Cleanup Widgets examples - nullptr

Cleanup the widgets examples - replace 0 with nullptr

Change-Id: Id4bf119b9a41f6d10117f3a613a6e604128fa196
Reviewed-by: Konstantin Shegunov <kshegunov@gmail.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

54 files changed, 91 insertions, 90 deletions

diff --git a/examples/widgets/animation/animatedtiles/main.cpp b/examples/widgets/animation/animatedtiles/main.cpp
index 8edd64e482..553b620e41 100644
--- a/examples/widgets/animation/animatedtiles/main.cpp
+++ b/examples/widgets/animation/animatedtiles/main.cpp
@@ -69,7 +69,7 @@ class Button : public QGraphicsWidget
 {
     Q_OBJECT
 public:
-    Button(const QPixmap &pixmap, QGraphicsItem *parent = 0)
+    Button(const QPixmap &pixmap, QGraphicsItem *parent = nullptr)
         : QGraphicsWidget(parent), _pix(pixmap)
     {
         setAcceptHoverEvents(true);
diff --git a/examples/widgets/animation/easing/window.h b/examples/widgets/animation/easing/window.h
index 2b7b2a5bf3..541377a981 100644
--- a/examples/widgets/animation/easing/window.h
+++ b/examples/widgets/animation/easing/window.h
@@ -66,7 +66,7 @@ public:
 class Window : public QWidget {
     Q_OBJECT
 public:
-    Window(QWidget *parent = 0);
+    Window(QWidget *parent = nullptr);
 private slots:
     void curveChanged(int row);
     void pathChanged(int index);
diff --git a/examples/widgets/animation/moveblocks/main.cpp b/examples/widgets/animation/moveblocks/main.cpp
index e59b17cbf9..d03b57cd5e 100644
--- a/examples/widgets/animation/moveblocks/main.cpp
+++ b/examples/widgets/animation/moveblocks/main.cpp
@@ -169,7 +169,8 @@ class GraphicsView : public QGraphicsView
 {
     Q_OBJECT
 public:
-    GraphicsView(QGraphicsScene *scene, QWidget *parent = NULL) : QGraphicsView(scene, parent)
+    GraphicsView(QGraphicsScene *scene, QWidget *parent = nullptr)
+        : QGraphicsView(scene, parent)
     {
     }
 
diff --git a/examples/widgets/animation/stickman/graphicsview.cpp b/examples/widgets/animation/stickman/graphicsview.cpp
index 9cb57fcd9e..7058e15345 100644
--- a/examples/widgets/animation/stickman/graphicsview.cpp
+++ b/examples/widgets/animation/stickman/graphicsview.cpp
@@ -55,7 +55,9 @@
 #include <QtWidgets/QGraphicsScene>
 #include <QtWidgets/QGraphicsView>
 
-GraphicsView::GraphicsView(QWidget *parent) : QGraphicsView(parent), m_editor(0) {}
+GraphicsView::GraphicsView(QWidget *parent)
+    : QGraphicsView(parent), m_editor(nullptr)
+{}
 
 void GraphicsView::keyPressEvent(QKeyEvent *e)
 {
diff --git a/examples/widgets/animation/stickman/graphicsview.h b/examples/widgets/animation/stickman/graphicsview.h
index 56396bb780..361fee219d 100644
--- a/examples/widgets/animation/stickman/graphicsview.h
+++ b/examples/widgets/animation/stickman/graphicsview.h
@@ -58,7 +58,7 @@ class GraphicsView: public QGraphicsView
 {
     Q_OBJECT
 public:
-    GraphicsView(QWidget *parent = 0);
+    GraphicsView(QWidget *parent = nullptr);
 
 protected:
     void resizeEvent(QResizeEvent *event) override;
diff --git a/examples/widgets/animation/stickman/lifecycle.cpp b/examples/widgets/animation/stickman/lifecycle.cpp
index 5d4c406b2e..046e3f4cd1 100644
--- a/examples/widgets/animation/stickman/lifecycle.cpp
+++ b/examples/widgets/animation/stickman/lifecycle.cpp
@@ -175,9 +175,8 @@ void LifeCycle::addActivity(const QString &fileName, Qt::Key key, QObject *sende
     QState *state = makeState(m_alive, fileName);
     m_alive->addTransition(new KeyPressTransition(m_keyReceiver, key, state));
 
-    if((sender != NULL) || (signal != NULL)) {
+    if (sender || signal)
         m_alive->addTransition(sender, signal, state);
-    }
 }
 
 QState *LifeCycle::makeState(QState *parentState, const QString &animationFileName)
@@ -192,7 +191,7 @@ QState *LifeCycle::makeState(QState *parentState, const QString &animationFileNa
     }
 
     const int frameCount = animation.totalFrames();
-    QState *previousState = 0;
+    QState *previousState = nullptr;
     for (int i=0; i<frameCount; ++i) {
         animation.setCurrentFrame(i);
 
@@ -204,7 +203,7 @@ QState *LifeCycle::makeState(QState *parentState, const QString &animationFileNa
 //! [1]
 
         frameState->setObjectName(QString::fromLatin1("frame %0").arg(i));
-        if (previousState == 0)
+        if (previousState == nullptr)
             topLevel->setInitialState(frameState);
         else
 //! [2]
diff --git a/examples/widgets/animation/stickman/stickman.cpp b/examples/widgets/animation/stickman/stickman.cpp
index 8b183d87d5..5725f64eec 100644
--- a/examples/widgets/animation/stickman/stickman.cpp
+++ b/examples/widgets/animation/stickman/stickman.cpp
@@ -176,8 +176,7 @@ Node *StickMan::node(int idx) const
 {
     if (idx >= 0 && idx < NodeCount)
         return m_nodes[idx];
-    else
-        return 0;
+    return nullptr;
 }
 
 void StickMan::timerEvent(QTimerEvent *)
diff --git a/examples/widgets/animation/sub-attaq/animationmanager.cpp b/examples/widgets/animation/sub-attaq/animationmanager.cpp
index 62dac7852a..e3dc27f37f 100644
--- a/examples/widgets/animation/sub-attaq/animationmanager.cpp
+++ b/examples/widgets/animation/sub-attaq/animationmanager.cpp
@@ -56,7 +56,7 @@
 #include <QtCore/QDebug>
 
 // the universe's only animation manager
-AnimationManager *AnimationManager::instance = 0;
+AnimationManager *AnimationManager::instance = nullptr;
 
 AnimationManager::AnimationManager()
 {
diff --git a/examples/widgets/animation/sub-attaq/boat.cpp b/examples/widgets/animation/sub-attaq/boat.cpp
index 9f4feba2ec..9037d54878 100644
--- a/examples/widgets/animation/sub-attaq/boat.cpp
+++ b/examples/widgets/animation/sub-attaq/boat.cpp
@@ -92,8 +92,9 @@ static QAbstractAnimation *setupDestroyAnimation(Boat *boat)
 
 
 
-Boat::Boat() : PixmapItem(QString("boat"), GraphicsScene::Big),
-    speed(0), bombsAlreadyLaunched(0), direction(Boat::None), movementAnimation(0)
+Boat::Boat()
+    : PixmapItem(QString("boat"), GraphicsScene::Big),
+      speed(0), bombsAlreadyLaunched(0), direction(Boat::None)
 {
     setZValue(4);
     setFlags(QGraphicsItem::ItemIsFocusable);
diff --git a/examples/widgets/animation/sub-attaq/boat_p.h b/examples/widgets/animation/sub-attaq/boat_p.h
index de11ff9555..8ebfeb27f5 100644
--- a/examples/widgets/animation/sub-attaq/boat_p.h
+++ b/examples/widgets/animation/sub-attaq/boat_p.h
@@ -146,7 +146,8 @@ private:
 class MoveStateRight : public QState
 {
 public:
-    explicit MoveStateRight(Boat *boat,QState *parent = 0) : QState(parent), boat(boat)
+    explicit MoveStateRight(Boat *boat, QState *parent = nullptr)
+        : QState(parent), boat(boat)
     {
     }
 protected:
@@ -163,7 +164,8 @@ private:
 class MoveStateLeft : public QState
 {
 public:
-    explicit MoveStateLeft(Boat *boat,QState *parent = 0) : QState(parent), boat(boat)
+    explicit MoveStateLeft(Boat *boat, QState *parent = nullptr)
+        : QState(parent), boat(boat)
     {
     }
 protected:
@@ -180,7 +182,8 @@ private:
 class StopState : public QState
 {
 public:
-    explicit StopState(Boat *boat,QState *parent = 0) : QState(parent), boat(boat)
+    explicit StopState(Boat *boat, QState *parent = nullptr)
+        : QState(parent), boat(boat)
     {
     }
 protected:
@@ -198,13 +201,14 @@ private:
 class LaunchStateRight : public QState
 {
 public:
-    explicit LaunchStateRight(Boat *boat,QState *parent = 0) : QState(parent), boat(boat)
+    explicit LaunchStateRight(Boat *boat, QState *parent = nullptr)
+        : QState(parent), boat(boat)
     {
     }
 protected:
     void onEntry(QEvent *) override
     {
-        Bomb *b = new Bomb();
+        Bomb *b = new Bomb;
         b->setPos(boat->x()+boat->size().width(),boat->y());
         GraphicsScene *scene = static_cast<GraphicsScene *>(boat->scene());
         scene->addItem(b);
@@ -219,13 +223,14 @@ private:
 class LaunchStateLeft : public QState
 {
 public:
-    explicit LaunchStateLeft(Boat *boat,QState *parent = 0) : QState(parent), boat(boat)
+    explicit LaunchStateLeft(Boat *boat, QState *parent = nullptr)
+        : QState(parent), boat(boat)
     {
     }
 protected:
     void onEntry(QEvent *) override
     {
-        Bomb *b = new Bomb();
+        Bomb *b = new Bomb;
         b->setPos(boat->x() - b->size().width(), boat->y());
         GraphicsScene *scene = static_cast<GraphicsScene *>(boat->scene());
         scene->addItem(b);
diff --git a/examples/widgets/animation/sub-attaq/mainwindow.cpp b/examples/widgets/animation/sub-attaq/mainwindow.cpp
index b08a7d9f98..a4bb15b383 100644
--- a/examples/widgets/animation/sub-attaq/mainwindow.cpp
+++ b/examples/widgets/animation/sub-attaq/mainwindow.cpp
@@ -63,7 +63,8 @@
 # include <QtOpenGL/QtOpenGL>
 #endif
 
-MainWindow::MainWindow() : QMainWindow(0)
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent)
 {
     QMenu *file = menuBar()->addMenu(tr("&File"));
 
diff --git a/examples/widgets/animation/sub-attaq/mainwindow.h b/examples/widgets/animation/sub-attaq/mainwindow.h
index 8d3cc85cd1..c4fb9d324d 100644
--- a/examples/widgets/animation/sub-attaq/mainwindow.h
+++ b/examples/widgets/animation/sub-attaq/mainwindow.h
@@ -62,7 +62,7 @@ class MainWindow : public QMainWindow
 {
 Q_OBJECT
 public:
-    MainWindow();
+    MainWindow(QWidget *parent = nullptr);
 
 private:
     GraphicsScene *scene;
diff --git a/examples/widgets/animation/sub-attaq/pixmapitem.cpp b/examples/widgets/animation/sub-attaq/pixmapitem.cpp
index 0723cdfb5d..9475d5c3f8 100644
--- a/examples/widgets/animation/sub-attaq/pixmapitem.cpp
+++ b/examples/widgets/animation/sub-attaq/pixmapitem.cpp
@@ -54,7 +54,8 @@
 //Qt
 #include <QPainter>
 
-PixmapItem::PixmapItem(const QString &fileName,GraphicsScene::Mode mode, QGraphicsItem * parent) : QGraphicsObject(parent)
+PixmapItem::PixmapItem(const QString &fileName,GraphicsScene::Mode mode, QGraphicsItem * parent)
+    : QGraphicsObject(parent)
 {
     if (mode == GraphicsScene::Big)
         pix  = QPixmap(QStringLiteral(":/big/") + fileName);
diff --git a/examples/widgets/animation/sub-attaq/pixmapitem.h b/examples/widgets/animation/sub-attaq/pixmapitem.h
index de8ed67a38..ec5c01857f 100644
--- a/examples/widgets/animation/sub-attaq/pixmapitem.h
+++ b/examples/widgets/animation/sub-attaq/pixmapitem.h
@@ -60,7 +60,7 @@
 class PixmapItem : public QGraphicsObject
 {
 public:
-    PixmapItem(const QString &fileName, GraphicsScene::Mode mode, QGraphicsItem * parent = 0);
+    PixmapItem(const QString &fileName, GraphicsScene::Mode mode, QGraphicsItem *parent = nullptr);
     PixmapItem(const QString &fileName, QGraphicsScene *scene);
     QSizeF size() const;
     QRectF boundingRect() const override;
diff --git a/examples/widgets/animation/sub-attaq/qanimationstate.cpp b/examples/widgets/animation/sub-attaq/qanimationstate.cpp
index fc0da7cea2..ef88df8abe 100644
--- a/examples/widgets/animation/sub-attaq/qanimationstate.cpp
+++ b/examples/widgets/animation/sub-attaq/qanimationstate.cpp
@@ -84,7 +84,7 @@ machine.start();
   Constructs a new state with the given \a parent state.
 */
 QAnimationState::QAnimationState(QState *parent)
-    : QState(parent), m_animation(0)
+    : QState(parent), m_animation(nullptr)
 {
 }
 
diff --git a/examples/widgets/animation/sub-attaq/states.cpp b/examples/widgets/animation/sub-attaq/states.cpp
index 8a3a97a20f..cda10ccdaf 100644
--- a/examples/widgets/animation/sub-attaq/states.cpp
+++ b/examples/widgets/animation/sub-attaq/states.cpp
@@ -67,11 +67,8 @@
 #include <QtCore/QRandomGenerator>
 
 PlayState::PlayState(GraphicsScene *scene, QState *parent)
-    : QState(parent),
-    scene(scene),
-    machine(0),
-    currentLevel(0),
-    score(0)
+    : QState(parent), scene(scene), machine(nullptr),
+      currentLevel(0), score(0)
 {
 }
 
diff --git a/examples/widgets/desktop/systray/main.cpp b/examples/widgets/desktop/systray/main.cpp
index 49b0e10412..4e3e628767 100644
--- a/examples/widgets/desktop/systray/main.cpp
+++ b/examples/widgets/desktop/systray/main.cpp
@@ -62,7 +62,7 @@ int main(int argc, char *argv[])
     QApplication app(argc, argv);
 
     if (!QSystemTrayIcon::isSystemTrayAvailable()) {
-        QMessageBox::critical(0, QObject::tr("Systray"),
+        QMessageBox::critical(nullptr, QObject::tr("Systray"),
                               QObject::tr("I couldn't detect any system tray "
                                           "on this system."));
         return 1;
diff --git a/examples/widgets/desktop/systray/window.cpp b/examples/widgets/desktop/systray/window.cpp
index 05944c92a7..31fcd84821 100644
--- a/examples/widgets/desktop/systray/window.cpp
+++ b/examples/widgets/desktop/systray/window.cpp
@@ -176,7 +176,7 @@ void Window::showMessage()
 //! [6]
 void Window::messageClicked()
 {
-    QMessageBox::information(0, tr("Systray"),
+    QMessageBox::information(nullptr, tr("Systray"),
                              tr("Sorry, I already gave what help I could.\n"
                                 "Maybe you should try asking a human?"));
 }
diff --git a/examples/widgets/dialogs/classwizard/classwizard.cpp b/examples/widgets/dialogs/classwizard/classwizard.cpp
index 3eab2f5fb2..81adf85b0d 100644
--- a/examples/widgets/dialogs/classwizard/classwizard.cpp
+++ b/examples/widgets/dialogs/classwizard/classwizard.cpp
@@ -139,7 +139,7 @@ void ClassWizard::accept()
 
     QFile headerFile(outputDir + '/' + header);
     if (!headerFile.open(QFile::WriteOnly | QFile::Text)) {
-        QMessageBox::warning(0, QObject::tr("Simple Wizard"),
+        QMessageBox::warning(nullptr, QObject::tr("Simple Wizard"),
                              QObject::tr("Cannot write file %1:\n%2")
                              .arg(headerFile.fileName())
                              .arg(headerFile.errorString()));
@@ -195,7 +195,7 @@ void ClassWizard::accept()
 
     QFile implementationFile(outputDir + '/' + implementation);
     if (!implementationFile.open(QFile::WriteOnly | QFile::Text)) {
-        QMessageBox::warning(0, QObject::tr("Simple Wizard"),
+        QMessageBox::warning(nullptr, QObject::tr("Simple Wizard"),
                              QObject::tr("Cannot write file %1:\n%2")
                              .arg(implementationFile.fileName())
                              .arg(implementationFile.errorString()));
diff --git a/examples/widgets/dialogs/findfiles/window.cpp b/examples/widgets/dialogs/findfiles/window.cpp
index 1b16cdcd35..e1f7ccdcc4 100644
--- a/examples/widgets/dialogs/findfiles/window.cpp
+++ b/examples/widgets/dialogs/findfiles/window.cpp
@@ -182,7 +182,7 @@ QStringList Window::findFiles(const QStringList &files, const QString &text)
 
     for (int i = 0; i < files.size(); ++i) {
         progressDialog.setValue(i);
-        progressDialog.setLabelText(tr("Searching file number %1 of %n...", 0, files.size()).arg(i));
+        progressDialog.setLabelText(tr("Searching file number %1 of %n...", nullptr, files.size()).arg(i));
         QCoreApplication::processEvents();
 //! [6]
 
@@ -237,7 +237,7 @@ void Window::showFiles(const QStringList &paths)
         filesTable->setItem(row, 0, fileNameItem);
         filesTable->setItem(row, 1, sizeItem);
     }
-    filesFoundLabel->setText(tr("%n file(s) found (Double click on a file to open it)", 0, paths.size()));
+    filesFoundLabel->setText(tr("%n file(s) found (Double click on a file to open it)", nullptr, paths.size()));
     filesFoundLabel->setWordWrap(true);
 }
 //! [8]
diff --git a/examples/widgets/dialogs/standarddialogs/dialog.cpp b/examples/widgets/dialogs/standarddialogs/dialog.cpp
index 74a4131b38..4b59aab887 100644
--- a/examples/widgets/dialogs/standarddialogs/dialog.cpp
+++ b/examples/widgets/dialogs/standarddialogs/dialog.cpp
@@ -65,7 +65,7 @@
 class DialogOptionsWidget : public QGroupBox
 {
 public:
-    explicit DialogOptionsWidget(QWidget *parent = 0);
+    explicit DialogOptionsWidget(QWidget *parent = nullptr);
 
     void addCheckBox(const QString &text, int value);
     void addSpacer();
@@ -492,7 +492,7 @@ void Dialog::questionMessage()
 void Dialog::warningMessage()
 {
     QMessageBox msgBox(QMessageBox::Warning, tr("QMessageBox::warning()"),
-                       MESSAGE, 0, this);
+                       MESSAGE, nullptr, this);
     msgBox.setDetailedText(MESSAGE_DETAILS);
     msgBox.addButton(tr("Save &Again"), QMessageBox::AcceptRole);
     msgBox.addButton(tr("&Continue"), QMessageBox::RejectRole);
diff --git a/examples/widgets/graphicsview/embeddeddialogs/customproxy.cpp b/examples/widgets/graphicsview/embeddeddialogs/customproxy.cpp
index c181a03e85..f510ebc07f 100644
--- a/examples/widgets/graphicsview/embeddeddialogs/customproxy.cpp
+++ b/examples/widgets/graphicsview/embeddeddialogs/customproxy.cpp
@@ -55,7 +55,7 @@
 #include <QGraphicsScene>
 
 CustomProxy::CustomProxy(QGraphicsItem *parent, Qt::WindowFlags wFlags)
-    : QGraphicsProxyWidget(parent, wFlags), popupShown(false), currentPopup(0)
+    : QGraphicsProxyWidget(parent, wFlags), popupShown(false), currentPopup(nullptr)
 {
     timeLine = new QTimeLine(250, this);
     connect(timeLine, &QTimeLine::valueChanged,
@@ -133,7 +133,7 @@ QVariant CustomProxy::itemChange(GraphicsItemChange change, const QVariant &valu
                 currentPopup->installSceneEventFilter(this);
         } else if (scene()) {
             currentPopup->removeSceneEventFilter(this);
-            currentPopup = 0;
+            currentPopup = nullptr;
         }
     } else if (currentPopup && change == ItemSceneHasChanged) {
         currentPopup->installSceneEventFilter(this);
diff --git a/examples/widgets/graphicsview/embeddeddialogs/main.cpp b/examples/widgets/graphicsview/embeddeddialogs/main.cpp
index cbd5dd5890..501405e3ff 100644
--- a/examples/widgets/graphicsview/embeddeddialogs/main.cpp
+++ b/examples/widgets/graphicsview/embeddeddialogs/main.cpp
@@ -66,7 +66,7 @@ int main(int argc, char *argv[])
 
     for (int y = 0; y < gridSize; ++y) {
         for (int x = 0; x < gridSize; ++x) {
-            CustomProxy *proxy = new CustomProxy(0, Qt::Window);
+            CustomProxy *proxy = new CustomProxy(nullptr, Qt::Window);
             proxy->setWidget(new EmbeddedDialog);
 
             QRectF rect = proxy->boundingRect();
diff --git a/examples/widgets/layouts/borderlayout/borderlayout.cpp b/examples/widgets/layouts/borderlayout/borderlayout.cpp
index 9b142584c9..c929d3b2a4 100644
--- a/examples/widgets/layouts/borderlayout/borderlayout.cpp
+++ b/examples/widgets/layouts/borderlayout/borderlayout.cpp
@@ -98,10 +98,7 @@ int BorderLayout::count() const
 QLayoutItem *BorderLayout::itemAt(int index) const
 {
     ItemWrapper *wrapper = list.value(index);
-    if (wrapper)
-        return wrapper->item;
-    else
-        return 0;
+    return wrapper ? wrapper->item : nullptr;
 }
 
 QSize BorderLayout::minimumSize() const
@@ -111,7 +108,7 @@ QSize BorderLayout::minimumSize() const
 
 void BorderLayout::setGeometry(const QRect &rect)
 {
-    ItemWrapper *center = 0;
+    ItemWrapper *center = nullptr;
     int eastWidth = 0;
     int westWidth = 0;
     int northHeight = 0;
@@ -189,7 +186,7 @@ QLayoutItem *BorderLayout::takeAt(int index)
         ItemWrapper *layoutStruct = list.takeAt(index);
         return layoutStruct->item;
     }
-    return 0;
+    return nullptr;
 }
 
 void BorderLayout::add(QLayoutItem *item, Position position)
diff --git a/examples/widgets/layouts/flowlayout/flowlayout.cpp b/examples/widgets/layouts/flowlayout/flowlayout.cpp
index 9203da0ba1..b7064d98b1 100644
--- a/examples/widgets/layouts/flowlayout/flowlayout.cpp
+++ b/examples/widgets/layouts/flowlayout/flowlayout.cpp
@@ -116,8 +116,7 @@ QLayoutItem *FlowLayout::takeAt(int index)
 {
     if (index >= 0 && index < itemList.size())
         return itemList.takeAt(index);
-    else
-        return 0;
+    return nullptr;
 }
 //! [5]
 
@@ -215,7 +214,7 @@ int FlowLayout::smartSpacing(QStyle::PixelMetric pm) const
         return -1;
     } else if (parent->isWidgetType()) {
         QWidget *pw = static_cast<QWidget *>(parent);
-        return pw->style()->pixelMetric(pm, 0, pw);
+        return pw->style()->pixelMetric(pm, nullptr, pw);
     } else {
         return static_cast<QLayout *>(parent)->spacing();
     }
diff --git a/examples/widgets/mainwindows/mainwindow/colorswatch.cpp b/examples/widgets/mainwindows/mainwindow/colorswatch.cpp
index 720f9a2085..240a04c897 100644
--- a/examples/widgets/mainwindows/mainwindow/colorswatch.cpp
+++ b/examples/widgets/mainwindows/mainwindow/colorswatch.cpp
@@ -584,7 +584,7 @@ void ColorSwatch::changeVerticalTitleBar(bool on)
 QSize BlueTitleBar::minimumSizeHint() const
 {
     QDockWidget *dw = qobject_cast<QDockWidget*>(parentWidget());
-    Q_ASSERT(dw != 0);
+    Q_ASSERT(dw);
     QSize result(leftPm.width() + rightPm.width(), centerPm.height());
     if (dw->features() & QDockWidget::DockWidgetVerticalTitleBar)
         result.transpose();
@@ -605,7 +605,7 @@ void BlueTitleBar::paintEvent(QPaintEvent*)
     QRect rect = this->rect();
 
     QDockWidget *dw = qobject_cast<QDockWidget*>(parentWidget());
-    Q_ASSERT(dw != 0);
+    Q_ASSERT(dw);
 
     if (dw->features() & QDockWidget::DockWidgetVerticalTitleBar) {
         QSize s = rect.size();
@@ -632,7 +632,7 @@ void BlueTitleBar::mouseReleaseEvent(QMouseEvent *event)
     QRect rect = this->rect();
 
     QDockWidget *dw = qobject_cast<QDockWidget*>(parentWidget());
-    Q_ASSERT(dw != 0);
+    Q_ASSERT(dw);
 
     if (dw->features() & QDockWidget::DockWidgetVerticalTitleBar) {
         QPoint p = pos;
@@ -676,7 +676,7 @@ void BlueTitleBar::mouseReleaseEvent(QMouseEvent *event)
 void BlueTitleBar::updateMask()
 {
     QDockWidget *dw = qobject_cast<QDockWidget*>(parent());
-    Q_ASSERT(dw != 0);
+    Q_ASSERT(dw);
 
     QRect rect = dw->rect();
     QPixmap bitmap(dw->size());
diff --git a/examples/widgets/mainwindows/mainwindow/toolbar.cpp b/examples/widgets/mainwindows/mainwindow/toolbar.cpp
index 7c96f5b1be..096d3df5a8 100644
--- a/examples/widgets/mainwindows/mainwindow/toolbar.cpp
+++ b/examples/widgets/mainwindows/mainwindow/toolbar.cpp
@@ -208,7 +208,7 @@ ToolBar::ToolBar(const QString &title, QWidget *parent)
 void ToolBar::updateMenu()
 {
     QMainWindow *mainWindow = qobject_cast<QMainWindow *>(parentWidget());
-    Q_ASSERT(mainWindow != 0);
+    Q_ASSERT(mainWindow);
 
     const Qt::ToolBarArea area = mainWindow->toolBarArea(this);
     const Qt::ToolBarAreas areas = allowedAreas();
@@ -313,7 +313,7 @@ void ToolBar::place(Qt::ToolBarArea area, bool p)
         return;
 
     QMainWindow *mainWindow = qobject_cast<QMainWindow *>(parentWidget());
-    Q_ASSERT(mainWindow != 0);
+    Q_ASSERT(mainWindow);
 
     mainWindow->addToolBar(area, this);
 
@@ -355,7 +355,7 @@ void ToolBar::placeBottom(bool p)
 void ToolBar::insertToolBarBreak()
 {
     QMainWindow *mainWindow = qobject_cast<QMainWindow *>(parentWidget());
-    Q_ASSERT(mainWindow != 0);
+    Q_ASSERT(mainWindow);
 
     mainWindow->insertToolBarBreak(this);
 }
diff --git a/examples/widgets/mainwindows/mdi/mainwindow.cpp b/examples/widgets/mainwindows/mdi/mainwindow.cpp
index 188de1893e..1e87c5a747 100644
--- a/examples/widgets/mainwindows/mdi/mainwindow.cpp
+++ b/examples/widgets/mainwindows/mdi/mainwindow.cpp
@@ -242,7 +242,7 @@ void MainWindow::about()
 
 void MainWindow::updateMenus()
 {
-    bool hasMdiChild = (activeMdiChild() != 0);
+    bool hasMdiChild = (activeMdiChild() != nullptr);
     saveAct->setEnabled(hasMdiChild);
     saveAsAct->setEnabled(hasMdiChild);
 #ifndef QT_NO_CLIPBOARD
@@ -483,7 +483,7 @@ MdiChild *MainWindow::activeMdiChild() const
 {
     if (QMdiSubWindow *activeSubWindow = mdiArea->activeSubWindow())
         return qobject_cast<MdiChild *>(activeSubWindow->widget());
-    return 0;
+    return nullptr;
 }
 
 QMdiSubWindow *MainWindow::findMdiChild(const QString &fileName) const
@@ -495,7 +495,7 @@ QMdiSubWindow *MainWindow::findMdiChild(const QString &fileName) const
         if (mdiChild->currentFile() == canonicalFilePath)
             return window;
     }
-    return 0;
+    return nullptr;
 }
 
 void MainWindow::switchLayoutDirection()
diff --git a/examples/widgets/mainwindows/sdi/mainwindow.cpp b/examples/widgets/mainwindows/sdi/mainwindow.cpp
index d44f7c918d..f3e3af8a1b 100644
--- a/examples/widgets/mainwindows/sdi/mainwindow.cpp
+++ b/examples/widgets/mainwindows/sdi/mainwindow.cpp
@@ -478,5 +478,5 @@ MainWindow *MainWindow::findMainWindow(const QString &fileName) const
             return mainWin;
     }
 
-    return 0;
+    return nullptr;
 }
diff --git a/examples/widgets/widgets/analogclock/analogclock.h b/examples/widgets/widgets/analogclock/analogclock.h
index 19e580d1ac..e2486a915f 100644
--- a/examples/widgets/widgets/analogclock/analogclock.h
+++ b/examples/widgets/widgets/analogclock/analogclock.h
@@ -59,7 +59,7 @@ class AnalogClock : public QWidget
     Q_OBJECT
 
 public:
-    AnalogClock(QWidget *parent = 0);
+    AnalogClock(QWidget *parent = nullptr);
 
 protected:
     void paintEvent(QPaintEvent *event) override;
diff --git a/examples/widgets/widgets/calculator/button.h b/examples/widgets/widgets/calculator/button.h
index 057640700f..7c6f26867f 100644
--- a/examples/widgets/widgets/calculator/button.h
+++ b/examples/widgets/widgets/calculator/button.h
@@ -59,7 +59,7 @@ class Button : public QToolButton
     Q_OBJECT
 
 public:
-    explicit Button(const QString &text, QWidget *parent = 0);
+    explicit Button(const QString &text, QWidget *parent = nullptr);
 
     QSize sizeHint() const override;
 };
diff --git a/examples/widgets/widgets/calculator/calculator.h b/examples/widgets/widgets/calculator/calculator.h
index 6d7e336347..937de185e7 100644
--- a/examples/widgets/widgets/calculator/calculator.h
+++ b/examples/widgets/widgets/calculator/calculator.h
@@ -64,7 +64,7 @@ class Calculator : public QWidget
     Q_OBJECT
 
 public:
-    Calculator(QWidget *parent = 0);
+    Calculator(QWidget *parent = nullptr);
 
 private slots:
     void digitClicked();
diff --git a/examples/widgets/widgets/charactermap/characterwidget.h b/examples/widgets/widgets/charactermap/characterwidget.h
index 53add51e6f..34e061e96b 100644
--- a/examples/widgets/widgets/charactermap/characterwidget.h
+++ b/examples/widgets/widgets/charactermap/characterwidget.h
@@ -68,7 +68,7 @@ class CharacterWidget : public QWidget
     Q_OBJECT
 
 public:
-    CharacterWidget(QWidget *parent = 0);
+    CharacterWidget(QWidget *parent = nullptr);
     QSize sizeHint() const override;
 
 public slots:
diff --git a/examples/widgets/widgets/charactermap/mainwindow.cpp b/examples/widgets/widgets/charactermap/mainwindow.cpp
index 76bd8f7799..1b6f77bf30 100644
--- a/examples/widgets/widgets/charactermap/mainwindow.cpp
+++ b/examples/widgets/widgets/charactermap/mainwindow.cpp
@@ -188,7 +188,7 @@ void MainWindow::filterChanged(int f)
     const QFontComboBox::FontFilter filter =
         filterCombo->itemData(f).value<QFontComboBox::FontFilter>();
     fontCombo->setFontFilters(filter);
-    statusBar()->showMessage(tr("%n font(s) found", 0, fontCombo->count()));
+    statusBar()->showMessage(tr("%n font(s) found", nullptr, fontCombo->count()));
 }
 
 void MainWindow::findSizes(const QFont &font)
diff --git a/examples/widgets/widgets/codeeditor/codeeditor.h b/examples/widgets/widgets/codeeditor/codeeditor.h
index 65be76d81d..fcfc188cf2 100644
--- a/examples/widgets/widgets/codeeditor/codeeditor.h
+++ b/examples/widgets/widgets/codeeditor/codeeditor.h
@@ -70,7 +70,7 @@ class CodeEditor : public QPlainTextEdit
     Q_OBJECT
 
 public:
-    CodeEditor(QWidget *parent = 0);
+    CodeEditor(QWidget *parent = nullptr);
 
     void lineNumberAreaPaintEvent(QPaintEvent *event);
     int lineNumberAreaWidth();
diff --git a/examples/widgets/widgets/digitalclock/digitalclock.h b/examples/widgets/widgets/digitalclock/digitalclock.h
index 4365b965bf..31c12f39ab 100644
--- a/examples/widgets/widgets/digitalclock/digitalclock.h
+++ b/examples/widgets/widgets/digitalclock/digitalclock.h
@@ -59,7 +59,7 @@ class DigitalClock : public QLCDNumber
     Q_OBJECT
 
 public:
-    DigitalClock(QWidget *parent = 0);
+    DigitalClock(QWidget *parent = nullptr);
 
 private slots:
     void showTime();
diff --git a/examples/widgets/widgets/elidedlabel/elidedlabel.h b/examples/widgets/widgets/elidedlabel/elidedlabel.h
index 8a2a40f49a..9d4fe5fef3 100644
--- a/examples/widgets/widgets/elidedlabel/elidedlabel.h
+++ b/examples/widgets/widgets/elidedlabel/elidedlabel.h
@@ -65,7 +65,7 @@ class ElidedLabel : public QFrame
     Q_PROPERTY(bool isElided READ isElided)
 
 public:
-    explicit ElidedLabel(const QString &text, QWidget *parent = 0);
+    explicit ElidedLabel(const QString &text, QWidget *parent = nullptr);
 
     void setText(const QString &text);
     const QString & text() const { return content; }
diff --git a/examples/widgets/widgets/elidedlabel/testwidget.h b/examples/widgets/widgets/elidedlabel/testwidget.h
index 840bc98b40..cd309d2316 100644
--- a/examples/widgets/widgets/elidedlabel/testwidget.h
+++ b/examples/widgets/widgets/elidedlabel/testwidget.h
@@ -64,7 +64,7 @@ class TestWidget : public QWidget
     Q_OBJECT
 
 public:
-    TestWidget(QWidget *parent = 0);
+    TestWidget(QWidget *parent = nullptr);
 
 protected:
     void resizeEvent(QResizeEvent *event) override;
diff --git a/examples/widgets/widgets/groupbox/window.h b/examples/widgets/widgets/groupbox/window.h
index 566fafa151..1f041fd003 100644
--- a/examples/widgets/widgets/groupbox/window.h
+++ b/examples/widgets/widgets/groupbox/window.h
@@ -63,7 +63,7 @@ class Window : public QWidget
     Q_OBJECT
 
 public:
-    Window(QWidget *parent = 0);
+    Window(QWidget *parent = nullptr);
 
 private:
     QGroupBox *createFirstExclusiveGroup();
diff --git a/examples/widgets/widgets/lineedits/window.cpp b/examples/widgets/widgets/lineedits/window.cpp
index 47324589b7..0926f6f20b 100644
--- a/examples/widgets/widgets/lineedits/window.cpp
+++ b/examples/widgets/widgets/lineedits/window.cpp
@@ -206,7 +206,7 @@ void Window::validatorChanged(int index)
 {
     switch (index) {
     case 0:
-        validatorLineEdit->setValidator(0);
+        validatorLineEdit->setValidator(nullptr);
         break;
     case 1:
         validatorLineEdit->setValidator(new QIntValidator(
diff --git a/examples/widgets/widgets/movie/movieplayer.h b/examples/widgets/widgets/movie/movieplayer.h
index 9fa9604025..7d143bd37c 100644
--- a/examples/widgets/widgets/movie/movieplayer.h
+++ b/examples/widgets/widgets/movie/movieplayer.h
@@ -70,7 +70,7 @@ class MoviePlayer : public QWidget
     Q_OBJECT
 
 public:
-    MoviePlayer(QWidget *parent = 0);
+    MoviePlayer(QWidget *parent = nullptr);
     void openFile(const QString &fileName);
 
 private slots:
diff --git a/examples/widgets/widgets/scribble/scribblearea.h b/examples/widgets/widgets/scribble/scribblearea.h
index 7729fb5b89..100c45e133 100644
--- a/examples/widgets/widgets/scribble/scribblearea.h
+++ b/examples/widgets/widgets/scribble/scribblearea.h
@@ -62,7 +62,7 @@ class ScribbleArea : public QWidget
     Q_OBJECT
 
 public:
-    ScribbleArea(QWidget *parent = 0);
+    ScribbleArea(QWidget *parent = nullptr);
 
     bool openImage(const QString &fileName);
     bool saveImage(const QString &fileName, const char *fileFormat);
diff --git a/examples/widgets/widgets/shapedclock/shapedclock.h b/examples/widgets/widgets/shapedclock/shapedclock.h
index 6468d21618..a854d956b3 100644
--- a/examples/widgets/widgets/shapedclock/shapedclock.h
+++ b/examples/widgets/widgets/shapedclock/shapedclock.h
@@ -59,7 +59,7 @@ class ShapedClock : public QWidget
     Q_OBJECT
 
 public:
-    ShapedClock(QWidget *parent = 0);
+    ShapedClock(QWidget *parent = nullptr);
     QSize sizeHint() const override;
 
 protected:
diff --git a/examples/widgets/widgets/sliders/slidersgroup.h b/examples/widgets/widgets/sliders/slidersgroup.h
index 76dcbee0d8..7be8a3b4f8 100644
--- a/examples/widgets/widgets/sliders/slidersgroup.h
+++ b/examples/widgets/widgets/sliders/slidersgroup.h
@@ -66,7 +66,7 @@ class SlidersGroup : public QGroupBox
 
 public:
     SlidersGroup(Qt::Orientation orientation, const QString &title,
-                 QWidget *parent = 0);
+                 QWidget *parent = nullptr);
 
 signals:
     void valueChanged(int value);
diff --git a/examples/widgets/widgets/styles/widgetgallery.h b/examples/widgets/widgets/styles/widgetgallery.h
index ec6edff536..9ee65c21c4 100644
--- a/examples/widgets/widgets/styles/widgetgallery.h
+++ b/examples/widgets/widgets/styles/widgetgallery.h
@@ -78,7 +78,7 @@ class WidgetGallery : public QDialog
     Q_OBJECT
 
 public:
-    WidgetGallery(QWidget *parent = 0);
+    WidgetGallery(QWidget *parent = nullptr);
 
 private slots:
     void changeStyle(const QString &styleName);
diff --git a/examples/widgets/widgets/stylesheet/stylesheeteditor.h b/examples/widgets/widgets/stylesheet/stylesheeteditor.h
index 65a3018adb..f51af7877c 100644
--- a/examples/widgets/widgets/stylesheet/stylesheeteditor.h
+++ b/examples/widgets/widgets/stylesheet/stylesheeteditor.h
@@ -60,7 +60,7 @@ class StyleSheetEditor : public QDialog
     Q_OBJECT
 
 public:
-    StyleSheetEditor(QWidget *parent = 0);
+    StyleSheetEditor(QWidget *parent = nullptr);
 
 private slots:
     void on_styleCombo_activated(const QString &styleName);
diff --git a/examples/widgets/widgets/tablet/tabletapplication.h b/examples/widgets/widgets/tablet/tabletapplication.h
index 6b3b2a1730..9b4a4f1886 100644
--- a/examples/widgets/widgets/tablet/tabletapplication.h
+++ b/examples/widgets/widgets/tablet/tabletapplication.h
@@ -61,15 +61,14 @@ class TabletApplication : public QApplication
     Q_OBJECT
 
 public:
-    TabletApplication(int &argv, char **args)
-    : QApplication(argv, args) {}
+    using QApplication::QApplication;
 
     bool event(QEvent *event) override;
     void setCanvas(TabletCanvas *canvas)
         { m_canvas = canvas; }
 
 private:
-    TabletCanvas *m_canvas;
+    TabletCanvas *m_canvas = nullptr;
 };
 //! [0]
 
diff --git a/examples/widgets/widgets/tetrix/tetrixboard.h b/examples/widgets/widgets/tetrix/tetrixboard.h
index 7c6871dfbd..86bcfa4d6e 100644
--- a/examples/widgets/widgets/tetrix/tetrixboard.h
+++ b/examples/widgets/widgets/tetrix/tetrixboard.h
@@ -67,7 +67,7 @@ class TetrixBoard : public QFrame
     Q_OBJECT
 
 public:
-    TetrixBoard(QWidget *parent = 0);
+    TetrixBoard(QWidget *parent = nullptr);
 
     void setNextPieceLabel(QLabel *label);
     QSize sizeHint() const override;
diff --git a/examples/widgets/widgets/tooltips/sortingbox.cpp b/examples/widgets/widgets/tooltips/sortingbox.cpp
index 766815e8e9..5f8d96f110 100644
--- a/examples/widgets/widgets/tooltips/sortingbox.cpp
+++ b/examples/widgets/widgets/tooltips/sortingbox.cpp
@@ -64,7 +64,7 @@ SortingBox::SortingBox(QWidget *parent)
     setBackgroundRole(QPalette::Base);
 //! [2]
 
-    itemInMotion = 0;
+    itemInMotion = nullptr;
 
 //! [3]
     newCircleButton = createToolButton(tr("New Circle"),
@@ -179,7 +179,7 @@ void SortingBox::mouseReleaseEvent(QMouseEvent *event)
 {
     if (event->button() == Qt::LeftButton && itemInMotion) {
         moveItemTo(event->pos());
-        itemInMotion = 0;
+        itemInMotion = nullptr;
     }
 }
 //! [13]
diff --git a/examples/widgets/widgets/validators/ledwidget.h b/examples/widgets/widgets/validators/ledwidget.h
index dcbfb176c2..c4b406db23 100644
--- a/examples/widgets/widgets/validators/ledwidget.h
+++ b/examples/widgets/widgets/validators/ledwidget.h
@@ -59,7 +59,7 @@ class LEDWidget : public QLabel
 {
     Q_OBJECT
 public:
-    LEDWidget(QWidget *parent = 0);
+    LEDWidget(QWidget *parent = nullptr);
 public slots:
     void flash();
 
diff --git a/examples/widgets/widgets/validators/localeselector.h b/examples/widgets/widgets/validators/localeselector.h
index 05290eae81..611e2da66e 100644
--- a/examples/widgets/widgets/validators/localeselector.h
+++ b/examples/widgets/widgets/validators/localeselector.h
@@ -58,7 +58,7 @@ class LocaleSelector : public QComboBox
     Q_OBJECT
 
 public:
-    LocaleSelector(QWidget *parent = 0);
+    LocaleSelector(QWidget *parent = nullptr);
 
 signals:
     void localeSelected(const QLocale &locale);
diff --git a/examples/widgets/widgets/wiggly/dialog.h b/examples/widgets/widgets/wiggly/dialog.h
index a0981dc6b6..357b6354b5 100644
--- a/examples/widgets/widgets/wiggly/dialog.h
+++ b/examples/widgets/widgets/wiggly/dialog.h
@@ -59,7 +59,7 @@ class Dialog : public QDialog
     Q_OBJECT
 
 public:
-    explicit Dialog(QWidget *parent = 0);
+    explicit Dialog(QWidget *parent = nullptr);
 };
 //! [0]
 
diff --git a/examples/widgets/widgets/wiggly/wigglywidget.h b/examples/widgets/widgets/wiggly/wigglywidget.h
index 58a7d045e1..1d909c34da 100644
--- a/examples/widgets/widgets/wiggly/wigglywidget.h
+++ b/examples/widgets/widgets/wiggly/wigglywidget.h
@@ -60,7 +60,7 @@ class WigglyWidget : public QWidget
     Q_OBJECT
 
 public:
-    WigglyWidget(QWidget *parent = 0);
+    WigglyWidget(QWidget *parent = nullptr);
 
 public slots:
     void setText(const QString &newText) { text = newText; }
diff --git a/examples/widgets/widgets/windowflags/previewwindow.h b/examples/widgets/widgets/windowflags/previewwindow.h
index e9efd09507..9bb487e8ab 100644
--- a/examples/widgets/widgets/windowflags/previewwindow.h
+++ b/examples/widgets/widgets/windowflags/previewwindow.h
@@ -64,7 +64,7 @@ class PreviewWindow : public QWidget
     Q_OBJECT
 
 public:
-    PreviewWindow(QWidget *parent = 0);
+    PreviewWindow(QWidget *parent = nullptr);
 
     void setWindowFlags(Qt::WindowFlags flags);