More Qt5 style connect conversions

src/app/qgisapp.h

@@ -798,6 +798,12 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
 
     void renameView();
 
+    void showProgress( int progress, int totalSteps );
+    void showStatusMessage( const QString &message );
+
+    //! set the active layer
+    bool setActiveLayer( QgsMapLayer * );
+
   protected:
 
     //! Handle state changes (WindowTitleChange)
@@ -1118,8 +1124,6 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     void showSelectedLayers();
     //! Return pointer to the active layer
     QgsMapLayer *activeLayer();
-    //! set the active layer
-    bool setActiveLayer( QgsMapLayer * );
     //! Open the help contents in a browser
     void helpContents();
     //! Open the API documentation in a browser
@@ -1263,10 +1267,9 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
 
     void selectionChanged( QgsMapLayer *layer );
 
-    void showProgress( int progress, int totalSteps );
     void extentChanged();
     void showRotation();
-    void showStatusMessage( const QString &message );
+
     void displayMapToolMessage( const QString &message, QgsMessageBar::MessageLevel level = QgsMessageBar::INFO );
     void displayMessage( const QString &title, const QString &message, QgsMessageBar::MessageLevel level );
     void removeMapToolMessage();

src/app/qgsbookmarks.cpp

@@ -56,13 +56,13 @@ QgsBookmarks::QgsBookmarks( QWidget *parent )
   QAction *btnImport = share->addAction( tr( "&Import" ) );
   btnExport->setIcon( QgsApplication::getThemeIcon( QStringLiteral( "/mActionSharingExport.svg" ) ) );
   btnImport->setIcon( QgsApplication::getThemeIcon( QStringLiteral( "/mActionSharingImport.svg" ) ) );
-  connect( btnExport, SIGNAL( triggered() ), this, SLOT( exportToXml() ) );
+  connect( btnExport, &QAction::triggered, this, &QgsBookmarks::exportToXml );
-  connect( btnImport, SIGNAL( triggered() ), this, SLOT( importFromXml() ) );
+  connect( btnImport, &QAction::triggered, this, &QgsBookmarks::importFromXml );
   btnImpExp->setMenu( share );
 
-  connect( actionAdd, SIGNAL( triggered() ), this, SLOT( addClicked() ) );
+  connect( actionAdd, &QAction::triggered, this, &QgsBookmarks::addClicked );
-  connect( actionDelete, SIGNAL( triggered() ), this, SLOT( deleteClicked() ) );
+  connect( actionDelete, &QAction::triggered, this, &QgsBookmarks::deleteClicked );
-  connect( actionZoomTo, SIGNAL( triggered() ), this, SLOT( zoomToBookmark() ) );
+  connect( actionZoomTo, &QAction::triggered, this, &QgsBookmarks::zoomToBookmark );
 
   mBookmarkToolbar->addWidget( btnImpExp );
 
@@ -394,9 +394,9 @@ void QgsBookmarks::exportToXml()
 
 QgsProjectBookmarksTableModel::QgsProjectBookmarksTableModel()
 {
-  QObject::connect(
+  connect(
-    QgisApp::instance(), SIGNAL( projectRead() ),
+    QgisApp::instance(), &QgisApp::projectRead,
-    this, SLOT( projectRead() ) );
+    this, &QgsProjectBookmarksTableModel::projectRead );
 }
 
 int QgsProjectBookmarksTableModel::rowCount( const QModelIndex &parent ) const
@@ -507,25 +507,25 @@ QgsMergedBookmarksTableModel::QgsMergedBookmarksTableModel( QAbstractTableModel
   , mProjectOpen( false )
 {
   connect(
-    QgisApp::instance(), SIGNAL( projectRead() ),
+    QgisApp::instance(), &QgisApp::projectRead,
-    this, SLOT( projectRead() ) );
+    this, &QgsMergedBookmarksTableModel::projectRead );
 
   connect(
-    &mQgisTableModel, SIGNAL( layoutChanged() ),
+    &mQgisTableModel, &QAbstractTableModel::layoutChanged,
-    this, SLOT( allLayoutChanged() ) );
+    this, &QgsMergedBookmarksTableModel::allLayoutChanged );
   connect(
-    &mQgisTableModel, SIGNAL( dataChanged( const QModelIndex &, const QModelIndex & ) ),
+    &mQgisTableModel, &QAbstractTableModel::dataChanged,
-    this, SLOT( qgisDataChanged( const QModelIndex &, const QModelIndex & ) ) );
+    this, &QgsMergedBookmarksTableModel::qgisDataChanged );
   connect(
-    &mQgisTableModel, SIGNAL( rowsInserted( const QModelIndex &, int, int ) ),
+    &mQgisTableModel, &QAbstractTableModel::rowsInserted,
-    this, SLOT( allLayoutChanged() ) );
+    this, &QgsMergedBookmarksTableModel::allLayoutChanged );
   connect(
-    &mQgisTableModel, SIGNAL( rowsRemoved( const QModelIndex &, int, int ) ),
+    &mQgisTableModel, &QAbstractTableModel::rowsRemoved,
-    this, SLOT( allLayoutChanged() ) );
+    this, &QgsMergedBookmarksTableModel::allLayoutChanged );
 
   connect(
-    &projectTableModel, SIGNAL( layoutChanged() ),
+    &projectTableModel, &QAbstractTableModel::layoutChanged,
-    this, SLOT( allLayoutChanged() ) );
+    this, &QgsMergedBookmarksTableModel::allLayoutChanged );
 }
 
 int QgsMergedBookmarksTableModel::rowCount( const QModelIndex &parent ) const

src/app/qgsbookmarks.h

@@ -84,8 +84,8 @@ class QgsMergedBookmarksTableModel: public QAbstractTableModel
     void moveBookmark( QAbstractTableModel &modelFrom, QAbstractTableModel &modelTo, int row );
 
   private slots:
-    void projectRead() { mProjectOpen = true; };
+    void projectRead() { mProjectOpen = true; }
-    void allLayoutChanged() { emit layoutChanged(); };
+    void allLayoutChanged() { emit layoutChanged(); }
     void qgisDataChanged( const QModelIndex &topLeft, const QModelIndex &bottomRight )
     {
       emit dataChanged( topLeft, bottomRight );

src/app/qgsclipboard.cpp

@@ -43,7 +43,7 @@ QgsClipboard::QgsClipboard()
   , mFeatureFields()
   , mUseSystemClipboard( false )
 {
-  connect( QApplication::clipboard(), SIGNAL( dataChanged() ), this, SLOT( systemClipboardChanged() ) );
+  connect( QApplication::clipboard(), &QClipboard::dataChanged, this, &QgsClipboard::systemClipboardChanged );
 }
 
 QgsClipboard::~QgsClipboard()

src/app/qgscustomization.cpp

@@ -57,10 +57,10 @@ QgsCustomizationDialog::QgsCustomizationDialog( QWidget * parent, QSettings * se
 
   mLastDirSettingsName  = QStringLiteral( "/UI/lastCustomizationDir" );
   //treeWidget->hideColumn(0)
-  connect( buttonBox->button( QDialogButtonBox::Ok ), SIGNAL( clicked() ), this, SLOT( ok() ) );
+  connect( buttonBox->button( QDialogButtonBox::Ok ), &QAbstractButton::clicked, this, &QgsCustomizationDialog::ok );
-  connect( buttonBox->button( QDialogButtonBox::Apply ), SIGNAL( clicked() ), this, SLOT( apply() ) );
+  connect( buttonBox->button( QDialogButtonBox::Apply ), &QAbstractButton::clicked, this, &QgsCustomizationDialog::apply );
-  connect( buttonBox->button( QDialogButtonBox::Cancel ), SIGNAL( clicked() ), this, SLOT( cancel() ) );
+  connect( buttonBox->button( QDialogButtonBox::Cancel ), &QAbstractButton::clicked, this, &QgsCustomizationDialog::cancel );
-  connect( buttonBox->button( QDialogButtonBox::Reset ), SIGNAL( clicked() ), this, SLOT( reset() ) );
+  connect( buttonBox->button( QDialogButtonBox::Reset ), &QAbstractButton::clicked, this, &QgsCustomizationDialog::reset );
 
 }
 

src/app/qgsdecorationcopyrightdialog.cpp

@@ -33,7 +33,7 @@ QgsDecorationCopyrightDialog::QgsDecorationCopyrightDialog( QgsDecorationCopyrig
   restoreGeometry( settings.value( QStringLiteral( "Windows/DecorationCopyright/geometry" ) ).toByteArray() );
 
   QPushButton *applyButton = buttonBox->button( QDialogButtonBox::Apply );
-  connect( applyButton, SIGNAL( clicked() ), this, SLOT( apply() ) );
+  connect( applyButton, &QAbstractButton::clicked, this, &QgsDecorationCopyrightDialog::apply );
 
   grpEnable->setChecked( mDeco.enabled() );
   // text

src/app/qgsdecorationgriddialog.cpp

@@ -61,7 +61,7 @@ QgsDecorationGridDialog::QgsDecorationGridDialog( QgsDecorationGrid &deco, QWidg
 
   updateGuiElements();
 
-  connect( buttonBox->button( QDialogButtonBox::Apply ), SIGNAL( clicked() ), this, SLOT( apply() ) );
+  connect( buttonBox->button( QDialogButtonBox::Apply ), &QAbstractButton::clicked, this, &QgsDecorationGridDialog::apply );
 
 }
 

src/app/qgsdecorationnortharrowdialog.cpp

@@ -31,7 +31,7 @@ QgsDecorationNorthArrowDialog::QgsDecorationNorthArrowDialog( QgsDecorationNorth
   restoreGeometry( settings.value( QStringLiteral( "Windows/DecorationNorthArrow/geometry" ) ).toByteArray() );
 
   QPushButton *applyButton = buttonBox->button( QDialogButtonBox::Apply );
-  connect( applyButton, SIGNAL( clicked() ), this, SLOT( apply() ) );
+  connect( applyButton, &QAbstractButton::clicked, this, &QgsDecorationNorthArrowDialog::apply );
 
   // rotation
   rotatePixmap( mDeco.mRotationInt );

src/app/qgsdecorationscalebardialog.cpp

@@ -30,7 +30,7 @@ QgsDecorationScaleBarDialog::QgsDecorationScaleBarDialog( QgsDecorationScaleBar
   restoreGeometry( settings.value( QStringLiteral( "Windows/DecorationScaleBar/geometry" ) ).toByteArray() );
 
   QPushButton *applyButton = buttonBox->button( QDialogButtonBox::Apply );
-  connect( applyButton, SIGNAL( clicked() ), this, SLOT( apply() ) );
+  connect( applyButton, &QAbstractButton::clicked, this, &QgsDecorationScaleBarDialog::apply );
 
   // set the map units in the spin box
   spnSize->setShowClearButton( false );

src/app/qgsdxfexportdialog.cpp

@@ -440,10 +440,10 @@ QgsDxfExportDialog::QgsDxfExportDialog( QWidget *parent, Qt::WindowFlags f )
   mTreeView->resizeColumnToContents( 0 );
   mTreeView->header()->show();
 
-  connect( mFileLineEdit, SIGNAL( textChanged( const QString & ) ), this, SLOT( setOkEnabled() ) );
+  connect( mFileLineEdit, &QLineEdit::textChanged, this, &QgsDxfExportDialog::setOkEnabled );
-  connect( this, SIGNAL( accepted() ), this, SLOT( saveSettings() ) );
+  connect( this, &QDialog::accepted, this, &QgsDxfExportDialog::saveSettings );
-  connect( mSelectAllButton, SIGNAL( clicked() ), this, SLOT( selectAll() ) );
+  connect( mSelectAllButton, &QAbstractButton::clicked, this, &QgsDxfExportDialog::selectAll );
-  connect( mDeselectAllButton, SIGNAL( clicked() ), this, SLOT( deSelectAll() ) );
+  connect( mDeselectAllButton, &QAbstractButton::clicked, this, &QgsDxfExportDialog::deSelectAll );
 
   mFileLineEdit->setFocus();
 

src/app/qgsfeatureaction.cpp

@@ -84,11 +84,11 @@ QgsAttributeDialog *QgsFeatureAction::newDialog( bool cloneFeature )
       QgsFeature &feat = const_cast<QgsFeature &>( *dialog->feature() );
       QgsFeatureAction *a = new QgsFeatureAction( action.name(), feat, mLayer, action.id(), -1, dialog );
       dialog->addAction( a );
-      connect( a, SIGNAL( triggered() ), a, SLOT( execute() ) );
+      connect( a, &QAction::triggered, a, &QgsFeatureAction::execute );
 
       QAbstractButton *pb = dialog->findChild<QAbstractButton *>( action.name() );
       if ( pb )
-        connect( pb, SIGNAL( clicked() ), a, SLOT( execute() ) );
+        connect( pb, &QAbstractButton::clicked, a, &QgsFeatureAction::execute );
     }
   }
 
@@ -207,7 +207,7 @@ bool QgsFeatureAction::addFeature( const QgsAttributeMap &defaultAttributes, boo
     dialog->setMode( QgsAttributeForm::AddFeatureMode );
     dialog->setEditCommandMessage( text() );
 
-    connect( dialog->attributeForm(), SIGNAL( featureSaved( const QgsFeature & ) ), this, SLOT( onFeatureSaved( const QgsFeature & ) ) );
+    connect( dialog->attributeForm(), &QgsAttributeForm::featureSaved, this, &QgsFeatureAction::onFeatureSaved );
 
     if ( !showModal )
     {

src/app/qgsfieldcalculator.cpp

@@ -51,8 +51,8 @@ QgsFieldCalculator::QgsFieldCalculator( QgsVectorLayer *vl, QWidget *parent )
   populateFields();
   populateOutputFieldTypes();
 
-  connect( builder, SIGNAL( expressionParsed( bool ) ), this, SLOT( setOkButtonState() ) );
+  connect( builder, &QgsExpressionBuilderWidget::expressionParsed, this, &QgsFieldCalculator::setOkButtonState );
-  connect( mOutputFieldWidthSpinBox, SIGNAL( editingFinished() ), this, SLOT( setPrecisionMinMax() ) );
+  connect( mOutputFieldWidthSpinBox, &QAbstractSpinBox::editingFinished, this, &QgsFieldCalculator::setPrecisionMinMax );
 
   QgsDistanceArea myDa;
   myDa.setSourceCrs( vl->crs() );

src/app/qgsfieldsproperties.cpp

@@ -63,11 +63,11 @@ QgsFieldsProperties::QgsFieldsProperties( QgsVectorLayer *layer, QWidget *parent
   mToggleEditingButton->setIcon( QgsApplication::getThemeIcon( QStringLiteral( "/mActionToggleEditing.svg" ) ) );
   mCalculateFieldButton->setIcon( QgsApplication::getThemeIcon( QStringLiteral( "/mActionCalculateField.svg" ) ) );
 
-  connect( mToggleEditingButton, SIGNAL( clicked() ), this, SIGNAL( toggleEditing() ) );
+  connect( mToggleEditingButton, &QAbstractButton::clicked, this, &QgsFieldsProperties::toggleEditing );
-  connect( mLayer, SIGNAL( editingStarted() ), this, SLOT( editingToggled() ) );
+  connect( mLayer, &QgsVectorLayer::editingStarted, this, &QgsFieldsProperties::editingToggled );
-  connect( mLayer, SIGNAL( editingStopped() ), this, SLOT( editingToggled() ) );
+  connect( mLayer, &QgsVectorLayer::editingStopped, this, &QgsFieldsProperties::editingToggled );
-  connect( mLayer, SIGNAL( attributeAdded( int ) ), this, SLOT( attributeAdded( int ) ) );
+  connect( mLayer, &QgsVectorLayer::attributeAdded, this, &QgsFieldsProperties::attributeAdded );
-  connect( mLayer, SIGNAL( attributeDeleted( int ) ), this, SLOT( attributeDeleted( int ) ) );
+  connect( mLayer, &QgsVectorLayer::attributeDeleted, this, &QgsFieldsProperties::attributeDeleted );
 
   // tab and group display
   mAddItemButton->setEnabled( false );
@@ -100,8 +100,8 @@ QgsFieldsProperties::QgsFieldsProperties( QgsVectorLayer *layer, QWidget *parent
   mFieldsList->setSelectionMode( QAbstractItemView::ExtendedSelection );
   mFieldsList->verticalHeader()->hide();
 
-  connect( mDesignerTree, SIGNAL( itemSelectionChanged() ), this, SLOT( onAttributeSelectionChanged() ) );
+  connect( mDesignerTree, &QTreeWidget::itemSelectionChanged, this, &QgsFieldsProperties::onAttributeSelectionChanged );
-  connect( mFieldsList, SIGNAL( itemSelectionChanged() ), this, SLOT( onAttributeSelectionChanged() ) );
+  connect( mFieldsList, &QTableWidget::itemSelectionChanged, this, &QgsFieldsProperties::onAttributeSelectionChanged );
 
   mRelationsList = new DragList( mRelationsFrame );
   mRelationsFrameLayout->addWidget( mRelationsList );
@@ -262,7 +262,7 @@ void QgsFieldsProperties::loadAttributeEditorTree()
 
 void QgsFieldsProperties::loadRows()
 {
-  disconnect( mFieldsList, SIGNAL( cellChanged( int, int ) ), this, SLOT( attributesListCellChanged( int, int ) ) );
+  disconnect( mFieldsList, &QTableWidget::cellChanged, this, &QgsFieldsProperties::attributesListCellChanged );
   const QgsFields &fields = mLayer->fields();
 
   mIndexedWidgets.clear();
@@ -272,7 +272,7 @@ void QgsFieldsProperties::loadRows()
     attributeAdded( i );
 
   mFieldsList->resizeColumnsToContents();
-  connect( mFieldsList, SIGNAL( cellChanged( int, int ) ), this, SLOT( attributesListCellChanged( int, int ) ) );
+  connect( mFieldsList, &QTableWidget::cellChanged, this, &QgsFieldsProperties::attributesListCellChanged );
   updateFieldRenamingStatus();
 }
 
@@ -310,7 +310,7 @@ void QgsFieldsProperties::setRow( int row, int idx, const QgsField &field )
     QToolButton *editExpressionButton = new QToolButton;
     editExpressionButton->setProperty( "Index", idx );
     editExpressionButton->setIcon( QgsApplication::getThemeIcon( QStringLiteral( "/mIconExpression.svg" ) ) );
-    connect( editExpressionButton, SIGNAL( clicked() ), this, SLOT( updateExpression() ) );
+    connect( editExpressionButton, &QAbstractButton::clicked, this, &QgsFieldsProperties::updateExpression );
     expressionWidget->layout()->setContentsMargins( 0, 0, 0, 0 );
     expressionWidget->layout()->addWidget( editExpressionButton );
     expressionWidget->layout()->addWidget( new QLabel( mLayer->expressionField( idx ) ) );
@@ -343,7 +343,7 @@ void QgsFieldsProperties::setRow( int row, int idx, const QgsField &field )
   cfg.mButton = pb;
   mFieldsList->setCellWidget( row, AttrEditTypeCol, pb );
 
-  connect( pb, SIGNAL( pressed() ), this, SLOT( attributeTypeDialog() ) );
+  connect( pb, &QAbstractButton::pressed, this, &QgsFieldsProperties::attributeTypeDialog );
 
   setConfigForRow( row, cfg );
 
@@ -1167,7 +1167,7 @@ DesignerTree::DesignerTree( QgsVectorLayer *layer, QWidget *parent )
   : QTreeWidget( parent )
   , mLayer( layer )
 {
-  connect( this, SIGNAL( itemDoubleClicked( QTreeWidgetItem *, int ) ), this, SLOT( onItemDoubleClicked( QTreeWidgetItem *, int ) ) );
+  connect( this, &QTreeWidget::itemDoubleClicked, this, &DesignerTree::onItemDoubleClicked );
 }
 
 QTreeWidgetItem *DesignerTree::addItem( QTreeWidgetItem *parent, QgsFieldsProperties::DesignerTreeItemData data )
@@ -1370,8 +1370,8 @@ void DesignerTree::onItemDoubleClicked( QTreeWidgetItem *item, int column )
     QDialogButtonBox *buttonBox = new QDialogButtonBox( QDialogButtonBox::Ok
         | QDialogButtonBox::Cancel );
 
-    connect( buttonBox, SIGNAL( accepted() ), &dlg, SLOT( accept() ) );
+    connect( buttonBox, &QDialogButtonBox::accepted, &dlg, &QDialog::accept );
-    connect( buttonBox, SIGNAL( rejected() ), &dlg, SLOT( reject() ) );
+    connect( buttonBox, &QDialogButtonBox::rejected, &dlg, &QDialog::reject );
 
     layout->addWidget( buttonBox );
 
@@ -1408,8 +1408,8 @@ void DesignerTree::onItemDoubleClicked( QTreeWidgetItem *item, int column )
 
     QDialogButtonBox *buttonBox = new QDialogButtonBox( QDialogButtonBox::Ok | QDialogButtonBox::Cancel );
 
-    connect( buttonBox, SIGNAL( accepted() ), &dlg, SLOT( accept() ) );
+    connect( buttonBox, &QDialogButtonBox::accepted, &dlg, &QDialog::accept );
-    connect( buttonBox, SIGNAL( rejected() ), &dlg, SLOT( reject() ) );
+    connect( buttonBox, &QDialogButtonBox::rejected, &dlg, &QDialog::reject );
 
     dlg.layout()->addWidget( buttonBox );
 
@@ -1434,8 +1434,8 @@ void DesignerTree::onItemDoubleClicked( QTreeWidgetItem *item, int column )
     QDialogButtonBox *buttonBox = new QDialogButtonBox( QDialogButtonBox::Ok
         | QDialogButtonBox::Cancel );
 
-    connect( buttonBox, SIGNAL( accepted() ), &dlg, SLOT( accept() ) );
+    connect( buttonBox, &QDialogButtonBox::accepted, &dlg, &QDialog::accept );
-    connect( buttonBox, SIGNAL( rejected() ), &dlg, SLOT( reject() ) );
+    connect( buttonBox, &QDialogButtonBox::rejected, &dlg, &QDialog::reject );
 
     dlg.layout()->addWidget( buttonBox );
 

src/app/qgsguivectorlayertools.cpp

@@ -178,8 +178,8 @@ void QgsGuiVectorLayerTools::commitError( QgsVectorLayer *vlayer ) const
   showMore->setSizePolicy( QSizePolicy::Maximum, QSizePolicy::Preferred );
   showMore->addAction( act );
   showMore->setDefaultAction( act );
-  connect( showMore, SIGNAL( triggered( QAction * ) ), mv, SLOT( exec() ) );
+  connect( showMore, &QToolButton::triggered, mv, &QDialog::exec );
-  connect( showMore, SIGNAL( triggered( QAction * ) ), showMore, SLOT( deleteLater() ) );
+  connect( showMore, &QToolButton::triggered, showMore, &QObject::deleteLater );
 
   // no timeout set, since notice needs attention and is only shown first time layer is labeled
   QgsMessageBarItem *errorMsg = new QgsMessageBarItem(

src/app/qgshandlebadlayers.cpp

@@ -72,9 +72,9 @@ QgsHandleBadLayers::QgsHandleBadLayers( const QList<QDomNode> &layers )
   buttonBox->addButton( mBrowseButton, QDialogButtonBox::ActionRole );
   mBrowseButton->setDisabled( true );
 
-  connect( mLayerList, SIGNAL( itemSelectionChanged() ), this, SLOT( selectionChanged() ) );
+  connect( mLayerList, &QTableWidget::itemSelectionChanged, this, &QgsHandleBadLayers::selectionChanged );
-  connect( mBrowseButton, SIGNAL( clicked() ), this, SLOT( browseClicked() ) );
+  connect( mBrowseButton, &QAbstractButton::clicked, this, &QgsHandleBadLayers::browseClicked );
-  connect( buttonBox->button( QDialogButtonBox::Apply ), SIGNAL( clicked() ), this, SLOT( apply() ) );
+  connect( buttonBox->button( QDialogButtonBox::Apply ), &QAbstractButton::clicked, this, &QgsHandleBadLayers::apply );
 
   mLayerList->clear();
   mLayerList->setSortingEnabled( true );
@@ -133,7 +133,7 @@ QgsHandleBadLayers::QgsHandleBadLayers( const QList<QDomNode> &layers )
       btn->setMinimumHeight( 24 );
       btn->setText( tr( "Edit" ) );
       btn->setProperty( "row", j );
-      connect( btn, SIGNAL( clicked() ), this, SLOT( editAuthCfg() ) );
+      connect( btn, &QAbstractButton::clicked, this, &QgsHandleBadLayers::editAuthCfg );
       mLayerList->setCellWidget( j, 3, btn );
     }
     else

src/app/qgsidentifyresultsdialog.cpp

@@ -89,8 +89,8 @@ QgsIdentifyResultsWebView::QgsIdentifyResultsWebView( QWidget *parent ) : QgsWeb
 #ifdef QGISDEBUG
   settings()->setAttribute( QWebSettings::DeveloperExtrasEnabled, true );
 #endif
-  connect( page(), SIGNAL( downloadRequested( QNetworkRequest ) ), this, SLOT( downloadRequested( QNetworkRequest ) ) );
+  connect( page(), &QWebPage::downloadRequested, this, &QgsIdentifyResultsWebView::downloadRequested );
-  connect( page(), SIGNAL( unsupportedContent( QNetworkReply * ) ), this, SLOT( unsupportedContent( QNetworkReply * ) ) );
+  connect( page(), &QWebPage::unsupportedContent, this, &QgsIdentifyResultsWebView::unsupportedContent );
 }
 
 
@@ -153,7 +153,7 @@ void QgsIdentifyResultsWebView::contextMenuEvent( QContextMenuEvent *e )
     return;
 
   QAction *action = new QAction( tr( "Print" ), this );
-  connect( action, SIGNAL( triggered() ), this, SLOT( print() ) );
+  connect( action, &QAction::triggered, this, &QgsIdentifyResultsWebView::print );
   menu->addAction( action );
   menu->exec( e->globalPos() );
   delete menu;
@@ -272,7 +272,7 @@ QgsIdentifyResultsWebViewItem::QgsIdentifyResultsWebViewItem( QTreeWidget *treeW
   mWebView = new QgsIdentifyResultsWebView( treeWidget );
   mWebView->hide();
   setText( 0, tr( "Loading..." ) );
-  connect( mWebView->page(), SIGNAL( loadFinished( bool ) ), this, SLOT( loadFinished( bool ) ) );
+  connect( mWebView->page(), &QWebPage::loadFinished, this, &QgsIdentifyResultsWebViewItem::loadFinished );
 }
 
 void QgsIdentifyResultsWebViewItem::loadFinished( bool ok )
@@ -285,7 +285,7 @@ void QgsIdentifyResultsWebViewItem::loadFinished( bool ok )
   // Span columns to save some space, must be after setItemWidget() to take effect.
   setFirstColumnSpanned( true );
 
-  disconnect( mWebView->page(), SIGNAL( loadFinished( bool ) ), this, SLOT( loadFinished( bool ) ) );
+  disconnect( mWebView->page(), &QWebPage::loadFinished, this, &QgsIdentifyResultsWebViewItem::loadFinished );
 
 }
 
@@ -389,19 +389,19 @@ QgsIdentifyResultsDialog::QgsIdentifyResultsDialog( QgsMapCanvas *canvas, QWidge
   mPlot->setSizePolicy( sizePolicy );
   mPlot->updateGeometry();
 
-  connect( lstResults, SIGNAL( itemExpanded( QTreeWidgetItem * ) ),
+  connect( lstResults, &QTreeWidget::itemExpanded,
-           this, SLOT( itemExpanded( QTreeWidgetItem * ) ) );
+           this, &QgsIdentifyResultsDialog::itemExpanded );
 
-  connect( lstResults, SIGNAL( currentItemChanged( QTreeWidgetItem *, QTreeWidgetItem * ) ),
+  connect( lstResults, &QTreeWidget::currentItemChanged,
-           this, SLOT( handleCurrentItemChanged( QTreeWidgetItem *, QTreeWidgetItem * ) ) );
+           this, &QgsIdentifyResultsDialog::handleCurrentItemChanged );
 
-  connect( lstResults, SIGNAL( itemClicked( QTreeWidgetItem *, int ) ),
+  connect( lstResults, &QTreeWidget::itemClicked,
-           this, SLOT( itemClicked( QTreeWidgetItem *, int ) ) );
+           this, &QgsIdentifyResultsDialog::itemClicked );
 
-  connect( mActionPrint, SIGNAL( triggered( bool ) ), this, SLOT( printCurrentItem() ) );
+  connect( mActionPrint, &QAction::triggered, this, &QgsIdentifyResultsDialog::printCurrentItem );
-  connect( mOpenFormAction, SIGNAL( triggered( bool ) ), this, SLOT( featureForm() ) );
+  connect( mOpenFormAction, &QAction::triggered, this, &QgsIdentifyResultsDialog::featureForm );
-  connect( mClearResultsAction, SIGNAL( triggered( bool ) ), this, SLOT( clear() ) );
+  connect( mClearResultsAction, &QAction::triggered, this, &QgsIdentifyResultsDialog::clear );
-  connect( mHelpToolButton, SIGNAL( clicked() ), this, SLOT( helpRequested() ) );
+  connect( mHelpToolButton, &QAbstractButton::clicked, this, &QgsIdentifyResultsDialog::helpRequested );
 }
 
 QgsIdentifyResultsDialog::~QgsIdentifyResultsDialog()
@@ -453,13 +453,13 @@ void QgsIdentifyResultsDialog::addFeature( QgsVectorLayer *vlayer, const QgsFeat
     layItem->setData( 0, Qt::UserRole, QVariant::fromValue( qobject_cast<QObject *>( vlayer ) ) );
     lstResults->addTopLevelItem( layItem );
 
-    connect( vlayer, SIGNAL( destroyed() ), this, SLOT( layerDestroyed() ) );
+    connect( vlayer, &QObject::destroyed, this, &QgsIdentifyResultsDialog::layerDestroyed );
-    connect( vlayer, SIGNAL( crsChanged() ), this, SLOT( layerDestroyed() ) );
+    connect( vlayer, &QgsMapLayer::crsChanged, this, &QgsIdentifyResultsDialog::layerDestroyed );
-    connect( vlayer, SIGNAL( featureDeleted( QgsFeatureId ) ), this, SLOT( featureDeleted( QgsFeatureId ) ) );
+    connect( vlayer, &QgsVectorLayer::featureDeleted, this, &QgsIdentifyResultsDialog::featureDeleted );
-    connect( vlayer, SIGNAL( attributeValueChanged( QgsFeatureId, int, const QVariant & ) ),
+    connect( vlayer, &QgsVectorLayer::attributeValueChanged,
-             this, SLOT( attributeValueChanged( QgsFeatureId, int, const QVariant & ) ) );
+             this, &QgsIdentifyResultsDialog::attributeValueChanged );
-    connect( vlayer, SIGNAL( editingStarted() ), this, SLOT( editingToggled() ) );
+    connect( vlayer, &QgsVectorLayer::editingStarted, this, &QgsIdentifyResultsDialog::editingToggled );
-    connect( vlayer, SIGNAL( editingStopped() ), this, SLOT( editingToggled() ) );
+    connect( vlayer, &QgsVectorLayer::editingStopped, this, &QgsIdentifyResultsDialog::editingToggled );
   }
 
   QgsIdentifyResultsFeatureItem *featItem = new QgsIdentifyResultsFeatureItem( vlayer->fields(), f, vlayer->crs() );
@@ -522,7 +522,7 @@ void QgsIdentifyResultsDialog::addFeature( QgsVectorLayer *vlayer, const QgsFeat
       twi->setData( 0, Qt::UserRole + 1, qVariantFromValue( qobject_cast<QObject *>( action ) ) );
       actionItem->addChild( twi );
 
-      connect( action, SIGNAL( destroyed() ), this, SLOT( mapLayerActionDestroyed() ) );
+      connect( action, &QObject::destroyed, this, &QgsIdentifyResultsDialog::mapLayerActionDestroyed );
     }
   }
 
@@ -798,15 +798,16 @@ void QgsIdentifyResultsDialog::addFeature( QgsRasterLayer *layer,
       QTreeWidgetItem *formatItem = new QTreeWidgetItem( QStringList() << ' ' + tr( "Format" ) );
       layItem->addChild( formatItem );
       lstResults->setItemWidget( formatItem, 1, formatCombo );
-      connect( formatCombo, SIGNAL( currentIndexChanged( int ) ), this, SLOT( formatChanged( int ) ) );
+      connect( formatCombo, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ),
+               this, static_cast<void ( QgsIdentifyResultsDialog::* )( int )>( &QgsIdentifyResultsDialog::formatChanged ) );
     }
     else
     {
       delete formatCombo;
     }
 
-    connect( layer, SIGNAL( destroyed() ), this, SLOT( layerDestroyed() ) );
+    connect( layer, &QObject::destroyed, this, &QgsIdentifyResultsDialog::layerDestroyed );
-    connect( layer, SIGNAL( crsChanged() ), this, SLOT( layerDestroyed() ) );
+    connect( layer, &QgsMapLayer::crsChanged, this, &QgsIdentifyResultsDialog::layerDestroyed );
   }
   // Set/reset getFeatureInfoUrl (currently only available for Feature, so it may change if format changes)
   layItem->setData( 0, GetFeatureInfoUrlRole, params.value( QStringLiteral( "getFeatureInfoUrl" ) ) );
@@ -1481,14 +1482,14 @@ void QgsIdentifyResultsDialog::disconnectLayer( QObject *layer )
   QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( layer );
   if ( vlayer )
   {
-    disconnect( vlayer, SIGNAL( featureDeleted( QgsFeatureId ) ), this, SLOT( featureDeleted( QgsFeatureId ) ) );
+    disconnect( vlayer, &QgsVectorLayer::featureDeleted, this, &QgsIdentifyResultsDialog::featureDeleted );
-    disconnect( vlayer, SIGNAL( attributeValueChanged( QgsFeatureId, int, const QVariant & ) ),
+    disconnect( vlayer, &QgsVectorLayer::attributeValueChanged,
-                this, SLOT( attributeValueChanged( QgsFeatureId, int, const QVariant & ) ) );
+                this, &QgsIdentifyResultsDialog::attributeValueChanged );
-    disconnect( vlayer, SIGNAL( editingStarted() ), this, SLOT( editingToggled() ) );
+    disconnect( vlayer, &QgsVectorLayer::editingStarted, this, &QgsIdentifyResultsDialog::editingToggled );
-    disconnect( vlayer, SIGNAL( editingStopped() ), this, SLOT( editingToggled() ) );
+    disconnect( vlayer, &QgsVectorLayer::editingStopped, this, &QgsIdentifyResultsDialog::editingToggled );
   }
 
-  disconnect( layer, SIGNAL( destroyed() ), this, SLOT( layerDestroyed() ) );
+  disconnect( layer, &QObject::destroyed, this, &QgsIdentifyResultsDialog::layerDestroyed );
 }
 
 void QgsIdentifyResultsDialog::featureDeleted( QgsFeatureId fid )
@@ -1742,9 +1743,11 @@ void QgsIdentifyResultsDialog::layerProperties()
 
 void QgsIdentifyResultsDialog::activateLayer()
 {
-  connect( this, SIGNAL( activateLayer( QgsMapLayer * ) ), QgisApp::instance(), SLOT( setActiveLayer( QgsMapLayer * ) ) );
+  connect( this, static_cast<void ( QgsIdentifyResultsDialog::* )( QgsMapLayer * )>( &QgsIdentifyResultsDialog::activateLayer )
+           , QgisApp::instance(), &QgisApp::setActiveLayer );
   emit activateLayer( layer( lstResults->currentItem() ) );
-  disconnect( this, SIGNAL( activateLayer( QgsMapLayer * ) ), QgisApp::instance(), SLOT( setActiveLayer( QgsMapLayer * ) ) );
+  disconnect( this, static_cast<void ( QgsIdentifyResultsDialog::* )( QgsMapLayer * )>( &QgsIdentifyResultsDialog::activateLayer ),
+              QgisApp::instance(), &QgisApp::setActiveLayer );
 }
 
 void QgsIdentifyResultsDialog::layerProperties( QTreeWidgetItem *item )

src/app/qgsjoindialog.cpp

@@ -57,8 +57,8 @@ QgsJoinDialog::QgsJoinDialog( QgsVectorLayer *layer, QList<QgsMapLayer *> alread
   }
 
   connect( mJoinLayerComboBox, &QgsMapLayerComboBox::layerChanged, this, &QgsJoinDialog::checkDefinitionValid );
-  connect( mJoinFieldComboBox, SIGNAL( fieldChanged( QString ) ), this, SLOT( checkDefinitionValid() ) );
+  connect( mJoinFieldComboBox, &QgsFieldComboBox::fieldChanged, this, &QgsJoinDialog::checkDefinitionValid );
-  connect( mTargetFieldComboBox, SIGNAL( fieldChanged( QString ) ), this, SLOT( checkDefinitionValid() ) );
+  connect( mTargetFieldComboBox, &QgsFieldComboBox::fieldChanged, this, &QgsJoinDialog::checkDefinitionValid );
 
   checkDefinitionValid();
 }

src/app/qgslabelengineconfigdialog.cpp

@@ -26,9 +26,9 @@ QgsLabelEngineConfigDialog::QgsLabelEngineConfigDialog( QWidget *parent )
 {
   setupUi( this );
 
-  connect( buttonBox, SIGNAL( accepted() ), this, SLOT( onOK() ) );
+  connect( buttonBox, &QDialogButtonBox::accepted, this, &QgsLabelEngineConfigDialog::onOK );
-  connect( buttonBox->button( QDialogButtonBox::RestoreDefaults ), SIGNAL( clicked() ),
+  connect( buttonBox->button( QDialogButtonBox::RestoreDefaults ), &QAbstractButton::clicked,
-           this, SLOT( setDefaults() ) );
+           this, &QgsLabelEngineConfigDialog::setDefaults );
 
   QgsLabelingEngine engine;
   engine.readSettingsFromProject( QgsProject::instance() );

src/app/qgslabelinggui.cpp

@@ -63,13 +63,13 @@ QgsLabelingGui::QgsLabelingGui( QgsVectorLayer *layer, QgsMapCanvas *mapCanvas,
   , mMode( NoLabels )
 {
   // connections for groupboxes with separate activation checkboxes (that need to honor data defined setting)
-  connect( mBufferDrawChkBx, SIGNAL( toggled( bool ) ), this, SLOT( updateUi() ) );
+  connect( mBufferDrawChkBx, &QAbstractButton::toggled, this, &QgsLabelingGui::updateUi );
-  connect( mShapeDrawChkBx, SIGNAL( toggled( bool ) ), this, SLOT( updateUi() ) );
+  connect( mShapeDrawChkBx, &QAbstractButton::toggled, this, &QgsLabelingGui::updateUi );
-  connect( mShadowDrawChkBx, SIGNAL( toggled( bool ) ), this, SLOT( updateUi() ) );
+  connect( mShadowDrawChkBx, &QAbstractButton::toggled, this, &QgsLabelingGui::updateUi );
-  connect( mDirectSymbChkBx, SIGNAL( toggled( bool ) ), this, SLOT( updateUi() ) );
+  connect( mDirectSymbChkBx, &QAbstractButton::toggled, this, &QgsLabelingGui::updateUi );
-  connect( mFormatNumChkBx, SIGNAL( toggled( bool ) ), this, SLOT( updateUi() ) );
+  connect( mFormatNumChkBx, &QAbstractButton::toggled, this, &QgsLabelingGui::updateUi );
-  connect( mScaleBasedVisibilityChkBx, SIGNAL( toggled( bool ) ), this, SLOT( updateUi() ) );
+  connect( mScaleBasedVisibilityChkBx, &QAbstractButton::toggled, this, &QgsLabelingGui::updateUi );
-  connect( mFontLimitPixelChkBox, SIGNAL( toggled( bool ) ), this, SLOT( updateUi() ) );
+  connect( mFontLimitPixelChkBox, &QAbstractButton::toggled, this, &QgsLabelingGui::updateUi );
 
   mFieldExpressionWidget->registerExpressionContextGenerator( this );
 

src/app/qgslabelingwidget.cpp

@@ -33,14 +33,14 @@ QgsLabelingWidget::QgsLabelingWidget( QgsVectorLayer *layer, QgsMapCanvas *canva
 {
   setupUi( this );
 
-  connect( mEngineSettingsButton, SIGNAL( clicked() ), this, SLOT( showEngineConfigDialog() ) );
+  connect( mEngineSettingsButton, &QAbstractButton::clicked, this, &QgsLabelingWidget::showEngineConfigDialog );
 
   mLabelModeComboBox->setCurrentIndex( -1 );
   mLabelGui = new QgsLabelingGui( nullptr, mCanvas, nullptr, this );
   mStackedWidget->addWidget( mLabelGui );
 
-  connect( mLabelModeComboBox, SIGNAL( currentIndexChanged( int ) ), this, SLOT( labelModeChanged( int ) ) );
+  connect( mLabelModeComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsLabelingWidget::labelModeChanged );
-  connect( mLabelGui, SIGNAL( widgetChanged() ), this, SIGNAL( widgetChanged() ) );
+  connect( mLabelGui, &QgsTextFormatWidget::widgetChanged, this, &QgsLabelingWidget::widgetChanged );
   setLayer( layer );
 }
 

src/app/qgslayerstylingwidget.cpp

@@ -58,7 +58,7 @@ QgsLayerStylingWidget::QgsLayerStylingWidget( QgsMapCanvas *canvas, const QList<
 {
   setupUi( this );
 
-  connect( QgsProject::instance(), SIGNAL( layerWillBeRemoved( QgsMapLayer * ) ), this, SLOT( layerAboutToBeRemoved( QgsMapLayer * ) ) );
+  connect( QgsProject::instance(), static_cast < void ( QgsProject::* )( QgsMapLayer * ) > ( &QgsProject::layerWillBeRemoved ), this, &QgsLayerStylingWidget::layerAboutToBeRemoved );
 
   QgsSettings settings;
   mLiveApplyCheck->setChecked( settings.value( QStringLiteral( "UI/autoApplyStyling" ), true ).toBool() );
@@ -76,15 +76,15 @@ QgsLayerStylingWidget::QgsLayerStylingWidget( QgsMapCanvas *canvas, const QList<
   QList<QgsMapLayerConfigWidgetFactory *> l;
   setPageFactories( pages );
 
-  connect( mUndoButton, SIGNAL( pressed() ), this, SLOT( undo() ) );
+  connect( mUndoButton, &QAbstractButton::pressed, this, &QgsLayerStylingWidget::undo );
-  connect( mRedoButton, SIGNAL( pressed() ), this, SLOT( redo() ) );
+  connect( mRedoButton, &QAbstractButton::pressed, this, &QgsLayerStylingWidget::redo );
 
-  connect( mAutoApplyTimer, SIGNAL( timeout() ), this, SLOT( apply() ) );
+  connect( mAutoApplyTimer, &QTimer::timeout, this, &QgsLayerStylingWidget::apply );
 
-  connect( mOptionsListWidget, SIGNAL( currentRowChanged( int ) ), this, SLOT( updateCurrentWidgetLayer() ) );
+  connect( mOptionsListWidget, &QListWidget::currentRowChanged, this, &QgsLayerStylingWidget::updateCurrentWidgetLayer );
-  connect( mButtonBox->button( QDialogButtonBox::Apply ), SIGNAL( clicked() ), this, SLOT( apply() ) );
+  connect( mButtonBox->button( QDialogButtonBox::Apply ), &QAbstractButton::clicked, this, &QgsLayerStylingWidget::apply );
   connect( mLayerCombo, &QgsMapLayerComboBox::layerChanged, this, &QgsLayerStylingWidget::setLayer );
-  connect( mLiveApplyCheck, SIGNAL( toggled( bool ) ), this, SLOT( liveApplyToggled( bool ) ) );
+  connect( mLiveApplyCheck, &QAbstractButton::toggled, this, &QgsLayerStylingWidget::liveApplyToggled );
 
   mStackedWidget->setCurrentIndex( 0 );
 }
@@ -108,11 +108,11 @@ void QgsLayerStylingWidget::blockUpdates( bool blocked )
 
   if ( blocked )
   {
-    disconnect( mCurrentLayer, SIGNAL( styleChanged() ), this, SLOT( updateCurrentWidgetLayer() ) );
+    disconnect( mCurrentLayer, &QgsMapLayer::styleChanged, this, &QgsLayerStylingWidget::updateCurrentWidgetLayer );
   }
   else
   {
-    connect( mCurrentLayer, SIGNAL( styleChanged() ), this, SLOT( updateCurrentWidgetLayer() ) );
+    connect( mCurrentLayer, &QgsMapLayer::styleChanged, this, &QgsLayerStylingWidget::updateCurrentWidgetLayer );
   }
 }
 
@@ -123,7 +123,7 @@ void QgsLayerStylingWidget::setLayer( QgsMapLayer *layer )
 
   if ( mCurrentLayer )
   {
-    disconnect( mCurrentLayer, SIGNAL( styleChanged() ), this, SLOT( updateCurrentWidgetLayer() ) );
+    disconnect( mCurrentLayer, &QgsMapLayer::styleChanged, this, &QgsLayerStylingWidget::updateCurrentWidgetLayer );
   }
 
   if ( !layer || !layer->isSpatial() )
@@ -145,7 +145,7 @@ void QgsLayerStylingWidget::setLayer( QgsMapLayer *layer )
 
   mUndoWidget->setUndoStack( layer->undoStackStyles() );
 
-  connect( mCurrentLayer, SIGNAL( styleChanged() ), this, SLOT( updateCurrentWidgetLayer() ) );
+  connect( mCurrentLayer, &QgsMapLayer::styleChanged, this, &QgsLayerStylingWidget::updateCurrentWidgetLayer );
 
   int lastPage = mOptionsListWidget->currentIndex().row();
   mOptionsListWidget->blockSignals( true );
@@ -222,7 +222,7 @@ void QgsLayerStylingWidget::apply()
   if ( !mCurrentLayer )
     return;
 
-  disconnect( mCurrentLayer, SIGNAL( styleChanged() ), this, SLOT( updateCurrentWidgetLayer() ) );
+  disconnect( mCurrentLayer, &QgsMapLayer::styleChanged, this, &QgsLayerStylingWidget::updateCurrentWidgetLayer );
 
   QString undoName = QStringLiteral( "Style Change" );
 
@@ -270,7 +270,7 @@ void QgsLayerStylingWidget::apply()
     QgsProject::instance()->setDirty( true );
     mCurrentLayer->triggerRepaint();
   }
-  connect( mCurrentLayer, SIGNAL( styleChanged() ), this, SLOT( updateCurrentWidgetLayer() ) );
+  connect( mCurrentLayer, &QgsMapLayer::styleChanged, this, &QgsLayerStylingWidget::updateCurrentWidgetLayer );
 }
 
 void QgsLayerStylingWidget::autoApply()
@@ -332,7 +332,7 @@ void QgsLayerStylingWidget::updateCurrentWidgetLayer()
     QgsMapLayerConfigWidget *panel = mUserPages[row]->createWidget( mCurrentLayer, mMapCanvas, true, mWidgetStack );
     if ( panel )
     {
-      connect( panel, SIGNAL( widgetChanged( QgsPanelWidget * ) ), this, SLOT( autoApply() ) );
+      connect( panel, &QgsPanelWidget::widgetChanged, this, &QgsLayerStylingWidget::autoApply );
       mWidgetStack->setMainPanel( panel );
     }
   }
@@ -353,7 +353,7 @@ void QgsLayerStylingWidget::updateCurrentWidgetLayer()
         QgsRendererPropertiesDialog *styleWidget = new QgsRendererPropertiesDialog( vlayer, QgsStyle::defaultStyle(), true, mStackedWidget );
         styleWidget->setMapCanvas( mMapCanvas );
         styleWidget->setDockMode( true );
-        connect( styleWidget, SIGNAL( widgetChanged() ), this, SLOT( autoApply() ) );
+        connect( styleWidget, &QgsRendererPropertiesDialog::widgetChanged, this, &QgsLayerStylingWidget::autoApply );
         QgsPanelWidgetWrapper *wrapper = new QgsPanelWidgetWrapper( styleWidget, mStackedWidget );
         wrapper->setDockMode( true );
         connect( styleWidget, &QgsRendererPropertiesDialog::showPanel, wrapper, &QgsPanelWidget::openPanel );
@@ -366,7 +366,7 @@ void QgsLayerStylingWidget::updateCurrentWidgetLayer()
         {
           mLabelingWidget = new QgsLabelingWidget( 0, mMapCanvas, mWidgetStack );
           mLabelingWidget->setDockMode( true );
-          connect( mLabelingWidget, SIGNAL( widgetChanged() ), this, SLOT( autoApply() ) );
+          connect( mLabelingWidget, &QgsLabelingWidget::widgetChanged, this, &QgsLayerStylingWidget::autoApply );
         }
         mLabelingWidget->setLayer( vlayer );
         mWidgetStack->setMainPanel( mLabelingWidget );
@@ -415,7 +415,7 @@ void QgsLayerStylingWidget::updateCurrentWidgetLayer()
           }
         }
         mRasterStyleWidget->setDockMode( true );
-        connect( mRasterStyleWidget, SIGNAL( widgetChanged() ), this, SLOT( autoApply() ) );
+        connect( mRasterStyleWidget, &QgsPanelWidget::widgetChanged, this, &QgsLayerStylingWidget::autoApply );
         mWidgetStack->setMainPanel( mRasterStyleWidget );
         break;
       }
@@ -424,7 +424,7 @@ void QgsLayerStylingWidget::updateCurrentWidgetLayer()
       {
         QgsRasterTransparencyWidget *transwidget = new QgsRasterTransparencyWidget( rlayer, mMapCanvas, mWidgetStack );
         transwidget->setDockMode( true );
-        connect( transwidget, SIGNAL( widgetChanged() ), this, SLOT( autoApply() ) );
+        connect( transwidget, &QgsPanelWidget::widgetChanged, this, &QgsLayerStylingWidget::autoApply );
         mWidgetStack->setMainPanel( transwidget );
         break;
       }
@@ -437,10 +437,10 @@ void QgsLayerStylingWidget::updateCurrentWidgetLayer()
             mRasterStyleWidget = new QgsRendererRasterPropertiesWidget( rlayer, mMapCanvas, mWidgetStack );
             mRasterStyleWidget->syncToLayer( rlayer );
           }
-          connect( mRasterStyleWidget, SIGNAL( widgetChanged() ), this, SLOT( autoApply() ) );
+          connect( mRasterStyleWidget, &QgsPanelWidget::widgetChanged, this, &QgsLayerStylingWidget::autoApply );
 
           QgsRasterHistogramWidget *widget = new QgsRasterHistogramWidget( rlayer, mWidgetStack );
-          connect( widget, SIGNAL( widgetChanged() ), this, SLOT( autoApply() ) );
+          connect( widget, &QgsPanelWidget::widgetChanged, this, &QgsLayerStylingWidget::autoApply );
           QString name = mRasterStyleWidget->currentRenderWidget()->renderer()->type();
           widget->setRendererWidget( name, mRasterStyleWidget->currentRenderWidget() );
           widget->setDockMode( true );

src/app/qgsmaplayerstyleguiutils.cpp

@@ -35,14 +35,14 @@ QAction *QgsMapLayerStyleGuiUtils::actionAddStyle( QgsMapLayer *layer, QObject *
 {
   QAction *a = new QAction( tr( "Add..." ), parent );
   a->setData( QVariant::fromValue<QObject *>( layer ) );
-  connect( a, SIGNAL( triggered() ), this, SLOT( addStyle() ) );
+  connect( a, &QAction::triggered, this, &QgsMapLayerStyleGuiUtils::addStyle );
   return a;
 }
 
 QAction *QgsMapLayerStyleGuiUtils::actionRemoveStyle( QgsMapLayer *layer, QObject *parent )
 {
   QAction *a = new QAction( tr( "Remove Current" ), parent );
-  a->connect( a, SIGNAL( triggered() ), this, SLOT( removeStyle() ) );
+  connect( a, &QAction::triggered, this, &QgsMapLayerStyleGuiUtils::removeStyle );
   a->setData( QVariant::fromValue<QObject *>( layer ) );
   a->setEnabled( layer->styleManager()->styles().count() > 1 );
   return a;
@@ -51,7 +51,7 @@ QAction *QgsMapLayerStyleGuiUtils::actionRemoveStyle( QgsMapLayer *layer, QObjec
 QAction *QgsMapLayerStyleGuiUtils::actionRenameStyle( QgsMapLayer *layer, QObject *parent )
 {
   QAction *a = new QAction( tr( "Rename Current..." ), parent );
-  a->connect( a, SIGNAL( triggered() ), this, SLOT( renameStyle() ) );
+  connect( a, &QAction::triggered, this, &QgsMapLayerStyleGuiUtils::renameStyle );
   a->setData( QVariant::fromValue<QObject *>( layer ) );
   return a;
 }
@@ -68,7 +68,7 @@ QList<QAction *> QgsMapLayerStyleGuiUtils::actionsUseStyle( QgsMapLayer *layer,
     if ( name.isEmpty() )
       name = defaultStyleName();
     QAction *actionUse = new QAction( name, parent );
-    connect( actionUse, SIGNAL( triggered() ), this, SLOT( useStyle() ) );
+    connect( actionUse, &QAction::triggered, this, &QgsMapLayerStyleGuiUtils::useStyle );
     actionUse->setCheckable( true );
     actionUse->setChecked( active );
     actionUse->setEnabled( !onlyOneStyle );

src/app/qgsmaptooladdcircularstring.cpp

@@ -34,7 +34,7 @@ QgsMapToolAddCircularString::QgsMapToolAddCircularString( QgsMapToolCapture *par
 {
   if ( mCanvas )
   {
-    connect( mCanvas, SIGNAL( mapToolSet( QgsMapTool *, QgsMapTool * ) ), this, SLOT( setParentTool( QgsMapTool *, QgsMapTool * ) ) );
+    connect( mCanvas, &QgsMapCanvas::mapToolSet, this, &QgsMapToolAddCircularString::setParentTool );
   }
 }
 
@@ -48,7 +48,7 @@ QgsMapToolAddCircularString::QgsMapToolAddCircularString( QgsMapCanvas *canvas )
 {
   if ( mCanvas )
   {
-    connect( mCanvas, SIGNAL( mapToolSet( QgsMapTool *, QgsMapTool * ) ), this, SLOT( setParentTool( QgsMapTool *, QgsMapTool * ) ) );
+    connect( mCanvas, &QgsMapCanvas::mapToolSet, this, &QgsMapToolAddCircularString::setParentTool );
   }
 }
 

src/app/qgsmaptoolchangelabelproperties.cpp

@@ -66,7 +66,7 @@ void QgsMapToolChangeLabelProperties::canvasReleaseEvent( QgsMapMouseEvent *e )
                               mCurrentLabel.pos.labelFont,
                               labeltext, nullptr );
 
-    connect( &d, SIGNAL( applied() ), this, SLOT( dialogPropertiesApplied() ) );
+    connect( &d, &QgsLabelPropertyDialog::applied, this, &QgsMapToolChangeLabelProperties::dialogPropertiesApplied );
     if ( d.exec() == QDialog::Accepted )
     {
       applyChanges( d.changedProperties() );

src/app/qgsmaptoolcircularstringradius.cpp

@@ -159,7 +159,7 @@ void QgsMapToolCircularStringRadius::createRadiusSpinBox()
   mRadiusSpinBox->setPrefix( tr( "Radius: " ) );
   mRadiusSpinBox->setValue( mRadius );
   QgisApp::instance()->addUserInputWidget( mRadiusSpinBox );
-  QObject::connect( mRadiusSpinBox, SIGNAL( valueChanged( double ) ), this, SLOT( updateRadiusFromSpinBox( double ) ) );
+  connect( mRadiusSpinBox, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsMapToolCircularStringRadius::updateRadiusFromSpinBox );
   mRadiusSpinBox->setFocus( Qt::TabFocusReason );
 }
 

src/app/qgsmaptoolidentifyaction.cpp

@@ -52,12 +52,12 @@ QgsMapToolIdentifyAction::QgsMapToolIdentifyAction( QgsMapCanvas *canvas )
   QPixmap myIdentifyQPixmap = QPixmap( ( const char ** ) identify_cursor );
   mCursor = QCursor( myIdentifyQPixmap, 1, 1 );
 
-  connect( this, SIGNAL( changedRasterResults( QList<IdentifyResult> & ) ), this, SLOT( handleChangedRasterResults( QList<IdentifyResult> & ) ) );
+  connect( this, &QgsMapToolIdentify::changedRasterResults, this, &QgsMapToolIdentifyAction::handleChangedRasterResults );
 
   mIdentifyMenu->setAllowMultipleReturn( true );
 
   QgsMapLayerAction *attrTableAction = new QgsMapLayerAction( tr( "Show attribute table" ), mIdentifyMenu, QgsMapLayer::VectorLayer, QgsMapLayerAction::MultipleFeatures );
-  connect( attrTableAction, SIGNAL( triggeredForFeatures( QgsMapLayer *, const QList<QgsFeature> ) ), this, SLOT( showAttributeTable( QgsMapLayer *, const QList<QgsFeature> ) ) );
+  connect( attrTableAction, &QgsMapLayerAction::triggeredForFeatures, this, &QgsMapToolIdentifyAction::showAttributeTable );
   identifyMenu()->addCustomAction( attrTableAction );
 }
 
@@ -75,8 +75,8 @@ QgsIdentifyResultsDialog *QgsMapToolIdentifyAction::resultsDialog()
   {
     mResultsDialog = new QgsIdentifyResultsDialog( mCanvas, mCanvas->window() );
 
-    connect( mResultsDialog, SIGNAL( formatChanged( QgsRasterLayer * ) ), this, SLOT( formatChanged( QgsRasterLayer * ) ) );
+    connect( mResultsDialog.data(), static_cast<void ( QgsIdentifyResultsDialog::* )( QgsRasterLayer * )>( &QgsIdentifyResultsDialog::formatChanged ), this, &QgsMapToolIdentify::formatChanged );
-    connect( mResultsDialog, SIGNAL( copyToClipboard( QgsFeatureStore & ) ), this, SLOT( handleCopyToClipboard( QgsFeatureStore & ) ) );
+    connect( mResultsDialog.data(), &QgsIdentifyResultsDialog::copyToClipboard, this, &QgsMapToolIdentifyAction::handleCopyToClipboard );
   }
 
   return mResultsDialog;
@@ -115,8 +115,8 @@ void QgsMapToolIdentifyAction::canvasPressEvent( QgsMapMouseEvent *e )
 void QgsMapToolIdentifyAction::canvasReleaseEvent( QgsMapMouseEvent *e )
 {
   resultsDialog()->clear();
-  connect( this, SIGNAL( identifyProgress( int, int ) ), QgisApp::instance(), SLOT( showProgress( int, int ) ) );
+  connect( this, &QgsMapToolIdentifyAction::identifyProgress, QgisApp::instance(), &QgisApp::showProgress );
-  connect( this, SIGNAL( identifyMessage( QString ) ), QgisApp::instance(), SLOT( showStatusMessage( QString ) ) );
+  connect( this, &QgsMapToolIdentifyAction::identifyMessage, QgisApp::instance(), &QgisApp::showStatusMessage );
 
   identifyMenu()->setResultsIfExternalAction( false );
 
@@ -129,8 +129,8 @@ void QgsMapToolIdentifyAction::canvasReleaseEvent( QgsMapMouseEvent *e )
 
   QList<IdentifyResult> results = QgsMapToolIdentify::identify( e->x(), e->y(), mode );
 
-  disconnect( this, SIGNAL( identifyProgress( int, int ) ), QgisApp::instance(), SLOT( showProgress( int, int ) ) );
+  disconnect( this, &QgsMapToolIdentifyAction::identifyProgress, QgisApp::instance(), &QgisApp::showProgress );
-  disconnect( this, SIGNAL( identifyMessage( QString ) ), QgisApp::instance(), SLOT( showStatusMessage( QString ) ) );
+  disconnect( this, &QgsMapToolIdentifyAction::identifyMessage, QgisApp::instance(), &QgisApp::showStatusMessage );
 
   if ( results.isEmpty() )
   {

src/app/qgsmaptoolmeasureangle.cpp

@@ -34,8 +34,8 @@ QgsMapToolMeasureAngle::QgsMapToolMeasureAngle( QgsMapCanvas *canvas )
 {
   mToolName = tr( "Measure angle" );
 
-  connect( canvas, SIGNAL( destinationCrsChanged() ),
+  connect( canvas, &QgsMapCanvas::destinationCrsChanged,
-           this, SLOT( updateSettings() ) );
+           this, &QgsMapToolMeasureAngle::updateSettings );
 }
 
 QgsMapToolMeasureAngle::~QgsMapToolMeasureAngle()
@@ -96,7 +96,7 @@ void QgsMapToolMeasureAngle::canvasReleaseEvent( QgsMapMouseEvent *e )
     {
       mResultDisplay = new QgsDisplayAngle( this );
       mResultDisplay->setWindowFlags( mResultDisplay->windowFlags() | Qt::Tool );
-      QObject::connect( mResultDisplay, SIGNAL( rejected() ), this, SLOT( stopMeasuring() ) );
+      connect( mResultDisplay, &QDialog::rejected, this, &QgsMapToolMeasureAngle::stopMeasuring );
     }
     configureDistanceArea();
     createRubberBand();

src/app/qgsmaptooloffsetcurve.cpp

@@ -334,16 +334,16 @@ void QgsMapToolOffsetCurve::createDistanceWidget()
 
   mDistanceWidget->setFocus( Qt::TabFocusReason );
 
-  QObject::connect( mDistanceWidget, SIGNAL( valueChanged( double ) ), this, SLOT( placeOffsetCurveToValue() ) );
+  connect( mDistanceWidget, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsMapToolOffsetCurve::placeOffsetCurveToValue );
-  QObject::connect( mDistanceWidget, SIGNAL( editingFinished() ), this, SLOT( applyOffset() ) );
+  connect( mDistanceWidget, &QAbstractSpinBox::editingFinished, this, &QgsMapToolOffsetCurve::applyOffset );
 }
 
 void QgsMapToolOffsetCurve::deleteDistanceWidget()
 {
   if ( mDistanceWidget )
   {
-    QObject::disconnect( mDistanceWidget, SIGNAL( valueChanged( double ) ), this, SLOT( placeOffsetCurveToValue() ) );
+    disconnect( mDistanceWidget, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsMapToolOffsetCurve::placeOffsetCurveToValue );
-    QObject::disconnect( mDistanceWidget, SIGNAL( editingFinished() ), this, SLOT( applyOffset() ) );
+    disconnect( mDistanceWidget, &QAbstractSpinBox::editingFinished, this, &QgsMapToolOffsetCurve::applyOffset );
     mDistanceWidget->releaseKeyboard();
     mDistanceWidget->deleteLater();
   }

src/app/qgsmaptoolpinlabels.cpp

@@ -36,8 +36,8 @@ QgsMapToolPinLabels::QgsMapToolPinLabels( QgsMapCanvas *canvas )
 {
   mToolName = tr( "Pin labels" );
 
-  connect( QgisApp::instance()->actionToggleEditing(), SIGNAL( triggered() ), this, SLOT( updatePinnedLabels() ) );
+  connect( QgisApp::instance()->actionToggleEditing(), &QAction::triggered, this, &QgsMapToolPinLabels::updatePinnedLabels );
-  connect( canvas, SIGNAL( renderComplete( QPainter * ) ), this, SLOT( highlightPinnedLabels() ) );
+  connect( canvas, &QgsMapCanvas::renderComplete, this, &QgsMapToolPinLabels::highlightPinnedLabels );
 }
 
 QgsMapToolPinLabels::~QgsMapToolPinLabels()

src/app/qgsmaptoolrotatefeature.cpp

@@ -74,7 +74,7 @@ QgsAngleMagnetWidget::QgsAngleMagnetWidget( const QString &label, QWidget *paren
 
   // connect signals
   mAngleSpinBox->installEventFilter( this );
-  connect( mAngleSpinBox, SIGNAL( valueChanged( double ) ), this, SLOT( angleSpinBoxValueChanged( double ) ) );
+  connect( mAngleSpinBox, static_cast < void ( QgsDoubleSpinBox::* )( double ) > ( &QgsDoubleSpinBox::valueChanged ), this, &QgsAngleMagnetWidget::angleSpinBoxValueChanged );
 
   // config focus
   setFocusProxy( mAngleSpinBox );
@@ -466,16 +466,16 @@ void QgsMapToolRotateFeature::createRotationWidget()
   QgisApp::instance()->addUserInputWidget( mRotationWidget );
   mRotationWidget->setFocus( Qt::TabFocusReason );
 
-  QObject::connect( mRotationWidget, SIGNAL( angleChanged( double ) ), this, SLOT( updateRubberband( double ) ) );
+  connect( mRotationWidget, &QgsAngleMagnetWidget::angleChanged, this, &QgsMapToolRotateFeature::updateRubberband );
-  QObject::connect( mRotationWidget, SIGNAL( angleEditingFinished( double ) ), this, SLOT( applyRotation( double ) ) );
+  connect( mRotationWidget, &QgsAngleMagnetWidget::angleEditingFinished, this, &QgsMapToolRotateFeature::applyRotation );
 }
 
 void QgsMapToolRotateFeature::deleteRotationWidget()
 {
   if ( mRotationWidget )
   {
-    QObject::disconnect( mRotationWidget, SIGNAL( angleChanged( double ) ), this, SLOT( updateRubberband( double ) ) );
+    disconnect( mRotationWidget, &QgsAngleMagnetWidget::angleChanged, this, &QgsMapToolRotateFeature::updateRubberband );
-    QObject::disconnect( mRotationWidget, SIGNAL( angleEditingFinished( double ) ), this, SLOT( applyRotation( double ) ) );
+    disconnect( mRotationWidget, &QgsAngleMagnetWidget::angleEditingFinished, this, &QgsMapToolRotateFeature::applyRotation );
     mRotationWidget->releaseKeyboard();
     mRotationWidget->deleteLater();
   }

src/app/qgsmaptoolsimplify.cpp

@@ -39,9 +39,9 @@ QgsSimplifyDialog::QgsSimplifyDialog( QgsMapToolSimplify *tool, QWidget *parent
   cboToleranceUnits->setCurrentIndex( ( int ) mTool->toleranceUnits() );
 
   // communication with map tool
-  connect( spinTolerance, SIGNAL( valueChanged( double ) ), mTool, SLOT( setTolerance( double ) ) );
+  connect( spinTolerance, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), mTool, &QgsMapToolSimplify::setTolerance );
-  connect( cboToleranceUnits, SIGNAL( currentIndexChanged( int ) ), mTool, SLOT( setToleranceUnits( int ) ) );
+  connect( cboToleranceUnits, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), mTool, &QgsMapToolSimplify::setToleranceUnits );
-  connect( okButton, SIGNAL( clicked() ), mTool, SLOT( storeSimplified() ) );
+  connect( okButton, &QAbstractButton::clicked, mTool, &QgsMapToolSimplify::storeSimplified );
 }
 
 void QgsSimplifyDialog::updateStatusText()

src/app/qgsmeasuredialog.cpp

@@ -39,12 +39,12 @@ QgsMeasureDialog::QgsMeasureDialog( QgsMeasureTool *tool, Qt::WindowFlags f )
 
   QPushButton *nb = new QPushButton( tr( "&New" ) );
   buttonBox->addButton( nb, QDialogButtonBox::ActionRole );
-  connect( nb, SIGNAL( clicked() ), this, SLOT( restart() ) );
+  connect( nb, &QAbstractButton::clicked, this, &QgsMeasureDialog::restart );
 
   // Add a configuration button
   QPushButton *cb = new QPushButton( tr( "&Configuration" ) );
   buttonBox->addButton( cb, QDialogButtonBox::ActionRole );
-  connect( cb, SIGNAL( clicked() ), this, SLOT( openConfigTab() ) );
+  connect( cb, &QAbstractButton::clicked, this, &QgsMeasureDialog::openConfigTab );
 
   mMeasureArea = tool->measureArea();
   mTotal = 0.;
@@ -66,8 +66,8 @@ QgsMeasureDialog::QgsMeasureDialog( QgsMeasureTool *tool, Qt::WindowFlags f )
 
   updateSettings();
 
-  connect( mUnitsCombo, SIGNAL( currentIndexChanged( int ) ), this, SLOT( unitsChanged( int ) ) );
+  connect( mUnitsCombo, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsMeasureDialog::unitsChanged );
-  connect( buttonBox, SIGNAL( rejected() ), this, SLOT( reject() ) );
+  connect( buttonBox, &QDialogButtonBox::rejected, this, &QgsMeasureDialog::reject );
   connect( mTool->canvas(), &QgsMapCanvas::destinationCrsChanged, this, &QgsMeasureDialog::crsChanged );
 
   groupBox->setCollapsed( true );

src/app/qgsmergeattributesdialog.cpp

@@ -62,7 +62,7 @@ QgsMergeAttributesDialog::QgsMergeAttributesDialog( const QgsFeatureList &featur
   QHeaderView *verticalHeader = mTableWidget->verticalHeader();
   if ( verticalHeader )
   {
-    QObject::connect( mTableWidget, SIGNAL( itemSelectionChanged() ), this, SLOT( selectedRowChanged() ) );
+    connect( mTableWidget, &QTableWidget::itemSelectionChanged, this, &QgsMergeAttributesDialog::selectedRowChanged );
   }
   mTableWidget->setSelectionBehavior( QAbstractItemView::SelectRows );
   mTableWidget->setSelectionMode( QAbstractItemView::SingleSelection );
@@ -73,8 +73,8 @@ QgsMergeAttributesDialog::QgsMergeAttributesDialog( const QgsFeatureList &featur
   QgsSettings settings;
   restoreGeometry( settings.value( QStringLiteral( "Windows/MergeAttributes/geometry" ) ).toByteArray() );
 
-  connect( mSkipAllButton, SIGNAL( clicked() ), this, SLOT( setAllToSkip() ) );
+  connect( mSkipAllButton, &QAbstractButton::clicked, this, &QgsMergeAttributesDialog::setAllToSkip );
-  connect( mTableWidget, SIGNAL( cellChanged( int, int ) ), this, SLOT( tableWidgetCellChanged( int, int ) ) );
+  connect( mTableWidget, &QTableWidget::cellChanged, this, &QgsMergeAttributesDialog::tableWidgetCellChanged );
 }
 
 QgsMergeAttributesDialog::QgsMergeAttributesDialog()
@@ -210,8 +210,8 @@ QComboBox *QgsMergeAttributesDialog::createMergeComboBox( QVariant::Type columnT
   newComboBox->addItem( tr( "Skip attribute" ), "skip" );
   newComboBox->addItem( tr( "Manual value" ), "manual" );
 
-  QObject::connect( newComboBox, SIGNAL( currentIndexChanged( const QString & ) ),
+  connect( newComboBox, static_cast<void ( QComboBox::* )( const QString & )>( &QComboBox::currentIndexChanged ),
-                    this, SLOT( comboValueChanged( const QString & ) ) );
+           this, &QgsMergeAttributesDialog::comboValueChanged );
   return newComboBox;
 }
 

src/app/qgsnewspatialitelayerdialog.cpp

@@ -78,10 +78,10 @@ QgsNewSpatialiteLayerDialog::QgsNewSpatialiteLayerDialog( QWidget *parent, Qt::W
 
   pbnFindSRID->setEnabled( mDatabaseComboBox->count() );
 
-  connect( mNameEdit, SIGNAL( textChanged( QString ) ), this, SLOT( nameChanged( QString ) ) );
+  connect( mNameEdit, &QLineEdit::textChanged, this, &QgsNewSpatialiteLayerDialog::nameChanged );
-  connect( mAttributeView, SIGNAL( itemSelectionChanged() ), this, SLOT( selectionChanged() ) );
+  connect( mAttributeView, &QTreeWidget::itemSelectionChanged, this, &QgsNewSpatialiteLayerDialog::selectionChanged );
-  connect( leLayerName, SIGNAL( textChanged( QString ) ), this, SLOT( checkOk() ) );
+  connect( leLayerName, &QLineEdit::textChanged, this, &QgsNewSpatialiteLayerDialog::checkOk );
-  connect( checkBoxPrimaryKey, SIGNAL( clicked() ), this, SLOT( checkOk() ) );
+  connect( checkBoxPrimaryKey, &QAbstractButton::clicked, this, &QgsNewSpatialiteLayerDialog::checkOk );
 
   mAddAttributeButton->setEnabled( false );
   mRemoveAttributeButton->setEnabled( false );