui->trackerUpButton, &QPushButton::clicked, m_trackerList, &TrackerList::moveSelectionUp);
+    connect(m_ui->trackerDownButton, &QPushButton::clicked, m_trackerList, &TrackerList::moveSelectionDown);
     m_ui->horizontalLayout_trackers->insertWidget(0, m_trackerList);
     connect(m_trackerList->header(), SIGNAL(sectionMoved(int,int,int)), m_trackerList, SLOT(saveSettings()));
     connect(m_trackerList->header(), SIGNAL(sectionResized(int,int,int)), m_trackerList, SLOT(saveSettings()));
@@ -155,23 +156,23 @@ PropertiesWidget::PropertiesWidget(QWidget *parent, MainWindow *mainWindow, Tran
     m_tabBar = new PropTabBar();
     m_tabBar->setContentsMargins(0, 5, 0, 0);
     m_ui->verticalLayout->addLayout(m_tabBar);
-    connect(m_tabBar, SIGNAL(tabChanged(int)), m_ui->stackedProperties, SLOT(setCurrentIndex(int)));
-    connect(m_tabBar, SIGNAL(tabChanged(int)), this, SLOT(saveSettings()));
-    connect(m_tabBar, SIGNAL(visibilityToggled(bool)), SLOT(setVisibility(bool)));
-    connect(m_tabBar, SIGNAL(visibilityToggled(bool)), this, SLOT(saveSettings()));
+    connect(m_tabBar, &PropTabBar::tabChanged, m_ui->stackedProperties, &QStackedWidget::setCurrentIndex);
+    connect(m_tabBar, &PropTabBar::tabChanged, this, &PropertiesWidget::saveSettings);
+    connect(m_tabBar, &PropTabBar::visibilityToggled, this, &PropertiesWidget::setVisibility);
+    connect(m_tabBar, &PropTabBar::visibilityToggled, this, &PropertiesWidget::saveSettings);
     // Dynamic data refresher
     m_refreshTimer = new QTimer(this);
-    connect(m_refreshTimer, SIGNAL(timeout()), this, SLOT(loadDynamicData()));
+    connect(m_refreshTimer, &QTimer::timeout, this, &PropertiesWidget::loadDynamicData);
     m_refreshTimer->start(3000); // 3sec
     m_editHotkeyFile = new QShortcut(Qt::Key_F2, m_ui->filesList, nullptr, nullptr, Qt::WidgetShortcut);
-    connect(m_editHotkeyFile, SIGNAL(activated()), SLOT(renameSelectedFile()));
+    connect(m_editHotkeyFile, &QShortcut::activated, this, &PropertiesWidget::renameSelectedFile);
     m_editHotkeyWeb = new QShortcut(Qt::Key_F2, m_ui->listWebSeeds, nullptr, nullptr, Qt::WidgetShortcut);
-    connect(m_editHotkeyWeb, SIGNAL(activated()), SLOT(editWebSeed()));
-    connect(m_ui->listWebSeeds, SIGNAL(doubleClicked(QModelIndex)), SLOT(editWebSeed()));
+    connect(m_editHotkeyWeb, &QShortcut::activated, this, &PropertiesWidget::editWebSeed);
+    connect(m_ui->listWebSeeds, &QListWidget::doubleClicked, this, &PropertiesWidget::editWebSeed);
     m_deleteHotkeyWeb = new QShortcut(QKeySequence::Delete, m_ui->listWebSeeds, nullptr, nullptr, Qt::WidgetShortcut);
-    connect(m_deleteHotkeyWeb, SIGNAL(activated()), SLOT(deleteSelectedUrlSeeds()));
+    connect(m_deleteHotkeyWeb, &QShortcut::activated, this, &PropertiesWidget::deleteSelectedUrlSeeds);
     m_openHotkeyFile = new QShortcut(Qt::Key_Return, m_ui->filesList, nullptr, nullptr, Qt::WidgetShortcut);
-    connect(m_openHotkeyFile, SIGNAL(activated()), SLOT(openSelectedFile()));
+    connect(m_openHotkeyFile, &QShortcut::activated, this, &PropertiesWidget::openSelectedFile);
 }
 
 PropertiesWidget::~PropertiesWidget()

src/gui/properties/proptabbar.cpp

@@ -99,7 +99,8 @@ PropTabBar::PropTabBar(QWidget *parent)
     addWidget(speedButton);
     m_btnGroup->addButton(speedButton, SpeedTab);
     // SIGNAL/SLOT
-    connect(m_btnGroup, SIGNAL(buttonClicked(int)), SLOT(setCurrentIndex(int)));
+    connect(m_btnGroup, static_cast<void (QButtonGroup::*)(int)>(&QButtonGroup::buttonClicked)
+            , this, &PropTabBar::setCurrentIndex);
     // Disable buttons focus
     foreach (QAbstractButton *btn, m_btnGroup->buttons())
         btn->setFocusPolicy(Qt::NoFocus);

src/gui/properties/trackerlist.cpp

@@ -78,10 +78,10 @@ TrackerList::TrackerList(PropertiesWidget *properties)
             resizeColumnToContents(i);
     // Context menu
     setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(this, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(showTrackerListMenu(QPoint)));
+    connect(this, &QWidget::customContextMenuRequested, this, &TrackerList::showTrackerListMenu);
     // Header context menu
     header()->setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(header(), SIGNAL(customContextMenuRequested(const QPoint&)), this, SLOT(displayToggleColumnsMenu(const QPoint&)));
+    connect(header(), &QWidget::customContextMenuRequested, this, &TrackerList::displayToggleColumnsMenu);
     // Set DHT, PeX, LSD items
     m_DHTItem = new QTreeWidgetItem({ "",  "** [DHT] **", "", "0", "", "", "0" });
     insertTopLevelItem(0, m_DHTItem);
@@ -112,10 +112,13 @@ TrackerList::TrackerList(PropertiesWidget *properties)
     headerItem()->setTextAlignment(COL_PEERS, (Qt::AlignRight | Qt::AlignVCenter));
     headerItem()->setTextAlignment(COL_DOWNLOADED, (Qt::AlignRight | Qt::AlignVCenter));
     // Set hotkeys
-    m_editHotkey = new QShortcut(Qt::Key_F2, this, SLOT(editSelectedTracker()), nullptr, Qt::WidgetShortcut);
-    connect(this, SIGNAL(doubleClicked(QModelIndex)), SLOT(editSelectedTracker()));
-    m_deleteHotkey = new QShortcut(QKeySequence::Delete, this, SLOT(deleteSelectedTrackers()), nullptr, Qt::WidgetShortcut);
-    m_copyHotkey = new QShortcut(QKeySequence::Copy, this, SLOT(copyTrackerUrl()), nullptr, Qt::WidgetShortcut);
+    m_editHotkey = new QShortcut(Qt::Key_F2, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_editHotkey, &QShortcut::activated, this, &TrackerList::editSelectedTracker);
+    connect(this, &QAbstractItemView::doubleClicked, this, &TrackerList::editSelectedTracker);
+    m_deleteHotkey = new QShortcut(QKeySequence::Delete, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_deleteHotkey, &QShortcut::activated, this, &TrackerList::deleteSelectedTrackers);
+    m_copyHotkey = new QShortcut(QKeySequence::Copy, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_copyHotkey, &QShortcut::activated, this, &TrackerList::copyTrackerUrl);
 
     // This hack fixes reordering of first column with Qt5.
     // https://github.com/qtproject/qtbase/commit/e0fc088c0c8bc61dbcaf5928b24986cd61a22777

src/gui/properties/trackersadditiondlg.cpp

@@ -71,8 +71,9 @@ void TrackersAdditionDlg::on_uTorrentListButton_clicked()
 {
     m_ui->uTorrentListButton->setEnabled(false);
     Net::DownloadHandler *handler = Net::DownloadManager::instance()->downloadUrl(m_ui->list_url->text(), true);
-    connect(handler, SIGNAL(downloadFinished(QString, QString)), this, SLOT(parseUTorrentList(QString, QString)));
-    connect(handler, SIGNAL(downloadFailed(QString, QString)), this, SLOT(getTrackerError(QString, QString)));
+    connect(handler, static_cast<void (Net::DownloadHandler::*)(const QString &, const QString &)>(&Net::DownloadHandler::downloadFinished)
+            , this, &TrackersAdditionDlg::parseUTorrentList);
+    connect(handler, &Net::DownloadHandler::downloadFailed, this, &TrackersAdditionDlg::getTrackerError);
     // Just to show that it takes times
     setCursor(Qt::WaitCursor);
 }

src/gui/rss/htmlbrowser.cpp

@@ -22,7 +22,7 @@ HtmlBrowser::HtmlBrowser(QWidget *parent)
     qDebug() << "HtmlBrowser  cache path:" << m_diskCache->cacheDirectory() << " max size:" << m_diskCache->maximumCacheSize() / 1024 / 1024 << "MB";
     m_netManager->setCache(m_diskCache);
 
-    connect(m_netManager, SIGNAL(finished(QNetworkReply *)), this, SLOT(resourceLoaded(QNetworkReply*)));
+    connect(m_netManager, &QNetworkAccessManager::finished, this, &HtmlBrowser::resourceLoaded);
 }
 
 HtmlBrowser::~HtmlBrowser()

src/gui/scanfoldersdelegate.cpp

@@ -71,7 +71,8 @@ QWidget *ScanFoldersDelegate::createEditor(QWidget *parent, const QStyleOptionVi
         editor->addItem(index.data().toString());
     }
 
-    connect(editor, SIGNAL(currentIndexChanged(int)), this, SLOT(comboboxIndexChanged(int)));
+    connect(editor, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
+            , this, &ScanFoldersDelegate::comboboxIndexChanged);
     return editor;
 }
 

src/gui/search/searchtab.cpp

@@ -129,23 +129,23 @@ SearchTab::SearchTab(SearchHandler *searchHandler, QWidget *parent)
 
     updateFilter();
 
-    connect(m_ui->filterMode, static_cast<void(QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
+    connect(m_ui->filterMode, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
             , this, &SearchTab::updateFilter);
     connect(m_ui->minSeeds, &QAbstractSpinBox::editingFinished, this, &SearchTab::updateFilter);
-    connect(m_ui->minSeeds, static_cast<void(QSpinBox::*)(int)>(&QSpinBox::valueChanged)
+    connect(m_ui->minSeeds, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged)
             , this, &SearchTab::updateFilter);
     connect(m_ui->maxSeeds, &QAbstractSpinBox::editingFinished, this, &SearchTab::updateFilter);
-    connect(m_ui->maxSeeds, static_cast<void(QSpinBox::*)(int)>(&QSpinBox::valueChanged)
+    connect(m_ui->maxSeeds, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged)
             , this, &SearchTab::updateFilter);
     connect(m_ui->minSize, &QAbstractSpinBox::editingFinished, this, &SearchTab::updateFilter);
-    connect(m_ui->minSize, static_cast<void(QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged)
+    connect(m_ui->minSize, static_cast<void (QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged)
             , this, &SearchTab::updateFilter);
     connect(m_ui->maxSize, &QAbstractSpinBox::editingFinished, this, &SearchTab::updateFilter);
-    connect(m_ui->maxSize, static_cast<void(QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged)
+    connect(m_ui->maxSize, static_cast<void (QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged)
             , this, &SearchTab::updateFilter);
-    connect(m_ui->minSizeUnit, static_cast<void(QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
+    connect(m_ui->minSizeUnit, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
             , this, &SearchTab::updateFilter);
-    connect(m_ui->maxSizeUnit, static_cast<void(QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
+    connect(m_ui->maxSizeUnit, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged)
             , this, &SearchTab::updateFilter);
 
     connect(m_ui->resultsBrowser, &QAbstractItemView::doubleClicked, this, &SearchTab::onItemDoubleClicked);

src/gui/shutdownconfirmdlg.cpp

@@ -66,7 +66,7 @@ ShutdownConfirmDlg::ShutdownConfirmDlg(QWidget *parent, const ShutdownDialogActi
     move(Utils::Misc::screenCenter(this));
 
     m_timer.setInterval(1000); // 1sec
-    connect(&m_timer, SIGNAL(timeout()), this, SLOT(updateSeconds()));
+    connect(&m_timer, &QTimer::timeout, this, &ShutdownConfirmDlg::updateSeconds);
 
     Utils::Gui::resize(this);
 }

src/gui/speedlimitdlg.cpp

@@ -40,8 +40,9 @@ SpeedLimitDialog::SpeedLimitDialog(QWidget *parent)
     qDebug("Bandwidth allocation dialog creation");
 
     // Connect to slots
-    connect(m_ui->bandwidthSlider, SIGNAL(valueChanged(int)), this, SLOT(updateSpinValue(int)));
-    connect(m_ui->spinBandwidth, SIGNAL(valueChanged(int)), this, SLOT(updateSliderValue(int)));
+    connect(m_ui->bandwidthSlider, &QSlider::valueChanged, this, &SpeedLimitDialog::updateSpinValue);
+    connect(m_ui->spinBandwidth, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged)
+            , this, &SpeedLimitDialog::updateSliderValue);
 
     Utils::Gui::resize(this);
 }

src/gui/torrentcontentfiltermodel.cpp

@@ -35,7 +35,7 @@ TorrentContentFilterModel::TorrentContentFilterModel(QObject *parent)
     : QSortFilterProxyModel(parent)
     , m_model(new TorrentContentModel(this))
 {
-    connect(m_model, SIGNAL(filteredFilesChanged()), this, SIGNAL(filteredFilesChanged()));
+    connect(m_model, &TorrentContentModel::filteredFilesChanged, this, &TorrentContentFilterModel::filteredFilesChanged);
     setSourceModel(m_model);
     // Filter settings
     setFilterKeyColumn(TorrentContentModelItem::COL_NAME);

src/gui/torrentmodel.cpp

@@ -61,19 +61,20 @@ TorrentModel::TorrentModel(QObject *parent)
     : QAbstractListModel(parent)
 {
     // Load the torrents
-    foreach (BitTorrent::TorrentHandle *const torrent, BitTorrent::Session::instance()->torrents())
+    using namespace BitTorrent;
+    foreach (TorrentHandle *const torrent, Session::instance()->torrents())
         addTorrent(torrent);
 
     // Listen for torrent changes
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentAdded(BitTorrent::TorrentHandle * const)), SLOT(addTorrent(BitTorrent::TorrentHandle * const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentAboutToBeRemoved(BitTorrent::TorrentHandle * const)), SLOT(handleTorrentAboutToBeRemoved(BitTorrent::TorrentHandle * const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentsUpdated()), SLOT(handleTorrentsUpdated()));
-
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentFinished(BitTorrent::TorrentHandle * const)), SLOT(handleTorrentStatusUpdated(BitTorrent::TorrentHandle * const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentMetadataLoaded(BitTorrent::TorrentHandle * const)), SLOT(handleTorrentStatusUpdated(BitTorrent::TorrentHandle * const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentResumed(BitTorrent::TorrentHandle * const)), SLOT(handleTorrentStatusUpdated(BitTorrent::TorrentHandle * const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentPaused(BitTorrent::TorrentHandle * const)), SLOT(handleTorrentStatusUpdated(BitTorrent::TorrentHandle * const)));
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentFinishedChecking(BitTorrent::TorrentHandle * const)), SLOT(handleTorrentStatusUpdated(BitTorrent::TorrentHandle * const)));
+    connect(Session::instance(), &Session::torrentAdded, this, &TorrentModel::addTorrent);
+    connect(Session::instance(), &Session::torrentAboutToBeRemoved, this, &TorrentModel::handleTorrentAboutToBeRemoved);
+    connect(Session::instance(), &Session::torrentsUpdated, this, &TorrentModel::handleTorrentsUpdated);
+
+    connect(Session::instance(), &Session::torrentFinished, this, &TorrentModel::handleTorrentStatusUpdated);
+    connect(Session::instance(), &Session::torrentMetadataLoaded, this, &TorrentModel::handleTorrentStatusUpdated);
+    connect(Session::instance(), &Session::torrentResumed, this, &TorrentModel::handleTorrentStatusUpdated);
+    connect(Session::instance(), &Session::torrentPaused, this, &TorrentModel::handleTorrentStatusUpdated);
+    connect(Session::instance(), &Session::torrentFinishedChecking, this, &TorrentModel::handleTorrentStatusUpdated);
 }
 
 int TorrentModel::rowCount(const QModelIndex &index) const

src/gui/transferlistwidget.cpp

@@ -280,19 +280,24 @@ TransferListWidget::TransferListWidget(QWidget *parent, MainWindow *mainWindow)
     setContextMenuPolicy(Qt::CustomContextMenu);
 
     // Listen for list events
-    connect(this, SIGNAL(doubleClicked(QModelIndex)), this, SLOT(torrentDoubleClicked()));
-    connect(this, SIGNAL(customContextMenuRequested(const QPoint &)), this, SLOT(displayListMenu(const QPoint &)));
+    connect(this, &QAbstractItemView::doubleClicked, this, &TransferListWidget::torrentDoubleClicked);
+    connect(this, &QWidget::customContextMenuRequested, this, &TransferListWidget::displayListMenu);
     header()->setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(header(), SIGNAL(customContextMenuRequested(const QPoint &)), this, SLOT(displayDLHoSMenu(const QPoint &)));
-    connect(header(), SIGNAL(sectionMoved(int, int, int)), this, SLOT(saveSettings()));
-    connect(header(), SIGNAL(sectionResized(int, int, int)), this, SLOT(saveSettings()));
-    connect(header(), SIGNAL(sortIndicatorChanged(int, Qt::SortOrder)), this, SLOT(saveSettings()));
-
-    m_editHotkey = new QShortcut(Qt::Key_F2, this, SLOT(renameSelectedTorrent()), nullptr, Qt::WidgetShortcut);
-    m_deleteHotkey = new QShortcut(QKeySequence::Delete, this, SLOT(softDeleteSelectedTorrents()), nullptr, Qt::WidgetShortcut);
-    m_permDeleteHotkey = new QShortcut(Qt::SHIFT + Qt::Key_Delete, this, SLOT(permDeleteSelectedTorrents()), nullptr, Qt::WidgetShortcut);
-    m_doubleClickHotkey = new QShortcut(Qt::Key_Return, this, SLOT(torrentDoubleClicked()), nullptr, Qt::WidgetShortcut);
-    m_recheckHotkey = new QShortcut(Qt::CTRL + Qt::Key_R, this, SLOT(recheckSelectedTorrents()), nullptr, Qt::WidgetShortcut);
+    connect(header(), &QWidget::customContextMenuRequested, this, &TransferListWidget::displayDLHoSMenu);
+    connect(header(), &QHeaderView::sectionMoved, this, &TransferListWidget::saveSettings);
+    connect(header(), &QHeaderView::sectionResized, this, &TransferListWidget::saveSettings);
+    connect(header(), &QHeaderView::sortIndicatorChanged, this, &TransferListWidget::saveSettings);
+
+    m_editHotkey = new QShortcut(Qt::Key_F2, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_editHotkey, &QShortcut::activated, this, &TransferListWidget::renameSelectedTorrent);
+    m_deleteHotkey = new QShortcut(QKeySequence::Delete, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_deleteHotkey, &QShortcut::activated, this, &TransferListWidget::softDeleteSelectedTorrents);
+    m_permDeleteHotkey = new QShortcut(Qt::SHIFT + Qt::Key_Delete, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_permDeleteHotkey, &QShortcut::activated, this, &TransferListWidget::permDeleteSelectedTorrents);
+    m_doubleClickHotkey = new QShortcut(Qt::Key_Return, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_doubleClickHotkey, &QShortcut::activated, this, &TransferListWidget::torrentDoubleClicked);
+    m_recheckHotkey = new QShortcut(Qt::CTRL + Qt::Key_R, this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(m_recheckHotkey, &QShortcut::activated, this, &TransferListWidget::recheckSelectedTorrents);
 
     // This hack fixes reordering of first column with Qt5.
     // https://github.com/qtproject/qtbase/commit/e0fc088c0c8bc61dbcaf5928b24986cd61a22777
@@ -861,58 +866,58 @@ void TransferListWidget::displayListMenu(const QPoint&)
 
     // Create actions
     QAction actionStart(GuiIconProvider::instance()->getIcon("media-playback-start"), tr("Resume", "Resume/start the torrent"), nullptr);
-    connect(&actionStart, SIGNAL(triggered()), this, SLOT(startSelectedTorrents()));
+    connect(&actionStart, &QAction::triggered, this, &TransferListWidget::startSelectedTorrents);
     QAction actionPause(GuiIconProvider::instance()->getIcon("media-playback-pause"), tr("Pause", "Pause the torrent"), nullptr);
-    connect(&actionPause, SIGNAL(triggered()), this, SLOT(pauseSelectedTorrents()));
+    connect(&actionPause, &QAction::triggered, this, &TransferListWidget::pauseSelectedTorrents);
     QAction actionForceStart(GuiIconProvider::instance()->getIcon("media-seek-forward"), tr("Force Resume", "Force Resume/start the torrent"), nullptr);
-    connect(&actionForceStart, SIGNAL(triggered()), this, SLOT(forceStartSelectedTorrents()));
+    connect(&actionForceStart, &QAction::triggered, this, &TransferListWidget::forceStartSelectedTorrents);
     QAction actionDelete(GuiIconProvider::instance()->getIcon("edit-delete"), tr("Delete", "Delete the torrent"), nullptr);
-    connect(&actionDelete, SIGNAL(triggered()), this, SLOT(softDeleteSelectedTorrents()));
+    connect(&actionDelete, &QAction::triggered, this, &TransferListWidget::softDeleteSelectedTorrents);
     QAction actionPreview_file(GuiIconProvider::instance()->getIcon("view-preview"), tr("Preview file..."), nullptr);
-    connect(&actionPreview_file, SIGNAL(triggered()), this, SLOT(previewSelectedTorrents()));
+    connect(&actionPreview_file, &QAction::triggered, this, &TransferListWidget::previewSelectedTorrents);
     QAction actionSet_max_ratio(QIcon(QLatin1String(":/icons/skin/ratio.png")), tr("Limit share ratio..."), nullptr);
-    connect(&actionSet_max_ratio, SIGNAL(triggered()), this, SLOT(setMaxRatioSelectedTorrents()));
+    connect(&actionSet_max_ratio, &QAction::triggered, this, &TransferListWidget::setMaxRatioSelectedTorrents);
     QAction actionSet_upload_limit(GuiIconProvider::instance()->getIcon("kt-set-max-upload-speed"), tr("Limit upload rate..."), nullptr);
-    connect(&actionSet_upload_limit, SIGNAL(triggered()), this, SLOT(setUpLimitSelectedTorrents()));
+    connect(&actionSet_upload_limit, &QAction::triggered, this, &TransferListWidget::setUpLimitSelectedTorrents);
     QAction actionSet_download_limit(GuiIconProvider::instance()->getIcon("kt-set-max-download-speed"), tr("Limit download rate..."), nullptr);
-    connect(&actionSet_download_limit, SIGNAL(triggered()), this, SLOT(setDlLimitSelectedTorrents()));
+    connect(&actionSet_download_limit, &QAction::triggered, this, &TransferListWidget::setDlLimitSelectedTorrents);
     QAction actionOpen_destination_folder(GuiIconProvider::instance()->getIcon("inode-directory"), tr("Open destination folder"), nullptr);
-    connect(&actionOpen_destination_folder, SIGNAL(triggered()), this, SLOT(openSelectedTorrentsFolder()));
+    connect(&actionOpen_destination_folder, &QAction::triggered, this, &TransferListWidget::openSelectedTorrentsFolder);
     QAction actionIncreasePriority(GuiIconProvider::instance()->getIcon("go-up"), tr("Move up", "i.e. move up in the queue"), nullptr);
-    connect(&actionIncreasePriority, SIGNAL(triggered()), this, SLOT(increasePrioSelectedTorrents()));
+    connect(&actionIncreasePriority, &QAction::triggered, this, &TransferListWidget::increasePrioSelectedTorrents);
     QAction actionDecreasePriority(GuiIconProvider::instance()->getIcon("go-down"), tr("Move down", "i.e. Move down in the queue"), nullptr);
-    connect(&actionDecreasePriority, SIGNAL(triggered()), this, SLOT(decreasePrioSelectedTorrents()));
+    connect(&actionDecreasePriority, &QAction::triggered, this, &TransferListWidget::decreasePrioSelectedTorrents);
     QAction actionTopPriority(GuiIconProvider::instance()->getIcon("go-top"), tr("Move to top", "i.e. Move to top of the queue"), nullptr);
-    connect(&actionTopPriority, SIGNAL(triggered()), this, SLOT(topPrioSelectedTorrents()));
+    connect(&actionTopPriority, &QAction::triggered, this, &TransferListWidget::topPrioSelectedTorrents);
     QAction actionBottomPriority(GuiIconProvider::instance()->getIcon("go-bottom"), tr("Move to bottom", "i.e. Move to bottom of the queue"), nullptr);
-    connect(&actionBottomPriority, SIGNAL(triggered()), this, SLOT(bottomPrioSelectedTorrents()));
+    connect(&actionBottomPriority, &QAction::triggered, this, &TransferListWidget::bottomPrioSelectedTorrents);
     QAction actionSetTorrentPath(GuiIconProvider::instance()->getIcon("inode-directory"), tr("Set location..."), nullptr);
-    connect(&actionSetTorrentPath, SIGNAL(triggered()), this, SLOT(setSelectedTorrentsLocation()));
+    connect(&actionSetTorrentPath, &QAction::triggered, this, &TransferListWidget::setSelectedTorrentsLocation);
     QAction actionForce_recheck(GuiIconProvider::instance()->getIcon("document-edit-verify"), tr("Force recheck"), nullptr);
-    connect(&actionForce_recheck, SIGNAL(triggered()), this, SLOT(recheckSelectedTorrents()));
+    connect(&actionForce_recheck, &QAction::triggered, this, &TransferListWidget::recheckSelectedTorrents);
     QAction actionForce_reannounce(GuiIconProvider::instance()->getIcon("document-edit-verify"), tr("Force reannounce"), nullptr);
-    connect(&actionForce_reannounce, SIGNAL(triggered()), this, SLOT(reannounceSelectedTorrents()));
+    connect(&actionForce_reannounce, &QAction::triggered, this, &TransferListWidget::reannounceSelectedTorrents);
     QAction actionCopy_magnet_link(GuiIconProvider::instance()->getIcon("kt-magnet"), tr("Copy magnet link"), nullptr);
-    connect(&actionCopy_magnet_link, SIGNAL(triggered()), this, SLOT(copySelectedMagnetURIs()));
+    connect(&actionCopy_magnet_link, &QAction::triggered, this, &TransferListWidget::copySelectedMagnetURIs);
     QAction actionCopy_name(GuiIconProvider::instance()->getIcon("edit-copy"), tr("Copy name"), nullptr);
-    connect(&actionCopy_name, SIGNAL(triggered()), this, SLOT(copySelectedNames()));
+    connect(&actionCopy_name, &QAction::triggered, this, &TransferListWidget::copySelectedNames);
     QAction actionCopyHash(GuiIconProvider::instance()->getIcon("edit-copy"), tr("Copy hash"), nullptr);
     connect(&actionCopyHash, &QAction::triggered, this, &TransferListWidget::copySelectedHashes);
     QAction actionSuper_seeding_mode(tr("Super seeding mode"), nullptr);
     actionSuper_seeding_mode.setCheckable(true);
-    connect(&actionSuper_seeding_mode, SIGNAL(triggered()), this, SLOT(toggleSelectedTorrentsSuperSeeding()));
+    connect(&actionSuper_seeding_mode, &QAction::triggered, this, &TransferListWidget::toggleSelectedTorrentsSuperSeeding);
     QAction actionRename(GuiIconProvider::instance()->getIcon("edit-rename"), tr("Rename..."), nullptr);
-    connect(&actionRename, SIGNAL(triggered()), this, SLOT(renameSelectedTorrent()));
+    connect(&actionRename, &QAction::triggered, this, &TransferListWidget::renameSelectedTorrent);
     QAction actionSequential_download(tr("Download in sequential order"), nullptr);
     actionSequential_download.setCheckable(true);
-    connect(&actionSequential_download, SIGNAL(triggered()), this, SLOT(toggleSelectedTorrentsSequentialDownload()));
+    connect(&actionSequential_download, &QAction::triggered, this, &TransferListWidget::toggleSelectedTorrentsSequentialDownload);
     QAction actionFirstLastPiece_prio(tr("Download first and last pieces first"), nullptr);
     actionFirstLastPiece_prio.setCheckable(true);
-    connect(&actionFirstLastPiece_prio, SIGNAL(triggered()), this, SLOT(toggleSelectedFirstLastPiecePrio()));
+    connect(&actionFirstLastPiece_prio, &QAction::triggered, this, &TransferListWidget::toggleSelectedFirstLastPiecePrio);
     QAction actionAutoTMM(tr("Automatic Torrent Management"), nullptr);
     actionAutoTMM.setCheckable(true);
     actionAutoTMM.setToolTip(tr("Automatic mode means that various torrent properties(eg save path) will be decided by the associated category"));
-    connect(&actionAutoTMM, SIGNAL(triggered(bool)), this, SLOT(setSelectedAutoTMMEnabled(bool)));
+    connect(&actionAutoTMM, &QAction::triggered, this, &TransferListWidget::setSelectedAutoTMMEnabled);
     // End of actions
 
     // Enable/disable pause/start action given the DL state

src/gui/updownratiodlg.cpp

@@ -69,9 +69,10 @@ UpDownRatioDlg::UpDownRatioDlg(bool useDefault, qreal initialRatioValue,
     m_ui->timeSpinBox->setMaximum(maxTimeValue);
     m_ui->timeSpinBox->setValue(initialTimeValue);
 
-    connect(m_ui->buttonGroup, SIGNAL(buttonClicked(int)), SLOT(handleRatioTypeChanged()));
-    connect(m_ui->checkMaxRatio, SIGNAL(toggled(bool)), this, SLOT(enableRatioSpin()));
-    connect(m_ui->checkMaxTime, SIGNAL(toggled(bool)), this, SLOT(enableTimeSpin()));
+    connect(m_ui->buttonGroup, static_cast<void (QButtonGroup::*)(int)>(&QButtonGroup::buttonClicked)
+            , this, &UpDownRatioDlg::handleRatioTypeChanged);
+    connect(m_ui->checkMaxRatio, &QCheckBox::toggled, this, &UpDownRatioDlg::enableRatioSpin);
+    connect(m_ui->checkMaxTime, &QCheckBox::toggled, this, &UpDownRatioDlg::enableTimeSpin);
 
     handleRatioTypeChanged();