Fix C++20 deprecation warnings

source/actions/undomanager.cpp

@@ -54,7 +54,7 @@ void UndoManager::push(QUndoCommand *cmd, int affectedSystem)
     auto onUndo = new SignalOnUndo();
     if (affectedSystem >= 0)
     {
-        connect(onUndo, &SignalOnUndo::triggered, [=]() {
+        connect(onUndo, &SignalOnUndo::triggered, [=, this]() {
             onSystemChanged(affectedSystem);
         });
     }
@@ -70,7 +70,7 @@ void UndoManager::push(QUndoCommand *cmd, int affectedSystem)
     auto onRedo = new SignalOnRedo();
     if (affectedSystem >= 0)
     {
-        connect(onRedo, &SignalOnRedo::triggered, [=]() {
+        connect(onRedo, &SignalOnRedo::triggered, [=, this]() {
             onSystemChanged(affectedSystem);
         });
     }

source/app/recentfiles.cpp

@@ -84,7 +84,7 @@ void RecentFiles::updateMenu()
         auto fileAction = new QAction(fileName, myRecentFilesMenu);
         myRecentFilesMenu->addAction(fileAction);
 
-        connect(fileAction, &QAction::triggered, [=]() {
+        connect(fileAction, &QAction::triggered, [=, this]() {
             handleFileSelection(fileName);
         });
     }

source/app/scorearea.cpp

@@ -92,7 +92,7 @@ void ScoreArea::renderDocument(const Document &document)
 
     myCaretPainter = new CaretPainter(
         document.getCaret(), document.getViewOptions(), *myActivePalette);
-    myCaretPainter->subscribeToMovement([=]() {
+    myCaretPainter->subscribeToMovement([this]() {
         adjustScroll();
     });
 

source/dialogs/bulkconverterdialog.cpp

@@ -154,11 +154,11 @@ BulkConverterDialog::BulkConverterDialog(QWidget *parent,
     auto flags = windowFlags();
     setWindowFlags(flags | Qt::WindowStaysOnTopHint);
 
-    connect(ui->fileLocatorSource, &QAbstractButton::clicked, [=]() {
+    connect(ui->fileLocatorSource, &QAbstractButton::clicked, [this]() {
         setPath(ui->sourcePathEdit);
     });
 
-    connect(ui->fileLocatorDestination, &QAbstractButton::clicked, [=]() {
+    connect(ui->fileLocatorDestination, &QAbstractButton::clicked, [this]() {
         setPath(ui->destinationPathEdit);
     });
 
@@ -170,7 +170,7 @@ BulkConverterDialog::BulkConverterDialog(QWidget *parent,
 
     convertButton()->setEnabled(false);
     convertButton()->setText(tr("Convert"));
-    connect(convertButton(), &QAbstractButton::clicked, [=](){ convert(); });
+    connect(convertButton(), &QAbstractButton::clicked, [this](){ convert(); });
     connect(ui->buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject);
 }
 

source/dialogs/infodialog.cpp

@@ -32,7 +32,7 @@ InfoDialog::InfoDialog(QWidget *parent) :
 
     setInfo();
 
-    connect(ui->copyToClipboardButton, &QAbstractButton::clicked, [=]() {
+    connect(ui->copyToClipboardButton, &QAbstractButton::clicked, [this]() {
         QClipboard *clipboard = QApplication::clipboard();
         clipboard->setText(ui->appInfo->toPlainText());
     });

source/dialogs/keysignaturedialog.cpp

@@ -40,10 +40,10 @@ KeySignatureDialog::KeySignatureDialog(QWidget *parent,
     else
         ui->minorKeyButton->setChecked(true);
 
-    connect(ui->majorKeyButton, &QAbstractButton::clicked, [=]() {
+    connect(ui->majorKeyButton, &QAbstractButton::clicked, [this]() {
         populateKeyTypes(KeySignature::Major);
     });
-    connect(ui->minorKeyButton, &QAbstractButton::clicked, [=]() {
+    connect(ui->minorKeyButton, &QAbstractButton::clicked, [this]() {
         populateKeyTypes(KeySignature::Minor);
     });
 

source/dialogs/viewfilterdialog.cpp

@@ -110,10 +110,10 @@ void ViewFilterDialog::update(const std::vector<std::string> &names,
             ui->filterRuleLayout->addWidget(widget);
 
             connect(widget, &FilterRuleWidget::changed,
-                    [=](const FilterRule &rule) {
+                    [=, this](const FilterRule &rule) {
                 myPresenter->editRule(i, rule);
             });
-            connect(widget, &FilterRuleWidget::removeRequested, [=]() {
+            connect(widget, &FilterRuleWidget::removeRequested, [=, this]() {
                 myPresenter->removeRule(i);
             });
         }

source/painters/caretpainter.cpp

@@ -39,7 +39,7 @@ CaretPainter::CaretPainter(const Caret &caret, const ViewOptions &view_options,
       myViewOptions(view_options),
       myPalette(palette),
       myCaretConnection(
-          caret.subscribeToChanges([=]() { onLocationChanged(); }))
+          caret.subscribeToChanges([this]() { onLocationChanged(); }))
 {
 }
 

source/widgets/clickablelabel.cpp

@@ -27,7 +27,7 @@ ClickableLabel::ClickableLabel(QWidget *parent)
 
 void ClickableLabel::enterEvent(QEvent *)
 {
-    setFrameStyle(QFrame::StyledPanel | QFrame::Raised);
+    setFrameStyle(static_cast<int>(QFrame::StyledPanel) | static_cast<int>(QFrame::Raised));
     setCursor(Qt::PointingHandCursor);
 }
 

source/widgets/instruments/instrumentpanel.cpp

@@ -38,9 +38,9 @@ void InstrumentPanel::reset(const Score &score)
     {
         auto item = new InstrumentPanelItem(this, i, score.getInstruments()[i]);
         connect(item, &InstrumentPanelItem::instrumentEdited,
-                [=](const Instrument &inst) { instrumentEdited(i, inst); });
+                [=, this](const Instrument &inst) { instrumentEdited(i, inst); });
         connect(item, &InstrumentPanelItem::instrumentRemoved,
-                [=]() { instrumentRemoved(i); });
+                [=, this]() { instrumentRemoved(i); });
 
         myLayout->addWidget(item);
     }

source/widgets/instruments/instrumentpanelitem.cpp

@@ -48,7 +48,7 @@ InstrumentPanelItem::InstrumentPanelItem(QWidget *parent, int instrumentIndex,
             ui->instrumentNameLabel, &QWidget::hide);
     connect(ui->instrumentNameLabel, &ClickableLabel::clicked,
             ui->instrumentNameEdit, &QWidget::show);
-    connect(ui->instrumentNameLabel, &ClickableLabel::clicked, [=]()
+    connect(ui->instrumentNameLabel, &ClickableLabel::clicked, [this]()
     { ui->instrumentNameEdit->setFocus(); });
 
     connect(ui->instrumentNameEdit, &QLineEdit::editingFinished, this,

source/widgets/mixer/mixer.cpp

@@ -39,10 +39,10 @@ void Mixer::reset(const Score &score)
     {
         auto item = new MixerItem(this, i, score.getPlayers()[i], myDictionary);
         connect(item, &MixerItem::playerEdited,
-                [=](const Player &player, bool undoable) {
+                [=, this](const Player &player, bool undoable) {
                     playerEdited(i, player, undoable);
                 });
-        connect(item, &MixerItem::playerRemoved, [=]() { playerRemoved(i); });
+        connect(item, &MixerItem::playerRemoved, [=, this]() { playerRemoved(i); });
         myLayout->addWidget(item);
     }
 }

source/widgets/mixer/mixeritem.cpp

@@ -52,17 +52,17 @@ MixerItem::MixerItem(QWidget *parent, int playerIndex, const Player &player,
             &QWidget::hide);
     connect(ui->playerNameLabel, &ClickableLabel::clicked, ui->playerNameEdit,
             &QWidget::show);
-    connect(ui->playerNameLabel, &ClickableLabel::clicked, [=]() {
+    connect(ui->playerNameLabel, &ClickableLabel::clicked, [this]() {
         ui->playerNameEdit->setFocus();
     });
 
     connect(ui->playerNameEdit, &QLineEdit::editingFinished, this,
             &MixerItem::onPlayerNameEdited);
 
-    connect(ui->playerVolume, &QSlider::valueChanged, [=]() {
+    connect(ui->playerVolume, &QSlider::valueChanged, [this]() {
         onEdited(false);
     });
-    connect(ui->playerPan, &QDial::valueChanged, [=]() {
+    connect(ui->playerPan, &QDial::valueChanged, [this]() {
         onEdited(false);
     });
 

source/widgets/playback/playbackwidget.cpp

@@ -258,7 +258,7 @@ PlaybackWidget::setupZoomComboBox(double initial_zoom)
     ui->zoomComboBox->setValidator(new PercentageValidator(ui->zoomComboBox));
 
     connect(ui->zoomComboBox, &QComboBox::currentTextChanged,
-            [=](const QString &text) {
+            [this](const QString &text) {
                 // Trigger an update for the stylesheet.
                 ui->zoomComboBox->style()->unpolish(ui->zoomComboBox);
                 ui->zoomComboBox->style()->polish(ui->zoomComboBox);