From ece0c0a5e7e0b18beb58ccd868bde54c7be64f78 Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Fri, 22 Nov 2019 14:46:58 +0100
Subject: 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>
---
 src/widgets/itemviews/qabstractitemdelegate.cpp   |  2 +-
 src/widgets/itemviews/qabstractitemview.cpp       | 48 +++++++++---------
 src/widgets/itemviews/qcolumnview.cpp             | 12 ++---
 src/widgets/itemviews/qdatawidgetmapper.cpp       |  8 +--
 src/widgets/itemviews/qdirmodel.cpp               | 20 ++++----
 src/widgets/itemviews/qheaderview.cpp             | 18 +++----
 src/widgets/itemviews/qitemdelegate.cpp           | 18 +++----
 src/widgets/itemviews/qitemeditorfactory.cpp      | 14 +++---
 src/widgets/itemviews/qlistview.cpp               | 14 +++---
 src/widgets/itemviews/qlistwidget.cpp             | 22 ++++-----
 src/widgets/itemviews/qstyleditemdelegate.cpp     | 10 ++--
 src/widgets/itemviews/qtablewidget.cpp            | 60 +++++++++++------------
 src/widgets/itemviews/qtreeview.cpp               | 18 +++----
 src/widgets/itemviews/qtreewidget.cpp             | 56 ++++++++++-----------
 src/widgets/itemviews/qtreewidgetitemiterator.cpp | 16 +++---
 15 files changed, 168 insertions(+), 168 deletions(-)

(limited to 'src/widgets/itemviews')

diff --git a/src/widgets/itemviews/qabstractitemdelegate.cpp b/src/widgets/itemviews/qabstractitemdelegate.cpp
index eecc18e5c7..bb47881c03 100644
--- a/src/widgets/itemviews/qabstractitemdelegate.cpp
+++ b/src/widgets/itemviews/qabstractitemdelegate.cpp
@@ -255,7 +255,7 @@ QWidget *QAbstractItemDelegate::createEditor(QWidget *,
                                              const QStyleOptionViewItem &,
                                              const QModelIndex &) const
 {
-    return 0;
+    return nullptr;
 }
 
 
diff --git a/src/widgets/itemviews/qabstractitemview.cpp b/src/widgets/itemviews/qabstractitemview.cpp
index b1557e9af4..67c01adea7 100644
--- a/src/widgets/itemviews/qabstractitemview.cpp
+++ b/src/widgets/itemviews/qabstractitemview.cpp
@@ -77,13 +77,13 @@ QT_BEGIN_NAMESPACE
 
 QAbstractItemViewPrivate::QAbstractItemViewPrivate()
     :   model(QAbstractItemModelPrivate::staticEmptyModel()),
-        itemDelegate(0),
-        selectionModel(0),
+        itemDelegate(nullptr),
+        selectionModel(nullptr),
         ctrlDragSelectionFlag(QItemSelectionModel::NoUpdate),
         noSelectionOnMousePress(false),
         selectionMode(QAbstractItemView::ExtendedSelection),
         selectionBehavior(QAbstractItemView::SelectItems),
-        currentlyCommittingEditor(0),
+        currentlyCommittingEditor(nullptr),
         pressedModifiers(Qt::NoModifier),
         pressedPosition(QPoint(-1, -1)),
         pressedAlreadySelected(false),
@@ -145,8 +145,8 @@ void QAbstractItemViewPrivate::init()
 
     q->setAttribute(Qt::WA_InputMethodEnabled);
 
-    verticalScrollMode = static_cast<QAbstractItemView::ScrollMode>(q->style()->styleHint(QStyle::SH_ItemView_ScrollMode, 0, q, 0));
-    horizontalScrollMode = static_cast<QAbstractItemView::ScrollMode>(q->style()->styleHint(QStyle::SH_ItemView_ScrollMode, 0, q, 0));
+    verticalScrollMode = static_cast<QAbstractItemView::ScrollMode>(q->style()->styleHint(QStyle::SH_ItemView_ScrollMode, nullptr, q, nullptr));
+    horizontalScrollMode = static_cast<QAbstractItemView::ScrollMode>(q->style()->styleHint(QStyle::SH_ItemView_ScrollMode, nullptr, q, nullptr));
 }
 
 void QAbstractItemViewPrivate::setHoverIndex(const QPersistentModelIndex &index)
@@ -757,7 +757,7 @@ void QAbstractItemView::setModel(QAbstractItemModel *model)
 QAbstractItemModel *QAbstractItemView::model() const
 {
     Q_D(const QAbstractItemView);
-    return (d->model == QAbstractItemModelPrivate::staticEmptyModel() ? 0 : d->model);
+    return (d->model == QAbstractItemModelPrivate::staticEmptyModel() ? nullptr : d->model);
 }
 
 /*!
@@ -915,7 +915,7 @@ QVariant QAbstractItemView::inputMethodQuery(Qt::InputMethodQuery query) const
 void QAbstractItemView::setItemDelegateForRow(int row, QAbstractItemDelegate *delegate)
 {
     Q_D(QAbstractItemView);
-    if (QAbstractItemDelegate *rowDelegate = d->rowDelegates.value(row, 0)) {
+    if (QAbstractItemDelegate *rowDelegate = d->rowDelegates.value(row, nullptr)) {
         if (d->delegateRefCount(rowDelegate) == 1) {
             disconnect(rowDelegate, SIGNAL(closeEditor(QWidget*,QAbstractItemDelegate::EndEditHint)),
                        this, SLOT(closeEditor(QWidget*,QAbstractItemDelegate::EndEditHint)));
@@ -949,7 +949,7 @@ void QAbstractItemView::setItemDelegateForRow(int row, QAbstractItemDelegate *de
 QAbstractItemDelegate *QAbstractItemView::itemDelegateForRow(int row) const
 {
     Q_D(const QAbstractItemView);
-    return d->rowDelegates.value(row, 0);
+    return d->rowDelegates.value(row, nullptr);
 }
 
 /*!
@@ -975,7 +975,7 @@ QAbstractItemDelegate *QAbstractItemView::itemDelegateForRow(int row) const
 void QAbstractItemView::setItemDelegateForColumn(int column, QAbstractItemDelegate *delegate)
 {
     Q_D(QAbstractItemView);
-    if (QAbstractItemDelegate *columnDelegate = d->columnDelegates.value(column, 0)) {
+    if (QAbstractItemDelegate *columnDelegate = d->columnDelegates.value(column, nullptr)) {
         if (d->delegateRefCount(columnDelegate) == 1) {
             disconnect(columnDelegate, SIGNAL(closeEditor(QWidget*,QAbstractItemDelegate::EndEditHint)),
                        this, SLOT(closeEditor(QWidget*,QAbstractItemDelegate::EndEditHint)));
@@ -1009,7 +1009,7 @@ void QAbstractItemView::setItemDelegateForColumn(int column, QAbstractItemDelega
 QAbstractItemDelegate *QAbstractItemView::itemDelegateForColumn(int column) const
 {
     Q_D(const QAbstractItemView);
-    return d->columnDelegates.value(column, 0);
+    return d->columnDelegates.value(column, nullptr);
 }
 
 /*!
@@ -1084,7 +1084,7 @@ void QAbstractItemView::setCurrentIndex(const QModelIndex &index)
 {
     Q_D(QAbstractItemView);
     if (d->selectionModel && (!index.isValid() || d->isIndexEnabled(index))) {
-        QItemSelectionModel::SelectionFlags command = selectionCommand(index, 0);
+        QItemSelectionModel::SelectionFlags command = selectionCommand(index, nullptr);
         d->selectionModel->setCurrentIndex(index, command);
         d->currentIndexSet = true;
         if ((command & QItemSelectionModel::Current) == 0)
@@ -1201,7 +1201,7 @@ void QAbstractItemView::edit(const QModelIndex &index)
     Q_D(QAbstractItemView);
     if (Q_UNLIKELY(!d->isIndexValid(index)))
         qWarning("edit: index was invalid");
-    if (Q_UNLIKELY(!edit(index, AllEditTriggers, 0)))
+    if (Q_UNLIKELY(!edit(index, AllEditTriggers, nullptr)))
         qWarning("edit: editing failed");
 }
 
@@ -1286,7 +1286,7 @@ QAbstractItemView::ScrollMode QAbstractItemView::verticalScrollMode() const
 
 void QAbstractItemView::resetVerticalScrollMode()
 {
-    auto sm = static_cast<ScrollMode>(style()->styleHint(QStyle::SH_ItemView_ScrollMode, 0, this, 0));
+    auto sm = static_cast<ScrollMode>(style()->styleHint(QStyle::SH_ItemView_ScrollMode, nullptr, this, nullptr));
     setVerticalScrollMode(sm);
     d_func()->verticalScrollModeSet = false;
 }
@@ -1323,7 +1323,7 @@ QAbstractItemView::ScrollMode QAbstractItemView::horizontalScrollMode() const
 
 void QAbstractItemView::resetHorizontalScrollMode()
 {
-    auto sm = static_cast<ScrollMode>(style()->styleHint(QStyle::SH_ItemView_ScrollMode, 0, this, 0));
+    auto sm = static_cast<ScrollMode>(style()->styleHint(QStyle::SH_ItemView_ScrollMode, nullptr, this, nullptr));
     setHorizontalScrollMode(sm);
     d_func()->horizontalScrollModeSet = false;
 }
@@ -1964,7 +1964,7 @@ void QAbstractItemView::mouseDoubleClickEvent(QMouseEvent *event)
     QPersistentModelIndex persistent = index;
     emit doubleClicked(persistent);
     if ((event->button() == Qt::LeftButton) && !edit(persistent, DoubleClicked, event)
-        && !style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, 0, this))
+        && !style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, nullptr, this))
         emit activated(persistent);
     d->pressedIndex = QModelIndex();
 }
@@ -2388,7 +2388,7 @@ void QAbstractItemView::keyPressEvent(QKeyEvent *event)
             setFocus();
         QItemSelectionModel::SelectionFlags command = selectionCommand(newCurrent, event);
         if (command != QItemSelectionModel::NoUpdate
-             || style()->styleHint(QStyle::SH_ItemView_MovementWithoutUpdatingSelection, 0, this)) {
+             || style()->styleHint(QStyle::SH_ItemView_MovementWithoutUpdatingSelection, nullptr, this)) {
             // note that we don't check if the new current index is enabled because moveCursor() makes sure it is
             if (command & QItemSelectionModel::Current) {
                 d->selectionModel->setCurrentIndex(newCurrent, QItemSelectionModel::NoUpdate);
@@ -2654,7 +2654,7 @@ bool QAbstractItemView::edit(const QModelIndex &index, EditTrigger trigger, QEve
     if (!d->isIndexValid(index))
         return false;
 
-    if (QWidget *w = (d->persistent.isEmpty() ? static_cast<QWidget*>(0) : d->editorForIndex(index).widget.data())) {
+    if (QWidget *w = (d->persistent.isEmpty() ? static_cast<QWidget*>(nullptr) : d->editorForIndex(index).widget.data())) {
         if (w->focusPolicy() == Qt::NoFocus)
             return false;
         w->setFocus();
@@ -2692,7 +2692,7 @@ bool QAbstractItemView::edit(const QModelIndex &index, EditTrigger trigger, QEve
     if (trigger == SelectedClicked)
         d->delayedEditing.start(QApplication::doubleClickInterval(), this);
     else
-        d->openEditor(index, d->shouldForwardEvent(trigger, event) ? event : 0);
+        d->openEditor(index, d->shouldForwardEvent(trigger, event) ? event : nullptr);
 
     return true;
 }
@@ -2909,7 +2909,7 @@ void QAbstractItemView::commitData(QWidget *editor)
     editor->removeEventFilter(delegate);
     delegate->setModelData(editor, d->model, index);
     editor->installEventFilter(delegate);
-    d->currentlyCommittingEditor = 0;
+    d->currentlyCommittingEditor = nullptr;
 }
 
 /*!
@@ -3260,7 +3260,7 @@ QWidget* QAbstractItemView::indexWidget(const QModelIndex &index) const
         if (QWidget *editor = d->editorForIndex(index).widget.data())
             return editor;
 
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -3673,7 +3673,7 @@ void QAbstractItemView::currentChanged(const QModelIndex &current, const QModelI
             if (d->autoScroll)
                 scrollTo(current);
             update(current);
-            edit(current, CurrentChanged, 0);
+            edit(current, CurrentChanged, nullptr);
             if (current.row() == (d->model->rowCount(d->root) - 1))
                 d->fetchMore();
         } else {
@@ -3737,7 +3737,7 @@ QStyleOptionViewItem QAbstractItemView::viewOptions() const
     if (d->iconSize.isValid()) {
         option.decorationSize = d->iconSize;
     } else {
-        int pm = style()->pixelMetric(QStyle::PM_SmallIconSize, 0, this);
+        int pm = style()->pixelMetric(QStyle::PM_SmallIconSize, nullptr, this);
         option.decorationSize = QSize(pm, pm);
     }
     option.decorationPosition = QStyleOptionViewItem::Left;
@@ -3745,7 +3745,7 @@ QStyleOptionViewItem QAbstractItemView::viewOptions() const
     option.displayAlignment = Qt::AlignLeft|Qt::AlignVCenter;
     option.textElideMode = d->textElideMode;
     option.rect = QRect();
-    option.showDecorationSelected = style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, 0, this);
+    option.showDecorationSelected = style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, nullptr, this);
     if (d->wrapItemText)
         option.features = QStyleOptionViewItem::WrapText;
     option.locale = locale();
@@ -4231,7 +4231,7 @@ QWidget *QAbstractItemViewPrivate::editor(const QModelIndex &index,
     if (!w) {
         QAbstractItemDelegate *delegate = delegateForIndex(index);
         if (!delegate)
-            return 0;
+            return nullptr;
         w = delegate->createEditor(viewport, options, index);
         if (w) {
             w->installEventFilter(delegate);
diff --git a/src/widgets/itemviews/qcolumnview.cpp b/src/widgets/itemviews/qcolumnview.cpp
index a4eed2d885..4d0161025c 100644
--- a/src/widgets/itemviews/qcolumnview.cpp
+++ b/src/widgets/itemviews/qcolumnview.cpp
@@ -142,7 +142,7 @@ void QColumnView::setResizeGripsVisible(bool visible)
             connect(grip, SIGNAL(gripMoved(int)), this, SLOT(_q_gripMoved(int)));
         } else {
             QWidget *widget = view->cornerWidget();
-            view->setCornerWidget(0);
+            view->setCornerWidget(nullptr);
             widget->deleteLater();
         }
     }
@@ -327,7 +327,7 @@ void QColumnView::scrollTo(const QModelIndex &index, ScrollHint hint)
     }
 
 #if QT_CONFIG(animation)
-    if (const int animationDuration = style()->styleHint(QStyle::SH_Widget_Animation_Duration, 0, this)) {
+    if (const int animationDuration = style()->styleHint(QStyle::SH_Widget_Animation_Duration, nullptr, this)) {
         d->currentAnimation.setDuration(animationDuration);
         d->currentAnimation.setEndValue(newScrollbarValue);
         d->currentAnimation.start();
@@ -638,7 +638,7 @@ void QColumnViewPrivate::_q_clicked(const QModelIndex &index)
 {
     Q_Q(QColumnView);
     QModelIndex parent = index.parent();
-    QAbstractItemView *columnClicked = 0;
+    QAbstractItemView *columnClicked = nullptr;
     for (int column = 0; column < columns.count(); ++column) {
         if (columns.at(column)->rootIndex() == parent) {
             columnClicked = columns[column];
@@ -666,7 +666,7 @@ void QColumnViewPrivate::_q_clicked(const QModelIndex &index)
 QAbstractItemView *QColumnViewPrivate::createColumn(const QModelIndex &index, bool show)
 {
     Q_Q(QColumnView);
-    QAbstractItemView *view = 0;
+    QAbstractItemView *view = nullptr;
     if (model->hasChildren(index)) {
         view = q->createColumn(index);
         q->connect(view, SIGNAL(clicked(QModelIndex)),
@@ -1045,8 +1045,8 @@ QColumnViewPrivate::QColumnViewPrivate()
 :  QAbstractItemViewPrivate()
 ,showResizeGrips(true)
 ,offset(0)
-,previewWidget(0)
-,previewColumn(0)
+,previewWidget(nullptr)
+,previewColumn(nullptr)
 {
 }
 
diff --git a/src/widgets/itemviews/qdatawidgetmapper.cpp b/src/widgets/itemviews/qdatawidgetmapper.cpp
index 125ee73194..24039c42f6 100644
--- a/src/widgets/itemviews/qdatawidgetmapper.cpp
+++ b/src/widgets/itemviews/qdatawidgetmapper.cpp
@@ -56,7 +56,7 @@ public:
     Q_DECLARE_PUBLIC(QDataWidgetMapper)
 
     QDataWidgetMapperPrivate()
-        : model(QAbstractItemModelPrivate::staticEmptyModel()), delegate(0),
+        : model(QAbstractItemModelPrivate::staticEmptyModel()), delegate(nullptr),
           orientation(Qt::Horizontal), submitPolicy(QDataWidgetMapper::AutoSubmit)
     {
     }
@@ -226,7 +226,7 @@ void QDataWidgetMapperPrivate::_q_modelDestroyed()
 {
     Q_Q(QDataWidgetMapper);
 
-    model = 0;
+    model = nullptr;
     q->setModel(QAbstractItemModelPrivate::staticEmptyModel());
 }
 
@@ -374,7 +374,7 @@ QAbstractItemModel *QDataWidgetMapper::model() const
 {
     Q_D(const QDataWidgetMapper);
     return d->model == QAbstractItemModelPrivate::staticEmptyModel()
-            ? static_cast<QAbstractItemModel *>(0)
+            ? static_cast<QAbstractItemModel *>(nullptr)
             : d->model;
 }
 
@@ -567,7 +567,7 @@ QWidget *QDataWidgetMapper::mappedWidgetAt(int section) const
             return e.widget;
     }
 
-    return 0;
+    return nullptr;
 }
 
 /*!
diff --git a/src/widgets/itemviews/qdirmodel.cpp b/src/widgets/itemviews/qdirmodel.cpp
index c9e7c7b7a6..0d387d7def 100644
--- a/src/widgets/itemviews/qdirmodel.cpp
+++ b/src/widgets/itemviews/qdirmodel.cpp
@@ -75,7 +75,7 @@ class QDirModelPrivate : public QAbstractItemModelPrivate
 public:
     struct QDirNode
     {
-        QDirNode() : parent(0), populated(false), stat(false) {}
+        QDirNode() : parent(nullptr), populated(false), stat(false) {}
         QDirNode *parent;
         QFileInfo info;
         QIcon icon; // cache the icon
@@ -238,7 +238,7 @@ QDirModel::QDirModel(const QStringList &nameFilters,
     d->nameFilters = nameFilters.isEmpty() ? QStringList(QLatin1String("*")) : nameFilters;
     d->filters = filters;
     d->sort = sort;
-    d->root.parent = 0;
+    d->root.parent = nullptr;
     d->root.info = QFileInfo();
     d->clear(&d->root);
 }
@@ -293,7 +293,7 @@ QModelIndex QDirModel::index(int row, int column, const QModelIndex &parent) con
     if (row >= p->children.count())
         return QModelIndex();
     // now get the internal pointer for the index
-    QDirModelPrivate::QDirNode *n = d->node(row, d->indexValid(parent) ? p : 0);
+    QDirModelPrivate::QDirNode *n = d->node(row, d->indexValid(parent) ? p : nullptr);
     Q_ASSERT(n);
 
     return createIndex(row, column, n);
@@ -310,8 +310,8 @@ QModelIndex QDirModel::parent(const QModelIndex &child) const
     if (!d->indexValid(child))
         return QModelIndex();
     QDirModelPrivate::QDirNode *node = d->node(child);
-    QDirModelPrivate::QDirNode *par = (node ? node->parent : 0);
-    if (par == 0) // parent is the root node
+    QDirModelPrivate::QDirNode *par = (node ? node->parent : nullptr);
+    if (par == nullptr) // parent is the root node
         return QModelIndex();
 
     // get the parent's row
@@ -1159,7 +1159,7 @@ void QDirModelPrivate::init()
     filters = QDir::AllEntries | QDir::NoDotAndDotDot;
     sort = QDir::Name;
     nameFilters << QLatin1String("*");
-    root.parent = 0;
+    root.parent = nullptr;
     root.info = QFileInfo();
     clear(&root);
     roleNames.insert(QDirModel::FileIconRole, QByteArrayLiteral("fileIcon")); // == Qt::decoration
@@ -1170,7 +1170,7 @@ void QDirModelPrivate::init()
 QDirModelPrivate::QDirNode *QDirModelPrivate::node(int row, QDirNode *parent) const
 {
     if (row < 0)
-        return 0;
+        return nullptr;
 
     bool isDir = !parent || parent->info.isDir();
     QDirNode *p = (parent ? parent : &root);
@@ -1179,7 +1179,7 @@ QDirModelPrivate::QDirNode *QDirModelPrivate::node(int row, QDirNode *parent) co
 
     if (Q_UNLIKELY(row >= p->children.count())) {
         qWarning("node: the row does not exist");
-        return 0;
+        return nullptr;
     }
 
     return const_cast<QDirNode*>(&p->children.at(row));
@@ -1190,7 +1190,7 @@ QVector<QDirModelPrivate::QDirNode> QDirModelPrivate::children(QDirNode *parent,
     Q_ASSERT(parent);
     QFileInfoList infoList;
     if (parent == &root) {
-        parent = 0;
+        parent = nullptr;
         infoList = QDir::drives();
     } else if (parent->info.isDir()) {
         //resolve directory links only if requested.
@@ -1333,7 +1333,7 @@ void QDirModelPrivate::appendChild(QDirModelPrivate::QDirNode *parent, const QSt
     QDirModelPrivate::QDirNode node;
     node.populated = false;
     node.stat = shouldStat;
-    node.parent = (parent == &root ? 0 : parent);
+    node.parent = (parent == &root ? nullptr : parent);
     node.info = QFileInfo(path);
     node.info.setCaching(true);
 
diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index d7bdf6aa4c..790f305463 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -1583,7 +1583,7 @@ int QHeaderView::minimumSectionSize() const
     Q_D(const QHeaderView);
     if (d->minimumSectionSize == -1) {
         QSize strut = QApplication::globalStrut();
-        int margin = 2 * style()->pixelMetric(QStyle::PM_HeaderMargin, 0, this);
+        int margin = 2 * style()->pixelMetric(QStyle::PM_HeaderMargin, nullptr, this);
         if (d->orientation == Qt::Horizontal)
             return qMax(strut.width(), (fontMetrics().maxWidth() + margin));
         return qMax(strut.height(), (fontMetrics().height() + margin));
@@ -2883,12 +2883,12 @@ void QHeaderView::paintSection(QPainter *painter, const QRect &rect, int logical
     opt.text = d->model->headerData(logicalIndex, d->orientation,
                                     Qt::DisplayRole).toString();
 
-    int margin = 2 * style()->pixelMetric(QStyle::PM_HeaderMargin, 0, this);
+    int margin = 2 * style()->pixelMetric(QStyle::PM_HeaderMargin, nullptr, this);
 
-    const Qt::Alignment headerArrowAlignment = static_cast<Qt::Alignment>(style()->styleHint(QStyle::SH_Header_ArrowAlignment, 0, this));
+    const Qt::Alignment headerArrowAlignment = static_cast<Qt::Alignment>(style()->styleHint(QStyle::SH_Header_ArrowAlignment, nullptr, this));
     const bool isHeaderArrowOnTheSide = headerArrowAlignment & Qt::AlignVCenter;
     if (isSortIndicatorShown() && sortIndicatorSection() == logicalIndex && isHeaderArrowOnTheSide)
-        margin += style()->pixelMetric(QStyle::PM_HeaderMarkSize, 0, this);
+        margin += style()->pixelMetric(QStyle::PM_HeaderMarkSize, nullptr, this);
 
     const QVariant variant = d->model->headerData(logicalIndex, d->orientation,
                                                   Qt::DecorationRole);
@@ -2896,8 +2896,8 @@ void QHeaderView::paintSection(QPainter *painter, const QRect &rect, int logical
     if (opt.icon.isNull())
         opt.icon = qvariant_cast<QPixmap>(variant);
     if (!opt.icon.isNull()) // see CT_HeaderSection
-        margin += style()->pixelMetric(QStyle::PM_SmallIconSize, 0, this) +
-                  style()->pixelMetric(QStyle::PM_HeaderMargin, 0, this);
+        margin += style()->pixelMetric(QStyle::PM_SmallIconSize, nullptr, this) +
+                  style()->pixelMetric(QStyle::PM_HeaderMargin, nullptr, this);
 
     if (d->textElideMode != Qt::ElideNone) {
         const QRect textRect = style()->subElementRect(QStyle::SE_HeaderLabel, &opt, this);
@@ -3275,7 +3275,7 @@ int QHeaderViewPrivate::sectionHandleAt(int position)
         return -1;
     int log = logicalIndex(visual);
     int pos = q->sectionViewportPosition(log);
-    int grip = q->style()->pixelMetric(QStyle::PM_HeaderGripMargin, 0, q);
+    int grip = q->style()->pixelMetric(QStyle::PM_HeaderGripMargin, nullptr, q);
 
     bool atLeft = position < pos + grip;
     bool atRight = (position > pos + q->sectionSize(log) - grip);
@@ -3814,10 +3814,10 @@ void QHeaderViewPrivate::updateDefaultSectionSizeFromStyle()
 {
     Q_Q(QHeaderView);
     if (orientation == Qt::Horizontal) {
-        defaultSectionSize = q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeHorizontal, 0, q);
+        defaultSectionSize = q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeHorizontal, nullptr, q);
     } else {
         defaultSectionSize = qMax(q->minimumSectionSize(),
-                                  q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeVertical, 0, q));
+                                  q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeVertical, nullptr, q));
     }
 }
 
diff --git a/src/widgets/itemviews/qitemdelegate.cpp b/src/widgets/itemviews/qitemdelegate.cpp
index 460764f1b8..daea907963 100644
--- a/src/widgets/itemviews/qitemdelegate.cpp
+++ b/src/widgets/itemviews/qitemdelegate.cpp
@@ -77,7 +77,7 @@ class QItemDelegatePrivate : public QAbstractItemDelegatePrivate
     Q_DECLARE_PUBLIC(QItemDelegate)
 
 public:
-    QItemDelegatePrivate() : f(0), clipPainting(true) {}
+    QItemDelegatePrivate() : f(nullptr), clipPainting(true) {}
 
     inline const QItemEditorFactory *editorFactory() const
         { return f ? f : QItemEditorFactory::defaultFactory(); }
@@ -149,7 +149,7 @@ QRect QItemDelegatePrivate::textLayoutBounds(const QStyleOptionViewItem &option,
     QStyle *style = w ? w->style() : QApplication::style();
     const bool wrapText = option.features & QStyleOptionViewItem::WrapText;
     // see QItemDelegate::drawDisplay
-    const int textMargin = style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, w) + 1;
+    const int textMargin = style->pixelMetric(QStyle::PM_FocusFrameHMargin, nullptr, w) + 1;
     switch (option.decorationPosition) {
     case QStyleOptionViewItem::Left:
     case QStyleOptionViewItem::Right:
@@ -502,9 +502,9 @@ QWidget *QItemDelegate::createEditor(QWidget *parent,
 {
     Q_D(const QItemDelegate);
     if (!index.isValid())
-        return 0;
+        return nullptr;
     const QItemEditorFactory *factory = d->f;
-    if (factory == 0)
+    if (factory == nullptr)
         factory = QItemEditorFactory::defaultFactory();
     QWidget *w = factory->createEditor(index.data(Qt::EditRole).userType(), parent);
     if (w)
@@ -533,7 +533,7 @@ void QItemDelegate::setEditorData(QWidget *editor, const QModelIndex &index) con
 
     if (!n.isEmpty()) {
         if (!v.isValid())
-            v = QVariant(editor->property(n).userType(), (const void *)0);
+            v = QVariant(editor->property(n).userType(), (const void *)nullptr);
         editor->setProperty(n, v);
     }
 #endif
@@ -586,7 +586,7 @@ void QItemDelegate::updateEditorGeometry(QWidget *editor,
     QPixmap pixmap = decoration(option, index.data(Qt::DecorationRole));
     QString text = QItemDelegatePrivate::replaceNewLine(index.data(Qt::DisplayRole).toString());
     QRect pixmapRect = QRect(QPoint(0, 0), option.decorationSize).intersected(pixmap.rect());
-    QRect textRect = textRectangle(0, option.rect, option.font, text);
+    QRect textRect = textRectangle(nullptr, option.rect, option.font, text);
     QRect checkRect = doCheck(option, textRect, index.data(Qt::CheckStateRole));
     QStyleOptionViewItem opt = option;
     opt.showDecorationSelected = true; // let the editor take up all available space
@@ -654,7 +654,7 @@ void QItemDelegate::drawDisplay(QPainter *painter, const QStyleOptionViewItem &o
 
     const QWidget *widget = d->widget(option);
     QStyle *style = widget ? widget->style() : QApplication::style();
-    const int textMargin = style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, widget) + 1;
+    const int textMargin = style->pixelMetric(QStyle::PM_FocusFrameHMargin, nullptr, widget) + 1;
     QRect textRect = rect.adjusted(textMargin, 0, -textMargin, 0); // remove width padding
     const bool wrapText = opt.features & QStyleOptionViewItem::WrapText;
     d->textOption.setWrapMode(wrapText ? QTextOption::WordWrap : QTextOption::ManualWrap);
@@ -841,7 +841,7 @@ void QItemDelegate::doLayout(const QStyleOptionViewItem &option,
     const bool hasText = textRect->isValid();
     const bool hasMargin = (hasText | hasPixmap | hasCheck);
     const int frameHMargin = hasMargin ?
-                style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, widget) + 1 : 0;
+                style->pixelMetric(QStyle::PM_FocusFrameHMargin, nullptr, widget) + 1 : 0;
     const int textMargin = hasText ? frameHMargin : 0;
     const int pixmapMargin = hasPixmap ? frameHMargin : 0;
     const int checkMargin = hasCheck ? frameHMargin : 0;
@@ -1242,7 +1242,7 @@ QStyleOptionViewItem QItemDelegate::setOptions(const QModelIndex &index,
         opt.palette.setBrush(QPalette::Text, qvariant_cast<QBrush>(value));
 
     // disable style animations for checkboxes etc. within itemviews (QTBUG-30146)
-    opt.styleObject = 0;
+    opt.styleObject = nullptr;
 
     return opt;
 }
diff --git a/src/widgets/itemviews/qitemeditorfactory.cpp b/src/widgets/itemviews/qitemeditorfactory.cpp
index 8ed2ee5f28..f874597d59 100644
--- a/src/widgets/itemviews/qitemeditorfactory.cpp
+++ b/src/widgets/itemviews/qitemeditorfactory.cpp
@@ -91,7 +91,7 @@ class QUIntSpinBox : public QSpinBox
     Q_OBJECT
     Q_PROPERTY(uint value READ uintValue WRITE setUIntValue NOTIFY uintValueChanged USER true)
 public:
-    explicit QUIntSpinBox(QWidget *parent = 0)
+    explicit QUIntSpinBox(QWidget *parent = nullptr)
       : QSpinBox(parent)
     {
         connect(this, SIGNAL(valueChanged(int)), SIGNAL(uintValueChanged()));
@@ -176,7 +176,7 @@ QWidget *QItemEditorFactory::createEditor(int userType, QWidget *parent) const
     QItemEditorCreatorBase *creator = creatorMap.value(userType, 0);
     if (!creator) {
         const QItemEditorFactory *dfactory = defaultFactory();
-        return dfactory == this ? 0 : dfactory->createEditor(userType, parent);
+        return dfactory == this ? nullptr : dfactory->createEditor(userType, parent);
     }
     return creator->createWidget(parent);
 }
@@ -295,8 +295,8 @@ QWidget *QDefaultItemEditorFactory::createEditor(int userType, QWidget *parent)
     default: {
         // the default editor is a lineedit
         QExpandingLineEdit *le = new QExpandingLineEdit(parent);
-        le->setFrame(le->style()->styleHint(QStyle::SH_ItemView_DrawDelegateFrame, 0, le));
-        if (!le->style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, 0, le))
+        le->setFrame(le->style()->styleHint(QStyle::SH_ItemView_DrawDelegateFrame, nullptr, le));
+        if (!le->style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, nullptr, le))
             le->setWidgetOwnsGeometry(true);
         return le; }
 #else
@@ -304,7 +304,7 @@ QWidget *QDefaultItemEditorFactory::createEditor(int userType, QWidget *parent)
         break;
 #endif
     }
-    return 0;
+    return nullptr;
 }
 
 QByteArray QDefaultItemEditorFactory::valuePropertyName(int userType) const
@@ -335,11 +335,11 @@ QByteArray QDefaultItemEditorFactory::valuePropertyName(int userType) const
     }
 }
 
-static QItemEditorFactory *q_default_factory = 0;
+static QItemEditorFactory *q_default_factory = nullptr;
 struct QDefaultFactoryCleaner
 {
     inline QDefaultFactoryCleaner() {}
-    ~QDefaultFactoryCleaner() { delete q_default_factory; q_default_factory = 0; }
+    ~QDefaultFactoryCleaner() { delete q_default_factory; q_default_factory = nullptr; }
 };
 
 /*!
diff --git a/src/widgets/itemviews/qlistview.cpp b/src/widgets/itemviews/qlistview.cpp
index 04cddf2926..de32082b5a 100644
--- a/src/widgets/itemviews/qlistview.cpp
+++ b/src/widgets/itemviews/qlistview.cpp
@@ -933,8 +933,8 @@ QStyleOptionViewItem QListView::viewOptions() const
     QStyleOptionViewItem option = QAbstractItemView::viewOptions();
     if (!d->iconSize.isValid()) { // otherwise it was already set in abstractitemview
         int pm = (d->viewMode == QListView::ListMode
-                  ? style()->pixelMetric(QStyle::PM_ListViewIconSize, 0, this)
-                  : style()->pixelMetric(QStyle::PM_IconViewIconSize, 0, this));
+                  ? style()->pixelMetric(QStyle::PM_ListViewIconSize, nullptr, this)
+                  : style()->pixelMetric(QStyle::PM_IconViewIconSize, nullptr, this));
         option.decorationSize = QSize(pm, pm);
     }
     if (d->viewMode == QListView::IconMode) {
@@ -1688,7 +1688,7 @@ bool QListView::event(QEvent *e)
 
 QListViewPrivate::QListViewPrivate()
     : QAbstractItemViewPrivate(),
-      commonListView(0),
+      commonListView(nullptr),
       wrap(false),
       space(0),
       flow(QListView::TopToBottom),
@@ -1733,10 +1733,10 @@ void QListViewPrivate::prepareItemsLayout()
     // Qt::ScrollBarAlwaysOn but scrollbar extent must be deduced if policy
     // is Qt::ScrollBarAsNeeded
     int verticalMargin = vbarpolicy==Qt::ScrollBarAsNeeded
-        ? q->style()->pixelMetric(QStyle::PM_ScrollBarExtent, 0, vbar) + frameAroundContents
+        ? q->style()->pixelMetric(QStyle::PM_ScrollBarExtent, nullptr, vbar) + frameAroundContents
         : 0;
     int horizontalMargin =  hbarpolicy==Qt::ScrollBarAsNeeded
-        ? q->style()->pixelMetric(QStyle::PM_ScrollBarExtent, 0, hbar) + frameAroundContents
+        ? q->style()->pixelMetric(QStyle::PM_ScrollBarExtent, nullptr, hbar) + frameAroundContents
         : 0;
 
     layoutBounds.adjust(0, 0, -verticalMargin, -horizontalMargin);
@@ -3072,7 +3072,7 @@ void QIconModeViewBase::doDynamicLayout(const QListViewLayoutInfo &info)
         moved.resize(items.count());
 
     QRect rect(QPoint(), topLeft);
-    QListViewItem *item = 0;
+    QListViewItem *item = nullptr;
     for (int row = info.first; row <= info.last; ++row) {
         item = &items[row];
         if (isHidden(row)) {
@@ -3178,7 +3178,7 @@ QVector<QModelIndex> QIconModeViewBase::intersectingSet(const QRect &area) const
     QVector<QModelIndex> res;
     that->interSectingVector = &res;
     that->tree.climbTree(area, &QIconModeViewBase::addLeaf, data);
-    that->interSectingVector = 0;
+    that->interSectingVector = nullptr;
     return res;
 }
 
diff --git a/src/widgets/itemviews/qlistwidget.cpp b/src/widgets/itemviews/qlistwidget.cpp
index 1931360dbc..f71e0f2822 100644
--- a/src/widgets/itemviews/qlistwidget.cpp
+++ b/src/widgets/itemviews/qlistwidget.cpp
@@ -75,7 +75,7 @@ void QListModel::clear()
     for (int i = 0; i < items.count(); ++i) {
         if (items.at(i)) {
             items.at(i)->d->theid = -1;
-            items.at(i)->view = 0;
+            items.at(i)->view = nullptr;
             delete items.at(i);
         }
     }
@@ -96,7 +96,7 @@ void QListModel::remove(QListWidgetItem *item)
     Q_ASSERT(row != -1);
     beginRemoveRows(QModelIndex(), row, row);
     items.at(row)->d->theid = -1;
-    items.at(row)->view = 0;
+    items.at(row)->view = nullptr;
     items.removeAt(row);
     endRemoveRows();
 }
@@ -156,11 +156,11 @@ void QListModel::insert(int row, const QStringList &labels)
 QListWidgetItem *QListModel::take(int row)
 {
     if (row < 0 || row >= items.count())
-        return 0;
+        return nullptr;
 
     beginRemoveRows(QModelIndex(), row, row);
     items.at(row)->d->theid = -1;
-    items.at(row)->view = 0;
+    items.at(row)->view = nullptr;
     QListWidgetItem *item = items.takeAt(row);
     endRemoveRows();
     return item;
@@ -263,7 +263,7 @@ bool QListModel::insertRows(int row, int count, const QModelIndex &parent)
 
     beginInsertRows(QModelIndex(), row, row + count - 1);
     QListWidget *view = qobject_cast<QListWidget*>(QObject::parent());
-    QListWidgetItem *itm = 0;
+    QListWidgetItem *itm = nullptr;
 
     for (int r = row; r < row + count; ++r) {
         itm = new QListWidgetItem;
@@ -282,10 +282,10 @@ bool QListModel::removeRows(int row, int count, const QModelIndex &parent)
         return false;
 
     beginRemoveRows(QModelIndex(), row, row + count - 1);
-    QListWidgetItem *itm = 0;
+    QListWidgetItem *itm = nullptr;
     for (int r = row; r < row + count; ++r) {
         itm = items.takeAt(row);
-        itm->view = 0;
+        itm->view = nullptr;
         itm->d->theid = -1;
         delete itm;
     }
@@ -1220,7 +1220,7 @@ void QListWidgetPrivate::_q_emitCurrentItemChanged(const QModelIndex &current,
     //persistentCurrent is invalid if something changed the model in response
     //to the currentItemChanged signal emission and the item was removed
     if (!persistentCurrent.isValid()) {
-        currentItem = 0;
+        currentItem = nullptr;
     }
 
     emit q->currentTextChanged(currentItem ? currentItem->text() : QString());
@@ -1478,7 +1478,7 @@ QListWidgetItem *QListWidget::item(int row) const
 {
     Q_D(const QListWidget);
     if (row < 0 || row >= d->model->rowCount())
-        return 0;
+        return nullptr;
     return d->listModel()->at(row);
 }
 
@@ -1548,7 +1548,7 @@ QListWidgetItem *QListWidget::takeItem(int row)
 {
     Q_D(QListWidget);
     if (row < 0 || row >= d->model->rowCount())
-        return 0;
+        return nullptr;
     return d->listModel()->take(row);
 }
 
@@ -2064,7 +2064,7 @@ QListWidgetItem *QListWidget::itemFromIndex(const QModelIndex &index) const
     Q_D(const QListWidget);
     if (d->isIndexValid(index))
         return d->listModel()->at(index.row());
-    return 0;
+    return nullptr;
 }
 
 /*!
diff --git a/src/widgets/itemviews/qstyleditemdelegate.cpp b/src/widgets/itemviews/qstyleditemdelegate.cpp
index 702e290da3..f42af2ea00 100644
--- a/src/widgets/itemviews/qstyleditemdelegate.cpp
+++ b/src/widgets/itemviews/qstyleditemdelegate.cpp
@@ -83,7 +83,7 @@ class QStyledItemDelegatePrivate : public QAbstractItemDelegatePrivate
     Q_DECLARE_PUBLIC(QStyledItemDelegate)
 
 public:
-    QStyledItemDelegatePrivate() : factory(0) { }
+    QStyledItemDelegatePrivate() : factory(nullptr) { }
 
     static const QWidget *widget(const QStyleOptionViewItem &option)
     {
@@ -351,7 +351,7 @@ void QStyledItemDelegate::initStyleOption(QStyleOptionViewItem *option,
     option->backgroundBrush = qvariant_cast<QBrush>(index.data(Qt::BackgroundRole));
 
     // disable style animations for checkboxes etc. within itemviews (QTBUG-30146)
-    option->styleObject = 0;
+    option->styleObject = nullptr;
 }
 
 /*!
@@ -426,7 +426,7 @@ QWidget *QStyledItemDelegate::createEditor(QWidget *parent,
 {
     Q_D(const QStyledItemDelegate);
     if (!index.isValid())
-        return 0;
+        return nullptr;
     return d->editorFactory()->createEditor(index.data(Qt::EditRole).userType(), parent);
 }
 
@@ -450,7 +450,7 @@ void QStyledItemDelegate::setEditorData(QWidget *editor, const QModelIndex &inde
 
     if (!n.isEmpty()) {
         if (!v.isValid())
-            v = QVariant(editor->property(n).userType(), (const void *)0);
+            v = QVariant(editor->property(n).userType(), (const void *)nullptr);
         editor->setProperty(n, v);
     }
 #endif
@@ -507,7 +507,7 @@ void QStyledItemDelegate::updateEditorGeometry(QWidget *editor,
     //or it is in a QTableView
 #if QT_CONFIG(tableview) && QT_CONFIG(lineedit)
     if (qobject_cast<QExpandingLineEdit*>(editor) && !qobject_cast<const QTableView*>(widget))
-        opt.showDecorationSelected = editor->style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, 0, editor);
+        opt.showDecorationSelected = editor->style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, nullptr, editor);
     else
 #endif
         opt.showDecorationSelected = true;
diff --git a/src/widgets/itemviews/qtablewidget.cpp b/src/widgets/itemviews/qtablewidget.cpp
index 91860341ee..8f37ef4c3d 100644
--- a/src/widgets/itemviews/qtablewidget.cpp
+++ b/src/widgets/itemviews/qtablewidget.cpp
@@ -49,7 +49,7 @@ QT_BEGIN_NAMESPACE
 
 QTableModel::QTableModel(int rows, int columns, QTableWidget *parent)
     : QAbstractTableModel(parent),
-      prototype(0),
+      prototype(nullptr),
       tableItems(rows * columns, 0),
       verticalHeaderItems(rows, 0),
       horizontalHeaderItems(columns, 0)
@@ -104,18 +104,18 @@ bool QTableModel::removeRows(int row, int count, const QModelIndex &)
     beginRemoveRows(QModelIndex(), row, row + count - 1);
     int i = tableIndex(row, 0);
     int n = count * columnCount();
-    QTableWidgetItem *oldItem = 0;
+    QTableWidgetItem *oldItem = nullptr;
     for (int j = i; j < n + i; ++j) {
         oldItem = tableItems.at(j);
         if (oldItem)
-            oldItem->view = 0;
+            oldItem->view = nullptr;
         delete oldItem;
     }
     tableItems.remove(qMax(i, 0), n);
     for (int v = row; v < row + count; ++v) {
         oldItem = verticalHeaderItems.at(v);
         if (oldItem)
-            oldItem->view = 0;
+            oldItem->view = nullptr;
         delete oldItem;
     }
     verticalHeaderItems.remove(row, count);
@@ -129,13 +129,13 @@ bool QTableModel::removeColumns(int column, int count, const QModelIndex &)
         return false;
 
     beginRemoveColumns(QModelIndex(), column, column + count - 1);
-    QTableWidgetItem *oldItem = 0;
+    QTableWidgetItem *oldItem = nullptr;
     for (int row = rowCount() - 1; row >= 0; --row) {
         int i = tableIndex(row, column);
         for (int j = i; j < i + count; ++j) {
             oldItem = tableItems.at(j);
             if (oldItem)
-                oldItem->view = 0;
+                oldItem->view = nullptr;
             delete oldItem;
         }
         tableItems.remove(i, count);
@@ -143,7 +143,7 @@ bool QTableModel::removeColumns(int column, int count, const QModelIndex &)
     for (int h=column; h<column+count; ++h) {
         oldItem = horizontalHeaderItems.at(h);
         if (oldItem)
-            oldItem->view = 0;
+            oldItem->view = nullptr;
         delete oldItem;
     }
     horizontalHeaderItems.remove(column, count);
@@ -162,7 +162,7 @@ void QTableModel::setItem(int row, int column, QTableWidgetItem *item)
 
     // remove old
     if (oldItem)
-        oldItem->view = 0;
+        oldItem->view = nullptr;
     delete tableItems.at(i);
 
     QTableWidget *view = qobject_cast<QTableWidget*>(QObject::parent());
@@ -180,7 +180,7 @@ void QTableModel::setItem(int row, int column, QTableWidgetItem *item)
         if (row < colItems.count())
             colItems.remove(row);
         int sortedRow;
-        if (item == 0) {
+        if (item == nullptr) {
             // move to after all non-0 (sortable) items
             sortedRow = colItems.count();
         } else {
@@ -222,7 +222,7 @@ QTableWidgetItem *QTableModel::takeItem(int row, int column)
     long i = tableIndex(row, column);
     QTableWidgetItem *itm = tableItems.value(i);
     if (itm) {
-        itm->view = 0;
+        itm->view = nullptr;
         itm->d->id = -1;
         tableItems[i] = 0;
         const QModelIndex ind = index(row, column);
@@ -239,7 +239,7 @@ QTableWidgetItem *QTableModel::item(int row, int column) const
 QTableWidgetItem *QTableModel::item(const QModelIndex &index) const
 {
     if (!isValid(index))
-        return 0;
+        return nullptr;
     return tableItems.at(tableIndex(index.row(), index.column()));
 }
 
@@ -277,7 +277,7 @@ void QTableModel::setHorizontalHeaderItem(int section, QTableWidgetItem *item)
         return;
 
     if (oldItem)
-        oldItem->view = 0;
+        oldItem->view = nullptr;
     delete oldItem;
 
     QTableWidget *view = qobject_cast<QTableWidget*>(QObject::parent());
@@ -299,7 +299,7 @@ void QTableModel::setVerticalHeaderItem(int section, QTableWidgetItem *item)
         return;
 
     if (oldItem)
-        oldItem->view = 0;
+        oldItem->view = nullptr;
     delete oldItem;
 
     QTableWidget *view = qobject_cast<QTableWidget*>(QObject::parent());
@@ -315,10 +315,10 @@ void QTableModel::setVerticalHeaderItem(int section, QTableWidgetItem *item)
 QTableWidgetItem *QTableModel::takeHorizontalHeaderItem(int section)
 {
     if (section < 0 || section >= horizontalHeaderItems.count())
-        return 0;
+        return nullptr;
     QTableWidgetItem *itm = horizontalHeaderItems.at(section);
     if (itm) {
-        itm->view = 0;
+        itm->view = nullptr;
         itm->itemFlags &= ~ItemIsHeaderItem;
         horizontalHeaderItems[section] = 0;
     }
@@ -328,10 +328,10 @@ QTableWidgetItem *QTableModel::takeHorizontalHeaderItem(int section)
 QTableWidgetItem *QTableModel::takeVerticalHeaderItem(int section)
 {
     if (section < 0 || section >= verticalHeaderItems.count())
-        return 0;
+        return nullptr;
     QTableWidgetItem *itm = verticalHeaderItems.at(section);
     if (itm) {
-        itm->view = 0;
+        itm->view = nullptr;
         itm->itemFlags &= ~ItemIsHeaderItem;
         verticalHeaderItems[section] = 0;
     }
@@ -571,7 +571,7 @@ void QTableModel::ensureSorted(int column, Qt::SortOrder order,
     sorting.reserve(count);
     for (int row = start; row <= end; ++row) {
         QTableWidgetItem *itm = item(row, column);
-        if (itm == 0) {
+        if (itm == nullptr) {
             // no more sortable items (all 0-items are
             // at the end of the table when it is sorted)
             break;
@@ -649,7 +649,7 @@ QVector<QTableWidgetItem*> QTableModel::columnItems(int column) const
     items.reserve(rc);
     for (int row = 0; row < rc; ++row) {
         QTableWidgetItem *itm = item(row, column);
-        if (itm == 0) {
+        if (itm == nullptr) {
             // no more sortable items (all 0-items are
             // at the end of the table when it is sorted)
             break;
@@ -718,7 +718,7 @@ QVariant QTableModel::headerData(int section, Qt::Orientation orientation, int r
     if (section < 0)
         return QVariant();
 
-    QTableWidgetItem *itm = 0;
+    QTableWidgetItem *itm = nullptr;
     if (orientation == Qt::Horizontal && section < horizontalHeaderItems.count())
         itm = horizontalHeaderItems.at(section);
     else if (orientation == Qt::Vertical && section < verticalHeaderItems.count())
@@ -741,7 +741,7 @@ bool QTableModel::setHeaderData(int section, Qt::Orientation orientation,
        (orientation == Qt::Vertical && verticalHeaderItems.size() <= section))
     return false;
 
-    QTableWidgetItem *itm = 0;
+    QTableWidgetItem *itm = nullptr;
     if (orientation == Qt::Horizontal)
         itm = horizontalHeaderItems.at(section);
     else
@@ -764,14 +764,14 @@ void QTableModel::clear()
 {
     for (int j = 0; j < verticalHeaderItems.count(); ++j) {
         if (verticalHeaderItems.at(j)) {
-            verticalHeaderItems.at(j)->view = 0;
+            verticalHeaderItems.at(j)->view = nullptr;
             delete verticalHeaderItems.at(j);
             verticalHeaderItems[j] = 0;
         }
     }
     for (int k = 0; k < horizontalHeaderItems.count(); ++k) {
         if (horizontalHeaderItems.at(k)) {
-            horizontalHeaderItems.at(k)->view = 0;
+            horizontalHeaderItems.at(k)->view = nullptr;
             delete horizontalHeaderItems.at(k);
             horizontalHeaderItems[k] = 0;
         }
@@ -784,7 +784,7 @@ void QTableModel::clearContents()
     beginResetModel();
     for (int i = 0; i < tableItems.count(); ++i) {
         if (tableItems.at(i)) {
-            tableItems.at(i)->view = 0;
+            tableItems.at(i)->view = nullptr;
             delete tableItems.at(i);
             tableItems[i] = 0;
         }
@@ -853,7 +853,7 @@ QMimeData *QTableModel::mimeData(const QModelIndexList &indexes) const
     // cachedIndexes is a little hack to avoid copying from QModelIndexList to
     // QList<QTreeWidgetItem*> and back again in the view
     cachedIndexes = indexes;
-    QMimeData *mimeData = (view ? view->mimeData(items) : 0);
+    QMimeData *mimeData = (view ? view->mimeData(items) : nullptr);
     cachedIndexes.clear();
     return mimeData;
 }
@@ -2040,7 +2040,7 @@ QTableWidgetItem *QTableWidget::takeItem(int row, int column)
     Q_D(QTableWidget);
     QTableWidgetItem *item = d->tableModel()->takeItem(row, column);
     if (item)
-        item->view = 0;
+        item->view = nullptr;
     return item;
 }
 
@@ -2076,7 +2076,7 @@ QTableWidgetItem *QTableWidget::takeVerticalHeaderItem(int row)
     Q_D(QTableWidget);
     QTableWidgetItem *itm = d->tableModel()->takeVerticalHeaderItem(row);
     if (itm)
-        itm->view = 0;
+        itm->view = nullptr;
     return itm;
 }
 
@@ -2115,7 +2115,7 @@ QTableWidgetItem *QTableWidget::takeHorizontalHeaderItem(int column)
     Q_D(QTableWidget);
     QTableWidgetItem *itm = d->tableModel()->takeHorizontalHeaderItem(column);
     if (itm)
-        itm->view = 0;
+        itm->view = nullptr;
     return itm;
 }
 
@@ -2126,7 +2126,7 @@ void QTableWidget::setVerticalHeaderLabels(const QStringList &labels)
 {
     Q_D(QTableWidget);
     QTableModel *model = d->tableModel();
-    QTableWidgetItem *item = 0;
+    QTableWidgetItem *item = nullptr;
     for (int i = 0; i < model->rowCount() && i < labels.count(); ++i) {
         item = model->verticalHeaderItem(i);
         if (!item) {
@@ -2144,7 +2144,7 @@ void QTableWidget::setHorizontalHeaderLabels(const QStringList &labels)
 {
     Q_D(QTableWidget);
     QTableModel *model = d->tableModel();
-    QTableWidgetItem *item = 0;
+    QTableWidgetItem *item = nullptr;
     for (int i = 0; i < model->columnCount() && i < labels.count(); ++i) {
         item = model->horizontalHeaderItem(i);
         if (!item) {
diff --git a/src/widgets/itemviews/qtreeview.cpp b/src/widgets/itemviews/qtreeview.cpp
index 442369c2ec..9aba17be70 100644
--- a/src/widgets/itemviews/qtreeview.cpp
+++ b/src/widgets/itemviews/qtreeview.cpp
@@ -1517,7 +1517,7 @@ void QTreeView::drawTree(QPainter *painter, const QRegion &region) const
 /// ### move to QObject :)
 static inline bool ancestorOf(QObject *widget, QObject *other)
 {
-    for (QObject *parent = other; parent != 0; parent = parent->parent()) {
+    for (QObject *parent = other; parent != nullptr; parent = parent->parent()) {
         if (parent == widget)
             return true;
     }
@@ -1888,7 +1888,7 @@ void QTreeView::mousePressEvent(QMouseEvent *event)
 {
     Q_D(QTreeView);
     bool handled = false;
-    if (style()->styleHint(QStyle::SH_ListViewExpand_SelectMouseType, 0, this) == QEvent::MouseButtonPress)
+    if (style()->styleHint(QStyle::SH_ListViewExpand_SelectMouseType, nullptr, this) == QEvent::MouseButtonPress)
         handled = d->expandOrCollapseItemAtPos(event->pos());
     if (!handled && d->itemDecorationAt(event->pos()) == -1)
         QAbstractItemView::mousePressEvent(event);
@@ -1907,7 +1907,7 @@ void QTreeView::mouseReleaseEvent(QMouseEvent *event)
     } else {
         if (state() == QAbstractItemView::DragSelectingState || state() == QAbstractItemView::DraggingState)
             setState(QAbstractItemView::NoState);
-        if (style()->styleHint(QStyle::SH_ListViewExpand_SelectMouseType, 0, this) == QEvent::MouseButtonRelease)
+        if (style()->styleHint(QStyle::SH_ListViewExpand_SelectMouseType, nullptr, this) == QEvent::MouseButtonRelease)
             d->expandOrCollapseItemAtPos(event->pos());
     }
 }
@@ -1944,7 +1944,7 @@ void QTreeView::mouseDoubleClickEvent(QMouseEvent *event)
         if (edit(persistent, DoubleClicked, event) || state() != NoState)
             return; // the double click triggered editing
 
-        if (!style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, 0, this))
+        if (!style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, nullptr, this))
             emit activated(persistent);
 
         d->pressedIndex = QModelIndex();
@@ -2208,7 +2208,7 @@ QModelIndex QTreeView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifie
             d->collapse(vi, true);
             d->moveCursorUpdatedView = true;
         } else {
-            bool descend = style()->styleHint(QStyle::SH_ItemView_ArrowKeysNavigateIntoChildren, 0, this);
+            bool descend = style()->styleHint(QStyle::SH_ItemView_ArrowKeysNavigateIntoChildren, nullptr, this);
             if (descend) {
                 QModelIndex par = current.parent();
                 if (par.isValid() && par != rootIndex())
@@ -2244,7 +2244,7 @@ QModelIndex QTreeView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifie
             d->expand(vi, true);
             d->moveCursorUpdatedView = true;
         } else {
-            bool descend = style()->styleHint(QStyle::SH_ItemView_ArrowKeysNavigateIntoChildren, 0, this);
+            bool descend = style()->styleHint(QStyle::SH_ItemView_ArrowKeysNavigateIntoChildren, nullptr, this);
             if (descend) {
                 QModelIndex idx = d->modelIndex(d->below(vi));
                 if (idx.parent() == current)
@@ -3051,7 +3051,7 @@ void QTreeViewPrivate::initialize()
     header->setDefaultAlignment(Qt::AlignLeft|Qt::AlignVCenter);
     q->setHeader(header);
 #if QT_CONFIG(animation)
-    animationsEnabled = q->style()->styleHint(QStyle::SH_Widget_Animation_Duration, 0, q) > 0;
+    animationsEnabled = q->style()->styleHint(QStyle::SH_Widget_Animation_Duration, nullptr, q) > 0;
     QObject::connect(&animatedOperation, SIGNAL(finished()), q, SLOT(_q_endAnimatedOperation()));
 #endif // animation
 }
@@ -3344,7 +3344,7 @@ void QTreeViewPrivate::layout(int i, bool recursiveExpanding, bool afterIsUninit
     int hidden = 0;
     int last = 0;
     int children = 0;
-    QTreeViewItem *item = 0;
+    QTreeViewItem *item = nullptr;
     for (int j = first; j < first + count; ++j) {
         current = model->index(j - first, 0, parent);
         if (isRowHidden(current)) {
@@ -3955,7 +3955,7 @@ int QTreeViewPrivate::accessibleTree2Index(const QModelIndex &index) const
 void QTreeViewPrivate::updateIndentationFromStyle()
 {
     Q_Q(const QTreeView);
-    indent = q->style()->pixelMetric(QStyle::PM_TreeViewIndentation, 0, q);
+    indent = q->style()->pixelMetric(QStyle::PM_TreeViewIndentation, nullptr, q);
 }
 
 /*!
diff --git a/src/widgets/itemviews/qtreewidget.cpp b/src/widgets/itemviews/qtreewidget.cpp
index cce0773fec..ddb31523fd 100644
--- a/src/widgets/itemviews/qtreewidget.cpp
+++ b/src/widgets/itemviews/qtreewidget.cpp
@@ -144,7 +144,7 @@ QTreeModel::~QTreeModel()
     clear();
     headerItem->view = nullptr;
     delete headerItem;
-    rootItem->view = 0;
+    rootItem->view = nullptr;
     delete rootItem;
 }
 
@@ -160,8 +160,8 @@ void QTreeModel::clear()
     beginResetModel();
     for (int i = 0; i < rootItem->childCount(); ++i) {
         QTreeWidgetItem *item = rootItem->children.at(i);
-        item->par = 0;
-        item->view = 0;
+        item->par = nullptr;
+        item->view = nullptr;
         delete item;
     }
     rootItem->children.clear();
@@ -214,7 +214,7 @@ void QTreeModel::setColumnCount(int columns)
 QTreeWidgetItem *QTreeModel::item(const QModelIndex &index) const
 {
     if (!index.isValid())
-        return 0;
+        return nullptr;
     return static_cast<QTreeWidgetItem*>(index.internalPointer());
 }
 
@@ -515,9 +515,9 @@ bool QTreeModel::removeRows(int row, int count, const QModelIndex &parent) {
     for (int i = row + count - 1; i >= row; --i) {
         QTreeWidgetItem *child = itm ? itm->takeChild(i) : rootItem->children.takeAt(i);
         Q_ASSERT(child);
-        child->view = 0;
+        child->view = nullptr;
         delete child;
-        child = 0;
+        child = nullptr;
     }
     blocker.unblock();
 
@@ -1612,11 +1612,11 @@ QTreeWidgetItem::~QTreeWidgetItem()
         }
     } else if (model) {
         if (this == model->headerItem) {
-            model->headerItem = 0;
+            model->headerItem = nullptr;
         } else {
             int i = model->rootItem->children.indexOf(this);
             if (i >= 0) {
-                model->beginRemoveItems(0, i, 1);
+                model->beginRemoveItems(nullptr, i, 1);
                 // users _could_ do changes when connected to rowsAboutToBeRemoved,
                 // so we check again to make sure 'i' is valid
                 if (!model->rootItem->children.isEmpty() && model->rootItem->children.at(i) == this)
@@ -1630,9 +1630,9 @@ QTreeWidgetItem::~QTreeWidgetItem()
     for (int i = 0; i < children.count(); ++i) {
         QTreeWidgetItem *child = children.at(i);
         // make sure the child does not try to remove itself from our children list
-        child->par = 0;
+        child->par = nullptr;
         // make sure the child does not try to remove itself from the top level list
-        child->view = 0;
+        child->view = nullptr;
         delete child;
     }
 
@@ -1648,16 +1648,16 @@ QTreeWidgetItem::~QTreeWidgetItem()
 */
 QTreeWidgetItem *QTreeWidgetItem::clone() const
 {
-    QTreeWidgetItem *copy = 0;
+    QTreeWidgetItem *copy = nullptr;
 
     QStack<const QTreeWidgetItem*> stack;
     QStack<QTreeWidgetItem*> parentStack;
     stack.push(this);
     parentStack.push(0);
 
-    QTreeWidgetItem *root = 0;
-    const QTreeWidgetItem *item = 0;
-    QTreeWidgetItem *parent = 0;
+    QTreeWidgetItem *root = nullptr;
+    const QTreeWidgetItem *item = nullptr;
+    QTreeWidgetItem *parent = nullptr;
     while (!stack.isEmpty()) {
         // get current item, and copied parent
         item = stack.pop();
@@ -1992,8 +1992,8 @@ void QTreeWidgetItem::write(QDataStream &out) const
     \sa data(), flags()
 */
 QTreeWidgetItem::QTreeWidgetItem(const QTreeWidgetItem &other)
-    : rtti(Type), values(other.values), view(0),
-      d(new QTreeWidgetItemPrivate(this)), par(0),
+    : rtti(Type), values(other.values), view(nullptr),
+      d(new QTreeWidgetItemPrivate(this)), par(nullptr),
       itemFlags(other.itemFlags)
 {
     d->display = other.d->display;
@@ -2036,14 +2036,14 @@ void QTreeWidgetItem::addChild(QTreeWidgetItem *child)
 */
 void QTreeWidgetItem::insertChild(int index, QTreeWidgetItem *child)
 {
-    if (index < 0 || index > children.count() || child == 0 || child->view != 0 || child->par != 0)
+    if (index < 0 || index > children.count() || child == nullptr || child->view != nullptr || child->par != nullptr)
         return;
 
     if (QTreeModel *model = treeModel()) {
         const bool wasSkipSort = model->skipPendingSort;
         model->skipPendingSort = true;
         if (model->rootItem == this)
-            child->par = 0;
+            child->par = nullptr;
         else
             child->par = this;
         if (view->isSortingEnabled()) {
@@ -2103,12 +2103,12 @@ QTreeWidgetItem *QTreeWidgetItem::takeChild(int index)
         if (model) model->beginRemoveItems(this, index, 1);
         d->updateHiddenStatus(children.at(index), false);
         QTreeWidgetItem *item = children.takeAt(index);
-        item->par = 0;
+        item->par = nullptr;
         QStack<QTreeWidgetItem*> stack;
         stack.push(item);
         while (!stack.isEmpty()) {
             QTreeWidgetItem *i = stack.pop();
-            i->view = 0;
+            i->view = nullptr;
             for (int c = 0; c < i->children.count(); ++c)
                 stack.push(i->children.at(c));
         }
@@ -2116,7 +2116,7 @@ QTreeWidgetItem *QTreeWidgetItem::takeChild(int index)
         if (model) model->endRemoveRows();
         return item;
     }
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -2163,7 +2163,7 @@ void QTreeWidgetItem::insertChildren(int index, const QList<QTreeWidgetItem*> &c
                 stack.push(child);
         }
         if (model && (model->rootItem == this))
-            child->par = 0;
+            child->par = nullptr;
         else
             child->par = this;
     }
@@ -2206,12 +2206,12 @@ QList<QTreeWidgetItem*> QTreeWidgetItem::takeChildren()
         if (model) model->beginRemoveItems(this, 0, children.count());
         for (int n = 0; n < children.count(); ++n) {
             QTreeWidgetItem *item = children.at(n);
-            item->par = 0;
+            item->par = nullptr;
             QStack<QTreeWidgetItem*> stack;
             stack.push(item);
             while (!stack.isEmpty()) {
                 QTreeWidgetItem *i = stack.pop();
-                i->view = 0;
+                i->view = nullptr;
                 for (int c = 0; c < i->children.count(); ++c)
                     stack.push(i->children.at(c));
             }
@@ -3306,7 +3306,7 @@ QTreeWidgetItem *QTreeWidget::itemAbove(const QTreeWidgetItem *item) const
 {
     Q_D(const QTreeWidget);
     if (item == d->treeModel()->headerItem)
-        return 0;
+        return nullptr;
     const QModelIndex index = d->index(item);
     const QModelIndex above = indexAbove(index);
     return d->item(above);
@@ -3321,7 +3321,7 @@ QTreeWidgetItem *QTreeWidget::itemBelow(const QTreeWidgetItem *item) const
 {
     Q_D(const QTreeWidget);
     if (item == d->treeModel()->headerItem)
-        return 0;
+        return nullptr;
     const QModelIndex index = d->index(item);
     const QModelIndex below = indexBelow(index);
     return d->item(below);
@@ -3424,14 +3424,14 @@ QMimeData *QTreeWidget::mimeData(const QList<QTreeWidgetItem*> items) const
         for (const auto *item : items) {
             if (Q_UNLIKELY(!item)) {
                 qWarning("QTreeWidget::mimeData: Null-item passed");
-                return 0;
+                return nullptr;
             }
 
             for (int c = 0; c < item->values.count(); ++c) {
                 const QModelIndex index = indexFromItem(item, c);
                 if (Q_UNLIKELY(!index.isValid())) {
                     qWarning() << "QTreeWidget::mimeData: No index associated with item :" << item;
-                    return 0;
+                    return nullptr;
                 }
                 indexes << index;
             }
diff --git a/src/widgets/itemviews/qtreewidgetitemiterator.cpp b/src/widgets/itemviews/qtreewidgetitemiterator.cpp
index 14c19fcb9c..a24106d90e 100644
--- a/src/widgets/itemviews/qtreewidgetitemiterator.cpp
+++ b/src/widgets/itemviews/qtreewidgetitemiterator.cpp
@@ -90,7 +90,7 @@ QTreeWidgetItemIterator::QTreeWidgetItemIterator(const QTreeWidgetItemIterator &
 */
 
 QTreeWidgetItemIterator::QTreeWidgetItemIterator(QTreeWidget *widget, IteratorFlags flags)
-: current(0), flags(flags)
+: current(nullptr), flags(flags)
 {
     Q_ASSERT(widget);
     QTreeModel *model = qobject_cast<QTreeModel*>(widget->model());
@@ -266,7 +266,7 @@ bool QTreeWidgetItemIterator::matchesFlags(const QTreeWidgetItem *item) const
 QTreeWidgetItem* QTreeWidgetItemIteratorPrivate::nextSibling(const QTreeWidgetItem* item) const
 {
     Q_ASSERT(item);
-    QTreeWidgetItem *next = 0;
+    QTreeWidgetItem *next = nullptr;
     if (QTreeWidgetItem *par = item->parent()) {
         int i = par->indexOfChild(const_cast<QTreeWidgetItem*>(item));
         next = par->child(i + 1);
@@ -280,9 +280,9 @@ QTreeWidgetItem* QTreeWidgetItemIteratorPrivate::nextSibling(const QTreeWidgetIt
 
 QTreeWidgetItem *QTreeWidgetItemIteratorPrivate::next(const QTreeWidgetItem *current)
 {
-    if (!current) return 0;
+    if (!current) return nullptr;
 
-    QTreeWidgetItem *next = 0;
+    QTreeWidgetItem *next = nullptr;
     if (current->childCount()) {
         // walk the child
         m_parentIndex.push(m_currentIndex);
@@ -307,9 +307,9 @@ QTreeWidgetItem *QTreeWidgetItemIteratorPrivate::next(const QTreeWidgetItem *cur
 
 QTreeWidgetItem *QTreeWidgetItemIteratorPrivate::previous(const QTreeWidgetItem *current)
 {
-    if (!current) return 0;
+    if (!current) return nullptr;
 
-    QTreeWidgetItem *prev = 0;
+    QTreeWidgetItem *prev = nullptr;
     // walk the previous sibling
     QTreeWidgetItem *parent = current->parent();
     prev = parent ? parent->child(m_currentIndex - 1)
@@ -347,7 +347,7 @@ void QTreeWidgetItemIteratorPrivate::ensureValidIterator(const QTreeWidgetItem *
     // we need to adjust the iterator.
     if (nextItem == itemToBeRemoved) {
         QTreeWidgetItem *parent = nextItem;
-        nextItem = 0;
+        nextItem = nullptr;
         while (parent && !nextItem) {
             nextItem = nextSibling(parent);
             parent = parent->parent();
@@ -358,7 +358,7 @@ void QTreeWidgetItemIteratorPrivate::ensureValidIterator(const QTreeWidgetItem *
             if (!(q->matchesFlags(nextItem))) ++(*q);
         } else {
             // set it to null.
-            q->current = 0;
+            q->current = nullptr;
             m_parentIndex.clear();
             return;
         }
-- 
cgit v1.2.3