Tidy nullptr usage

Move away from using 0 as pointer literal.

Done using clang-tidy. This is not complete as
run-clang-tidy can't handle all of qtbase in one go.

Change-Id: I1076a21f32aac0dab078af6f175f7508145eece0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

11 files changed, 124 insertions, 124 deletions

diff --git a/src/widgets/dialogs/qcolordialog.cpp b/src/widgets/dialogs/qcolordialog.cpp
index d00a600424..689002b589 100644
--- a/src/widgets/dialogs/qcolordialog.cpp
+++ b/src/widgets/dialogs/qcolordialog.cpp
@@ -192,7 +192,7 @@ class QWellArray : public QWidget
     Q_PROPERTY(int selectedRow READ selectedRow)
 
 public:
-    QWellArray(int rows, int cols, QWidget* parent=0);
+    QWellArray(int rows, int cols, QWidget* parent=nullptr);
     ~QWellArray() {}
     QString cellContent(int row, int col) const;
 
@@ -744,7 +744,7 @@ class QColorLuminancePicker : public QWidget
 {
     Q_OBJECT
 public:
-    QColorLuminancePicker(QWidget* parent=0);
+    QColorLuminancePicker(QWidget* parent=nullptr);
     ~QColorLuminancePicker();
 
 public slots:
@@ -789,7 +789,7 @@ QColorLuminancePicker::QColorLuminancePicker(QWidget* parent)
     :QWidget(parent)
 {
     hue = 100; val = 100; sat = 100;
-    pix = 0;
+    pix = nullptr;
     //    setAttribute(WA_NoErase, true);
 }
 
@@ -812,7 +812,7 @@ void QColorLuminancePicker::setVal(int v)
     if (val == v)
         return;
     val = qMax(0, qMin(v,255));
-    delete pix; pix=0;
+    delete pix; pix=nullptr;
     repaint();
     emit newHsv(hue, sat, val);
 }
@@ -861,7 +861,7 @@ void QColorLuminancePicker::setCol(int h, int s , int v)
     val = v;
     hue = h;
     sat = s;
-    delete pix; pix=0;
+    delete pix; pix=nullptr;
     repaint();
 }
 
@@ -1678,8 +1678,8 @@ void QColorDialogPrivate::init(const QColor &initial)
     q->setWindowTitle(QColorDialog::tr("Select Color"));
 
     // default: use the native dialog if possible.  Can be overridden in setOptions()
-    nativeDialogInUse = (platformColorDialogHelper() != 0);
-    colorPickingEventFilter = 0;
+    nativeDialogInUse = (platformColorDialogHelper() != nullptr);
+    colorPickingEventFilter = nullptr;
     nextCust = 0;
 
     if (!nativeDialogInUse)
@@ -1703,7 +1703,7 @@ void QColorDialogPrivate::initWidgets()
     QHBoxLayout *topLay = new QHBoxLayout();
     mainLay->addLayout(topLay);
 
-    leftLay = 0;
+    leftLay = nullptr;
 
 #if defined(QT_SMALL_COLORDIALOG)
     smallDisplay = true;
@@ -1773,8 +1773,8 @@ void QColorDialogPrivate::initWidgets()
         pWidth = 150;
         pHeight = 100;
 #endif
-        custom = 0;
-        standard = 0;
+        custom = nullptr;
+        standard = nullptr;
     }
 
     QVBoxLayout *rightLay = new QVBoxLayout;
@@ -2302,7 +2302,7 @@ void QColorDialog::done(int result)
     if (d->receiverToDisconnectOnClose) {
         disconnect(this, SIGNAL(colorSelected(QColor)),
                    d->receiverToDisconnectOnClose, d->memberToDisconnectOnClose);
-        d->receiverToDisconnectOnClose = 0;
+        d->receiverToDisconnectOnClose = nullptr;
     }
     d->memberToDisconnectOnClose.clear();
 }
diff --git a/src/widgets/dialogs/qdialog.cpp b/src/widgets/dialogs/qdialog.cpp
index 3cdd9a5f04..362200a4fd 100644
--- a/src/widgets/dialogs/qdialog.cpp
+++ b/src/widgets/dialogs/qdialog.cpp
@@ -187,7 +187,7 @@ QWindow *QDialogPrivate::transientParentWindow() const
         return parent->windowHandle();
     else if (q->windowHandle())
         return q->windowHandle()->transientParent();
-    return 0;
+    return nullptr;
 }
 
 bool QDialogPrivate::setNativeDialogVisible(bool visible)
@@ -214,7 +214,7 @@ QVariant QDialogPrivate::styleHint(QPlatformDialogHelper::StyleHint hint) const
 void QDialogPrivate::deletePlatformHelper()
 {
     delete m_platformHelper;
-    m_platformHelper = 0;
+    m_platformHelper = nullptr;
     m_platformHelperCreated = false;
     nativeDialogInUse = false;
 }
@@ -460,7 +460,7 @@ void QDialogPrivate::setDefault(QPushButton *pushButton)
 */
 void QDialogPrivate::setMainDefault(QPushButton *pushButton)
 {
-    mainDef = 0;
+    mainDef = nullptr;
     setDefault(pushButton);
 }
 
@@ -602,7 +602,7 @@ int QDialog::exec()
     }
     if (guard.isNull())
         return QDialog::Rejected;
-    d->eventLoop = 0;
+    d->eventLoop = nullptr;
 
     setAttribute(Qt::WA_ShowModal, wasShowModal);
 
@@ -679,12 +679,12 @@ void QDialog::contextMenuEvent(QContextMenuEvent *e)
 #else
     QWidget *w = childAt(e->pos());
     if (!w) {
-        w = rect().contains(e->pos()) ? this : 0;
+        w = rect().contains(e->pos()) ? this : nullptr;
         if (!w)
             return;
     }
     while (w && w->whatsThis().size() == 0 && !w->testAttribute(Qt::WA_CustomWhatsThis))
-        w = w->isWindow() ? 0 : w->parentWidget();
+        w = w->isWindow() ? nullptr : w->parentWidget();
     if (w) {
         QPointer<QMenu> p = new QMenu(this);
         QAction *wt = p.data()->addAction(tr("What's This?"));
@@ -1191,7 +1191,7 @@ void QDialog::setSizeGripEnabled(bool enabled)
             d->resizer->show();
         } else {
             delete d->resizer;
-            d->resizer = 0;
+            d->resizer = nullptr;
         }
     }
 #endif // QT_CONFIG(sizegrip)
diff --git a/src/widgets/dialogs/qerrormessage.cpp b/src/widgets/dialogs/qerrormessage.cpp
index f0ec2c0102..790d09414b 100644
--- a/src/widgets/dialogs/qerrormessage.cpp
+++ b/src/widgets/dialogs/qerrormessage.cpp
@@ -149,13 +149,13 @@ QSize QErrorMessageTextView::sizeHint() const
     \sa QMessageBox, QStatusBar::showMessage(), {Standard Dialogs Example}
 */
 
-static QErrorMessage * qtMessageHandler = 0;
+static QErrorMessage * qtMessageHandler = nullptr;
 
 static void deleteStaticcQErrorMessage() // post-routine
 {
     if (qtMessageHandler) {
         delete qtMessageHandler;
-        qtMessageHandler = 0;
+        qtMessageHandler = nullptr;
     }
 }
 
@@ -252,8 +252,8 @@ QErrorMessage::QErrorMessage(QWidget * parent)
 QErrorMessage::~QErrorMessage()
 {
     if (this == qtMessageHandler) {
-        qtMessageHandler = 0;
-        QtMessageHandler tmp = qInstallMessageHandler(0);
+        qtMessageHandler = nullptr;
+        QtMessageHandler tmp = qInstallMessageHandler(nullptr);
         // in case someone else has later stuck in another...
         if (tmp != jump)
             qInstallMessageHandler(tmp);
@@ -293,7 +293,7 @@ void QErrorMessage::done(int a)
 QErrorMessage * QErrorMessage::qtHandler()
 {
     if (!qtMessageHandler) {
-        qtMessageHandler = new QErrorMessage(0);
+        qtMessageHandler = new QErrorMessage(nullptr);
         qAddPostRoutine(deleteStaticcQErrorMessage); // clean up
         qtMessageHandler->setWindowTitle(QCoreApplication::applicationName());
         qInstallMessageHandler(jump);
diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index fbcc02accd..f0bd08a778 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -531,15 +531,15 @@ void QFileDialog::changeEvent(QEvent *e)
 QFileDialogPrivate::QFileDialogPrivate()
     :
 #if QT_CONFIG(proxymodel)
-        proxyModel(0),
+        proxyModel(nullptr),
 #endif
-        model(0),
+        model(nullptr),
         currentHistoryLocation(-1),
-        renameAction(0),
-        deleteAction(0),
-        showHiddenAction(0),
+        renameAction(nullptr),
+        deleteAction(nullptr),
+        showHiddenAction(nullptr),
         useDefaultCaption(true),
-        qFileDialogUi(0),
+        qFileDialogUi(nullptr),
         options(QFileDialogOptions::create())
 {
 }
@@ -882,14 +882,14 @@ void QFileDialog::setVisible(bool visible)
 #if QT_CONFIG(fscompleter)
             // So the completer doesn't try to complete and therefore show a popup
             if (!d->nativeDialogInUse)
-                d->completer->setModel(0);
+                d->completer->setModel(nullptr);
 #endif
         } else {
             d->createWidgets();
             setAttribute(Qt::WA_DontShowOnScreen, false);
 #if QT_CONFIG(fscompleter)
             if (!d->nativeDialogInUse) {
-                if (d->proxyModel != 0)
+                if (d->proxyModel != nullptr)
                     d->completer->setModel(d->proxyModel);
                 else
                     d->completer->setModel(d->model);
@@ -1824,7 +1824,7 @@ QModelIndex QFileDialogPrivate::rootIndex() const {
 
 QAbstractItemView *QFileDialogPrivate::currentView() const {
     if (!qFileDialogUi->stackedWidget)
-        return 0;
+        return nullptr;
     if (qFileDialogUi->stackedWidget->currentWidget() == qFileDialogUi->listView->parent())
         return qFileDialogUi->listView;
     return qFileDialogUi->treeView;
@@ -2038,7 +2038,7 @@ QAbstractItemDelegate *QFileDialog::itemDelegate() const
 {
     Q_D(const QFileDialog);
     if (!d->usingWidgets())
-        return 0;
+        return nullptr;
     return d->qFileDialogUi->listView->itemDelegate();
 }
 
@@ -2776,7 +2776,7 @@ void QFileDialog::done(int result)
     if (d->receiverToDisconnectOnClose) {
         disconnect(this, d->signalToDisconnectOnClose,
                    d->receiverToDisconnectOnClose, d->memberToDisconnectOnClose);
-        d->receiverToDisconnectOnClose = 0;
+        d->receiverToDisconnectOnClose = nullptr;
     }
     d->memberToDisconnectOnClose.clear();
     d->signalToDisconnectOnClose.clear();
@@ -3015,7 +3015,7 @@ void QFileDialogPrivate::init(const QUrl &directory, const QString &nameFilter,
     }
 
     q->setAcceptMode(QFileDialog::AcceptOpen);
-    nativeDialogInUse = platformFileDialogHelper() != 0;
+    nativeDialogInUse = platformFileDialogHelper() != nullptr;
     if (!nativeDialogInUse)
         createWidgets();
     q->setFileMode(QFileDialog::AnyFile);
@@ -3273,7 +3273,7 @@ void QFileDialog::setProxyModel(QAbstractProxyModel *proxyModel)
             this, SLOT(_q_rowsInserted(QModelIndex)));
     }
 
-    if (proxyModel != 0) {
+    if (proxyModel != nullptr) {
         proxyModel->setParent(this);
         d->proxyModel = proxyModel;
         proxyModel->setSourceModel(d->model);
@@ -3286,13 +3286,13 @@ void QFileDialog::setProxyModel(QAbstractProxyModel *proxyModel)
         connect(d->proxyModel, SIGNAL(rowsInserted(QModelIndex,int,int)),
             this, SLOT(_q_rowsInserted(QModelIndex)));
     } else {
-        d->proxyModel = 0;
+        d->proxyModel = nullptr;
         d->qFileDialogUi->listView->setModel(d->model);
         d->qFileDialogUi->treeView->setModel(d->model);
 #if QT_CONFIG(fscompleter)
         d->completer->setModel(d->model);
         d->completer->sourceModel = d->model;
-        d->completer->proxyModel = 0;
+        d->completer->proxyModel = nullptr;
 #endif
         connect(d->model, SIGNAL(rowsInserted(QModelIndex,int,int)),
             this, SLOT(_q_rowsInserted(QModelIndex)));
@@ -3330,27 +3330,27 @@ QAbstractProxyModel *QFileDialog::proxyModel() const
 void QFileDialogPrivate::createToolButtons()
 {
     Q_Q(QFileDialog);
-    qFileDialogUi->backButton->setIcon(q->style()->standardIcon(QStyle::SP_ArrowBack, 0, q));
+    qFileDialogUi->backButton->setIcon(q->style()->standardIcon(QStyle::SP_ArrowBack, nullptr, q));
     qFileDialogUi->backButton->setAutoRaise(true);
     qFileDialogUi->backButton->setEnabled(false);
     QObject::connect(qFileDialogUi->backButton, SIGNAL(clicked()), q, SLOT(_q_navigateBackward()));
 
-    qFileDialogUi->forwardButton->setIcon(q->style()->standardIcon(QStyle::SP_ArrowForward, 0, q));
+    qFileDialogUi->forwardButton->setIcon(q->style()->standardIcon(QStyle::SP_ArrowForward, nullptr, q));
     qFileDialogUi->forwardButton->setAutoRaise(true);
     qFileDialogUi->forwardButton->setEnabled(false);
     QObject::connect(qFileDialogUi->forwardButton, SIGNAL(clicked()), q, SLOT(_q_navigateForward()));
 
-    qFileDialogUi->toParentButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogToParent, 0, q));
+    qFileDialogUi->toParentButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogToParent, nullptr, q));
     qFileDialogUi->toParentButton->setAutoRaise(true);
     qFileDialogUi->toParentButton->setEnabled(false);
     QObject::connect(qFileDialogUi->toParentButton, SIGNAL(clicked()), q, SLOT(_q_navigateToParent()));
 
-    qFileDialogUi->listModeButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogListView, 0, q));
+    qFileDialogUi->listModeButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogListView, nullptr, q));
     qFileDialogUi->listModeButton->setAutoRaise(true);
     qFileDialogUi->listModeButton->setDown(true);
     QObject::connect(qFileDialogUi->listModeButton, SIGNAL(clicked()), q, SLOT(_q_showListView()));
 
-    qFileDialogUi->detailModeButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogDetailedView, 0, q));
+    qFileDialogUi->detailModeButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogDetailedView, nullptr, q));
     qFileDialogUi->detailModeButton->setAutoRaise(true);
     QObject::connect(qFileDialogUi->detailModeButton, SIGNAL(clicked()), q, SLOT(_q_showDetailsView()));
 
@@ -3361,7 +3361,7 @@ void QFileDialogPrivate::createToolButtons()
     qFileDialogUi->forwardButton->setFixedSize(toolSize);
     qFileDialogUi->toParentButton->setFixedSize(toolSize);
 
-    qFileDialogUi->newFolderButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogNewFolder, 0, q));
+    qFileDialogUi->newFolderButton->setIcon(q->style()->standardIcon(QStyle::SP_FileDialogNewFolder, nullptr, q));
     qFileDialogUi->newFolderButton->setFixedSize(toolSize);
     qFileDialogUi->newFolderButton->setAutoRaise(true);
     qFileDialogUi->newFolderButton->setEnabled(false);
@@ -3598,7 +3598,7 @@ void QFileDialogPrivate::_q_showContextMenu(const QPoint &position)
     Q_UNUSED(position);
 #else
     Q_Q(QFileDialog);
-    QAbstractItemView *view = 0;
+    QAbstractItemView *view = nullptr;
     if (q->viewMode() == QFileDialog::Detail)
         view = qFileDialogUi->treeView;
     else
diff --git a/src/widgets/dialogs/qfilesystemmodel.cpp b/src/widgets/dialogs/qfilesystemmodel.cpp
index 79a7c23e0d..914c845565 100644
--- a/src/widgets/dialogs/qfilesystemmodel.cpp
+++ b/src/widgets/dialogs/qfilesystemmodel.cpp
@@ -586,9 +586,9 @@ QModelIndex QFileSystemModel::parent(const QModelIndex &index) const
         return QModelIndex();
 
     QFileSystemModelPrivate::QFileSystemNode *indexNode = d->node(index);
-    Q_ASSERT(indexNode != 0);
+    Q_ASSERT(indexNode != nullptr);
     QFileSystemModelPrivate::QFileSystemNode *parentNode = indexNode->parent;
-    if (parentNode == 0 || parentNode == &d->root)
+    if (parentNode == nullptr || parentNode == &d->root)
         return QModelIndex();
 
     // get the parent's row
@@ -608,7 +608,7 @@ QModelIndex QFileSystemModel::parent(const QModelIndex &index) const
 QModelIndex QFileSystemModelPrivate::index(const QFileSystemModelPrivate::QFileSystemNode *node, int column) const
 {
     Q_Q(const QFileSystemModel);
-    QFileSystemModelPrivate::QFileSystemNode *parentNode = (node ? node->parent : 0);
+    QFileSystemModelPrivate::QFileSystemNode *parentNode = (node ? node->parent : nullptr);
     if (node == &root || !parentNode)
         return QModelIndex();
 
diff --git a/src/widgets/dialogs/qfontdialog.cpp b/src/widgets/dialogs/qfontdialog.cpp
index 3da829d328..fe8f88d64f 100644
--- a/src/widgets/dialogs/qfontdialog.cpp
+++ b/src/widgets/dialogs/qfontdialog.cpp
@@ -276,7 +276,7 @@ void QFontDialogPrivate::init()
        mainGrid->setColumnMinimumWidth(3, spacing);
 
        int margin = 0;
-       mainGrid->getContentsMargins(0, 0, 0, &margin);
+       mainGrid->getContentsMargins(nullptr, nullptr, nullptr, &margin);
 
        mainGrid->setRowMinimumHeight(3, margin);
        mainGrid->setRowMinimumHeight(6, 2);
@@ -435,7 +435,7 @@ bool QFontDialog::eventFilter(QObject *o , QEvent *e)
             QCoreApplication::sendEvent(d->sizeList, k);
 
             if (ci != d->sizeList->currentItem()
-                    && style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, this))
+                    && style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, this))
                 d->sizeEdit->selectAll();
             return true;
         } else if ((o == d->familyList || o == d->styleList) &&
@@ -445,7 +445,7 @@ bool QFontDialog::eventFilter(QObject *o , QEvent *e)
             return true;
         }
     } else if (e->type() == QEvent::FocusIn
-               && style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, this)) {
+               && style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, this)) {
         if (o == d->familyList)
             d->familyEdit->selectAll();
         else if (o == d->styleList)
@@ -550,7 +550,7 @@ void QFontDialogPrivate::updateFamilies()
     else
         familyList->setCurrentItem(0);
     familyEdit->setText(familyList->currentText());
-    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, q)
+    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, q)
             && familyList->hasFocus())
         familyEdit->selectAll();
 
@@ -602,7 +602,7 @@ void QFontDialogPrivate::updateStyles()
         }
 
         styleEdit->setText(styleList->currentText());
-        if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, q)
+        if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, q)
                 && styleList->hasFocus())
             styleEdit->selectAll();
 
@@ -641,7 +641,7 @@ void QFontDialogPrivate::updateSizes()
 
         const QSignalBlocker blocker(sizeEdit);
         sizeEdit->setText((smoothScalable ? QString::number(size) : sizeList->currentText()));
-        if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, q)
+        if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, q)
                 && sizeList->hasFocus())
             sizeEdit->selectAll();
     } else {
@@ -692,7 +692,7 @@ void QFontDialogPrivate::_q_familyHighlighted(int i)
     Q_Q(QFontDialog);
     family = familyList->text(i);
     familyEdit->setText(family);
-    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, q)
+    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, q)
             && familyList->hasFocus())
         familyEdit->selectAll();
 
@@ -709,7 +709,7 @@ void QFontDialogPrivate::_q_styleHighlighted(int index)
     Q_Q(QFontDialog);
     QString s = styleList->text(index);
     styleEdit->setText(s);
-    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, q)
+    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, q)
             && styleList->hasFocus())
         styleEdit->selectAll();
 
@@ -728,7 +728,7 @@ void QFontDialogPrivate::_q_sizeHighlighted(int index)
     Q_Q(QFontDialog);
     QString s = sizeList->text(index);
     sizeEdit->setText(s);
-    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, q)
+    if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, nullptr, q)
             && sizeEdit->hasFocus())
         sizeEdit->selectAll();
 
@@ -1019,7 +1019,7 @@ void QFontDialog::done(int result)
     if (d->receiverToDisconnectOnClose) {
         disconnect(this, SIGNAL(fontSelected(QFont)),
                    d->receiverToDisconnectOnClose, d->memberToDisconnectOnClose);
-        d->receiverToDisconnectOnClose = 0;
+        d->receiverToDisconnectOnClose = nullptr;
     }
     d->memberToDisconnectOnClose.clear();
 }
diff --git a/src/widgets/dialogs/qinputdialog.cpp b/src/widgets/dialogs/qinputdialog.cpp
index 3cfe8367e0..1cb4be0682 100644
--- a/src/widgets/dialogs/qinputdialog.cpp
+++ b/src/widgets/dialogs/qinputdialog.cpp
@@ -138,7 +138,7 @@ class QInputDialogDoubleSpinBox : public QDoubleSpinBox
     Q_OBJECT
 
 public:
-    QInputDialogDoubleSpinBox(QWidget *parent = 0)
+    QInputDialogDoubleSpinBox(QWidget *parent = nullptr)
         : QDoubleSpinBox(parent) {
         connect(lineEdit(), SIGNAL(textChanged(QString)), this, SLOT(notifyTextChanged()));
         connect(this, SIGNAL(editingFinished()), this, SLOT(notifyTextChanged()));
@@ -171,7 +171,7 @@ private:
 class QInputDialogListView : public QListView
 {
 public:
-    QInputDialogListView(QWidget *parent = 0) : QListView(parent) {}
+    QInputDialogListView(QWidget *parent = nullptr) : QListView(parent) {}
     QVariant inputMethodQuery(Qt::InputMethodQuery query) const override
     {
         if (query == Qt::ImEnabled)
@@ -223,8 +223,8 @@ public:
 };
 
 QInputDialogPrivate::QInputDialogPrivate()
-    : label(0), buttonBox(0), lineEdit(0), plainTextEdit(0), intSpinBox(0), doubleSpinBox(0),
-      comboBox(0), listView(0), inputWidget(0), mainLayout(0)
+    : label(nullptr), buttonBox(nullptr), lineEdit(nullptr), plainTextEdit(nullptr), intSpinBox(nullptr), doubleSpinBox(nullptr),
+      comboBox(nullptr), listView(nullptr), inputWidget(nullptr), mainLayout(nullptr)
 {
 }
 
@@ -1174,7 +1174,7 @@ void QInputDialog::done(int result)
     if (d->receiverToDisconnectOnClose) {
         disconnect(this, signalForMember(d->memberToDisconnectOnClose),
                    d->receiverToDisconnectOnClose, d->memberToDisconnectOnClose);
-        d->receiverToDisconnectOnClose = 0;
+        d->receiverToDisconnectOnClose = nullptr;
     }
     d->memberToDisconnectOnClose.clear();
 }
diff --git a/src/widgets/dialogs/qmessagebox.cpp b/src/widgets/dialogs/qmessagebox.cpp
index 8dad212692..17d199cb4f 100644
--- a/src/widgets/dialogs/qmessagebox.cpp
+++ b/src/widgets/dialogs/qmessagebox.cpp
@@ -97,7 +97,7 @@ public:
     class TextEdit : public QTextEdit
     {
     public:
-        TextEdit(QWidget *parent=0) : QTextEdit(parent) { }
+        TextEdit(QWidget *parent=nullptr) : QTextEdit(parent) { }
 #ifndef QT_NO_CONTEXTMENU
         void contextMenuEvent(QContextMenuEvent * e) override
         {
@@ -108,7 +108,7 @@ public:
 #endif // QT_NO_CONTEXTMENU
     };
 
-    QMessageBoxDetailsText(QWidget *parent=0)
+    QMessageBoxDetailsText(QWidget *parent=nullptr)
         : QWidget(parent)
         , copyAvailable(false)
     {
@@ -197,12 +197,12 @@ class QMessageBoxPrivate : public QDialogPrivate
     Q_DECLARE_PUBLIC(QMessageBox)
 
 public:
-    QMessageBoxPrivate() : escapeButton(0), defaultButton(0), checkbox(0), clickedButton(0), detailsButton(0),
+    QMessageBoxPrivate() : escapeButton(nullptr), defaultButton(nullptr), checkbox(nullptr), clickedButton(nullptr), detailsButton(nullptr),
 #if QT_CONFIG(textedit)
-                           detailsText(0),
+                           detailsText(nullptr),
 #endif
                            compatMode(false), autoAddOkButton(true),
-                           detectedEscapeButton(0), informativeLabel(0),
+                           detectedEscapeButton(nullptr), informativeLabel(nullptr),
                            options(QMessageDialogOptions::create()) { }
 
     void init(const QString &title = QString(), const QString &text = QString());
@@ -274,7 +274,7 @@ void QMessageBoxPrivate::init(const QString &title, const QString &text)
 
     label = new QLabel;
     label->setObjectName(QLatin1String("qt_msgbox_label"));
-    label->setTextInteractionFlags(Qt::TextInteractionFlags(q->style()->styleHint(QStyle::SH_MessageBox_TextInteractionFlags, 0, q)));
+    label->setTextInteractionFlags(Qt::TextInteractionFlags(q->style()->styleHint(QStyle::SH_MessageBox_TextInteractionFlags, nullptr, q)));
     label->setAlignment(Qt::AlignVCenter | Qt::AlignLeft);
     label->setOpenExternalLinks(true);
     iconLabel = new QLabel(q);
@@ -283,7 +283,7 @@ void QMessageBoxPrivate::init(const QString &title, const QString &text)
 
     buttonBox = new QDialogButtonBox;
     buttonBox->setObjectName(QLatin1String("qt_msgbox_buttonbox"));
-    buttonBox->setCenterButtons(q->style()->styleHint(QStyle::SH_MessageBox_CenterButtons, 0, q));
+    buttonBox->setCenterButtons(q->style()->styleHint(QStyle::SH_MessageBox_CenterButtons, nullptr, q));
     QObject::connect(buttonBox, SIGNAL(clicked(QAbstractButton*)),
                      q, SLOT(_q_buttonClicked(QAbstractButton*)));
     setupLayout();
@@ -927,9 +927,9 @@ void QMessageBox::removeButton(QAbstractButton *button)
     Q_D(QMessageBox);
     d->customButtonList.removeAll(button);
     if (d->escapeButton == button)
-        d->escapeButton = 0;
+        d->escapeButton = nullptr;
     if (d->defaultButton == button)
-        d->defaultButton = 0;
+        d->defaultButton = nullptr;
     d->buttonBox->removeButton(button);
     d->updateSize();
 }
@@ -952,9 +952,9 @@ void QMessageBox::setStandardButtons(StandardButtons buttons)
 
     QList<QAbstractButton *> buttonList = d->buttonBox->buttons();
     if (!buttonList.contains(d->escapeButton))
-        d->escapeButton = 0;
+        d->escapeButton = nullptr;
     if (!buttonList.contains(d->defaultButton))
-        d->defaultButton = 0;
+        d->defaultButton = nullptr;
     d->autoAddOkButton = false;
     d->updateSize();
 }
@@ -1081,7 +1081,7 @@ void QMessageBoxPrivate::detectEscapeButton()
     for (auto *button : buttons) {
         if (buttonBox->buttonRole(button) == QDialogButtonBox::RejectRole) {
             if (detectedEscapeButton) { // already detected!
-                detectedEscapeButton = 0;
+                detectedEscapeButton = nullptr;
                 break;
             }
             detectedEscapeButton = button;
@@ -1094,7 +1094,7 @@ void QMessageBoxPrivate::detectEscapeButton()
     for (auto *button : buttons) {
         if (buttonBox->buttonRole(button) == QDialogButtonBox::NoRole) {
             if (detectedEscapeButton) { // already detected!
-                detectedEscapeButton = 0;
+                detectedEscapeButton = nullptr;
                 break;
             }
             detectedEscapeButton = button;
@@ -1189,7 +1189,7 @@ void QMessageBox::setCheckBox(QCheckBox *cb)
         d->checkbox->hide();
         layout()->removeWidget(d->checkbox);
         if (d->checkbox->parentWidget() == this) {
-            d->checkbox->setParent(0);
+            d->checkbox->setParent(nullptr);
             d->checkbox->deleteLater();
         }
     }
@@ -1433,9 +1433,9 @@ void QMessageBox::changeEvent(QEvent *ev)
     {
         if (d->icon != NoIcon)
             setIcon(d->icon);
-        Qt::TextInteractionFlags flags(style()->styleHint(QStyle::SH_MessageBox_TextInteractionFlags, 0, this));
+        Qt::TextInteractionFlags flags(style()->styleHint(QStyle::SH_MessageBox_TextInteractionFlags, nullptr, this));
         d->label->setTextInteractionFlags(flags);
-        d->buttonBox->setCenterButtons(style()->styleHint(QStyle::SH_MessageBox_CenterButtons, 0, this));
+        d->buttonBox->setCenterButtons(style()->styleHint(QStyle::SH_MessageBox_CenterButtons, nullptr, this));
         if (d->informativeLabel)
             d->informativeLabel->setTextInteractionFlags(flags);
         Q_FALLTHROUGH();
@@ -1624,7 +1624,7 @@ static QMessageBox::StandardButton showNewMessageBox(QWidget *parent,
 
     QMessageBox msgBox(icon, title, text, QMessageBox::NoButton, parent);
     QDialogButtonBox *buttonBox = msgBox.findChild<QDialogButtonBox*>();
-    Q_ASSERT(buttonBox != 0);
+    Q_ASSERT(buttonBox != nullptr);
 
     uint mask = QMessageBox::FirstButton;
     while (mask <= QMessageBox::LastButton) {
@@ -2001,7 +2001,7 @@ QAbstractButton *QMessageBoxPrivate::abstractButtonForId(int id) const
     if (result)
         return result;
     if (id & QMessageBox::FlagMask)    // for compatibility with Qt 4.0/4.1 (even if it is silly)
-        return 0;
+        return nullptr;
     return q->button(newButton(id));
 }
 
@@ -2522,13 +2522,13 @@ void QMessageBox::setDetailedText(const QString &text)
             d->detailsText->hide();
             d->detailsText->deleteLater();
         }
-        d->detailsText = 0;
+        d->detailsText = nullptr;
         removeButton(d->detailsButton);
         if (d->detailsButton) {
             d->detailsButton->hide();
             d->detailsButton->deleteLater();
         }
-        d->detailsButton = 0;
+        d->detailsButton = nullptr;
     } else {
         if (!d->detailsText) {
             d->detailsText = new QMessageBoxDetailsText(this);
@@ -2577,12 +2577,12 @@ void QMessageBox::setInformativeText(const QString &text)
             d->informativeLabel->hide();
             d->informativeLabel->deleteLater();
         }
-        d->informativeLabel = 0;
+        d->informativeLabel = nullptr;
     } else {
         if (!d->informativeLabel) {
             QLabel *label = new QLabel;
             label->setObjectName(QLatin1String("qt_msgbox_informativelabel"));
-            label->setTextInteractionFlags(Qt::TextInteractionFlags(style()->styleHint(QStyle::SH_MessageBox_TextInteractionFlags, 0, this)));
+            label->setTextInteractionFlags(Qt::TextInteractionFlags(style()->styleHint(QStyle::SH_MessageBox_TextInteractionFlags, nullptr, this)));
             label->setAlignment(Qt::AlignTop | Qt::AlignLeft);
             label->setOpenExternalLinks(true);
             label->setWordWrap(true);
@@ -2644,20 +2644,20 @@ void QMessageBox::setWindowModality(Qt::WindowModality windowModality)
 QPixmap QMessageBoxPrivate::standardIcon(QMessageBox::Icon icon, QMessageBox *mb)
 {
     QStyle *style = mb ? mb->style() : QApplication::style();
-    int iconSize = style->pixelMetric(QStyle::PM_MessageBoxIconSize, 0, mb);
+    int iconSize = style->pixelMetric(QStyle::PM_MessageBoxIconSize, nullptr, mb);
     QIcon tmpIcon;
     switch (icon) {
     case QMessageBox::Information:
-        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxInformation, 0, mb);
+        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxInformation, nullptr, mb);
         break;
     case QMessageBox::Warning:
-        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxWarning, 0, mb);
+        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxWarning, nullptr, mb);
         break;
     case QMessageBox::Critical:
-        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxCritical, 0, mb);
+        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxCritical, nullptr, mb);
         break;
     case QMessageBox::Question:
-        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxQuestion, 0, mb);
+        tmpIcon = style->standardIcon(QStyle::SP_MessageBoxQuestion, nullptr, mb);
     default:
         break;
     }
@@ -2739,7 +2739,7 @@ void QMessageBoxPrivate::helperDone(QDialog::DialogCode code, QPlatformDialogHel
 
 QPixmap QMessageBox::standardIcon(Icon icon)
 {
-    return QMessageBoxPrivate::standardIcon(icon, 0);
+    return QMessageBoxPrivate::standardIcon(icon, nullptr);
 }
 
 /*!
diff --git a/src/widgets/dialogs/qprogressdialog.cpp b/src/widgets/dialogs/qprogressdialog.cpp
index 189dcd2989..94d3928c8b 100644
--- a/src/widgets/dialogs/qprogressdialog.cpp
+++ b/src/widgets/dialogs/qprogressdialog.cpp
@@ -65,13 +65,13 @@ class QProgressDialogPrivate : public QDialogPrivate
     Q_DECLARE_PUBLIC(QProgressDialog)
 
 public:
-    QProgressDialogPrivate() : label(0), cancel(0), bar(0),
+    QProgressDialogPrivate() : label(nullptr), cancel(nullptr), bar(nullptr),
         shown_once(false),
         cancellation_flag(false),
         setValue_called(false),
         showTime(defaultShowTime),
 #ifndef QT_NO_SHORTCUT
-        escapeShortcut(0),
+        escapeShortcut(nullptr),
 #endif
         useDefaultCancelText(false)
     {
@@ -112,7 +112,7 @@ void QProgressDialogPrivate::init(const QString &labelText, const QString &cance
     label = new QLabel(labelText, q);
     bar = new QProgressBar(q);
     bar->setRange(min, max);
-    int align = q->style()->styleHint(QStyle::SH_ProgressDialog_TextLabelAlignment, 0, q);
+    int align = q->style()->styleHint(QStyle::SH_ProgressDialog_TextLabelAlignment, nullptr, q);
     label->setAlignment(Qt::Alignment(align));
     autoClose = true;
     autoReset = true;
@@ -132,12 +132,12 @@ void QProgressDialogPrivate::init(const QString &labelText, const QString &cance
 void QProgressDialogPrivate::layout()
 {
     Q_Q(QProgressDialog);
-    int sp = q->style()->pixelMetric(QStyle::PM_LayoutVerticalSpacing, 0, q);
-    int mb = q->style()->pixelMetric(QStyle::PM_LayoutBottomMargin, 0, q);
-    int ml = qMin(q->width() / 10, q->style()->pixelMetric(QStyle::PM_LayoutLeftMargin, 0, q));
-    int mr = qMin(q->width() / 10, q->style()->pixelMetric(QStyle::PM_LayoutRightMargin, 0, q));
+    int sp = q->style()->pixelMetric(QStyle::PM_LayoutVerticalSpacing, nullptr, q);
+    int mb = q->style()->pixelMetric(QStyle::PM_LayoutBottomMargin, nullptr, q);
+    int ml = qMin(q->width() / 10, q->style()->pixelMetric(QStyle::PM_LayoutLeftMargin, nullptr, q));
+    int mr = qMin(q->width() / 10, q->style()->pixelMetric(QStyle::PM_LayoutRightMargin, nullptr, q));
     const bool centered =
-        bool(q->style()->styleHint(QStyle::SH_ProgressDialog_CenterCancelButton, 0, q));
+        bool(q->style()->styleHint(QStyle::SH_ProgressDialog_CenterCancelButton, nullptr, q));
 
     int additionalSpacing = 0;
     QSize cs = cancel ? cancel->sizeHint() : QSize(0,0);
@@ -188,7 +188,7 @@ void QProgressDialogPrivate::_q_disconnectOnClose()
     if (receiverToDisconnectOnClose) {
         QObject::disconnect(q, SIGNAL(canceled()), receiverToDisconnectOnClose,
                             memberToDisconnectOnClose);
-        receiverToDisconnectOnClose = 0;
+        receiverToDisconnectOnClose = nullptr;
     }
     memberToDisconnectOnClose.clear();
 }
@@ -418,7 +418,7 @@ void QProgressDialog::setCancelButton(QPushButton *cancelButton)
     } else {
 #ifndef QT_NO_SHORTCUT
         delete d->escapeShortcut;
-        d->escapeShortcut = 0;
+        d->escapeShortcut = nullptr;
 #endif
     }
     d->adoptChildWidget(cancelButton);
@@ -450,7 +450,7 @@ void QProgressDialogPrivate::setCancelButtonText(const QString &cancelButtonText
             q->setCancelButton(new QPushButton(cancelButtonText, q));
         }
     } else {
-        q->setCancelButton(0);
+        q->setCancelButton(nullptr);
     }
     ensureSizeIsAtLeastSizeHint();
 }
diff --git a/src/widgets/dialogs/qsidebar.cpp b/src/widgets/dialogs/qsidebar.cpp
index 2c8c66e1e2..dfb707eda0 100644
--- a/src/widgets/dialogs/qsidebar.cpp
+++ b/src/widgets/dialogs/qsidebar.cpp
@@ -73,7 +73,7 @@ void QSideBarDelegate::initStyleOption(QStyleOptionViewItem *option,
 
     Example usage: File dialog sidebar and combo box
  */
-QUrlModel::QUrlModel(QObject *parent) : QStandardItemModel(parent), showFullPath(false), fileSystemModel(0)
+QUrlModel::QUrlModel(QObject *parent) : QStandardItemModel(parent), showFullPath(false), fileSystemModel(nullptr)
 {
 }
 
@@ -298,7 +298,7 @@ void QUrlModel::setFileSystemModel(QFileSystemModel *model)
 {
     if (model == fileSystemModel)
         return;
-    if (fileSystemModel != 0) {
+    if (fileSystemModel != nullptr) {
         disconnect(model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),
             this, SLOT(dataChanged(QModelIndex,QModelIndex)));
         disconnect(model, SIGNAL(layoutChanged()),
@@ -307,7 +307,7 @@ void QUrlModel::setFileSystemModel(QFileSystemModel *model)
             this, SLOT(layoutChanged()));
     }
     fileSystemModel = model;
-    if (fileSystemModel != 0) {
+    if (fileSystemModel != nullptr) {
         connect(model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),
             this, SLOT(dataChanged(QModelIndex,QModelIndex)));
         connect(model, SIGNAL(layoutChanged()),
diff --git a/src/widgets/dialogs/qwizard.cpp b/src/widgets/dialogs/qwizard.cpp
index 7c4a473976..a4789f40b1 100644
--- a/src/widgets/dialogs/qwizard.cpp
+++ b/src/widgets/dialogs/qwizard.cpp
@@ -115,7 +115,7 @@ static QWidget *iWantTheFocus(QWidget *ancestor)
                 return candidate;
         }
     }
-    return 0;
+    return nullptr;
 }
 
 static bool objectInheritsXAndXIsCloserThanY(const QObject *object, const QByteArray &classX,
@@ -165,7 +165,7 @@ static const char *changed_signal(int which)
     };
     Q_STATIC_ASSERT(7 == NFallbackDefaultProperties);
     Q_UNREACHABLE();
-    return 0;
+    return nullptr;
 }
 
 class QWizardDefaultProperty
@@ -286,9 +286,9 @@ class QWizardHeader : public QWidget
 public:
     enum RulerType { Ruler };
 
-    inline QWizardHeader(RulerType /* ruler */, QWidget *parent = 0)
+    inline QWizardHeader(RulerType /* ruler */, QWidget *parent = nullptr)
         : QWidget(parent) { setFixedHeight(2); }
-    QWizardHeader(QWidget *parent = 0);
+    QWizardHeader(QWidget *parent = nullptr);
 
     void setup(const QWizardLayoutInfo &info, const QString &title,
                const QString &subTitle, const QPixmap &logo, const QPixmap &banner,
@@ -438,7 +438,7 @@ void QWizardHeader::paintEvent(QPaintEvent * /* event */)
 class QWizardRuler : public QWizardHeader
 {
 public:
-    inline QWizardRuler(QWidget *parent = 0)
+    inline QWizardRuler(QWidget *parent = nullptr)
         : QWizardHeader(Ruler, parent) {}
 };
 
@@ -684,7 +684,7 @@ void QWizardPrivate::init()
     std::fill(btns, btns + QWizard::NButtons, nullptr);
 
     antiFlickerWidget = new QWizardAntiFlickerWidget(q, this);
-    wizStyle = QWizard::WizardStyle(q->style()->styleHint(QStyle::SH_WizardStyle, 0, q));
+    wizStyle = QWizard::WizardStyle(q->style()->styleHint(QStyle::SH_WizardStyle, nullptr, q));
     if (wizStyle == QWizard::MacStyle) {
         opts = (QWizard::NoDefaultButton | QWizard::NoCancelButton);
     } else if (wizStyle == QWizard::ModernStyle) {
@@ -836,7 +836,7 @@ void QWizardPrivate::switchToPage(int newId, Direction direction)
         newPage && newPage->isCommitPage() ? QWizard::CommitButton : QWizard::NextButton;
     QAbstractButton *nextOrFinishButton =
         btns[canContinue ? nextOrCommit : QWizard::FinishButton];
-    QWidget *candidate = 0;
+    QWidget *candidate = nullptr;
 
     /*
         If there is no default button and the Next or Finish button
@@ -887,7 +887,7 @@ static const char * buttonSlots(QWizard::WizardButton which)
     case QWizard::NoButton:
         Q_UNREACHABLE();
     };
-    return 0;
+    return nullptr;
 };
 
 QWizardLayoutInfo QWizardPrivate::layoutInfoForCurrentPage()
@@ -898,14 +898,14 @@ QWizardLayoutInfo QWizardPrivate::layoutInfoForCurrentPage()
     QWizardLayoutInfo info;
 
     const int layoutHorizontalSpacing = style->pixelMetric(QStyle::PM_LayoutHorizontalSpacing);
-    info.topLevelMarginLeft = style->pixelMetric(QStyle::PM_LayoutLeftMargin, 0, q);
-    info.topLevelMarginRight = style->pixelMetric(QStyle::PM_LayoutRightMargin, 0, q);
-    info.topLevelMarginTop = style->pixelMetric(QStyle::PM_LayoutTopMargin, 0, q);
-    info.topLevelMarginBottom = style->pixelMetric(QStyle::PM_LayoutBottomMargin, 0, q);
-    info.childMarginLeft = style->pixelMetric(QStyle::PM_LayoutLeftMargin, 0, titleLabel);
-    info.childMarginRight = style->pixelMetric(QStyle::PM_LayoutRightMargin, 0, titleLabel);
-    info.childMarginTop = style->pixelMetric(QStyle::PM_LayoutTopMargin, 0, titleLabel);
-    info.childMarginBottom = style->pixelMetric(QStyle::PM_LayoutBottomMargin, 0, titleLabel);
+    info.topLevelMarginLeft = style->pixelMetric(QStyle::PM_LayoutLeftMargin, nullptr, q);
+    info.topLevelMarginRight = style->pixelMetric(QStyle::PM_LayoutRightMargin, nullptr, q);
+    info.topLevelMarginTop = style->pixelMetric(QStyle::PM_LayoutTopMargin, nullptr, q);
+    info.topLevelMarginBottom = style->pixelMetric(QStyle::PM_LayoutBottomMargin, nullptr, q);
+    info.childMarginLeft = style->pixelMetric(QStyle::PM_LayoutLeftMargin, nullptr, titleLabel);
+    info.childMarginRight = style->pixelMetric(QStyle::PM_LayoutRightMargin, nullptr, titleLabel);
+    info.childMarginTop = style->pixelMetric(QStyle::PM_LayoutTopMargin, nullptr, titleLabel);
+    info.childMarginBottom = style->pixelMetric(QStyle::PM_LayoutBottomMargin, nullptr, titleLabel);
     info.hspacing = (layoutHorizontalSpacing == -1)
         ? style->layoutSpacing(QSizePolicy::DefaultType, QSizePolicy::DefaultType, Qt::Horizontal)
         : layoutHorizontalSpacing;
@@ -959,7 +959,7 @@ void QWizardPrivate::recreateLayout(const QWizardLayoutInfo &info)
     for (int i = mainLayout->count() - 1; i >= 0; --i) {
         QLayoutItem *item = mainLayout->takeAt(i);
         if (item->layout()) {
-            item->layout()->setParent(0);
+            item->layout()->setParent(nullptr);
         } else {
             delete item;
         }
@@ -2281,7 +2281,7 @@ void QWizard::removePage(int id)
 {
     Q_D(QWizard);
 
-    QWizardPage *removedPage = 0;
+    QWizardPage *removedPage = nullptr;
 
     // update startItem accordingly
     if (d->pageMap.count() > 0) { // only if we have any pages
@@ -2792,7 +2792,7 @@ QAbstractButton *QWizard::button(WizardButton which) const
         return d->vistaHelper->backButton();
 #endif
     if (!d->ensureButton(which))
-        return 0;
+        return nullptr;
     return d->btns[which];
 }