diff --git a/CHANGES b/CHANGES
index e645377d..cd9c843c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,10 @@
 Release Highlights
 ==================
 
+Version 3.1.0 (unreleased):
+--------------------------
+ * Bug fix: Fix model about to be reset
+
 Version 3.0.1 (unreleased):
 ---------------------------
  * Add WebAssembly demo-example
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f6c20535..0ed72615 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,8 +65,8 @@ project(
 )
 
 set(${PROJECT_NAME}_VERSION_MAJOR 3)
-set(${PROJECT_NAME}_VERSION_MINOR 0)
-set(${PROJECT_NAME}_VERSION_PATCH 1)
+set(${PROJECT_NAME}_VERSION_MINOR 1)
+set(${PROJECT_NAME}_VERSION_PATCH 0)
 set(${PROJECT_NAME}_VERSION
     ${${PROJECT_NAME}_VERSION_MAJOR}.${${PROJECT_NAME}_VERSION_MINOR}.${${PROJECT_NAME}_VERSION_PATCH}
 )
diff --git a/conan/conanfile.py b/conan/conanfile.py
index ac6851a1..3750cd21 100644
--- a/conan/conanfile.py
+++ b/conan/conanfile.py
@@ -10,7 +10,7 @@
 
 class KdchartConan(ConanFile):
     name = "KDChart"
-    version = "3.0.1"
+    version = "3.1.0"
     license = ("https://raw.githubusercontent.com/KDAB/KDChart/master/LICENSES/MIT.txt")
     author = "Klaralvdalens Datakonsult AB (KDAB) info@kdab.com"
     url = "https://github.com/KDAB/KDChart.git"
diff --git a/examples/Axis/Labels/mainwindow.cpp b/examples/Axis/Labels/mainwindow.cpp
index 435ae6fb..88422039 100644
--- a/examples/Axis/Labels/mainwindow.cpp
+++ b/examples/Axis/Labels/mainwindow.cpp
@@ -94,8 +94,8 @@ MainWindow::MainWindow(QWidget *parent)
     m_legend->setAlignment(Qt::AlignTop);
     m_chart->addLegend(m_legend);
 
-    connect(m_annotations, SIGNAL(toggled(bool)), SLOT(annotationsToggled(bool)));
-    connect(m_linesOnAnnotations, SIGNAL(toggled(bool)), SLOT(gridLinesOnAnnotationsToggled(bool)));
+    connect(m_annotations, &QCheckBox::toggled, this, &MainWindow::annotationsToggled);
+    connect(m_linesOnAnnotations, &QCheckBox::toggled, this, &MainWindow::gridLinesOnAnnotationsToggled);
 }
 
 void MainWindow::annotationsToggled(bool showAnnotations)
diff --git a/examples/DrawIntoPainter/framewidget.cpp b/examples/DrawIntoPainter/framewidget.cpp
index 31089bd6..7a697b9a 100644
--- a/examples/DrawIntoPainter/framewidget.cpp
+++ b/examples/DrawIntoPainter/framewidget.cpp
@@ -26,7 +26,7 @@ void FrameWidget::setChart(KDChart::Chart *chart)
     mChart = chart;
     // This is necessary because Chart can't automatically schedule somebody else (this object) to
     // call its custom paint method.
-    connect(mChart, SIGNAL(propertiesChanged()), SLOT(update()));
+    connect(mChart, &KDChart::Chart::propertiesChanged, this, QOverload<>::of(&FrameWidget::update));
 }
 
 void FrameWidget::paintEvent(QPaintEvent *e)
diff --git a/examples/DrawIntoPainter/mainwindow.cpp b/examples/DrawIntoPainter/mainwindow.cpp
index aee6c9b3..9b1bd31f 100644
--- a/examples/DrawIntoPainter/mainwindow.cpp
+++ b/examples/DrawIntoPainter/mainwindow.cpp
@@ -82,8 +82,8 @@ MainWindow::MainWindow(QWidget *parent)
 #ifdef USE_FRAME_WIDGET
     chartFrameWidget->setChart(m_chart);
     // make sure, we re-draw after changing one of the chart's properties
-    connect(m_chart, SIGNAL(propertiesChanged()),
-            chartFrameWidget, SLOT(update()));
+    connect(m_chart, &KDChart::Chart::propertiesChanged,
+            chartFrameWidget, QOverload<>::of(&FrameWidget::update));
 #else
     chartLayout->addWidget(m_chart);
 #endif
diff --git a/examples/Gantt/legend_example/entrydialog.cpp b/examples/Gantt/legend_example/entrydialog.cpp
index acb72138..6baa2e22 100644
--- a/examples/Gantt/legend_example/entrydialog.cpp
+++ b/examples/Gantt/legend_example/entrydialog.cpp
@@ -40,9 +40,10 @@ void EntryDialog::init()
     for (int row = 0; row < model->rowCount(); ++row)
         addDependItem(model, model->index(row, 0));
 
-    connect(ui->startDate, SIGNAL(dateTimeChanged(const QDateTime &)), this, SLOT(updateEndDate(const QDateTime &)));
-    connect(ui->readOnly, SIGNAL(toggled(bool)), this, SLOT(disableEditing(bool)));
-    connect(ui->type, SIGNAL(currentIndexChanged(int)), this, SLOT(typeChanged(int)));
+    connect(ui->startDate, &QDateTimeEdit::dateTimeChanged,
+            this, &EntryDialog::updateEndDate);
+    connect(ui->readOnly, &QCheckBox::toggled, this, &EntryDialog::disableEditing);
+    connect(ui->type, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &EntryDialog::typeChanged);
 
     ui->startDate->setDateTime(QDateTime::currentDateTime());
     typeChanged(0);
diff --git a/examples/Gantt/legend_example/mainwindow.cpp b/examples/Gantt/legend_example/mainwindow.cpp
index 2031a4ee..b724016e 100644
--- a/examples/Gantt/legend_example/mainwindow.cpp
+++ b/examples/Gantt/legend_example/mainwindow.cpp
@@ -64,10 +64,10 @@ MainWindow::MainWindow(QWidget *parent, Qt::WindowFlags flags)
     leftView->setColumnHidden(5, true);
     leftView->header()->setStretchLastSection(true);
 
-    connect(ui->ganttView->leftView(), SIGNAL(customContextMenuRequested(const QPoint &)),
-            this, SLOT(showContextMenu(const QPoint &)));
-    connect(ui->ganttView->selectionModel(), SIGNAL(selectionChanged(const QItemSelection &, const QItemSelection &)),
-            this, SLOT(enableActions(const QItemSelection &)));
+    connect(ui->ganttView->leftView(), &QAbstractItemView::customContextMenuRequested,
+            this, &MainWindow::showContextMenu);
+    connect(ui->ganttView->selectionModel(), &QItemSelectionModel::selectionChanged,
+            this, &MainWindow::enableActions);
 }
 
 MainWindow::~MainWindow()
@@ -128,22 +128,22 @@ void MainWindow::initActions()
 {
     newEntryAction = new QAction(tr("New entry"), this);
     newEntryAction->setShortcut(QKeySequence::New);
-    connect(newEntryAction, SIGNAL(triggered()), this, SLOT(addNewEntry()));
+    connect(newEntryAction, &QAction::triggered, this, &MainWindow::addNewEntry);
 
     removeEntryAction = new QAction(tr("Remove entry"), this);
     removeEntryAction->setShortcut(QKeySequence::Delete);
-    connect(removeEntryAction, SIGNAL(triggered()), this, SLOT(removeEntry()));
+    connect(removeEntryAction, &QAction::triggered, this, &MainWindow::removeEntry);
 
     zoomInAction = new QAction(tr("Zoom In"), this);
     zoomInAction->setShortcut(QKeySequence::ZoomIn);
-    connect(zoomInAction, SIGNAL(triggered()), this, SLOT(zoomIn()));
+    connect(zoomInAction, &QAction::triggered, this, &MainWindow::zoomIn);
 
     zoomOutAction = new QAction(tr("Zoom Out"), this);
     zoomOutAction->setShortcut(QKeySequence::ZoomOut);
-    connect(zoomOutAction, SIGNAL(triggered()), this, SLOT(zoomOut()));
+    connect(zoomOutAction, &QAction::triggered, this, &MainWindow::zoomOut);
 
     zoomFitAction = new QAction(tr("Zoom to Fit"), this);
-    connect(zoomFitAction, SIGNAL(triggered()), this, SLOT(zoomFit()));
+    connect(zoomFitAction, &QAction::triggered, this, &MainWindow::zoomFit);
 
     ui->ganttView->leftView()->setContextMenuPolicy(Qt::CustomContextMenu);
     ui->ganttView->leftView()->addAction(newEntryAction);
@@ -160,11 +160,11 @@ void MainWindow::initActions()
 
     QMenu *scaleMenu = menuBar()->addMenu(tr("Scale"));
 
-    scaleMenu->addAction(tr("Auto"), this, SLOT(scaleAuto()));
-    scaleMenu->addAction(tr("Hour"), this, SLOT(scaleHour()));
-    scaleMenu->addAction(tr("Day"), this, SLOT(scaleDay()));
-    scaleMenu->addAction(tr("Week"), this, SLOT(scaleWeek()));
-    scaleMenu->addAction(tr("Month"), this, SLOT(scaleMonth()));
+    scaleMenu->addAction(tr("Auto"), this, &MainWindow::scaleAuto);
+    scaleMenu->addAction(tr("Hour"), this, &MainWindow::scaleHour);
+    scaleMenu->addAction(tr("Day"), this, &MainWindow::scaleDay);
+    scaleMenu->addAction(tr("Week"), this, &MainWindow::scaleWeek);
+    scaleMenu->addAction(tr("Month"), this, &MainWindow::scaleMonth);
 
     enableActions(QItemSelection());
 }
@@ -314,14 +314,14 @@ void MainWindow::zoomOut()
 
 void MainWindow::zoomFit()
 {
-    QModelIndexList selectedIndexes = ui->ganttView->selectionModel()->selectedIndexes();
+    const QModelIndexList selectedIndexes = ui->ganttView->selectionModel()->selectedIndexes();
 
     if (selectedIndexes.isEmpty()) {
         return;
     }
 
     KDGantt::Span span;
-    Q_FOREACH (QModelIndex idx, selectedIndexes) {
+    for (QModelIndex idx : selectedIndexes) {
         const KDGantt::Span s = grid->mapToChart(grid->model()->index(idx.row(), 0));
         if (span.isValid()) {
             span = span.expandedTo(s);
diff --git a/examples/Gantt/project/mainwindow.cpp b/examples/Gantt/project/mainwindow.cpp
index a768d7f6..b245b983 100644
--- a/examples/Gantt/project/mainwindow.cpp
+++ b/examples/Gantt/project/mainwindow.cpp
@@ -275,28 +275,28 @@ MainWindow::MainWindow(QWidget *parent)
     auto *fileMenu = new QMenu(tr("&File"));
 
 #ifndef QT_NO_PRINTER
-    fileMenu->addAction(tr("&Save as PDF..."), this, SLOT(slotFileSavePdf()));
-    fileMenu->addAction(tr("&Print..."), this, SLOT(slotFilePrint()));
+    fileMenu->addAction(tr("&Save as PDF..."), this, &MainWindow::slotFileSavePdf);
+    fileMenu->addAction(tr("&Print..."), this, &MainWindow::slotFilePrint);
 #endif
 
     fileMenu->addSeparator();
-    fileMenu->addAction(tr("&Quit"), this, SLOT(slotFileQuit()));
+    fileMenu->addAction(tr("&Quit"), this, &MainWindow::slotFileQuit);
 
     mb->addMenu(fileMenu);
 
     auto *toolsMenu = new QMenu(tr("&Tools"));
 
-    toolsMenu->addAction(tr("&New Item"), this, SLOT(slotToolsNewItem()));
-    toolsMenu->addAction(tr("&Add Item"), this, SLOT(slotToolsAppendItem()));
+    toolsMenu->addAction(tr("&New Item"), this, &MainWindow::slotToolsNewItem);
+    toolsMenu->addAction(tr("&Add Item"), this, &MainWindow::slotToolsAppendItem);
     toolsMenu->addSeparator();
     QMenu *alignMenu = toolsMenu->addMenu(tr("Ali&gn"));
-    alignMenu->addAction(tr("&Left"), this, SLOT(slotAlignLeft()));
-    alignMenu->addAction(tr("&Center"), this, SLOT(slotAlignCenter()));
-    alignMenu->addAction(tr("&Right"), this, SLOT(slotAlignRight()));
-    alignMenu->addAction(tr("&Hidden"), this, SLOT(slotAlignHidden()));
+    alignMenu->addAction(tr("&Left"), this, &MainWindow::slotAlignLeft);
+    alignMenu->addAction(tr("&Center"), this, &MainWindow::slotAlignCenter);
+    alignMenu->addAction(tr("&Right"), this, &MainWindow::slotAlignRight);
+    alignMenu->addAction(tr("&Hidden"), this, &MainWindow::slotAlignHidden);
     toolsMenu->addSeparator();
-    toolsMenu->addAction(tr("&Collapse All"), this, SLOT(slotCollapseAll()));
-    toolsMenu->addAction(tr("&Expand All"), this, SLOT(slotExpandAll()));
+    toolsMenu->addAction(tr("&Collapse All"), this, &MainWindow::slotCollapseAll);
+    toolsMenu->addAction(tr("&Expand All"), this, &MainWindow::slotExpandAll);
 
     mb->addMenu(toolsMenu);
 
@@ -331,7 +331,7 @@ SavePdfDialog::SavePdfDialog(QWidget *parent)
     m_fileEdit->setText(QFileInfo(QDir::homePath(), "gantt.pdf").absoluteFilePath());
     fileLayout->addWidget(m_fileEdit);
     auto *m_fileButton = new QPushButton("...", this);
-    connect(m_fileButton, SIGNAL(clicked()), this, SLOT(fileButtonClicked()));
+    connect(m_fileButton, &QPushButton::clicked, this, &SavePdfDialog::fileButtonClicked);
     fileLayout->addWidget(m_fileButton);
 
     m_rowLabels = new QCheckBox(tr("Row Header"), this);
@@ -344,8 +344,8 @@ SavePdfDialog::SavePdfDialog(QWidget *parent)
 
     auto *btnBox = new QDialogButtonBox(this);
     btnBox->setStandardButtons(QDialogButtonBox::Save | QDialogButtonBox::Cancel);
-    connect(btnBox, SIGNAL(accepted()), this, SLOT(accept()));
-    connect(btnBox, SIGNAL(rejected()), this, SLOT(reject()));
+    connect(btnBox, &QDialogButtonBox::accepted, this, &SavePdfDialog::accept);
+    connect(btnBox, &QDialogButtonBox::rejected, this, &SavePdfDialog::reject);
     l->addWidget(btnBox);
 
     resize(QSize(400, 100).expandedTo(minimumSizeHint()));
diff --git a/examples/LeveyJennings/Simple/main.cpp b/examples/LeveyJennings/Simple/main.cpp
index ba8733f1..68e6b3d2 100644
--- a/examples/LeveyJennings/Simple/main.cpp
+++ b/examples/LeveyJennings/Simple/main.cpp
@@ -31,7 +31,7 @@ class SelectionAnimator : public QObject
         , view(view)
     {
         auto *const t = new QTimer(this);
-        connect(t, SIGNAL(timeout()), this, SLOT(animate()));
+        connect(t, &QTimer::timeout, this, &SelectionAnimator::animate);
         t->start(1000);
     }
 
diff --git a/examples/Lines/Advanced/mainwindow.cpp b/examples/Lines/Advanced/mainwindow.cpp
index 90561c0b..8db1dde0 100644
--- a/examples/Lines/Advanced/mainwindow.cpp
+++ b/examples/Lines/Advanced/mainwindow.cpp
@@ -50,7 +50,7 @@ MainWindow::MainWindow(QWidget *parent)
     m_chart->setGlobalLeading(20, 20, 20, 20);
     // Instantiate the timer
     auto *timer = new QTimer(this);
-    connect(timer, SIGNAL(timeout()), this, SLOT(slot_timerFired()));
+    connect(timer, &QTimer::timeout, this, &MainWindow::slot_timerFired);
     timer->start(30);
 
     // Change the cursor to IBeamCursor inside Chart widget.
diff --git a/examples/ModelView/TableView/mainwindow.cpp b/examples/ModelView/TableView/mainwindow.cpp
index 40168a40..fc30bae8 100644
--- a/examples/ModelView/TableView/mainwindow.cpp
+++ b/examples/ModelView/TableView/mainwindow.cpp
@@ -43,14 +43,16 @@ MainWindow::MainWindow()
     initializeData();
     setupViews();
 
-    connect(openAction, SIGNAL(triggered()), this, SLOT(openFile()));
-    connect(saveAction, SIGNAL(triggered()), this, SLOT(saveFile()));
-    connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
+    connect(openAction, &QAction::triggered, this, [this] {
+        openFile();
+    });
+    connect(saveAction, &QAction::triggered, this, &MainWindow::saveFile);
+    connect(quitAction, &QAction::triggered, qApp, &QApplication::quit);
 
-    connect(m_selectionModel, SIGNAL(selectionChanged(const QItemSelection &, const QItemSelection &)),
-            this, SLOT(selectionChanged(const QItemSelection &, const QItemSelection &)));
+    connect(m_selectionModel, &QItemSelectionModel::selectionChanged,
+            this, &MainWindow::selectionChanged);
 
-    connect(m_diagramView, SIGNAL(clicked(const QModelIndex &)), SLOT(itemClicked(const QModelIndex &)));
+    connect(m_diagramView, &BarDiagram::clicked, this, &MainWindow::itemClicked);
 
     menuBar()->addMenu(fileMenu);
     statusBar();
diff --git a/examples/Pie/Advanced/mainwindow.cpp b/examples/Pie/Advanced/mainwindow.cpp
index 945e922f..199d530a 100644
--- a/examples/Pie/Advanced/mainwindow.cpp
+++ b/examples/Pie/Advanced/mainwindow.cpp
@@ -42,7 +42,7 @@ MainWindow::MainWindow(QWidget *parent)
     m_chart->coordinatePlane()->replaceDiagram(m_pie);
 
     m_timer = new QTimer(this);
-    connect(m_timer, SIGNAL(timeout()), this, SLOT(slotNextFrame()));
+    connect(m_timer, &QTimer::timeout, this, &MainWindow::slotNextFrame);
 }
 
 void MainWindow::on_startPositionSB_valueChanged(double pos)
diff --git a/examples/Plotter/BigDataset/MainWidget.cpp b/examples/Plotter/BigDataset/MainWidget.cpp
index 2526270c..7822160d 100644
--- a/examples/Plotter/BigDataset/MainWidget.cpp
+++ b/examples/Plotter/BigDataset/MainWidget.cpp
@@ -55,17 +55,17 @@ MainWidget::MainWidget()
     m_functionSelector << m_controls.sineRadio << m_controls.triangleRadio << m_controls.squareRadio
                        << m_controls.noiseRadio << m_controls.oneDivSineRadio
                        << m_controls.sineOneDivRadio;
-    foreach (QRadioButton *r, m_functionSelector) {
-        connect(r, SIGNAL(toggled(bool)), SLOT(functionToggled(bool)));
+    for (QRadioButton *r : qAsConst(m_functionSelector)) {
+        connect(r, &QRadioButton::toggled, this, &MainWidget::functionToggled);
     }
 
-    connect(m_controls.runButton, SIGNAL(toggled(bool)),
-            &m_model, SLOT(setRunning(bool)));
+    connect(m_controls.runButton, &QPushButton::toggled,
+            &m_model, &Model::setRunning);
 
     // order matters again
     m_addPointsButtons << m_controls.add1kButton << m_controls.add10kButton << m_controls.add100kButton;
-    foreach (QPushButton *b, m_addPointsButtons) {
-        connect(b, SIGNAL(clicked(bool)), SLOT(addPointsButtonClicked()));
+    for (QPushButton *b : qAsConst(m_addPointsButtons)) {
+        connect(b, &QPushButton::clicked, this, &MainWidget::addPointsButtonClicked);
     }
 }
 
diff --git a/examples/Plotter/BigDataset/Model.cpp b/examples/Plotter/BigDataset/Model.cpp
index 30086417..3cb0f990 100644
--- a/examples/Plotter/BigDataset/Model.cpp
+++ b/examples/Plotter/BigDataset/Model.cpp
@@ -26,7 +26,7 @@ static const qreal s_stepWidth = 0.1;
 Model::Model()
 {
     m_appendTimer.setInterval(3);
-    connect(&m_appendTimer, SIGNAL(timeout()), SLOT(appendPoint()));
+    connect(&m_appendTimer, &QTimer::timeout, this, &Model::appendPoint);
     // pre-fill some values
     appendPoints(100);
 }
diff --git a/examples/Plotter/BubbleChart/mainwindow.cpp b/examples/Plotter/BubbleChart/mainwindow.cpp
index ca0b8159..f1cffb9f 100644
--- a/examples/Plotter/BubbleChart/mainwindow.cpp
+++ b/examples/Plotter/BubbleChart/mainwindow.cpp
@@ -78,7 +78,7 @@ MainWindow::MainWindow(QWidget *parent)
     m_plotter->addAxis(xAxis2);
     m_plotter->addAxis(yAxis);
     m_plotter->addAxis(yAxis2);
-    connect(threeDEnabled, SIGNAL(toggled(bool)), this, SLOT(setMarkerAttributes()));
+    connect(threeDEnabled, &QCheckBox::toggled, this, &MainWindow::setMarkerAttributes);
 
     m_chart->coordinatePlane()->replaceDiagram(m_plotter);
     m_chart->setGlobalLeading(20, 20, 20, 20);
diff --git a/examples/Plotter/Timeline/main.cpp b/examples/Plotter/Timeline/main.cpp
index dd90e3f4..ec6dc0a1 100644
--- a/examples/Plotter/Timeline/main.cpp
+++ b/examples/Plotter/Timeline/main.cpp
@@ -43,7 +43,7 @@ class ChartWidget : public QWidget
         auto *button = new QPushButton("Animate", leftWidget);
         leftLayout->addWidget(button);
         button->setCheckable(true);
-        connect(button, SIGNAL(toggled(bool)), this, SLOT(buttonToggled(bool)));
+        connect(button, &QPushButton::toggled, this, &ChartWidget::buttonToggled);
 
         auto *tv = new QTreeView(leftWidget);
         leftLayout->addWidget(tv);
@@ -74,17 +74,19 @@ class ChartWidget : public QWidget
 
         plotter->setModel(proxy);
 
-        connect(proxy, SIGNAL(rowsInserted(QModelIndex, int, int)),
-                m_chart->coordinatePlane(), SLOT(adjustRangesToData()));
-        connect(proxy, SIGNAL(rowsRemoved(QModelIndex, int, int)),
-                m_chart->coordinatePlane(), SLOT(adjustRangesToData()));
+        auto coordinatePlane = qobject_cast<KDChart::CartesianCoordinatePlane *>(m_chart->coordinatePlane());
+        connect(proxy, &TimeChartModel::rowsInserted,
+                coordinatePlane, &KDChart::CartesianCoordinatePlane::adjustRangesToData);
+        connect(proxy, &TimeChartModel::rowsRemoved,
+                coordinatePlane, &KDChart::CartesianCoordinatePlane::adjustRangesToData);
 
         proxy->setVisibleRange(QDateTime(QDate(2010, 3, 15), QTime()),
                                QDateTime(QDate(2010, 5, 18), QTime()));
-        qobject_cast<KDChart::CartesianCoordinatePlane *>(m_chart->coordinatePlane())->adjustRangesToData();
+        coordinatePlane->adjustRangesToData();
+
 
         m_timer = new QTimer(this);
-        connect(m_timer, SIGNAL(timeout()), this, SLOT(slotTimeout()));
+        connect(m_timer, &QTimer::timeout, this, &ChartWidget::slotTimeout);
     }
 private slots:
     void slotTimeout()
diff --git a/examples/RealTime/main.cpp b/examples/RealTime/main.cpp
index 019f4b5b..8e552969 100644
--- a/examples/RealTime/main.cpp
+++ b/examples/RealTime/main.cpp
@@ -39,8 +39,8 @@ class ChartWidget : public QWidget
         l->addWidget(&m_chart);
         setLayout(l);
         m_timer = new QTimer(this);
-        connect(m_timer, SIGNAL(timeout()),
-                this, SLOT(slotTimeout()));
+        connect(m_timer, &QTimer::timeout,
+                this, &ChartWidget::slotTimeout);
         m_timer->start(200);
     }
 
diff --git a/examples/Stock/Advanced/mainwindow.cpp b/examples/Stock/Advanced/mainwindow.cpp
index ba75c6d2..e7548b78 100644
--- a/examples/Stock/Advanced/mainwindow.cpp
+++ b/examples/Stock/Advanced/mainwindow.cpp
@@ -51,7 +51,7 @@ MainWindow::MainWindow(QWidget *parent)
     m_diagram.addAxis(bottomAxis);
     m_diagram.addAxis(bottomAxis);
     applyColor(QColor("chartreuse"));
-    const bool connected = connect(colorChooser, SIGNAL(clicked()), SLOT(chooseColor()));
+    const bool connected = connect(colorChooser, &QPushButton::clicked, this, &MainWindow::chooseColor);
     Q_ASSERT(connected);
     Q_UNUSED(connected);
 
diff --git a/examples/TernaryCharts/Advanced/mainwindow.cpp b/examples/TernaryCharts/Advanced/mainwindow.cpp
index 94e99c2e..3ae49d2e 100644
--- a/examples/TernaryCharts/Advanced/mainwindow.cpp
+++ b/examples/TernaryCharts/Advanced/mainwindow.cpp
@@ -47,8 +47,8 @@ MainWindow::MainWindow(QWidget *parent)
 
     setupModel();
     m_diagram->setModel(&m_model);
-    connect(m_diagram, SIGNAL(clicked(QModelIndex)),
-            SLOT(indexClicked(QModelIndex)));
+    connect(m_diagram, &KDChart::TernaryPointDiagram::clicked,
+            this, &MainWindow::indexClicked);
 }
 
 void MainWindow::setupModel()
diff --git a/examples/Widget/Advanced/mainwindow.cpp b/examples/Widget/Advanced/mainwindow.cpp
index 7c56de37..74569c59 100644
--- a/examples/Widget/Advanced/mainwindow.cpp
+++ b/examples/Widget/Advanced/mainwindow.cpp
@@ -28,12 +28,12 @@ MainWindow::MainWindow(QWidget *parent)
 
     typeSelector->setCurrentIndex(1); // we start by LineDiagram
 
-    connect(typeSelector, SIGNAL(activated(int)), SLOT(changeType()));
+    connect(typeSelector, QOverload<int>::of(&QComboBox::activated), this, &MainWindow::changeType);
 
-    connect(btnAddDataset, SIGNAL(clicked()), SLOT(addDataset()));
+    connect(btnAddDataset, &QPushButton::clicked, this, &MainWindow::addDataset);
 
-    connect(leadingSelector, SIGNAL(valueChanged(int)),
-            this, SLOT(changeLeading(int)));
+    connect(leadingSelector, QOverload<int>::of(&QSpinBox::valueChanged),
+            this, &MainWindow::changeLeading);
 }
 
 void MainWindow::changeType()
@@ -58,10 +58,10 @@ void MainWindow::changeLeading(int leading)
 
 void MainWindow::addDataset()
 {
-    QStringList parts = lineAddDataset->text().split(';');
+    const QStringList parts = lineAddDataset->text().split(';');
     bool ok;
     QVector<qreal> vec;
-    foreach (const QString &str, parts) {
+    for (const QString &str : parts) {
         const qreal val = str.toDouble(&ok);
         if (ok)
             vec.append(val);
diff --git a/examples/Zoom/ScrollBars/mainwindow.cpp b/examples/Zoom/ScrollBars/mainwindow.cpp
index ef9083ab..95896265 100644
--- a/examples/Zoom/ScrollBars/mainwindow.cpp
+++ b/examples/Zoom/ScrollBars/mainwindow.cpp
@@ -51,7 +51,7 @@ MainWindow::MainWindow(QWidget *parent)
     m_lines->addAxis(yAxis);
     m_chart->coordinatePlane()->replaceDiagram(m_lines);
 
-    connect(m_chart, SIGNAL(propertiesChanged()), SLOT(applyNewZoomParameters()));
+    connect(m_chart, &Chart::propertiesChanged, this, &MainWindow::applyNewZoomParameters);
 
     // Set up the legend
     m_legend = new Legend(m_lines, m_chart);
diff --git a/examples/demo/axissettings.cpp b/examples/demo/axissettings.cpp
index d5c6b874..254bc129 100644
--- a/examples/demo/axissettings.cpp
+++ b/examples/demo/axissettings.cpp
@@ -60,10 +60,10 @@ void AxisSettings::Private::init()
     ui.axisSelection->addItem(QIcon(), tr("Right Y-Axis"), CartesianAxis::Right);
     ui.axisSelection->addItem(QIcon(), tr("Bottom X-Axis"), CartesianAxis::Bottom);
     ui.axisSelection->addItem(QIcon(), tr("Top X-Axis"), CartesianAxis::Top);
-    connect(ui.axisSelection, SIGNAL(currentIndexChanged(int)), this, SLOT(currentIndexChanged(int)));
-    connect(ui.axisVisibility, SIGNAL(toggled(bool)), this, SLOT(setVisible(bool)));
-    connect(ui.majorTicks, SIGNAL(toggled(bool)), this, SLOT(setShowMajorTickMarks(bool)));
-    connect(ui.minorTicks, SIGNAL(toggled(bool)), this, SLOT(setShowMinorTickMarks(bool)));
+    connect(ui.axisSelection, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::currentIndexChanged);
+    connect(ui.axisVisibility, &QCheckBox::toggled, this, &Private::setVisible);
+    connect(ui.majorTicks, &QCheckBox::toggled, this, &Private::setShowMajorTickMarks);
+    connect(ui.minorTicks, &QCheckBox::toggled, this, &Private::setShowMinorTickMarks);
     ui.axisSelection->setCurrentIndex(0);
 }
 
@@ -74,8 +74,8 @@ void AxisSettings::Private::currentIndexChanged(int index)
     auto *plane = qobject_cast<CartesianCoordinatePlane *>(m_chart->coordinatePlane());
     auto *diag = qobject_cast<AbstractCartesianDiagram *>(m_chart->coordinatePlane()->diagram());
     if (plane && diag) {
-        QVector<CartesianAxis *> axes = diag->axes().toVector();
-        Q_FOREACH (CartesianAxis *axis, axes) {
+        const auto axes = diag->axes();
+        for (CartesianAxis *axis : axes) {
             if (axis->position() == pos) {
                 m_currentAxis = axis;
                 break;
@@ -109,9 +109,9 @@ void AxisSettings::Private::setVisible(bool value)
     auto *plane = qobject_cast<CartesianCoordinatePlane *>(m_chart->coordinatePlane());
     auto *diag = qobject_cast<AbstractCartesianDiagram *>(m_chart->coordinatePlane()->diagram());
     if (plane && diag) {
-        QVector<CartesianAxis *> axes = m_axisCache[plane];
+        const QVector<CartesianAxis *> axes = m_axisCache[plane];
         bool foundAxis = false;
-        Q_FOREACH (CartesianAxis *axis, axes) {
+        for (CartesianAxis *axis : axes) {
             if (axis->position() == pos) {
                 foundAxis = true;
                 if (!value) {
diff --git a/examples/demo/datasetsettings.cpp b/examples/demo/datasetsettings.cpp
index 882bff6b..9803129d 100644
--- a/examples/demo/datasetsettings.cpp
+++ b/examples/demo/datasetsettings.cpp
@@ -126,9 +126,9 @@ DatasetSettings::DatasetSettings(Chart *chart, QWidget *parent)
     d->ui->colorDisplay->setStyle(QStyleFactory::create(QStringLiteral("cleanlooks")));
     d->ui->outlineBtn->setStyle(QStyleFactory::create(QStringLiteral("cleanlooks")));
 #endif
-    connect(d->ui->datasetSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(indexChanged(int)));
-    connect(d->ui->colorDisplay, SIGNAL(clicked()), d, SLOT(changeColor()));
-    connect(d->ui->outlineBtn, SIGNAL(clicked()), d, SLOT(changeOutline()));
+    connect(d->ui->datasetSelector, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &DatasetSettings::indexChanged);
+    connect(d->ui->colorDisplay, &QPushButton::clicked, d, &Private::changeColor);
+    connect(d->ui->outlineBtn, &QPushButton::clicked, d, &Private::changeOutline);
 }
 
 DatasetSettings::~DatasetSettings()
diff --git a/examples/demo/datavaluesettings.cpp b/examples/demo/datavaluesettings.cpp
index 18a9b0fc..ae2adeab 100644
--- a/examples/demo/datavaluesettings.cpp
+++ b/examples/demo/datavaluesettings.cpp
@@ -93,28 +93,28 @@ void DataValueSettings::Private::init()
 
 void DataValueSettings::Private::connectWidgets()
 {
-    connect(ui->scopeBarDatasetSB, SIGNAL(valueChanged(int)), this, SLOT(on_scopeBarDatasetSB_valueChanged(int)));
-    connect(ui->scopeBarItemSB, SIGNAL(valueChanged(int)), this, SLOT(on_scopeBarItemSB_valueChanged(int)));
-    connect(ui->scopeDatasetSB, SIGNAL(valueChanged(int)), this, SLOT(on_scopeDatasetSB_valueChanged(int)));
-    connect(ui->scopeOneBarRB, SIGNAL(toggled(bool)), this, SLOT(on_scopeOneBarRB_toggled(bool)));
-    connect(ui->scopeDatasetRB, SIGNAL(toggled(bool)), this, SLOT(on_scopeDatasetRB_toggled(bool)));
-    connect(ui->scopeCommonRB, SIGNAL(toggled(bool)), this, SLOT(on_scopeCommonRB_toggled(bool)));
-    connect(ui->paintValuesCB, SIGNAL(toggled(bool)), this, SLOT(on_paintValuesCB_toggled(bool)));
-    connect(ui->fontCombo, SIGNAL(currentIndexChanged(QString)), this, SLOT(on_fontCombo_currentIndexChanged(QString)));
-    connect(ui->relativeSizeSB, SIGNAL(valueChanged(int)), this, SLOT(on_relativeSizeSB_valueChanged(int)));
-    connect(ui->minimumSizeSB, SIGNAL(valueChanged(int)), this, SLOT(on_minimumSizeSB_valueChanged(int)));
-    connect(ui->rotationSB, SIGNAL(valueChanged(int)), this, SLOT(on_rotationSB_valueChanged(int)));
-    connect(ui->posPosCombo, SIGNAL(currentIndexChanged(QString)), this, SLOT(on_posPosCombo_currentIndexChanged(QString)));
-    connect(ui->posAlignCombo, SIGNAL(currentIndexChanged(QString)), this, SLOT(on_posAlignCombo_currentIndexChanged(QString)));
-    connect(ui->posPadHoriSB, SIGNAL(valueChanged(int)), this, SLOT(on_posPadHoriSB_valueChanged(int)));
-    connect(ui->posPadVertSB, SIGNAL(valueChanged(int)), this, SLOT(on_posPadVertSB_valueChanged(int)));
-    connect(ui->negPosCombo, SIGNAL(currentIndexChanged(QString)), this, SLOT(on_negPosCombo_currentIndexChanged(QString)));
-    connect(ui->negAlignCombo, SIGNAL(currentIndexChanged(QString)), this, SLOT(on_negAlignCombo_currentIndexChanged(QString)));
-    connect(ui->negPadHoriSB, SIGNAL(valueChanged(int)), this, SLOT(on_negPadHoriSB_valueChanged(int)));
-    connect(ui->negPadVertSB, SIGNAL(valueChanged(int)), this, SLOT(on_negPadVertSB_valueChanged(int)));
-    connect(ui->labelLE, SIGNAL(textEdited(QString)), this, SLOT(on_labelLE_textEdited(QString)));
-    connect(ui->prefixLE, SIGNAL(textEdited(QString)), this, SLOT(on_prefixLE_textEdited(QString)));
-    connect(ui->suffixLE, SIGNAL(textEdited(QString)), this, SLOT(on_suffixLE_textEdited(QString)));
+    connect(ui->scopeBarDatasetSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_scopeBarDatasetSB_valueChanged);
+    connect(ui->scopeBarItemSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_scopeBarItemSB_valueChanged);
+    connect(ui->scopeDatasetSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_scopeDatasetSB_valueChanged);
+    connect(ui->scopeOneBarRB, &QRadioButton::toggled, this, &Private::on_scopeOneBarRB_toggled);
+    connect(ui->scopeDatasetRB, &QRadioButton::toggled, this, &Private::on_scopeDatasetRB_toggled);
+    connect(ui->scopeCommonRB, &QRadioButton::toggled, this, &Private::on_scopeCommonRB_toggled);
+    connect(ui->paintValuesCB, &QCheckBox::toggled, this, &Private::on_paintValuesCB_toggled);
+    connect(ui->fontCombo, QOverload<int>::of(&QFontComboBox::currentIndexChanged), this, &Private::on_fontCombo_currentIndexChanged);
+    connect(ui->relativeSizeSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_relativeSizeSB_valueChanged);
+    connect(ui->minimumSizeSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_minimumSizeSB_valueChanged);
+    connect(ui->rotationSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_rotationSB_valueChanged);
+    connect(ui->posPosCombo, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::on_posPosCombo_currentIndexChanged);
+    connect(ui->posAlignCombo, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::on_posAlignCombo_currentIndexChanged);
+    connect(ui->posPadHoriSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_posPadHoriSB_valueChanged);
+    connect(ui->posPadVertSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_posPadVertSB_valueChanged);
+    connect(ui->negPosCombo, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::on_negPosCombo_currentIndexChanged);
+    connect(ui->negAlignCombo, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::on_negAlignCombo_currentIndexChanged);
+    connect(ui->negPadHoriSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_negPadHoriSB_valueChanged);
+    connect(ui->negPadVertSB, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::on_negPadVertSB_valueChanged);
+    connect(ui->labelLE, &QLineEdit::textEdited, this, &Private::on_labelLE_textEdited);
+    connect(ui->prefixLE, &QLineEdit::textEdited, this, &Private::on_prefixLE_textEdited);
+    connect(ui->suffixLE, &QLineEdit::textEdited, this, &Private::on_suffixLE_textEdited);
 }
 
 DataValueSettings::DataValueSettings(KDChart::Chart *chart, QWidget *parent)
diff --git a/examples/demo/diagramsettings.cpp b/examples/demo/diagramsettings.cpp
index 65d770ff..33e8b0d1 100644
--- a/examples/demo/diagramsettings.cpp
+++ b/examples/demo/diagramsettings.cpp
@@ -166,11 +166,11 @@ void DiagramSettings::Private::init()
     ui->diagramBackground->setStyle(QStyleFactory::create(QStringLiteral("cleanlooks")));
 #endif
 
-    connect(ui->threeDSelector, SIGNAL(toggled(bool)), this, SLOT(changeThreeD()));
-    connect(ui->diagramBackground, SIGNAL(clicked()), this, SLOT(changeBackgroundColor()));
-    connect(ui->visibleBtn, SIGNAL(toggled(bool)), this, SLOT(changeBackgroundVisibility()));
-    connect(ui->barHeightInput, SIGNAL(valueChanged(int)), this, SLOT(changeThreeD()));
-    connect(ui->autoGradient, SIGNAL(toggled(bool)), this, SLOT(changeAutoGradient()));
+    connect(ui->threeDSelector, &QCheckBox::toggled, this, &Private::changeThreeD);
+    connect(ui->diagramBackground, &QPushButton::clicked, this, &Private::changeBackgroundColor);
+    connect(ui->visibleBtn, &QCheckBox::toggled, this, &Private::changeBackgroundVisibility);
+    connect(ui->barHeightInput, QOverload<int>::of(&QSpinBox::valueChanged), this, &Private::changeThreeD);
+    connect(ui->autoGradient, &QCheckBox::toggled, this, &Private::changeAutoGradient);
 
     qq->refreshSettings();
 }
diff --git a/examples/demo/diagramtypedialog.cpp b/examples/demo/diagramtypedialog.cpp
index d8023302..9b6a34a9 100644
--- a/examples/demo/diagramtypedialog.cpp
+++ b/examples/demo/diagramtypedialog.cpp
@@ -75,8 +75,8 @@ void DiagramTypeDialog::Private::init()
     m_typemap[DiagramTypeDialog::Line] = DiagramTypeDialog::Normal;
     m_typemap[DiagramTypeDialog::Plotter] = DiagramTypeDialog::Normal;
 
-    connect(ui.typeSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(typeChanged(int)));
-    connect(ui.subtypeSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(subtypeChanged(int)));
+    connect(ui.typeSelector, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::typeChanged);
+    connect(ui.subtypeSelector, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::subtypeChanged);
 }
 
 void DiagramTypeDialog::Private::createPlanes()
diff --git a/examples/demo/gradientdialog.cpp b/examples/demo/gradientdialog.cpp
index 4d858c1d..dc2f5dce 100644
--- a/examples/demo/gradientdialog.cpp
+++ b/examples/demo/gradientdialog.cpp
@@ -100,7 +100,7 @@ void GradientDialog::Private::updateGradientDisplay()
     gradient.setStart(0, 0);
     gradient.setStart(1, 0);
     gradient.setCoordinateMode(QGradient::ObjectBoundingMode);
-    Q_FOREACH (const QGradientStop &stop, m_gradient)
+    for (const QGradientStop &stop : qAsConst(m_gradient))
         gradient.setColorAt(stop.first, stop.second);
     QPalette palette = ui->gradientDisplay->palette();
     palette.setBrush(QPalette::Window, gradient);
@@ -128,8 +128,8 @@ void GradientDialog::Private::init()
     redSpin->setMaximum(255);
     redSpin->setAccelerated(true);
     redSpin->setValue(redSlider->value());
-    connect(redSpin, SIGNAL(valueChanged(int)), redSlider, SLOT(setValue(int)));
-    connect(redSlider, SIGNAL(valueChanged(int)), redSpin, SLOT(setValue(int)));
+    connect(redSpin, QOverload<int>::of(&QSpinBox::valueChanged), redSlider, &ColorSlider::setValue);
+    connect(redSlider, &ColorSlider::valueChanged, redSpin, &QSpinBox::setValue);
     redLayout->addWidget(redSlider);
     redLayout->addWidget(redSpin);
 
@@ -148,8 +148,8 @@ void GradientDialog::Private::init()
     greenSpin->setMaximum(255);
     greenSpin->setAccelerated(true);
     greenSpin->setValue(greenSlider->value());
-    connect(greenSpin, SIGNAL(valueChanged(int)), greenSlider, SLOT(setValue(int)));
-    connect(greenSlider, SIGNAL(valueChanged(int)), greenSpin, SLOT(setValue(int)));
+    connect(greenSpin, QOverload<int>::of(&QSpinBox::valueChanged), greenSlider, &ColorSlider::setValue);
+    connect(greenSlider, &ColorSlider::valueChanged, greenSpin, &QSpinBox::setValue);
     greenLayout->addWidget(greenSlider);
     greenLayout->addWidget(greenSpin);
 
@@ -168,22 +168,22 @@ void GradientDialog::Private::init()
     blueSpin->setMaximum(255);
     blueSpin->setAccelerated(true);
     blueSpin->setValue(blueSlider->value());
-    connect(blueSpin, SIGNAL(valueChanged(int)), blueSlider, SLOT(setValue(int)));
-    connect(blueSlider, SIGNAL(valueChanged(int)), blueSpin, SLOT(setValue(int)));
+    connect(blueSpin, QOverload<int>::of(&QSpinBox::valueChanged), blueSlider, &ColorSlider::setValue);
+    connect(blueSlider, &ColorSlider::valueChanged, blueSpin, &QSpinBox::setValue);
     blueLayout->addWidget(blueSlider);
     blueLayout->addWidget(blueSpin);
 
     updateGradientDisplay();
 
-    connect(redSlider, SIGNAL(valueChanged(int)), this, SLOT(resetColors()));
-    connect(greenSlider, SIGNAL(valueChanged(int)), this, SLOT(resetColors()));
-    connect(blueSlider, SIGNAL(valueChanged(int)), this, SLOT(resetColors()));
+    connect(redSlider, &ColorSlider::valueChanged, this, &Private::resetColors);
+    connect(greenSlider, &ColorSlider::valueChanged, this, &Private::resetColors);
+    connect(blueSlider, &ColorSlider::valueChanged, this, &Private::resetColors);
 
-    connect(ui->newStop, SIGNAL(clicked()), this, SLOT(insertItem()));
-    connect(ui->deleteStop, SIGNAL(clicked()), this, SLOT(deleteItem()));
-    connect(ui->stopSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(changedIndex(int)));
+    connect(ui->newStop, &QPushButton::clicked, this, &Private::insertItem);
+    connect(ui->deleteStop, &QPushButton::clicked, this, &Private::deleteItem);
+    connect(ui->stopSelector, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &Private::changedIndex);
 
-    connect(ui->stopPosition, SIGNAL(valueChanged(double)), this, SLOT(changeStopPosition(double)));
+    connect(ui->stopPosition, QOverload<double>::of(&QDoubleSpinBox::valueChanged), this, &Private::changeStopPosition);
 }
 
 GradientDialog::GradientDialog(QWidget *parent)
@@ -230,7 +230,7 @@ QGradient GradientDialog::gradient() const
     gradient.setStart(0, 0);
     gradient.setStart(1, 0);
     gradient.setCoordinateMode(QGradient::ObjectBoundingMode);
-    Q_FOREACH (const QGradientStop &stop, d->m_gradient)
+    for (const QGradientStop &stop : qAsConst(d->m_gradient))
         gradient.setColorAt(stop.first, stop.second);
     return gradient;
 }
@@ -239,7 +239,7 @@ void GradientDialog::setGradient(const QGradient &gradient)
     d->m_gradient.clear();
     d->ui->stopSelector->clear();
     const QGradientStops stops = gradient.stops();
-    Q_FOREACH (const QGradientStop &stop, stops) {
+    for (const QGradientStop &stop : stops) {
         d->m_gradient.append(stop);
     }
     QStringList newEntries;
diff --git a/examples/demo/main.cpp b/examples/demo/main.cpp
index 16755858..b277296f 100644
--- a/examples/demo/main.cpp
+++ b/examples/demo/main.cpp
@@ -38,8 +38,8 @@
 //    l->addWidget(&m_chart);
 //    setLayout(l);
 //    m_timer = new QTimer(this);
-//    connect( m_timer, SIGNAL( timeout() ),
-//             this, SLOT( slotTimeout() ) );
+//    connect( m_timer, &QTimer::timeout,
+//             this, &ChartWidget::slotTimeout );
 //    m_timer->start( 200 );
 //  }
 
diff --git a/examples/demo/mainwindow.cpp b/examples/demo/mainwindow.cpp
index f95d3568..73939b05 100644
--- a/examples/demo/mainwindow.cpp
+++ b/examples/demo/mainwindow.cpp
@@ -95,7 +95,7 @@ MainWindow::Private::Private(MainWindow *q)
     auto *diagramTypeSettingsDock = new QDockWidget(tr("DiagramType"), qq);
     diagramTypeSettingsDock->setWidget(diagramTypeSettings);
     diagramTypeSettingsDock->setFloating(false);
-    connect(diagramTypeSettings, SIGNAL(diagramTypeChanged(DiagramType, Subtype)), this, SLOT(changedChartType()));
+    connect(diagramTypeSettings, &DiagramTypeDialog::diagramTypeChanged, this, &Private::changedChartType);
     q->addDockWidget(Qt::LeftDockWidgetArea, diagramTypeSettingsDock);
 
     auto *axisSettings = new AxisSettings(m_chartWin, qq);
@@ -103,15 +103,15 @@ MainWindow::Private::Private(MainWindow *q)
     axisSettingsDock->setWidget(axisSettings);
     axisSettingsDock->setFloating(false);
     q->addDockWidget(Qt::LeftDockWidgetArea, axisSettingsDock);
-    connect(diagramTypeSettings, SIGNAL(diagramTypeChanged(DiagramType, Subtype)), axisSettings, SLOT(diagramTypeChanged()));
+    connect(diagramTypeSettings, &DiagramTypeDialog::diagramTypeChanged, axisSettings, &AxisSettings::diagramTypeChanged);
 
     auto *setSettings = new DatasetSettings(m_chartWin, qq);
     auto *setSettingsDock = new QDockWidget(tr("DatasetSettings"), qq);
     setSettingsDock->setWidget(setSettings);
     setSettingsDock->setFloating(false);
     q->addDockWidget(Qt::LeftDockWidgetArea, setSettingsDock);
-    connect(this, SIGNAL(datasetCountChanged(int)), setSettings, SLOT(setDatasetCount(int)));
-    connect(diagramTypeSettings, SIGNAL(diagramTypeChanged(DiagramType, Subtype)), setSettings, SLOT(diagramTypeChanged()));
+    connect(this, &Private::datasetCountChanged, setSettings, &DatasetSettings::setDatasetCount);
+    connect(diagramTypeSettings, &DiagramTypeDialog::diagramTypeChanged, setSettings, &DatasetSettings::diagramTypeChanged);
     setSettings->setDatasetCount(m_model->columnCount());
 
     auto *diagSettings = new DiagramSettings(m_chartWin, qq);
@@ -119,14 +119,14 @@ MainWindow::Private::Private(MainWindow *q)
     diagSettingsDock->setWidget(diagSettings);
     diagSettingsDock->setFloating(false);
     q->addDockWidget(Qt::LeftDockWidgetArea, diagSettingsDock);
-    connect(diagramTypeSettings, SIGNAL(diagramTypeChanged(DiagramType, Subtype)), diagSettings, SLOT(refreshSettings()));
+    connect(diagramTypeSettings, &DiagramTypeDialog::diagramTypeChanged, diagSettings, &DiagramSettings::refreshSettings);
 
     auto *dataValueSettings = new DataValueSettings(m_chartWin, qq);
     auto *dataValueSettingsDock = new QDockWidget(tr("DataValueSettings"), qq);
     dataValueSettingsDock->setWidget(dataValueSettings);
     dataValueSettingsDock->setFloating(false);
     q->addDockWidget(Qt::RightDockWidgetArea, dataValueSettingsDock);
-    connect(diagramTypeSettings, SIGNAL(diagramTypeChanged(DiagramType, Subtype)), dataValueSettings, SLOT(refresh()));
+    connect(diagramTypeSettings, &DiagramTypeDialog::diagramTypeChanged, dataValueSettings, &DataValueSettings::refresh);
 }
 
 int MainWindow::Private::datasetCount() const
diff --git a/qtests/CartesianDiagramDataCompressor/CartesianDiagramDataCompressorTests.cpp b/qtests/CartesianDiagramDataCompressor/CartesianDiagramDataCompressorTests.cpp
index c0c1c9d6..dda9af60 100644
--- a/qtests/CartesianDiagramDataCompressor/CartesianDiagramDataCompressorTests.cpp
+++ b/qtests/CartesianDiagramDataCompressor/CartesianDiagramDataCompressorTests.cpp
@@ -117,10 +117,9 @@ private slots:
     {
         // test 1: valid point:
         {
-            QModelIndexList indexes;
             CachePosition point(0, 0);
-            indexes = compressor.mapToModel(point);
-            Q_FOREACH (const QModelIndex &index, indexes) {
+            const auto indexes = compressor.mapToModel(point);
+            for (const QModelIndex &index : indexes) {
                 QVERIFY2(compressor.mapToCache(index) == point,
                          "index mapToModel does not map back to the original cache point");
             }
diff --git a/qtests/DrawIntoPainter/mainwindow.cpp b/qtests/DrawIntoPainter/mainwindow.cpp
index c8e71d32..3ba41f02 100644
--- a/qtests/DrawIntoPainter/mainwindow.cpp
+++ b/qtests/DrawIntoPainter/mainwindow.cpp
@@ -81,8 +81,8 @@ MainWindow::MainWindow(QWidget *parent)
 #ifdef USE_FRAME_WIDGET
     chartFrameWidget->setChart(m_chart);
     // make sure, we re-draw after changing one of the chart's properties
-    connect(m_chart, SIGNAL(propertiesChanged()),
-            chartFrameWidget, SLOT(update()));
+    connect(m_chart, &Chart::propertiesChanged,
+            chartFrameWidget, QOverload<>::of(&QWidget::update));
 #else
     chartLayout->addWidget(m_chart);
 #endif
diff --git a/qtests/DrawIntoPainter/mainwindow.ui b/qtests/DrawIntoPainter/mainwindow.ui
index da9773db..e8797b38 100644
--- a/qtests/DrawIntoPainter/mainwindow.ui
+++ b/qtests/DrawIntoPainter/mainwindow.ui
@@ -13,7 +13,9 @@
    <string>KD Chart drawing into a foreign QPainter </string>
   </property>
   <property name="windowIcon" >
-   <iconset/>
+   <iconset>
+    <normaloff/>
+   </iconset>
   </property>
   <layout class="QGridLayout" >
    <property name="margin" >
diff --git a/qtests/ParamVsParam/ModelParamVsParam.cpp b/qtests/ParamVsParam/ModelParamVsParam.cpp
index ec8cdd97..f7e93882 100644
--- a/qtests/ParamVsParam/ModelParamVsParam.cpp
+++ b/qtests/ParamVsParam/ModelParamVsParam.cpp
@@ -14,7 +14,7 @@ ModelParamVsParam::ModelParamVsParam(
     QObject *p_parent)
     : QStandardItemModel(p_parent)
 {
-    connect(&m_timer, SIGNAL(timeout()), SLOT(timeout()));
+    connect(&m_timer, &QTimer::timeout, this, &ModelParamVsParam::timeout);
     // m_timer.setSingleShot(true);
     m_timer.setInterval(2000);
 } // ModelParamVsParam::ModelParamVsParam()
diff --git a/qtests/ParamVsParam/main.cpp b/qtests/ParamVsParam/main.cpp
index 5bad1fa8..dcfd1a55 100644
--- a/qtests/ParamVsParam/main.cpp
+++ b/qtests/ParamVsParam/main.cpp
@@ -28,7 +28,7 @@ private slots:
         qDebug() << "time constructor:" << t.elapsed() << "ms";
 
         mainWindow.show();
-        QTimer::singleShot(0, qApp, SLOT(quit()));
+        QTimer::singleShot(0, qApp, &QCoreApplication::quit);
 
         qDebug() << "time show():" << t.elapsed() << "ms";
         // uncomment to see it blink:
diff --git a/qtests/ParamVsParam/mainwindow.cpp b/qtests/ParamVsParam/mainwindow.cpp
index 41284861..459d2e30 100644
--- a/qtests/ParamVsParam/mainwindow.cpp
+++ b/qtests/ParamVsParam/mainwindow.cpp
@@ -31,9 +31,9 @@ MainWindow::MainWindow(
     , m_nrOfSamplesLineEdit(new QLineEdit("4"))
     , m_paramVsParamGridLayout(new QGridLayout)
 {
-    connect(m_timeoutLineEdit, SIGNAL(editingFinished()), SLOT(timeoutEditingFinished()));
-    connect(m_nrOfParametersLineEdit, SIGNAL(editingFinished()), SLOT(editingFinished()));
-    connect(m_nrOfSamplesLineEdit, SIGNAL(editingFinished()), SLOT(editingFinished()));
+    connect(m_timeoutLineEdit, &QLineEdit::editingFinished, this, &MainWindow::timeoutEditingFinished);
+    connect(m_nrOfParametersLineEdit, &QLineEdit::editingFinished, this, &MainWindow::editingFinished);
+    connect(m_nrOfSamplesLineEdit, &QLineEdit::editingFinished, this, &MainWindow::editingFinished);
 
     auto *vBoxLayout = new QVBoxLayout;
     setLayout(vBoxLayout);
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4543adfb..9de77583 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier: MIT
 #
 
-add_definitions(-DQT_NO_KEYWORDS -DQT_NO_CAST_FROM_BYTEARRAY -Demit=)
+add_definitions(-DQT_NO_KEYWORDS -DQT_NO_CAST_FROM_BYTEARRAY -DQT_NO_SIGNALS_SLOTS_KEYWORDS)
 
 set(FORMS KDChart/KDChartDatasetSelector.ui)
 set(RESOURCES KDChart/KDAB_kdchart_LeveyJennings_resources.qrc)
diff --git a/src/KDChart/Cartesian/DiagramFlavors/KDChartPercentPlotter_p.cpp b/src/KDChart/Cartesian/DiagramFlavors/KDChartPercentPlotter_p.cpp
index ebf9170c..9c765ddb 100644
--- a/src/KDChart/Cartesian/DiagramFlavors/KDChartPercentPlotter_p.cpp
+++ b/src/KDChart/Cartesian/DiagramFlavors/KDChartPercentPlotter_p.cpp
@@ -112,7 +112,7 @@ void PercentPlotter::paint(PaintContext *ctx)
     QList<qreal> xValues = diagramValues.keys();
     // make sure it's sorted
     std::sort(xValues.begin(), xValues.end());
-    Q_FOREACH (const qreal xValue, xValues) {
+    for (const qreal xValue : qAsConst(xValues)) {
         // the y-values to the current x-value
         QVector<QPair<Value, QModelIndex>> &yValues = diagramValues[xValue];
         Q_ASSERT(yValues.count() == colCount);
diff --git a/src/KDChart/Cartesian/KDChartAbstractCartesianDiagram.cpp b/src/KDChart/Cartesian/KDChartAbstractCartesianDiagram.cpp
index 16c97dbe..727b34bb 100644
--- a/src/KDChart/Cartesian/KDChartAbstractCartesianDiagram.cpp
+++ b/src/KDChart/Cartesian/KDChartAbstractCartesianDiagram.cpp
@@ -46,7 +46,7 @@ AbstractCartesianDiagram::AbstractCartesianDiagram(QWidget *parent, CartesianCoo
 
 KDChart::AbstractCartesianDiagram::~AbstractCartesianDiagram()
 {
-    Q_FOREACH (CartesianAxis *axis, d->axesList) {
+    for (CartesianAxis *axis : qAsConst(d->axesList)) {
         axis->deleteObserver(this);
     }
     d->axesList.clear();
@@ -55,14 +55,14 @@ KDChart::AbstractCartesianDiagram::~AbstractCartesianDiagram()
 void AbstractCartesianDiagram::init()
 {
     d->compressor.setModel(attributesModel());
-    connect(this, SIGNAL(layoutChanged(AbstractDiagram *)),
-            &d->compressor, SLOT(slotDiagramLayoutChanged(AbstractDiagram *)));
-    connect(this, SIGNAL(attributesModelAboutToChange(AttributesModel *, AttributesModel *)),
-            this, SLOT(connectAttributesModel(AttributesModel *)));
+    connect(this, &AbstractCartesianDiagram::layoutChanged,
+            &d->compressor, &CartesianDiagramDataCompressor::slotDiagramLayoutChanged);
+    connect(this, &AbstractCartesianDiagram::attributesModelAboutToChange,
+            this, &AbstractCartesianDiagram::connectAttributesModel);
 
     if (d->plane) {
-        connect(d->plane, SIGNAL(viewportCoordinateSystemChanged()),
-                this, SIGNAL(viewportCoordinateSystemChanged()));
+        connect(d->plane, &AbstractCoordinatePlane::viewportCoordinateSystemChanged,
+                this, &AbstractCartesianDiagram::viewportCoordinateSystemChanged);
     }
 }
 
@@ -101,31 +101,32 @@ void KDChart::AbstractCartesianDiagram::layoutPlanes()
 void KDChart::AbstractCartesianDiagram::setCoordinatePlane(AbstractCoordinatePlane *plane)
 {
     if (coordinatePlane()) {
-        disconnect(attributesModel(), SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-                   coordinatePlane(), SLOT(relayout()));
-        disconnect(attributesModel(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-                   coordinatePlane(), SLOT(relayout()));
-        disconnect(attributesModel(), SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-                   coordinatePlane(), SLOT(relayout()));
-        disconnect(attributesModel(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-                   coordinatePlane(), SLOT(relayout()));
+        disconnect(attributesModel(), &AttributesModel::rowsRemoved,
+                   coordinatePlane(), &AbstractCoordinatePlane::relayout);
+        disconnect(attributesModel(), &AttributesModel::rowsInserted,
+                   coordinatePlane(), &AbstractCoordinatePlane::relayout);
+        disconnect(attributesModel(), &AttributesModel::columnsRemoved,
+                   coordinatePlane(), &AbstractCoordinatePlane::relayout);
+        disconnect(attributesModel(), &AttributesModel::columnsInserted,
+                   coordinatePlane(), &AbstractCoordinatePlane::relayout);
         disconnect(coordinatePlane());
     }
 
     AbstractDiagram::setCoordinatePlane(plane);
     if (plane) {
         // Readjust the layout when the dataset count changes
-        connect(attributesModel(), SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-                plane, SLOT(relayout()));
-        connect(attributesModel(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-                plane, SLOT(relayout()));
-        connect(attributesModel(), SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-                plane, SLOT(relayout()));
-        connect(attributesModel(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-                plane, SLOT(relayout()));
-        connect(plane, SIGNAL(viewportCoordinateSystemChanged()),
-                this, SIGNAL(viewportCoordinateSystemChanged()));
-        connect(plane, SIGNAL(viewportCoordinateSystemChanged()), this, SLOT(update()));
+        connect(attributesModel(), &AttributesModel::rowsRemoved,
+                plane, &AbstractCoordinatePlane::relayout);
+        connect(attributesModel(), &AttributesModel::rowsInserted,
+                plane, &AbstractCoordinatePlane::relayout);
+        connect(attributesModel(), &AttributesModel::columnsRemoved,
+                plane, &AbstractCoordinatePlane::relayout);
+        connect(attributesModel(), &AttributesModel::columnsInserted,
+                plane, &AbstractCoordinatePlane::relayout);
+        connect(plane, &AbstractCoordinatePlane::viewportCoordinateSystemChanged,
+                this, &AbstractCartesianDiagram::viewportCoordinateSystemChanged);
+        connect(plane, &AbstractCoordinatePlane::viewportCoordinateSystemChanged,
+                this, &AbstractCartesianDiagram::update);
     }
 }
 
diff --git a/src/KDChart/Cartesian/KDChartBarDiagram.cpp b/src/KDChart/Cartesian/KDChartBarDiagram.cpp
index 94f9f76a..2d5a8218 100644
--- a/src/KDChart/Cartesian/KDChartBarDiagram.cpp
+++ b/src/KDChart/Cartesian/KDChartBarDiagram.cpp
@@ -89,8 +89,8 @@ void BarDiagram::Private::setOrientationAndType(Qt::Orientation o, BarDiagram::B
     // AbstractAxis settings - see AbstractDiagram and CartesianAxis
     barDia->setPercentMode(type == BarDiagram::Percent);
     barDia->setDataBoundariesDirty();
-    emit barDia->layoutChanged(barDia);
-    emit barDia->propertiesChanged();
+    Q_EMIT barDia->layoutChanged(barDia);
+    Q_EMIT barDia->propertiesChanged();
 }
 
 #define d d_func()
@@ -180,7 +180,7 @@ Qt::Orientation BarDiagram::orientation() const
 void BarDiagram::setBarAttributes(const BarAttributes &ba)
 {
     d->attributesModel->setModelData(QVariant::fromValue(ba), BarAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -189,7 +189,7 @@ void BarDiagram::setBarAttributes(const BarAttributes &ba)
 void BarDiagram::setBarAttributes(int column, const BarAttributes &ba)
 {
     d->setDatasetAttrs(column, QVariant::fromValue(ba), BarAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -201,7 +201,7 @@ void BarDiagram::setBarAttributes(const QModelIndex &index, const BarAttributes
         d->attributesModel->mapFromSource(index),
         QVariant::fromValue(ba),
         BarAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -241,8 +241,8 @@ void BarDiagram::setThreeDBarAttributes(const ThreeDBarAttributes &threeDAttrs)
 {
     setDataBoundariesDirty();
     d->attributesModel->setModelData(QVariant::fromValue(threeDAttrs), ThreeDBarAttributesRole);
-    emit layoutChanged(this);
-    emit propertiesChanged();
+    Q_EMIT layoutChanged(this);
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -252,8 +252,8 @@ void BarDiagram::setThreeDBarAttributes(int column, const ThreeDBarAttributes &t
 {
     setDataBoundariesDirty();
     d->setDatasetAttrs(column, QVariant::fromValue(threeDAttrs), ThreeDBarAttributesRole);
-    // emit layoutChanged( this );
-    emit propertiesChanged();
+    // Q_EMIT layoutChanged( this );
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -266,8 +266,8 @@ void BarDiagram::setThreeDBarAttributes(const QModelIndex &index, const ThreeDBa
         d->attributesModel->mapFromSource(index),
         QVariant::fromValue(threeDAttrs),
         ThreeDBarAttributesRole);
-    // emit layoutChanged( this );
-    emit propertiesChanged();
+    // Q_EMIT layoutChanged( this );
+    Q_EMIT propertiesChanged();
 }
 
 /**
diff --git a/src/KDChart/Cartesian/KDChartBarDiagram_p.cpp b/src/KDChart/Cartesian/KDChartBarDiagram_p.cpp
index 05dc83c6..ac96bd22 100644
--- a/src/KDChart/Cartesian/KDChartBarDiagram_p.cpp
+++ b/src/KDChart/Cartesian/KDChartBarDiagram_p.cpp
@@ -69,7 +69,7 @@ void BarDiagram::BarDiagramType::paintBars(PaintContext *ctx, const QModelIndex
             bool drawIt = false;
             bool hasPointOutside = false;
             const QRectF r(ctx->rectangle().adjusted(0, -1, 1, 0));
-            Q_FOREACH (QPointF pt, topPoints) {
+            for (QPointF pt : qAsConst(topPoints)) {
                 if (r.contains(pt)) {
                     drawIt = true;
                 } else {
diff --git a/src/KDChart/Cartesian/KDChartCartesianAxis.cpp b/src/KDChart/Cartesian/KDChartCartesianAxis.cpp
index 15f79f36..a64d46ee 100644
--- a/src/KDChart/Cartesian/KDChartCartesianAxis.cpp
+++ b/src/KDChart/Cartesian/KDChartCartesianAxis.cpp
@@ -133,12 +133,14 @@ TickIterator::TickIterator(CartesianAxis *a, CartesianCoordinatePlane *plane, ui
 static QMultiMap<qreal, QString> allAxisAnnotations(const AbstractCoordinatePlane *plane, bool isY)
 {
     QMultiMap<qreal, QString> annotations;
-    Q_FOREACH (const AbstractDiagram *diagram, plane->diagrams()) {
+    const auto constDiagrams = plane->diagrams();
+    for (const AbstractDiagram *diagram : constDiagrams) {
         const auto *cd = qobject_cast<const AbstractCartesianDiagram *>(diagram);
         if (!cd) {
             continue;
         }
-        Q_FOREACH (const CartesianAxis *axis, cd->axes()) {
+        const auto axes = cd->axes();
+        for (const CartesianAxis *axis : axes) {
             const CartesianAxis::Private *axisPriv = CartesianAxis::Private::get(axis);
             if (axisPriv->isVertical() == isY) {
                 annotations.unite(axisPriv->annotations);
@@ -379,7 +381,7 @@ CartesianAxis::~CartesianAxis()
         auto *cd = qobject_cast<AbstractCartesianDiagram *>(d->mDiagram);
         cd->takeAxis(this);
     }
-    Q_FOREACH (AbstractDiagram *diagram, d->secondaryDiagrams) {
+    for (AbstractDiagram *diagram : qAsConst(d->secondaryDiagrams)) {
         auto *cd = qobject_cast<AbstractCartesianDiagram *>(diagram);
         cd->takeAxis(this);
     }
@@ -390,7 +392,7 @@ void CartesianAxis::init()
     d->customTickLength = 3;
     d->position = Bottom;
     setCachedSizeDirty();
-    connect(this, SIGNAL(coordinateSystemChanged()), SLOT(coordinateSystemChanged()));
+    connect(this, &AbstractAxis::coordinateSystemChanged, this, &CartesianAxis::coordinateSystemChanged);
 }
 
 bool CartesianAxis::compare(const CartesianAxis *other) const
diff --git a/src/KDChart/Cartesian/KDChartCartesianCoordinatePlane.cpp b/src/KDChart/Cartesian/KDChartCartesianCoordinatePlane.cpp
index 412ab39a..3746b8a8 100644
--- a/src/KDChart/Cartesian/KDChartCartesianCoordinatePlane.cpp
+++ b/src/KDChart/Cartesian/KDChartCartesianCoordinatePlane.cpp
@@ -61,10 +61,10 @@ void CartesianCoordinatePlane::addDiagram(AbstractDiagram *diagram)
                "CartesianCoordinatePlane::addDiagram", "Only cartesian "
                                                        "diagrams can be added to a cartesian coordinate plane!");
     AbstractCoordinatePlane::addDiagram(diagram);
-    connect(diagram, SIGNAL(layoutChanged(AbstractDiagram *)),
-            SLOT(slotLayoutChanged(AbstractDiagram *)));
+    connect(diagram, &AbstractDiagram::layoutChanged, this,
+            &CartesianCoordinatePlane::slotLayoutChanged);
 
-    connect(diagram, SIGNAL(propertiesChanged()), this, SIGNAL(propertiesChanged()));
+    connect(diagram, &AbstractDiagram::propertiesChanged, this, &CartesianCoordinatePlane::propertiesChanged);
 }
 
 void CartesianCoordinatePlane::paint(QPainter *painter)
@@ -127,7 +127,8 @@ QRectF CartesianCoordinatePlane::getRawDataBoundingRectFromDiagrams() const
     qreal minY = 0;
     qreal maxY = 0;
     bool bStarting = true;
-    Q_FOREACH (const AbstractDiagram *diagram, diagrams()) {
+    const auto constDiagrams = diagrams();
+    for (const AbstractDiagram *diagram : constDiagrams) {
         QPair<QPointF, QPointF> dataBoundariesPair = diagram->dataBoundaries();
         // qDebug() << "CartesianCoordinatePlane::getRawDataBoundingRectFromDiagrams()\ngets diagram->dataBoundaries: " << dataBoundariesPair.first << dataBoundariesPair.second;
         if (bStarting || dataBoundariesPair.first.x() < minX)
@@ -413,7 +414,7 @@ void CartesianCoordinatePlane::handleFixedDataCoordinateSpaceRelation(const QRec
         if (doneSetZoomCenter(newCenter))
             changed = true;
         if (changed)
-            emit propertiesChanged();
+            Q_EMIT propertiesChanged();
     }
 }
 
@@ -436,7 +437,7 @@ void CartesianCoordinatePlane::setIsometricScaling(bool isOn)
     if (d->isometricScaling != isOn) {
         d->isometricScaling = isOn;
         layoutDiagrams();
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -485,7 +486,7 @@ void CartesianCoordinatePlane::setZoomFactors(qreal factorX, qreal factorY)
 {
     if (doneSetZoomFactorX(factorX) || doneSetZoomFactorY(factorY)) {
         d->coordinateTransformation.updateTransform(logicalArea(), drawingArea());
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -493,7 +494,7 @@ void CartesianCoordinatePlane::setZoomFactorX(qreal factor)
 {
     if (doneSetZoomFactorX(factor)) {
         d->coordinateTransformation.updateTransform(logicalArea(), drawingArea());
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -501,7 +502,7 @@ void CartesianCoordinatePlane::setZoomFactorY(qreal factor)
 {
     if (doneSetZoomFactorY(factor)) {
         d->coordinateTransformation.updateTransform(logicalArea(), drawingArea());
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -509,7 +510,7 @@ void CartesianCoordinatePlane::setZoomCenter(const QPointF &point)
 {
     if (doneSetZoomCenter(point)) {
         d->coordinateTransformation.updateTransform(logicalArea(), drawingArea());
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -543,10 +544,12 @@ void CartesianCoordinatePlane::setAxesCalcModes(AxesCalcMode mode)
     if (d->coordinateTransformation.axesCalcModeY != mode || d->coordinateTransformation.axesCalcModeX != mode) {
         d->coordinateTransformation.axesCalcModeY = mode;
         d->coordinateTransformation.axesCalcModeX = mode;
-        emit propertiesChanged();
-        emit viewportCoordinateSystemChanged();
-        Q_FOREACH (AbstractDiagram *diag, diagrams())
+        Q_EMIT propertiesChanged();
+        Q_EMIT viewportCoordinateSystemChanged();
+        const auto constDiagrams = diagrams();
+        for (AbstractDiagram *diag : constDiagrams) {
             slotLayoutChanged(diag);
+        }
     }
 }
 
@@ -554,9 +557,9 @@ void CartesianCoordinatePlane::setAxesCalcModeY(AxesCalcMode mode)
 {
     if (d->coordinateTransformation.axesCalcModeY != mode) {
         d->coordinateTransformation.axesCalcModeY = mode;
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
         setGridNeedsRecalculate();
-        emit viewportCoordinateSystemChanged();
+        Q_EMIT viewportCoordinateSystemChanged();
     }
 }
 
@@ -564,8 +567,8 @@ void CartesianCoordinatePlane::setAxesCalcModeX(AxesCalcMode mode)
 {
     if (d->coordinateTransformation.axesCalcModeX != mode) {
         d->coordinateTransformation.axesCalcModeX = mode;
-        emit propertiesChanged();
-        emit viewportCoordinateSystemChanged();
+        Q_EMIT propertiesChanged();
+        Q_EMIT viewportCoordinateSystemChanged();
     }
 }
 
@@ -588,8 +591,8 @@ void CartesianCoordinatePlane::setHorizontalRange(const QPair<qreal, qreal> &ran
         d->horizontalMin = range.first;
         d->horizontalMax = range.second;
         layoutDiagrams();
-        emit propertiesChanged();
-        emit boundariesChanged();
+        Q_EMIT propertiesChanged();
+        Q_EMIT boundariesChanged();
     }
 }
 
@@ -601,8 +604,8 @@ void CartesianCoordinatePlane::setVerticalRange(const QPair<qreal, qreal> &range
         d->verticalMin = range.first;
         d->verticalMax = range.second;
         layoutDiagrams();
-        emit propertiesChanged();
-        emit boundariesChanged();
+        Q_EMIT propertiesChanged();
+        Q_EMIT boundariesChanged();
     }
 }
 
@@ -624,7 +627,7 @@ void CartesianCoordinatePlane::adjustRangesToData()
     d->verticalMin = dataBoundingRect.top();
     d->verticalMax = dataBoundingRect.bottom();
     layoutDiagrams();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void CartesianCoordinatePlane::adjustHorizontalRangeToData()
@@ -633,7 +636,7 @@ void CartesianCoordinatePlane::adjustHorizontalRangeToData()
     d->horizontalMin = dataBoundingRect.left();
     d->horizontalMax = dataBoundingRect.right();
     layoutDiagrams();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void CartesianCoordinatePlane::adjustVerticalRangeToData()
@@ -642,7 +645,7 @@ void CartesianCoordinatePlane::adjustVerticalRangeToData()
     d->verticalMin = dataBoundingRect.bottom();
     d->verticalMax = dataBoundingRect.top();
     layoutDiagrams();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void CartesianCoordinatePlane::setAutoAdjustHorizontalRangeToData(unsigned int percentEmpty)
@@ -652,7 +655,7 @@ void CartesianCoordinatePlane::setAutoAdjustHorizontalRangeToData(unsigned int p
         d->horizontalMin = 0.0;
         d->horizontalMax = 0.0;
         layoutDiagrams();
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -663,7 +666,7 @@ void CartesianCoordinatePlane::setAutoAdjustVerticalRangeToData(unsigned int per
         d->verticalMin = 0.0;
         d->verticalMax = 0.0;
         layoutDiagrams();
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -687,7 +690,7 @@ void CartesianCoordinatePlane::setGridAttributes(
         d->gridAttributesVertical = a;
     setHasOwnGridAttributes(orientation, true);
     update();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void CartesianCoordinatePlane::resetGridAttributes(Qt::Orientation orientation)
@@ -714,7 +717,7 @@ void CartesianCoordinatePlane::setHasOwnGridAttributes(Qt::Orientation orientati
         d->hasOwnGridAttributesHorizontal = on;
     else
         d->hasOwnGridAttributesVertical = on;
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 bool CartesianCoordinatePlane::hasOwnGridAttributes(Qt::Orientation orientation) const
@@ -728,7 +731,7 @@ void CartesianCoordinatePlane::setAutoAdjustGridToZoom(bool autoAdjust)
     if (d->autoAdjustGridToZoom != autoAdjust) {
         d->autoAdjustGridToZoom = autoAdjust;
         d->grid->setNeedRecalculate();
-        emit propertiesChanged();
+        Q_EMIT propertiesChanged();
     }
 }
 
@@ -748,7 +751,7 @@ AbstractCoordinatePlane *CartesianCoordinatePlane::sharedAxisMasterPlane(QPainte
     const CartesianAxis *sharedAxis = nullptr;
     if (diag != nullptr) {
         const CartesianAxisList axes = diag->axes();
-        Q_FOREACH (const CartesianAxis *a, axes) {
+        for (const CartesianAxis *a : axes) {
             auto *p = const_cast<CartesianCoordinatePlane *>(
                 dynamic_cast<const CartesianCoordinatePlane *>(a->coordinatePlane()));
             if (p != nullptr && p != this) {
@@ -788,7 +791,7 @@ void CartesianCoordinatePlane::setHorizontalRangeReversed(bool reverse)
 
     d->reverseHorizontalPlane = reverse;
     layoutDiagrams();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 bool CartesianCoordinatePlane::isHorizontalRangeReversed() const
@@ -803,7 +806,7 @@ void CartesianCoordinatePlane::setVerticalRangeReversed(bool reverse)
 
     d->reverseVerticalPlane = reverse;
     layoutDiagrams();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 bool CartesianCoordinatePlane::isVerticalRangeReversed() const
@@ -843,7 +846,8 @@ void CartesianCoordinatePlane::setGeometry(const QRect &rectangle)
 
     AbstractCoordinatePlane::setGeometry(d->geometry);
 
-    Q_FOREACH (AbstractDiagram *diagram, diagrams()) {
+    const auto constDiagrams = diagrams();
+    for (AbstractDiagram *diagram : constDiagrams) {
         diagram->resize(d->geometry.size());
     }
 }
diff --git a/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.cpp b/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.cpp
index 8889f979..97e20698 100644
--- a/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.cpp
+++ b/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.cpp
@@ -52,7 +52,8 @@ CartesianDiagramDataCompressor::AggregatedDataValueAttributes CartesianDiagramDa
 
     // aggregate attributes from all indices in the same CachePosition as index
     CartesianDiagramDataCompressor::AggregatedDataValueAttributes aggregated;
-    Q_FOREACH (const QModelIndex &neighborIndex, mapToModel(position)) {
+    const auto modelList = mapToModel(position);
+    for (const QModelIndex &neighborIndex : modelList) {
         DataValueAttributes attrs = diagram->dataValueAttributes(neighborIndex);
         // only store visible and unique attributes
         if (!attrs.isVisible()) {
@@ -283,30 +284,30 @@ void CartesianDiagramDataCompressor::setModel(QAbstractItemModel *model)
     }
 
     if (m_model != nullptr) {
-        disconnect(m_model, SIGNAL(headerDataChanged(Qt::Orientation, int, int)),
-                   this, SLOT(slotModelHeaderDataChanged(Qt::Orientation, int, int)));
-        disconnect(m_model, SIGNAL(dataChanged(QModelIndex, QModelIndex)),
-                   this, SLOT(slotModelDataChanged(QModelIndex, QModelIndex)));
-        disconnect(m_model, SIGNAL(layoutChanged()),
-                   this, SLOT(slotModelLayoutChanged()));
-        disconnect(m_model, SIGNAL(rowsAboutToBeInserted(QModelIndex, int, int)),
-                   this, SLOT(slotRowsAboutToBeInserted(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(rowsInserted(QModelIndex, int, int)),
-                   this, SLOT(slotRowsInserted(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(rowsAboutToBeRemoved(QModelIndex, int, int)),
-                   this, SLOT(slotRowsAboutToBeRemoved(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(rowsRemoved(QModelIndex, int, int)),
-                   this, SLOT(slotRowsRemoved(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(columnsAboutToBeInserted(QModelIndex, int, int)),
-                   this, SLOT(slotColumnsAboutToBeInserted(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(columnsInserted(QModelIndex, int, int)),
-                   this, SLOT(slotColumnsInserted(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(columnsRemoved(QModelIndex, int, int)),
-                   this, SLOT(slotColumnsRemoved(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(columnsAboutToBeRemoved(QModelIndex, int, int)),
-                   this, SLOT(slotColumnsAboutToBeRemoved(QModelIndex, int, int)));
-        disconnect(m_model, SIGNAL(modelReset()),
-                   this, SLOT(rebuildCache()));
+        disconnect(m_model, &QAbstractItemModel::headerDataChanged,
+                   this, &CartesianDiagramDataCompressor::slotModelHeaderDataChanged);
+        disconnect(m_model, &QAbstractItemModel::dataChanged,
+                   this, &CartesianDiagramDataCompressor::slotModelDataChanged);
+        disconnect(m_model, &QAbstractItemModel::layoutChanged,
+                   this, &CartesianDiagramDataCompressor::slotModelLayoutChanged);
+        disconnect(m_model, &QAbstractItemModel::rowsAboutToBeInserted,
+                   this, &CartesianDiagramDataCompressor::slotRowsAboutToBeInserted);
+        disconnect(m_model, &QAbstractItemModel::rowsInserted,
+                   this, &CartesianDiagramDataCompressor::slotRowsInserted);
+        disconnect(m_model, &QAbstractItemModel::rowsAboutToBeRemoved,
+                   this, &CartesianDiagramDataCompressor::slotRowsAboutToBeRemoved);
+        disconnect(m_model, &QAbstractItemModel::rowsRemoved,
+                   this, &CartesianDiagramDataCompressor::slotRowsRemoved);
+        disconnect(m_model, &QAbstractItemModel::columnsAboutToBeInserted,
+                   this, &CartesianDiagramDataCompressor::slotColumnsAboutToBeInserted);
+        disconnect(m_model, &QAbstractItemModel::columnsInserted,
+                   this, &CartesianDiagramDataCompressor::slotColumnsInserted);
+        disconnect(m_model, &QAbstractItemModel::columnsRemoved,
+                   this, &CartesianDiagramDataCompressor::slotColumnsRemoved);
+        disconnect(m_model, &QAbstractItemModel::columnsAboutToBeRemoved,
+                   this, &CartesianDiagramDataCompressor::slotColumnsAboutToBeRemoved);
+        disconnect(m_model, &QAbstractItemModel::modelReset,
+                   this, &CartesianDiagramDataCompressor::rebuildCache);
         m_model = nullptr;
     }
 
@@ -314,29 +315,30 @@ void CartesianDiagramDataCompressor::setModel(QAbstractItemModel *model)
 
     if (model != nullptr) {
         m_model = model;
-        connect(m_model, SIGNAL(headerDataChanged(Qt::Orientation, int, int)),
-                SLOT(slotModelHeaderDataChanged(Qt::Orientation, int, int)));
-        connect(m_model, SIGNAL(dataChanged(QModelIndex, QModelIndex)),
-                SLOT(slotModelDataChanged(QModelIndex, QModelIndex)));
-        connect(m_model, SIGNAL(layoutChanged()),
-                SLOT(slotModelLayoutChanged()));
-        connect(m_model, SIGNAL(rowsAboutToBeInserted(QModelIndex, int, int)),
-                SLOT(slotRowsAboutToBeInserted(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(rowsInserted(QModelIndex, int, int)),
-                SLOT(slotRowsInserted(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(rowsAboutToBeRemoved(QModelIndex, int, int)),
-                SLOT(slotRowsAboutToBeRemoved(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(rowsRemoved(QModelIndex, int, int)),
-                SLOT(slotRowsRemoved(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(columnsAboutToBeInserted(QModelIndex, int, int)),
-                SLOT(slotColumnsAboutToBeInserted(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(columnsInserted(QModelIndex, int, int)),
-                SLOT(slotColumnsInserted(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(columnsRemoved(QModelIndex, int, int)),
-                SLOT(slotColumnsRemoved(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(columnsAboutToBeRemoved(QModelIndex, int, int)),
-                SLOT(slotColumnsAboutToBeRemoved(QModelIndex, int, int)));
-        connect(m_model, SIGNAL(modelReset()), SLOT(rebuildCache()));
+        connect(m_model, &QAbstractItemModel::headerDataChanged,
+                this, &CartesianDiagramDataCompressor::slotModelHeaderDataChanged);
+        connect(m_model, &QAbstractItemModel::dataChanged,
+                this, &CartesianDiagramDataCompressor::slotModelDataChanged);
+        connect(m_model, &QAbstractItemModel::layoutChanged,
+                this, &CartesianDiagramDataCompressor::slotModelLayoutChanged);
+        connect(m_model, &QAbstractItemModel::rowsAboutToBeInserted,
+                this, &CartesianDiagramDataCompressor::slotRowsAboutToBeInserted);
+        connect(m_model, &QAbstractItemModel::rowsInserted,
+                this, &CartesianDiagramDataCompressor::slotRowsInserted);
+        connect(m_model, &QAbstractItemModel::rowsAboutToBeRemoved,
+                this, &CartesianDiagramDataCompressor::slotRowsAboutToBeRemoved);
+        connect(m_model, &QAbstractItemModel::rowsRemoved,
+                this, &CartesianDiagramDataCompressor::slotRowsRemoved);
+        connect(m_model, &QAbstractItemModel::columnsAboutToBeInserted,
+                this, &CartesianDiagramDataCompressor::slotColumnsAboutToBeInserted);
+        connect(m_model, &QAbstractItemModel::columnsInserted,
+                this, &CartesianDiagramDataCompressor::slotColumnsInserted);
+        connect(m_model, &QAbstractItemModel::columnsRemoved,
+                this, &CartesianDiagramDataCompressor::slotColumnsRemoved);
+        connect(m_model, &QAbstractItemModel::columnsAboutToBeRemoved,
+                this, &CartesianDiagramDataCompressor::slotColumnsAboutToBeRemoved);
+        connect(m_model, &QAbstractItemModel::modelReset,
+                this, &CartesianDiagramDataCompressor::rebuildCache);
     }
     rebuildCache();
     calculateSampleStepWidth();
@@ -478,7 +480,7 @@ void CartesianDiagramDataCompressor::retrieveModelData(const CachePosition &posi
             }
             result.value = std::numeric_limits<qreal>::quiet_NaN();
             result.key = 0.0;
-            Q_FOREACH (const QModelIndex &index, indexes) {
+            for (const QModelIndex &index : indexes) {
                 const qreal value = m_modelCache.data(index);
                 if (!ISNAN(value)) {
                     result.value = ISNAN(result.value) ? value : result.value + value;
@@ -490,7 +492,7 @@ void CartesianDiagramDataCompressor::retrieveModelData(const CachePosition &posi
             result.value /= indexes.size();
         }
 
-        Q_FOREACH (const QModelIndex &index, indexes) {
+        for (const QModelIndex &index : indexes) {
             // the DataPoint point is visible if any of the underlying, aggregated points is visible
             if (m_model->data(index, DataHiddenRole).value<bool>() == false) {
                 result.hidden = false;
diff --git a/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.h b/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.h
index 2b600ff3..3ba16a48 100644
--- a/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.h
+++ b/src/KDChart/Cartesian/KDChartCartesianDiagramDataCompressor_p.h
@@ -61,6 +61,7 @@ class KDCHART_EXPORT CartesianDiagramDataCompressor : public QObject
 {
     Q_OBJECT
     friend class ::CartesianDiagramDataCompressorTests;
+    friend class AbstractCartesianDiagram;
 
 public:
     class DataPoint
diff --git a/src/KDChart/Cartesian/KDChartLeveyJenningsAxis.cpp b/src/KDChart/Cartesian/KDChartLeveyJenningsAxis.cpp
index f04ae992..a37fe028 100644
--- a/src/KDChart/Cartesian/KDChartLeveyJenningsAxis.cpp
+++ b/src/KDChart/Cartesian/KDChartLeveyJenningsAxis.cpp
@@ -44,7 +44,7 @@ LeveyJenningsAxis::~LeveyJenningsAxis()
         auto *cd = qobject_cast<LeveyJenningsDiagram *>(d->mDiagram);
         cd->takeAxis(this);
     }
-    Q_FOREACH (AbstractDiagram *diagram, d->secondaryDiagrams) {
+    for (AbstractDiagram *diagram : qAsConst(d->secondaryDiagrams)) {
         auto *cd = qobject_cast<LeveyJenningsDiagram *>(diagram);
         cd->takeAxis(this);
     }
diff --git a/src/KDChart/Cartesian/KDChartLeveyJenningsDiagram.cpp b/src/KDChart/Cartesian/KDChartLeveyJenningsDiagram.cpp
index 0ec8d628..f5f6f8f2 100644
--- a/src/KDChart/Cartesian/KDChartLeveyJenningsDiagram.cpp
+++ b/src/KDChart/Cartesian/KDChartLeveyJenningsDiagram.cpp
@@ -300,40 +300,41 @@ float LeveyJenningsDiagram::calculatedStandardDeviation() const
     return d->calculatedStandardDeviation;
 }
 
-void LeveyJenningsDiagram::setModel(QAbstractItemModel *model)
-{
-    if (this->model() != nullptr) {
-        disconnect(this->model(), SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
-                   this, SLOT(calculateMeanAndStandardDeviation()));
-        disconnect(this->model(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-                   this, SLOT(calculateMeanAndStandardDeviation()));
-        disconnect(this->model(), SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-                   this, SLOT(calculateMeanAndStandardDeviation()));
-        disconnect(this->model(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-                   this, SLOT(calculateMeanAndStandardDeviation()));
-        disconnect(this->model(), SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-                   this, SLOT(calculateMeanAndStandardDeviation()));
-        disconnect(this->model(), SIGNAL(modelReset()),
-                   this, SLOT(calculateMeanAndStandardDeviation()));
-        disconnect(this->model(), SIGNAL(layoutChanged()),
-                   this, SLOT(calculateMeanAndStandardDeviation()));
+void LeveyJenningsDiagram::setModel(QAbstractItemModel *newModel)
+{
+    QAbstractItemModel *oldModel = model();
+    if (oldModel != nullptr) {
+        disconnect(oldModel, &QAbstractItemModel::dataChanged,
+                   this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        disconnect(oldModel, &QAbstractItemModel::rowsInserted,
+                   this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        disconnect(oldModel, &QAbstractItemModel::rowsRemoved,
+                   this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        disconnect(oldModel, &QAbstractItemModel::columnsInserted,
+                   this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        disconnect(oldModel, &QAbstractItemModel::columnsRemoved,
+                   this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        disconnect(oldModel, &QAbstractItemModel::modelReset,
+                   this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        disconnect(oldModel, &QAbstractItemModel::layoutChanged,
+                   this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
     }
-    LineDiagram::setModel(model);
-    if (this->model() != nullptr) {
-        connect(this->model(), SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
-                this, SLOT(calculateMeanAndStandardDeviation()));
-        connect(this->model(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-                this, SLOT(calculateMeanAndStandardDeviation()));
-        connect(this->model(), SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-                this, SLOT(calculateMeanAndStandardDeviation()));
-        connect(this->model(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-                this, SLOT(calculateMeanAndStandardDeviation()));
-        connect(this->model(), SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-                this, SLOT(calculateMeanAndStandardDeviation()));
-        connect(this->model(), SIGNAL(modelReset()),
-                this, SLOT(calculateMeanAndStandardDeviation()));
-        connect(this->model(), SIGNAL(layoutChanged()),
-                this, SLOT(calculateMeanAndStandardDeviation()));
+    LineDiagram::setModel(newModel);
+    if (newModel != nullptr) {
+        connect(newModel, &QAbstractItemModel::dataChanged,
+                this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        connect(newModel, &QAbstractItemModel::rowsInserted,
+                this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        connect(newModel, &QAbstractItemModel::rowsRemoved,
+                this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        connect(newModel, &QAbstractItemModel::columnsInserted,
+                this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        connect(newModel, &QAbstractItemModel::columnsRemoved,
+                this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        connect(newModel, &QAbstractItemModel::modelReset,
+                this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
+        connect(newModel, &QAbstractItemModel::layoutChanged,
+                this, &LeveyJenningsDiagram::calculateMeanAndStandardDeviation);
 
         calculateMeanAndStandardDeviation();
     }
@@ -360,7 +361,7 @@ void LeveyJenningsDiagram::calculateMeanAndStandardDeviation() const
 
     qreal sum = 0.0;
     qreal sumSquares = 0.0;
-    Q_FOREACH (qreal value, values) {
+    for (qreal value : qAsConst(values)) {
         sum += value;
         sumSquares += value * value;
     }
@@ -477,13 +478,13 @@ void LeveyJenningsDiagram::drawChanges(PaintContext *ctx)
 {
     const unsigned int minTime = timeRange().first.toSecsSinceEpoch();
 
-    Q_FOREACH (const QDateTime &dt, d->fluidicsPackChanges) {
+    for (const QDateTime &dt : qAsConst(d->fluidicsPackChanges)) {
         const qreal xValue = (dt.toSecsSinceEpoch() - minTime) / static_cast<qreal>(24 * 60 * 60);
         const QPointF point(xValue, 0.0);
         drawFluidicsPackChangedSymbol(ctx, point);
     }
 
-    Q_FOREACH (const QDateTime &dt, d->sensorChanges) {
+    for (const QDateTime &dt : qAsConst(d->sensorChanges)) {
         const qreal xValue = (dt.toSecsSinceEpoch() - minTime) / static_cast<qreal>(24 * 60 * 60);
         const QPointF point(xValue, 0.0);
         drawSensorChangedSymbol(ctx, point);
diff --git a/src/KDChart/Cartesian/KDChartLineDiagram.cpp b/src/KDChart/Cartesian/KDChartLineDiagram.cpp
index d9f32810..5f1b6db4 100644
--- a/src/KDChart/Cartesian/KDChartLineDiagram.cpp
+++ b/src/KDChart/Cartesian/KDChartLineDiagram.cpp
@@ -121,8 +121,8 @@ void LineDiagram::setType(const LineType type)
     // AbstractAxis settings - see AbstractDiagram and CartesianAxis
     setPercentMode(type == LineDiagram::Percent);
     setDataBoundariesDirty();
-    emit layoutChanged(this);
-    emit propertiesChanged();
+    Q_EMIT layoutChanged(this);
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -144,8 +144,8 @@ void LineDiagram::setCenterDataPoints(bool center)
     //  A      B    =\        A      B
     //  1......2    =/    1......2......3
     setDataBoundariesDirty();
-    emit layoutChanged(this);
-    emit propertiesChanged();
+    Q_EMIT layoutChanged(this);
+    Q_EMIT propertiesChanged();
 }
 
 bool LineDiagram::centerDataPoints() const
@@ -171,7 +171,7 @@ void LineDiagram::setLineAttributes(const LineAttributes &la)
     d->attributesModel->setModelData(
         QVariant::fromValue(la),
         LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -182,7 +182,7 @@ void LineDiagram::setLineAttributes(
     const LineAttributes &la)
 {
     d->setDatasetAttrs(column, QVariant::fromValue(la), LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -191,7 +191,7 @@ void LineDiagram::setLineAttributes(
 void LineDiagram::resetLineAttributes(int column)
 {
     d->resetDatasetAttrs(column, LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -205,7 +205,7 @@ void LineDiagram::setLineAttributes(
         d->attributesModel->mapFromSource(index),
         QVariant::fromValue(la),
         LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -215,7 +215,7 @@ void LineDiagram::resetLineAttributes(const QModelIndex &index)
 {
     d->attributesModel->resetData(
         d->attributesModel->mapFromSource(index), LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -259,7 +259,7 @@ void LineDiagram::setThreeDLineAttributes(
     d->attributesModel->setModelData(
         QVariant::fromValue(la),
         ThreeDLineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -271,7 +271,7 @@ void LineDiagram::setThreeDLineAttributes(
 {
     setDataBoundariesDirty();
     d->setDatasetAttrs(column, QVariant::fromValue(la), ThreeDLineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -286,7 +286,7 @@ void LineDiagram::setThreeDLineAttributes(
         d->attributesModel->mapFromSource(index),
         QVariant::fromValue(la),
         ThreeDLineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -338,7 +338,7 @@ void LineDiagram::setValueTrackerAttributes(const QModelIndex &index,
     d->attributesModel->setData(d->attributesModel->mapFromSource(index),
                                 QVariant::fromValue(va),
                                 KDChart::ValueTrackerAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -364,7 +364,7 @@ qreal LineDiagram::lineTension() const
 void LineDiagram::setLineTension(qreal tension)
 {
     d->tension = tension;
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void LineDiagram::resizeEvent(QResizeEvent *)
diff --git a/src/KDChart/Cartesian/KDChartPlotter.cpp b/src/KDChart/Cartesian/KDChartPlotter.cpp
index 35147b9a..770b49e9 100644
--- a/src/KDChart/Cartesian/KDChartPlotter.cpp
+++ b/src/KDChart/Cartesian/KDChartPlotter.cpp
@@ -45,14 +45,14 @@ void Plotter::init()
     d->normalPlotter = new NormalPlotter(this);
     d->percentPlotter = new PercentPlotter(this);
     d->implementor = d->normalPlotter;
-    QObject *test = d->implementor->plotterPrivate();
-    connect(this, SIGNAL(boundariesChanged()), test, SLOT(changedProperties()));
-    // The signal is connected to the superclass's slot at this point because the connection happened
+    Private *test = d->implementor->plotterPrivate();
+    connect(this, &Plotter::boundariesChanged, test, &Private::changedProperties);
+    // The signal is connected to the superclass's AbstractDiagram slot at this point because the connection happened
     // in its constructor when "its type was not Plotter yet".
-    disconnect(this, SIGNAL(attributesModelAboutToChange(AttributesModel *, AttributesModel *)),
-               this, SLOT(connectAttributesModel(AttributesModel *)));
-    connect(this, SIGNAL(attributesModelAboutToChange(AttributesModel *, AttributesModel *)),
-            this, SLOT(connectAttributesModel(AttributesModel *)));
+    disconnect(this, &AbstractDiagram::attributesModelAboutToChange,
+               this, &Plotter::connectAttributesModel);
+    connect(this, &Plotter::attributesModelAboutToChange,
+            this, &Plotter::connectAttributesModel);
     setDatasetDimensionInternal(2);
 }
 
@@ -95,12 +95,12 @@ void Plotter::connectAttributesModel(AttributesModel *newModel)
         d->compressor.setModel(nullptr);
         if (attributesModel() != d->plotterCompressor.model()) {
             d->plotterCompressor.setModel(attributesModel());
-            connect(&d->plotterCompressor, SIGNAL(boundariesChanged()), this, SLOT(setDataBoundariesDirty()));
+            connect(&d->plotterCompressor, &PlotterDiagramCompressor::boundariesChanged, this, &Plotter::setDataBoundariesDirty);
             if (useDataCompression() != Plotter::SLOPE) {
-                connect(coordinatePlane(), SIGNAL(internal_geometryChanged(QRect, QRect)),
-                        this, SLOT(setDataBoundariesDirty()));
-                connect(coordinatePlane(), SIGNAL(geometryChanged(QRect, QRect)),
-                        this, SLOT(setDataBoundariesDirty()));
+                connect(coordinatePlane(), &AbstractCoordinatePlane::internal_geometryChanged,
+                        this, &Plotter::setDataBoundariesDirty);
+                connect(coordinatePlane(), &AbstractCoordinatePlane::geometryChanged,
+                        this, &Plotter::setDataBoundariesDirty);
                 calcMergeRadius();
             }
         }
@@ -171,8 +171,8 @@ void Plotter::setType(const PlotType type)
     default:
         Q_ASSERT_X(false, "Plotter::setType", "unknown plotter subtype");
     }
-    bool connection = connect(this, SIGNAL(boundariesChanged()),
-                              d->implementor->plotterPrivate(), SLOT(changedProperties()));
+    bool connection = connect(this, &Plotter::boundariesChanged,
+                              d->implementor->plotterPrivate(), &KDChart::Plotter::Private::changedProperties);
     Q_ASSERT(connection);
     Q_UNUSED(connection);
 
@@ -180,8 +180,8 @@ void Plotter::setType(const PlotType type)
     Q_ASSERT(d->implementor->type() == type);
 
     setDataBoundariesDirty();
-    emit layoutChanged(this);
-    emit propertiesChanged();
+    Q_EMIT layoutChanged(this);
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -198,7 +198,7 @@ Plotter::PlotType Plotter::type() const
 void Plotter::setLineAttributes(const LineAttributes &la)
 {
     d->attributesModel->setModelData(QVariant::fromValue(la), LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -207,7 +207,7 @@ void Plotter::setLineAttributes(const LineAttributes &la)
 void Plotter::setLineAttributes(int column, const LineAttributes &la)
 {
     d->setDatasetAttrs(column, QVariant::fromValue(la), LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -216,7 +216,7 @@ void Plotter::setLineAttributes(int column, const LineAttributes &la)
 void Plotter::resetLineAttributes(int column)
 {
     d->resetDatasetAttrs(column, LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -226,7 +226,7 @@ void Plotter::setLineAttributes(const QModelIndex &index, const LineAttributes &
 {
     d->attributesModel->setData(d->attributesModel->mapFromSource(index),
                                 QVariant::fromValue(la), LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -236,7 +236,7 @@ void Plotter::resetLineAttributes(const QModelIndex &index)
 {
     d->attributesModel->resetData(
         d->attributesModel->mapFromSource(index), LineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -275,7 +275,7 @@ void Plotter::setThreeDLineAttributes(const ThreeDLineAttributes &la)
 {
     setDataBoundariesDirty();
     d->attributesModel->setModelData(QVariant::fromValue(la), ThreeDLineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -285,7 +285,7 @@ void Plotter::setThreeDLineAttributes(int column, const ThreeDLineAttributes &la
 {
     setDataBoundariesDirty();
     d->setDatasetAttrs(column, QVariant::fromValue(la), ThreeDLineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -296,7 +296,7 @@ void Plotter::setThreeDLineAttributes(const QModelIndex &index, const ThreeDLine
     setDataBoundariesDirty();
     d->attributesModel->setData(d->attributesModel->mapFromSource(index), QVariant::fromValue(la),
                                 ThreeDLineAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -346,7 +346,7 @@ void Plotter::setValueTrackerAttributes(const QModelIndex &index, const ValueTra
 {
     d->attributesModel->setData(d->attributesModel->mapFromSource(index),
                                 QVariant::fromValue(va), KDChart::ValueTrackerAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
diff --git a/src/KDChart/Cartesian/KDChartPlotterDiagramCompressor.cpp b/src/KDChart/Cartesian/KDChartPlotterDiagramCompressor.cpp
index 4f9cf832..1402a44a 100644
--- a/src/KDChart/Cartesian/KDChartPlotterDiagramCompressor.cpp
+++ b/src/KDChart/Cartesian/KDChartPlotterDiagramCompressor.cpp
@@ -523,7 +523,7 @@ bool PlotterDiagramCompressor::Private::inBoundaries(Qt::Orientation orient, con
 //        }
 //    }
 //    setBoundaries( qMakePair( QPointF( minX, minY ), QPointF( maxX, maxY ) ) );
-//    emit m_parent->rowCountChanged();
+//    Q_EMIT m_parent->rowCountChanged();
 //}
 #include <QDebug>
 // TODO this is not threadsafe do never try to invoke the painting in a different thread than this
@@ -629,7 +629,7 @@ void PlotterDiagramCompressor::Private::rowsInserted(const QModelIndex & /*paren
             }
         }
     }
-    emit m_parent->rowCountChanged();
+    Q_EMIT m_parent->rowCountChanged();
 }
 
 void PlotterDiagramCompressor::setCompressionModel(CompressionMode value)
@@ -638,7 +638,7 @@ void PlotterDiagramCompressor::setCompressionModel(CompressionMode value)
     if (d->m_mode != value) {
         d->m_mode = value;
         d->clearBuffer();
-        emit rowCountChanged();
+        Q_EMIT rowCountChanged();
     }
 }
 
@@ -646,7 +646,7 @@ void PlotterDiagramCompressor::Private::setBoundaries(const Boundaries &bound)
 {
     if (bound != m_boundary) {
         m_boundary = bound;
-        emit m_parent->boundariesChanged();
+        Q_EMIT m_parent->boundariesChanged();
     }
 }
 
@@ -735,7 +735,7 @@ void PlotterDiagramCompressor::setForcedDataBoundaries(const QPair<qreal, qreal>
         d->m_forcedXBoundaries = bounds;
     }
     d->clearBuffer();
-    emit boundariesChanged();
+    Q_EMIT boundariesChanged();
 }
 
 QAbstractItemModel *PlotterDiagramCompressor::model() const
@@ -756,9 +756,9 @@ void PlotterDiagramCompressor::setModel(QAbstractItemModel *model)
         d->m_bufferlist.resize(datasetCount());
         d->m_accumulatedDistances.resize(datasetCount());
         d->calculateDataBoundaries();
-        connect(d->m_model, SIGNAL(rowsInserted(QModelIndex, int, int)), d, SLOT(rowsInserted(QModelIndex, int, int)));
-        connect(d->m_model, SIGNAL(modelReset()), d, SLOT(clearBuffer()));
-        connect(d->m_model, SIGNAL(destroyed(QObject *)), d, SLOT(setModelToZero()));
+        connect(d->m_model, &QAbstractItemModel::rowsInserted, d, &Private::rowsInserted);
+        connect(d->m_model, &QAbstractItemModel::modelReset, d, &Private::clearBuffer);
+        connect(d->m_model, &QAbstractItemModel::destroyed, d, &Private::setModelToZero);
     }
 }
 
@@ -786,7 +786,7 @@ void PlotterDiagramCompressor::setMergeRadius(qreal radius)
     if (d->m_mergeRadius != radius) {
         d->m_mergeRadius = radius;
         if (d->m_mode != PlotterDiagramCompressor::SLOPE)
-            emit rowCountChanged();
+            Q_EMIT rowCountChanged();
     }
 }
 
@@ -794,7 +794,7 @@ void PlotterDiagramCompressor::setMaxSlopeChange(qreal value)
 {
     if (d->m_maxSlopeRadius != value) {
         d->m_maxSlopeRadius = value;
-        emit boundariesChanged();
+        Q_EMIT boundariesChanged();
     }
 }
 
diff --git a/src/KDChart/Cartesian/KDChartStockDiagram.cpp b/src/KDChart/Cartesian/KDChartStockDiagram.cpp
index 009b69e8..f9b0e8a0 100644
--- a/src/KDChart/Cartesian/KDChartStockDiagram.cpp
+++ b/src/KDChart/Cartesian/KDChartStockDiagram.cpp
@@ -57,7 +57,7 @@ void StockDiagram::init()
 void StockDiagram::setType(Type type)
 {
     d->type = type;
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -73,7 +73,7 @@ void StockDiagram::setStockBarAttributes(const StockBarAttributes &attr)
     attributesModel()->setModelData(
         QVariant::fromValue(attr),
         StockBarAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 StockBarAttributes StockDiagram::stockBarAttributes() const
@@ -84,7 +84,7 @@ StockBarAttributes StockDiagram::stockBarAttributes() const
 void StockDiagram::setStockBarAttributes(int column, const StockBarAttributes &attr)
 {
     d->setDatasetAttrs(column, QVariant::fromValue(attr), StockBarAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 StockBarAttributes StockDiagram::stockBarAttributes(int column) const
@@ -105,7 +105,7 @@ void StockDiagram::setThreeDBarAttributes(const ThreeDBarAttributes &attr)
     attributesModel()->setModelData(
         QVariant::fromValue(attr),
         ThreeDBarAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
@@ -130,7 +130,7 @@ ThreeDBarAttributes StockDiagram::threeDBarAttributes() const
 void StockDiagram::setThreeDBarAttributes(int column, const ThreeDBarAttributes &attr)
 {
     d->setDatasetAttrs(column, QVariant::fromValue(attr), StockBarAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 /**
diff --git a/src/KDChart/Cartesian/PaintingHelpers_p.cpp b/src/KDChart/Cartesian/PaintingHelpers_p.cpp
index f499c282..70c72497 100644
--- a/src/KDChart/Cartesian/PaintingHelpers_p.cpp
+++ b/src/KDChart/Cartesian/PaintingHelpers_p.cpp
@@ -256,7 +256,7 @@ void paintElements(AbstractDiagram::Private *diagramPrivate, PaintContext *ctx,
     QBrush curBrush;
     QPen curPen;
     QPolygonF points;
-    Q_FOREACH (const LineAttributesInfo &lineInfo, lineList) {
+    for (const LineAttributesInfo &lineInfo : lineList) {
         const QModelIndex &index = lineInfo.index;
         const ThreeDLineAttributes td = threeDLineAttributes(diagram, index);
 
@@ -295,7 +295,7 @@ void paintElements(AbstractDiagram::Private *diagramPrivate, PaintContext *ctx,
         paintObject(diagramPrivate, ctx, curBrush, curPen, points);
     }
 
-    Q_FOREACH (const LineAttributesInfo &lineInfo, lineList) {
+    for (const LineAttributesInfo &lineInfo : lineList) {
         const ValueTrackerAttributes vt = valueTrackerAttributes(diagram, lineInfo.index);
         if (vt.isEnabled()) {
             PaintingHelpers::paintValueTracker(ctx, vt, lineInfo.nextValue);
diff --git a/src/KDChart/KDChartAbstractArea.cpp b/src/KDChart/KDChartAbstractArea.cpp
index 3335ef4f..fdf54f2b 100644
--- a/src/KDChart/KDChartAbstractArea.cpp
+++ b/src/KDChart/KDChartAbstractArea.cpp
@@ -137,5 +137,5 @@ QRect AbstractArea::areaGeometry() const
 
 void AbstractArea::positionHasChanged()
 {
-    emit positionChanged(this);
+    Q_EMIT positionChanged(this);
 }
diff --git a/src/KDChart/KDChartAbstractAreaWidget.cpp b/src/KDChart/KDChartAbstractAreaWidget.cpp
index 805c493b..f95b8a30 100644
--- a/src/KDChart/KDChartAbstractAreaWidget.cpp
+++ b/src/KDChart/KDChartAbstractAreaWidget.cpp
@@ -169,5 +169,5 @@ QRect AbstractAreaWidget::areaGeometry() const
 
 void AbstractAreaWidget::positionHasChanged()
 {
-    emit positionChanged(this);
+    Q_EMIT positionChanged(this);
 }
diff --git a/src/KDChart/KDChartAbstractAxis.cpp b/src/KDChart/KDChartAbstractAxis.cpp
index ce803a67..e16879a0 100644
--- a/src/KDChart/KDChartAbstractAxis.cpp
+++ b/src/KDChart/KDChartAbstractAxis.cpp
@@ -53,8 +53,8 @@ bool AbstractAxis::Private::setDiagram(AbstractDiagram *diagram_, bool delayedIn
         delete observer;
         if (mDiagram) {
             observer = new DiagramObserver(mDiagram, mAxis);
-            const bool con = connect(observer, SIGNAL(diagramDataChanged(AbstractDiagram *)),
-                                     mAxis, SIGNAL(coordinateSystemChanged()));
+            const bool con = connect(observer, &DiagramObserver::diagramDataChanged,
+                                     mAxis, &AbstractAxis::coordinateSystemChanged);
             Q_UNUSED(con)
             Q_ASSERT(con);
             bNewDiagramStored = true;
@@ -101,7 +101,7 @@ AbstractAxis::AbstractAxis(AbstractDiagram *diagram)
     : AbstractArea(new Private(diagram, this))
 {
     init();
-    QTimer::singleShot(0, this, SLOT(delayedInit()));
+    QTimer::singleShot(0, this, &AbstractAxis::delayedInit);
 }
 
 AbstractAxis::~AbstractAxis()
@@ -159,8 +159,8 @@ void AbstractAxis::deleteObserver(AbstractDiagram *diagram)
 void AbstractAxis::connectSignals()
 {
     if (d->observer) {
-        const bool con = connect(d->observer, SIGNAL(diagramDataChanged(AbstractDiagram *)),
-                                 this, SIGNAL(coordinateSystemChanged()));
+        const bool con = connect(d->observer, &DiagramObserver::diagramDataChanged,
+                                 this, &AbstractAxis::coordinateSystemChanged);
         Q_UNUSED(con);
         Q_ASSERT(con);
     }
diff --git a/src/KDChart/KDChartAbstractCoordinatePlane.cpp b/src/KDChart/KDChartAbstractCoordinatePlane.cpp
index 5fe5fc41..d38051fa 100644
--- a/src/KDChart/KDChartAbstractCoordinatePlane.cpp
+++ b/src/KDChart/KDChartAbstractCoordinatePlane.cpp
@@ -40,14 +40,14 @@ AbstractCoordinatePlane::AbstractCoordinatePlane(KDChart::Chart *parent)
 
 AbstractCoordinatePlane::~AbstractCoordinatePlane()
 {
-    emit destroyedCoordinatePlane(this);
+    Q_EMIT destroyedCoordinatePlane(this);
 }
 
 void AbstractCoordinatePlane::init()
 {
     d->initialize(); // virtual method to init the correct grid: cartesian, polar, ...
-    connect(this, SIGNAL(internal_geometryChanged(QRect, QRect)),
-            this, SIGNAL(geometryChanged(QRect, QRect)),
+    connect(this, &AbstractCoordinatePlane::internal_geometryChanged,
+            this, &AbstractCoordinatePlane::geometryChanged,
             Qt::QueuedConnection);
 }
 
@@ -61,13 +61,13 @@ void AbstractCoordinatePlane::addDiagram(AbstractDiagram *diagram)
     diagram->setCoordinatePlane(this);
     layoutDiagrams();
     layoutPlanes(); // there might be new axes, etc
-    connect(diagram, SIGNAL(modelsChanged()), this, SLOT(layoutPlanes()));
-    connect(diagram, SIGNAL(modelDataChanged()), this, SLOT(update()));
-    connect(diagram, SIGNAL(modelDataChanged()), this, SLOT(relayout()));
-    connect(this, SIGNAL(boundariesChanged()), diagram, SIGNAL(boundariesChanged()));
+    connect(diagram, &AbstractDiagram::modelsChanged, this, &AbstractCoordinatePlane::layoutPlanes);
+    connect(diagram, &AbstractDiagram::modelDataChanged, this, &AbstractCoordinatePlane::update);
+    connect(diagram, &AbstractDiagram::modelDataChanged, this, &AbstractCoordinatePlane::relayout);
+    connect(this, &AbstractCoordinatePlane::boundariesChanged, diagram, &AbstractDiagram::boundariesChanged);
 
     update();
-    emit boundariesChanged();
+    Q_EMIT boundariesChanged();
 }
 
 /*virtual*/
@@ -99,9 +99,9 @@ void AbstractCoordinatePlane::takeDiagram(AbstractDiagram *diagram)
         d->diagrams.removeAt(idx);
         diagram->setParent(nullptr);
         diagram->setCoordinatePlane(nullptr);
-        disconnect(diagram, SIGNAL(modelsChanged()), this, SLOT(layoutPlanes()));
-        disconnect(diagram, SIGNAL(modelDataChanged()), this, SLOT(update()));
-        disconnect(diagram, SIGNAL(modelDataChanged()), this, SLOT(relayout()));
+        disconnect(diagram, &AbstractDiagram::modelsChanged, this, &AbstractCoordinatePlane::layoutPlanes);
+        disconnect(diagram, &AbstractDiagram::modelDataChanged, this, &AbstractCoordinatePlane::update);
+        disconnect(diagram, &AbstractDiagram::modelDataChanged, this, &AbstractCoordinatePlane::relayout);
         layoutDiagrams();
         update();
     }
@@ -127,7 +127,7 @@ ConstAbstractDiagramList AbstractCoordinatePlane::diagrams() const
 #ifndef QT_NO_STL
     qCopy(d->diagrams.begin(), d->diagrams.end(), std::back_inserter(list));
 #else
-    Q_FOREACH (AbstractDiagram *a, d->diagrams)
+    for (AbstractDiagram *a : d->diagrams)
         list.push_back(a);
 #endif
     return list;
@@ -216,7 +216,7 @@ void KDChart::AbstractCoordinatePlane::setGeometry(const QRect &r)
     if (d->geometry != r) {
         // inform the outside word by Signal geometryChanged()
         // via a queued connection to internal_geometryChanged()
-        emit internal_geometryChanged(d->geometry, r);
+        Q_EMIT internal_geometryChanged(d->geometry, r);
 
         d->geometry = r;
         // Note: We do *not* call update() here
@@ -232,19 +232,19 @@ QRect KDChart::AbstractCoordinatePlane::geometry() const
 void KDChart::AbstractCoordinatePlane::update()
 {
     // qDebug("KDChart::AbstractCoordinatePlane::update() called");
-    emit needUpdate();
+    Q_EMIT needUpdate();
 }
 
 void KDChart::AbstractCoordinatePlane::relayout()
 {
     // qDebug("KDChart::AbstractCoordinatePlane::relayout() called");
-    emit needRelayout();
+    Q_EMIT needRelayout();
 }
 
 void KDChart::AbstractCoordinatePlane::layoutPlanes()
 {
     // qDebug("KDChart::AbstractCoordinatePlane::relayout() called");
-    emit needLayoutPlanes();
+    Q_EMIT needLayoutPlanes();
 }
 
 void KDChart::AbstractCoordinatePlane::setRubberBandZoomingEnabled(bool enable)
@@ -268,7 +268,7 @@ void KDChart::AbstractCoordinatePlane::setCornerSpacersEnabled(bool enable)
         return;
 
     d->enableCornerSpacers = enable;
-    emit needRelayout();
+    Q_EMIT needRelayout();
 }
 
 bool KDChart::AbstractCoordinatePlane::isCornerSpacersEnabled() const
@@ -305,7 +305,7 @@ void KDChart::AbstractCoordinatePlane::mousePressEvent(QMouseEvent *event)
         }
     }
 
-    Q_FOREACH (AbstractDiagram *a, d->diagrams) {
+    for (AbstractDiagram *a : qAsConst(d->diagrams)) {
         a->mousePressEvent(event);
     }
 }
@@ -317,7 +317,7 @@ void KDChart::AbstractCoordinatePlane::mouseDoubleClickEvent(QMouseEvent *event)
         // which is pretty annoying when zooming out fast
         mousePressEvent(event);
     }
-    Q_FOREACH (AbstractDiagram *a, d->diagrams) {
+    for (AbstractDiagram *a : qAsConst(d->diagrams)) {
         a->mouseDoubleClickEvent(event);
     }
 }
@@ -367,7 +367,7 @@ void KDChart::AbstractCoordinatePlane::mouseReleaseEvent(QMouseEvent *event)
         event->accept();
     }
 
-    Q_FOREACH (AbstractDiagram *a, d->diagrams) {
+    for (AbstractDiagram *a : qAsConst(d->diagrams)) {
         a->mouseReleaseEvent(event);
     }
 }
@@ -381,7 +381,7 @@ void KDChart::AbstractCoordinatePlane::mouseMoveEvent(QMouseEvent *event)
         event->accept();
     }
 
-    Q_FOREACH (AbstractDiagram *a, d->diagrams) {
+    for (AbstractDiagram *a : qAsConst(d->diagrams)) {
         a->mouseMoveEvent(event);
     }
 }
diff --git a/src/KDChart/KDChartAbstractDiagram.cpp b/src/KDChart/KDChartAbstractDiagram.cpp
index a9263560..5d060db1 100644
--- a/src/KDChart/KDChartAbstractDiagram.cpp
+++ b/src/KDChart/KDChartAbstractDiagram.cpp
@@ -44,7 +44,7 @@ AbstractDiagram::AbstractDiagram(QWidget *parent, AbstractCoordinatePlane *plane
 
 AbstractDiagram::~AbstractDiagram()
 {
-    emit aboutToBeDestroyed();
+    Q_EMIT aboutToBeDestroyed();
     delete _d;
 }
 
@@ -116,21 +116,21 @@ void AbstractDiagram::setModel(QAbstractItemModel *newModel)
 
     scheduleDelayedItemsLayout();
     setDataBoundariesDirty();
-    emit modelsChanged();
+    Q_EMIT modelsChanged();
 }
 
 void AbstractDiagram::setSelectionModel(QItemSelectionModel *newSelectionModel)
 {
     if (selectionModel()) {
-        disconnect(selectionModel(), SIGNAL(currentChanged(QModelIndex, QModelIndex)), this, SIGNAL(modelsChanged()));
-        disconnect(selectionModel(), SIGNAL(selectionChanged(QItemSelection, QItemSelection)), this, SIGNAL(modelsChanged()));
+        disconnect(selectionModel(), &QItemSelectionModel::currentChanged, this, &AbstractDiagram::modelsChanged);
+        disconnect(selectionModel(), &QItemSelectionModel::selectionChanged, this, &AbstractDiagram::modelsChanged);
     }
     QAbstractItemView::setSelectionModel(newSelectionModel);
     if (selectionModel()) {
-        connect(selectionModel(), SIGNAL(currentChanged(QModelIndex, QModelIndex)), this, SIGNAL(modelsChanged()));
-        connect(selectionModel(), SIGNAL(selectionChanged(QItemSelection, QItemSelection)), this, SIGNAL(modelsChanged()));
+        connect(selectionModel(), &QItemSelectionModel::currentChanged, this, &AbstractDiagram::modelsChanged);
+        connect(selectionModel(), &QItemSelectionModel::selectionChanged, this, &AbstractDiagram::modelsChanged);
     }
-    emit modelsChanged();
+    Q_EMIT modelsChanged();
 }
 
 /*! Sets an external AttributesModel on this diagram. By default, a diagram has it's
@@ -157,7 +157,7 @@ void AbstractDiagram::setAttributesModel(AttributesModel *amodel)
     d->setAttributesModel(amodel);
     scheduleDelayedItemsLayout();
     setDataBoundariesDirty();
-    emit modelsChanged();
+    Q_EMIT modelsChanged();
 }
 
 bool AbstractDiagram::usesExternalAttributesModel() const
@@ -231,19 +231,19 @@ void AbstractDiagram::setHidden(const QModelIndex &index, bool hidden)
         conditionallyMapFromSource(index),
         QVariant::fromValue(hidden),
         DataHiddenRole);
-    emit dataHidden();
+    Q_EMIT dataHidden();
 }
 
 void AbstractDiagram::setHidden(int dataset, bool hidden)
 {
     d->setDatasetAttrs(dataset, QVariant::fromValue(hidden), DataHiddenRole);
-    emit dataHidden();
+    Q_EMIT dataHidden();
 }
 
 void AbstractDiagram::setHidden(bool hidden)
 {
     d->attributesModel->setModelData(QVariant::fromValue(hidden), DataHiddenRole);
-    emit dataHidden();
+    Q_EMIT dataHidden();
 }
 
 bool AbstractDiagram::isHidden() const
@@ -275,13 +275,13 @@ void AbstractDiagram::setDataValueAttributes(const QModelIndex &index,
 {
     d->attributesModel->setData(conditionallyMapFromSource(index), QVariant::fromValue(a),
                                 DataValueLabelAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void AbstractDiagram::setDataValueAttributes(int dataset, const DataValueAttributes &a)
 {
     d->setDatasetAttrs(dataset, QVariant::fromValue(a), DataValueLabelAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 DataValueAttributes AbstractDiagram::dataValueAttributes() const
@@ -320,7 +320,7 @@ DataValueAttributes AbstractDiagram::dataValueAttributes(const QModelIndex &inde
 void AbstractDiagram::setDataValueAttributes(const DataValueAttributes &a)
 {
     d->attributesModel->setModelData(QVariant::fromValue(a), DataValueLabelAttributesRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void AbstractDiagram::setAllowOverlappingDataValueTexts(bool allow)
@@ -329,7 +329,7 @@ void AbstractDiagram::setAllowOverlappingDataValueTexts(bool allow)
     attrs.setShowOverlappingDataLabels(allow);
     setDataValueAttributes(attrs);
     d->allowOverlappingDataValueTexts = allow;
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 bool AbstractDiagram::allowOverlappingDataValueTexts() const
@@ -340,7 +340,7 @@ bool AbstractDiagram::allowOverlappingDataValueTexts() const
 void AbstractDiagram::setAntiAliasing(bool enabled)
 {
     d->antiAliasing = enabled;
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 bool AbstractDiagram::antiAliasing() const
@@ -351,7 +351,7 @@ bool AbstractDiagram::antiAliasing() const
 void AbstractDiagram::setPercentMode(bool percent)
 {
     d->percent = percent;
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 bool AbstractDiagram::percentMode() const
@@ -603,20 +603,20 @@ void AbstractDiagram::setPen(const QModelIndex &index, const QPen &pen)
     attributesModel()->setData(
         conditionallyMapFromSource(index),
         QVariant::fromValue(pen), DatasetPenRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void AbstractDiagram::setPen(const QPen &pen)
 {
     attributesModel()->setModelData(
         QVariant::fromValue(pen), DatasetPenRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void AbstractDiagram::setPen(int dataset, const QPen &pen)
 {
     d->setDatasetAttrs(dataset, QVariant::fromValue(pen), DatasetPenRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 QPen AbstractDiagram::pen() const
@@ -645,20 +645,20 @@ void AbstractDiagram::setBrush(const QModelIndex &index, const QBrush &brush)
     attributesModel()->setData(
         conditionallyMapFromSource(index),
         QVariant::fromValue(brush), DatasetBrushRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void AbstractDiagram::setBrush(const QBrush &brush)
 {
     attributesModel()->setModelData(
         QVariant::fromValue(brush), DatasetBrushRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void AbstractDiagram::setBrush(int dataset, const QBrush &brush)
 {
     d->setDatasetAttrs(dataset, QVariant::fromValue(brush), DatasetBrushRole);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 QBrush AbstractDiagram::brush() const
@@ -803,7 +803,7 @@ void AbstractDiagram::setSelection(const QRect &rect, QItemSelectionModel::Selec
 {
     const QModelIndexList indexes = d->indexesIn(rect);
     QItemSelection selection;
-    Q_FOREACH (const QModelIndex &index, indexes) {
+    for (const QModelIndex &index : indexes) {
         selection.append(QItemSelectionRange(index));
     }
     selectionModel()->select(selection, command);
@@ -812,7 +812,8 @@ void AbstractDiagram::setSelection(const QRect &rect, QItemSelectionModel::Selec
 QRegion AbstractDiagram::visualRegionForSelection(const QItemSelection &selection) const
 {
     QPolygonF polygon;
-    Q_FOREACH (const QModelIndex &index, selection.indexes()) {
+    const auto constIndexes = selection.indexes();
+    for (const QModelIndex &index : constIndexes) {
         polygon << d->reverseMapper.polygon(index.row(), index.column());
     }
     return polygon.isEmpty() ? QRegion() : QRegion(polygon.toPolygon());
@@ -938,7 +939,7 @@ void AbstractDiagram::setDatasetDimensionInternal(int dimension)
     d->datasetDimension = dimension;
     d->attributesModel->setDatasetDimension(dimension);
     setDataBoundariesDirty();
-    emit layoutChanged(this);
+    Q_EMIT layoutChanged(this);
 }
 
 qreal AbstractDiagram::valueForCell(int row, int column) const
diff --git a/src/KDChart/KDChartAbstractDiagram_p.cpp b/src/KDChart/KDChartAbstractDiagram_p.cpp
index b9a41891..a4bbaca6 100644
--- a/src/KDChart/KDChartAbstractDiagram_p.cpp
+++ b/src/KDChart/KDChartAbstractDiagram_p.cpp
@@ -96,39 +96,39 @@ void AbstractDiagram::Private::setAttributesModel(AttributesModel *amodel)
         if (qobject_cast<PrivateAttributesModel *>(attributesModel)) {
             delete attributesModel;
         } else {
-            disconnect(attributesModel, SIGNAL(rowsInserted(QModelIndex, int, int)),
-                       diagram, SLOT(setDataBoundariesDirty()));
-            disconnect(attributesModel, SIGNAL(columnsInserted(QModelIndex, int, int)),
-                       diagram, SLOT(setDataBoundariesDirty()));
-            disconnect(attributesModel, SIGNAL(rowsRemoved(QModelIndex, int, int)),
-                       diagram, SLOT(setDataBoundariesDirty()));
-            disconnect(attributesModel, SIGNAL(columnsRemoved(QModelIndex, int, int)),
-                       diagram, SLOT(setDataBoundariesDirty()));
-            disconnect(attributesModel, SIGNAL(modelReset()),
-                       diagram, SLOT(setDataBoundariesDirty()));
-            disconnect(attributesModel, SIGNAL(layoutChanged()),
-                       diagram, SLOT(setDataBoundariesDirty()));
-            disconnect(attributesModel, SIGNAL(dataChanged(QModelIndex, QModelIndex)),
-                       diagram, SIGNAL(modelDataChanged()));
+            disconnect(attributesModel, &AttributesModel::rowsInserted,
+                       diagram, &AbstractDiagram::setDataBoundariesDirty);
+            disconnect(attributesModel, &AttributesModel::columnsInserted,
+                       diagram, &AbstractDiagram::setDataBoundariesDirty);
+            disconnect(attributesModel, &AttributesModel::rowsRemoved,
+                       diagram, &AbstractDiagram::setDataBoundariesDirty);
+            disconnect(attributesModel, &AttributesModel::columnsRemoved,
+                       diagram, &AbstractDiagram::setDataBoundariesDirty);
+            disconnect(attributesModel, &AttributesModel::modelReset,
+                       diagram, &AbstractDiagram::setDataBoundariesDirty);
+            disconnect(attributesModel, &AttributesModel::layoutChanged,
+                       diagram, &AbstractDiagram::setDataBoundariesDirty);
+            disconnect(attributesModel, &AttributesModel::dataChanged,
+                       diagram, &AbstractDiagram::modelDataChanged);
         }
     }
 
-    emit diagram->attributesModelAboutToChange(amodel, attributesModel);
-
-    connect(amodel, SIGNAL(rowsInserted(QModelIndex, int, int)),
-            diagram, SLOT(setDataBoundariesDirty()));
-    connect(amodel, SIGNAL(columnsInserted(QModelIndex, int, int)),
-            diagram, SLOT(setDataBoundariesDirty()));
-    connect(amodel, SIGNAL(rowsRemoved(QModelIndex, int, int)),
-            diagram, SLOT(setDataBoundariesDirty()));
-    connect(amodel, SIGNAL(columnsRemoved(QModelIndex, int, int)),
-            diagram, SLOT(setDataBoundariesDirty()));
-    connect(amodel, SIGNAL(modelReset()),
-            diagram, SLOT(setDataBoundariesDirty()));
-    connect(amodel, SIGNAL(layoutChanged()),
-            diagram, SLOT(setDataBoundariesDirty()));
-    connect(amodel, SIGNAL(dataChanged(QModelIndex, QModelIndex)),
-            diagram, SIGNAL(modelDataChanged()));
+    Q_EMIT diagram->attributesModelAboutToChange(amodel, attributesModel);
+
+    connect(amodel, &AttributesModel::rowsInserted,
+            diagram, &AbstractDiagram::setDataBoundariesDirty);
+    connect(amodel, &AttributesModel::columnsInserted,
+            diagram, &AbstractDiagram::setDataBoundariesDirty);
+    connect(amodel, &AttributesModel::rowsRemoved,
+            diagram, &AbstractDiagram::setDataBoundariesDirty);
+    connect(amodel, &AttributesModel::columnsRemoved,
+            diagram, &AbstractDiagram::setDataBoundariesDirty);
+    connect(amodel, &AttributesModel::modelReset,
+            diagram, &AbstractDiagram::setDataBoundariesDirty);
+    connect(amodel, &AttributesModel::layoutChanged,
+            diagram, &AbstractDiagram::setDataBoundariesDirty);
+    connect(amodel, &AttributesModel::dataChanged,
+            diagram, &AbstractDiagram::modelDataChanged);
 
     attributesModel = amodel;
 }
@@ -372,7 +372,7 @@ void AbstractDiagram::Private::paintDataValueTextsAndMarkers(
     ctx->painter()->setClipping(false);
 
     if (paintMarkers && !justCalculateRect) {
-        Q_FOREACH (const LabelPaintInfo &info, cache.paintReplay) {
+        for (const LabelPaintInfo &info : qAsConst(cache.paintReplay)) {
             diagram->paintMarker(ctx->painter(), info.index, info.markerPos);
         }
     }
@@ -389,7 +389,7 @@ void AbstractDiagram::Private::paintDataValueTextsAndMarkers(
 
     forgetAlreadyPaintedDataValues();
 
-    Q_FOREACH (const LabelPaintInfo &info, cache.paintReplay) {
+    for (const LabelPaintInfo &info : qAsConst(cache.paintReplay)) {
         const QPointF pos = info.labelArea.elementAt(0);
         paintDataValueText(ctx->painter(), info.attrs, pos, info.isValuePositive,
                            info.value, justCalculateRect, cumulatedBoundingRect);
diff --git a/src/KDChart/KDChartAttributesModel.cpp b/src/KDChart/KDChartAttributesModel.cpp
index a3fe93c8..5e66ff81 100644
--- a/src/KDChart/KDChartAttributesModel.cpp
+++ b/src/KDChart/KDChartAttributesModel.cpp
@@ -366,7 +366,7 @@ bool AttributesModel::setData(const QModelIndex &index, const QVariant &value, i
         QMap<int, QMap<int, QVariant>> &colDataMap = d->dataMap[index.column()];
         QMap<int, QVariant> &dataMap = colDataMap[index.row()];
         dataMap.insert(role, value);
-        emit attributesChanged(index, index);
+        Q_EMIT attributesChanged(index, index);
         return true;
     }
 }
@@ -394,18 +394,18 @@ bool AttributesModel::setHeaderData(int section, Qt::Orientation orientation,
             int numRows = rowCount(QModelIndex());
             int numCols = columnCount(QModelIndex());
             if (orientation == Qt::Horizontal && numRows > 0)
-                emit attributesChanged(index(0, section, QModelIndex()),
-                                       index(numRows - 1, section, QModelIndex()));
+                Q_EMIT attributesChanged(index(0, section, QModelIndex()),
+                                         index(numRows - 1, section, QModelIndex()));
             else if (orientation == Qt::Vertical && numCols > 0)
-                emit attributesChanged(index(section, 0, QModelIndex()),
-                                       index(section, numCols - 1, QModelIndex()));
-            emit headerDataChanged(orientation, section, section);
+                Q_EMIT attributesChanged(index(section, 0, QModelIndex()),
+                                         index(section, numCols - 1, QModelIndex()));
+            Q_EMIT headerDataChanged(orientation, section, section);
 
             // FIXME: This only makes sense for orientation == Qt::Horizontal,
             // but what if orientation == Qt::Vertical?
             if (section != -1 && numRows > 0)
-                emit dataChanged(index(0, section, QModelIndex()),
-                                 index(numRows - 1, section, QModelIndex()));
+                Q_EMIT dataChanged(index(0, section, QModelIndex()),
+                                   index(numRows - 1, section, QModelIndex()));
         }
         return true;
     }
@@ -448,8 +448,8 @@ bool KDChart::AttributesModel::setModelData(const QVariant value, int role)
     int numRows = rowCount(QModelIndex());
     int numCols = columnCount(QModelIndex());
     if (sourceModel() && numRows > 0 && numCols > 0) {
-        emit attributesChanged(index(0, 0, QModelIndex()),
-                               index(numRows - 1, numCols - 1, QModelIndex()));
+        Q_EMIT attributesChanged(index(0, 0, QModelIndex()),
+                                 index(numRows - 1, numCols - 1, QModelIndex()));
         beginResetModel();
         endResetModel();
     }
@@ -479,56 +479,61 @@ int AttributesModel::columnCount(const QModelIndex &index) const
     }
 }
 
-void AttributesModel::setSourceModel(QAbstractItemModel *sourceModel)
-{
-    if (this->sourceModel() != nullptr) {
-        disconnect(this->sourceModel(), SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
-                   this, SLOT(slotDataChanged(const QModelIndex &, const QModelIndex &)));
-        disconnect(this->sourceModel(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-                   this, SLOT(slotRowsInserted(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-                   this, SLOT(slotRowsRemoved(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)),
-                   this, SLOT(slotRowsAboutToBeInserted(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(rowsAboutToBeRemoved(const QModelIndex &, int, int)),
-                   this, SLOT(slotRowsAboutToBeRemoved(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-                   this, SLOT(slotColumnsInserted(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-                   this, SLOT(slotColumnsRemoved(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(columnsAboutToBeInserted(const QModelIndex &, int, int)),
-                   this, SLOT(slotColumnsAboutToBeInserted(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(columnsAboutToBeRemoved(const QModelIndex &, int, int)),
-                   this, SLOT(slotColumnsAboutToBeRemoved(const QModelIndex &, int, int)));
-        disconnect(this->sourceModel(), SIGNAL(modelReset()),
-                   this, SIGNAL(modelReset()));
-        disconnect(this->sourceModel(), SIGNAL(layoutChanged()),
-                   this, SIGNAL(layoutChanged()));
-    }
-    QAbstractProxyModel::setSourceModel(sourceModel);
-    if (this->sourceModel() != nullptr) {
-        connect(this->sourceModel(), SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
-                this, SLOT(slotDataChanged(const QModelIndex &, const QModelIndex &)));
-        connect(this->sourceModel(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-                this, SLOT(slotRowsInserted(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-                this, SLOT(slotRowsRemoved(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)),
-                this, SLOT(slotRowsAboutToBeInserted(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(rowsAboutToBeRemoved(const QModelIndex &, int, int)),
-                this, SLOT(slotRowsAboutToBeRemoved(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-                this, SLOT(slotColumnsInserted(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-                this, SLOT(slotColumnsRemoved(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(columnsAboutToBeInserted(const QModelIndex &, int, int)),
-                this, SLOT(slotColumnsAboutToBeInserted(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(columnsAboutToBeRemoved(const QModelIndex &, int, int)),
-                this, SLOT(slotColumnsAboutToBeRemoved(const QModelIndex &, int, int)));
-        connect(this->sourceModel(), SIGNAL(modelReset()),
-                this, SIGNAL(modelReset()));
-        connect(this->sourceModel(), SIGNAL(layoutChanged()),
-                this, SIGNAL(layoutChanged()));
+void AttributesModel::setSourceModel(QAbstractItemModel *newModel)
+{
+    QAbstractItemModel *oldModel = sourceModel();
+    if (oldModel != nullptr) {
+        disconnect(oldModel, &QAbstractItemModel::dataChanged,
+                   this, &AttributesModel::slotDataChanged);
+        disconnect(oldModel, &QAbstractItemModel::rowsInserted,
+                   this, &AttributesModel::slotRowsInserted);
+        disconnect(oldModel, &QAbstractItemModel::rowsRemoved,
+                   this, &AttributesModel::slotRowsRemoved);
+        disconnect(oldModel, &QAbstractItemModel::rowsAboutToBeInserted,
+                   this, &AttributesModel::slotRowsAboutToBeInserted);
+        disconnect(oldModel, &QAbstractItemModel::rowsAboutToBeRemoved,
+                   this, &AttributesModel::slotRowsAboutToBeRemoved);
+        disconnect(oldModel, &QAbstractItemModel::columnsInserted,
+                   this, &AttributesModel::slotColumnsInserted);
+        disconnect(oldModel, &QAbstractItemModel::columnsRemoved,
+                   this, &AttributesModel::slotColumnsRemoved);
+        disconnect(oldModel, &QAbstractItemModel::columnsAboutToBeInserted,
+                   this, &AttributesModel::slotColumnsAboutToBeInserted);
+        disconnect(oldModel, &QAbstractItemModel::columnsAboutToBeRemoved,
+                   this, &AttributesModel::slotColumnsAboutToBeRemoved);
+        disconnect(oldModel, &QAbstractItemModel::modelAboutToBeReset,
+                   this, &AttributesModel::modelAboutToBeReset);
+        disconnect(oldModel, &QAbstractItemModel::modelReset,
+                   this, &AttributesModel::modelReset);
+        disconnect(oldModel, &QAbstractItemModel::layoutChanged,
+                   this, &AttributesModel::layoutChanged);
+    }
+    QAbstractProxyModel::setSourceModel(newModel);
+    if (newModel != nullptr) {
+        connect(newModel, &QAbstractItemModel::dataChanged,
+                this, &AttributesModel::slotDataChanged);
+        connect(newModel, &QAbstractItemModel::rowsInserted,
+                this, &AttributesModel::slotRowsInserted);
+        connect(newModel, &QAbstractItemModel::rowsRemoved,
+                this, &AttributesModel::slotRowsRemoved);
+        connect(newModel, &QAbstractItemModel::rowsAboutToBeInserted,
+                this, &AttributesModel::slotRowsAboutToBeInserted);
+        connect(newModel, &QAbstractItemModel::rowsAboutToBeRemoved,
+                this, &AttributesModel::slotRowsAboutToBeRemoved);
+        connect(newModel, &QAbstractItemModel::columnsInserted,
+                this, &AttributesModel::slotColumnsInserted);
+        connect(newModel, &QAbstractItemModel::columnsRemoved,
+                this, &AttributesModel::slotColumnsRemoved);
+        connect(newModel, &QAbstractItemModel::columnsAboutToBeInserted,
+                this, &AttributesModel::slotColumnsAboutToBeInserted);
+        connect(newModel, &QAbstractItemModel::columnsAboutToBeRemoved,
+                this, &AttributesModel::slotColumnsAboutToBeRemoved);
+        connect(newModel, &QAbstractItemModel::modelAboutToBeReset,
+                this, &AttributesModel::modelAboutToBeReset);
+        connect(newModel, &QAbstractItemModel::modelReset,
+                this, &AttributesModel::modelReset);
+        connect(newModel, &QAbstractItemModel::layoutChanged,
+                this, &AttributesModel::layoutChanged);
     }
 }
 
@@ -640,7 +645,7 @@ void AttributesModel::slotColumnsRemoved(const QModelIndex &parent, int start, i
 
 void AttributesModel::slotDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
 {
-    emit dataChanged(mapFromSource(topLeft), mapFromSource(bottomRight));
+    Q_EMIT dataChanged(mapFromSource(topLeft), mapFromSource(bottomRight));
 }
 
 void AttributesModel::setDefaultForRole(int role, const QVariant &value)
diff --git a/src/KDChart/KDChartChart.cpp b/src/KDChart/KDChartChart.cpp
index e008a34b..0fe96eb5 100644
--- a/src/KDChart/KDChartChart.cpp
+++ b/src/KDChart/KDChartChart.cpp
@@ -270,7 +270,7 @@ void Chart::Private::slotUnregisterDestroyedHeaderFooter(HeaderFooter *hf)
 void Chart::Private::slotUnregisterDestroyedPlane(AbstractCoordinatePlane *plane)
 {
     coordinatePlanes.removeAll(plane);
-    Q_FOREACH (AbstractCoordinatePlane *p, coordinatePlanes) {
+    for (AbstractCoordinatePlane *p : qAsConst(coordinatePlanes)) {
         if (p->referenceCoordinatePlane() == plane) {
             p->setReferenceCoordinatePlane(nullptr);
         }
@@ -328,8 +328,10 @@ static QVector<LayoutGraphNode *> getPrioritySortedConnectedComponents(QVector<L
 {
     QVector<LayoutGraphNode *> connectedComponents;
     QHash<LayoutGraphNode *, VisitorState> visitedComponents;
-    Q_FOREACH (LayoutGraphNode *node, nodeList)
+    for (LayoutGraphNode *node : qAsConst(nodeList)) {
         visitedComponents[node] = Unknown;
+    }
+
     for (int i = 0; i < nodeList.size(); ++i) {
         LayoutGraphNode *curNode = nodeList[i];
         LayoutGraphNode *representativeNode = curNode;
@@ -380,7 +382,8 @@ void checkExistingAxes(LayoutGraphNode *node)
     if (node && node->diagramPlane && node->diagramPlane->diagram()) {
         auto *diag = qobject_cast<AbstractCartesianDiagram *>(node->diagramPlane->diagram());
         if (diag) {
-            Q_FOREACH (const CartesianAxis *axis, diag->axes()) {
+            const auto constAxes = diag->axes();
+            for (const CartesianAxis *axis : constAxes) {
                 switch (axis->position()) {
                 case (CartesianAxis::Top):
                     node->topAxesLayout = true;
@@ -430,19 +433,24 @@ static CoordinatePlaneList findSharingAxisDiagrams(AbstractCoordinatePlane *plan
         return CoordinatePlaneList();
 
     QList<CartesianAxis *> axes;
-    Q_FOREACH (CartesianAxis *axis, diagram->axes()) {
-        if ((type == Chart::Private::Ordinate && (axis->position() == CartesianAxis::Left || axis->position() == CartesianAxis::Right))
-            || (type == Chart::Private::Abscissa && (axis->position() == CartesianAxis::Top || axis->position() == CartesianAxis::Bottom))) {
-            axes.append(axis);
+    {
+        const auto constAxes = diagram->axes();
+        for (CartesianAxis *axis : constAxes) {
+            if ((type == Chart::Private::Ordinate && (axis->position() == CartesianAxis::Left || axis->position() == CartesianAxis::Right))
+                || (type == Chart::Private::Abscissa && (axis->position() == CartesianAxis::Top || axis->position() == CartesianAxis::Bottom))) {
+                axes.append(axis);
+            }
         }
     }
-    Q_FOREACH (AbstractCoordinatePlane *curPlane, list) {
+
+    for (AbstractCoordinatePlane *curPlane : list) {
         auto *diagram =
             qobject_cast<AbstractCartesianDiagram *>(curPlane->diagram());
         if (!diagram)
             continue;
-        Q_FOREACH (CartesianAxis *curSearchedAxis, axes) {
-            Q_FOREACH (CartesianAxis *curAxis, diagram->axes()) {
+        for (CartesianAxis *curSearchedAxis : axes) {
+            const auto constAxes = diagram->axes();
+            for (CartesianAxis *curAxis : constAxes) {
                 if (curSearchedAxis == curAxis) {
                     result.append(curPlane);
                     if (!sharedAxes->contains(curSearchedAxis))
@@ -466,7 +474,7 @@ QVector<LayoutGraphNode *> Chart::Private::buildPlaneLayoutGraph()
     QHash<AbstractCoordinatePlane *, LayoutGraphNode *> planeNodeMapping;
     QVector<LayoutGraphNode *> allNodes;
     // create all nodes and a mapping between plane and nodes
-    Q_FOREACH (AbstractCoordinatePlane *curPlane, coordinatePlanes) {
+    for (AbstractCoordinatePlane *curPlane : qAsConst(coordinatePlanes)) {
         if (curPlane->diagram()) {
             allNodes.append(new LayoutGraphNode);
             allNodes[allNodes.size() - 1]->diagramPlane = curPlane;
@@ -476,7 +484,7 @@ QVector<LayoutGraphNode *> Chart::Private::buildPlaneLayoutGraph()
         }
     }
     // build the graph connections
-    Q_FOREACH (LayoutGraphNode *curNode, allNodes) {
+    for (LayoutGraphNode *curNode : qAsConst(allNodes)) {
         QVector<CartesianAxis *> sharedAxes;
         CoordinatePlaneList xSharedPlanes = findSharingAxisDiagrams(curNode->diagramPlane, coordinatePlanes, Abscissa, &sharedAxes);
         Q_ASSERT(sharedAxes.size() < 2);
@@ -562,20 +570,22 @@ QHash<AbstractCoordinatePlane *, PlaneInfo> Chart::Private::buildPlaneLayoutInfo
      * laid out vertically or horizontally next to each other. */
     QHash<CartesianAxis *, AxisInfo> axisInfos;
     QHash<AbstractCoordinatePlane *, PlaneInfo> planeInfos;
-    Q_FOREACH (AbstractCoordinatePlane *plane, coordinatePlanes) {
+    for (AbstractCoordinatePlane *plane : qAsConst(coordinatePlanes)) {
         PlaneInfo p;
         // first check if we share space with another plane
         p.referencePlane = plane->referenceCoordinatePlane();
         planeInfos.insert(plane, p);
 
-        Q_FOREACH (AbstractDiagram *abstractDiagram, plane->diagrams()) {
+        const auto constDiagrams = plane->diagrams();
+        for (AbstractDiagram *abstractDiagram : constDiagrams) {
             auto *diagram =
                 qobject_cast<AbstractCartesianDiagram *>(abstractDiagram);
             if (!diagram) {
                 continue;
             }
 
-            Q_FOREACH (CartesianAxis *axis, diagram->axes()) {
+            const auto constAxes = diagram->axes();
+            for (CartesianAxis *axis : constAxes) {
                 if (!axisInfos.contains(axis)) {
                     /* If this is the first time we see this axis, add it, with the
                      * current plane. The first plane added to the chart that has
@@ -637,11 +647,11 @@ void Chart::Private::slotLayoutPlanes()
     if (hadPlanesLayout)
         planesLayout->getContentsMargins(&left, &top, &right, &bottom);
 
-    Q_FOREACH (AbstractLayoutItem *plane, planeLayoutItems) {
+    for (AbstractLayoutItem *plane : qAsConst(planeLayoutItems)) {
         plane->removeFromParentLayout();
     }
     // TODO they should get a correct parent, but for now it works
-    Q_FOREACH (AbstractLayoutItem *plane, planeLayoutItems) {
+    for (AbstractLayoutItem *plane : qAsConst(planeLayoutItems)) {
         if (dynamic_cast<AutoSpacerLayoutItem *>(plane))
             delete plane;
     }
@@ -679,7 +689,8 @@ void Chart::Private::slotLayoutPlanes()
                 col = 0;
                 for (LayoutGraphNode *curColComponent = curRowComponent; curColComponent; curColComponent = curColComponent->leftSuccesor) {
                     Q_ASSERT(curColComponent->diagramPlane->diagrams().size() == 1);
-                    Q_FOREACH (AbstractDiagram *diagram, curColComponent->diagramPlane->diagrams()) {
+                    const auto constDiagrams = curColComponent->diagramPlane->diagrams();
+                    for (AbstractDiagram *diagram : constDiagrams) {
                         const int planeRowOffset = 1; // curColComponent->topAxesLayout ? 1 : 0;
                         const int planeColOffset = 1; // curColComponent->leftAxesLayout ? 1 : 0;
                         // qDebug() << Q_FUNC_INFO << row << col << planeRowOffset << planeColOffset;
@@ -699,7 +710,8 @@ void Chart::Private::slotLayoutPlanes()
                                 curColComponent->sharedSuccesor->diagramPlane->setParentLayout(gridPlaneLayout);
                                 planeLayoutItems << curColComponent->sharedSuccesor->diagramPlane;
                             }
-                            Q_FOREACH (CartesianAxis *axis, cartDiag->axes()) {
+                            const auto constAxes = cartDiag->axes();
+                            for (CartesianAxis *axis : constAxes) {
                                 if (axis->isAbscissa()) {
                                     if (curColComponent->bottomSuccesor)
                                         continue;
@@ -802,7 +814,7 @@ void Chart::Private::slotLayoutPlanes()
          * gets their own. See buildPlaneLayoutInfos() for more details. */
         QHash<AbstractCoordinatePlane *, PlaneInfo> planeInfos = buildPlaneLayoutInfos();
         QHash<AbstractAxis *, AxisInfo> axisInfos;
-        Q_FOREACH (AbstractCoordinatePlane *plane, coordinatePlanes) {
+        for (AbstractCoordinatePlane *plane : qAsConst(coordinatePlanes)) {
             Q_ASSERT(planeInfos.contains(plane));
             PlaneInfo &pi = planeInfos[plane];
             const int column = pi.horizontalOffset;
@@ -834,7 +846,8 @@ void Chart::Private::slotLayoutPlanes()
             // qDebug() << "Chart slotLayoutPlanes() calls planeLayout->addItem("<< row << column << ")";
             planeLayout->setRowStretch(row, 2);
             planeLayout->setColumnStretch(column, 2);
-            Q_FOREACH (AbstractDiagram *abstractDiagram, plane->diagrams()) {
+            const auto constDiagrams = plane->diagrams();
+            for (AbstractDiagram *abstractDiagram : constDiagrams) {
                 auto *diagram =
                     qobject_cast<AbstractCartesianDiagram *>(abstractDiagram);
                 if (!diagram) {
@@ -878,7 +891,8 @@ void Chart::Private::slotLayoutPlanes()
                 }
 
                 // pi.leftAxesLayout->setSizeConstraint( QLayout::SetFixedSize );
-                Q_FOREACH (CartesianAxis *axis, diagram->axes()) {
+                const auto constAxes = diagram->axes();
+                for (CartesianAxis *axis : constAxes) {
                     if (axisInfos.contains(axis)) {
                         continue; // already laid out this one
                     }
@@ -1038,7 +1052,7 @@ void Chart::Private::slotResizePlanes()
         layout->activate();
     }
     // Adapt diagram drawing to the new size
-    Q_FOREACH (AbstractCoordinatePlane *plane, coordinatePlanes) {
+    for (AbstractCoordinatePlane *plane : qAsConst(coordinatePlanes)) {
         plane->layoutDiagrams();
     }
 }
@@ -1046,7 +1060,7 @@ void Chart::Private::slotResizePlanes()
 void Chart::Private::updateDirtyLayouts()
 {
     if (isPlanesLayoutDirty) {
-        Q_FOREACH (AbstractCoordinatePlane *p, coordinatePlanes) {
+        for (AbstractCoordinatePlane *p : qAsConst(coordinatePlanes)) {
             p->setGridNeedsRecalculate();
             p->layoutPlanes();
             p->layoutDiagrams();
@@ -1083,13 +1097,13 @@ void Chart::Private::paintAll(QPainter *painter)
 
     chart->reLayoutFloatingLegends();
 
-    Q_FOREACH (AbstractLayoutItem *planeLayoutItem, planeLayoutItems) {
+    for (AbstractLayoutItem *planeLayoutItem : qAsConst(planeLayoutItems)) {
         planeLayoutItem->paintAll(*painter);
     }
-    Q_FOREACH (TextArea *textLayoutItem, textLayoutItems) {
+    for (TextArea *textLayoutItem : qAsConst(textLayoutItems)) {
         textLayoutItem->paintAll(*painter);
     }
-    Q_FOREACH (Legend *legend, legends) {
+    for (Legend *legend : qAsConst(legends)) {
         const bool hidden = legend->isHidden() && legend->testAttribute(Qt::WA_WState_ExplicitShowHide);
         if (!hidden) {
             // qDebug() << "painting legend at " << legend->geometry();
@@ -1196,12 +1210,12 @@ void Chart::insertCoordinatePlane(int index, AbstractCoordinatePlane *plane)
         return;
     }
 
-    connect(plane, SIGNAL(destroyedCoordinatePlane(AbstractCoordinatePlane *)),
-            d, SLOT(slotUnregisterDestroyedPlane(AbstractCoordinatePlane *)));
-    connect(plane, SIGNAL(needUpdate()), this, SLOT(update()));
-    connect(plane, SIGNAL(needRelayout()), d, SLOT(slotResizePlanes()));
-    connect(plane, SIGNAL(needLayoutPlanes()), d, SLOT(slotLayoutPlanes()));
-    connect(plane, SIGNAL(propertiesChanged()), this, SIGNAL(propertiesChanged()));
+    connect(plane, &AbstractCoordinatePlane::destroyedCoordinatePlane,
+            d, &Private::slotUnregisterDestroyedPlane);
+    connect(plane, &AbstractCoordinatePlane::needUpdate, this, QOverload<>::of(&Chart::update));
+    connect(plane, &AbstractCoordinatePlane::needRelayout, d, &Private::slotResizePlanes);
+    connect(plane, &AbstractCoordinatePlane::needLayoutPlanes, d, &Private::slotLayoutPlanes);
+    connect(plane, &AbstractCoordinatePlane::propertiesChanged, this, &Chart::propertiesChanged);
     d->coordinatePlanes.insert(index, plane);
     plane->setParent(this);
     d->slotLayoutPlanes();
@@ -1237,9 +1251,9 @@ void Chart::takeCoordinatePlane(AbstractCoordinatePlane *plane)
         d->mouseClickedPlanes.removeAll(plane);
     }
     d->slotLayoutPlanes();
-    // Need to emit the signal: In case somebody has connected the signal
+    // Need to Q_EMIT the signal: In case somebody has connected the signal
     // to her own slot for e.g. calling update() on a widget containing the chart.
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void Chart::setGlobalLeading(int left, int top, int right, int bottom)
@@ -1369,7 +1383,7 @@ void Chart::resizeEvent(QResizeEvent *event)
 
 void Chart::reLayoutFloatingLegends()
 {
-    Q_FOREACH (Legend *legend, d->legends) {
+    for (Legend *legend : qAsConst(d->legends)) {
         const bool hidden = legend->isHidden() && legend->testAttribute(Qt::WA_WState_ExplicitShowHide);
         if (legend->position().isFloating() && !hidden) {
             // resize the legend
@@ -1402,7 +1416,7 @@ void Chart::paintEvent(QPaintEvent *)
 {
     QPainter painter(this);
     d->paintAll(&painter);
-    emit finishedDrawing();
+    Q_EMIT finishedDrawing();
 }
 
 void Chart::addHeaderFooter(HeaderFooter *hf)
@@ -1418,10 +1432,10 @@ void Chart::addHeaderFooter(HeaderFooter *hf)
 
     d->headerFooters.append(hf);
     d->textLayoutItems.append(hf);
-    connect(hf, SIGNAL(destroyedHeaderFooter(HeaderFooter *)),
-            d, SLOT(slotUnregisterDestroyedHeaderFooter(HeaderFooter *)));
-    connect(hf, SIGNAL(positionChanged(HeaderFooter *)),
-            d, SLOT(slotHeaderFooterPositionChanged(HeaderFooter *)));
+    connect(hf, &HeaderFooter::destroyedHeaderFooter,
+            d, &Private::slotUnregisterDestroyedHeaderFooter);
+    connect(hf, &HeaderFooter::positionChanged,
+            d, &Private::slotHeaderFooterPositionChanged);
 
     // set the text attributes (why?)
 
@@ -1468,8 +1482,8 @@ void Chart::takeHeaderFooter(HeaderFooter *headerFooter)
     if (idx == -1) {
         return;
     }
-    disconnect(headerFooter, SIGNAL(destroyedHeaderFooter(HeaderFooter *)),
-               d, SLOT(slotUnregisterDestroyedHeaderFooter(HeaderFooter *)));
+    disconnect(headerFooter, &HeaderFooter::destroyedHeaderFooter,
+               d, &Private::slotUnregisterDestroyedHeaderFooter);
 
     d->headerFooters.takeAt(idx);
     headerFooter->removeFromParentLayout();
@@ -1511,7 +1525,7 @@ void Chart::addLegend(Legend *legend)
 {
     legend->show();
     addLegendInternal(legend, true);
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void Chart::addLegendInternal(Legend *legend, bool setMeasures)
@@ -1600,11 +1614,11 @@ void Chart::addLegendInternal(Legend *legend, bool setMeasures)
         sameAlignmentLayout->addItem(new MyWidgetItem(legend, legend->alignment()));
     }
 
-    connect(legend, SIGNAL(destroyedLegend(Legend *)),
-            d, SLOT(slotUnregisterDestroyedLegend(Legend *)));
-    connect(legend, SIGNAL(positionChanged(AbstractAreaWidget *)),
-            d, SLOT(slotLegendPositionChanged(AbstractAreaWidget *)));
-    connect(legend, SIGNAL(propertiesChanged()), this, SIGNAL(propertiesChanged()));
+    connect(legend, &Legend::destroyedLegend,
+            d, &Private::slotUnregisterDestroyedLegend);
+    connect(legend, &Legend::positionChanged,
+            d, &Private::slotLegendPositionChanged);
+    connect(legend, &Legend::propertiesChanged, this, &Chart::propertiesChanged);
 
     d->slotResizePlanes();
 }
@@ -1640,7 +1654,7 @@ void Chart::takeLegend(Legend *legend)
     legend->setParent(nullptr);
 
     d->slotResizePlanes();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 Legend *Chart::legend()
@@ -1648,7 +1662,7 @@ Legend *Chart::legend()
     return d->legends.isEmpty() ? 0 : d->legends.first();
 }
 
-LegendList Chart::legends()
+LegendList Chart::legends() const
 {
     return d->legends;
 }
@@ -1657,7 +1671,7 @@ void Chart::mousePressEvent(QMouseEvent *event)
 {
     const QPoint pos = mapFromGlobal(event->globalPos());
 
-    Q_FOREACH (AbstractCoordinatePlane *plane, d->coordinatePlanes) {
+    for (AbstractCoordinatePlane *plane : qAsConst(d->coordinatePlanes)) {
         if (plane->geometry().contains(event->pos()) && plane->diagrams().size() > 0) {
             QMouseEvent ev(QEvent::MouseButtonPress, pos, event->globalPos(),
                            event->button(), event->buttons(), event->modifiers());
@@ -1671,7 +1685,7 @@ void Chart::mouseDoubleClickEvent(QMouseEvent *event)
 {
     const QPoint pos = mapFromGlobal(event->globalPos());
 
-    Q_FOREACH (AbstractCoordinatePlane *plane, d->coordinatePlanes) {
+    for (AbstractCoordinatePlane *plane : qAsConst(d->coordinatePlanes)) {
         if (plane->geometry().contains(event->pos()) && plane->diagrams().size() > 0) {
             QMouseEvent ev(QEvent::MouseButtonPress, pos, event->globalPos(),
                            event->button(), event->buttons(), event->modifiers());
@@ -1689,7 +1703,7 @@ void Chart::mouseMoveEvent(QMouseEvent *event)
         QSet<AbstractCoordinatePlane *>::fromList(d->mouseClickedPlanes);
 #endif
 
-    Q_FOREACH (AbstractCoordinatePlane *plane, d->coordinatePlanes) {
+    for (AbstractCoordinatePlane *plane : qAsConst(d->coordinatePlanes)) {
         if (plane->geometry().contains(event->pos()) && plane->diagrams().size() > 0) {
             eventReceivers.insert(plane);
         }
@@ -1697,7 +1711,7 @@ void Chart::mouseMoveEvent(QMouseEvent *event)
 
     const QPoint pos = mapFromGlobal(event->globalPos());
 
-    Q_FOREACH (AbstractCoordinatePlane *plane, eventReceivers) {
+    for (AbstractCoordinatePlane *plane : qAsConst(eventReceivers)) {
         QMouseEvent ev(QEvent::MouseMove, pos, event->globalPos(),
                        event->button(), event->buttons(), event->modifiers());
         plane->mouseMoveEvent(&ev);
@@ -1713,7 +1727,7 @@ void Chart::mouseReleaseEvent(QMouseEvent *event)
         QSet<AbstractCoordinatePlane *>::fromList(d->mouseClickedPlanes);
 #endif
 
-    Q_FOREACH (AbstractCoordinatePlane *plane, d->coordinatePlanes) {
+    for (AbstractCoordinatePlane *plane : qAsConst(d->coordinatePlanes)) {
         if (plane->geometry().contains(event->pos()) && plane->diagrams().size() > 0) {
             eventReceivers.insert(plane);
         }
@@ -1721,7 +1735,7 @@ void Chart::mouseReleaseEvent(QMouseEvent *event)
 
     const QPoint pos = mapFromGlobal(event->globalPos());
 
-    Q_FOREACH (AbstractCoordinatePlane *plane, eventReceivers) {
+    for (AbstractCoordinatePlane *plane : qAsConst(eventReceivers)) {
         QMouseEvent ev(QEvent::MouseButtonRelease, pos, event->globalPos(),
                        event->button(), event->buttons(), event->modifiers());
         plane->mouseReleaseEvent(&ev);
@@ -1735,8 +1749,9 @@ bool Chart::event(QEvent *event)
     if (event->type() == QEvent::ToolTip) {
         const QHelpEvent *const helpEvent = static_cast<QHelpEvent *>(event);
         for (int stage = 0; stage < 2; ++stage) {
-            Q_FOREACH (const AbstractCoordinatePlane *const plane, d->coordinatePlanes) {
-                Q_FOREACH (const AbstractDiagram *diagram, plane->diagrams()) {
+            for (const AbstractCoordinatePlane *const plane : qAsConst(d->coordinatePlanes)) {
+                const auto constDiagrams = plane->diagrams();
+                for (const AbstractDiagram *diagram : constDiagrams) {
 
                     QModelIndex index;
                     if (stage == 0) {
diff --git a/src/KDChart/KDChartChart.h b/src/KDChart/KDChartChart.h
index 8b8bf0f9..ed95e90e 100644
--- a/src/KDChart/KDChartChart.h
+++ b/src/KDChart/KDChartChart.h
@@ -271,7 +271,7 @@ class KDCHART_EXPORT Chart : public QWidget
      * The list of all legends associated with the chart.
      * @return The list of all legends associated with the chart.
      */
-    LegendList legends();
+    LegendList legends() const;
 
     /**
      * Add the given legend to the chart. The chart takes ownership.
diff --git a/src/KDChart/KDChartDatasetProxyModel.cpp b/src/KDChart/KDChartDatasetProxyModel.cpp
index 1f0c9b06..3db94e25 100644
--- a/src/KDChart/KDChartDatasetProxyModel.cpp
+++ b/src/KDChart/KDChartDatasetProxyModel.cpp
@@ -252,15 +252,15 @@ void DatasetProxyModel::initializeDatasetDecriptors(
 void DatasetProxyModel::setSourceModel(QAbstractItemModel *m)
 {
     if (sourceModel()) {
-        disconnect(sourceModel(), SIGNAL(layoutChanged()),
-                   this, SLOT(resetDatasetDescriptions()));
+        disconnect(sourceModel(), &QAbstractItemModel::layoutChanged,
+                   this, &DatasetProxyModel::resetDatasetDescriptions);
     }
     QSortFilterProxyModel::setSourceModel(m);
     mRootIndex = QModelIndex();
     if (m) {
-        connect(m, SIGNAL(layoutChanged()),
-                this, SLOT(resetDatasetDescriptions()));
-        connect(m, SIGNAL(layoutChanged()), this, SIGNAL(layoutChanged()));
+        connect(m, &QAbstractItemModel::layoutChanged,
+                this, &DatasetProxyModel::resetDatasetDescriptions);
+        connect(m, &QAbstractItemModel::layoutChanged, this, &DatasetProxyModel::layoutChanged);
     }
     resetDatasetDescriptions();
 }
diff --git a/src/KDChart/KDChartDatasetSelector.cpp b/src/KDChart/KDChartDatasetSelector.cpp
index 2d9c0f97..2c5d6e28 100644
--- a/src/KDChart/KDChartDatasetSelector.cpp
+++ b/src/KDChart/KDChartDatasetSelector.cpp
@@ -68,7 +68,7 @@ void DatasetSelectorWidget::on_groupBox_toggled(bool state)
     if (state) {
         calculateMapping();
     } else {
-        emit mappingDisabled();
+        Q_EMIT mappingDisabled();
     }
 }
 
@@ -103,19 +103,19 @@ void DatasetSelectorWidget::resetDisplayValues()
     mUi->sbColumnCount->setMaximum(mSourceColumnCount);
     mUi->sbColumnCount->setValue(mSourceColumnCount);
     mUi->groupBox->setChecked(false);
-    emit mappingDisabled();
+    Q_EMIT mappingDisabled();
 }
 
 void DatasetSelectorWidget::calculateMapping()
 {
     if (mSourceColumnCount < 2 && mSourceRowCount < 2) {
         mUi->groupBox->setEnabled(false);
-        emit mappingDisabled();
+        Q_EMIT mappingDisabled();
     } else {
         mUi->groupBox->setEnabled(true);
 
         if (!mUi->groupBox->isChecked()) {
-            emit mappingDisabled();
+            Q_EMIT mappingDisabled();
             return;
         }
 
@@ -161,6 +161,6 @@ void DatasetSelectorWidget::calculateMapping()
         }
 
         // and tell the world:
-        emit configureDatasetProxyModel(rowConfig, columnConfig);
+        Q_EMIT configureDatasetProxyModel(rowConfig, columnConfig);
     }
 }
diff --git a/src/KDChart/KDChartDiagramObserver.cpp b/src/KDChart/KDChartDiagramObserver.cpp
index 92dd527c..6b4a4a8b 100644
--- a/src/KDChart/KDChartDiagramObserver.cpp
+++ b/src/KDChart/KDChartDiagramObserver.cpp
@@ -23,9 +23,9 @@ DiagramObserver::DiagramObserver(AbstractDiagram *diagram, QObject *parent)
     , m_diagram(diagram)
 {
     if (m_diagram) {
-        connect(m_diagram, SIGNAL(destroyed(QObject *)), SLOT(slotDestroyed(QObject *)));
-        connect(m_diagram, SIGNAL(aboutToBeDestroyed()), SLOT(slotAboutToBeDestroyed()));
-        connect(m_diagram, SIGNAL(modelsChanged()), SLOT(slotModelsChanged()));
+        connect(m_diagram, &AbstractDiagram::destroyed, this, &DiagramObserver::slotDestroyed);
+        connect(m_diagram, &AbstractDiagram::aboutToBeDestroyed, this, &DiagramObserver::slotAboutToBeDestroyed);
+        connect(m_diagram, &AbstractDiagram::modelsChanged, this, &DiagramObserver::slotModelsChanged);
     }
     init();
 }
@@ -55,31 +55,32 @@ void DiagramObserver::init()
     if (m_attributesmodel)
         disconnect(m_attributesmodel);
 
-    const bool con = connect(m_diagram, SIGNAL(viewportCoordinateSystemChanged()), this, SLOT(slotDataChanged()));
+    const bool con = connect(m_diagram, &AbstractDiagram::viewportCoordinateSystemChanged,
+                             this, QOverload<>::of(&DiagramObserver::slotDataChanged));
     Q_ASSERT(con);
     Q_UNUSED(con)
-    connect(m_diagram, SIGNAL(dataHidden()), SLOT(slotDataHidden()));
+    connect(m_diagram, &AbstractDiagram::dataHidden, this, &DiagramObserver::slotDataHidden);
 
     if (m_diagram->model()) {
-        connect(m_diagram->model(), SIGNAL(dataChanged(QModelIndex, QModelIndex)),
-                SLOT(slotDataChanged(QModelIndex, QModelIndex)));
-        connect(m_diagram->model(), SIGNAL(rowsInserted(QModelIndex, int, int)),
-                SLOT(slotDataChanged()));
-        connect(m_diagram->model(), SIGNAL(columnsInserted(QModelIndex, int, int)),
-                SLOT(slotDataChanged()));
-        connect(m_diagram->model(), SIGNAL(rowsRemoved(QModelIndex, int, int)),
-                SLOT(slotDataChanged()));
-        connect(m_diagram->model(), SIGNAL(columnsRemoved(QModelIndex, int, int)),
-                SLOT(slotDataChanged()));
-        connect(m_diagram->model(), SIGNAL(modelReset()),
-                SLOT(slotDataChanged()));
-        connect(m_diagram->model(), SIGNAL(headerDataChanged(Qt::Orientation, int, int)),
-                SLOT(slotHeaderDataChanged(Qt::Orientation, int, int)));
+        connect(m_diagram->model(), &QAbstractItemModel::dataChanged,
+                this, QOverload<QModelIndex, QModelIndex>::of(&DiagramObserver::slotDataChanged));
+        connect(m_diagram->model(), &QAbstractItemModel::rowsInserted,
+                this, QOverload<>::of(&DiagramObserver::slotDataChanged));
+        connect(m_diagram->model(), &QAbstractItemModel::columnsInserted,
+                this, QOverload<>::of(&DiagramObserver::slotDataChanged));
+        connect(m_diagram->model(), &QAbstractItemModel::rowsRemoved,
+                this, QOverload<>::of(&DiagramObserver::slotDataChanged));
+        connect(m_diagram->model(), &QAbstractItemModel::columnsRemoved,
+                this, QOverload<>::of(&DiagramObserver::slotDataChanged));
+        connect(m_diagram->model(), &QAbstractItemModel::modelReset,
+                this, QOverload<>::of(&DiagramObserver::slotDataChanged));
+        connect(m_diagram->model(), &QAbstractItemModel::headerDataChanged,
+                this, &DiagramObserver::slotHeaderDataChanged);
     }
 
     if (m_diagram->attributesModel())
-        connect(m_diagram->attributesModel(), SIGNAL(attributesChanged(QModelIndex, QModelIndex)),
-                SLOT(slotAttributesChanged(QModelIndex, QModelIndex)));
+        connect(m_diagram->attributesModel(), &AttributesModel::attributesChanged,
+                this, QOverload<QModelIndex, QModelIndex>::of(&DiagramObserver::slotAttributesChanged));
     m_model = m_diagram->model();
     m_attributesmodel = m_diagram->attributesModel();
 }
@@ -87,16 +88,16 @@ void DiagramObserver::init()
 void DiagramObserver::slotDestroyed(QObject *)
 {
     // qDebug() << this << "emits signal\n"
-    //         "    emit diagramDestroyed(" <<  m_diagram << ")";
+    //         "    Q_EMIT diagramDestroyed(" <<  m_diagram << ")";
     AbstractDiagram *diag = m_diagram;
     disconnect(m_diagram, nullptr, this, nullptr);
     m_diagram = nullptr;
-    emit diagramDestroyed(diag);
+    Q_EMIT diagramDestroyed(diag);
 }
 
 void DiagramObserver::slotAboutToBeDestroyed()
 {
-    emit diagramAboutToBeDestroyed(m_diagram);
+    Q_EMIT diagramAboutToBeDestroyed(m_diagram);
 }
 
 void DiagramObserver::slotModelsChanged()
@@ -109,7 +110,7 @@ void DiagramObserver::slotModelsChanged()
 void DiagramObserver::slotHeaderDataChanged(Qt::Orientation, int, int)
 {
     // qDebug() << "DiagramObserver::slotHeaderDataChanged()";
-    emit diagramDataChanged(m_diagram);
+    Q_EMIT diagramDataChanged(m_diagram);
 }
 
 void DiagramObserver::slotDataChanged(QModelIndex, QModelIndex)
@@ -120,13 +121,13 @@ void DiagramObserver::slotDataChanged(QModelIndex, QModelIndex)
 void DiagramObserver::slotDataChanged()
 {
     // qDebug() << "DiagramObserver::slotDataChanged()";
-    emit diagramDataChanged(m_diagram);
+    Q_EMIT diagramDataChanged(m_diagram);
 }
 
 void DiagramObserver::slotDataHidden()
 {
     // qDebug() << "DiagramObserver::slotDataHidden()";
-    emit diagramDataHidden(m_diagram);
+    Q_EMIT diagramDataHidden(m_diagram);
 }
 
 void DiagramObserver::slotAttributesChanged(QModelIndex, QModelIndex)
@@ -137,5 +138,5 @@ void DiagramObserver::slotAttributesChanged(QModelIndex, QModelIndex)
 void DiagramObserver::slotAttributesChanged()
 {
     // qDebug() << "DiagramObserver::slotAttributesChanged()";
-    emit diagramAttributesChanged(m_diagram);
+    Q_EMIT diagramAttributesChanged(m_diagram);
 }
diff --git a/src/KDChart/KDChartHeaderFooter.cpp b/src/KDChart/KDChartHeaderFooter.cpp
index 52471d34..5cb604f8 100644
--- a/src/KDChart/KDChartHeaderFooter.cpp
+++ b/src/KDChart/KDChartHeaderFooter.cpp
@@ -46,7 +46,7 @@ HeaderFooter::HeaderFooter(Chart *parent)
 
 HeaderFooter::~HeaderFooter()
 {
-    emit destroyedHeaderFooter(this);
+    Q_EMIT destroyedHeaderFooter(this);
 }
 
 void HeaderFooter::setParent(QObject *parent)
@@ -98,7 +98,7 @@ void HeaderFooter::setType(HeaderFooterType type)
 {
     if (d->type != type) {
         d->type = type;
-        emit positionChanged(this);
+        Q_EMIT positionChanged(this);
     }
 }
 
@@ -111,7 +111,7 @@ void HeaderFooter::setPosition(Position position)
 {
     if (d->position != position) {
         d->position = position;
-        emit positionChanged(this);
+        Q_EMIT positionChanged(this);
     }
 }
 
diff --git a/src/KDChart/KDChartLegend.cpp b/src/KDChart/KDChartLegend.cpp
index 12c53604..59356e07 100644
--- a/src/KDChart/KDChartLegend.cpp
+++ b/src/KDChart/KDChartLegend.cpp
@@ -74,7 +74,7 @@ Legend::Legend(AbstractDiagram *diagram, QWidget *parent)
 
 Legend::~Legend()
 {
-    emit destroyedLegend(this);
+    Q_EMIT destroyedLegend(this);
 }
 
 void Legend::init()
@@ -125,7 +125,7 @@ QSize Legend::sizeHint() const
 #ifdef DEBUG_LEGEND_PAINT
     qDebug() << "Legend::sizeHint() started";
 #endif
-    Q_FOREACH (AbstractLayoutItem *paintItem, d->paintItems) {
+    for (AbstractLayoutItem *paintItem : qAsConst(d->paintItems)) {
         paintItem->sizeHint();
     }
     return AbstractAreaWidget::sizeHint();
@@ -212,7 +212,7 @@ void Legend::paint(QPainter *painter)
 
     activateTheLayout();
 
-    Q_FOREACH (AbstractLayoutItem *paintItem, d->paintItems) {
+    for (AbstractLayoutItem *paintItem : qAsConst(d->paintItems)) {
         paintItem->paint(painter);
     }
 
@@ -224,7 +224,7 @@ void Legend::paint(QPainter *painter)
 uint Legend::datasetCount() const
 {
     int modelLabelsCount = 0;
-    Q_FOREACH (DiagramObserver *observer, d->observers) {
+    for (DiagramObserver *observer : d->observers) {
         AbstractDiagram *diagram = observer->diagram();
         Q_ASSERT(diagram->datasetLabels().count() == diagram->datasetBrushes().count());
         modelLabelsCount += diagram->datasetLabels().count();
@@ -284,14 +284,10 @@ void Legend::addDiagram(AbstractDiagram *newDiagram)
         } else {
             d->observers.append(observer);
         }
-        connect(observer, SIGNAL(diagramAboutToBeDestroyed(AbstractDiagram *)),
-                SLOT(resetDiagram(AbstractDiagram *)));
-        connect(observer, SIGNAL(diagramDataChanged(AbstractDiagram *)),
-                SLOT(setNeedRebuild()));
-        connect(observer, SIGNAL(diagramDataHidden(AbstractDiagram *)),
-                SLOT(setNeedRebuild()));
-        connect(observer, SIGNAL(diagramAttributesChanged(AbstractDiagram *)),
-                SLOT(setNeedRebuild()));
+        connect(observer, &DiagramObserver::diagramAboutToBeDestroyed, this, &Legend::resetDiagram);
+        connect(observer, &DiagramObserver::diagramDataChanged, this, &Legend::setNeedRebuild);
+        connect(observer, &DiagramObserver::diagramDataHidden, this, &Legend::setNeedRebuild);
+        connect(observer, &DiagramObserver::diagramAttributesChanged, this, &Legend::setNeedRebuild);
         setNeedRebuild();
     }
 }
@@ -317,10 +313,13 @@ void Legend::removeDiagram(AbstractDiagram *oldDiagram)
     if (oldDiagram) {
         DiagramObserver *oldObs = d->findObserverForDiagram(oldDiagram);
         if (oldObs) {
+            d->observers.removeOne(oldObs);
             delete oldObs;
-            d->observers.removeAt(d->observers.indexOf(oldObs));
         }
-        setNeedRebuild();
+
+        // We might be in the middle of a KDChart dctor and hit the assertObjectType
+        // so queue the rebuild
+        QMetaObject::invokeMethod(this, &Legend::setNeedRebuild, Qt::QueuedConnection);
     }
 }
 
@@ -408,8 +407,8 @@ void Legend::setPosition(Position position)
 
 void Legend::emitPositionChanged()
 {
-    emit positionChanged(this);
-    emit propertiesChanged();
+    Q_EMIT positionChanged(this);
+    Q_EMIT propertiesChanged();
 }
 
 Position Legend::position() const
@@ -776,7 +775,7 @@ void Legend::resizeEvent(QResizeEvent *event)
 #endif
     forceRebuild();
     sizeHint();
-    QTimer::singleShot(0, this, SLOT(emitPositionChanged()));
+    QTimer::singleShot(0, this, &Legend::emitPositionChanged);
 }
 
 void Legend::Private::fetchPaintOptions(Legend *q)
@@ -1002,7 +1001,7 @@ void Legend::buildLegend()
 
     updateToplevelLayout(this);
 
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 #ifdef DEBUG_LEGEND_PAINT
     qDebug() << "leaving Legend::buildLegend()";
 #endif
@@ -1135,7 +1134,7 @@ int Legend::heightForWidth(int width) const
 
     int currentLineWidth = 0;
     int currentLineHeight = 0;
-    Q_FOREACH (const HDatasetItem &hdsItem, d->hLayoutDatasets) {
+    for (const HDatasetItem &hdsItem : qAsConst(d->hLayoutDatasets)) {
         const int payloadWidth = hdsItem.markerLine->sizeHint().width() + hdsItem.label->sizeHint().width();
         if (!currentLineWidth) {
             // first iteration
diff --git a/src/KDChart/KDChartModelDataCache_p.cpp b/src/KDChart/KDChartModelDataCache_p.cpp
index 02c84997..65d5c76a 100644
--- a/src/KDChart/KDChartModelDataCache_p.cpp
+++ b/src/KDChart/KDChartModelDataCache_p.cpp
@@ -26,26 +26,26 @@ ModelSignalMapperConnector::~ModelSignalMapperConnector()
 
 void ModelSignalMapperConnector::connectSignals(QAbstractItemModel *model)
 {
-    connect(model, SIGNAL(destroyed()), this, SLOT(resetModel()));
-    connect(model, SIGNAL(columnsInserted(QModelIndex, int, int)), this, SLOT(columnsInserted(QModelIndex, int, int)));
-    connect(model, SIGNAL(columnsRemoved(QModelIndex, int, int)), this, SLOT(columnsRemoved(QModelIndex, int, int)));
-    connect(model, SIGNAL(dataChanged(QModelIndex, QModelIndex)), this, SLOT(dataChanged(QModelIndex, QModelIndex)));
-    connect(model, SIGNAL(layoutChanged()), this, SLOT(layoutChanged()));
-    connect(model, SIGNAL(modelReset()), this, SLOT(modelReset()));
-    connect(model, SIGNAL(rowsInserted(QModelIndex, int, int)), this, SLOT(rowsInserted(QModelIndex, int, int)));
-    connect(model, SIGNAL(rowsRemoved(QModelIndex, int, int)), this, SLOT(rowsRemoved(QModelIndex, int, int)));
+    connect(model, &QAbstractItemModel::destroyed, this, &ModelSignalMapperConnector::resetModel);
+    connect(model, &QAbstractItemModel::columnsInserted, this, &ModelSignalMapperConnector::columnsInserted);
+    connect(model, &QAbstractItemModel::columnsRemoved, this, &ModelSignalMapperConnector::columnsRemoved);
+    connect(model, &QAbstractItemModel::dataChanged, this, &ModelSignalMapperConnector::dataChanged);
+    connect(model, &QAbstractItemModel::layoutChanged, this, &ModelSignalMapperConnector::layoutChanged);
+    connect(model, &QAbstractItemModel::modelReset, this, &ModelSignalMapperConnector::modelReset);
+    connect(model, &QAbstractItemModel::rowsInserted, this, &ModelSignalMapperConnector::rowsInserted);
+    connect(model, &QAbstractItemModel::rowsRemoved, this, &ModelSignalMapperConnector::rowsRemoved);
 }
 
 void ModelSignalMapperConnector::disconnectSignals(QAbstractItemModel *model)
 {
-    disconnect(model, SIGNAL(destroyed()), this, SLOT(resetModel()));
-    disconnect(model, SIGNAL(columnsInserted(QModelIndex, int, int)), this, SLOT(columnsInserted(QModelIndex, int, int)));
-    disconnect(model, SIGNAL(columnsRemoved(QModelIndex, int, int)), this, SLOT(columnsRemoved(QModelIndex, int, int)));
-    disconnect(model, SIGNAL(dataChanged(QModelIndex, QModelIndex)), this, SLOT(dataChanged(QModelIndex, QModelIndex)));
-    disconnect(model, SIGNAL(layoutChanged()), this, SLOT(layoutChanged()));
-    disconnect(model, SIGNAL(modelReset()), this, SLOT(modelReset()));
-    disconnect(model, SIGNAL(rowsInserted(QModelIndex, int, int)), this, SLOT(rowsInserted(QModelIndex, int, int)));
-    disconnect(model, SIGNAL(rowsRemoved(QModelIndex, int, int)), this, SLOT(rowsRemoved(QModelIndex, int, int)));
+    disconnect(model, &QAbstractItemModel::destroyed, this, &ModelSignalMapperConnector::resetModel);
+    disconnect(model, &QAbstractItemModel::columnsInserted, this, &ModelSignalMapperConnector::columnsInserted);
+    disconnect(model, &QAbstractItemModel::columnsRemoved, this, &ModelSignalMapperConnector::columnsRemoved);
+    disconnect(model, &QAbstractItemModel::dataChanged, this, &ModelSignalMapperConnector::dataChanged);
+    disconnect(model, &QAbstractItemModel::layoutChanged, this, &ModelSignalMapperConnector::layoutChanged);
+    disconnect(model, &QAbstractItemModel::modelReset, this, &ModelSignalMapperConnector::modelReset);
+    disconnect(model, &QAbstractItemModel::rowsInserted, this, &ModelSignalMapperConnector::rowsInserted);
+    disconnect(model, &QAbstractItemModel::rowsRemoved, this, &ModelSignalMapperConnector::rowsRemoved);
 }
 
 void ModelSignalMapperConnector::resetModel()
diff --git a/src/KDChart/KDChartPalette.cpp b/src/KDChart/KDChartPalette.cpp
index 4a8bfbe6..9967bce6 100644
--- a/src/KDChart/KDChartPalette.cpp
+++ b/src/KDChart/KDChartPalette.cpp
@@ -160,7 +160,7 @@ void Palette::addBrush(const QBrush &brush, int position)
     } else {
         d->brushes.insert(position, brush);
     }
-    emit changed();
+    Q_EMIT changed();
 }
 
 QBrush Palette::getBrush(int position) const
@@ -175,5 +175,5 @@ void Palette::removeBrush(int position)
     if (position < 0 || position >= size())
         return;
     d->brushes.remove(position);
-    emit changed();
+    Q_EMIT changed();
 }
diff --git a/src/KDChart/KDChartTextArea.cpp b/src/KDChart/KDChartTextArea.cpp
index a3d3cfe9..d570278f 100644
--- a/src/KDChart/KDChartTextArea.cpp
+++ b/src/KDChart/KDChartTextArea.cpp
@@ -90,5 +90,5 @@ QRect TextArea::areaGeometry() const
 
 void TextArea::positionHasChanged()
 {
-    emit positionChanged(this);
+    Q_EMIT positionChanged(this);
 }
diff --git a/src/KDChart/KDChartTextLabelCache.cpp b/src/KDChart/KDChartTextLabelCache.cpp
index 099d5ba7..931603fa 100644
--- a/src/KDChart/KDChartTextLabelCache.cpp
+++ b/src/KDChart/KDChartTextLabelCache.cpp
@@ -245,17 +245,18 @@ void PrerenderedLabel::paint() const
         painter.setPen(QPen(Qt::red, 2));
         painter.setBrush(Qt::red);
         // paint markers for the reference points
-        QList<KDChartEnums::PositionValue> positions;
-        positions << KDChartEnums::PositionCenter
-                  << KDChartEnums::PositionNorthWest
-                  << KDChartEnums::PositionNorth
-                  << KDChartEnums::PositionNorthEast
-                  << KDChartEnums::PositionEast
-                  << KDChartEnums::PositionSouthEast
-                  << KDChartEnums::PositionSouth
-                  << KDChartEnums::PositionSouthWest
-                  << KDChartEnums::PositionWest;
-        Q_FOREACH (KDChartEnums::PositionValue position, positions) { // krazy:exclude=foreach
+        const QList<KDChartEnums::PositionValue> positions = {
+            KDChartEnums::PositionCenter,
+            KDChartEnums::PositionNorthWest,
+            KDChartEnums::PositionNorth,
+            KDChartEnums::PositionNorthEast,
+            KDChartEnums::PositionEast,
+            KDChartEnums::PositionSouthEast,
+            KDChartEnums::PositionSouth,
+            KDChartEnums::PositionSouthWest,
+            KDChartEnums::PositionWest,
+        };
+        for (KDChartEnums::PositionValue position : positions) {
             static const double Radius = 0.5;
             static const double Diameter = 2 * Radius;
 
diff --git a/src/KDChart/KDChartWidget.cpp b/src/KDChart/KDChartWidget.cpp
index 3214d677..6766d84e 100644
--- a/src/KDChart/KDChartWidget.cpp
+++ b/src/KDChart/KDChartWidget.cpp
@@ -431,13 +431,15 @@ void Widget::setType(ChartType chartType, SubType chartSubType)
                     qobject_cast<AbstractCartesianDiagram *>(coordinatePlane()->diagram());
                 auto *newDiag =
                     qobject_cast<AbstractCartesianDiagram *>(diag);
-                Q_FOREACH (CartesianAxis *axis, oldDiag->axes()) {
+                const auto constAxes = oldDiag->axes();
+                for (CartesianAxis *axis : constAxes) {
                     oldDiag->takeAxis(axis);
                     newDiag->addAxis(axis);
                 }
             }
 
-            Q_FOREACH (Legend *l, d->m_chart.legends()) {
+            const auto constLegends = d->m_chart.legends();
+            for (Legend *l : constLegends) {
                 l->setDiagram(diag);
             }
 
diff --git a/src/KDChart/Polar/KDChartAbstractPieDiagram.cpp b/src/KDChart/Polar/KDChartAbstractPieDiagram.cpp
index 6afdd39f..d113d551 100644
--- a/src/KDChart/Polar/KDChartAbstractPieDiagram.cpp
+++ b/src/KDChart/Polar/KDChartAbstractPieDiagram.cpp
@@ -103,19 +103,19 @@ bool AbstractPieDiagram::autoRotateLabels() const
 void AbstractPieDiagram::setPieAttributes(const PieAttributes &attrs)
 {
     d->attributesModel->setModelData(QVariant::fromValue(attrs), PieAttributesRole);
-    emit layoutChanged(this);
+    Q_EMIT layoutChanged(this);
 }
 
 void AbstractPieDiagram::setPieAttributes(int column, const PieAttributes &attrs)
 {
     d->setDatasetAttrs(column, QVariant::fromValue(attrs), PieAttributesRole);
-    emit layoutChanged(this);
+    Q_EMIT layoutChanged(this);
 }
 
 void AbstractPieDiagram::setPieAttributes(const QModelIndex &index, const PieAttributes &attrs)
 {
     d->attributesModel->setData(index, QVariant::fromValue(attrs), PieAttributesRole);
-    emit layoutChanged(this);
+    Q_EMIT layoutChanged(this);
 }
 
 PieAttributes AbstractPieDiagram::pieAttributes() const
@@ -142,19 +142,19 @@ PieAttributes AbstractPieDiagram::pieAttributes(const QModelIndex &index) const
 void AbstractPieDiagram::setThreeDPieAttributes(const ThreeDPieAttributes &tda)
 {
     d->attributesModel->setModelData(QVariant::fromValue(tda), ThreeDPieAttributesRole);
-    emit layoutChanged(this);
+    Q_EMIT layoutChanged(this);
 }
 
 void AbstractPieDiagram::setThreeDPieAttributes(int column, const ThreeDPieAttributes &tda)
 {
     d->setDatasetAttrs(column, QVariant::fromValue(tda), ThreeDPieAttributesRole);
-    emit layoutChanged(this);
+    Q_EMIT layoutChanged(this);
 }
 
 void AbstractPieDiagram::setThreeDPieAttributes(const QModelIndex &index, const ThreeDPieAttributes &tda)
 {
     model()->setData(index, QVariant::fromValue(tda), ThreeDPieAttributesRole);
-    emit layoutChanged(this);
+    Q_EMIT layoutChanged(this);
 }
 
 ThreeDPieAttributes AbstractPieDiagram::threeDPieAttributes() const
diff --git a/src/KDChart/Polar/KDChartPieDiagram.cpp b/src/KDChart/Polar/KDChartPieDiagram.cpp
index f64b4c05..78b54e3c 100644
--- a/src/KDChart/Polar/KDChartPieDiagram.cpp
+++ b/src/KDChart/Polar/KDChartPieDiagram.cpp
@@ -489,7 +489,7 @@ void PieDiagram::paintInternal(PaintContext *paintContext)
     const QPointF center = paintContext->rectangle().center();
     const PainterSaver painterSaver(paintContext->painter());
     paintContext->painter()->setBrush(Qt::NoBrush);
-    Q_FOREACH (const LabelPaintInfo &pi, d->labelPaintCache.paintReplay) {
+    for (const LabelPaintInfo &pi : qAsConst(d->labelPaintCache.paintReplay)) {
         // we expect the PainterPath to be a rectangle
         if (pi.labelArea.elementCount() != 5) {
             continue;
diff --git a/src/KDChart/Polar/KDChartPolarCoordinatePlane.cpp b/src/KDChart/Polar/KDChartPolarCoordinatePlane.cpp
index 72c58d69..b834a24a 100644
--- a/src/KDChart/Polar/KDChartPolarCoordinatePlane.cpp
+++ b/src/KDChart/Polar/KDChartPolarCoordinatePlane.cpp
@@ -54,8 +54,7 @@ void PolarCoordinatePlane::addDiagram(AbstractDiagram *diagram)
                "PolarCoordinatePlane::addDiagram", "Only polar"
                                                    "diagrams can be added to a polar coordinate plane!");
     AbstractCoordinatePlane::addDiagram(diagram);
-    connect(diagram, SIGNAL(layoutChanged(AbstractDiagram *)),
-            SLOT(slotLayoutChanged(AbstractDiagram *)));
+    connect(diagram, &AbstractDiagram::layoutChanged, this, &PolarCoordinatePlane::slotLayoutChanged);
 }
 
 void PolarCoordinatePlane::paint(QPainter *painter)
@@ -148,7 +147,8 @@ void PolarCoordinatePlane::layoutDiagrams()
     // FIXME distribute space according to options:
     const qreal oldStartPosition = startPosition();
     d->coordinateTransformations.clear();
-    Q_FOREACH (AbstractDiagram *diagram, diagrams()) {
+    const auto constDiagrams = diagrams();
+    for (AbstractDiagram *diagram : constDiagrams) {
         auto *polarDiagram = dynamic_cast<AbstractPolarDiagram *>(diagram);
         Q_ASSERT(polarDiagram);
         QPair<QPointF, QPointF> dataBoundariesPair = polarDiagram->dataBoundaries();
@@ -307,7 +307,7 @@ void KDChart::PolarCoordinatePlane::setGridAttributes(
         d->gridAttributesSagittal = a;
     setHasOwnGridAttributes(circular, true);
     update();
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 void KDChart::PolarCoordinatePlane::resetGridAttributes(
@@ -349,7 +349,7 @@ void KDChart::PolarCoordinatePlane::setHasOwnGridAttributes(
         d->hasOwnGridAttributesCircular = on;
     else
         d->hasOwnGridAttributesSagittal = on;
-    emit propertiesChanged();
+    Q_EMIT propertiesChanged();
 }
 
 bool KDChart::PolarCoordinatePlane::hasOwnGridAttributes(
diff --git a/src/KDChart/Polar/KDChartRadarDiagram.cpp b/src/KDChart/Polar/KDChartRadarDiagram.cpp
index 2aca9786..62c33568 100644
--- a/src/KDChart/Polar/KDChartRadarDiagram.cpp
+++ b/src/KDChart/Polar/KDChartRadarDiagram.cpp
@@ -250,7 +250,7 @@ void RadarDiagram::paint(PaintContext *ctx,
 
         // first fill the areas with the brush-color and the defined alpha-value.
         if (d->fillAlpha > 0.0) {
-            Q_FOREACH (const Polygon &p, polygons) {
+            for (const Polygon &p : polygons) {
                 PainterSaver painterSaver(ctx->painter());
                 ctx->painter()->setRenderHint(QPainter::Antialiasing);
                 QBrush br = p.brush;
@@ -264,7 +264,7 @@ void RadarDiagram::paint(PaintContext *ctx,
         }
 
         // then draw the poly-lines.
-        Q_FOREACH (const Polygon &p, polygons) {
+        for (const Polygon &p : polygons) {
             PainterSaver painterSaver(ctx->painter());
             ctx->painter()->setRenderHint(QPainter::Antialiasing);
             ctx->painter()->setBrush(p.brush);
diff --git a/src/KDChart/ReverseMapper.cpp b/src/KDChart/ReverseMapper.cpp
index 78456902..2553f6f9 100644
--- a/src/KDChart/ReverseMapper.cpp
+++ b/src/KDChart/ReverseMapper.cpp
@@ -54,9 +54,9 @@ QModelIndexList ReverseMapper::indexesIn(const QRect &rect) const
 {
     Q_ASSERT(m_diagram);
     if (m_scene && m_scene->sceneRect().intersects(rect)) {
-        QList<QGraphicsItem *> items = m_scene->items(rect);
+        const QList<QGraphicsItem *> items = m_scene->items(rect);
         QModelIndexList indexes;
-        Q_FOREACH (QGraphicsItem *item, items) {
+        for (QGraphicsItem *item : items) {
             auto *i = qgraphicsitem_cast<ChartGraphicsItem *>(item);
             if (i) {
                 QModelIndex index(m_diagram->model()->index(i->row(), i->column(), m_diagram->rootIndex())); // checked
@@ -73,9 +73,9 @@ QModelIndexList ReverseMapper::indexesAt(const QPointF &point) const
 {
     Q_ASSERT(m_diagram);
     if (m_scene && m_scene->sceneRect().contains(point)) {
-        QList<QGraphicsItem *> items = m_scene->items(point);
+        const QList<QGraphicsItem *> items = m_scene->items(point);
         QModelIndexList indexes;
-        Q_FOREACH (QGraphicsItem *item, items) {
+        for (QGraphicsItem *item : items) {
             auto *i = qgraphicsitem_cast<ChartGraphicsItem *>(item);
             if (i) {
                 QModelIndex index(m_diagram->model()->index(i->row(), i->column(), m_diagram->rootIndex())); // checked
diff --git a/src/KDChart/Ternary/KDChartTernaryAxis.cpp b/src/KDChart/Ternary/KDChartTernaryAxis.cpp
index 44020601..329e7556 100644
--- a/src/KDChart/Ternary/KDChartTernaryAxis.cpp
+++ b/src/KDChart/Ternary/KDChartTernaryAxis.cpp
@@ -66,9 +66,11 @@ void TernaryAxis::paintCtx(PaintContext *paintContext)
     // QObject* refArea = plane->parent();
 
     // paint the axis label (across the triangle, that one):
-    QList<PrerenderedLabel *> labels;
-    labels << m_label << m_fifty;
-    Q_FOREACH (PrerenderedLabel *label, labels) {
+    const QList<PrerenderedLabel *> labels = {
+        m_label,
+        m_fifty,
+    };
+    for (PrerenderedLabel *label : labels) {
         const QPixmap &pixmap = label->pixmap();
         QPointF point = plane->translate(label->position())
             - label->referencePointLocation();
diff --git a/src/KDChart/Ternary/KDChartTernaryCoordinatePlane.cpp b/src/KDChart/Ternary/KDChartTernaryCoordinatePlane.cpp
index 4a895d58..2386f9eb 100644
--- a/src/KDChart/Ternary/KDChartTernaryCoordinatePlane.cpp
+++ b/src/KDChart/Ternary/KDChartTernaryCoordinatePlane.cpp
@@ -67,11 +67,13 @@ void TernaryCoordinatePlane::layoutDiagrams()
     {
         QSizeF topleft(0.0, 0.0);
         QSizeF bottomRight(0.0, 0.0);
-        Q_FOREACH (AbstractDiagram *abstractDiagram, diagrams()) {
+        const auto constDiagrams = diagrams();
+        for (AbstractDiagram *abstractDiagram : constDiagrams) {
             auto *diagram =
                 qobject_cast<AbstractTernaryDiagram *>(abstractDiagram);
             Q_ASSERT(diagram);
-            Q_FOREACH (TernaryAxis *axis, diagram->axes()) {
+            const auto constAxes = diagram->axes();
+            for (TernaryAxis *axis : constAxes) {
                 QPair<QSizeF, QSizeF> margin = axis->requiredMargins();
                 topleft = topleft.expandedTo(margin.first);
                 bottomRight = bottomRight.expandedTo(margin.second);
diff --git a/src/KDChart/Ternary/KDChartTernaryGrid.cpp b/src/KDChart/Ternary/KDChartTernaryGrid.cpp
index e2d8c1b5..0ba849e2 100644
--- a/src/KDChart/Ternary/KDChartTernaryGrid.cpp
+++ b/src/KDChart/Ternary/KDChartTernaryGrid.cpp
@@ -80,7 +80,7 @@ void TernaryGrid::drawGrid(PaintContext *context)
 
     QVector<QLineF> lines[MaxDepth];
     {
-        Q_FOREACH (const TickInfo &tick, m_tickInfo) {
+        for (const TickInfo &tick : qAsConst(m_tickInfo)) {
             const qreal &percent = tick.percentage;
             { // draw parallels to B
                 TernaryPoint ternaryStart(percent, 1.0 - percent);
@@ -150,7 +150,7 @@ void TernaryGrid::drawGrid(PaintContext *context)
                       percentages.end());
 
     {
-        Q_FOREACH (const TickInfo &tick, percentages) {
+        for (const TickInfo &tick : percentages) {
             const qreal &percent = tick.percentage;
             { // BC axis markers:
                 const QPointF markerDistance(FullMarkerDistanceBC
diff --git a/src/KDGantt/kdganttconstraintmodel.cpp b/src/KDGantt/kdganttconstraintmodel.cpp
index 25644401..a1b8d128 100644
--- a/src/KDGantt/kdganttconstraintmodel.cpp
+++ b/src/KDGantt/kdganttconstraintmodel.cpp
@@ -116,14 +116,14 @@ void ConstraintModel::addConstraint(const Constraint &c)
         d->constraints.push_back(c);
         d->addConstraintToIndex(c.startIndex(), c);
         d->addConstraintToIndex(c.endIndex(), c);
-        emit constraintAdded(c);
+        Q_EMIT constraintAdded(c);
     } else if ((*it).dataMap() != c.dataMap()) {
         Constraint tmp(*it); // save to avoid re-entrancy issues
         removeConstraint(tmp);
         d->constraints.push_back(c);
         d->addConstraintToIndex(c.startIndex(), c);
         d->addConstraintToIndex(c.endIndex(), c);
-        emit constraintAdded(c);
+        Q_EMIT constraintAdded(c);
     }
 }
 
@@ -148,7 +148,7 @@ bool ConstraintModel::removeConstraint(const Constraint &c)
     if (rc) {
         d->removeConstraintFromIndex(c.startIndex(), c);
         d->removeConstraintFromIndex(c.endIndex(), c);
-        emit constraintRemoved(c);
+        Q_EMIT constraintRemoved(c);
     }
 
     return rc;
@@ -160,8 +160,8 @@ bool ConstraintModel::removeConstraint(const Constraint &c)
  */
 void ConstraintModel::clear()
 {
-    QList<Constraint> lst = constraints();
-    Q_FOREACH (const Constraint &c, lst) {
+    const QList<Constraint> lst = constraints();
+    for (const Constraint &c : lst) {
         removeConstraint(c);
     }
 }
@@ -171,7 +171,7 @@ void ConstraintModel::cleanup()
 {
 #if 0
     QSet<Constraint> orphans;
-    Q_FOREACH( const Constraint& c, d->constraints ) {
+    for (const Constraint& c, qAsConst(d->constraints)) {
         if ( !c.startIndex().isValid() || !c.endIndex().isValid() ) orphans.insert( c );
     }
     //qDebug() << "Constraint::cleanup() found" << orphans << "orphans";
@@ -198,14 +198,14 @@ QList<Constraint> ConstraintModel::constraintsForIndex(const QModelIndex &idx) c
     if (!idx.isValid()) {
         // Because of a Qt bug we need to treat this as a special case
         QSet<Constraint> result;
-        Q_FOREACH (const Constraint &c, d->constraints) {
+        for (const Constraint &c : d->constraints) {
             if (!c.startIndex().isValid() || !c.endIndex().isValid())
                 result.insert(c);
         }
         return result.values();
     } else {
         QList<Constraint> result;
-        Q_FOREACH (const Constraint &c, d->constraints) {
+        for (const Constraint &c : d->constraints) {
             if (c.startIndex() == idx || c.endIndex() == idx)
                 result.push_back(c);
         }
@@ -222,7 +222,8 @@ bool ConstraintModel::hasConstraint(const Constraint &c) const
 {
     /*
     // Because of a Qt bug we have to search like this
-    Q_FOREACH( Constraint c2, d->constraints ) {
+    const auto constraints = model.constraints();
+    for ( Constraint c2 : constraints ) {
         if ( c==c2 ) return true;
     }
     return false;
@@ -241,7 +242,8 @@ bool ConstraintModel::hasConstraint(const Constraint &c) const
 QDebug operator<<(QDebug dbg, const KDGantt::ConstraintModel &model)
 {
     dbg << "KDGantt::ConstraintModel[ " << static_cast<const QObject *>(&model) << ": [\n";
-    Q_FOREACH (const Constraint &c, model.constraints()) {
+    const auto constraints = model.constraints();
+    for (const Constraint &c : constraints) {
         dbg << "\t" << c << "\n";
     }
     dbg << "]\n";
diff --git a/src/KDGantt/kdganttconstraintproxy.cpp b/src/KDGantt/kdganttconstraintproxy.cpp
index db3eba39..142b8dea 100644
--- a/src/KDGantt/kdganttconstraintproxy.cpp
+++ b/src/KDGantt/kdganttconstraintproxy.cpp
@@ -36,10 +36,10 @@ void ConstraintProxy::setSourceModel(ConstraintModel *src)
 
     copyFromSource();
 
-    connect(m_source, SIGNAL(constraintAdded(const KDGantt::Constraint &)),
-            this, SLOT(slotSourceConstraintAdded(const KDGantt::Constraint &)));
-    connect(m_source, SIGNAL(constraintRemoved(const KDGantt::Constraint &)),
-            this, SLOT(slotSourceConstraintRemoved(const KDGantt::Constraint &)));
+    connect(m_source, &ConstraintModel::constraintAdded,
+            this, &ConstraintProxy::slotSourceConstraintAdded);
+    connect(m_source, &ConstraintModel::constraintRemoved,
+            this, &ConstraintProxy::slotSourceConstraintRemoved);
 }
 
 void ConstraintProxy::setDestinationModel(ConstraintModel *dest)
@@ -50,10 +50,10 @@ void ConstraintProxy::setDestinationModel(ConstraintModel *dest)
 
     copyFromSource();
 
-    connect(m_destination, SIGNAL(constraintAdded(const KDGantt::Constraint &)),
-            this, SLOT(slotDestinationConstraintAdded(const KDGantt::Constraint &)));
-    connect(m_destination, SIGNAL(constraintRemoved(const KDGantt::Constraint &)),
-            this, SLOT(slotDestinationConstraintRemoved(const KDGantt::Constraint &)));
+    connect(m_destination, &ConstraintModel::constraintAdded,
+            this, &ConstraintProxy::slotDestinationConstraintAdded);
+    connect(m_destination, &ConstraintModel::constraintRemoved,
+            this, &ConstraintProxy::slotDestinationConstraintRemoved);
 }
 
 void ConstraintProxy::setProxyModel(QAbstractProxyModel *proxy)
@@ -64,8 +64,8 @@ void ConstraintProxy::setProxyModel(QAbstractProxyModel *proxy)
         m_proxy->disconnect(this);
     m_proxy = proxy;
     if (m_proxy) {
-        connect(m_proxy, SIGNAL(layoutChanged()), this, SLOT(slotLayoutChanged()));
-        connect(m_proxy, SIGNAL(modelReset()), this, SLOT(slotLayoutChanged()));
+        connect(m_proxy, &QAbstractProxyModel::layoutChanged, this, &ConstraintProxy::slotLayoutChanged);
+        connect(m_proxy, &QAbstractProxyModel::modelReset, this, &ConstraintProxy::slotLayoutChanged);
     }
 }
 
@@ -89,7 +89,7 @@ void ConstraintProxy::copyFromSource()
         if (!m_source)
             return;
         const QList<Constraint> lst = m_source->constraints();
-        Q_FOREACH (const Constraint &c, lst) {
+        for (const Constraint &c : lst) {
             Constraint temp(m_proxy->mapFromSource(c.startIndex()), m_proxy->mapFromSource(c.endIndex()),
                             c.type(), c.relationType(), c.dataMap());
             m_destination->addConstraint(temp);
diff --git a/src/KDGantt/kdganttdatetimegrid.cpp b/src/KDGantt/kdganttdatetimegrid.cpp
index 83d0acf2..050a8587 100644
--- a/src/KDGantt/kdganttdatetimegrid.cpp
+++ b/src/KDGantt/kdganttdatetimegrid.cpp
@@ -311,7 +311,7 @@ QDateTime DateTimeGrid::startDateTime() const
 void DateTimeGrid::setStartDateTime(const QDateTime &dt)
 {
     d->startDateTime = dt;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! \returns The width in pixels for each day in the grid.
@@ -345,7 +345,7 @@ void DateTimeGrid::setDayWidth(qreal w)
 {
     assert(w > 0);
     d->dayWidth = w;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! \param s The scale to be used to paint the grid.
@@ -365,7 +365,7 @@ void DateTimeGrid::setDayWidth(qreal w)
 void DateTimeGrid::setScale(Scale s)
 {
     d->scale = s;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! \returns The scale used to paint the grid.
@@ -390,7 +390,7 @@ void DateTimeGrid::setUserDefinedLowerScale(DateTimeScaleFormatter *lower)
 {
     delete d->lower;
     d->lower = lower;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! Sets the scale formatter for the upper part of the header to the
@@ -404,7 +404,7 @@ void DateTimeGrid::setUserDefinedUpperScale(DateTimeScaleFormatter *upper)
 {
     delete d->upper;
     d->upper = upper;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! \return The DateTimeScaleFormatter being used to render the lower scale.
@@ -429,7 +429,7 @@ DateTimeScaleFormatter *DateTimeGrid::userDefinedUpperScale() const
 void DateTimeGrid::setWeekStart(Qt::DayOfWeek ws)
 {
     d->weekStart = ws;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! \returns The start day of the week */
@@ -447,7 +447,7 @@ Qt::DayOfWeek DateTimeGrid::weekStart() const
 void DateTimeGrid::setFreeDays(const QSet<Qt::DayOfWeek> &fd)
 {
     d->freeDays = fd;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! \returns The days marked as free in the grid. */
@@ -489,7 +489,7 @@ void DateTimeGrid::setRowSeparators(bool enable)
 void DateTimeGrid::setNoInformationBrush(const QBrush &brush)
 {
     d->noInformationBrush = brush;
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 /*! \returns the brush used to mark rows with no information.
@@ -590,7 +590,7 @@ bool DateTimeGrid::mapFromChart(const Span &span, const QModelIndex &idx,
     QDateTime st = d->chartXtoDateTime(span.start());
     QDateTime et = d->chartXtoDateTime(span.start() + span.length());
     // qDebug() << "DateTimeGrid::mapFromChart("<<span<<") => "<< st << et;
-    Q_FOREACH (const Constraint &c, constraints) {
+    for (const Constraint &c : constraints) {
         if (c.type() != Constraint::TypeHard || !isSatisfiedConstraint(c))
             continue;
         if (c.startIndex() == idx) {
diff --git a/src/KDGantt/kdganttforwardingproxymodel.cpp b/src/KDGantt/kdganttforwardingproxymodel.cpp
index c40b41b2..685e5e8d 100644
--- a/src/KDGantt/kdganttforwardingproxymodel.cpp
+++ b/src/KDGantt/kdganttforwardingproxymodel.cpp
@@ -88,31 +88,31 @@ void ForwardingProxyModel::setSourceModel(QAbstractItemModel *model)
     if (!model)
         return;
 
-    connect(model, SIGNAL(modelAboutToBeReset()), this, SLOT(sourceModelAboutToBeReset()));
-    connect(model, SIGNAL(modelReset()), this, SLOT(sourceModelReset()));
-    connect(model, SIGNAL(layoutAboutToBeChanged()), this, SLOT(sourceLayoutAboutToBeChanged()));
-    connect(model, SIGNAL(layoutChanged()), this, SLOT(sourceLayoutChanged()));
-
-    connect(model, SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
-            this, SLOT(sourceDataChanged(const QModelIndex &, const QModelIndex &)));
-
-    connect(model, SIGNAL(columnsAboutToBeInserted(const QModelIndex &, int, int)),
-            this, SLOT(sourceColumnsAboutToBeInserted(const QModelIndex &, int, int)));
-    connect(model, SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-            this, SLOT(sourceColumnsInserted(const QModelIndex &, int, int)));
-    connect(model, SIGNAL(columnsAboutToBeRemoved(const QModelIndex &, int, int)),
-            this, SLOT(sourceColumnsAboutToBeRemoved(const QModelIndex &, int, int)));
-    connect(model, SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-            this, SLOT(sourceColumnsRemoved(const QModelIndex &, int, int)));
-
-    connect(model, SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)),
-            this, SLOT(sourceRowsAboutToBeInserted(const QModelIndex &, int, int)));
-    connect(model, SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-            this, SLOT(sourceRowsInserted(const QModelIndex &, int, int)));
-    connect(model, SIGNAL(rowsAboutToBeRemoved(const QModelIndex &, int, int)),
-            this, SLOT(sourceRowsAboutToBeRemoved(const QModelIndex &, int, int)));
-    connect(model, SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-            this, SLOT(sourceRowsRemoved(const QModelIndex &, int, int)));
+    connect(model, &QAbstractItemModel::modelAboutToBeReset, this, &ForwardingProxyModel::sourceModelAboutToBeReset);
+    connect(model, &QAbstractItemModel::modelReset, this, &ForwardingProxyModel::sourceModelReset);
+    connect(model, &QAbstractItemModel::layoutAboutToBeChanged, this, &ForwardingProxyModel::sourceLayoutAboutToBeChanged);
+    connect(model, &QAbstractItemModel::layoutChanged, this, &ForwardingProxyModel::sourceLayoutChanged);
+
+    connect(model, &QAbstractItemModel::dataChanged,
+            this, &ForwardingProxyModel::sourceDataChanged);
+
+    connect(model, &QAbstractItemModel::columnsAboutToBeInserted,
+            this, &ForwardingProxyModel::sourceColumnsAboutToBeInserted);
+    connect(model, &QAbstractItemModel::columnsInserted,
+            this, &ForwardingProxyModel::sourceColumnsInserted);
+    connect(model, &QAbstractItemModel::columnsAboutToBeRemoved,
+            this, &ForwardingProxyModel::sourceColumnsAboutToBeRemoved);
+    connect(model, &QAbstractItemModel::columnsRemoved,
+            this, &ForwardingProxyModel::sourceColumnsRemoved);
+
+    connect(model, &QAbstractItemModel::rowsAboutToBeInserted,
+            this, &ForwardingProxyModel::sourceRowsAboutToBeInserted);
+    connect(model, &QAbstractItemModel::rowsInserted,
+            this, &ForwardingProxyModel::sourceRowsInserted);
+    connect(model, &QAbstractItemModel::rowsAboutToBeRemoved,
+            this, &ForwardingProxyModel::sourceRowsAboutToBeRemoved);
+    connect(model, &QAbstractItemModel::rowsRemoved,
+            this, &ForwardingProxyModel::sourceRowsRemoved);
 }
 
 /*! Called when the source model is about to be reset.
@@ -140,7 +140,7 @@ void ForwardingProxyModel::sourceModelReset()
 void ForwardingProxyModel::sourceLayoutAboutToBeChanged()
 {
     // qDebug() << "ForwardingProxyModel::sourceLayoutAboutToBeChanged()";
-    emit layoutAboutToBeChanged();
+    Q_EMIT layoutAboutToBeChanged();
 }
 
 /*! Called when the layout of the source model has changed.
@@ -159,7 +159,7 @@ void ForwardingProxyModel::sourceLayoutChanged()
 void ForwardingProxyModel::sourceDataChanged(const QModelIndex &from, const QModelIndex &to)
 {
     // qDebug() << "ForwardingProxyModel::sourceDataChanged("<<from<<to<<")";
-    emit dataChanged(mapFromSource(from), mapFromSource(to));
+    Q_EMIT dataChanged(mapFromSource(from), mapFromSource(to));
 }
 
 /*! Called just before columns are inserted into the source model.
diff --git a/src/KDGantt/kdganttgraphicsitem.cpp b/src/KDGantt/kdganttgraphicsitem.cpp
index ce662bb4..c3dfaea8 100644
--- a/src/KDGantt/kdganttgraphicsitem.cpp
+++ b/src/KDGantt/kdganttgraphicsitem.cpp
@@ -267,14 +267,16 @@ void GraphicsItem::removeEndConstraint(ConstraintGraphicsItem *item)
 
 void GraphicsItem::updateConstraintItems()
 {
-    { // Workaround for multiple definition error with MSVC6
-        Q_FOREACH (ConstraintGraphicsItem *item, m_startConstraints) {
+    {
+        // Workaround for multiple definition error with MSVC6
+        for (ConstraintGraphicsItem *item : qAsConst(m_startConstraints)) {
             QPointF s = startConnector(item->constraint().relationType());
             item->setStart(s);
         }
     }
-    { // Workaround for multiple definition error with MSVC6
-        Q_FOREACH (ConstraintGraphicsItem *item, m_endConstraints) {
+    {
+        // Workaround for multiple definition error with MSVC6
+        for (ConstraintGraphicsItem *item : qAsConst(m_endConstraints)) {
             QPointF e = endConnector(item->constraint().relationType());
             item->setEnd(e);
         }
diff --git a/src/KDGantt/kdganttgraphicsscene.cpp b/src/KDGantt/kdganttgraphicsscene.cpp
index 5e013bcf..80a4652c 100644
--- a/src/KDGantt/kdganttgraphicsscene.cpp
+++ b/src/KDGantt/kdganttgraphicsscene.cpp
@@ -68,8 +68,8 @@ void GraphicsScene::Private::resetConstraintItems()
     q->clearConstraintItems();
     if (constraintModel.isNull())
         return;
-    QList<Constraint> clst = constraintModel->constraints();
-    Q_FOREACH (const Constraint &c, clst) {
+    const QList<Constraint> clst = constraintModel->constraints();
+    for (const Constraint &c : clst) {
         createConstraintItem(c);
     }
     q->updateItems();
@@ -163,7 +163,7 @@ void GraphicsScene::init()
 {
     setItemIndexMethod(QGraphicsScene::NoIndex);
     setConstraintModel(new ConstraintModel(this));
-    connect(d->grid, SIGNAL(gridChanged()), this, SLOT(slotGridChanged()));
+    connect(d->grid, &AbstractGrid::gridChanged, this, &GraphicsScene::slotGridChanged);
 }
 
 /* NOTE: The delegate should really be a property
@@ -230,10 +230,10 @@ void GraphicsScene::setConstraintModel(ConstraintModel *cm)
     }
     d->constraintModel = cm;
 
-    connect(cm, SIGNAL(constraintAdded(const KDGantt::Constraint &)),
-            this, SLOT(slotConstraintAdded(const KDGantt::Constraint &)));
-    connect(cm, SIGNAL(constraintRemoved(const KDGantt::Constraint &)),
-            this, SLOT(slotConstraintRemoved(const KDGantt::Constraint &)));
+    connect(cm, &ConstraintModel::constraintAdded,
+            this, &GraphicsScene::slotConstraintAdded);
+    connect(cm, &ConstraintModel::constraintRemoved,
+            this, &GraphicsScene::slotConstraintRemoved);
     d->resetConstraintItems();
 }
 
@@ -268,7 +268,7 @@ void GraphicsScene::setGrid(AbstractGrid *grid)
         model = d->grid->model();
     }
     d->grid = grid;
-    connect(d->grid, SIGNAL(gridChanged()), this, SLOT(slotGridChanged()));
+    connect(d->grid, &AbstractGrid::gridChanged, this, &GraphicsScene::slotGridChanged);
     d->grid->setModel(model);
     slotGridChanged();
 }
@@ -419,7 +419,7 @@ void GraphicsScene::insertItem(const QPersistentModelIndex &idx, GraphicsItem *i
         // Create items for constraints
         const QModelIndex sidx = summaryHandlingModel()->mapToSource(idx);
         const QList<Constraint> clst = d->constraintModel->constraintsForIndex(sidx);
-        Q_FOREACH (const Constraint &c, clst) {
+        for (const Constraint &c : clst) {
             QModelIndex other_idx;
             if (c.startIndex() == sidx) {
                 other_idx = c.endIndex();
@@ -469,7 +469,7 @@ void GraphicsScene::removeItem(const QModelIndex &idx)
                 QSet<ConstraintGraphicsItem *>::fromList(startConstraints) + QSet<ConstraintGraphicsItem *>::fromList(endConstraints);
 #endif
 
-            Q_FOREACH (ConstraintGraphicsItem *citem, clst) {
+            for (ConstraintGraphicsItem *citem : clst) {
                 d->deleteConstraintItem(citem);
             }
         }
@@ -565,7 +565,7 @@ void GraphicsScene::slotGridChanged()
 {
     updateItems();
     update();
-    emit gridChanged();
+    Q_EMIT gridChanged();
 }
 
 void GraphicsScene::helpEvent(QGraphicsSceneHelpEvent *helpEvent)
@@ -621,22 +621,22 @@ void GraphicsScene::drawForeground(QPainter *painter, const QRectF &rect)
 
 void GraphicsScene::itemEntered(const QModelIndex &idx)
 {
-    emit entered(idx);
+    Q_EMIT entered(idx);
 }
 
 void GraphicsScene::itemPressed(const QModelIndex &idx)
 {
-    emit pressed(idx);
+    Q_EMIT pressed(idx);
 }
 
 void GraphicsScene::itemClicked(const QModelIndex &idx)
 {
-    emit clicked(idx);
+    Q_EMIT clicked(idx);
 }
 
 void GraphicsScene::itemDoubleClicked(const QModelIndex &idx)
 {
-    emit qrealClicked(idx);
+    Q_EMIT qrealClicked(idx);
 }
 
 void GraphicsScene::setDragSource(GraphicsItem *item)
@@ -791,7 +791,7 @@ void GraphicsScene::doPrint(QPainter *painter, const QRectF &targetRect,
         } while ((sidx = rowController()->indexBelow(sidx)).isValid());
         // Add a little margin to textWidth
         textWidth += QFontMetricsF(sceneFont).horizontalAdvance(QString::fromLatin1("X"));
-        Q_FOREACH (QGraphicsTextItem *item, textLabels) {
+        for (QGraphicsTextItem *item : qAsConst(textLabels)) {
             item->setPos(scnRect.left() - textWidth, item->y());
             item->show();
         }
diff --git a/src/KDGantt/kdganttgraphicsview.cpp b/src/KDGantt/kdganttgraphicsview.cpp
index 88771634..97ed3aaf 100644
--- a/src/KDGantt/kdganttgraphicsview.cpp
+++ b/src/KDGantt/kdganttgraphicsview.cpp
@@ -269,22 +269,22 @@ void GraphicsView::Private::slotRowsRemoved(const QModelIndex &parent, int start
 void GraphicsView::Private::slotItemClicked(const QModelIndex &idx)
 {
     QModelIndex sidx = idx; // scene.summaryHandlingModel()->mapToSource( idx );
-    emit q->clicked(sidx);
+    Q_EMIT q->clicked(sidx);
     if (q->style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, nullptr, q))
-        emit q->activated(sidx);
+        Q_EMIT q->activated(sidx);
 }
 
 void GraphicsView::Private::slotItemDoubleClicked(const QModelIndex &idx)
 {
     QModelIndex sidx = idx; // scene.summaryHandlingModel()->mapToSource( idx );
-    emit q->qrealClicked(sidx);
+    Q_EMIT q->qrealClicked(sidx);
     if (!q->style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, nullptr, q))
-        emit q->activated(sidx);
+        Q_EMIT q->activated(sidx);
 }
 
 void GraphicsView::Private::slotHeaderContextMenuRequested(const QPoint &pt)
 {
-    emit q->headerContextMenuRequested(headerwidget.mapToGlobal(pt));
+    Q_EMIT q->headerContextMenuRequested(headerwidget.mapToGlobal(pt));
 }
 
 /*!\class KDGantt::GraphicsView kdganttgraphicsview.h KDGanttGraphicsView
@@ -315,22 +315,32 @@ GraphicsView::GraphicsView(QWidget *parent)
 #if defined KDAB_EVAL
     EvalDialog::checkEvalLicense("KD Gantt");
 #endif
-    connect(horizontalScrollBar(), SIGNAL(valueChanged(int)),
-            this, SLOT(slotHorizontalScrollValueChanged(int)));
-    connect(&_d->scene, SIGNAL(gridChanged()),
-            this, SLOT(slotGridChanged()));
-    connect(&_d->scene, SIGNAL(entered(const QModelIndex &)),
-            this, SIGNAL(entered(const QModelIndex &)));
-    connect(&_d->scene, SIGNAL(pressed(const QModelIndex &)),
-            this, SIGNAL(pressed(const QModelIndex &)));
-    connect(&_d->scene, SIGNAL(clicked(const QModelIndex &)),
-            this, SLOT(slotItemClicked(const QModelIndex &)));
-    connect(&_d->scene, SIGNAL(qrealClicked(const QModelIndex &)),
-            this, SLOT(slotItemDoubleClicked(const QModelIndex &)));
-    connect(&_d->scene, SIGNAL(sceneRectChanged(const QRectF &)),
-            this, SLOT(updateSceneRect()));
-    connect(&_d->headerwidget, SIGNAL(customContextMenuRequested(const QPoint &)),
-            this, SLOT(slotHeaderContextMenuRequested(const QPoint &)));
+    connect(horizontalScrollBar(), &QScrollBar::valueChanged,
+            this, [this](int value) {
+                _d->slotHorizontalScrollValueChanged(value);
+            });
+    connect(&_d->scene, &GraphicsScene::gridChanged,
+            this, [this] {
+                _d->slotGridChanged();
+            });
+    connect(&_d->scene, &GraphicsScene::entered,
+            this, &GraphicsView::entered);
+    connect(&_d->scene, &GraphicsScene::pressed,
+            this, &GraphicsView::pressed);
+    connect(&_d->scene, &GraphicsScene::clicked,
+            this, [this](const QModelIndex &index) {
+                _d->slotItemClicked(index);
+            });
+    connect(&_d->scene, &GraphicsScene::qrealClicked,
+            this, [this](const QModelIndex &index) {
+                _d->slotItemDoubleClicked(index);
+            });
+    connect(&_d->scene, &GraphicsScene::sceneRectChanged,
+            this, &GraphicsView::updateSceneRect);
+    connect(&_d->headerwidget, &HeaderWidget::customContextMenuRequested,
+            this, [this](const QPoint &point) {
+                _d->slotHeaderContextMenuRequested(point);
+            });
     setScene(&_d->scene);
 
     // HACK!
@@ -371,8 +381,7 @@ void GraphicsView::setModel(QAbstractItemModel *model)
     }
 
     d->scene.setModel(model);
-    connect(model, SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
-            this, SLOT(updateSceneRect()));
+    connect(model, &QAbstractItemModel::dataChanged, this, &GraphicsView::updateSceneRect);
     updateScene();
 }
 
@@ -391,22 +400,38 @@ void GraphicsView::setSummaryHandlingModel(QAbstractProxyModel *proxyModel)
     /* Connections. We have to rely on the treeview
      * to receive the signals before we do(!)
      */
-    connect(proxyModel, SIGNAL(columnsInserted(const QModelIndex &, int, int)),
-            this, SLOT(slotColumnsInserted(const QModelIndex &, int, int)));
-    connect(proxyModel, SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
-            this, SLOT(slotColumnsRemoved(const QModelIndex &, int, int)));
-    connect(proxyModel, SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
-            this, SLOT(slotDataChanged(const QModelIndex &, const QModelIndex &)));
-    connect(proxyModel, SIGNAL(layoutChanged()),
-            this, SLOT(slotLayoutChanged()));
-    connect(proxyModel, SIGNAL(modelReset()),
-            this, SLOT(slotModelReset()));
-    connect(proxyModel, SIGNAL(rowsInserted(const QModelIndex &, int, int)),
-            this, SLOT(slotRowsInserted(const QModelIndex &, int, int)));
-    connect(proxyModel, SIGNAL(rowsAboutToBeRemoved(const QModelIndex &, int, int)),
-            this, SLOT(slotRowsAboutToBeRemoved(const QModelIndex &, int, int)));
-    connect(proxyModel, SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
-            this, SLOT(slotRowsRemoved(const QModelIndex &, int, int)));
+    connect(proxyModel, &QAbstractProxyModel::columnsInserted,
+            this, [this](const QModelIndex &parent, int first, int last) {
+                d->slotColumnsInserted(parent, first, last);
+            });
+    connect(proxyModel, &QAbstractProxyModel::columnsRemoved,
+            this, [this](const QModelIndex &parent, int first, int last) {
+                d->slotColumnsRemoved(parent, first, last);
+            });
+    connect(proxyModel, &QAbstractProxyModel::dataChanged,
+            this, [this](const QModelIndex &topLeft, const QModelIndex &bottomRight) {
+                d->slotDataChanged(topLeft, bottomRight);
+            });
+    connect(proxyModel, &QAbstractProxyModel::layoutChanged,
+            this, [this] {
+                d->slotLayoutChanged();
+            });
+    connect(proxyModel, &QAbstractProxyModel::modelReset,
+            this, [this] {
+                d->slotModelReset();
+            });
+    connect(proxyModel, &QAbstractProxyModel::rowsInserted,
+            this, [this](const QModelIndex &parent, int first, int last) {
+                d->slotRowsInserted(parent, first, last);
+            });
+    connect(proxyModel, &QAbstractProxyModel::rowsAboutToBeRemoved,
+            this, [this](const QModelIndex &parent, int first, int last) {
+                d->slotRowsAboutToBeRemoved(parent, first, last);
+            });
+    connect(proxyModel, &QAbstractProxyModel::rowsRemoved,
+            this, [this](const QModelIndex &parent, int first, int last) {
+                d->slotRowsRemoved(parent, first, last);
+            });
 
     updateScene();
 }
diff --git a/src/KDGantt/kdganttgraphicsview.h b/src/KDGantt/kdganttgraphicsview.h
index b945c213..65ddf248 100644
--- a/src/KDGantt/kdganttgraphicsview.h
+++ b/src/KDGantt/kdganttgraphicsview.h
@@ -36,22 +36,6 @@ class KDGANTT_EXPORT GraphicsView : public QGraphicsView
     KDGANTT_DECLARE_PRIVATE_BASE_POLYMORPHIC(GraphicsView)
 
     Q_PROPERTY(bool readOnly READ isReadOnly WRITE setReadOnly)
-
-    Q_PRIVATE_SLOT(d, void slotGridChanged())
-    Q_PRIVATE_SLOT(d, void slotHorizontalScrollValueChanged(int))
-    Q_PRIVATE_SLOT(d, void slotHeaderContextMenuRequested(const QPoint &))
-    /* slots for QAbstractItemModel signals */
-    Q_PRIVATE_SLOT(d, void slotColumnsInserted(const QModelIndex &parent, int start, int end))
-    Q_PRIVATE_SLOT(d, void slotColumnsRemoved(const QModelIndex &parent, int start, int end))
-    Q_PRIVATE_SLOT(d, void slotDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight))
-    Q_PRIVATE_SLOT(d, void slotLayoutChanged())
-    Q_PRIVATE_SLOT(d, void slotModelReset())
-    Q_PRIVATE_SLOT(d, void slotRowsInserted(const QModelIndex &parent, int start, int end))
-    Q_PRIVATE_SLOT(d, void slotRowsAboutToBeRemoved(const QModelIndex &parent, int start, int end))
-    Q_PRIVATE_SLOT(d, void slotRowsRemoved(const QModelIndex &parent, int start, int end))
-
-    Q_PRIVATE_SLOT(d, void slotItemClicked(const QModelIndex &idx))
-    Q_PRIVATE_SLOT(d, void slotItemDoubleClicked(const QModelIndex &idx))
 public:
     explicit GraphicsView(QWidget *parent = nullptr);
     ~GraphicsView() override;
diff --git a/src/KDGantt/kdganttlegend.cpp b/src/KDGantt/kdganttlegend.cpp
index 369cbefc..5974eb92 100644
--- a/src/KDGantt/kdganttlegend.cpp
+++ b/src/KDGantt/kdganttlegend.cpp
@@ -68,21 +68,22 @@ QSize Legend::minimumSizeHint() const
     return measureItem(rootIndex());
 }
 
-void Legend::setModel(QAbstractItemModel *model)
+void Legend::setModel(QAbstractItemModel *newModel)
 {
-    if (this->model() != nullptr) {
-        disconnect(this->model(), SIGNAL(dataChanged(QModelIndex, QModelIndex)), this, SLOT(modelDataChanged()));
-        disconnect(this->model(), SIGNAL(rowsRemoved(QModelIndex, int, int)), this, SLOT(modelDataChanged()));
-        disconnect(this->model(), SIGNAL(columnsRemoved(QModelIndex, int, int)), this, SLOT(modelDataChanged()));
+    QAbstractItemModel *oldModel = model();
+    if (oldModel != nullptr) {
+        disconnect(oldModel, &QAbstractItemModel::dataChanged, this, &Legend::modelDataChanged);
+        disconnect(oldModel, &QAbstractItemModel::rowsRemoved, this, &Legend::modelDataChanged);
+        disconnect(oldModel, &QAbstractItemModel::columnsRemoved, this, &Legend::modelDataChanged);
     }
 
-    QAbstractItemView::setModel(model);
-    d->proxyModel.setSourceModel(model);
+    QAbstractItemView::setModel(newModel);
+    d->proxyModel.setSourceModel(newModel);
 
-    if (this->model() != nullptr) {
-        connect(this->model(), SIGNAL(dataChanged(QModelIndex, QModelIndex)), this, SLOT(modelDataChanged()));
-        connect(this->model(), SIGNAL(rowsRemoved(QModelIndex, int, int)), this, SLOT(modelDataChanged()));
-        connect(this->model(), SIGNAL(columnsRemoved(QModelIndex, int, int)), this, SLOT(modelDataChanged()));
+    if (newModel != nullptr) {
+        connect(newModel, &QAbstractItemModel::dataChanged, this, &Legend::modelDataChanged);
+        connect(newModel, &QAbstractItemModel::rowsRemoved, this, &Legend::modelDataChanged);
+        connect(newModel, &QAbstractItemModel::columnsRemoved, this, &Legend::modelDataChanged);
     }
 }
 
diff --git a/src/KDGantt/kdganttsummaryhandlingproxymodel.cpp b/src/KDGantt/kdganttsummaryhandlingproxymodel.cpp
index 54dcdcd4..96c996b7 100644
--- a/src/KDGantt/kdganttsummaryhandlingproxymodel.cpp
+++ b/src/KDGantt/kdganttsummaryhandlingproxymodel.cpp
@@ -172,7 +172,7 @@ void SummaryHandlingProxyModel::sourceDataChanged(const QModelIndex &from, const
             // qDebug() << "removing " << parentIdx << "from cache";
             d->removeFromCache(dataIdx);
             QModelIndex proxyDataIdx = mapFromSource(dataIdx);
-            emit dataChanged(proxyDataIdx, proxyDataIdx);
+            Q_EMIT dataChanged(proxyDataIdx, proxyDataIdx);
         }
     } while ((parentIdx = model->parent(parentIdx)) != QModelIndex());
 
@@ -256,7 +256,7 @@ bool SummaryHandlingProxyModel::setData(const QModelIndex &index, const QVariant
                 // qDebug() << "removing " << parentIdx << "from cache";
                 d->removeFromCache(parentIdx);
                 QModelIndex proxyParentIdx = mapFromSource(parentIdx);
-                emit dataChanged(proxyParentIdx, proxyParentIdx);
+                Q_EMIT dataChanged(proxyParentIdx, proxyParentIdx);
             }
         } while ((parentIdx = model->parent(parentIdx)) != QModelIndex());
     }
diff --git a/src/KDGantt/kdganttview.cpp b/src/KDGantt/kdganttview.cpp
index 79125e69..9ee1b5a1 100644
--- a/src/KDGantt/kdganttview.cpp
+++ b/src/KDGantt/kdganttview.cpp
@@ -281,21 +281,30 @@ void View::setLeftView(QAbstractItemView *aiv)
     d->leftWidget = aiv;
     d->splitter.insertWidget(0, d->leftWidget);
 
-    if (qobject_cast<QTreeView *>(d->leftWidget)) {
-        connect(d->leftWidget, SIGNAL(collapsed(const QModelIndex &)),
-                this, SLOT(slotCollapsed(const QModelIndex &)));
-        connect(d->leftWidget, SIGNAL(expanded(const QModelIndex &)),
-                this, SLOT(slotExpanded(const QModelIndex &)));
+    auto leftWidgetTreeView = qobject_cast<QTreeView *>(d->leftWidget);
+    if (leftWidgetTreeView) {
+        connect(leftWidgetTreeView, &QTreeView::collapsed,
+                this, [this](const QModelIndex &index) {
+                    d->slotCollapsed(index);
+                });
+        connect(leftWidgetTreeView, &QTreeView::expanded,
+                this, [this](const QModelIndex &index) {
+                    d->slotExpanded(index);
+                });
     }
 
-    connect(d->gfxview->verticalScrollBar(), SIGNAL(valueChanged(int)),
-            d->leftWidget->verticalScrollBar(), SLOT(setValue(int)));
-    connect(d->leftWidget->verticalScrollBar(), SIGNAL(valueChanged(int)),
-            d->gfxview->verticalScrollBar(), SLOT(setValue(int)));
-    connect(d->leftWidget->verticalScrollBar(), SIGNAL(rangeChanged(int, int)),
-            this, SLOT(slotLeftWidgetVerticalRangeChanged(int, int)));
-    connect(d->gfxview->verticalScrollBar(), SIGNAL(rangeChanged(int, int)),
-            this, SLOT(slotGfxViewVerticalRangeChanged(int, int)));
+    connect(d->gfxview->verticalScrollBar(), &QScrollBar::valueChanged,
+            d->leftWidget->verticalScrollBar(), &QScrollBar::setValue);
+    connect(d->leftWidget->verticalScrollBar(), &QScrollBar::valueChanged,
+            d->gfxview->verticalScrollBar(), &QScrollBar::setValue);
+    connect(d->leftWidget->verticalScrollBar(), &QScrollBar::rangeChanged,
+            this, [this](int min, int max) {
+                d->slotLeftWidgetVerticalRangeChanged(min, max);
+            });
+    connect(d->gfxview->verticalScrollBar(), &QScrollBar::rangeChanged,
+            this, [this](int min, int max) {
+                d->slotLeftWidgetVerticalRangeChanged(min, max);
+            });
 }
 
 /*! Sets \a ctrl to be the rowcontroller used by this View.
@@ -625,7 +634,7 @@ KDAB_SCOPED_UNITTEST_SIMPLE(KDGantt, View, "test")
 {
     View view(nullptr);
 #if 0 // GUI tests do not work well on the server
-    QTimer::singleShot( 1000, qApp, SLOT( quit() ) );
+    QTimer::singleShot( 1000, qApp, &QCoreApplication::quit );
     view.show();
 
     qApp->exec();
@@ -635,7 +644,7 @@ KDAB_SCOPED_UNITTEST_SIMPLE(KDGantt, View, "test")
     view.setLeftView( tv );
     view.setRowController( new TreeViewRowController(tv,view.ganttProxyModel()) );
 
-    QTimer::singleShot( 1000, qApp, SLOT( quit() ) );
+    QTimer::singleShot( 1000, qApp, &QCoreApplication::quit );
 
     qApp->exec();
     QPixmap screenshot2 = QPixmap::grabWidget( &view );
@@ -646,7 +655,7 @@ KDAB_SCOPED_UNITTEST_SIMPLE(KDGantt, View, "test")
     view.setLeftView(lv);
     view.setRowController( new ListViewRowController(lv,view.ganttProxyModel()));
     view.show();
-    QTimer::singleShot( 1000, qApp, SLOT( quit() ) );
+    QTimer::singleShot( 1000, qApp, &QCoreApplication::quit );
     qApp->exec();
 #endif
 }
diff --git a/src/KDGantt/kdganttview.h b/src/KDGantt/kdganttview.h
index 40921b56..59ae7a83 100644
--- a/src/KDGantt/kdganttview.h
+++ b/src/KDGantt/kdganttview.h
@@ -36,11 +36,6 @@ class KDGANTT_EXPORT View : public QWidget
 {
     Q_OBJECT
     KDGANTT_DECLARE_PRIVATE_BASE_POLYMORPHIC_QWIDGET(View)
-    Q_PRIVATE_SLOT(d, void slotCollapsed(const QModelIndex &))
-    Q_PRIVATE_SLOT(d, void slotExpanded(const QModelIndex &))
-    Q_PRIVATE_SLOT(d, void slotVerticalScrollValueChanged(int))
-    Q_PRIVATE_SLOT(d, void slotLeftWidgetVerticalRangeChanged(int, int))
-    Q_PRIVATE_SLOT(d, void slotGfxViewVerticalRangeChanged(int, int))
 
 public:
     explicit View(QWidget *parent = nullptr);
diff --git a/tests/DelayedData/main.cpp b/tests/DelayedData/main.cpp
index 74a7a624..494b55ed 100644
--- a/tests/DelayedData/main.cpp
+++ b/tests/DelayedData/main.cpp
@@ -54,10 +54,10 @@ class ChartWidget : public QWidget
 
         m_rowbutton.setText(tr("Add rows"));
         m_colbutton.setText(tr("Add columns"));
-        connect(&m_rowbutton, SIGNAL(clicked()),
-                this, SLOT(addRows()));
-        connect(&m_colbutton, SIGNAL(clicked()),
-                this, SLOT(addCols()));
+        connect(&m_rowbutton, &QPushButton::clicked,
+                this, &ChartWidget::addRows);
+        connect(&m_colbutton, &QPushButton::clicked,
+                this, &ChartWidget::addCols);
 
         auto *l = new QVBoxLayout(this);
         l->addWidget(&m_chart);
diff --git a/tests/Gantt/apireview/entrydialog.cpp b/tests/Gantt/apireview/entrydialog.cpp
index 582a793e..da4baed8 100644
--- a/tests/Gantt/apireview/entrydialog.cpp
+++ b/tests/Gantt/apireview/entrydialog.cpp
@@ -40,8 +40,9 @@ void EntryDialog::init()
     for (int row = 0; row < model->rowCount(); ++row)
         addDependItem(model, model->index(row, 0));
 
-    connect(ui->startDate, SIGNAL(dateTimeChanged(const QDateTime &)), this, SLOT(updateEndDate(const QDateTime &)));
-    connect(ui->readOnly, SIGNAL(toggled(bool)), this, SLOT(disableEditing(bool)));
+    connect(ui->startDate, &QDateTimeEdit::dateTimeChanged,
+            this, &EntryDialog::updateEndDate);
+    connect(ui->readOnly, &QCheckBox::toggled, this, &EntryDialog::disableEditing);
 
     ui->startDate->setDateTime(QDateTime::currentDateTime());
 }
diff --git a/tests/Gantt/apireview/mainwindow.cpp b/tests/Gantt/apireview/mainwindow.cpp
index 49307f2e..928ee9a9 100644
--- a/tests/Gantt/apireview/mainwindow.cpp
+++ b/tests/Gantt/apireview/mainwindow.cpp
@@ -47,15 +47,15 @@ MainWindow::MainWindow(QWidget *parent, Qt::WindowFlags flags)
     leftView->setColumnHidden(5, true);
     leftView->header()->setStretchLastSection(true);
 
-    connect(ui->ganttView->leftView(), SIGNAL(customContextMenuRequested(const QPoint &)),
-            this, SLOT(showContextMenu(const QPoint &)));
-    connect(ui->ganttView->selectionModel(), SIGNAL(selectionChanged(const QItemSelection &, const QItemSelection &)),
-            this, SLOT(enableActions(const QItemSelection &)));
-
-    connect(ui->ganttView->graphicsView(), SIGNAL(clicked(const QModelIndex &)),
-            this, SLOT(slotClicked(const QModelIndex &)));
-    connect(ui->ganttView->graphicsView(), SIGNAL(qrealClicked(const QModelIndex &)),
-            this, SLOT(slotDoubleClicked(const QModelIndex &)));
+    connect(ui->ganttView->leftView(), &QAbstractItemView::customContextMenuRequested,
+            this, &MainWindow::showContextMenu);
+    connect(ui->ganttView->selectionModel(), &QItemSelectionModel::selectionChanged,
+            this, &MainWindow::enableActions);
+
+    connect(ui->ganttView->graphicsView(), &KDGantt::GraphicsView::clicked,
+            this, &MainWindow::slotClicked);
+    connect(ui->ganttView->graphicsView(), &KDGantt::GraphicsView::qrealClicked,
+            this, &MainWindow::slotDoubleClicked);
 }
 
 void MainWindow::initModel()
@@ -77,25 +77,25 @@ void MainWindow::initActions()
 {
     newEntryAction = new QAction(tr("New entry"), this);
     newEntryAction->setShortcut(QKeySequence::New);
-    connect(newEntryAction, SIGNAL(triggered()), this, SLOT(addNewEntry()));
+    connect(newEntryAction, &QAction::triggered, this, &MainWindow::addNewEntry);
 
     removeEntryAction = new QAction(tr("Remove entry"), this);
     removeEntryAction->setShortcut(QKeySequence::Delete);
-    connect(removeEntryAction, SIGNAL(triggered()), this, SLOT(removeEntry()));
+    connect(removeEntryAction, &QAction::triggered, this, &MainWindow::removeEntry);
 
     demoAction = new QAction(tr("Demo entry"), this);
-    connect(demoAction, SIGNAL(triggered()), this, SLOT(addDemoEntry()));
+    connect(demoAction, &QAction::triggered, this, &MainWindow::addDemoEntry);
 
     printAction = new QAction(tr("Print Preview..."), this);
-    connect(printAction, SIGNAL(triggered()), this, SLOT(printPreview()));
+    connect(printAction, &QAction::triggered, this, &MainWindow::printPreview);
 
     zoomInAction = new QAction(tr("Zoom In"), this);
     zoomInAction->setShortcut(QKeySequence::ZoomIn);
-    connect(zoomInAction, SIGNAL(triggered()), this, SLOT(zoomIn()));
+    connect(zoomInAction, &QAction::triggered, this, &MainWindow::zoomIn);
 
     zoomOutAction = new QAction(tr("Zoom Out"), this);
     zoomOutAction->setShortcut(QKeySequence::ZoomOut);
-    connect(zoomOutAction, SIGNAL(triggered()), this, SLOT(zoomOut()));
+    connect(zoomOutAction, &QAction::triggered, this, &MainWindow::zoomOut);
 
     ui->ganttView->leftView()->setContextMenuPolicy(Qt::CustomContextMenu);
     ui->ganttView->leftView()->addAction(newEntryAction);
diff --git a/tests/Gantt/customconstraints/main.cpp b/tests/Gantt/customconstraints/main.cpp
index 57e4b205..6b994f52 100644
--- a/tests/Gantt/customconstraints/main.cpp
+++ b/tests/Gantt/customconstraints/main.cpp
@@ -107,8 +107,8 @@ class MyWidget : public QWidget
         view.setGrid(&grid);
         view.setModel(&model);
 
-        connect(&slider, SIGNAL(valueChanged(int)),
-                this, SLOT(slotZoom(int)));
+        connect(&slider, &QSlider::valueChanged,
+                this, &MyWidget::slotZoom);
     }
 
 public slots:
diff --git a/tests/Gantt/gfxview/main.cpp b/tests/Gantt/gfxview/main.cpp
index 9076c691..168bd87d 100644
--- a/tests/Gantt/gfxview/main.cpp
+++ b/tests/Gantt/gfxview/main.cpp
@@ -157,8 +157,8 @@ int main(int argc, char **argv)
     view->setModel(&model);
 #if 0
     QPushButton* pb = new QPushButton( QObject::tr( "Reset" ) );
-    QObject::connect( pb, SIGNAL( clicked() ),
-                      &model, SIGNAL( modelReset() ) );
+    QObject::connect( pb, &QPushButton::clicked,
+                      &model, &MyStandardItemModel::modelReset );
     pb->show();
 #endif
     return app.exec();
diff --git a/tests/Gantt/listview/main.cpp b/tests/Gantt/listview/main.cpp
index 1d2a562a..5785888f 100644
--- a/tests/Gantt/listview/main.cpp
+++ b/tests/Gantt/listview/main.cpp
@@ -110,8 +110,8 @@ class MyWidget : public QWidget
         view.setGrid(&grid);
         view.setModel(&model);
         // view.setConstraintModel( &cmodel );
-        connect(&slider, SIGNAL(valueChanged(int)),
-                this, SLOT(slotZoom(int)));
+        connect(&slider, &QSlider::valueChanged,
+                this, &MyWidget::slotZoom);
     }
 
 public slots:
diff --git a/tests/Gantt/reorder/main.cpp b/tests/Gantt/reorder/main.cpp
index f6a896da..b5ca1ebb 100644
--- a/tests/Gantt/reorder/main.cpp
+++ b/tests/Gantt/reorder/main.cpp
@@ -100,61 +100,6 @@ class MyTaskModel : public QAbstractTableModel
     }
 };
 
-/* Test class to see the effect of moving rows */
-class MoveHelper : public QObject
-{
-public:
-    MoveHelper(MyTaskModel *model,
-               KDGantt::ConstraintModel *,
-               KDGantt::View *,
-#if 0
-                KDGantt::ConstraintModel* constraints,
-                KDGantt::View* view,
-#endif
-               int row1, int row2)
-        : QObject(model)
-        , m_model(model)
-        ,
-#if 0
-          m_constraints( constraints ),
-          m_view( view ),
-#endif
-        m_row1(row1)
-        , m_row2(row2)
-    {
-    }
-
-    void showContraints(const QString & /*pfx*/)
-    {
-#if 0
-        qDebug() << pfx << *m_constraints;
-        qDebug() << "0:" << m_constraints->constraintsForIndex( m_model->index( 0, 0 ) );
-        qDebug() << "1:"<< m_constraints->constraintsForIndex( m_model->index( 1, 0 ) );
-        qDebug() << "2:"<< m_constraints->constraintsForIndex( m_model->index( 2, 0 ) );
-        qDebug() << "3:"<< m_constraints->constraintsForIndex( m_model->index( 3, 0 ) );
-#endif
-    }
-
-    ~MoveHelper() override
-    {
-        qDebug() << "Moving row" << m_row1 << "to" << m_row2;
-        showContraints("Before:");
-        m_model->moveRow(m_row1, m_row2);
-        showContraints("After:");
-
-        // Hack until KDGantt supports this:
-        // m_view->setConstraintModel( m_constraints );
-    }
-
-private:
-    MyTaskModel *m_model;
-#if 0
-    KDGantt::ConstraintModel* m_constraints;
-    KDGantt::View* m_view;
-#endif
-    int m_row1, m_row2;
-};
-
 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
@@ -172,8 +117,11 @@ int main(int argc, char **argv)
     view->setConstraintModel(&constraints);
     view->show();
 
-    /* After 5 seconds, move row 1 to pos 0: */
-    QTimer::singleShot(5000, new MoveHelper(&model, &constraints, view, 1, 0), SLOT(deleteLater()));
+    QTimer::singleShot(5000, &app, [&model] {
+        /* After 5 seconds, move row 1 to pos 0: */
+        qDebug() << "Moving row" << 1 << "to" << 0;
+        model.moveRow(1, 0);
+    });
 
     return app.exec();
 }
diff --git a/tests/Gantt/view/main.cpp b/tests/Gantt/view/main.cpp
index 2a13b0bf..d84c67b2 100644
--- a/tests/Gantt/view/main.cpp
+++ b/tests/Gantt/view/main.cpp
@@ -118,19 +118,19 @@ class MyWidget : public QWidget
         view.setGrid(&grid);
         view.setModel(&model);
         // view.setConstraintModel( &cmodel );
-        connect(&slider, SIGNAL(valueChanged(int)),
-                this, SLOT(slotZoom(int)));
+        connect(&slider, &QSlider::valueChanged,
+                this, &MyWidget::slotZoom);
 
         auto *pb1 = new QPushButton(tr("Print Preview..."));
         auto *pb2 = new QPushButton(tr("Print..."));
         l->addWidget(pb1);
         l->addWidget(pb2);
-        connect(pb1, SIGNAL(clicked()), this, SLOT(slotPrintPreview()));
-        connect(pb2, SIGNAL(clicked()), this, SLOT(slotPrint()));
+        connect(pb1, &QPushButton::clicked, this, &MyWidget::slotPrintPreview);
+        connect(pb2, &QPushButton::clicked, this, &MyWidget::slotPrint);
 
         view.graphicsView()->setHeaderContextMenuPolicy(Qt::CustomContextMenu);
-        connect(view.graphicsView(), SIGNAL(headerContextMenuRequested(const QPoint &)),
-                this, SLOT(slotHeaderMenu(const QPoint &)));
+        connect(view.graphicsView(), &KDGantt::GraphicsView::headerContextMenuRequested,
+                this, &MyWidget::slotHeaderMenu);
     }
 
 public slots: