widget: Replace old-style Qt connect() calls

24 files changed, 154 insertions, 119 deletions

diff --git a/src/widget/wbattery.cpp b/src/widget/wbattery.cpp
index f8880e85ac..7a20dc2c6a 100644
--- a/src/widget/wbattery.cpp
+++ b/src/widget/wbattery.cpp
@@ -10,8 +10,9 @@ WBattery::WBattery(QWidget* parent)
           m_pBattery(Battery::getBattery(this)) {
     setVisible(false);
     if (m_pBattery) {
-        connect(m_pBattery.data(), SIGNAL(stateChanged()),
-                this, SLOT(update()));
+        connect(m_pBattery.data(), &Battery::stateChanged, this, [this]() {
+            update();
+        });
     }
 }
 
diff --git a/src/widget/wbeatspinbox.cpp b/src/widget/wbeatspinbox.cpp
index 2414ff5665..9373f56499 100644
--- a/src/widget/wbeatspinbox.cpp
+++ b/src/widget/wbeatspinbox.cpp
@@ -30,8 +30,10 @@ WBeatSpinBox::WBeatSpinBox(QWidget* parent,
     lineEdit()->setFocusPolicy(Qt::ClickFocus);
 
     setValue(m_valueControl.get());
-    connect(this, SIGNAL(valueChanged(double)),
-            this, SLOT(slotSpinboxValueChanged(double)));
+    connect(this,
+            QOverload<double>::of(&QDoubleSpinBox::valueChanged),
+            this,
+            &WBeatSpinBox::slotSpinboxValueChanged);
     m_valueControl.connectValueChanged(this, &WBeatSpinBox::slotControlValueChanged);
 }
 
diff --git a/src/widget/wcombobox.cpp b/src/widget/wcombobox.cpp
index 5bf9314c8d..9e682c2be7 100644
--- a/src/widget/wcombobox.cpp
+++ b/src/widget/wcombobox.cpp
@@ -6,8 +6,10 @@
 WComboBox::WComboBox(QWidget* pParent)
         : QComboBox(pParent),
           WBaseWidget(this) {
-    connect(this, SIGNAL(currentIndexChanged(int)),
-            this, SLOT(slotCurrentIndexChanged(int)));
+    connect(this,
+            QOverload<int>::of(&QComboBox::currentIndexChanged),
+            this,
+            &WComboBox::slotCurrentIndexChanged);
 }
 
 void WComboBox::setup(const QDomNode& node, const SkinContext& context) {
diff --git a/src/widget/wcoverart.cpp b/src/widget/wcoverart.cpp
index 36a22ee75b..7e25b28665 100644
--- a/src/widget/wcoverart.cpp
+++ b/src/widget/wcoverart.cpp
@@ -40,16 +40,12 @@ WCoverArt::WCoverArt(QWidget* parent,
                 this,
                 &WCoverArt::slotCoverFound);
     }
-    connect(m_pMenu, SIGNAL(coverInfoSelected(const CoverInfoRelative&)),
-            this, SLOT(slotCoverInfoSelected(const CoverInfoRelative&)));
-    connect(m_pMenu, SIGNAL(reloadCoverArt()),
-            this, SLOT(slotReloadCoverArt()));
+    connect(m_pMenu, &WCoverArtMenu::coverInfoSelected, this, &WCoverArt::slotCoverInfoSelected);
+    connect(m_pMenu, &WCoverArtMenu::reloadCoverArt, this, &WCoverArt::slotReloadCoverArt);
 
     if (m_pPlayer != nullptr) {
-        connect(m_pPlayer, SIGNAL(newTrackLoaded(TrackPointer)),
-                this, SLOT(slotLoadTrack(TrackPointer)));
-        connect(m_pPlayer, SIGNAL(loadingTrack(TrackPointer, TrackPointer)),
-                this, SLOT(slotLoadingTrack(TrackPointer, TrackPointer)));
+        connect(m_pPlayer, &BaseTrackPlayer::newTrackLoaded, this, &WCoverArt::slotLoadTrack);
+        connect(m_pPlayer, &BaseTrackPlayer::loadingTrack, this, &WCoverArt::slotLoadingTrack);
 
         // just in case a track is already loaded
         slotLoadTrack(m_pPlayer->getLoadedTrack());
@@ -174,8 +170,10 @@ void WCoverArt::slotCoverFound(
 
 void WCoverArt::slotLoadTrack(TrackPointer pTrack) {
     if (m_loadedTrack) {
-        disconnect(m_loadedTrack.get(), SIGNAL(coverArtUpdated()),
-                   this, SLOT(slotTrackCoverArtUpdated()));
+        disconnect(m_loadedTrack.get(),
+                &Track::coverArtUpdated,
+                this,
+                &WCoverArt::slotTrackCoverArtUpdated);
     }
     m_lastRequestedCover = CoverInfo();
     m_loadedCover = QPixmap();
diff --git a/src/widget/wcoverartmenu.cpp b/src/widget/wcoverartmenu.cpp
index c77e93731c..437ab6d1b9 100644
--- a/src/widget/wcoverartmenu.cpp
+++ b/src/widget/wcoverartmenu.cpp
@@ -19,17 +19,17 @@ WCoverArtMenu::~WCoverArtMenu() {
 void WCoverArtMenu::createActions() {
     m_pChange = new QAction(tr("Choose new cover",
             "change cover art location"), this);
-    connect(m_pChange, SIGNAL(triggered()), this, SLOT(slotChange()));
+    connect(m_pChange, &QAction::triggered, this, &WCoverArtMenu::slotChange);
     addAction(m_pChange);
 
     m_pUnset = new QAction(tr("Clear cover",
             "clears the set cover art -- does not touch files on disk"), this);
-    connect(m_pUnset, SIGNAL(triggered()), this, SLOT(slotUnset()));
+    connect(m_pUnset, &QAction::triggered, this, &WCoverArtMenu::slotUnset);
     addAction(m_pUnset);
 
     m_pReload = new QAction(tr("Reload from file/folder",
             "reload cover art from file metadata or folder"), this);
-    connect(m_pReload, SIGNAL(triggered()), this, SIGNAL(reloadCoverArt()));
+    connect(m_pReload, &QAction::triggered, this, &WCoverArtMenu::reloadCoverArt);
     addAction(m_pReload);
 }
 
diff --git a/src/widget/weffect.cpp b/src/widget/weffect.cpp
index 8754a99987..e62fd529d9 100644
--- a/src/widget/weffect.cpp
+++ b/src/widget/weffect.cpp
@@ -31,8 +31,7 @@ void WEffect::setup(const QDomNode& node, const SkinContext& context) {
 void WEffect::setEffectSlot(EffectSlotPointer pEffectSlot) {
     if (pEffectSlot) {
         m_pEffectSlot = pEffectSlot;
-        connect(pEffectSlot.data(), SIGNAL(updated()),
-                this, SLOT(effectUpdated()));
+        connect(pEffectSlot.data(), &EffectSlot::updated, this, &WEffect::effectUpdated);
         effectUpdated();
     }
 }
diff --git a/src/widget/weffectchain.cpp b/src/widget/weffectchain.cpp
index cf6ccda72a..9d2121ff24 100644
--- a/src/widget/weffectchain.cpp
+++ b/src/widget/weffectchain.cpp
@@ -28,8 +28,10 @@ void WEffectChain::setup(const QDomNode& node, const SkinContext& context) {
 void WEffectChain::setEffectChainSlot(EffectChainSlotPointer pEffectChainSlot) {
     if (pEffectChainSlot) {
         m_pEffectChainSlot = pEffectChainSlot;
-        connect(pEffectChainSlot.data(), SIGNAL(updated()),
-                this, SLOT(chainUpdated()));
+        connect(pEffectChainSlot.data(),
+                &EffectChainSlot::updated,
+                this,
+                &WEffectChain::chainUpdated);
         chainUpdated();
     }
 }
diff --git a/src/widget/weffectparameterbase.cpp b/src/widget/weffectparameterbase.cpp
index f2b46be289..8fa10e93ad 100644
--- a/src/widget/weffectparameterbase.cpp
+++ b/src/widget/weffectparameterbase.cpp
@@ -13,8 +13,10 @@ void WEffectParameterBase::setEffectParameterSlot(
         EffectParameterSlotBasePointer pEffectParameterSlot) {
     m_pEffectParameterSlot = pEffectParameterSlot;
     if (m_pEffectParameterSlot) {
-        connect(m_pEffectParameterSlot.data(), SIGNAL(updated()),
-                this, SLOT(parameterUpdated()));
+        connect(m_pEffectParameterSlot.data(),
+                &EffectParameterSlotBase::updated,
+                this,
+                &WEffectParameterBase::parameterUpdated);
     }
     parameterUpdated();
 }
diff --git a/src/widget/weffectparameterknob.cpp b/src/widget/weffectparameterknob.cpp
index 087f819115..6b07483b61 100644
--- a/src/widget/weffectparameterknob.cpp
+++ b/src/widget/weffectparameterknob.cpp
@@ -17,8 +17,10 @@ void WEffectParameterKnob::setEffectParameterSlot(
         EffectParameterSlotPointer pParameterSlot) {
     m_pEffectParameterSlot = pParameterSlot;
     if (m_pEffectParameterSlot) {
-        connect(m_pEffectParameterSlot.data(), SIGNAL(updated()),
-                this, SLOT(parameterUpdated()));
+        connect(m_pEffectParameterSlot.data(),
+                &EffectParameterSlot::updated,
+                this,
+                &WEffectParameterKnob::parameterUpdated);
     }
     parameterUpdated();
 }
diff --git a/src/widget/weffectparameterknobcomposed.cpp b/src/widget/weffectparameterknobcomposed.cpp
index f4d03a6226..df10fc7544 100644
--- a/src/widget/weffectparameterknobcomposed.cpp
+++ b/src/widget/weffectparameterknobcomposed.cpp
@@ -22,8 +22,10 @@ void WEffectParameterKnobComposed::setEffectParameterSlot(
         EffectParameterSlotPointer pParameterSlot) {
     m_pEffectParameterSlot = pParameterSlot;
     if (m_pEffectParameterSlot) {
-        connect(m_pEffectParameterSlot.data(), SIGNAL(updated()),
-                this, SLOT(parameterUpdated()));
+        connect(m_pEffectParameterSlot.data(),
+                &EffectParameterSlot::updated,
+                this,
+                &WEffectParameterKnobComposed::parameterUpdated);
     }
     parameterUpdated();
 }
diff --git a/src/widget/weffectpushbutton.cpp b/src/widget/weffectpushbutton.cpp
index 58fceb97de..1e21fd34ce 100644
--- a/src/widget/weffectpushbutton.cpp
+++ b/src/widget/weffectpushbutton.cpp
@@ -15,8 +15,7 @@ void WEffectPushButton::setup(const QDomNode& node, const SkinContext& context)
     WPushButton::setup(node, context);
 
     m_pButtonMenu = new QMenu(this);
-    connect(m_pButtonMenu, SIGNAL(triggered(QAction*)),
-            this, SLOT(slotActionChosen(QAction*)));
+    connect(m_pButtonMenu, &QMenu::triggered, this, &WEffectPushButton::slotActionChosen);
     setFocusPolicy(Qt::NoFocus);
 }
 
@@ -35,8 +34,10 @@ void WEffectPushButton::setEffectParameterSlot(
         EffectButtonParameterSlotPointer pParameterSlot) {
     m_pEffectParameterSlot = pParameterSlot;
     if (m_pEffectParameterSlot) {
-        connect(m_pEffectParameterSlot.data(), SIGNAL(updated()),
-                this, SLOT(parameterUpdated()));
+        connect(m_pEffectParameterSlot.data(),
+                &EffectParameterSlot::updated,
+                this,
+                &WEffectPushButton::parameterUpdated);
     }
     parameterUpdated();
 }
diff --git a/src/widget/weffectselector.cpp b/src/widget/weffectselector.cpp
index 2909336601..f6c567158f 100644
--- a/src/widget/weffectselector.cpp
+++ b/src/widget/weffectselector.cpp
@@ -27,12 +27,18 @@ void WEffectSelector::setup(const QDomNode& node, const SkinContext& context) {
             node, context, m_pChainSlot);
 
     if (m_pEffectSlot != nullptr) {
-        connect(m_pEffectsManager, SIGNAL(visibleEffectsUpdated()),
-                this, SLOT(populate()));
-        connect(m_pEffectSlot.data(), SIGNAL(updated()),
-                this, SLOT(slotEffectUpdated()));
-        connect(this, SIGNAL(currentIndexChanged(int)),
-                this, SLOT(slotEffectSelected(int)));
+        connect(m_pEffectsManager,
+                &EffectsManager::visibleEffectsUpdated,
+                this,
+                &WEffectSelector::populate);
+        connect(m_pEffectSlot.data(),
+                &EffectSlot::updated,
+                this,
+                &WEffectSelector::slotEffectUpdated);
+        connect(this,
+                QOverload<int>::of(&WEffectSelector::currentIndexChanged),
+                this,
+                &WEffectSelector::slotEffectSelected);
     } else {
         SKIN_WARNING(node, context)
                 << "EffectSelector node could not attach to effect slot.";
diff --git a/src/widget/wknob.cpp b/src/widget/wknob.cpp
index 80395ab5c9..891134f62b 100644
--- a/src/widget/wknob.cpp
+++ b/src/widget/wknob.cpp
@@ -26,8 +26,9 @@ WKnob::WKnob(QWidget* pParent)
         : WDisplay(pParent),
           m_renderTimer(mixxx::Duration::fromMillis(20),
                         mixxx::Duration::fromSeconds(1)) {
-    connect(&m_renderTimer, SIGNAL(update()),
-            this, SLOT(update()));
+    connect(&m_renderTimer, &WidgetRenderTimer::update, this, [this]() {
+        update();
+    });
     setFocusPolicy(Qt::NoFocus);
 }
 
diff --git a/src/widget/wknobcomposed.cpp b/src/widget/wknobcomposed.cpp
index 1d686e2da0..5e804ea939 100644
--- a/src/widget/wknobcomposed.cpp
+++ b/src/widget/wknobcomposed.cpp
@@ -21,8 +21,9 @@ WKnobComposed::WKnobComposed(QWidget* pParent)
           m_arcPenCap(Qt::FlatCap),
           m_renderTimer(mixxx::Duration::fromMillis(20),
                         mixxx::Duration::fromSeconds(1)) {
-    connect(&m_renderTimer, SIGNAL(update()),
-            this, SLOT(update()));
+    connect(&m_renderTimer, &WidgetRenderTimer::update, this, [this]() {
+        update();
+    });
 }
 
 void WKnobComposed::setup(const QDomNode& node, const SkinContext& context) {
diff --git a/src/widget/wlibrarytableview.cpp b/src/widget/wlibrarytableview.cpp
index 06740d3bf9..0baabfc6bd 100644
--- a/src/widget/wlibrarytableview.cpp
+++ b/src/widget/wlibrarytableview.cpp
@@ -44,8 +44,10 @@ WLibraryTableView::WLibraryTableView(QWidget* parent,
     setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
     setAlternatingRowColors(true);
 
-    connect(verticalScrollBar(), SIGNAL(valueChanged(int)),
-            this, SIGNAL(scrollValueChanged(int)));
+    connect(verticalScrollBar(),
+            &QScrollBar::valueChanged,
+            this,
+            &WLibraryTableView::scrollValueChanged);
 
     setTabKeyNavigation(false);
 }
diff --git a/src/widget/wmainmenubar.cpp b/src/widget/wmainmenubar.cpp
index c5ee65edf0..f4d04078a1 100644
--- a/src/widget/wmainmenubar.cpp
+++ b/src/widget/wmainmenubar.cpp
@@ -103,7 +103,7 @@ void WMainMenuBar::initialize() {
     pFileQuit->setStatusTip(quitText);
     pFileQuit->setWhatsThis(buildWhatsThis(quitTitle, quitText));
     pFileQuit->setMenuRole(QAction::QuitRole);
-    connect(pFileQuit, SIGNAL(triggered()), this, SIGNAL(quit()));
+    connect(pFileQuit, &QAction::triggered, this, &WMainMenuBar::quit);
     pFileMenu->addAction(pFileQuit);
 
     addMenu(pFileMenu);
@@ -117,11 +117,9 @@ void WMainMenuBar::initialize() {
     pLibraryRescan->setStatusTip(rescanText);
     pLibraryRescan->setWhatsThis(buildWhatsThis(rescanTitle, rescanText));
     pLibraryRescan->setCheckable(false);
-    connect(pLibraryRescan, SIGNAL(triggered()),
-            this, SIGNAL(rescanLibrary()));
+    connect(pLibraryRescan, &QAction::triggered, this, &WMainMenuBar::rescanLibrary);
     // Disable the action when a scan is active.
-    connect(this, SIGNAL(internalLibraryScanActive(bool)),
-            pLibraryRescan, SLOT(setDisabled(bool)));
+    connect(this, &WMainMenuBar::internalLibraryScanActive, pLibraryRescan, &QAction::setDisabled);
     pLibraryMenu->addAction(pLibraryRescan);
 
     pLibraryMenu->addSeparator();
@@ -136,8 +134,7 @@ void WMainMenuBar::initialize() {
     pLibraryCreatePlaylist->setShortcutContext(Qt::ApplicationShortcut);
     pLibraryCreatePlaylist->setStatusTip(createPlaylistText);
     pLibraryCreatePlaylist->setWhatsThis(buildWhatsThis(createPlaylistTitle, createPlaylistText));
-    connect(pLibraryCreatePlaylist, SIGNAL(triggered()),
-            this, SIGNAL(createPlaylist()));
+    connect(pLibraryCreatePlaylist, &QAction::triggered, this, &WMainMenuBar::createPlaylist);
     pLibraryMenu->addAction(pLibraryCreatePlaylist);
 
     QString createCrateTitle = tr("Create New &Crate");
@@ -150,8 +147,7 @@ void WMainMenuBar::initialize() {
     pLibraryCreateCrate->setShortcutContext(Qt::ApplicationShortcut);
     pLibraryCreateCrate->setStatusTip(createCrateText);
     pLibraryCreateCrate->setWhatsThis(buildWhatsThis(createCrateTitle, createCrateText));
-    connect(pLibraryCreateCrate, SIGNAL(triggered()),
-            this, SIGNAL(createCrate()));
+    connect(pLibraryCreateCrate, &QAction::triggered, this, &WMainMenuBar::createCrate);
     pLibraryMenu->addAction(pLibraryCreateCrate);
 
     addMenu(pLibraryMenu);
@@ -289,10 +285,11 @@ void WMainMenuBar::initialize() {
     pViewFullScreen->setChecked(false);
     pViewFullScreen->setStatusTip(fullScreenText);
     pViewFullScreen->setWhatsThis(buildWhatsThis(fullScreenTitle, fullScreenText));
-    connect(pViewFullScreen, SIGNAL(triggered(bool)),
-            this, SIGNAL(toggleFullScreen(bool)));
-    connect(this, SIGNAL(internalFullScreenStateChange(bool)),
-            pViewFullScreen, SLOT(setChecked(bool)));
+    connect(pViewFullScreen, &QAction::triggered, this, &WMainMenuBar::toggleFullScreen);
+    connect(this,
+            &WMainMenuBar::internalFullScreenStateChange,
+            pViewFullScreen,
+            &QAction::setChecked);
     pViewMenu->addAction(pViewFullScreen);
 
     addMenu(pViewMenu);
@@ -348,10 +345,11 @@ void WMainMenuBar::initialize() {
     pOptionsRecord->setCheckable(true);
     pOptionsRecord->setStatusTip(recordText);
     pOptionsRecord->setWhatsThis(buildWhatsThis(recordTitle, recordText));
-    connect(pOptionsRecord, SIGNAL(triggered(bool)),
-            this, SIGNAL(toggleRecording(bool)));
-    connect(this, SIGNAL(internalRecordingStateChange(bool)),
-            pOptionsRecord, SLOT(setChecked(bool)));
+    connect(pOptionsRecord, &QAction::triggered, this, &WMainMenuBar::toggleRecording);
+    connect(this,
+            &WMainMenuBar::internalRecordingStateChange,
+            pOptionsRecord,
+            &QAction::setChecked);
     pOptionsMenu->addAction(pOptionsRecord);
 
 #ifdef __BROADCAST__
@@ -368,10 +366,11 @@ void WMainMenuBar::initialize() {
     pOptionsBroadcasting->setStatusTip(broadcastingText);
     pOptionsBroadcasting->setWhatsThis(buildWhatsThis(broadcastingTitle, broadcastingText));
 
-    connect(pOptionsBroadcasting, SIGNAL(triggered(bool)),
-            this, SIGNAL(toggleBroadcasting(bool)));
-    connect(this, SIGNAL(internalBroadcastingStateChange(bool)),
-            pOptionsBroadcasting, SLOT(setChecked(bool)));
+    connect(pOptionsBroadcasting, &QAction::triggered, this, &WMainMenuBar::toggleBroadcasting);
+    connect(this,
+            &WMainMenuBar::internalBroadcastingStateChange,
+            pOptionsBroadcasting,
+            &QAction::setChecked);
     pOptionsMenu->addAction(pOptionsBroadcasting);
 #endif
 
@@ -391,8 +390,7 @@ void WMainMenuBar::initialize() {
     pOptionsKeyboard->setChecked(keyboardShortcutsEnabled);
     pOptionsKeyboard->setStatusTip(keyboardShortcutText);
     pOptionsKeyboard->setWhatsThis(buildWhatsThis(keyboardShortcutTitle, keyboardShortcutText));
-    connect(pOptionsKeyboard, SIGNAL(triggered(bool)),
-            this, SIGNAL(toggleKeyboardShortcuts(bool)));
+    connect(pOptionsKeyboard, &QAction::triggered, this, &WMainMenuBar::toggleKeyboardShortcuts);
 
     pOptionsMenu->addAction(pOptionsKeyboard);
 
@@ -409,8 +407,7 @@ void WMainMenuBar::initialize() {
     pOptionsPreferences->setStatusTip(preferencesText);
     pOptionsPreferences->setWhatsThis(buildWhatsThis(preferencesTitle, preferencesText));
     pOptionsPreferences->setMenuRole(QAction::PreferencesRole);
-    connect(pOptionsPreferences, SIGNAL(triggered()),
-            this, SIGNAL(showPreferences()));
+    connect(pOptionsPreferences, &QAction::triggered, this, &WMainMenuBar::showPreferences);
     pOptionsMenu->addAction(pOptionsPreferences);
 
     addMenu(pOptionsMenu);
@@ -429,8 +426,7 @@ void WMainMenuBar::initialize() {
         pDeveloperReloadSkin->setShortcutContext(Qt::ApplicationShortcut);
         pDeveloperReloadSkin->setStatusTip(reloadSkinText);
         pDeveloperReloadSkin->setWhatsThis(buildWhatsThis(reloadSkinTitle, reloadSkinText));
-        connect(pDeveloperReloadSkin, SIGNAL(triggered()),
-                this, SIGNAL(reloadSkin()));
+        connect(pDeveloperReloadSkin, &QAction::triggered, this, &WMainMenuBar::reloadSkin);
         pDeveloperMenu->addAction(pDeveloperReloadSkin);
 
         QString developerToolsTitle = tr("Developer &Tools");
@@ -445,10 +441,11 @@ void WMainMenuBar::initialize() {
         pDeveloperTools->setChecked(false);
         pDeveloperTools->setStatusTip(developerToolsText);
         pDeveloperTools->setWhatsThis(buildWhatsThis(developerToolsTitle, developerToolsText));
-        connect(pDeveloperTools, SIGNAL(triggered(bool)),
-                this, SIGNAL(toggleDeveloperTools(bool)));
-        connect(this, SIGNAL(internalDeveloperToolsStateChange(bool)),
-                pDeveloperTools, SLOT(setChecked(bool)));
+        connect(pDeveloperTools, &QAction::triggered, this, &WMainMenuBar::toggleDeveloperTools);
+        connect(this,
+                &WMainMenuBar::internalDeveloperToolsStateChange,
+                pDeveloperTools,
+                &QAction::setChecked);
         pDeveloperMenu->addAction(pDeveloperTools);
 
         QString enableExperimentTitle = tr("Stats: &Experiment Bucket");
@@ -465,8 +462,10 @@ void WMainMenuBar::initialize() {
             enableExperimentTitle, enableExperimentToolsText));
         pDeveloperStatsExperiment->setCheckable(true);
         pDeveloperStatsExperiment->setChecked(Experiment::isExperiment());
-        connect(pDeveloperStatsExperiment, SIGNAL(triggered(bool)),
-                this, SLOT(slotDeveloperStatsExperiment(bool)));
+        connect(pDeveloperStatsExperiment,
+                &QAction::triggered,
+                this,
+                &WMainMenuBar::slotDeveloperStatsExperiment);
         pDeveloperMenu->addAction(pDeveloperStatsExperiment);
 
         QString enableBaseTitle = tr("Stats: &Base Bucket");
@@ -483,8 +482,10 @@ void WMainMenuBar::initialize() {
             enableBaseTitle, enableBaseToolsText));
         pDeveloperStatsBase->setCheckable(true);
         pDeveloperStatsBase->setChecked(Experiment::isBase());
-        connect(pDeveloperStatsBase, SIGNAL(triggered(bool)),
-                this, SLOT(slotDeveloperStatsBase(bool)));
+        connect(pDeveloperStatsBase,
+                &QAction::triggered,
+                this,
+                &WMainMenuBar::slotDeveloperStatsBase);
         pDeveloperMenu->addAction(pDeveloperStatsBase);
 
         // "D" cannont be used with Alt here as it is already by the Developer menu
@@ -502,8 +503,10 @@ void WMainMenuBar::initialize() {
         pDeveloperDebugger->setCheckable(true);
         pDeveloperDebugger->setStatusTip(scriptDebuggerText);
         pDeveloperDebugger->setChecked(scriptDebuggerEnabled);
-        connect(pDeveloperDebugger, SIGNAL(triggered(bool)),
-                this, SLOT(slotDeveloperDebugger(bool)));
+        connect(pDeveloperDebugger,
+                &QAction::triggered,
+                this,
+                &WMainMenuBar::slotDeveloperDebugger);
         pDeveloperMenu->addAction(pDeveloperDebugger);
 
         addMenu(pDeveloperMenu);
@@ -592,8 +595,7 @@ void WMainMenuBar::initialize() {
     pHelpAboutApp->setStatusTip(aboutText);
     pHelpAboutApp->setWhatsThis(buildWhatsThis(aboutTitle, aboutText));
     pHelpAboutApp->setMenuRole(QAction::AboutRole);
-    connect(pHelpAboutApp, SIGNAL(triggered()),
-            this, SIGNAL(showAbout()));
+    connect(pHelpAboutApp, &QAction::triggered, this, &WMainMenuBar::showAbout);
 
     pHelpMenu->addAction(pHelpAboutApp);
     addMenu(pHelpMenu);
@@ -671,10 +673,14 @@ void WMainMenuBar::slotVisitUrl(const QString& url) {
 void WMainMenuBar::createVisibilityControl(QAction* pAction,
                                            const ConfigKey& key) {
     auto pConnection = new VisibilityControlConnection(this, pAction, key);
-    connect(this, SIGNAL(internalOnNewSkinLoaded()),
-            pConnection, SLOT(slotReconnectControl()));
-    connect(this, SIGNAL(internalOnNewSkinAboutToLoad()),
-            pConnection, SLOT(slotClearControl()));
+    connect(this,
+            &WMainMenuBar::internalOnNewSkinLoaded,
+            pConnection,
+            &VisibilityControlConnection::slotReconnectControl);
+    connect(this,
+            &WMainMenuBar::internalOnNewSkinAboutToLoad,
+            pConnection,
+            &VisibilityControlConnection::slotClearControl);
 }
 
 void WMainMenuBar::onNumberOfDecksChanged(int decks) {
@@ -693,8 +699,7 @@ VisibilityControlConnection::VisibilityControlConnection(
         : QObject(pParent),
           m_key(key),
           m_pAction(pAction) {
-    connect(m_pAction, SIGNAL(triggered(bool)),
-            this, SLOT(slotActionToggled(bool)));
+    connect(m_pAction, &QAction::triggered, this, &VisibilityControlConnection::slotActionToggled);
 }
 
 void VisibilityControlConnection::slotClearControl() {
diff --git a/src/widget/wmainmenubar.h b/src/widget/wmainmenubar.h
index 643f386b21..7f305ac4b2 100644
--- a/src/widget/wmainmenubar.h
+++ b/src/widget/wmainmenubar.h
@@ -17,9 +17,11 @@ class VisibilityControlConnection : public QObject {
     VisibilityControlConnection(QObject* pParent, QAction* pAction,
                                 const ConfigKey& key);
 
-  private slots:
+  public slots:
     void slotClearControl();
     void slotReconnectControl();
+
+  private slots:
     void slotControlChanged();
     void slotActionToggled(bool toggle);
 
diff --git a/src/widget/wrecordingduration.cpp b/src/widget/wrecordingduration.cpp
index b7a62c5946..7d314408cd 100644
--- a/src/widget/wrecordingduration.cpp
+++ b/src/widget/wrecordingduration.cpp
@@ -11,10 +11,14 @@ WRecordingDuration::~WRecordingDuration() {
 
 void WRecordingDuration::setup(const QDomNode& node, const SkinContext& context) {
     WLabel::setup(node, context);
-    connect(m_pRecordingManager, SIGNAL(durationRecorded(QString)),
-        this, SLOT(refreshLabel(QString)));
-    connect(m_pRecordingManager, SIGNAL(isRecording(bool)),
-            this, SLOT(slotRecordingInactive(bool)));
+    connect(m_pRecordingManager,
+            &RecordingManager::durationRecorded,
+            this,
+            &WRecordingDuration::refreshLabel);
+    connect(m_pRecordingManager,
+            &RecordingManager::isRecording,
+            this,
+            &WRecordingDuration::slotRecordingInactive);
 
     // When we're recording show text from "InactiveText" node
     QString inactiveText;
diff --git a/src/widget/wslidercomposed.cpp b/src/widget/wslidercomposed.cpp
index a954dad852..a2c5aab587 100644
--- a/src/widget/wslidercomposed.cpp
+++ b/src/widget/wslidercomposed.cpp
@@ -49,8 +49,9 @@ WSliderComposed::WSliderComposed(QWidget * parent)
       m_pHandle(nullptr),
       m_renderTimer(mixxx::Duration::fromMillis(20),
                     mixxx::Duration::fromSeconds(1)) {
-    connect(&m_renderTimer, SIGNAL(update()),
-            this, SLOT(update()));
+    connect(&m_renderTimer, &WidgetRenderTimer::update, this, [this]() {
+        update();
+    });
 }
 
 WSliderComposed::~WSliderComposed() {
diff --git a/src/widget/wspinny.cpp b/src/widget/wspinny.cpp
index 334c75fc31..406750c962 100644
--- a/src/widget/wspinny.cpp
+++ b/src/widget/wspinny.cpp
@@ -87,18 +87,14 @@ WSpinny::WSpinny(
     }
 
     if (m_pPlayer != nullptr) {
-        connect(m_pPlayer, SIGNAL(newTrackLoaded(TrackPointer)),
-                this, SLOT(slotLoadTrack(TrackPointer)));
-        connect(m_pPlayer, SIGNAL(loadingTrack(TrackPointer, TrackPointer)),
-                this, SLOT(slotLoadingTrack(TrackPointer, TrackPointer)));
+        connect(m_pPlayer, &BaseTrackPlayer::newTrackLoaded, this, &WSpinny::slotLoadTrack);
+        connect(m_pPlayer, &BaseTrackPlayer::loadingTrack, this, &WSpinny::slotLoadingTrack);
         // just in case a track is already loaded
         slotLoadTrack(m_pPlayer->getLoadedTrack());
     }
 
-    connect(m_pCoverMenu, SIGNAL(coverInfoSelected(const CoverInfoRelative&)),
-        this, SLOT(slotCoverInfoSelected(const CoverInfoRelative&)));
-    connect(m_pCoverMenu, SIGNAL(reloadCoverArt()),
-        this, SLOT(slotReloadCoverArt()));
+    connect(m_pCoverMenu, &WCoverArtMenu::coverInfoSelected, this, &WSpinny::slotCoverInfoSelected);
+    connect(m_pCoverMenu, &WCoverArtMenu::reloadCoverArt, this, &WSpinny::slotReloadCoverArt);
 
     setAttribute(Qt::WA_NoSystemBackground);
     setAttribute(Qt::WA_OpaquePaintEvent);
@@ -237,16 +233,20 @@ void WSpinny::setup(const QDomNode& node, const SkinContext& context) {
 
 void WSpinny::slotLoadTrack(TrackPointer pTrack) {
     if (m_loadedTrack) {
-        disconnect(m_loadedTrack.get(), SIGNAL(coverArtUpdated()),
-                   this, SLOT(slotTrackCoverArtUpdated()));
+        disconnect(m_loadedTrack.get(),
+                &Track::coverArtUpdated,
+                this,
+                &WSpinny::slotTrackCoverArtUpdated);
     }
     m_lastRequestedCover = CoverInfo();
     m_loadedCover = QPixmap();
     m_loadedCoverScaled = QPixmap();
     m_loadedTrack = pTrack;
     if (m_loadedTrack) {
-        connect(m_loadedTrack.get(), SIGNAL(coverArtUpdated()),
-                this, SLOT(slotTrackCoverArtUpdated()));
+        connect(m_loadedTrack.get(),
+                &Track::coverArtUpdated,
+                this,
+                &WSpinny::slotTrackCoverArtUpdated);
     }
 
     slotTrackCoverArtUpdated();
@@ -255,8 +255,10 @@ void WSpinny::slotLoadTrack(TrackPointer pTrack) {
 void WSpinny::slotLoadingTrack(TrackPointer pNewTrack, TrackPointer pOldTrack) {
     Q_UNUSED(pNewTrack);
     if (m_loadedTrack && pOldTrack == m_loadedTrack) {
-        disconnect(m_loadedTrack.get(), SIGNAL(coverArtUpdated()),
-                   this, SLOT(slotTrackCoverArtUpdated()));
+        disconnect(m_loadedTrack.get(),
+                &Track::coverArtUpdated,
+                this,
+                &WSpinny::slotTrackCoverArtUpdated);
     }
     m_loadedTrack.reset();
     m_lastRequestedCover = CoverInfo();
diff --git a/src/widget/wsplitter.cpp b/src/widget/wsplitter.cpp
index 4372f9d9a9..1afbf4e119 100644
--- a/src/widget/wsplitter.cpp
+++ b/src/widget/wsplitter.cpp
@@ -6,8 +6,7 @@ WSplitter::WSplitter(QWidget* pParent, UserSettingsPointer pConfig)
         : QSplitter(pParent),
           WBaseWidget(this),
           m_pConfig(pConfig) {
-    connect(this, SIGNAL(splitterMoved(int,int)),
-            this, SLOT(slotSplitterMoved()));
+    connect(this, &WSplitter::splitterMoved, this, &WSplitter::slotSplitterMoved);
 }
 
 void WSplitter::setup(const QDomNode